Search results for "Transportation"
showing 10 items of 860 documents
Mindfulness, inattention and performance in a driving simulator
2015
The following study will explore the link between mindfulness, driver inattention and a number of driving performance variables that were tested using the SIMUVEG driving simulator. 67 subjects between the ages of 19 and 27 completed the mindful attention awareness scale, attention-related driving errors scale and attention-related cognitive errors scale questionnaires, and were evaluated in two driving performance measures: time to line-crossing and mean speed. The results did not show a correlation between driving performance and mindfulness measures; they did show low but significant correlations with driver inattention measures. A regression analysis suggested that the specific measure …
In-Depth Analysis of Pricing Problem Relaxations for the Capacitated Arc-Routing Problem
2015
Recently, Bode and Irnich [Bode C, Irnich S (2012) Cut-first branch-and-price-second for the capacitated arc-routing problem. Oper. Res. 60(5):1167–1182] presented a cut-first branch-and-price-second algorithm for solving the capacitated arc-routing problem (CARP). The fundamental difference to other approaches for exactly solving the CARP is that the entire algorithm works directly on the typically sparse underlying graph representing the street network. This enables the use of highly efficient dynamic programming-based pricing algorithms to solve the column-generation subproblem also known as the pricing problem. The contribution of this paper is the in-depth analysis of the CARP pricing…
Effective Handling of Dynamic Time Windows and Its Application to Solving the Dial-a-Ride Problem
2015
A dynamic time window relates to two operations that must be executed within a given time meaning that the difference between the points in time when the two operations are performed is bounded from above. The most prevalent context of dynamic time windows is when precedence is given for the two operations so that it is a priori specified that one operation must take place before the other. A prominent vehicle routing problem with dynamic time windows and precedence is the dial-a-ride problem (DARP), where user-specified transportation requests from origin to destination points must be serviced. The paper presents a new branch-and-cut-and-price solution approach for the DARP, the prototypi…
An Online Time Warping based Map Matching for Vulnerable Road Users’ Safety
2018
International audience; High penetration rate of Smartphones and their increased capabilities to sense, compute, store and communicate have made the devices vital components of intelligent transportation systems. However, their GPS positions accuracy remains insufficient for a lot of location-based applications especially traffic safety ones. In this paper, we developed a new algorithm which is able to improve smartphones GPS accuracy for vulnerable road users' traffic safety. It is a two-stage algorithm: in the first stage GPS readings obtained from smartphones are passed through Kalman filter to smooth deviated reading. Then an adaptive online time warping based map matching is applied to…
From cars to bikes – the feasibility and effect of using e-bikes, longtail bikes and traditional bikes for transportation among parents of children a…
2017
Abstract Background The present study aims to increase bicycling and level of physical activity (PA), and thereby promote health in parents of toddlers, by giving access to different bicycle types. There is a need for greater understanding of e-bikes and their role in the transportation network, and further effects on PA levels and health. Moreover, longtail bikes could meet certain practical needs not fulfilled by e-bikes or traditional bikes, hence increased knowledge regarding their feasibility should be obtained. No previous studies have investigated whether providing an e-bike or a longtail bike over an extended period in a sample of parents of toddlers influence objectively assessed a…
Rail freight transport and demand requirements : an analysis of attribute cut-offs through a stated preference experiment
2014
This paper analyses the choice between road and rail in Spain where rail market share for freight is still residual. Discrete choice models are estimated with data obtained through a two-phase fieldwork, thus allowing us to carry out a stated preference efficient design for each interviewee. We analyse the existence of attribute cut-offs and the presence of a segment of the population with a zero value of frequency. Our results show that ignoring the existence of cut-offs and segments of the population with polarised valuations can lead to erroneous conclusions in terms of the possibilities of rail for absorbing significant quota.
Geovisualizing the sail-to-steam transition through vessel movement data
2017
International audience; Technological transitions in the maritime and port industries go along with increased transport and economic efficiency, resulting in faster movements and longer travelled distances. Yet, such transformations may also enhance disparities between winners and loosers, should they be ports or shipping companies. This research focuses on the particular case of the transition from sail to steam over the period 1890-1925, which witnesses the rapid replacement of sailing vessels, the latter concentrating 65% of the world fleet in 1890 but only 3.5% in 1925. It applies a variety of measures to compare how these two layers overlap in the network (at links and ports) and what …
Smart cities approach for Colombian Context. Learning from ITS experiences and linking with government organization
2015
The forecast (world bank) related to the growth of world population tends to be around 9000 million to 2050 and most of the people will live in the cities or in conurbations, this means that, a new approach for support the development of the cities needs to be analyzed. Currently, the mankind has developed and produce a lot of technology advances and many of them are related to the Information and communications technology (ICT). In this way, ICT has become in a key element for the development of the cities, even, introduce the ICT concept in the context of the cities has provoked a new scope for the cities that is called Smart City or Digital City. In this paper, it is presented an approac…
Does Urban Security Modulate Transportation Choices and Travel Behavior of Citizens? A National Study in the Dominican Republic
2020
Introduction: Traditionally, the scientific literature on urban and transportation dynamics addresses many topics, but the security-related outcomes of users remain a pending issue, especially in emerging countries and their cities. Nevertheless, recent evidence suggests that, especially in developing countries, security issues may influence people’s decision-making in the choice of transport means, daily urban-trip patterns and road behaviors of users. Objective: The purpose of this study was to explore the relationships between the perceived security (in both urban environments and public transport systems) and the daily-travel behavior and trip patterns of the Dominican Republic populati…
Cost analysis of the facilities deterioration in wastewater treatment plants: A dynamic approach
2019
Abstract The implementation of the Directive 91/271 / CEE resulted in the proliferation of new Wastewater Treatment Plants (WWTPs) all around Europe. These facilities, which are compound by a wide range of assets (civil works, electromechanical equipment, pipelines, etc.), are ageing and deteriorating having an impact on the efficiency of the process. It is founded that repairs and corrective maintenance costs have increased in the last years, due to the deterioration process. Therefore, the aim of the present study is to focus on the cost effects of the deterioration process of the facilities in different wastewater treatment technologies. The analysis of these impacts will allow the opera…