We present a new partitioning algorithm for grids obtained by adaptive reenement. The method uses the adaptive reenement tree to obtain information unavailable to other partitioning methods which use only the nal grid and/or some geometric data. The algorithm requires (typically) O(log(N)) operations after an O(N) preprocessing step. The method is guaranteed to produce perfectly balanced connec...

This paper presents a study of image simplification techniques as a first stage to define a multiresolution registration framework. We propose here a new approach for image registration based on the partitioning of the source images in binary-space (BSP) and quad-tree structures. These partitioned images have been obtained with a maximum mutual information gain algorithm. Multimodal registratio...

Let an edge cut partition the vertex set of an n-dimensional quadratic grid with the side length a into k subsets A1, ..., Ak with ||Ai| − |Aj || ≤ 1. We consider the problem of determining the minimal size c(n, k, a) of such a cut and present its asymptotic c(n, k, a) ∼ nan−1 n √ k as a, k →∞ and k/an → 0. The same asymptotic holds for partitioning of the n-dimensional torus. We present also s...

We present a new approach for the parallel adaption of multigrids on distributed memory architectures. It is based on a simple, object-oriented data structure employing arrays rather than the more customary linked lists. The particular problem of dynamic load balancing is solved using an innovative recursive partitioning strategy. Large-scale computations on a Cray T3E system using up to 512 pr...

We propose an efficient, accurate method to integrate the basins of attraction of a smooth function defined on a general discrete grid and apply it to the Bader charge partitioning for the electron charge density. Starting with the evolution of trajectories in space following the gradient of charge density, we derive an expression for the fraction of space neighboring each grid point that flows...

Partitioning a graph into three pieces, with two of them large and connected, and the third a small “separator” set, is useful for improving the performance of a number of combinatorial algorithms. This is done using the second eigenvector of a matrix defined solely in terms of the incidence matrix, called the graph Laplacian. For sparse graphs, the eigenvector can be efficiently computed using...

The desirable global scalability of Grid systems has steered the research towards the employment of the peer-to-peer (P2P) paradigm for the development of new resource discovery systems. As Grid systems mature, the requirements for such a mechanism have grown from simply locating the desired service to compose more than one service to achieve a goal. In Semantic Grid, resource discovery systems...

The desirable global scalability of Grid systems has steered the research towards the employment of the peer-to-peer (P2P) paradigm for the development of new resource discovery systems. As Grid systems mature, the requirements for such a mechanism have grown from simply locating the desired service to compose more than one service to achieve a goal. In Semantic Grid, resource discovery systems...

In this paper, we propose a new multidimensional access method, called the buddy-tree, to support point as well as spatial data in a dynamic environment. The buddy-tree can be seen as a compromise of the R-tree and the grid file, but it is fundamentally different from each of them. Because grid files loose performance for highly correlated data, the buddy-tree is designed to organize such data ...

We classify clustering algorithms into sequence-based tech-niques|which transform the object net into a linear sequence|and partition-based clustering algorithms. Tsangaris and Naughton TN91, TN92] have shown that the partition-based techniques are superior. However , their work is based on a single partitioning algorithm, the Kernig-han and Lin heuristics, which is not applicable to realistica...