Functional requirements document for the Earth Observing System Data and Information System (EOSDIS) Scientific Computing Facilities (SCF) of the NASA/MSFC Earth Science and Applications Division, 1992

Five scientists at MSFC/ESAD have EOS SCF investigator status. Each SCF has unique tasks which require the establishment of a computing facility dedicated to accomplishing those tasks. A SCF Working Group was established at ESAD with the charter of defining the computing requirements of the individual SCFs and recommending options for meeting these requirements. The primary goal of the working group was to determine which computing needs can be satisfied using either shared resources or separate but compatible resources, and which needs require unique individual resources. The requirements investigated included CPU-intensive vector and scalar processing, visualization, data storage, connectivity, and I/O peripherals. A review of computer industry directions and a market survey of computing hardware provided information regarding important industry standards and candidate computing platforms. It was determined that the total SCF computing requirements might be most effectively met using a hierarchy consisting of shared and individual resources. This hierarchy is composed of five major system types: (1) a supercomputer class vector processor; (2) a high-end scalar multiprocessor workstation; (3) a file server; (4) a few medium- to high-end visualization workstations; and (5) several low- to medium-range personal graphics workstations. Specific recommendations for meeting the needs of each of these types are presented

Overview of database projects

The use of entity and object oriented data modeling techniques for managing Computer Aided Design (CAD) is explored

Physiological system modelling

Computer graphics has a major impact in our day-to-day life. It is used in diverse areas such as displaying the results of engineering and scientific computations and visualization, producing television commercials and feature films, simulation and analysis of real world problems, computer aided design, graphical user interfaces that increases the communication bandwidth between humans and machines, etc Scientific visualization is a well-established method for analysis of data, originating from scientific computations, simulations or measurements. The development and implementation of the 3Dgen software was developed by the author using OpenGL and C language was presented in this report 3Dgen was used to visualize threedimensional cylindrical models such as pipes and also for limited usage in virtual endoscopy. Using the developed software a model was created using the centreline data input by the user or from the output of some other program, stored in a normal text file. The model was constructed by drawing surface polygons between two adjacent centreline points. The software allows the user to view the internal and external surfaces of the model. The software was designed in such a way that it runs in more than one operating systems with minimal installation procedures Since the size of the software is very small it can be stored in a 1 44 Megabyte floppy diskette. Depending on the processing speed of the PC the software can generate models of any length and size Compared to other packages, 3Dgen has minimal input procedures was able to generate models with smooth bends. It has both modelling and virtual exploration features. For models with sharp bends the software generates an overshoot

Geometric abstractions for conceptual design support

Thesis (Ocean. E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1994, and Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1994.Includes bibliographical references (leaves 151-154).by Georgios A. Margelis.M.S.Ocean.E

Concurrent Probabilistic Simulation of High Temperature Composite Structural Response

A computational structural/material analysis and design tool which would meet industry's future demand for expedience and reduced cost is presented. This unique software 'GENOA' is dedicated to parallel and high speed analysis to perform probabilistic evaluation of high temperature composite response of aerospace systems. The development is based on detailed integration and modification of diverse fields of specialized analysis techniques and mathematical models to combine their latest innovative capabilities into a commercially viable software package. The technique is specifically designed to exploit the availability of processors to perform computationally intense probabilistic analysis assessing uncertainties in structural reliability analysis and composite micromechanics. The primary objectives which were achieved in performing the development were: (1) Utilization of the power of parallel processing and static/dynamic load balancing optimization to make the complex simulation of structure, material and processing of high temperature composite affordable; (2) Computational integration and synchronization of probabilistic mathematics, structural/material mechanics and parallel computing; (3) Implementation of an innovative multi-level domain decomposition technique to identify the inherent parallelism, and increasing convergence rates through high- and low-level processor assignment; (4) Creating the framework for Portable Paralleled architecture for the machine independent Multi Instruction Multi Data, (MIMD), Single Instruction Multi Data (SIMD), hybrid and distributed workstation type of computers; and (5) Market evaluation. The results of Phase-2 effort provides a good basis for continuation and warrants Phase-3 government, and industry partnership

Interactive Graphics-Based Musculotendon Modeling for Reconstructive Surgery of the Hand.

This research has been directed at studying and developing a prototype research and clinical Computer Aided Design (CAD) tool to be used for planning tendon paths in hand reconstructive surgery. Of equal importance is the goal of having an educational tool for teaching hand biomechanics to students of this specialty. The application of CAD to rehabilitative surgery of the hand is a new field of endeavor. There are currently no existing commercial products designed to assist the orthopedic surgeon in planning these complex procedures. Additionally, orthopedic surgeons are not trained in mechanics, kinematics, math modeling, or the use of computers. It was also our intent to study the mechanisms and the efficacy of the application of CAD techniques to tendon transfer surgery. Through this research the following advances have been made: (1) creation of interactive 3D tendon path definition tools. (2) creation of software to calculate tendon excursion from an arbitrary tendon path crossing any number of joints. (3) creation of a model to interactively compute and display the forces in muscle and tendon. (4) creation of an environment to help surgeons evaluate the consequences of a simulated tendon transfer operation when a tendon is lengthened, rerouted, or reattached in a new location. It also has been one of the primary concerns in this research that an interactive graphical surgical workstation must present a natural, user-friendly environment to the orthopedic surgeon user. Additionally, this workstation must ultimately aid the surgeon in helping his patient or in doing his work more efficiently or more reliably. This work therefore includes a study of the usefulness of such a workstation as perceived by the orthopedic surgery community

A Survey of Driving Research Simulators Around the World.

The literature review is part of the EPSRC funded project "Driver performance in the EPSRC driving simulator: a validation study". The aim of the project is to validate this simulator, located at the Department of Psychology, University of Leeds, and thereby to indicate the strengths and weaknesses of the existing configuration. It will provide guidance on how the simulator can be modified and overcome any deficiencies that are detected and also provide "benchmarks" against which other simulators can be compared. The literature review will describe the technical characteristics of the most well-known driving simulators around the world, their special features and their application areas until today. The simulators will be described and compared according to their cost (low, medium and high) and also contact addresses and photographs of the simulators will be provided by the end of the paper. In the process of gathering this information, it became apparent that there are mainly two types of papers published - either in journals or in proceedings from conferences: those describing only the technical characteristics of a specific simulator and those referring only to the applications of a specific simulator. For the first type of papers, the level of detail, format and content varies significantly where for the second one it has been proven extremely difficult to find any information about the technical characteristics of the simulator where the study had been carried out. A number of details provided in this paper are part of personal communication, or personal visits to those particular driving simulator centres or from the World Wide Web. It should also be noted here that most of the researchers contacted here offered very detail technical characteristics and application areas of their driving simulators and the author is grateful to them

Research into software executives for space operations support

Research concepts pertaining to a software (workstation) executive which will support a distributed processing command and control system characterized by high-performance graphics workstations used as computing nodes are presented. Although a workstation-based distributed processing environment offers many advantages, it also introduces a number of new concerns. In order to solve these problems, allow the environment to function as an integrated system, and present a functional development environment to application programmers, it is necessary to develop an additional layer of software. This 'executive' software integrates the system, provides real-time capabilities, and provides the tools necessary to support the application requirements

Graphics Technology in Space Applications (GTSA 1989)

This document represents the proceedings of the Graphics Technology in Space Applications, which was held at NASA Lyndon B. Johnson Space Center on April 12 to 14, 1989 in Houston, Texas. The papers included in these proceedings were published in general as received from the authors with minimum modifications and editing. Information contained in the individual papers is not to be construed as being officially endorsed by NASA

Integración de las funciones de programación de máquinas herramientas de control numérico mediante una aplicación orientada a objetos

Dentro de un entorno integrado de fabricación asistida por computador, el intercambio de información de fabricación entre los distintos sistemas CAX y los sistemas CNC presenta una serie de aspectos problemáticos: 1. En su gran mayoría, los sistemas CAX actuales no han sido diseñados para compartir información, por lo que disponen de una estructura de datos específica y cerrada. 2. Los distintos tipos de sistemas CAX operan sobre niveles de abstracción de información de producto y procesos distintos. 3. El intercambio de información de fabricación se realiza a nivel de trayectoria, y principalmente en código ISO. 4. Adicionalmente a las palabras APT, existe un grupo de palabras de postprocesador normalizadas que permiten traducir ciertas operaciones de mecanizado (operaciones de taladrado) a código ISO. Sin embargo, la implementación de estas palabras de postprocesador depende de cada sistema CAM, y adicionalmente, los patrones geométricos de localización y las operaciones de fresado no son soportadas. 5. Existe una carencia en la estandarización de las operaciones básicas de mecanizado. Dicha estandarización debería permitir el desarrollo de un protocolo para el intercambio de información a nivel de operaciones. Este protocolo sería la base para el intercambio de información de operaciones entre distintos sistemas CAM, y entre sistemas CAM y sistemas CNC, conduciendo a una mejora en la programación automática de las MHCN. Con objeto de mejorar estos aspectos problemáticos, en la Tesis se ha desarrollado un modelo de información a nivel de operaciones para procesos de taladrado y fresado. En el desarrollo de dicho modelo se ha adoptado la norma para representación e intercambio de información de producto ISO 10303-STEP. El modelo de información define una estructura de datos que se emplea posteriormente en el desarrollo de una aplicación orientada a objetos para la programación automática de MHCN a nivel de operaciones en formato STEP. La aplicación tiene como entrada información geométrica (vía ficheros STEP) e información tecnológica de los procesos (vía ficheros de procesos ASCII). La generación de estos ficheros se realiza en un sistema CAD/CAM comercial. XVII In the computer aided manufacturing integrated environment, some problematic issues arise in tiie exchange of manufacturing information between the different CAD/CAM systems and the CNC systems: 1. Currently, most of the CAX systems have not been developed to share information, due to that, these systems have a proprietary and specific data structure. 2. The current CAX systems operate on different levels of abstraction of the product and processes information. 3. The manufacturing information exchange is carried out at the toolpath level, and mainly in the ISO code. 4. In addition to the APT words, there is a group of standardized postprocessor words which allow to translate some machining operations (drilling ones) into ISO code. However, the implementation of these postprocessor words depends on each CAM system, and besides that the milling operations and the machining location patterns are not completely supported. 5. There is a lack in the standardization of the basic machining operations. Such standardization should allow to define a consistent protocol for the exchange of information at the machining operation level. This protocol should allow to exchange and share manufacturing processes information between dissimilar CAM systems, and between CAM systems and CNC systems as well. This way should led to an improvement in the CNC machine tool automatic programming. In order to improve these problematic issues, an information model on the operation level for drilling and milling processes has been developed in the Thesis. The standard ISO 10303-STEP for representation and exchange of product information has been adopted in the model development. This information model defines a data structure which is the basis for the later development of an object-oriented STEP based application. This prototype application can be used for the automatic programming of CNC machine tools in the operation level. The inputs to the application are STEP geometry files for the geometric information, and ASCII process files for the process technological information. These files are generated in a commercial CAD/CAM system