It is shown that the four vector extrapolation methods, minimal polynomial extrapolation, reduced rank extrapolation, modified minimal polynomial extrapolation, and topological epsilon algorithm, when applied to linearly generated vector sequences, are Krylov subspace methods, and are equivalent to some well known conjugate gradient type methods. A unified recursive method that includes the con...

1 University of Utah, U.S.A. Abstract The standard velocity projection scheme for the Material Point Method (MPM) and a typical form of the GIMP Method are examined. It is demonstrated that the fidelity of information transfer from a particle representation to the computational grid is strongly dependent on particle density and location. In addition, use of non-uniform grids and even non-unifor...

We describe an algorithm for optimization of a smooth function subject to general linear constraints. An algorithm of the gradient projection class is used, with the important feature that the \projection" at each iteration is performed using a primal-dual interior point method for convex quadratic programming. Convergence properties can be maintained even if the projection is done inexactly in...

In this paper we study proximal conditional-gradient (CG) and proximal gradient-projection type algorithms for a block-structured constrained nonconvex optimization model, which arises naturally from tensor data analysis. First, we introduce a new notion of -stationarity, which is suitable for the structured problem under consideration. We then propose two types of first-order algorithms for th...

The projection method is a widely used fractional-step algorithm for solving the incompressible Navier–Stokes equations. Despite numerous improvements to the methodology, however, imposing physical boundary conditions with projection-based fluid solvers remains difficult, and obtaining high-order accuracy may not be possible for some choices of boundary conditions. In this work, we present an u...

the study describes the synthesis and characterization of zinc(ii) minoxidil nanocomposite (1). the reaction between zinc(ii) acetate, minoxidil, {c9h15n5o=minoxidil=(2,4-diamino-6-piperidine-1-yl) pyrimidine n-oxide)} as a ligand and ki as bridging agent, in methanol at 60°c leads to the formation of nano-sized zn(ii) minoxidil nanocomposite, 1. characterization of (1) was carried out by eleme...

Pressure correction schemes and the method of characteristics are combined to obtain numerical approximation procedures for incompressible Navier-Stokes ows on massive parallel computers. The projection step is carried out with a new more eecient parallel preconditioned conjugate gradient method and for the computation of the characteristics we use a fast local Crank-Nicholson solver for linear...

Many problems in image analysis and computer vision involving boundaries and regions can be cast in a variational formulation. This means that m-surfaces, e.g. curves and surfaces, are determined as minimizers of functionals using e.g. the variational level set method. In this paper we consider such variational problems with constraints given by functionals. We use the geometric interpretation ...

Regularization of ill-posed linear inverse problems via l1 penalization has been proposed for cases where the solution is known to be (almost) sparse. One way to obtain the minimizer of such an l1 penalized functional is via an iterative soft-thresholding algorithm. We propose an alternative implementation to l1-constraints, using a gradient method, with projection on l1-balls. The correspondin...

Non-unitary joint diagonalization of complex symmetric matrices is an important technique in signal processing. The so-called complex oblique projective (COP) manifold has been shown to be an appropriate manifold setting for analyzing the problem and developing geometric algorithms for minimizing the off-norm cost function. However, the recent identification of the COP manifold as a collection ...