Search results for "NETWORK"
showing 10 items of 7718 documents
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 …
A GIS-Based Methodology to Estimate the Potential Demand of an Integrated Transport System
2017
In the design of a new public transport system or of an extension of an existing system, the choice of a suitable placement of stations and stops in the territory and the definition of the main axes are very important. The different choice in the number and distribution of the stops of a road transport system or of a railway transport system, in fact, makes the system more or less widespread and affects the consistency of the catchment area and the attractiveness of the system. The accessibility of a system, add to the reliability in providing the service, is the fundamental parameter influencing the modal split of the users. Therefore, the Public Administration must have tools able to eval…
Competition and cooperation for intermodal container transhipment: A network optimization approach
2018
Abstract This study presents an analysis of cross-border competition and cooperation between ports in Bangladesh and India. Nepal and Bhutan are countries without access to seaports — two landlocked countries in South Asia, depending solely on the Indian port of Kolkata for their international seaborne trade. Alternatives do exist in the Bangladeshi ports of Chittagong and Mongla but these are not exploited, in spite of trade agreements that allow access to a third country's port, and/or crossing the land of a third, intermediate, country. We formulate a mixed integer linear programming optimization model to find the optimum economic benefit of port users (serving Bhutan, Nepal and Northeas…
Signaling Reduction in 5G eV2X Communications Based on Vehicle Grouping
2019
Groups of users, sometimes referred to as clusters, have been exploited in several works to enhance wireless communications. Leveraging on previous ideas, the main goal of this paper is to take advantage of vehicle grouping in order to reduce uplink signaling in fifth generation (5G) vehicular communications. Several schemes to reduce uplink signaling are proposed and particularized in two specific 5G uses cases: the reporting of Channel Busy Ratio (CBR), and the reporting of beam measurements in beam management procedures. The achieved signaling reduction is analytically evaluated in an example of urban scenario with high vehicle densities for different group sizes. The signaling load can …
Availability, demand, perceived constraints and disuse of ADAS technologies in Spain: findings from a national study
2019
Advanced Driver Assistance Systems (ADAS), created for enhancing the driving experience and actively preventing road crashes, have been progressively incorporated in vehicle designing essentially during the last decade. However, the literature has shown how some of these assisting technologies are not used by drivers in tandem with their potential. The aims of this study were, first, to examine the availability and demand of ADAS technologies among Spanish drivers and, secondly, to explore the perceived constraints and discouraging reasons for avoiding the use of ADAS available in their vehicles. For this national cross-sectional study, data from 1,207 Spanish drivers were analyzed. The res…
Les trajectoires des footballeurs africains à la lumière de la mondialisation.
2010
Depuis la promulgation de l’arrêt « Bosman » en 1995, le nombre de joueurs expatriés recensés dans les principaux championnats européens a considérablement augmenté. Cet article montre que cette augmentation a surtout concerné les joueurs originaires d’Afrique et d’Amérique latine. Leur mobilité intervient dans un contexte très spéculatif au sein duquel de nombreux intermédiaires interagissent pour construire les canaux migratoires permettant aux joueurs de circuler à travers différents pays. Les trajectoires idéales — typiques de joueurs africains en Europe — permettent d’illustrer les logiques sociales, géographiques et économiques à la base de ces flux. Since the “Bosman” law in 1995, t…
Differences in the Exchange of Contents of Different Countries in Social Network Sites
2017
The global tool social network sites (SNSs) depend on local issues. The paper compares Latvia (LV), Hungary (HU), United Kingdom (UK) and Germany (GER) to identify similarities and differences in the kind of content which is forwarded to private SNSs. The research evaluates if the global tool SNSs depend on local issues e.g. the country of origin of the member. The influence of the cultural background on the intensity to exchange information is explored in the paper. The research has been done via a survey, survey data were analysed with indicators descriptive statistics, ANOVA to test the difference between the countries and correlation analysis to analyse correlation between factors of so…
Are frequent users of social network sites good information evaluators? An investigation of adolescents’ sourcing abilities (¿Son los usuarios frecue…
2019
This study investigates the relationship between teenagers’ use of social networking sites (SNS) and their sourcing abilities. Sourcing is defined as students’ ability (1) to discriminate reliable ...
Social interaction in management group meetings: a case study of Finnish hospital.
2016
Purpose – The purpose of this paper is to understand the role of management group meetings (MGMs) in hospital organization by examining the social interaction in these meetings. Design/methodology/approach – This case study approaches social interaction from a structuration point of view. Social network analysis and qualitative content analysis are applied. Findings – The findings show that MGMs are mainly forums for information sharing. Meetings are not held for problem solving or decision making, and operational coordinating is limited. Meeting interaction is very much focused on the chair, and most of the discussion takes place between the chair and one other member, not between members…
History of Data Centre Development
2012
International audience; Computers are used to solve different problems. For solving these problems computer software and hardware are used, but for operations of those computing facilities a Data Centre is necessary. Therefore, development of the data centre is subordinated to solvable tasks and computing resources. We are studying the history of data centres’ development, taking into consideration an understanding of this. In the beginning of the computer era computers were installed in computing centres, because all computing centres have defined requirements according to whom their operation is intended for. Even though the concept of ‘data centre’ itself has been used since the 1990s, t…