Showing papers in "Computers & Operations Research in 2004"

TL;DR: A GA without trip delimiters, hybridized with a local search procedure is proposed, which outperforms most published TS heuristics on the 14 classical Christofides instances and becomes the best solution method for the 20 large-scale instances generated by Golden et al.

TL;DR: This paper presents an algorithm that builds on the Savings based Ant System and enhances its performance in terms of computational effort by decomposing the problem and solving only the much smaller subproblems resulting from the decomposition.

TL;DR: This paper studies the efficiency and robustness of some recent and well known population set-based direct search global optimization methods such as Controlled Random Search, Differential Evolution and the Genetic Algorithm.

TL;DR: The Network DEA Model allows individual DMU managers to focus efficiency-enhancing strategies on the individual stages of the production process, and can detect inefficiencies that the standard DEA Model misses.

TL;DR: This paper describes a Genetic Algorithms approach to a manpower-scheduling problem arising at a major UK hospital that is able to find high quality solutions and is both faster and more flexible than a recently published Tabu Search approach.

TL;DR: This paper deals with a classic flow-shop scheduling problem with makespan criterion and proposes a new very fast local search procedure based on a tabu search approach.

TL;DR: A special purpose genetic algorithm is developed for the solution of a class of spatial planning problems in which different land uses have to be allocated across a geographical region, subject to a variety of constraints and conflicting management objectives.

TL;DR: This work discusses 18 estimating methods for deriving preference values from pairwise judgment matrices under a common framework of effectiveness: distance minimization and correctness in error free cases and points out the importance of commensurate scales when aggregating all the columns of a judgment matrix.

TL;DR: This work proposes a solution method based on tabu search for solving the VRPTWSD without imposing any restrictions on the split delivery options and gives an analysis of experimental results on problems with 100 customers.

TL;DR: This article investigates the inventory problem for items received with imperfect quality, where, upon the arrival of order lot, 100% screening process is performed and the items of imperfect quality are sold as a single batch at a discounted price, prior to receiving the next shipment.

TL;DR: In this article, the authors propose genetic programming as a means to automatically generate short-term trading rules on the stock markets, rather than using a composite stock index for this purpose, the trading rules are adjusted to individual stocks.

TL;DR: Computational results show the proposed technique to be very competitive with the best-known heuristic routing procedures providing some new best- known solutions.

TL;DR: An algorithm to determine the economic order quantity for exponentially deteriorating items under the conditions of permissible delay in payments is developed and the objective function is modeled as a total variable cost-minimization problem.

TL;DR: The MCLP is formulated in the presence of partial coverage, a solution procedure based on Lagrangean relaxation is developed and the effect of the approach on the optimal solution by comparing it with the classical approach is shown.

TL;DR: This paper is the first to apply ACS for the n/m/P/Cmax problem, an NP-hard sequencing problem which is used to find a processing order of n different jobs to be processed on m machines in the same sequence with minimizing the makespan.

TL;DR: It is shown that even if a matrix will pass a consistency test successfully, it can be contradictory.

TL;DR: The Lagrangean/surrogate relaxation is directly identified from the master problem dual and provides new bounds and new productive columns through a modified knapsack subproblem, and the overall column generation process is accelerated, even when multiple pricing is observed.

TL;DR: Both empirical and trading simulation experiments suggest that the proposed hybrid approach not only produces better exchange rate forecasts but also results in higher investment returns than the single-stage models.

TL;DR: In this study an integrated system for the organization of a car pooling service is presented, using several current Information and Communication Technologies (ICT's) technologies: web, GIS and SMS.

TL;DR: The results obtained are considerably better than those reported previously and constitute the best solutions known for the benchmark problems as to date.

TL;DR: It is shown that the efficiency of GAs in solving a flowshop problem can be improved significantly by tailoring the various GA operators to suit the structure of the problem by presenting empirical evidence via extensive simulation studies supported by statistical tests of improvement in efficiency.

TL;DR: In this paper, the robust deviation shortest path problem with interval data is studied and an exact algorithm based on a very simple concept is described, and some practical improvements to the basic idea, which speed up the method, are also presented.

TL;DR: A multi-criteria decision analysis based process that would empower DM project teams to do thorough experimentation and analysis without being overwhelmed by the task of analyzing a significant number of DTs would offer a positive contribution to the DM process.

TL;DR: The GFPP method combines the group synthesis and prioritization stages into a coherent integrated framework, which does not need additional aggregation procedures and provides a meaningful indicator for measuring the level of group satisfaction and group consistency.

TL;DR: An inventory model for deteriorating items with stock dependent and time-varying demand rates for a finite time planning horizon is presented and a procedure for finding the optimal replenishment schedule is suggested.

TL;DR: This paper investigates the effectiveness and efficiency of using genetic search methods to support the scheduling decisions made by TMA, which is charged with the complex task of scheduling arriving aircraft to available runways in a manner that minimizes delays and satisfies safety constraints.

TL;DR: The application of fuzzy sets theory to the Black-Scholes formula and put-call parity relationship is proposed and it is proposed that the European option price will turn into a fuzzy number, making the financial analyst who can pick any European option prices with an acceptable belief degree for the later use.

TL;DR: This model uses scenario-based dynamic simulations to study the short product life cycle ease, exemplified by TamagotchiTM, which was the first of the virtual pet toys, and has three components, market, retail and factory.

TL;DR: Two lower bounding procedures and six heuristics for this problem are developed and compared and the aim is to pack items into the minimum number of bins subject to incompatibility restrictions.

TL;DR: This work investigates how the longest processing time first algorithm (LPT) would perform in the worst case and shows that a slight modification of LPT could significantly improve its worst-case performance.