Search results for "OPERATION"
showing 10 items of 2969 documents
The directed profitable rural postman problem with incompatibility constraints
2017
[EN] In this paper, we study a variant of the directed rural postman problem (RPP) where profits are asso- ciated with arcs to be served, and incompatibility constraints may exist between nodes and profitable arcs leaving them. If convenient, some of the incompatibilities can be removed provided that penalties are paid. The problem looks for a tour starting and ending at the depot that maximizes the difference between collected profits and total cost as sum of traveling costs and paid penalties, while satisfying remaining incompatibilities. The problem finds application in the domain of road transportation service, and in particular in the context of horizontal collaboration among carriers …
The periodic rural postman problem with irregular services on mixed graphs
2019
Abstract In this paper, we deal with an extension of the rural postman problem in which some links of a mixed graph must be traversed a given number of times over a time horizon. These links represent entities that must be serviced a specified number of times in some subsets of days (or periods) of the time horizon. The aim is to design a set of minimum-cost tours, one for each day/period of the time horizon, that satisfy the service requirements. We refer to this problem as the periodic rural postman problem with irregular services (PRPP–IS). Some practical applications of the problem can be found in road maintenance operations and road network surveillance, for example. In order to solve …
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…
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…
Acquisition of Generic Competencies Through Project Simulation in Translation Studies
2017
Motivated by the research in several international and interdisciplinary initiatives, for example, P21 Partnership for 21st Century Learning or the Collegiate Learning Assessment instruments, we seek for a scalable and measureable set of generic competencies for translation studies. Up to now, the acquisition of competencies in translation studies has primarily been operationalized by implementing authentic projects in higher education classes using socio-constructivist approaches. This results in a hybridization of subject-specific competencies and generic competencies in translator education. Because of the necessity to focus on the acquisition of generic competencies as a primary learnin…
European dominance in multistage ultramarathons: an analysis of finisher rate and performance trends from 1992 to 2010
2013
Mohannad Abou Shoak,1 Beat Knechtle,1,2 Christoph Alexander Rüst,1 Romuald Lepers,3 Thomas Rosemann11Institute of General Practice and for Health Services Research, University of Zurich, Zurich, Switzerland; 2Gesundheitszentrum St Gallen, St Gallen, Switzerland; 3INSERM U1093, Faculty of Sport Sciences, University of Burgundy, Dijon, FranceBackground: Participation and performance trends regarding the nationality of ultraendurance athletes have been investigated in the triathlon, but not in running. The present study aimed to identify the countries in which multistage ultramarathons were held around the world and the nationalities of successful finishers.Methods: Finisher rates and…
The Effect of Course Length on Individual Medley Swimming Performance in National and International Athletes
2014
Abstract Effects of course length (25 m versus 50 m) and advances in performance of individual medley swimming were examined for men and women in Swiss national competitions and FINA World Championships during 2000-2011. Linear regression and analysis of variance (ANOVA) were used to analyse 200 m and 400 m race results for 26,081 swims on the Swiss high score list and 382 FINA finalists. Swiss and FINA swimmers of both sexes were, on average, 4.3±3.2% faster on short courses for both race distances. Sex-related differences in swim speed were significantly greater for FINA swimmers competing in short-course events than in long-course events (10.3±0.2% versus 9.7±0.3%, p<0.01), but did no…
Evaluation of the 2-Methoxyethanol as Entrainer in Ethanol–Water and 1-Propanol–Water Mixtures
2013
In this paper, 2-methoxyethanol (commercially known as methyl cellosolve) is proposed as a potential entrainer for extractive distillation processes involving water–alcohol mixtures. The two alcohols studied in this work are ethanol and 1-propanol. Thereby, isobaric vapor–liquid equilibrium (VLE) data at atmospheric pressure have been measured for the ternary systems ethanol + water + 2-methoxyethanol and 1-propanol + water + 2-methoxyethanol. Moreover, data of the binary systems formed by the 2-methoxyethanol and each of the other chemicals used (ethanol, water, 1-propanol) have been obtained. The well-known local composition models Wilson, UNIQUAC, and NRTL have been used to correlate bin…
Building a statistical surveillance dashboard for COVID-19 infection worldwide
2020
When a pandemic like the current novel coronavirus (COVID-19) breaks out, it is important that authorities, healthcare organizations and official decision makers, have in place an effective monitoring system to promptly analyze data, create new insights into problematic areas and generate actionable knowledge for fact-based decision making. The aim of this article is to describe an initial work focused on building a comprehensive statistical surveillance dashboard for the epidemic of COVID-19, which can be exploited also for future needs. We propose novel ways of exploring, analyzing and presenting data, using metrics that have not been used previously. We also show the steps necessary to b…