Modification Of Membership Function Research Articles

Multi-objective performance investigation of orthopaedic bone drilling using Taguchi membership function.

Orthopaedic bone drilling attacks the surrounded bone cells and tissues in terms of thermal and mechanical in such a way that these cells can get damaged permanently. This damage to the surrounding of drill point upsurges the rehabilitation time of injury and in some cases leads to the failure of the bone screw joint. This study is based on the optimization of multiple response characteristics to minimize the damage during the bone drilling. All real-life problems, including bone drilling, require the multiple response optimization for getting a combined optimization result for all countable response characteristics. The Taguchi optimization technique is observed as a highly recommended tool for single response optimization. This article uses the Taguchi technique with little modification of membership function that will help to convert the multiple response characteristics into single response and further optimize it as a single function of performance. Rotational speed, feed rate of tool at three different levels with three different kinds of drilling tools are the drilling parameters selected for the study. The objective of this study is to minimize the surface roughness and thrust force simultaneously. Analysis of variance helps to find the percentage contribution and significance of each parameter on the performance.

A new method for fuzzy rule base reduction

This paper presents a new approach for fuzzy rule base reduction using similarity concepts and interpolation techniques. The algorithm consists on: First, measure similarity between rules for the best choice of which of them will be deleted. This operation is done without modification of membership functions. Second, if a new input data is presented to the fuzzy system, interpolation techniques will be used to take into account this arriving data. The main idea of this work is to improve accuracy of the fuzzy system after reduction step. A comparative study between three interpolation methods is done. A mathematical case is treated to show the performance of the proposed method.

Handling of inconsistent rules with an extended model of fuzzy reasoning

It may not always be possible for an expert to provide a set of completely consistent rules. Even if the rules are consistent, all rules may not have equal importance to control the system. Moreover, for a fuzzy controller, the rule-base is usually tuned through modification of membership functions. Effect of changing a membership function is global in the sense that it influences all rules that involve the membership function. Here we propose a very effective extension of the conventional fuzzy reasoning system with incorporation of an importance factor for each rule. This factor allows tuning of the system at the rule level. Of course, one can still tune the membership functions. It enables the system to cope with incorrect and/or incompatible rules and thereby enhances the robustness, flexibility and system modeling capability. The proposed model is quite general and can be used in different applications including control. In the present investigation, we demonstrate with extensive simulation how for a control application inconsistent rules can be dealt with.

Fuzzy Diagnostic Expert System for Ultrasonic Testing. Selection of Fuzzy Connectives and Modification of Membership Functions.

A diagnostic fuzzy expert system for ultrasonic testing (UT). which has been constructed by the authors indicates good agreement between the results obtained by the system and UT experts. The knowledge is represented in terms of fuzzy production rules, and the result is inferenced by the logical product as a fuzzy connective. This paper attempts to improve the jnference result by selecting fuzzy connectives, and membership functions based on the knowledge from several UT experts. When the fuzzy connective is selected as the algebraic product and the membership functions are modified, the results obtained are superior to previous results.