Scipedia: Documents published in 2011

Transport capacity constraints on the mass transit system: a systemic analysis

Scipedia content — Mon, 22 Mar 2021 23:51:26 +0100

International audience; A public passenger transit system is complex, because it involves two types of traffic unit, passengers and vehicles. The system operations require supplying passengers with stations where they can access vehicles and then travel in them between stations. These operations are subject to various capacity constraints, depending on the traffic type and the situation in the system. The article provides a framework for the analysis of a mass transit system, broken down into four subsystems that respectively pertain to the Passenger, the Vehicle, the Station and the Line. Each subsystem consists of several components that are involved in the system processes and interactions. Within this framework, capacity phenomena are identified, described qualitatively and classified into seven broad categories, namely: (i) the vehicle capacity of an infrastructure; (ii) the vehicle fleet; (iii) the passenger capacity of a vehicle; (iv) the passenger capacity of a route; (v) the passenger capacity of a station; (vi) the vehicle storage and movement capacity of a station; (vii) the capacity of a station for interface with personal transport modes. Moreover, it is shown that capacity phenomena can interact in congestion gears, which impair capacity. Lastly, there are complex retroactive effects that involve either network management or demand behaviour (through route choice which depends on quality of service hence on congestion). © 2011 The Author(s).

Document type: Article

Is European school transport safe?—The need for a “door-to-door” perspective

Scipedia content — Mon, 22 Mar 2021 21:37:10 +0100

To identify and establish the number and aetiology behind children being killed or injured during school transport from a door-to-door perspective by using experience from Sweden and the UK. Available crash data were analysed. In total, 361 children in Sweden during 1994–2001, i.e. 24% of the 1,515 identified children aged 6–16 who were injured or killed were identified in 256 school transport events. The predominant reason for being killed or injured when travelling on school transportation was when children were outside the bus (74%), either when passing the bus to cross the street, running in front of the bus (21%) or behind the bus (30%). Contrary to the general belief that children older than 12 are mature enough to handle traffic, more than 50% of the fatal injuries in Sweden affected children aged 13–16. Similar results were found in the UK. The afternoon school journeys, pedestrians after alighting from the bus, and those in situations that deviated from their normal routine were found to be particularly vulnerable. The travel chain perspective/or door to door perspective offers a promising approach for understanding school transport risks and for identifying effective countermeasures; including around bus stops and on the way to/from the bus stop. Data collection needs to be revised to reflect this approach.

Document type: Article

Multicast Network Performance using Multiprotocol Label Switching Together with Signaling Standards

Scipedia content — Mon, 22 Mar 2021 19:36:23 +0100

Este artículo expone los resultados de una evaluación del sistema de conmutación de etiquetas multiprotocolo (MPLS) como tecnología multidifusión (envío de datos desde una fuente a varios usuarios) utilizando el protocolo de reserva de recursos con extensiones de ingeniería de tráfico (RSVP-TE). Para determinar las ventajas de ésta implementación, el sistema se compara con el funcionamiento de una red de transmisión de data-gramas IP basada en el estándar independiente multienvío en modo denso (PIM-DM). Las simulaciones son realizadas utilizando los paquetes de software OPNET y GNS-3. Se concluye que la conmutación de etiquetas MPLS utilizando RSVP-TE posee ventajas muy superiores a otras arquitecturas. Dichas ventajas incluyen una respuesta más rápida ante fallas en los enlaces, menor retardo y fluctuación y la posibilidad de reservar ancho de banda para tráfico con prioridad. The present article shows the results of the evaluation of Multiprotocol Label Switching (MPLS) as a technology for the transfer of multicast traffic (sending data from one source to several users) through the use of signaling protocols such as RSVP-TE. To identify the advantages of such an implementation, the setup in this work is compared to a multicast IP network based on the PIM-DM protocol. Simulations were carried out using software packages such as OPNET and GNS-3. It was found that MPLS+RSVP-TE offers greater advantages over other architectures. Some of these advantages include quicker link-failure response, shorter delays and less jitter, and also the possibility to reserve bandwidth for priority traffic.

Document type: Article

Influence of the stop/start system on CO2 emissions of a diesel vehicle in urban traffic

Scipedia content — Mon, 22 Mar 2021 19:34:03 +0100

This paper presents measurements of carbon dioxide (CO2) emission and efficiency of stop/start technology on a diesel vehicle in urban traffic. Two four-wheel-drive diesel vehicles with on-board exhaust emission and vehicle activity measurement systems were tested in two urban driving circuits representative of downtown Madrid. The vehicles had similar turbocharged and intercooled diesel engines fulfilling the same Euro 4 emissions regulation; but one had an improved engine incorporating stop/start technology. CO2 emission reduction of more than 20% for the car equipped with the stop/start system was obtained. Regardless of the variability in driving style, the grade and type of streets, traffic congestion, and the engine operating temperature, the car equipped with the stop/start system has intrinsically a lower CO2 emission factor.

Document type: Article

Disruption-Free Green Traffic Engineering with NotVia Fast Reroute

Scipedia content — Tue, 16 Feb 2021 13:22:26 +0100

We introduce a practical green traffic engineering technique in fast reroute (FRR) enabled IP networks which is able to avoid transient routing disruption caused by sleeping-mode reconfigurations during runtime. Following the description on the time-driven "delegate before sleep" operations based on the NotVia FRR platform, we also propose a simple optimization algorithm for selecting sleeping links and determining the sleeping duration according to dynamic traffic behaviors. The aim of the approach is to avoid traffic congestion due to reduced network capabilities during off-peak operation time.

Sleep and Alertness in North Sea Helicopter Operations

Scipedia content — Tue, 16 Feb 2021 13:19:17 +0100

Introduction : Dutch North Sea helicopter operations are characterized by multiple sector flights to offshore platforms under difficult environmental conditions. In the context of a Ministry of Transport program to improve safety levels of helicopter operations, we assessed effects of pre-duty sleep, pre-duty travel time, and workload factors on the alertness and vigilance of pilots. Method : Data of 24 pilots comprising 224 duty days were analyzed. Pilots performed 10-min test sessions after wake up, pre-duty, halfway-duty, end-duty, and at bedtime during normal duty rosters. Test sessions included completion of a vigilance task, vigor and sleepiness ratings, and questions on sleep and operational characteristics. Pilots wore an actometer to objectify sleep data. Results : Vigor scores were high and sleepiness levels were low during the entire flight duty periods (FDPs), while vigilance was impaired only 6.8% in the course of the FDPs. Pre-duty sleep before morning duties was 1.5 h shorter than sleep before duties starting after midday. Longer pre-duty travel time was correlated with shorter pre-duty sleep and lower vigilance levels during duty. Conclusion : During the FDPs, pilots maintained alertness and vigilance levels that may be considered safe in terms of alertness-related flight safety. This favorable outcome may be attributed to reasonable length of FDPs, favorable circadian start and end times of duties, sufficient opportunities for restorative pre-duty sleep, and relatively good weather conditions. Appropriate FDP scheduling is an important measure to optimize alertness of helicopter pilots who have to cope with adverse environmental conditions and limited landing and air traffic control facilities.

Differential Techniques for High-Resolution BOTDA: An Analytical Approach

Scipedia content — Tue, 16 Feb 2021 13:17:08 +0100

We derive an analytical solution for the differential gain in Brillouin optical time-domain analysis. The found solution gives insight into the mechanisms leading to the high-spatial and spectral resolution observed in differential schemes. An experimental test has been carried out to validate the analytical solution.

On the electrification of road transport - Learning rates and price forecasts for hybrid-electric and battery-electric vehicles

Scipedia content — Tue, 16 Feb 2021 13:14:02 +0100

Hybrid-electric vehicles (HEVs) and battery-electric vehicles (BEVs) are currently more expensive than conventional passenger cars but may become cheaper due to technological learning. Here, we obtain insight into the prospects of future price decline by establishing ex-post learning rates for HEVs and ex-ante price forecasts for HEVs and BEVs. Since 1997, HEVs have shown a robust decline in their price and price differential at learning rates of 7±2% and 23±5%, respectively. By 2010, HEVs were only 31±22€2010kW−1 more expensive than conventional cars. Mass-produced BEVs are currently introduced into the market at prices of 479±171€2010kW−1, which is 285±213€2010kW−1 and 316±209€2010kW−1 more expensive than HEVs and conventional cars. Our forecast suggests that price breakeven with these vehicles may only be achieved by 2026 and 2032, when 50 and 80 million BEVs, respectively, would have been produced worldwide. We estimate that BEVs may require until then global learning investments of 100–150 billion € which is less than the global subsidies for fossil fuel consumption paid in 2009. These findings suggest that HEVs, including plug-in HEVs, could become the dominant vehicle technology in the next two decades, while BEVs may require long-term policy support.

Evaluating cooperative ITS applications for sustainable and safe mobility with iTETRIS

Scipedia content — Tue, 16 Feb 2021 13:08:11 +0100

We see today urban traffic growing faster than the capacity of road infrastructures and posing a challenge to traffic safety and to the sustainability of our mobility. In this context, cooperative mobility strategies are expected to become a key enabler for a better usage of the available road infrastructures. Considering the estimation by the American Automotive Association of the yearly cost of traffic safety to 160 billion USD, or the yearly cost of traffic congestion to 50 billion EUR by the European Commission, local road authorities are facing a strategic challenge to develop and propose cooperative ITS applications to the public. The question is how can the actual worth of investment and effectiveness of cooperative ITS applications on city road traffic be estimated? To answer this question, new tools capable of providing realistic and large scale assessments and guidelines to road authorities are required. To this aim, we need to define an extensible architecture allowing the interactions of realistic models spanning from wireless communication to traffic and mechanical engineering, and provide a modular integration methodology of cooperative ITS applications. In this talk, we present the outcome of the recently completed work of the European FP7 project iTETRIS during which an open, ETSI standard compliant, and flexible ITS simulation platform has been developed. We describe the modeling challenges, design choices, selected scenarios, and illustrate the benefits and functionalities of the iTETRIS platform through the integration of exemplary key cooperative ITS applications. We further discuss future evolutions, trends, and potential roles of simulations and the iTETRIS platform to reach sustainable and safe mobility resulting in economical, social and ecological wealth improvements.

The influence of automation support on performance, workload, and situation awareness of Air Traffic Controllers

Scipedia content — Tue, 16 Feb 2021 13:00:44 +0100

decision support tool, called Speed and Route Advisor (SARA), was developed at Schiphol Airport to help air traffic controllers achieve increased accuracy in traffic delivery. Its influence on controller performance, workload, and situation awareness was evaluated in a real-time simulation and in an operational trial. The findings indicate that this additional system support is necessary to achieve higher accuracy without increasing the controllers; workload. At the same time, controllers must stay in the loop to maintain situation awareness. This must be kept in mind while designing decision support systems such as SARA. © 2012 Taylor and Francis Group, LLC.

Experimental demonstration of impairment-aware PCE for multi-bit-rate WSONs

Scipedia content — Tue, 16 Feb 2021 12:56:58 +0100

In emerging multi-bit-rate wavelength switched optical networks (WSONs), the coexistence of lightpaths operating at different bit-rates and modulation formats (e.g., based on amplitude and phase modulation) induces relevant traffic dependent detrimental effects that need to be considered during impairment-aware routing and wavelength assignment (IA-RWA). The considerable complexity of IA-RWA computation has driven the Internet Engineering Task Force (IETF) to propose specific path computation element (PCE) architectures in support of IA-RWA for WSONs. In this paper, following the IETF indications, we expand two PCE architectures and experimentally evaluate five different PCE architectural solutions, performing either combined or separated impairment estimation and RWA, with on-line and off-line computation of impairment validated paths, and with the possible utilization of a novel PCE Protocol (PCEP) extension. Results in terms of traffic engineering performance, path computation delivery time and amount of exchanged PCEP messages are reported and discussed to highlight the benefits and application scenarios of the considered PCE architectures.

Optimizing network load balancing: an hybridization approach of metaheuristics with column generation

Scipedia content — Tue, 16 Feb 2021 12:56:06 +0100

Given a capacitated telecommunications network with single path routing and an estimated traffic demand matrix, we aim to determine the routing path of each traffic commodity such that the whole set of paths provide an optimal network load balancing. In a recent paper, we have proposed a column generation based heuristic where, in the first step, we use column generation to solve a linear programming relaxation of the original problem (obtaining, in this way, a lower bound and a set of paths for each commodity) and, in the second step, we apply a multi-start local search with path relinking heuristic on the solution space defined by the paths of the first step. Here, we propose a hybridization approach of the metaheuristic with column generation that can be seen as an enhanced version of the previous approach: we run column generation not only at the beginning (to define the initial search space) but also during the search. These additional column generation steps consist in solving a perturbed problem defined by the incumbent solution. In the previous paper, we have shown that the first approach is efficient in obtaining near optimal routing solutions within short running times. With the enhanced version, we show through computational results that the additional paths, introduced by the additional column generation steps, either improve the efficiency of the algorithm or show similar efficiency in the cases where the original algorithm is already very efficient. This work has been conducted under the project PTDC/EIA-EIA/100645/2008 "SearchCol: Meta-heuristic Search by Column generation" (funded by FCT) and under the European FP7 Network of Excellence "Euro-NF". Dorabella Santos was funded by Portuguese FCT under post-doc grant SFRH/BPD/41581/2007. Michal Pioro was funded by Polish Ministry of Science and Higher Education under research grant N517 397334.

Historical variation in the capital costs of natural gas, carbon dioxide and hydrogen pipelines and implications for future infrastructure

Scipedia content — Tue, 16 Feb 2021 12:52:24 +0100

The construction of large pipeline infrastructures for CH 4 , CO 2 and H 2 transportation usually constitutes a major and time-consuming undertaking, because of safety and environmental issues, legal and (geo)political siting arguments, technically un-trivial installation processes, and/or high investment cost requirements. In this paper we focus on the latter and present an overview of both the total costs and cost components of the transmission of these three gases via pipelines. Possible intricacies and external factors that strongly influence these costs, like the choice of location and terrain, are also included in our analysis. Our cost breakdown estimates are based on transportation data for CH 4 , which we adjust for CO 2 and H 2 in order to account for the specific additional characteristics of these two gases. Our main finding is that the economics of CH 4 , CO 2 and H 2 transportation through pipelines are volatile. In particular for CH 4 and CO 2 the overall trend seems that pipeline construction costs have not decreased over recent decades or, at least, that possible reductions in overall costs have been outshadowed by the variability in the costs of key inputs. We speculate on the reasons why we observe limited learning-by-doing effects and expect that negligible construction cost reductions for future CH 4 and CO 2 pipeline projects will materialize. Cost data of individual pipeline projects may strongly deviate from the global average because of national or regional effects, such as related to varying costs of labor and fluctuating market prices of components like steel. We conclude that only in an optimistic scenario we may observe learning effects for H 2 pipeline construction activity in the future, but there are currently insufficient data to fully support the limited evidence for this claim, so that the uncertainty of this prediction for now remains large.

Going soft: on how Subjective Variables Explain Modal Choices for Leisure Travel

Scipedia content — Tue, 16 Feb 2021 12:49:20 +0100

Most studies on the link between the built environment and modal choice characterize and model this relationship by objectively measureable characteristics such as density and diversity. Recently, within the debate on residential self-selection, attention has also been paid to the importance of subjective influences such as the individual’s perception of the built environment and his/her residential attitudes and preferences, resulting in models that take account of both the objective and subjective characteristics of the built environment. However, self-selection might occur on other points than residential location as well. Expanding the analysis to also include both objective and subjective characteristics at other model levels (i.e., not only stage of life characteristics but also personal lifestyles; not only car availability but also travel attitudes, not only modal choice but also mode specific attitudes) is the purpose of this paper. To this end, a modal choice model for leisure trips is developed using data on personal lifestyles and attitudes, collected via an Internet survey, and estimated using a path model consisting of a set of simultaneously estimated equations between observed variables. While controlling for subjective lifestyles and attitudes, the effects of the built environment and car availability on modal choice can more correctly be determined and thus insights into self-selection mechanisms can be gained. Moreover, we compared the results of a model with and without these subjective influences. The results show that subjective characteristics at various model levels are important decisive factors of modal choices for leisure travel.

TePiTri : a screening method for assessing terrorist-related pipeline transport risks

Scipedia content — Tue, 16 Feb 2021 12:36:57 +0100

The article proposes an approach to determine relative terrorist-related security risk levels of pipeline transportation. Pipeline routes are divided into smaller route segments. Subsequently, likelihood scores of possible terrorist-related incidents are determined per route segment and per transport route. A likelihood grade (LG) per pipeline transport route is determined. Next, the consequences of incident scenarios are quantitatively assessed and a consequence grade (CG) is determined. Using the LGs and CGs, pipeline routes' terrorist risk levels are determined. This leads to a user-friendly threat assessment tool, which can be used by pipeline security management to screen pipeline networks for terrorist-related risks. Security Journal (2012) 25, 173-186. doi:10.1057/sj.2011.17; published online 20 June 2011

Mobilità Urbana Sostenibile: strategie attuali e nuove sfide per le città europee

Scipedia content — Tue, 16 Feb 2021 12:36:17 +0100

Nel decennio 2001-2010 numerosi passi sono stati compiuti dall’Unione Europea per orientare le città europee verso forme di mobilità sostenibile. Finalità comune alle numerose iniziative messe in campo dall’UE è stata quella di promuovere, soprattutto nelle aree urbane, un aumento della mobilità – indispensabile per lo sviluppo competitivo delle città e per garantire ai cittadini elevate opportunità di accesso alle dotazioni urbane – e una contemporanea drastica riduzione dei significativi costi ambientali che ad essa risultano, a tutt’oggi, associati."br /"Strategie, iniziative e ricerche in ambito europeo sono state orientate, nel corso del decennio 2001-2010, a promuovere una sostanziale limitazione del trasporto individuale su gomma all’interno delle aree urbane e ad incentivare forme di mobilità sostenibile. Più specificamente, strategie e azioni sono state prioritariamente rivolte a: favorire innovazioni relative ai modi e ai mezzi del trasporto urbano; garantire un riequilibrio intermodale all’interno delle aree urbane, favorendo il trasporto pubblico, soprattutto su ferro, e gli spostamenti pedonali e ciclabili; superare la settorialità che ha a lungo caratterizzato la pianificazione dei trasporti, delineando processi di governo basati sull’integrazione tra politiche e strumenti per la pianificazione della città, dei trasporti e dell’ambiente (Galderisi, 2007). A partire dal 2007, l’Unione Europea ha ulteriormente e significativamente intensificato il proprio impegno per una riduzione dei costi ambientali della mobilità urbana: dal Libro Verde sul Trasporto Urbano, al Patto dei Sindaci mirato a coinvolgere attivamente le città europee nel percorso verso la sostenibilità energetica ed ambientale e, ancora, al più recente Libro Bianco sui Trasporti del 2011, numerose sono state le iniziative messe in campo dall’Unione Europea per dare concretezza e operatività agli indirizzi già delineati nel Libro Bianco del 2001."br /"Inoltre, le nuove sfide ambientali che le città, e non solo quelle europee, sono chiamate ad affrontare nel prossimo futuro, dai cambiamenti climatici ai crescenti costi e alla progressiva riduzione del petrolio (prospettiva di lungo termine ma di certo non trascurabile), hanno contribuito a rafforzare la centralità del tema della mobilità urbana anche in ambito scientifico e nuove prospettive di ricerca che inquadrano tale tematica nella più ampia griglia teorica della costruzione di città “resilienti” vanno sempre più chiaramente delineandosi."br /"Pertanto, a partire da una sintetica rassegna delle più recenti iniziative messe in campo dall’Unione Europea per una mobilità urbana sostenibile, il presente contributo focalizza l’attenzione sulla rilevante influenza che il concetto di resilienza sta oggi assumendo nella revisione delle politiche per la mobilità in ambito urbano e, soprattutto, nel fornire una decisiva spinta verso una più efficace integrazione tra governo delle trasformazioni urbane e governo della mobilità.

The environmental impact and risk assessment of CO2 capture, transport and storage – An evaluation of the knowledge base

Scipedia content — Tue, 16 Feb 2021 12:26:21 +0100

In this study, we identify and characterize known and new environmental consequences associated with CO 2 capture from power plants, transport by pipeline and storage in geological formations. We have reviewed (analogous) environmental impact assessment procedures and scientific literature on carbon capture and storage (CCS) options. Analogues include the construction of new power plants, transport of natural gas by pipelines, underground natural gas storage (UGS), natural gas production and enhanced oil recovery (EOR) projects. It is investigated whether crucial knowledge on environmental impacts is lacking that may postpone the implementation of CCS projects. This review shows that the capture of CO 2 from power plants results in a change in the environmental profile of the power plant. This change encompasses both increase and reduction of key atmospheric emissions, being: NO x , SO 2 , NH 3 , particulate matter, Hg, HF and HCl. The largest trade-offs are found for the emission of NO x and NH 3 when equipping power plants with post-combustion capture. Synergy is expected for SO 2 emissions, which are low for all power plants with CO 2 capture. An increase in water consumption ranging between 32% and 93% and an increase in waste and by-product creation with tens of kilotonnes annually is expected for a large-scale power plant (1 GW e ), but exact flows and composition are uncertain. The cross-media effects of CO 2 capture are found to be uncertain and to a large extent not quantified. For the assessment of the safety of CO 2 transport by pipeline at high pressure an important knowledge gap is the absence of validated release and dispersion models for CO 2 releases. We also highlight factors that result in some (not major) uncertainties when estimating the failure rates for CO 2 pipelines. Furthermore, uniform CO 2 exposure thresholds, detailed dose–response models and specific CO 2 pipeline regulation are absent. Most gaps in environmental information regarding the CCS chain are identified and characterized for the risk assessment of the underground, non-engineered, part of the storage activity. This uncertainty is considered to be larger for aquifers than for hydrocarbon reservoirs. Failure rates are found to be heavily based on expert opinions and the dose–response models for ecosystems or target species are not yet developed. Integration and validation of various sub-models describing fate and transport of CO 2 in various compartments of the geosphere is at an infant stage. In conclusion, it is not possible to execute a quantitative risk assessment for the non-engineered part of the storage activity with high confidence.

Distributed Sensing at Centimeter-Scale Spatial Resolution by BOFDA: Measurements and Signal Processing

Scipedia content — Tue, 16 Feb 2021 12:25:07 +0100

In this paper, we demonstrate high spatial (≈3 cm) and spectral (≈30 MHz) resolution Brillouin sensing by use of Brillouin optical frequency-domain analysis (BOFDA) and signal processing. An iterative method is employed to correct the acquired data from spurious effects associated to acoustic wave modulation and relevant in the high spatial resolution regime. Experimental tests demonstrate that the proposed algorithm allows to reconstruct the Brillouin shift profile with the full spatial resolution allowed by the system bandwidth.

Comparison of driver behaviour and saturation flow in China and the Netherlands

Scipedia content — Tue, 16 Feb 2021 12:21:13 +0100

In Chinese cities, the poor performance of signalised intersections is one of the causes of urban congestion. The reasons for this have been investigated through a comparative study of the saturation flow characteristics on intersections in three Chinese and two Netherlandish cities. The analysis shows that the utilisation of the roads around Chinese intersections is 20-30 worse compared to the Netherlands intersections. The first cause is the long start lag at Chinese intersections, which is mainly brought by the presence of conflicting vehicles and pedestrians at the beginning of the green phase. The further reasons for that phenomenon are the large size of the Chinese intersections and the limited utilisation of the available space. Another cause is the driver behaviour, that is, the long and irregular time headways and sudden lane changing on the observed Chinese intersections. Chinese drivers adapt themselves to the local conditions and behave differently from Dutch drivers, giving a less efficient traffic system. The different driver behaviour in China has the consequence that most microscopic simulation programmes have to be adapted, calibrated and validated for Chinese situations. © 2012 The Institution of Engineering and Technology.

Transient drift flux modelling of severe slugging in pipeline-riser systems

Scipedia content — Tue, 16 Feb 2021 12:18:50 +0100

large number of pipelines in the petroleum industry simultaneously transport gas and liquid. Transient behaviour of multiphase flow is frequently encountered in these pipelines. A common example is severe slugging that can occur in multiphase flow systems where a pipeline segment with a downward or even horizontal inclination is followed by a riser segment with an upward inclination. Transient flow conditions associated with severe slugging are relatively slow. Therefore, a transient drift flux model consisting of one momentum balance equation might suffice to express the dynamics of severe slugging. We present a transient drift flux model to simulate severe slugging phenomenon in pipeline-riser systems. The present model contains recently published correlations by Shi et al. for the drift flux slip model which cover the complete range of flow conditions without introducing any discontinuities in the calculated flow parameters. Thus, the transient simulations are converging rapidly and efficiently without applying any form of smoothing. The present model is tested against experimental data for severe slugging showing a better performance than previously published models.

Mobile applications discovery: A subscriber-centric approach

Scipedia content — Tue, 16 Feb 2021 12:12:34 +0100

Rapid adoption of smartphones and the business success of the Apple App Store have resulted in the rampant growth of mobile applications. Seeking new revenue opportunities from application development has created a gold rush. However, free or very cheap applications constitute a great bulk of the application downloads putting great pricing pressure on the developers. Furthermore, usage statistics suggest that most of the applications have been either one-trick applications or are downright useless, meriting no attention from the user beyond the first day. This is not surprising since cheap prices will dissuade developers from investing large sums of money to continue to develop more sophisticated, high quality applications. Developers have been complaining about the lack of visibility of their applications in stores that are beginning to resemble a high volume warehouse. It is clear that enhancing application discovery and building better marketing tools will be essential for the continued success of the mobile application marketplace and application stores. This paper proposes and investigates techniques for effective discovery of applications by matching user interests with application characteristics, with a special focus on adapting classical data mining techniques to user ratings of the applications. The user ratings are leveraged to make recommendations on potential applications of interest. Publisher's Version

Unlocking the potential of time-driven activity-based costing for small logistics companies

Scipedia content — Tue, 16 Feb 2021 12:09:38 +0100

This paper reports on the development of a time-driven activity-based costing (TDABC) model in a small-sized road transport and logistics company. Activity-based costing (ABC) leads to increased accuracy benefiting decision-making, but the costs of implementation can be high. TDABC tries to overcome some of the disadvantages of ABC and seems particularly useful for the road transport and logistics sector. We find that small firms can benefit from TDABC because of the use of simplified parameters. However, the lack of quantitative data on cost drivers remains a problem. To enhance the effectiveness and efficiency of TDABC, a thorough redesign of the company's recording system is recommended. © 2012 Copyright Taylor and Francis Group, LLC.

The climate value of cycling

Scipedia content — Tue, 16 Feb 2021 12:05:01 +0100

The reduction of CO 2 emissions constitutes one of the largest challenges of the current era. Sustainable transportation, and especially cycling, can contribute to the mitigation of CO 2 emissions since cycling possesses an intrinsic zero‐emission value. Few studies have been conducted that appraise the CO 2 reduction potential of cycling. Opportunity costs enable the estimation of avoided CO 2 emissions resulting from bicycle trips. The methodology developed in this research allows the attribution of a climate value to cycling by substituting bicycle trips with their most likely alternative transportation modes and calculating the resulting additional CO 2 emissions. The methodology uses data on the current modal shares of cycling mobility, the competition of cycling with other transportation modes, and CO 2 emission factors to calculate the climate value of cycling. When it is assumed that the avoided CO 2 emissions of cycling mobility could be traded on financial carbon markets, the climate value of cycling represents a monetary value. Application of the methodology to the case of Bogota, Colombia — a city with a current bicycle modal share of 3.3% on a total of 10 million daily trips — results in a climate value of cycling of 55,115 tons of CO 2 per year, corresponding to an economic value of between 1 and 7 million US dollars when traded on the carbon market.

A small step toward environmentally sustainable transport? The media debate over the Finnish carbon dioxide-based car tax reform

Scipedia content — Tue, 16 Feb 2021 12:02:20 +0100

Societies are increasingly characterised by increasing mobility of people and materials. Consequently, harmful environmental impacts of transport are likely to increase unless specific policies aimed at mitigating these impacts can be successfully implemented. Based on EU-level requirements for carbon dioxide emission reductions, a car tax reform was enacted in Finland in 2008. By using the environmental protection process (EPP) framework as a conceptual tool, we perform a quantitative content analysis of media discussion of the car tax reform. The EPP framework is an integrative tool, aimed at an overall view of the characteristics of environmental problems and mitigation measures. The results show that societal factors, emissions, measures and the potential side-effects of the reform dominated the media discussion. Short-term impacts were emphasised over longer-term perspectives in the discussion’s future-orientation. Overall, it seems that in spite of a relatively wide-ranging discussion, the media debate contributed only marginally to public understanding of the prerequisites for environmentally sustainable transport.

Estimation of Stray Current From a DC-Electrified Railway and Impressed Potential on a Buried Pipe

Scipedia content — Tue, 16 Feb 2021 12:01:50 +0100

DC-electrified traction systems are a potential source of stray current that may corrode internal and external structures and installations. The stray current intensity depends on several factors (traction current, rail insulation, concrete mat and piers resistance), that are accounted for in the proposed model. The case of a viaduct and a victim-buried pipeline is considered in detail, and the estimated impressed voltage on the pipe is compared successfully with experimental results.

Winning or losing from dynamic bottleneck congestion pricing?

Scipedia content — Tue, 16 Feb 2021 11:52:29 +0100

This paper analyses the efficiency and distributional impacts of congestion pricing in Vickrey's (1969) dynamic bottleneck model of congestion, allowing for continuous distributions of values of time and schedule delay. We find that congestion pricing can leave a majority of travellers better off even without returning the toll revenues to them. We also find that the consumer surplus losses or gains from tolling are not strictly monotonic in the value of time, because they also depend on the value of schedule delays. The greatest losses are not incurred by drivers with the lowest value of time, but by users with an intermediate value of schedule delays and the lowest value of time for that value of schedule delays. For second-best pricing with an untolled alternative, the pattern of distributional effects is quite similar to that for first-best pricing. In contrast with results from prior static models, users who are indifferent between the two alternative routes are not the ones who gain least from this type of second-best pricing. Our results suggest that, in assessing the distributional impacts of road congestion pricing, it is important to take into account both the distribution of the value of time and of the value of schedule delays, as well as the dynamics of departure time choice.

Driving simulation study for the analysis of distraction effects in longitudinal driving behaviour

Scipedia content — Tue, 16 Feb 2021 11:51:46 +0100

This paper is presenting a driver behaviour investigation conducted within the framework of ISi-PADAS (Integrated Human Modelling and Simulation to support Human Error Risk Analysis of Partially Autonomous Driver Assistance Systems) European Project under the 7th Framework Programme (FP7), running from September 2008 to September 2011. This research has been developed at an initial phase of the project to support the conception of a new driver assistance system aimed at improving longitudinal driving by means of information, warning and intervention strategies. In this research, the contribution to the system conception is based on providing a knowledge base of driver behaviour through the conduction of simulator experiments, so that driver modelling can be supported by driving performance data corresponding to specific scenarios of interest. In particular, this paper is aimed at investigating driver behaviour under different circumstances, namely, different longitudinal driving scenarios and distraction caused by a visual and a cognitive secondary task while driving. This way, visual and cognitive distraction effects on longitudinal driving can be analysed, focusing on the driving situations of interest. This paper provides a thorough description of the rationale behind the investigation and describes the methodology and procedure used for the experiments conduction. Moreover, the main results achieved through this research and how these results are linked to the modelling phase inside the ISi-PADAS project are covered within this paper.

Human Factors and Bioagent Transmission following an Indoor Bioterror Attack

Scipedia content — Tue, 16 Feb 2021 11:51:08 +0100

The spread of bioagent through the population in a building following a bioattack is dependent on the built environment, the characteristics of the agent and the medium in which it is introduced, and the actions of individuals inside the building. While there has been a great deal of research on the spread of contaminants in indoor environments, many studies do not take into account the impact of human factors on bioagent spread and transmission. This paper discusses how bioagents may be spread through an indoor environment following an attack due to the behaviours and characteristics of the building population, in terms of their typical behaviour, as well as any emergency response measures they implement. Modelling methodologies are proposed which can be used to supplement existing air transport and Markovian models in order to take into account the actions and decisions of the building population.

A new approach to air traffic controller workload measurement and modelling

Scipedia content — Tue, 16 Feb 2021 11:47:24 +0100

WOS: 000289132000007

Purpose - The purpose of this paper is to develop an analytical approach for workload measurement based on the task times and the changing task priorities of en route air traffic controllers (EATC). Design/methodology/approach - A model called Total Airspace Workload Measurement Model was developed to measure EATC workload. Turkish airspace was chosen for practical application of the model. A survey was conducted of EATC to calculate the weighting coefficients and times of different tasks defined in the model. The survey results were analyzed with SPSS 15.0. The real traffic data of Turkish airspace for two peak hours period in heavy traffic covering August 2007 was provided by the General Directorate of Turkish airports. Geomedia 6.0 was employed for the visualization of the real traffic data. Findings - The total airspace workload during two peak hours of traffic, estimated reference sector capacity and the number of operational sector were defined and calculated to analyze the distribution of workload among sectors. Practical implications - This study can be used for en route sector design such as decision of the number of operational sectors and planning of sectors capacity in the strategic level. Air traffic control service providers can also refer to this study for human resources and equipment planning. Originality/value - A number of parameters and variables were defined and included in the model by taking into consideration the different service types provided by EATC. All parameters and variables were identified with the task times of the controller. This analytical approach can be applied to those particular airspaces which have different characteristics.

Automated On-Ramp Merging System for Congested Traffic Situations

Scipedia content — Tue, 16 Feb 2021 11:41:04 +0100

Traffic merging in urban environments is one of the main causes of traffic congestion. From the driver's point of view, the difficulty arises along the on-ramp where the merging vehicle's driver has to discern whether he should accelerate or decelerate to enter the main road. In parallel, the drivers of the vehicles already on the major road may have to modify their speeds to permit the entrance of the merging vehicle, thus affecting the traffic flow. This paper presents an approach to merging from a minor to a major road in congested traffic situations. An automated merging system that was developed with two principal goals, i.e., to permit the merging vehicle to sufficiently fluidly enter the major road to avoid congestion on the minor road and to modify the speed of the vehicles already on the main road to minimize the effect on that already congested main road, is described. A fuzzy controller is developed to act on the vehicles' longitudinal control - throttle and brake pedals - following the references set by a decision algorithm. Data from other vehicles are acquired using wireless vehicle-to-infrastructure (V2I) communication. A system installed in the infrastructure that is capable of assessing road traffic conditions in real time is responsible for transmitting the data of the vehicles in the surrounding area. Three production vehicles were used in the experimental phase to validate the proposed system at the facilities of the Centro de Automática y Robótica with encouraging results.

Peer Reviewed

Traffic control and intelligent vehicle highway systems: a survey

Scipedia content — Tue, 16 Feb 2021 11:38:24 +0100

Traffic congestion in highway networks is one of the main issues to be addressed by today's traffic management schemes. Automation combined with the increasing market penetration of on-line communication, navigation and advanced driver assistance systems will ultimately result in intelligent vehicle highway systems (IVHS) that distribute intelligence between roadside infrastructure and vehicles and that - in particular on the longer term - are one of the most promising solutions to the traffic congestion problem. In this study, the authors present a survey on traffic management and control frameworks for IVHS. First, they give a short overview of the main currently used traffic control methods for freeways. Next, they discuss IVHS-based traffic control measures. Then, various traffic management architectures for IVHS such as PATH, Dolphin, Auto21 CDS etc. are discussed and a comparison of the various frameworks is presented. Finally, the authors sketch how existing traffic control methodologies could fit in an IVHS-based traffic control set-up. © 2011 The Institution of Engineering and Technology.

Rail commuting to workplaces in Belgium : a multilevel approach

Scipedia content — Tue, 16 Feb 2021 11:38:04 +0100

In their continuous battle against congestion and pollution, governments nowadays promote rail as an environmentally friendly Single Occupant Vehicle (SOV) alternative. For comparison, the energy consumption per person kilometre for rail is 0.14 kWh/pkm while that for a car is 0.48 kWh/pkm (Boussauw and Witlox 2009), and electric trains have no direct emissions of air pollutants like PM 10 and NO x. Modal shift policies often target the daily commute since home to work travel is concentrated in the congested peak hours and commuters' travel behaviour is more regular. This regular character seems to fit well with the scheduled nature of rail, and the central location of railway stations fits with the relative concentration of jobs in congested cities (Riguelle, Thomas, and Verhetsel 2007). Furthermore, both cities and public transport are predominant in the sustainable mobility paradigm (Banister 2008). Therefore, the location of jobs in city-regions and the link with rail use, are at the core of our analysis. Besides environmental objectives, employment concerns motivate governments to invest in railways. Indeed, rail can keep jobs in city centres accessible. This indicates that rail can contribute to all three dimensions of sustainability and sustainable transport, the environmental, the social and the economic dimension (Boschmann and Kwan 2008).

Generation of continuously adjustable vehicle models using symbolic reduction methods

Scipedia content — Tue, 16 Feb 2021 11:28:16 +0100

Vehicle dynamics has been an active field of research for many decades. The well-known single-track model already introduced in 1940 by Riekert and Schunck is still used to explain fundamental effects in vehicle dynamics such as under- and oversteering. However, meanwhile also very complex multibody dynamics models exist, which allow very detailed simulations. On the other hand, real-time computations necessary for active safety and driver assistance systems are demanded for models of lower complexity. As important effects at the handling limits are not covered by the linear single-track model, but complex multibody models cannot be integrated fast enough by electronic control units of safety systems, models with an adjustable degree of complexity are desired. As an example, model-predictive control is an upcoming field of application and relies on models that are integrated over the prediction horizon. Therefore, the selection of an appropriate model is an important task. The crux of the matter is to make a compromise between computation time and accuracy of the model having only a rough guess of the accuracy of the model. In this contribution a systematic approach is proposed. Instead of selecting an existing model, which is supposed to match requirements in computation time and level of detail, a complex model is reduced to match the requirements using symbolic model reduction techniques. This approach has two major advantages: First, the accuracy can be set by the user. Second, the model is continuously adjustable in its complexity or propagation precision.

A Cooperative Approach to Traffic Congestion Detection With Complex Event Processing and VANET

Scipedia content — Tue, 16 Feb 2021 11:26:21 +0100

Currently, distributed traffic information systems have come up as one of the most important approaches for detecting traffic flow problems on a road. For that purpose, they usually make use of the location information that vehicles share among them through periodical messages that are transmitted across a vehicular ad hoc network (VANET). This paper puts forward an event-driven architecture (EDA) as a novel mechanism to get insight into VANET messages to detect different levels of traffic jams; furthermore, it also takes into account environmental data that come from external data sources, such as weather conditions. The proposed EDA has been developed through the complex-event-processing technology. Simulation tests show that the proposed mechanism can detect traffic congestions, which involve different numbers of lanes and lengths with short delay.

Modelling the impact of stream impurities on ductile fractures in CO2 pipelines

Scipedia content — Tue, 16 Feb 2021 11:19:40 +0100

This paper describes the development, validation and application of a fully coupled dynamic boundary fracture model for predicting ductile fracture behaviour in CO 2 pipelines. The application of the model to an hypothetical but realistic CO 2 pipeline reveals the profound effects of the line temperature and the types of impurities present in the CO 2 stream on the pipeline's propensity to fracture propagation. It is found that the pure CO 2 and the post-combustion pipelines exhibit very similar and highly temperature dependent propensity to fracture propagation. An increase in the line temperature from 20 to 30 °C results in the transition from a relatively short to a long running propagating facture. The situation becomes progressively worse in moving from the pre-combustion to the oxy-fuel stream. In the latter case, long running ductile fractures are observed at all the temperatures under consideration. All of the above findings are successfully explained by examining the fluid depressurisation trajectories during fracture propagation relative to the phase equilibrium envelopes.

Subliminal Persuasion and Its Potential for Driver Behavior Adaptation

Scipedia content — Tue, 16 Feb 2021 11:15:40 +0100

Mental overload is a problem drivers are increasingly exposed to in today's complex task of vehicle operation and is one of the causes of traffic accidents or hazards. To keep road safety high but allow for additional information to be forwarded to the driver, we propose to employ subliminal persuasion: a technique where the information is transferred below the level of conscious awareness. Thus, the driver becomes aware of the information, but his/her cognitive load is unaltered. To analyze the potential of this approach, we have designed a case study implementing an “eco-driving” strategy operating in the background. Driving economy is thereby estimated based on vehicles' mileage gathered in real time from numerous sensors in and around the car, and information is conveyed to the driver with very light, not attentively perceivable, vibration patterns originating from tactor elements integrated into the safety belt or the car seat. The main research hypothesis followed in this paper and investigated in real driving studies is that drivers would operate their vehicles more economically on vibrotactile instructions perceived inattentively, as compared with the case without any notifications. Indeed, results indicate an improvement in driving economy for segments driven with subliminal feedback compared with routes driven without assistance but not without qualifications. Statistical significance has been proven for the safety belt interface, whereas it has not been substantiated for the tactile car seat. (However, more research is needed to validate the applicability of subliminal persuasion across a wider range of driving and in-vehicle tasks.).

Long-range distributed Brillouin fiber sensors by use of an unbalanced double sideband probe

Scipedia content — Tue, 16 Feb 2021 11:14:12 +0100

We propose and demonstrate a long-range Brillouin Optical Time-Domain Analysis (BOTDA) distributed sensing system making use of an unbalanced double sideband probe formed by a Stokes and an anti-Stokes line. In particular, we show that for each measuring condition an optimal Stokes /anti-Stokes input power ratio exists, allowing a larger suppression of nonlocal effects induced by pump depletion. Experiments on a 50 km single-mode sensing fiber with 5 meters spatial resolution are reported.

Variation-Tolerant Architecture for Ultra Low Power Shared-L1 Processor Clusters

Scipedia content — Tue, 16 Feb 2021 11:10:42 +0100

In this brief, we propose a variation-tolerant architecture for shared-L1 processor clusters working at near-threshold (NT). Our variation-tolerant technique is able to compensate the effect of delay variations, which are exacerbated by moving to the NT region, on the processor to memory communication by adding one or two stages of controllable pipelines. Moreover, we propose a reconfigurable address-interleaving technique, which enables us to shut down some of the memory blocks if they are either too slow due to the variation or not needed by the application (to reduce power consumption). Experimental results show that our speed adaptation approach is able to compensate up to 90% degradation in the request path with less than 2% hardware overhead for a shared-L1 cluster with 16 processors and 32 memory banks. The configurable interleaving technique has an overhead of 10% on the request timing path of a 16 × 32 interconnection network.

Price: Hybrid geographic and contact-based forwarding in delay-tolerant networks

Scipedia content — Tue, 16 Feb 2021 11:03:59 +0100

International audience; Similarity-based techniques relying on contact patterns among nodes have shown to provide high delivery success rate when performing routing in delay-tolerant networks (DTN). Nevertheless, such approaches work well only when nodes exhibit high similarity values. In this paper, we propose Price (Periodicity-based Routing in Intermittently-Connected Environments), an agenda-based greedy forwarding scheme for DTNs that combines geographic-oriented forwarding with contact-based forwarding by relying packets according to predictable patterns of locations and contacts. We define the operation of Price and evaluate the performance of geographic forwarding under the framework of graph navigation to unveil a small-world phenomenon. We then gauge the performance of Price using a real-life mobility data set according to various well-known routing solutions such as Flooding, Prophet, Bubble Rap, and Wait. Simulation results show that Price largely outperforms other solutions, especially in terms of combined cost/delivery ratio.

MARITIME TRAFFIC EXTERNALITIES IN THE GULF OF FINLAND UNTIL 2030

Scipedia content — Tue, 16 Feb 2021 11:02:33 +0100

Maritime traffic in the Gulf of Finland has grown remarkably during the 2000s. This increase has an impact on the environment and exposes it to risks. These problems should be controlled to guarantee sustainable development and the welfare of inhabitants in the area. A method for estimating the impact of ship-originated air emissions on the environment is to calculate their environmental externalities which are a part of the total marginal social costs of shipping. The internalization of externalities as a control method of transport would comply with the polluter pays principle and act as a fair traffic control method between transport modes. In this paper, we present the results of CO2, NOx, SOx and PM emissions originating from ships and their externalities in the Gulf of Finland up to 2015. The calculation algorithm developed for this study produces emission estimates per annum and converts them into externalities. We focus on passenger, tanker, general cargo, Ro-Ro, container and bulk vessel ship types representing almost 90% of the total NOx emissions of shipping in the area. Scenario modelling is a method for estimating the effects of forthcoming or planned regulations and helps with targeting emission abatement actions to maximize their profit. The results of the calculation algorithm show that externalities can be used as a consultative tool for transport-related decision-making. The costs are given at the price levels of the year 2000. The total external cost of ship-originated CO2, NOx, SOx and PM emissions in the Gulf of Finland was almost €175 million in 2007. Due to increased traffic volumes, these costs will increase to nearly €214 million in 2015. The majority of externalities are produced by CO2 emissions. If we deduct CO2 externalities from the results, we get total externalities of €57 million in 2007. Following eight years (2015), externalities would be 28% or €41 million lower. This would be as a result of regulation reducing the sulphur content of marine fuels. Regulating SOx and PM emissions will slow down the increasing trend of shipborne externalities in the Gulf of Finland; however, the externalities are still growing. In order to achieve a downward trend, the two major compounds resulting in externalities must be reduced, which requires strict actions to lower shipborne CO2 and NOx emissions. First Published Online: 30 Mar 2012

High-Spatial- and Spectral-Resolution Time-Domain Brillouin Distributed Sensing by Use of Two Frequency-Shifted Optical Beam Pairs

Scipedia content — Tue, 16 Feb 2021 10:59:47 +0100

We present a novel scheme aimed to improve spectral resolution in Brillouin distributed sensors based on single-mode standard fibers. The method makes use of two frequency-shifted optical pairs, the first one (the "writing" pair) devoted to excite the acoustic wave and the second one (the "reading" pair) employed to perform Brillouin gain interrogation. A numerical analysis demonstrates the capability of the method to ensure high spectral resolution even when operating in the high-spatial-resolution (~1 m or less) regime. Preliminary experimental results carried out at 1-m spatial resolution are also reported.

Resilient critical infrastructure management with a service oriented architecture: A test case using airport collaborative decision making

Scipedia content — Tue, 16 Feb 2021 10:49:48 +0100

Resilient critical infrastructure management with a service oriented architecture: A test case using airport collaborative decision making"/jats:title" "jats:p"The SERSCIS approach aims to support the use of interconnected systems of services in Critical Infrastructure (CI) applications. The problem of system interconnectedness is aptly demonstrated by ‘Airport Collaborative Decision Making’ (A-CDM). Failure or underperformance of any of the interlinked ICT systems may compromise the ability of airports to plan their use of resources to sustain high levels of air traffic, or to provide accurate aircraft movement forecasts to the wider European air traffic management systems. The proposed solution is to introduce further SERSCIS ICT components to manage dependability and interdependency. These use semantic models of the critical infrastructure, including its ICT services, to identify faults and potential risks and to increase human awareness of them. Semantics allow information and services to be described in a way that makes them understandable to computers. Thus when a failure (or a threat of it) is detected, SERSCIS components can take action to manage the consequences, including changing the interdependency relationships between services. In some cases, the components will be able to take action autonomously, e.g., to manage ‘local’ issues such as the allocation of CPU time to maintain service performance, or the selection of services where there are redundant sources available. In other cases the components will alert human operators so they can take action instead. The goal of this paper is to describe a Service Oriented Architecture (SOA) that can be used to address the management of ICT components and interdependencies in critical infrastructure systems.

Application of vehicular communications for improving the efficiency of traffic in urban areas

Scipedia content — Tue, 16 Feb 2021 10:46:15 +0100

This paper studies the impacts of vehicular communications on efficiency of traffic in urban areas. We consider a Green Light Optimized Speed Advisory application implementation in a typical reference area and present the results of its performance analysis using an integrated cooperative intelligent transportation systems simulation platform. In addition, we study route alternation using vehicle-to-infrastructure and vehicle-to-vehicle communications. Our interest was to monitor the impacts of these applications on fuel and traffic efficiency by introducing metrics for average fuel consumption, average stop time behind a traffic light and average trip time, respectively. For gathering the results, we implemented two traffic scenarios defining routes through an urban area including traffic lights. The simulations are varied for different penetration rates of application-equipped vehicles, driver's compliance to the advised speed and traffic density. Our results indicate that Green Light Optimized Speed Advisory systems could improve fuel consumption, reduce traffic congestion in junctions and the total trip time. Copyright © 2011 John Wiley & Sons, Ltd.

Give or take? Rewards versus charges for a congested bottleneck

Scipedia content — Tue, 16 Feb 2021 10:41:45 +0100

This paper analyzes the possibilities to relieve traffic congestion using subsidies instead of Pigouvian taxes, as well as revenue-neutral combinations of rewards and taxes ('feebates'). The model considers a Vickrey-ADL model of bottleneck congestion with endogenous scheduling. With inelastic demand, a fine (time-varying) reward is found to be equivalent to a fine toll, and to a continuum of combinations of time-varying tolls and rewards, including fine feebates. When demand is price-sensitive, a reward becomes less attractive from the efficiency viewpoint, because it attracts additional users to the congested bottleneck. As a result, both the second-best optimal fraction of rewarded travelers in the scheme, and the relative efficiency that can be achieved with it, decrease when demand becomes more elastic. Our analytical and simulation results for coarse schemes reveal that a coarse reward is less effective than a coarse feebate, which is itself less effective than a coarse toll. The most efficient coarse system is the step toll, which is also allowed to be positive in the fringes of the peak. Despite the smaller efficiency gains, rewards and feebates may be attractive to use in circumstances where public and political acceptability of tolling is especially low, so that its implementation is unlikely, including the temporary use of price incentives in case of road works and large-scale events. © 2011 Elsevier B.V.

Electrospun nanofibers for enhancing structural performance of composite materials

Scipedia content — Tue, 16 Feb 2021 10:38:47 +0100

Over the past six decades, engineered composite materials found wide ranging applications in land, sea and air transport vehicles, space exploration, military equipment and defense, storage, buildings and construction, chemical processing, electrical engineering, healthcare, and general engineering industries. Performance of engineered composites is tailored for an intended application by judiciously selecting the matrix and reinforcement materials, by modifying the fiber–matrix interface, and by controlling the architecture of fibers in the matrix. Most widely used reinforcement fibers are micron size diameter fibers. There is growing need for engineered composites with enhanced structural performance in newer applications as well as existing applications, which are expected to meet higher functional requirements and enhanced safety requirements. Moreover the global movement toward sustainable development is seeking engineered materials which are environmentally benign. Recently the electrospinning process has emerged as a viable industrial process to produce nanofibers from a variety of materials including naturally occurring polymers. This paper illustrates the benefits of using electrospun nanofibers in enhancing the structural performance of engineered composite materials. Copyright 2010 John Wiley & Sons, Ltd.

Il nodo della stazione ferroviaria come luogo di riconciliazione di conflitti urbani

Scipedia content — Tue, 16 Feb 2021 10:37:17 +0100

Despite railway infrastructure was the structural framework on which modern European States were developed, contributing to unify territories and to the establishment of Nations, right from the beginning, the relationship between railway and city has been characterized by physical, functional and social conflicts, mainly because of a lack of integration between infrastructural and urban policies, which have been produced strong conflicts during decades. These critical situations have concentrated on the railway stations surrounding areas, which have started symbolizing the main conflicts that are taking place inside the cities."/p""p"Similarly to what happened in the XIX century, today railway is a strategic infrastructure for the European territory development, thanks to the introduction of high speed transport systems and the promotion of rail transport as a more sustainable transportation system, which can quickly connect metropolitan central areas, more and more impenetrable by private vehicles, and key functions centres for the contemporary urban systems."/p""p"In this framework, railway stations are becoming public places representing a complex society which is more and more dedicated to motion; thus they offer an unmissable chance not only to carry out urban development and spatial cohesion policies, but also to compose old tensions caused by the sharing of physical space, which is more and more scarce and valuable, and by ghettoization phenomena which have been produced at local scale, between rail infrastructure and the surrounding urban context. Today, such conflicts are growing and they are involving many actors who express a lot of different interests, needs and expectations, relating to the station areas’ destiny."/p""p"Starting from the analysis of some conflicting situations between rail stations and the surrounding areas which have took place until today, this paper investigates some recent renewal interventions on Italian and European main railway nodes, their complex dynamics and the role of the most important players involved in these developments."/p""p"Contemporary main rail stations are addressed as complex systems operating in a condition characterized by a dynamic balance among the different elements which form them; the interpretation of their polysemic nature allows to identify the most suitable design procedures and intervention strategies to make stations the privileged places where to compose the conflicts between contemporary city and railway. Therefore, the purpose of this paper is to identify and to analyze crucial issues in order to build new liveable and effective developments. They refer, for instance, to the rail station configuration in order to be at the same time an efficient interchange transportation node and a meaningful and multifunctional city centre, but also to the detection of the most suitable tools and procedures to drive the urban and infrastructural transformations and to the proper involvement in the decision process of the different stakeholders who could be interested in these urban changes.

Dependence on technology, drivers, roads, and congestion of real-world vehicle fuel consumption

Scipedia content — Tue, 16 Feb 2021 10:36:07 +0100

The Dutch national transport CO2 emissions are determined by summing individual cases: a particular vehicle, on a particular road and traffic situation. In this paper the different aspects and the relations among them, as used in emission predictions, are outlined. In particular the central role that the CO2 type-approval value (from the NEDC test) plays in the real-world CO2 emissions since 2000 is clarified. © The author(s) and/or their employer(s), 2012.

Potential Consumers, Information Services and Sites Test

Scipedia content — Tue, 16 Feb 2021 10:33:41 +0100

The purpose of this paper is to review the most recent and relevant business intelligence and market foresight analyses on electric vehicles in order to build a picture on the current market activities and offerings. The reference material was clustered in three main sources: 1) market foresight analyses 2) information services development activities, 3) probe of electric vehicle test sites. The future EV market is seen to have a promising growth potential, though the proper business models that could meet consumer aspirations are still called for. The growing potential of EV market has been stimulating the development of several types of services that support EV deployment, e.g. information services. The test sites are already emerging around the globe and the master driver seems to be the automotive industry.

Multi-Objective Traffic Engineering for Future Networks

Scipedia content — Tue, 16 Feb 2021 10:33:15 +0100

n important goal towards the design of Future Networks is to achieve the best ratio of performance to energy consumption and at the same time assure manageability. This paper presents a general problem formulation for Energy-Aware Traffic Engineering and proposes a distributed, heuristic Energy-Aware Traffic Engineering scheme (ETE) that provides load balancing and energy-awareness in accordance with the operator's needs. Simulation results of ETE compared to the optimal network performance confirm the capability of ETE to meeting the needs of Future Networks.

Interaction of caisson foundations with a seismically rupturing normal fault: Centrifuge testing versus numerical simulation

Scipedia content — Tue, 16 Feb 2021 10:27:19 +0100

Dramatic failures have occurred in recent earthquakes due to the interplay of surface structures with outcropping fault ruptures, highlighting the need to account for fault induced loading in seismic design. Current research into the mechanisms of fault rupture–foundation–structure interaction has revealed a potentially favourable role of caissons in comparison to other foundation types. This paper explores the mechanisms of normal fault rupture interaction with caisson foundations, with an integrated approach using both experiments and analysis. A series of centrifuge model tests were first conducted to study the response of a square (in plan) caisson foundation of dimensions 5 m x 5 m x 10 m, founded on a 15 m thick layer of dry dense sand. Nonlinear 3-D numerical simulation of the problem was then developed and adequately validated against centrifuge test results. Depending on its position relative to the fault, the caisson is found to interact with the fault rupture, sometimes modifying spectacularly the free field rupture path. Acting as a kinematic constraint, the caisson “forces” the rupture to divert on either one, or both, of its sides. The numerical study was extended to gain further insight into the effect of the exact position of the caisson relative to the fault outcrop. Different mechanisms taking place for different caisson positions are identified, and their effect on the response of the system is discussed

Connect & Drive: design and evaluation of cooperative adaptive cruise control for congestion reduction

Scipedia content — Tue, 16 Feb 2021 10:25:04 +0100

Road throughput can be increased by driving at small inter-vehicle time gaps. The amplification of velocity disturbances in upstream direction, however, poses limitations to the minimum feasible time gap. This effect is covered by the notion of string stability. String-stable behavior is thus considered an essential requirement for the design of automatic distance control systems, which are needed to allow for safe driving at time gaps well below 1 s. Using wireless inter-vehicle communications to provide real-time information of the preceding vehicle, in addition to the information obtained by common Adaptive Cruise Control (ACC) sensors, appears to significantly decrease the feasible time gap, which is shown by practical experiments with a test fleet consisting of six passenger vehicles. The large-scale deployment of this system, known as Cooperative ACC (CACC), however, poses challenges with respect to the reliability of the wireless communication system. A solution for this scalability problem can be found in decreasing the transmission power and/or beaconing rate, or adapting the communications protocol. Although the main CACC objective is to increase road throughput, the first commercial application of CACC is foreseen to be in truck platooning, since short distance following is expected to yield significant fuel savings in this case.

Forecasting world and regional aviation jet fuel demands to the mid-term (2025)

Scipedia content — Tue, 16 Feb 2021 10:23:23 +0100

This article provides jet fuel demand projections at the worldwide level and for eight geographical zones until 2025. Air traffic forecasts are performed using dynamic panel-data econometrics. Then, the conversion of air traffic projections into quantities of jet fuel is accomplished by using a complementary approach to the 'Traffic Efficiency' method developed previously by the UK Department of Trade and Industry to support the Intergovernmental Panel on Climate Change (IPCC, 1999). According to our main scenario, air traffic should increase by about 100% between 2008 and 2025 at the world level, corresponding to a yearly average growth rate of 4.7%. World jet fuel demand is expected to increase by about 38% during the same period, corresponding to a yearly average growth rate of 1.9% per year. According to these results, energy efficiency improvements allow reducing the effect of air traffic rise on the increase in jet fuel demand, but do not annihilate it. Jet fuel demand is thus unlikely to diminish unless there is a radical technological shift, or air travel demand is restricted.

Preserving Confidentiality in PCE-based Multi-domain Networks

Scipedia content — Tue, 16 Feb 2021 10:21:05 +0100

The path computation element (PCE) architecture has been proposed to effectively enable multi-domain traffic engineering (TE) in generalized multiprotocol label switching (GMPLS) networks while providing an adequate level of confidentiality among domains. However, a malicious utilization of the procedures defined within the PCE architecture might affect the confidentiality of network domain information in a multi-domain multi-carrier network scenario. This paper discusses the critical issues of the PCE architecture in terms of confidentiality. A two-step authorization scheme, named the behavior-based PCE authorization policy (BPAP), is proposed. The BPAP includes a novel add-on PCE component and a central authorization policy server to protect against confidentiality breaking. The scheme is based on the PCE protocol (PCEP) client behavior analysis and includes attack pattern detection procedures and possible partial information filtering of the reply message. The applicability of the BPAP scheme is validated in wavelength switched optical networks (WSONs) through simulations focusing on the exchange of a restricted set of available resources. Finally, a BPAP implementation is experimentally evaluated, showing the efficiency of the two-step scheme in terms of scalability, capability to limit the discovery of critical information, and reactivity to confidential attacks.

A tool for component-based schedulability analysis of distributed real-time pipelines

Scipedia content — Tue, 16 Feb 2021 10:17:54 +0100

In many scenarios, such as in the automotive context [1], [2], the complexity of developing a distributed real-time embedded (DRE) system is reduced by dividing the system into separate components, possibly developed by a different teams or third-party companies. The component-based approach does simplify both the analysis and the integration, although it introduce some waste of resource.

Human Pose Estimation and Activity Recognition From Multi-View Videos: Comparative Explorations of Recent Developments

Scipedia content — Tue, 16 Feb 2021 10:16:18 +0100

This paper presents a review and comparative study of recent multi-view approaches for human 3D pose estimation and activity recognition. We discuss the application domain of human pose estimation and activity recognition and the associated requirements, covering: advanced human–computer interaction (HCI), assisted living, gesture-based interactive games, intelligent driver assistance systems, movies, 3D TV and animation, physical therapy, autonomous mental development, smart environments, sport motion analysis, video surveillance, and video annotation. Next, we review and categorize recent approaches which have been proposed to comply with these requirements. We report a comparison of the most promising methods for multi-view human action recognition using two publicly available datasets: the INRIA Xmas Motion Acquisition Sequences (IXMAS) Multi-View Human Action Dataset, and the i3DPost Multi-View Human Action and Interaction Dataset. To compare the proposed methods, we give a qualitative assessment of methods which cannot be compared quantitatively, and analyze some prominent 3D pose estimation techniques for application, where not only the performed action needs to be identified but a more detailed description of the body pose and joint configuration. Finally, we discuss some of the shortcomings of multi-view camera setups and outline our thoughts on future directions of 3D body pose estimation and human action recognition.

Spatial Resolution Enhancement in Preactivated BOTDA Schemes by Numerical Processing

Scipedia content — Tue, 16 Feb 2021 10:10:52 +0100

novel processing algorithm is demonstrated for time-domain high-resolution Brillouin schemes based on acoustic field preactivation. An iterative method is employed to correct the measured data from spurious effects associated with acoustic wave transients. Based on a model of the stimulated Brillouin scattering in the frequency domain, the spatial resolution degrading features are computed and subtracted from the acquired data. Experimental tests with 20-cm spatial resolution and dark-pulse pumping are reported.

Citymobil, advanced transport for the urban environment : an update

Scipedia content — Tue, 16 Feb 2021 10:08:33 +0100

CityMobil was an integrated project in the Sixth Framework Program of the European Union. The objective of the project was to achieve more effective organization of urban transport for more rational use of motorized traffic with less congestion and pollution, safer driving, a higher quality of living, and enhanced integration with spatial development. This objective was reached by developing integrated traffic solutions: advanced concepts for innovative autonomous and automated road vehicles for passengers and goods embedded in an advanced spatial setting. The project was split into two parts: (a) research and development and (b) demonstration. The primary aim of the research and development part was to identify, address, and, where possible, eliminate barriers that still blocked the large-scale implementation of automated transport systems in urban traffic. The heart of the demonstration part consisted of three large-scale implementations of automated transport systems in urban areas and a number of smaller showcases and demonstrations. CityMobil was a 5-year project that started in May 2006 and ended in December 2011. The project results were presented at a final conference in Brussels, Belgium. This paper provides an update of a paper presented in 2009 and includes an overview of the final CityMobil results. The detailed results are available on the CityMobil website: www.citymobil-project.eu.

Evolution of grid-based services for Diffusion Tensor Image analysis

Scipedia content — Tue, 16 Feb 2021 10:06:46 +0100

nalyzing Diffusion Tensor Image data of the human brain of large study groups is complex and demands new, sophisticated and computationally intensive pipelines that can efficiently be executed. We present our progress over the past five years in the development and porting of the DTI analysis pipeline to a grid infrastructure. Starting with simple jobs submitted from the command-line, we moved towards a workflow-based implementation and finally into the e-BioInfra Gateway, which offers a web interface for the execution of selected biomedical data analysis software on the Dutch Grid. This gateway is currently being actively used by neuroscientists and for educational purposes. (C) 2012 Elsevier B.V. All rights reserved

Managing the future internet through intelligent in-network substrates

Scipedia content — Tue, 16 Feb 2021 10:01:13 +0100

The current Internet has been founded on the architectural premise of a simple network service used to interconnect relatively intelligent end systems. While this simplicity allowed it to reach an impressive scale, the predictive manner in which ISP networks are currently planned and configured through external management systems and the uniform treatment of all traffic are hampering its use as a unifying multi-service network. The future Internet will need to be more intelligent and adaptive, optimizing continuously the use of its resources and recovering from transient problems, faults and attacks without any impact on the demanding services and applications running over it. This article describes an architecture that allows intelligence to be introduced within the network to support sophisticated self-management functionality in a coordinated and controllable manner. The presented approach, based on intelligent substrates, can potentially make the Internet more adaptable, agile, sustainable, and dependable given the requirements of emerging services with highly demanding traffic and rapidly changing locations. We discuss how the proposed framework can be applied to three representative emerging scenarios: dynamic traffic engineering (load balancing across multiple paths); energy efficiency in ISP network infrastructures; and cache management in content-centric networks.

A Decision-Support System for the Car Pooling Problem

Scipedia content — Tue, 16 Feb 2021 09:58:19 +0100

The continuous increase of human mobility combined with a relevant use of private vehicles contributes to increase the ill effects of vehicle externalities on the environment, e.g. high levels of air pollution, toxic emissions, noise pollution, and on the quality of life, e.g. parking problem, traffic congestion, and increase in the number of crashes and accidents. Transport demand management plays a very critical role in achieving greenhouse gas emission reduction targets. This study demonstrates that car pooling (CP) is an effective strategy to reduce transport volumes, transportation costs and related hill externalities in agreement with EU programs of emissions reduction targets. This paper presents an original approach to solve the CP problem. It is based on hierarchical clustering models, which have been adopted by an original decision support system (DSS). The DSS helps mobility managers to generate the pools and to design feasible paths for shared vehicles. A significant case studies and obtained results by the application of the proposed models are illustrated. They demonstrate the effectiveness of the approach and the supporting decisions tool.

Seamless networking for aeronautical communications: One major aspect of the SANDRA concept

Scipedia content — Tue, 16 Feb 2021 09:56:13 +0100

In air transportation one major bottleneck stressing capacity limits is identified: aeronautical communications. By the 2025 timeframe aircraft operations are expected to double [1]. Well-founded concerns doubt that current air transportation systems will be able to cope with this growth, e.g., already VHF (Very High Frequency) communication capacity is expected to saturate in Europe by 2020-2025 [2]. Meeting these growing demands require systems providing flight information and processes in real-time including high flexibility. Also new security requirements are affecting the ability to move people and cargo efficiently. Ongoing research activities, projects, and programs are developing the fundamental methods, concepts, and technologies for future aeronautical communications enabling higher capacities in air transportation. In the following section, we give an overview of the current status, major activities and trends in the field of aeronautical communications. Finally, the European research project SANDRA (Seamless Aeronautical Networking through integration of Data links, Radios, and Antennas) is introduced and its recent results toward a seamless networking design are presented.

On the mobility policies of companies: what are the good practices?: the Belgian case

Scipedia content — Tue, 16 Feb 2021 09:52:34 +0100

Companies play an important role in the mobility debate as they can be considered as the primary 'creators' of commuting traffic. In recent years, companies have developed a variety of initiatives to improve the mobility of their employees, although their visions and actions are often neglected in the research literature. This paper aims at identifying the good practice in mobility policies of workplaces located in Belgium. To achieve this objective, existing research and two large-scale Belgian surveys of commuting are analysed. First, workplaces are clustered in order to identify those where the alternative modes of transport which are promoted by the policy are popular among employees. Then, quantitative analyses are performed to find out what are the good practices of mobility policies. The results show that the best way of promoting an alternative mode of transport depends on company's characteristics. The promotion of bicycles is most appropriate for small workplaces, while larger workplaces and those located in built-up areas or city centres are more suitable for the promotion of public transport. Financial incentives, provision of facilities, diffusion of information and parking management all play an important role in mobility management. (C) 2011 Elsevier Ltd. All rights reserved.

Numerical Recovery of Gas Flows in Pipeline Systems

Scipedia content — Mon, 15 Feb 2021 12:00:55 +0100

Optimal control, prevention and investigation of accidents, and detection of discrepancies in estimated gas supply and distribution volumes are relevant problems of trunkline operation. Efficient dealing with these production tasks is based on the numerical recovery of spacetime distribution of nonisothermal transient flow parameters of transmitted gas mixtures based on full-scale measurements in a substantially limited number of localities spaced considerable distances apart along the gas pipelines. The paper describes a practical method of such recovery by defining and solving a special identification problem. Simulations of product flow parameters in extended branched pipelines, involving calculations of the target function and constraint function for the identification problem of interest, are done in the 1D statement. In conclusion, results of practical application of the method in the gas industry are briefly discussed.

Document type: Article

The Optimal Dispatch of Traffic and Patrol Police Service Platforms

Scipedia content — Mon, 15 Feb 2021 10:22:13 +0100

The main goal of this paper is to present a minmax programming model for the optimal dispatch of Traffic and Patrol Police Service Platforms with single traffic congestion. The objective is to minimize the longest time of the dispatch for Traffic and Patrol Police Service Platforms. Some numerical experiments are carried out, and the optimal project is given.

Document type: Article

Evaluation of Congestion Relief Proposals in a Capital City

Scipedia content — Mon, 15 Feb 2021 10:19:02 +0100

This paper aims at analyzing three different solutions suggested for traffic congestion relief in Port Louis, the busiest city of Mauritius. It evaluates the impact of the three alternatives which are the use of Light Rail Transit (LRT) as an alternative mode of transport, the construction of a Ring road around Port Louis, and the upgrading of the current bus network into a Bus Rapid Transit (BRT) system. The impact of these three solutions has been evaluated by performing Traffic Cellular Automata (TCA) simulations. Our studies reveal that the Ring road will lead to more congestion while introducing the LRT or upgrading the current bus network will reduce congestion significantly.

Document type: Article

Using AHP method for determining the significance of quality criteria of passenger transportation by train based on service people

Scipedia content — Mon, 15 Feb 2021 10:13:46 +0100

The need for improving quality of passenger transportation by rail transport to increase the competitiveness of this means of transport is demonstrated. Major criteria influencing the quality of passenger transportation by rail transport are defined and expert evaluation questionnaires, allowing the authors to obtain the data on the presented criterion significance from the respondents (service people of the train) are prepared. The searching for ways of determining suitability of mathematical statistics methods for checking the concordance of expert judgements is described. For this purpose, the AHP (Analytic Hierarchy Process) method, allowing pairwise criteria evaluation, is used. Based on the calculated average values of the criterion significance and ranks, obtained using the data elicited from the questionnaires filled by the service staff of the trains (train masters, mechanic operators-electricians, conductors, etc.), the priority order of the criteria is determined. Article in Lithuanian. Traukinius aptarnaujančio personalo nuomonės apie keleivių vežimo kokybės kriterijų svarbą nustatymas ahp metodu Santrauka. Pagrįsta būtinybė gerinti keleivių vežimo geležinkeliais kokybę, kad šios rūšies transportas tobulėtų ir taptų konkurencingu tarp kitų transporto rūšių. Susisteminti svarbiausi kriterijai, turintys įtakos keleivių vežimo geležinkeliais kokybei. Sudarytos ekspertinio tyrimo anketos, leidusios surinkti duomenis apie respondentų (traukinius aptarnaujančio personalo) nuomonę nustatant kriterijų, pateiktų anketose, svarbą. Pateikta matematinės statistikos metodų, leidžiančių nustatyti ekspertų nuomonių suderinamumą, tinkamumo paieška. Tam taikytas hierarchijų analizės proceso (Analytic Hierarchy Process – AHP) metodas, leidžiantis kriterijus lyginti poromis (Saaty metodas). Pagal traukinius aptarnaujančio personalo (traukinio viršininkų, mechanikų elektrikų, vagonų palydovų) apklausos anketinių duomenų apskaičiuotus kriterijų svarbos vidurkius ir rangus nustatyti jų prioritetai. Reikšminiai žodžiai: geležinkelių transportas, keleivių vežimas, kokybės kriterijai, AHP metodas, svarbumas, konkordancija.

Document type: Article

Autoregressive nonlinear time-series modeling of traffic fatalities in Europe

Scipedia content — Mon, 15 Feb 2021 09:46:29 +0100

The objective of this paper is to provide a parsimonious model for linking motorization level with the decreasing fatality rates observed across EU countries during the last three decades. A macroscopic analysis of road-safety in Europe at the country level is proposed through the application of non-linear models correlating fatalities and vehicles for the period between 1970 and 2002. Given the time series nature of road safety data, these models result in auto-correlated residuals, thus violating at least one of the assumptions of non-linear regression. Autoregressive forms of the considered models that overcome these limitations and provide superior predictive capabilities are also considered. An autoregressive log-transformed model seems to outperform the base autoregressive non-linear model in this respect. The use of these models allowed for the identification of the best and worst performing countries. The proposed models can prove useful for assessing the road safety performance of the examined countries, as well as for obtaining some insight on the current and future trends of less developed countries.

Document type: Article

Domino inspired MOBILE networks

Scipedia content — Fri, 12 Feb 2021 16:22:54 +0100

El pdf del artículo es la versión post-print.

MOBILE networks can be operated in a gate-level pipelined fashion allowing high through-output. If MOBILE gates are directly chained, a four-phase clock scheme is required. A single phase scheme has been recently reported that alternates rising and falling edge-triggered MOBILE gates. A novel two-phase interconnection scheme resembling conventional domino pipelines is proposed and validated. It exhibits advantages in terms of speed with respect to both four-phase and single-phase interconnection schemes. In addition, the new architecture improves logic flexibility regarding the domino pipeline counterpart, since inverting and non-inverting stages can be interspersed.

This work has been funded in part by the Spanish Ministry of Science and Innovation with support from ERDF under Project TEC2010-18937 and in part by the Consejería de Innovación, Ciencia y Empresa, Junta de Andalucía under Project TIC-2961.

Peer Reviewed

Document type: Article

Kuznets curve and urban transport the scope of I+M programs

Scipedia content — Fri, 12 Feb 2021 16:02:06 +0100

In this article possibilities of application of Kuznets Curve in the domain of urban development and urban transport are tested. Comparative analysis of GRP per capita, local air pollutant and CO2 emission levels, and different urban and transport development strategies of world metropolises, clearly shows that EKC concept and I+M programs are highly overrated. [Projekat Ministarstva nauke Republike Srbije, br. 37010]

Document type: Article

Human Mobility Networks, Travel Restrictions, and the Global Spread of 2009 H1N1 Pandemic

Scipedia content — Fri, 12 Feb 2021 15:13:05 +0100

fter the emergence of the H1N1 influenza in 2009, some countries responded with travel-related controls during the early stage of the outbreak in an attempt to contain or slow down its international spread. These controls along with self-imposed travel limitations contributed to a decline of about 40% in international air traffic to/from Mexico following the international alert. However, no containment was achieved by such restrictions and the virus was able to reach pandemic proportions in a short time. When gauging the value and efficacy of mobility and travel restrictions it is crucial to rely on epidemic models that integrate the wide range of features characterizing human mobility and the many options available to public health organizations for responding to a pandemic. Here we present a comprehensive computational and theoretical study of the role of travel restrictions in halting and delaying pandemics by using a model that explicitly integrates air travel and short-range mobility data with high-resolution demographic data across the world and that is validated by the accumulation of data from the 2009 H1N1 pandemic. We explore alternative scenarios for the 2009 H1N1 pandemic by assessing the potential impact of mobility restrictions that vary with respect to their magnitude and their position in the pandemic timeline. We provide a quantitative discussion of the delay obtained by different mobility restrictions and the likelihood of containing outbreaks of infectious diseases at their source, confirming the limited value and feasibility of international travel restrictions. These results are rationalized in the theoretical framework characterizing the invasion dynamics of the epidemics at the metapopulation level.

This work has been partially funded by the National Institutes of Health R21-DA024259 award, the Lilly Endowment grant 2008 1639-000 and the DTRA-1-0910039 award to AV; the EC-ICT contract no. 231807 (EPIWORK) to AV and VC; the EC-FET contract no. 233847 (DYNANETS) to AV, VC, and JJR; the ERC Ideas contract n.ERC-2007-Stg204863 (EPIFOR) to VC, PB, CP, and MT. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Peer reviewed

Document type: Article

Model Predictive Control-Based Fast Charging for Vehicular Batteries

Scipedia content — Fri, 12 Feb 2021 15:09:36 +0100

Battery fast charging is one of the most significant and difficult techniques affecting the commercialization of electric vehicles (EVs). In this paper, we propose a fast charge framework based on model predictive control, with the aim of simultaneously reducing the charge duration, which represents the out-of-service time of vehicles, and the increase in temperature, which represents safety and energy efficiency during the charge process. The RC model is employed to predict the future State of Charge (SOC). A single mode lumped-parameter thermal model and a neural network trained by real experimental data are also applied to predict the future temperature in simulations and experiments respectively. A genetic algorithm is then applied to find the best charge sequence under a specified fitness function, which consists of two objectives: minimizing the charging duration and minimizing the increase in temperature. Both simulation and experiment demonstrate that the Pareto front of the proposed method dominates that of the most popular constant current constant voltage (CCCV) charge method.

Document type: Article

Application of dea method to intermodal container transport

Scipedia content — Fri, 12 Feb 2021 15:05:09 +0100

In order to make better assessment of intermodal container transportation, the authors have analyzed DEA (Data Envelopment Analysis) method in deciding the most favorable container line from Serbian ports to the near East ports. To allow for applications to a wide variety of activities, term organization unit (Decision Making Unit – DMU) refers to container line. DEA Method has been used to give the estimation of efficiency of operations in organization units. Organization units are container lines in which containers are loaded with mineral water in bottles. The main points in transportation net are factories of mineral water (Knjaz Milos Arandjelovac and Minaqua Novi Sad), Serbian ports ( the Port of Belgrade, the Port of Danube Pancevo and the Port of Prahovo) and nine Mediterranean ports in the near East area. Amount of mineral water that is dispatching from factories to Serbian ports is equal to amount that can be loaded to one container. Having containerized in Serbian ports mineral water is reloaded to the river–sea ships with unified dimensions, so the ships are continuing to travel to the near East ports. The near East ports are the ending points. Input variables in DEA problem are transportation costs and strategy resistance factor in function of container line. Time traveling of one container is in a function of container line and transportation capabilities of container lines are output variables. Transportation costs are counted on the base of integer programming method and Dijkstra algorithm. First Published Online: 05 Oct 2011

Document type: Article

Investigating the accelerated deterioration of flexible pavement using two-stage design analysis approach

Scipedia content — Fri, 12 Feb 2021 14:22:30 +0100

The accelerated deterioration of flexible pavement and its relation to design strength requirements is a major problem facing highway engineers. The goal of this research is to investigate a possible relationship between the accelerated pavement deterioration rates and pavement design strength using a two-stage design analysis approach. The approach in this study applies a two-stage solution to the three popular design methods of flexible pavement (i.e. California Department of Transportation (Caltrans) method, the American Association of State Highway and Transportation Officials (AASHTO) method, and the Asphalt Institute (AI) method) to yield pavement designs using stage load applications values specified for each investigated design load applications level. The resulting two-stage pavement designs are then used to obtain an indicator called the stage design strength ratio (percentage) defined as the ratio of the relative strength change to the design relative strength. The sample results indicate that the stage design strength ratio is relatively low compared to the corresponding increase in load applications especially at advanced service times. This could be a major contributing factor to the accelerated deterioration of flexible pavement. Therefore, it is recommended to provide initially stronger pavement structures. This can be done by either designing flexible pavement for a longer design period than the typical 20 years suggested by most design methods or using a higher terminal present serviceability index as in the case of the AASHTO design method.

Document type: Article

Assessing the value of information for retail distribution of perishable goods

Scipedia content — Fri, 12 Feb 2021 13:45:22 +0100

This paper addresses quantitative methods for estimating the value of information from ITS in urban freight distribution. A real-life application on the retail distribution of perishable goods is considered. The problem is formulated as a vehicle routing problem with soft time windows and time-dependent travel times, and solved by using information affected by different degrees of detail and reliability. The practical performance of these solutions is then evaluated by simulation, to assess the joint benefit of using more reliable and detailed information with different solution algorithms.

Document type: Article

An Assessment of Psychological Noise Reduction by Landscape Plants

Scipedia content — Fri, 12 Feb 2021 12:53:22 +0100

The emphasis in the term ‘Green Transportation’ is on the word ‘green’. Green transportation focuses on the construction of a slow transport system with a visually pleasing, easy and secure trip environment composed of urban parks, green roadside spaces and some other space that is full of landscape plants. This trip environment encourages residents to make trip choices that reduce fuel consumption and pollution and is one of the most important ways of popularizing green transportation. To study the psychological benefits provided by urban parks and other landscape environments, we combined a subjective approach (a questionnaire) with an objective quantitative approach (emotional tests using an electroencephalogram

EEG). Using a questionnaire survey, we found that 90% of the subjects believed that landscape plants contribute to noise reduction and that 55% overrated the plants’ actual ability to attenuate noise. Two videos (showing a traffic scene and a plant scene) were shown to 40 participants on video glasses. We detected and recorded EEG values with a portable electroencephalograph, and a comparison between the results of the two groups revealed that there was a highly significant asymmetry between the EEG activity of the vegetation scene and traffic scene groups. The results suggest that the emotions aroused by noise and visual stimuli are manifested in the synchronization of beta frequency band and the desynchronization of alpha frequency band, indicating that landscape plants can moderate or buffer the effects of noise. These findings indicate that landscape plants provide excess noise attenuating effects through subjects’ emotional processing, which we term ‘psychological noise reduction’.

Document type: Article

A Study of Headway Maintenance for Bus Routes: Causes and Effects of “Bus Bunching” in Extensive and Congested Service Areas

Scipedia content — Thu, 11 Feb 2021 14:25:48 +0100

A healthy and efficient public transit system is indispensable to reduce congestion, emissions, energy consumption, and car dependency in urban areas. The objective of this research is to 1) develop methods to evaluate and visualize bus service reliability for transit agencies in various temporal and spatial aggregation levels; 2) identify the recurrent unreliability trends of bus routes (focusing on high-frequency service periods) and understand their characteristics, causes and effects; and 3) model service times using linear regression models. This research utilized six months of archived automatic vehicle location (AVL) and automatic passenger count (APC) data from a low-performance route (Route 15) of TriMet, the public transit provider in the Portland metropolitan area. Route 15 has experienced difficulties in terms of schedule adherence and headway regularity. This research developed methods to summarize causes of bus bunching. The authors first determined the frequency of each cause (expressed as percentages) meeting pre-determined thresholds. Next, they performed a sensitivity analysis to demonstrate how cause percentage results change using varying difficulty levels of bus bunching thresholds. Finally, the authors investigated how cause percentage results vary spatially along different route segments. This research also developed novel ways to summarize and visualize vast amounts of bus route operations data in an insightful and intuitive manner: 1) a route/stop level visualization performance measure framework using color contour diagrams and 2) a dynamic interactive bus monitoring visualization framework based on a Google Maps platform. Visualizations proposed in this study can aid transit agency managers and operators to identify operational problems and better understand how such problems propagate spatially and temporally across routes. Finally, regression models were estimated to understand the key factors impacting dwell and travel times.

Colluvium flows as a hazard to pipelines in northeastern British Columbia

Scipedia content — Thu, 11 Feb 2021 14:22:18 +0100

Advanced Driver Assistance System Supporting Routing and Navigation for Fully Electric Vehicles

Scipedia content — Mon, 08 Feb 2021 12:35:49 +0100

The emergence of Fully Electric Vehicles has sparkled visions of pollution- and noise free cities. However, towards this challenging end, a lot has yet to be accomplished. One of the first priorities should be placed on improving the reliability and energy efficiency of the fully electric vehicles. This paper presents a new Advanced Driver Assistance System that has been implemented, which automatically helps the driver to save more energy while on-trip, by choosing the most energy efficient routes and by providing recommendations whenever necessary. This advanced functionality is based on the collection and exploitation of experiences - through machine learning.

Analytical Capacity Limits of Personal Rapid Transit Stations

Scipedia content — Mon, 08 Feb 2021 12:28:38 +0100

Personal Rapid Transit (PRT) is becoming recognised as a high quality public transport mode. However, there is little literature available for designers and planners of PRT systems, particularly on the capacity and size characteristics of stations. This article will summarize and compare estimations of capacity for serial-type and "sawtooth"-type PRT stations. Station characteristics are a complex function of geometry, vehicle dynamics, boarding strategies and user behavior. Both analytical and micro simulation techniques have been used and the capacities and space-efficiencies with various load assumptions are compared. The results will be useful for selecting the most suitable station for a given space constraint and demand scenario.

Aircraft Sequencing Problems via a Rolling Horizon AlgorithmCombinatorial Optimization

Scipedia content — Mon, 08 Feb 2021 12:27:22 +0100

ft sequencing on the runway is a challenging optimization problem that aims to reduce the delays and the air traffic controllers workload in a scenario characterized by a continuous growth of the air transportation demand. In this paper we consider the problem of sequencing both arrivals and departures on a single runway airport. We formalize the problem using a Mixed Integer Programming Model and we propose a rolling horizon solution approach. Computational results on real-world air traffic instances from the Milano Linate Airport are reported. The results show that the proposed approach is able to significantly improve on the First Come First Served (FCFS) sequence.

Architectures and tools enabling seamless mobility in future collaborative networks

Scipedia content — Mon, 08 Feb 2021 12:26:33 +0100

This paper focuses on the concept of the seamless mobility (provided by vertical handover mechanisms) in heterogeneous Future Internet Networks in the context of the HURRICANE project. We discuss future open collaborative network architectures and propose a set of entities that ensure seamless mobility and service continuity, from infrastructural/operational and business standpoints: an 802.21-like implementation of vertical handover, supported by an innovative business modelling software package, which replaces the traditional operations support stack with a more dynamic, marketplace-oriented system. We also discuss, an approach to distributed, policy-based, vertical handover management and a model for such policies, based on the monitorization and analysis of Call Detail Records that reveals users’ behavioural patterns and allows personalization. Project INFSO-ICT-216006 HURRICANE (Handovers for Ubiquitous and optimal bRoadbandconnectIvity among CooperAtive Networking Environments) Fundação para a Ciência e a Tecnologia (FCT) - Pluriannual Funding Program

Steering and evasion assist

Scipedia content — Mon, 08 Feb 2021 12:24:19 +0100

Steering and evasion assistance defines a new and future class of driver assistance systems to avoid an impending collision with other traffic participants. Dynamic and kinematic considerations reveal that an evasive steering maneuver has high potential for collision avoidance in many driving situations. Three different system layouts are described: driver-initiated evasion, corrective evasion, and automatic evasion assistance. Since an automatic steering intervention is a challenging and responsible task, the technological requirements for situation analysis and environment perception are stated. Many technical solutions for a steering intervention are conceivable; therefore several actuator concepts are discussed and assessed with respect to human machine interface (HMI) impacts. A short survey of research activities of industry and academia is given. As an example for a research level prototype, the Daimler automatic evasion assistance system for pedestrian protection is presented in detail. Based on binocular stereo vision, crossing pedestrians are detected by fusion of a pedestrian classification module with a 6D-Vision moving object detection module. Time-To-X criticality measures are used for situation analysis and prediction as well as for maneuver decision. Tested on a proving ground, the prototype system is able to decide within a fraction of a second whether to perform automatic braking or evasive steering, at vehicle speeds of urban traffic environment. By this it is shown that automatic steering and evasion assistance comes to reality and will be introduced stepwise to the market.

Is stereoscopic 3D a better choice for information representation in the car?

Scipedia content — Mon, 08 Feb 2021 12:14:29 +0100

In modern cars users need to interact with safety and comfort functions, driver assistance systems, and infotainment devices. Basic requirements include the perception of the current status and of information items as well as the control of functions. Handling that myriad amount of information while driving requires an appropriate interaction design, structure and visualization of the data. This paper investigates potentials and limitations of stereoscopic 3D for visualizing an in-vehicle information system. We developed a spatial in-car visualization concept that exploits three dimensions for the system's output. Based on a prototype, that implements the central functionality of our concept, we evaluate the 3D representation. A laboratory study with 32 users indicates that stereoscopic 3D is the better choice as it improves the user experience, increases the attractiveness, and helps the user in recognizing the current state of the system. The study shows no significant differences between non-stereoscopic and stereoscopic representations in the users' workload. This indicates that stereoscopic visualizations have no negative impact on the primary driving task.

Towards a realistic optimization of urban traffic flows

Scipedia content — Mon, 08 Feb 2021 10:17:29 +0100

In spite of recent advances in Intelligent Transport, vehicular traffic dynamics are still hard to represent and analyze. Most of the previous work on traffic regards highways or single lanes where vehicles interact in one dimension. Models for multi-dimensional vehicle-to-vehicle interactions and models for urban intersections are quite complicated and hardly applicable on a large scale. Nonetheless, urban traffic jams are an actual problem that requires a solution. This paper proposes a method to optimize urban traffic layout using basic heuristics and computationally efficient simulations. Instead of modeling an entire urban map with hundreds of intersections, each typology of intersection is simulated in order to understand how it responds to different traffic patterns and intensities. This knowledge is leveraged to allow the computation of minimal delay route on the complete road map. In order to validate our model, we use the solution obtained with our heuristic to derive the average travel delay through simulation on realistic Manhattan topologies with different intersection types. Â© 2012 IEEE.

Architecture methodology in the instant mobility project

Scipedia content — Mon, 08 Feb 2021 10:13:58 +0100

Msocket: Multiple Stack Support for the Berkeley Socket API

Scipedia content — Mon, 08 Feb 2021 10:13:33 +0100

The de-facto standard for network programming, the Berkeley socket API, supports several protocol families. Unfortunately, it has a significant limitation in only allowing a single implementation for each supported protocol family. Hence, using Berkeley sockets, it is impossible to access multiple distinct networking stacks for the same protocol, e.g. multiple TCP/IP stacks. This paper defines, msocket, an extension to the Berkeley socket API which overcomes this limitation. msocket has been implemented as a feature of the View-OS project. Finally, we illustrate the utility and effectiveness of our extended API by providing some examples of its use.

Performance assessment of congestion resolution scheduling in asynchronous 3-Level Integrated Hybrid Optical Network (A-3LIHON)

Scipedia content — Mon, 08 Feb 2021 10:08:14 +0100

This paper describes the congestion resolution mech- anism adopted in the network interfaces of the 3-Level Inte- grated Hybrid Optical Network (3LIHON). In 3LIHON, three service levels, namely guaranteed transparent service, real time statistically multiplexed packet service, and best effort basic Internet service are considered. The proposed mechanism is designed to meet Quality-of-Service requirements in future In- ternet scenarios, when mixing these traffic classes on a generic output node interface. Delay and loss performance obtained with this mechanism are evaluated by asynchronous simulation. Insights in reciprocal influence of traffic integrated on the same interface are reported and discussed for different sample hybrid traffic mixes. In particular loss for real-time traffic can be kept under reasonable values with a proper traffic dimensioning. Furthermore, delays for the best effort class are negligible compared to aggregation and propagation delays. The novel results obtained can be applied to support switch design and quality traffic engineering in hybrid networking.

A Generic Concept of a System for Predicting Driving Behaviors

Scipedia content — Mon, 08 Feb 2021 10:04:15 +0100

Today, many vehicles are equipped with Advanced Driver Assistance Systems (ADAS) to warn the driver about the potential danger of a scene, but in some situations the warning is not early enough to avoid an accident. A solution for preparing the driver and giving him the time to react to such dangerous events is to predict the behavior of other traffic participants. This paper describes a method to predict the behavior of the surrounding vehicles by a classification approach. However, the behavior alternatives strongly depend on the scenario faced by the target vehicle. Where most of the state-of-the-art approaches focus on a single scenario, the concept presented in this paper aims at a generic solution, allowing for behavior prediction for a large amount of different scenes. The idea of the method is to categorize scenes into a hierarchy from the most generic ones in the top nodes to the most specific ones in the leaves. Every node of the hierarchy is a scene containing a set of classifiers to predict the possible behaviors. GPS and digital maps provide the static information about the infrastructure, which is used to determine the nodes fitting to the current situation. As a first step this paper shows accurate prediction of traffic participants behavior in highway entrance situations for a prediction horizon of up to 3 seconds.

Development options for the Dutch gas distribution grid in a changing gas market

Scipedia content — Mon, 08 Feb 2021 10:04:02 +0100

The Dutch gas distribution grid faces several changes in the near future. Among others, the share of green gas will grow, the interaction with the electricity distribution grid and local heat grids will increase, and the grid will transform from a mono-gas system to a multi-gas system. The gas distribution grid is likely to be expanded with novel components, e.g. blending stations, gas storage sites, and gas compressor stations. Furthermore, these changes require the currently passive gas distribution grid to become a smart gas grid that monitors and controls the gas pressure, gas flow, and gas quality. Therefore, the distribution service operators need to make investments in the gas distribution grid. When looking at for example the introduction of green gas, a decision tree on the optimal green gas supply configuration can be identified. Decisions in this respect consider, among others, the location of several process steps (perform the process step locally at a small scale or centrally at a larger scale) and the addition of components like a gas storage site or a compressor station. Due to the multitude of development options for the gas distribution grid and the fact that the best solution is largely dependent on the local situation and performance criteria (e.g. CO 2 emission minimization or cost minimization), a tool is required that can generate situation specific solutions. Each solution generated by the tool should have its own advantages and disadvantages. Generating multiple options and showing the advantage and disadvantage of them provides the distribution service operators insight in the available options and eases the decision making on investments of the gas distribution grid.

Future internet for a personal travel companion service

Scipedia content — Mon, 08 Feb 2021 09:59:29 +0100

The EC-funded project Instant Mobility is defining a comprehensive architecture for transport and mobility applications that aim to innovate by introducing future Internet technologies to this domain. A set of core enabling technologies are being developed by other projects in the Future Internet PPP such as FI-WARE, while the transport domain Instant Mobility project will use these generic enablers where available, and will develop its own enablers where necessary. In this paper, we describe an Internet-based “multimodal travel platform” that provides information and services able to support new types of connected transport applications. The considered scenario, a “Personal Travel Companion”, is centred on multimodal travellers (both drivers and passengers). Almost all modes of transport are present in this scenario: private car, public transport modes, car sharing, ride sharing, bikes, etc. The project defines requirements for future Internet technology tools and enablers that can support services available to any Internet-connected traveller, whether using a portable, vehicle-based or fixed terminal. Future Internet technologies offer new horizons for transport information systems and propose for travellers a new experience with means of transport. We are designing and implementing a prototype for multimodal travel assistance taking advantage of these technologies. A demonstration of the application is planned in the ITS world congress - Vienna 2012, while the final prototype is due on March 2013.

A smart communication gateway for V2I applications in Public Transport

Scipedia content — Mon, 08 Feb 2021 09:59:04 +0100

In this paper, we present a smart gateway which improves communication between future Public Transport vehicles and their back-offices. This gateway implements context based wireless access network selection and improves end-toend communication Quality of Service (QoS) responding by this way to the requirements of the new intelligent transportation systems architecture developed in Europe through the European Bus System of the Future (EBSF) project. This Service Oriented Architecture (SOA) allows resource sharing such as Vehicle to Infrastructure communications (V2I). We show that the proposed smart gateway respond to the requirements of the EBSF project and going straightforward we demonstrate its effectiveness in an alarm scenario which is a critical scenario that the gateway has to handle.

Understanding road scenes using visual cues and GPS information

Scipedia content — Mon, 08 Feb 2021 09:57:44 +0100

Understanding road scenes is important in computer vision with different applications to improve road safety (e.g., advanced driver assistance systems) and to develop autonomous driving systems (e.g., Google driver-less vehicle). Current vision---based approaches rely on the robust combination of different technologies including color and texture recognition, object detection, scene context understanding. However, the performance of these approaches drops---off in complex acquisition conditions with reduced visibility (e.g., dusk, dawn, night) or adverse weather conditions (e.g., rainy, snowy, foggy). In these adverse situations any prior information about the scene is relevant to constraint the process. Therefore, in this demo we show a novel approach to obtain on---line prior information about the road ahead a moving vehicle to improve road scene understanding algorithms. This combination exploits the robustness of digital databases and the adaptation of algorithms based on visual information acquired in real time. Experimental results in challenging road scenarios show the applicability of the algorithm to improve vision---based road scene understanding algorithms. Furthermore, the algorithm can also be applied to correct imprecise road information in the database.

Semi-Supervised Training Set Adaption to Unknown Countries for Traffic Sign Classifiers

Scipedia content — Mon, 08 Feb 2021 09:56:53 +0100

Traffic signs in Western European countries share many similarities but also can vary in colour, size, and depicted symbols. Statistical pattern classification methods are used for the automatic recognition of traffic signs in state-of-the-art driver assistance systems. Training a classifier separately for each country requires a huge amount of training data labelled by human annotators. In order to reduce these efforts, a self-learning approach extends the recognition capability of an initial German classifier to other European countries. After the most informative samples have been selected by the confidence band method from a given pool of unlabelled traffic signs, the classifier assigns labels to them. Furthermore, the performance of the self-learning classifier is improved by incorporating synthetically generated samples into the self-learning process. The achieved classification rates are comparable to those of classifiers trained with fully labelled samples.

Spatial ray features for real-time ego-lane extraction

Scipedia content — Mon, 08 Feb 2021 09:51:26 +0100

In order to support driver assistance systems in unconstrained environments, we propose to extend local appearance-based road classification with a spatial feature generation and classification. Therefore, a hierarchical approach consisting of multiple low level base classifiers, the novel spatial feature generation, as well as a final road terrain classification, is used. The system perceives a variety of local properties of the environment by means of base classifiers operating on patches extracted from monocular camera images, each represented in a metric confidence map. The core of the proposed approach is the computation of spatial ray features (SPRAY) from these confidence maps. With this, the road-terrain classifier can decide based on local visual properties and their spatial layout in the scene. In order to show the feasibility of the approach, the extraction and evaluation of the metric ego-lane driving corridor on an inner city stream is demonstrated. This is a challenging task because on a local appearance level, ego-lane is not distinguishable from other asphalt parts on the road. However, by incorporating the proposed SPRAY features the distinction is possible without requiring an explicit lane model. Due to the parallel structure of this bottom-up approach, the implemented system operates in real-time with approximately 25 Hz on a GPU.

A sequential testing approach for change-point detection on bus door systems

Scipedia content — Mon, 08 Feb 2021 09:47:43 +0100

Detecting change-points and anomalies on sequential data is common in various domains such as fraud detection for credit cards, intrusion detection for cyber-security or military surveillance [1]. This study is motivated by the predictive maintenance of pneumatic doors in transit buses. For this purpose, buses are instrumented and data are collected through embedded sensors. Inspired by the CUSUM and GLR approaches, this paper deals with on-line change-point detection on sequential data where each observation consists in a bivariate curve. The system is considered out of control when a change occurs in the curves probability distribution. A specific regression model is used to describe the curves. The unknown parameters of this model are estimated using the maximum likelihood principle. Experimental studies performed on realistic data demonstrate the promising behavior of the proposed method.

Weather applications and services in field operational tests

Scipedia content — Mon, 08 Feb 2021 09:43:28 +0100

The European Commission has a key role in Europe to fund initiatives to put effectively into practice important ITS objectives, solutions and applications which contribute to safer and more sustainable transportation systems. One outcome is the 7th Framework Programme project FOTsis (Field Operational Test on safe, intelligent and sustainable road operation). FOTsis is a large-scale ITS field test of road infrastructure management systems implemented at nine test highways in four European countries. Weather-driven solutions and services have a fundamental role in the FOTsis service palette due to the fact that adverse weather accounts for some of the most notorious disruptions in road transportation and addressing huge economic impacts. The FOTsis end-to-end weather applications represent both the realization of a multi-disciplinary solution-oriented approach applied in the road transportation field, and the employment of weather information in a near-real-time context. The FOTsis framework was introduced at the previous ITS World Congress, Vienna 2012. The present paper illustrates the first practical solutions implemented at the dedicated FOTsis test highways in summer 2013. Future perspectives of the project are also highlighted.

Air traffic management in the single European sky : standardisation of safety and liability issues

Scipedia content — Sun, 07 Feb 2021 13:38:19 +0100

This paper aims to analyse the European system of Air Traffic Management (ATM) as a specific case study of risk regulation in the framework of the European integration process. At the present, the implementation of the Single European Sky is a growing area of EU policy, which shows the potential and the difficulties of coordinating national competences in a supranational regulatory framework. This search for coordination has a direct impact on air traffic safety itself and it involves the development of risk mitigation policies at both the EU level and at the level of individual Member States. The existing trade off between risk and safety as conveyed by technology affects both the instruments and the content of risk management. Since the failure of safety measures when providing air services could result in disaster, regulation needs to address this issue. Two main questions assist in the implementation of the regulatory framework: what level of protection is appropriate against such uncertainty and the risks of possible catastrophic impact, and who bears the risk in case the delivered safety system fails. Precautionary safety standards on the one hand and liability remedies on the other are therefore addressed as the key issues for the regulation and distribution of risks. By focusing on these issues, the fragmentation of the current legal framework in ATM illustrates the current legal difficulties in the integration of the European skies.

Bottom-up quantifications of selected measures to reduce GHG emissions of transport for the time horizons 2020 and 2050. Cost assessment of GHG mitigation measures of transport: Deliverable D 3.1 (D3); Annex 1: Road Technology Measures; Annex 2.1: Road Mode - Universal Policy Measures; Annex 2.2: Road Mode - Urban Measures; Annex 3: Rail Transport Mode Measures; Annex 4: Shipping Mode Measures; Annex 6.1: Alternative Fuel Measures - Biofuels; Annex 6.2: Alternative Fuel Measures - Hydrogen

Scipedia content — Sun, 07 Feb 2021 13:38:06 +0100

This report extends the analysis of single measures (i.e. technologies and policies) to reduce GHG emissions of transport by a cost assessment for each measure. Costs are assessed from different perspectives. In particular the user perspective and the society perspective have been applied for the analysis in GHG-TransPoRD. As a starting point an approach consisting of five levels of sophistication for cost assessments has been developed to provide a generic framework for the cost assessment. The most sophisticated levels were based on the learning curve concept. However, it turned out that these concepts were applicable for road technologies and biofuels only, while the empirical database for other modes was too limited. Thus depending on the measure abatement cost by measure have been assessed taking the different perspectives and applying different levels of sophistication. This limits the comparability of abatement cost across modes, though within each mode / area abatement cost of different measures should be comparable. Draft cost estimates have been presented and discussed with stakeholders at the 3rd workshop "http://www.ghg-transpord.eu/ghg-transpord/inhalte/events/workshop3.php" of GHG-TransPoRD. Additionally to the cost assessment a patent analysis is carried out on major technologies like fuel cells, hybrid and electric vehicles, lithium-ion batteries and biofuels. This analysis should support the assessment of future cost of such technologies. These cost trends or directly the learning curves will be implemented in the GHG-TransPoRD models for the scenario analysis in WP4. These trends constitute the main output of this deliverable.

Bridging the high level policy context - conclusions and recommendations: Deliverable D 5.2

Scipedia content — Sun, 07 Feb 2021 13:37:41 +0100

This report summarizes and reflects the scenario and policy related activities of GHG-TransPoRD starting with the policy description of the Energy Framework (see D2.1) and the Reference Scenario (see D4.1). Concerning the latter it makes a qualitative exploration of the robustness of all scenarios tested by considering the possibility of alternative reference scenarios than the one chosen by the project, essentially by posing the question "if the world, and hence the EU, were to develop in a different way to that specified by the Reference Scenario, what difference would this make to the perceived success or failure of respective policy packages". In answering this question, it creates a framework of alternative (reference) scenarios which is consistent with recent thinking on scenario concepts provided by researchers associated with the Intergovernmental Panel on Climate Change (IPCC). Building on both indicator studies on sustainable transport and the available output indicators of the integrated assessment model tool box of GHG-TransPoRD an assessment framework is developed and filled by the results of the scenarios. The assessment framework integrates economic, environmental and social indicators, and is applied to identify the distribution of costs and benefits between users, government, urban and inter-urban trips as well as between Member States of the different scenarios. It is noted that the observed somewhat uneven distribution of costs and benefits between users, government, urban trips, inter-urban trips and between Member States suggests that a number of implementation challenges will exist. Policies which are inequitable are typically unpopular, furthermore policies which are expensive for government would be also difficult to implement. Transport policies will therefore be needed to address these imbalances, and economic policies will need to ensure growth is maximised, but without sacrifycing equality. The spatial variation in impacts between Member States would suggest that policy needs to be sensitive to local conditions. Finally, the report presents some alternative future images of society as well as their implications for transport and summarizes the recommendations of GHG-TransPoRD that have been developed building on the quantitative analysis (see D4.1) and taking into account the scenario and policy considerations in this report.

Enhancing the Value of an Incidents Database with an Interactive Visualization Tool

Scipedia content — Wed, 03 Feb 2021 22:01:36 +0100

The growing capabilities of computational tools and the advent of multiple data providing systems have increased the needs and ability to process large sets of microscopic data. Since the data are not directly suited for analysis or modeling, they are often stocked without further question, while they could shine a new light on critical traffic phenomena such as congestion. This research is a spin-off of a project on the modelling of travel time reliability on highway corridors. The project relies on floating cars data but has also led to the exploration of historical incidents datasets that required various pre-processing steps. A visualization tool was developed using Microsoft Excel in an innovative way. This paper reports on the development of this tool that provides some insight into the analytical potentialities of the incident databases. Four years of data are examined and converted into usable information through cross-examination and interactivity.