Several combinatorial optimization problems can be formulated as large size SetCovering Problems. In this work, we use the Set-Covering formulation to obtain a general heuristic algorithm for this type of problems, and describe our implementation of the algorithm for solving two variants of the well-known (One-Dimensional) Bin Packing Problem: the Two-Constraint Bin Packing Problem and the basi...

The use of the stationary phase principle is often advocated for evaluating the spectrum of a chirp. This issue is considered here in detail, especially with respect to the quantitative control of the corresponding approximation error. A careful analysis leads to the introduction of a refined criterion, which turns out to be much more complicated than the heuristic conditions which are usually ...

In this paper, we propose a two-level fault tolerance strategy for wavelength-routed alloptical networks. The first-level strategy is applied to handle the large-scale disaster induced failures while the second-level strategy protects the network against regular single-link failures. The first-level fault tolerance is achieved by solving a topological optimization problem to re-regulate the tra...

simulation of turbulence boiling, generation of vapour and predication of its behaviour are still subject to debate in the two-phase flow area and they receive a high level of worldwide attention. in this study, a new arrangement of the three dimensional governing equations for turbulence two-phase flow with heat and mass transfer are derived by using ensemble averaging two-fluid model and util...

In this paper, we investigate the optimal assignment problem of cells in PCS (Personal Communication Service) to switches in a wireless ATM network. Given cells and switches on an ATM network (whose locations are fixed and known), the problem is grouping cells into clusters and assigning these clusters to the switches in an optimum manner. This problem is modeled as a complex integer programmin...

in this paper we consider a nonlinear two-phase stefan problem in one-dimensional space. the problem is mapped into a nonlinear volterra integral equation for the free boundary.

in this paper, the capacitated location-routing problem with fuzzy demands (clrp-fd) is considered. the clrp-fd is composed of two well-known problems: facility location problem and vehicle routing problem. the problem has many real-life applications of which some have been addressed in the literature such as management of hazardous wastes and food and drink distribution. in clrp-fd, a set of c...

Recently a characterization of the Lovász theta number based on convex quadratic programming was established. As a consequence of this formulation, we introduce a new upper bound on the stability number of a graph which slightly improves the theta number. Like this number, the new bound can be characterized as the minimum of a function whose values are the optimum values of convex quadratic pro...

This paper presents a novel GRASP algorithm based on a new randomized heuristic for solving the capacitated vehicle routing problem. This problem is characterized by a fleet of homogenous vehicle capacity that will start from one depot, to serve a number of customers with demands that are less than the vehicle capacity. The proposed method is based on a new constructive heuristic, and a simulat...