perm filename JAN.ABS[BIB,CSR]2 blob sn#394245 filedate 1978-11-15 generic text, type C, neo UTF8

COMMENT ⊗ VALID 00004 PAGES C REC PAGE DESCRIPTION C00001 00001 C00002 00002 .REQUIRE "ABSTRA.CMD[BIB,CSR]" SOURCE FILE C00003 00003 .once center <<general instructions>> C00014 00004 %4********************************************************************************%1 C00016 ENDMK C⊗; .REQUIRE "ABSTRA.CMD[BIB,CSR]" SOURCE FILE .every heading (January,1979 Reports,{Page}) .at "∞" ⊂"%4α∞%*"⊃ .next page .once center <<general instructions>> %3MOST RECENT CS REPORTS - JANUARY 1979 @Listed below are abstracts of the most recent reports published by the Computer Science Department of Stanford University. @TO REQUEST REPORTS:##Check the appropriate places on the enclosed order form, and return the entire order form page (including mailing label) by January 19, 1979. In many cases we can print only a limited number of copies, and requests will be filled on a first come, first serve basis. If the code (FREE) is printed on your mailing label, you will not be charged for hardcopy. This exemption from payment is limited primarily to libraries. (The costs shown include all applicable sales taxes. PLEASE SEND NO MONEY NOW, WAIT UNTIL YOU GET AN INVOICE.) @ALTERNATIVELY: Copies of most Stanford CS Reports may be obtained by writing (about 2 months after MOST RECENT CS REPORTS listing) to NATIONAL TECHNICAL INFORMATION SERVICE, 5285 Port Royal Road, Springfield, Virginia 22161. Stanford Ph.D. theses are available from UNIVERSITY MICROFILMS, 300 North Zeeb Road, Ann Arbor, Michigan 48106. .begin nofill %4-------------------------------------------------------------------------------------%1 %3STAN-CS-79-691 THE CONSTRUCTION OF INITIAL DATA FOR HYPERBOLIC SYSTEMS FROM NONSTANDARD DATA %3Author:%1 Kenneth P. Bube↔(Thesis) .end @%3Abstract:%1@We study the first order systems of hyperbolic partial differential equations with periodic boundary conditions in the space variables for which complete initial data are not available. We suppose that we can measure %2u%1↑I , the first %2j%1 components of a solution %2u%1 of the system, perhaps with its time derivatives, but cannot measure %2u%2∩[II] , the rest of the components of %2u%1 , completely and accurately at any time level. Such problems arise in geophysical application where satelites are used to collect data. We consider two questions. How much information do we need to determine the solution %2u%1 uniquely in a way which depends continuously on the data? How do we use these data compuationally to obtain complete initial data at some time level? @We investigate several approaches to answering these questions. We show that under certain hypotheses %2u%1∩[II] at the initial time is determined uniquely by and depends continuously on the data obtained by measuring either %2u%1↑I over a whole time interval or %2u%1↑I and its first time derivative at the initial time, together ith either %2u%1∩[II] on a hyperplane in space of one lower dimension or a finite number of Fourier coefficients of %2u%1∩[II] at the initial time. Our results demonstrate that it is possible to reduce the data requirements of %2u%1∩[II] if sufficient information about %2u%2↑I is available. @One appliction we examine is the effect of the Coriolis term in the linearized shallow water equations on the possibility of recovering the wind fields from the geopotential height. @We present algorithms and computational results for these approaches for a model two-by-two system, and examine the method for intermittent updating currently being used in numerical weather prediction as a method for the assimilation of data. Our results suggest that the use of different frequencies of updating is important to avoid slow convergence. .begin nofill No. of pages: 119 Available in microfiche only. %4-------------------------------------------------------------------------------------%1 %3HPP-77-39 MODELS OF LEARNING SYSTEMS %3Authors:%1 Bruce G. Buchanan, Tom M. Mitchell, Reid G. Smith & C. Richard Johnson Jr. .end @%3Abstract:%1@The terms adaptation, learning, concept-formation, induction, self-organization, and self-repair have all been used in the context of learning system (LS) research. In this article, three distinct approaches to machine learning and adaptation are considered: (%2i%1) the adaptive control approach, (%2ii%1) the pattern recognition approach, and (%2iii%1) the artificial intelligence approach. @Progress in each of these areas is summarized in the first part of the article. In the next part a general model for learning systems is presented that allows characterization and comparison of individual algorithms and programs in all these areas. The model details the functional components felt to be essential for any learning system, independent of the techniques used for its construction, and the specific environment in which it operates. Specific examples of learning systems are described in terms of the model. .begin nofill No. of pages: 38 Cost: $ 2.80 %4-------------------------------------------------------------------------------------%1 %3STAN-CS-79-693 A CLASS OF SOLUTIONS TO THE GOSSIP PROBLEM %3Author:%1 Douglas B. West .end @%3Abstract:%1@We characterize and count optimal solutions to the gossip problem in which no one hears his own information. That is, we consider graphs with %2n%1 vertices where the edges have a linear ordering such that an increasing path exists from each vertex to every other, but there is no increasing path from any vertex to itself. Such graphs exist only when %2n%1 is even, in which case the fewest number of edges is %22n-4%1, as in the original gossip problem. We characterize optimal solutions of this sort (NOHO-graphs) using a correspondence with a set of permutations and binary sequences. This correspondence enables us to count these solutions and several subclasses of solutions. The numbers of solutions in each class are simple powers of %22%1 and %23%1, with exponents determined by %2n%1. We also show constructively that NOHO-graphs are planar and Hamiltonian, and we mention applications to related problems. .begin nofill No. of pages: 61 Cost: $ 3.45 %4-------------------------------------------------------------------------------------%1 %3STAN-CS-79-694 COMPUTER SCIENCE AT STANFORD, 1977-1978 %3Editor:%1 Jonathan King .end @%3Abstract:%1@This report is a review of Stanford Computer Science Department activities for the academic year 1977-78. The report includes: .begin indent 5 1.##The Chairman's overview of the important events of the year. 2.##Recent activities and interests of faculty members and research associates arranged by research specialty. 3.##Advanced doctoral students in each specialty and their research topics. 4.##Recipients of M.S. and Ph.D. degrees. 5.##Speakers at seminar and colloquia series. 6.##Bibliography of Computer Science Department technical reports. .end .begin nofill No. of pages: 27 Cost: $ 2.50 %4-------------------------------------------------------------------------------------%1 %4********************************************************************************%1 %4********************************************************************************%1 .end .once center %3ATTENTION! %3@Due to the rising costs of printing, postage and handling, we find it is now necessary to prune our mailing list. We will NOT drop anyone who specifically asks not to be, but your cooperation is essential. Here is how to determine if you are in danger of being dropped from our mailing list: @@(1) you have not ordered any reports from us in the last year, and @@(2) you do not check the appropriate box on the attached order form and return it to us by the deadline.%1 @The management wishes to extend its thanks for your cooperation in helping us to curb our expenses. .break .begin nofill %4********************************************************************************%1 %4********************************************************************************%1 .end