Showing papers in "Electronic Notes in Discrete Mathematics in 2004"

TL;DR: An Ant Colony algorithm (ACO) is developed for the Capacitated Vehicle Routing Problem (CVRP) based on the metaheuristic technique introduced by Colorni, Dorigo and Maniezzo.

TL;DR: On a set of benchmark instances, this genetic algorithm hybridized with two known heuristic methods for the Heterogeneous Fleet Vehicle Routing Problem produces high-quality solutions, including several new best-known solutions.

TL;DR: A mathematical model and a heuristic procedure based on Tabu Search are introduced for the problem of Aggregate Production Planning at a sawmill to determine the volumes of different products with different tree trunk types and using different cut schemes.

TL;DR: This work establishes the complexity of the minimum clique partition problem and the maximum independent set problem for penny graphs, both NP-complete, and presents two approximation algorithms for finding clique partitions.

TL;DR: The shortest path problem on weighted directed graphs is one of the basic network optimization problems, and depending on the implementation used for maintaining a service priority queue, Dijkstra’s algo-rithm has complexity O(|V|).

TL;DR: This work introduces a GRASP for designing the access network topology of a Wide Area Network (WAN), which is NP-hard, and can modeled as a variant of the Steiner Problem in Graphs.

TL;DR: This work verifies the TCC for powers of cycles Cnk, n even and 2 < k < ⌊n/2⌋, showing that there exists and can be polynomially constructed a (Δ(G) + 2)-total colouring for these graphs.

TL;DR: It is shown that the breaks maximization problem and the distance minimiza- tion problem are equivalent for a new class of uniform problem instances and this relation is used to prove the optimality of solutions found by a heuristic to the mirrored traveling tournament problem.

TL;DR: It is shown that for q ≥ 2 the problem BCPq is NP-hard in the strong sense, even on q-connected graphs, which implies that this problem does not admit a FPTAS, unless P = NP.

TL;DR: It can be concluded that the sequential dynamic is a low cost, effective and very fast local minima optimization heuristic for the Graph Bisection Problem.

TL;DR: It is proved that to compute v d ( G ) is Max SNP-hard when restricted to a cubic input G and that a polynomial 3 4 -approximation algorithm for finding a maximum planar induced subgraph of a maximum degree 3 graph is exhibited.

TL;DR: This work considers a multidimensional generalization of the bin packing problem, namely, packing 2−dimensional rectangles into the minimum number of unit squares, where 90 degree rotations are allowed, and proposes a polynomial time algorithm for packing rectangles onto bins whose sides have length.

TL;DR: A way to eliminate redundant solutions (due to geometrical symmetries) of linear integer programs by adding appropriate inequalities to a given formulation is presented.

TL;DR: This paper proves new complexity results of edge modification problems in some graph classes, such as, interval, circular-arc, permutation, circle, bridge and weakly chordal graphs.

TL;DR: This paper proposes algorithms for finding the maximum cardinality and weight of a clique-independent set of a 3 K 2 ¯ -free CA graph and applies the algorithms to the special case of an H C A graph.

TL;DR: This work proposes a method to compress any Helly circle representation of a graph and gives some ideas to advance in an inductive proof of the diamond conjecture.

TL;DR: An O ( n 3 ) -time algorithm for star cutset sandwich problem ; and an NP-completeness transformation from 1-in-3 3SAT (without negative literals) to clique cut set sandwich problem is proposed.

TL;DR: This work proposes a new definition that respects repeats and define loop graphs as the intersection graphs of arcs of a loop, and characterize the trees that are loop graphs.

TL;DR: A new polynomial time algorithm for finding a 1-restricted simple 2-matching with a maximum number of edges is presented and a Tutte-Berge-type formula is presented for this problem.

TL;DR: It is shown that the non commutativity of the diagram can be explicitly proved in any number of iterations of the N+–operator and if the diagram commutes in k=O(1) iterations, P=NP.

TL;DR: It is proved that if G has m edges then any clique-critical graph in K−1(G) has at most 2m vertices, and the only way of adding vertices to a graph without changing its clique graph is shown.

TL;DR: It is proved necessary and sufficient conditions that a prime comparability graph must verify for being a treelike comparabilityGraphs based on the modular decomposition gives a characterization of treeliked graphs.

TL;DR: This work uses a structural characterization of threshold graphs for solving difficult problems: enumerating all the maximal independent sets and the chromatic index problem.

TL;DR: This paper aims to demonstrate the efforts towards in-situ applicability of EMMARM, as to provide real-time information about concrete mechanical properties such as E-modulus and compressive strength.

TL;DR: A decomposition method is used to encode rhombus tilings and a useful characterization for a sequence of bits to encode a tiling is given, and an order structure on the space of tilings is shown to be a graded poset, from which connectivity is deduced.

TL;DR: It is found that two of the necessary conditions of near-ideal clutters become sufficient for clutters such that every minimal vertex cover is minimum.

TL;DR: This paper presents a way to represent compactly all modular-pairs of a cograph G by using the modular decomposition of this cograph.

TL;DR: A new class B + is defined that, in particular, contains the known k–minimal graphs, and a characterization of these three classes in terms of the disjunctive rank is obtained, allowing a simpler proof of the rank invariance under graph odd subdivisions in these classes.

TL;DR: It is proved that the family of forbidden induced subgraphs for a graph G such that the clique graph of G is Kp-free is finite, providing a proof of a conjecture in F. Protti and J. Szwarcfiter's Clique-Inverse Graphs of K3-free and K4-free Graphs.

TL;DR: The worst-case performance of several algorithms for the Steiner problem in directed networks is analize and the empirical performance of a proposed hybrid approach is analized for some instances from the simple location problem.