Search results for "Operations Research"
showing 10 items of 1297 documents
A functional approach to monitor and recognize patterns of daily traffic profiles
2014
Functional Data Analysis (FDA) is a collection of statistical techniques for the analysis of information on curves or functions. This paper presents a new methodology for analyzing the daily traffic flow profiles based on the employment of FDA. A daily traffic profile corresponds to a single datum rather than a large set of traffic counts. This insight provides ideal information for strategic decision-making regarding road expansion, control, and other long-term decisions. Using Functional Principal Component Analysis the data are projected into a low dimensional space: the space of the first functional principal components. Each curve is represented by their vector of scores on this basis.…
Selección de personal basada en métodos difusos
2011
[ES] Las decisiones de los directivos en cuanto a la selección de personal determinan en gran medida el éxito de la empresa. Una elección adecuada de los empleados proporciona una ventaja comparativa. Proponemos un método borroso para la selección de personal basado en la gestión de competencias y la comparación con la valoración que la empresa considera más adecuada para cada trabajo (el candidato ideal). Nuestro método utiliza la distancia de Hamming y el Matching Level Index. Los algoritmos, implementados con el software Sta¿Designer, nos permite establecer un ranking de candidatos, incluso cuando las competencias del candidato ideal han sido evaluadas tan solo en parte. Nuestro enfoque …
Special issue of Computers and Operations Research: GRASP with Path Relinking: Developments and applications
2013
Assessing the Performance of Interactive Multiobjective Optimization Methods
2021
Interactive methods are useful decision-making tools for multiobjective optimization problems, because they allow a decision-maker to provide her/his preference information iteratively in a comfortable way at the same time as (s)he learns about all different aspects of the problem. A wide variety of interactive methods is nowadays available, and they differ from each other in both technical aspects and type of preference information employed. Therefore, assessing the performance of interactive methods can help users to choose the most appropriate one for a given problem. This is a challenging task, which has been tackled from different perspectives in the published literature. We present a …
Scheduling projects with limited number of preemptions
2009
A recent paper (Ballestin F, Valls V, Quintanilla S. Preemption in resource-constrained project scheduling. European Journal of Operational Research 2008;189:1136-152) revealed the potential benefits of allowing one interruption when scheduling activities in a resource-constrained project. This paper further investigates the effect of interruption on project length in more general cases. To achieve this, a new model that covers most practical applications of discrete activity preemption is proposed and a metaheuristic algorithm for the problem is developed. Computational experiments on the standard j120 and j30 sets generated using ProGen study the difference in makespan between allowing m …
Bootstrapping profit change: An application to Spanish banks
2012
The aim of this study is to provide a tool which enables us to conduct statistical analysis in the context of changes in productivity and profit. We build on previous initiatives to decompose profit change into mutually exclusive and exhaustive sources. To do this we use distance functions, which are calculated empirically using linear programming techniques. However, we may not learn a great deal by solving these linear programs unless methods of statistical analysis are used to examine the properties of the relevant estimators. Our purpose is to provide a methodology based on bootstrap that allows us to conduct statistical inference for the profit change decomposition. Thus, it will be po…
Relative risk estimation of dengue disease at small spatial scale
2017
Abstract Background Dengue is a high incidence arboviral disease in tropical countries around the world. Colombia is an endemic country due to the favourable environmental conditions for vector survival and spread. Dengue surveillance in Colombia is based in passive notification of cases, supporting monitoring, prediction, risk factor identification and intervention measures. Even though the surveillance network works adequately, disease mapping techniques currently developed and employed for many health problems are not widely applied. We select the Colombian city of Bucaramanga to apply Bayesian areal disease mapping models, testing the challenges and difficulties of the approach. Methods…
Fake news on Facebook and their impact on supply chain disruption during COVID-19
2022
AbstractSocial media (SM) fake news has become a serious concern especially during COVID-19. In this study, we develop a research model to investigate to what extent SM fake news contributes to supply chain disruption (SCD), and what are the different SM affordances that contribute to SM fake news. To test the derived hypotheses with survey data, we have applied partial least square based structural equation modelling (PLS-SEM) technique. Further, to identify how different configurations of SC resilience (SCR) capabilities reduce SCD, we have used fuzzy set qualitative comparative analysis (fsQCA). The results show that SM affordances lead to fake news, which increases consumer panic buying…
Das Dualproblem in der linearen Planungsrechnung
1959
Der folgende Beitrag zeigt den okonomischen Hintergrund des mathematischen Problems der Dualitat. Es werden das Beispiel eines Primal- und des zugehorigen Dualproblems sowie die allgemeinen Eigenschaften der Dualitat behandelt. Wahrend die Losung der ursprunglichen Aufgabe eine optimale Ausnutzung der vorhandenen Betriebskapazitaten im Hinblick auf den erreichbaren Maximalgewinn anstrebte, werden durch die Losung des Dualproblems diesen einzelnen Kapazitaten, dem Grade ihrer Knappheit entsprechend, bestimmte Werte zugerechnet. Aus diesen Werten konnen wertvolle Hinweise fur die Kapazitatsplanung gewonnen werden.
Zur Bestimmung der wirtschaftlichen Bestellmenge bei Preisstaffeln
1970
Es wird ein analytisches Verfahren zur Berechnung der wirtschaftlichen Bestellmenge unter Berucksichtigung einer Mengen-Preis-Staffel beschrieben. Wahrend man bei der klassischen Losung dieses Problems zu vorgegebenem Bedarfiterativ den gunstigsten Preisnachlas bestimmt, wird bei dieser Methode gefragt, fur welchen Jahresbedarfsbereich ein vorgegebener Rabatt optimal ist. Aus dieser Fragestellung heraus kann eine Tabelle entwickelt werden, der die wirtschaftlichen Bestellmengen unmittelbar zu entnehmen sind. Das Verfahren eignet sich besonders zur Behandlung gleichartiger Produkte, deren Preis sich nach derselben Mengen-Preis-Staffel richtet.