Date: Mon 22 Aug 1988 22:27-EDT From: AIList Moderator Nick Papadakis Reply-To: AIList@mc.lcs.mit.edu Us-Mail: MIT LCS, 545 Tech Square, Rm# NE43-504, Cambridge MA 02139 Phone: (617) 253-6524 Subject: AIList Digest V8 #63 To: AIList@mc.lcs.mit.edu Status: R AIList Digest Tuesday, 23 Aug 1988 Volume 8 : Issue 63 Queries and Responses: Category Theory in AI Camera Stabilization Speech rec. using neural nets Sigmoid function MACSYMA Availability ELIZA ---------------------------------------------------------------------- Date: 18 Aug 88 10:23:55 GMT From: mcvax!ukc!strath-cs!glasgow!jack@uunet.uu.net (Jack Campin) Subject: Re: Category Theory in AI geddis@atr-la.atr.junet (Donald F. Geddis) wrote: >>dpb@philabs.philips.com (Paul Benjamin) writes: >> Some of us here at Philips Laboratories are using universal >> algebra, and more particularly category theory, to formalize >> concepts in the areas of representation, inference and >> learning. >I'm familiar with those areas of AI, but not with category theory (or >universal algebra, for that matter). Can anyone give a short summary for the >layman of those two mathematical topics? And perhaps a pointer as to how >they might be useful in formalizing certain AI concepts. Thanks! A short summary is tricky without knowing your mathematical background and maybe impossible for a real honest-to-goodness layman. A good book to start with is Herrlich and Strecker's, but if you don't know what a group is, forget it. Arbib and Manes' "Arrows, Structures and Functors" is also OK, but mainly applies it to automata theory (not a booming enterprise these days). Category theory generalizes the notions of "set" and "function", or more generally "mathematical structure" and "mapping that preserves that structure" (where the structures might be, say, n-dimensional Euclidean spaces, and the mappings projections, embeddings and other distance-preserving functions). Its aim is to describe classes of mathematical object (groups, topological spaces, partially ordered sets, ...) by looking at the maps between them, and then to describe relationships between these classes. It captures a lot of otherwise indescribable mathematical notions of "unique" or "natural" objects or maps in a class (the empty set, Descartes' construction of the Euclidean plane as the "product" of two lines, the class of all possible strings in an alphabet, ...). The major application of it to computer science so far is in the semantics of higher-order polymorphic type systems (which can't be described in set theory). David Rydeheard and Rod Burstall have just published a book "Computational Category Theory" that describes categorical constructions algorithmically (in Standard ML) and has a useful bibliography. But a lot of computer science literature that uses category theory does not do so in an essential way; the commutative diagrams are just there to give the authors some mathematical street cred. I can't imagine what category theory has to contribute to knowledge representation (though I can just about imagine it helping to describe neural nets in a more abstract way). Can the philabs people say more about what they're up to? -- ARPA: jack%cs.glasgow.ac.uk@nss.cs.ucl.ac.uk USENET: jack@cs.glasgow.uucp JANET:jack@uk.ac.glasgow.cs useBANGnet: ...mcvax!ukc!cs.glasgow.ac.uk!jack Mail: Jack Campin, Computing Science Dept., Glasgow Univ., 17 Lilybank Gardens, Glasgow G12 8QQ, SCOTLAND work 041 339 8855 x 6045; home 041 556 1878 ------------------------------ Date: 18 Aug 88 16:48:27 GMT From: pacbell!hoptoad!dasys1!step!perl@ames.arpa (Robert Perlberg) Subject: Re: Camera Stabilization In a previous article, John B. Nagle writes: > Panasonic showed a gyroscopically stablized consumer-grade camcorder > at the Consumer Electronics Show this summer. It should be available at > Japanese retailers by the end of the year. This may be a promising approach. The Panasonic Steadi-Cam has no gyros. The lens and image sensor are mounted on a gimbaled platform along with pitch and yaw sensors which drive motors which move the platform to compensate for camera body movement. Robert Perlberg Dean Witter Reynolds Inc., New York phri!{dasys1 | philabs | manhat}!step!perl -- "I am not a language ... I am a free man!" ------------------------------ Date: 19 Aug 88 18:05:25 GMT From: att!chinet!mcdchg!clyde!watmath!watvlsi!watale!dixit@bloom-beaco n.mit.edu (Nibha Dixit) Subject: Speech rec. using neural nets Is anyody out there looking at speech recognition using neural networks? There has been some amount of work done in pattern recognition for images, but is there anything specific being done about speech? -- Nibha Dixit (U of Waterloo, Waterloo, Ont.) ...!watmath!watale!dixit or dixit@watale.waterloo.cdn dixit@watale.waterloo.edu or dixit@watale.waterloo.bitnet ------------------------------ Date: Sat, 20 Aug 88 15:06:38 -0200 From: Antti Ylikoski Subject: Sigmoid function One way to build a circuit that produces the true sigmoid function would be to store the value-argument pairs into a ROM and use the following circuit: f |-----------------| |------| |-----------------| input ---> | A / D converter |->| ROM |->| D / A converter | ---> output |-----------------| |------| |-----------------| Antti (Andy) Ylikoski Helsinki University of Technology (I think a better translation would be Helsinki Institute of technology) Digital Systems Laboratory YLIKOSKI@FINFUN.BITNET OPMVAX::YLIKOSKI (DECnet) mcvax!hutds!ayl (UUCP) ------------------------------ Date: Sat, 20 Aug 88 23:41 EDT From: Nick Papadakis Subject: MACSYMA Availability If the messages I have received since my posting in AIList V8 #35 are any gauge, there seems to be a fair amount of misinformation on the subject of MACSYMA and where to get it. The following is a summary of the best information I have been able to garner via numerous telephone conversations (I had requested hardcopy, but am tired of waiting for it to arrive). * * * The original MACSYMA code is owned by MIT, which has granted licenses to distribute it to three other organizations. SYMBOLICS: Runs on Apollo, Sun, Symbolics, and all VAXes. Licenses range from about $5K to $15K (US prices, for commercial customers) Probably the most sophisticated version, many enhancements. Source code is NOT provided. Call 1-800-622-7962, (in Mass. (617) 621-7770) or email petti@ALLEGHENY.SCRC.Symbolics.COM NESC (National Energy Software Center): Referred to as 'DOE MACSYMA'. Runs on Alliant, Celerity, Data-General, Encore, LMI Lambda, Sun, Symbolics, TI Explorer, VAX. About $2K to $3K for non-subscribers (subscribers get 2 programs free, subscriptions are $2.5K to $3.5K) Source code IS provided. Call Margaret Butler (312) 972-7250 [As of March 87, an improved version of DOE MACSYMA for the TI Explorer (including the SHARE libraries), was available to any NESC licensee from Hyde%NGSTL1@TI-CSL.CSNET@RELAY.CS.NET] INTERMATH - This startup company's product is still in the works, but they are interested in talking to people who "might want to embed some portion of MACSYMA's functionality in another system". Call (617) 868-4510 * * * Now for the distressing part. The MIT patent office states that DOE (via NESC) is only permitted to distribute MACSYMA to government agencies, contractors, and grantees. NESC says that is completely untrue, and that they will continue to distribute to commercial customers. Symbolics has trademarked the name 'MACSYMA'. DOE claims that "it wasn't theirs to trademark." I'm not sure I want to know precisely what causes such a massive failure of communication. I am _quite_ sure that I do *not* wish to receive (and will not post) any more messages pointing out that the version being distributed by a certain company was 'the only licensed version' and that all others were 'bootleg'. This list exists to inform the AI community, and not to serve any commercial interest. It is clear that the various versions available have varying degrees of enhancement and support. The informed customer will take this into account when making a decision. I think it is unfortunate when the good efforts of those who have worked to enhance a product are compromised by the unsavory tactics of others seeking to promote it. - nick ------------------------------ Date: Sun, 21 Aug 88 17:56:44 From: ZZZO%DHVRRZN1.BITNET@CUNYVM.CUNY.EDU Subject: ELIZA Date: 21 August 1988, 17:53:57 MEZ From: Wolfgang Zocher (0511) 762-3684 ZZZO at DHVRRZN1 To: AILIST at AI.AI.MIT Subject: Need for ELIZA For the purpose of demonstration in a Lisp-course I need a Common Lisp version of the ELIZA (Doctor) program (evtl. with Scripts)... can anyone help me??? WZ (ZZZO at DHVRRZN1) ------------------------------ End of AIList Digest ********************