We prove that every tower of normal filters of height δ (δ supercompact) is precipitous assuming that each normal filter in the tower is the club filter restricted to a stationary set. We give an example to show that this assumption is necessary. We also prove that every normal filter can be generically extended to a well-founded V -ultrafilter (assuming large cardinals). In this paper we inves...

We introduce the concept of a ⊗-closed set and a ⊗-homomorphism in lattice implication algebras, and we discuss some of their properties. Next, we introduce the fuzzy implicative filter and obtain equivalent conditions. Finally, we discuss the operation ⊗, fuzzy filters, and fuzzy implicative filters. 2000 Mathematics Subject Classification. 03G10, 06B10, 94D05.

The concept of quasi-coincidence of a fuzzy interval value with an interval valued fuzzy set is considered. In fact, this is a generalization of quasi-coincidence of a fuzzy point with a fuzzy set. By using this new idea, the notion of interval valued (∈,∈ ∨q)-fuzzy filters in BL-algebras which is a generalization of fuzzy filters of BL-algebras, is defined, and related properties are investiga...

According to the poor adaptive ability of traditional filter algorithm in the estimation for traffic state and travel time with Kalman filter, an improved fuzzy adaptive Kalman filtering method was proposed. The new interest of observation noise was defined, and the fuzzy logic was used to adjust the importance weights of system noise and observation noise through on-line monitoring the interes...

This paper studies fuzzy hyperbolic H∞ filter for signal estimation of nonlinear continuous-time systems with state time delay. The fuzzy hyperbolic model (FHM) can be used to establish models for certain unknown complex systems. Furthermore, the main advantage of using the FHM over the Takagi-Sugeno fuzzy model are that no premise structure identification is needed and no completeness design o...

In this paper a new fuzzy filter for the removal of additive Gaussian noise in colour image sequences is presented. The proposed method, which is a colour extension of our previous work on greyscale images, consists of two subfilters. The first subfilter averages the noise in each of the colour bands separately. In this averaging, the weights of the neighbouring pixels are determined by fuzzy r...

In a fuzzy topology on a set X, the limit of a prefilter (i.e. a filter in the lattice [0,i] X) is calculated from the fuzzy closure. In this way convergence is derived from a fuzzy topology. In our paper we start with any rule "lira" which to any prefilter on X assigns, a function lira E [0,i] X. We give necessary and sufficient conditions for the function lim in order that it can be derived f...

The neural network's performance can be measured by efficiency and accuracy. The major disadvantages of neural network approach are that the generalization capability of neural networks is often significantly low, and it may take a very long time to tune the weights in the net to generate an accurate model for a highly complex and nonlinear systems. This paper presents a novel Neuro-fuzzy archi...

Spam email, is the practice of frequently sending unwanted email messages, usually with commercial content, in large quantities to a set of indiscriminate email accounts. However, since spammers continuously improve their techniques in order to compromise the spam filters, building a spam filter that can be incrementally learned and adapted became an active research field. Researches employed m...