Search results for " logistics"
showing 10 items of 399 documents
Using Genetic Algorithms for Optimizing the PPC in the Highway Horizontal Alignment Design.
2016
Various studies have emphasized the interesting advantages related to the use of new transition curves for improving the geometric design of highway horizontal alignments. In a previous paper, one of the writers proposed a polynomial curve, called a polynomial parametric curve (PPC), proving its efficiency in solving several design problems characterized by a very complex geometry (egg-shaped transition, transition between reversing circular curves, semidirect and inner-loop connections, and so on). The PPC also showed considerable advantages from a dynamic perspective, as evidenced by the analysis of the main dynamic variables related to motion (as well as rate of change of radial accelera…
Understanding the Health Disaster: Research Design for the Response to the 2014 West African Ebola Outbreak
2015
International audience; The 2014 Ebola outbreak in West Africa is the largest ever in history, affecting multiple countries and to this date, the World Health Organization has registered more than 6,500 deaths attributed to Ebola. The challenges arising from this outbreak to responders worldwide do not follow the standard characterisation or response patterns of natural sudden onset vs. conflict disasters. Rather, it is a medical emergency, which is intertwined with multiple challenges in the sectors decision-making, coordination, logistics and information management. In this paper, we present our research framework, which is based on desk research and initial interviews with responders. Th…
High Quality Reconstruction of Dynamic Objects using 2D-3D Camera Fusion
2017
International audience; In this paper, we propose a complete pipeline for high quality reconstruction of dynamic objects using 2D-3D camera setup attached to a moving vehicle. Starting from the segmented motion trajectories of individual objects, we compute their precise motion parameters, register multiple sparse point clouds to increase the density, and develop a smooth and textured surface from the dense (but scattered) point cloud. The success of our method relies on the proposed optimization framework for accurate motion estimation between two sparse point clouds. Our formulation for fusing it closest-point and it consensus based motion estimations, respectively in the absence and pres…
Modéliser le rôle des paysages dans les choix d'itinéraires pédestres
2008
Actuellement, la marche a pied suscite un regain d'interet comme mode de transport complementaire. Dans le cadre de cet article, nous partons de l'hypothese que l'adaptation de l'environnement urbain aux attentes des pietons, notamment d'un point de vue paysager, est une etape essentielle de la revalorisation de ce mode de deplacement. A cette fin, nous proposons une demarche permettant de decrire les comportements pedestres et d'identifier les preferences paysageres des pietons dans les villes de Besancon et de Lille. La methode d'analyse se fonde sur les modeles de choix discret, couramment utilises dans la modelisation des choix individuels. Celle-ci permet de mesurer, de maniere desagre…
Forecasting Passenger Traffic for a Regional Airport
2019
Abstract The purpose of the present research is estimating the potential traffic for SIA (Sibiu International Airport, SBZ) for the year 2017. Predicting as accurate as possible the passenger traffic for a certain airport is an aspect of major importance for both the airport management and the airline companies. The theoretical quality of the forecasting models for air traffic of passengers is fundamental for obtaining the most accurate predictions. In this regard, a two-step process was used in developing the traffic forecasting model: (1) Identifying the proper regression model for traffic estimation based on the number of aircraft departures, and (2) Forecasting the number of aircraft de…
Evaluation of Roundabout Safety Performance through Surrogate Safety Measures from Microsimulation
2018
The paper presents a microsimulation-based approach for roundabout safety performance evaluation. Based on a sample of Slovenian roundabouts, the vehicle trajectories exported from AIMSUN and VISSIM were used to estimate traffic conflicts using the Surrogate Safety Assessment Model (SSAM). AIMSUN and VISSIM were calibrated for single-lane, double-lane and turbo roundabouts using the corresponding empirical capacity function which included critical and follow-up headways estimated through meta-analysis. Based on calibration of the microsimulation models, a crash prediction model from simulated peak hour conflicts for a sample of Slovenian roundabouts was developed. A generalized linear model…
The Association Between Transportation and Life-Space Mobility in Community-Dwelling Older People With or Without Walking Difficulties.
2016
Objective: The aim of this study is to examine whether a persons’ most frequently used mode of transportation is associated with life-space mobility and whether the association differs between persons with or without walking difficulties. Method: Life-space mobility was measured with the Life-Space Assessment in 848 community-dwelling men and women aged 75 to 90 years. Six separate mobility groups were formed according to the most frequently used mode of transportation (car driver, car passenger, public transportation) combined with the presence or absence of difficulties walking 2 km. Results: Car drivers without walking difficulties had the highest life-space mobility scores, and car pas…
A Branch-and-Cut Algorithm for the Single Truck and Trailer Routing Problem with Satellite Depots
2016
International audience; In the single truck and trailer routing problem with satellite depots (STTRPSD), a truck with a detachable trailer based at a main depot must serve the demand of a set of customers accessible only by truck. Therefore, before serving the customers, it is necessary to detach the trailer in an appropriate parking place (called either a satellite depot or a trailer point) and transfer goods between the truck and the trailer. This problem has applications in milk collection for farms that cannot be reached using large vehicles. In this work we present an integer programming formulation of the STTRPSD. This formulation is tightened with several families of valid inequaliti…
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…
Application of queuing methodology to analyze congestion: A case study of the Manila International Container Terminal, Philippines
2016
The objective of this paper is to apply queuing methodology in order to analyze congestion at the Manila International Container Terminal (MICT) in the Port of Manila, the Philippines. The vessels calling at the MICT have to wait in a queue before receiving services at berths because of congestion. For vessel operators and cargo owners this situation creates waiting time costs and delays in delivery of goods to final customers. One option to decrease waiting time is to expand capacity by increasing the number of berths. Construction of a new berth is a time consuming and costly procedure, which needs to be considered carefully before being implemented. To determine whether the data collecte…