Iranian Journal of Fuzzy SystemsIranian Journal of Fuzzy Systems
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Feed provided by Iranian Journal of Fuzzy Systems. Click to visit.Cover vol. 15, no. 1, February 2018
http://ijfs.usb.ac.ir/article_3585_509.html
Wed, 31 Jan 2018 20:30:00 +0100INVENTORY MODEL WITH DEMAND AS TYPE-2 FUZZY NUMBER: A FUZZY DIFFERENTIAL EQUATION APPROACH
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An inventory model is formulated with type-2 fuzzy parameters under trade credit policy and solved by using Generalized Hukuhara derivative approach. Representing demand parameter of each expert's opinion is a membership function of type-1 and thus, this membership function again becomes fuzzy. The final opinion of all experts is expressed by a type-2 fuzzy variable. For this present problem, to get corresponding defuzzified values of the triangular type-2 fuzzy demand parameters, first critical value (CV)-based reduction methods are applied to reduce corresponding type-1 fuzzy variables which becomes pentagonal in form. After that $alpha$- cut of a pentagonal fuzzy number is used to construct the upper $alpha$- cut and lower $alpha$- cut of the fuzzy differential equation. Different cases are considered for fuzzy differential equation: gH-(i) differentiable and gH-(ii) differentiable systems. The objective of this paper is to find out the optimal time so as to minimize the total inventory cost. The considered problem ultimately reduces to a multi-objective problem which is solved by weighted sum method and global criteria method. Finally the model is solved by generalised reduced gradient method using LINGO (13.0) software. The proposed model and technique are lastly illustrated by providing numerical examples. Results from two methods are compared and some sensitivity analyses both in tabular and graphical forms are presented and discussed. The effects of total cost with respect to the change of demand related parameter ($beta$), holding cost parameter ($r$), unit purchasing cost parameter ($p$), interest earned $(i_e)$ and interest payable $(i_p)$ are discussed. We also find the solutions for type-1 and crisp demand as particular cases of type-2 fuzzy variable. This present study can be applicable in many aspects in many real life situations where type-1 fuzzy set is not sufficient to formulate the mathematical model. From the numerical studies, it is observed that under both gH-(i) and gH-(ii) cases, total cost of the system gradually reduces for the sub-cases - 1.1, 1.2 and 1.3 depending upon the positions of N(trade credit for customer) and M (trade credit for retailer) with respect to T (time period).Wed, 28 Feb 2018 20:30:00 +0100SHAPLEY FUNCTION BASED INTERVAL-VALUED INTUITIONISTIC FUZZY VIKOR TECHNIQUE FOR CORRELATIVE ...
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Interval-valued intuitionistic fuzzy set (IVIFS) has developed to cope with the uncertainty of imprecise human thinking. In the present communication, new entropy and similarity measures for IVIFSs based on exponential function are presented and compared with the existing measures. Numerical results reveal that the proposed information measures attain the higher association with the existing measures, which demonstrate their efficiency and reliability. To deal with the interactive characteristics among the elements in a set, Shapley weighted similarity measure based on proposed similarity measure for IVIFSs is discussed via Shapley function. Thereafter, the linear programming model for optimal fuzzy measure is originated for incomplete information about the weights of the criteria and thus, the optimal weight vector is obtained in terms of Shapley values. Further, the VIKOR technique is discussed for correlative multi-criteria decision making problems under interval-valued intuitionistic fuzzy environment. Finally, an example of investment problem is presented to exemplify the application of the proposed technique under incomplete and uncertain information situation.Wed, 28 Feb 2018 20:30:00 +0100ITERATIVE METHOD FOR SOLVING TWO-DIMENSIONAL NONLINEAR FUZZY INTEGRAL EQUATIONS USING FUZZY ...
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In this paper, we propose an iterative procedure based on two dimensionalfuzzy block-pulse functions for solving nonlinear fuzzy Fredholm integralequations of the second kind. The error estimation and numerical stabilityof the proposed method are given in terms of supplementary Lipschitz condition.Finally, illustrative examples are included in order to demonstrate the accuracyand convergence of the proposed method.Wed, 28 Feb 2018 20:30:00 +0100SOME SIMILARITY MEASURES FOR PICTURE FUZZY SETS AND THEIR APPLICATIONS
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In this work, we shall present some novel process to measure the similarity between picture fuzzy sets. Firstly, we adopt the concept of intuitionistic fuzzy sets, interval-valued intuitionistic fuzzy sets and picture fuzzy sets. Secondly, we develop some similarity measures between picture fuzzy sets, such as, cosine similarity measure, weighted cosine similarity measure, set-theoretic similarity measure, weighted set-theoretic cosine similarity measure, grey similarity measure and weighted grey similarity measure. Then, we apply these similarity measures between picture fuzzy sets to building material recognition and minerals field recognition. Finally, two illustrative examples are given to demonstrate the efficiency of the similarity measures for building material recognition and minerals field recognition.Wed, 28 Feb 2018 20:30:00 +0100A NEW APPROACH FOR PARAMETER ESTIMATION IN FUZZY LOGISTIC REGRESSION
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Logistic regression analysis is used to model categorical dependent variable. It is usually used in social sciences and clinical research. Human thoughts and disease diagnosis in clinical research contain vagueness. This situation leads researchers to combine fuzzy set and statistical theories. Fuzzy logistic regression analysis is one of the outcomes of this combination and it is used in situations where the classical logistic regression assumptions' are not satisfied. Also it can be used if the observations or their relations are vague. In this study, a model called “Fuzzy Logistic Regression Based on Revised Tanaka's Fuzzy Linear Regression Model” is proposed. In this regard, the methodology and formulation of the proposed model is explained in detail and the revised Tanaka's regression model is used to estimate the parameters. The Revised Tanaka's Regression model is an extension of Tanaka's Regression Model in which the objection function is developed. An application is performed on birth weight data set. Also, an application of diabetes data set used in Pourahmad et al.'s study was conducted via our proposed data set. The validity of the model is shown by the help of goodness – of –fit criteria called Mean Degree Memberships (MDM).Wed, 28 Feb 2018 20:30:00 +0100QUANTALE-VALUED GAUGE SPACES
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We introduce a quantale-valued generalization of approach spaces in terms of quantale-valued gauges. The resulting category is shown to be topological and to possess an initially dense object. Moreover we show that the category of quantale-valued approach spaces defined recently in terms of quantale-valued closures is a coreflective subcategory of our category and, for certain choices of the quantale, is even isomorphic to our category. Finally, the category of quantale-valued metric spaces is shown to be coreflectively embedded in our category.Wed, 28 Feb 2018 20:30:00 +0100ON TRUNCATED MEASURES OF INCOME INEQUALITY FROM A FUZZY PERSPECTIVE
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In most statistical analysis, inequality or extent of variation in income isrepresented in terms of certain summary measures. But some authors arguedthat the concept of inequality is vague and thus cannot be measured as anexact concept. Therefore, fuzzy set theory provides naturally a useful toolfor such circumstances. In this paper we have introduced a real-valued fuzzymethod of illustrating the measures of income inequality in truncated randomvariables based on the case where the conditional events are vague. Toguarantee certain relevant properties of these measures, we first selectedthree main families of measures and obtained their closed formulas, thenused two simulated and real data set to illustrate the usefulness of derivedresults.Wed, 28 Feb 2018 20:30:00 +0100A NEW APPROACH IN FAILURE MODES AND EFFECTS ANALYSIS BASED ON COMPROMISE SOLUTION BY ...
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Failure modes and effects analysis (FMEA) is a well-known risk analysis approach that has been conducted to distinguish, analyze and mitigate serious failure modes. It demonstrates the effectiveness and the ability of understanding and documenting in a clear manner; however, the FMEA has weak points and it has been criticized by some authors. For example, it does not consider relative importance among three risk factors (i.e., $ O, S $ and $ D $). Different sequences of $ O $, $ S $ and $ D $ may result in exactly the same value of risk priority number (RPN), but their semantic risk implications may be totally different and these three risk factors are difficult to be precisely expressed. This study introduces a new interval-valued intuitionistic fuzzy (IVIF)-decision approach based on compromise solution concept that defeats the above weak points and improves the traditional FMEA's results. This study firstly employs both subjective and objective weights in the decision process simultaneously. Secondly, there are two kinds of subjective weights performed in the study: aggregated weights obtained by experts' assessments as well as entropy measure. Thirdly, this approach is defined under an IVIF-environment to ensure that the evaluation information would be preserved, and the uncertainties could be handled during the computations. Hence, it considers uncertainty in experts' judgments as well as reduces the probability of obtaining two ranking orders with the same value. Finally, the alternatives are ranked with a new collective index according to the compromise solution concept. To show the effectiveness of the proposed approach, two practical examples are solved from the recent literature in engineering applications. The proposed decision approach has an acceptable performance. Also, its advantages have been mentioned in comparison with other decision approaches.Wed, 28 Feb 2018 20:30:00 +0100ON SOMEWHAT FUZZY AUTOMATA CONTINUOUS FUNCTIONS IN FUZZY AUTOMATA TOPOLOGICAL SPACES
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In this paper, the concepts of somewhat fuzzy automata continuous functions and somewhat fuzzy automata open functions in fuzzy automata topological spaces are introduced and some interesting properties of these functions are studied. In this connection, the concepts of fuzzy automata resolvable spaces and fuzzy automata irresolvable spaces are also introduced and their properties are studied.Wed, 28 Feb 2018 20:30:00 +0100Persian-translation vol. 15, no. 1, February 2018
http://ijfs.usb.ac.ir/article_3586_509.html
Wed, 31 Jan 2018 20:30:00 +0100OPTIMAL LOT-SIZING DECISIONS WITH INTEGRATED PURCHASING, MANUFACTURING AND ASSEMBLING FOR ...
http://ijfs.usb.ac.ir/article_3007_0.html
This work applies fuzzy sets to the integration of purchasing, manufacturing and assembling of production planning decisions with multiple suppliers, multiple components and multiple machines in remanufacturing systems. The developed fuzzy multi-objective linear programming model (FMOLP) simultaneously minimizes total costs, total $text{CO}_2$ emissions and total lead time with reference to customer demand, due date, supplier/manufacturer capacity, lot-size release and machine yield. The proposed FMOLP model provides a recoverable remanufacturing framework that facilitates fuzzy decision-making, enabling the decision maker (DM) to adjust interactively the membership function or parameters during the solution procedure to obtain a preferred and satisfactory solution. To test of the model, it was implemented in various scenarios with a remanufacturing production system. The analytical results in this work can help planner by enabling systematic analysis of the cost-effectiveness of remanufacturing systems and their potential for improving $text{CO}_2$ emissions and lead time in terms of remanufacturing planning. Future investigations may apply the related patterns of non-linear membership functions to develop an actual remanufacturing planning decision.Sat, 18 Feb 2017 20:30:00 +0100FUZZY LOGISTIC DIFFERENCE EQUATION
http://ijfs.usb.ac.ir/article_3066_0.html
In this study, we consider two different inequivalent formulations of the logistic difference equation $x_{n+1}= beta x_n(1- x_n), n=0,1,..., $ where $x_n$ is a sequence of fuzzy numbers and $beta$ is a positive fuzzy number. The major contribution of this paper is to study the existence, uniqueness and global behavior of the solutions for two corresponding equations, using the concept of Hukuhara difference for fuzzy numbers. Finally, some examples are given to illustrate our results.Fri, 03 Mar 2017 20:30:00 +0100TREND-CYCLE ESTIMATION USING FUZZY TRANSFORM OF HIGHER DEGREE
http://ijfs.usb.ac.ir/article_3067_0.html
In this paper, we provide theoretical justification for the application of higher degree fuzzy transform in time series analysis. Under the assumption that a time series can be additively decomposed into a trend-cycle, a seasonal component and a random noise, we demonstrate that the higher degree fuzzy transform technique can be used for the estimation of the trend-cycle, which is one of the basic tasks in time series analysis. We prove that high frequencies appearing in the seasonal component can be arbitrarily suppressed and that random noise, as a stationary process, can be successfully decreased using the fuzzy transform of higher degree with a reasonable adjustment of parameters of a generalized uniform fuzzy partition.Fri, 03 Mar 2017 20:30:00 +0100TRANSPORT EQUATION WITH FUZZY DATA
http://ijfs.usb.ac.ir/article_3069_0.html
In this paper, we use the generalized differentiability concept tostudy the fuzzy transport equation. We consider transport equationin the homogeneous and non-homogeneous cases with fuzzy initialcondition. We present the solution when speed parameter is a fuzzynumber too. Our method is based on the construction of the solutionsby employing Zadeh's extension principle.Fri, 03 Mar 2017 20:30:00 +0100POINTWISE CONVERGENCE TOPOLOGY AND FUNCTION SPACES IN FUZZY ANALYSIS
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We study the space of all continuous fuzzy-valued functions from a space $X$ into the space of fuzzy numbers $(mathbb{E}sp{1},dsb{infty})$ endowed with the pointwise convergence topology. Our results generalize the classical ones for continuous real-valued functions. The field of applications of this approach seems to be large, since the classical case allows many known devices to be fitted to general topology, functional analysis, coding theory, Boolean rings, etc.Sat, 01 Jul 2017 19:30:00 +0100BASES AND CIRCUITS OF FUZZIFYING MATROIDS
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In this paper, as an application of fuzzy matroids, the fuzzifying greedy algorithm is proposed and an achievableexample is given. Basis axioms and circuit axioms of fuzzifying matroids, which are the semantic extension for the basis axioms and circuit axioms of crisp matroids respectively, are presented. It is proved that a fuzzifying matroid is equivalent to a mapping which satisfies the basis axioms or circuit axioms.Sat, 01 Jul 2017 19:30:00 +0100BASE AXIOMS AND SUBBASE AXIOMS IN M-FUZZIFYING CONVEX SPACES
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Based on a completely distributive lattice $M$, base axioms and subbase axioms are introduced in $M$-fuzzifying convex spaces. It is shown that a mapping $mathscr{B}$ (resp. $varphi$) with the base axioms (resp. subbase axioms) can induce a unique $M$-fuzzifying convex structure with $mathscr{B}$ (resp. $varphi$) as its base (resp. subbase). As applications, it is proved that bases and subbases can be used to characterize CP mappings and CC mappings between $M$-fuzzifying convex spaces.Sat, 01 Jul 2017 19:30:00 +0100ON THE MATCHING NUMBER OF AN UNCERTAIN GRAPH
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Uncertain graphs are employed to describe graph models with indeterministicinformation that produced by human beings. This paper aims to study themaximum matching problem in uncertain graphs.The number of edges of a maximum matching in a graph is called matching numberof the graph. Due to the existence of uncertain edges, the matching number of an uncertain graph is essentially an uncertain variable.Different from that in a deterministic graph, it is more meaningful to investigate theuncertain measure that an uncertain graph is $k$-edge matching (i.e., the matching number is greater than or equal to $k$).We first study the properties of the matching number of an uncertain graph,and then give a fundamental formula for calculating the uncertain measure. We further prove that the fundamental formula can be transformed into a simplified form. What is more, a polynomial time algorithmto numerically calculate the uncertain measure is derived from the simplified form.Finally, some numerical examples are illustrated to show the application and efficiency of the algorithm.Sat, 01 Jul 2017 19:30:00 +0100RESOLUTION OF NONLINEAR OPTIMIZATION PROBLEMS SUBJECT TO BIPOLAR MAX-MIN FUZZY RELATION ...
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This paper studies the nonlinear optimization problems subject to bipolar max-min fuzzy relation equation constraints. The feasible solution set of the problems is non-convex, in a general case. Therefore, conventional nonlinear optimization methods cannot be ideal for resolution of such problems. Hence, a Genetic Algorithm (GA) is proposed to find their optimal solution. This algorithm uses the structure of the feasible domain of the problems and lower and upper bound of the feasible solution set to choose the initial population. The GA employs two different crossover operations: 1- N-points crossover and 2- Arithmetic crossover. We run the GA with two crossover operations for some test problems and compare their results and performance to each other. Also, their results are compared with the results of other authors' works.Sat, 01 Jul 2017 19:30:00 +0100SOME PROPERTIES OF UNCERTAIN INTEGRAL
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Uncertainty theory is a mathematical methodology for dealing withnon-determinate phenomena in nature. As we all know, uncertainprocess and uncertain integral are important contents of uncertaintytheory, so it is necessary to have deep research. This paperpresents the definition and discusses some properties of strongcomonotonic uncertain process. Besides, some useful formulas ofuncertain integral such as nonnegativity, monotonicity, intermediateresults are studied.Sat, 01 Jul 2017 19:30:00 +0100ADMISSIBLE PARTITION FOR BL-GENERAL FUZZY AUTOMATON
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In this note, we define the concepts of admissible relation and admissible partition for an arbitrary BL-general fuzzy automaton.In particular, a connection between the admissible partition and the quotient BL-general fuzzy automaton is presented.It is shown that if we use the maximal admissible partition, then we obtain a quotient BL-general fuzzy automaton and this quotient is minimal. Finally, we present some examples to clarify the notions and results of this paper.Sat, 01 Jul 2017 19:30:00 +0100AN INVESTIGATION ON THE CO-ANNIHILATORS IN TRIANGLE ALGEBRAS
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In this paper, we introduce the notion of co-annihilator of a subsetin a triangle algebra. It is shown that the co-annihilator of asubset is an interval valued residuated lattice (IVRL)-filter. Also, aspecial set of a triangle algebra is defined and the relationshipbetween this set and co-annihilator of a subset in triangle algebrais considered. Finally, co-annihilators preserving congruencerelation, or $CP$-congruence are defined and some results of themare given.Sat, 01 Jul 2017 19:30:00 +0100L-CONVEX SYSTEMS AND THE CATEGORICAL ISOMORPHISM TO SCOTT-HULL OPERATORS
http://ijfs.usb.ac.ir/article_3296_0.html
The concepts of $L$-convex systems and Scott-hull spaces are proposed on frame-valued setting. Also, we establish the categorical isomorphism between $L$-convex systems and Scott-hull spaces. Moreover, it is proved that the category of $L$-convex structures is bireflective in the category of $L$-convex systems. Furthermore, the quotient systems of $L$-convex systems are studied.Sun, 02 Jul 2017 19:30:00 +0100(1612-3379) POWERSET OPERATORS OF EXTENSIONAL FUZZY SETS
http://ijfs.usb.ac.ir/article_3318_0.html
Powerset structures of extensional fuzzy sets in sets with similarity relations are investigated. It is proved that extensional fuzzy sets have powerset structures which are powerset theories in the category of sets with similarity relations, and some of these powerset theories are defined also by algebraic theories (monads). Between Zadeh's fuzzy powerset theory and the classical powerset theory there exists a strong relation, which can be represented as a homomorphism. Analogical results are also proved for new powerset theories of extensional fuzzy sets.Sun, 27 Aug 2017 19:30:00 +0100(1704-3609) A NEW SECRET SHARING SCHEME ADVERSARY FUZZY STRUCTURE BASED ON AUTOMATA
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In this paper, we introduce a new verifiable multi-use multi-secretsharing scheme based on automata and one-way hash function. The scheme has theadversary fuzzy structure and satisfy the following properties:1) The dealer can change the participants and the adversary fuzzy structure without refreshing any participants' real-shadow. 2) The scheme is based on the inversion of weakly invertible finite automata and its security depends on the properties of the one-way hash functions.3) The scheme does not encounter time-consuming computationslike discrete logarithm problem.4) The validity of the transmitted data can be verified by the combiner and participants.5) Every participant has only one reusable real-shadow,whereas the most of other existing schemes have more than one shadow.In addition, the proposed scheme which is based on automata has all the properties of a perfect scheme.Finally, the comparisons among other schemes and our scheme prove the efficiency of our scheme.Tue, 05 Sep 2017 19:30:00 +0100(1702-3470) TOPOLOGICAL CHARACTERIZATION FOR FUZZY REGULAR LANGUAGES
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We present a topological characterization for fuzzy regular languages:we show that there is a bijective correspondence between fuzzy regular languagesand the set of all clopen fuzzy subsets with finite image in the induced fuzzy topological space of Stone space (Profinite space), and then we give a representation of closed fuzzy subsets in the induced fuzzy topological space via fuzzy regular languages.Moreover, we prove that the induced fuzzy topological space has a basis consisting of leveled characteristic functions of the closure of cut languages of fuzzy regular languages.Sat, 09 Sep 2017 19:30:00 +0100(1512-2657) GENERALIZED RESIDUATED LATTICES BASED F-TRANSFORM
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The aim of the present work is to study the $F$-transform over a generalized residuated lattice. We discuss the properties that are common with the $F$-transform over a residuated lattice. We show that the $F^{uparrow}$-transform can be used in establishing a fuzzy (pre)order on the set of fuzzy sets.Sat, 09 Sep 2017 19:30:00 +0100(1704-3631) SOLUTION AND STABILITY OF QUATTUORVIGINTIC FUNCTIONAL EQUATION IN INTUITIONISTIC ...
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In this paper, we investigate the general solution and the generalized Hyers-Ulam stability of a new functional equation which is called quattuorvigintic functional equation in intuitionistic fuzzy normed spaces by using the fixed point method.These results can be regarded as an important extension of stability results corresponding to functional equations on normed spaces.Fri, 15 Sep 2017 19:30:00 +0100(1611-3294) Testing statistical hypotheses under fuzzy data and based on a new signed distance
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This paper deals with the problem of testing statisticalhypotheses when the available data are fuzzy. In this approach, wefirst obtain a fuzzy test statistic based on fuzzy data, and then,based on a new signed distance between fuzzy numbers, we introducea new decision rule to accept/reject the hypothesis of interest.The proposed approach is investigated for two cases: the casewithout nuisance parameters and the case with nuisance parameters.This method is employed to test the hypotheses for the mean of anormal distribution with known/unknown variance, the variance of anormal distribution, the difference of means of two normaldistributions with known/unknown variances, and the ratio ofvariances of two normal distributions.Fri, 15 Sep 2017 19:30:00 +0100(1611-3292) FURTHER RESULTS OF CONVERGENCE OF UNCERTAIN RANDOM SEQUENCES
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Convergence is an issue being widely concerned about. Thus, in this paper, we mainly put forward two types of concepts of convergence in mean and convergence in distribution for the sequence of uncertain random variables. Then some of theorems are proved to show the relations among the three convergence concepts that are convergence in mean, convergence in measure and convergence in distribution. Furthermore, several examples are given to illustrate how we use the theorems to make sure the uncertain random sequence being convergent. Finally, several counterexamples are taken to explain the relations between these different types of convergence.Fri, 15 Sep 2017 19:30:00 +0100(1510-2544) SOME FUNDAMENTAL RESULTS ON FUZZY CALCULUS
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In this paper, we study fuzzy calculus in two main branches differential and integral. Some rules for finding limit and $gH$-derivative of $gH$-difference, constant multiple of two fuzzy-valued functions are obtained and we also present fuzzy chain rule for calculating $gH$-derivative of a composite function. Two techniques namely, Leibniz's rule and integration by parts are introduced for fuzzy integrals. Furthermore, we prove three essential theorems such as a fuzzy intermediate value theorem, fuzzy mean value theorem for integral and mean value theorem for $gH$-derivative. We derive a Bolzano's theorem, Rolle's theorem and some properties for $gH$-differentiable functions. To illustrate and explain these rules and theorems, we have provided several examples in details.Tue, 19 Sep 2017 19:30:00 +0100(1606-2986) TREE AUTOMATA BASED ON COMPLETE RESIDUATED LATTICE-VALUED LOGIC: REDUCTION ...
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In this paper, at first we define the concepts of response function and accessible states of a complete residuated lattice-valued (for simplicity we write $mathcal{L}$-valued) tree automaton with a threshold $c.$ Then, related to these concepts, we prove some lemmas and theorems that are applied in considering some decision problems such as finiteness-value and emptiness-value of recognizable tree languages. Moreover, we propose a reduction algorithm for $mathcal{L}$-valued tree automata with a threshold $c.$ The goal of reducing an $ mathcal{L}$-valued tree automaton is to obtain an $mathcal{L}$-valued tree automaton with reduced number of states %that all of its states are accessible all of which are accessible, in addition it recognizes the same language as the first one given. We compare our algorithm with some other algorithms in the literature. Finally, utilizing the obtained results, we consider some fundamental decision problems for $mathcal{L}$-valued tree automata including the membership-value, the emptiness-value, the finiteness-value, the intersection-value and the equivalence-value problems.Tue, 03 Oct 2017 20:30:00 +0100(1611-3300) A NEW MULTIPLE CRITERIA DECISION-MAKING METHOD BASED ON BIPOLAR FUZZY SOFT GRAPHS
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In this research study, we present a novel frame work for handling bipolar fuzzy soft information by combining bipolar fuzzy soft sets with graphs. We introduce several basic notions concerning bipolar fuzzy soft graphs and investigate some related properties. We also consider the application of the bipolar fuzzy soft graphs. In particular, three efficient algorithms are developed to solve multiple criteria decision-making problems regarding social network, investment in shares and detection of bipolar disorder in children.Sat, 07 Oct 2017 20:30:00 +0100(1605-2930) INTEGRABILITY OF AN INTERVAL-VALUED MULTIFUNCTION WITH RESPECT TO AN ...
http://ijfs.usb.ac.ir/article_3406_0.html
Intervals are related to the representation of uncertainty. In this sense, we introduce an integral of Gould type for an interval-valued multifunction relative to an interval-valued set multifunction, withrespect to Guo and Zhang order relation. Classical and specific properties of this new type of integral are established and several examples and applications from multicriteria decision makingproblems are provided.Fri, 13 Oct 2017 20:30:00 +0100(1603-2816) A NEW WAY TO EXTEND FUZZY IMPLICATIONS
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The main purpose of this paper is to use a new way to extendfuzzy implications $I$ from a generalized sublattice $M$ to a bounded lattice$L$, such that the extended implications preserve many of the considered properties of fuzzy implications on $M$.Furthermore, as a special case, we investigate the extension of $(S,N)-$implications. Results indicate that the extended implications preserve many of the considered properties of $(S,N)$-implications.Fri, 13 Oct 2017 20:30:00 +0100(1703-3555) STRATIFIED (L,M)-FUZZY DERIVED SPACES
http://ijfs.usb.ac.ir/article_3408_0.html
In this paper, the concepts of derived sets and derived operators are generalized to $(L, M)$-fuzzy topological spaces and their characterizations are given.What is more, it is shown that the category of stratified $(L, M)$-fuzzy topological spaces,the category of stratified $(L, M)$-fuzzy closure spaces and the category of stratified $(L, M)$-fuzzy quasi-neighborhood spaces are all isomorphic to the category of stratified $(L, M)$-fuzzy derived spaces.Fri, 20 Oct 2017 20:30:00 +0100(1610-3221) THE UNIFORM BOUNDEDNESS PRINCIPLE IN FUZZIFYING TOPOLOGICAL LINEAR SPACES
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The main purpose of this study is to discuss the uniform boundednessprinciple in fuzzifying topological linear spaces. At first the concepts of uniformly boundedness principle and fuzzy equicontinuous family of linear operators are proposed, then the relations betweenfuzzy equicontinuous and uniformly bounded are studied, and with the help of net convergence, the characterization of fuzzy equicontinuous is proved. Finally, the famous theorem of the uniformboundedness principle is presented in fuzzifying topological linearspaces.Fri, 27 Oct 2017 20:30:00 +0100(1605-2938) ON Q-BITOPOLOGICAL SPACES
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We study here $T_{0}$-$Q$-bitopological spaces and sober $Q$-bitopological spaces and their relationship with two particular Sierpinski objects in the category of $Q$-bitopological spaces. The epireflective hulls of both these Sierpinski objects in the category of $Q$-bitopological spaces turn out to be the category of $T_0$-$Q$-bitopological spaces. We show that only one of these Sierpinski objects is sober $Q$-bitopological space and its epireflective hull in the category of $T_0$-$Q$-bitopological spaces turns out to be the category of saturated $T_{0}$-$Q$-bitopological spaces.Fri, 27 Oct 2017 20:30:00 +0100(1705-3665) CHARACTERIZATIONS OF (L,M)-FUZZY TOPOLOGY DEGREES
http://ijfs.usb.ac.ir/article_3426_0.html
In this paper, characterizations of the degree to which a mapping $mathcal{T} : L^{X}longrightarrow M$ is an $(L, M)$-fuzzy topology are studied in detail.What is more, the degree to which an $L$-subset is an $L$-open set with respect to $mathcal{T}$ is introduced.Based on that, the degrees to which a mapping $f: Xlongrightarrow Y$ is continuous,open, closed or a quotient mapping with respect to $mathcal{T}_{X}$ and $mathcal{T}_{Y}$ are defined, and their characterizations are given, respectively.Besides, the relationships among the continuity degrees, the openness degrees, the closedness degrees and the quotient degrees of mappings are discussed.Fri, 03 Nov 2017 20:30:00 +0100(1611-3323) ASSOCIATED PROBABILITY INTUITIONISTIC FUZZY WEIGHTED OPERATORS IN BUSINESS START-UP ...
http://ijfs.usb.ac.ir/article_3427_0.html
In the study, we propose the Associated Probability Intuitionistic Fuzzy Weighted Averaging (As-P-IFWA) and the Associated Probability Intuitionistic Fuzzy Weighted Geometric (As-P-IFWG) aggregation operators with associated probabilities of a fuzzy measure presenting an uncertainty. Decision makers' evaluations are given as intuitionistic fuzzy values and are used as the arguments of the aggregation operators. In the paper, we prove correctness of extensions and show the conjugate connections between the constructed operators. Several versions of the new operators are successfully used in the business start-up decision making problem.Fri, 03 Nov 2017 20:30:00 +0100(1703-3544) DISTURBANCE REJECTION IN NONLINEAR SYSTEMS USING NEURO-FUZZY MODEL
http://ijfs.usb.ac.ir/article_3428_0.html
The problem of disturbance rejection in the control of nonlinear systems with additive disturbance generated by some unforced nonlinear systems, was formulated and solved by {itshape Mukhopadhyay} and {itshape Narendra}, they applied the idea of increasing the order of the system, using neural networks the model of multilayer perceptron on several systems of varying complexity, so the objective of this work is using the same idea with two other recent methods fast and reliable ; fuzzy set systems and hybrid neuro-fuzzy systems respectively to compute the control law which minimizes the effect of the disturbance at the output of nonlinear systems. The application of the methods previously cited in form of results is presented to determine the identification model and to provide theoretical justification to existence a solution of disturbance rejection. Our better results with fuzzy systems and neuro-fuzzy systems are presented and discussed in detail in this paper with several systems of increasing complexity.Sun, 05 Nov 2017 20:30:00 +0100(1609-3172) QUANTALE-VALUED SUP-ALGEBRAS
http://ijfs.usb.ac.ir/article_3440_0.html
Based on the notion of Q-sup-lattices (a fuzzy counterpart of com-plete join-semilattices valuated in a commutative quantale), we present theconcept of Q-sup-algebras { Q-sup-lattices endowed with a collection of fini-tary operations compatible with the fuzzy joins. Similarly to the crisp caseinvestigated in [30], we characterize their subalgebras and quotients, and fol-lowing [20], we show that the category of Q-sup-algebras is isomorphic to acertain subcategory of a category of Q-modules.Fri, 10 Nov 2017 20:30:00 +0100(1612-3355) OPTIMAL STATISTICAL TESTS BASED ON FUZZY RANDOM VARIABLES
http://ijfs.usb.ac.ir/article_3441_0.html
A novel approach is proposed for the problem of testing statisticalhypotheses about the fuzzy mean of a fuzzy random variable. The conceptof the (uniformly) most powerful test is extended to the (uniformly) mostpowerful fuzzy-valued test in which the test function is a fuzzy set representingthe degrees of rejection and acceptance of the hypothesis of interest. For thispurpose, the concepts of fuzzy test statistic and fuzzy critical value have beendefined using the cuts (levels) of the fuzzy observations and fuzzy parameter.In order to make a decision as a fuzzy test, a well-known method is employedto compare the observed fuzzy test statistic and the fuzzy critical value. Inthis work, we focus on the case in which the fuzzy data are observations of anormal fuzzy random variable. The proposed approach is general so that itcan be applied to other kinds of fuzzy random variables as well. Numericalexamples, including a lifetime testing problem, are provided to illustrate theproposed optimal tests.Mon, 13 Nov 2017 20:30:00 +0100(1702-3500) FINITE-TIME PASSIVITY OF DISCRETE-TIME T-S FUZZY NEURAL NETWORKS WITH TIME-VARYING ...
http://ijfs.usb.ac.ir/article_3443_0.html
This paper focuses on the problem of finite-time boundedness andfinite-time passivity of discrete-time T-S fuzzy neural networks with time-varying delays. A suitable Lyapunov{Krasovskii functional(LKF) is estab-lished to derive sufficient condition for finite-time passivity of discrete-timeT-S fuzzy neural networks. The dynamical system is transformed into a T-Sfuzzy model with uncertain parameters. Furthermore, the obtained passiv-ity criteria is established in terms of Linear matrix inequality (LMI), whichcan be easily checked by using the efficient MATLAB LMI toolbox. Finally,some numerical cases are given to illustrate the effectiveness of the proposedapproach.Sat, 30 Sep 2017 20:30:00 +0100(1612-3363) REDUCTION OF INVERTER OUTPUT CURRENT RIPPLE IN CONNECTION OF FUEL CELL TO THE POWER ...
http://ijfs.usb.ac.ir/article_3445_0.html
In this paper, a method is introduced which reduces the harmonicdistortion of the inverter output current, connecting the fuel cell to the ACload. Using FUZZY LOGIC-PI (FLPI), the controlling method is engagedin optimum tuning of the PI controller coefficients of this converter. Thisconverter has only one DC-AC boost inverter and simultaneously has the taskof increasing voltage level and generating the AC power. In order to controlthe inverter output voltage, an internal current control loop and an externalvoltage control loop are used. Designing the control of each loop is doneseparately based on FLPI controller. Simulation results for proposed fuel cellenergy system in the presence of this controller imply good performance ofFLPI and suitable mitigation of inverter output current ripple.Mon, 27 Nov 2017 20:30:00 +0100(1701-3445) CONNECTING T AND LATTICE-VALUED CONVERGENCES
http://ijfs.usb.ac.ir/article_3447_0.html
T-filters can be used to define T-convergence spaces in the latticevaluedcontext. Connections between T-convergence spaces and lattice-valuedconvergence spaces are given. Regularity of a T-convergence space has recentlybeen defined and studied by Fang and Yue. An equivalent characterizationis given in the present work in terms of convergence of closures of T-filters.Moreover, a compactication of a T-convergence space is constructed wheneverL is a complete Boolean algebra.Sun, 03 Dec 2017 20:30:00 +0100(1702-3478) ADAPTIVE BACKSTEPPING CONTROL OF UNCERTAIN FRACTIONAL ORDER SYSTEMS BY FUZZY ...
http://ijfs.usb.ac.ir/article_3448_0.html
In this paper, a novel problem of observer-based adaptive fuzzyfractional control for fractional order dynamic systems with commensurateorders is investigated; the control scheme is constructed by using the back-stepping and adaptive technique. Dynamic surface control method is used toavoid the problem of explosion of complexity which is caused by backsteppingdesign process. Fuzzy logic systems are used to approximate the unknown non-linear functions. A fractional order Lyapunov function is defined at each stageand the negativity of an overall Lyapunov function is ensured by proper selec-tion of the control law. It is proven that the proposed controller guaranteesthe boundedness property for all the signals and also the tracking error canconverge to a small neighborhood of the origin. Simulation examples are givento demonstrate the effectiveness and robustness of the proposed controllers.Sun, 03 Dec 2017 20:30:00 +0100(1606-3017) ADAPTIVE FUZZY TRACKING CONTROL FOR A CLASS OF PERTURBED NONLINEARLY PARAMETERIZED ...
http://ijfs.usb.ac.ir/article_3466_0.html
In this paper, an adaptive fuzzy tracking control approach is proposedfor a class of single-input single-output (SISO) nonlinear systems inwhich the unknown continuous functions may be nonlinearly parameterized.During the controller design procedure, the fuzzy logic systems (FLS) in Mamdanitype are applied to approximate the unknown continuous functions, andthen, based on the minimal learning parameters (MLP) algorithm and theadaptive backstepping dynamic surface control (DSC) technique, a new adaptivefuzzy backstepping control scheme is developed. The main advantages ofour approach include: (i) unlike the existing results which deal with the nonlinearlyparameterized functions by using the separation principle, the nonlinearlyparameterized functions are lumped into the continuous functions whichcan be approximated by using the FLS, (ii) only one parameter needs to beadjusted online in controller design procedure, which reduces the online computationburden greatly, and our development is able to eliminate the problemof ”explosion of complexity” inherent in the existing backstepping-based methods.It is proven that the proposed design method is able to guarantee thatall the signals in the closed-loop system are bounded and the tracking erroris smaller than a prescribed error bound. Finally, two examples are used toshow the effectiveness of the proposed approach.Sat, 09 Dec 2017 20:30:00 +0100(1704-3569) HESITANT FUZZY INFORMATION MEASURES DERIVED FROM T-NORMS AND S-NORMS
http://ijfs.usb.ac.ir/article_3491_0.html
In this contribution, we first introduce the concept of metricalT-norm-based similarity measure for hesitant fuzzy sets (HFSs) by using theconcept of T-norm-based distance measure. Then, the relationship of theproposed metrical T-norm-based similarity measures with the other kind ofinformation measure, called the metrical T-norm-based entropy measure isdiscussed. The main feature of the proposed metrical T-norm-based similar-ity measures is a possibility of comparing similarity between HFSs withoutregarding what value is returned by the similarity measure. To illustrate theapplication of the proposed metrical T-norm-based similarity measures, weconsider two problems of medical diagnosis and pattern recognition to com-pare the proposed metrical T-norm-based similarity measures with a numberof the existing HFS similarity measures.Sun, 17 Dec 2017 20:30:00 +0100(1703-3524) PROPERTY ANALYSIS OF TRIPLE IMPLICATION METHOD FOR APPROXIMATE REASONING ON ...
http://ijfs.usb.ac.ir/article_3492_0.html
Firstly, two kinds of natural distances between intuitionistic fuzzysets are generated by the classical natural distance between fuzzy sets undera unified framework of residual intuitionistic implication operators. Second-ly, the continuity and approximation property of a method for solving intu-itionistic fuzzy reasoning are defined. It is proved that the triple implicationmethod for intuitionistic fuzzy modus ponens has both continuity and approx-imation property with respect to these two kinds of natural distances basedon Lukasiewicz implication, meanwhile the triple implication method for in-tuitionistic fuzzy modus tollens possesses unconditional continuity and con-ditional approximation property. Finally, some robustness results about thetriple implication method of intuitionistic fuzzy reasoning are given.Sun, 17 Dec 2017 20:30:00 +0100(1610-3210) MAN - MACHINE INTERACTION SYSTEM FOR SUBJECT INDEPENDENT SIGN LANGUAGE RECOGNITION ...
http://ijfs.usb.ac.ir/article_3536_0.html
Sign language recognition has spawned more and more interestin humancomputer interaction society. The major challenge that SLR recog-nition faces now is developing methods that will scale well with increasingvocabulary size with a limited set of training data for the signer independentapplication. The automatic SLR based on hidden Markov models (HMMs) isvery sensitive to gesture's shape information that makes the accurate param-eters of the HMM not capable of characterizing the ambiguous distributionsof the observations in gesture's features. This paper presents an extension ofthe HMMs using interval type-2 fuzzy sets (IT2FSs) to produce interval type-2fuzzy HMMs to model uncertainties of hypothesis spaces (unknown varieties ofparameters of the decision function). The benefit of this enlargement is that itcan control both the randomness and fuzziness of traditional HMM mapping.Membership function (MF) of type-2 FS is three-dimensional that providesadditional degrees of freedom to evaluate HMM's uncertainties. This systemaspires to be a solution to the scalability problem, i.e. has real potential forapplication on a large vocabulary. Furthermore, it does not rely on the use ofdata gloves or other means as input devices, and operates in isolated signer-independent modes. Experimental results show that the interval type-2 fuzzyHMM has a comparable performance as that of the fuzzy HMM but is morerobust to the gesture variation, while it retains almost the same computationalcomplexity as that of the FHMM.Fri, 12 Jan 2018 20:30:00 +0100(1612-3365) ON TOPOLOGICAL EQ-ALGEBRAS
http://ijfs.usb.ac.ir/article_3550_0.html
In this paper, by using a special family of filters F on an EQ-algebra E, we construct a topology TF on E and show that (E, TF) is atopological EQ-algebra. First of all, we give some properties of topologicalEQ-algebras and investigate the interaction of topological EQ-algebras andquotient topological EQ-algebras. Then we obtain the form of closure of eachsubset and show that (E; TF) is a zero-dimensional space. Finally, we introducethe concept of convergence of sequences on topological EQ-algebras and givea condition under which the limit of a sequence is unique.Fri, 26 Jan 2018 20:30:00 +0100(1605-2951) A NOVEL TRIANGULAR INTERVAL TYPE-2 INTUITIONISTIC FUZZY SETS AND THEIR AGGREGATION ...
http://ijfs.usb.ac.ir/article_3559_0.html
The objective of this work is to present a triangular interval type-2 (TIT2) intuitionistic fuzzy sets and their corresponding aggregation opera-tors, namely, TIT2 intuitionistic fuzzy weighted averaging, TIT2 intuitionisticfuzzy ordered weighted averaging and TIT2 intuitionistic fuzzy hybrid aver-aging based on Frank norm operation laws. Furthermore, based on these op-erators, an approach to multi-criteria decision-making, in which assessmentsare in the form of TIT2 intuitionistic fuzzy numbers has been developed. Apractical example to illustrate the decision-making process has been presentedand compared their results with the existing operator results.Tue, 30 Jan 2018 20:30:00 +0100(1609-3148) THE CHAIN PROPERTIES AND LI-YORKE SENSITIVITY OF ZADEH'S EXTENSION ON THE SPACE OF ...
http://ijfs.usb.ac.ir/article_3587_0.html
Some characterizations on the chain recurrence, chain transitivity,chain mixing property, shadowing and h-shadowing for Zadeh's extension areobtained. Besides, it is proved that a dynamical system is spatiotemporallychaotic provided that the Zadeh's extension is Li-Yorke sensitive.Tue, 13 Feb 2018 20:30:00 +0100