Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!uflorida!simulation From: simulation@uflorida.cis.ufl.edu (Moderator: Paul Fishwick) Newsgroups: comp.simulation Subject: SIMULATION DIGEST V12 N7 Message-ID: <21256@uflorida.cis.ufl.EDU> Date: 20 Nov 89 14:39:53 GMT Sender: fishwick@uflorida.cis.ufl.EDU Reply-To: simulation@uflorida.cis.ufl.edu Lines: 425 Approved: fishwick@uflorida.cis.ufl.edu Volume: 12, Issue: 7, Mon Nov 20 09:39:42 EST 1989 +----------------+ | TODAY'S TOPICS | +----------------+ (1) Correction about Tech. Reports (2) Dynamic Parallelism (3) Survey on Research Center (4) Ternary Simulation (5) NewsGroup Discussion: Virtual-Worlds * Moderator: Paul Fishwick, Univ. of Florida * Send topical mail to: simulation@bikini.cis.ufl.edu OR post to comp.simulation via USENET * Archives available via FTP to bikini.cis.ufl.edu, login as 'ftp', use your last name as the password, change directory to pub/simdigest. * Simulation Tools available by doing above and changing the directory to pub/simdigest/tools. ----------------------------------------------------------------------------- Date: Fri, 10 Nov 89 08:31:33 -0800 From: liny@cs.washington.edu (Yi-Bing Lin) Return-Path: To: fishwick@bikini.cis.ufl.edu Subject: Correction Dear Prof. Fishwick, Please post this message in the SIMULATION DIGEST. Thanks, Jason (Yi-Bing Lin) ------------------------------------------------------------------- I posted the abstracts of two papers in Simulation Digest (V12, N16). These papers are JUST technical reports submitted for publication. They are NOT accepted by 1990 Distributed Simulation. Sorry for the mistake. Jason Lin ------------------------------ Date: Sat, 11 Nov 89 14:30:29 PST From: chkim%pollux.usc.edu@usc.edu (Chinhyun Kim) To: fpst@hubcap.clemson.edu, simulation@bikini.cis.ufl.edu Subject: Dynamic parallelism Hi, the following is an article I want to post to your newsgroup. ---------------------------Article starts here--------------------------- In numerical analysis, arrays being indexed by other arrays as shown below are supposed to be very common in programs involving sparse matrices, fluid flow simulations, etc. If one wanted to parallelize this loop during compilation, he/she would have to know the values of B(i) and C(i). If they are not known at compile time, it will be impossible to parallelize the operations in the loop and thus must be executed in sequential manner. There are, however, ways to parallelize the operations in the loop by checking data dependency during run time and letting operations which are free of data dependency to execute in parallel. This kind of parallelism which can be determined only during run time is called, "dynamic parallelism". A(i) = ..... ; A(i)'s are initialized. B(i) = .... ; B(i)'s are determined. C(i) = .... ; C(i)'s are determined. DO i = 1..N A(B(i)) = ..... ; Array A is updated. T(i) = A(C(i)) + .. ; Array A is consumed for some operation. ENDDO I am currently working on ways to exploit dynamic parallelism as opposed to static parallelism which the compiler assesses parallelism during compilation. The model of computation is data-flow and the specific type of data-flow computer model is tagged token data-flow computer. I am using a mechanism known as "token relabeling" to do this. The results of my simulation so far is good. However, I have some fundamental questions to ask. Q1. In exactly what type of numerical simulations do such loops appear and why are they necessary? Q2. Are there other ways to do it without having the subscripts unknown at compile time, i.e. is exploitation of dynamic parallelism avoidable while still achieving parallel execution? Q3. Is it possible for me to get the fragment of the simulation program which has such loop? i.e. assuming answer to the first part of question 1 is true. Answers to these questions will be appreciated very much. Chinhyun Kim chkim@pollux.usc.edu ------------------------------ From: Robert Cole Date: 15 Nov 89 12:01:39 GMT To: comp-simulation@rutgers.edu Subject: Submission for comp-simulation Responding-System: cica.cica.indiana.edu Path: cica!cole From: cole@cica.cica.indiana.edu (Robert Cole) Newsgroups: comp.graphics,comp.simulation,comp.software-eng Subject: repost survey - PLEASE help Date: 15 Nov 89 12:01:38 GMT Reply-To: cole@cica.indiana.edu (Robert Cole) Distribution: na Organization: Indiana University, Bloomington This is a repost of a message which only went out on comp.graphics So far I've only received one response (which was excellent!) and two messages from SIGGRAPH committee members expressing interest in the survey results. If you are associated with a Center such as below or have contacts at such centers, please see that this gets into appropriate hands so that we can get a good selection of answers. Thanks! **************************************************** CICA is the Center for Innovative Computer Applications at Indiana University. As a special projects organization for the Office of University Computing, CICA has begun a two year commitment to usage of high-end graphics in the various sciences (such as Chemistry, Geology, Astronomy, Computer Science, Mathematics) and other disciplines such as Fine Arts and Theatre at Indiana. We are in the process of evaluating our existence in relation to other special university computing centers and trying to determine what it is that is needed for success as a nationally recognized center. Please help us by e-mailing a reply to the following questions. Your response can be sent to cole@cica.cica.indiana.edu Thank you for your help... 1. What is a 4-5 sentence mission statement for your organization? 2. What are your main goals? 3. What are your main accomplishments? 4. When was the organization founded? 5. Please fill in the answers to the following based upon the first year of existence: a. Number of staff b. Number of projects undertaken c. Approximate budget d. Percentage of budget from institution e. Percentage of budget from external sources 6. Please fill in the answers to the following based on current levels: a. Number of staff b. Number of projects undertaken c. Approximate budget d. Percentage of budget from institution e. Percentage of budget from external sources 7. Any words of wisdom for a fledgling center? ------------------------------ To: comp-simulation@cwi.nl Path: tuewsd!tuewsk!wstomv From: wstomv@lso.win.tue.nl (Tom Verhoeff) Newsgroups: tue.general,nlnet.general,comp.theory,comp.lsi,comp.simulation,sci.electronics Subject: 2nd NFI seminar by J. A. Brzozowski at EUT Keywords: Asynchrononous Circuit Theory, (Ternary) Simulation Date: 16 Nov 89 09:03:49 GMT Sender: news@lso.win.tue.nl Distribution: nlnet EINDHOVEN UNIVERSITY OF TECHNOLOGY DEPARTMENT OF MATHEMATICS AND COMPUTING SCIENCE The second seminar in the NFI seminar series ASYNCHRONOUS CIRCUIT THEORY and TESTING OF SEQUENTIAL CIRCUITS by Professor J. A. Brzozowski will be held on Friday December 1st 1989 from 10.45 to 12.30 in lecture room Hoofdgebouw 8.78. The topic is TERNARY SIMULATION Abstract: In 1964 Eichelberger proposed the use of ternary simulation for the analysis of races and hazards in asynchronous circuits. His method was applied to the "feedback-delay" model of sequential circuit in which the circuit state is determined by the state of a set of wires having the property that cutting all the wires in the set results in a loop-free circuit. Eichelberger's treatment was rather informal and the results of his simulation were not completely understood. Nevertheless, the method has been used rather widely; for example, it is available in commercial logic simulators. In 1976 Eichelberger's ternary algorithm was applied by Brzozowski and Yoeli to the "gate-delay" model in which each gate is assumed to have a delay. The results of this ternary simulation were then compared with the results of the binary race analysis of the same circuit; in the binary analysis the "General Multiple-Winner" model of races was used. A partial characterization was found, but it was conjectured that the correspondence would be complete if wire delays would be included, i.e. if the "gate-and-wire-delay" model were used in the binary analysis. Eichelberger's method consists of two parts, which he called Procedure A and Procedure B. In 1983 Bryant found a characterization of Procedure A using the "wire-delay" model. He has also incorporated ternary simulation techniques in his switch-level simulator, MOSSIM, designed to model MOS circuits. The method was introduced without proper justification. A mathematical foundation for the use of ternary simulation for MOS circuits was found by Lengauer and Naher. However, these results cannot be directly carried over to gate circuits. The 1976 conjecture was finally proved correct in 1985 by Brzozowski and Seger. A sketch of the proof of this result will be given in this talk, and some important consequences of this result will be discussed. The main reference for this lecture is: J.A. Brzozowski and C.-J. Seger, "A Characterization of Ternary Simulation of Gate Networks," IEEE Trans. Computers, Vol. C-36, No. 11, Nov. 1987, pp. 1318-1327. For more information call: Mrs. F. van Neerven 040 - 47 39 02, or Prof. J. A. Brzozowski 040 - 47 27 44. ------------------------------ To: uunet.uu.net!comp-simulation@lll-crg.llnl.gov Path: well!bluefire From: well!bluefire@lll-crg.llnl.gov (Bob Jacobson) Newsgroups: comp.simulation Subject: CALL FOR DISCUSSION: SCI.VIRTUAL-WORLDS Summary: Initiation of discussion. Keywords: virtual worlds, virtual reality, artificial reality Date: 20 Nov 89 06:30:51 GMT Reply-To: well!bluefire@lll-crg.llnl.gov (Bob Jacobson) Followup-To: news.groups Organization: Human Interface Technology Lab, Univ. of Washington The following message has been posted to news.announce.newgroups. A discussion has begun in news.groups. We hope this conference's members will join in. CALL FOR DISCUSSION OF A PROPOSED NEW NEWSGROUP: SCI.VIRTUAL-WORLDS Why this new newsgroup? ----------------------- This is a proposal to create a new newsgroup on Usenet, sci.virtual-worlds. This proposal is being made by the Human Interface Technology Laboratory at the University of Washington, which proposes to host this newsgroup for the study of "virtual- world" phenomena. According to the procedures agreed upon by Usenet adminis- trators, a new newsgroup must be offered to the Usenet community for from 14 to 30 days' worth of discussion prior to the taking of a formal vote on the newsgroup's desirability. Please accept this as our offer to discuss the new newsgroup we propose, sci.virtual-worlds. We have until December 15th. We are making this proposal because we believe that the coming proliferation of virtual-world phenomena, made possible by powerful virtual-interface technology, requires the scientific community served by Usenet to begin debating how this technology will be employed. Further, with additional research on virtual-world phenomena taking place at more and more research sites, and in a growing number of fields -- aerospace, medicine, entertainment, education, and science -- it is imperative that there be a forum where the outcomes of this research can be shared most widely. Initial directions for this newsgroup have been suggested by various participants in the alt.cyberpunk newsgroup and its derivative newsgroups. However, to ensure the highest level of discussion regarding virtual worlds, we believe that this subject should be elevated to the level of a sci. newsgroup, with the formal endorsement of the Usenet community. What is a virtual world? ------------------------ A "virtual world" is a unique, intangible but highly designed information environment generated by a computer and transmitted by "virtual-interface" technology to a user who "enters" the virtual world via appropriate sensory-exchange devices. Best known of these devices are the Super Cockpit, a cabled helmet- and-uniform ensemble worn by Air Force pilots to "bond" them to their planes; and a video facemask and data glove developed by NASA and refined by VPL and Autodesk. The virtual-world environment can be as complex as a three- dimensional "sense surround" comprising seamless visual, aural, and tactile cues; or as simple as a computer conferencing system. Virtual worlds are designed to increase the bandwidth of communi- cation between the computer and the human being, to facilitate their interaction, and ultimately to improve the human being's understanding and performance. In short, a virtual world is created to exploit the perceptual and cognitive skills of human beings: to design computer systems that communicate with human beings on human terms, rather than the other way around. Virtual worlds are also known by the popular term "cyber- space," coined by the author William Gibson (NEUROMANCER) to describe the environment within future computer networks as experienced by future "cowboys" who "ride" the global Net via headsets and laptop "decks." Other terms used to describe virtual-world phenomena are "virtual reality" and "artificial reality." The substance of the proposed newsgroup --------------------------------------- The subject of this newsgroup will be virtual worlds, in all their aspects: the theory of virtuality, the technology that is being developed and employed to create virtual-world environments, the people and places working on virtual worlds, and the philoso- phical questions and social consequences attendant upon the emergence of this new medium of communication. Sci.virtual-worlds will be a scientific, economic, philoso- phical, and spiritual examination of the particular phenomena that are associated with the creation and experience of virtual worlds. Moderating the conference will be Howard Rheingold, WELL host and author (TOOLS FOR THOUGHT) who is currently researching virtual- world developments for a book in preparation. Assisting Rheingold will be Drs. Thomas Furness and Robert Jacobson, director and associate director, respectively, of the Human Interface Techno- logy Laboratory at the University of Washington. Who could join this newgroup? ----------------------------- Anyone with a serious interest in virtual-world phenomena and/or technology would be invited to join this newsgroup. Researchers are currently developing sophisticated virtual interface systems at the University of Washington, MIT, the University of North Carolina, the University of Utah, Brigham Young University, Autodesk, VPL, and NASA. In the next year, several books on virtual worlds will be published. There are a number of articles about virtual-world theory and practice already available in professional and popular journals. Additionally, practitioners in many professional fields and practices are beginning to investigate the use of virtual-world technology to solve problems in the conduct of their work. Among these are chemists, aerospace engineers, medical doctors, educa- tors, and motion-picture special-effects producers. Sci.virtual-worlds would be a place where this diverse and active community of researchers and practitioners can join together to share knowledge and reflect upon its meaning. Future plans ------------ The Laboratory intends to make available via Usenet a database referencing the items in its considerable library regarding virtual-worlds phenomena and research. The database is in prepara- tion. An announcement will be made when this archive is publicly available. Please join in the discussion! ------------------------------ This is your opportunity to voice an opinion regarding the new newsgroup proposed in this article. If you agree with our general premises, your can also help shape the future of sci.virtual-worlds. Please take advantage and let us know what you think. The dialogue will be conducted in newsgroup news.groups, where you should direct your comments. For more information, contact Robert Jacobson at the follow- ing telephone or email numbers: (206) 543-5075 (Laboratory) bluefire@well.uucp (206) 726-1537 (Home) MCI Mai: Robert Jacobson You may also contact Howard Rheingold at hlr@well.uucp. ------------------------------ END OF SIMULATION DIGEST ************************