A Compiler and Runtime Infrastructure for Automatic Program Distribution

This paper presents the design and the implementation of a compiler and runtime infrastructure for automatic program distribution. We are building a research infrastructure that enables experimentation with various program partitioning and mapping strategies and the study of automatic distribution's effect on resource consumption (e.g., CPU, memory, communication). Since many optimization techniques are faced with conflicting optimization targets (e.g., memory and communication), we believe that it is important to be able to study their interaction. We present a set of techniques that enable flexible resource modeling and program distribution. These are: dependence analysis, weighted graph partitioning, code and communication generation, and profiling. We have developed these ideas in the context of the Java language. We present in detail the design and implementation of each of the techniques as part of our compiler and runtime infrastructure. Then, we evaluate our design and present preliminary experimental data for each component, as well as for the entire system

A high-speed digital signal processor for atmospheric radar, part 7.3A

The Model SP-320 device is a monolithic realization of a complex general purpose signal processor, incorporating such features as a 32-bit ALU, a 16-bit x 16-bit combinatorial multiplier, and a 16-bit barrel shifter. The SP-320 is designed to operate as a slave processor to a host general purpose computer in applications such as coherent integration of a radar return signal in multiple ranges, or dedicated FFT processing. Presently available is an I/O module conforming to the Intel Multichannel interface standard; other I/O modules will be designed to meet specific user requirements. The main processor board includes input and output FIFO (First In First Out) memories, both with depths of 4096 W, to permit asynchronous operation between the source of data and the host computer. This design permits burst data rates in excess of 5 MW/s

Techniques for the study of gravity waves and turbulence (keynote paper), part 4

Probably one of the most important achievements mesosphere stratosphere troposphere (MST) radars can make toward increasing the understanding of the dynamics of the atmosphere is to determine the exact relationship between the generation of turbulence and the sources of high shear or convectively unstable flows. An important theoretical tool, the gravity-wave breaking through which one can begin to understand spontaneous generation of turbulence model is discussed. In this model, large amplitude gravity waves produce local regions where the Richardson number (N sup 2/U sub Z sup 2) is less than 1/4 thus giving rise to turbulent flows. Thus the appearance of turbulent layers can often be interpreted as a breaking-gravity-wave signature. Even though the techniques for studying gravity waves and turbulence may be quite different (and historically have resulted in somewhat separate bodies of literature), it is clear from the wave-breaking model that the phenomena are intimately linked. The techniques for measurements of gravity wave flow fields and turbulent regions by MST radar should show cognizance of some of the theoretical questions raised by the wave-breaking model

A modification to BURS in codegeneration

In this report a modification to a BURS algorithm is presented. With this modification we have a nearly linear run-time instead of a the exponentiell run-time

The design of a digital voice data compression technique for orbiter voice channels

Voice bandwidth compression techniques were investigated to anticipate link margin difficulties in the shuttle S-band communication system. It was felt that by reducing the data rate on each voice channel from the baseline 24 (or 32) Kbps to 8 Kbps, additional margin could be obtained. The feasibility of such an alternate voice transmission system was studied. Several factors of prime importance that were addressed are: (1) achieving high quality voice at 8 Kbps; (2) performance in the presence of the anticipated shuttle cabin environmental noise; (3) performance in the presence of the anticipated channel error statistics; and (4) minimal increase in size, weight, and power over the current baseline voice processor