krj@na.toronto.edu (Ken Jackson) (10/09/88)
NA Digest Sunday, October 9, 1988 Volume 88 : Issue 40 Today's Editor: Cleve Moler Today's Topics: Pascal QZ Software Wanted Basis for Linear Equalities Conference in Chile Numerical Expert System Positions Available at University of Florida Singularity of 0-1 Matrices Faculty Position at Cornell ------------------------------------------------------- From: K. Veselic <MA704%DHAFEU11.BITNET@Forsythe.Stanford.EDU> Date: Mon, 03 Oct 88 14:47:29 SET Subject: Pascal QZ Software Wanted Who can supply a Pascal (possibly Turbo-Pascal) version of the QZ algorithm for the generalized eigenvalue problem A*x = lambda*B*x (the routines QZHES, QZIT, QZVAL, QZVEC)? Thanks in advance. K. Veselic, Fernuniversitaet Hagen, Germany (ma704@dhafeu11.bitnet or na.veselic) Acknowledge-To: <MA704@DHAFEU11.BITNET> ------------------------------ From: Michael Cohen <mike%bucasb.BU.EDU@bu-it.bu.edu> Date: Mon, 3 Oct 88 10:10:34 EDT Subject: Basis for Linear Equalities Last week, Arnold Neumaier posed the followinging problem: Let C be the set of n-dimensional real vectors satisfying the system of linear inequalities Ax >= b. By a well-known theorem, every point x in C is a convex combination of at most n+1 vertices of C (and of at most n if x lies on the boundary). Are there efficient algorithms to find such vertices and the corresponding coefficients? I am also interested in this problem. All the algorithms I know to do the task have far worse than exponential complexity in the number of inequalities. --Michael Cohen ------------------------------ From: DKGAVAA%CFRVM.BITNET@Forsythe.Stanford.EDU Date: 4 Oct 88 15:08 GMT Subject: Conference in Chile A conference entitled COMPUTATIONAL METHODS AND FUNCTION THEORY will be held March 13-18, 1989 at the Universidad Tecnica Federico Santa Maria in Valparaiso, Chile. The conference organizers are D. Gaier, St. Ruscheweyh, E.B. Saff, L. Salinas and R.S.Varga. For further information contact St.Ruscheweyh, CMFT '89< Matematica, UTFSM Casilla 110-V Valparaiso, Chile Telex 230338-UTFSM_CL ------------------------------ From: Valeria Frontini <AFT0%ICINECA.BITNET@Forsythe.Stanford.EDU> Date: Fri, 23 Sep 88 11:51:03 ITA Subject: Numerical Expert System I should like to know if anyone has implemented a numerical expert system, to help end-users finding the appropriate software for their needs. I already know and I am trying to implement NITPACK, and asked informations about NEXUS, which is under development. Many thanks Valeria Frontini Valeria Frontini CINECA via Magnanelli 6/3 I-40033 Casalecchio di Reno Bologna Italia E-mail: AFT0 at ICINECA (Earn-Bitnet) na.frontini Na-net ------------------------------ From: <sigmon@lab3.math.ufl.edu> Date: Wed, 5 Oct 88 11:36:04 EDT Subject: Positions Available at University of Florida POSITIONS AVAILABLE UNIVERSITY OF FLORIDA Department of Mathematics The Department of Mathematics is in the third year of a five year program to fill over 20 new tenure track faculty positions with mathematicians of exceptional caliber. The department invites applications for six tenure-track positions for the fall semester 1989. Applications from junior candidates are especially welcome. Outstanding candidates in all areas of applied and pure mathematics are invited to apply for these positions. Senior candidates should have distinguished research records, and junior candidates are expected to have made significant research contributions. Every candidate is expected to possess a strong commitment to teaching. One position will be reserved for a senior candidate in partial differential equations. Strong preference will be given to arithmetic geometers and number theorists in filling a second position. Among other areas of interest to the department are dynamical systems, algebraic geometry, and harmonic analysis. Candidates should forward a resume (including a list of publications) and should arrange for at least three letters of recommedation to be sent to: David A. Drake, Chair Department of Mathematics University of Florida Gainesville, FL 32611 All applications for the academic year 1989-90 must be completed by December 31, l988. The University of Florida is an equal opportunity employer. ------------------------------ From: Michael A. de la Maza <thefool@athena.mit.edu> Date: 6 Oct 88 00:08:53 GMT Subject: Singularity of 0-1 Matrices Excuse me for posting the following question on multiple math boards, but no one over in sci.math seems to be able to solve it... Suppose you are allowed to fill a matrix only with 0s and 1s. Given this restriction there are 16 2x2 matrices. 6 of them are invertible, ten of them are not. Generalize to NxN matrices. How many are invertible, how many are not? -- Michael de la Maza thefool@athena.mit.edu [Ed. Note: What is the field? Does 1+1 = 0 or 2?] ------------------------------ From: Michael Todd <miketodd@gvax.cs.cornell.edu> Date: Fri, 7 Oct 88 13:15:01 EDT Subject: Faculty Position at Cornell Here is an announcement for a faculty position in operations research at Cornell. Applications from women and minorities are especially welcome. FACULTY POSITION ANNOUNCEMENT School of Operations Research and Industrial Engineering Cornell University The school seeks applications for a tenure-track opening at the assistant professor level for Fall 1989. Applications in all areas of operations research and industrial engineering will be considered; however, special attention will be given to applicants whose expertise is in the area of optimization. Candidates should have a strong record of achievement or clearly evident potential in both research and teaching. Send resume to: Chairman, Search Committee School of Operations Research and Industrial Engineering 319 Upson Hall Cornell University Ithaca, NY 14853 AA/EOE ------------------------------ End of NA Digest ************************** ------- Reposted by -- Kenneth R. Jackson, krj@na.toronto.edu (on Internet, CSNet, Computer Science Dept., ARPAnet, BITNET) University of Toronto, krj@na.utoronto.ca (CDNnet and other Toronto, Canada M5S 1A4 X.400 nets (Europe)) (416) 978-7075