HLP (hub location problem) tries to find locations of hub facilities and assignment of nodes to extended facilities. Hubs are facilities to collect, arrange, and distribute commodities in telecommunication networks, cargo delivery systems, etc. Hubs are very crucial and their inaccessibility impresses on network whole levels. In this paper, first, total reliability of the network is defined bas...

multi objective quadratic fractional programming (moqfp) problem involves optimization of several objective functions in the form of a ratio of numerator and denominator functions which involve both contains linear and quadratic forms with the assumption that the set of feasible solutions is a convex polyhedral with a nite number of extreme points and the denominator part of each of the object...

in this paper, genetic programming is applied for quality improvement of noisy speech signal. therefore, a system including both spectral subtraction and genetic programming is implemented for speech enhancement. in the proposed method, first noise is reduced by spectral subtraction. in the next step, genetic programming trees are trained for more enhancement of noisy signal by mapping the sign...

The level of traac and the distribution of traac tend to vary in a telecommunications network. Obtaining a minimum-cost network for multi-hour traac proole is a large-scale optimization problem. We formulate this as a linear programming problem and use this as a basis for comparing the eecacy of the heuristics we introduce. Our heuristic is to view this as a multi-period network planning proble...

Linear bilevel programming is a decision making problem with a two-level decentralized organization. The leader is in the upper level and the follower, in the lower level. This study addresses linear bilevel multi-objective multi-follower programming (LB-MOMFP) problem, a special case of linear bilevel programming problems with one leader and multiple followers where each decision maker has sev...

Wildfires are of the forest-related disasters caused by inhumane factors.  Spreading of these fires is due to the increase of the density of flammable plants. Two important approaches to prevent this occurrence are fuel treatment and fire suppression resources preparedness. In this paper, a mixed integer programming model is proposed based on the covering location and assignment problems which ...

Abstract: In recent decades, high profits of extended warranty have caused that third-party firms consider it as a lucrative after-sales service. However, customers division in terms of risk aversion and effect of offering extended warranty on manufacturers’ basic warranty should be investigated through adjusting such services. Since risk-averse customers welcome extended warranty, while the cu...