Tech Briefs

JPF-NAS Extension of Java Pathfinder

Java PathFinder (JPF) version 7 provides basic support for verifying the distributed Java applications. It can receive a distributed Java application as input that is perceived as multiple Java processes. However, JPF does account for communication between processes of the distributed application, and it thus cannot be used to verify any realistic distributed Java application. Applying JPF on distributed applications requires a model of inter-process communication (IPC) and process aware scheduling.

Posted in: Briefs, Electronics & Computers, Information Sciences, Software, Architecture, Communication protocols, Computer software and hardware

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Institutional Budgeting Tool (IBT)

The Jet Propulsion Laboratory's Institutional Budgeting Tool (IBT) was designed and developed to meet the needs of JPL's budget planners, numbering 1,600, who required a robust and state-of-the-art budgeting application. JPL's budgeting process had been constrained by legacy tools that presented usability and performance issues and lacked critical innovative budgeting features. IBT delivered superior user experience, system performance, and modern features necessary for essential laboratory budgeting.

Posted in: Briefs, Electronics & Computers, Information Sciences, Software, Computer software and hardware, Financial management

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Tubes Standards-Compliant C Header Library

Due to limitations imposed by transistor physics as device geometries continue to get finer and finer, the time when each new generation of processors was clocked faster than its predecessors is largely over. Nevertheless, as individual processor cores get smaller, chip manufacturers have turned instead to cramming a large number of cores onto a single die. Consequently, nearly all commercially available CPUs (central processing units), even those used in smartphones, already depend upon a multicore architecture. Unfortunately, the programming languages used for nearly all commercial software projects are really intended for generating code for a single CPU core. Though extensions exist that support multiple cores, it is something that is essentially tacked on, not part of the core language's constructs.

Posted in: Briefs, Electronics & Computers, Information Sciences, Software, Architecture, Computer software and hardware, Transistors, Terminology

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Techniques for Conducting Effective Concept Design and Design-to-Cost Trade Studies

Concept design plays a central role in project success for space missions, as the product of concept design effectively locks in the majority of system lifecycle cost. It involves a concurrent investigation of requirements and multiple mission characteristics such as flight dynamics, design, performance, concept of operations, technology, verification approach, launch and ground interfaces, cost, schedule, and risk.

Posted in: Briefs, Electronics & Computers, Information Sciences, Software, Life cycle analysis, Cost analysis, Systems engineering

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HyDE Model-Based Diagnosis Engine for Stochastic Hybrid Systems

Model-based diagnosis deals with the problem of diagnosing faults in systems using a model of the system for guidance. This problem is complicated by the presence of hybrid dynamics in the system (continuous evolution of the system interspersed with discrete events like commands to change configuration), as well as uncertainties in the form of model approximations and sensor noise. Several model-based technologies have been developed and successfully demonstrated using discrete abstractions of the system as models. These techniques are severely restricted in model expressiveness due to the discrete nature of the models. Moreover, sophisticated model abstraction techniques, as well as algorithms to convert continuous data to discrete form, need to be developed for such an approach to work. Recently, there have been efforts to develop diagnostic engines for hybrid and stochastic systems. However, these techniques have either focused on parametric faults, or use a probabilistic approach to fault identification. Consistency-based approaches that have been successfully demonstrated using discrete models have not been extended to work with stochastic and hybrid models.

Posted in: Briefs, Electronics & Computers, Information Sciences, Software, Computer simulation, Failure analysis, Scale models, Diagnostics

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Use of Beam Deflection to Control an Electron Beam Wire Deposition Process

NASA Langley Research Center researchers have a strong technology foundation in the use of electron-beam (e-beam) deposition for freeform fabrication of complex shaped metal parts. While e-beam wire deposition is of interest for rapid prototyping of metal parts, cost-effective near-net shape manufacturing, and potential use in space, it is also of intense interest for industrial welding and fabrication in a range of applications, from small components to large aerospace structures. Through significant advancements in techniques to improve control of the process, NASA greatly expands upon the capabilities of the e-beam fabrication and welding process.

Posted in: Briefs, Manufacturing & Prototyping, Performance upgrades, Fabrication, Welding, Metals

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Thermal Stir Welding Process

NASA's Marshall Space Flight Center is developing an improved joining technology called thermal stir welding that improves upon fusion welding and friction stir welding. This new technology enables a superior joining method by allowing manufacturers to join dissimilar materials and to weld at high rates. NASA's technology offers users an exciting alternative to state-of-the-art fusion and friction stir welding technologies.

Posted in: Briefs, Manufacturing & Prototyping, Manufacturing equipment and machinery, Welding

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