Xref: utzoo comp.realtime:661 comp.ai:6931 Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uunet!wang!wdr From: wdr@wang.com (William Ricker) Newsgroups: comp.realtime,comp.ai Subject: Re: Fuzzy Logic Introduction? Message-ID: Date: 30 May 90 22:52:06 GMT References: <766@ssc.UUCP> <3128@se-sd.SanDiego.NCR.COM> Organization: Wang Labs, Lowell MA, USA Lines: 54 jim@se-sd.SanDiego.NCR.COM (Jim Ruehlin) writes: >Speaking of fuzzy logic, can anyone post pros/cons to this technique? >I've heard that it's a good way to represent "partial ownership" of >elements of a set. That is exactly what Fuzzy Sets represent. Fuzzy Logic is to Fuzzy Sets as Logic is to Set Theory in general. > I've also heard that it's nothing more than probability >theory (the rebuttal to this is that it's really more like "possibility >theory"). People also try to confuse it with compounded independant probabilties or Baysian probabilities; these are potential models for fuzzy arithmetics, but not usually the ideal ones. I like the phrase "possibility theory", but I'm not sure it is any more intuitive than "fuzzy set". >The best explication of it I heard may be that it's a "user friendly" >probability theory. However, if you look at the math at first it's hard >to see why! When Fuzzy Sets membership and Fuzzy Logic statements are translated into Liguistic Variables, then you have a "user friendly" theory. However, the fact that "really like bald" and "like really bald" don't commute does pose problems to some users; as does an age-gap in the connotation of (the fuzzy modifier function associated with) "like". See the Kurt Schmucker book I cited in my other article on this topic, for which I now supply a full bibliographic entry: Schmucker, Kurt J. /Fuzzy sets, natural language computations, and risk analysis./ Computer Science Press, 1983. 0-914894-38-?. My corporate library has it catalogued as QA 248.S345.1983 [Lib.Cong]; I credit their on-line cat for the bib. here (and blame it for the missing check digit on the ISBN -- which probably fell off the end due to the old Pub# for CSP, which has a new shorter number now). I recently picked up a used book on Fuzzy Logic & Expert Systems, but haven't read it yet, so I can't review it. I haven't tried to do anything fuzzy yet, as the project I bought Schmucker for died prematurely, but have considered implementing fuzzy sets in either Prolog or Smalltalk as extensions of the existing Set implementations. Prolog also has the nice feature of providing reasonable DCG (definite clause grammar) support, which should ease translation to & from liguistic variables. Perhaps I can remember to find the books at home and check their bibliographies for you-all. [[Support a 2nd Person Plural pronoun as well as a 3rd Person singular neutral-but-human!:-] /bill/ -- /bill ricker/ wdr@wang.com a/k/a wricker@northeastern.edu *** Warning: This account not authorized to express opinions ***