Journal of Intelligent & Fuzzy Systems - Volume 18, issue 4

Authors: Al-Jarrah, Omar | Shaout, Adnan

Article Type: Research Article

Abstract: Advances in home and automotive and entertainment system technology have made it possible to offer exceptional sound quality reproduction to consumers. In recent years, automotive audio systems' quality has approached that of home systems. However, high and variable ambient noise levels remain difficult to overcome and impose a major limitation on the automotive sound system. Currently, some of these systems use classical controllers, which are based on the estimation of the ambient noise using the speed …of the vehicle. Due to the effects of road and weather conditions and other factors such as the status of the windows or sunroof, these systems do not provide adequate noise compensation. Other systems measure the noise levels inside the vehicle and use complicated circuitry and algorithms for compensation. This paper introduces the application of fuzzy logic for automatic volume control in automotive systems that compensates for interior and exterior noise while excluding the effect of passengers' conservation. In stead of using simple table-based approaches which need excessive tuning or complex DSP approaches which need large processing power and suffer from non-linearity, we utilize the expertise of human drivers and the power of fuzzy logic to develop an automatic volume control that is simple to develop, easy to implement, and yet powerful. We have conducted several experiments on real audio signals and the results prove the effectiveness of the proposed approach. Show more

Keywords: Automatic volume control, automotive industry, audio systems, simulation, speed, ambient noise, fuzzy logic

Citation: Journal of Intelligent & Fuzzy Systems, vol. 18, no. 4, pp. 329-343, 2007

Authors: Ayaǧ, Zeki | Özdemir, Rıfat Gürcan

Article Type: Research Article

Abstract: In mass production, assembly-line balancing (ALB) problem has been a critical and repetitive issue for companies for long time. On the other hand, equipment selection for stations has also been another important problem at the design stage of an assembly-line system. In this paper, both problems are handled simultaneously. Therefore first, goal programming (GP) method, a well-suited technique is used to develop a preemptive formulation to joint both of the problems, when the nature of the …problem consists of several conflicting objectives, and some mathematical constraints on solutions. Second, an AHP method based on fuzzy scales which is incorporated with the GP is also used due to the fact that it takes both qualitative and quantitative judgments of decision-maker(s) into consideration to rank the equipment alternatives for stations by weight. The fuzzy AHP as one of the most commonly used multiple-criteria decision making (MCDM) methods has been effectively used for more than decade in both academic research and practice, and takes the vagueness and uncertainty on judgments of decision-maker(s) into consideration due to the fact that the crisp pairwise comparison in the conventional AHP seems to insufficient and imprecise to capture the right judgments of decision-maker(s). In short, in this study, a combined fuzzy AHP-GP approach is proposed to evaluating assembly-line design alternatives with equipment selection. An integer GP formulation is constructed, which also uses the fuzzy AHP scores of equipment alternatives, and employs them as one of the goals. Then, the mathematical model is solved to find out the ultimate alternative in terms of the minimized equipment cost and the maximized preference measures of decision-maker(s). The proposed approach is also illustrated on a sample case study. Show more

Keywords: Fuzzy logic, analytic hierarchy process (AHP), goal programming (GP), assembly line design (ALD), assembly-line balancing (ALB)

Citation: Journal of Intelligent & Fuzzy Systems, vol. 18, no. 4, pp. 345-362, 2007

Authors: Tavakkoli-Moghaddam, R. | Aryanezhad, M.B. | Safaei, N. | Vasei, M. | Azaron, A.

Article Type: Research Article

Abstract: This paper presents a fuzzy linear mix-integer programming model for design of cellular manufacturing systems with fuzzy part demands and product mix changeable under a multi-period planning horizon. In this dynamic condition, the best cell design for one period may not be efficient for subsequent periods and the reconfiguration of cells is required. The proposed model can determine the production volume for each part considering its fuzzy demand. The other advantages of the proposed model are …as follows: considering inter-cell material handling with constant batch size, alternative process plan for part types, operation sequence, machine relocation, machine replication, machine utilization and cell number flexibility. Main constraints are the cell size, machine capacity and production volume limitations. The objective is to minimize the sum of the constant/variable/relocation machine costs as well as inter-cell movements cost. Because of the complexity of the proposed model, which is a combinatorial nonlinear optimization, we develop an efficient genetic algorithm with novel representation and operators for solving the proposed model. 29 small, medium and large-sized problems are generated to evaluate the performance of the proposed model and the efficiency of the developed genetic algorithm. Show more

Keywords: Cellular manufacturing systems (CMS), fuzzy, genetic algorithms

Citation: Journal of Intelligent & Fuzzy Systems, vol. 18, no. 4, pp. 363-376, 2007

Authors: Davvaz, B. | Corsini, P.

Article Type: Research Article

Abstract: The aim of this paper is to introduce the notion of a fuzzy and anti fuzzy n-ary subhypergroup of an n-ary hypergroup and to extend the fuzzy results of fundamental equivalence relations to n-ary hypergroups.

Keywords: Hypergroup, n-ary hypergroup, fuzzy subset, n-ary subhypergroup, fuzzy n-ary subhypergroup, fundamental equivalence relation

Citation: Journal of Intelligent & Fuzzy Systems, vol. 18, no. 4, pp. 377-382, 2007

Authors: Huang, Xiaoxia

Article Type: Research Article

Abstract: This paper discusses portfolio selection problem in fuzzy environment. In the paper, security returns are regarded as fuzzy variables. Based on credibility measure and the expected value operator and variance operator based on credibility, two new types of fuzzy mean-variance models are proposed. A hybrid intelligent algorithm is provided to give a general solution of the optimization problems. Numerical examples are also presented to illustrate the optimization idea and the effectiveness of the proposed …algorithm. Show more

Keywords: Portfolio selection, fuzzy set, mean-variance model, fuzzy programming

Citation: Journal of Intelligent & Fuzzy Systems, vol. 18, no. 4, pp. 383-390, 2007

Authors: Majumdar, Kausik Kumar | Majumder, Dwijesh Dutta

Article Type: Research Article

Abstract: In this paper we have divided the fuzzy systems into two classes namely, knowledge-based fuzzy systems and model-based fuzzy systems. Here we have shown that the uncertain information processing capability of fuzzy set theory based techniques can successfully be employed for modeling and simulation of complex real life natural systems through fuzzy model-based approach. Three case studies in the form of genesis of tropical cyclone, evolution of tumor in human tissues and occurrence of turbulence in …a fluid flow have been discussed with fuzzy model-based approach. A fuzzy evolutionary algorithm has been described for solving a set of one dimensional fuzzy differential inclusion relations. Show more

Keywords: Fuzzy knowledge-based system, fuzzy model-based system, fuzzy expert system, fuzzy controller, fuzzy differential inclusion relations, fuzzy evolutionary algorithm

Citation: Journal of Intelligent & Fuzzy Systems, vol. 18, no. 4, pp. 391-403, 2007

Authors: Kuo, Chung-Feng Jeffrey | Chiu, Chin-Hsun

Article Type: Research Article

Abstract: This research is intended to establish faster and more accurate automatic focusing control for the complementary metal-oxide semiconductor's (CMOS) image sensing module. Because it would be difficult to formulate the dynamic mathematic model for the automatic focusing system, this innovative research will use the intelligent control method to manipulate the auto-focus system so as to control the motor rotating angle to move the lens position for achieving the auto-focus purpose of the CMOS image sensing module. …In this respect, the modulation transfer function (MTF) is used as a key indicator to describe the developing quality of the image system. By using the image sensing module, this research will retrieve the MTF for examining graphic image and the change of MTF is used as the input parameters of the fuzzy controller. After the fuzzy rule base and the membership function are established, by the process of fuzzy inference, actual rotating angle of the motor will be obtained by defuzzifying the fuzzy output so as to achieve the auto-focus purpose for the CMOS image sensing module. The performance of an improved membership function for this fuzzy controller can be effectively shown through the experiment. Show more

Keywords: Fuzzy controller, auto-focus control, modulation transfer function, automatic production line

Citation: Journal of Intelligent & Fuzzy Systems, vol. 18, no. 4, pp. 405-415, 2007

Authors: Hong, Won-Sin | Chen, Shi-Jay | Wang, Li-Hui | Chen, Shyi-Ming

Article Type: Research Article

Abstract: In this paper, we present a new prioritized information fusion method for handling fuzzy information retrieval problems in the generalized fuzzy number environment, where generalized fuzzy numbers are used to represent the degrees of strength with which documents satisfy particular criteria. The proposed prioritized information fusion method can retrieve documents more analogous to the intuition of the human being than Chen-and-Chen's method [8] and Yager's method [21]. It can overcome their drawbacks …for dealing with document retrieval. Show more

Keywords: Prioritized information fusion, generalized trapezoidal fuzzy numbers, center-of-gravity method, fuzzy information retrieval

Citation: Journal of Intelligent & Fuzzy Systems, vol. 18, no. 4, pp. 417-431, 2007