Iranian Journal of Fuzzy SystemsIranian Journal of Fuzzy Systems
http://ijfs.usb.ac.ir/
Sun, 11 Dec 2016 15:09:45 +0100FeedCreatorIranian Journal of Fuzzy Systems
http://ijfs.usb.ac.ir/
Feed provided by Iranian Journal of Fuzzy Systems. Click to visit.Cover vol. 13, no. 5, October 2016
http://ijfs.usb.ac.ir/article_2735_366.html
Fri, 28 Oct 2016 20:30:00 +0100New Approach to Exponential Stability Analysis and Stabilization for Delayed T-S Fuzzy ...
http://ijfs.usb.ac.ir/article_2730_366.html
This paper is concerned with delay-dependent exponential stability analysis and stabilization for continuous-time T-S fuzzy Markovian jump systems with mode-dependent time-varying delay. By constructing a novel Lyapunov-Krasovskii functional and utilizing some advanced techniques, less conservative conditions are presented to guarantee the closed-loop system is mean-square exponentially stable. Then, the stabilization conditions are derived and the fuzzy controller can be obtained by solving a set solutions of LMIs. The upper bound of time-delay that the system can be stabilized is given by using an optimal algorithm. Two examples are presented to illustrate the effectiveness and potential of our methods.Sat, 29 Oct 2016 20:30:00 +0100Assessing process performance with incapability index based on fuzzy critical value
http://ijfs.usb.ac.ir/article_2731_366.html
Process capability indices are considered as an important concept in statistical quality control. They have been widely used in the manufacturing industry to provide numerical measures on process performance. Moreover, some incapability indices have been introduced to account the process performance. In this paper, we focus on the one proposed by Chen ~cite{Che:Stat}. In today's modern world, accurate and flexible information is needed. So, we apply fuzzy logic to measure the process incapability. Buckley's approach is used to fuzzify this index and to make a decision on process incapability, we utilize fuzzy critical value. Numerical examples are presented to demonstrate the performance and effectiveness of the proposed index.Sat, 29 Oct 2016 20:30:00 +0100Profit maximization solid transportation problem under budget constraint using fuzzy measures
http://ijfs.usb.ac.ir/article_2732_366.html
Fixed charge solid transportation problems are formulated as profit maximization problems under a budget constraint at each destination. Here item is purchased in different depots at different prices. Accordingly the item is transported to different destinations from different depots using different vehicles. Unitsare sold from different destinations to the customers at different selling prices. Here selling prices, purchasing costs, unit transportation costs, fixed charges, sources at origins, demands at destinations, conveyances capacities are assumed to be crisp or fuzzy. Budget constraints at destinations are imposed. Itis also assumed that transported units are integer multiple of packets. So the problem is formulated as constraint optimization integer programming problem in crisp and fuzzy environments. Asoptimization of fuzzy objective as well as consideration of fuzzy constraint is not well defined, different measures possibility/necessity/credibility of fuzzy event are used to transform the problem into equivalent crisp problem. The reduced crisp problem is solved following generalized reduced gradient(GRG) method using lingo software. A dominance based genetic algorithm (DBGA) and a particle swarm optimization (PSO) technique using swap sequence are also developed for this purpose and are used to solve the model. The models are illustrated with numerical examples. The results obtained using DBGA and PSO are compared with those obtained from GRG.Moreover, a statistical analysis is presented to compare the algorithms.Sat, 29 Oct 2016 20:30:00 +0100Derived fuzzy importance of attributes based on the weakest triangular norm-based fuzzy ...
http://ijfs.usb.ac.ir/article_2734_366.html
The correlation between the performance of attributes and the overallsatisfaction such as they are perceived by the customers is often used tocalculate the importance of attributes in the crisp case. Recently, the methodwas extended, based on the standard Zadeh extension principle, to the fuzzycase, taking into account the specificity of the human thinking. Thedifficulties of calculation are important and only approximations of theanalytic results can be obtained. In the present paper we give a simplifiedand exact method to compute the derived importance of the attributes in thecase of input data given by triangular fuzzy numbers. The effectivecalculation is based on the $T_{W}$-extension principle and it uses reasonablecomputer resources even if a large number of attributes and customers isconsidered. The proposed derived method is later on compared with othermethods of calculation of the fuzzy importance of attributes. The results ofa survey with respect to the quality of hotel services in Oradea (Romania)are subject to the application of the proposed method.Sat, 29 Oct 2016 20:30:00 +0100A Hyers-Ulam-Rassias stability result for functional equations in Intuitionistic Fuzzy Banach spaces
http://ijfs.usb.ac.ir/article_2755_366.html
Hyers-Ulam-Rassias stability have been studied in the contexts of several areas of mathematics. The concept of fuzziness and its extensions have been introduced to almost all branches of mathematics in recent times.Here we define the cubic functional equation in 2-variables and establish that Hyers-Ulam-Rassias stability holds for such equations in intuitionistic fuzzy Banach spaces.Sat, 29 Oct 2016 20:30:00 +0100MULTI-ATTRIBUTE DECISION MAKING METHOD BASED ON BONFERRONI MEAN OPERATOR and possibility degree ...
http://ijfs.usb.ac.ir/article_2756_366.html
This paper proposes a new approach based on Bonferroni mean operator and possibility degree to solve fuzzy multi-attribute decision making (FMADM) problems in which the attribute value takes the form of interval type-2 fuzzy numbers. We introduce the concepts of interval possibility mean value and present a new method for calculating the possibility degree of two interval trapezoidal type-2 fuzzy sets (IT2 TrFSs). Then, we develop two aggregation techniques, which are called the interval type-2 trapezoidal fuzzy Bonferroni mean (IT2TFBM) operator and the interval type-2 trapezoidal fuzzy weighted Bonferroni mean (IT2TFWBM) operator. We study their properties and discuss their special cases. Based on the IT2TFWBM operator and the possibility degree, a new method of multi-attribute decision making with interval type-2 trapezoidal fuzzy information is proposed. Finally, an illustrative example is given to verify the developed approaches and to demonstrate their practicality and effectiveness.Sat, 29 Oct 2016 20:30:00 +0100Triangular Intuitionistic Fuzzy Triple Bonferroni Harmonic Mean Operators and Application to ...
http://ijfs.usb.ac.ir/article_2757_366.html
As an special intuitionistic fuzzy set defined on the real number set, triangular intuitionistic fuzzy number (TIFN) is a fundamental tool for quantifying an ill-known quantity. In order to model the decision maker's overall preference with mandatory requirements, it is necessary to develop some Bonferroni harmonic mean operators for TIFNs which can be used to effectively intergrate the information of attribute values for multi-attribute group decision making (MAGDM) with TIFNs. The purpose of this paper is to develop some Bonferroni harmonic operators of TIFNs and apply to the MAGDM problems with TIFNs. The weighted possibility means of TIFN are firstly defined. Hereby, a new lexicographic approach is presented to rank TIFNs sufficiently considering the risk preference of decision maker. The sensitivity analysis on the risk preference parameter is made. Then, three kinds of triangular intuitionistic fuzzy Bonferroni harmonic aggregation operators are defined, including a triangular intuitionistic fuzzy triple weighted Bonferroni harmonic mean operator (TIFTWBHM) operator, a triangular intuitionistic fuzzy triple ordered weighted Bonferroni harmonic mean (TIFTOWBHM) operator and a triangular intuitionistic fuzzy triple hybrid Bonferroni harmonic mean (TIFTHBHM) operator. Some desirable properties for these operators are discussed in detail. By using the TIFTWBHM operator, we can obtain the individual overall attribute values of alternatives, which are further integrated into the collective ones by the TIFTHBHM operator. The ranking order of alternatives is generated according to the collective overall attribute values of alternatives. A real investment selection case study verifies the validity and applicability of the proposed method.Sat, 29 Oct 2016 20:30:00 +0100Image Backlight Compensation Using Recurrent Functional Neural Fuzzy Networks Based on Modified ...
http://ijfs.usb.ac.ir/article_2609_0.html
In this study, an image backlight compensation method using adaptive luminance modification is proposed for efficiently obtaining clear images.The proposed method combines the fuzzy C-means clustering method, a recurrent functional neural fuzzy network (RFNFN), and a modified differential evolution.The proposed RFNFN is based on the two backlight factors that can accurately detect the compensation degree. According to the backlight level,the compensation curve function of a backlight image can be adaptively adjusted. In our experiments, six backlight images are used to verify the performance of proposed method.Experimental results demonstrate that the proposed method performs well in backlight problems.Sat, 29 Oct 2016 20:30:00 +0100On the multivariate process capability vector in fuzzy environment
http://ijfs.usb.ac.ir/article_2758_366.html
The production of a process is expected to meet customer demands, specifications or engineering tolerances. The ability of a process to meet these expectations is expresed as a single number using a process capability index. When the quality of the products relates to more than one characteristic, multivariate process capability indices are applied. As it is known, in some circumstances we are faced with imprecise data. So, fuzzy logic is engaged to deal with them. In this article, the specification limits and the target value of each characteristic and also, the data gathered from the process are assumed to be imprecise and a new fuzzy multivariate capability vector is introduced. As a whole, the present article provides a research of the application of fuzzy logic in multivariate capability vector.Sat, 29 Oct 2016 20:30:00 +0100A new attitude coupled with the basic fuzzy thinking to distance between two fuzzy numbers
http://ijfs.usb.ac.ir/article_2610_0.html
Fuzzy measures are suitable in analyzing human subjective evaluation processes. Several different strategies have been proposed for distance of fuzzy numbers. The distances introduced for fuzzy numbers can be categorized in two groups:1. The crisp distances which explain crisp values for the distance between two fuzzy numbers.2. The fuzzy distance which introduce a fuzzy distance for normal fuzzy numbers. It was introduced by Voxman cite{33} for the first time through using $alpha$-cut.However, both mentioned concepts can lead to unsatisfactory results from the applications point of view, but there is no method, which gives a satisfactory result to all situations. In this paper, a new attitude coupled with fuzzy thinking to the fuzzy distance function on the set of fuzzy numbers is proposed. In this new fuzzy distance, we considered both mentioned attitudes, then we introduced new fuzzy distance based on a combination (hybrid) of those two. Some properties of the proposed fuzzy distance have been discussed. Finally, several examples have been provided to explain the application of the proposed method and compare with other methods.Sat, 29 Oct 2016 20:30:00 +0100Cartesian-closedness of the category of $L$-fuzzy Q-convergence spaces
http://ijfs.usb.ac.ir/article_2759_366.html
The definition of $L$-fuzzy Q-convergence spaces is presented by Pang and Fang in 2011. However, Cartesian-closedness of the category of $L$-fuzzy Q-convergence spaces is not investigated. This paper focuses on Cartesian-closedness of the category of $L$-fuzzy Q-convergence spaces, and it is shown that the category $L$-$mathbf{QFCS}$ of $L$-fuzzy Q-convergence spaces is Cartesian-closed.Sat, 29 Oct 2016 20:30:00 +0100A new approach for solving fuzzy linear Volterra integro-differential equations
http://ijfs.usb.ac.ir/article_2611_0.html
In this paper, a fuzzy numerical procedure for solving fuzzy linear Volterra integro-differential equations of the second kind under strong generalized differentiability is designed. Unlike the existing numerical methods, we do not replace the original fuzzy equation by a $2times 2$ system ofcrisp equations, that is the main difference between our method and other numerical methods.Error analysis and numerical examples are given to show the convergency and efficiency of theproposed method, respectively.Sat, 05 Nov 2016 20:30:00 +0100Persian-translation vol. 13, no. 5, October 2016
http://ijfs.usb.ac.ir/article_2760_366.html
Sat, 29 Oct 2016 20:30:00 +0100A new multi-objective optimization approach for sustainable project portfolio selection: A ...
http://ijfs.usb.ac.ir/article_2612_0.html
Organizations need to evaluate project proposals and select the ones that are the most effective in reaching the strategic goals by considering sustainability issue. In order to enhance the effectiveness and the efficiency of project oriented organizations, in this paper a new multi-objective decision making (MODM) approach of sustainable project portfolio selection is proposed which applies interval-valued fuzzy sets (IVFSs) to consider uncertainty. In the proposed approach, in addition to sustainability criteria, other practical criteria including non-beneficial benefits, strategic alignment, organizational readiness and project risk are incorporated. The presented approach consists of three main parts: In the first part, a novel composite risk return index based on the IVFSs is introduced and used to form the first model to evaluate the financial return and risk of the proposed projects. In the second part, a new risk reduction compromise ratio model is introduced to evaluate projects versus non-financial criteria. Finally, an MODM model is presented to form the overall objective function of the approach. In order to make the approach more suitable for real-world situations, a group of applicable constraints is included in the proposed approach. The constraints are based on limitations and issues existing in practical project portfolio management. Due to importance of uncertainty and risk in project portfolio selection, they are addressed separately in three parts of the approach. In the first part, a novel downside risk measure is introduced and applied to assess financial risk of projects. In the second part of the approach, not only project risk is accounted for as a criterion, but also a new method is introduced to control and limit the risk of uncertainty and to use the advantages of IVFSs. Finally, the proposed IVF-MODM approach is applied to select the optimal sustainable project portfolio in real case study of a holding company in a developing country. The results show that the approach can successfully address highly uncertain environments. Moreover, risk has been fully explored from different perspectives. Eventually, the approach provided the decision makers with more flexibility in focusing on financial and non-financial criteria in the selection process.Sat, 05 Nov 2016 20:30:00 +0100Stability analysis and feedback control of T-S fuzzy hyperbolic delay model for a class of ...
http://ijfs.usb.ac.ir/article_2613_0.html
In this paper, a new T-S fuzzy hyperbolic delay model for a class of nonlinear systems with time-varying delay, is presented to address the problems of stability analysis and feedback control. Fuzzy controller is designed based on the parallel distributed compensation (PDC), and with a new Lyapunov function, delay dependent asymptotic stability conditions of the closed-loop system are derived via linear matrix inequalities (LMIs). Besides, considering the differences between the model and the real system, we extent the model to uncertain T-S fuzzy hyperbolic delay model. Based on the uncertain model, a robust $H_{infty}$ fuzzy controller is obtained and stability conditions are developed in terms of LMIs. The main advantage of the control based on T-S fuzzy hyperbolic delay model is that it can achieve small control amplitude via ``soft'' constraint approach. Finally, a numerical example and the Van de Vusse example are given to validate the advantages of the proposed method.Sat, 05 Nov 2016 20:30:00 +0100Some results on $L$-complete lattices
http://ijfs.usb.ac.ir/article_2614_0.html
The paper deals with special types of $L$-ordered sets, $L$-fuzzy complete lattices, and fuzzy directed complete posets.First, a theorem for constructing monotone maps is proved, a characterization for monotone maps on an $L$-fuzzycomplete lattice is obtained, andit's proved that if $f$ is a monotone map on an $L$-fuzzy complete lattice $(P;e)$, thenthe least fixpoint of $f$ is meet of a special element of $L^P$. A relation between $L$-fuzzy complete lattices and fixpoints is found andfuzzy versions of monotonicity, rolling, fusion and exchange rules on $L$-complete lattices are stated.Finally, we investigate the set of all monotone maps on a fuzzy directed complete posets, $DCPO$s, andfind a condition which under the set of all fixpoints of a monotone map on a fuzzy $DCPO$ is a fuzzy $DCPO$.Sat, 05 Nov 2016 20:30:00 +0100$M$-fuzzifying interval spaces
http://ijfs.usb.ac.ir/article_2615_0.html
In this paper, we introduce the notion of $M$-fuzzifying interval spaces, and discuss the relationship between $M$-fuzzifying interval spaces and $M$-fuzzifying convex structures.It is proved that the category {bf MYCSA2} can be embedded in the category {bf MYIS} as a reflective subcategory, where {bf MYCSA2} and {bf MYIS} denote the category of $M$-fuzzifying convex structures of $M$-fuzzifying arity $leq 2$ and the category of $M$-fuzzifying interval spaces, respectively. Under the framework of $M$-fuzzifying interval spaces, subspaces and product spaces are presented and some of their fundamental properties are obtained.Sat, 05 Nov 2016 20:30:00 +0100Structural properties of fuzzy graphs
http://ijfs.usb.ac.ir/article_2616_0.html
Matroids are important combinatorial structures and connect closelywith graphs. Matroids and graphs were all generalized to fuzzysetting respectively. This paper tries to study connections betweenfuzzy matroids and fuzzy graphs. For a given fuzzy graph, we firstinduce a sequence of matroids from a sequence of crisp graph, i.e.,cuts of the fuzzy graph. A fuzzy matroid, named graph fuzzy matroid,is then constructed by using the sequence of matroids. An equivalentdescription of graphic fuzzy matroids is given and their propertiesof fuzzy bases and fuzzy circuits are studied.Sun, 06 Nov 2016 20:30:00 +0100Counting distinct fuzzy subgroups of some rank-3 abelian groups
http://ijfs.usb.ac.ir/article_2617_0.html
In this paper we classify fuzzy subgroups of a rank-3 abelian group $G = mathbb{Z}_{p^n} + mathbb{Z}_p + mathbb{Z}_p$ for any fixed prime $p$ and any positive integer $n$, using a natural equivalence relation given in cite{mur:01}. We present and prove explicit polynomial formulae for the number of (i) subgroups, (ii) maximal chains of subgroups, (iii) distinct fuzzy subgroups, (iv) non-isomorphic maximal chains of subgroups and (v) classes of isomorphic fuzzy subgroups of $G$. Illustrative examples are provided.Sun, 06 Nov 2016 20:30:00 +0100Formal balls in fuzzy partial metric spaces
http://ijfs.usb.ac.ir/article_2619_0.html
In this paper, the poset $BX$ of formal balls is studied in fuzzy partial metric space $(X,p,*)$. We introduce the notion of layered complete fuzzy partial metric space and get that the poset $BX$ of formal balls is a dcpo if and only if $(X,p,*)$ is layered complete fuzzy partial metric space.Sun, 06 Nov 2016 20:30:00 +0100Soft Computing Based on a Modified MCDM Approach under Intuitionistic Fuzzy Sets
http://ijfs.usb.ac.ir/article_2620_0.html
The current study set to extend a new VIKOR method as a compromise ranking approach to solve multiple criteria decision-making (MCDM) problems through intuitionistic fuzzy analysis. Using compromise method in MCDM problems contributes to the selection of an alternative as close as possible to the positive ideal solution and far away from the negative ideal solution, concurrently. Using Atanassov intuitionistic fuzzy sets (A-IFSs) may simultaneously express the degree of membership and non-membership to decision makers (DMs) to describe uncertain situations in decision-making problems. The proposed intuitionistic fuzzy VIKOR indicates the degree of satisfaction and dissatisfaction of each alternative with respect to each criterion and the relative importance of each criterion, respectively, by degrees of membership and non-membership. Thus, the ratings for the importance of criteria, DMs, and alternatives are in linguistic variables and expressed in intuitionistic fuzzy numbers. Using IFS aggregation operators and with respect to subjective judgment and objective information, the most suitable alternative is indicated among potential alternatives. Moreover, practical examples illustrate the procedure of the proposed method.Sun, 06 Nov 2016 20:30:00 +0100SOME TOPOLOGICAL PROPERTIES OF SPECTRUM OF FUZZY SUBMODULES
http://ijfs.usb.ac.ir/article_2659_0.html
Let R be a commutative ring with identity andM be an R-module.Let FSpec(M) denote the collection of all prime fuzzy submodules of M. Inthis regards some basic properties of Zariski topology on FSpec(M) are in-vestigated. In particular, we prove some equivalence conditions for irreduciblesubsets of this topological space and it is shown that under certain conditionsFSpec(M) is a T0-space or Hausdor.Thu, 29 Dec 2016 20:30:00 +0100S-approximation Spaces: A Fuzzy Approach
http://ijfs.usb.ac.ir/article_2660_0.html
In this paper, we study the concept of S-approximation spaces in fuzzy set theory and investigate its properties. Along introducing three pairs of lower and upper approximation operators for fuzzy S-approximation spaces, their properties under different assumptions, e.g. monotonicity and weak complement compatibility are studied. By employing two thresholds for minimum acceptance accuracy and maximum rejection error, these spaces are interpreted in three-way decision systems by defining the corresponding positive, negative and boundary regions.Mon, 19 Dec 2016 20:30:00 +0100Probabilistic Normed Groups
http://ijfs.usb.ac.ir/article_2661_0.html
In this paper, we introduce the probabilistic normed groups. Among other results, we investigate the continuityof inner automorphisms of a group and the continuity of left and right shifts in probabilistic group-norm. We also study midconvex functions defined on probabilistic normed groups and give some results about locally boundedness of such functions.Sun, 04 Dec 2016 20:30:00 +0100Support vector regression with random output variable and probabilistic constraints
http://ijfs.usb.ac.ir/article_2662_0.html
Support Vector Regression (SVR) solves regression problems based on the concept of Support Vector Machine (SVM). In this paper, a new model of SVR with probabilistic constraints is proposed that any of output data and bias are considered the random variable with uniform probability function. Using the new proposed method, the optimal hyperplane regression can be obtained by solving a quadratic optimization problem. The proposedmethod is illustrated by several simulated data and real datasets for both models (linear and nonlinear) with probabilistic constraints.Sun, 04 Dec 2016 20:30:00 +0100Some Results of Moments of Uncertain Random Variables
http://ijfs.usb.ac.ir/article_2663_0.html
Chance theory is a mathematical methodology for dealing with indeterminatephenomena including uncertainty and randomness.Consequently, uncertain random variable is developed to describe the phenomena which involveuncertainty and randomness.Thus, uncertain random variable is a fundamental concept in chance theory.This paper provides some practical quantities to describe uncertain random variable.The typical one is the expected value, which is the uncertain version of thecenter of gravity of a physical body.Mathematically, expectations are integrals with respect to chance distributionsor chance measures.In fact, expected values measure the center of gravity of a distribution; they aremeasures of location. In order to describe a distribution in brief terms thereexist additional measures, such as the variance which measures the dispersionor spread, and moments.For calculating the moments of uncertain random variable, some formulas are provided through chance distribution and inverse chance distribution. The main results are explained by using several examples.Sun, 04 Dec 2016 20:30:00 +0100Group Generalized Interval-valued Intuitionistic Fuzzy Soft Sets and Their Applications in\\ ...
http://ijfs.usb.ac.ir/article_2664_0.html
Interval-valued intuitionistic fuzzy sets (IVIFSs) are widely used to handle uncertainty and imprecision in decision making. However, in more complicated environment, it is difficult to express the uncertain information by an IVIFS with considering the decision-making preference. Hence, this paper proposes a group generalized interval-valued intuitionistic fuzzy soft set (G-GIVIFSS) which contains the basic description by interval-valued intuitionistic fuzzy soft set (IVIFSS) on the alternatives and a group of experts' evaluation of it. It contributes the following threefold: 1) A generalized interval-valued intuitionistic fuzzy soft set (GIVIFSS) is proposed by introducing an interval-valued intuitionistic fuzzy parameter, which reflects a new and senior expert's opinion on the basic description. The operations, properties and aggregation operators of GIVIFSS are discussed. 2) Based on GIVIFSS, a G-GIVIFSS is then proposed to reduce the impact of decision-making preference by introducing more parameters by a group of experts. Its important operations, properties and the weighted averaging operator are also defined. 3) A multi-attribute group decision making model based on G-GIVIFSS weighted averaging operator is built to solve the group decision making problems in the more universal IVIF environment, and two practical examples are taken to validate the efficiency and effectiveness of the proposed model.Sun, 04 Dec 2016 20:30:00 +0100On local Hudetz $g$-entropy
http://ijfs.usb.ac.ir/article_2665_0.html
In this paper, a local approach to the concept of Hudetz $g$-entropy is presented. The introduced concept is stated in terms of Hudetz $g$-entropy. This representation is based on the concept of $g$-ergodic decomposition which is a result of the Choquet's representation Theorem for compact convex metrizable subsets of locally convex spaces.Sun, 04 Dec 2016 20:30:00 +0100A Tauberian theorem for $(C,1,1)$ summable double sequences of fuzzy numbers
http://ijfs.usb.ac.ir/article_2666_0.html
In this paper, we determine necessary and sufficient Tauberian conditions under which convergence in Pringsheim's sense of a double sequence of fuzzy numbers follows from its $(C,1,1)$ summability. These conditions are satisfied if the double sequence of fuzzy numbers is slowly oscillating in different senses. We also construct some interesting double sequences of fuzzy numbers.Sun, 04 Dec 2016 20:30:00 +0100RS-BL-algebras are MV-algebras
http://ijfs.usb.ac.ir/article_2667_0.html
We prove that RS-BL-algebras are MV-algebras.Sun, 04 Dec 2016 20:30:00 +0100UNIVERSAL APPROXIMATION OF INTERVAL-VALUED FUZZY SYSTEMS BASED ON INTERVAL-VALUED IMPLICATIONS
http://ijfs.usb.ac.ir/article_2764_0.html
It is firstly proved that the multi-input-single-output (MISO) fuzzysystems based on interval-valued R- and S-implications can approximate anycontinuous function defined on a compact set to arbitrary accuracy. A formulato compute the lower upper bounds on the number of interval-valued fuzzysets needed to achieve a pre-specified approximation accuracy for an arbitrarymultivariate continuous function is then presented. In addition, a method todesign the interval-valued fuzzy systems based on R- and S-implications inorder to approximate a given continuous function with a required approximationaccuracy is represented. Finally, two numerical examples are provided toillustrate the proposed procedure.Thu, 29 Dec 2016 20:30:00 +0100IMPLICATIONS, COIMPLICATIONS AND LEFT SEMI-UNINORMS ON A COMPLETE LATTICE
http://ijfs.usb.ac.ir/article_2769_0.html
In this paper, we firstly show that the N-dual operation of theright residual implication, which is induced by a left-conjunctive right arbitrary_-distributive left semi-uninorm, is the right residual coimplication inducedby its N-dual operation. As a dual result, the N-dual operation ofthe right residual coimplication, which is induced by a left-disjunctive rightarbitrary ^-distributive left semi-uninorm, is the right residual implicationinduced by its N-dual operation. Then, we demonstrate that the N-dualoperations of the left semi-uninorms induced by an implication and a coimplication,which satisfy the neutrality principle, are the left semi-uninorms.Finally, we reveal the relationships between conjunctive right arbitrary _-distributive left semi-uninorms induced by implications and disjunctive rightarbitrary ^-distributive left semi-uninorms induced by coimplications, whereboth implications and coimplications satisfy the neutrality principle.Thu, 29 Dec 2016 20:30:00 +0100FUZZY FRACTIONAL PARTIAL DIFFERENTIAL EQUATIONS IN PARTIALLY ORDERED METRIC SPACES
http://ijfs.usb.ac.ir/article_2770_0.html
In this paper, we consider fuzzy fractional partial differential equations under Caputo generalized Hukuhara differentiability. Some new results on the existence and uniqueness of two types of fuzzy solutions are studied via weakly contractive mapping in the partially ordered metric space. Some application examples are presented to illustrate our main results.Thu, 29 Dec 2016 20:30:00 +0100A JOINT DUTY CYCLE SCHEDULING AND ENERGY AWARE ROUTING APPROACH BASED ON EVOLUTIONARY GAME FOR ...
http://ijfs.usb.ac.ir/article_2771_0.html
Network throughput and energy conservation are two conflicting important performance metrics for wireless sensor networks. Since these two objectives are in conflict with each other, it is difficult to achieve them simultaneously. In this paper, a joint duty cycle scheduling and energy aware routing approach is proposed based on evolutionary game theory which is called DREG. Making a trade-off between energy conservation and network throughput, the proposed approach prolongs the network lifetime. The paper is divided into the following sections: Initially, the discussion is presented on how the sensor nodes can be scheduled to sleep or wake up in order to reduce energy consumption in idle listening. The sensor wakeup/sleep scheduling problem with multiple objectives is formulated as an evolutionary game theory. Then, the evolutionary game theory is applied to find an optimal wakeup/sleep scheduling policy, based on a trade-off between network throughput and energy efficiency for each sensor. The evolutionary equilibrium is proposed as a solution for this game. In addition, a routing approach is adopted to propose an energy aware fuzzy logic in order to prolong the network lifetime. The results show that the proposed routing approach balances energy consumption among the sensor nodes in the network, avoiding rapid energy depletion of sensors that have less energy. The proposed simulation study shows the more efficient performance of the proposed system than other methods in term of network lifetime and throughput.Thu, 29 Dec 2016 20:30:00 +0100MULTI-OBJECTIVE ROUTING AND SCHEDULING IN FLEXIBLE MANUFACTURING SYSTEMS UNDER UNCERTAINTY
http://ijfs.usb.ac.ir/article_2772_0.html
The efficiency of transportation system management plays an important role in the planning and operation efficiency of flexible manufacturing systems. Automated Guided Vehicles (AGV) are part of diversified and advanced techniques in the field of material transportation which have many applications today and act as an intermediary between operating and storage equipment and are routed and controlled by an intelligent computer system. In this study, a two-objective mathematical programming model is presented to integrate flow shop scheduling and routing AVGs in a flexible manufacturing system. In real-life problems parameters like demand, due dates and processing times are always uncertain. Therefore, in order to solve a realistic problem, foregoing parameters are considered as fuzzy in our proposed model. Subsequently, to solve fuzzy mathematical programming model, one of the most effective technique in the literature is used. To solve the problem studied, two meta-heuristic algorithms of Non-dominated Sorting Genetic Algorithm-II (NSGAII) and multi-objective particle swarm optimization (MOPSO) are offered that the accuracy of mathematical models and efficiency of algorithms provided are assessed through numerical examples.Tue, 29 Nov 2016 20:30:00 +0100SOLUTION-SET INVARIANT MATRICES AND VECTORS IN FUZZY RELATION INEQUALITIES BASED ON ...
http://ijfs.usb.ac.ir/article_2773_0.html
Fuzzy relation inequalities based on max-F composition are discussed, where F is a binary aggregation on [0,1]. For a fixed fuzzy relation inequalities system $ A circ^{F}textbf{x}leqtextbf{b}$, we characterize all matrices $ A^{'} $ For which the solution set of the system $ A^{' } circ^{F}textbf{x}leqtextbf{b}$ is the same as the original solution set. Similarly, for a fixed matrix $ A $, the possible perturbations $ b^{'} $ of the right-hand side vector $ b $ not modifying the original solution set are determined. Several illustrative examples are included to clarify the results of the paper.Thu, 29 Dec 2016 20:30:00 +0100FIXED POINT THEOREMS FOR ORDERED CONTRACTIVE MAPPINGS IN THE WEAK NON-ARCHIMEDEAN FUZZY METRIC ...
http://ijfs.usb.ac.ir/article_2788_0.html
In this paper, the author establishes some fixed point theorems fornonlinear contractive operators in the partially ordered weak non-Archimedeanfuzzy metric spaces. A fuzzy extension theorem of Boyd and Wong's nonlinearcontraction theorem is presented. As a consequence, our main results improvedand generalized some recent coupled fixed point theorems and coincidencepoint theorems.Sat, 09 Dec 2017 20:30:00 +0100ON THE SYSTEM OF LEVEL-ELEMENTS INDUCED BY AN L-SUBSET
http://ijfs.usb.ac.ir/article_2789_0.html
This paper focuses on the relationship between an L-subset andthe system of level-elements induced by it, where the underlying lattice L isa complete residuated lattice and the domain set of L-subset is an L-partiallyordered set (X, P). Firstly, we obtain the sufficient and necessary conditionthat an L-subset is represented by its system of level-elements. Then, a newrepresentation theorem of intersection-preserving L-subsets is shown by usingunion-preserving system of elements. At last, another representation theoremof compatible intersection-preserving L-subsets is obtained by means ofcompatible union-preserving system of elements.Sat, 09 Dec 2017 20:30:00 +0100ROBUST FUZZY CONTROL DESIGN USING GENETIC ALGORITHM OPTIMIZATION APPROACH: CASE STUDY OF SPARK ...
http://ijfs.usb.ac.ir/article_2790_0.html
In the case of widely-uncertain non-linear system control design,it was very difficult to design a single controller to overcome control designspecifications in all of its dynamical characteristics uncertainties. To resolvethese problems, a new design method of robust fuzzy control proposed. Thesolution offered was by creating multiple soft-switching with Takagi-Sugenofuzzy model for optimal solution control at all operating points that generateuncertainties. Optimal solution control at each operating point was calculatedusing genetic algorithm. A case study of engine torque control of spark ignitionengine model was used to prove this new method of robust fuzzy control design.From the simulation results, it can be concluded that the controller operatesvery well for a wide uncertainty.Sat, 09 Dec 2017 20:30:00 +0100STABILITY OF THE JENSEN'S FUNCTIONAL EQUATION IN MULTI-FUZZY NORMED SPACES
http://ijfs.usb.ac.ir/article_2791_0.html
In this paper, we define the notion of (dual) multi-fuzzy normedspaces and describe some properties of them. We then investigate Ulam-Hyersstability of Jensen’s functional equation for mappings from linear spaces intomulti-fuzzy normed spaces. We establish an asymptotic behavior of the Jensenequation in the framework of multi-fuzzy normed spaces.Sat, 09 Dec 2017 20:30:00 +0100FUZZY PREORDERED SET, FUZZY TOPOLOGY AND FUZZY AUTOMATON BASED ON GENERALIZED RESIDUATED LATTICE
http://ijfs.usb.ac.ir/article_2792_0.html
This work is towards the study of the relationship between fuzzypreordered sets and Alexandrov (left/right) fuzzy topologies based on gener-alized residuated lattices here the fuzzy sets are equipped with generalizedresiduated lattice in which the commutative property doesn't hold. Further,the obtained results are used in the study of fuzzy automata theory.Sat, 09 Dec 2017 20:30:00 +0100GRADED DIUNIFORMITIES
http://ijfs.usb.ac.ir/article_2793_0.html
Graded ditopological texture spaces have been presented and discussedin categorical aspects by Lawrence M. Brown and Alexander Sostakin [7]. In this paper, the authors generalize the structure of diuniformity inditopological texture spaces defined in [13] to the graded ditopological texturespaces and investigate graded ditopologies generated by graded diuniformities.The autors also compare the properties of diuniformities and graded diuniformities.Sat, 09 Dec 2017 20:30:00 +0100M-FUZZIFYING MATROIDS INDUCED BY M-FUZZIFYING CLOSURE OPERATORS
http://ijfs.usb.ac.ir/article_2794_0.html
In this paper, the notion of closure operators of matroids is gen-eralized to fuzzy setting which is called M-fuzzifying closure operators, andsome properties of M-fuzzifying closure operators are discussed. The M-fuzzifying matroid induced by an M-fuzzifying closure operator can induce anM-fuzzifying closure operator. Finally, the characterizations of M-fuzzifyingacyclic matroids are given.Sat, 09 Dec 2017 20:30:00 +0100SELECTIVE GROUPOIDS AND FRAMEWORKS INDUCED BY FUZZY SUBSETS
http://ijfs.usb.ac.ir/article_2795_0.html
In this paper, we show that every selective groupoid induced by afuzzy subset is a pogroupoid, and we discuss several properties in quasi orderedsets by introducing the notion of a framework.Sat, 09 Dec 2017 20:30:00 +0100INFORMATION MEASURES BASED TOPSIS METHOD FOR MULTICRITERIA DECISION MAKING PROBLEM IN ...
http://ijfs.usb.ac.ir/article_2796_0.html
In the fuzzy set theory, information measures play a paramountrole in several areas such as decision making, pattern recognition etc. In thispaper, similarity measure based on cosine function and entropy measures basedon logarithmic function for IFSs are proposed. Comparisons of proposed simi-larity and entropy measures with the existing ones are listed. Numerical resultslimpidly betoken the efficiency of these measures over others. An intuitionisticfuzzy weighted measures (IFWM) with TOPSIS method for multi-criteria de-cision making (MCDM) quandary is introduced to grade the alternatives. Thisapproach is predicated on entropy and weighted similarity measures for IFSs.An authentic case study is discussed to rank the four organizations. To com-pare the different rankings, a portfolio selection problem is considered. Variousportfolios have been constructed and analysed for their risk and return. It hasbeen examined that if the portfolios are developed using the ranking obtainedwith proposed method, the return is increased with slight increment in risk.Sat, 09 Dec 2017 20:30:00 +0100