Colloquiam: Documents published in 2016

The analysis and Research of the Runway Conflict Detection System

Scipedia content — Mon, 01 Feb 2021 16:23:17 +0100

With the increasing volume of air traffic, the workload of controllers’ and pilots’continued to rise which makes the runway incursions grow rapidly and the air safety become more seriously. The runway is one of the most important maneuver area in the aircraft ground movement, as more than half of the aircraft incidences occur during the aircraft takeoff or landing stage, thus enhancing runway safety management is very important, and the research of the runway incursion detection is needed. In order to avoid runway incursions, we studied the runway conflict alerting system which based on the radar detection. This system discussed the runway conflict detection problem from the perspective of the air traffic control. Affecting factors which contain the physical properties of aircraft types, wake turbulence, radar error as well as pilot judgment and reaction time are all taking into consideration. At tht same time, this system analyzed the effect factors of runway incursions. The system used caculation between the invading aircraft and the normal aircraft, at last, it will g ive avoidance suggestions. It can make the crew more efficient. The simulation example shows the effectiveness of the invasion of the runway conflict detection strategies. Keywords-runway; conflict detection; air traffic control; controller; alarm

Cause Analysis and Treatment Measures of Urban Traffic Congestion

Scipedia content — Mon, 01 Feb 2021 16:21:47 +0100

Effect of Residual Forming Stresses on Fracture in ERW Pipe

Scipedia content — Mon, 01 Feb 2021 16:20:06 +0100

Many older pipelines contain significant residual stress due to the forming process. Cold expansion or a normalizing heat treatment can virtually eliminate residual forming stresses, but these practices were less common in the past. In the absence of cold expansion or normalization, residual forming stresses can be reduced by hydrostatic testing or operating pressures, but not eliminated entirely. Residual stresses can contribute to fracture in pipelines, particularly when the material toughness is low."/jats:p" "jats:p"This article presents a series of analyses that seek to quantify the magnitude of residual forming stresses as well as their impact on pipeline integrity. The pipe forming process was simulated with elastic-plastic finite element analyses, which considered the effect of subsequent loading on relaxation of residual stresses. A second set of finite element simulations were used to quantify the effect of residual stresses on fracture behavior.

Lying Your Way to Better Traffic Engineering

Scipedia content — Mon, 01 Feb 2021 16:19:03 +0100

To optimize the flow of traffic in IP networks, operators do traffic engineering (TE), i.e., tune routing-protocol parameters in response to traffic demands. TE in IP networks typically involves configuring static link weights and splitting traffic between the resulting shortest-paths via the Equal-Cost-MultiPath (ECMP) mechanism. Unfortunately, ECMP is a notoriously cumbersome and indirect means for optimizing traffic flow, often leading to poor network performance. Also, obtaining accurate knowledge of traffic demands as the input to TE is elusive, and traffic conditions can be highly variable, further complicating TE. We leverage recently proposed schemes for increasing ECMP's expressiveness via carefully disseminated bogus information ("lies") to design COYOTE, a readily deployable TE scheme for robust and efficient network utilization. COYOTE leverages new algorithmic ideas to configure (static) traffic splitting ratios that are optimized with respect to all (even adversarially chosen) traffic scenarios within the operator's "uncertainty bounds". Our experimental analyses show that COYOTE significantly outperforms today's prevalent TE schemes in a manner that is robust to traffic uncertainty and variation. We discuss experiments with a prototype implementation of COYOTE.

Thermographic detection of abraded pipeline walls in the industrial installations

Scipedia content — Mon, 01 Feb 2021 16:10:41 +0100

The aim of this paper is to develop a new method for detection of abraded walls in the industrial pipelines. The reason of the reduction of pipelines wall thickness is mainly long time exploitation. Also high temperature and variable pressure of the transported medium cause of faster walls abrasion process in the pipelines. Too long exploitation can lead to break a pipeline’s wall, and in the case of a dangerous gas it may lead to an explosion. The presented results show the dependence between surface temperature and a wall thickness of the pipeline.

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

Scipedia content — Mon, 01 Feb 2021 15:54:19 +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.

Benefit opportunities for integrated surface and airspace departure scheduling: A study of operations at Charlotte-Douglas International Airport

Scipedia content — Mon, 01 Feb 2021 15:50:22 +0100

NASA is collaborating with the FAA and aviation industry to develop and demonstrate new capabilities that integrate arrival, departure, and surface air-traffic operations. The concept relies on trajectory-based departure scheduling and collaborative decision making to reduce delays and uncertainties in taxi and climb operations. The paper describes the concept and benefit mechanisms aimed at improving flight efficiency and predictability while maintaining or improving operational throughput. The potential impact of the technology is studied and discussed through a quantitative analysis of relevant shortfalls at the site identified for initial deployment and demonstration in 2017: Charlotte-Douglas International Airport. Results from trajectory analysis indicate substantial opportunity to reduce taxi delays for both departures and arrivals by metering departures at the gate in a manner that maximizes throughput while adhering to takeoff restrictions due mostly to airspace constraints. Substantial taxi-out delay reduction is shown for flights subject to departure restrictions stemming from traffic-flow management initiatives. Opportunities to improve the predictability of taxi, takeoff, and climb operations are examined and their potential impact on airline scheduling decisions and air-traffic forecasting is discussed. In addition, the potential to improve throughput with departure scheduling that maximizes use of available runway and airspace capacity is analyzed.

A multi-format floating-point multiplier for power-efficient operations

Scipedia content — Fri, 29 Jan 2021 01:04:43 +0100

In this work, we present a radix-16 multi-format multiplier to multiply 64-bit unsigned integer operands, double-precision and single-precision operands. The multiplier is sectioned in two lanes such that two single-precision multiplications can be computed in parallel. Radix-16 is chosen for the reduced number of partial products and the resulting power savings. The experimental results show that high power efficiency is obtained by issuing two single-precision multiplications per cycle. Moreover, by converting the double-precision numbers which fit to single-precision, further energy can be saved.

Big data research and application in oil pipeline inspection

Scipedia content — Fri, 29 Jan 2021 00:59:47 +0100

MESS: A Prototype for the Cherenkov Telescope Array Pipelines Framework

Scipedia content — Fri, 29 Jan 2021 00:58:59 +0100

A Novel Robotic System for Inner Wall Derusting and Grinding of Pressure Pipelines

Scipedia content — Fri, 29 Jan 2021 00:58:28 +0100

A risk and threat assessment approaches overview in autonomous systems of systems

Scipedia content — Fri, 29 Jan 2021 00:54:52 +0100

Systems of systems (SoS) have been introduced in early 1990s in air traffic control domain, defense and information technologies. Systems like this contain a set of components, being systems itself, with constituent components retaining operational independence. The definition and configuration of SoS have evolutionary nature and emergent behavior is one of the many important characteristics to be mentioned. Over the past ten years fast technological and industrial advances in the domain of autonomous and cooperating systems started to occur, which created new opportunities to use the benefits of SoS. In the near future, fully autonomous and cooperating systems are expected to become our reality and increase the production efficiency, while decreasing the human effort in harmful environments. There exist the need to make sure that critical properties of SoS, such as safety and security are guaranteed as a joint effort, since it is not sufficient anymore to address these properties independently in the development process. In this paper an overview of the most common approaches and methods used to provide reasoning about joint safety and security is provided, as well as a check of the latest updates in standards related to these properties SafeCOP - Safe Cooperating Cyber-Physical Systems using Wireless Communication Closing the safety-security gap in software intensive systems SAFSEC-CPS -- Securing the safety of autonomous cyber-physical system

Study on Continuous Descent Operation for Efficient Air Transport System

Scipedia content — Fri, 29 Jan 2021 00:51:57 +0100

Quality approach on strengthening Rapid Penang services in Penang tourism sites

Scipedia content — Fri, 29 Jan 2021 00:51:25 +0100

The effectiveness and efficiency of the public transport system is fundamental to the sustainable development of the country. In Malaysia, Penang is an example of a tourist destination with many attractions, particularly cultural attractions and heritage sites. Nowadays, most people refuse to use public transport because of the inefficient service performance and low quality of existing services that can contribute to traffic congestion and pollution. The main objective of this study was to identify Rapid Penang service performance. Two different routes had been selected, namely U101 and U104. In this study, 100 respondents among Rapid Penang users for each route were involved in the survey questionnaire. Both qualitative and quantitative methods were used to measure the performance of Rapid Penang buses on the routes chosen. The initial finding from the observation shows that the respondents’ contribution is significant and more than half of the respondents are school or university students. In terms of ...

How Do Layered Airspace Design Parameters Affect Airspace Capacity and Safety? The Influence of Traffic Structure on Airspace Capacity

Scipedia content — Fri, 29 Jan 2021 00:51:09 +0100

International audience; Airspace structure can be used as a procedural mechanism for a priori separation and organization of en-route air traffic. Although many studies have explored novel structuring methods to increase en-route airspace capacity, the relationship between the level of structuring of traffic and airspace capacity is not well established. To better understand the influence of traffic structure on airspace capacity, in this research, four airspace concepts, representing discrete points along the dimension of structure, were compared using large-scale simulation experiments. By subjecting the concepts to multiple traffic demand scenarios, the structure-capacity relationship was inferred from the effect of traffic demand variations on safety, efficiency and stability metrics. These simulations were performed within the context of a future personal aerial transportation system, and considered both nominal and non-nominal conditions. Simulation results suggest that the structuring of traffic must take into account the expected traffic demand pattern to be beneficial in terms of capacity. Furthermore, for the heterogeneous, or uniformly distributed, traffic demand patterns considered in this work, a decentralized layered airspace concept, in which each altitude band limited horizontal travel to within a predefined heading range, led to the best balance of all the metrics considered.

Effects on network performance

Scipedia content — Fri, 29 Jan 2021 00:30:47 +0100

Traffic congestion leads to delays and increased carbon dioxide (CO2) emissions. Traffic management measures such as providing information on environmental route costs have been proposed to mitigate congestion. Multi-criteria routing dynamic traffic assignment (MCR-DTA) models are needed to evaluate the effectiveness of such measures. This paper presents a simulation-based bi-level optimization method to solve the MCR-DTA problem, which works as follows. Route costs include travel times and emissions, but those are updated inside two different loops. In the inner loop, emission costs are considered fixed; the assignment is performed by updating route travel times, using a traditional DTA tool. Then, in the outer loop, emissions are calculated based on link loads and fed back to the DTA tool, which performs a new assignment. The MCR user equilibrium is found when emissions or predefined generalized costs converge to an equilibrium. The bi-level method is first tested on a small network, showing that the proposed method is able to effectively solve the MCR-DTA problem. Next, the method is applied to a medium-size urban network. The results show that if drivers choose routes based on emissions besides travel time, the average travel time and emissions per vehicle decrease. This occurs because congested links have a higher impact on route costs; hence the equilibrium is pushed away from the single-criteria routing (SCR) user optimum towards the SCR system optimum. Results support the conclusion that informing drivers about CO2 emissions per route can potentially lead to decreased delay and emissions in real networks.

Experimental Performance Evaluation of Cloud-Based Analytics-as-a-Service

Scipedia content — Fri, 29 Jan 2021 00:22:20 +0100

n increasing number of Analytics-as-a-Service solutions has recently seen the light, in the landscape of cloud-based services. These services allow flexible composition of compute and storage components, that create powerful data ingestion and processing pipelines. This work is a first attempt at an experimental evaluation of analytic application performance executed using a wide range of storage service configurations. We present an intuitive notion of data locality, that we use as a proxy to rank different service compositions in terms of expected performance. Through an empirical analysis, we dissect the performance achieved by analytic workloads and unveil problems due to the impedance mismatch that arise in some configurations. Our work paves the way to a better understanding of modern cloud-based analytic services and their performance, both for its end-users and their providers.

Comment: Longer version of the paper in Submission at IEEE CLOUD'16

Using crowd sensed data as input to congestion model

Scipedia content — Fri, 29 Jan 2021 00:20:39 +0100

Emission of airborne pollutants and climate gasses from the transport sector is a growing problem, both in indus- trialised and developing countries. Planning of urban transport system is essential to minimise the environmental, health and economic impact of congestion in the transport system. To get accurate and timely information on traffic congestion, and by extension information on air pollution, near real time traffic models are needed. We present in this paper an implementation of the Restricted Stochastic User equilibrium model, that is capable to model congestions for very large Urban traffic systems, in less than an hour. The model is implemented in an open source database system, for easy interface with GIS resources and crowd sensed transportation data. Emission of airborne pollutants and climate gasses from the transport sector is a growing problem, both in indus- trialised and developing countries. Planning of urban transport system is essential to minimise the environmental, health and economic impact of congestion in the transport system. To get accurate and timely information on traffic congestion, and by extension information on air pollution, near real time traffic models are needed. We present in this paper an implementation of the Restricted Stochastic User equilibrium model, that is capable to model congestions for very large Urban traffic systems, in less than an hour. The model is implemented in an open source database system, for easy interface with GIS resources and crowd sensed transportation data.

SDN-based traffic engineering for improved resilience in integrated satellite-terrestrial backhaul networks

Scipedia content — Fri, 29 Jan 2021 00:18:48 +0100

© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

Resilience and high availability are considered as essential requirements in 5G networks. To fullfil these requirements, the integration of a satellite component within mobile backhaul networks arises as a compelling proposition to provide backup connectivity to critical cell sites and divert traffic from congested areas so that a limited capacity in their terrestrial links could be supplemented during peak-time or even replaced in case of total/partial failure or maintenance. This is especially of interest for public protection and disaster relief (PPDR) communications in remote/rural areas that might require the fast deployment of nework capacity as well as in distressed areas where the terrestrial backhaul infrastructure might have suffered damages. This paper first describes an architectural framework that enables the integration and management of the satellite capacity as a constituent part of a Software Defined Networking (SDN) -based traffic engineered mobile backhaul network. Then, a SDN-based Traffic Engineering (TE) application is proposed to manage some amount of dynamically steerable satellite capacity provisioned for resilience purposes to maximize a network utility function under both failure and nonfailure conditions in the terrestrial links. Numerical results are presented to assess the benefits of the proposed TE application and its performance is compared to that of a traditional overflow solution.

Peer Reviewed

Research on the Impact of Road Construction on Traffic Congestion

Scipedia content — Fri, 29 Jan 2021 00:15:28 +0100

Does the "tunnel effect" still remains in 2016?

Scipedia content — Fri, 29 Jan 2021 00:11:41 +0100

The Channel tunnel and the Eurostar TGV have been a great chance for the Nord-Pas de Calais Region replacing it in a European and French geography. The accompanying 'Transmanche plan' has provided new infrastructures, regional integration and new opportunities. They permitted the openness to Europe and neighbourhood regions and replace definitely the Region in a European dynamic. Nevertheless, the present changing economic context, new political philosophy and the wear dried up the driving forces. If the development conditions are there it lacks a new vision and a new engine. The restructuration around the Channel tunnel concession, the Port of Calais and the rail market with new operators could be the challenge for a new development for the Kent - Nord-Pas-de-Calais integrated maritime region.; Le tunnel sous la Manche et le TGV Eurostar ont été une grande chance pour le Nord-Pas de Calais le replaçant dans une géographie européenne et française. Le «plan Transmanche" d'accompagnement a fourni de nouvelles infrastructures, l'intégration régionale et de nouvelles opportunités. Ils ont permis l'ouverture vers l'Europe et les régions voisines et de replacer définitivement la région dans une dynamique européenne. Néanmoins, le changement actuel de contexte économique, la nouvelle philosophie politique et l'usure ont tari ces forces motrices. Si les conditions de développement sont là, il manque une nouvelle vision et un nouveau moteur. La restructuration autour de la concession du Tunnel sous la Manche, le port de Calais et le marché ferroviaire avec de nouveaux opérateurs pourraient être le défi pour un nouveau développement pour la région maritime intégrée du Kent - Nord-Pas-de-Calais.

Addressing inter-organisational process flexibility using versions: The VP2M approach

Scipedia content — Thu, 28 Jan 2021 23:57:08 +0100

International audience; Process flexibility has been investigated in depth in the context of intra-organisational processes, but it is still an open issue when processes cross the boundaries of companies. In this paper, we address the modelling of flexible inter-organisational processes using a version-based approach. Indeed, versions are known to be a powerful technique to deal with variability, evolution and adaptation of processes, which are the three main needs of process flexibility. More precisely, this paper presents VP2M (Version of Process Meta-Model), a meta-model supporting the modelling of versions of inter-organisational processes, addressing both static and dynamic aspects of VP2M. It also illustrates process version modelling within the Subsea Pipeline process example.

Towards characterizing international routing detours

Scipedia content — Thu, 28 Jan 2021 23:51:33 +0100

There are currently no requirements (technical or otherwise) that BGP paths must be contained within national boundaries. Indeed, some paths experience international detours, i.e., originate in one country, cross international boundaries and return to the same country. In most cases these are sensible traffic engineering or peering decisions at ISPs that serve multiple countries. In some cases such detours may be suspicious. Characterizing international detours is useful to a number of players: (a) network engineers trying to diagnose persistent problems, (b) policy makers aiming at adhering to certain national communication policies, (c) entrepreneurs looking for opportunities to deploy new networks, or (d) privacy-conscious states trying to minimize the amount of internal communication traversing different jurisdictions. In this paper we characterize international detours in the Internet during the month of January 2016. To detect detours we sample BGP RIBs every 8 hours from 461 RouteViews and RIPE RIS peers spanning 30 countries. Then geolocate visible ASes by geolocating each BGP prefix announced by each AS, mapping its presence at IXPs and geolocation infrastructure IPs. Finally, analyze each global BGP RIB entry looking for detours. Our analysis shows more than 5K unique BGP prefixes experienced a detour. A few ASes cause most detours and a small fraction of prefixes were affected the most. We observe about 544K detours. Detours either last for a few days or persist the entire month. Out of all the detours, more than 90% were transient detours that lasted for 72 hours or less. We also show different countries experience different characteristics of detours.

Immersive solutions for future Air Traffic Control and Management

Scipedia content — Thu, 28 Jan 2021 23:50:57 +0100

International audience; In this paper we review the activities of Air Tra c Control and Management (ATC/M) and expose scenarios that illustrate current and future challenges in this domain. In particular we look at those challenges that can be tackled with the use of immersion. We introduce the concepts of an immersive Remote Tower and Collaborative Immersive Trajectory analysis. These make use of immersive technologies such as Head Mounted Displays (HMDs) or large, tiled displays to immerse users in their tasks, better supporting the management and analysis of the complex data produced in this domain

On Designing SDN Services for Energy-Aware Traffic Engineering

Scipedia content — Thu, 28 Jan 2021 23:50:03 +0100

experimenting with energy-aware techniques on large-scale production infrastructure is prohibitive, several traffic-engineering strategies have been evaluated using discrete-event simulation. The present work discusses (i) challenges towards building testbeds that allow researchers and practitioners to validate and evaluate the performance of energy-aware traffic-engineering strategies and (ii) requirements when porting simulations to testbeds. We discuss a proof-of-concept platform and an application that use and provide Software-Defined Network (SDN) services created on the Open Network Operating System (ONOS) to validate previously proposed energy-aware traffic engineering strategies. We detail the platform and illustrate how it has been used for performance evaluation.

The Flow and Use of Knowledge in Networks of Electric Mobility

Scipedia content — Thu, 28 Jan 2021 23:48:01 +0100

UID/SOC/04647/2013 The paper discusses the main drivers of the flow and use of knowledge in decision networks of sustainable electric mobility. Electric mobility can have a significant impact in a transition to a more sustainable mobility system. There are reasons to believe that this transition can be knowledge–dependent. Examples suggest that the use of bits and concealed tacit knowledge in decision networks are significantly relevant to this transition. Literature shows that transfers of tacit knowledge occur in networks with developed individual social capital and are conditioned by earlier personal interactions. Social capital can provide centrality and power to actors in networks. It can be enhanced by developing trust and displaying and/or implying possession of knowledge relevant for present or future action. Tacit knowledge in technology innovation decisions, in particular, is thought to be significantly valued, because innovation is permeated by strong elements of uncertainty and complexity that drive actors to seek for non–explicit forms of knowledge in networks of near–peers. The paper concludes that the urge for knowledge in situations where not much can be found may drive decision–makers to over rely on partial and partisan knowledge during decision–making. The paper ends with a discussion about the need for more research concerning knowledge in emergent decision networks of electric mobility. publishersversion published

Analysis on Externality of Traffic Jams in Beijing--Based on Supply-demand Equilibrium

Scipedia content — Thu, 28 Jan 2021 23:45:50 +0100

Enhanced Inter-Vehicular relative positioning

Scipedia content — Thu, 28 Jan 2021 23:44:36 +0100

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Intelligent Transportation System (ITS) applications for integral and cooperative vehicle safety as well as some Advanced Driver Assistance Systems (ADASs) benefit from precise determination of relative positions between dynamic traffic objects. With conventional Global Navigation Satellite System (GNSS) measurements, e.g. using Global Positioning System (GPS), the required accuracy cannot be achieved. For this reason, an exchange of GNSS observations via Vehicular Ad-Hoc Network (VANET) is proposed in this paper. In particular, the European Inter-Vehicle Communication (IVC) protocol stack ITS-G5 is employed. With these exchanged GNSS observations, Differential GNSS (DGNSS) or Real-Time Kinematic (RTK) calculations provide a precise relative position vector. However, due to relative movement of traffic objects, this position vector becomes obsolete for increasing transmission delays. For this reason, a mitigating kinematic model is set up and validated experimentally. With respect to fixed RTK solutions, this kinematic model reduces the errors by an average of 61% compared to position calculations ignoring IVC latency.

PoliMappers: activities and objectives

Scipedia content — Thu, 28 Jan 2021 23:41:44 +0100

Clusters and communities in air traffic delay networks

Scipedia content — Thu, 28 Jan 2021 23:34:54 +0100

The air transportation system is a network of many interacting, capacity-constrained elements. When the demand for airport and airspace resources exceed the available capacities of these resources, delays occur. The state of the air transportation system at any time can be represented as a weighted directed graph in which the nodes correspond to airports, and the weight on each arc is the delay experienced by departures on that origin-destination pair. Over the course of any day, the state of the system progresses through a time-series, where the state at any time-step is the weighted directed graph described above. This paper presents algorithms for the clustering of air traffic delay network data from the US National Airspace System, in order to identify characteristic delay states (i.e., weighted directed graphs) as well as characteristic types-of-days (i.e., sequences of such weighted directed graphs) that are experienced by the air transportation system. The similarity of delay states during clustering are evaluated on the basis of not only the in- and out-degrees of the nodes (the total inbound and outbound delays), but also network-theoretic properties such as the eigenvector centralities, and the hub and authority scores of different nodes. Finally, the paper looks at community detection, that is, the grouping of nodes (airports) based on their similarities within a system delay state. The type of day is found to have an impact on the observed community structures.

United States. National Aeronautics and Space Administration (FA8721-05-C-0002)

National Science Foundation (U.S.) (1239054)

Document type: Conference object

Modeling of two sub-reach water systems: Application to navigation canals in the North of France

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

Inland navigation networks are large-scale systems that can be described by using the nonlinear Saint-Venant partial differential equations. However, as there is no analytical solution for them, simplified models are used instead for modeling purposes. This work addresses the modeling of two sub-reach systems by means of the well-known Integrator Delay Zero model. Two main scenarios are considered: in the first one, the two partial models are independently computed one from each other; the second one uses previous knowledge of the whole two sub-reach system in order to ensure the flow consistency along the system. The application of these two methodologies to a part of the navigation network in the north of France serves as the case study for this work.

Peer Reviewed

Planning Under Uncertainty for Aggregated Electric Vehicle Charging with Renewable Energy Supply

Scipedia content — Thu, 28 Jan 2021 23:27:29 +0100

Renewable energy sources introduce uncertainty regarding generated power in smart grids. For instance, power that is generated by wind turbines is time-varying and dependent on the weather. Electric vehicles will become increasingly important in the development of smart grids with a high penetration of renewables, because their flexibility makes it possible to charge their batteries when renewable supply is available. Charging of electric vehicles can be challenging, however, because of uncertainty in renewable supply and the potentially large number of vehicles involved. In this paper we propose a vehicle aggregation framework which uses Markov Decision Processes to control 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, reduces cost of customers and reduces consumption of conventionally-generated power.

Fault Tree Establishment of Flight Conflict Based on the HAZOP Method

Scipedia content — Thu, 28 Jan 2021 23:26:42 +0100

ming at the issues of subjectivity, coverage and ambiguity, this paper presents a systematic approach to constructing fault trees of flight conflict at airport based on HAZOP. First, the necessary deviation events are determined by associating the HAZOP guide words with the ATC parameters of terminal area, the causes and results of the deviation are analyzed in order to determine the paternity of the effectiveness of the proposed approach, and then the modeling process of the airport where two planes flight conflict happened in the United States is presented. This method can establish fault tree normatively, and provide a scientific and rational way to identify the inherent or potential risks within the airport.

Design of air corridor structures for enhanced traffic performance

Scipedia content — Thu, 28 Jan 2021 23:24:40 +0100

International audience; After introducing the concept of airstream as a special corridor organization, this paper proposes a design method to establish a network of such air corridors over a given geographic area. A case study involving East Asia is displayed.

Composite Materials Flaws Detection and Measurement by Infrared Thermography

Scipedia content — Thu, 28 Jan 2021 23:20:22 +0100

Composite materials are large used today in various industrial fields such as: aeronautics, military equipment, pipelines for oil transport; frequently must meet serious requirements about the quality. This paper presents the results of an experimental study on the possibilities and limits of flaws detection and measurement in composite materials by infrared thermography. In a research contract developed in our university were designed and processed samples with artificial defects in composite materials: CFRP, GRFP and Dyneema. The main aim of experimental research was to assess size of flaws positioned at different depths related to the examination area. The samples were investigated by infrared thermography and then the results were verified by different ultrasonic methods.

VANET Coverage Analysis for GPS Augmentation Data in Rural Area

Scipedia content — Thu, 28 Jan 2021 23:17:19 +0100

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Enhanced position accuracy is key for modern navigation systems, location based services and applications based on Inter-Vehicle Communication (IVC). Position data are the foundation for deriving vehicle trajectories used for assessing a situation's criticality in vehicle safety. Thus, especially Advanced Driver Assistance Systems (ADASs) and integral safety applications bene t from nearby vehicles spreading their positions periodically with high accuracy. Positioning based on Global Navigation Satellite System (GNSS) measurements can be enhanced by established Cooperative Positioning (CP) methods like Real-Time Kinematic (RTK) and Di fferential GNSS (DGNSS). Conventional CP relies on positioning correction data from a third party, whereas this paper introduces a self-su fficient CP system based on Precise Point Positioning (PPP) and Vehicular Ad-Hoc Network (VANET) technology requiring no infrastructure. Furthermore, the data dissemination process and achievable coverage are analysed by a simulation study for a rural area in Bavaria, Germany. For this purpose, the simulation employs the European IVC protocol stack ITS-G5. While the general feasibility of this CP approach could be assured, some remaining issues regarding employed network protocols were discovered as well.

Reliability, Safety, and Security of Railway Systems. Modelling, Analysis, Verification, and Certification

Scipedia content — Thu, 28 Jan 2021 23:16:29 +0100

Highly automated transport systems play an important role in the transformation towards a digital society, and planning the optimal routes for a set of fleet vehicles has been proved useful for improving the delivered services. Traditionally, routes are planned beforehand. However, with the advent of autonomous urban transport systems (e.g. autonomous cars), possible obstructions of tracks due to traffic congestion or bad weather conditions need to be handled on the fly. In this paper we tackle the problem of dynamically computing routes of vehicles in urban lines in the presence of potential obstructions. The problem is formulated as an integer linear optimization problem. The proposed algorithm will assign routes to vehicles dynamically, considering the track segments that are no longer available and the positions of the vehicles in the urban area. The recomputed routes guarantee the minimal waiting time for passengers. Safety of the computed routes is also guaranteed.

New Continuous-Time Formulation and Algorithm for Crude-Oil Scheduling Problems with Oil Residency Time Constraint and Pipeline Transportation

Scipedia content — Thu, 28 Jan 2021 23:05:31 +0100

The optimal scheduling of crude-oil operation in refineries has been studied by various groups during the past decade, leading to different mixed integer linear programming or mixed nonlinear programming formulations. This paper proposes a new MINLP formulation with an oil residency time constraint and common pipeline transportation that is based on single-operation sequencing (SOS). An effective choice strategy for priority-slot number is presented. This model is also developed upon the representation of a crude-oil scheduling by a single sequence of transportation operations. A method is proposed to solve this model which can get optimal solution with the smallest priority-slot number if it exists.

A Model for Urban Road Network Vulnerability Analysis Based on Cumulative Prospect Theory

Scipedia content — Thu, 28 Jan 2021 22:53:55 +0100

Research on the impact of maritime transport service in the trade deficit

Scipedia content — Thu, 28 Jan 2021 22:52:42 +0100

ording to the different modes of transport, transport services is divided into the four ways of air transport, sea transport, land transport and pipeline transport. thereinto, the maritime transport service is traffic in a way that transport volume of maritime transport service accounted for more than two third of the total transport volume. Maritime transport service is the main transportation mode in the world, which has an important position in foreign trade, but also has an important impact on the trade deficit. This paper systematically analyzes the influence factors of the maritime transport service in the trade deficit, and proposes that the trade barriers, transport costs, transport efficiency and labor capital and other factors are the most important factors of maritime transport service in the trade deficit. Finally, direct at the influence factors of maritime transport service in trade deficit, some relevant suggestions are put forward.

Fractal Dimension Analysis of Pipelines Thermograms for Hidden Defects Detection

Scipedia content — Thu, 28 Jan 2021 22:51:49 +0100

STUDY OF THE STRESS-STRAIN BEHAVIOR AND STRENGTH CHARACTERISTICS OF SEALER DEVICES FOR OIL-TRUNK PIPELINES

Scipedia content — Thu, 28 Jan 2021 22:51:31 +0100

Clock Synchronization Considerations in Security Informed Safety Assurance of Autonomous Systems of Systems

Scipedia content — Thu, 28 Jan 2021 22:47:29 +0100

Over the past decade, fast technological and industrial advances have been happening in the area of autonomous Systems of Systems (SoS). A SoS is built upon integration of several systems, where the complexity of such a structure is exponentially higher which brings challenges to its analysis. However, it also has provided a large set of new opportunities in domains such as air traffic control, defense, construction industry, etc. It is expected that fully autonomous and cooperating systems will increase the production efficiency, while decreasing (potentially completely replacing) the human effort in harmful environments. In order to enable this, we need to make sure that critical properties of SoS, such as safety and security are guaranteed. We believe that it is not sufficient anymore to analyze and guarantee these properties independently, but we have to be able to address safety and security in a joint effort. Communications in systems with any type of real-time requirements, where data validity is based on its freshness, rely on clock synchronization (CSyn) allowing its subsystems to cooperate and work coherently. Considering reliable and predictable communication as one of the main assets contributing to correct functionality of such systems, protecting CSyn from malicious adversaries should be one of the highest priority efforts in SoS. In this paper we show how CSyn breaches can influence security, and ultimately safety of complex and autonomous SoS, further we identify a missing piece to consider in safety assurance, namely assurance with respect to reliable communications between systems within the SoS. We demonstrate how an outcome of a security analysis can be used as input for the overall safety analysis and we use an autonomous quarry as an example application to illustrate our findings.

A data-driven approach for characterising the charging demand of electric vehicles: A UK case study

Scipedia content — Thu, 28 Jan 2021 22:45:30 +0100

the number of electric vehicles increases, the impact of their charging on distribution networks is being investigated using different load profiles. Due to the lack of real charging data, the majority of these load impact studies are making assumptions for the electric vehicle charging demand profiles. In this paper a two-step modelling framework was developed to extract the useful information hidden in real EVs charging event data. Real EVs charging demand data were obtained from Plugged-in Midlands (PiM) project, one of the eight ‘Plugged-in Places’ projects supported by the UK Office for Low Emission Vehicles (OLEV). A data mining model was developed to investigate the characteristics of electric vehicle charging demand in a geographical area. A Fuzzy-Based model aggregates these characteristics and estimates the potential relative risk level of EVs charging demand among different geographical areas independently to their actual corresponding distribution networks. A case study with real charging and weather data from three counties in UK is presented to demonstrate the modelling framework.

Document type: Article

Identification of tidal-traffic patterns in metro-area mobile networks via matrix factorization based model

Scipedia content — Thu, 28 Jan 2021 22:44:29 +0100

Due to the highly predictable daily movements of citizens in urban areas, mobile traffic shows repetitive patterns with spatio-temporal variations. This phenomenon is known as Tidal Effect analogy to the rise and fall of the sea levels. Recognizing and defining traffic load patterns at the base station thus plays a vital role in traffic engineering, network design and load balancing since it represents an important solution for the Internet Service Providers (ISPs) that face network congestion problems or over-provisioning of the link capacity. Previous works have dealt with the classification and identification of patterns through the use of techniques, which inspect the flow of data of a particular application. But they assume prior knowledge on the stream of data packets, making the trend identification much inefficient. Recent methods based on machine learning techniques build their classification models based on sample data collected at certain points of the network with high accuracy. Therefore, in this paper, we address the problem by applying matrix factorization based models on real-world datasets, identifying typical patterns from data streams, which frequently occur in the network, without investigating the type of flows. For that, we propose a Collective Non-negative Matrix Factorization based model combining multi-source data, such as point of interests attributes, traffic data and base station information, identifying the basic patterns of those areas of the city that present the same type of attributes. The experimental results show the effectiveness of our proposed approach compared with the baselines.

The influence of pipeline supports stiffness onto the water hammer run

Scipedia content — Thu, 28 Jan 2021 22:38:10 +0100

International audience; Water hammer (WH) phenomenon may produce various undesired effects in pipelines. Dynamic interaction between the liquid and the structure is known to influence the transient pipe flow parameters in non-rigid systems. One can expect that due to basic energy conservation considerations the energy outflow from the liquid to the elastic structure would result in lowering of WH pressures. However, this effect is not unambiguous and is not clearly and uniquely explained in literature. Thus, its proper understanding is of great practical importance. In the paper the authors try to examine these effects mainly on the basis of experimental results acquired from measurements at a special test rig designed and constructed at the Institute of Fluid-Flow Machinery in Gdansk. The main part of the rig is a cooper pipeline of the length of about 59m, fixed to the floor with a number of elastic supports. WH runs were generated, measured and analyzed for supports of varying stiffness. Pipeline free vibrations induced by mechanical shock were measured as well. The conclusions have been found and they are presented in the paper. Still, a very important part of the job was to find the physical interpretation and explanation of the results, which allows for understanding of that phenomenon.

Multiple Views on Safety-Critical Automation: Aircrafts, Autonomous Vehicles, Air Traffic Management and Satellite Ground Segments Perspectives

Scipedia content — Thu, 28 Jan 2021 22:36:04 +0100

International audience; This SIG focuses on the engineering of automation in interactive critical systems. Automation has already been studied in a number of (sub-) disciplines and application fields: design, human factors, psychology, (software) engineering, aviation, health care, games. One distinguishing feature of the area we are focusing on is that in the field of interactive critical systems properties such as reliability, dependability, fault-tolerance are as important as usability, user experience or overall acceptance issues. The SIG targets at two problem areas: first the engineering of the user interaction with (partly-) autonomous systems: how to design, build and assess autonomous behavior, especially in cases where there is a need to represent on the user interface both autonomous and interactive objects. An example of such integration is the representation of an unmanned aerial vehicle (UAV) (where no direct interaction is possible), together with aircrafts (that have to be instructed by an air traffic controller to avoid the UAV). Second the design and engineering of user interaction in general for autonomous objects/systems (for example a cruise control in a car or an autopilot in an aircraft).

Sustainable Transport in Campus Area: E-Bike

Scipedia content — Thu, 28 Jan 2021 22:32:19 +0100

Situation awareness for UAV operating in terminal areas using bearing-only observations and circuit flight rules

Scipedia content — Thu, 28 Jan 2021 22:31:42 +0100

Situation awareness is required for an Unmanned Aerial Vehicle (UAV) when it makes an arrival at an uncontrolled airfield. Since no air traffic control service is available, the UAV needs to detect and track other traffic aircraft by using its onboard sensors. General aviation pilots obtain enough situation awareness to operate in these environments, only using their vision and radio messages heard from other traffic aircraft. To improve the target tracking performance of a UAV, the circuit flight rules and standard radio messages are incorporated to provide extra knowledge about the target behaviour. This is achieved by using the multiple models to describe the target motions in different flight phases and characterising the phase transition in a stochastic manner. Consequently, an interacting multiple model particle filter with state-dependent transition probabilities is developed to perform Bayesian filtering with bearing-only observations from a vision sensor.

QAestro – Semantic-Based Composition of Question Answering Pipelines

Scipedia content — Thu, 28 Jan 2021 22:15:27 +0100

The demand for interfaces that allow users to interact with computers in an intuitive, effective, and efficient way is increasing. Question Answering (QA) systems address this need by answering questions posed by humans using knowledge bases. In recent years, many QA systems and related components have been developed both by practitioners and the research community. Since QA involves a vast number of (partially overlapping) subtasks, existing QA components can be combined in various ways to build tailored QA systems that perform better in terms of scalability and accuracy in specific domains and use cases. However, to the best of our knowledge, no systematic way exists to formally describe and automatically compose such components. Thus, in this work, we introduce QAestro, a framework for semantically describing both QA components and developer requirements for QA component composition. QAestro relies on a controlled vocabulary and the Local-as-View (LAV) approach to model QA tasks and components, respectively. Furthermore, the problem of QA component composition is mapped to the problem of LAV query rewriting, and state-of-the-art SAT solvers are utilized to efficiently enumerate the solutions. We have formalized 51 existing QA components implemented in 20 QA systems using QAestro. Our empirical results suggest that QAestro enumerates the combinations of QA components that effectively implement QA developer requirements.

Delivering data reduction pipelines to science users

Scipedia content — Thu, 28 Jan 2021 22:13:00 +0100

The European Southern Observatory has a long history of providing specialized data processing algorithms, called recipes, for most of its instruments. These recipes are used for both operational purposes at the observatory sites, and for data reduction by the scientists at their home institutions. The two applications require substantially different environments for running and controlling the recipes. In this papers, we describe the ESOReflex environment that is used for running recipes on the users’ desktops. ESOReflex is a workflow driven data reduction environment. It allows intuitive representation, execution and modification of the data reduction workflow, and has facilities for inspection of and interaction with the data. It includes fully automatic data organization and visualization, interaction with recipes, and the exploration of the provenance tree of intermediate and final data products. ESOReflex uses a number of innovative concepts that have been described in Ref. 1. In October 2015, the complete system was released to the public. ESOReflex allows highly efficient data reduction, using its internal bookkeeping database to recognize and skip previously completed steps during repeated processing of the same or similar data sets. It has been widely adopted by the science community for the reduction of VLT data.

A novel framework for modeling and mitigating distributed link flooding attacks

Scipedia content — Thu, 28 Jan 2021 21:54:00 +0100

Distributed link-flooding attacks constitute a new class of attacks with the potential to segment large areas of the Internet. Their distributed nature makes detection and mitigation very hard. This work proposes a novel framework for the analytical modeling and optimal mitigation of such attacks. The detection is modeled as a problem of relational algebra, representing the association of potential attackers (bots) to potential targets. The analysis seeks to optimally dissolve all but the malevolent associations. The framework is implemented at the level of online Traffic Engineering (TE), which is naturally triggered on link-flooding events. The key idea is to continuously re-route traffic in a manner that makes persistent participation to link-flooding events highly improbable for any benign source. Thus, bots are forced to adopt a suspicious behavior to remain effective, revealing their presence. The load-balancing objective of TE is not affected at all. Extensive simulations on various topologies validate our analytical findings.

Comment: 9 pages, 8 figures, IEEE INFOCOM 2016

Privacy issues of ISPs in the modern web

Scipedia content — Thu, 28 Jan 2021 21:50:37 +0100

In recent years, privacy issues in the networking field are getting more important. In particular, there is a lively debate about how Internet Service Providers (ISPs) should collect and treat data coming from passive network measurements. This kind of information, such as flow records or HTTP logs, carries considerable knowledge from several points of view: traffic engineering, academic research, and web marketing can take advantage from passive network measurements on ISP customers. Nevertheless, in many cases collected measurements contain personal and confidential information about customers exposed to monitoring, thus raising several ethical issues. Modern web is very different from the one we experienced few years ago: web services converged to few protocols (i.e., HTTP and HTTPS) and a large share of traffic is encrypted. The aim of this work is to provide an insight about which information is still visible to ISPs, with particular attention to novel and emerging protocols, and to what extent it carries personal information. We illustrate that sensible information, such as website history, is still exposed to passive monitoring. We illustrate privacy and ethical issues deriving by the current situation and provide general guidelines and best practices to cope with the collection of network traffic measurements.

Unmanned Aerial Systems Traffic Management (UTM): Safely Enabling UAS Operations in Low-Altitude Airspace

Scipedia content — Thu, 28 Jan 2021 21:49:50 +0100

JIFX 16-3 Joint Interagency Field Experimentation; 9-13 May 2016; Camp Roberts, CA; United States Currently, there is no established infrastructure to enable and safely manage the widespread use of low-altitude airspace and UAS flight operations. Given this, and understanding that the FAA faces a mandate to modernize the present air traffic management system through computer automation and significantly reduce the number of air traffic controllers by FY 2020, the FAA maintains that a comprehensive, yet fully automated UAS traffic management (UTM) system for low-altitude airspace is needed. The concept of UTM is to begin by leveraging concepts from the system of roads, lanes, stop signs, rules and lights that govern vehicles on the ground today. Building on its legacy of work in air traffic management (ATM), NASA is working with industry to develop prototype technologies for a UAS Traffic Management (UTM) system that would evolve airspace integration procedures for enabling safe, efficient low-altitude flight operations that autonomously manage UAS operating in an approved low-altitude airspace environment. UTM is a cloud-based system that will autonomously manage all traffic at low altitudes to include UASs being operated beyond visual line of sight of an operator. UTM would thus enable safe and efficient flight operations by providing fully integrated traffic management services such as airspace design, corridors, dynamic geofencing, severe weather and wind avoidance, congestion management, terrain avoidance, route planning re-routing, separation management, sequencing spacing, and contingency management. UTM removes the need for human operators to continuously monitor aircraft operating in approved areas. NASA envisions concepts for two types of UTM systems. The first would be a small portable system, which could be moved between geographical areas in support of operations such as precision agriculture and public safety. The second would be a Persistent system, which would support low-altitude operations in an approved area by providing continuous automated coverage. Both would require persistent communication, navigation, and surveillance (CNS) coverage to track, ensure, and monitor conformance. UTM is creating an airspace management tool that allows the ATM system to accommodate the number of UAS that will operate in the low altitude airspace. The analogy is just because we have a car, whether its autonomous or someone is driving, does not diminish the need for a road or road signs or rules of the road. WBS 154692.02.10.01.01 NPS Sponsorship Approved for public release; distribution is unlimited.

Analyzing the operational capacity effects of the monitor Alert paramater (MAP)

Scipedia content — Thu, 28 Jan 2021 21:42:49 +0100

The FAA's Air Traffic Organization (ATO) Office of Performance Analysis is responsible for developing indicators and providing analysis on the operational efficiency of the NAS and to ensure its databases provide the necessary information for linking performance to root causes. The focus of this paper is the primary indicator of capacity within a sector, the Monitor Alert Parameter (MAP), an indicator designed to alert personnel when traffic levels in a given sector may be at a level that will affect the efficiency of the system. Over the past decade, however, it has come under some criticism for being too simplistic in its calculation with the obvious implication that some MAP values do not represent the real trigger point at which the balance between sector capacity and traffic volume require a closer look. A search for studies on this subject yields sparse results with cursory connections. This paper will review and analyze the current FAA policy for MAP and discuss the challenges and potential shortfalls of the current implementation of baseline MAP values. Further, it will discuss the challenges associated with measuring the effectiveness of this tool. Finally, this paper draws conclusions and makes recommendations focused on enabling a more comprehensive analysis of sector capacity limitations on the efficiency of the NAS.

ICAROUS: Integrated configurable algorithms for reliable operations of unmanned systems

Scipedia content — Thu, 28 Jan 2021 21:38:44 +0100

NASA's Unmanned Aerial System (UAS) Traffic Management (UTM) project aims at enabling near-term, safe operations of small UAS vehicles in uncontrolled airspace, i.e., Class G airspace. A far-term goal of UTM research and development is to accommodate the expected rise in small UAS traffic density throughout the National Airspace System (NAS) at low altitudes for beyond visual line-of-sight operations. This paper describes a new capability referred to as ICAROUS (Integrated Configurable Algorithms for Reliable Operations of Unmanned Systems), which is being developed under the UTM project. ICAROUS is a software architecture comprised of highly assured algorithms for building safety-centric, autonomous, unmanned aircraft applications. Central to the development of the ICAROUS algorithms is the use of well-established formal methods to guarantee higher levels of safety assurance by monitoring and bounding the behavior of autonomous systems. The core autonomy-enabling capabilities in ICAROUS include constraint conformance monitoring and contingency control functions. ICAROUS also provides a highly configurable user interface that enables the modular integration of mission-specific software components.

EEG-Based Human Factors Evaluation of Conflict Resolution Aid and Tactile User Interface in Future Air Traffic Control Systems

Scipedia content — Thu, 28 Jan 2021 21:35:34 +0100

Currently, Air Traffic Control (ATC) systems are reliable with automation supports, however, the increased traffic density and complex air traffic situations bring new challenges to ATC systems and air-traffic controllers (ATCOs). We conduct an experiment to evaluate the current ATC system and test conflict resolution automation and tactile user interface to be the inputs of the future ATC system. We propose an Electroencephalogram (EEG)-based system to monitor and analyze human factors measurements of ATCOs in ATC systems to apply it in our experiment. The EEG-based tools are used to monitor and record the brain states of ATCOs during the experiment. Real-time EEG-based human factors evaluation of an ATC system allows researchers to analyze the changes of ATCOs' brain states during the performance of various ATC tasks. Based on the analyses of the objective real time data together with the subjective feedback from ATCOs, we are able to reliably evaluate current ATC systems and refine new concepts of future ATC system.

Least Restrictive and Minimally Deviating Supervisor for Safe Semi-Autonomous Driving at an Intersection: An MIQP Approach

Scipedia content — Thu, 28 Jan 2021 21:34:26 +0100

International audience; Although significant progress has been made in the last few years towards cooperative and autonomous driving, the transition from human-driven to fully automated vehicles is expected to happen slowly. The question of semi-autonomous driving, where Advanced Driver Assistance Systems assist human drivers in their decisions, will therefore become increasingly important. In this paper, we consider the problem of safe intersection crossing for semi-autonomous vehicles with communication capacities. We design an intersection supervisor based on a mixed-integer quadratic programming approach which monitors the control inputs of each vehicle, and overrides those controls when necessary to ensure that all vehicles can navigate safely. Moreover, the solution control deviates minimally from the vehicles target inputs: overriding only occurs when it is strictly necessary, in which case the control is chosen as close as possible to the driver's intent. We theoretically prove that the supervisor needs only consider a finite future time horizon to ensure safety and deadlock avoidance over an infinite time horizon, and we demonstrate through simulation that this algorithm can work in real time. Additionally, unlike previous work, our formulation is suitable for complex intersection geometries with a high number of vehicles.

Aggregation of single-phase electric vehicles for frequency control provision based on unidirectional charging

Scipedia content — Thu, 28 Jan 2021 21:27:33 +0100

the use of electric vehicles grows there is a greater possibility of using aggregated sets of electric vehicles as a large flexible unit to assist with the control of the power system. In this paper, the possibility of using electric vehicles as a flexible load for frequency control is investigated. The investigations are performed in a Pan-European interconnected grid with varying wind power penetration and different operational scenarios. Within this grid, the paper focuses on primary frequency control provision from electric vehicles and how the system behaves as the vehicles are being controlled within their respective areas. The investigations show that electric vehicles can be used for primary frequency control with different wind power penetration. By controlling the vehicles, the steady state frequency is improved and, since the vehicles react fast enough to the frequency changes, also frequency nadir and rate of change of frequency are positively affected.

Delayed location management in network mobility environments

Scipedia content — Thu, 28 Jan 2021 21:26:22 +0100

Conference of 12th EAI International Conference on Heterogeneous Networking for Quality, Reliability, Security and Robustness, QShine 2016 ; Conference Date: 7 July 2016 Through 8 July 2016; Conference Code:196279; International audience; Network mobility basic support (NEMO-BS) supports efficient group mobility. However, when NEMO-BS is applied to public transportation systems where mobile nodes (MNs) frequently get in/off the public transportation, significant signaling overhead owing to frequent and unnecessary binding updates can occur. To address this problem, we propose a delayed location management (DLM) scheme where an MN postpones its binding update for a pre-defined timer to mitigate the binding update overhead. To evaluate the performance of DLM, we develop an analytical model for the binding update cost and the packet delivery cost during the boarding time. Evaluation results demonstrate that DLM can reduce the binding update cost and packet delivery cost by choosing an appropriate timer.

Interactions between vulnerable road users and automated vehicles: A synthesis of literature and framework for future research

Scipedia content — Thu, 28 Jan 2021 21:18:06 +0100

Partially and fully automated vehicles (AVs) are being developed and tested in different countries. These vehicles are being designed to reduce and ultimately eliminate the role of human drivers in the future. Most fatal accidents of vulnerable road users (VRUs), pedestrians, cyclists and mopeds, involve a motorized vehicle. In addition, most of the accidents involving VRUs and motorized vehicles happen at road crossings. By replacing human-driven vehicles with automated vehicles, the human role will be altered and reduced which could lead to an increase in traffic safety. However, drivers are not the only ones who will have to adapt to automated vehicles, other road users, such as pedestrians and cyclists, will have to interact with vehicles with various levels of automation, too. Pedestrians and cyclists will still be humans and might behave in an unpredictable manner which could lead to unsafe behaviors. The main goal of this paper is to propose a theoretical framework which describes the interactions between automated vehicles and road user behavior under different road design conditions. This is a prerequisite to understand how to design safe urban environments where VRUs and automated vehicles can interact safely. A synthesis of the existing literature about the interactions between automated vehicles and VRUs, and the main factors that could influence VRUs’ behavior is presented. The results of the synthesis and the identified knowledge gaps are discussed. Based on this, a theoretical framework for the interactions between VRUs and automated vehicles is developed and discussed.

Trade-off analysis of a service-oriented and hierarchical queuing mechanism

Scipedia content — Thu, 28 Jan 2021 21:15:19 +0100

This paper sketches a service-oriented and hierarchical queuing mechanism designed to manage radio buffers while delivering web services. The goal is avoid buffer overflow implementing a three-level queuing mechanism. The first level is the message queue which stores messages from user-facing services. At the second level, the messages are fragmented into IP packets which are stored in the packet queue. Finally, the third level is the radio buffer itself. As a result, a multi-homed node has queues for each radio, capturing the likely differences of data rate, buffer size and current usage. A prototype based on web services was tested using real military radios; VHF radios with large coverage (∼20 km) but very low data rate (2.4–9.6 kbps). We analyzed the trade-offs within the system configuration, targeting at an optimal and robust radio buffer management.

Failure Mode, Effects and Criticality Analysis of Railway Rolling Stock Assets

Scipedia content — Thu, 28 Jan 2021 21:12:50 +0100

International audience; In recent years, a great deal of attention has been paid to the analysis of failure modes occurring in railway infrastructure assets, e.g. bridges, rail tracks, sleepers, etc. However, there have been few attempts by researchers to develop failure criticality assessment models for railway rolling stock. A rolling stock failure may be very costly in terms of monetary loss and/or passenger inconvenience. It may also cause delays to train services or even result in catastrophic derailment accidents. In this paper, a failure mode, effects and criticality analysis approach is presented to identify, analyse and evaluate the causes and consequences of rolling stock failures. The most critical failure modes with respect to both reliability and economics are identified and potential protective measures are then proposed to prevent their recurrence. For the purpose of illustrating the proposed approach, the model is applied to a rolling stock passenger door system. The data required for the study are collected from both the literature and the maintenance information system available in a Scottish train operating company. The results of this study can be used to plan a cost-effective preventive maintenance programme for different components of rolling stock.

Understanding Capabilities, Functionings and Travel in High and Low Income Neighbourhoods in Manila

Scipedia content — Thu, 28 Jan 2021 21:05:58 +0100

Transport plays an important role in helping people to access activities and participate in life. The availability of transport networks, the modes available, new infrastructure proposals, and the type of urban development can all impact on and change activity participation, and hence contribute to social equity in the city. This article uses surveys in low and high income neighbourhoods in Manila, the Philippines, to assess the social equity implications of differential access to transport. The analysis demonstrates how the theoretical framework of the Capability Approach (Nussbaum, 2003; Sen, 1985, 1999, 2009) can be used to assess what individuals might be able to access (capabilities) versus their actual travel (functionings). The spatial patterns of travel and access to activities are assessed, demonstrating significant differences by gender, age, income and neighbourhood, in terms of travel mode and cost of travel; health, physical and mental integrity; senses, imagination and thoughts; reasoning and planning; social interaction; natural environment; sustainable modes; and information. This approach to assessing the transport dimensions of social equity offers much potential, based not only on access to resources or consumption of mobility, but also in the opportunities that people have in relation to their activity participation. The case study context is also informative, with Manila providing an example of an Asian city with high levels of private car usage, high levels of congestion, and large spatial and income differentials in travel and associated social equity.

A Framework for BPMS Performance and Cost Evaluation on the Cloud

Scipedia content — Thu, 28 Jan 2021 21:04:03 +0100

International audience; In this paper, we describe a framework that allows to automate and repeat business process execution on different cloud configurations. We present how and why the different components of the experimentation pipeline-like Ansible, Docker and Jenkins-have been set up, and the kind of results we obtained on a large set of configurations from the AWS public cloud. It allows us to calculate actual prices regarding the cost of process execution, in order to compare not only pure performance but also the economic dimension of process execution.

Real-time performance and safety validation of an integrated vehicle dynamic control strategy

Scipedia content — Thu, 28 Jan 2021 20:59:57 +0100

The state of the art in automotive control has proposed several analytical, simulation and experimental studies of longitudinal adaptive cruise control strategies, and of lateral control strategies. However, methodical integration of these two strategies is to a large extent missing, as well as validation in real-time computing environment of the safety and performance of longitudinal and lateral integrated solutions. This work proposes a real-time validation of an integrated vehicle dynamic control strategy, designed to create safe interaction between longitudinal and lateral controllers: the integrated system is designed, implemented and tested through Dynacar, a real-time simulation environment for the development and validation of vehicle embedded functionalities. The results show that the proposed integrated controller satisfies the performance in terms of real-time computation, path tracking and collision avoidance for various driving situations.

Collective Travel Planning in Spatial Networks

Scipedia content — Thu, 28 Jan 2021 20:56:32 +0100

Travel planning and recommendation are important aspects of transportation. We propose and investigate a novel Collective Travel Planning (CTP) query that finds the lowest-cost route connecting multiple sources and a destination, via at most $k$ meeting points. When multiple travelers target the same destination (e.g., a stadium or a theater), they may want to assemble at meeting points and then go together to the destination by public transport to reduce their global travel cost (e.g., energy, money, or greenhouse-gas emissions). This type of functionality holds the potential to bring significant benefits to society and the environment, such as reducing energy consumption and greenhouse-gas emissions, enabling smarter and greener transportation, and reducing traffic congestions. The CTP query is Max SNP-hard. To compute the query efficiently, we develop two algorithms, including an exact algorithm and an approximation algorithm. The exact algorithm is capable finding the optimal result for small values of $k$ (e.g., $k = 2$ ) in interactive time, while the approximation algorithm, which has a $5$ -approximation ratio, is suitable for other situations. The performance of the CTP query is studied experimentally with real and synthetic spatial data.

AIV and FIV in Pipelines, Plants, and Facilities

Scipedia content — Thu, 28 Jan 2021 20:53:05 +0100

Acoustic-induced vibration (AIV) and flow-induced vibration (FIV) are two common phenomena that can lead to vibration-induced fatigue failures in piping systems. Pipeline facility managers, operators, designers, and engineers are faced with identifying and mitigating the risks of AIV and FIV to avoid catastrophic instances of vibration-induced fatigue failures in their facilities. This paper identifies common challenges to conventional AIV/FIV analyses methods, and discusses advanced techniques available to address these challenges."/jats:p" "jats:p"Acoustic-induced vibrations are caused by the sound energy created by flow through pressure reducing devices like valves or restrictive orifice plates. This sound energy can cause the piping wall to vibrate, thus exciting, and possibly damaging, any nearby small-bore branch connections. Flow-induced vibrations are caused by pulsations induced by flow past dead legs in piping systems. These pulsations can create shaking forces that cause vibrations of piping, vessels, and equipment. The two phenomena will be compared and contrasted, while offering simple tips and best practices in identifying, evaluating, and solving these two common flow-induced issues."/jats:p" "jats:p"A field case study utilizing pulsation and vibration measurements between a line heater and inlet separator for a gas plant will be presented and discussed. The case presents an opportunity to investigate mainline and small-bore piping AIV/FIV risks in plants, provides example data of clear AIV and FIV phenomena, and identifies complex situations that require more rigorous analysis. Advanced techniques for analyzing and solving complex issues that are commonly found in piping systems will be explored. Further, the case highlights the benefits of early screening and preventive considerations of upset conditions when dealing with flow-induced pulsation and vibration issues."/jats:p" "jats:p"In this paper, the reader will gain an increased understanding of the importance of AIV/FIV in maintaining integrity of their facilities, and be provided with tools and knowledge to mitigate any risks that may be encountered.

Research on Intermodal External Costs of International Container

Scipedia content — Thu, 28 Jan 2021 20:44:47 +0100

The Belt and Road" strategic concept is inseparable from the support of transport, and intermodal container is an effective way to solve the problem of sustainable transport over long distances. "Chongqing New Europe" channel as the cross-border trade of goods multimodal transport channels to container rail transport way for "along the way" alternative development paths. Intermodal transport external cost is an important reference for policy-making, but the lack of in-depth study, empirical study less. Based on the analysis of multimodal transport external costs, "Chongqing New Europe" intermodal rail transport external costs compare with the sea. This paper presents the structural model of the multimodal transport external cost, the establishment of cost model can characterize the damage factor, application of damage cost method factor monetization, end use cost model for Shanghai to Duisburg two multimodal approach way were compared. The results showed that the external costs of waterway transport unit minimum, followed by rail transport, again are road transport, which should give priority to the main transport waterway transport, multimodal transport emissions and costs of each mode of transport in the external account are the largest proportion of the total cost.

Performance assessment for intermodal transportation systems: A case study

Scipedia content — Thu, 28 Jan 2021 20:39:22 +0100

This paper proposes a methodology to evaluate an Intermodal Transportation System (ITS). These systems are very complex and a lot of different actors are involved. The evaluation process should take into account concurrent needs and goals. Moreover, the data and the importance of different indicators are strictly related to the judgments of individual experts. Then it is necessary to have a methodology able to collect all the independent judgments and merge them in order to evaluate the whole system performances. The paper proposes a general methodology based on the Analytic Hierarchy Process to evaluate the behavior of the ITS system. Moreover, the hierarchy including the typical factors that compose a logistic system has been identified. In order to show the effectiveness of the proposed methodology, we present a real case study consisting of the port of Trieste (Italy), the intermodal terminal and the highway connecting them. Several Key Performance Indicators are evaluated to provide assessment procedure.

INVESTIGATING THE POTENTIAL OF ACTIVITY TRACKING APP DATA TO ESTIMATE CYCLE FLOWS IN URBAN AREAS

Scipedia content — Thu, 28 Jan 2021 20:38:45 +0100

Traffic congestion and its associated environmental effects pose a significant problem for large cities. Consequently, promoting and investing in green travel modes such as cycling is high on the agenda for many transport authorities. In order to target investment in cycling infrastructure and improve the experience of cyclists on the road, it is important to know where they are. Unfortunately, investment in intelligent transportation systems over the years has mainly focussed on monitoring vehicular traffic, and comparatively little is known about where cyclists are on a day to day basis. In London, for example, there are a limited number of automatic cycle counters installed on the network, which provide only part of the picture. These are supplemented by surveys that are carried out infrequently. Activity tracking apps on smart phones and GPS devices such as Strava have become very popular over recent years. Their intended use is to track physical activity and monitor training. However, many people routinely use such apps to record their daily commutes by bicycle. At the aggregate level, these data provide a potentially rich source of information about the movement and behaviour of cyclists. Before such data can be relied upon, however, it is necessary to examine their representativeness and understand their potential biases. In this study, the flows obtained from Strava Metro (SM) are compared with those obtained during the 2013 London Cycle Census (LCC). A set of linear regression models are constructed to predict LCC flows using SM flows along with a number of dummy variables including road type, hour of day, day of week and presence/absence of cycle lane. Cross-validation is used to test the fitted models on unseen LCC sites. SM flows are found to be a statistically significant (p<0.0001) predictor of total flows as measured by the LCC and the models yield R squared statistics of ~0.7 before considering spatio-temporal variation. The initial results indicate that data collected using fitness tracking apps such as Strava are a promising data source for traffic managers. Future work will incorporate the spatio-temporal structure in the data to better account for the spatial and temporal variation in the ratio of SM flows to LCC flows.

Mobile Device Sensing System for Urban Goods Distribution Logistics

Scipedia content — Thu, 28 Jan 2021 20:34:10 +0100

This paper presents a low cost mobile application (app) integrated on an Internet of Things (IoT) ecosystem, which uses varied sensor information collected by mobile devices to track and assist on the logistics of urban goods distribution processes. The proposed approach is leveraged by the trend of decreasing costs for mobile data communication in urban environments. Taking into account basic sensor data available in mobile devices (e.g., GPS, accelerometer and magnetometer), it is possible to track the users’ movements and adopted routes, identify transit times and driving styles, identify the quality of roads, and track the process of loading/unloading of urban goods. This data can also be analyzed through a data mining process to identify patterns, present driving advice and perform a resource optimization process. 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

A Hybrid Iterative Local Search Algorithm for the Electric Fleet Size and Mix Vehicle Routing Problem with Time Windows and Recharging Stations

Scipedia content — Thu, 28 Jan 2021 20:31:24 +0100

As the cities around the world become larger, quality of life of the citizens is more and more threatened due to the traffic congestion, energy consumption, noise disturbance and carbon emissions because of of increasing transport. Electrical vehicles present an opportunity to reduce greenhouse gas emissions. But limited driving range and long recharging times are among the challenges that the research community has to face. This paper proposes an iterative local search algorithm coupled with a set partitioning model to solve The Electric Fleet Size and Mix Vehicle Routing Problem with Time Windows and Recharging Stations. Several types of electrical vehicles with varying driving range, capacity and fixed cost should service a set of customers within their time limits and during their tours each vehicle can be recharged in stations. We show the efficiency and the quality of our method by solving benchmark instances of the Heterogeneous Fleet Electric Vehicle Problems with Time Windows.

Development of sustainable transport in smart cities

Scipedia content — Thu, 28 Jan 2021 20:30:36 +0100

© 2017 IEEE. Smart Mobility is one of the main directions of transportation systems development in Smart Cities. In this case along with intellectualization of management the issue of transition to 'green', safe and sustainable modes of transport, such as bicycle, should be solved. Democracy and availability, cheapness and environmental friendliness, promotion of healthy lifestyle are the reasons for the growing popularity of this mode of transport all over the world. This paper proposes one of the possible ways of bicycle transport development in smart city, that allows expanding the number of users by reducing physical requirements for cyclist. The proposed development represents a concept of the Smart Bike that monitors condition of the cyclist and environment and turns on electric motor in critical situations. This reduces physical load of cyclist, as well as the battery consumption, that positively affects the ecology of Smart Cities.

Controlled Triangular Batches Petri Nets for hybrid mesoscopic modeling of traffic road networks under VSL control

Scipedia content — Thu, 28 Jan 2021 20:30:02 +0100

In the discrete event and hybrid systems theory, Batches Petri Nets (BPN) have been defined as an extension of Hybrid Petri nets for representing in a single node a linear relation between flow and density. This formalism and its extensions allow us to delay flows according to accumulation phenomena. Applied to mesoscopic modeling of traffic road networks, Triangular Batches Petri Nets (TBPN) have been defined as a triangular flow-density relation, allowing the representation of traffic congestion/decongestion phenomena. When variable speed limit (VSL) control is applied on the traffic road networks, i.e., a method that improves the traffic conditions by the reduction of congestion, Controlled Triangular Batches Petri Nets (CTBPN) can be used for analyzing such phenomena. In this paper, we present the hybrid formalism defined in CTBPN, i.e., the hybrid behavior of a batch in free, congestion or decongestion behavior. As an illustrative example, the congestion/decongestion phenomena on a road section and the impact of a VSL control are shown.

Time-optimal Coordination of Mobile Robots along Specified Paths

Scipedia content — Thu, 28 Jan 2021 20:27:40 +0100

In this paper, we address the problem of time-optimal coordination of mobile robots under kinodynamic constraints along specified paths. We propose a novel approach based on time discretization that leads to a mixed-integer linear programming (MILP) formulation. This problem can be solved using general-purpose MILP solvers in a reasonable time, resulting in a resolution-optimal solution. Moreover, unlike previous work found in the literature, our formulation allows an exact linear modeling (up to the discretization resolution) of second-order dynamic constraints. Extensive simulations are performed to demonstrate the effectiveness of our approach.

Comment: Published in 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)

Mobile EEG-based situation awareness recognition for air traffic controllers

Scipedia content — Thu, 28 Jan 2021 20:27:21 +0100

With the growing volume and complexity of air traffic, air traffic controllers (ATCOs) encounter heavier burden nowadays. Therefore, human factors study in air traffic control (ATC) is increasingly essential, paving the way to a safer air transportation system. In this paper, we conducted an ATC experiment, where Electroencephalogram (EEG) data were collected throughout the experiment. Compared to traditional questionnaires and psychological tests used in human factors study, the proposed novel EEG approach provides monitoring of situation awareness (SA) in a non-invasive and non-interruptive fashion. SA was represented as the response latency in situation present assessment method (SPAM), which was predicted from EEG signals using three machine learning algorithms. Support vector regression obtained the lowest prediction error of 1.5 seconds, which is lower than 10% of the range of actual response latency. The results show that EEG is a promising approach forward in measuring situation awareness of ATCOs in both real-time and accurate manner.

Research about Monitoring Systems of Special Roads Based on 4G

Scipedia content — Thu, 28 Jan 2021 20:24:52 +0100

Monitoring systems of special roads based on 4G start point video monitoring systems designing of special roads. Combined with special roads of several major features, it is concluded that the ideal way of information transmission is 4G communication technology, and through the monitoring method research of traffic flow, combined with the structure of the monitoring system and 4G video transmission technology, the ideal special roads traffic flow monitoring and information transmission system can be designed. For 4G communication technology application in highway monitoring system it has important foresee and practical guiding significance, and for the special roads of traffic flow monitoring it has a very important role. 1. Preface With the development of national economy, transportation is playing an increasingly important role in economic development. Transportation safety is getting more and more attentions in the special roads. It's necessary to set up monitoring systems to monitor the traffic flow data and ensure the traffic safety. About special road, it usually refers to road which is beyond normal variations in designing limits and under the influence of the special climate condition or geographical conditions including landform and physiognomy, such as extra-long highway tunnel, extra-long bridge, long downhill, geological disasters (earthquakes, landslides) road, city T-junction, etc. Because of the relatively poor linear, big traffic flow, bad driving behavior of drivers, vehicle performance and other factors in these roads, it's very easy to cause traffic accidents. It's necessary to set up monitoring systems to monitor the traffic flow data and ensure the traffic safety. 4G technology not only supports images, music, video and other media forms of wireless transmission, but also has the advantages of high transmission rate, good adaptability, low cost, etc. Using 4G wireless transmission technology can solve the problem of repaved communication pipelines. It is a kind of new type and high quality way of information transmission. Therefore, using the research about monitoring systems of special roads on 4G can fully make advanced modern network technology and communication technology apply to traffic management. So it can better achieve the goal of traffic information real-time and two-way transmission to reduce the occurrence of the traffic incidents.

HPAZ: a High-throughput Pipeline Architecture of ZUC in Hardware

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

In this paper, we propose a high-throughput pipeline architecture of the stream cipher ZUC which has been included in the security portfolio of 3GPP LTE-Advanced. In the literature, the schema with the highest throughput only implements the working stage of ZUC. The schemas which implement ZUC completely can only achieve a much lower throughput, since a self-feedback loop in the critical path significantly reduces the operating frequency. In this paper we design a mixed two-stage pipeline architecture which not only completely implements ZUC but also significantly raises the throughput. We have implemented our architecture in FPGAs and ASICs. In FPGAs platform, the new architecture increases the throughput by 45%, compared with the latest work, and particularly the new architecture also saves nearly 12% of hardware resources. In the 65nm ASIC technology, the throughput of the new design can up to 80Gbps, which is 2.7 times faster than the fastest one in the literature, in particular, it also saves at least 40% of hardware resources. In addition to the academic design, compared with the fastest commercial design, the new architecture doubles the throughput of that. To the best of our knowledge, this evaluation result is so far the best outcome.

Demo- The SABER system for window-based hybrid stream processing with GPGPUs

Scipedia content — Thu, 28 Jan 2021 20:18:07 +0100

Heterogeneous architectures that combine multi-core CPUs with many-core GPGPUs have the potential to improve the performance of data-intensive stream processing applications. Yet, a stream processing engine must execute streaming SQL queries with sufficient data-parallelism to fully utilise the available heterogeneous processors, and decide how to use each processor in the most effective way. Addressing these challenges, we demonstrate S aber , a hybrid high-performance relational stream processing engine for CPUs and GPGPUs. S aber executes window-based streaming SQL queries in a data-parallel fashion and employs an adaptive scheduling strategy to balance the load on the different types of processors. To hide data movement costs, S aber pipelines the transfer of stream data between CPU and GPGPU memory. In this paper, we review the design principles of S aber in terms of its hybrid stream processing model and its architecture for query execution. We also present a web front-end that monitors processing throughput.

Research into Various Aspects of Loss Brought by Urban Traffic Congestion and Countermeasures

Scipedia content — Thu, 28 Jan 2021 20:11:40 +0100

With the development of economy, Chinese urbanization has accelerated already, the people's living standards and quality of life have also increased steadily, and car ownership has gradually increased. Traffic congestion caused by a series of reasons including road planning and traffic control has become a big problem which cannot be ignored blocking the urbanization city. This paper chooses Huilongguan area as the research object, visiting the residents there and field research, we acquire the relevant data and then analyze environmental pollution, energy consumption and various losses which brought by the traffic congestion. Finally, provide the improvement of the relevant recommendations.

Algorithm development for night charging electric vehicles optimization in big data applications

Scipedia content — Thu, 28 Jan 2021 20:08:16 +0100

In this paper a night charging method that optimizes the recharging process of electric vehicles (EVs) depending on hourly energy price in a peer to peer (P2P) energy trading system is presented. This algorithm determines how much energy should be recharged in the battery of each EV and the corresponding time slot to do it, avoiding the discontinuities in the charging process and considering the users’ personal mobility constraints.

Reduction of Energy Costs and Traffic Flow Rate in Urban Logistics Process

Scipedia content — Thu, 28 Jan 2021 20:06:48 +0100

Energy cost is a phenomenon relating to logistics and transportation activities of logistics operators as well as governments local authorities and citizens. Actually all the logistics parties may be affected by energy costs. At the same time logistics and transportation flow rate is declining continuously. Increases in traffic volume and decreased logistics flow rate cause to decrease in logistics productivity and efficiency in a city. On the other hand changes in these factors cause to increase energy cost. Minimum energy consumption plays an important role for efficient and productive urban logistics operations. Increasing traffic volume and congestion may absorb the energy of cities in addition to that it causes to increase energy requirements of urban areas. According to scientific research a significant correlation can be seen between traffic volume congestion energy cost and using the urban economic resources. This study focus on relations between these factors and it tried to show that ways for reduction of energy cost on optimum traffic volume and traffic flow rate. In addition to that the findings of this study depend on fieldwork related to Istanbul city. (C) 2017 The Authors. Published by Elsevier Ltd.

Including congestion effects in urban road traffic CO2 emissions modelling: Do Local Government Authorities have the right options?

Scipedia content — Thu, 28 Jan 2021 20:03:34 +0100

Tailpipe emissions from vehicles on urban road networks have damaging impacts, with the problem exacerbated by the common occurrence of congestion. This article focuses on carbon dioxide because it is the largest constituent of road traffic greenhouse gas emissions. Local Government Authorities (LGAs) are typically responsible for facilitating mitigation of these emissions, and critical to this task is the ability to assess the impact of transport interventions on road traffic emissions for a whole network."br/""br/"This article presents a contemporary review of literature concerning road traffic data and its use by LGAs in emissions models (EMs). Emphasis on the practicalities of using data readily available to LGAs to estimate network level emissions and inform effective policy is a relatively new research area, and this article summarises achievements so far. Results of the literature review indicate that readily available data are aggregated at traffic level rather than disaggregated at individual vehicle level. Hence, a hypothesis is put forward that optimal EM complexity is one using traffic variables as inputs, allowing LGAs to capture the influence of congestion whilst avoiding the complexity of detailed EMs that estimate emissions at vehicle level."br/""br/"Existing methodologies for estimating network emissions based on traffic variables typically have limitations. Conclusions are that LGAs do not necessarily have the right options, and that more research in this domain is required, both to quantify accuracy and to further develop EMs that explicitly include congestion, whilst remaining within LGA resource constraints.

A Novel Dual Traffic/Flash Flood Monitoring System Using Passive Infrared/Ultrasonic Sensors

Scipedia content — Thu, 28 Jan 2021 20:01:00 +0100

Floods are the most common type of natural disaster, causing thousands of casualties every year. Among these events, urban flash floods are particularly deadly because of the short timescales on which they occur, and because of the high concentration of population in cities. Since most flash flood casualties are caused by a lack of information, it is critical to generate accurate and detailed warnings of flash floods. However, deploying an infrastructure that solely monitor flash floods makes little economic sense, since the average periodicity of catastrophic flash floods exceeds the lifetime of a typical sensor network. To address this issue, we propose a new sensing device that can simultaneously monitor urban flash floods and another phenomenon of interest (traffic congestion on the present case). This sensing device is based on the combination of an ultrasonic rangefinder with one or multiple remote temperature sensors. We show an implementation of this device, and illustrate its performance in both traffic flow and flash flood sensing. Field data shows that the sensor can detect vehicles with a 99% accuracy, in addition to estimating their speed and classifying them in function of their length. The same sensor can also monitor urban water levels with an accuracy of less than 2 cm. Two of the sensors have been deployed in a flood prone area, where they captured the only (minor) flash flood that occurred over the one-year test period, with no false detection, and an agreement in the estimated water level estimate (during the flash flood event) of about 2 cm.

Time scales for scour below pipelines and around vertical piles due to nonlinear random waves

Scipedia content — Thu, 28 Jan 2021 19:59:48 +0100

This paper provides a practical stochastic method by which the time scale for the equilibrium scour depth below pipelines and around slender vertical piles exposed to long-crested (2D) and short-crested (3D) nonlinear random waves can be derived. The approach is based on assuming the waves to be a stationary narrow-band random process, adopting the Forristall (2000) wave crest height distribution representing both 2D and 3D nonlinear random waves. Moreover, the time scale for regular waves given by Sumer and Fredsoe (2002) are used. Examples of results are also presented.

Advanced RADAR Sensors Modeling for Driving Assistance Systems Testing

Scipedia content — Thu, 28 Jan 2021 19:57:26 +0100

EuCAP 2016 - 10th European Conference on Antennas and Propagation, Davos, SUISSE, 10-/04/2016 - 15/04/2016; With Advanced Driver Assistance Systems (ADAS) getting always more sophisticated, the related Virtual Prototyping platforms have to propose a very high level of accuracy with improved flexibility regarding vehicles, sensors, environments and scenarios. In this paper a new strategy is introduced for RADAR sensors modeling aimed at allowing high accuracy while limiting the related development efforts.

Motion Planning for Urban Autonomous Driving using Bezier Curves and MPC

Scipedia content — Thu, 28 Jan 2021 19:56:32 +0100

International audience; — This paper presents a real-time motion planning scheme for urban autonomous driving that will be deployed as a basis for cooperative maneuvers defined in the European project AutoNet2030. We use a path-velocity decomposition approach to separate the motion planning problem into a path planning problem and a velocity planning problem. The path planner first generates a collision-free piecewise linear path and then uses quintic Bézier curves to smooth the path with C 2 continuity. A derive-free optimization technique Subplex is used to further smooth the curvature of the path in a best-effort basis. The velocity planner generates an optimal velocity profile along the reference path using Model Predictive Control (MPC), taking into account user preferences and cooperative maneuver requirements. Simulation results are presented to validate the approach, with special focus on the flexibility, cooperative-awareness and efficiency of the algorithms.

Cost-Benefit Analysis of a Novel DC Fast-Charging Station with a Local Battery Storage for EVs

Scipedia content — Thu, 28 Jan 2021 19:55:50 +0100

The increasing penetration of Electric Vehicles (EVs) and their charging systems is representing new high-power consumption loads for the distribution system operators (DSOs). To solve the problem of the EV range in terms of driving kilometers, the car manufacturers have invested resources on new EV models by increasing the size of the batteries. To satisfy EV load demand of the new EV models in urban areas the public DC Fast-Charging Station (DCFCS) is indispensable to recharge EVs rapidly. The introduction of the Battery Energy Storage within the DCFCSs is considered in this paper an alternative solution to reduce the operational costs of the charging stations as well as the ability to mitigate negative impacts during the congestion on the power grids. An accurate description of the DCFCS and its design system has been implemented, which is able to decouple the peak load demand caused by EVs on the main grid and decrease the connection fees. Finally, an economic evaluation is done to evaluate the feasibility and the cost-benefit analysis (CBA) of the DCFCSs. The proposed approach considers various technical and economic issues, such as cost of installation, connection fees and life cycle cost of the batteries. The proposed cost-benefit analysis can be used to verify the effectiveness and applicability of DCFCS in large scale.

A data hiding approach for sensitive smartphone data

Scipedia content — Thu, 28 Jan 2021 19:54:18 +0100

We develop and evaluate a data hiding method that enables smartphones to encrypt and embed sensitive information into carrier streams of sensor data. Our evaluation considers multiple handsets and a variety of data types, and we demonstrate that our method has a computational cost that allows real-time data hiding on smartphones with negligible distortion of the carrier stream. These characteristics make it suitable for smartphone applications involving privacy-sensitive data such as medical monitoring systems and digital forensics tools.

Screening methodology for bank erosion estimation at pipeline watercourse crossings

Scipedia content — Thu, 28 Jan 2021 19:53:06 +0100

screening level model was developed to estimate bank erosion at pipeline watercourse crossings to provide estimates of the probability of pipeline exposure resulting from various extreme flood events. The model uses estimates of flood duration and maximum water velocity during flooding to predict the amount of bank erosion that would occur and compares the results to the horizontal “setback” distance. When the predicted horizontal erosion is equal to horizontal distance between the pipeline and the bank position, the probability of that flood occurring is equal to the probability of pipeline exposure due to bank erosion. The results of the bank erosion calculation can then be compared to: the probability of the flood causing exposure by scour and/or avulsion; regulatory acceptance criteria for pipelines; and company integrity objectives to assess the need for additional investigation or proactive mitigation.

Prediction of Transportation Network Based on PageRank Algorithm

Scipedia content — Thu, 28 Jan 2021 19:52:19 +0100

a new research field, network science is gaining more and more attention with the networking of human society. Urban traffic is a kind of typical complex network, the analysis of its property is becoming a hot topic. The research of the urban traffic network congestion is presented in this paper. Through in-depth analysis of the urban traffic network features and a variety of circumstances which lead to traffic congestion, we build a complex network model which the nodes represent specific roads. In this model, we get the PageRank algorithm improved which in the field of search engines, and we apply it to a transportation network. Then we predict the situations of urban traffic network congestion with this model. Finally, comprehensive tests are conducted with the data from the monitoring of real roads. The experimental results show that the model proposed in this paper can simulate the change of traffic flow, which has a good forecast effect on the urban traffic congestion and also has a referential value to the planning of urban traffic.

FACTS2: Extended simulation framework for ATM communication demand analysis of Europe

Scipedia content — Thu, 28 Jan 2021 19:44:38 +0100

The modernization of the European air transportation system will increase the need for data communication. This creates the need for large-scale simulations to ascertain that new aeronautical communication systems fulfil the requirements of future air traffic management communication. The German Aerospace Center (DLR) created a framework for such simulations based on service-oriented software architecture. The Framework for Aeronautical Communications and Traffic Simulations 2 (FACTS2) is based on the concept of service oriented simulation: Creating complex simulations from simple software building blocks called "services". In this paper we describe the extension of the FACTS2 simulation framework by a communication load simulation suitable to feed aeronautical communication technology evaluations. We create a simulation toolchain from existing and new FACTS2 simulation services and interconnect them using XML and the UNIX pipe interface. We demonstrate our method with the air traffic management communication demand analysis of the continental European airspace. Our results indicate that the expected air traffic management communication load for the ESRA08 area is below 3,000 kbps in the ground-to-air direction and less than 1,000 kbps in the air-to ground direction until 2035.

Energy consumption minimization in railway planning

Scipedia content — Thu, 28 Jan 2021 19:43:42 +0100

EEEIC 2016 - 17th IEEE International Conference on Environment and Electrical Engineering , Florence, Italie, 06-/06/2016 - 08/06/2016; The estimation of running times is essential for the railway timetable definition. The trains travel duration must respect some constraints, which depend on the railway network. Usually, the running times minimize the trains travel duration on the railway network. They are typically calculated without considering the energy consumption. The green transportation has recently gained significant importance. In this paper, the energy consumption in the running times estimation is taken into account by defining an optimization problem to calculate the running times for the railway timetable definition. This optimization problem finds the running times which minimize the energy consumption. Precisely, an algorithm to handle the optimization problem with the integration platform for multiobjective and multi-disciplinary optimization modeFRONTIER is defined. The algorithm is tested on a case study and the results are validated with the OpenTrack Railway Simulation Tool.

Rational Stress Limits and Load Factors for Finite Element Analyses in Pipeline Applications: Part III — Elastic-Plastic Load Factor Development

Scipedia content — Thu, 28 Jan 2021 19:42:32 +0100

In this paper, a methodology is presented to develop load factors for use in elastic-plastic assessments of pipelines and their components. The load factors are based on the pipe material properties and the ASME pipeline code’s design margin for the service and location of the pipeline installation [1, 2]. These codes are recognized by 49 CFR 192 and 195 [3, 4]."/jats:p" "jats:p"Minimum required load factors for internal pressure loads can be derived analytically based on design equations from the ASME B31 piping codes and minimum material requirements for API 5L line pipe [6]. Once the load factor is established for a particular case, the elastic-plastic methodology may be used in the Finite Element Analysis (FEA) of pipelines and related components. This methodology is particularly useful in the assessment of existing systems when linear elastic numerical analysis shows that local stresses may exceed the elastic design limits."/jats:p" "jats:p"Two case studies are presented showing analyses performed with Abaqus [5], a commercial, general purpose FEA software package. The first case study provides an assessment of a large diameter elbow where the stress on the outer fibers of the intrados exceeded the longitudinal stress limits from B31.8. The second case study examines an assessment of a tee connection where the stresses on the ID exceeded the yield strength of the component. In addition to the case studies, the paper also presents the results of a full-scale test that demonstrated what margin was present when the numerical calculations were based on specified minimum properties."/jats:p" "jats:p"This paper is not intended to revise or replace any provision of B31.4 and/or B31.8 [1, 2]. Instead, it provides the means for calculating load factors that can be used with an elastic-plastic analysis approach in a manner that provides the same design margins as the ASME B31 codes. The approach described in this paper is intended for use in the detailed FEA of pipelines and their associated components.

Smart mobility: A survey

Scipedia content — Thu, 28 Jan 2021 19:27:53 +0100

Internet of Things (IoT) describes a world where everyday objects are always connected to the Internet, allowing them to communicate and interact with each other. By connecting these everyday objects to the Internet and making them available everywhere at any time, IoT allows to remotely monitor, manage, and gather status information about them and their surrounding environment. IoT is a revolutionary concept that brought new experiences to everyday life and enabled Smart City initiatives all over the world. These initiatives are using a combination of technology paired with physical infrastructure and services, to improve people's quality of life. One of the high-priority domain to support the Smart City's vision is the field of Smart Mobility. This paper reviews the current IoT approaches and concepts related to Smart Cities and Smart Mobility. In addition, it analyzes distinct features and numerous applications covering both Intelligent Transportation and Real Time Traffic Management Systems.

Controller team possibilities for sectorless air traffic management

Scipedia content — Thu, 28 Jan 2021 19:27:24 +0100

Sectorless air traffic management is an en-route concept, which eliminates the need for control sectors. Instead of assigning a geographic area (sector), air traffic controllers are assigned certain aircraft. Controllers are responsible for their assigned aircraft all the way from entry to exit. In previous simulations, one controller was responsible for six aircraft at the same time. As these aircraft can be located anywhere in the sectorless airspace, controllers were provided with one traffic display for each assigned aircraft. This discussion paper suggests other possibili-ties for providing traffic information to sectorless air traffic controllers. Instead of having one traffic display for each aircraft under control (tiled display), controllers could work with a general map, a zoom display to magnify certain traffic situations, or a combination of such displays. We revisit the concept of controller teams and explore alternatives. In addition to working alone or in pairs of executive and controller, the sectorless air traffic management concept opens possibilities for innovative teamwork. For example, there could be a team of one coordinator and several executives, or even a control-room team. This paper gives examples of new display and team ideas and discusses their respective advantages and disadvantages. We argue that the way traffic information is displayed to controllers affects their mental models and working methods. In addition, we provide results on the tiled display from previous simulations and introduce ideas for future research.

Road Network Traffic Congestion Evaluation Simulation Model based on Complex Network

Scipedia content — Thu, 28 Jan 2021 19:24:23 +0100

To deeply analyze the dynamic evolution process of traffic congestion on road network and provide policy analysis tools for traffic congestion governance, the article proposed a traffic congestion evaluation simulation model on based on complex road network. By introducing section impedance concept into complex network theories, it achieved combination of topology model and traffic model on road network. Moreover, it proposed assessment methods on road network access capacity traversing in virtual test vehicles which could assess the road access capacity under different road network. At last, on PC system, it managed complete network congestion assessment simulation system, and made simulation analysis on factors affecting the access capacity such as number of road congestion, traffic flow and road network topology. The simulation results are same with classical theoretical analysis on traffic, and could reflect more dynamic process information, which shown that the model could make traffic network congestion assessment accurately and effectively as well as provide basis for related traffic congestion management decisions. Introduction In recent years, several researching groups had conducted researches on structural analysis of traffic network. Research results of Hui Yong Et al shown that public traffic network in Shanghai and Beijing presented a structural feature of Small World and Power Law. While Zong Yueguang research further proved the complex nature of network structure in traffic network. In his doctor papers, Wu Jianjun had made systematic analysis of complex network nature of traffic network structure, while Zhang Chen Et al.had analyzed the bus line Network Topology in Shanghai and Zhang Yong Et al. had conducted further study on robustness of traffic network on the basis of traffic network complexity. Traffic Flow Simulation had become a research focus in recent years, while the existing traffic simulation research still concentrated on simulation of dynamic evolution of microscopic traffic flow, which lack of consideration of traffic network structural factors. On the other hand, most of researches on traffic network concerned more about the structural characteristics of traffic network while lacked of traffic flow consideration. Through transmission dynamics characteristics of traffic, Li Shubin Et al. had studied the impact on traffic congestion by traffic network topology. Sun H Et al. had proposed the traffic dynamic theoretical model taking traffic network topology into consideration. By making full use of computing power of calculation simulation technology, the article would base on complex network theory and by section impedance model, introduce the traffic network congestion simulating evaluation taking traffic flow into consideration to achieve fine-grained. Construction of traffic network congestion evaluation and simulation model based on complex network Complex network theory Small-World model was firstly proposed by D. Watts Et al. and was used to simulate relation of human and society. The following researches shown that many structures in human living environment could be presented by Small-World model, such as grid structure and traffic network. 6th International Conference on Machinery, Materials, Environment, Biotechnology and Computer (MMEBC 2016) © 2016. The authors Published by Atlantis Press 2107 Small-World model could be described with Figure 1. Figure 1 Small-World model of D. Watts As shown in Figure 1, Small-World Topology was a topology between rule model (as shown in left side of Figure 1) and completely random model (as shown in right side of Figure 1). In Small-World structure, sides with some proportion (Pr) would be treated in random while most sides would remain a rule structure. Random sides connected knots with distant relation, thus it is also called "Short Cut". The mean value, which defined the minimum distance between two random points in the topology, is called characteristic path of the topology. The existence of random sides significantly shorten characteristic path length of the topology. Decrease of characteristic path promoted the accessibility and connectivity of topology. In following researches, several teams had studied the information transmission and robustness of Small-World structure [12]. Results of existing researches shown that there is Small-World structure in city traffic network. In certain area, sections had close connection while different areas were connected with main lines. Sections within area are equal to rule sides of Small-World while the main lines between areas could be regarded as Short Cut side of Small-World, subject to Small-World structure, a simulation model of traffic network could be created. Section impedance model Section impedance model was used to analyze the section delay issues caused by traffic flow, including time of vehicles through section and waiting time at intersection. Section impedance model was the most common model in practice as a computing model proposed by FHWA [2], as shown in Formula 1: ttaa = ttaa �1 + αα( xxaa ccaa � )ββ� (1) Of which ta means section impedance, ta means the impedance value of section with traffic flow of 0. α and β are correction factors, in general, α = 0.15 and β = 4.0.xa means flow on section and ca means the actual accessibility of section other than the maximum accessibility. When the flow increased to ca , the related impedance value would be 1.15 times of ta. A problem lied in such model existence was that, when the traffic flow was infinitely close to section accessibility, the section impedance would not approach infinity, which is non-conformance to fact. In fact, when the traffic flow exceeded section accessibility, the section would be completed blocked, the infinity through section impedance would be regarded as the section was removed from the network. Thus, Davidson proposed a new section impedance calculation model, as shown in Formula 2[3]: ttaa = ttaa �1 + JJ( xxaa (ccaa − xxaa) � )� (2) Of which J is correction factor and ca is section accessibilty, xa ca ⁄ is general unit in traffic engineering, usually called ratio of "flow/capacity" or congestion coefficient, other symbols in formula had the same meaning with that in Formula 1. According to Formula 2, when the congestion coefficient is 1, the section impedance would approach infinity. When the traffic flow is 0, the section impedance would be ta. Compared to the impedance model of FHWA, this model could better reflect the actual flow characteristics of the section. Thus, on construction of section Increasing randomness Regular Small World Random

Towards SDN/NFV-enabled satellite ground segment systems: End-to-End Traffic Engineering Use Case

Scipedia content — Thu, 28 Jan 2021 19:22:28 +0100

Key features of satellite communications such as wide-scale coverage, broadcast/multicast support and high availability, together with significant amounts of new satellite capacity coming online, anticipate new opportunities for satellite communications services as an integral part within upcoming 5G systems. To materialize these opportunities, satellite communications services have to be provisioned and operated in a more flexible, agile and cost-effective manner than done today. In this context, this paper firstly describes the architecture of a satellite ground segment system that builds on the introduction of Software Defined Networking (SDN) and Network Function Virtualization (NFV) technologies and then examines a use case for the realization of End-to-End Traffic Engineering in a combined terrestrial-satellite network used for mobile backhauling.

Peer Reviewed

Document type: Conference object

Assessing the impacts of goods deliveries’ double line parking on the overall traffic under realistic conditions

Scipedia content — Thu, 28 Jan 2021 19:21:25 +0100

International audience; This paper proposes a framework for quantifying the macroscopic impacts of delivery goods made by double-parked vehicles in urban arterial using microscopic simulation. It is applied to a real urban corridor: the Lafayette Avenue in Lyon (France). The framework combines traffic states with stochastic and microscopic freight demand generation model, i.e. the delivery movements and the delivery duration. Cooperative and competitive scenarios are considered. Impacts of goods delivery have been captured in a traffic evaluation model. The results of these configurations’ assessment are discussed. Finally, practical implications for transport planners are highlighted.