Journal of Intelligent & Fuzzy Systems - Volume 35, issue 2

Authors: Fardad, Noorollah | Soleymani, Soodabeh | Faghihi, Faramarz

Article Type: Research Article

Abstract: In order to avoid the environmental emission of fossil fuels, renewable energy resources expansion trend is undeniable. This paper analyzes the possibility of cooperation between neighboring independent microgids in a smart grid with renewable resources considering the security assets and vulnerabilities. The ultimate goal is to decrease the overall security risks on the smart grid. Modeling of microgrids cooperation is formulated via a coalition game definition considering the permissible amount of their vulnerabilities. Load shedding minimization can be obtained during cyber-attack occurrence for each member of coalition microgrids. This paper presents a comprehensive algorithm for optimal coalition of neighboring microgrids …based on a utility function calculation which has three major components: Budget for Attack (BA), Budget for Defense (BD) and microgrid relationship effectiveness, to contribute more understanding, microgrid relationship effectiveness formulation is developed by the introduction of friction and influence matrices. Proportional Fairness (PF) index is employed to illustrate the improvement of utility function in case of optimal coalition in comparison with non-cooperative state. Microgrids coalition optimal choice based on suggested algorithm is validated by probability attack and loss of load probability (LOLP) simulation for each microgrid before and after the coalition form. Show more

Keywords: Smart grid, microgrids, cyber-attacks, coalitional game theory, defense budget

DOI: 10.3233/JIFS-171980

Citation: Journal of Intelligent & Fuzzy Systems, vol. 35, no. 2, pp. 2063-2077, 2018

Authors: Wang, Gang | Jia, Ru | Song, Huadong | Liu, Jinhai

Article Type: Research Article

Abstract: In this paper, a new method, namely, the dynamic delay partitioning method, is firstly developed to solve the problems of stability analysis and stabilization for a class of unknown nonlinear systems. To study the system stability and facilitate the design of fuzzy controller, Takagi-Sugeno (T-S) fuzzy models are employed to represent the system dynamics of the unknown nonlinear systems. Different from previous results, the delay interval [0, d  (t )] is partitioned into some variable subintervals by employing dynamic delay partitioning method. Thus, new delay-dependent stability criteria for fuzzy time-delay systems is derived, which is less conservative than previous results. …By the criteria, the approach to design a fuzzy controller is developed. Two examples are provided to demonstrate the effectiveness for conservatism reduction. Show more

Keywords: Dynamic delay partition, nonlinear systems, Takagi-Sugeno (T-S) fuzzy model, time-varying delay, stabilization.

DOI: 10.3233/JIFS-172012

Citation: Journal of Intelligent & Fuzzy Systems, vol. 35, no. 2, pp. 2079-2090, 2018

Authors: Wang, Ning | Xu, Chengshun | Du, Xiuli | Zhang, Mingju | Lu, Xinyue

Article Type: Research Article

Abstract: In industrial engineering, the components of a critical system are capable of being in partial failure modes, except for “perfect state” and “complete failure”, and the failure behavior of those usually manifests as dynamicity and dependence. However, traditional dynamic fault trees (DFTs), which represent an event as a dichotomous variable, and the extended ones in probability risk assessment cannot actually grasp the dynamic properties of some multi-state systems (MSSs). For these issues, this article further extends the classical DFT language for sequential, prior and trigger-dependent MSSs and presents a unified framework of probability risk analysis based on the dynamic Bayesian …net (DBN). First, three types of multi-state dynamic gates (MSDGs) for representation of the above-mentioned failure behavior were defined, and the algorithm for mapping MSDGs to DBNs was proposed. Next, this paper employs the classic Markov chain based on the improved approach of Kronecker algebra to verify these models. Finally, combining a specific example of a shield excavation system, we discuss how the MSDGs can be adopted as a compact modeling language and analyze the dynamic probability risk of the system by compiling the model into a DBN. Show more

Keywords: DBN, multi-state system, dependability, dynamic property, Markov method

DOI: 10.3233/JIFS-172063

Citation: Journal of Intelligent & Fuzzy Systems, vol. 35, no. 2, pp. 2091-2103, 2018

Authors: Akram, Muhammad | Shumaiza, | Arshad, Maham

Article Type: Research Article

Abstract: Fuzzy rough set is a hybrid tool for handling indeterminate, inconsistent and uncertain information that exist in real life. Graph theory has numerous applications in various disciplines, including modern sciences and technology, database theory, computer networks, expert systems and image capturing. In this paper, we apply fuzzy rough set theory to graph theory and investigate a new kind of graph structure which is called fuzzy rough digraphs. Then we describe some of their theoretical properties. Finally, we consider applications of fuzzy rough digraphs in decision-making to demonstrate the applicability, feasibility, effectiveness of the proposed algorithm.

Keywords: Fuzzy tolerance relation, fuzzy rough digraphs, homomorphism, decision making

DOI: 10.3233/JIFS-172069

Citation: Journal of Intelligent & Fuzzy Systems, vol. 35, no. 2, pp. 2105-2121, 2018

Authors: Abd El-latif, A. M.

Article Type: Research Article

Abstract: In this paper, we introduce a generalized fuzzy soft rough model. A pair of new fuzzy soft rough approximations namely, fuzzy soft I ℙ -lower approximation and fuzzy soft I ℙ -upper approximation is proposed and their related properties are presented. Furthermore, we have succeeded to reduce the fuzzy soft boundary region comparing with already known in the literature. Finally, we obtain the structure of fuzzy soft ideal rough topologies induced by fuzzy soft sets and fuzzy ideals.

Keywords: Fuzzy soft sets, Soft rough sets, Fuzzy soft rough sets, Generalized fuzzy soft rough approximations, Fuzzy soft ideal rough topologies

DOI: 10.3233/JIFS-172076

Citation: Journal of Intelligent & Fuzzy Systems, vol. 35, no. 2, pp. 2123-2136, 2018

Authors: Khalil, Ahmed Mostafa | Li, Sheng-Gang | You, Fei | Ma, Sheng-Quan

Article Type: Research Article

Abstract: The aim of this paper is to introduce and study the concepts of fuzzifying semipre-θ -neighborhood system of a point, fuzzifying semipre-θ -closure of a set, fuzzifying semipre-θ -interior of a set, fuzzifying semipre-θ -open sets and fuzzifying semipre-θ -closed sets in fuzzifying topological spaces, and investigate some of their basic properties. Also, we present two types of functions in a fuzzifying topological spaces called fuzzifying strong β -irresolute and fuzzifying weak β -irresolute functions. The interrelations of these functions with the parallel existing allied concepts are established. Further, several characterizations of these functions along with different …conditions for their existence are obtained. Show more

Keywords: Łukasiewicz logic, fuzzifying topology, fuzzifying semipre-θ-closure of a set, fuzzifying semipre-θ-closed set, fuzzifying strong semipre-irresolute function

DOI: 10.3233/JIFS-172094

Citation: Journal of Intelligent & Fuzzy Systems, vol. 35, no. 2, pp. 2137-2148, 2018

Authors: Kamankesh, Hamidreza | Zhang, Daming

Article Type: Research Article

Abstract: This paper investigates the optimal structure switching in the microgrid for improving the electrical services for cost minimization and power quality improvement. The proposed framework makes use of some tie and sectionalizing switches for changing the microgrid feeding path to the electrical consumers and thus minimizing the resistive power losses. This concept is assimilated with the mobile storage capability of electric vehicles to improve the operation of the microgrid. The wöhler curve is used to model the degradation costs of battery charging and discharging process in the electric vehicles. The proposed problem is formulated as a mixed-integer nonlinear optimization problem …which is solved using the social spider optimization algorithm. Also, an effective two-phase modification method is developed to improve the algorithm diversity and avoid the premature convergence. An IEEE test system is used to investigate the performance of the proposed model. Show more

Keywords: Renewable energy sources, switching of feeders, microgrid, electric vehicle, wöhler curve

DOI: 10.3233/JIFS-172126

Citation: Journal of Intelligent & Fuzzy Systems, vol. 35, no. 2, pp. 2149-2159, 2018

Authors: Hong, Zhiyong | Rong, Yuan | Qin, Ya | Liu, Yi

Article Type: Research Article

Abstract: The present work is focused on hesitant fuzzy multi-attribute decision making (HF-MADM) problem with the hesitant fuzzy information based on a new aggregation operator. To begin with, we present the new hesitant fuzzy dual Muirhead mean (HFDMM) to deal with MADM problems, including the HFDMM and the hesitant fuzzy dual weighted Muirhead mean (HFDWMM) operator, the main advantages of the two aggregation operators are that they can capture interrelationships of multiple attributes among any number of attributes by a parameter vector P and make information aggregation process more flexible by the parameter vector P . In addition, some properties …of HFDMM and HFDWMM are obtained and some special cases are discussed where the parameter vector takes some different values. Moreover, we present a new method to solve the MADM problems with hesitant fuzzy information based on HFDWMM. Finally, an illustrative example is provided to show the feasibility and validity of the new method, the influences of parameter vector P on the decision making results are investigated and the advantages of proposed methods by comparing with the other existing methods are also analyzed by the example. Show more

Keywords: Hesitant fuzzy set, Muirhead Mean Operators, Dual Muirhead Mean, aggregation operators, multiple attribute decision making

DOI: 10.3233/JIFS-172139

Citation: Journal of Intelligent & Fuzzy Systems, vol. 35, no. 2, pp. 2161-2172, 2018

Authors: Al Rawashdeh, Ahmed | Mehmood, Nayyar | Rashid, Maliha

Article Type: Research Article

Abstract: Branciari defined the integral contractions to generalize the Banach contraction principle. Moreover recently Phiangsungnoen proved a fixed point theorem to generalize the ordered structure and contractive conditions with admissible mappings. In this article, we prove some coincidence and common fixed point theorems for a pair of L -fuzzy mappings satisfying integral β -admissible and generalize integral contractions. These results generalize the above famous results and many others in the literature. We define two types of fuzzy functional inclusions and prove existence of their solutions as a consequence of our results. Some nontrivial examples are given to provide significance of ourresults.

Keywords: Integral contractions, L-fuzzy mappings, β - admissible , functional inclusions

DOI: 10.3233/JIFS-172155

Citation: Journal of Intelligent & Fuzzy Systems, vol. 35, no. 2, pp. 2173-2187, 2018

Authors: Long, Xiqing | Liu, Yi | Xu, Yang

Article Type: Research Article

Abstract: In this paper, we further study the theory of A-subsets in lattice implication algebras. To begin with, we introduce the propositions of homomorphism image and original image of A-subsets in lattice implication algebras. In addition, the notion of A*-subsets is introduced and some properties of A*-subsets are also investigated in lattice implication algebras. Finally, we introduce the notion of involutory LI-ideals with respect to an LI-ideal A and denote the set of all of them by S A (L ). Then S A (L ) can be made into a complete Boolean lattice and a lattice …implication algebra with respect to the suit operations, respectively. Show more

Keywords: Lattice implication algebras, LI-ideal, A-subset, homomorphism

DOI: 10.3233/JIFS-172169

Citation: Journal of Intelligent & Fuzzy Systems, vol. 35, no. 2, pp. 2189-2198, 2018