8,146 research outputs found
Study of Tools Interoperability
Interoperability of tools usually refers to a combination of methods and techniques that address the problem of making a collection of tools to work together. In this study we survey different notions that are used in this context: interoperability, interaction and integration. We point out relation between these notions, and how it maps to the interoperability problem.
We narrow the problem area to the tools development in academia. Tools developed in such environment have a small basis for development, documentation and maintenance. We scrutinise some of the problems and potential solutions related with tools interoperability in such environment. Moreover, we look at two tools developed in the Formal Methods and Tools group1, and analyse the use of different integration techniques
Slisp: A Flexible Software Toolkit for Hybrid, Embedded and Distributed Applications
We describe Slisp (pronounced âEss-Lispâ), a hybrid LispâC programming toolkit for the development of scriptable and distributed applications. Computationally expensive operations implemented as separate C-coded modules are selectively compiled into a small Xlisp interpreter, then called as Lisp functions in a Lisp-coded program. The resulting hybrid program may run in several modes: as a stand-alone executable, embedded in a different C program, as a networked server accessed from another Slisp client, or as a
networked server accessed from a C-coded client. Five years of experience with Slisp, as well experience with other scripting languages such as Tcl and Perl, are summarized. These experiences suggest that Slisp will be most useful for mid-sized applications in which the kinds of scripting and embeddability features provided by Tcl and Perl can be extended in an efďŹcient manner to larger applications, while maintaining a
well-deďŹned standard (Common Lisp) for these extensions. In addition, the generality of Lisp makes Lisp a good candidate for an application-level communication language in distributed environments
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
Space Station Freedom data management system growth and evolution report
The Information Sciences Division at the NASA Ames Research Center has completed a 6-month study of portions of the Space Station Freedom Data Management System (DMS). This study looked at the present capabilities and future growth potential of the DMS, and the results are documented in this report. Issues have been raised that were discussed with the appropriate Johnson Space Center (JSC) management and Work Package-2 contractor organizations. Areas requiring additional study have been identified and suggestions for long-term upgrades have been proposed. This activity has allowed the Ames personnel to develop a rapport with the JSC civil service and contractor teams that does permit an independent check and balance technique for the DMS
VXA: A Virtual Architecture for Durable Compressed Archives
Data compression algorithms change frequently, and obsolete decoders do not
always run on new hardware and operating systems, threatening the long-term
usability of content archived using those algorithms. Re-encoding content into
new formats is cumbersome, and highly undesirable when lossy compression is
involved. Processor architectures, in contrast, have remained comparatively
stable over recent decades. VXA, an archival storage system designed around
this observation, archives executable decoders along with the encoded content
it stores. VXA decoders run in a specialized virtual machine that implements an
OS-independent execution environment based on the standard x86 architecture.
The VXA virtual machine strictly limits access to host system services, making
decoders safe to run even if an archive contains malicious code. VXA's adoption
of a "native" processor architecture instead of type-safe language technology
allows reuse of existing "hand-optimized" decoders in C and assembly language,
and permits decoders access to performance-enhancing architecture features such
as vector processing instructions. The performance cost of VXA's virtualization
is typically less than 15% compared with the same decoders running natively.
The storage cost of archived decoders, typically 30-130KB each, can be
amortized across many archived files sharing the same compression method.Comment: 14 pages, 7 figures, 2 table
The F-18 systems research aircraft facility
To help ensure that new aerospace initiatives rapidly transition to competitive U.S. technologies, NASA Dryden Flight Research Facility has dedicated a systems research aircraft facility. The primary goal is to accelerate the transition of new aerospace technologies to commercial, military, and space vehicles. Key technologies include more-electric aircraft concepts, fly-by-light systems, flush airdata systems, and advanced computer architectures. Future aircraft that will benefit are the high-speed civil transport and the National AeroSpace Plane. This paper describes the systems research aircraft flight research vehicle and outlines near-term programs
Telescience Testbed Pilot Program
The Telescience Testbed Pilot Program is developing initial recommendations for requirements and design approaches for the information systems of the Space Station era. During this quarter, drafting of the final reports of the various participants was initiated. Several drafts are included in this report as the University technical reports
NASA's supercomputing experience
A brief overview of NASA's recent experience in supercomputing is presented from two perspectives: early systems development and advanced supercomputing applications. NASA's role in supercomputing systems development is illustrated by discussion of activities carried out by the Numerical Aerodynamical Simulation Program. Current capabilities in advanced technology applications are illustrated with examples in turbulence physics, aerodynamics, aerothermodynamics, chemistry, and structural mechanics. Capabilities in science applications are illustrated by examples in astrophysics and atmospheric modeling. Future directions and NASA's new High Performance Computing Program are briefly discussed
Open Source Software: From Open Science to New Marketing Models
-Open source Software; Intellectual Property; Licensing; Business Model.
- âŚ