Search results for " transportation"
showing 10 items of 511 documents
Two-Player Noncooperative Games over a Freight Transportation Network''
2004
A game between two players acting on the same road transportation network is considered in this paper. The first player aims at minimizing the transportation costs, whereas the second player aims at maximizing her profit (or, in general, her utility) that is proportional to the flow passing through the arcs under her control. We introduce bilevel linear programming formulations for this problem. We derive conditions of existence and properties of the equilibrium points and propose an algorithm finding a local optimal solution. Finally, we present an application of the model to a real system involving trucks travelling through Europe from a Middle Eastern country.
The environmental benefits of carsharing: The case study of Palermo
2020
Abstract The problems related to traffic emissions are becoming increasingly pressing and serious, especially in big cities where the private car plays the main role in the mobility of people, being excessively used, while walking, cycling and the use of public transport are often seen as secondary options and are hampered by a poorly urban environment. Therefore, solutions must be found to reduce the number of cars circulating in the city and to support the most sustainable modes of transport at the same time, in order to reduce emissions of greenhouse gases and harmful substances. A modal alternative which is of undoubted interest could be represented by carsharing, which is a mode comple…
Measuring spatial concentration: A transportation problem approach
2019
This paper will propose an index for measuring spatial concentration, which is based on the solution of a particular transportation problem. This approach extends a new index proposed for the measurement of seasonality to the spatial case, and it takes into account the level of the concentration of the phenomenon of interest according to its spatial distribution. Various properties of the proposed index, which make it a desirable measure for spatial concentration, will also be described. An empirical application, using data from selected European countries, will be provided, and the results derived from the proposed index will be compared with those derived from currently used indices. Este…
Online shortest paths with confidence intervals for routing in a time varying random network
2018
International audience; The increase in the world's population and rising standards of living is leading to an ever-increasing number of vehicles on the roads, and with it ever-increasing difficulties in traffic management. This traffic management in transport networks can be clearly optimized by using information and communication technologies referred as Intelligent Transport Systems (ITS). This management problem is usually reformulated as finding the shortest path in a time varying random graph. In this article, an online shortest path computation using stochastic gradient descent is proposed. This routing algorithm for ITS traffic management is based on the online Frank-Wolfe approach.…
Public transportation and fear of crime at BRT Systems: Approaching to the case of Barranquilla (Colombia) through integrated choice and latent varia…
2021
Abstract Security perception and Fear of Crime (FoC) in urban scenarios have the potential to affect travel behavior, changing people’s travel choices and patterns. In this sense, the feeling of being “safe” or “at-risk” in public transportation not only depends on observable factors like illumination, travel companionship or transport crowding, but also on unobservable individual-specific latent attributes, among which fear of crime constitutes a major issue to consider in transport security policy-making. This study aimed to describe the relationships among sociodemographic features, travel situations, system-design features, and the Fear of Crime at three different locations (buses, bus …
Special Section on ITS Services to Smart City Context [Guest Editorial]
2018
The seven articles in this special section focus on new trends and developments in the intelligent transportation markets. Since the earliest of times, transportation has changed and revolutionized society and industry. Many of technology advances were focused on transportation and their means (road, rail, air, water, etc.) even, today there exist several areas of the knowledge that are focused on it. As time goes by, new terms have been established where technology is present as well, for instance, Intelligent Transportation Systems (ITS), Smart Cities, Smart Territory, Blockchain, Internet of Things, virtualization, Cloud computing, Intelligent Vehicles, embedded computing, Deep learning,…
Energy and environmental life cycle assessment of an institutional catering service: An Italian case study
2019
Food production is recognised as one of the major drivers for global environmental pressure. In the last years, changes in consumption models result in an increasing population consuming food out of home that pose the catering service sector at the centre of the European Union policies aimed at improving the environmental sustainability of the food sector. In this framework, better technical knowledge on the environmental impacts of catering service is essential in order to identify potential actions towards a more sustainable food sector. This article presents an environmental assessment of a school catering service operating in Italy and delivering approximately 2,518,128 meals per year. …
Activity report of the French transportation geographers
2010
The Transportation Commission of the Comité National Français de Géographie (led by president J. Varlet, Université de Savoie in Chambéry, and secretary M.-A. Lanneaux, University of Lille) is made up of 46 members as of June 1st, 2010, not including a number of geographers not registered with the Commission but doing research in transportation.
'Not as safe as I believed': Differences in perceived and self-reported cycling behavior between riders and non-riders
2021
Cycling behavior remains a key issue for explaining several traffic causalities occurring every day. However, recent studies have shown how the assessment of the own safety-related behaviors on the road may substantially differ from how third parties assess them. Thus, the aim of this study was to evaluate the differences between cyclists’ self-reported behavior and the proxy-reported behavior that other (non-cyclist) road users perceive from bike riders. For this purpose, this study used data from two samples: (i) 1064 cyclists (M = 32.83 years) answering the Cycling Behavior Questionnaire—CBQ, and (ii) 1070 non-cyclists (M = 30.83 years) answering an adapted version of the CBQ for externa…
Fuzzy Discrete Event Simulation for Fuzzy Production Systems Analysis
1998
Abstract Fuzzy production systems are characterised by vagueness in data and requirements that very often cannot be reduced to stochastic models. Therefore, such production systems cannot be analysed by using classical techniques such as Queue Theory or Discrete Simulation Analysis. On the other hand the great diffusion of Fuzzy Production environments in small and medium enterprises claims for the development of new analysis tools. This paper proposes a new approach to Discrete Event Simulation able to treat with fuzzy variables. A new methodology has been proposed to process fuzzy information within discrete event simulation and a prototype of a Fuzzy Discrete Event Simulator has been dev…