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Type-2 Fuzzy Logic Questions:
Type-2 Fuzzy Logic Questions Answered:
- What does fuzzy logic do?
- What's the difference between type-1 and type-2?
- What's a type-2 fuzzy set?
- What evidence is there that type-2 works better than type-1?
- Where can I find out more?
- Who hosts type2fuzzylogic.org?
- Who controls the content of site?
- How can I add content to the site?
- How are the publications statistics compiled?
- What is RSS?
Type-2 Fuzzy Logic Questions Answered:
- What does fuzzy logic do?
Fuzzy logic is a way of representing and modelling uncertainty and imprecision. The basic premise is that most (all) applications in the general area of modelling decision making have to cope with imprecision in data, knowledge, rules etc. It provides a way of not ignoring this imprecision but using it to make better computer systems. It is used heavily in control applications and, the argument by some is, has not made as big an impact as expected in modelling human decision making. Hence the interest in type-2 fuzzy sets.
Back to top - What's the difference between type-1 and type-2?
A type-1 approach models uncertainty using a number between zero and one. It is crisp. Type-2 fuzzy logic represents uncertainty using a function which is itself a type-1 fuzzy number. Sometimes type-2 is referred to as fuzzy fuzzy because of this.
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What's a type-2 fuzzy set?
A type-2 fuzzy set maps elements in a crisp domain to type-1 fuzzy numbers bounded in the range [0,1]. We denote a fuzzy set as type-2 by placing a tilde character above the name of the set. For example a the type-2 fuzzy set fast would be denoted as
.
Since the value at each point in a type-2 fuzzy set is given as a function, type-2 fuzzy sets are three-dimensional. The type-2 fuzzy set fast is depicted below:
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What evidence is there that type-2 works better than type-1?
A number of researchers have recently shown in certain applications that type-2 can outperform type-1. If you look at papers by Hagras (Essex University), John (De Montfort University) and Mendel (University of Southern California) you will see number of application led papers. The number of application papers is growing and they all show an improvement over type-1.
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Where can I find out more?
Jerry Mendel has a book (Uncertain Rule-Based Fuzzy Logic Systems: Introduction and New Directions) which is a very good starting point. The paper by mendel and John (Type-2 Fuzzy Sets Made Simple) gives a good explanation of some of the basics and the various operations. And, of course, see our links page!
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- Who hosts type2fuzzylogic.org?
Type2fuzzylogic.org is hosted by the Centre for Computational Intelligence within the Faculty of Computer Sciences and Engineering at De Montfort University, Leicester, United Kingdom. The site was conceived and designed by Simon Coupland in consultation with Robert John. We felt there was a need for an online resource to keep track of developments in the growing field of type-2 fuzzy logic.
Back to top - Who controls the content of site?
The majority of the content of this site is user generate, so in a sense you control the content of this site. We reserve the right to remove any material which we deem to be inappropriate, offensive or inaccurate. If you feel this site contains material which should be removed the please email the webmaster.
Back to top - How can I add content to the site?
There are five main areas where users can add content:- The publications database,
- The links page,
- News pieces,
- Announcements of upcoming events, and
- Online profiles.
Back to top - How are the publications statistics compiled?
We use the data from the publications database on the site to automatically generate the statistics. To get the Author list we count the number of times each Author has there name on a paper. If the name appears in different formats, i.e. Simon Coupland and Coupland, S., then each version of the name is counted separately. This is why we ask that you enter Author name in the standard format of family name followed by initial for example, Rowling, J.K.
Back to top - What is RSS?
RSS stands for Really Simple Syndication. It is an XML technology that allows pieces of software called newsreaders to gather information from a website without the user having to visit the site. When some new sinformation has been posted on that site the newsreader alerts the user with a summary of the new content. Type2fuzzylogic.org currently hosts two news feeds, one for news and one for events. These feeds are located at:
News: http://www.type2fuzzylogic.org/news/rss.php
Events: http://www.type2fuzzylogic.org/events/rss.php
If you think we should make more use of RSS feeds then email the webmaster with your suggestions.
Newsreaders are freely available for Windows, Linux, Mac and via the World Wide Web including:- For Windows
- For Linux
- For Mac OS X
- Web Based
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