Showing papers in "Electronic Notes in Discrete Mathematics in 2013"

TL;DR: FCA explicitly formalises extension and intension of a concept, their mutual relationships, and the fact that increasing intent implies decreasing extent and vice versa, and allows to derive a concept hierarchy from a given dataset.

TL;DR: This work proposes an integer linear programming formulation (ILP) and develops a matheuristic based on the decomposition of the ILP formulation into two problems which are equivalent to a Multi-depot Traveling Salesman Problem with Time Windows.

TL;DR: This work takes as base model a Markovian formulation of a closed queuing network with finite buffer and time dependent service time, and discusses heuristics: a scenario approach, a fluid approximation, simplified stochastic models and asymptotic approximations.

TL;DR: This problem is here addressed by a simple, but efficient tabu search approach which had improved several upper bounds of the considered instances.

TL;DR: Lower bounds based on a Dantzig-Wolfe decomposition and column generation as well as upper bounds obtained by an evolutionary local search approach (ELS) are presented.

TL;DR: This paper outlines various procedures for estimating maximum likelihood (ML) via the expectation-maximization (EM) algorithm, the computationally efficient minimum discrepancy (MD) estimation as well as MDML, a hybrid method combining the two approaches.

TL;DR: An integrated approach, based on the column generation technique, is proposed to solve the planning and routing problem and preliminary results on real data show the effectiveness of the proposed approach.

TL;DR: Computational results on real instances show that pattern generation policies are crucial to address scheduling and routing in large Home Care instances.

TL;DR: Explicit constructions in Extremal graph theory give appropriate lower bound for Turan type problems as mentioned in this paper, and explicit constructions can be used in various problems of Information Security, such as cyber-attacks.

TL;DR: It is shown that several P 3 ⁎ -convexity parameters (hull number, convexity number, Caratheodory number, Radon number, interval number and percolation time) are NP-hard even on bipartite graphs.

TL;DR: This work proposes to model the resulting problem of balancing the load of the stations as a General Pickup and Delivery Problem, and discusses possible heuristic approaches both for the static (offline) and the dynamic (online) version of the problem, and gives approximation results.

TL;DR: Some new ideas are presented which appear to significantly reduce computational times while solving to optimality even large instances.

TL;DR: A game-theoretic approach to optimize the strategies of toll enforcement on a motorway network with an arbitrary topology is presented, and it is shown that a Nash equilibrium can be computed with an LP and a MIP for the computation of a Stackelberg equilibrium.

TL;DR: A mixed-integer linear program (MILP), a cutting plane algorithm, and a column-and-cut algorithm that add constraints to repair vulnerabilities in partial network designs are presented.

TL;DR: A Pareto local search algorithm is proposed for the biobjective version of the adjacent only quadratic minimum spanning tree problem where the costs of interaction effects between every pair of adjacent edges are included in the objective function.

TL;DR: This paper presents a mathematical formulation based on a binary variable for each potential crew and aircraft route, and describes a column-generation algorithm for obtaining heuristic solutions, and gives computational results on real-world instances.

TL;DR: This paper approximate the DRSSPP with a semidefinite programming problem, which is solvable in polynomial time and provides tight lower bounds and the objective is to minimize the sum of the path cost and the expected path delay penalty.

TL;DR: An upper bound on the modularity of r-regular graphs as a function of the edge expansion (or isoperimetric number) under the restriction that each part in the authors' partition has a sub-linear numbers of vertices is given.

TL;DR: Upper bounds are established on the number of all 2- and 3-dimensional simplices induced by a set of n points P ⊂ R 3 which satisfy the condition that the lengths of their sides belong to the set of k largest distances determined by P.

TL;DR: This paper focuses on the class [⌞] (the edge intersection graphs of ⌞-shapes) and shows that testing for membership in [�OO�] is NP-complete, and gives a characterization and polytime recognition algorithm for special subclasses of Split ∩ [ �OO� ].

TL;DR: This is the first work dedicated to the exact resolution of m-CTP, and preliminary computational experiments suggest that both the lower bounds provided by the formulation behind BP and the CGH upper bounds are of good quality.

TL;DR: A reformulation that allows stronger linear programming bounds to be computed in a particular case of the quadratic minimum spanning tree problem in which interaction costs only apply for adjacent edges is introduced.

TL;DR: This paper proves the Harary-Hill conjecture for monotone drawings of Kn, that is, drawings where all vertices have different x-coordinates and the edges are x-monotone curves.

TL;DR: This work addresses the network routing problem where, given a graph with arc capacities and a set of origin-destination pairs with unknown demands, one must route each commodity over a single path so as to maximize the throughput, subject to the constraint that the flows are allocated according to the MMF principle.

TL;DR: A new variant of the connected facility location problem that allows for modeling mixed deployment strategies (FTTC/FTTB/FTTH) in the design of local access telecommunication networks is introduced.

TL;DR: A capacitated multiple allocation hub location problem, which arose from a network design problem in German wagonload traffic, is presented and heuristic solution approaches based on local improvements and CPLEX are developed.

TL;DR: This work defines μ-density as a characteristic of quality for the kind of coverings codes called multiple coverings of the farthest-off points (MCF) in projective spaces P G ( N, q ) and proposes Constructions of small ( 1, μ ) -saturating sets improving the probabilistic bound.

TL;DR: A mixed integer linear programming formulation stemming from network flow optimization is used to construct a heuristic based on limiting the total number of interconnecting paths when implementing fiber duct sharing, and a disintegration heuristic involving the construction of valid clusters from the output of a k means algorithm is proposed.

TL;DR: A new type of upper bound for the smallest size t 2 ( 2 , q ) of a complete arc in the projective plane P G ( 2, q ) is proposed and an algorithm FOP using any fixed order of points in P G (-2, q) for constructing complete arcs is proposed.

TL;DR: This work proposes a conjecture on combinatorial characterization of N + -perfect graphs and makes progress towards such a full combinatorsial characterization by establishing a new, close relationship among N +-perfect graphs, near-bipartite graphs and a newly introduced concept of full-support-perfect graph.