Search results for "Transportation"
showing 10 items of 860 documents
Visualization practices in Scandinavian newsrooms : a qualitative study
2017
The visualization of numeric data is becoming an important element in journalism, and new tools and platforms make the development of data visualization in the news discourse accelerate. In this paper we present an interview study investigating this development in Scandinavian newsrooms. Editorial leaders, data journalists, graphic designers, and developers in 10 major news organizations in Norway, Sweden and Denmark inform the study on a range of issues concerning visual practices and experiences in the newsrooms. Elements of tension are revealed on issues concerning the role and effect of complex, exploratory data visualizations and concerning the role of ordinary journalists in the produ…
Optimal Management of Human Resources in Transhipment Container Ports
2014
Human resources allocation plays a key role in Transhipment Maritime Container Terminals to achieve high levels of productivity and provide high quality services to shipping companies. The deep interest of container terminals in this issue can be supported by optimization methods. In this work, an optimization model is proposed to determine the optimal daily allocation of crane operators and trailer drivers. Different requirements are taken into account for permanent staff, external workers and personnel shortfall. Since workforce undermanning is a crucial factor for both shipping companies and container terminals, we aim to show that personnel shortfalls and operation delays can be signifi…
Traffic simulation models calibration using speed–density relationship: An automated procedure based on genetic algorithm
2016
Calibration of traffic models.Calibration as optimization problem.Use of genetic algorithm. This paper presents the first results of a research which applied a genetic algorithm to calibrate a microscopic traffic simulation model based on speed-density relationships. A large set of traffic data collected from the A22 Freeway, Italy, was used and a comparison was performed between the field measurements and the simulation outputs obtained for a test freeway segment by using the Aimsun microscopic simulator.The calibration was formulated as an optimization problem to be solved based on a genetic algorithm; the objective function was defined in order to minimize the differences between the sim…
The potential of optimization in communal routing problems: case studies from Finland
2009
Abstract: In many European countries, municipalities offer their inhabitants a wide variety of social services. In this paper we will focus on efficiently scheduling home care, transportation of the elderly, and home meal delivery. These so-called municipal or communal routing problems can be modeled as different variants of the vehicle routing problem, a well-known optimization problem from the literature. We present a focused literature review and report on case studies using Finnish data. The computational results show that there is a significant potential for cost savings for all applications considered.
Integer programming models for the pre-marshalling problem
2019
[EN] The performance of shipping companies greatly depends on reduced berthing times. The trend towards bigger ships and shorter berthing times places severe stress on container terminals, which cannot simply increase the available cranes indefinitely. Therefore, the focus is on optimizing existing resources. An effective way of speeding up the loading/unloading operations of ships at the container terminal is to use the idle time before the arrival of a ship for sorting the stored containers in advance. The pre-marshalling problem consists in rearranging the containers placed in a bay in the order in which they will be required later, looking for a sequence with the minimum number of moves…
Technical and economical comparison between different topologies of PV plant under mismatch effect
2014
This paper presents a technical and economical comparative analysis between two topology of photovoltaic plant. In particular the performances of series-parallel (SP) and total cross tied (TCT), topologies are taken into account, referring to a partially shaded photovoltaic plant. Thanks to a simulation model developed, in the paper the mismatch effects due to three different shading conditions, for SP and TCT topology plant, are quantified. Since the TCT solution, even though increase the energy production, raise the complexity of plants as well as their costs, an evaluation of the individual costs of each component of a SP and TCT plant topology, as PV modules, support structure, inverter…
Determinants of elimination decisions in the activity scheduling process
2016
[EN] This paper presents an analysis on the determinants related to a particular rescheduling decision in the activity-travel scheduling process: elimination decisions, which consist in the non-execution of pre-planned activity-travel episodes. Data used come from an in-depth computer-assisted telephone interview (CATI) follow up survey carried out during the implementation of the first wave of an activity scheduling process panel survey. Open-ended answers related to the reasons associated to changes between pre-planned and executed agenda are studied. First, an interpretative qualitative method based on analytic induction (AI) is used to cope with the complex nature of the rescheduling de…
Effects of a Travel Behaviour Change Program on Sustainable Travel
2018
The main objective of the present study is to analyse the effect of a Travel Behaviour Change Program (TBCP) based on health improvement actions, in relation to a potential for an increase in walking and cycling, with reference to particular groups of people defined according to sociodemographics. A TBCP consisting of three persuasion actions based on health improvements was planned and executed in Valencia (Spain). A two-wave panel survey was used to study the effects of taking part in the TBCP. The panel survey collected data related to activity-travel scheduling process before and after the execution of the TBCP. To study the influence of participating in the TBCP, respondents were separ…
The combined distribution/assignment problem in transportation network planning: a parallel approach on hypercube architecture
1995
The joint distribution/assignment problem plays a central role in urban transport network planning. In this problem, according to the mathematical model proposed by S. P. Evans, the trips are iteratively calculated and assigned to the network in such a way that the resulting traffic flows pattern satisfies the selfish equilibrium condition. Unfortunately the number of variables and constraints increase hardly with the greatness of the networks causing long computational time for the equilibrium solution. In this paper an nCUBE 2 parallel computing architecture is employed to solve the combined problem and to asses the potential of MIMD machines to handle large scale transportation network p…
Cumbersome but desirable—Breaking the code of everyday cycling
2020
IntroductionCycling for transport could integrate physical activity (PA) into daily routines and potentially increase total PA levels. However, for parents with young children, most factors affecting transport mode choice tend to facilitate car use. Greater insight is necessary into reasons for (not) using sustainable transport modes in parents with young children. Therefore, the objective of this study was to explore the experiences, including motives, perceptions, attitudes, and norms, of parents of young children by using an e-bike, a longtail bike, and a traditional bike for everyday travel to the workplace, kindergarten, and the grocery store during the autumn, winter, and spring, in n…