Two independent high-resolution moisture-sensing techniques, x-ray absorption and light transmission, have been developed for use in two-dimensional, thin-slab experimental systems. The techniques yield full-field measurement capabilities with exceptional resolution of moisture content in time and space. These techniques represent powerful tools for the experimentalist to investigate processes governing unsaturated flow and transport through fractured and nonfractured porous media. Evaluation of these techniques has been accomplished by direct comparison of data obtained by means of the x-ray and light techniques as well as comparison with data collected by gravimetric and gamma-ray densitometry techniques. Results show excellent agreement between data collected by the four moisture-content measurement techniques. This program was established to support the Yucca Mountain Site Characterization Project.

I describe an automated approach to partial evaluation based on simplification and implemented by program transformations. The approach emphasizes program algebra and relies on canonical forms and distributive laws to expose instances to which simplifications can be applied. I discuss some of the considerations that led to the design of this approach. This design discussion should be useful both in understanding the structure of the partial evaluation transformations, and as an example of how to approach the design of automated program transformations in general. This approach to partial evaluation has been applied to a number of practical examples of moderate complexity, including: the running example used in this paper, proving an identity for lists, and eliminating a virtual data structure from a specification of practical interest. The chief practical barrier to its wider application is the growth of the intermediate program text during partial evaluation. Despite this limitation, this approach has the virtues of being implemented, automated, and able to partially evaluate specifications containing implicit data, including some specifications of practical interest.

We have modeled gyrotron windows and gyrotron amplifier sever structures for TE modes in the 100--150 GHz range and have computed the reflection and transmission characteristics from the field data. Good agreement with frequency domain codes and analytic analysis have been obtained for some simple geometries. We present results for realistic structures with lossy coatings and describe implementation of microwave diagnostics.

This paper presents a graphics renderer which incorporates new partitioning methodologies of memory and work for efficient execution on a parallel computer. The Task Adaptive domain decomposition scheme is an image space method involving dynamic partitioning of rectangular pixel area tasks. The author shows that this method requires little overhead, allows coherence within a parallel context, handles worst case scenarios effectively, and executes efficiently with little processor synchronization necessary. Previous research in the area of memory and work decompositions for graphics rendering has been primarily limited to simulation studies and little practical experience. The algorithm presented here has been implemented on a scalable distributed memory multiprocessor and tested on a variety of input scenes. The author presents a theoretical and practical analysis in order to contrast its predicted and actual success. The implementation analysis indicates that load imbalance is the major cause of performance degradation at the higher processor counts. Even so, on a variety of test scenes, an average rendering speedup of 79 was achieved utilizing 96 processors on the BBN TC2000 multiprocessor with a processor efficiency range of 66% to 94%.

I describe an automated approach to partial evaluation based on simplification and implemented by program transformations. The approach emphasizes program algebra and relies on canonical forms and distributive laws to expose instances to which simplifications can be applied. I discuss some of the considerations that led to the design of this approach. This design discussion should be useful both in understanding the structure of the partial evaluation transformations, and as an example of how to approach the design of automated program transformations in general. This approach to partial evaluation has been applied to a number of practical examples of moderate complexity, including: the running example used in this paper, proving an identity for lists, and eliminating a virtual data structure from a specification of practical interest. The chief practical barrier to its wider application is the growth of the intermediate program text during partial evaluation. Despite this limitation, this approach has the virtues of being implemented, automated, and able to partially evaluate specifications containing implicit data, including some specifications of practical interest.