Search results for " operations"
showing 10 items of 1066 documents
Decision Suport System for Manufacturing Processes Reengineering based upon Fuzzy Logic Techniques
2012
Abstract This work presents a method for taking the decision of reengineering a production system, based upon fuzzy techniques. The main advantage of this method is, after authors' opinion, is the ease of its implementation together with the reduced time for gathering data and processing it. Multi-variable decision systems are usually based upon complicated mathematical methods and involved a large amount of data to be processed. The fuzzy approach presented here is based only on five input variables and one output variable. The data for the model are gathered by simple queries and quizzes. Human perception, the main point of fuzzy logic, is widely used here for gathering input data for the…
Fuzzy fixed points of generalized F2-geraghty type fuzzy mappings and complementary results
2016
The aim of this paper is to introduce generalized F2-Geraghty type fuzzy mappings on a metric space for establishing the existence of fuzzy fixed points of such mappings. As an application of our result, we obtain the existence of common fuzzy fixed point for a generalized F2-Geraghty type fuzzy hybrid pair. These results unify, generalize and complement various known comparable results in the literature. An example and an application to theoretical computer science are presented to support the theory proved herein. Also, to suggest further research on fuzzy mappings, a Feng–Liu type theorem is proved.
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…
Managing information security risks during new technology adoption
2012
Author's version of an article in the journal: Computers and Security. Also available from the publisher at: http://dx.doi.org/10.1016/j.cose.2012.09.001 In the present study, we draw on previous system dynamics research on operational transition and change of vulnerability to investigate the role of incident response capability in controlling the severity of incidents during the adoption of new technology. Toward this end, we build a system dynamics model using the Norwegian Oil and Gas Industry as the context. The Norwegian Oil and Gas Industry has started to adopt new information communication technology to connect its offshore platforms, onshore control centers, and suppliers. In oil co…
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.