2018-12-16T13:52:39Z
http://ijfs.usb.ac.ir/?_action=export&rf=summon&issue=324
Iranian Journal of Fuzzy Systems
IJFS
1735-0654
1735-0654
2015
12
2
Cover vol. 12, no.2, April 2015
2015
04
29
0
http://ijfs.usb.ac.ir/article_2648_7da56e08e1a4fb3a8299936955a993e7.pdf
Iranian Journal of Fuzzy Systems
IJFS
1735-0654
1735-0654
2015
12
2
A TS Fuzzy Model Derived from a Typical Multi-Layer Perceptron
A.
Kalhor
B. N.
Aarabi
C.
Lucas
B.
Tarvirdizadeh
In this paper, we introduce a Takagi-Sugeno (TS) fuzzy model which is derived from a typical Multi-Layer Perceptron Neural Network (MLP NN). At first, it is shown that the considered MLP NN can be interpreted as a variety of TS fuzzy model. It is discussed that the utilized Membership Function (MF) in such TS fuzzy model, despite its flexible structure, has some major restrictions. After modifying the MF, we introduce a TS fuzzy model whose MFs are tunable near and far from focal points, separately. To identify such TS fuzzy model, an incremental learning algorithm, based on an efficient space partitioning technique, is proposed. Through an illustrative example, the methodology of the learning algorithm is explained. Next, through two case studies: approximation of a nonlinear function for a sun sensor and identification of a pH neutralization process, the superiority of the introduced TS fuzzy model in comparison to some other TS fuzzy models and MLP NN is shown.
Takagi-Sugeno fuzzy model
Multi layer perceptron
Tunable membership functions
Nonlinear function approximation
pH neutralization process
2015
04
29
1
21
http://ijfs.usb.ac.ir/article_1979_0f5c1f01dfef9d988a11fdcb9b404174.pdf
Iranian Journal of Fuzzy Systems
IJFS
1735-0654
1735-0654
2015
12
2
Modeling of Epistemic Uncertainty in Reliability Analysis of Structures Using a Robust Genetic Algorithm
Mansour
Bagheri
Mahmoud
Miri
Naser
Shabakhty
In this paper the fuzzy structural reliability index was determined through modeling epistemic uncertainty arising from ambiguity in statistical parameters of random variables. The First Order Reliability Method (FORM) has been used and a robust genetic algorithm in the alpha level optimization method has been proposed for the determination of the fuzzy reliability index. The sensitivity level of fuzzy response due to the introduced epistemic uncertainty was also measured using the modified criterion of Shannon entropy. By introducing bounds of uncertainty, the fuzzy response obtained from the proposed method presented more realistic estimation of the structure reliability compared to classic methods. This uncertainty interval is of special importance in concrete structures since the quality of production and implementation of concrete varies in different cross sections in reality. The proposed method is implementable in reliability problems in which most of random variables are fuzzy sets and in problems containing non-linear limit state functions and provides a precise acceptable response. The capabilities of the proposed method were demonstrated using different examples. The results indicated the accuracy of the proposed method and showed that classical methods like FORM cover only special case of the proposed method.
Fuzzy reliability index
Alpha level optimization method
Genetic Algorithm
First order reliability method
2015
04
29
23
40
http://ijfs.usb.ac.ir/article_1980_705e7461f624d40c8f31e42874bb83cb.pdf
Iranian Journal of Fuzzy Systems
IJFS
1735-0654
1735-0654
2015
12
2
EQ-logics with delta connective
M.
Dyba
V.
Novak
In this paper we continue development of formal theory of a special class offuzzy logics, called EQ-logics. Unlike fuzzy logics being extensions of theMTL-logic in which the basic connective is implication, the basic connective inEQ-logics is equivalence. Therefore, a new algebra of truth values calledEQ-algebra was developed. This is a lower semilattice with top element endowed with two binaryoperations of fuzzy equality and multiplication. EQ-algebra generalizesresiduated lattices, namely, every residuated lattice is an EQ-algebra but notvice-versa.In this paper, we introduce additional connective $logdelta$ in EQ-logics(analogous to Baaz delta connective in MTL-algebra based fuzzy logics) anddemonstrate that the resulting logic has again reasonable properties includingcompleteness. Introducing $Delta$ in EQ-logic makes it possible to prove alsogeneralized deduction theorem which otherwise does not hold in EQ-logics weakerthan MTL-logic.
EQ-algebra
EQ-logic
Equational logic
Delta connective
Generalized deduction theorem
2015
04
29
41
61
http://ijfs.usb.ac.ir/article_1981_f9c205b6a230d24728542018f1b3f176.pdf
Iranian Journal of Fuzzy Systems
IJFS
1735-0654
1735-0654
2015
12
2
Bifuzzy core of fuzzy automata
S. P.
Tiwari
Anupam K.
Singh
Shambhu
Sharan
Vijay K.
Yadav
The purpose of the present work is to introduce the concept of bifuzzy core of a fuzzy automaton, which induces a bifuzzy topology on the state-set of this fuzzy automaton. This is shown that this bifuzzy topology can be used to characterize the concepts such as bifuzzy family of submachines, bifuzzy separable family and bifuzzy retrievable family of a fuzzy automaton.
Fuzzy automata
Bifuzzy source
Bifuzzy successor
Bifuzzy core
Bifuzzy topology
2015
04
29
63
73
http://ijfs.usb.ac.ir/article_1982_23e6f3744366279e9ec0ca3d46e6e982.pdf
Iranian Journal of Fuzzy Systems
IJFS
1735-0654
1735-0654
2015
12
2
Existence and uniqueness of the solution of nonlinear fuzzy Volterra integral equations
T.
Allahviranloo
P.
Salehi
M.
Nejatiyan
In this paper the fixed point theorem of Schauder is used to prove the existence of a continuous solution of the nonlinear fuzzy Volterra integral equations. Then using some conditions the uniqueness of the solution is investigated.
Fuzzy numbers
Fuzzy Volterra integral equations
Existence and uniqueness
2015
04
29
75
86
http://ijfs.usb.ac.ir/article_1983_4e17db286a759c153db5a9aa92c5c1e3.pdf
Iranian Journal of Fuzzy Systems
IJFS
1735-0654
1735-0654
2015
12
2
Existence and uniqueness of the solution of fuzzy-valued integral equations of mixed type
R.
Ezzati
F.
Mokhtarnejad
In this paper, existence theorems for the fuzzy Volterra-Fredholm integral equations of mixed type (FVFIEMT) involving fuzzy number valued mappings have been investigated. Then, by using Banach's contraction principle, sufficient conditions for the existence of a unique solution of FVFIEMT are given. Finally, illustrative examples are presented to validate the obtained results.
Fuzzy Volterra-Fredholm integral equation
Two-dimensional integral equation
Fuzzy integral equations of mixed type
Fuzzy valued function
2015
04
29
87
94
http://ijfs.usb.ac.ir/article_1984_9ce4534f838ac7a99de3ae4a02061f23.pdf
Iranian Journal of Fuzzy Systems
IJFS
1735-0654
1735-0654
2015
12
2
Fuzzy resolvent equation with $H(cdot,cdot)$-$phi$-$eta$-accretive operator in Banach spaces
Rais
Ahmad
Mohd
Dilshad
In this paper, we introduce and study fuzzy variational-like inclusion, fuzzy resolvent equation and $H(cdot,cdot)$-$phi$-$eta$-accretive operator in realĀ uniformly smooth Banach spaces. It is established that fuzzy variational-like inclusion is equivalent to a fixed point problem as well as to a fuzzy resolvent equation. This equivalence is used to define an iterative algorithm for solving fuzzy resolvent equation. Some examples are given.
Fuzzy variational-like inclusion
Fuzzy resolvent equation
$H(cdot
cdot)$-$phi$-$eta$-accretive operator
Algorithm
Fixed point
2015
04
29
95
106
http://ijfs.usb.ac.ir/article_1985_86f566343f7b89986c214aecb2f7d718.pdf
Iranian Journal of Fuzzy Systems
IJFS
1735-0654
1735-0654
2015
12
2
Classifying fuzzy normal subgroups of finite groups
Marius
Tarnauceanu
In this paper a first step in classifying the fuzzy normalsubgroups of a finite group is made. Explicit formulas for thenumber of distinct fuzzy normal subgroups are obtained in theparticular cases of symmetric groups and dihedral groups.
Fuzzy normal subgroups
Chains of normal
subgroups
Maximal chains of normal subgroups
Symmetric groups
Dihedral groups
2015
04
29
107
115
http://ijfs.usb.ac.ir/article_1986_41edad298512bef030d02e273bcb6a1c.pdf
Iranian Journal of Fuzzy Systems
IJFS
1735-0654
1735-0654
2015
12
2
Numerical solutions of nonlinear fuzzy Fredholm integro-differential equations of the second kind
M.
Mosleh
M.
Otadi
In this paper, we use parametric form of fuzzy number, then aniterative approach for obtaining approximate solution for a classof nonlinear fuzzy Fredholmintegro-differential equation of the second kindis proposed. This paper presents a method based on Newton-Cotesmethods with positive coefficient. Then we obtain approximatesolution of the nonlinear fuzzy integro-differential equations by an iterativeapproach.
Nonlinear fuzzy integro-differential equations
Newton-Cotes methods
2015
04
29
117
127
http://ijfs.usb.ac.ir/article_1987_0cf46298a686ec0a96c8d069d42f41f9.pdf
Iranian Journal of Fuzzy Systems
IJFS
1735-0654
1735-0654
2015
12
2
Generated $textbf{textit{L}}$-subgroup of an $textbf{textit{L}}$-group
Naseem
Ajmal
Iffat
Jahan
In this paper, we extend the construction of a fuzzy subgroup generated by a fuzzy subset to $L$-setting. This construction is illustrated by an example. We also prove that for an $L$-subset of a group, the subgroup generated by its level subset is the level subset of the subgroup generated by that $L$-subset provided the given $L$-subset possesses sup-property.
$L$-algebra
$L$-subgroup
Normal $L$-subgroup
Generated $L$-subgroup
2015
04
29
129
136
http://ijfs.usb.ac.ir/article_1988_1a3e3cd32dc886edfac691c6b2b2e9e0.pdf
Iranian Journal of Fuzzy Systems
IJFS
1735-0654
1735-0654
2015
12
2
A New Approach to Caristi's Fixed Point Theorem on Non-Archimedean Fuzzy Metric Spaces
S.
Sedghi
N.
Shobkolaei
I.
Altun
In the present paper, we give a new approach to Caristi's fixed pointtheorem on non-Archimedean fuzzy metric spaces. For this we define anordinary metric $d$ using the non-Archimedean fuzzy metric $M$ on a nonemptyset $X$ and we establish some relationship between $(X,d)$ and $(X,M,ast )$%. Hence, we prove our result by considering the original Caristi's fixedpoint theorem.
Fixed point
Caristi map
Fuzzy metric space
2015
04
29
137
143
http://ijfs.usb.ac.ir/article_1989_f8d6aae87a58b7c8804d05459ea70ac5.pdf
Iranian Journal of Fuzzy Systems
IJFS
1735-0654
1735-0654
2015
12
2
Persian-translation vol. 12, no.2, April 2015
2015
04
29
147
157
http://ijfs.usb.ac.ir/article_2649_c4b7501bfa4858c0dbecc382a6043f85.pdf