NASA Scientific and Technical Aerospace Reports

to reveal faults within itself during testing is found in [Voas91b]. A piece of software that is likely to reveal faults within itself
during testing is said to have high testability. A piece of software that is not likely to reveal faults within itself during testing
is said to have low testability. It is preferable to design software with higher testabilities from the outset, i.e., create software
with as high of a degree of testability as possible to avoid the problems of having undetected faults that are associated with
low testability. Information loss is a phenomenon that occurs during program execution that increases the likelihood that a
fault will remain undetected. In this paper, I identify two brad classes of information loss, define them, and suggest ways of
predicting the potential for information loss to occur. We do this in order to decrease the likelihood that faults will remain
undetected during testing.
Author
Software Engineering; Fault Tolerance; Performance Tests; Computer Systems Programs
20040121089 NASA Langley Research Center, Hampton, VA, USA
High Level Design Proof of a Reliable Computing Platform
DiVito, Ben L.; Butler, Ricky W.; Caldwell, James L.; [1991]; 13 pp.; In English; Second International Working Conference
on Dependable Computing for Critical Applications, 18-20 Feb. 1991, Tucson, AZ, USA; Original contains black and white
illustrations; Copyright; Avail: CASI; A03, Hardcopy
An architecture for fault-tolerant computing is formalized and shown to satisfy a key correctness property. The reliable
computing platform uses replicated processors and majority voting to achieve fault tolerance. Under the assumption of a
majority of processors working in each frame, we show that the replicated system computes the same results as a single
processor system not subject to failures. Sufficient conditions are obtained to establish that the replicated system recovers from
transient faults within a bounded amount of time. Three different voting schemes are examined and proved to satisfy the
bounded recovery time conditions.
Author
Fault Tolerance; Reliability Analysis; Architecture (Computers); Mathematical Models; Program Verification (Computers)
20040121114 Bethune-Cookman Coll., Daytona Beach, FL, USA
Web Audio/Video Streaming Tool
Guruvadoo, Eranna K.; 2003 Research Reports: NASA/ASEE Fellowship Program; December 15, 2003, pp. L-1 - L-7; In
English; See also 20040121096; No Copyright; Avail: CASI; A02, Hardcopy
In order to promote NASA-wide educational outreach program to educate and inform the public of space exploration,
NASA, at Kennedy Space Center, is seeking efficient ways to add more contents to the web by streaming audio/video files.
This project proposes a high level overview of a framework for the creation, management, and scheduling of audio/video
assets over the web. To support short-term goals, the prototype of a web-based tool is designed and demonstrated to automate
the process of streaming audio/video files. The tool provides web-enabled users interfaces to manage video assets, create
publishable schedules of video assets for streaming, and schedule the streaming events. These operations are performed on
user-defined and system-derived metadata of audio/video assets stored in a relational database while the assets reside on
separate repository. The prototype tool is designed using ColdFusion 5.0.
Author
Audio Data; Video Data; Relational Data Bases
62
COMPUTER SYSTEMS
Includes computer networks and distributed processing systems. For information systems see 82 Documentation and Information
Science. For computer systems applied to specific applications, see the associated category.
20040111457 Washington Univ., Seattle, WA
Enforceable Network Protocols
Anderson, Tom E.; Wetherall, David J.; Jun. 2004; 17 pp.; In English; Original contains color illustrations
Contract(s)/Grant(s): F30602-00-2-0565; DARPA ORDER-K294; Proj-K294
Report No.(s): AD-A425347; AFRL-IF-RS-TR-2004-184; No Copyright; Avail: CASI; A03, Hardcopy
We propose to dramatically improve the reliability, fault tolerance, and survivability of wide area networks by
systematically rethinking network design using the principle that the operation of network protocols should be enforceable -
the correct operation of a protocol should not depend on trust. We propose to rethink four areas of network protocol design:
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