@phdthesis{Aie02a, author = "R.M. Aiex", title = "Uma investiga\c{c}\~ao experimental da distribui\c{c}\~ao de probabilidade de tempo de solu\c{c}\~ao em heur\'{\i}sticas {GRASP} e sua aplica\c{c}\~ao na an\'alise de implementa\c{c}\~oes paralelas", school = "Department of Computer Science, Catholic University of Rio de Janeiro", address = "Rio de Janeiro, Brazil", year = "2002", annote = "This thesis describes a new methodology for the analysis of {GRASP}. Hybrid strategies with path-relinking are also proposed. These are studied on the 3-index assignment problem as well as the job shop scheduling problem and analyzed with the proposed methodology to predict qualitatively how the quality of the solution varies in a parallel independent {GRASP}.", } @Article{AieBinRes03a, author = "R.M. Aiex and S. Binato and M.G.C. Resende", title = "Parallel {GRASP} with path-relinking for job shop scheduling", journal = "Parallel Computing", volume = {29}, pages = {393--430}, year = "2003", annote = "In this paper, a parallel {GRASP} with path-relinking as intensification strategy for the job shop problem is described using some ideas proposed in the {GRASP} of Binato et al. (2002). During the construction phase, the restricted candidate list is made up of elements that among those that can be added to the current partial solution without causing any infeasibility have greedy function value above a specified threshold. While in Binato et al. (2002) the greedy function value of an operation $k$ is the makespan resulting from the inclusion of $k$ to the already scheduled operations, in this paper the authors propose the so called {\em time-remaining} function. It is a new greedy function to be used in conjunction with the makespan and that favors operations from jobs having long remaining processing times. The authors employ the two exchange local searches used in Binato et al. (2002). Two parallelization strategies are proposed: an independent and a cooperative strategy. The independent strategy shows a sub-linear speedup, while the cooperative one shows an approximate linear speedup, thus confirming that the extra time spent for processes communication is compensated by an increase in solution quality.", } @Article{AieResRib02a, author = "R.M. Aiex and M.G.C. Resende and C.C. Ribeiro", title = "Probability distribution of solution time in {GRASP}: {A}n experimental investigation", journal = "Journal of Heuristics", volume = "8", pages = "343--373", year = "2002", annote = "The authors study the probability distributions of solution time to a sub-optimal target value in five {GRASPs} that have appeared in the literature and for which source code is available. The distributions are estimated by running 12,000 independent runs of the heuristic. Standard methodology for graphical analysis is used to compare the empirical and theoretical distributions and estimate the parameters of the distributions. They conclude that the solution time to a sub-optimal target value fits a two-parameter exponential distribution. Hence, it is possible to approximately achieve linear speed-up by implementing {GRASP} in parallel.", } @mastersthesis{Alv98a, author = "A.C.F. Alvim", title = "Parallelization strategies for the metaheuristic {GRASP}", school = "Department of Computer Science, Catholic University of Rio de Janeiro", address = "Rio de Janeiro, RJ 22453-900 Brazil", month = "April", year = "1998", annote = "Two parallelization strategies for {GRASP} are discussed and compared: parallelization by distributing {GRASP} iterations and parallelization by varying the {GRASP} random parameter $\alpha$. Both strategies are adapted to several parallel computation models, such as MPI (Message Passing Interface) and PVM (Parallel Virtual Machine). In Portuguese." } @techreport{AlvRib98a, author = "A.C.F. Alvim and C.C. Ribeiro", title = "Load balancing in the parallelization of the metaheuristic {GRASP}", institution = "Department of Computer Science, Catholic University of Rio de Janeiro", address = "Rio de Janeiro, RJ 22453-900 Brazil", year = "1998", annote = "Two parallelization strategies for {GRASP} are compared. The difference between the two strategies concerns the way in which data is partitioned: pre-scheduled (static load balancing) or self-scheduled (dynamic load balancing). The strategies have been tested considering an application to optimal traffic assignment in TDMA satellite system. Best results have been obtained by using the self-scheduling strategy. In Portuguese." } @techreport{DiaVelSol99a, author = {J.C.Z. Diaz and J.S. Vel\'azquez and J.F. Solis}, title = {{Un modelo tipo {GRASP} para la paralelizaci\'on de algoritmos en computadoras {MIMD}: Aplicaci\'on al algoritmo de Jarmenson}}, institution = {Universidad Aut\'onoma del Estado de Morelos, Facultad de Ciencias}, address = {Cuernavaca, Morelos, Mexico}, annote = {In this paper, the authors use a {GRASP} to optimize operations needed to parallelize algorithms on a MIMD. The greedy criterion is to minimize the cost associated with comunication among processors, while local search uses an exchange neighborhood structure. In Spanish.}, year = {1999} } @Article{FeoResSmi94a, author = "T.A. Feo and M.G.C. Resende and S.H. Smith", title = "A greedy randomized adaptive search procedure for maximum independent set", journal = "Operations Research", volume = "42", pages = "860--878", year = "1994", annote = "A {GRASP} for approximately solving the maximum independent set problem is described. The greedy function chosen orders admissible vertices with respect to the minimum admissible vertex degree. The adjective admissible is referred to a vertex that is not adjacent to any vertex in the current independent set. The neighborhood definition used in the local search is $(2,1)$-exchange, where two nonadjacent vertices can be added to the current solution if a single vertex from the solution is removed. The proposed heuristic can be easily implemented in parallel by decomposing the problem into smaller subproblems, each defined by conditioning on vertices being in the solution. An implementation of this algorithm was tested on a MIMD computer with up to eight processors. Average linear speedup is observed.", } @phdthesis{Mar99a, author = "S.L. Martins", title = "Estrat\'egias de Paraleliza\c{c}\~ao de Metaheur\'{\i}sticas em Ambientes de Mem\'oria Distribu\'{\i}da", school = "Department of Computer Science, Catholic University of Rio de Janeiro", address = "Rio de Janeiro, Brazil", year = "1999", annote = "This thesis considers parallelization strategies for metaheuristics in distributed memory environments. {GRASPs} for the Steiner tree problem in graphs are described and implemented in parallel. In Portuguese." } @Article{MarResRibPar00b, author = "S.L. Martins and M.G.C. Resende and C.C. Ribeiro and P.M. Pardalos", title = "A parallel {GRASP} for the {Steiner} tree problem in graphs using a hybrid local search strategy", journal = "Journal of Global Optimization", volume = "17", year = "2000", pages = "267--283", annote = "This paper presents a {GRASP} for the Steiner problem in graphs. The construction phase is based on the Mehlhorn distance network heuristic, which consists of computing the modified distance network graph and using Kruskal's algorithm to solve the minimum spanning tree problem for the resulting graph. The local search is done by using a combination of key-path based local search and node based local search.", } @incollection{MurParPit98b, author = "R.A. Murphey and P.M. Pardalos and L.S. Pitsoulis", title = "A parallel {GRASP} for the data association multidimensional assignment problem", booktitle = "Parallel Processing of Discrete Problems", editor = "P.M. Pardalos", series = "The {IMA} Volumes in Mathematics and its Applications", publisher = "Springer-Verlag", volume = "106", pages = "159--180", year = "1998", annote = "A {GRASP} for finding good solutions for the data association multidimensional assignment problem is described. At each discrete time interval, the data set is formulated as a multidimensional assignment problem (MAP) with a maximum likelihood cost function. A near-optimal solution to each MAP is obtained with a {GRASP}. The proposed method can be easily parallelized to substantially decrease the running time." } @incollection{ParPitMavRes95a, author = "P.M. Pardalos and L. Pitsoulis and T. Mavridou and M.G.C. Resende", title = "Parallel search for combinatorial optimization: {G}enetic algorithms, simulated annealing and {GRASP}", booktitle = "Parallel Algorithms for Irregularly Structured Problems, Proceedings of the Second International Workshop --Irregular'95", editor = "A. Ferreira and J. Rolim", series = "Lecture Notes in Computer Science", publisher = "Springer-Verlag", volume = "980", year = "1995", pages = "317--331", annote = "This paper summarizes some parallel search techniques for approximating the global optimal solution of combinatorial optimization problems. For large-scale problems, one of the main limitations of heuristic search is its computational complexity. Therefore, efficient parallel implementation of search algorithms can significantly increase the size of the problems that can be solved.", } @incollection{ParPitRes95a, author = "P.M. Pardalos and L.S. Pitsoulis and M.G.C. Resende", title = "A parallel {GRASP} implementation for the quadratic assignment problem", booktitle = "Parallel Algorithms for Irregularly Structured Problems~-- Irregular'94", editor = "A. Ferreira and J. Rolim", publisher = "Kluwer Academic Publishers", year = "1995", pages = "115--130", annote = "Efficient parallel techniques for large-scale sparse quadratic assignment problems are discussed. The paper provides a detailed description of a parallel implementation on an MIMD computer of the sequential {GRASP} proposed by Li, Pardalos, and Resende (1994) for solving the QAP. The {GRASP} iterations are distributed among the processors. Each processor is given its own input data and random number sequence and are run independently. A shared global variable stores the value of the incumbent solution." } @Article{ParPitRes96a, author = "P.M. Pardalos and L.S. Pitsoulis and M.G.C. Resende", title = "A parallel {GRASP} for {MAX-SAT} problems", journal = "Lecture Notes in Computer Science", volume = "1184", pages = "575--585", year = "1996", annote = "A parallel {GRASP} for weighted maximum satisfiability (MAX-SAT) problem is proposed. The {GRASP} is based on the serial {GRASP} presented by Resende, Pitsoulis, and Pardalos (1997). The parallel implementation distributes the {GRASP} iterations among several processors operating in parallel, avoiding that two processors have as input the same random number generator seed. The best solution found among all processors is identified and used as solution of the problem.", } @Article{RibRos02a, author = "C.C. Ribeiro and I. Rosseti", title = "A parallel {GRASP} for the 2-path network design problem", journal = "Lecture Notes in Computer Science", volume = "2004", pages = "922--926", year = "2002", annote = "Given a connected undirected graph $G(V,E)$, a nonnegative edge weight function $w:\ E\rightarrow {\mathbb R}^+$, and a set $D$ of pairs of origin-destination nodes, the $2$-path network design problem consists in finding a minimum weighted subset of edges $E'\subseteq E$ containing a $2$-path between the extremities of every origin-destination pair in $D$. In this paper, a parallel {GRASP} with path-relinking is proposed for solving this problem.", } @mastersthesis{Riv98a, author = "L.I.D. Rivera", title = "Evaluation of parallel implementations of heuristics for the course scheduling problem", school = "Instituto Tecnologico y de Estudios Superiores de Monterrey", address = "Monterrey, Mexico", year = "1998", annote = "This thesis presents several parallel implementations of heuristics for the course scheduling problem. One of the heuristics is a {GRASP}. In Spanish." } @techreport{AieRes03a, author = {R.M. Aiex and M.G.C. Resende}, title = {Parallel strategies for {GRASP} with path-relinking}, institution = {Internet and Network Systems Research Center, AT\&T Labs Research}, address = {Florham Park, NJ}, year = {2003}, annote = { This paper analyzes two parallel strategies for GRASP with path-relinking and proposes a criterion to predict parallel efficiency based on experiments with a sequential implementation of the algorithm. Independent and cooperative parallel strategies are described and implemented for the 3-index assignment problem and the job-shop scheduling problem. The computational results for independent parallel strategies are shown to qualitatively behave as predicted by the criterion. }, }