When the time span of an event is imprecise, it can be represented by a fuzzy set, called a fuzzy time interval. In this paper we propose a representation for 13 relations that can hold between intervals. Since our model is based on fuzzy orderings of time points, it is not only suitable to express precise relationships between imprecise events (“the mid 1930’s came before the late 1930’s) but ...

This paper presents a diagnosis framework based on a qualitative model of the process. Starting from a dynamic abstraction procedure under a defined operating mode a fuzzy partitioning of the variables evolution is made, defining for each measured or observable variable a number of qualitative states. Then time Fuzzy intervals representing the moment of state change are defined. The process beh...

Recognition and classification of different power quality events is of great importance in power systems which should be done on line. For this purpose, different methods are presented which each has advantages and disadvantages. In this paper, recognition way is presented for power quality disturbances such as sag, swell, outage, surge and normal based on fuzzy systems. In this method, voltage...

His paper was selected over ten others in scoring by an international panel of judges who are experts in fuzzy logics. The award, sponsored by the conference organizers and announced Wednesday (July 5), includes a cash prize of $2,500 plus hotel accommodations for the Fourth Annual International Conference on Fuzzy Theory and Technology September 28-October 1 in Wrightsville Beach, N.C. The gen...

The in ltration process is generally described by a nonlinear di erential equation, which can be solved by iteration methods such as a Newton-Raphson method. In this paper we propose a Discrete Event System Speci cation(DEVS) model for Green-Ampt in ltration. We show that this model can be approximated using Genetic Algorithm optimization of a fuzzy system. The fuzzy approximation is shown to b...

estimation of parameters of a hydrologic model is undertaken using a procedure called “calibration” in order to obtain predictions as close as possible to observed values. this study aimed to use the particle swarm optimization (pso) algorithm for automatic calibration of the hec-hms hydrologic model, which includes a library of different event-based models for simulating the rainfall-runoff pr...

 This work develops a knowledge based system to autonomous navigation using Fuzzy Cognitive Maps (FCM). A new variant of FCM, named Event Driven-Fuzzy Cognitive Maps, (ED-FCM) is used to model decision tasks and/or make inference in the robot or mobile navigation. Fuzzy Cognitive Maps is a tool that modeling qualitative knowledge in minds maps structured way through concepts and causal relatio...

Automatic classification of seismic events is of great importance due to the large amount of data received continuously. Seismic analysts classify events by visual inspection and calculation of event signal characteristics. This process is subjective and demands hard work as well as a significant amount of time and considerable experience. A reliable automatic classification task considerably r...