Search

In this paper an effective model to rank candidates in a preferential election is proposed. It is an extension and simplified form of a recently proposed model for ranking efficient candidates. The model consists of fewer constraints and can he used for ranking inefficient as well as efficient candidates. Some techniques are introduced to decrease the complexity of the proposed model by obtaining some of the results by inspection. Keywords: Data envelopment analysis; Ranking; Voting, 1. Introduction A well-known method for ranking candidates in a ranked voting system is to compare the weighted sum of their votes after determining suitable weights. Cook and Kress [1] [...]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ejor.2004.09.045 Byline: M. Soleimani-damaneh (a), G.R. Jahanshahloo (a), A.A. Foroughi (b) Abstract: In a recent paper by Chen [Chen, Y., 2005. Measuring super-efficiency in DEA in the presence of infeasibility. European Journal of Operational Research 161 (1), 447-468], he deals with the infeasibility of super-efficiency DEA models in variable returns to scale (VRS) technology. He provides a necessary and sufficient condition for simultaneous infeasibility of input- and output-oriented super-efficiency DEA models in VRS case, then he claims that both of these models are infeasible only for a rare situation. In this paper, we present some counterexamples and comments to the contention by Chen. Author Affiliation: (a) Faculty of Mathematical Sciences and Computer Engineering, Teacher Training University, 15618 Tehran, Iran (b) Department of Mathematics, University of Qom, Isfahan Old Road, 37165 Qom, Iran Article History: Received 6 April 2004; Accepted 20 September 2004

This paper provides a modification of a recently developed common weight model for technology selection. The discrimination power of the existing model depends on a discriminating parameter. Although larger values of this parameter can give more discrimination, it should also be small enough to guarantee the existence of at least one efficient DMU. Hence, different values of this parameter should be examined to determine the proper value. In the model proposed here, the largest possible value of the parameter is utilised to maximise the discrimination power, and the existence of an efficient DMU is guaranteed by adding a few constraints. In addition, the paper presents comments on existing models, and the properties and the advantages of the model are explained. The contents of the paper are illustrated by several numerical examples. [ABSTRACT FROM AUTHOR]

Byline: M. Tamiz, A.A. Foroughi This paper provides enhancements to a Data Envelopment Analysis (DEA) and Assurance Region (AR) model for a ranked voting system. A transformation of the given data reduces the number of constraints on the weights in the model, thus making it more effective and easier to solve. Another advantage of the improved model is to decrease the effect of inefficient candidates on the efficiency of the efficient candidates. The advantages of the proposed enhancements are illustrated by an example.