eng
University of Sistan and Baluchestan
Iranian Journal of Fuzzy Systems
1735-0654
1735-0654
2015-06-01
12
3
0
10.22111/ijfs.2015.2646
2646
Cover vol. 12, no.3, June 2015
http://ijfs.usb.ac.ir/article_2646_1c9f91d00aec73fbd39d7a287b238786.pdf
eng
University of Sistan and Baluchestan
Iranian Journal of Fuzzy Systems
1735-0654
1735-0654
2015-06-30
12
3
1
16
10.22111/ijfs.2015.2016
2016
مقاله پژوهشی
Admissibility analysis for discrete-time singular systems with time-varying delays by adopting the state-space Takagi-Sugeno fuzzy model
P. Balasubramaniam -pour
balugru@gmail.com
1
L. Jarina Banu
ljarina88@gmail.com
2
Department of Mathematics, Gandhigram Rural Institute - Deemed University, Gandhigram - 624 302, Tamilnadu, India
Department of Mathematics, Gandhigram Rural Institute - Deemed University, Gandhigram - 624 302, Tamilnadu, India
This paper is pertained with the problem of admissibility analysis of uncertain discrete-time nonlinear singular systems by adopting the state-space Takagi-Sugeno fuzzy model with time-delays and norm-bounded parameter uncertainties. Lyapunov Krasovskii functionals are constructed to obtain delay-dependent stability condition in terms of linear matrix inequalities, which is dependent on the lower and upper delay bounds. Finally, numerical examples are provided to substantiate the theoretical results.
http://ijfs.usb.ac.ir/article_2016_669277d9b51e99a79677006ff39992f9.pdf
Discrete-time Singular system
Takagi-Sugeno fuzzy systems
stability
Lyapunov-Krasovskii functional
linear matrix inequality (LMI)
eng
University of Sistan and Baluchestan
Iranian Journal of Fuzzy Systems
1735-0654
1735-0654
2015-06-30
12
3
17
29
10.22111/ijfs.2015.2017
2017
مقاله پژوهشی
Fuzzy Risk Analysis Based on Ranking of Fuzzy Numbers Via New Magnitude Method
T. Hajjari
tayebehajjari@iaufb.ac.ir
1
Mathematics Department, Firoozkooh Branch of Islamic Azad University, Firoozkooh, Iran
Ranking fuzzy numbers plays a main role in many applied models inreal world and in particular decision-making procedures. In manyproposed methods by other researchers may exist some shortcoming.The most commonly used approaches for ranking fuzzy numbers isbased on defuzzification method. Many ranking fuzzy numberscannot discriminate between two symmetric fuzzy numbers withidentical core. In 2009, Abbasbandy and Hajjari proposed anapproach for ranking normal trapezoidal fuzzy numbers, whichcomputed the magnitude of fuzzy numbers namely ``Mag" method.Then Hajjari extended it for non-normal trapezoidal fuzzy numbersand also for all generalized fuzzy numbers. However, thesemethods have the weakness that we mentioned above. Moreover, theresult is not consistent with human intuition in this case.Therefore, we are going to present a new method to overcome thementioned weakness. In order to overcome the shortcoming, a newmagnitude approach for ranking trapezoidal fuzzy numbers based onminimum and maximum points and the value of fuzzy numbers isgiven. The new method is illustrated by some numerical examplesand in particular, the results of ranking by the proposed methodand some common and existing methods for ranking fuzzy numbers iscompared to verify the advantages of presented method.
http://ijfs.usb.ac.ir/article_2017_2a119e1745d62f0454344e08d761a5e9.pdf
Decision-Making
Magnitude
Fuzzy numbers
Ranking
eng
University of Sistan and Baluchestan
Iranian Journal of Fuzzy Systems
1735-0654
1735-0654
2015-06-30
12
3
31
45
10.22111/ijfs.2015.2018
2018
مقاله پژوهشی
Fixed Fuzzy Points of Fuzzy Mappings in Hausdorff Fuzzy Metric Spaces with Application
Calogero Vetro
calogero.vetro@unipa.it
1
Mujahid Abbas
mujahid.abbas@up.ac.za
2
Basit Ali
basit.aa@gmail.com
3
Dipartimento di Matematica e Informatica, Universita degli Studi di Palermo, Via Archirafi 34, 90123 Palermo, Italy
Department of Mathematics and Applied Mathematics, University of Pretoria, Lynnwood road, Pretoria 0002, South Africa, Department of Mathematics, Syed Babar Ali School of Science and Engineering (SBASSE), Lahore University of Management Sciences (LUMS), Lahore, 54792, Pakistan
Department of Mathematics, Syed Babar Ali School of Science and Engi- neering (SBASSE), Lahore University of Management Sciences (LUMS), Lahore, 54792, Pakistan
Recently, Phiangsungnoen et al. [J. Inequal. Appl. 2014:201 (2014)] studied fuzzy mappings in the framework of Hausdorff fuzzy metric spaces.Following this direction of research, we establish the existence of fixed fuzzy points of fuzzy mappings. An example is given to support the result proved herein; we also present a coincidence and common fuzzy point result. Finally, as an application of our results, we investigate the existence of solution for somerecurrence relations associated to the analysis of quicksort algorithms.
http://ijfs.usb.ac.ir/article_2018_344dee53e41664d8f01d067965c0e8b6.pdf
Fuzzy metric space
Fuzzy mapping
Fixed fuzzy point
Quicksort algorithm
eng
University of Sistan and Baluchestan
Iranian Journal of Fuzzy Systems
1735-0654
1735-0654
2015-06-30
12
3
47
55
10.22111/ijfs.2015.2019
2019
مقاله پژوهشی
Some classes of statistically convergent sequences of fuzzy numbers generated by a modulus function
U. Cakan
umitcakan@gmail.com
1
Y. Altin
yaltin23@yahoo.com
2
Department of Mathematics, Nevsehir Hac Bektas Veli University, Nevsehir- Turkey
Department of Mathematics, Firat University, Elazig-Turkey
The purpose of this paper is to generalize the concepts of statisticalconvergence of sequences of fuzzy numbers defined by a modulus functionusing difference operator $Delta$ and give some inclusion relations.
http://ijfs.usb.ac.ir/article_2019_acdb38af96e8a2b1a9eb92353d97a5e2.pdf
Sequence of fuzzy numbers
Statistical convergence
Modulus function
eng
University of Sistan and Baluchestan
Iranian Journal of Fuzzy Systems
1735-0654
1735-0654
2015-06-30
12
3
57
94
10.22111/ijfs.2015.2020
2020
مقاله پژوهشی
Categorically-algebraic topology and its applications
Sergey A. Solovyov
sergejs.solovjovs@lumii.lv
1
Institute of Mathematics, Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 616 69 Brno, Czech Republic and Institute of Mathematics and Computer Science, University of Latvia, Raina bulvaris 29, LV-1459 Riga, Latvia
This paper introduces a new approach to topology, based on category theory and universal algebra, and called categorically-algebraic (catalg) topology. It incorporates the most important settings of lattice-valued topology, including poslat topology of S.~E.~Rodabaugh, $(L,M)$-fuzzy topology of T.~Kubiak and A.~v{S}ostak, and $M$-fuzzy topology on $L$-fuzzy sets of C.~Guido. Moreover, its respective categories of topological structures are topological over their ground categories. The theory also extends the notion of topological system of S.~Vickers (and its numerous many-valued modifications of J.~T.~Denniston, A.~Melton and S.~E.~Rodabaugh), and shows that the categories of catalg topological structures are isomorphic to coreflective subcategories of the categories of catalg topological systems. This extension initiates a new approach to soft topology, induced by the concept of soft set of D.~Molodtsov, and currently pursued by various researchers.
http://ijfs.usb.ac.ir/article_2020_3928dce38a41f1ffb43078cccd8ae550.pdf
Categorically-algebraic topology
Lattice-valued topology
Soft topology
Topological category
Topological system
Topological theory
eng
University of Sistan and Baluchestan
Iranian Journal of Fuzzy Systems
1735-0654
1735-0654
2015-06-30
12
3
95
112
10.22111/ijfs.2015.2021
2021
مقاله پژوهشی
Convergence, Consistency and Stability in Fuzzy Differential Equations
R. Ezzati
ezati@kiau.ac.ir
1
K. Maleknejad
maleknejad@iust.ac.ir
2
S. Khezerloo
s_khezerloo@azad.ac.ir
3
M. Khezerloo
khezerloo@iasbs.ac.ir
4
Department of Mathematics, Karaj Branch, Islamic Azad University, Karaj, Iran
Department of Mathematics, Karaj Branch, Islamic Azad University, Karaj, Iran
Department of Mathematics, Islamic Azad University - South Tehran Branch, Tehran, Iran
Department of Mathematics, Institute for Advanced Studies in Basic Sciences(IASBS), P.O. BOX 45195-1159, Zanjan, Iran
In this paper, we consider First-order fuzzy differential equations with initial value conditions. The convergence, consistency and stability of difference method for approximating the solution of fuzzy differential equations involving generalized H-differentiability, are studied. Then the local truncation error is defined and sufficient conditions for convergence, consistency and stability of difference method are provided and fuzzy stiff differential equation and one example are presented to illustrate the accuracy and capability of our proposed concepts.
http://ijfs.usb.ac.ir/article_2021_27827fb7f621d2c20415fb8f401902e5.pdf
Consistence
stability
Local truncation error
Generalized differentiability
Fuzzy stiff differential equation
eng
University of Sistan and Baluchestan
Iranian Journal of Fuzzy Systems
1735-0654
1735-0654
2015-06-29
12
3
113
125
10.22111/ijfs.2015.2022
2022
مقاله پژوهشی
Interval Type-2 Fuzzy Rough Sets and Interval Type-2 Fuzzy Closure Spaces
Shambhu Sharan
shambhupuremaths@gmail.com
1
S. P. Tiwari
sptiwarimaths@gmail.com
2
V. K. Yadav
vijayyadav3254@gmail.com
3
School of Advanced Sciences, VIT University,Vellore-632014,Tamil Nadu, India
Department of Applied Mathematics, Indian School of Mines, Dhanbad- 826004, India
Department of Applied Mathematics, Indian School of Mines, Dhanbad- 826004, India
The purpose of the present work is to establish a one-to-one correspondence between the family of interval type-2 fuzzy reflexive/tolerance approximation spaces and the family of interval type-2 fuzzy closure spaces.
http://ijfs.usb.ac.ir/article_2022_3ededbfe97b2d5a0693ea6c5302fba77.pdf
Interval type-2 fuzzy set
Interval type-2
fuzzy rough set
Interval type-2 fuzzy reflexive approximation
space
Interval type-2 fuzzy tolerance approximation space
Interval type-2 fuzzy closure space
Interval type-2 fuzzy
topology
eng
University of Sistan and Baluchestan
Iranian Journal of Fuzzy Systems
1735-0654
1735-0654
2015-06-30
12
3
127
135
10.22111/ijfs.2015.2023
2023
مقاله پژوهشی
Boundedness of linear order-homomorphisms in $L$-topological vector spaces
Hua-Peng Zhang
huapengzhang@163.com
1
Jin-Xuan Fang
jxfang@njnu.edu.cn
2
School of Science, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
School of Mathematical Sciences, Nanjing Normal University, Nanjing 210023, China
A new definition of boundedness of linear order-homomorphisms (LOH)in $L$-topological vector spaces is proposed. The new definition iscompared with the previous one given by Fang [The continuity offuzzy linear order-homomorphism, J. Fuzzy Math. 5 (4) (1997)829$-$838]. In addition, the relationship between boundedness andcontinuity of LOHs is discussed. Finally, a new uniform boundednessprinciple in $L$-topological vector spaces is established in thesense of a new definition of uniform boundedness for a family ofLOHs.
http://ijfs.usb.ac.ir/article_2023_6994345f4f77c7f78c179cfc9a2c1c83.pdf
$L$-topological vector space
Linear order-homomorphism
Bounde-dness
eng
University of Sistan and Baluchestan
Iranian Journal of Fuzzy Systems
1735-0654
1735-0654
2015-06-30
12
3
137
149
10.22111/ijfs.2015.2024
2024
مقاله پژوهشی
Distinct Fuzzy Subgroups of a Dihedral Group of Order $2pqrs$ for Distinct Primes $p, , q, , r$ and $s$
Babington Makamba
bmakamba@ufh.ac.za
1
Odilo Ndiweni
ondiweni@ufh.ac.za
2
Department of Mathematics, University of Fort Hare, Alice 5700 , Eastern Cape , South Africa
Department of Mathematics, University of Fort Hare, Alice 5700 , Eastern Cape , South Africa
In this paper we classify fuzzy subgroups of the dihedral group $D_{pqrs}$ for distinct primes $p$, $q$, $r$ and $s$. This follows similar work we have done on distinct fuzzy subgroups of some dihedral groups.We present formulae for the number of (i) distinct maximal chains of subgroups, (ii) distinct fuzzy subgroups and (iii) non-isomorphic classes of fuzzy subgroups under our chosen equivalence and isomorphism. Some results presented here hold for any dihedral group of order $2n$ where $n$ is a product of any number of distinct primes.
http://ijfs.usb.ac.ir/article_2024_a19538744d9dc0e80b3a8fe6a94fe7a9.pdf
Dihedral group
Equivalence
Isomorphism
Fuzzy subgroup
Maximal chain
Keychain
Distinguishing factor
eng
University of Sistan and Baluchestan
Iranian Journal of Fuzzy Systems
1735-0654
1735-0654
2015-06-30
12
3
151
166
10.22111/ijfs.2015.2025
2025
مقاله پژوهشی
Solvable $L$-subgroup of an $L$-group
Iffat Jahan
ij.umar@yahoo.com
1
Naseem Ajmal
nasajmal@yahoo.com
2
Department of Mathematics, Ramjas College,, University of Delhi,, Delhi-110007, India
Department of Mathematics, Zakir Husain Delhi College,, J.N.Marg, University of Delhi, Delhi-110006, India
In this paper, we study the notion of solvable $L$-subgroup of an $L$-group and provide its level subset characterization and this justifies the suitability of this extension. Throughout this work, we have used normality of an $L$-subgroup of an $L$-group in the sense of Wu rather than Liu.
http://ijfs.usb.ac.ir/article_2025_54e716181d9591e118bc01071c130667.pdf
$L$-algebra
$L$-subgroup
Normal $L$-subgroup
Solvable $L$-subgroup
Derived series
Solvable series
eng
University of Sistan and Baluchestan
Iranian Journal of Fuzzy Systems
1735-0654
1735-0654
2015-06-29
12
3
169
178
10.22111/ijfs.2015.2647
2647
Persian-translation vol. 12, no.3, June 2015
http://ijfs.usb.ac.ir/article_2647_57c7fc92eea1f99ca53467fa3f4fe555.pdf