Vendor managed inventory is a continuous replenishment program that is designed to provide major cost saving benefits for both vendors and retailers. Previous research on this area mainly included single objective optimization models where the objective is to minimize the total supply chain costs or to maximize the total supply chain benefits. This paper presents a bi-objective mathematical mod...

The recently presented sequential unconstrained minimization algorithm SUMMA is extended to provide a framework for the derivation of block-iterative, or partial-gradient, optimization methods. This BI-SUMMA includes, and is motivated by, block-iterative versions of the algebraic reconstruction technique (ART) and its multiplicative variant, the MART. The BI-SUMMA approach is designed to provid...

This paper presents a method for searching ground states of Ising spin glasses. The Ising model is one of the most commonly used because of its simplicity and its accuracy in representing real problems. We tackle the problem of finding ground states with particle swarm optimization (PSO), a population-based stochastic optimization technique inspired by social behavior of bird flocking. The pape...

Topology optimization has been an interesting area of research in recent years.  The main focus of this paper is to use an evolutionary swarm intelligence algorithm to perform Isogeometric Topology optimization of continuum structures.  A two-dimensional plate is analyzed statically and the nodal displacements are calculated.  The nodal displacements using Isogeometric analysis are found to be ...

The k-median problem is a well-known strongly NP-hard combinatorial optimization problem of both theoretical and practical significance. The previous best approximation ratio for this problem is 2.611+ǫ (Bryka et al. 2014) based on an (1, 1.95238219) bi-factor approximation algorithm for the classical facility location problem (FLP). This work offers an improved algorithm with an approximation ...

Methyl tertiary butyl ether (MTBE) is known as a promising substitute for tetra ethyl lead (TEL) in order to increase the octane number of gasoline. MTBE process, as many other processes, has two distinguished section, namely reaction section and separation section. In this paper we focus only on synthesis and optimization of separation section of this process. In order to achieve this obje...

High amounts of waste paper are disposed of every year in Iran posing the health hazard and environmental damages instead of being recovered. Collection, recovery and proper disposal of waste paper without damaging the environment need to design an efficient closed-loop supply chain network. The main objective of this paper is introducing a bi-objective, multi-echelon, multi-product and single-...

In this paper, mixed categorical structural optimization problems are investigated. The aim is to minimize the weight of a truss structure with respect cross-section areas, materials, and type. proposed methodology consists using bi-level decomposition involving two problems: master slave. problem formulated as mixed-integer linear where constraints incrementally augmented outer approximations ...

This paper introduces a Travel Demand Management (TDM) model in order to decrease the transportation externalities by affecting on passengers’travel choices. Thus, a bi-objective bi-modal optimization model for road pricing is developed aiming to enhance environmental and social sustainability by considering to minimize the air pollution and maximize the social welfare as its objectives. This m...