Journal of Intelligent & Fuzzy Systems - Volume 19, issue 6

Authors: Burgin, Mark | Duman, Oktay

Article Type: Research Article

Abstract: Statistical convergence was introduced in connection with problems of series summation. Only later it was demonstrated that statistical convergence is closely related to convergence of the main statistical characteristics. Statistical limits are defined relaxing conditions on conventional convergence. The main idea of the statistical convergence of a sequence l is that the majority of elements from l converge and we do not care what is going on with other elements. At the …same time, it is known that sequences that come from real life sources, such as measurement and computation, do not allow, in a general case, to test whether they converge or statistically converge in the strict mathematical sense. To overcome these limitations, fuzzy convergence was introduced earlier in the context of neoclassical analysis and fuzzy statistical convergence is introduced and studied in this paper. We find relations between fuzzy statistical convergence of a sequence and fuzzy statistical convergence of its subsequences (Theorem 2.1), as well as between fuzzy statistical convergence of a sequence and conventional convergence of its subsequences (Theorem 2.2). It is demonstrated what operations with fuzzy statistical limits are induced by operations on sequences (Theorem 2.3) and how fuzzy statistical limits of different sequences influence one another (Theorem 2.4). In Section 3, relations between fuzzy statistical convergence and fuzzy convergence of statistical characteristics, such as the mean (average) and standard deviation, are studied (Theorems 3.1 and 3.2). Show more

Keywords: Statistical convergence, fuzzy sets, fuzzy limits, statistics, mean, standard deviation, fuzzy convergence, fuzzy density

Citation: Journal of Intelligent & Fuzzy Systems, vol. 19, no. 6, pp. 385-392, 2008

Authors: Hong, Sung Kyung

Article Type: Research Article

Abstract: This paper describes a compensation strategy utilizing fuzzy logic methodology to augment the performance of low cost micromechanical gyros. Among many serious parameters affecting the performance of MEMS gyros, our attention is focused on the scale factor error due to its nonlinearity and asymmetry. Motivated by the capability of fuzzy logic in managing nonlinear mapping, a fuzzy logic based compensation algorithm is proposed. The ADXRS 300 gyros of Analog Device were selected as the candidates at …our lab. Experimental results demonstrate that gyros augmented by proposed approach show improvements in scale factor error of an order of magnitude (extremely linear output) throughout operating dynamic range. Show more

Citation: Journal of Intelligent & Fuzzy Systems, vol. 19, no. 6, pp. 393-398, 2008

Authors: Pach, F.P. | Gyenesei, A. | Abonyi, J.

Article Type: Research Article

Abstract: Effective methods for feature and model structure selection are very important for data-driven modeling, data mining, and system identification tasks. This paper presents a new method for selecting important variables (regressors) in nonlinear (dynamic) models with mixed discrete (categorical, fuzzy) and continuous inputs and outputs. The proposed method applies fuzzy association rule mining. The selection process of the important variables is based on two interesting measures of the mined association rules.

Keywords: Feature selection, model order selection, fuzzy association rules, process modeling

Citation: Journal of Intelligent & Fuzzy Systems, vol. 19, no. 6, pp. 399-407, 2008

Authors: Wang, Junyan | Zhao, Ruiqing | Tang, Wansheng

Article Type: Research Article

Abstract: In this paper, we study revenue-sharing contract in a supply chain with fuzzy demand. Under such a contract, a retailer pays a supplier a wholesale price for each unit purchased, plus a percentage of the revenue generated by the retailer that is determined by retailer's purchase quantity and price. We address the contract under two kinds of fuzzy demands which depend on the retailer's selling price based on game theory. The effectiveness of the revenue-sharing contract …under fuzzy demands is proved. Show more

Keywords: Fuzzy demand, supply chain, revenue-sharing, contract, game theory

Citation: Journal of Intelligent & Fuzzy Systems, vol. 19, no. 6, pp. 409-420, 2008