In this paper we investigate some well established and more recent methods that aim at approximating the vector exp(A)v when A is a large symmetric negative semidefinite matrix, by efficiently combining subspace projections and spectral transformations. We show that some recently developed acceleration procedures may be restated as preconditioning techniques for the partial fraction expansion f...

Web clients in the developing world experience long response times due to poor network connectivity. This paper evaluates existing and new web acceleration techniques using access traces from Iraq, Zambia, and Cambodia. We validate the effectiveness of proxy caching and observe around 40% cache hit ratio. But our evaluation finds limited benefit of web prefetching (<1% hit rate by the history-b...

In this paper, we investigate the feasibility of using accelerating simulation techniques in mobile ad hoc networks. We propose two approaches both of which use a hybrid simulation technique to gain acceleration for simulation by taking advantage of their particular characteristics.

We present an approach for the acceleration of the restarted Arnoldi iteration for the computation of a number of eigenvalues of the standard eigenproblem Ax = λx. This study applies the Chebyshev polynomial to the restarted Arnoldi iteration and proves that it computes necessary eigenvalues with far less complexity than the QR method. We also discuss the dependence of the convergence rate of t...

position-command-following problem for asymptotically stable inear systems is considered. To account for modeling limitations, e assume that a model is not available. Instead, acceleration ata are used to construct a compliance (position-output) model, hich is subsequently used to design a position servo loop. Furhermore, we assume that the acceleration measurements obtained rom inertial sensor...

There is a small but vigorous community working on advanced accelerator concepts in the United States. This effort, principally supported by the DOE, is deemed important for the long term vitality of High Energy Physics (HEP). In addition, the program contributes essential technology and accelerator science to the benefit of all fields using accelerators in their research. Although the research...

Mutual information based nonrigid registration of medical images is a popular approach. The coordinate mapping that relates the two images is found in an iterative optimisation procedure. In every iteration a computationally expensive evaluation of the mutual information’s derivative is required. In this work two acceleration strategies are compared. The first technique aims at reducing the num...

We will present a model for the strategic design of the global supply chain of an individual company. The model presented is a multi-period, two-stage stochastic, multi-country, multi-product, multi-echelon formulation based on forecasted exchange rates and with bill of materials (BOM) flow conservation. The objective is maximization of the expected value of the time-discounted world-wide after...

The computation of a few eigenvalues and the corresponding eigenvectors of large complex non hermitian matrices arises in many applications in science and engineering such as magnetohydrodynamic or electromagnetism [6], where the eigenvalues of interest often belong to some region of the complex plane. If the size of the matrices is relatively small, then the problem can be solved by the standa...