فهرست مطالب

fuzzy systems - Volume:14 Issue: 4, 2017
  • Volume:14 Issue: 4, 2017
  • تاریخ انتشار: 1396/06/15
  • تعداد عناوین: 9
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  • J. De Andres-Sanchez *, L. Gonzalez-Vila Puchades Pages 1-25
    The concept of fuzzy random variable has been applied in several papers to model the present value of life insurance liabilities. It allows the fuzzy uncertainty of the interest rate and the probabilistic behaviour of mortality to be used throughout the valuation process without any loss of information. Using this framework, and considering a triangular interest rate, this paper develops closed expressions for the expected present value and its defuzzified value, the variance and the distribution function of several well-known actuarial liabilities structures, namely life insurances, endowments and life annuities.
    Keywords: Financial pricing, Life insurance, Endowment, Life annuity, Stochastic mortality, Fuzzy numbers, Fuzzy triangular interest rate, Fuzzy random variable, Fuzzy financial mathematics, Fuzzy life insurance mathematics
  • Muhammad Akram, Neha Waseem, Wieslaw A. Dudek * Pages 27-50
    In this research paper, we present a novel frame work for handling $m$-polar information by combining the theory of $m-$polar fuzzy sets with graphs. We introduce certain types of edge regular $m-$polar fuzzy graphs and edge irregular $m-$polar fuzzy graphs. We describe some useful properties of edge regular, strongly edge irregular and strongly edge totally irregular $m-$polar fuzzy graphs. We discuss the relationship between degree of a vertex and degree of an edge in an $m-$polar fuzzy graph. We investigate edge irregularity on a path on $2n$ vertices and barbell graph $B_{n,n}.$ We also present an application of $m-$polar fuzzy graph to decision making.
    Keywords: Barbell graph, $m-$polar fuzzy sets, $m-$polar fuzzy graphs, Strongly edge totally irregular $m-$polar fuzzy graphs, Decision making
  • Jozsef Dombi, Tamas Szepe* Pages 51-66
    Fuzzy control is one of the most important parts of fuzzy theory for which several approaches exist. Mamdani uses $\alpha$-cuts and builds the union of the membership functions which is called the aggregated consequence function. The resulting function is the starting point of the defuzzification process. In this article, we define a more natural way to calculate the aggregated consequence function via arithmetical operators. Defuzzification is the optimum value of the resultant membership function. The left and right hand sides of the membership function will be handled separately. Here, we present a new ABFC (Arithmetic Based Fuzzy Control) algorithm based on arithmetic operations which use a new defuzzification approach. The solution is much smoother, more accurate, and much faster than the classical Mamdani controller.
    Keywords: Fuzzy controller, Mamdani controller, Defuzzification, Fuzzy arithmetic
  • Lotfi Chaouech *, Mo^Ez Soltani, Slim Dhahri, Abdelkader Chaari Pages 67-85
    This paper addresses the problems caused by an inappropriate selection of sliding surface parameters in fuzzy sliding mode controllers via an optimization approach. In particular, the proposed method employs the parallel distributed compensator scheme to design the state feedback based control law. The controller gains are determined in offline mode via a linear quadratic regular. The particle swarm optimization is incorporated into the linear quadratic regular technique for determining the optimal weight matrices. Consequently, an optimal sliding surface is obtained using the scalar $sign$ function. This latter is used to design the proposed control law. Finally, the effectiveness of the proposed fuzzy sliding mode controller based on parallel distributed compensator and using particle swarm optimization is evaluated by comparing the obtained results with other reported in literature.
    Keywords: Sliding mode control, Takagi-Sugeno fuzzy model, Particle swarm optimization, Parallel distributed compensator, Linear quadratic regulator
  • Barbara Pekala *, Krzysztof Balicki Pages 87-98
    In this paper, the problem of measuring the degree of inclusion and similarity measure for two interval-valued intuitionistic fuzzy sets is considered. We propose inclusion and similarity measure by using order on interval-valued intuitionistic fuzzy sets connected with lexicographical order. Moreover, some properties of inclusion and similarity measure and some correlation, between them and aggregations are examined. Finally, we have included example of ranking problem in car showrooms.
    Keywords: Interval-valued intuitionistic fuzzy sets, Inclusion measure, Similarity measure
  • Jing Hao *, Shasha Huang Pages 99-115
    $L$-fuzzy rough sets are extensions of the classical rough sets by relaxing the equivalence relations to $L$-relations. The topological structures induced by $L$-fuzzy rough sets have opened up the way for applications of topological facts and methods in granular computing. In this paper, we firstly prove that each arbitrary $L$-relation can generate an Alexandrov $L$-topology. Based on this fact, we introduce the topological similarity of $L$-relations, denote it by T-similarity, and we give intuitive characterization of T-similarity. Then we introduce the variations of a given $L$-relation and investigate the relationship among them. Moreover, we prove that each $L$-relation is uniquely topological similar to an $L$-preorder. Finally, we investigate the related algebraic structures of different sets of $L$-relations on the universe.
    Keywords: $L$-fuzzy rough set, $L$-relation, Alexandrov $L$-topology, $L$-preorder, Topological similarity
  • Mojtaba Ghanbari * Pages 117-137
    In this manuscript, we introduce a new class of fuzzy problems, namely ``fuzzy inclusion linear systems" and propose a fuzzy solution set for it. Then, we present a theoretical discussion about the relationship between the fuzzy solution set of a fuzzy inclusion linear system and the algebraic solution of a fuzzy linear system. New necessary and sufficient conditions are derived for obtaining the unique algebraic solution for a fuzzy linear system. Also, all new concepts are illustrated by numerical examples.
    Keywords: Fuzzy linear system, Fuzzy inclusion linear system, Fuzzy solution set, Lower $r$-boundary, Upper $r$-boundary
  • Hongjun Zhou, Hui-Xian Shi * Pages 139-161
    $R\sb{0}$-algebras, which were proved to be equivalent to Esteva and Godo's NM-algebras modelled by Fodor's nilpotent minimum t-norm, are the equivalent algebraic semantics of the left-continuous t-norm based fuzzy logic firstly introduced by Guo-jun Wang in the mid 1990s.
    In this paper, we first establish a Stone duality for the category of MV-skeletons of $R\sb{0}$-algebras and the category of three-valued Stone spaces.
    Then we extend Flaminio-Montagna internal states to $R\sb{0}$-algebras.
    Such internal states must be idempotent MV-endomorphisms of $R\sb{0}$-algebras.
    Lastly we present a Stone duality for the category of MV-skeletons of $R\sb{0}$-algebras with Flaminio-Montagna internal states and the category of three-valued Stone spaces with Zadeh type idempotent continuous endofunctions.
    These dualities provide a topological viewpoint for better understanding of the algebraic structures of $R\sb{0}$-algebras.
    Keywords: $Rsb{0}$-algebra, Nilpotent minimum algebra, MV-skeleton, Internal state, Stone duality
  • A. Ghareeb* Pages 163-168
    In this paper, we show the redundancies of multiset topological spaces. It is proved that $(P^\star(U),\sqsubseteq)$ and $(Ds(\varphi(U)),\subseteq)$ are isomorphic. It follows that multiset topological spaces are superfluous and unnecessary in the theoretical view point.
    Keywords: Multiset, Multiset topology, Isomorphism