Search results for "050210 logistics & transportation"
showing 10 items of 331 documents
Branch-Price-and-Cut for the Soft-Clustered Capacitated Arc-Routing Problem
2021
The soft-clustered capacitated arc-routing problem (SoftCluCARP) is a variant of the classical capacitated arc-routing problem. The only additional constraint is that the set of required edges, that is, the streets to be serviced, is partitioned into clusters, and feasible routes must respect the soft-cluster constraint, that is, all required edges of the same cluster must be served by the same vehicle. In this article, we design an effective branch-price-and-cut algorithm for the exact solution of the SoftCluCARP. Its new components are a metaheuristic and branch-and-cut-based solvers for the solution of the column-generation subproblem, which is a profitable rural clustered postman tour …
Arc routing problems: A review of the past, present, and future
2020
[EN] Arc routing problems (ARPs) are defined and introduced. Following a brief history of developments in this area of research, different types of ARPs are described that are currently relevant for study. In addition, particular features of ARPs that are important from a theoretical or practical point of view are discussed. A section on applications describes some of the changes that have occurred from early applications of ARP models to the present day and points the way to emerging topics for study. A final section provides information on libraries and instance repositories for ARPs. The review concludes with some perspectives on future research developments and opportunities for emergin…
A branch-and-cut algorithm for the Profitable Windy Rural Postman Problem
2016
[EN] In this paper we study the profitable windy rural postman problem. This is an arc routing problem with profits defined on a windy graph in which there is a profit associated with some of the edges of the graph, consisting of finding a route maximizing the difference between the total profit collected and the total cost. This problem generalizes the rural postman problem and other well-known arc routing problems and has real-life applications, mainly in snow removal operations. We propose here a formulation for the problem and study its associated polyhedron. Several families of facet-inducing inequalities are described and used in the design of a branch-and-cut procedure. The algorithm…
Solving the length constrained K-drones rural postman problem
2021
[EN] In this paper we address the Length Constrained K-Drones Rural Postman Problem (LC K-DRPP). This is a continuous optimization problem where a fleet of homogeneous drones have to jointly service (traverse) a set of (curved or straight) lines of a network. Unlike the vehicles in classical arc routing problems, a drone can enter a line through any of its points, service a portion of that line, exit through another of its points, then travel directly to any point on another line, and so on. Moreover, since the range of the drones is restricted, the length of each route is limited by a maximum distance. Some applications for drone arc routing problems include inspection of pipelines, railwa…
Examining the effect of adverse weather on road transportation using weather and traffic sensors.
2018
Adverse weather related to reduced visibility caused by fog and rain can seriously affect the mobility and safety of drivers. It is meaningful to develop effective intelligent transportation system (ITS) strategies to mitigate the negative effects of these different types of adverse weather related to reduced visibility by investigating the effect of rain and fog on traffic parameters. A number of previous researches focused on analyzing the effect of adverse weather related to reduced visibility by using simulated traffic and weather data. There are few researchers that addressed the impact of adverse weather instances using real-time data. Moreover, this paper conducts comprehensive inves…
Detection of steering direction using EEG recordings based on sample entropy and time-frequency analysis.
2016
Monitoring driver's intentions beforehand is an ambitious aim, which will bring a huge impact on the society by preventing traffic accidents. Hence, in this preliminary study we recorded high resolution electroencephalography (EEG) from 5 subjects while driving a car under real conditions along with an accelerometer which detects the onset of steering. Two sensor-level analyses, sample entropy and time-frequency analysis, have been implemented to observe the dynamics before the onset of steering. Thus, in order to classify the steering direction we applied a machine learning algorithm consisting of: dimensionality reduction and classification using principal-component-analysis (PCA) and sup…
Aviation Crew Recovery Experiences on Outstations
2016
Abstract ACMI flight crews spend considerable time away from home on outstations. This study suggests that this long term stay carries its own considerations in regards to rest recovery with practical implications for Fatigue Risk Management as prescribed by ICAO. Four recovery experiences, Work Detachment, Control, Relaxation and Mastery, are identified and correlated with 28 crew behaviours on base. The results indicate improvement considerations for airline management organizing a long term contract with ACMI crews, in particular to increase schedule stability to improve the crew member’s sense of Control.
Optimization of urban delivery systems based on electric assisted cargo bikes with modular battery size, taking into account the service requirements…
2021
The implementation of new forms of urban mobility is a fundamental challenge for improving the performance of city logistic systems in terms of efficiency and sustainability. For such purposes, the exploitation of electric vehicles is currently being investigated as an alternative to traditional internal combustion engines. In particular, the employment of lightweight electric cargo bikes is seen as an attractive possibility for designing improved city distribution systems. Such vehicles, however, present substantial limitations related to their endurance, speed, power, and recharging times; therefore, their configuration must be optimized considering the actual operational context and the …
SOCIAL NETWORKS, BIG DATA AND TRANSPORT PLANNING
2016
[EN] The characteristics of people who are related or tied to each individual affects her activity-travel behavior. That influence is especially associated to social and recreational activities, which are increasingly important. Collecting high quality data from those social networks is very difficult using traditional travel surveys, because respondents are asked about their general social life, which is most demanding to remember that specific facts. On the other hand, currently there are different potential sources of transport data, which is characterized by the huge amount of information available, the velocity with it is obtained and the variety of format in which is presented. This s…
Worldwide research output trends on drinking and driving from 1956 to 2015.
2020
This study seeks to analyze worldwide research activity on drinking and driving of macro-actors (countries and research fields) and meso-actors (institutions, journals, articles, co-substance(s) studied) during the last 6 decades (between 1956 and 2015). Web of Science and Elsevier Scopus were searched using terms referred to drinking and driving, including terms related to vehicles and way spaces. Overlapping was excluded and absence of false positives was confirmed. Articles on alcohol with/without other psychoactive substances were assessed quantitatively (bibliometric measures). Well identified by All Science Journal Classification system (ASJC) (Elsevier Scopus), an increase in the num…