Journal of Intelligent & Fuzzy Systems - Volume 32, issue 1

Authors: Aliannezhadi, Samaneh | Ardalan, Shadi Shahab | Abbasi Molai, Ali

Article Type: Research Article

Abstract: In this paper, the problem of maximizing a monomial geometric objective function subject to bipolar max-product fuzzy relation constraints is studied. First of all, it is shown that the bipolar max-product Fuzzy Relation Inequality (FRI) system can equivalently be converted to a bipolar max-product Fuzzy Relation Equation (FRE) system. Hence, the structure of feasible domain of the problem is determined in the case of the bipolar max-product FRE system. It is shown that its solution set is non-convex, in a general case. Some sufficient conditions are proposed for solution existence of its feasible domain. An algorithm is designed to solve …the optimization problem with regard to the structure of its feasible domain and the properties of the objective function. Its importance is also illustrated by an application example in the area of economics and covering problem. Some numerical examples are given to illustrate the above points. Show more

Keywords: Bipolar fuzzy relation equation, max-product composition, non-convex optimization, bipolar variables

DOI: 10.3233/JIFS-151820

Citation: Journal of Intelligent & Fuzzy Systems, vol. 32, no. 1, pp. 337-350, 2017

Authors: Hemmati, R. | Rahideh, A.

Article Type: Research Article

Abstract: In this investigation, an optimal design procedure for tubular linear brushless permanent magnet (PM) machines has been proposed. A two-dimensional analytical magnetic field model in cylindrical coordinates has been employed to quickly and accurately calculate the magnetic flux density distribution and electromagnetic force. The objectives of the optimization problem are to simultaneously minimize the power losses and machine volume and the constraints are to ensure to develop the required level of electromagnetic force and to avoid saturation in the back-iron. The optimization problem has been solved using two types of metaheuristic optimization techniques, i.e., particle swarm optimization (PSO), and fuzzy …adaptive PSO (FAPSO). The design procedure has been implemented on a case study to illustrate the capability of the proposed approach. Show more

Keywords: Analytic solution, electromagnetic force, linear machines, metaheuristic, optimization, two-dimensional model

DOI: 10.3233/JIFS-151847

Citation: Journal of Intelligent & Fuzzy Systems, vol. 32, no. 1, pp. 351-362, 2017

Authors: Armand, A. | Allahviranloo, T. | Abbasbandy, S. | Gouyandeh, Z.

Article Type: Research Article

Abstract: The fuzzy variation iteration method is investigated to solve a linear fractional differential equation under Caputo generalized Hukuhara differentiability. This method is based on the use of Lagrange multipliers for identification of optimal value in the correction functionals by using fuzzy integration by parts. In this scheme, the correction, functional can make without converting fuzzy fractional differential equation to two crisp equations. To this, derivative of the product of two functions and integration by parts is obtained for fuzzy valued functions. The effectiveness of the proposed method is verified by solving two of the important applications of these equations are …fractional relaxation and oscillation differential equations. Show more

Keywords: Caputo generalized Hukuhara derivative, fuzzy integration by parts, fuzzy variation iteration method, fractional relaxation-oscillation differential equation, basset equation, Bagley-Torvik equation

DOI: 10.3233/JIFS-151940

Citation: Journal of Intelligent & Fuzzy Systems, vol. 32, no. 1, pp. 363-371, 2017

Authors: Kamankesh, Hamidreza | Agelidis, Vassilios G.

Article Type: Research Article

Abstract: This paper investigates the optimal operation and management of micro-grids (MGs) considering the high penetration of different types of renewable energy sources (RESs) and plug-in electric vehicles (PEVs). Optimal operation of MG is a precious and economic strategy for improving the situation of MG from different aspects such as reducing power losses and total costs, improving the reliability and enhancing the voltage level of buses. In order to achieve these goals, a new formulation is proposed to model the stochastic and volatile behaviors of RESs as well as PEVs. Also, the idea of vehicle-2-grid (V2G) is employed to provide a …bi-directional power exchange (either charging/discharging) between PEV and the main grid during the parking hours. In order to model the uncertainties of the problem, a new sufficient stochastic optimization framework based on unscented transform (UT) and krill herd algorithm (KH) is proposed too. The feasibility and performance of the proposed method are examined on a typical grid-connected MG considering different types of RESs including Photovoltaics (PVs), Fuel Cell (FC), Micro Turbine (MT) and Wind Turbine (WT). Show more

Keywords: Micro grid (RMG), renewable energy sources (RESs), plug-in electric vehicle (PEV) and Vehicle-2-Grid (V2G)

DOI: 10.3233/JIFS-151955

Citation: Journal of Intelligent & Fuzzy Systems, vol. 32, no. 1, pp. 373-387, 2017

Authors: Zirkohi, Majid Moradi

Article Type: Research Article

Abstract: Hyperchaotic systems have more complex dynamics than the low-dimensional chaotic system. Since hyperchaotic systems have many applications, controlling these systems for engineering applications is a new and attractive field. This paper investigates a design scheme for a class of nonlinear systems with uncertainties and unknown disturbances. In this regard, the idea of classical model reference control, feedback linearization, sliding mode control technique and interval type-2 fuzzy systems (IT2FLS) are combined to suggest a novel hybrid control scheme to resolve the model reference control problem and address the tracking problem for the novel uncertain hyperchaotic Lü system. The IT2FLS is used …to approximate the unknown nonlinear terms in control law. The interval type-2 fuzzy adaptation law adjusts the consequent parameters of the rules based on a Lyapunov synthesis approach. It is further equipped with a novel PI type switching structure to attenuate the chattering of the switching law resulting from the fast and large bounded unknown disturbances. There are three major contributions worthy of emphasis. Firstly, the dynamics of the system need not to be known and just the relative degree should be known in advance, which is more flexible in the real implementations. Secondly, it can be applied to a wide range of chaotic or hyperchaotic systems, which is its unique feature. Finally, having applied the proposed approach, both the transient and steady state behavior are improved. Using the Lyapunov theory, the stability of the proposed controller is proved. Compared to conventional sliding mode control and type-1 fuzzy controller, simulation results illustrate that although the proposed approach is highly effective in providing a good tracking performance even in the face of external disturbance and uncertainty; however, it is more computational compared to other mentioned methods, as expected. Show more

Keywords: Hyperchaotic systems, type-2 fuzzy systems, Lü system, PI type switching structure

DOI: 10.3233/JIFS-151981

Citation: Journal of Intelligent & Fuzzy Systems, vol. 32, no. 1, pp. 389-400, 2017

Authors: Wang, Yongquan | Chen, Tianjiao

Article Type: Research Article

Abstract: Adhesively bonded bars are a new technique of bars anchorage. It has been widely used in rehabilitation, renovation and repairs of concrete structures, as it is easy to anchor steel to concrete. But the bond behavior of adhesively bonded bar is greatly different from that of ordinary bars in concrete. No analysis methods for adhesively bonded bars are presented in concrete structure code. Although there are plenty of experiment and study about this field, but they are mainly about static study. There is few experiments and study about anti-seismic, so we know little about the seismic behavior of chemically planted-bar. …In this paper, we investigate the multiple attribute decision making problems for performance evaluation on the water endurance of chemical adhesive steel bar in concrete with triangular fuzzy information. Motivated by the ideal of Bonferroni mean and dependent aggregating operators, we develop the dependent triangular fuzzy Bonferroni mean (DTFBM) operator for aggregating the triangular fuzzy information. Finally, a practical example for performance evaluation on the water endurance of chemical adhesive steel bar in concrete is given to verify the developed approach and to demonstrate its practicality and effectiveness. Show more

Keywords: Performance evaluation, triangular fuzzy numbers, Bonferroni mean, dependent triangular fuzzy Bonferroni mean (DTFBM) operator, water endurance, chemical adhesive steel bar in concrete

DOI: 10.3233/JIFS-151994

Citation: Journal of Intelligent & Fuzzy Systems, vol. 32, no. 1, pp. 401-407, 2017

Authors: Aghayi, Nazila

Article Type: Research Article

Abstract: Being a nonparametric method, data envelopment analysis (DEA) is confined to measuring the efficiency of a collection of decision making units (DMUs) consuming multiple crisp inputs to produce multiple crisp outputs. Since not all data in the real world have determined values, and input and output values for DMUs are often subject to fluctuation, the concept of fuzziness has been introduced to deal with such imprecise data. This study intends to evaluate the cost efficiency of DMUs in three different scenarios, with one distinct model proposed for each scenario. The main idea is to use the alpha-cut method and the …extension principle to convert the fuzzy cost efficiency model into a family of conventional crisp DEA models by obtaining one lower bound and one upper bound for the cost efficiency score of a DMU for any α varying between 0 and 1. When the lower and upper bounds are invertible with respect to α, the membership function of the fuzzy efficiency of a DMU— which falls within the scope of parametric programming problems— can be obtained by finding the inverse of the lower and upper bounds as well as employing the extension principle. In this case, the value of fuzzy cost efficiency varies between 0 and 1. Otherwise, the cost efficiency scores of DMUs can be specified as intervals, which are actually α-cuts of the fuzzy membership function, by collecting results for different α values. Furthermore, we demonstrate that Farrell’s decomposition also holds for cost efficiency with fuzzy data. In addition, all DMUs are divided into three classes in each scenario, with cost-efficient and cost-inefficient DMUs falling into independent classes. In other words, units which are cost-inefficient in the upper bound for any α ranging between 0 and 1 will definitely be cost-inefficient in the lower bound, too, and the units will be cost-efficient in the upper bound if they are cost-efficient in the lower bound for a specific α varying between 0 and 1. Moreover, the upper bound of units that are cost-inefficient in the lower bound could not be judged in terms of cost efficiency. Finally, a practical example dealing with data on all branches of the National Bank of Iran across Ardabil Province, Iran, during 2012–2014 is provided to demonstrate the applicability of the proposed method. Show more

Keywords: Data envelopment analysis, cost efficiency, membership function, parametric programming, α -cut, fuzzy

DOI: 10.3233/JIFS-152079

Citation: Journal of Intelligent & Fuzzy Systems, vol. 32, no. 1, pp. 409-420, 2017

Authors: Arya, Rubi | Singh, Pitam

Article Type: Research Article

Abstract: This paper presents a fuzzy parameter based iterative method for solving multi-objective linear fractional optimization problems. Using the proposed method, number of ε -fuzzy efficient and fuzzy efficient solutions can be generated. The obtained fuzzy efficient solutions or ε -fuzzy efficient solutions have some addition features in terms of percentage contribution of each objective. The relative importance of each objective can be found in terms of satisfaction degree, value of membership function at the obtained solution, for each objective. Some theoretical results are also established for the validation of the proposed method and the method is coded in matlab (version …R2014b). The efficiency of the method is verified by applying on numerical problems. Show more

Keywords: Multi-objective optimization, linear fractional programming, multi-criteria decision making, fuzzy optimization, iterative method

DOI: 10.3233/JIFS-152087

Citation: Journal of Intelligent & Fuzzy Systems, vol. 32, no. 1, pp. 421-433, 2017

Authors: Mirdar Harijani, Kh. | Anvariyeh, S.M.

Article Type: Research Article

Abstract: In this paper, fuzzy absolute value on a ring is defined. It is proved that every absolute value can induce a fuzzy absolute value. It is also proved that every fuzzy valued ring induce a fuzzy metric space and a fuzzy norm space. In addition, the notion of a Cauchy sequence and completion of a fuzzy valued ring are given and some of their properties are investigated. Finally, it is proved that every fuzzy valued ring has a completion.

Keywords: Completion, fuzzy absolute value, fuzzy metric space, fuzzy set, fuzzy valued ring

DOI: 10.3233/JIFS-152155

Citation: Journal of Intelligent & Fuzzy Systems, vol. 32, no. 1, pp. 435-441, 2017

Authors: Mahanta, J. | Das, P.K.

Article Type: Research Article

Abstract: Fuzzy soft topological space was introduced and studied by B. Tanay et al. [8 ]. This paper introduces fuzzy soft point and study the concept of neighborhood of a fuzzy soft point in a fuzzy soft topological space alongwith the study of fuzzy soft closure and fuzzy soft interior. Further, separation axioms and connectedness are introduced and investigated for fuzzy soft topological spaces.

Keywords: Fuzzy soft point, fuzzy soft topological space, fuzzy soft closure, fuzzy soft connectedness, fuzzy soft separation

DOI: 10.3233/JIFS-152165

Citation: Journal of Intelligent & Fuzzy Systems, vol. 32, no. 1, pp. 443-450, 2017