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Ahmadian A.,University of Malaya | Salahshour S.,Islamic Azad University at Mobarakeh | Chan C.S.,University of Malaya
IEEE Transactions on Fuzzy Systems | Year: 2017

In this paper, a new formula of fuzzy Caputo fractional-order derivatives (0 < v ≤ 1) in terms of shifted Chebyshev polynomials is derived. The proposed approach introduces a shifted Chebyshev operational matrix in combination with a shifted Chebyshev tau technique for the numerical solution of linear fuzzy fractional-order differential equations. The main advantage of the proposed approach is that it simplifies the problem alike in solving a system of fuzzy algebraic linear equations. An approximated error bound between the exact solution and the proposed fuzzy solution with respect to the number of fuzzy rules and solution errors is derived. Furthermore, we also discuss the convergence of the proposed method from the fuzzy perspective. Experimentally, we show the strength of the proposed method in solving a variety of fractional differential equation models under uncertainty encountered in engineering and physical phenomena (i.e., viscoelasticity, oscillations, and resistor-capacitor (RC) circuits). Comparisons are also made with solutions obtained by the Laguerre polynomials and the fractional Euler method. © 2016 IEEE.

Hadi-Vencheh A.,Islamic Azad University at Khorasgan | Mokhtarian M.N.,Islamic Azad University at Mobarakeh
Expert Systems with Applications | Year: 2011

This paper proposes a new fuzzy MCDM (FMCDM) approach based on centroid of fuzzy numbers for ranking of alternatives. The FMCDM approach allows decision makers (DMs) to evaluate alternatives using linguistic terms such as very high, high, slightly high, medium, slightly low, low, very low or none rather than precise numerical values, allows them to express their opinions independently, and also provides an algorithm to aggregate the assessments of alternatives. Three numerical examples are investigated using the FMCDM approach to illustrate its applications. It is shown that the FMCDM approach offers a flexible, practical and effective way of group decision making. © 2010 Elsevier Ltd. All rights reserved.

Salahshour S.,Islamic Azad University at Mobarakeh | Allahviranloo T.,Islamic Azad University at Tehran
Soft Computing | Year: 2013

A natural way to model dynamic systems under uncertainty is to use fuzzy initial value problems (FIVPs) and related uncertain systems. In this paper, we express the fuzzy Laplace transform and then some of its well-known properties are investigated. In addition, an existence theorem is given for fuzzy-valued function which possess the fuzzy Laplace transform. Consequently, we investigate the solutions of FIVPs and the solutions in state-space description of fuzzy linear continuous-time systems under generalized H-differentiability as two new applications of fuzzy Laplace transforms. Finally, some examples are given to show the efficiency of the proposed method. © 2012 Springer-Verlag.

Allahviranloo T.,Islamic Azad University at Tehran | Salahshour S.,Islamic Azad University at Mobarakeh
Soft Computing | Year: 2011

In this paper, we study the numerical method for solving hybrid fuzzy differential using Euler method under generalized Hukuhara differentiability. To this end, we determine the Euler method for both cases of H-differentiability. Also, the convergence of the proposed method is studied and the characteristic theorem is given for both cases. Finally, some numerical examples are given to illustrate the efficiency of the proposed method under generalized Hukuhara differentiability instead of suing Hukuhara differentiability. © 2010 Springer-Verlag.

Hadi-Vencheh A.,Islamic Azad University at Mobarakeh | Niazi-Motlagh M.,Islamic Azad University at Mobarakeh
International Journal of Computer Integrated Manufacturing | Year: 2011

Selecting an appropriate supplier is now one of the most important decisions of the purchasing department. Liu and Hai (Liu, F.H.F. and Hai, H.L., 2005. The voting analytic hierarchy process method for selecting supplier. International Journal of Production Economics, 97, 308-317) proposed a voting analytic hierarchy process method for selecting suppliers. Despite its many advantages, Liu and Hai's model (LH-model) has some shortcomings. In this article, the authors present an extended version of the LH-model for multi-criteria supplier selection problem. An illustrative example is presented to compare the authors' model and the LH-model. © 2011 Taylor & Francis.

Fazaeli R.,Islamic Azad University at Shahreza | Aliyan H.,Islamic Azad University at Mobarakeh | Moghadam M.,University of Isfahan | Masoudinia M.,Islamic Azad University at Shahreza
Journal of Molecular Catalysis A: Chemical | Year: 2013

Porous materials based on chromium (III) terephthalate metal organic frameworks (Cr-MIL(101)) and their new composites with vanadium oxide has emerged as a potential catalyst because of its high specific surface area, tunable pore size, and unique structure. The structural and textural characterization of V@MIL(101) were done using FTIR, X-ray diffraction, N 2 adsorption-desorption, and TEM. XRD and adsorption-desorption analysis shows that the mesostructure of MIL-101 remains intact after vanadium oxide modifications, while spectral technique show the successful immobilizing of the neat vanadium oxide inside the MIL-101 cavities. These new catalysts were found to be highly effective for selective oxidation of sulfides to sulfoxides and sulfones with H2O2 at room temperature and the 4.2% V@MIL(101) catalyst showed the highest activity. The PW12@MCF im heterogeneous system showed high catalytic oxidative activity in the treatment of commodity gasoline. © 2013 Elsevier B.V. All rights reserved.

Koupaei J.A.,Payame Noor University | Abdechiri M.,Islamic Azad University at Mobarakeh
Applied Soft Computing Journal | Year: 2013

Optimal allocation of the sensor in a wireless sensor network (WSN) is required to have a satisfactory fault diagnosis within the system. In fact, the sensor nodes in the network should be located in an arrangement to maximize the failure diagnosis. In this paper, the sensor deployment optimization to diagnose the distributed failures in a wireless unmanned aerial vehicles (UAVs) network has been studied. In this way, a novel evolutionary optimization algorithm inspired by the gases Brownian and turbulent rotational motion is utilized which is called Discrete Gases Brownian Motion Optimization (DGBMO) algorithm. An integer linear programming (ILP) approach is used to formulate the sensor deployment. Then the sensor deployment optimization is solved by DGBMO as well as generic ILP solvers and Boolean satisfiability-based ILP solvers. The results show that DGBMO is suitable for sensor disposition optimization especially in large-sized UAV networks. © 2012 Elsevier B.V. All rights reserved.

Allahviranloo T.,Islamic Azad University at Tehran | Salahshour S.,Islamic Azad University at Mobarakeh
Procedia Computer Science | Year: 2011

Linear systems have important applications in many branches of science and engineering in many applications, at least some of the parameters of the system are represented by fuzzy rather than crisp numbers. So, it is immensely important to develop a numerical procedure that would appropriately treat general fuzzy linear systems and solve them. In this paper, we propose bounded and symmetric solutions of fully fuzzy linear systems in the dual form (DFFLS) based on a 1-cut expansion. To this end, we solve the 1-cut of a DFFLS (we assumed that the 1-cut of a DFFLS is a crisp linear system), then some unknown symmetric spreads are allocated to each row of a 1-cut of a DFFLS. So, after some manipulations, the original DFFLS is transformed to solving 2 * n linear equations to find the symmetric spreads. However, our method always give us a fuzzy vector solution. Moreover, we show that the bounded and symmetric solution of the DFFLS will be placed in the tolerable solution set (TSS) and in the controllable solution set (CSS), respectively. Also, an economic example is solved to illustrate the ability of proposed method and a new pattern is suggested for comparing the obtained solutions. © 2010 Published by Elsevier Ltd.

Allahviranloo T.,Islamic Azad University at Mobarakeh | Salahshour S.,Islamic Azad University at Mobarakeh
Communications in Computer and Information Science | Year: 2010

In this paper, a new approach for solving first order fuzzy differential equations (FDEs) with fuzzy initial value is considered under strongly generalized H-differentiability. In order to obtain solution of FDE, we extend the 1-cut solution of original problem. This extension is constructed based on the allocating some unknown spreads to 1-cut solution, then created value is replaced in the original FDE. However obtaining solutions of FDE is equivalent to determine the unknown spreads while 1-cut solution is derived via previous step (in general, 1-cut of FDE is interval differential equation). Moreover, we will introduce three new set solutions for FDEs based on the concepts of united solution set, tolerable solution set and controllable solution set. Indeed, our approach is designed to obtain such new solution sets while one of them has pessimistic/optimitic attitude. Finally, some numerical examples are solved to illustrate the approach. © Springer-Verlag Berlin Heidelberg 2010.

Farhadi M.,Islamic Azad University at Mobarakeh | Ismail R.,National University of Malaysia | Fooladi M.,Islamic Azad University at Mobarakeh
PLoS ONE | Year: 2012

In recent years, progress in information and communication technology (ICT) has caused many structural changes such as reorganizing of economics, globalization, and trade extension, which leads to capital flows and enhancing information availability. Moreover, ICT plays a significant role in development of each economic sector, especially during liberalization process. Growth economists predict that economic growth is driven by investments in ICT. However, empirical studies on this issue have produced mixed results, regarding to different research methodology and geographical configuration of the study. This paper examines the impact of Information and Communication Technology (ICT) use on economic growth using the Generalized Method of Moments (GMM) estimator within the framework of a dynamic panel data approach and applies it to 159 countries over the period 2000 to 2009. The results indicate that there is a positive relationship between growth rate of real GDP per capita and ICT use index (as measured by the number of internet users, fixed broadband internet subscribers and the number of mobile subscription per 100 inhabitants). We also find that the effect of ICT use on economic growth is higher in high income group rather than other groups. This implies that if these countries seek to enhance their economic growth, they need to implement specific policies that facilitate ICT use. © 2012 Farhadi et al.

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