In this paper, a closed-loop location-inventory problem for spare parts is presented. The proposed supply chain network includes two echelons, namely (1) distribution centers (DCs) and repairing centers (RCs) and (2) operational bases. Multiple spare parts are distributed among operational bases from distribution centers in the forward supply chain and failed spare parts from operational bases ...

In integer programming, {0, 1/2}-cuts are Gomory–Chvátal cuts that can be derived from the original linear system by using coefficients of value 0 or 1/2 only. The separation problem for {0, 1/2}-cuts is strongly NP-hard. We show that separation remains strongly NP-hard, even when all integer variables are binary. © 2011 Elsevier B.V. All rights reserved.

During the last decade, significant progresses have been made in solving the Protein Threading Problem (PTP). However, all previous approaches to PTP only perform global sequence–structure alignment. This obvious limitation is in clear contrast with the ”world of sequences”, where local sequence-sequence alignments are widely used to find functionally important regions in families of proteins. ...

Symmetry is mainly exploited in mathematical programming in order to reduce the computation times of enumerative algorithms. The most widespread approach rests on: (a) finding symmetries in the problem instance; (b) reformulating the problem so that it does not allow some of the symmetric optima; (c) solving the modified problem. Sometimes (b) and (c) are performed concurrently: the solution al...

In this paper we present several algorithms which combine a partial enumeration with meta-heuristics for the solution of general mixed-integer programming problems. The enumeration is based on the primal values assignable to the integer variables of the problem. We develop some algorithms for this integration, and test them using a set of well-known benchmark problems. Key-words: Enumeration, L...

In the context of multiple constant multiplication (MCM) design, we propose a novel common sub-expression elimination (CSE) algorithm that models the optimal synthesis of coefficients into a 0-1 mixedinteger linear programming (MILP) problem with a user-defined generic logic depth constraint. We also propose an efficient solution space, which combines all minimal signed digit (MSD) representati...

Multicommodity distribution problem is one of the most interesting and useful models in mathematical programming due to its major role in distribution networks. The purpose of this paper is to describe and solve a special class of multicommodity distribution problems in which shipment of a commodity from a plant to a customer would go through different distribution centers. The problem is t...

In this article, the design of a Supply Chain Network (SCN) consisting of several suppliers, production plants, distribution centers and retailers, is considered. Demands of retailers are considered stochastic parameters, so we generate amounts of data via simulation to extract a few demand scenarios. Then a mixed integer two-stage programming model is developed to optimize simultaneously two o...