NASA Scientific and Technical Aerospace Reports

of rigorous formal mathematical validation procedures. However, formal specification and verification will only be tractable
if the system is designed in a manner that lends itself to formal methods. Likewise, accurate reliability analysis will only be
tractable if the number of interacting components that must be individually included in a single reliability model is kept to
a low number and if their failure behavior interactions can be modeled simply. Also, the system must be designed such that
the system reliability does not directly depend on system parameters that cannot be accurately determined. This paper presents
a design methodology based on the concept of designing a system in such a manner that it can be rigorously validated, or
‘design for validation."
Author
Program Verification (Computers); Reliability Analysis; Civil Aviation
20040121003 NASA Marshall Space Flight Center, Huntsville, AL, USA
Generalized Fluid System Simulation Program
Majumdar, Alok Kumar, Inventor; Bailey, John W., Inventor; Schallhorn, Paul Alan, Inventor; Steadman, Todd E., Inventor;
June 08, 2004; 35 pp.; In English; Original contains black and white illustrations
Patent Info.: Filed 7 May 1999; US-Patent-6,748,349; US-Patent-Appl-SN-313576; NASA-Case-MFS-31303-1; No
Copyright; Avail: CASI; A03, Hardcopy
A general purpose program implemented on a computer analyzes steady state and transient flow in a complex fluid
network, modeling phase changes, compressibility, mixture thermodynamics and external body forces such as gravity and
centrifugal force. A preprocessor provides for the inter- active development of a fluid network simulation having nodes and
branches. Mass, energy, and specie conservation equations are solved at the nodes, and momentum conservation equations are
solved in the branches. Contained herein are subroutines for computing ‘real fluid’ thermodynamic and thermophysical
properties for 12 fluids, and a number of different source options are provided for model- ing momentum sources or sinks in
the branches. The system of equations describing the fluid network is solved by a hybrid numerical method that is a
combination of the Newton-Raphson and successive substitution methods. Application and verification of this invention are
provided through an example problem, which demonstrates that the predictions of the present invention compare most
reasonably with test data.
Author
Computer Programs; Fluid Flow; Computerized Simulation; Gravitation; Centrifugal Force; Thermodynamic Properties
20040121024 NASA Goddard Space Flight Center, Greenbelt, MD, USA, Halcyon Systems, Inc., San Francisco, CA, USA
Data Management as a Cluster Middleware Centerpiece
Zero, Jose; McNab, David; Sawyer, William; Cheung, Samson; Duffy, Daniel; Rood, Richard; Webster, Phil; Palm, Nancy;
Salmon, Ellen; Schardt, Tom; NASA/IEEE MSST 2004 Twelfth NASA Goddard Conference on Mass Storage Systems and
Technologies in cooperation with the Twenty-First IEEE Conference on Mass Storage Systems and Technologies; April 2004,
pp. 93-103; In English; See also 20040121020; No Copyright; Avail: CASI; A03, Hardcopy
Through earth and space modeling and the ongoing launches of satellites to gather data, NASA has become one of the
largest producers of data in the world. These large data sets necessitated the creation of a Data Management System (DMS)
to assist both the users and the administrators of the data. Halcyon Systems Inc. was contracted by the NASA Center for
Computational Sciences (NCCS) to produce a Data Management System. The prototype of the DMS was produced by
Halcyon Systems Inc. (Halcyon) for the Global Modeling and Assimilation Office (GMAO). The system, which was
implemented and deployed within a relatively short period of time, has proven to be highly reliable and deployable. Following
the prototype deployment, Halcyon was contacted by the NCCS to produce a production DMS version for their user
community. The system is composed of several existing open source or government-sponsored components such as the San
Diego Supercomputer Center s (SDSC) Storage Resource Broker (SRB), the Distributed Oceanographic Data System
(DODS), and other components. Since Data Management is one of the foremost problems in cluster computing, the final
package not only extends its capabilities as a Data Management System, but also to a cluster management system. This
Cluster/Data Management System (CDMS) can be envisioned as the integration of existing packages.
Author
Data Management; Oceanographic Parameters; Management Systems; Applications Programs (Computers)
20040121034 Colorado Univ., Boulder, CO, USA
Challenges in Long-Term Data Stewardship
Duerr, Ruth; Parsons, Mark A.; Marquis, Melinda; Dichtl, Rudy; Mullins, Teresa; NASA/IEEE MSST 2004 Twelfth NASA
Goddard Conference on Mass Storage Systems and Technologies in cooperation with the Twenty-First IEEE Conference on
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