Colloquiam: Documents published in 2016

Using Fractional Calculus for Cooperative Car-Following Control

Scipedia content — Thu, 28 Jan 2021 19:19:38 +0100

International audience; The Cooperative Adaptive Cruise Control (CACC) is one of the most promising aiding systems to improve traffic flow in highways. When it comes to design a proper control algorithm, robustness against non-modeled dynamics and noise plays a key role not only for improving controller performance but also for increasing the ability of handling heterogeneous vehicle strings. This paper proposes a fractional order controller that is able to deal with non-modeled dynamics whereas keeping simplicity and a low computational cost. System robustness and string stability responses are analyzed for a string of six vehicles, showing a good performance.

Feasibility study on high-speed rail and air cooperation

Scipedia content — Thu, 28 Jan 2021 19:18:04 +0100

Keywords: air transport, rail, hub-spoke, cooperation, energy consumption Abstract. The development of air transport and high-speed rail (HSR) is facing two problems. One is competition, having been stated in many literatures focusing on the economic distances; and another is stresses from large investments, energy consumption and environmental degradation. In this paper, the feasibility of HSR-air transport cooperation is discussed, aiming to prevent excessive service and reduce emissions, but not hurt travelers. The feasible regions are calculated based on a total cost model and Lotka-Volterra equation, identifying in which situations air and HSR could cooperate. Based on this method, some measures are proposed to increase the possibility of cooperation. Some typical city-pairs in China are empirically discussed and the cooperation indexes are calculated.

Development of a self-propelled capsule robot for pipeline inspection

Scipedia content — Thu, 28 Jan 2021 19:17:06 +0100

This paper introduces a current research project carried out in the Robert Gordon University for developing the prototype of the vibro-impact capsule robot for pipeline inspection. The project aims to address the technical bottlenecks which have been encountered by current pipeline technologies with a particular focus on oil industry. In order to verify the concept, a dummy capsule prototype with a diameter of 80 mm is designed and manufactured for testing in a 2.5 meter long section of 140 mm nominal diameter clear PVCu pipe with a flow velocity up to 0.3 m/s. By using the experimental test bed, the prototype of the capsule system can be tested at various flow rates, and the experimental results could be used for comparing with CFD simulation results for optimization.

Crowdsourcing: A building block for smart cities

Scipedia content — Thu, 28 Jan 2021 19:14:27 +0100

This talk will present a vision, and real-world examples, of the use of mobile crowdsourcing for building a variety of smart-city applications and services. I will first describe the paradigm of centrally-coordinated crowdsourcing, where the crowdsourcing platform intelligently recommends different tasks to different candidate workers, and contrast it with today's prevalent paradigm, where workers select and perform tasks in an uncoordinated, opportunistic fashion. I will then describe real-world examples of such crowdsourcing (and participatory sensing) for two applications: (a) smart campus monitoring and (b) last-mile urban logistics (package pickup and delivery). The talk will also describe the opportunities and open challenges involved in making such crowdsourcing an organic part of real-time municipal services monitoring and delivery.

Study on Modeling and Simulation Technology of Comprehensive Passenger Hub System

Scipedia content — Thu, 28 Jan 2021 19:07:16 +0100

Giving priority to the development of urban public transport is not only an effective measure to alleviate urban traffic congestion, but an inevitable requirement for improving urban livingenvironment and promoting the sustainable development of cities. System simulation of scheduling time and inventory time for comprehensive passenger hub system of Shenyang North Railway Station by using object oriented discrete modeling and simulation theory are studied to meeting passengers' demand and improve the efficiency of the public transportation system. Transportation simulation platform is built by using computer simulation and the station simulation model is set up, which are to find out the bottleneck of the whole system and formulate adjustment and optimization scheme, providing a feasible solutionfor the bus company bus scheduling decision.

Priorita mezinárodní nákladní dopravy v překrývající části RFC 7 a 9 RFC Kolín - Česká Třebová

Scipedia content — Thu, 28 Jan 2021 18:54:48 +0100

This article deals with the railway traffic control and railway traffic equipment in terms of implementation of TSI. The main goal is to research the optimal priority of international freight expresses, especially in the overlapping sections, which represent critical line sections of European freight corridors. This article shows this problem in the context in the overlapping section of RFC 7 and RFC 9 Kolín – Ceská Trebová. There are mentioned possibilities of using of ETCS and implementation of automatic train paths.

Charging Electric Vehicles from Solar Energy: Integrated Converter and Charging Algorithms

Scipedia content — Thu, 28 Jan 2021 18:54:15 +0100

Definition of Design Patterns for Advanced Driver Assistance Systems

Scipedia content — Thu, 28 Jan 2021 18:47:31 +0100

dvanced Driver Assistance Systems (ADAS) are embedded systems in the automotive domain which play an important role for safety enhancement. They are subject to several complex hardware and software constraints, and executed in a highly variable environment. Thus, the design of these systems is a very important task but becomes increasingly difficult, especially with the lack of generic reusable templates for ADAS. So, in this paper, we propose three design patterns covering design problems relative to the following key tasks: sensing, processing and control of sensor data, and taking actions (warning and actuation). These patterns are specified using the Unified Modeling Language (UML) to represent structural and behavioral information. This paper also describes two examples of ADAS that illustrate how we have applied these patterns.

Research on the Technology of Urban Road Traffic System

Scipedia content — Thu, 28 Jan 2021 18:46:49 +0100

Urban road traffic system is a system which is a collection of its internal factors, complex open, large randomized controlled. It has the basic characteristics of relevance, dynamic balance and structural. The characteristics of urban road traffic system determine the complexity that problems. Despite the rapid increase about the supply ability of urban road traffic system, the urban road traffic problems did not get substantial solution. Urban road traffic system and city scale “interaction expansion”, the vicious inflation does not only increase the residents' travel cost, but also makes the whole society pay a high price. Keywords-Urban road; The traffic system; economic evaluation

Multilink Micro Robots Designed for Inspection in Pipes of Small Diameters

Scipedia content — Thu, 28 Jan 2021 18:46:15 +0100

The importance of designing robotic platforms for pipes of small diameters inspection is connected with necessity of efficiency improvement in technical diagnostics of pipelines of different use, especially in mechanical engineering. This paper is devoted to in-pipe micro robot design. Different techniques of the robotâs motion inside a pipeline have been discussed. The proposed design of the in-pipe robot may be used in experimental investigation of different inspection techniques. The method of determining the speed of micro robot allows finding the speed of micro robot when it moves in different environments with different viscosity under the absence and presence of excessive pressure in the piping system.

Simulation of pipeline gas leakage

Scipedia content — Thu, 28 Jan 2021 18:41:54 +0100

This article deals with the problem of simulation of gas leaks in pipelines and development of a prototype simulator. The prototype provides leakage simulation into water and in different kinds of soils without changing the physical properties of them. It is analyzed the behaviour of the system for different sizes of leaks and different pressures. Experimental results of the characterization of pipeline gas leakage are presented. The images of temperature anomaly were received by means of the infrared camera (Infrared camera model Palm IR 250 by Raytheon).

Composing Patterns to Construct Secure Systems

Scipedia content — Thu, 28 Jan 2021 18:40:46 +0100

Building secure applications requires significant expertise. Secure platforms and security patterns have been proposed to alleviate this problem. However, correctly applying patterns to use platform features is still highly expertise-dependent. Patterns are informal and there is a gap between them and platform features. We propose the concept of reusable verified design fragments, which package security patterns and platform features and are verified to provide assurance about their security properties. Design fragments can be composed through four primitive tactics. The verification of the composed design against desired security properties is presented in an assurance case. We demonstrate our approach by securing a Continuous Deployment pipeline and show that the tactics are sufficient to compose design fragments into a secure system. Finally, we formally define composition tactics, which are intended to support the development of systems that are secure by construction.

FlowConvertor: Enabling Portability of SDN Applications

Scipedia content — Thu, 28 Jan 2021 18:39:21 +0100

Software-Defined Networking (SDN) provides network administrators opportunities to control network devices more simply and easily than in traditional networking. However, heterogeneity in switch hardware, especially in forwarding pipeline architecture, renders the task of network application developers and network administrators tedious, by hampering portability across switch models. In this paper, we propose FlowConvertor, an algorithm capable of converting rules from any forwarding pipeline to any other different forwarding pipeline, as long as both pipelines offer compatible operations. More precisely, FlowConvertor is an online algorithm that operates on flow updates issued to the origin pipeline and computes the corresponding updates for the target pipeline in real time. Performance evaluation shows that the latency introduced by FlowConvertor on the path between the SDN controller and the target switch is of the order of 1ms in most cases, and is thus acceptable for practical deployment.

IoT system for anytime/anywhere monitoring and control of vehicles’ parameters

Scipedia content — Thu, 28 Jan 2021 18:38:38 +0100

This paper presents an IoT (Internet of Things) system designed to allow the monitoring and control of parameters of the users’ vehicles, anytime and anywhere in the world, through the Internet. The system prototype was developed and tested using an electric vehicle (EV) and the respective sensor systems. The main components of the proposed IoT system are: a Bluetooth Low Energy (BLE) intra-vehicular wireless sensor network (IVWSN); a mobile device that acts both as the vehicle’s gateway, connecting the IVWSN to the Internet, and as the vehicle’s human machine interface (HMI); an online server/database, based on Firebase; a client, which can be either a mobile device or a personal computer; and a residential wireless sensor network (WSN). The use of a wireless network to collect sensor data inside of the vehicle introduces some advantages when compared with conventional wired networks, whereas the inclusion of a residential WSNs in the proposed IoT architecture allows the provision of additional features, such as automatic control of the EV battery charging process. Experimental results are provided to assess the performance of the developed IVWSN and HMI. This work has been supported by COMPETE: POCI-01-0145- FEDER-007043 and FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2013. info:eu-repo/semantics/publishedVersion

Planning under Uncertainty for Aggregated Electric Vehicle Charging using Markov Decision Processes

Scipedia content — Thu, 28 Jan 2021 18:37:16 +0100

The increasing penetration of renewable energy sources and electric vehicles raises important challenges related to the operation of electricity grids. For instance, the amount of power generated by wind turbines is time-varying and dependent on the weather, which makes it hard to match flexible electric vehicle demand and uncertain wind power supply. In this paper we propose a vehicle aggregation framework which uses Markov Decision Processes to control charging of multiple electric vehicles and deals with uncertainty in renewable supply. We present a grouping technique to address the scalability aspects of our framework. In experiments we show that the aggregation framework maximizes the profit of the aggregator while reducing usage of conventionally-generated power and cost of customers.

Low-Frequency Acoustic Signals Propagation in Buried Pipelines

Scipedia content — Thu, 28 Jan 2021 18:31:16 +0100

The article deals with the issues concerning acoustic signals propagation in the large-diameter oil pipelines caused by mechanical action on the pipe body. Various mechanisms of signals attenuation are discussed. It is shown that the calculation of the attenuation caused only by internal energy loss, i.e, the presence of viscosity, thermal conductivity and liquid pipeline wall friction lead to low results. The results of experimental studies, carried out using the existing pipeline with a diameter of 1200 mm. are shown. It is experimentally proved that the main mechanism of signal attenuation is the energy emission into the environment. The numerical values of attenuation coefficients that are 0,14- 0.18 dB/m for the pipeline of 1200 mm in diameter, in the frequency range from 50 Hz to 500 Hz, are determined.

Using OSM, Geo-Tagged FLICKR Photos and Authoritative Data: A Quality Perspective

Scipedia content — Thu, 28 Jan 2021 18:24:03 +0100

The appearance of OpenStreetMap (OSM) in 2004 sparked a phenomenon known as Volunteered Geographic Information (VGI). Today, VGI comes in many flavours (e.g. toponyms, GPS tracks, geo-tagged photos, micro-blogging or complete topographic maps) and from various sources. One subject that has attracted research interest from the early days of VGI is how good such datasets are and how to combine them with authoritative datasets. To this end, the paper explores three intertwined subjects from a quality point of view First, we examine the topo-semantic consistency of OSM data by evaluating a number of rules between polygonal and linear features and then paying special attention to quality of Points of Interest (POIs). A number of topo-semantic rules will be used to evaluate the valididy of features’ location. The focus then turns to the use of geo-tagged photos to evaluate the location and type of OSM data and to disambiguate topological issues that arise when different OSM layers overlap.

SimSmartMobility: inzicht in de effecten van Smart Mobility maatregelen door simulatie

Scipedia content — Thu, 28 Jan 2021 18:20:57 +0100

Overheden en marktpartijen investeren momenteel veel in Smart Mobility toepassingen en dit roept vragen op over de effecten van deze innovatieve mobiliteitsoplossingen. SimSmartMobility is een platform voor simulaties van Smart Mobility en richt zich op het steeds beter kunnen beantwoorden van deze vragen. In dit discussiepaper geven we een korte toelichting op SimSmartMobility. Vervolgens bespreken we waarom simulatie van Smart Mobility een belangrijke stap is in het verkrijgen van meer inzicht in de effecten van Smart Mobility en welke type vragen met SimSmartMobility beantwoord kunnen worden. Tot slot poneren we een aantal stellingen voor een discussie zodat we tijdens het NVC met u hierover in gesprek kunnen gaan en de inzichten uit de discussie kunnen gebruiken om de toepassing en doorontwikkeling SimSmartMobility zo goed mogelijk aan te sluiten bij uw wensen.

URBAN REGENERATION PROGRAMS FOR SUSTAINABLE PLANNING IN HIGHLY VULNERABLE URBAN CONTEXTS

Scipedia content — Thu, 28 Jan 2021 18:19:50 +0100

Topics of sustainable urban development and environmental sustainability are worldwide considered as fundamental for every strategy of urban transformation, renewal and regeneration. In particular, urban regenerations are urban re-development programs involving the rebirth or renewal of selected urban areas or district that have faced periods of decline due to compounding and intersecting pressures. The programs cover many aspects of the area to be re-generated such as physical, social and environmental contexts. Re-use of already built up areas and buildings, reduction of the demand for new soils to be developed, increasing of appealing of dense city areas, increasing of social and spatial resilience are among the positive consequences of these programs. However, in the current debate about urban regeneration, few studies have evaluated the real environmental outcomes and effectiveness of regeneration programs in terms of physical variables such as new provided greenspaces, accessibility to public transportation, climate change or seismic risk reduction. This paper proposes a method to quantify the real outcomes and effectiveness of urban regeneration programs with reference to the above mentioned variables. As a real experience of urban planning, the new Local Spatial Plan for the Municipality of Catania, a medium sized city in Southern Italy, is presented. The city is characterised by a high density urban fabric, a general lack of urban greenspaces and high levels of traffic congestion due to a massive use of private transportation. The urban fabric is also very vulnerable to seismic and climate change risks. Among the transformation tools, the new Local spatial plan proposes regeneration actions aimed at the complete regeneration of old and dilapidated areas, not classified as historical heritage and heavily vulnerable to seismic risk. These actions include the complete demolition and reconstruction of these areas within clearly defined boundaries, contributing to minimise soil consumption, maintaining as open public spaces the majority of existing non urbanised areas within the densely built-up settlement. The program of regeneration can dramatically contributes to the reduction of seismic and climate change risk and achieve a general requalification of the urban environment. Starting from this planning experience, this paper focus on the evaluation of the regenerations programs included in the Local Spatial Plan. Regeneration Areas (RAs) have been identified by the municipality as characterized by high level of seismic vulnerability, urban degradation, lack of public services and urban environment quality. For the chosen areas, this study proposes the evaluation of the transformations potentially occurring in the urban context by the proposed regeneration program. The following aspects are evaluated: reduction of risks (in terms of exposition and vulnerability to seismic and climate change related risks) 2 International Scientific Conference GEOBALCANICA 2016 256 mobility (concerning the presence of public means of transports, distance to the transit stops, roads, pedestrian and cycling lanes) accessibility increase (in terms of access to trip attractions) land-use diversity (in terms of number and distribution of different land uses) public spaces and services (in terms of extension and functions) Each of the aforementioned aspects are evaluated by spatial indicators calculated by GIS. All indicators are calculated at different and size increasing units, in order to understand the effect of a single regeneration project and of a number of concurrent projects within the considered geographical units. The geographical units are the RAs and districts. Different combinations of regeneration projects will be thus evaluated to highlight which projects produce the most relevant effects, calculated with the proposed indicators. This will allow the municipality to define scenarios of regeneration priority, in terms of which projects might be financed and implemented firstly because of their higher positive effect on the urban environment. Such scenarios will generate positive effects not only to the single areas to be regenerated but also to wider urban contexts, significantly reducing the urban vulnerability to seismic and climate change risks and at the same time producing more livable and healthy urban environment.

An Introduction to ACAS Xu and the Challenges Ahead

Scipedia content — Thu, 28 Jan 2021 18:13:41 +0100

ording to a 2013 AUVSI report, delays in integrating Unmanned Aerial Systems (UAS) into the National Airspace System (NAS) could cost more than $10 billions a year for the United States alone. Worldwide regulatory bodies are under pressure by the UAS industry to accelerate the regulation process, but safety remains their main objective. One condition for the safe introduction of UAS in the NAS is for them to be equipped with a collision avoidance system. Though the existing Airborne Collision Avoidance System II (ACAS II) could have been an option, the transformations of air traffic management engaged through NextGen (US) and SESAR (Europe) led to the definition of a new ACAS based on new logics, namely ACAS X. Its definition contains in particular two variations : ACAS Xa, for large aircraft, and ACAS Xu, for unmanned aircraft. As noted in a 2014 RTCA annual report, divide in technological knowledge between those experienced in ACAS II and those involved in the development of ACAS X is a concern. To help preventing this divide we believe it is essential to keep the community updated with the latest evolutions of the ACAS X standards. As work on Minimum Operational Performance Standards (MOPS) for ACAS Xu just started, it is of interest to know which parts of the MOPS are already decided, which remain flexible for the industries to make the difference and which are open research problems. Being a member of the ACAS X family, ACAS Xu lays on the same foundations as the well defined ACAS Xa standard. This work proposes an introduction to the ACAS Xa/Xu common basis, as it is unlikely to change, including the general architecture and Collision Avoidance (CA) logics. It is followed by a presentation of concepts specific to ACAS Xu such as the tailored threat logic, horizontal CA logic, CA coordination and automatic responses. For the flexible part, we believe it mainly concerns the surveillance sources. Instead of a precise standard, the regulation is likely to ask for requirements on the sensors capabilities. A state of the art of recent works allows proposing minimum sensor performances and focusing on an essential set of sensors. This work is concluded by presenting future challenges that need to be addressed to build a safe ACAS Xu baseline and to extend it to smaller and lower altitude UAS.

Scheduling electric vehicles with shared charging stations

Scipedia content — Thu, 28 Jan 2021 18:06:58 +0100

Zimbabwe has one of the highest maternal death rates in the world, partly because of the difficulty in getting expectant mothers from rural villages to health care facilities. Specifically designed electric vehicles, called African Solar Taxis, are currently being developed for a rural hospital in Zimbabwe. The vehicles will be charged at solar charging stations located at the hospital and at heath clinics. The vehicles have limited speed and range, and charging is slow compared to conventional vehicles; because of this, efficient scheduling is important. In this article we describe a method for scheduling multiple taxis that share a common charging station. References African Solar Taxis, September 2016. http://africansolartaxi.com . A. Albrecht and P. Pudney. Pick up and delivery with a solar-recharged vehicle. In 22nd National Conference of the Australian Operations Research Society (ASOR 2013), pages 239–246. Australian Society for Operations Research, Dec. 2013. http://www.asor.org.au/conferences/asor2013/J8/albrecht.pdf . K. Marriott and P. J. Stuckey. A MiniZinc tutorial. Technical report, 2015. http://www.minizinc.org/downloads/doc-latest/minizinc-tute.pdf . N. M. Moghaddam. The partially rechargeable electric vehicle routing problem with time windows and capacitated charging stations. PhD thesis, Clemson University, 2015. http://tigerprints.clemson.edu/cgi/viewcontent.cgi?article=3210&context=all_theses . H. Wang and R. Cheu. Operations of a taxi fleet for advance reservations using electric vehicles and charging stations. Trans. Res. Rec.: J. Trans. Res. Board, 2352:1–10, 2013. doi:10.3141/2352-01 . H. P. Williams. Model Building in Mathematical Programming. Wiley, 4th edition, 1999. http://au.wiley.com/WileyCDA/WileyTitle/productCd-1118443330.html .

Coordination of scheduling decisions in the management of airport airspace and taxiway operations

Scipedia content — Thu, 28 Jan 2021 18:06:40 +0100

This paper addresses the real-time problem of coordinating aircraft ground and air operations in an airport area. At a congested airport, airborne decisions are related to take-off and landing operations, while ground (taxiway) decisions consist of scheduling aircraft movements between the gates and the runways. Since the runways are the initial/terminal points of both decisions, coordinated actions have a great potential to improve the overall performance. However, in the traffic control practice the different decisions are taken by different controllers, at least in large airports. Weak coordination may result in long queues at the runways, with increasing aircraft delays and energy consumption. This paper investigates models, methods and policies for improving the coordination between taxiway scheduling and airborne scheduling. The performance of a solution is measured in terms of delay and travel time, the latter being related to the energy consumption of an aircraft. A microscopic mathematical formulation is adopted to achieve reliable solutions. Exact and heuristic methods have been analysed in combination with the different policies, based on practical-size instances from Amsterdam Schiphol airport, in the Netherlands. Computational experience shows that good quality solutions can be found within limited time, compatible with real-time operations. ISSN:2352-1465

DLATK: Differential Language Analysis ToolKit

Scipedia content — Thu, 28 Jan 2021 18:06:16 +0100

We present Differential Language Analysis Toolkit (DLATK), an open-source python package and command-line tool developed for conducting social-scientific language analyses. While DLATK provides standard NLP pipeline steps such as tokenization or SVM-classification, its novel strengths lie in analyses useful for psychological, health, and social science: (1) incorporation of extra-linguistic structured information, (2) specified levels and units of analysis (e.g. document, user, community), (3) statistical metrics for continuous outcomes, and (4) robust, proven, and accurate pipelines for social-scientific prediction problems. DLATK integrates multiple popular packages (SKLearn, Mallet), enables interactive usage (Jupyter Notebooks), and generally follows object oriented principles to make it easy to tie in additional libraries or storage technologies.

Fleet Management and The Adoption of Innovations by Corporate Car Fleets: An Exploratory Approach

Scipedia content — Thu, 28 Jan 2021 18:04:31 +0100

International audience; Understanding the processes that guide fleet management by corporations is key to assessing the potential role corporations could play in the transition towards a more sustainable mobility system, and to drawing operational policy conclusions accordingly. Building on the information collected through 44 interviews with decision-makers from 22 large organisations in the Paris region, we reach a much deeper understanding of the fleet management processes of large organisations. We find that the prospects for global optimisation of the corporate car fleet – from the perspectives of both purchase behaviours and daily operations –depend on the solutions that corporations can find to tackle the complexity of the decision-making processes for car fleet acquisition (e.g. through implementing car policies) and the shortcomings of information on fleet use and fleet costs (e.g. through deploying monitoring and tracking technologies). In order to discuss the outlook for electric vehicles and car-sharing services in corporate car fleets, we analyse the specific barriers to, and drivers of, their adoption, and report on some of the ‘best practices’ revealed by our survey.

System Performance of an Integrated Airborne Spacing Algorithm with Ground Automation

Scipedia content — Thu, 28 Jan 2021 18:01:22 +0100

The National Aeronautics and Space Administration's (NASA's) first Air Traffic Management (ATM) Technology Demonstration (ATD-1) was created to facilitate the transition of mature ATM technologies from the laboratory to operational use. The technologies selected for demonstration are the Traffic Management Advisor with Terminal Metering (TMA-TM), which provides precise time-based scheduling in the Terminal airspace; Controller Managed Spacing (CMS), which provides controllers with decision support tools to enable precise schedule conformance; and Interval Management (IM), which consists of flight deck automation that enables aircraft to achieve or maintain precise spacing behind another aircraft. Recent simulations and IM algorithm development at NASA have focused on trajectory-based IM operations where aircraft equipped with IM avionics are expected to achieve a spacing goal, assigned by air traffic controllers, at the final approach fix. The recently published IM Minimum Operational Performance Standards describe five types of IM operations. This paper discusses the results and conclusions of a human-in-the-loop simulation that investigated three of those IM operations. The results presented in this paper focus on system performance and integration metrics. Overall, the IM operations conducted in this simulation integrated well with ground-based decisions support tools and certain types of IM operational were able to provide improved spacing precision at the final approach fix; however, some issues were identified that should be addressed prior to implementing IM procedures into real-world operations.

A joint freight catchment and cost benefit analysis to assess rail urban logistics scenarios

Scipedia content — Thu, 28 Jan 2021 18:00:48 +0100

International audience; This paper presents a general framework to assess urban rail logistics suitability via a socio-economic cost benefit analysis and demand catchment assessment. First, we examine the main background issues related to data production in urban logistics and the needs of examining the economic viability of future projects. Second, we present methodology proposed that combines a classical CBA framework with a freight catchment analysis framework. Third, as an example of application, we propose to assess freight tramway deployment scenarios in Paris, France. The results show the potential of including demand catchment analysis in CBA to identify the suitable demand introduction strategy. However, it seems important to contextualize them, such methods being used to support decisions and not to substitute decision maker.

Reduced memory region based deep Convolutional Neural Network detection

Scipedia content — Thu, 28 Jan 2021 17:59:40 +0100

urate pedestrian detection has a primary role in automotive safety: for example, by issuing warnings to the driver or acting actively on car's brakes, it helps decreasing the probability of injuries and human fatalities. In order to achieve very high accuracy, recent pedestrian detectors have been based on Convolutional Neural Networks (CNN). Unfortunately, such approaches require vast amounts of computational power and memory, preventing efficient implementations on embedded systems. This work proposes a CNN-based detector, adapting a general-purpose convolutional network to the task at hand. By thoroughly analyzing and optimizing each step of the detection pipeline, we develop an architecture that outperforms methods based on traditional image features and achieves an accuracy close to the state-of-the-art while having low computational complexity. Furthermore, the model is compressed in order to fit the tight constrains of low power devices with a limited amount of embedded memory available. This paper makes two main contributions: (1) it proves that a region based deep neural network can be finely tuned to achieve adequate accuracy for pedestrian detection (2) it achieves a very low memory usage without reducing detection accuracy on the Caltech Pedestrian dataset.

Comment: IEEE 2016 ICCE-Berlin

Application of EUVC Algorithm to Evaluate Unconnected Vehicle in A Connected Vehicle Environment

Scipedia content — Thu, 28 Jan 2021 17:57:22 +0100

utomobile and Traffic Engineering College, Nanjing Forestry University, Nanjing, China. Corresponding author. Tel.: +86 13770562578 Automobile and Traffic Engineering College, Nanjing Forestry University, Nanjing, China. Corresponding author. Tel.: +86 13705180025 Automobile and Traffic Engineering College, Nanjing Forestry University, Nanjing, China. Corresponding author. Tel.: +86 15295510928 email: dongshanfenghui@126.com, *email: 743695641@qq.com, email: sallyct@qq.com

The Bus Line Supporting System Based On Learning Neural Network Model Applied In GIS

Scipedia content — Thu, 28 Jan 2021 17:55:29 +0100

With the rapid increase of urban population and rapidly widening scope of the city, the newly built residential areas emerging or leading to the existing bus lines could not meet the needs of the people’s activities. The phenomenon of the traffic congestion is becoming more and more serious. [1] According to the problem we based on the principle of convenient resident travel, we used the point line face integration optimization model to slow down the urban traffic congestion as the goal, combined with the population distribution model and the congestion nodes judging model. We make the city Chengdu as the research object and after our research the Chengdu bus route selection model is established. [2]At the same time, on the basis of this model combining with the ArcGIS technology, database technology achieved in the host framework programming language C# helped with the tool MATLAB combined with C++ language dynamic link library files and the algorithm model developed by the bus route selection model, we achieved our information system according the message or rules we mentioned in this passage. We compared our city bus route selection in the last part which we designed to the original route scheme optimization selection and further demonstrate the superiority of the new scheme. [3] Introduction The dramatic increase of population and the residential expansion in urban area will inevitably call larger and larger demand of the transportation, and it will result in traffic congestion. Factors caused by traffic jams are surrounding with the imbalance of the road population distributions, the capacity of road network and the traffic flow of roads each peak hour. That means it will increase the number of traffic flow translational velocity, the amount of motor vehicles, the number of traffic lights, etc. Based on the problem mentioned above in this passage, we catch the thought of the space factors and the traffic congestions in space appeared with three kinds of states like point, line and plane: Point It refers to the intersection of traffic congestion occurs separately which is only connected to its roads, and will not affect the adjacent intersections. Line It refers the traffic flow line corresponds with points due to some issues such as peak flows or the local traffic congestion which was not timely solved. Plane It refers to the traffic congestion related with sections overlapping between the road and road intersection and all of these points and lines constitute an appropriately traffic congestion. The model assumptions are listed below: The present study to optimize the bus line around the scope of population distribution in line follows a pattern that the nearly population increase gradually as the instance increasing. We assume that the population distribution is roughly accord with normal distribution along the bus lines. We assume that the daily average traffic flow per hour are roughly equal besides 7:00-9:00 and 18:00-20:00 when there is no emergency situation and the choice for route area within the scope of the traffic is equal to drivers. It’s equal to drivers for all choices of the route. 5th International Conference on Computer Sciences and Automation Engineering (ICCSAE 2015) © 2016. The authors Published by Atlantis Press 11

Understanding track loading requirements to achieve better track design

Scipedia content — Thu, 28 Jan 2021 17:53:04 +0100

This paper reviews current track loading requirement (ballasted and ballastless) Typical vehicle-track interaction loads are described along with their influential factors. Limits and influential factors are analysed against statistical evidence from vehicle dynamics measurement. Additional load combinations are presented as potentially relevant for track design. Discussion are made on the potential reduction of load from improved vehicle performance and slab track improved geometry, areas which might bear some benefits in terms of cost reduction for future slab track designs. This paper demonstrates that both vehicle measurement and simulations can provide an important source of information in terms of expected track loading and their limit values to help achieve cost reduction in track design.

A practical multi-plane routing-based traffic engineering scheme in evolutionary convergent all-IP access networks

Scipedia content — Thu, 28 Jan 2021 17:51:55 +0100

With the expected surge in the global IP traffic, service providers would need to adapt accordingly to operate disruption and loss free networks supported with the developing IP infrastructure. With the disposal of the hierarchical network structure, radio access networks are moving towards a flat-IP architecture and novel topological set-ups in the backhaul. Hence, a routing paradigm that employs suitable Traffic Engineering (TE) techniques aligned with the developing nature of future access networks must be applied. In this paper, Multi-Plane Routing (MPR) that consolidates various aspects in all-IP infrastructure is remodelled in consistent with this development. We propose a MPR-based TE approach considering two different scenarios to reflect the evolution in the architectural design of access network structures under a realistic traffic scenario with a varying range of internal/external traffic. Accordingly, a practical performance evaluation testing the validity of the aforementioned scenarios is presented. Our simulation results demonstrate a better achieved performance under the flat-IP structure in addition to MPR-based methods' superiority over legacy OSPF/Invcap. Performance degradation is observed with the rise in the internal traffic distribution for the different scenarios studied. Moreover, a new optimization framework for the offline and online TE mechanisms of MPR have been proposed.

Potential Operational Benefits of Multi-layer Point Merge System on Dense TMA Operation Hybrid arrival trajectory optimization applied to Beijing Capital International Airport

Scipedia content — Thu, 28 Jan 2021 17:47:24 +0100

International audience; 4D Trajectory optimization in dense terminal control area is one of the most challenging problems in air traffic management research. In order to efficiently and robustly land more aircraft at Beijing Capital International Airport (BCIA), one of the busiest airport in the world, a novel trajectory operation model is proposed, i.e. Multi-layer Point Merge (ML-PM) based Autonomous Arrival Management System. This paper aims at the evaluation of its potential operational benefits in terms of flight efficiency and runway throughput. Horizontal and Vertical profiles of ML-PM route network are introduced, the objective and constraints of this optimizing mathematical model are analyzed, especially the speed change profile and the conflict detection mode for merging zone. Then a case study is made by simulating arrival flows under three different operational modes: baseline, traditional point merge, and the ML-PM. Finally, the results show that rational arrival sequence and conflict-free trajectories are generated in ML-PM system, the benefits gained are very positive. Comparing with baseline and the traditional point merge system, ML-PM system shows good performance on flight time, fuel consumption, CO2 emission. The saving of fuel with ML-PM system is expected around 26838 Yuan per hour at BCIA compared with baseline scenario by numerical simulation. Furthermore, more flexible sequence position shift and continuous descent are possible in ML-PM system, and it is capable to handle the high-density operation environment.

Traffic Flow Prediction Based on the location of Big Data

Scipedia content — Thu, 28 Jan 2021 17:44:11 +0100

This article focuses on the design of intelligent transportation systems in the construction of the smart urban. Learning from the wisdom of traffic building programs, the paper is given the overall design of intelligent transportation process based on location big data. Lanzhou City was analyzed and designed using this method. The collected GPS big data was deeply excavated and analyzed through the mathematical model. Thus the clear city traffic analysis chart was got to predict the traffic flow. In the end the intelligent transportation was realized in the smart city. The arrival of the "smart city" is not only changing the quality of life of personal information, but also can be applied to urban public safety, manufacturing production, environmental monitoring, intelligent traffic, intelligent home, environmental monitoring and other fields. It can make full use of the social resources. It can greatly promote the enterprise to reduce the cost. It can make the government improve public service ability and city management efficiency.(1-3) From the point of the architecture of the smart city the wisdom of the city is based on the technology of the Internet of things, so the architecture of the smart city is similar to the internet of things. It is divided into four layers which are the perception layer, transport layer, system layer and application layer. The goal of the intelligent transportation system (ITS) is using the communication system to closely combine the transport system of people, vehicles and road. Advanced traffic control system and advanced traffic management system are required to provide real-time traffic flow information. Traffic flow analysis is an important research content in the transportation system. The traditional traffic flow model is described the traffic flow state variables (velocity, density and flow) with the change of time and space.(4-5) From the research of traffic flow, the research method of traffic flow is developed from the empirical method to the research method based on physical model and the mathematical model. Finally it returns to the initial empirical method.The Fig.1 is shown the platform of the location big data.(6-8) All study is based on the data. The location big data is studied through this platform. There are four steps which are data acquisition, data analysis, data calculation and data visualization. The intelligent transportation on business analysis can be got through those

Skin-Like Sensor Enabled Bridge Structural Health Monitoring System

Scipedia content — Thu, 28 Jan 2021 17:42:14 +0100

Structural health monitoring activities are of primal importance for managing transport infrastructure, however most SHM methodologies are based on point-based sensors that have limitations in terms of their spatial positioning requirements, cost of development and measurement range. This paper describes the progress on the SENSKIN EC project whose objective is to develop a dielectric-elastomer and micro-electronics-based sensor, formed from a large highly extensible capacitance sensing membrane supported by advanced microelectronic circuitry, for monitoring transport infrastructure bridges. Such a sensor could provide spatial measurements of strain in excess of 10%. The actual sensor along with the data acquisition module, the communication module and power electronics are all integrated into a compact unit, the SENSKIN device, which is energy-efficient, requires simple signal processing and it is easy to install over various surface types. In terms of communication, SENSKIN devices interact with each other to form the SENSKIN system; a fully distributed and autonomous wireless sensor network that is able to self-monitor. SENSKIN system utilizes Delay-/Disruption-Tolerant Networking technologies to ensure that the strain measurements will be received by the base station even under extreme conditions where normal communications are disrupted. This paper describes the architecture of the SENSKIN system and the development and testing of the first SENSKIN prototype sensor, the data acquisition system, and the communication system.

Heating of polyethylene pipes in the construction of gas pipelines at low temperatures

Scipedia content — Thu, 28 Jan 2021 17:38:08 +0100

This paper proposes a method for the determination of the duration of heating polyethylene pipes in coils by heated air during the installation and laying works in the construction of gas pipelines under the conditions of low temperatures. The mathematical model of thermal process of heating polyethylene pipes by heated air is considered. Calculation results on the heating duration of a polyethylene pipe are given in the range of external air temperatures at a known flow rate of heated air supplied inside the pipe.

Construction of winners and losers in the smart mobility innovation policy in the Netherlands

Scipedia content — Thu, 28 Jan 2021 17:35:08 +0100

Mobility innovations are deeply ingrained in societies, enabling us to perform certain actions and movements, which are essential for participating in the hyper-connected world (Hannam, Sheller, Urry; 2006). These innovations can be considered political as they unevenly allow various means and comfort of access to different societal groups. According to dominant policy frameworks, these groups (target groups) should be equally treated in policy as they share similarities. However, this is not the case according to the social construction and policy design framework. Policy-making (implicitly) differentiates between groups with the same characteristics by distributing to these different burdens and benefits, or wins and losses. This generates normative concerns of democracy, inclusion, and justice. In this research, we reflect on how social, technological, economic, and environmental wins and losses are distributed among target groups, and how these processes raise questions of the political nature of innovation. Current research on social construction in policy has focused on social policy, specifically in the areas of health and welfare (see Ingram, Schneider, Deleon; 2007). The role of science and technology, however, has been largely ignored. Hence, drawing from the Science and Technology Studies (STS), we demonstrate that considering the way in which specific technological innovations enable actors to perform certain actions within society, is essential for understanding the process of construction of target groups. Furthermore, STS insights enable us to reflect on (implicit) technical and social exclusion of user groups through innovation designs, or non-consideration in innovation policy (see e.g. Wyatt et al., 2002). We draw on different disciplines to explore a new field of smart mobility, which is arguably reshaping current transport policy domain. Smart mobility is leading to the emergence of mobility target groups, such as drivers of electric vehicles. This also generates new wins and losses for the groups. Furthermore, smart mobility is gaining increasing attention because it comes with great promises about solving societal issues such as congestion and air pollution. However, through the processes of excluding some target groups, smart mobility may fail to solve social challenges in an inclusive way. As an emerging policy domain, smart mobility is confined to a forward-looking policy agenda and we are interested in reflecting on what role STS could play in guiding more inclusive innovation policies. Empirically we focus on Smart Mobility policy in The Netherlands. Specifically, the Beter Benutten program regions of Maastricht and Brabant. This program aims to reduce traffic congestion by 20% and door-to-door travel time by 10%, by optimizing existing infrastructure usage and by improving mobility network interconnections (Tweede Kamer der Staten-Generaal, 2011). Using research methods based on the document analysis and semi-structured interviews, we show how this roadmap distributes wins and losses among (smart) mobility user groups.

Applicability study of an airport cement concrete pavement structure based on aircraft movements

Scipedia content — Thu, 28 Jan 2021 17:33:04 +0100

It is necessary for airfield managers to ensure that airfield pavement is used sustainably and to predict pavement service life accurately. According to the specification for design of airport cement concrete pavement, this paper adopts a reversed design method to study the applicability of an airport cement pavement structure, which constructs a limit state equation based on the number of aircraft surplus repeated action. What’s more, there are 4 confirmed key calculative parameters that have an effect on evaluating the applicability of airport cement pavement structure, i.e. load transfer coefficient, equivalent modulus of elasticity of foundation, thickness of pavement slab and flexural tensile strength of concrete. Taking some airport for example, the standard referenced values of pavement structure parameters have been set in advance. The level of 4 parameters variation selects 5% respectively. Then their effect of aircraft movements is analyzed correspondingly, i.e. the rank of influence degree is that: flexural tensile strength of concrete"thickness of pavement slab"load transfer coefficient"equivalent modulus of elasticity of foundation. In the meanwhile, with the effect of surplus aircraft movements analyzed deeply in different areas versus different types of aircraft, we can find that the distribution of aircraft movements in different areas of airport pavement is different in the same type. And where the most surplus movements take place is the central section of the runway. What’s more, it is necessary for the airfield pavement to limit This paper is part of the Proceedings of the 14 International Conference th

Design of a Dynamic Ship Draft Detection System in Inland Navigation

Scipedia content — Thu, 28 Jan 2021 17:32:30 +0100

A survey on smart traffic network control and optimization

Scipedia content — Thu, 28 Jan 2021 17:28:57 +0100

International audience; In the current day and age, traffic in urban areas is becoming more and more complex leading to congested roads and intersections. Hence, the need for sophisticated traffic control system to reduce the congestion and provide better flow management. In this paper, we present briefly the basic notions and the most important parameters that affects the traffic control. Then, we provide a survey on the main flow management systems that are available in the literature. Some possible future research works and propositions on intelligent traffic control are also provided.

Power Law Analysis Implications of the San Bruno Pipeline Failure

Scipedia content — Thu, 28 Jan 2021 17:26:20 +0100

When major pipeline incidents occur there is always a question as to how applicable the learnings from that incident are across the industry. To address this question for the San Bruno pipeline failure in 2010, an analysis of historical transmission pipeline industry events was conducted to determine if San Bruno was consistent with past industry performance or whether it was an outlier event. This paper draws on Power Law analysis to generate a characteristic curve of past transmission pipeline accidents in the US. Power Law, or Pareto, behavior has been observed for a wide variety of phenomenon, such as fire damage, earthquake damage and terrorist attacks. The size of these events is seen to follow not the typical normal distribution but the Power Law distribution, where low probability - high consequence (LPHC) events play a more significant role in the overall risk picture. Analysis shows that the consequences of pipeline incidents in a variety of pipeline industries (gas distribution, gas transmission, gas gathering and hazardous liquid pipelines) are seen to exhibit Power Law behavior. The Power Law model is seen to capture the distribution of the size of consequences from pipeline incidents and defines the relationship between the size of an incident and its frequency. Through characterization of these distributions, it is possible to project the likelihood or expected frequency of events of a given magnitude and to assess if a given incident fits within historical industry patterns; i.e. whether the incident is consistent with past observations or is an outlier."/jats:p" "jats:p"The Power Law analysis shows that the San Bruno incident, which caused eight fatalities and an estimated $380 million in property damage in 2010, is not an outlier. Rather, this incident lies on the Power Law curve for historical transmission pipeline incidents, with an estimated frequency of once every 40 years. The event is consistent with the history of gas transmission pipeline consequences in the US. This paper argues that the San Bruno incident, therefore, provides lessons relevant to the industry as whole.

Probabilistic Modelling of the Impact on Bus Punctuality of a Speed Limit Proposal in Edinburgh

Scipedia content — Thu, 28 Jan 2021 17:24:20 +0100

We propose a data-driven methodology for evaluating the impact of the introduction of a speed limit on the punctuality of bus services. In particular, we use high-frequency Automatic Vehicle Location data to parameterise a model that represents the movement of a bus along predefined patches of the route. We fit the probability distributions of the time spent in each patch to two classes of probability distributions: hyper-Erlang distributions, for which we use the tool HyperStar, and a variation of the three-parameter gamma distributions recommended by the Traffic Engineering Handbook. In both cases we obtain models that can be expressed using the framework of Probabilistic Timed Automata, allowing us to evaluate bus punctuality using the model checking tool UPPAAL. We conduct a case study involving a proposed speed limit in Edinburgh.

SAFEGUARD: An assured safety net technology for UAS

Scipedia content — Thu, 28 Jan 2021 17:23:50 +0100

demands increase to use unmanned aircraft systems (UAS) for a broad spectrum of commercial applications, regulatory authorities are examining how to safely integrate them without loss of safety or major disruption to existing airspace operations. This work addresses the development of the Safeguard system as an assured safety net technology for UAS. The Safeguard system monitors and enforces conformance to a set of rules defined prior to flight (e.g., geospatial stay-out or stay-in regions, speed limits, altitude limits). Safeguard operates independently of the UAS autopilot and is strategically designed in a way that can be realized by a small set of verifiable functions to simplify compliance with regulatory standards for commercial aircraft. A framework is described that decouples the system from any other devices on the UAS as well as introduces complementary positioning source(s) for applications that require integrity and availability beyond what the Global Positioning System (GPS) can provide. Additionally, the high level logic embedded within the software is presented, as well as the steps being taken toward verification and validation (V&V) of proper functionality. Next, an initial prototype implementation of the described system is disclosed. Lastly, future work including development, testing, and system V&V is summarized.

Capacity analysis of suburban rail networks

Scipedia content — Thu, 28 Jan 2021 17:23:24 +0100

Evaluation of a Tree-based Pipeline Optimization Tool for Automating Data Science

Scipedia content — Thu, 28 Jan 2021 17:15:48 +0100

the field of data science continues to grow, there will be an ever-increasing demand for tools that make machine learning accessible to non-experts. In this paper, we introduce the concept of tree-based pipeline optimization for automating one of the most tedious parts of machine learning---pipeline design. We implement an open source Tree-based Pipeline Optimization Tool (TPOT) in Python and demonstrate its effectiveness on a series of simulated and real-world benchmark data sets. In particular, we show that TPOT can design machine learning pipelines that provide a significant improvement over a basic machine learning analysis while requiring little to no input nor prior knowledge from the user. We also address the tendency for TPOT to design overly complex pipelines by integrating Pareto optimization, which produces compact pipelines without sacrificing classification accuracy. As such, this work represents an important step toward fully automating machine learning pipeline design.

Comment: 8 pages, 5 figures, preprint to appear in GECCO 2016, edits not yet made from reviewer commen

Faster-than-at-speed execution of functional programs: An experimental analysis

Scipedia content — Thu, 28 Jan 2021 17:15:29 +0100

International audience; Burn-In (BI) test is usually applied in manufacturing process to screen out chip early life failures, especially for safety critical applications. Unfortunately, this test method has elevated costs for companies. In recent days, Faster-than-at-Speed-Test (FAST) has become a useful technique to discover small delay defects. At the same time, overclocking methods to enhance system performances have been studied, which focus on temperature management to preserve system functionalities. In this paper, a FAST technique is approached with the aim of intentionally provoking a thermal overheating in the microprocessor by mean of the execution of functional test programs, partly regardless of system behavior preservation. The goal is to introduce an internal stress stronger than current procedures used during BI in order to speed up early detection of latent faults. The method illustrates how to avoid blocking configurations due to timing constraints violation and leads to a significant increase of the switching activity. Experimental results on a MIPS architecture show that, by using the described technique, the processor is not falling into an unpredictable state even at frequencies up to about 20 times higher than the nominal one and the switching activity is increasing up to 300% per nanoseconds.

A Bayesian Framework for Preventive Assistance at Road Intersections

Scipedia content — Thu, 28 Jan 2021 17:14:59 +0100

International audience; Modern vehicles embed an increasing number of Advanced Driving Assistance Systems (ADAS). Whilst such systems showed their capability to improve comfort and safety, most of them provide assistance only as a last resort, that is, they alert the driver or trigger automatic braking only when collision is imminent. This limitation is mainly due to the difficulty to accurately anticipate risk situations in order to provide the driver with preventive assistance, i.e. assistance allowing for comfortable reaction. This paper presents a Bayesian framework which aims to detect risk situations sufficiently early to trigger conventional curative assistance as well as preventive assistance. By taking into consideration the context, the vehicle state, the driver actuation and the manner how the driver usually negotiates given situations, the framework allows to infer which type of assistance is the most pertinent to be provided to the driver. The principles of this framework are applied to a fundamental case study, the arrival to a stop intersection. Results obtained from data recorded under controlled conditions are presented. They show that the framework allows to coherently detect risk situations and to identify what assistance, including preventive assistance, is the most appropriate for the situation.

AUGURY: A Time Series Based Application for the Analysis and Forecasting of System and Network Performance Metrics

Scipedia content — Thu, 28 Jan 2021 17:10:57 +0100

This paper presents AUGURY, an application for the analysis of monitoring data from computers, servers or cloud infrastructures. The analysis is based on the extraction of patterns and trends from historical data, using elements of time-series analysis. The purpose of AUGURY is to aid a server administrator by forecasting the behaviour and resource usage of specific applications and in presenting a status report in a concise manner. AUGURY provides tools for identifying network traffic congestion and peak usage times, and for making memory usage projections. The application data processing specialises in two tasks: the parametrisation of the memory usage of individual applications and the extraction of the seasonal component from network traffic data. AUGURY uses a different underlying assumption for each of these two tasks. With respect to the memory usage, a limited number of single-valued parameters are assumed to be sufficient to parameterize any application being hosted on the server. Regarding the network traffic data, long-term patterns, such as hourly or daily exist and are being induced by work-time schedules and automatised administrative jobs. In this paper, the implementation of each of the two tasks is presented, tested using locally-generated data, and applied to data from weather forecasting applications hosted on a web server. This data is used to demonstrate the insight that AUGURY can add to the monitoring of server and cloud infrastructures.

Comment: 8 pages, 9 figures, submitted to SYNASC2016

Predicting Ridership at railway intersection Station based on Accessibility Model

Scipedia content — Thu, 28 Jan 2021 17:03:56 +0100

Reasons for crack nucleation in welded joints of main gas-pipelines after a long-term operation

Scipedia content — Thu, 28 Jan 2021 17:00:49 +0100

crack of operational origin in the welded joint of the main gas pipeline is analyzed. The reasons for its nucleation and impact on technological microdefects that were formed earlier during the welding are found. Micromechanisms and stages of nucleation and propagation of the crack are investigated.

Legal Implications of airport privatization in India

Scipedia content — Wed, 27 Jan 2021 08:40:00 +0100

The air transport sector including airlines, airports and providers of air navigation services have largely been State controlled. Formerly, most airlines were State owned. However, the ownership pattern of airlines has changed gradually to the majority of the airlines being privately owned as a part of globalization and liberalization of economies. These observations can be made in the case of airports too. State owned airports are being privatized in many States due to various reasons. The trend started with the privatization of British Airports Authority (BAA) owned airports in United Kingdom (UK). Europe, Asia and Latin America are now witnessing privatization of airports on a fast track basis. Australia and New Zealand have also privatized their State owned airports in the last decade. Though the models vary depending upon the economic policy of the State, the concept of privatization or private participation in airport infrastructure is gaining momentum in these States. However, the United States of America (USA) remains an exception to this trend of airport privatization. In 2006, India joined the global trend of privatization in airport infrastructure, by privatizing two State owned airports in New Delhi and Mumbai. Though the first privately owned international airport started operations in 1999 in Kochi (Cochin),1 two other privately owned airports were operationalized in Bangalore and Hyderabad only in 2008.

Detection and Characterization of Road Accident Clusters in Texas Counties

Scipedia content — Tue, 26 Jan 2021 18:28:53 +0100

Traffic accidents count for one of the main causes of life losses globally as well as heavy burden of their consequents on societies, a matter which prompts researchers to discover the reasons of accidents occurrence and factors affect their severity. Therefore, in this study k-means clustering method is applied to analyze traffic accident data to identify the counties with the highest relatively severe accidents, considering all levels of crash severity, due to driver-related risk factors in Texas State. It analyzes recorded data of the statewide accidents occurred within 2013 to 2015, available from Texas Department of Transportation official website. As a result of this research the counties with similar status of crash severity were identified among which the counties in the most critical situation were distinguished, an outcome that can be useful for authorities such as transportation planners to make appropriate decisions in safety planning. Furthermore, some of the contributor factors that may intensify accidents were addressed. Keywords: Traffic safety, Accident, Severity, K-Means, Clustering ÖZ: Trafik kazaları günümüzde dünyadaki ölümlerin büyük bir oranını oluştururken, ayni zamanda toplumlar üzerindeki geri dönülemez etkileri de araştırmacılar tarafından büyük dikkat çekmekte ve araştırma konusu olmaktadır. Bu sebeple, bu araştırmada kümeleme metodu uygulanarak sürücü hatalarına bağlı trafik kazalarının Texastaki şehirlere göre olan oranları çıkarılmıştır. Teksas’ta 2013 yılından 2015 yılına kadar olan trafik kazaları bu bağlamda incelenmiş olup Ulaştırma Bakanlığınca yol güvenliğini sağlamak amacıyla yapılabilecek eylemler ve alınabilecek önlemler konusundaki icraatlara yönelik öneriler sunulmuştur. Bu öneriler trafik yönünden Teksas ile benzeşen diğer şehirlerde de kullanılabilir. Anahtar kelimeler: Trafik güvenliği, Kaza, Ciddiyet, K-Means, Kümeleme Master of Science in Civil Engineering. Thesis (M.S.)--Eastern Mediterranean University, Faculty of Engineering, Dept. of Civil Engineering, 2017. Supervisor: Assist. Prof. Dr. Mehmet Metin Kunt.

Decision-making for Sustainable Transport Planning: Reducing Car Dependency Culture in Alexandria, Egypt.

Scipedia content — Tue, 26 Jan 2021 18:26:34 +0100

This thesis aims at investigating the challenges and barriers of reducing car dependency culture to achieve urban sustainability in Egypt. This is operationalised by identifying different policy options and theoretically examining a nested-case study empirically. A more important purpose behind this academic enterprise was to find more robust and nuanced explanations of the constant failure of the transport planning system in Egyptian cities. The adoption of a cultural-oriented analytical framework to examine decision-making processes demonstrated a way forward in the re-evaluation of current transport policy directions in Egypt.The research applies qualitative methods to a nested case study in Alexandria through the Sustainable Urban Transport Project, 2032. The rigorous data-collection methods included extensive documentary analysis, elite interviews, semi-structured interviews and non-participant observations. The results obtained from applying these unconventional methods of social and political sciences in transport planning studies show the richness of these research methods in providing comprehensive explanations. This research illustrates the value of placing policy and transport-planning-related studies into the centre of different research positions. The main contributions of this research are grounded on a number of key research findings. First, the development of a cultural-oriented analytical framework based on the central thesis of polyrationality. Second, the research pioneers the approach of identifying the relevant stakeholders and contexts in transport decision-making processes in Egypt which serves as a basis for other future transport-related research for Egypt. This research builds the foundation for conducting multidisciplinary research for transport planning studies. The final contribution of this research suggests the need for mediators or policy analysts who have relevant education and knowledge in the transport planning sector to influence the decision-making processes.

Schematic bus transit maps for the web using genetic algorithms

Scipedia content — Tue, 26 Jan 2021 18:25:17 +0100

Dissertation submitted in partial fulfilment of the requirements for the degree of Master of Science in Geospatial Technologies The octilinear schematic map, layout recognized worldwide in metro maps, is an important transit informative tool. This research investigates how algorithms for the visualization of schematic maps can be availed in mobile web devices context in order to empower the efficiency in transmitting information of bus transit maps. A genetic algorithm for path octilinear schematization technique has been used and tested to create the schematic data. Location-based and interactivity functionalities were embedded to the resulting digital maps in order to create personalized maps to meet specific user needs. A prototype of a web application and real transit data of the city of Castellón in Spain was used to test the methodology. The results have shown that real time schematizations open possibilities concerning usability that add extra value to schematic transit maps. Additionally, suggested improvements have been made to the genetic algorithm and performance tests show that genetic algorithms are adequate, in terms of efficiency, to sketch bus transit maps automatically.

The case of cycling in Kisumu, Kenya

Scipedia content — Tue, 26 Jan 2021 18:24:21 +0100

Model-Based Design of an Electric Powertrain Vehicle; Focus on Physical Modeling of Lithium-ion Batteries

Scipedia content — Tue, 26 Jan 2021 18:16:56 +0100

Formula SAE (FSAE) vehicle systems are very complex. Understanding how subsystems effect the overall vehicle is essential for making design trade-offs. FSAE is a competitive environment. Teams need to have reliable and high performing vehicles to do well in competition. The Virginia Tech (VT) FSAE team has produced a prototype electric powertrain (EPT) vehicle, VTM16e, and will take their first EPT vehicle, VTM17e, to competition in 2017. The use of model-based design (MBD) for an EPT FSAE vehicle is investigated through this thesis. The goal of the research is to build the framework of a full vehicle simulation to take knowledge gained from the VTM16e prototype vehicle, and apply it to the VTM17e competition vehicle. A top-down, bottom-up approach is taken to build a full vehicle model of an EPT FSAE vehicle. A full vehicle simulation is built with subsystems to establish an overall structure and subsystem interactions. Individual subsystems are then focused on for testing and validation. Breaking the vehicle down into subsystems allows the overall model to be incrementally improved. The battery subsystem is focused on in this thesis. Extensive testing is performed on the batteries to characterize their performance. Computer models are generated from empirical data through parameter estimation techniques. Validation of the battery models is performed and the resulting model is incorporated into the overall vehicle model. Performance limits of the vehicle are determined through model exploration, and design modifications to increase the reliability and performance for the VTM17e vehicle are proposed. Master of Science

Determining the optimum detector locations at metering roundabouts using the queuing length estimation models /

Scipedia content — Tue, 26 Jan 2021 18:11:43 +0100

Thesis (PhD(Transport Engineering))--University of South Australia, 2017. Includes bibliographical references (pages 218-230) Traffic congestion, caused by the increased use of automobiles and limited land space, may generate unnecessary time consumption and pollutant emissions from the use of fossil fuels has become a serious social problem. Solving or minimising traffic congestion is a challenging task for traffic engineers and scholars, particularly at intersections with interrupted traffic flow, causing the most congestion having the majority of accidents. This research, therefore, formulated queuing length estimation models with six main parameters based on a conceptual model with three different models formulated in accordance with the role of each approach. Optimal detector locations were selected using the models.

Conribution to machine-to-machine architectures for smart grids

Scipedia content — Tue, 26 Jan 2021 18:06:49 +0100

The electrical grid is a huge and complex system which represents a critical infrastructure. Due to this fact, the electric power industry has traditionally adopted a conservative attitude regarding changes. As a result of that, the electrical grid has experienced very few breakthroughs for decades and currently is not prepared to face novel challenges, such as properly integrating DERs (Distributed Energy Resources) or proactively controlling the energy demand by means of the so-called DR (Demand Response) programs, which mainly derive from nowadays society concerns on global warming and climate change. Upgrading traditional electrical grid to the so-called Smart Grid represents one of the most complex engineering projects ever and will certainly drive the next wave of research and innovation in both the energy and the ICT (Information and Communications Technology) sectors. The road towards the Smart Grid will mean an unprecedented revolution especially at the power distribution and customer domains, since the unpredictable and uncontrollable nature of renewables will impose the coordination of generation and consumption points in almost real time. M2M (Machine-to-Machine) communications allow networked devices to communicate between them without further human intervention. What in the very beginning seemed to be a tailored solution for telemetry applications, has become a communications paradigm itself, addressing the myriad of applications existing and yet to be in the wide context of the Internet of Things. As a matter of fact, M2M communications represent one of the main pillars of the Smart Grid in that they will enable the bidirectional real-time exchange of information between the consumption and generation facilities to be monitored and controlled, and the information systems where the optimization processes run. There is a plethora of communications technologies and protocols available within the scope of M2M communications for the Smart Grid. Hence, research is needed in two directions. On the one side, it is required to evaluate how different communications architectures and technologies meet the specific requirements of the Smart Grid before undertaking the important investments needed to deploy this kind of infrastructures on a large scale. On the other side, it is crucial to develop common data models which serve as reference to future horizontal or wide scope protocols which expand across different domains or areas. This thesis aims to tackle these issues. The main goal of the thesis is to contribute to the area of M2M communications architectures tailored to the power distribution and customer domains of the Smart Grid. In order to achieve this overall objective, first we carry out a survey on the most relevant standardization activities developed in parallel to this thesis and on the most outstanding technological and research trends within the Smart Grid area, identifying gaps and challenges. Second, we propose a novel M2M communications architecture to support energy efficiency and optimum coordination of DER (Distributed Energy Resources) within the so-called energy-positive neighborhoods, which are neighborhoods which ensure a substantial part of their consumption by local generation based on renewables. The proposed architecture comprises three network segments, for the sake of flexibility and scalability, and combines different communications technologies to meet the specific communications requirements of each of them. Next, we model formally the domain of knowledge of energy efficiency platforms for energy-positive neighborhoods by means of an ontology developed in OWL (Ontology Web Language), with the aim that it becomes a reference data model for the application of M2M communications to this context. Thus, this ontology has been made public through the EC (European Commission) eeBuildings Data Model community, so that other researches can re-use it and extend it. We also propose a methodology that can be applied, in general, to characterize any communications overlay deployed on top of an infrastructure devoted to any purpose. Following this methodology, we model the traffic of the proposed M2M communications architecture in realistic large-scale scenarios. The main goal of this model is to ensure that potential works based on it actually mean and bring value to the interested parties. Although the model is tailored to the Portuguese power distribution grid, since it is based on actual data provided by EDP (Energias de Portugal), it can be easily adapted to other scenarios by suitably tuning the appropriate parameters. Taking this model as reference, we finally evaluate the core of the proposed M2M communications architecture twofold. On the one side, we analyze the impact of using IPSec (Internet Protocol Security) or TLS/SSL (Transport Layer Security/Secure Socket Layer) as VPN (Virtual Private Network) technologies on the operational costs of a potential energy efficiency platform which relies on the proposed M2M communications architecture. To the author’s best knowledge, no similar studies are available in the state of the art. The main conclusion of this analysis is that using TLS/SSL along with data aggregation is the best option to minimize operational costs at neighborhood level. On the other side, we evaluate by means of simulations the performance of IEEE 802.11b, using as metric the goodput (i.e., throughput at the application layer), and GPRS (General Packet Radio Service), using as metric the transmission time. The first conclusion of these simulations is along the line that IEEE 802.11b meets the requirements in terms of goodput of the NAN (Neighborhood Area Networks), which is of special interest to the Smart Grid community taking into account the low cost and wide adoption of this technology. The second conclusion of such simulations is that GPRS meets the requirements in terms of bandwidth of the backhaul network, thus confirming that it represents a very attractive technology considering that it is the most mature and widely deployed cellular technology in Europe.

Presidente: Jürgen Jähnert; Vocal: David Fernández Cambronero; Secretario: Francisco Valera Pintor

Dynamic Sectorization: assessment of new configurations of the Barcelona ACC sectorization

Scipedia content — Tue, 26 Jan 2021 18:02:08 +0100

decade ago, the SESAR programme was launched. SESAR aims to restructure of the European Air Traffic Management (ATM) through new infrastructure, systems and procedures inside a lesgislative European framework which will cover the future air traffic demand. One of the concepts borned with SESAR is the Dynamic Sectorization, where any necessary segregation is temporary, based on real-time usage within a specific period. The project focuses in the ACC of Barcelona West Airspace, which its maximum traffic demand is produced in summer, and the capacity is limited in the peak hours, causing the application of regulations, hence delay, almost in a daily basis in some of its sectors. This project covers an assessment based on the viability, benefits and inconveniences of two new possible configurations proposed by Enaire, the Air Navigation Service Provider in Spain, which are based in the FUA concept. For that, real air traffic samples are used from the months of July and August of 2015, and the configuration are simulated with EUROCONTROL NEST tool. The first configuration studies the possibility to rise the vertical limit between two sectors (Levante Upper, Levante Lower) from FL325 (3250 ft.) to FL345 (3450 ft.). The second configuration studies the possibility to incorporate temporary segregations between three sectors (Ponent 1 Upper, Ponent 1 Lower, Ponent 2) through the creation of two subsectors between them with the goal of joining them with the existing ones based on the traffic. Results show that in the first configuration the global conditions of capacity and saturation would be of the same order of magnitude, but having some benefits. The second configuration does not show any improvement with neither of the solutions provided, due to the capacity problem is focused in the airspace zone where the adaptable sectors have been created.

Definición de una Arquitectura de Referencia para Sistemas de Información en Redes de Sensores Inalámbricos Ubicuos basado en calidad de servicio

Scipedia content — Tue, 26 Jan 2021 18:01:15 +0100

Los rápidos avances tecnológicos han permitido una nueva generación de redes denominadas USN (Ubiquitous Sensor Network), donde los dispositivos móviles y pequeños sensores están presentes en todas partes y se entremezclan en las actividades cotidianas del ser humano. Esta nueva generación de redes permitirá ofrecer diferentes servicios a usuarios, a través de arquitecturas computacionales que integrarán: nuevas tecnologías, aplicaciones tecnológicas, redes de comunicaciones y otros servicios especializados. Con las redes USN se amplían las posibilidades de desarrollo tecnológico, sobre todo en el diseño de “ciudad inteligente”, y en otros sectores importantes de la economía como el agrícola y de transporte, entre otros. La investigación recoge una mirada a las principales propuestas realizadas en diferentes ámbitos por instituciones referentes - en especial en lo definido por la Unión Internacional de Telecomunicaciones – UIT/ITU, que han intentado estandarizar una arquitectura de referencia para este tipo de redes con el fin de reducir las complejidades de integración, el uso de múltiples tecnologías, la heterogeneidad de los diferentes protocolos existentes y facilitar: la interconexión, la comunicación y futuros desarrollos en este campo. A partir de una revisión sistemática y completa en la investigación, se logró la construcción del Estado del Arte que determinó las necesidades y características que deben ser satisfechas por una arquitectura de referencia para las redes USN, en especial, lo referente a calidad de servicio debido a que estas redes por su gran crecimiento y volumen de datos recolectados, no podrán atender la demanda requerida en los próximos años. La investigación aborda un estudio de la implementación de la calidad de servicio en Redes USN, teniendo en cuenta factores como el tiempo, la pérdida de información, diferenciación de servicios de emergencia y la capacidad de la red. Por ejemplo, en entornos inalámbricos es necesario alcanzar estabilidad y poca variabilidad en el tiempo tanto en la transmisión de los datos como en las peticiones realizadas por los diferentes actores. Además, se incorpora en cada una de las capas definidas de la arquitectura de referencia, la calidad de servicio como un componente esencial para garantizar la capacidad de la red para transmitir datos con los niveles de servicio adecuados de acuerdo con cada servicio definido. En las capa de la arquitectura se definen elementos estructurales que permiten pasar entre cada una los parámetros y métricas definidos, que evitan la pérdida o retraso de paquetes asociados a aplicaciones o servicios determinados previamente como críticos. Para el caso de las Redes USN integradas a los servicios ITS, fue necesario asociar un servicio de emergencia al conductor de un vehículo por estados de somnolencia como un evento súbito tal como se propone en (Garcés, Salgado, Andrés, and Henry, 2015). En este caso, los paquetes se transmiten con una clase de servicio mayor a las demás haciendo que en cada capa, la información/paquete tenga un tratamiento especial y prioritario durante su envío al middleware o en otros casos, a las aplicaciones o servicios finales. Dentro de la investigación, se analizaron los protocolos usados actualmente, revisando los modelos que soportan los volúmenes de datos requeridos por este tipo de redes, determinando aplicar en la capa MAC diferenciación de servicio, asociando clases de servicio sobre los paquetes y haciendo que la transmisión de estos, se sintonicen con las demás capas de la Red y con toda la arquitectura. Establecida la necesidad de contar con un modelo de diferenciación de servicio, se determinaron los requerimientos de calidad de servicio. Con la prueba de concepto se pudo utilizar un modelo continúo (transmisión de datos en intervalos de tiempo periódico) y orientado por consultas en donde los datos son solicitados por un receptor, dando origen a un Modelo Hibrido con datos y peticiones en intervalos de tiempo bien definidos a lo largo de la Red USN y de la Arquitectura en general. Por otro lado, y avanzando en el conocimiento de estas redes, dentro de la investigación se propuso una arquitectura de referencia aplicable a un caso de estudio de orden nacional e internacional, tomando el área de los Sistemas Inteligentes de Transporte SIT/ITS, como un sector fundamental en el desarrollo de las naciones y del cual se tiene pleno conocimiento por parte de los involucrados en la investigación. Abstract. The rapid technological advances have allowed a new generation of networks called USN (Ubiquitous Sensor Network), where the mobile devices and small sensors are present everywhere and are intermingled in the daily activities of the human being. This new generation of networks will allow to offer different services to users, through computational architectures that will integrate: New technologies, technological applications, communications networks and other specialized services. With the USN networks the possibilities of technological development are extended, especially in the design of "smart city", and in other important sectors of the economy as the agricultural and transport, among others. The research takes a look at the main proposals made in different fields by relevant institutions - especially as defined by the International Telecommunication Union, ITU-, which have tried to standardize a reference architecture for this type of networks in order to Reduce the complexity of integration, the use of multiple technologies, the heterogeneity of the different existing protocols and facilitate interconnection, communication and future developments in this field. From a systematic and complete review in the investigation, the State of the Art was achieved, which determined the needs and characteristics that must be satisfied by a reference architecture for the USN networks, especially the quality of service due to the fact that these networks due to their great growth and volume of data collected, will not be able to meet the demand demanded in the coming years. The research addresses a study of the implementation of quality of service in USN Networks, taking into account factors such as time, loss of information, differentiation of emergency services and network capacity. For example, in wireless environments it is necessary to achieve stability and little variability in time both in the transmission of data and in the requests made by different actors. In addition, quality of service is included in each of the defined layers of the reference architecture as an essential component to guarantee the capacity of the network to transmit data with the appropriate levels of service according to each defined service. In the layers of the architecture are defined structural elements that allow to pass between each one the defined parameters and metrics, that avoid the loss or delay of packages associated with applications or services previously determined as critical. In the case of USN networks integrated with the ITS services, it was necessary to associate an emergency service to the driver of a vehicle by states of drowsiness as a sudden event as proposed in (Garcés, Salgado, Andrés, and Henry, 2015). In this case, the packets are transmitted with a higher class of service than the others, causing the information / packet to have special and priority treatment during its delivery to the middleware or in other cases to the final applications or services. In the research, we analyzed the protocols currently used, reviewing the models that support the data volumes required by this type of networks, determining to apply service differentiation in the MAC layer, associating service classes on the packets and making the transmission of these, be tuned with the other layers of the Network and with all the architecture. Establishing the need to have a service differentiation model, the quality of service requirements were determined. With the proof of concept it was possible to use a continuous model (data transmission in periodic time intervals) and oriented by queries where the data are requested by a receiver, giving origin to a Hybrid Model with data and requests in good time intervals defined throughout the USN Network and Architecture in general. On the other hand, and advancing in the knowledge of these networks, the research proposed a reference architecture applicable to a national and international case study, taking the area of Intelligent Transport Systems SIT / ITS, as a Fundamental sector in the development of the nations and of which it is had full knowledge on the part of those involved in the investigation.

Strategic Air Traffic Planning Using Eulerian Route Based Modeling and Optimization

Scipedia content — Tue, 26 Jan 2021 17:59:07 +0100

Due to a soaring air travel growth in the last decades, air traffic management has become increasingly challenging. As a consequence, planning tools are being devised to help human decision-makers achieve a better management of air traffic. Planning tools are divided into two categories, strategic and tactical. Strategic planning generally addresses a larger planning domain and is performed days to hours in advance. Tactical planning is more localized and is performed hours to minutes in advance. An aggregate route model for strategic air traffic flow management is presented. It is an Eulerian model, describing the flow between cells of unidirectional point-to-point routes. Aggregate routes are created from flight trajectory data based on similarity measures. Spatial similarity is determined using the Frechet distance. The aggregate routes approximate actual well-traveled traffic patterns. By specifying the model resolution, an appropriate balance between model accuracy and model dimension can be achieved. For a particular planning horizon, during which weather is expected to restrict the flow, a procedure for designing airborne reroutes and augmenting the traffic flow model is developed. The dynamics of the traffic flow on the resulting network take the form of a discrete-time, linear time-invariant system. The traffic flow controls are ground holding, pre-departure rerouting and airborne rerouting. Strategic planning - determining how the controls should be used to modify the future traffic flow when local capacity violations are anticipated - is posed as an integer programming problem of minimizing a weighted sum of flight delays subject to control and capacity constraints. Several tests indicate the effectiveness of the modeling and strategic planning approach. In the final, most challenging, test, strategic planning is demonstrated for the six western-most Centers of the 22-Center national airspace. The planning time horizon is four hours long, and there is weather predicted that causes significant delays to the scheduled flights. Airborne reroute options are computed and added to the route model, and it is shown that the predicted delays can be significantly reduced. The test results also indicate the computational feasibility of the approach for a planning problem of this size.

Evaluation and Implementation of a Longitudinal Control in a Platoon of Radio Controlled Vehicles

Scipedia content — Tue, 26 Jan 2021 17:58:53 +0100

Over the past decades, congestion and emission problems has increased remarkablywhich escalates the demands on vehicles. The advancements withinthe eld of information and communication systems gives the opportunity todeal with the aforementioned problems. The concept of platooning shows tobe an attractive way of reducing both congestion and emissions by having ashort inter-vehicle spacing. The ndings in studies show that fuel reductionpotentials of 5-20 % are viable as a result of the lowered air drag by drivingin platoon. This thesis investigates the state of the art within the areaof intelligent transport systems (ITS) along with advanced driver assistancesystems (ADAS). Furthermore, the prosecuted work results in a proposedcontrol design for a longitudinal control in a platoon of vehicles. The platoonconsists of two homogeneous radio controlled vehicles (RCV) which aremodelled by taking advantage of system identication methods. The identi-ed plant models are implemented into a Simulink model where the controlsystem is developed. Moreover, the developed control system is implementedinto a real-time demonstrator for experimental evaluation. The results showsthat the modelled dynamics corresponds reasonably well with the real dynamicsof the system. The developed control system proves to work well andagree with the expectations of its performance obtained from simulations.The performance of the proposed controller has been evaluated by means ofsimulations and real experiments. The resulting control system consists ofPID controllers for both speed and spacing control. Under de senaste decennierna har mangden trakstockningar och problemmed utslapp okat - darmed aven kraven pa vara fordon. Samtidigt skaparframstegen inom informations- och kommunikationssystem mojligheter foratt hantera ovannamnda problem. Kolonnkorning, eller platooning har visatsig vara en eektiv metod for att minska saval trakstockningar som utslappsom en foljd av kortare avstand mellan fordon. Resultat fran studier visarhur en branslereduktion runt 5-20 % ar mojlig till foljd av det sankta luftmotstandet vid kolonnkorning. Avhandlingen undersoker teknikens standpunktinom intelligenta transportsystem (ITS) tillsammans med avancerade drivhjalpsystem(ADAS). Vidare resulterar arbetet i ett forslag till regleringsdesignfor en longitudinell kontroll i en kolonn av fordon. Kolonnen bestar av tvahomogena radiostyrda fordon (RCV) som modelleras genom att utnyttjametoder for systemidentiering. De identierade systemmodellerna implementerasi en Simulink-modell dar styrsystemet utvecklas. Dessutom implementerasdet utvecklade styrsystemet i en realtids-demonstration for experimentellutvardering. Resultaten visar att den modellerade dynamikenstammer bra overens med systemets verkliga dynamik. Det utvecklade styrsystemetvisar sig fungera bra och overensstammer med forvantningarna pa dessprestanda som erhallits genom simuleringar. Den foreslagna regulatorns prestandahar utvarderats med hjalp av simuleringar och verkliga experiment.Det resulterande styrsystemet bestar av PID regulatorer for bade hastighetsochavstandskontroll.

Aplicação de auxílio multicritério para escolha de alternativas de infraestrutura cicloviária

Scipedia content — Tue, 26 Jan 2021 17:56:40 +0100

Orientador: Maria Lucia Galves Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo Made available in DSpace on 2018-09-02T09:54:45Z (GMT). No. of bitstreams: 1 Alves_LuizMarceloTeixeira_M.pdf: 3480266 bytes, checksum: 0222637f425896327d1b1fb209bd6893 (MD5) Previous issue date: 2017 Resumo: A utilização da bicicleta como meio de transporte é algo amplamente discutido. Todo o ano esse modo de transporte ganha mais adeptos e as viagens de bicicleta voltam a ser relevantes em comparação com os demais modos. Diante disso, a inserção de infraestruturas cicloviárias passa a ter grande importância nas gestões públicas municipais que, em muitos casos sabem da necessidade de criação de infraestrutura e do estímulo ao uso deste modo, porém têm dificuldades na implantação de ciclovias, ciclofaixas e ciclorrotas por se tratar de algo que influencia a vida de todos os cidadãos, direta ou indiretamente, positiva ou negativamente. O objetivo deste trabalho é auxiliar a avaliação e escolha de alternativas de ligações cicloviárias entre a Av. Paulista e a Av. Brigadeiro Faria Lima, onde atualmente estão localizadas duas das ciclovias mais movimentadas da cidade de São Paulo. Para isso, foi utilizado o método de Auxílio Multicritério à Decisão (AMCD) para ajudar no entendimento do problema como um todo, e embasar a criação e avaliação das alternativas. Os resultados possibilitaram conhecer melhor os diversos pontos de vista dos atores envolvidos no processo decisório e avaliar o desempenho local e global de cada atributo, pilares para recomendação da melhor alternativa Abstract: The use of the bicycle as urban transport is a topic largely discussed around the world. Every year bicycle becomes more popular and cycling trips become more relevant compared to other types of transportation. Therefore, the insertion of bicycle infrastructure requires great effort by public administrations, that even knowing how important it is to stimulate the use of this transportation mode, have, in most cases, to face obstructions within implantation of cycling routes because of the great change that this represents in the life of every citizens, directly or indirectly, positively or negatively. The objective of this study is to support the choice and evaluation of alternatives for cycling routes between Paulista Avenue and Brigadeiro Faria Lima Avenue, two of the busiest cycleways in Sao Paulo City. In order to do this, it was adopted the Multi-criteria Decision Aid (MCDA), that should help understanding the problem, giving bases to the creation and evaluation of the different alternatives. The results allow to knowledge the different points of view of all actors involved in the decision process, and evaluate the local and global performance of each attribute, giving basic premise to identify the best alternative Mestrado Transportes Mestre em Engenharia Civil

Methods for Optimal Charging of Large Fleets of Electric Vehicles

Scipedia content — Tue, 26 Jan 2021 17:50:54 +0100

Today’s electric grid must be transformed to meet modern consumption behaviors and safely integrate renewable energy sources. This has led to major efforts to develop grid-scale energy management solutions and ensure safety and reliability of our modern power network. In particular, large penetrations of Plug-in Electric Vehicles (PEVs) are expected increase energy needs and peak consumption, which would bring new challenges for utilities and grid operators.In this work, we develop optimization methods to coordinate the charging of large fleets of PEVs in distribution grids. We show that different methods should be applied, based on the infrastructure requirements and the objective of the controller.The first Chapter Optimal Charging of Fleets of Electric Vehicles with Discrete Charging rates: PDE Modeling and Control Techniques presents a continuum modeling framework to coordinate PEV charging with discrete charging rates. We consider PEVs as loads, which diffuse along the State Of Energy (SOE) axis, and can be in three different categories: charging, discharging or idle. We use a discretized form of Partial Differential Equations (PDEs) to model the dynamics of the system and control the transitions between each category. The second Chapter Dual Splitting Framework for Optimal Charging of Fleets of Electric Vehicles with Continuous Charging rates proposes a tailored distributed optimization method to coordinate PEV charging for load shaping. Three iteration methods are presented and their convergence characteristics are detailed. The third Chapter Electric Vehicle Charging in the Smart Grid: Plug-and-Play Model Predictive Control techniques studies a voltage-regulation scenario for PEV charging. Power flow and distribution grid constraints are modeled, and PEV charging is controlled with Plug-and-Play Model Predictive Control. Finally, the final chapter Behavioral study of Demand Response programs studies the impact of non rational choices on energy consumption and on the success of Demand Response programs.

Hacking your ride: is Web 2.0 creating vulnerabilities to surface transportation?

Scipedia content — Tue, 26 Jan 2021 17:47:05 +0100

The purpose of this thesis is to determine the threats that social media and social navigation (SMSN) pose to the surface transportation system. The research catalogs the types of threats and SMSN's vulnerabilities, and uncovers terrorists' malign use of social media for intelligence gathering. Academic researchers have already discovered threats in social navigation platforms such as Waze and Google Maps; Sybil and man-in-the-middle attacks allow malicious actors to create traffic congestion and alternate vehicle routing. While this has not yet caused an attributable security concern to the vehicle surface transportation system, in the hands of malicious actors, these vulnerabilities could be exploited to orchestrate an attack that devastates infrastructure and risks human lives. http://archive.org/details/hackingyourridei1094550604 Transportation Services Manager, City of Los Altos, CA Approved for public release; distribution is unlimited.

Optimizacija linijskih sistema javnog prevoza putnika

Scipedia content — Tue, 26 Jan 2021 17:44:10 +0100

Analizom procesa kretanja vozila duž linije identifikovani su parametri koji utiču na širenje poremećaja intervala sleđenja. Na osnovu utvrđenih relacija između parametara, formiran je deterministički model. Modelom je predstavljeno širenje i slaganje više prostih poremećaja intervala sleđenja po stajalištima duž linije i po polascima u redu vožnje na jednoj liniji javnog gradskog prevoza putnika. U radu je izvršena matematička analiza složenog uticaja različitih parametara na širenje poremećaja intervala sleđenja vozila. Rezultati analize su pokazali da je u fazi projektovanja sistema u velikoj meri moguće uticati na sekundarne poremećaje intervala sleđenja i preventivno delovati na povećanje stepena ravnomernosti intervala sleđenja na liniji. U skladu sa zaključcima analize modela razvijen je postupak optimizacije kojim se sa aspekta vremena boravka putnika u sistemu i dostignute ravnomernosti intervala sleđenja, vrednuje podela dijametralne linije na dve radijalne."/p"

"p"An analysis of the process of vehicle movement along the line was used to identify the parameters which influence irregular headway propagation. The established relations between the parameters were used to form a deterministic model. The model describes the propagation and concurrence of numerous primary headway irregularities by the stops along the line and by the scheduled departure times at one urban public transport system line. The paper presents a mathematical analysis of the complex effect of various parameters on the irregular headway propagation. The results of the analysis have shown that the secondary headway irregularites could be largely affected during the transport system design phase, thus preventing the increase in the degree of headway uniformity along the line. In accordance with the conclusions of the model analysis, an optimisation method has been developed, which is used to evaluate the division of the diametrical line into two radial lines from the aspect of on-line travel time and the achieved headway uniformity.

Document type: Doctoral thesis

Optimization of railway network using smart-grid solutions

Scipedia content — Tue, 26 Jan 2021 17:43:50 +0100

Increasing energy efficiency is nowadays a requirement in all technical fields. The reduction of global consumption, thus carbon footprint, has become the world's priority, as for example, the climate and energy package of the European Union.Railways' share of energy consumption is one of the highest. Electrical solutions are developed in order to reduce these systems' losses, optimize their consumption and reduce global energy bill. Given their diversity, two main categories are considered in this study. The first one consists of urban lines that are characterized by a DC electrification and a relatively dense traffic. In this case, braking energy burned in trains' rheostats represents the main share of losses. The proposed solution is to recuperate this energy using a DC micro-grid implemented in a passengers' station. It allows an interaction with the non-railway electrical environment, for example, re-using this energy in charging electric hybrid buses parked nearby. The excess of braking energy is recuperated using a DC/DC converter and injected into a DC busbar. A second DC/DC converter will store it in a hybrid storage system. It will then serve to charge the buses connected to the DC busbar. The micro-grid is also connected to the grid using a low power AC/DC converter. A power management system ensures optimizing power flow between different components. An energy evaluation showed that this solution is a good Investment especially because no contract is needed with the energy provider. The system's stability is studied and a stabilizing command, the backstepping, is applied. This new smart station allows railways to communicate, energetically, with its evolving environment.The second category is suburban and high speed lines that are AC electrified. Contrarily to the previous case, braking energy is reinjected to the upper grid through substations. Therefore, a second solution is to reduce global energy consumption by optimizing trains' speed profiles and timetable's synchronization. It is done using a differential evolution algorithm. Each speed profile is divided into zones to which are associated driving parameters. The optimization of the latter allowed generating new optimal speed profiles and a less-consuming timetable. Simulation results showed that it is possible to make important energy savings while respecting train's punctuality.; L'amélioration de l'efficacité énergétique est devenue aujourd'hui une nécessité dans tous les domaines techniques. La réduction de la consommation, et donc du bilan carbone, est placée parmi les priorités mondiales tel que le paquet énergie-climat 2020 de l'Union Européenne.Les systèmes ferroviaires font partie des plus grands consommateurs d'énergie. Des solutions électriques sont développées pour réduire les pertes dans ces systèmes, optimiser la consommation et donc réduire la facture énergétique globale. Étant donné la diversité de ces systèmes, deux catégories principales sont considérées. La première regroupe les lignes urbaines caractérisées par une électrification en mode DC et un trafic relativement dense. Dans ce cas, l'énergie de freinage brûlée dans les rhéostats des trains constitue une perte considérable. La solution proposée consiste à récupérer cette énergie à l'aide d'un DC micro-grid installé dans une station passager. Elle permettra une interaction avec son environnement non-ferroviaire comme par exemple réutiliser cette énergie pour charger des bus électriques hybrides stationnant à proximité. Ce micro-grid contient un premier convertisseur DC/DC qui récupère l’excès d'énergie de freinage d'un train et l'injecte dans un DC busbar. Un deuxième convertisseur DC/DC va ensuite la stocker dans un système de stockage hybride pour que le bus électrique puisse se charger une fois branché au DC busbar. Le micro-grid est relié au réseau par un onduleur réversible AC/DC de faible puissance. L'ensemble est géré localement par un système gestion de puissance. Une évaluation énergétique montre que cette solution est intéressante lorsqu’un investissement, station de charge, est nécessaire pour charger les bus. En plus, dans le cas du DC micro-grid, aucun contrat avec le fournisseur d’électricité n’est nécessaire. La stabilité du système est aussi étudiée et une commande de stabilisation, le backstepping, est appliquée. Ce nouveau concept d’une future station intelligente permettra au système ferroviaire de communiquer avec son environnement qui est en pleine évolution.La deuxième catégorie est constituée par les lignes régionales et les lignes à grandes vitesses fonctionnant en mode AC. Contrairement au cas précédent, l’excès d’énergie de freinage est renvoyé à travers les sous-stations d’alimentation. Par conséquence, une deuxième solution propose la réduction de la consommation totale par l’optimisation du profile de vitesse de chaque train et la synchronisation de la grille horaire. Ceci est réalisé à l’aide d’un algorithme d’évolution différentielle. Chaque profile de vitesse est découpé en zones auxquelles sont attribuées des paramètres de conduite. L'optimisation de ces derniers permet de générer un nouveau profile de conduite optimal. Les résultats montrent la possibilité de faire des économies d’énergie tout en respectant la ponctualité des trains.

Integrating Computational and Participatory Simulations for Design in Complex Systems

Scipedia content — Tue, 26 Jan 2021 17:38:34 +0100

The understanding and conceptualization of cities and its constituent systems such as transportation and healthcare as open and complex is shifting the debates around the technical and communicative rationales of planning. Viewing cities in a holistic manner presents methodological challenges, where our understanding of complexity is applied in a tangible fashion to planning processes. Bridging the two rationales in the tools and methodologies of planning is necessary for the emergence of a 'non-linear rationality' of planning, one that accounts for and is premised upon complexity. Simulations representing complex systems provide evidence and support for planning, and have the potential to serve as an interface between the more abstract and political decision making and the material city systems. Moving beyond current planning methods, this thesis explores the role of simulations in planning. Recognizing the need for holistic representations, the thesis integrates multiple disparate simulations into a holistic whole achieving complex representations of systems. These representations are then applied and studied in an interactive environment to address planning problems in different contexts. The thesis contributes an approach towards the development of complex representations of systems; improvements on participatory methods to integrate computational simulations; a nuanced understanding of the relative value of simulation constructs; technologies and frameworks that facilitate the easy development of integrated simulations that can support participatory planning processes. The thesis develops contributions through experiments which involved problems and stakeholders from real world systems. The approach towards development of integrated simulations is realized in an open source framework. The framework creates computationally efficient, scalable and interactive simulations of complex systems, which used in a participatory manner delivers tangible plans and designs. "p"QC 20170602

Models and methods for Traffic Engineering problems with single-path routing

Scipedia content — Tue, 26 Jan 2021 17:32:08 +0100

Traffic Engineering (TE) uses methods and models from a variety of mathematical fields, such as statistics and optimization, to improve the performance of telecommunication networks. In this thesis, we study TE problems dealing with networks that impose single-path routing. As the name infers, in this type of routing, the traffic flow of each "commodity" cannot be split in its path between its origin and destination. Given its cheap cost, single-path routing is widely used in today's data centers, where thousands of stored servers perform computations or host Internet services. One common case of single-path routing is the one enforced by the Spanning Tree Protocol (STP) in switched Ethernet networks. The STP requires the network to keep its activated links loop-free, while maintaining the other redundant links ready for back-up, in case of link failure. The Multiple Spanning Tree Protocol (MSTP) extends the STP by installing multiple virtual networks compliant with the STP, over a single physical topology. Therefore, the MSTP is greatly beneficial for network service providers, as it allows for a more efficient use of the existing resources.Network design problems dealing with the MSTP are generally highly combinatorial and very hard to solve. As such, TE literature mainly suggests heuristic methods, which can quickly produce reasonable designs. Notwithstanding, due to a scarce existence of lower bounds to the optimum values of such problems, there is little knowledge about the quality of the solutions provided by these heuristics.In this sense, we propose mathematical programming models and methods that can provide optimal designs for these networks, or at the very least, obtain valid lower bounds. Taking into mind the goal of avoiding congestion in the network, we focus on two problems that deal with the following load-balancing objectives: the minimization of the worst-case link utilization, and the minimization of flow costs given by piecewise linear functions that penalize heavily-loaded links. The study of both these problems yielded relevant by-products: the first is the study of a MSTP network design problem, where we minimize the total load, and the second is the study of a fundamental unsplittable multicommodity flow problem with piecewise linear costs.For all the considered problems, we provide studies of complexity, extensive polyhedral studies to compare the proposed formulations, and a wide array of computational experiments to evaluate the performance of the proposed models and methods.

Doctorat en Sciences

info:eu-repo/semantics/nonPublished

Favoriser une mobilité durable : l’intégration du transport public multimodal à Addis Abeba

Scipedia content — Tue, 26 Jan 2021 17:26:25 +0100

ddis Ababa, with an area of 540 km2 and with population of 3.1 million people is experiencing a rapid pace of socio-economic and physical transformation. The city is not only the political, commercial, economic and financial hub of the country but also an international city serving as the seat of the African Union and various international organizations. Alike many African Cities, Addis Ababa has been undergoing a high rate of urbanization. This process of rapid urbanization has resulted in the increase in the size of the population and the physical expansion of the city. As a consequence, travel demand and length of the trip are increasing. Transportation plays a key role in determining the socioeconomic development and shaping the spatial development framework of the city. Equally important, transportation as derived demand is also a fundamental means for residents to fulfill their various activities. In Addis Ababa motorization, although on the increase, is low and public transportation is the most important mode of motorized mobility for the large majority of the city’s population. There are various formal and informal operators of the public transport mainly operating on individual basis. It is estimated that there are over 18,000 public transport vehicles that are daily running in Addis Ababa, most of them low capacity vehicles. Despite its importance, the public transport sector not only suffers from shortage, insufficient capital investment, and until recently lack of clear governmental policy and leadership but also from the absence of integrated approach to its operation, planning and management.Many cities in the North have embarked on integrating the provision of public transportation for nearly half a century now. In these cities, integration in public transportation has been recommended as a viable instrument for providing high quality and seamless urban transport and enhancing sustainable urban development. African cities which are characterized by their high urbanization rate, low level of private car ownership, deficient public transportation system and significant financial constraints lack public transportation integration experiences. The question is then ‘how do African cities replicate and implement public transport integration practices?’ that have been originally developed for the Cities of the North. The thesis attempts to answer this question and analyses the different forms of public transport integration. It then proposes a framework for implementing integrated public transport as a sustainable means of urban mobility in Addis Ababa.; Addis-Abeba, qui s’étend sur 540 km2 et compte 3,1 millions d’habitants, connait aujourd’hui des transformations socio-économiques et spatiales rapides. Elle n’est pas seulement le coeur politique, commercial, économique et financier du pays mais aussi une ville internationale accueillant le siège de l’Union africaine et d’autres institutions internationales. Comme d’autres villes africaines, elle connait un rythme élevé d’urbanisation. Ce processus a impliqué la croissance du nombre d’habitants mais aussi une extension spatiale accrue. En conséquence, la demande de déplacements et la longueur des parcours ont augmenté. Le transport joue ainsi un rôle clé, pesant sur le développement socio-économique et la configuration de l’espace urbain. Tout aussi important, en tant que demande dérivée, il joue sur la capacité des citadins à accomplir leurs diverses activités. La motorisation des ménages restant faible en dépit d’une lente progression, le transport public constitue le principal moyen d’accès à une mobilité motorisée pour la majorité de la population. L’offre est constituée d’une multitude d’opérateurs formels et informels, travaillant selon un schéma artisanal. On estime à plus de 18 000 les véhicules de transport public, la plupart de faible capacité, qui parcourent chaque jour les rues d’Addis-Abeba. En dépit de son importance, le transport public souffre de capacités d’investissement insuffisantes ainsi que, jusqu’à récemment, du manque d’une politique publique claire et affirmée. Il pâtit également de l’absence d’une approche intégrée, pour sa planification, sa gestion et sa mise en oeuvre. De nombreuses villes du Nord, parfois depuis près d’un demi-siècle, ont choisi de construire un service intégré de transport public. L’intégration y est vue comme un outil viable pour offrir un transport urbain de haute qualité et « sans couture », permettant un développement urbain durable. Par contre, les villes africaines, caractérisées par une urbanisation rapide, des taux d’équipement automobile faibles, un système de transport public déficient et des contraintes financières majeures manquent de telles expériences d’intégration du transport public. Notre question est donc : « Comment les villes africaines peuvent-elles reproduire et mettre en oeuvre des politiques d’intégration du transport public ? », originellement développées dans les villes du Nord. La thèse essaie d’apporter des éléments de réponse à cette question. Elle s’appuie sur une analyse des différentes formes d’intégration du transport public. Puis elle propose un schéma de conception et de mise en oeuvre d’un système de transport public intégré, appréhendé comme un outil de mobilité urbaine durable pour Addis-Abeba.

Roll-on/roll-off terminals and truck freight : improving competitiveness in a motorways of the sea context

Scipedia content — Tue, 26 Jan 2021 17:25:08 +0100

In recent years transport policy at an European Level has been focused on reducing the share of road transportation and promote alternative transportation means in order to reduce road congestion and carbon footprint. One of the solutions proposed has been promoting Short Sea Shipping (SSS) transportation combined with land transportation to become a door-to-door alternative to the monomodal road alternative. The maritime centered option would hit to birds with a stone: reduce congestion in the most urbanized areas of the European Union and partly replacing heavy polluting truck haulage for an environmentally friendlier option. The European Commission launched many polices and initiatives to make the modal shift happen, the crown jewel being the launch of multiple initiatives promoting the establishment of a system of Motorways of the Seas. Those are links between ports with higher standards in terms of travel time, costs and flexibility, which can compete one-on-one with road haulage among the countries in the Union. Despite different efforts from the public administration to kick off MoS lines and ensure their competitiveness, the expected momentum is still yet to come. In the light of this, this thesis aims at providing tools to assess the competitiveness of existing and MoS line to-be, to quantify the room for improvement available and the effects that some changes at an operational and strategical level might have on the success of any specific line. Particularly, the thesis presented aims at three specific objectives: (1) to identify the strategic potential of SSS in all its forms, considering the characteristics of the demand (goods to be moved) and the role of RoRo and MoS shipping in the global picture; (2) to identify the most sensible procedures in RoRo terminals operation to be addressed to improve their performance and perception from the end user, and; (3) To understand the costs of the supply chain, and the cost structure of RoRo shipping lines, and their sensitiveness in front of market changes, pricing and public funding policies. To approach each issue different qualitative, analytical and simulating models are used depending on the concerned problem. The strategic assessment makes use interviews to identify the main requirements that a transporter might face when dealing with SSS. The role of the terminal is assessed by means of two separate models: from one side an analytical model is used to assess the relationship between capacity and quality by means of quantifying the service time the ship spends in a port and calculate the probability of delays. On the other side, the resilience of the port is assessed with an arborescence interlinking its current vulnerabilities, their causes and effects and their probability to happen. Finally, and regarding the business models, first a cost and time model is constructed for each of them and tested against variations on some of the variables and from there, a tool to calculate the optimal deployment of the shipping line to ensure the maximum shift (or profit) is provided. In that case, the model is complemented with the adaptation of a transportation discrete choice model. Overall, the tools should be helpful to assess the potential of a shipping line from its planning level to its final operational deployment.

Els darrers anys, la política de transports a nivell europeu s'ha focalitzat en reduir el pes del transport per carretera de mercaderies i promoure mitjans de transport que li siguin alternatius, com a mesures per reduir la congestió a les carreteres i la petjada ecològica. Una de les solucions que s'ha posat sobre la taula, és l'anomenat Transport Marítim de Curta Distància (TMCD o SSS, en les seves sigles en anglès), com a una veritable alternativa bimodal (ferrocarril/carretera combinats amb transport marítim) a l'opció de transport monomodal per carretera. Diversos estudis certifiquen que el transport porta-a-porta transcorregut parcialment amb TMCD acostuma a registrar menors externalitats (bàsicament costos ambientals i de congestió) que el transport per carretera per cada tona transportada. Des d'un punt de vista operatiu, el TMCD i especialment la seva versió en forma d'Autopistes del Mar (AdM o MoS), enteses com a enllaços entre ports amb altes prestacions pel que fa a temps de viatge, flexibilitat i freqüència a un cost competitiu s'han estudiat àmpliament com a una alternativa directa i equivalent al transport per carretera. Però malgrat els esforços fets des de l'administració pública per promoure les línies d'AdM i assegurar-ne la competitivitat, aquestes no han obtingut l'impuls previst inicialment. L'objectiu d'aquesta tesi, de fet, és proveir un conjunt d'eines per tal d'avaluar la competitivitat de qualsevol AdM i quantificar-ne el marge de millora i l'efecte que alguns canvis a nivell operatiu i estratègic podrien tenir en la seva competitivitat , tan a nivell operatiu com estratègic, per tal de garantir-ne la competitivitat futura. De forma més específica, la tesi que aquí es presenta, analitza tres aspectes específics de les AdM: (1) Quines característiques a de tenir el seu mercat potencial a nivell estratègic, (2) con rol prenen les terminals portuàries, enteses com la baula dèbil de la cadena de transport, a nivell de la valoració qualitativa de la cadena de transport per part del seu usuari final i (3), possibles models de negoci pel transportista / propietari de la mercaderia per treure el màxim profit de les AdM. Cada un dels tres aspectes s'adreça mitjançant eines diferenciades que s'adaptin a la problemàtica plantejada. L'anàlisi estratègic es basa en entrevistes a usuaris de cadenes de transport per establir els principals requeriments del transportista que es pugui plantejar l'ús d'una AdM. A partir dels requeriments, es defineixen diversos models de cadena de transport, arribant a la conclusió que les cadenes 'push-pull' i 'push against stock' són les candidates que més es beneficiarien d'una AdM, almenys a nivell estratègic. El rol de la terminal s'analitza qualitativament analitzant-ne dos aspectes per separat: d'una banda es crea un model basat en una combinació de valors d'origen estocàstic, determinista i via simulació, per calcular el temps d'operació mínim d'un buc de càrrega rodada a una terminal marítima i la relació que hi ha entre nivell d'ús de la terminal i la seva capacitat. D'altra banda, també s'estableix un marc per quantificar la vulnerabilitat i resiliència de la terminal davant de elements que afectin la seva normal operació i com aquests poden afectar la qualitat percebuda del servei. Finalment, pel que fa als models de negoci pels transportistes, es construeix un model de costos i temps per cada un d'ells, se n'analitza la sensibilitat i el pes de les principals variables que els afecten com a eina per calcular el model de negoci, les característiques de la línia marítima i les tarifes de base a cobrar des de la perspectiva de la naviliera. Per assolir-ho, el model es complementa amb l'adopció d'un model d'elecció modal. Preses conjuntament, es proporciona una metodologia per ajudar a avaluar el potencial de futures AdM o millorar les existents i l'efecte que hi poden tenir les actuals i futures polítiques de transport.

Analysis, simulation and integration of the main powertrain components of an EV/HEV

Scipedia content — Tue, 26 Jan 2021 17:22:18 +0100

Detection of temporal patterns and events in time-dependent acceleration data : using the example of Vienna's metro rails

Scipedia content — Tue, 26 Jan 2021 17:21:37 +0100

von Alexander Litzellachner Zusammenfassung in deutscher Sprache Technische Universität Wien, Diplomarbeit, 2017

An analysis of public private partnership initiatives in containerised rail transport in India

Scipedia content — Tue, 26 Jan 2021 17:19:55 +0100

Electric vehicles in India and the national electric mobility mission plan 2020

Scipedia content — Tue, 26 Jan 2021 17:14:24 +0100

ngelo Das Mercês João Technische Universität Wien, Master Thesis, 2017

Análise série temporal para alocação ótima de eletropostos de recarga rápida em áreas urbanas

Scipedia content — Tue, 26 Jan 2021 16:57:31 +0100

Orientador: Fernanda Caseño Trindade Arioli Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação Made available in DSpace on 2018-09-01T05:22:22Z (GMT). No. of bitstreams: 1 Martins_MarceloCardosoSales_M.pdf: 3235752 bytes, checksum: b0da2fa1342140a1879cadc3c015be7a (MD5) Previous issue date: 2017 Resumo: Os veículos elétricos são uma opção de mobilidade que está se tornando mais popular a cada dia. Dentre os fatores que contribuem para isso estão a diminuição do seu preço, o aumento da sua autonomia e a crescente preocupação com questões ambientais. Para que os usuários consigam se locomover nas cidades utilizando os veículos elétricos, é necessário que existam eletropostos suficientes para a recarga destes. O local de instalação de eletropostos na rede elétrica exerce uma influência em aspectos técnicos da rede como suas perdas e perfil de tensão. Na primeira parte desta dissertação é elaborada uma curva de demanda de eletropostos de recarga rápida através de uma abordagem estocástica utilizando o método de Monte Carlo. Essa curva de demanda é utilizada nas simulações dos capítulos posteriores. Na segunda parte, são utilizados métodos de metaheurística para a solução do problema de alocação ótima de eletropostos de recarga rápida. Estes métodos são aplicados a vários cenários distintos em diferentes redes de distribuição. Ao final, é realizada uma comparação entre os métodos de alocação baseados em aspectos técnicos da rede e a alocação baseada no tráfego viário, e são discutidas as diferentes alternativas que podem ser adotadas de forma a mitigar os aspectos negativos que podem ser causados na rede elétrica Abstract: Electric vehicles are a mobility option that is becoming more popular every day. Among the factors contributing to this are the decrease of their price, the increase of their au-tonomy and the growing concern over environmental issues. In order to provide enough infra-structure to allow a wider use of the electric vehicles, it is necessary a sufficient number of charging stations. The location where the charging stations are installed in the distribution systems affects technical aspects of the network such as losses and voltage profile. In the first part of this thesis, a curve demand of fast charging stations is built through a stochastic ap-proach using the Monte Carlo method. This curve is used in later chapters. In the second part, meta-heuristics methods are used for solving the optimal allocation problem of fast charging stations. These methods solve several different scenarios including variations in the distribu-tion network, the objective function and the expected curve demand of charging stations. Fi-nally, comparisons between the results of the optimal allocation methods and an allocation based on road traffic is presented and different alternatives are discussed to mitigate the nega-tive technical aspects that can be caused in the power grid Mestrado Energia Eletrica Mestre em Engenharia Elétrica CAPES

Optimization of Ramp Area Aircraft Push Back Time Windows in the Presence of Uncertainty

Scipedia content — Tue, 26 Jan 2021 16:55:52 +0100

It is well known that airport surface traffic congestion at major airports is responsible for increased taxi-out times, fuel burn and excess emissions and there is potential to mitigate these negative consequences through optimizing airport surface traffic operations. Due to a highly congested voice communication channel between pilots and air traffic controllers and a data communication channel that is used only for limited functions, one of the most viable near-term strategies for improvement of the surface traffic is issuing a push back advisory to each departing aircraft.This dissertation focuses on the optimization of a push back time window for each departing aircraft. The optimization takes into account both spatial and temporal uncertainties of ramp area aircraft trajectories. The uncertainties are described by a stochastic kinematic model of aircraft trajectories, which is used to infer distributions of combinations of push back times that lead to conflict among trajectories from different gates. The model is validated and the distributions are included in the push back time window optimization. Under the assumption of a fixed taxiway spot schedule, the computed push back time windows can be integrated with a higher level taxiway scheduler to optimize the flow of traffic from the gate to the departure runway queue. To enable real-time decision making the computational time of the push back time window optimization is critical and is analyzed throughout.

Design of a Gearbox for an electric FSAE vehicle

Scipedia content — Tue, 26 Jan 2021 16:54:23 +0100

The main objective of this project is to design a new gearbox for an electric Formula SAE car. The last car had one motor for each wheel, and for the new car, only one motor will be used to give traction to the rear wheels. The gear selection has been done by using the Optimum Lap software. Which after giving the main parameters of the car as well as the geometry of the circuit, returns the data needed to design the powertrain system, among others. A comparison haas been done between the different transmission systems available. After deciding that the use of a gearbox is the best option, another comparison has been done to choose the type of gears. To do so three different basic designs have been done with CATIAV5. The selected option is to use three stage spur gears. To design the tooth form, materials and shaft-hub conection selection, the KISSSOFT software has been used. To optimize the different parts after designing them with CATIAV5, the parts have been meshed with HyperMesh and processed in Abaqus. The final design weights less than 6kg and contains all the parts needed inside of the gearbox. The connections to the motor or the wheels have not been designed.

Optimal design of a one-way carsharing system including electric vehicles

Scipedia content — Tue, 26 Jan 2021 16:50:39 +0100

This thesis focuses on the optimal design of one-way station-based carsharing systems. We consider the system design through two structural aspects: the optimal system dimensioning (number of parking places, vehicles, battery capacities, etc.) and the identification of appropriate stations’ locations. Although the addressed problems do not directly concern the system management, some relevant aspects (like vehicle relocation operations) are nonetheless part of the models. The modelling approach uses graph theory to represent the system dynamics over time and various optimization models (ILPs and MILPs) are proposed. The objective is to deduce an optimal shape of the whole system (number of vehicles, parking places, jockeys, stations’ locations, etc.) allowing to capture the maximum number of estimated time-dependent requests. Electric vehicles and power supply are also included in an enhanced model version and context related constraints ensure the integrity of the whole model. The optimization allows to study the impact of different power supply technologies and settle the minimal autonomy a shared vehicle necessitate in this environment. Models are applied to realistic case studies, using both random generated data and real estimated outputs of simulation tools. Strategies including vehicle relocation operations managed by jockeys (employees of the carsharing operator) are considered. We propose some graph simplifications reducing the problem size and leading to greatly improve solver capabilities as well as computation times. A greedy heuristic helping to quickly find feasible solutions and initialize the solver is also proposed and illustrated.; Cette thèse s'intéresse à la conception optimale d'un système d'autopartage de type one-way avec stations. Les problèmes abordés traitent de deux aspects structurels importants : le dimensionnement optimal du système (nombre de places de parking, de véhicules, de relocalisation de véhicules, etc.) et la localisation adéquate des stations. Bien que le management ou pilotage en temps réel du service ne soit pas l'objet de cette étude, certains aspects pertinents (relocalisation de véhicules, nombre de jockeys) ont toutefois été intégrés aux modèles. L'approche mathématique utilise des objets de la théorie des graphes pour représenter les systèmes dans le temps et les problèmes sont résolus grâce à la programmation linéaire en nombre entiers. L'objectif est d'identifier la structure du service permettant de capturer le plus de demandes possibles. L'introduction de véhicules électriques et de la puissance de charge en station sont étudiés dans un modèle dédié. Les expérimentations s'appuient sur des données réalistes, générées aléatoirement. Nous nous intéressons particulièrement aux pistes d'amélioration des temps de calculs et de réduction des graphes. Une heuristique gloutonne permettant d'identifier rapidement une solution réalisable est en particulier proposée. Enfin, une étude de dimensionnement des batteries confirme que des capacités deux fois inférieures à celles actuellement sur le marché sont viable dans le contexte urbain actuel.

Finding Similar Days for Air Traffic Management

Scipedia content — Tue, 26 Jan 2021 16:47:41 +0100

orts are central to stimulating the growth and development of economies around the world. With the trend of increasing demand for air travel and transportation of goods, there is mounting pressure on the existing airport infrastructure. This leads to an imbalance in the capacity and demand at airports that costs airlines, passengers and the economy at large billions of dollars. A cost-effective solution to this growing imbalance is to develop ways to utilize the existing infrastructure well. Information from historical days that are similar to a day of operations can be used to gain insights to support traffic management decisions on that day. Recent advances in machine learning and computing power have made it possible to mine and analyze sizable historical archives of different variables that characterize and influence airport operations. Finding similar historical days can help better understand the impact of different traffic management initiatives (TMIs) and identify areas of capacity underutilization. Reduction in airport capacity underutilization can lead to reduction in airport delays. Decision support tools that can identify similar days and the TMIs taken on these past similar days and their resulting outcomes can augment controller experience to guide decision-making on the reference day at an airport. This information can allow air traffic managers to make less conservative decisions and thus improve airport capacity and reduce delays. This dissertation develops similarity measures between days using airport capacity and demand data. We find that dimensionality reduction is feasible for capacity data, and base capacity similarity on the principal components. Dimensionality reduction cannot be efficiently performed on demand data; consequently demand similarity is based on original data in this case. We find that both capacity and demand data lack natural clusters and thus propose that similarity be viewed as a continuous measure. Finally we estimate measures of overall distance based on both capacity and demand similarity. The estimated distances are visualized using Metric Multidimensional Scaling plots and indicate that most days with significant air traffic management activity are similar to certain other days, validating the potential of this approach for decision support. Accurate demand and capacity estimates are necessary to generate meaningful similarity measures that can be used in decision-support tools. Predicting airport capacity accurately can also help make better tradeoffs between allowing more flights to operate at the airport and minimizing expensive airborne delay. We develop accurate demand estimates from the Aggregate Demand List (ADL), which contains fine-grained flight schedule data of all the flights operating at an airport. Capacity of an airport can be observed only at sufficiently large demand. However, if the throughput of an airport is limited by the demand, we can only conclude that the capacity is larger than or equal to the observed throughput. The inability to directly observe capacity makes capacity prediction a challenging and less explored problem. This dissertation applies machine-learning methods that incorporate observations censored by insufficient demand to develop an airport capacity prediction model. Specifically, we explore Kaplan Meier estimator, Cox Proportional Hazards model and Random Survival Forest model to predict airport capacity. These models predict a capacity distribution rather than a single capacity value for an hour of interest at an airport using its weather, fleet mix and scheduled demand data. The model results also indicate the influence of different variables on the capacity of the airport. Model performance is compared using several validation measures, including Integrated Brier Score (IBS), Concordance Index (C Index), R2 and RMSE of predicted throughput, that account for the presence of censored observations. The RSF model consistently outperforms the KM estimator and Cox model across all the validation measures. This dissertation also develops capacity based similarity metrics between two days using the predicted hourly capacity distributions. The evaluation of the estimated similarity metric is challenging owing to the lack of ground truth similarity measures. In this dissertation, we propose a framework to validate the estimated similarity metric between two days using predicted capacity CDFs, demand, TMI and operational outcomes data. The assumption for this framework is that days that are similar based on their capacity, demand and TMI features should be similar based on their operational outcomes. We use a Random Forest model to combine the capacity, demand and TMI based similarity metrics, supervised by operational outcomes similarity metric. This combined similarity matrix is evaluated by measuring its correlation with the operational outcomes similarity matrix on test data. The methodology developed in this dissertation to identify similar days can be extended to any airport around the world using their respective weather, demand, TMI and operational outcome data. This framework uses data that can be forecasted and thus can be used to guide decisions on a day-of-operations in order to guide decision making, as well as a post-operations setting to compare decisions and outcomes on similar historical days.

Data mining, GIS and multicriteria analysis combined for planning urban cycling networks

Scipedia content — Tue, 26 Jan 2021 16:44:07 +0100

bicicleta é vista hoje como uma alternativa para melhorar a mobilidade urbana de forma sustentável. Apesar disto, os procedimentos de planejamento disponíveis para o desenvolvimento de infraestruturas cicloviárias ainda não estão totalmente consolidadas. Sendo assim, este estudo visa desenvolver e aplicar um método objetivo para o planejamento de redes cicloviárias com base na mineração de dados desagregados de origem-destino, em recursos de SIG e de técnicas de análise multicritério. É sugerida a realização de três etapas: a) identificação, a partir do perfil de usuários reais, de usuários potenciais, b) planejamento de propostas de redes cicloviárias, e c) comparação entre as redes propostas e as definidas pelo poder municipal, considerando os usuários reais e potenciais e critérios de custos e benefícios. Como resultado positivo, o uso de dados desagregados permitiu mensurar e analisar a proximidade dos usuários às redes, a quantidade de pessoas atendidas e a identificação dos usuários potenciais. Além disso, a análise com base em critérios de custo e de benefício foi capaz de indicar, por exemplo, que a rede cicloviária existente (RCE) na cidade considerada como estudo de caso (São Carlos, SP, Brasil) não serve adequadamente os usuários, quando comparado às redes propostas. Cycling is seen nowadays as an alternative to improve urban mobility in a sustainable way. Nevertheless, the planning procedures available for developing cycling infrastructures are not yet fully consolidated. This study aims at the development and application of an objective method for planning cycling networks based on data-mining of disaggregated origindestination data, GIS resources and multicriteria analysis techniques. The method involves basically three steps: a) an identification of potential users based on real users profiles, b) planning of proposed cycling networks, and c) a comparison, considering real and potential users, as well as cost-benefit criteria, between the proposed networks and those actually developed by the municipality. As a positive outcome, the use of disaggregated data allows not only a reasonable estimate of the number of people served by the networks, but also a detailed analysis of their proximity to that infrastructure and an identification of potential users. Also, the analysis based on cost-benefit criteria was able to show, for example, that the existing cycling network (ECN) of the city taken as a case study (São Carlos, SP, Brazil) does not properly serve the users, when compared to the proposed networks.

Deep Convolutional Neural Networks for Real-Time Single Frame Monocular Depth Estimation

Scipedia content — Tue, 26 Jan 2021 16:43:20 +0100

Vision based active safety systems have become more frequently occurring in modern vehicles to estimate depth of the objects ahead and for autonomous driving (AD) and advanced driver-assistance systems (ADAS). In this thesis a lightweight deep convolutional neural network performing real-time depth estimation on single monocular images is implemented and evaluated. Many of the vision based automatic brake systems in modern vehicles only detect pre-trained object types such as pedestrians and vehicles. These systems fail to detect general objects such as road debris and roadside obstacles. In stereo vision systems the problem is resolved by calculating a disparity image from the stereo image pair to extract depth information. The distance to an object can also be determined using radar and LiDAR systems. By using this depth information the system performs necessary actions to avoid collisions with objects that are determined to be too close. However, these systems are also more expensive than a regular mono camera system and are therefore not very common in the average consumer car. By implementing robust depth estimation in mono vision systems the benefits from active safety systems could be utilized by a larger segment of the vehicle fleet. This could drastically reduce human error related traffic accidents and possibly save many lives. The network architecture evaluated in this thesis is more lightweight than other CNN architectures previously used for monocular depth estimation. The proposed architecture is therefore preferable to use on computationally lightweight systems. The network solves a supervised regression problem during the training procedure in order to produce a pixel-wise depth estimation map. The network was trained using a sparse ground truth image with spatially incoherent and discontinuous data and output a dense spatially coherent and continuous depth map prediction. The spatially incoherent ground truth posed a problem of discontinuity that was addressed by a masked loss function with regularization. The network was able to predict a dense depth estimation on the KITTI dataset with close to state-of-the-art performance.

Going Green: sustainability in the airline industry - TAP Group Study

Scipedia content — Tue, 26 Jan 2021 16:36:29 +0100

Sustainability reporting is nowadays one of the most important strategies of the businesses to present their green image. During the previous years, the topic of sustainability communication became popular among researchers who studied it in relation to different industries. However, the topic of sustainability communication was not widely developed in relation to aviation sector. This study aims to look how sustainability is perceived and communicated by the airline industry. Using a case study as a method, the thesis examines the sustainability practices of TAP Group by looking at company profile and history, annual sustainability reports and conducting semi-structured interviews within the company. The analysis of sustainability report has a qualitative nature and focuses mainly on three perspectives: environmental, economic and social. This part of the study found that TAP Group is making tremendous efforts to be perceived as a green airline by undertaking new initiatives each year since the beginning of reporting period. The biggest efforts are made in relation to environmental sustainability that is the largest issue for the industry. Another finding showed that the communication of sustainability in the company different departments is not well maintained and that company employees are not satisfied with this situation. The study also looked at several other airlines of different profiles and their initiatives regarding sustainability to maintain green image. As a sample the study analyzed profiles and sustainability communication of two additional airlines belonging to Star Alliance, two from the One World, two from SkyTeam and two independent low-cost airlines. It concludes that sustainability, especially the environmental perspective, is considered to be the most important and all actions are broadly communicated in the aviation industry. Another important finding shows that different airlines adopt communication channels but report the issues to different extent. This difference is most clearly visible in non-EU airlines that are far behind in sustainability reporting that European carriers. O transporte aéreo desempenha um papel muito importante ao permitir o contacto entre populações neste novo milénio, podendo ser considerado com um efetivo WOLD WIDE WEB ao permitir a ligação entre os diferentes países através das redes das distintas companhias aéreas. O transporte aéreo contribui igualmente de forma muito significativa para o desenvolvimento económico gerando, segundo a IATA (International Air Transport Association), cerca de 2,4 biliões de dólares americanos do produto mundial e empregando 58 milhões pessoas em todo o mundo (IATA, 2016). Segundo a mesma fonte, em 2034 esses valores atingirão os 6 biliões de dólares de contribuição para o produto mundial e os 105 milhões de empregos. Estes valores são ilustrativos da importância que o transporte aéreo tem na economia mundial. No entanto, esta atividade acarreta um custo elevado, uma vez que o aumento do consumo de combustíveis fósseis associado ao transporte aéreo tem aumentado e com isso a preocupação em relação à sua sustentabilidade. As emissões diretas não podendo ser completamente eliminadas podem ser reduzidas. De acordo com o CEO da IATA, o principal desafio é o da disponibilidade de biocombustíveis sustentáveis e a do seu preço. Muito terá de ser feito a uma escala global e nenhum Estado ou empresa de transporte aéreo poderá resolver o problema de forma isolada. Nesse sentido, e de acordo com a IATA, a configuração das infraestruturas e o planeamento das operações podem contribuir de forma efetiva para a redução das emissões. A sustentabilidade constitui, para muitos, um conceito vago e não apresenta uma definição universal. O termo sustentabilidade tem origem latina de sustinere e terá sido utilizado pela primeira vez na literatura relacionada com a produção florestal associada à “sustentabilidade da floresta” no início do século XVIII. Muito mais tarde, nos anos oitenta do século XX, a sustentabilidade associada ao desenvolvimento foi definida como “development that meets of the present without compromising the ability of future generations to meet those needs” (Brundtland et al., 1987, p. 398). Desde então, a sustentabilidade tem sido entendida centrada em três pilares: a economia, o ambiente e a sociedade (Thiele, 2013). As companhias aéreas encontram-se sob grande pressão por parte dos diferentes governos e das distintas entidades de regulação, no sentido de reportarem e implementarem práticas sustentáveis na sua atividade e as principais companhias aéreas têm vindo a publicar anualmente os seus relatórios de sustentabilidade onde apresentam as ações por si desenvolvidas e onde mostram o seu compromisso com os objetivos de sustentabilidade. Os relatórios de sustentabilidade destas empresas apresentam um vasto conjunto de informação acerca das ações por si desenvolvidas no âmbito económico, social e ambiental, bem como dos resultados dessas ações. O que tem faltado na discussão académica sobre a atividade do transporte aéreo é a apresentação de uma visão holística das ações para a sustentabilidade tomadas pelos diferentes atores desta indústria e de como essas ações são comunicadas pelas empresas, tanto internamente como externamente, aos seus clientes. Será que todas as empresas de transporte aéreo estão a desenvolver o mesmo tipo de ações? Haverá diferenças substanciais nos seus relatórios de sustentabilidade? Será que a estratégia de comunicação é efetiva? O presente trabalho pretende contribuir para preencher esta lacuna através da comparação das ações sustentáveis desenvolvidas pelas principais companhias de transporte aéreo e membros das diferentes alianças de transportadoras aéreas. Parte do estudo inclui entrevistas realizadas na TAP Portugal de forma a obter um conhecimento mais aprofundado da forma como o conceito de sustentabilidade é assumido por aquela empresa. A visão resultante das entrevistas conduzidas na TAP Portugal naturalmente não pode ser generalizada para todo o universo das empresas de transporte aéreo, mas permitiu obter um conhecimento frutuoso das diferentes ações sustentáveis assumidas pela empresa. Na primeira parte do trabalho, é apresentada uma breve análise das companhias aéreas analisadas e que integram diferentes alianças, através da análise das atividades desenvolvidas pelas companhias e pela informação disponível nos seus websites. A primeira constatação é de que existem grandes diferenças nas atividades desenvolvidas em termos de ações, ao mesmo tempo que existem referências às medidas de sustentabilidade desenvolvidas pela companhia, chegando a oferecer ao passageiro nesses sítios um calculador de emissões associadas à realização da sua viagem. É de assinalar que, atendendo à informação disponibilizada, existe uma falha de comunicação interna em relação às ações associadas aos princípios de sustentabilidade, uma vez que as empresas de transporte aéreo apenas disponibilizam os relatórios anuais e não apresentam nenhuma informação de como a comunicação é realizada internamente. Embora, seja possível que essas empresas disponham de canais de comunicação interna, essa informação não é mencionada de forma clara para o público em geral. Como resultado desta primeira parte, é possível concluir que as companhias aéreas, especialmente as europeias, se encontram empenhadas em serem mais sustentáveis e tentam seguir as linhas de orientação definidas pelas diferentes entidades de regulação. É de realçar que em relação às companhias analisadas, a Qatar airways, umas das principais companhias da atualidade, não publica qualquer relatório de sustentabilidade e demonstra um claro desinteresse sobre o tema. No âmbito da análise do caso de estudo, foram conduzidas duas entrevistas a responsáveis da TAP de forma a melhor perceber as ações no âmbito da sustentabilidade conduzidas na empresa e da forma como se procede à sua comunicação. A escolha do grupo TAP Portugal não foi casual. A TAP, companhia aérea nacional, foi uma das empresas de transporte aéreo do espaço europeia que foi pioneira que desenvolveu e promoveu o conceito de sustentabilidade no setor do transporte aéreo. A TAP publica relatórios de sustentabilidade desde 2006, tendo sido das primeiras a introduzir o programa de compensação de emissões de CO2 e é a segunda empresa mundial mais eficiente no que respeita ao consumo de combustível, sendo hoje uma das empresas que lideram o processo de integração dos princípios de sustentabilidade na sua atividade. Naturalmente, que os esforços da TAP são enormes, mas serão bem comunicados? Qual é o papel das ações sustentáveis na construção da imagem da empresa? Terá a sustentabilidade impacte positivo na perceção da imagem da companhia por parte dos colaboradores e dos passageiros? Quais são os objetivos futuros de uma companhia aérea? Quão sustentável é o grupo TAP quando comparado com as outras grandes companhias europeias? Finalmente, poderá uma companhia aérea vir a ser completamente sustentável no futuro? Estas questões iniciais foram desenvolvidas ao longo do processo de investigação. Para lhes responder, uma análise qualitativa de todos os relatórios de sustentabilidade da TAP foi realizada. Foram ainda realizadas duas entrevistas a um ex-piloto e um gestor de frota da TAP que, no seu dia-dia, aplicam e desenvolvem os programas de redução de emissões de CO2 através da redução de consumo de combustível e de eficiência na gestão de frota. Estas entrevistas, ajudaram a perceber as tendências de desenvolvimento das ações para a sustentabilidade do grupo TAP e permitiu perceber de que forma os conceitos de empresa sustentável é comunicada internamente. Depois de apresentados os resultados da análise dos relatórios de sustentabilidade e das entrevistas, são discutidos os resultados e respondidas as questões levantadas nesta dissertação. A principal conclusão deste trabalho é a da confirmação do que é referido na discussão académica, que nos últimos anos as companhias de transporte aéreo têm vindo a desenvolver grandes esforços para se tornarem mais sustentáveis. Por outro lado, verifica-se que o grupo TAP, quando comparada com as outras companhias de transporte aéreo, se apresenta bastante avançada na realização de ações de promoção de sustentabilidade. Contudo, as ações mais visíveis são as relacionadas com a vertente ambiental e não tanto na componente económica, encontrando-se neste caso numa situação menos favorável do que outras companhias. A dissertação também comprova que, apesar dos esforços, existe uma necessidade de desenvolver os processos de comunicação. Das entrevistas, foi possível identificar que a principal debilidade se relaciona com a fraca capacidade de comunicação na empresa. O estabelecimento de reuniões regulares, o desenvolvimento de relatórios internos e a motivação dos empregados da TAP foram apontados como elementos chave a desenvolver. Esta dissertação pretendeu contribuir para a discussão sobre a sustentabilidade e da sua relação com a atividade de transporte aéreo, a partir de uma visão holística da atividade. Este trabalho também apresenta como os princípios de sustentabilidade são comunicados, concluindo que há muito a fazer neste campo. As companhias necessitam de serem mais transparentes nas suas ações e comunicarem, com detalhe, os resultados. Como nota final, as grandes companhias extraeuropeias necessitam de serem mais ativas no campo da aplicação dos princípios de sustentabilidade. Como vimos na amostra, uma grande companhia não reporta nenhuma ação no âmbito da sustentabilidade.

Rebalancing strategies for bike-sharing systems: The case of "Bicing" Barcelona

Scipedia content — Tue, 26 Jan 2021 16:25:00 +0100

Popularity of shared vehicle systems in recent years makes necessary to stablish a design criteria in order to adapt those system to larger scales. Probably, the biggest problem to face is rebalancing. Present work stablishes an optimization method of those rebalancing operations, in particular for a bike-sharing system. In order to do this, two different methods are defined: periodic (or static) rebalancing and continuous (or dynamic) rebalancing. Results show that periodic rebalancing is more efficient but the level of service achieved is strongly capped by station size and bike fleet. On the other hand, continuous rebalancing is less efficient but allows a way higher level of service. For that reason, both rebalancing modes are complementary and necessary in order to reach a better level of service and lower costs than the current performance.

La popularidad que han adquirido los sistemas de vehículos compartidos en los últimos años ha hecho que sea necesario establecer una serie de criterios de diseño para poder adaptar estos sistemas a mayor escala. Probablemente el mayor problema de estos sistemas es el reposicionamiento. En el presente trabajo se pretende establecer un método de optimización de dichas operaciones de reposicionamiento, concretamente para el caso de bicicletas compartidas. Esta optimización se lleva a cabo a dos niveles: reposicionamiento periódico y continuo. Los resultados demuestran que el reposicionamiento periódico resulta más eficiente, pero el nivel de servicio que ofrece queda muy limitado por el tamaño de las estaciones. Por otro lado, el reposicionamiento continuo resulta menos eficiente pero puede alcanzar un nivel de servicio mucho mayor que el periódico. Por tanto, ambos modos son complementarios y necesarios para alcanzar mejores niveles de servicio o costes menores que los del actual servicio.

Bidirectional DC-DC converters for hybrid energy storage systems in electric vehicle applications

Scipedia content — Tue, 26 Jan 2021 16:24:08 +0100

Em um momento em que questões ambientais e a segurança energética estão numa posição de destaque, Veículos Elétricos (VEs) estão no centro das atenções. Entretanto, ainda é difícil para eles substituir os tradicionais veículos de combustão interna e a razão principal para isso é o seu sistema de energia. Normalmente, devido a suas características, baterias são usadas como banco de energia para VEs. No entanto, baterias também apresentam algumas limitações para essa aplicação e o problema no sistema de energia é relacionado a essas limitações. Uma das soluções propostas é se colocar baterias e supercapacitores (SC) em paralelo, resultando em um Sistema Híbrido de Armazenamento de Energia (SHAE). Para fazer essa configuração possível e o fluxo de potência controlável em um SHAE, um conversor CC-CC bidirecional interfaceando a bateria e o SC é necessário. Levando isso em consideração, o estudo de topologias CC-CC bidirecionais é apresentado nessa Dissertação de Mestrado. Primeiro, o estudo de um conversor CC-CC bidirecional com indutor dividido, envolvendo sua análise teórica em regime permanente, análise dinâmica e uma metodologia de projeto com resultados de simulação, é apresentado, resultando na construção de um protótipo experimental com as seguintes especificações de projeto: Fonte de tensão 1 de 300 V, fonte de tensão 2 de 96 V, frequência de comutação de 20 kHz e potência nominal de 1000 W. Então, o estudo de uma segunda topologia, um conversor CC-CC Buck-Boost ZVS bidirecional, envolvendo sua análise em regime permanente e uma metodologia de projeto com resultados de simulação, também é apresentado. In an era where environmental issues and the energetic safety are in an outstanding position, Electric Vehicles (EVs) are in the spotlight. However, it is difficult for them to replace the ICE vehicles and the main reason for that it is their energy system. Normally, due to some of their characteristics, batteries are used as energy bank in Electric Vehicles. Nevertheless, batteries also present some limitations for this application and the energy system problem is related to these limitations. One of the proposed solutions is to place batteries and Supercapacitors (SC) in parallel, resulting in a Hybrid Energy Storage System (HESS). To make this configuration possible and the power flow controllable in the HESS, a bidirectional DC-DC converter interfacing the battery and the SC is necessary. Taking this into account, the study of bidirectional DC-DC topologies is presented in this Master’s Thesis. First, a study of a bidirectional DC-DC converter with tapped inductor, involving its theoretical steady state analysis, dynamic analysis and design methodology with simulation results, is presented, resulting in the design of an experimental prototype with the following design specifications: Voltage source 1 of 300 V, voltage source 2 of 96 V, switching frequency of 20 kHz and rated power of 1000 W. Then, the study of a second topology, a bidirectional ZVS Buck-Boost DC-DC converter, involving he steady state analysis and a design methodology with simulation results, is also presented.

Fluxo de potência trifásico harmônico baseado no método backward/forward sweep para o estudo dos harmônicos gerados por cargas industriais e residenciais

Scipedia content — Tue, 26 Jan 2021 16:22:56 +0100

Orientador: Carlos Alberto Favarin Murari Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação Made available in DSpace on 2018-09-02T13:04:38Z (GMT). No. of bitstreams: 1 Franchi_ThiagoPrini_M.pdf: 6773708 bytes, checksum: e1f5720dfbe193d471334c043d398b80 (MD5) Previous issue date: 2017 Resumo: Com o aumento de cargas eletrônicas em geral, dos equipamentos ferromagnéticos e dos dispositivos a arco (cargas com características não lineares) conectados nas redes de distribuição de energia elétrica, intensificou o aparecimento de distúrbios e distorções nas formas de onda da tensão e da corrente degradando a qualidade da energia elétrica, sendo este o foco da pesquisa que norteou esta tese de mestrado. Foi desenvolvido um algoritmo fundamentado no método backward/forward sweep do tipo Ladder para realizar o cálculo do fluxo de potência trifásico em redes radiais tanto na frequência fundamental como nas frequências harmônicas. É descrita uma modelagem matemática das cargas não lineares industriais e residenciais (motor de indução trifásico, forno elétrico a arco, lâmpada fluorescente compacta e os sistemas de cargas de baterias para veículos elétricos), bem como, são apresentadas as formas de onda da tensão e da corrente nas barras da rede devido ao conteúdo harmônico proveniente dessas cargas não lineares e relatados os efeitos dos harmônicos nos componentes da rede elétrica, as distorções harmônicas e uma análise referente às principais normas nacionais e internacionais vigentes sobre harmônicos. Através deste estudo verificou-se que: nos ramos da rede as perdas são maiores no tronco principal (ramos que ligam a carga não linear a barra da subestação) e apresentam um comportamento semelhante ao conteúdo harmônico da carga não linear; nos bancos de capacitores há um aumento da potência reativa e da perda devido à presença das tensões harmônicas; a distorção harmônica total para a tensão é maior para as barras mais próximas da barra com a carga não linear (estando ou não no tronco principal); e a distorção harmônica total para a corrente é maior nos ramos que formam o tronco principal Abstract: With the increase of electronic loads in general, ferromagnetic equipment, and arc devices (loads with nonlinear characteristics) in the electrical energy distribution grid, it was verified the appearance of disturbances and distortions at the voltage and current waveforms damaging the quality of the electrical energy. Due to the concernment with the quality of the electrical energy, this work intends to develop an algorithm founded on the backward/forward sweep method of the Ladder type to perform the three-phase power flux calculus in radial grids, both in fundamental frequency and harmonics frequencies. In this dissertation it is presented an industrial nonlinear loads mathematical modeling and residential (three phase induction motor, electric arc furnaces, compact fluorescent lamps and battery load systems for electric vehicles), as well as, the voltage and current waveforms at the electric grid bars due to the harmonic content originated from nonlinear loads, the effects of the harmonics at the electrical grid components, the harmonic distortion and an analysis referring to the current main national standards about harmonics. Through this study it was verified that: the loses at the grid ramification is greater than the main stem (ramifications link the nonlinear load to the substation bar) and present a similar behavior to the nonlinear load harmonic content; capacitor banks present an increase at the reactive power and the loses caused by the presence of harmonic voltage; the voltage total harmonic distortion is greater for the bars closer to the bars with the nonlinear load (being or not in the mains stem); and the current total harmonic distortion is greater in the ramifications that form the main stem Mestrado Energia Eletrica Mestre em Engenharia Elétric

Essays in Industrial Organization and Environmental Economics

Scipedia content — Tue, 26 Jan 2021 16:13:01 +0100

This dissertation studies both theoretically and empirically how the allocation of subsidiesmight matter for economic outcomes in a two-sided market framework.The first chapter establishes a non-neutrality result with respect to subsidy allocation in the price theory of two-sided markets with membership externalities building on the works of Rochet and Tirole (2006) and Armstrong (2006). There are many examples of two-sided (or more generally, multi-sided) markets in which two (or more) groups of agents interact via intermediaries or “platforms.” The distinguishing feature of these markets is the presence of cross-group externalities: the benefit enjoyed by a member on one side depends on the number of members on the other side of the market. Examples of two-sided markets include: video game platforms, news media, credit cards, and electric vehicles. A basic feature of two-sided markets established by Rochet and Tirole (2006) is the non-neutrality of price structure, that is, how usage fees or membership prices are allocated between the two sides of the market have an impact on economic outcomes like buyer demand.In this work, I consider whether this non-neutrality in the price allocation carries over to the case of subsidies (or taxes) in two-sided markets. Specifically, I develop a stylistic two-sided market model to show that subsidies to the different sides of the market are non-neutral, in the sense that one dollar spent on subsidies given to one side of the market has a different economic impact as the same amount spent on subsidies given to end-users on the other side of the market. This result is driven by a key feature of two-sided markets: the positive network externalities between the two sides of the market. The non-neutrality of the allocation of subsidies has important implications for such quickly growing industries like the electric vehicle market in which currently most governments are subsidizing both sides of the market. Therefore, if we really want to learn where to give subsidies to achieve the policy goal of increased electric vehicle sales the findings of this chapter show that we need to empirically estimate the impact of price subsidies to buyers versus direct subsidies to charging stations using a two-sided market framework.The second chapter, building on the non-neutrality result of the first chapter, provides an empirical analysis of the impact of electric vehicle incentives on electric vehicle adoption that highlights the importance of accounting for the network externalities present in this market. I model the electric vehicle sector as a two-sided market with network externalities to determine which side of the market is more efficient to subsidize depending on key vehicle demand and charging station supply primitives. I use new, large-scale vehicle registry data from Norway to empirically estimate the impact that different subsidies have on electric vehicle adoption when network externalities are present. I present descriptive evidence to show that electric vehicle purchases are positively related to both consumer price and charging station subsidies. I then estimate a structural model of consumer vehicle choice and charging station entry, which incorporates flexible substitution patterns and allows me to analyze out-of-sample predictions of electric vehicle sales.In particular, the counterfactuals compare the impact of direct purchasing price subsidies to the impact of charging station subsidies. I find that between 2010 and 2015 every 100 million Norwegian kroner (around 12.39 million USD) spent on station subsidies alone resulted in 835 additional electric vehicle purchases compared to a counterfactual in which there are no subsidies on either side of the market. The same amount spent on price subsidies led to only an additional 387 electric vehicles being sold compared to a simulated scenario where there were no electric vehicle incentives. However, the relation inverts with increased spending, as the impact of station subsidies on electric vehicle purchases tapers off faster.

Reliability assessment of a bus transit network

Scipedia content — Tue, 26 Jan 2021 16:06:49 +0100

The reliability of transit modes is a crucial issue to guarantee their competitiveness and attractiveness. Experience shows that buses covering busy lines with short headways tend to arrive irregularly at their stops, often in bunches and therefore remarkably affecting the service. Hence, this work presents a stochastic model capable of representing the operational activity of a bus transit network and the service disruptions which eventually end up causing deviations from desired schedule. At the same time, the model is tested on an ideal route as a decision making tool.

Algorithm Engineering for Adaptive Route Planning

Scipedia content — Tue, 26 Jan 2021 16:04:05 +0100

Modernity in Transit: Sexual Harassment, Public Transportation and Urban Mobility in Bandung, Indonesia

Scipedia content — Tue, 26 Jan 2021 16:03:46 +0100

Safe travel and mobility in public space is critical for the emergence of women’s autonomy and confidence, and is linked to greater economic independence and enhanced freedoms, and yet, safe public travel remains tenuous for most women in the global south. This dissertation investigates the relationship between urban mobility and violence against women in public space. In Indonesia, the fourth most populous country in the world, public transportation systems are a powerful symbol of modernity and scientific progress and are tied to nationalist visions of economic development. Yet, the daily travels of urban women elicit a different set of imaginaries, ones defined by fear and anxiety from sexual assault. This dissertation interrogates increasing incidents of sexual harassment in public transportation against women, amid rapid urbanization in the capital city of West Java, Bandung. The dissertation reveals how urban women employ multiple social and cognitive practices to avoid risk and danger from assault in public space. It argues that an increasingly precarious urban landscape produces unique forms of “spatial feminist knowledge,” amongst urban women. These women develop individualized coping strategies and techniques in order to travel safely in public space. In doing so, public transportation is littered with multiple social and cultural meanings of inclusion and exclusion, of mobility and of constraint. As sexual violence becomes endemic to the urban terrain, private mobility is seen as the only solution for safe travel, rendering public transportation a site of naturalized violence. Global attempts to design out fear and reduce violent crimes against women, with “women only” transportation systems yield to traditional yet popular forms of gender segregation. The dissertation concludes that despite such popularity, these emergent designs serve as red herring solutions to the deeper more complicated question of the role of women in a rapidly changing society.

Transport Economics and Infrastructure: An Empirical Analysis of the Port Sector

Scipedia content — Tue, 26 Jan 2021 16:01:57 +0100

La presente tesis lleva a cabo un análisis empírico y económico de la infraestructura portuaria a través de la evaluación de políticas específicas. En primer lugar, la tesis se centra en cuantificar el impacto económico de la infraestructura portuaria sobre la industria. En segundo lugar, se mide el efecto de la competencia portuaria y su efecto sobre la demanda del tráfico. Finalmente, la tesis se centra en la evaluación de las políticas regulatoria de precios y su relevancia sobre el tráfico y los ingresos portuarios.

The present thesis carries out an empirical and economic analysis of the port infrastructure across the evaluation of specific policies. First, the thesis focuses on quantifying the economic impact of the port infrastructure on the industry. Secondly, there measures up the effect of the port competition and his effect on the demand of the traffic. Finally, the thesis focuses on the regulative evaluation of the policies of prices and his relevancy on the traffic and the port income.

Utilization of Forest Residue through Combined Heat and Power or Biorefinery for Applications in the Swedish Transportation Sector : a comparison in efficiency, emissions, economics and end usage

Scipedia content — Tue, 26 Jan 2021 15:54:30 +0100

Sweden has the goal of reaching a fossil independent transportation sector by 2030. Two ways to reach the goal is to increase the use of electric vehicles or produce more biofuels. Both alternatives could be powered by forest residue, which is an underutilized resource in the country. Electricity could be produced in a biomass fired Combined Heat and Power (CHP) plant, and biofuel could be produced in a biorefinery through gasification of biomass and Fischer-Tropsch process. When located in Stockholm County, both system can also distribute heat to the district heating system. It is however important to use the biomass in an energy-efficient way. The scope of this work has been to analyze the efficiency together with environmental and economic aspects of the two systems. To assess the efficiency and environmental impact of the two systems a forest to wheel study was made of the systems where the product was studied from harvesting of forest residue to driving the vehicle. The studied functional units were: kilometers driven by vehicle, kWh of district heating, CO2-equivalents of greenhouse gases and MWh of forest residue. The system using CHP technology and electric vehicles outperformed the biorefinery system on the two first functional units. Using the same amount of forest residue more than twice as much district heating and almost twice as many driven kilometers were produced in this system. The study also showed that both systems avoids significant greenhouse gas emissions and can be part of the solution to decrease emissions from road transportation. The profitability of investing in a CHP plant or a biorefinery was calculated through the net present value method. It showed that the expected energy prices are too low for the investments to be profitable. The CHP plant investment has a net present value of -1.6 billion SEK and the biorefinery investment has a net present value of -4.6 billion SEK. Furthermore, the biorefinery investment entails higher risk due to the high investment cost and uncommercialized technology. Both systems face barriers for implementation, these barriers have been studied qualitatively. Sverige har som mål att skapa en fossiloberoende fordonsflotta till år 2030. Två vägar som pekats ut för att nå målet är att öka användningen av eldrivna fordon eller att producera mer biobränsle. Båda alternativen kan drivas av skogsavfall, en råvara som det finns gott om i Sverige. Elektricitet kan produceras av skogsavfallet i ett kraftvärmeverk, och biobränsle i ett bioraffinaderi genom användning av förgasning och Fischer-Tropschmetoden. I Stockholms län skulle båda systemen dessutom kunna producera värme till Stockholms fjärrvärmesystem. Det är dock viktigt att använda skogsavfallet på ett resurseffektivt sätt. Därför undersöker detta arbete effektiviteten av de två olika systemen tillsammans med en analys av växthusgasutsläpp och ekonomiska förutsättningar. För att kunna utvärdera effektiviteten och klimatpåverkan av de två olika systemen utfördes en ”skog-till-hjul”-analys där produkten undersöktes från ursprunget, till drivandet av ett fordon. För att utföra studien definierades fyra funktionella enheter. De funktionella enheterna var: körsträcka med bil mätt i kilometer, kWh fjärrvärmeproduktion, CO2 ekvivalenter av växthusgasutsläpp och MWh skogsavfall. Studien visade att systemet där skogsavfallet används i ett kraftvärmeverk för att producera elektricitet och ladda elbilar hade bättre resultat i de två första funktionella enheterna. Systemet producerade nästan dubbelt så lång körsträcka och mer än dubbelt så mycket fjärrvärme som systemet där skogsavfallet används i ett bioraffinaderi och biobränslet används i dieselbilar. Studien visade även att båda system kan bidra till att sänka växthusgasutsläppen från transportsektorn. Lönsamheten att investera i ett kraftvärmeverk eller bioraffinaderi beräknades med nuvärdesmetoden. Studien visade att de förväntade framtida energipriserna är för låga för att investeringarna ska bli lönsamma. Kraftvärmeanläggningen hade ett nuvärde på -1.6 miljarder kronor, och bioraffinaderiet ett nuvärde på -4.6 miljarder kronor. Dessutom ansågs investeringen i ett bioraffinaderi vara en hög risk på grund av den höga investeringskostnaden och att tekniken idag inte är kommersialiserad. Det finns även en rad andra barriär för att genomföra de två olika systemen, dessa barriärer har studerats kvalitativt i arbetet.

Towards privacy-preserving network verification of inter-domain Software-Defined Networking

Scipedia content — Tue, 26 Jan 2021 15:54:02 +0100

SDN approaches to inter-domain routing promise better traffic engineering, enhanced security, and higher automation. Yet, naïve deployment of SDN on the Internet is dangerous as the control plane expressiveness of BGP is significantly more limited than the data plane expressiveness of SDN, which allows fine-grained rules to deflect traffic from BGP’s default routes. Most notably, this mismatch may lead to incorrect forwarding behaviors such as forwarding loops and blackholes, ultimately hindering SDN deployment at the inter-domain level. In this work, we make a first step towards verifying the correctness of inter-domain forwarding state with a focus on loop freedom while keeping private the SDN rules, as they comprise confidential routing information. To this end, we design a simple yet powerful primitive that allows two networks to verify whether their SDN rules overlap, i.e. the set of packets matched by these rules is non-empty, without leaking any information about the SDN rules. We propose an efficient implementation of this primitive by using recent advancements in Secure Multi-Party Computation and we then leverage it as the main building block for designing a system that detects Internet-wide forwarding loops among any set of SDN-enabled Internet eXchange Points. Master [120] : ingénieur civil en informatique, Université catholique de Louvain, 2017

Sistema de acionamento para máquina síncrona de magnetos permanentes com barramento CC de tensão variável para frenagem regenerativa em veículos elétricos

Scipedia content — Tue, 26 Jan 2021 15:51:39 +0100

Orientador: José Antenor Pomilio Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação Made available in DSpace on 2018-09-01T12:22:23Z (GMT). No. of bitstreams: 1 Queiroz_EliabeDuarte_M.pdf: 4253971 bytes, checksum: e6b1ae63bca2250466b591e34145cac9 (MD5) Previous issue date: 2017 Resumo: Este trabalho aborda o acionamento da máquina síncrona de magnetos permanentes em um sistema com frenagem regenerativa. O controle da máquina é realizado por orientação de fluxo e possui observadores para estimar a posição e a velocidade angular do rotor. O sistema de armazenamento de energia é uma topologia híbrida bateria/capacitor. A alimentação do inversor é fornecida por um barramento CC de tensão controlada por um conversor CC/CC elevador de tensão. Esse conversor é controlado por malhas aninhadas de corrente no indutor e tensão no capacitor, que determinam o fluxo de energia entre os sistemas de armazenamento. A referência da tensão CC é uma função da velocidade do rotor e possibilita que o capacitor forneça e absorva energia da máquina. O dimensionamento do capacitor do barramento CC e a administração de energia faz com que picos de potência na bateria sejam atenuados durante as acelerações e as desacelerações Abstract: his work adresses the driving of a permanent magnet synchronous machine in a system with regerative braking. The machine control is done by flux orientation and has observers for estimation of the rotor position and speed, needed in this control. The energy storage system is a hybrid topology battery/capacitor. The feeding of the inverter is supplied by the DC link that is controlled by a DC/DC boost converter. The converter control is executed by nested loops of inductor current and capacitor voltage that manages the energy flow between the storage systems. The DC voltage reference proposed is a function of the machine speed and it allows the DC link capacitor to supply and absorb kinetic energy from the machine. The sizing of the DC link capacitor and the energy managing makes the power peaks, in the battery, lower during the accelerations and the brakings Mestrado Energia Eletrica Mestre em Engenharia Elétrica 1490992 CAPES

Electric Mobility: Smart Transportation in Smart Cities

Scipedia content — Tue, 26 Jan 2021 15:49:48 +0100

2014 - 2015 One of the mega trends over the past century has been humanity’s move towards cities. Public Administration and Municipalities are facing a challenging task, to harmonize a sustainable urban development offering to people in city the best living conditions. Smart cities are now considered a winning urban strategy able to increase the quality of life by using technology in urban space, both improving the environmental quality and delivering better services to the citizens. Mobility is a key element to support this new approach in the growth of the cities. In fact, transport produces several negative impacts and problems for the quality of life in cities, such as, pollution, traffic and congestion. Therefore, Sustainable Mobility is one of the most promising topics in smart city, as it could produce high benefits for the quality of life of almost all the city stakeholders. The boldest and imminent challenge awaiting mobility in smart cities is the introduction of the electricity as energy vector instead of fossil fuels, concerning both the collective and the private transports. Electric public transport include electric city buses, trolleybuses, trams (or light rail), passenger trains and rapid transit (metro/subways/undergrounds, etc.). Even though railway systems are the most energy efficient than other transport modes, the enhancement of energy efficiency is an important issue to reduce their contributions to climate change further as well as to save and enlarge competition advantages involved. One key means for improving energy efficiency is to deploy advanced systems and innovative technologies. Additionally, electrification of the private road transport has emerged as a trend to support energy efficiency and CO2 emissions reduction targets. According to the International Energy Agency, in order to limit average global temperature increases to 2°C - the critical threshold that scientists say will prevent dangerous climate change -, by 2050, 21% of carbon reductions must come from the transport sector. Full electric vehicles (EVs) use electric motor and battery energy for propulsion, which has higher efficiency and lower operating cost compared to the conventional internal combustion engine vehicle. Today, there are more than 20 models offered by different brands covering different range of sizes, styles, prices and powertrains to suit the wider range of consumers as possible. The continuous development of lithium ion battery and of fast charging technology will be the major facilitators for EVs roll out in the very near future. However, the present EVs industry meets many technical limitations, such as high initial price, long battery recharge time, limited charging facilities and driving range. Although it is desirable a fast development from the start of electric mobility, its impact on the existing power grid must be assessed beforehand to see if it is necessary prior an adjustment of power infrastructure or/and the introduction of new services in the power grid. In fact, the interconnection of EVs on the power grid for charging their batteries potentially introduces negative impacts on grid operation: uncontrolled charging can significantly increase average load in the existing power systems, with problems in terms of reliability and overloads. If uncontrolled EV charging is added to the system, this can have effects both at the distribution and at the generation level. Controlled or smart charging will allow a much greater number of cars in the cities, avoiding local overload and allowing a faster EVs penetration without requiring an imminent improvement of the electricity generating and grid capacity. Smart charging might also allow load balancing both at sub-station and at the grid level, particularly with charging at peak wind supply times. This kind of use of EV battery capacity for storing electric energy may ease the integration of large scale intermittent electricity sources such as renewable energy sources. The proposed PhD Dissertation is developed in the context just described, mainly focusing the attention on the impact that electric mobility will have on the power systems and the effectiveness of solutions aimed to increase the reliability and resilience in the smart grid. In particular, it is addressed a scenario analysis regarding the electric vehicles charging management and some innovative solutions to increase energy efficiency in electrified transport systems. The first chapter emphasizes on the key aspects related to the sustainable mobility in the smart cities of the future. It provides a brief overview on the transport sector energy consumption expected in the next years. In particular, the chapter shows the significant contribution that the electrification of urban transport may provide to the sustainable mobility, and the serious concerns related to its impact on existing power systems. Chapter 2 proposes a solution method for an optimal generation rescheduling and load-shedding (GRLS) problem in microgrids in order to determine a stable equilibrium state following unexpected outages of generation or sudden increase in demand. The chapter mainly focuses on the mathematical formulation of the GRLS problem and the proposed solution algorithm. Finally, simulations results carried out by using a real case study data are presented and discussed. In Chapter 3, a simple and effective methodology is proposed to analyze data acquired during the fulfillment of the COSMO research project, and to identify typical load pattern for the EVs charging. The chapter also presents a novel scheduling problem formulation, flattening the demand load profile and minimizing the EVs charging costs, according to the electricity prices during the day. Finally, some simulations results are discussed, showing the effectiveness of the proposed methodology. Chapter 4 introduces some innovative solutions for energy efficiency in urban railway systems focusing, in particular, on energy storage systems and eco-drive operations in metro networks. The mathematical formulation of these optimization problems and the proposed solution algorithms are illustrated and discussed. The obtained results are part of the activity carried out in the SFERE research project. Finally, Chapter 5 ends the Dissertation with some concluding remarks and further developments of the proposed research activity. [edited by author] Una delle grandi tendenze nel corso del secolo scorso è stata la concentrazione della popolazione nelle città. Attualmente, le Pubbliche Amministrazioni e i Comuni si trovano ad affrontare un compito impegnativo per armonizzare uno sviluppo urbano sostenibile e offrire agli abitanti delle città le migliori condizioni di vita. Le smart cities sono ormai considerate una strategia urbana vincente in grado di aumentare la qualità della vita utilizzando la tecnologia, sia per il miglioramento della qualità ambientale che per fornire servizi migliori ai cittadini. A tale scopo, la mobilità risulta essere un elemento chiave per sostenere questo nuovo approccio nella crescita delle città. Infatti, i sistemi di trasporto urbano producono diversi effetti negativi sulla qualità della vita urbana, come ad esempio, inquinamento, traffico e congestione. Pertanto, la mobilità sostenibile è uno degli argomenti più interessanti per le smart cities, in quanto in grado produrre elevati benefici per la qualità della vita di quasi tutte le parti interessate degli agglomerati urbani. La sfida più audace e imminente per la mobilità nelle smart cities del futuro è l'introduzione dell'elettricità come vettore energetico al posto dei combustibili fossili, per quanto riguarda sia il trasporto collettivo che quello privato. I mezzi per il trasporto pubblico comprendono autobus elettrici, filobus, tram, treni passeggeri e trasporto rapido (metropolitane, etc.). Anche se i sistemi di trasporto su ferro sono più efficienti rispetto ad altri modi di trasporto, l’incremento dell'efficienza energetica è un tema importante per ridurre ulteriormente il loro contributo alle emissioni inquinanti e al consumo di energia. Le più promettenti soluzioni per migliorarne l'efficienza energetica consistono nell’implementazione di sistemi avanzati per il recupero dell’energia di frenata e tecnologie di controllo innovative. D’altro canto, l'elettrificazione del trasporto individuale su strada è emersa come una tendenza finalizzata a sostenere gli obiettivi di efficienza energetica e di riduzione delle emissioni di CO2. Secondo l'Agenzia Internazionale per l'Energia, al fine di limitare, entro il 2050, l'aumento della temperatura media globale a 2 °C - la soglia critica che gli scienziati suggeriscono di non superare per evitare pericolosi cambiamenti climatici -, il 21% delle riduzioni di biossido di carbonio deve provenire dal settore trasporti. I veicoli elettrici (EV) utilizzano un motore elettrico e l'energia accumulata nelle batterie per la propulsione, in modo da avere una maggiore efficienza e minori costi operativi rispetto ai veicoli convenzionali con motore a combustione interna. Oggi, esistono in commercio più di 20 modelli offerti da diverse case produttrici che coprono una ampia gamma di modelli che differiscono per dimensione, stile, prezzo e motorizzazione in modo da soddisfare il maggior numero di consumatori possibile. Il continuo sviluppo delle batterie al litio e delle tecnologie di ricarica rapida saranno i principali fattori abilitanti per la diffusione degli EV in un futuro molto prossimo. Tuttavia, l'attuale industria dei veicoli elettrici incontra molte limitazioni tecnico-economiche, come elevati costi, autonomia e tempi di ricarica della batteria, capillarità delle infrastrutture di ricarica. Sebbene sia auspicabile un rapido sviluppo della mobilità elettrica, il suo impatto sulla rete elettrica esistente deve essere investigato a fondo per verificare la necessità di potenziamenti delle infrastrutture e/o l'introduzione di nuovi servizi nella rete elettrica. Infatti, l'interconnessione dei veicoli elettrici con la rete di distribuzione dell’energia necessaria per la ricarica delle batterie può causare effetti negativi sul normale funzionamento del sistema elettrico: una ricarica degli EV non controllata può aumentare significativamente il carico medio negli impianti esistenti, introducendo problemi di affidabilità e sovraccarico. La ricarica intelligente o controllata degli EV consente, invece, di gestire un numero molto maggiore di autovetture elettriche nelle città, riducendo le possibilità di sovraccarico locale e di velocizzare la penetrazione della mobilità elettrica senza che rendere necessari imminenti potenziamenti dei sistemi di produzione di energia elettrica e incrementi della capacità di rete. La ricarica intelligente, inoltre, può anche influire sul bilanciamento del carico sia a livello della sottostazione elettrica che a livello di rete di distribuzione, in particolare quando si verificano molte sessioni di ricarica nelle ore di punta. Infatti, l’utilizzo della capacità della batteria degli EV per l’accumulo di energia elettrica può facilitare l'integrazione su larga scala delle fonti di energia non programmabili, come quelle rinnovabili. Il lavoro di tesi si sviluppa nel contesto di riferimento appena descritto, focalizzando l'attenzione soprattutto sull'impatto che la mobilità elettrica ha sui sistemi elettrici e sull'efficacia di nuove soluzioni finalizzate all’incremento dell'affidabilità nelle smart grids. In particolare, viene proposta un'analisi di scenario per quanto riguarda la gestione intelligente delle ricariche dei veicoli elettrici e alcune soluzioni innovative per aumentare l'efficienza energetica nei sistemi di trasporto elettrificati. Il primo capitolo sottolinea gli aspetti chiave relativi alla mobilità sostenibile nelle smart cities del futuro e fornisce una breve panoramica sul consumo energetico del settore trasporti previsto nel prossimo futuro. In particolare, vengono evidenziate da un lato il significativo contributo che l'elettrificazione dei trasporti urbani può fornire alla causa della mobilità sostenibile, e dall’altro, le gravi preoccupazioni legate all’impatto sui sistemi elettrici esistenti di un notevole incremento della domanda. Il Capitolo 2 propone un metodo per la soluzione del problema congiunto di scheduling dei generatori e load shedding (GRLS) all’interno di microgrids portando in conto l’incertezza sia sulla domanda che lato generazione. Il fine è determinare un nuovo stato di equilibrio stabile in seguito a guasti, riduzione della generazione da fonte rinnovabile o improvviso aumento della domanda. Il capitolo si concentra principalmente sulla formulazione matematica del problema GRLS e sull'algoritmo di soluzione proposto. Infine, sono presentati e commentati i risultati di simulazione basati su un caso studio reale. Nel Capitolo 3, è proposta una metodologia semplice ed efficace per identificare profili di carico tipico relativi alla ricarica di veicoli elettrici: in particolare, l’analisi condotta si basa sull’analisi dei dati acquisiti durante lo svolgimento del progetto di ricerca COSMO. Il capitolo, inoltre, introduce una formulazione matematica del problema dello scheduling delle ricariche dei veicoli elettrici, che garantisce un appiattimento del profilo di carico e riduce allo stesso tempo il costo della ricarica per gli utenti. Infine, sono commentati i risultati delle simulazioni eseguite dimostrando l'efficacia della metodologia proposta. Il Capitolo 4 introduce alcune soluzioni innovative per l'efficienza energetica nei sistemi di trasporto urbani: l’attenzione viene posta, in particolare, sui sistemi di accumulo dell’energia e sulla condotta di guida Eco-Drive in reti metropolitane. In dettaglio, nel capitolo, vengono introdotti e commentati la formulazione matematica dei problemi di ottimizzazione proposti e i rispettivi algoritmi di soluzione. I risultati ottenuti fanno parte delle attività svolte nell’ambito del progetto di ricerca SFERE. Infine, il Capitolo 5 conclude la tesi con alcune osservazioni finali e con i possibili sviluppi dell'attività di ricerca proposta. [a cura dell'autore] XIV n.s.

The Swiss singularity in the european high speed railway network

Scipedia content — Tue, 26 Jan 2021 15:47:55 +0100

Drivers to and barriers against sustainable consumption : exploring the role of consumer anticipated emotions in the context of consumer adoption of alternative fuel vehicles

Scipedia content — Tue, 26 Jan 2021 15:47:41 +0100

With the increasing environmental problems, sustainable consumption is an important consumer behavior. Therefore, it is important to investigate further the significant drivers to and barriers against sustainable consumption, in order to increase the share of sustainable consumption and understanding of consumer behavior. This dissertation identifies two gaps. The first is in understanding consumer positive and negative anticipated emotions as an important factor influencing high-involvement sustainable consumption. The second gap relates to the lack of understanding about the associations between anticipated emotions and personal moral norms in high-involvement sustainable consumption. Against this background, the aim is to contribute to the sustainable consumption literature by investigating the roles and relations of anticipated emotions, personal moral norms, and weighing costs and benefits as drivers to and barriers against consumer adoption of a high-involvement sustainable product. A literature review and two empirical studies were conducted. Consumer adoption of alternative fuel vehicles is the specific sustainable consumption. Using quantitative methods, this phenomenon is investigated in the empirical studies conducted in Sweden. It was shown that anticipated emotions have direct effects on consumers' intention to adopt alternative fuel vehicles. Moreover, positive anticipated emotions (e.g. pride, pleasure, happiness) are drivers of sustainable consumption, while negative anticipated emotions (e.g. regret, embarrassment) are barriers against the sustainable consumption. This dissertation suggests an extension to the norm activation model, and shows that moral norms, ascription of responsibility, and awareness of environmental problems influence consumers' intentions through consumers’ anticipated emotions. For people who perceive high social norms related to decreasing the environmental impacts of car driving, the influence of positive anticipated emotions and personal moral norms are stronger. This points toward the social aspect of sustainable consumption and suggests that targeting the consumers who perceive high social norms is an important step to promoting sustainable consumption. Findings would be of relevance to marketers, policymakers and environmental organizations. Creating awareness and communicating personal responsibilities and moral norms related to the environment and consumption are important drivers for consumer adoption of sustainable products. However, it is noteworthy that consumer anticipated emotions about high-involvement sustainable products (such as alternative fuel vehicle) have also important influence on the sustainable consumption. Thus, consumer anticipated emotions should be considered in designing promotion programs.

Application of Sustainable Development Concept as a Factor of International Competitiveness

Scipedia content — Tue, 26 Jan 2021 15:39:55 +0100

Tato diplomová práce se zaměřuje na aplikaci koncepce udržitelného rozvoje ve firmě Volkswagen Slovakia na posílení její konkurenceschopnosti. Automobilová společnost je analyzována jako hráč v odvětví udržitelné mobility a její současná strategie je zhodnocena v zmyslu udržitelnosti. Na základě nejrelevantnějších aspektů analytické části je navržena řada doporučení, které by měli podpořit působení firmy v oblasti výroby elektrických vozidel a poskytování transportních služeb a které by měli přispět k dosažení eko-konkurenční výhody v daném odvětví. This Master's thesis focuses on the application of the sustainable development concept in the company Volkswagen Slovakia to enhance its competitiveness. The automotive company is analysed as a player in the sustainable mobility industry and its current strategy is evaluated in sense of sustainability. Based on the most relevant aspects of the analytical part, several recommendations are suggested that should boost the firm's operations in the area of electric vehicles production and mobility service providing and which should contribute to achieving the eco-advantage in the industry. A

A comparative study of traditional and novel humidity sensing technologies in natural gas

Scipedia content — Tue, 26 Jan 2021 15:31:37 +0100

This thesis was carried out inside of the temperature and humidity laboratory (LabTH) of the Instituto Nacional de Tecnica Aeroespacial (INTA), which is the Spanish Designated Institute (DI) for the field of humidity and, therefore, holder of the national standards in such quantity. Among many other duties of a DI are to promote and participate in national and international R&D projects whose goals set were in line with those scored in the last European Roadmaps for the hygrometry field, for this particular case. For these reasons, and as a part of such participation in research projects, it is essential to emphasize that part of this thesis was developed inside of the framework of the joint research project “ENG01-Gas. Characterization of Energy Gases” which running under the European Metrology Research Program (EMRP), with the main target of supporting the natural gas industry to overcome its current big challenges. Moisture content is a key factor inside the natural gas (NG) industry. Not only does decrease the efficiency of the final product when the water content is high, but it can also trigger potentially dangerous conditions due to the formation of hydrates, that can block pipelines and damage pumping devices and produce other negative effects. For these reasons, accurate measurement and control of humidity is essential in all processing step of natural gas. However, current practice for such moisture measurements is for the devices to be calibrated at atmospheric pressure and in nitrogen or air as the matrix gas, conditions that vary significantly from those present in the actual industrial process, so their performance in real industrial conditions could be much smaller than expected and even insufficient. Besides, technologies traditionally used by NG industry, such us, condensation hygrometers and metal oxide capacitive probes, have some drawbacks that not always allow to measure and control humidity of NG with the accuracy and reliability desired. For all of that, metrology plays a very important role developing and validating new highly accurate measuring methods to achieve the industrial uncertainty required. In this sense, a total of 14 hygrometers, based on 6 different measurement technologies were studied. Techniques traditionally used, such as: condensation hygrometers, electrolytic and capacitive sensors based on metal oxides; were compared to novel and promising measuring technologies, which constitute the state of the art in the world of hygrometry, such as: microwave resonators, absorption spectroscopy and polymeric capacitive sensors. Comparative research of all these technologies was performed in two industrial facilities to simulate the most similar actual conditions in which they are used. First part of comparison was carried out in a laboratory using NG coming from the national distribution grid at absolute pressures up to 6 MPa directly and for the useful humidity range for the NG industry. The second part was performed in a drying plant associated to an underground gas storage (UGS) facility during all its production processes (injection and extraction) and during the intermediate shutdowns. The properly facilities needed for this comparative study were designed and assembled according to the standards and good practice guides about the sampling and handling of NG at high pressures. Measurement protocols were developed and various properties of the equipment were evaluated, thus validating relative performance of the different technologies with each other. Characteristics of the dynamic behaviour of the equipment (response times to changes in humidity and variations due to changes in pressure), as well as studies of short-term drift, hysteresis and linearity, were performed. Most instruments exhibited good behaviour regarding response time, hysteresis and under sudden pressure changes. In spite of the differences exhibited by certain equipment, due to factors and inconveniences explained, the consistency exhibited by the results demonstrates the validity of the experimental and analysis methods used, demonstrating the utility of all technologies for the requirements of the gas industry, with particular aspects in all cases. It must be highlighted the good behaviour of spectroscopic technology in every properties studied and, therefore its good performance in any condition evaluated. By the other hand, it must also be remarkable the promising outlook of the microwave resonator, a prototype still in development phase, as a humidity sensing technology in many applications. In addition, it participated in the development and validation phase of the quasi-spherical microwave resonator by evaluating its performance with real NG, for a water content range between 25 ppmv and 100 ppmv, and at a pressure of 0.75 MPa. Its performance was quite satisfactory showing itself as a promising technology in the field of hygrometry, but with issues yet to be developed for real industrial applications. As a proof of direct cooperation carried out in this thesis between manufacturers of measuring instruments, public research entity (INTA) and the Spanish national gas distributor (Enagas), some of the immediately outcomes were: renovation of part of the drying plant of Serrablo (Enagas) with a modern sampling system and, acquisition one of the spectroscopic instruments to be used in the most critical points of the national distribution grid. Summarizing, this thesis improved the knowledge of the humidity measurement in non-conventional gases traditionally used in national metrology institutes (NMIs) or DIs, increased the knowledge of the measurement technologies that resulted in the implementation of new improvements and updating in commercialized measurement equipment, and a much more accurate and reliable humidity control especially during the gas drying process.

Model-based prognostics for energy-constrained mobile systems operating in stochastic environments

Scipedia content — Tue, 26 Jan 2021 15:31:06 +0100

Due to development of novel and more efficient energy storage systems we bear witness to the dawn of a new era of mobile systems. They have become sophisticated in terms of hardware components and software applications which have made it possible to develop integrated solutions for a large number of imaginable applications ranging from electric vehicles all the way to fully autonomous systems operating in a wide variety of ecosystems, e.g., service, surveillance or bio-inspired robots. Generally it is expected that a mobile system exhibits a sufficient degree of autonomy in the sense of energy availability such that it at least accomplishes the mission objectives for which it is intended. Nevertheless, such autonomy, is influenced to a large extent by the remaining energy that can be retrieved from its energy storage system and by the environment conditions in which the system operates. Assessing the reliability of a mission requires using systems internal and external situational awareness to determine if the available energy at least meets the energy needs demanded by the future operation of the mobile system in order to determine its remaining useful life (RUL). Having this information as soon as possible may allow the decision maker to apply a contingency plan to intervene and reconfigure the mission execution strategy in order to improve the probability of success, in those situations in which the system becomes incapable of achieving the original mission objectives. Numerous studies have been published for assessing mission reliability and estimating the RUL of mobile systems. However, they deal with structured environment conditions and thus with relatively deterministic loads. Moreover, these approaches neglect the inherent uncertainty which stems from multiple sources such as the lack of knowledge about the true energy available in the mobile system, the noise introduced by sensors or the randomness of the operation environment, just to mention a few. The approach presented in this work is built around the belief that the RUL estimation is formulated as an uncertainty propagation problem. Accordingly, to estimate the RUL multiple sources of uncertainty involved in its estimation are first characterized and then propagated with the aim of computing their combined effect, expressed in terms of a probability density function. The approach developed here achieves this estimation in a Monte-Carlo fashion in which several RUL realizations are simulated in order to accurately estimate its entire probability distribution. The aim of this work is therefore devoted to develop a solution capable of estimating the RUL with application to energy-constrained mobile systems operating in stochastic environments.

Real Options Models for Better Investment Decisions in Road Infrastructure under Demand Uncertainty

Scipedia content — Tue, 26 Jan 2021 15:29:54 +0100

n efficient transportation system requires adequate and well-maintained infrastructure to relieve congestion, reduce accidents, and promote economic competitiveness. However, there is a growing gap between public financial commitments and the cost of maintaining, let alone expanding the U.S. road transportation infrastructure. Moreover, the tools used to evaluate transportation infrastructure investments are typically deterministic and rely on present value calculations, even though it is well-known that this approach is likely to result in sub-optimal decisions in the presence of uncertainty, which is pervasive in transportation infrastructure decisions. In this context, the purpose of this dissertation is to propose a framework based on real options and advanced numerical methods to make better road infrastructure decisions in the presence of demand uncertainty. I first develop a real options framework to find the optimal investment timing, endogenous toll rate, and road capacity of a private inter-city highway under demand uncertainty. Traffic congestion is represented by a BPR function, competition with an existing road is captured by user equilibrium, and travel demand between the two cities follows a geometric Brownian motion with a reflecting upper barrier. I derive semi-analytical solutions for the investment threshold, the dynamic toll rates and the optimum capacity. The result shows the importance of modeling congestion and an upper demand barrier – features that are missing from previous studies. I then extend this real options framework to study two additional ways of funding an inter-city highway project: with public funds or via a Public-Private Partnership (PPP). Using Monte Carlo simulation, I investigate the value of a non-compete clause for both a local government and for private firms involved in the PPP.Since road infrastructure investments are rarely made in isolation, I also extend my real options framework to the multi-period Continuous Network Design Problem (CNDP), to analyze the investment timing and capacity of multiple links under demand uncertainty. No algorithm is currently available to solve the multi-period CNDP under uncertainty in a reasonable time. I propose and test a new algorithm called “Approximate Least Square Monte Carlo simulation” that dramatically reduces the computing time to solve the CNDP while generating accurate solutions.