Search results for "Transportation"
showing 10 items of 860 documents
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…
The Windy clustered prize-collecting arc-routing problem
2011
This paper introduces the windy clustered prize-collecting arc-routing problem. It is an arc-routing problem where each demand edge is associated with a profit that is collected once if the edge is serviced, independent of the number of times the edge is traversed. It is further required that if a demand edge is serviced, then all the demand edges of its component are also serviced. A mathematical programming formulation is given and some polyhedral results including several facet-defining and valid inequalities are presented. The separation problem for the different families of inequalities is studied. Numerical results from computational experiments are analyzed. © 2011 INFORMS.
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…
Artilleriâ Velikogo Knâžestva Litovskogo v XVII v. : finansirovanie, voennye transportnye rashody, remeslennaâ rabota
2015
State artillery in Lithuania in the seventeenth century was relatively neglected area of military and only from 1637 years it constituted a separate body. In the second half of the seventeenth century cannon in the arsenals of Lithuania were outdated and there were rarely works with new ones. During this period, it also struggled with the problem of its unification. In the Grand Duchy of Lithuania there was also a private artillery, and the law allowed anyone nobleman, if he could afford it, to have a cannon. The private fortresses they were much more modern than the artillery State. Another issue was transporting artillery to the war,which was associated with the employment of many people,…
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…
Destination Attractiveness Drivers among Urban Hostel Tourists: An Analysis of Frustrators and Delighters
2015
This study is based on data from 679 tourists staying at hostel accommodation facilities in Zagreb, a propulsive city-break destination in Central Europe. Besides providing insight into the socio-demographic and behavioural characteristics of hostel tourists, this study uncovers determinant destination attributes influencing their perceptions of destination attractiveness. In particular, impact asymmetry analysis identified potential sources of delight and frustration among hostel tourists. Since the hostel tourist segment, as such, is almost completely unconsidered in contemporary tourism research, partly covered only by a few studies on youth travellers and backpackers, the results of thi…
Assessing the electricity consumption of outdoor lighting systems in the presence of automatic control: The OL-BAC factors method
2020
Abstract Building automation systems are able to influence significantly buildings’ energy performance. The BAC factors method, presented for the first time by the International Standard EN 15232, is the most used and simple instrument for evaluating the impact of such systems in terms of reduction of the electrical and thermal energy consumption of buildings services. Nevertheless, Standard EN 15232 does not take into consideration the automation of lighting systems serving buildings’ external areas like passages, gardens, entrance walkways, etc. In some cases, such areas can be very extended and, as a consequence, responsible for a not negligible percentage of the overall electricity cons…
Application of Radio Environment Map Reconstruction Techniques to Platoon-based Cellular V2X Communications
2020
Vehicle platoons involve groups of vehicles travelling together at a constant inter-vehicle distance, with different common benefits such as increasing road efficiency and fuel saving. Vehicle platooning requires highly reliable wireless communications to keep the group structure and carry out coordinated maneuvers in a safe manner. Focusing on infrastructure-assisted cellular vehicle to anything (V2X) communications, the amount of control information to be exchanged between each platoon vehicle and the base station is a critical factor affecting the communication latency. This paper exploits the particular structure and characteristics of platooning to decrease the control information exch…
Multidimensional prediction of work traffic crashes among Spanish professional drivers in cargo and passenger transportation
2020
The aim of this study was to examine the effect of different environmental, mechanical and individual factors associated with fatalities and serious injuries caused by work traffic accidents among cargo and passenger transport drivers (CPTD) in Spain. For this cross-sectional study, national data on work traffic accidents collected in Spain during the last 3 years were analyzed through a regression modeling approach, in order to predict the severity of traffic crashes involving CPTD. Using binary logistic regression analyses, it was found that the type of road and accident, the meteorological, light and vehicle conditions, individual characteristics and risky driving behaviors significantly…
Commuting accidents of Spanish professional drivers: when occupational risk exceeds the workplace
2019
Background. Work traffic accidents are an issue both in Spain and all over the world, and specific evidence on commuting accidents is scarce. Even though both industrial safety and welfare have been improved during the last decades, the commuting accidents rate is growing worldwide. Purpose. The aim of this study was to examine and describe the characteristics of commuting traffic crashes of Spanish professional drivers. Materials and methods. For this cross-sectional study, commuting accidents suffered by drivers during the last 12 years were analyzed. Crossed and heatmap-based analyses were performed in order to establish patterns and driver-based differences among commuting crashes. Resu…