reservoir models are initially generated from estimates of specific rock properties and maps of reservoir heterogeneity. many types of information are used in reservoir model construction. one of the most important sources of information comes from wells, including well logs and core samples. unfortunately well log and core data are local measurements that may not reflect the reservoir behavior...

This paper proves the invariance of the second-order modes of continuous-time systems under general frequency transformation, that is, under reactance function. The invariance is proved by obtaining the state-space representation of the transformed system, and its controllability / observability grammians in terms of those of the original system and the reactance system. This invariance propert...

This paper discusses the invariance of the second-order modes of 2-D separable denominator digital filters under frequency transformation. This paper first derives a state-space description for 2-D digital filters obtained by 2-D frequency transformation and then represents the controllability Gramians and the observability Gramians of the transformed 2-D digital filters. This description prove...

This paper discusses a new approach for implementing flexible frequencyband reallocation (FFBR) networks for bentpipe satellite payloads which are based on variable oversampled complex-modulated filter banks (FBs). We consider two alternatives to process real signals using real input/output and complex input/output FFBR networks (or simply real and complex FFBR networks, respectively). It is sh...

This paper presents a hybrid method for creating three-dimensional shapes by sketching silhouette curves. Given a silhouette curve, we approximate its medial axis as a set of line segments, and convolve a linearly weighted kernel along each segment. By summing the fields of all segments, an analytical convolution surface is obtained. The resulting generic shape has circular cross-section, but c...

This paper discusses the behavior of the second-order modes (Hankel singular values) of linear continuous-time systems under typical frequency transformations, such as lowpass-lowpass, lowpasshighpass, lowpass-bandpass, and lowpass-bandstop transformations. Our main result establishes the fact that the second-order modes are invariant under any of these typical frequency transformations. This m...

Instance-based learning methods like the nearest neighbour classiÿer generally suuer from the indiscriminate storage of all training instances, resulting in large memory requirements and slow execution speed. In this paper, new training set size reduction methods based on prototype generation and space partitioning are proposed. Experimental results show that the new algorithms achieve a very h...

The Sombrero distributed single address space operating system prototype is currently being implemented. The prototype includes an emulation of CPU-resident protection hardware necessary to fully utilize the properties of a single address space. The primary objective of the Sombrero project is to demonstrate that software development costs are sharply reduced in a single address space environme...