Genetic Algorithms Digest Friday, 29 Decemeber 1989 Volume 3 : Issue 22 - Send submissions to GA-List@AIC.NRL.NAVY.MIL - Send administrative requests to GA-List-Request@AIC.NRL.NAVY.MIL Today's Topics: - GAs for NNets - GA Workshop? - Fitness distribution - Variable string length - Pattern learning plan ****************************************************************************** CALENDAR OF GA-RELATED ACTIVITIES: (with GA-List issue reference) IJCNN Session on Evolutionary Processes (v3n10) Jan 15-19, 1990 Double Auction Tournament - Sante Fe Institute (v3n12) Mar 1990 Workshop on GAs, Sim. Anneal., Neural Nets - Glasgow (v3n15) May 9, 1990 7th Intl. Conference on Machine Learning (submissions 2/1/90) Jun 21-23, 1990 Workshop Foundations of GAs (v3n19) Jul 15-18, 1990 Conference on Simulation of Adaptive Behavior, Paris (v3n21) Sep 24-28, 1990 (Send announcements of other activities to GA-List@aic.nrl.navy.mil) ****************************************************************************** -------------------------------- From: George Robbins Date: Thu, 14 Dec 89 09:09:16 GMT Subject: GAs for NNets Hi, I am currently working on a system which designs neural net st structure using GAs, and have a question for anyone more neurally aware than myself. It has been suggested to me that a useful way to cut down the search space of possible nets is to only allow nets which have some regular pattern of connectivity between their layers, (oh, forgot to say we're principally interested in nets with hidden layers). It has further been argued that doing this will help to prevent the nets performance from fitting too closely to the training set, and hence losing the ability to generalise usefully. While I can see/imagine that regular patterns of connectivity may well be useful in image-processing type tasks, (where you're repeating some task over a large area of input nodes) I can see no a priori reason why regular connectivity patterns should be at all useful elsewhere. In fact i've been noted the work of Todd,Miller, and Hegde with interest: they found that irregular connectivities peformed well on a number of tasks - e.g. the four quadrant problem. Work using nets whose connectivity contains regular patterns abounds - perhaps through us imparting our own design biases to the nets we build. My questions are these: 1. does anyone out there have any experience of trying to evolve regular/irregular connectivity patterns in NNs. 2. does anyone know of any work done in NNs, (not necessarily evolved ones) which used irregular, (randomised or otherwise) connectivities 3. are there any informed opinions out there on whether regular connectivity pattens are likely to be useful. thanks for your time george@uk.co.logcam -------------------------------- Date: Mon, 18 Dec 89 16:34:52 EST From: S Khuri <@JHMAIL.HCF.JHU.EDU:kttur_s@JHUNIX.BITNET> Subject: GA Workshop? --To whom it may concern, Could you please send me some information on the workshop that will take place at Indiana University in July? Could you please include me on your mailing list too? Thanks. --Sam -------------------------------- Date: Thu, 14 Dec 89 17:09:38 -0500 From: androula@lips1.ecn.purdue.edu (Ioannis Androulakis) Subject: Fitness distribution Is there any way to identify any particular distribution that the performance measure, in GA search, follow, or that distribution should be viewed as a random function? In other words, do you think that, after the "initial transient" has been overcome, we could argue that the performance measure will follow some sort of a "normal" distribution which becomes sharper as the overall convergence is approached? Thank you, Ioannis P. Androulakis e-mail : androula@lips1.ecn.purdue.edu -------------------------------- Date: Tue, 19 Dec 89 15:29:10 -0500 From: androula@lips.ecn.purdue.edu (Ioannis Androulakis) Subject: Variable string length I am interested in any work that deals with variable string lengths. Thank you in advance, ioannis androula@lips1.ecn.purdue.edu -------------------------------- Date: Wed, 20 Dec 89 16:26:02 -0500 From: androula@lips1.ecn.purdue.edu (Ioannis Androulakis) Subject: Pattern learning plan I am interested in any information concerning the pattern learning plan. In other words how can I exploit the pattern of changes causing improvements from one generation to another. Thank you, Ioannis P. Androulakis androula@lips1.ecn.purude.edu -------------------------------- End of Genetic Algorithms Digest ********************************