Now showing items 1-20 of 150

    • An Accelerated Interior Point Method Whose Running Time Depends Only on A 

      Vavasis, Stephen A.; Ye, Yinyu (Cornell University, 1993-10)
      We propose a "layered-step" 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, 1992-07)
      A common feature of many scalable parallel machines is non-uniform 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, 1992-07)
      A common feature of many scalable parallel machines is non-uniform 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, 1997-02-06)
      We consider the weighted least-squares (WLS) problem with a very ill-conditioned weight matrix. Weighted least-squares 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, 1994-10)
      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 Semi-annual Research Activity Report, April 1992 - September 1992 

      Coleman, Thomas F. (Cornell University, 1992-11)
      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 Discrete-time Optimal Control Problems 

      Liao, Li-zhi; Shoemaker, Christine A. (Cornell University, 1992-07)
      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, 1994-12)
      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 ...
    • All-Electron Study of Gradient Corrections to the Local Density Functional in Metallic Systems 

      Khein, Alexander; Singh, D. J.; Umrigar, C. J. (Cornell University, 1994-08)
      Using the all-electron 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, 1996-01)
      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 single-processor case. Besides ...
    • The Application of Automatic Differentiation to Problems in Engineering Analysis 

      Chinchalkar, Shirish (Cornell University, 1993-12)
      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, 1992-11)
      Let A be an m-by-n 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 Object-Oriented Library for Asynchronous and Loosely Synchronous System Programming 

      Adamo, Jean-Marc (Cornell University, 1995-12)
      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 d-grid Cut by a Hyperplane 

      Mitchell, Scott A.; Vavasis, Stephen A. (Cornell University, 1995-11)
      We consider the problem of triangulating a d-dimensional uniform grid of d-cubes that is cut by a k-dimensional affine subspace. The goal is to obtain a triangulation with bounded aspect ratio. To achieve this goal, we ...
    • Automatic Optimization 

      Liao, Aiping (Cornell University, 1995-07)
      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, 1996-03)
      We present a simple model of a dynamical system driven slowly by externally-imposed 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, 1992-02)
      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 store-by-block schemes. We give results and ...
    • Block Factorizations on a Cluster of RS/6000s 

      Henry, Greg; Hoisie, Adolfy (Cornell University, 1992-02)
      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, Kim-Chuan; Trefethen, Lloyd N. (Cornell University, 1994-05)
      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 non-normal ...
    • Case Study in KSR Programming: Finding Outliers by the Minimum Volume Ellipsoid Method 

      Bergmark, Donna; Crovella, Mark (Cornell University, 1992-09)
      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 ...