Issue 10 Volume 41 May 16, 2003

Open architectures are gaining popularity for Integrated Vehicle Health Management (IVHM) applications due to the
diversity of subsystem health monitoring strategies in use and the need to integrate a variety of techniques at the system health
management level. The basic concept of an open architecture suggests that whatever monitoring or reasoning strategy a
subsystem wishes to deploy, the system architecture will support the needs of that subsystem and will be capable of
transmitting subsystem health status across subsystem boundaries and up to the system level for system-wide fault
identification and diagnosis. There is a need to understand the capabilities of various reasoning engines and how they, coupled
with intelligent monitoring techniques, can support fault detection and system level fault management. Researchers in IVHM
at NASA Ames Research Center are supporting the development of an IVHM system for liquefying-fuel hybrid rockets. In
the initial stage of this project, a few readily available reasoning engines were studied to assess candidate technologies for
application in next generation launch systems. Three tools representing the spectrum of model-based reasoning approaches,
from a quantitative simulation based approach to a graph-based fault propagation technique, were applied to model the
behavior of the Hybrid Combustion Facility testbed at Ames. This paper summarizes the characterization of the modeling
process for each of the techniques.
Author
Architecture (Computers); Diagnosis; Fault Detection; Health; Support Systems
20030032525 NASA Goddard Space Flight Center, Greenbelt, MD, USA
GFO Altimeter Engineering Assessment Report
Lockwood, Dennis W.; Hancock, David W., III; Hayne, George S.; Brooks, Ronald L.; March 2002; 82 pp.; In English;
Original contains black and white illustrations
Contract(s)/Grant(s): 622-47-36-02
Report No.(s): NASA/TM-2002-209984/VER1/VOL3; NAS 1.15:209984/VER1/VOL3; Copyright; Avail: CASI; A05,
Hardcopy
The U.S. Navy’s Geosat Follow-On (GFO) Mission, launched on February 20, 1998, is one of a series of altimetric
satellites which include Seasat, Geosat, ERS-1, and TOPEX/POSEIDON (T/P). The purpose of this report is to document the
GFO altimeter performance determined from the analyses and results performed by NASA’s GSFC and Wallops altimeter,
calibration team. It is the second of an anticipated series of NASA’s GSFC and Wallops GFO performance documents, each
of which will update assessment results. This report covers the performance from instrument acceptance by the Navy on
November 29, 2000, to the end of Cycle 20 on November 21, 2001. Data derived from GFO will lead to improvements in the
knowledge of ocean circulation, ice sheet topography, and climate change. In order to capture the maximum amount of
information from the GFO data, accurate altimeter calibrations are required for the civilian data set which NOAA will produce.
Wallops Flight Facility has provided similar products for the Geosat and T/P missions and is doing the same for GFO.
Author
Satellite Altimetry; Satellite-Borne Radar; Computer Programs; Software Reliability; Component Reliability; Reliability
Analysis; Satellite Instruments; Data Processing
20030032937 Memphis Univ., Memphis, TN
Simulation-Based Teaching and Learning for Electrophysiology by iCell
Demir, Semahat S.; Oct 2001; 5 pp.; In English; Original contains color illustrations
Report No.(s): AD-A410410; No Copyright; Avail: CASI; A01, Hardcopy
An interactive cell modeling web site, iCell, that integrates research and education, was developed as a simulation-based
teaching and learning tool for electrophysiology. The site consists of JAVA applets representing models of various cardiac cells
and neurons, and provides simulation data of their bioelectric activities at cellular level. Each JAVA-based model allows the
user to go through menu options to change model parameters, run and view simulation results. The site also has a glossary
section for the scientific tens. iCell has been used as a teaching and learning tool for four graduate courses at the Joint
Biomedical Engineering Program of University of Memphis and University of Tennessee. This modeling tool was also used
as a collaboration site among our colleagues interested in simulations of cell membrane activities. Scientists from the fields
of biosciences, engineering, life sciences and medical sciences in USA, Canada, China, Brazil, England, Ireland, the
Netherlands, New Zealand, Spain and Turkey have tested and utilized iCell as a simulation-based teaching, learning and
collaboration environment. The platform-independent software, iCell, provides us with an interactive and user-friendly
teaching and learning tool, and also a collaboration environment for electrophysiology to be shared over the Internet.
DTIC
Applications Programs (Computers); Electrophysiology; Education; Computerized Simulation; Cells (Biology)
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