Journal of Intelligent & Fuzzy Systems - Volume 20, issue 4, 5

Authors: Zhan, J. | Davvaz, B. | Shum, K.P.

Article Type: Research Article

Abstract: This paper concerns a relationship between fuzzy sets and algebraic hyperstructures. It is a continuation of ideas presented by Davvaz(Fuzy Sets Syst. 101: 191.195 1999) and Bhakat and Das(Fuzzy Sets Syst. 80: 359.368 1996). The concept of quasi-coincidence of a fuzzy interval value with an interval valued fuzzy set, which is a generalization of quasi-coincidence of a fuzzy point with a fuzzy set, is introduced. Using this new idea, the notion of interval valued (α, β)-fuzzy sub-hyperquasigroups in a hyperquasigroup, which is a generalization of a fuzzy sub-quasigroup, is defined, and related properties are investigated. In particular, the study of …interval valued (∈, ∈, ∨q)-fuzzy sub-hyperquasigroups in a hyperquasigroup is dealt with. Finally, we consider the concept of implication-based interval valued fuzzy sub-hyperquasigroups in a hyperquasigroup. Show more

Keywords: Hyperquasigroup, Interval valued (α, β)-fuzzy sub-hyperquasigroup, Interval valued (∈, ∈, ∨q)-fuzzy subhyperquasigroup, Fuzzy logic, Implication operator

DOI: 10.3233/IFS-2009-0423

Citation: Journal of Intelligent & Fuzzy Systems, vol. 20, no. 4, 5, pp. 147-157, 2009

Authors: Davvaz, B. | Kazanci, O. | Yamak, S.

Article Type: Research Article

Abstract: Recently, fuzzy n-ary polygroups were introduced and analyzed by Davvaz, Corsini and Leoreanu-Fotea. Fuzzy n-ary polygroups are suitable generalizations of n-ary polygroups and a special case of fuzzy n-ary hypergroups. The aim of this paper is to introduce the notion of an interval-valued fuzzy n-ary subpolygroup of an n-ary subpolygroup and to extend the fuzzy n-ary subpolygroup to interval-valued (∈, ∈, ∨q)-fuzzy n-ary subpolygroup. We also consider the concept of implication-based interval-valued fuzzy n-ary sub-polygroup in an n-ary polygroup, in particular, the implication operators in £ukasiewicz system of continuous-valued logic are discussed.

Keywords: n-ary polygroup, fuzzy n-ary subpolygroup, interval-valued (∈, ∈, ∨q)-fuzzy n-ary subpolygroup, fuzzy logic, implication operator

DOI: 10.3233/IFS-2009-0424

Citation: Journal of Intelligent & Fuzzy Systems, vol. 20, no. 4, 5, pp. 159-168, 2009

Authors: Ma, X. | Zhan, J. | Xiang, D.

Article Type: Research Article

Abstract: The aim of this paper is to introduce the concepts of (∈, ∈, ∨q)-fuzzy Boolean filters and (∈, ∈, ∨q)-fuzzy MV-filters in MTL-algebras. Some characterizations of these kinds of generalized fuzzy filters are derived. Finally, the concept of (∈, ∈, ∨q)-fuzzy G-filters in MTL-algebras is introduced. It is proved that an (∈, ∈, ∨q)-fuzzy filter of MTL-algebras is Boolean if and only if it is both an (∈, ∈, ∨q)-fuzzy G-filter and an (∈, ∈, ∨q)-fuzzy MV-filter.

Keywords: MTL-algebra, (∈, ∈, ∨q)-fuzzy Boolean filter, (∈, ∈, ∨q)-fuzzy G-filter, (∈, ∈, ∨q)-fuzzy MV-filter

DOI: 10.3233/IFS-2009-0425

Citation: Journal of Intelligent & Fuzzy Systems, vol. 20, no. 4, 5, pp. 169-174, 2009

Authors: Khushaba, R.N. | AlSukker, A. | Al-Ani, A. | Al-Jumaily, A. | Zomaya, A.Y.

Article Type: Research Article

Abstract: Accurate and computationally efficient myoelectric control strategies have been the focus of a great deal of research in recent years. Although many attempts exist in literature to develop such strategies, deficiencies still exist. One of the major challenges in myoelectric control is finding an optimal feature set that can best discriminate between classes. However, since the myoelectric signal is recorded using multi channels, the feature vector size can become very large. Hence a dimensionality reduction method is needed to identify an informative, yet small size feature set. This paper presents a new feature selection method based on modifying the Particle …Swarm Optimization (PSO) algorithm with the inclusion of Mutual Information (MI) measure. The new method, called BPSOMI, is a mixture of filter and wrapper approaches of feature selection. In order to prove its efficiency, the proposed method is tested against other dimensionality reduction techniques proving powerful classification accuracy. Show more

Keywords: Mutual information, Myoelectric control, Particle swarm optimization, Pattern recognition

DOI: 10.3233/IFS-2009-0426

Citation: Journal of Intelligent & Fuzzy Systems, vol. 20, no. 4, 5, pp. 175-185, 2009

Authors: Castillo-Toledo, B. | Di Gennaro, S. | Anzurez-Marin, J.

Article Type: Research Article

Abstract: In this paper we propose a solution to the model-based fault diagnosis problem for the class of non-linear dynamic systems subjected to be described by a Takagi-Sugeno fuzzy model. A fuzzy observer is designed to estimate the system's state vector and to derive a diagnostic signal-residual. The residual is generated by the comparison of the measured and the estimated outputs. The proposed scheme has been satisfactorily tested in simulation and in a real-time benchmark given by a Two-Tank Hydraulic System.

Keywords: Fault diagnosis, Fuzzy system, Takagi-Sugeno fuzzy models, Fuzzy Observers

DOI: 10.3233/IFS-2009-0427

Citation: Journal of Intelligent & Fuzzy Systems, vol. 20, no. 4, 5, pp. 187-199, 2009

Authors: Garrido, R. | Calderon, D. | Soria, A.

Article Type: Research Article

Abstract: This paper proposes a stable adaptive fuzzy controller applied to a servomotor for velocity tracking of time-varying references. The control law is composed of two parts. The first part comprises a Proportional controller plus feedforward compensation. An adaptive fuzzy compensator corresponds to the second part and counteracts the effects of nonlinear loads. The only a priori information about the servomotor parameters is a nominal value of the voltage input gain. A depart from current adaptive adaptive controllers is the fact that the proposed control law does not rely on a switching supervisor controller then avoiding chattering. Moreover, the desired time …varying reference feeds the membership functions instead of using the measured velocity, which is contaminated by noise. In this way, less measurement noise is injected to the closed loop system. The Lyapunov stability method allows concluding uniform ultimate boundedness of the closed loop system solutions. Experiments performed on a laboratory prototype allow comparing the proposed approach against a Proportional Integral controller endowed with feedforward compensation. Show more

Keywords: Fuzzy systems, Adaptive control, Velocity control, Servosystems, Real-Time control

DOI: 10.3233/IFS-2009-0428

Citation: Journal of Intelligent & Fuzzy Systems, vol. 20, no. 4, 5, pp. 201-209, 2009