University of Sistan and BaluchestanIranian Journal of Fuzzy Systems1735-065411420140830Cover vol. 11, no. 4, August 20140268510.22111/ijfs.2014.2685ENJournal Article20161017https://ijfs.usb.ac.ir/article_2685_df3214bfd0e8e4edcfffc5530c0163ea.pdfUniversity of Sistan and BaluchestanIranian Journal of Fuzzy Systems1735-065411420140830Robust stability of stochastic fuzzy impulsive recurrent neural networks with\ time-varying delays113162010.22111/ijfs.2014.1620ENM.Syed AliDepartment of Mathematics, Thiruvalluvar University, Vellore - 632
106, Tamilnadu, IndiaJournal Article20110108In this paper, global robust stability of stochastic impulsive recurrent neural networks with time-varying<br />delays which are represented by the Takagi-Sugeno (T-S) fuzzy models is considered. A novel Linear Matrix Inequality (LMI)-based stability criterion is obtained by using Lyapunov functional theory to guarantee the asymptotic stability of uncertain fuzzy stochastic impulsive recurrent neural networks with time-varying<br />delays. The results are related to the size of delay and impulses.<br />Finally, numerical examples and simulations are given to demonstrate the correctness of the theoretical results.https://ijfs.usb.ac.ir/article_1620_41dafc9887d401c5a0000ccd84aea553.pdfUniversity of Sistan and BaluchestanIranian Journal of Fuzzy Systems1735-065411420140830Some conditions under which slow oscillation of a sequence of fuzzy numbers follows from Ces`{a}ro summability of its generator sequence1522162110.22111/ijfs.2014.1621ENIbrahimCanakDepartment of Mathematics, Ege University, 35100, Izmir, Turkey0000-0002-1754-1685Journal Article20111008Let $(u_n)$ be a sequence of fuzzy numbers. We recover the slow oscillation of $(u_n)$ of fuzzy numbers from the Ces`{a}ro summability of its generator sequence and some additional conditions imposed on $(u_n)$. Further, fuzzy analogues of some well known classical Tauberian theorems for Ces`{a}ro summability method are established as particular cases.https://ijfs.usb.ac.ir/article_1621_c2384221ff3393272720aaa1f664d782.pdfUniversity of Sistan and BaluchestanIranian Journal of Fuzzy Systems1735-065411420140830A duality between fuzzy domains and strongly completely distributive $L$-ordered sets2343162210.22111/ijfs.2014.1622ENW.YaoDepartment of Mathematics, Hebei University of Science and Technology,
Shijiazhuang 050018, P.R. ChinaB.ZhaoDepartment of Mathematics, Shaanxi Normal University, Xi'an 710062,
P.R. ChinaJournal Article20130508The aim of this paper is to establish a fuzzy version of the duality<br />between domains and completely distributive lattices. All values are<br />taken in a fixed frame $L$. A definition of (strongly) completely<br />distributive $L$-ordered sets is introduced. The main result in<br />this paper is that the category of fuzzy domains is dually equivalent<br />to the category of strongly completely distributive $L$-ordered<br />sets. The results in this paper establish close connections among<br />fuzzy-set approach of quantitative domains and fuzzy topology with<br />modified $L$-sober spaces and spatial $L$-frames as links. In<br />addition, some mistakes in [K.R. Wagner, Liminf convergence in<br />$Omega$-categories, Theoretical Computer Science 184 (1997)<br />61--104] are pointed out.https://ijfs.usb.ac.ir/article_1622_dad91c3aea817c8872a7af7d2eb80c03.pdfUniversity of Sistan and BaluchestanIranian Journal of Fuzzy Systems1735-065411420140830Convergence of a semi-analytical method on the fuzzy linear systems4560162310.22111/ijfs.2014.1623ENMojtabaGhanbariDepartment of Mathematics, Aliabad Katoul Branch, Islamic
Azad University, Aliabad Katoul, Iran0000-0003-4790-769XRaheleNuraeiDepartment of Mathematics, South Tehran Branch, Islamic Azad
University, Tehran, IranJournal Article20120108In this paper, we apply the homotopy analysis method (HAM) for solving fuzzy linear systems and present the necessary and sufficient conditions for the convergence of series solution obtained via the HAM. Also, we present a new criterion for choosing a proper value of convergence-control parameter $hbar$ when the HAM is applied to linear system of equations. Comparisons are made between the results of the HAM and several well-known numerical algorithms such as Jacobi method (JM), Gauss-Seidel method (GSM), successive over relaxation method (SOR), Adomian decomposition method (ADM) and homotopy perturbation method (HPM).https://ijfs.usb.ac.ir/article_1623_7d9b0b310e31e8b8041af9982d4fdddf.pdfUniversity of Sistan and BaluchestanIranian Journal of Fuzzy Systems1735-065411420140830Fuzzy Acts over Fuzzy Semigroups and Sheaves6173162410.22111/ijfs.2014.1624ENM.HaddadiDepartment of Mathematics, Statistics and Computer Sciences, Semnan
University, Semnan, IranJournal Article20111008lthough fuzzy set theory and sheaf theory have been developed and studied independently, Ulrich Hohle shows that a large part of fuzzy set theory is in fact a subfield of sheaf theory. Many authors have studied mathematical structures, in particular, algebraic structures, in both categories of these generalized (multi)sets.<br /> Using Hohle's idea, we show that for a (universal) algebra $A$, the set of fuzzy algebras over $A$ and the set of subalgebras of the constant sheaf of algebras over $A$ are order isomorphic. Then, among other things, we study the category of fuzzy acts over a fuzzy semigroup, so to say, with its universal algebraic as well as classic algebraic definitions.https://ijfs.usb.ac.ir/article_1624_7915f082437e766d5e60d3f04c95a162.pdfUniversity of Sistan and BaluchestanIranian Journal of Fuzzy Systems1735-065411420140830A note on convergence in fuzzy metric spaces7585162510.22111/ijfs.2014.1625ENValentnGregoriInstituto Universitario de Matematica Pura y Aplicada, Universitat
Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia, Spain0000-0002-5983-6182Juan-JoseMinanaInstituto Universitario de Matematica Pura y Aplicada, Universitat
Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia, Spain0000-0001-9835-0700SamuelMorillasInstituto Universitario de Matematica Pura y Aplicada, Universitat
Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia, SpainJournal Article20130208The sequential $p$-convergence in a fuzzy metric space, in the sense of George and Veeramani, was introduced by D. Mihet as a weaker concept than convergence. Here we introduce a stronger concept called $s$-convergence, and we characterize those fuzzy metric spaces in which convergent sequences are $s$-convergent. In such a case $M$ is called an $s$-fuzzy metric. If $(N_M,ast)$ is a fuzzy metric on $X$ where $N_M(x,y)=bigwedge{M(x,y,t):t>0}$ then it is proved that the topologies deduced from $M$ and $N_M$ coincide if and only if $M$ is an $s$-fuzzy metric.https://ijfs.usb.ac.ir/article_1625_4434683a72324a1c1ff35fc7fe0b6565.pdfUniversity of Sistan and BaluchestanIranian Journal of Fuzzy Systems1735-065411420140830H"{o}lder summability method of fuzzy numbers and a Tauberian theorem8793162610.22111/ijfs.2014.1626ENIbrahimCanakDepartment of Mathematics, Ege University, 35100, Izmir, Turkey0000-0002-1754-1685Journal Article20120608In this paper we establish a Tauberian condition under which convergence follows from H"{o}lder summability of sequences of fuzzy numbers.https://ijfs.usb.ac.ir/article_1626_6d6b326e6429a049c79be13e505260bb.pdfUniversity of Sistan and BaluchestanIranian Journal of Fuzzy Systems1735-065411420140801Persian-translation vol. 11, no. 4, August 201497103268610.22111/ijfs.2014.2686ENJournal Article20161017https://ijfs.usb.ac.ir/article_2686_9fb11a1425907d3407c92ae6a853c5b2.pdf