Now showing items 348-367 of 777

    • Facets of Special Knapsack Equality Polytopes 

      Lee, E.K. (1993)
      The 0/1 knapsack equality polytope is, by definition, the convex hull of 0/1 solutions of a single linear equation. A special form of this polytope - where the defining linear equation has nonnegative integer coefficients ...
    • Fast Algorithms for Image Reconstruction with Application to Partially Parallel MR Imaging 

      Chen, Y.; Hager, W.W.; Huang, F.; Phan, D.T.; Ye, X.; Yin, W. (2011-09)
      This paper presents two fast algorithms for total variation-based image reconstruction in partially parallel magnetic resonance imaging (PPI) where the inversion matrix is large and ill-conditioned. These algorithms utilize ...
    • Fenchel Cutting Planes for Linear Integer Programming Problems 

      Boyd, E. Andrew (1990-10)
      The author recently introduced a new class of cutting planes for integer programs called Fenchel cuts which distinguish themselves from more conventional cuts in that they are generated by directly seeking to solve the ...
    • Fictitious Domain Methods for Viscous Flow Simulation 

      Glowinski, R.; Kearsley, A.J.; Pan, T.W.; Periaux, J. (1995-05)
      We discuss the fictitious domain solution of the Navier-Stokes equations modeling unsteady incompressible viscous flow. The method is based on a Lagrange multiplier treatment of the boundary conditions to be satisfied and ...
    • Filter Pattern Search Algorithms for Mixed Variable Constrained Optimization Problems 

      Abramson, Mark A.; Audet, Charles; Dennis, J.E. Jr. (2004-06)
      A new class of algorithms for solving nonlinearly constrained mixed variable optimization problems is presented. This class combines and extends the Audet-Dennis Generalized Pattern Search (GPS) algorithms for bound ...
    • Filtering Deterministic Layer Effects in Imaging 

      Borcea, L.; del Cueto, F. Gonzalez; Papanicolaou, G.; Tsogka, C. (2012)
      Sensor array imaging arises in applications such as nondestructive evaluation of materials with ultrasonic waves, seismic exploration, and radar. The sensors probe a medium with signals and record the resulting echoes, ...
    • Filtering Random Layering Effects For Imaging and Velocity Estimation 

      del Cueto, Fernando Gonzalez (2009-05)
      Imaging compactly supported reflectors in highly heterogeneous media is a challenging problem due to the significant interaction of waves with the medium which causes considerable delay spread and loss of coherence. The ...
    • Filtering Random Layering Effects in Imaging 

      Borcea, L.; del Cueto, F. Gonzalez; Papanicolaou, G.; Tsogka, C. (2008-10)
      Objects that are buried deep in heterogeneous media produce faint echoes which are difficult to distinguish from the backscattered field. Sensor array imaging in such media cannot work unless we filter out the backscattered ...
    • Finding Embedded Network Rows in Linear Programs I: Extraction Heuristics 

      Bixby, Robert E.; Fourer, Robert (1986-08)
      An embedded network within a linear program is, roughly speaking, a subset of constraints that represent conservation of flow. In this paper, we examine three broad classes of heuristic techniques - row-scanning deletion, ...
    • Finding Tours in the TSP 

      Applegate, David; Bixby, Robert; Chvatal, Vasek; Cook, William (1999-05)
      The traveling salesman problem, or TSP for short, is easy to state: given a finite number of "cities" along with the cost of travel between each pair of them, find the cheapest way of visiting all the cities and returning ...
    • Finite Element Approximations to the System of Shallow Water Equations, Part I: Continuous Time a Priori Error Estimates 

      Chippada, S.; Dawson, Clint N.; Martinez, M.L.; Wheeler, Mary F. (1995-12)
      Various sophisticated finite element models for surface water flow exist in the literature. Gray, Kolar, Luettich, Lynch and Westerink have developed a hydrodynamic model based on the generalized wave continuity equation ...
    • Fixed-Polynomial Approximate Spectral Transformations for Preconditioning the Eigenvalue Problem 

      Thornquist, Heidi Krista (2003-06)
      Arnoldi's method is often used to compute a few eigenvalues and eigenvectors of large, sparse matrices. When the eigenvalues of interest are not dominant or well-separated, this method may suffer from slow convergence. ...
    • Fixed-Polynomial Approximate Spectral Transformations for Preconditioning the Eigenvalue Problem 

      Thornquist, Heidi Krista (2006-05)
      Arnoldi's method is often used to compute a few eigenvalues and eigenvectors of large, sparse matrices. When the eigenvalues of interest are not dominant or wellseparated, this method may suffer from slow convergence. ...
    • Full-waveform inversion via source-receiver extension 

      Huang, Guanghui; Nammour, Rami; Symes, William (2017)
      Full-waveform inversion produces highly resolved images of the subsurface and quantitative estimation of seismic wave velocity, provided that its initial model is kinematically accurate at the longest data wavelengths. If ...
    • Generalizations of the Alternating Direction Method of Multipliers for Large-Scale and Distributed Optimization 

      Deng, Wei (2015-06)
      The alternating direction method of multipliers (ADMM) has been revived in recent years due to its effectiveness at solving many large-scale and distributed optimization problems, particularly arising from the areas of ...
    • Generalized Conjugate Directions 

      Dennis, J.E. Jr.; Turner, Kathryn (1985-12)
      This paper presents a simple unifying framework for a wide class of conjugate directions algorithms whose iterates minimize some quadratic functional over a subspace. Our approach is motivated by its advantages for nonlinear ...
    • Generalized Newton Methods for Crack Problems with Non-Penetration Condition 

      Hintermüller, M.; Kovtunenko, V.A.; Kunisch, K. (2003-11)
      A class of semismooth Newton methods for unilaterally constrained variational problems modelling cracks under a non-penetration condition are introduced and investigated. On the continuous level, a penalization technique ...
    • Generalized Pattern Searches with Derivative Information 

      Abramson, Mark A.; Audet, Charles; Dennis, J.E. Jr. (2002-06)
      A common question asked by users of direct search algorithms is how to use derivative information at iterates where it is available. This paper addresses that question with respect to Generalized Pattern Search (GPS) ...
    • Genetic Suppression of Transgenic APP Rescues Hypersynchronous Network Activity in a Mouse Model of Alzeimer's Disease 

      Born, Heather A.; Kim, Ji-Yoen; Savjani, Ricky R.; Das, Pritam; Dabaghian, Yuri A.; Guo, Qinxi; Yoo, Jong W.; Schuler, Dorothy R.; Cirrito, John R.; Zheng, Hui; Golde, Todd E.; Noebels, Jeffrey L.; Jankowsky, Joanna L. (2014)
      Alzheimer's disease (AD) is associated with an elevated risk for seizures that may be fundamentally connected to cognitive dysfunction. Supporting this link, many mouse models for AD exhibit abnormal electroencephalogram ...
    • Geometrical Optics for Quasi-P Waves: Theories and Numerical Methods 

      Qian, Jianliang (2000-04)
      The quasi-P wave in anisotropic solids is of practical importance in obtaining maximal imaging resolution in seismic exploration. The geometrical optics term in the asymptotic expansion for the wave characterizes the high ...