University of Sistan and Baluchestan Iranian Journal of Fuzzy Systems 1735-0654 6 1 2009 02 11 ROBUST $H_{\infty}$ CONTROL FOR T–S TIME-VARYING DELAY SYSTEMS WITH NORM BOUNDED UNCERTAINTY BASED ON LMI APPROACH ROBUST $H_{\infty}$ CONTROL FOR T–S TIME-VARYING DELAY SYSTEMS WITH NORM BOUNDED UNCERTAINTY BASED ON LMI APPROACH 1 14 214 10.22111/ijfs.2009.214 EN Han-Liang Huang Department of Mathematics, Beijing Institute of Technology, Beijing 100081, China Fu-Gui Shi Department of Mathematics, Beijing Institute of Technology, Beijing 100081, China Journal Article 2007 10 11 In this paper we consider the problem of delay-dependent robust H1 control for uncertain fuzzy systems with time-varying delay. The Takagi– Sugeno (T–S) fuzzy model is used to describe such systems. Time-delay is assumed to have lower and upper bounds. Based on the Lyapunov-Krasovskii functional method, a sufficient condition for the existence of a robust $H_{\infty}$ controller is obtained. The fuzzy state feedback gains are derived by solving pertinent LMIs. The proposed method can avoid restrictions on the derivative of the time-varying delay assumed in previous works. The effectiveness of our method is demonstrated by a numerical example.

https://ijfs.usb.ac.ir/article_214_04d0cd9efac09c8afac5f1cebbedce64.pdf

University of Sistan and Baluchestan Iranian Journal of Fuzzy Systems 1735-0654 6 1 2009 02 11 COMBINING FUZZY QUANTIFIERS AND NEAT OPERATORS FOR SOFT COMPUTING COMBINING FUZZY QUANTIFIERS AND NEAT OPERATORS FOR SOFT COMPUTING 15 25 216 10.22111/ijfs.2009.216 EN Ferenc Szidarovszky Systems and Industrial Engineering Department, University of Arizona, Tucson, Az 85721-0020, USA Mahdi Zarghami Faculty of Civil Engineering, University of Tabriz, Tabriz 51664, Iran Journal Article 2007 12 11 This paper will introduce a new method to obtain the order weights of the Ordered Weighted Averaging (OWA) operator. We will first show the relation between fuzzy quantifiers and neat OWA operators and then offer a new combination of them. Fuzzy quantifiers are applied for soft computing in modeling the optimism degree of the decision maker. In using neat operators, the ordering of the inputs is not needed resulting in better computation efficiency. The theoretical results will be illustrated in a water resources management problem. This case study shows that more sensitive decisions are obtained by using the new method.

https://ijfs.usb.ac.ir/article_216_718ace55bcfe8d8ebb8889beaac78deb.pdf

University of Sistan and Baluchestan Iranian Journal of Fuzzy Systems 1735-0654 6 1 2009 02 11 THE PERCENTILES OF FUZZY NUMBERS AND THEIR APPLICATIONS THE PERCENTILES OF FUZZY NUMBERS AND THEIR APPLICATIONS 27 44 217 10.22111/ijfs.2009.217 EN Eynollah Pasha Department of Mathematics, The teacher Training University, Tehran, Iran Abolfazl Saiedifar Department of Statistics, Science and Research branch, Islamic Azad University, Tehran 14515-775, Iran Babak Asady Department of Mathematics, Islamic Azad University, Arak, Iran Journal Article 2007 08 11 The purpose of this study is to find the percentiles of fuzzy numbers and to demonstrate their applications, which include finding weighted means, dispersion indices, and the percentile intervals of fuzzy numbers. The crisp approximations of fuzzy numbers introduced in this paper are new and interesting for the comparison of fuzzy environments, such as a variety of economic, financial, and engineering systems control problems.

https://ijfs.usb.ac.ir/article_217_28963c5c70c04cbeae3128254ac46d54.pdf

University of Sistan and Baluchestan Iranian Journal of Fuzzy Systems 1735-0654 6 1 2009 02 11 ABSORBENT ORDERED FILTERS AND THEIR FUZZIFICATIONS IN IMPLICATIVE SEMIGROUPS ABSORBENT ORDERED FILTERS AND THEIR FUZZIFICATIONS IN IMPLICATIVE SEMIGROUPS 45 61 219 10.22111/ijfs.2009.219 EN Young Bae Jun Department of Mathematics Education and (RINS), Gyeongsang National University, Chinju 660-701, Korea Chul Hwan Park Department of Mathematics, University of Ulsan, Ulsan 680-749, Korea D. R. Prince Williams Department of Information Technology, Salalah College of Technology, Post Box: 608, Salalah-211, Sultanate of Oman Journal Article 2007 10 11 The notion of absorbent ordered filters in implicative semigroups is introduced, and its fuzzification is considered. Relations among (fuzzy) ordered filters, (fuzzy) absorbent ordered filters, and (fuzzy) positive implicative ordered filters are stated. The extensionproperty for (fuzzy) absorbent ordered filters is established. Conditions for (fuzzy) ordered filters to be (fuzzy) absorbent ordered filters are provided. The notions of normal/maximal fuzzy absorbent ordered filters and complete absorbent ordered filters are introduced and their properties are investigated.

https://ijfs.usb.ac.ir/article_219_2b5d899b27b4fb5bad6f5035658c89f7.pdf

University of Sistan and Baluchestan Iranian Journal of Fuzzy Systems 1735-0654 6 1 2009 02 11 ON ($\epsilon, \epsilon \vee q$)-FUZZY IDEALS OF BCI-ALGEBRAS ON ($\epsilon, \epsilon \vee q$)-FUZZY IDEALS OF BCI-ALGEBRAS 81 94 222 10.22111/ijfs.2009.222 EN Jianming Zhan Department of Mathematics, Hubei Institute for Nationalities, Enshi, Hubei Province,445000, P. R. China Young Bae Jun Department of Mathematics Education, Gyeongsang National University, Chinju 660-701, Korea Bijan Davvaz Department of Mathematics, Yazd University, Yazd, Iran Journal Article 2007 11 11 The aim of this paper is to introduce the notions of ($\epsilon, \epsilon \vee q$)- fuzzy p-ideals, ($\epsilon, \epsilon \vee q$)-fuzzy q-ideals and ($\epsilon, \epsilon \vee q$)-fuzzy a-ideals in BCIalgebras and to investigate some of their properties. Several characterization theorems for these generalized fuzzy ideals are proved and the relationship among these generalized fuzzy ideals of BCI-algebras is discussed. It is shown that a fuzzy set of a BCI-algebra is an ($\epsilon, \epsilon \vee q$)-fuzzy a-ideal if and only if it is both an ($\epsilon, \epsilon \vee q$)-fuzzy p-ideal and an ($\epsilon, \epsilon \vee q$)-fuzzy q-ideal. Finally, the concept of implication-based fuzzy a-ideals in BCI-algebras is introduced and, in particular, the implication operators in Lukasiewicz system of continuousvalued logic are discussed.

https://ijfs.usb.ac.ir/article_222_5803dad8f3359c0150f261e18f2d8330.pdf