Islamic Azad University at Masjed Soleyman

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Masjed Soleyman, Iran

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Molla-Alizadeh-Zavardehi S.,Islamic Azad University at Masjed Soleyman | Sadi Nezhad S.,Islamic Azad University at Tehran | Tavakkoli-Moghaddam R.,University of Tehran | Yazdani M.,Islamic Azad University at Qazvin
Mathematical and Computer Modelling | Year: 2013

This paper investigates a fixed charge solid transportation problem (FCSTP) under a fuzzy environment, in which the both direct and fixed costs are supposed to be fuzzy numbers. This is one of the primary and most important problems in transportation and network research areas. To solve such a hard problem, three metaheuristics, namely variable neighborhood search (VNS), simulated annealing (SA) and hybrid VNS are employed. To the best of our knowledge, neither SA nor VNS has been considered for any kind of transportation problems. Besides, the novelty of the proposed algorithms is to use various new neighborhood structures related to the nature of the problem, which are proposed and used for the first time. The efficiency of employed parameters is measured by the Taguchi experimental design method that is a useful and new approach to tune the parameters and reduce the possible number of experiments in this research area. To evaluate the performance of the proposed algorithms, an extensive computational study has been conducted and the associated results obtained by the algorithms are compared with each other. Finally, a conclusion and further research areas are presented. © 2012 Elsevier Ltd.


Piri M.,Iran University of Science and Technology | Jasemi M.,Islamic Azad University at Masjed Soleyman | Abdi M.,Imam Hossein University
VINE | Year: 2013

Purpose: This paper experimentally examines the concept of intellectual capital in the Iranian space industries. The first objective of this study is to validate a model for assessing the relationships among some factors of intellectual capital and knowledge management; and organizational performance. The second objective is to evaluate the mediating role of some of them in the relationship between the intangible assets and organizational performance. Design/methodology/approach: The research is designed to utilize a systematic sampling and survey method. Intellectual capital here is decided to be four items of human, structural, innovation and cultural capital while two items of "knowledge development and sharing" and "learning and knowledge application" are considered for knowledge management. The structural equation modeling approach is used to validate the research model. Findings: These analyses suggest that human capital and structural capital are positively associated with organizational performance. The findings also indicate that both cultural capital and knowledge management practices fully mediate the effects of intangible assets on organizational performance while the latter does more. Originality/value: This study adds to the literature in two valuable ways. First, it validates a model for assessing the associations among organizational performance and adoption of knowledge management and intellectual capital. Second, it offers important results on the identification of mediating role of cultural capital and knowledge management practices. © Emerald Group Publishing Limited.


Molla-Alizadeh-Zavardehi S.,Islamic Azad University at Masjed Soleyman | Hajiaghaei-Keshteli M.,Islamic Azad University at Masjed Soleyman | Tavakkoli-Moghaddam R.,University of Tehran
Expert Systems with Applications | Year: 2011

This paper presents a mathematical model for a capacitated fixed-charge transportation problem in a two-stage supply chain network, in which potential places are candidate to be as distribution centers (DCs) and customers with particular demands. In contrast with the previous studies considered ample capacity for DCs, we consider the capacity for each DC. The presented model minimizes the total cost in such a way that some DCs are selected in order to supply demands of all the customers. To tackle such an NP-hard problem, we propose an artificial immune algorithm (AIA) and a genetic algorithm (GA) based on the spanning tree and Prüfer number representation. We introduce a new method to calculate the affinity value by using an adjustment rate. Furthermore, we apply the Taguchi experimental design method to set the proper values of AIA and GA parameters in order to improve their performances. Finally, we investigate the impact of increasing the problem size on the performance of our proposed algorithms. © 2011 Published by Elsevier Ltd.


Abdizadeh H.,University of Tehran | Baghchesara M.A.,Islamic Azad University at Masjed Soleyman
Ceramics International | Year: 2013

In the present study, an investigation has been carried out on the influences of ZrO2 content and casting temperature on mechanical properties and fracture behavior of A356 Al/ZrO2 composites. A356 aluminum alloy matrix composites reinforced with 5, 10 and 15 vol% ZrO 2 were fabricated at various casting temperatures, viz. 750, 850 and 950 °C via the stir casting method. Based on the obtained results, optimum amount of reinforcement and casting temperature were determined by evaluating the density and mechanical properties of the composites. Hardness and tensile tests were carried out in order to identify the mechanical properties of the composites. Fracture surfaces of the samples were also studied to identify the main fracture mechanism(s) of the composites. The results indicate that all samples fractured due to the inter-dendritic cracking of the matrix alloy. Reinforcing the Al matrix alloy with ZrO2 particles, improved the hardness and ultimate tensile strength of the alloy to the maximum values of 70 BHN and 232 MPa, respectively. Consequently, the highest mechanical properties were obtained by the specimen including 15% of ZrO2 produced at 750 °C. © 2012 Elsevier Ltd and Techna Group S.r.l.


Hajiaghaei-Keshteli M.,University of Tehran | Molla-Alizadeh-Zavardehi S.,Islamic Azad University at Masjed Soleyman | Tavakkoli-Moghaddam R.,University of Tehran
Computers and Industrial Engineering | Year: 2010

In this paper, we consider the fixed-charge transportation problem (FCTP) in which a fixed cost, sometimes called a setup cost, is incurred if another related variable assumes a nonzero value. To tackle such an NP-hard problem, there are several genetic algorithms based on spanning tree and Prüfer number representation. Contrary to the findings in previous works, considering the genetic algorithm (GA) based on spanning tree, we present a pioneer method to design a chromosome that does not need a repairing procedure for feasibility, i.e. all the produced chromosomes are feasible. Also, we correct the procedure provided in previous works, which designs transportation tree with feasible chromosomes. We show the previous procedure does not produce any transportation tree in some situations. Besides, some new crossover and mutation operators are developed and used in this work. Due to the significant role of crossover and mutation operators on the algorithm's quality, the operators and parameters need to be accurately calibrated to ensure the best performance. For this purpose, various problem sizes are generated at random and then a robust calibration is applied to the parameters using the Taguchi method. In addition, two problems with different sizes are solved to evaluate the performance of the presented algorithm and to compare that performance with LINGO and also with the solution presented in previous work. © 2010 Elsevier Ltd. All rights reserved.


Golobostanfard M.R.,University of Tehran | Abdizadeh H.,University of Tehran | Mohammadi S.,University of Tehran | Baghchesara M.A.,Islamic Azad University at Masjed Soleyman
Solar Energy Materials and Solar Cells | Year: 2014

Hybrid transparent conductive films (TCFs) based on indium tin oxide (ITO) and carbon nanotubes (CNTs) are prepared through a sol-gel dip coating method. The effect of CNT diameter on optoelectrical properties of TCF is investigated. The surface roughness and grain size are decreased and the optical transmittance is increased with CNT diameter. The existence of bundles in smaller CNTs is the main reason for lower transmittance in these samples. In terms of electrical resistivity, the large diameter CNT incorporated ITO film shows lower sheet resistance than bare ITO film at high enough film thicknesses. It seems that the large diameter CNT incorporation in ITO matrix can remarkably reduce the microcrack formation, especially at higher thicknesses, and act as nanobridges when microcracks are formed. Furthermore, the sensitivity of ITO film to thermal cycling is dramatically enhanced with these CNTs. In addition, the figure of merit of ITO film is considerably improved with large diameter CNT incorporation. © 2014 Elsevier B.V. All rights reserved.


Nasimi P.,Islamic Azad University at Science and Research of Fars | Haidari M.,Islamic Azad University at Masjed Soleyman
International Journal of Green Nanotechnology | Year: 2013

Researchers today are able to encapsulate medicine in nanoparticles, the size of viruses. The nanoparticles are effective for drug delivery-the delivery of the medicine to the body-because they can very precisely find diseased cells and carry the medicine to them. This means that one can suffice with less dosage and thereby fewer side effects. In addition, nanoscience and nanotechnological methods are spurring the development of more sophisticated tools for detecting diseases, such as cancer and atherosclerosis, at early stages and performing neurosurgery. Applications of nanotechnology in disease diagnoses are developing rapidly. Their unique size-dependent properties make these materials superior and indispensable in many areas of human activity. © The Author(s) 2013.


Shahebrahimi Y.,Islamic Azad University at Masjed Soleyman | Zonnouri A.,Islamic Azad University at Masjed Soleyman
Journal of Petroleum Science and Engineering | Year: 2013

In past, the Flory-Huggins model has been modified to predict the phase behavior of asphaltene precipitation phenomenon. This paper introduce a new thermodynamics model to predict amount of precipitated asphaltene. It was shown that the proposed model is comparable with experimental data and available models. The initial structure of proposed model is based on combination of two models, the Flory-Huggins model and one of the local composition models, None Random Two Liquid (NRTL). The Gibbs energy for mixture (oil+solvent) is expressed as a sum of two terms: (1) combinatorial contribution and (2) residual contribution. In the combinatorial contribution, the Flory-Huggins model, some physical properties such as volume and shape are important while in the residual contribution, the NRTL model, physical interactions are considered. Accuracy of this combinatorial model for predicting asphaltene precipitation is investigated using two crude oil samples, some precipitants such as n-C5, n-C6 and n-C7 at different temperatures. © 2013 Elsevier B.V.


Delavar M.R.,National University of Malaysia | Hajiaghaei-Keshteli M.,Islamic Azad University at Masjed Soleyman | Molla-Alizadeh-Zavardehi S.,Islamic Azad University at Masjed Soleyman
Expert Systems with Applications | Year: 2010

A main issue in supply chain management is coordinating production and distribution decisions. To achieve effective logistics scheduling, it is critical to integrate these two functions and plan them in a coordinated way. The problem is to determine both production schedule and air transportation allocation of orders to optimize customer service at minimum total cost. In order to solve the given problem, two genetic algorithm (GA) approaches are developed. However, the effectiveness of most metaheuristic algorithms is significantly depends on the correct choice of parameters. Hence, a Taguchi experimental design method is applied to set and estimate the proper values of GAs parameters to improve their performance. For the purpose of performance evaluation of proposed algorithms, various problem sizes are utilized and the computational results of GAs are compared with each other. Moreover, we investigate the impacts of the rise in the problem size on the performance of our algorithms. © 2010 Elsevier Ltd. All rights reserved.


Hajiaghaei-Keshteli M.,Islamic Azad University at Masjed Soleyman
Applied Soft Computing Journal | Year: 2011

In this paper, two stages of supply chain network; distribution centers (DCs) and customers, are considered. There are customers with particular demands and potential places which are candidate to be as distribution centers. Each of the potential DCs can ship to any of the customers. Two types of costs are considered; opening cost, assumed for opening a potential DC plus shipping cost per unit from DC to the customers. The proposed model selects some potential places as distribution centers in order to supply demands of all customers. In order to solve the given problem, two algorithms, genetic algorithm and artificial immune algorithm, are developed. The Taguchi experimental design method is applied to select the optimum parameters with the least possible number of experiments. For the purpose of performance evaluation of proposed algorithms, various problem sizes are utilized and the computational results of the algorithms are compared with each other. Finally, we investigate the impacts of the rise in the problem size on the performance of our algorithms. © 2010 Elsevier B.V. All rights reserved.

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