simulation@uflorida.cis.ufl.edu (Moderator: Paul Fishwick) (05/25/88)
Volume: 2, Issue: 8, Wed May 25 09:57:20 EDT 1988 +----------------+ | TODAY'S TOPICS | +----------------+ (1) Simulating Plans (2) Chaotic Behavior: The Devil's Staircase (3) Query: Info. on CM and TW Moderator: Paul Fishwick, Univ. of Florida Send topical mail to: simulation@uflorida.cis.ufl.edu ------------------------------ To: comp-simulation@ucbvax.Berkeley.EDU From: dan%meridian@ads.com (Dan Shapiro) Newsgroups: comp.simulation Subject: Re: SIMULATION DIGEST V2 N6 Date: 23 May 88 19:01:00 GMT Reply-To: dan%meridian@ads.com (Dan Shapiro) Organization: Advanced Decision Systems, Mt. View, CA (415) 941-3912 I'd like to know what techniques people have used to address the following problem: I'm trying to project future state in a wargame by simulating a military plan, and playing both sides automatically. The purpose is to predict deviations from expected outcomes. The issue is that the plan dictates a loosely ordered set of desired actions, but the tokens on the board also need to respond to the situation at hand. This creates a tension in the mechanism used to select actions which I need to resolve. For example, if your plan says to attack, but the situation pushes you onto the defensive, planned actions either have to be modified/refined, or held in abeyance. If the situation has deviated sufficiently far from expectation, then the plan will have to be abandoned entirely. The problem boils down to a need for techniques that provide some reactivity in the execution of a plan. Many simulation systems will have had to address this question (though I have only seen a few relatively simple techniques). What approaches have people used? Dan Shapiro (dan@ads.com) ------------------------------ To: simulation@bikini.cis.ufl.edu Cc: brooks@maddog.llnl.gov Subject: Devil's staircase? Reply-To: aboulanger@bbn.com Date: Tue, 24 May 88 10:07:44 EDT From: aboulang@WILMA.BBN.COM Sender: aboulang@WILMA.BBN.COM Eugene D. Brooks III writes: If the processors start with a random unconstrained address and start a vector request of a common stride (with caviats for say a stride of 2) the network falls into lock step after a "settling time" with a strange periodic behaviour of the memory subsystem. If a disturbance is made in the network after it falls into lockstep it bubbles out the conflict and falls into a different periodic motion. I have been studying asynchronous computations on the Butterfly. I have been interested in the issue of the dynamics of asynchronous parallel computation. On possibility that I have thought about, and you seem to provide evidence of, is the emergence of the so-called "Devil's staircase" in the dynamics of parallel computation. The Devil's staircase is the mode-locking/mode-hopping behavior on gets in non-linearly coupled oscillators. It is described in "The Devils Staircase", Per Bak, Physics Today. December 1986,38-45. If one plots the frequency ratio (of two systems; typically a driver oscillator, and a driven one), against time, one gets a fractal staircase of the residence times of the modes. Perhaps you can generate plots like this? For more than two computational entities involved, one would get fractal terraces and hyperterraces. Albert Boulanger BBN Labs aboulanger@bbn.com ------------------------------ From: ksr!guy@harvard.harvard.edu Date: Wed, 25 May 88 01:23:22 EDT Subject: simulation reference request Can you refer me to texts describing the two simulation strategies mentioned frequently in comp.simulation: chandy-misra and time-warp? Thanks. --Guy Hillyer ksr!guy@harvard.harvard.edu +--------------------------+ | END OF SIMULATION DIGEST | +--------------------------+