Showing papers in "International Transactions in Operational Research in 2009"

TL;DR: The evolution of supply chain management in disaster relief and the role of new players like the private sector are discussed.

TL;DR: Algorithmic aspects of GRASP, a greedy randomized adaptive search procedure for combinatorial optimization, are covered, including construction phase and local search phase.

TL;DR: The literature where GRASP is applied to scheduling, routing, logic, partitioning, location, graph theory, assignment, manufacturing, transportation, telecommunications, biology and related fields, automatic drawing, power systems, and VLSI design is covered.

TL;DR: A block-iterative projection algorithm for solving the consistent convex feasibility problem in a finite-dimensional Euclidean space that is resilient to bounded and summable perturbation (in the sense that convergence to a feasible point is retained even if such perturbations are introduced in each iterative step of the algorithm) is proposed.

TL;DR: A definition of sparseness of a family of operators is proposed and a string-averaging algorithmic scheme is investigated that favorably handles the common fixed points problem when the family of Operators is sparse.

TL;DR: The obtained results show, that the proposed model and algorithm is able to solve these problems within a reasonable time, giving solutions that respect all the constraints imposed and are feasible in a real world scenario.

TL;DR: A meta-algorithm called AMALGAM is applied for the first time to WDS design and uses multiple metaheuristics simultaneously in an attempt to improve optimization performance, demonstrating large cost savings and reliability improvements.

TL;DR: A different proof is given that uses the multiplicative form of the spectral theorem, and the theorem holds in any real or complex Hilbert space, not just in a real Hilbert space.

TL;DR: Two production inventory models are established for deteriorating items when the demand rate depends on the instantaneous inventory level and the Weibull distribution deterioration is considered.

TL;DR: The findings indicate that domestic firms, most of which are controlled by family-based governance structures, enjoy higher efficiencies than affiliates of multinational pharmaceutical majors.

TL;DR: The leader's problem is solved heuristically by an ascent algorithm, simulated annealing, and tabu search, using the efficient algorithm for the solution of the follower's problem.

TL;DR: This work proposes to use directional penetration depths to measure the amount of overlap between a pair of polygons, and presents an efficient algorithm to find a position with the minimum overlap for each polygon when it is translated in a specified direction.

TL;DR: The recently presented sequential unconstrained minimization algorithm, SUMMA, is extended to provide a framework for the derivation of block-iterative, or partial-gradient, optimization methods and is motivated by the algebraic reconstruction technique and its multiplicative variant, the MART.

TL;DR: In this article, the authors demonstrate how to capture the robustness of a transportation network in the case of degradable links represented by decreasing capacities using the use of Bureau of Public Roads user link travel cost functions.

TL;DR: A genetic algorithm (GA) is proposed addressing the guillotine case of the 2D-KP as well as the non-guillotineCase, where an orientation constraint may be taken into account and the given piece set may be constrained or unconstrained.

TL;DR: This is pioneering research in China for bus transit scheduling using computers based on a unified mode of operation and those developed to solve the specific problems of BJBUS, such as scheduling buses with built‐in meal periods, multi‐type bus scheduling, restricting drivers to one or two particular buses, etc.

TL;DR: This paper investigates the problems that arise with the fitting process by simulating various Coxian phase-type models for the representation of patient survival and examining the estimated parameter values and eigenvalues obtained.

TL;DR: The theory and computational results in 2D and 3D show the advantage of the bar relaxation, and the so-called probing (temporary fixing) of intersection variables of OPP is tested with the aim to strengthen the relaxations.

TL;DR: In this paper, a dynamic model is used to analyze the composition and stability of international environmental agreements (IEAs) in an asymmetrical framework, where signatory countries are assumed to optimize the total welfare of the international agreement's members, while non-signatory countries optimize their own individual welfare, taking into account the dynamics of the pollution stock.

TL;DR: A hybrid genetic algorithm for the problem of building a phylogenetic tree minimizing parsimony is developed that combines local search with a crossover strategy based on path-relinking, an intensification technique originally used in the context of other metaheuristics such as scatter search and GRASP.

TL;DR: An overview of pure parsimony haplotyping (PPH), which states that the optimal set of haplotypes for a given set of genotypes is that having minimal cardinality, is provided.

TL;DR: This paper details a mathematical formulation, a Mixed Integer Linear Program model, to solve the problem of determining the arrangement of a set of items in a cargo hold that optimizes the load balance.

TL;DR: A multi-population genetic algorithm for generating Pareto-optimal solutions of the problem of selecting suppliers for an organisation, where a number of suppliers have made price offers for supply of items, but have limited capacity.

TL;DR: A heuristic for the problem of placing irregular shapes in two or three dimensions within a container, such that the placement of the shapes is optimized for balance and inertia moment and no two shapes overlap is presented.

TL;DR: A decision support tool has been developed which incorporates a linear programming model as a central feature and is described in detail, and experience from the application of the tool is reported.

TL;DR: The shortest path problem between two specified vertices in digraphs containing negative cycles is interested in and a family of linear relaxations with fewer variables than the classical linear one is proposed.

TL;DR: The evolution of the activities and the achievements of Petrobras Operations Research group, created in the 1960s, and its work offering decision support to the most diverse segments of the company are described.

TL;DR: This issue features nine among the 32 submitted papers on cutting, packing and related problems, and introduces the pinwheel pattern as an alternative solution to the manufacturer's pallet loading problem, in which a single pallet has to be loaded with a maximum number of identical boxes.