‎in this paper, we study a flow shop batch processing machines scheduling problem. the fuzzy due dates are considered to make the problem more close to the reality. the objective function is taken as the weighted sum of fuzzy earliness and fuzzy tardiness. in order to tackle the given problem, we propose a hybrid electromagnetism-like (em) algorithm, in which the em is hybridized with a diversi...

The overall cost of companies dealing with the distribution tasks is considerably affected by the way that distributing vehicles are procured. In this paper, a more practical version of capacitated vehicle routing problem (CVRP) in which the decision of purchase or hire of vehicles is simultaneously considered is investigated. In CVRP model capacitated vehicles start from a single depot simulta...

This paper considers open-shop scheduling with no intermediate buffer to minimize total tardiness. This problem occurs in many production settings, in the plastic molding, chemical, and food processing industries. The paper mathematically formulates the problem by a mixed integer linear program. The problem can be optimally solved by the model. The paper also develops a novel metaheuristic base...

This paper presents a comparative study of two stochastic optimization methods: the electromagnetism-like algorithm (EMA) and the multilevel ant stigmergy algorithm (MASA) in computer-assisted design of universal electric motor rotor/stator geometry. The design goal was to minimize the power losses. The output of this study can be summarized in several important findings. Above all, both compar...

This paper deals with multi-period project portfolio selection problem. In this problem, the available budget is invested on the best portfolio of projects in each period such that the net profit is maximized. We also consider more realistic assumptions to cover wider range of applications than those reported in previous studies. A novel mathematical model is presented to solve the problem, con...

The goal of this work is to establish a new algorithm for computing the cohomology ring of cubical complexes. The cubical structure enables an explicit recurrence formula for the cup product. We derive this formula and, next, show how to extend the Mrozek and Batko [7] homology coreduction algorithm to the cohomology ring structure. The implementation of the algorithm is a work in progress. Thi...