Search results for "Operations"
showing 10 items of 1692 documents
Tabu search for a multi-objective routing problem
2006
Multi-objective optimization problems deal with the presence of different conflicting objectives. Given that it is not possible to obtain a single solution by optimizing all the objectives simultaneously, a common way to face these problems is to obtain a set of efficient solutions called the non-dominated frontier. In this paper, we address the problem of routing school buses with two objectives: minimize the number of buses, and minimize the longest time a student would have to stay in the bus. The trade-off in this problem is between service level, which is represented by the maximum route length, and operational cost, which is represented by the number of buses in the solution. We prese…
A bootstrap approach to analyse productivity growth in European banking
2010
This paper analyses productivity growth for European banks over the 1995–2001 period. In contrast to previous literature, our study covers the majority of current European Union (EU) countries—all except Greece and those joining the EU in 2004. We also use resampling methods so as to gain statistical precision, which turns out to be especially important due to the limitations of the database. In order to be consistent, we use additional nonparametric methods to disentangle why productivity differentials might exist. Results show that productivity growth has occurred in most countries, mainly due to improvements in production possibilities. The bootstrap analysis yields further evidence give…
Testing the Form of a Decision-maker's Multiattribute Value Function Based on Pairwise Preference Information
1989
In a recent paper we presented a test, based on pairwise preference information, to identify to which class of functions (linear, quasi-concave, or neither) a decision-maker's (implicit) value function belongs. In this note we investigate the power of the test. Some improvements to the test are also suggested.
Segmenting sport spectators: Construction and preliminary validation of the Sporting Event Experience Search (SEES) scale
2011
International audience; This study's goal was to create and test a tool for identifying different types of sport spectators. Based on four types of sporting-event consumers – aesthete, interactive, supporter, and opportunist – we developed the Sporting Event Experience Search Scale (SEES). We conducted an empirical investigation involving two sporting events with both live and mediated types of attendance. Although the first validation step failed to support the four-type structure for the mediated context, the scale appeared to be relevant in a live-attendance context. The SEES scale should therefore allow sporting-event managers to analyse the nature and then the expectations of sport spe…
Comparative evaluation of some interactive reference point-based methods for multi-objective optimisation
1999
Many real-world optimisation applications include several conflicting objectives of possibly nondifferentiable character. However, the lack of computationally efficient, interactive methods for nondifferentiable multi-objective optimisation problems is apparent. To satisfy this demand, a method called NIMBUS has been developed. Two versions of the basic method are presented and compared both theoretically and computationally. In order to give variety to the comparison, a related approach, called reference direction method is included. Theoretically, the methods differ in handling the information requested from the user. Numerical experiments indicate differences in computational efficiency …
Cooperative learning in creating and managing joint ventures
2014
Abstract This study examines how and under what conditions joint ventures facilitate cooperative learning. The study analyzes how a joint-venture approach facilitates initial learning in the cooperative process and considers to what extent inter-organizational factors such as commitment, trust, control and conflict resolution affect the partners involved. The study then compares these hypotheses based on a sample of 74 international joint ventures (IJVs). The results provide empirical evidence to show that commitment is both a significant and essential variable, yet they also illustrate that this type of cooperation is not enough on its own for partners to learn how to cooperate effectively.
Controlling risk through diversification in portfolio selection with non-historical information
2017
We deal with the portfolio selection problem for investors having information on the expected returns of the assets based not only on historical data. In the absence of a way of measuring the risk of non-historical information, the investor may try to adjust it through the consideration of a suitable set of diversification constraints. With this aim, we relate the concept of value of information (recently introduced by Kao and Steuer) to a qualitative subjective measure of the investor’s level of confidence in his/her non-historical information. As an illustration, we analyze the behavior of the proposed indicator in the Spanish IBEX35 index for risk, upper bound, semicontinuous variable an…
Greening the balanced scorecard
2010
Environmental management issues have received an increased amount of attention in recent years, as have various performance measurement systems (PMS) such as the balanced scorecard (BSC). However, implementation of these systems is challenging due to the differences found amongst the companies and users of PMS. This study investigates how the presence of particular supporting factors served to facilitate a PMS change that incorporated environmental measures. Utilization of extant change models enables us to investigate different change factors like advancing and hindering forces, momentum, and the leaders of change. We found two models appropriate for investigating environmental management …
Scatter tabu search for multiobjective clustering problems
2011
We propose a hybrid heuristic procedure based on scatter search and tabu search for the problem of clustering objects to optimize multiple criteria. Our goal is to search for good approximations of the efficient frontier for this class of problems and provide a means for improving decision making in multiple application areas. Our procedure can be viewed as an extension of SSPMO (a scatter search application to nonlinear multiobjective optimization) to which we add new elements and strategies specially suited for combinatorial optimization problems. Clustering problems have been the subject of numerous studies; however, most of the work has focused on single-objective problems. Clustering u…
Spatial mapping of price competition using logit-type market share models and store-level scanner-data
2009
This paper proposes a methodology to obtain reliable spatial maps of price competition using store-level scanner data. Specifically, a procedure to obtain a symmetric matrix of similarities between brands considering their substitutability depending on price variations is proposed. The matrix is derived from a market response model where price cross-effects are split into two components. The first component accounts for the fact that price variation in one brand can have different effects to price variation in other brands (ie j → j′≠j′ → j). The second component accounts for the fact that the price of each brand can have different effects across competing brands (ie j → j′≠j → j ″). The ma…