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Browsing Cornell Theory Center Technical Reports by Title
Now showing items 120 of 150

An Accelerated Interior Point Method Whose Running Time Depends Only on A
Vavasis, Stephen A.; Ye, Yinyu (Cornell University, 199310)We propose a "layeredstep" interior point (LIP) algorithm for linear programming. This algorithm follows the central path, either with shortsteps or with a new type of step called a "layered least squares" (LLS)step. The ... 
Access Normalization: Loop Restructuring for NUMA Compilers
Li, Wei; Pingali, Keshav (Cornell University, 199207)A common feature of many scalable parallel machines is nonuniform memory access  a processor can access data in its local memory ten to a thousand times faster than it can access local data. In addition, when a ... 
Access Normalization: Loop Restructuring for NUMA Compilers
Li, Wei; Pingali, Keshav (Cornell University, 199207)A common feature of many scalable parallel machines is nonuniform memory access  a processor can access data in its local memory ten to a thousand times faster than it can access local data. In addition, when a ... 
Accurate Solution of Weighted Least Squares by Iterative Methods
Bobrovnikova, Elena Y.; Vavasis, Stephen A. (Cornell University, 19970206)We consider the weighted leastsquares (WLS) problem with a very illconditioned weight matrix. Weighted leastsquares problems arise in many applications including linear programming, electrical networks, boundary value ... 
Advanced Computing Research Institute Annual Research Activity Report September 1993  September 1994
Pingali, Keshav (Cornell University, 199410)The Advanced Computing Research Institute (ACRI) is a unit of the Cornell Theory Center and is affiliated with the Cornell Computer Science Department. The ACRI is concerned with research in scientific computation and its ... 
Advanced Computing Research Institute Semiannual Research Activity Report, April 1992  September 1992
Coleman, Thomas F. (Cornell University, 199211)The Advanced Computing Research Institute (ACRI) is a unit of the Cornell Theory Center and is affiliated with the Cornell Computer Science Department. The ACRI is concerned with research in scientific computation ... 
Advantages of Differential Dynamic Programming Over Newton's Method for Discretetime Optimal Control Problems
Liao, Lizhi; Shoemaker, Christine A. (Cornell University, 199207)Differential Dynamic Programming (DDP) and stagewise Newton's method are both quadratically convergent algorithms for solving discrete time optimal control problems. Although these two algorithms share many theoretical ... 
An Affine Scaling Algorithm for Minimizing Total Variation in Image Enhancement
Li, Yuying; Santosa, Fadil (Cornell University, 199412)A computational algorithm is proposed for image enhancement based on total variation minimization with constraints. This constrained minimization problem is introduced by Rudin et al [13,14,15] to enhance blurred and noisy ... 
AllElectron Study of Gradient Corrections to the Local Density Functional in Metallic Systems
Khein, Alexander; Singh, D. J.; Umrigar, C. J. (Cornell University, 199408)Using the allelectron Linearized Augmented Plane Wave (LAPW) method, we calculate the effect of including gradient corrections to the exchange correlation functional on the structural properties of the simple metal Al, ... 
Analysis of the Early Workload on the Cornell Theory Center IBM SP2
Hotovy, Steven; Schneider, David; O'Donnell, Timothy (Cornell University, 199601)Parallel computers have matured to the point where they are capable of running a significant production workload. Characterizing this workload, however, is far more complicated than for the singleprocessor case. Besides ... 
The Application of Automatic Differentiation to Problems in Engineering Analysis
Chinchalkar, Shirish (Cornell University, 199312)Automatic differentiation is a technique of computing the derivative of a function or a subroutine written in a higher level language such as FORTRAN or C. Significant progress has been made in this field in the last few ... 
Approximation with Kronecker Products
Loan, Charles Van; Pitsianis, Nikos (Cornell University, 199211)Let A be an mbyn matrix with m=m1m2 and n=n1n2. We consider the problem of finding (mathematical formula omitted) so that (mathematical formula omitted) is minimized. This problem can be solved by computing the ... 
ARCH, An ObjectOriented Library for Asynchronous and Loosely Synchronous System Programming
Adamo, JeanMarc (Cornell University, 199512)ARCH is a C++based library for asynchronous and loosely synchronous system programming. The current version offers a set of programming constructs that are outlined below: *** Threads: The construct is presented as a ... 
An Aspect Ratio Bound for Triangulating a dgrid Cut by a Hyperplane
Mitchell, Scott A.; Vavasis, Stephen A. (Cornell University, 199511)We consider the problem of triangulating a ddimensional uniform grid of dcubes that is cut by a kdimensional affine subspace. The goal is to obtain a triangulation with bounded aspect ratio. To achieve this goal, we ... 
Automatic Optimization
Liao, Aiping (Cornell University, 199507)We propose some automatic techniques for unconstrained optimization with the objective function given by some computer program. We show that the Newton step can be calculated in O(m2) operations where m is the number of ... 
Avalanches, Scaling, and Coherent Noise
Newman, M.E.J.; Sneppen, Kim (Cornell University, 199603)We present a simple model of a dynamical system driven slowly by externallyimposed coherent noise. Although the system never becomes critical in the sense of possessing spatial correlations of arbitrarily long range, it ... 
BLAS Based on Block Data Structures
Henry, Greg (Cornell University, 199202)The optimization of the BLAS is discussed, with examples given for the IBM superscalar RISC S/6000. The approach suggested is to use block data structures based on storebyblock schemes. We give results and ... 
Block Factorizations on a Cluster of RS/6000s
Henry, Greg; Hoisie, Adolfy (Cornell University, 199202)This paper discusses optimizing computational linear algebra algorithms on a ring cluster of IBM RS/6000s. We offer the results of a block Cholesky factorization and the underlying BLAS to demonstrate the advantage ... 
Calculation of Pseudospectra by the Arnoldi Iteration
Toh, KimChuan; Trefethen, Lloyd N. (Cornell University, 199405)The Arnoldi iteration, usually viewed as a method for calculating eigenvalues, can also be used to estimate pseudospectra. This possibility may be of practical importance, for in applications involving highly nonnormal ... 
Case Study in KSR Programming: Finding Outliers by the Minimum Volume Ellipsoid Method
Bergmark, Donna; Crovella, Mark (Cornell University, 199209)This case study describes the enablement of a parallel application on Cornell Theory Center's KSR1, a highly parallel machine from Kendall Square Research. The application is from statistics, and exposes some interesting ...