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Brown, Robert L.

Publications and source records attributed to Brown, Robert L..

IRAS F15307+3252: A hyperluminous infrared galaxy at z = 0.93

A new hyperluminous infrared galaxy in the Infrared Astronomy Satellite (IRAS) Faint Source Catalog is identified at a redshift of 0.93. This object has a bolometric luminosity of approximately 10(exp 13) solar luminosity, a very large ratio of infrared-to-optical luminosity, warm dust emission, a ratio of infrared-to-radio flux densities consistent with other infrared galaxies, and an optical spectrum similar to a Seyfert 2 galaxy. IRAS F15307+3552 shares these characteristics and its radio-to-optical spectral energy distribution with two other infrared galaxies, F10214+4724 and P09104+4109. Discovery of a third object with these properties defines an extreme subclass of ultraluminous galaxies powered primarily by star formation. The systematic method used to find this object begins the process of determining the space density of these most luminous examples of the infrared galaxy phenomenon.

Cutri, Roc M.

Workshop on NASA workstation technology

RIACS hosted a workshop which was designed to foster communication among those people within NASA working on workstation related technology, to share technology, and to learn about new developments and futures in the larger university and industrial workstation communities. Herein, the workshop is documented along with its conclusions. It was learned that there is both a large amount of commonality of requirements and a wide variation in the modernness of in-use technology among the represented NASA centers.

Brown, Robert L.

An application for multi-person task synchronization

Computer applications are studied that will enable a group of people to synchronize their actions when following a predefined task sequence. It is assumed that the people involved only have computer workstations available to them for communication. Hence, the approach is to study how the computer can be used to help a group remain synchronized. A series of applications were designed and developed that can be used as vehicles for experimentation. An example of how this technique can be used for a remote coaching capability is explained in a report describing an experiment that simulated a Life Sciences experiment on-board Space Station Freedom, with a ground based principal investigator providing the expertise by coaching the on-orbit mission specialist.

Brown, Robert L.

Evaluation of the Dornier Gmbh interactive grid generation system

An interactive grid generation program, INGRID, is investigated and evaluated. A description of the task and work performed, a description and evaluation of INGRID, and a discussion of the possibilities for bringing INGRID into the NASA and Numerical Aerodynamic Simulator (NAS) computing environments is included. The interactive grid generation program was found to be a viable approach for grid generation and determined that it could be converted to work in the NAS environment but that INGRID does not solve the fundamentally hard problems associated with grid generation, specifically, domain decomposition.

Brown, Robert L.

A distributed program composition system

A graphical technique for creating distributed computer programs is investigated and a prototype implementation is described which serves as a testbed for the concepts. The type of programs under examination is restricted to those comprising relatively heavyweight parts that intercommunicate by passing messages of typed objects. Such programs are often presented visually as a directed graph with computer program parts as the nodes and communication channels as the edges. This class of programs, called parts-based programs, is not well supported by existing computer systems; much manual work is required to describe the program to the system, establish the communication paths, accommodate the heterogeneity of data types, and to locate the parts of the program on the various systems involved. The work described solves most of these problems by providing an interface for describing parts-based programs in this class in a way that closely models the way programmers think about them: using sketches of diagraphs. Program parts, the computational modes of the larger program system are categorized in libraries and are accessed with browsers. The process of programming has the programmer draw the program graph interactively. Heterogeneity is automatically accommodated by the insertion of type translators where necessary between the parts. Many decisions are necessary in the creation of a comprehensive tool for interactive creation of programs in this class. Possibilities are explored and the issues behind such decisions are presented. An approach to program composition is described, not a carefully implemented programming environment. However, a prototype implementation is described that can demonstrate the ideas presented.

Brown, Robert L.

Telescience workstation

As part of the Telescience Testbed Pilot Program, the Universities Space Research Association/ Research Institute for Advanced Computer Science (USRA/RIACS) proposed to support remote communication by providing a network of human/machine interfaces, computer resources, and experimental equipment which allows: remote science, collaboration, technical exchange, and multimedia communication. The telescience workstation is intended to provide a local computing environment for telescience. The purpose of the program are as follows: (1) to provide a suitable environment to integrate existing and new software for a telescience workstation; (2) to provide a suitable environment to develop new software in support of telescience activities; (3) to provide an interoperable environment so that a wide variety of workstations may be used in the telescience program; (4) to provide a supportive infrastructure and a common software base; and (5) to advance, apply, and evaluate the telescience technolgy base. A prototype telescience computing environment designed to bring practicing scientists in domains other than their computer science into a modern style of doing their computing was created and deployed. This environment, the Telescience Windowing Environment, Phase 1 (TeleWEn-1), met some, but not all of the goals stated above. The TeleWEn-1 provided a window-based workstation environment and a set of tools for text editing, document preparation, electronic mail, multimedia mail, raster manipulation, and system management.

Brown, Robert L.

Two demonstrators and a simulator for a sparse, distributed memory

Described are two programs demonstrating different aspects of Kanerva's Sparse, Distributed Memory (SDM). These programs run on Sun 3 workstations, one using color, and have straightforward graphically oriented user interfaces and graphical output. Presented are descriptions of the programs, how to use them, and what they show. Additionally, this paper describes the software simulator behind each program.

Brown, Robert L.

On evaluating parallel computer systems

A workshop was held in an attempt to program real problems on the MIT Static Data Flow Machine. Most of the architecture of the machine was specified but some parts were incomplete. The main purpose for the workshop was to explore principles for the evaluation of computer systems employing new architectures. Principles explored were: (1) evaluation must be an integral, ongoing part of a project to develop a computer of radically new architecture; (2) the evaluation should seek to measure the usability of the system as well as its performance; (3) users from the application domains must be an integral part of the evaluation process; and (4) evaluation results should be fed back into the design process. It is concluded that the general organizational principles are achievable in practice from this workshop.

Adams, George B., III