Step fixed-charge transportation problem is an extended version of the fixed charge transportation problem, is one of the most important problems in transportation research area. To tackle such an NP-hard problem, we present Gravitational Search Algorithm (GSA). We solve the randomly generated problems by GSA and also with Genetic Algorithm (GA) to compare them. The obtained results show the proficiency of GSA comparison with GA.
In Typhoid fever is one of the most common diseases caused by food and water pollution and one of the environmental problems currently in the industrialized world. The infectious disease, like other diseases, including AIDS, hepatitis, etc., is modeled as a nonlinear differential equation system. In this paper, a matrix-Galerkin method is introduced for the numerical study of the mathematical model of Typhoid fever. This method in based on matrix-algabraic computation of Galerkin method that converts the model to algebraic equations. The main purpose is to find an approximate solution with a simple algorithm to determine the population behavior in the Typhoid model. The results of the method show the accuracy and efficiency of the method.
In Data Envelopment Analysis (DEA) models, for measuring the relative efficiency of Decision Making Units (DMUs), for a large dataset with many inputs/outputs would need to have a long time with a huge computer. This paper proposed and developed the Differential evolution (DE) for DEA. DE requirements for computer memory and CPU time are far less than that needed by conventional DEA methods and can therefore be a useful tool in measuring the efficiency of large datasets. Since the operators have important roles on the fitness of the algorithms, all the operators and parameters are calibrated by means of the Taguchi experimental design in order to improve their performances.
Iron mines are already a sizable segment of the Iranian economy, but it has huge potential for development and can be the driver of further growth. This paper presents a strategic approach with hybrid Grey Relational Analysis (GRA) and Interpretive Structural Modeling (ISM) methodology for improving iron mines in Iran. At first these studies are established strategies and after that presented hybrid GRA and ISM analyses. The result shows the strategic of priorities improvement iron mines are arranged in four levels in Iran: First, an innovative mining and minerals industry with an excellent knowledge base, second, dialogue and cooperation to promote innovation and growth, third, Framework conditions and infrastructure for competitiveness and growth, forth level, a mining and minerals industry in harmony with the environment, culture and other industries and an internationally renowned, active and attractive mining and minerals industry.