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Raised Relief Mars Globe Brings the Red Planet Closer

When the Mars Reconnaissance Orbiter (MRO) entered the Red Planet's atmosphere in March 2006, it joined the ranks of other noble explorers studying the planet over the past 2,000-plus years. This new NASA orbiter will study the Martian atmosphere and surface, and probe underground in search of past and present water, making it one of the most advanced studies of the planet to date. People have been aware of the existence of Mars and in awe of its presence for centuries, ever since early humans noticed that it did not shimmer like the surrounding stars.

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X-Ray Vision



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Four-Quadrant Analog Multipliers Using G4-FETs

Devices with independently biased multiple inputs are exploited to simplify multiplier circuits. Theoretical analysis and some experiments have shown that the silicon-on-insulator (SOI) 4-gate transistors known as G4-FETs can be used as building blocks of four-quadrant analog voltage multiplier circuits. Whereas a typical prior analog voltage multiplier contains between six and 10 transistors, it is possible to construct a superior voltage multiplier using only four G4-FETs.

Posted in: Briefs, TSP

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SSRL Emergency Response Shore Tool

The SSRL Emergency Response Shore Tool (wherein “SSRL” signifies “Smart Systems Research Laboratory”) is a computer program within a system of communication and mobile-computing software and hardware being developed to increase the situational awareness of first responders at building collapses. This program is intended for use mainly in planning and constructing shores to stabilize partially collapsed structures. The program consists of client and server components, runs in the Windows operating system on commercial off-the-shelf portable computers, and can utilize such additional hardware as digital cameras and Global Positioning System devices.

Posted in: Briefs, TSP

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Automated Synthesis of Architectures of Avionic Systems

The Architecture Synthesis Tool (AST) is software that automatically synthesizes software and hardware architectures of avionic systems. The AST is expected to be most helpful during initial formulation of an avionic-system design, when system requirements change frequently and manual modification of architecture is time-consuming and susceptible to error. The AST comprises two parts: (1) an architecture generator, which utilizes a genetic algorithm to create a multitude of architectures; and (2) a functionality evaluator, which analyzes the architectures for viability, rejecting most of the non-viable ones. The functionality evaluator generates and uses a viability tree — a hierarchy representing functions and components that perform the functions such that the system as a whole performs system-level functions representing the requirements for the system as specified by a user. Architectures that survive the functionality evaluator are further evaluated by the selection process of the genetic algorithm. Architectures found to be most promising to satisfy the user’s requirements and to perform optimally are selected as parents to the next generation of architectures. The foregoing process is iterated as many times as the user desires. The final output is one or a few viable architectures that satisfy the user’s requirements.

Posted in: Briefs, TSP

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Partial Automation of Requirements Tracing

Requirements Tracing on Target (RETRO) is software for after-the-fact tracing of textual requirements to support independent verification and validation of software. RETRO applies one of three user-selectable information-retrieval techniques: (1) term frequency/inverse document frequency (TF/IDF) vector retrieval, (2) TF/IDF vector retrieval with simple thesaurus, or (3) keyword extraction. One component of RETRO is the graphical user interface (GUI) for use in initiating a requirements-tracing project (a pair of artifacts to be traced to each other, such as a requirements spec and a design spec). Once the artifacts have been specified and the IR technique chosen, another component constructs a representation of the artifact elements and stores it on disk.

Posted in: Briefs, TSP

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Predicting Lifetime of a Thermomechanically Loaded Component

NASALIFE is a computer program for predicting the lifetime, as affected by low cycle fatigue (LCF) and creep rupture, of a structural component subject to temporally varying, multiaxial thermomechanical loads. The component could be, for example, part of an aircraft turbine engine. Empirical data from LCF tests, creep rupture tests, and static tensile tests are used as references for predicting the number of missions the component can withstand under a given thermomechanical loading condition. The user prepares an input file containing the creep-rupture and cyclic-fatigue information, temperature-dependent material properties, and mission loading and control flags. The creep rupture information can be entered in tabular form as stress versus life or by means of parameters of the Larson- Miller equation. The program uses the Walker mean-stress model to adjust predicted life for ranges of the ratio between the maximum and minimum stresses. Data representing complex load cycles are reduced by the rainflow counting method. Miner’s rule is utilized to combine the damage at different load levels. Finally, the program determines the total damage due to creep and combines it with the fatigue damage due to the cyclic loading and predicts the approximate number of missions a component can endure before failing. This work was done by Pappu L. N. Murthy of Glenn Research Center, John Z. Gyekenyesi of N&R Engineering and Management Services Corp., Subodh Mital of the University of Toledo, and David N. Brewer of the U. S. Army Aviation Systems Command. For further information, access the Technical Support Package (TSP) free online at www.techbriefs.com/tsp under the Software category. Inquiries concerning rights for the commercial use of this invention should be addressed to NASA Glenn Research Center, Innovative Partnerships Office, Attn: Steve Fedor, Mail Stop 4–8, 21000 Brookpark Road, Cleveland, Ohio 44135. Refer to LEW-18081.

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White Papers

White Paper: Computer System Design for Critical Applications
Sponsored by Sealevel
IEC 61131-3 Now in Motion
Sponsored by Trio Motion
When Wire Feedthroughs Make Sense
Sponsored by Douglas Electrical Components
Improving Medical Devices with Force Sensing Technology
Sponsored by tekscan
Specifying Actuators for Heavy-Duty Packaging Applications
Sponsored by Rollon
Designing Ring Projections for Hermetic Sealing
Sponsored by Miyachi Unitek

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