Product-line engineering can result in cost savings and increases in productivity. In addition, in safetycritical systems, the approach has the potential for reuse of analysis and testing results which can lead to a safer system. Nevertheless, there are times when it seems like a product family approach should work when, in fact, there are difficulties in properly defining the boundaries of the...

For hierarchical matrices, approximations of the matrix-matrix sum and product can be computed in almost linear complexity, and using these matrix operations it is possible to construct the matrix inverse, efficient precondi-tioners based on approximate factorizations or solutions of certain matrix equations. H 2-matrices are a variant of hierarchical matrices which allow us to perform certain ...

We prove that the dimension of trivariate tensor-product spline space of tri-degree (m,m,m) with maximal order of smoothness over a threedimensional domain coincides with the number of tensor-product B-spline basis functions acting effectively on the domain considered. A domain is required to belong to a certain class. This enables us to show that, for a certain assumption about the configurati...

Selecting the most suitable alternative under uncertainty is considered as a critical decision-making problem that affects the success of organizations. In the selection process, there are a number of assessment criteria, considered by a group of decision makers, which often could be established in a multi-level hierarchy structure. The aim of this paper is to introduce a new hierarchical multi...

In this paper we describe our hierarchical higher order radiosity implementation, called HIRAD. We present a number of improvements to the original wavelet radiosity method: We propose new basis functions for (convex) quadrilaterals and for triangles offering finer granularity than the usual product-1D bases, a new refinement criterion for hierarchical refinement and a very general strategy for...