Search Results - subject:"Algorithms"

A local refinement algorithm for the longest-edge trisection of triangle meshes

Plaza, Ángel; Falcón, Sergio; Suárez, José P.; … - In: Mathematics and Computers in Simulation (MATCOM) 82 (2012) 12, pp. 2971-2981

In this paper we present a local refinement algorithm based on the longest-edge trisection of triangles. Local trisection patterns are used to generate a conforming triangulation, depending on the number of non-conforming nodes per edge presented. We describe the algorithm and provide a study of...

Persistent link: https://www.econbiz.de/10011050172

Adaptive BDDC in three dimensions

Mandel, Jan; Sousedík, Bedřich; Šístek, Jakub - In: Mathematics and Computers in Simulation (MATCOM) 82 (2012) 10, pp. 1812-1831

The adaptive BDDC method is extended to the selection of face constraints in three dimensions. A new implementation of the BDDC method is presented based on a global formulation without an explicit coarse problem, with massive parallelism provided by a multifrontal solver. Constraints are...

Persistent link: https://www.econbiz.de/10011050668

Face-based selection of corners in 3D substructuring

Šístek, Jakub; Čertíková, Marta; Burda, Pavel; … - In: Mathematics and Computers in Simulation (MATCOM) 82 (2012) 10, pp. 1799-1811

revisit existing algorithms for selection of corners. The main contribution of this paper consists of proposing a new …

Persistent link: https://www.econbiz.de/10011050970

Covering moving points with anchored disks

Bautista-Santiago, C.; Díaz-Báñez, J.M.; … - In: European Journal of Operational Research 216 (2012) 2, pp. 278-285

to solve more general optimization problems. Our algorithms are efficient for constant values of k. …

Persistent link: https://www.econbiz.de/10011052404

Improving the efficiency of a best-first bottom-up approach for the Constrained 2D Cutting Problem

de Armas, Jesica; Miranda, Gara; León, Coromoto - In: European Journal of Operational Research 219 (2012) 2, pp. 201-213

This work introduces several improvements in the solution of the Constrained 2D Cutting Problem. Such improvements combine the detection of dominated and duplicated cutting patterns with the implementation of parallel approaches for best-first search methods. The analysis of symmetries and...

Persistent link: https://www.econbiz.de/10011052407

An Integer Linear Programming based heuristic for the Capacitated m-Ring-Star Problem

Naji-Azimi, Zahra; Salari, Majid; Toth, Paolo - In: European Journal of Operational Research 217 (2012) 1, pp. 17-25

We address the Capacitated m-Ring-Star Problem in which the aim is to find m rings (simple cycles) visiting a central depot, a subset of customers and a subset of potential (Steiner) nodes, while customers not belonging to any ring must be “allocated” to a visited (customer or Steiner) node....

Persistent link: https://www.econbiz.de/10011052628

Time and work generalised precedence relationships in project scheduling with pre-emption: An application to the management of Service Centres

Quintanilla, Sacramento; Pérez, Ángeles; Lino, Pilar; … - In: European Journal of Operational Research 219 (2012) 1, pp. 59-72

In this paper we present an application of project scheduling concepts and solution procedures for the solution of a complex problem that comes up in the daily management of many company Service Centres. The real problem has been modelled as a multi-mode resource-constrained project scheduling...

Persistent link: https://www.econbiz.de/10011052651

Enumerating K best paths in length order in DAGs

Pascoal, Marta M.B.; Sedeño-Noda, Antonio - In: European Journal of Operational Research 221 (2012) 2, pp. 308-316

We address the problem of finding the K best paths connecting a given pair of nodes in a directed acyclic graph (DAG) with arbitrary lengths. One of the main results in this paper is the proof that a tree representing the kth shortest path is obtained by an arc exchange in one of the previous...

Persistent link: https://www.econbiz.de/10011052691

Multi-objective evolutionary algorithm for donor–recipient decision system in liver transplants

Cruz-Ramı´rez, Manuel; Hervás-Martı´nez, César; … - In: European Journal of Operational Research 222 (2012) 2, pp. 317-327

This paper reports on a decision support system for assigning a liver from a donor to a recipient on a waiting-list that maximises the probability of belonging to the survival graft class after a year of transplant and/or minimises the probability of belonging to the non-survival graft class in...

Persistent link: https://www.econbiz.de/10011052800

Accelerating the quadratic lower-bound algorithm via optimizing the shrinkage parameter

Tian, Guo-Liang; Tang, Man-Lai; Liu, Chunling - In: Computational Statistics & Data Analysis 56 (2012) 2, pp. 255-265

When the Newton–Raphson algorithm or the Fisher scoring algorithm does not work and the EM-type algorithms are not … available, the quadratic lower-bound (QLB) algorithm may be a useful optimization tool. However, like all EM-type algorithms … surrogate functions Qr(θ|θ(t)) that induces a class of QLB algorithms indexed by a ‘shrinkage parameter’ r (r∈R) and then to …

Persistent link: https://www.econbiz.de/10011056438