The paper deals with the problem of determining stability margin of a linear continuous-time systems with fuzzy parametric uncertainty. The coefficients of characteristic polynomial with linear affine dependency on system parameters are considered. The system parameters are described by fuzzy numbers with nonsymmetric triangular membership functions. An elegant solution, graphical in nature, ba...

In this study, the roll, yaw and depth fuzzy control of an Au- tonomous Underwater Vehicle (AUV) are addressed. Yaw and roll angles are regulated only using their errors and rates, but due to the complexity of depth dynamic channel, additional pitch rate quantity is used to improve the depth loop performance. The discussed AUV has four aps at the rear of the vehicle as actuators. Two rule bases...

Li and Yu (Fuzzy Sets and Systems 101 (1999) 109) argued that the model of Yang et al. for fuzzy programming (Fuzzy Sets and Systems 41 (1991) 39) is correct only for a speci2c type of piecewise linear membership function and proposed their model for other type of membership functions. This study generalizes the model of Yang et al. A numerical example indicates that the model of Li and Yu is i...

In this paper, by means of fuzzy approaches, an accurate method is introduced for edging of color photographs. The difference between our method with other similar methods is the use of a morphological operation to think or thick the obtained edges. In this proposed method, a 3×3 window is dragged on the photo. For each block, 12 point sets will be defined, each including two non-overlapping po...

This paper presents a new method for fine-tuning the Gaussian membership functions of a fuzzy neural network (FNN) to improve approximation accuracy. This method results in special shape membership functions without the convex property. We first recall that any continuous function can be represented by a linear combination of Gaussian functions with any standard deviation. Therefore, the Gaussi...

Classical deterministic inventory models consider the demand rate to be either constant or time-dependent but independent from the stock status. However, for a certain type of inventory, the demand rate may be in-fluenced by the stock level. Also in many real-life problems, some products such as fruits, vegetables, phar-maceuticals and volatile liquids continuously deteriorate to evaporation, o...

This paper explores the use of fuzzy membership values generated by fuzzy c-means clustering (FCM) method to predict soil properties over space. A weighted average model was used on fuzzy membership to get soil properties. To validate the efficiency of this model, it was then compared with a multiple linear regression model between the soil property and terrain attributes. Four indices were cal...

This paper explains the approximation of a membership function obtained by entropy regularization of the fuzzy c-means (FCM) method. By regularizing FCM with fuzzy entropy, a membership function similar to the Fermi-Dirac distribution function is obtained. We propose a new clustering method, in which the minimum of the Helmholtz free energy for FCM is searched by deterministic annealing (DA), w...