Sliding-window based search is a widely used technique for object localization. However, for objects of non-rectangle shapes, noises in windows may mislead the localization, causing unsatisfactory results. In this paper, we propose an efficient bottom-up approach for detecting arbitrary-shape objects using image grids as basic components. First, a test image is partitioned into n × n grids and ...

Special purpose high performance computers are expensive and rare, but workstation clusters are cheap and becoming common. Emerging technology offers the opportunity to integrate clusters into a single high performance computer a computational Grid. The acceptance of computational Grids, however, is seriously hampered by the difficulty of efficiently managing the parallelism in such heterogeneo...

We explain a general concept for the implementation of adaptive multigrid methods for conforming, nonconforming and mixed finite elements on locally refined grids. AMS Subject Classification: 65N30

In the present study we propose an adaptive mesh refinement (AMR) strategy which can be coupled with embedded boundary methods in a straightforward manner. The building-block of the AMR solver is a structured Cartesian solver employed on a hierarchy of sub-grids. A fractional-step formulation is used for the time advancement, and all spatial derivatives are discretized on a staggered grid using...

In this paper, dynamic p-adaptive Runge–Kutta discontinuous Galerkin (RKDG) methods for the twodimensional shallow water equations (SWE) are investigated. The p-adaptive algorithm that is implemented dynamically adjusts the order of the elements of an unstructured triangular grid based on a simple measure of the local flow properties of the numerical solution. Time discretization is accomplishe...

Abstract We describe an adaptive hp-refinement local finite element procedure for the parallel solution of hyperbolic systems of conservation laws on rectangular domains. The local finite element procedure utilizes spaces of piecewise-continuous polynomials of arbitrary degree and coordinated explicit Runge-Kutta temporal integration. A solution limiting procedure produces monotonic solutions n...

Acut-cell approach to computational fluid dynamics that uses themedian dual of a tetrahedral background grid is described. The discrete adjoint is also calculated for an adaptive method to control error in a specified output. The adaptive method is applied to sonic boom prediction by specifying an integral of offbody pressure signature as the output. These predicted signatures are compared to w...