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showing 10 items of 8951 documents
The facility location problem with capacity transfers
2020
Abstract This paper explores the concept of capacity transfer in the context of capacitated facility location problems. This is accomplished by assuming that facilities with surplus capacity/production can cooperate with those facing shortage by transferring part of that capacity/production. Such a transfer incurs a cost that nonetheless may be compensated by savings both in the installation costs and in the distribution costs. Mixed-integer mathematical programming models are proposed for the problem. A distinction is made between the case in which the triangle inequality holds for the transfer costs and the case in which it does not. We present compact models, which are enhanced with vali…
Messages beyond the phone: Processing variable message signs while attending hands-free phone calls.
2021
We examined the effects of different types of cognitive distraction coming from a hands-free phone conversation on the processing of information provided by variable message signs (VMS), on driving performance indicators, and on a physiological index of mental effort (heart rate). Participants drove a route in a driving simulator and had to respond to VMS messages under three conditions: no-distraction, visuospatial distraction (attending phone calls with questions inducing visuospatial processing), and conceptual distraction (attending phone calls with questions requiring semantic memory). Results showed more errors responding to VMS messages in the visuospatial distraction condition. In a…
Relative Reachability Analysis as a Tool for Urban Mobility Planning
2019
There is a plethora of user-oriented route planning applications and systems that enable the computation of the fastest journey between two locations using different transportation modes, e.g., car, public transport, walking, bicycle. While useful for individuals, they are of limited interest to a class of users that may be interested in a more global and comparative view of transportation systems in general. In this context, we adopt the view of an urban planner. Urban planners may be interested in queries such as "if a new transit stop was to be introduced in a given location, would that bring the travel time to a given point-of-interest (POI) or area-of-interest (AOI) by bus closer to th…
Does higher technical efficiency induce a higher service level? A paradox association in the context of port operations
2020
Abstract Researchers and practitioners are benchmarking technical efficiency of ports and exploring the drivers of high efficiency. Paradoxically, this study argues that high technical efficiency (TE = 1) is not always essential, but an optimal level needs to be achieved while balancing the port service level. This study applies data envelopment analysis (DEA) and free disposal hull (FDH) methods to perform efficiency rankings of 38 container terminals from 17 different ports in 12 Asian countries. Four terminals are technically efficient (TE = 1) in all frontier approaches, thereof one Bangladeshi, one Chinese, one Indian and one Vietnamese. Furthermore, this study presents a case study co…
Measuring situations that stress Mexicans while driving
2016
The purpose of this paper is to construct a scale that will help determine the aspects involved in driving a motor vehicle that influence the levels of stress in a human being. Two complementary studies were conducted: the first one determined, by qualitative methods, the aspects of driving that 103 participants found most stressful whilst driving; the second was a validation of the scale constructed with said information on 295 participants (142 males, 153 females, age mean 37.41, std. dev. 14.008). The scale included 22 situations that were then evaluated on a Likert scale to assess the level of stress they evoke. These items were arranged on 3 factors, and descriptive statistics were com…
How is the Driver's Workload Influenced by the Road Environment?
2017
Abstract This paper focuses on the study of the driver's workload while driving on a rural two-lane road with different traffic flows. The aim of the research is to examine a parameter that could be representative of the driving effort, quite sensible to the external factors that cause disturbance to the regular driving activity. To solve this problem, the authors used a specific instrumented vehicle for monitoring some physiological parameters of the driver (as the eye movements and the Galvanic Skin Resistance), referring their values to the road context. The results are very interesting and confirm that knowing the workload is useful to improve the road safety only if it is related to th…
Methodology and trends for an intelligent transport system in developing countries
2018
Abstract Increasingly, the technologies that are used in telecommunications contribute to improve intelligent transport systems. These technologies are systems that offer several concepts like vehicular ad hoc networks, which allow reduction of traffic accidents, traffic congestion and consequently increase road safety and the comfort of road users. Developing countries in general and those of sub-Sahara in particular do not have telecommunication infrastructures, even road infrastructures for the implementation of an intelligent transport system. Moreover, with the serious increase in vehicles in these countries, the problem of traffic regulation arise especially in the inter-urban context…
Assessing cruise port of call performance: a passenger-based approach using PLS modelling
2017
ABSTRACTIn the present context of booming cruise demand, the study aims to advance the knowledge on port of call performance from cruise passengers’ perspective. The aim of this investigation was twofold: (1) to examine the structural links among port of call perceived quality–satisfaction–future intentions (revisit and word-of-mouth (WOM) behaviour); and (2) to test the moderating effect of cruisers’ motivation (push versus pull factors) to visit the port of call on the proposed structural links. Partial least squares path modelling was used to test the proposed model with a sample of 492 cruise passengers at a Mediterranean port of call. The findings revealed that port of call quality has…
Cimo: An efficient 2-phases calculator of multimodal itineraries for real trans-territories based on a dynamic programming
2015
In this work we propose an exact solution for calculating multimodal itinerary. This solution is named Cimo (Calculateur d'Itineraires Multimodaux Ordonnes). Cimo is an exact optimal itineraries' calculator wherein itineraries are sorted, multimodal, and trans-territorial. The solution is based on a dynamic programming algorithm "cut", "price" and "share". This solution is multi-objectives and multi-constraints. Several versions of this algorithm are proposed following a methodological approach that enables evaluation of efficiency and complexity's gain : through theoretical calculus and benchmarks. In the first version of realistic problem, we propose a solution with itineraries calculated…
Branch-and-price-and-cut for a service network design and hub location problem
2015
In the context of combined road-rail freight transport, we study the integrated tactical planning of hub locations and the design of a frequency service network. We consider a number of real-world constraints such as multiple transshipments of requests at hubs, transport time limits for requests, request splitting, and outsourcing possibilities. To our knowledge, the combination of problem features we deal with has not been described before. We present a path-based model and solve it with a branch-and-price-and-cut algorithm. Computational experiments show that large realistic instances from a major German rail freight company can be solved close to optimality within one hour on a standard …