Search results for "Operations research"
showing 7 items of 1297 documents
Are quality management practices enough to improve process innovation?
2015
The popularity of quality management as a system for continuous improvement has not been accompanied by deep theoretical understanding of its effects on process innovation. In this work, the resource-based view serves as the basis for the construction of a model designed to explain the effects of quality management practices (QMP) on process innovation performance and the mediating role of dynamic capabilities in this relationship. The empirical data were analysed using the structural equation modelling technique by examining 6 competing models that represent full, partial mediation and non-mediation relationships on a sample of 550 Spanish industrial companies. The findings indicate that t…
About the problems caused by the Gini and Kakwani index of inequality measurement
1997
On fait le point sur les faiblesses des indices de Gini et de Kakwani lorsque la dominance entre distributions n’est pas garantie : à un même Gini peuvent correspondre plusieurs distributions différentes et à une même valeur du Kakwani peuvent correspondre une infinité de couples d’ indices de Gini. On propose alors d ’approximer la courbe de Lorenz typiquement en deux ou trois parties linéaires, puis de décrire la position de son coude ou de ses deux coudes par deux ou quatre nombres qui suffisent caractériser complètement sa forme et la catégorie à laquelle elle appartient. Une procédure de choix entre distributions est proposée, basée sur une application du maximin : entre deux distribut…
Clean Agent Selection Approached by Fuzzy TOPSIS Decision-Making Method
2008
Abstract. It is well known that halons are ozone-depleting substances and their release into the atmosphere has contributed in the last decades to the reduction in the ozone layer. In consequence to the Montreal Protocol, an international agreement designed to gradually eliminate the use of such substances, fire protection industry researchers faced the challenge of finding effective solutions to replace halon extinguishers. This research aims to provide a method to support the decision maker in the selection of the most suitable extinguisher substance for a specific application. According to such framework, a set of quantitative and qualitative criteria has been established in the decision…
A two-phase insertion technique of unexpected customers for a dynamic dial-a-ride problem
2006
Abstract This work deals with a dynamic dial-a-ride problem with time window constraints. In particular, new unplanned requests for service may arise at a vehicle stop and the driver must decide in real-time whether to accept or reject them. For this problem, we have developed a two-phase insertion algorithm based on route perturbations: the first phase, which is run off-line when the vehicle moves between two successive stops, aims at creating a feasible neighborhood of the current route; while the second phase, which is run in real-time every time a new request occurs, inserts, when possible, the delivery stop of the new customer in the current route.
Minimizing fleet operating costs for a container transportation company
2006
Abstract This paper focuses on a fleet management problem that arises in container trucking industry. From the container transportation company perspective, the present and future operating costs to minimize can be divided in three components: the routing costs, the resource (i.e., driver and truck) assignment costs and the container repositioning costs (i.e., the costs of restoring a given container fleet distribution over the serviced territory, as requested by the shippers that own the containers). This real-world problem has been modeled as an integer programming problem. The proposed solution approach is based on the decomposition of this problem in three simpler sub-problems associate…
Reliable Outer Bounds for the Dual Simplex Algorithm with Interval Right-hand Side
2013
International audience; In this article, we describe the reliable computation of outer bounds for linear programming problems occuring in linear relaxations derived from the Bernstein polynomials. The computation uses interval arithmetic for the Gauss-Jordan pivot steps on a simplex tableau. The resulting errors are stored as interval right hand sides. Additionally, we show how to generate a start basis for the linear programs of this type. We give details of the implementation using OpenMP and comment on numerical experiments.
Psychological contract profiles among permanent and temporary agency workers
2016
Purpose– Based on the psychological contract (PC) theory, the purpose of this paper is to identify PC profiles, differentiating between permanent and temporary agency workers (TAW). Moreover, the authors analyzed whether different profiles presented different levels of work engagement.Design/methodology/approach– A cross-sectional survey data analysis of 2,867 workers, of whom 1,046 were TAW, was analyzed using latent profile analyses.Findings– Four PC profiles were identified, which differed quantitatively in terms of the overall dimension levels (i.e. balanced, relational and transactional) for PC (i.e. content and fulfillment). ANCOVAs showed that the relational/balanced dominant and tra…