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Transforming DAVE-ML Models to Executable C/C++

Lyndon B. Johnson Space Center, Houston, Texas DMLtoC.xsl is an XSLT (Extensible Stylesheet Language Transformations) transform that converts a vehicle model described in DAVE-ML (an XML markup language) into a “C” language version of the same model. DAVE-ML is a markup language for describing aerodynamic vehicle models. A DAVE-ML representation of an aero-model is composed of elements and sub-elements that describe variables, variable initialization, mathematical expressions for calculating variable values, interpolation functions, and break-point values. The DMLtoC.xsl XSLT transform transforms a DAVE-ML description of an aerodynamic model into executable C code by transforming each of the model elements, as appropriate, into C/C++ variable declarations, variable initializers, assignment statements, function calls, and interpolation data structures while preserving the corresponding relationships between these elements.

Posted in: Briefs, TSP

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Context-Based Configuration Management System

Ames Research Center, Moffett Field, California This invention provides a visual and textual system, including a set of intuitive icons representing different activities, for indicating status of and/or change in a document or documents and/or in project operations, using the icons to indicate the presence of different classes of changes that have been introduced in the version displayed. Three distinct classes of status/changes are indicated, each class using one of several visually distinguishable icons to indicate the class and including additional textual information associated with the icon. Icons from different classes of activities have different shapes to allow for easier distinction between the classes.

Posted in: Briefs

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Mesh: Lightweight Grid Middleware Using Existing Secure Shell Infrastructure

This program has applications in homeland security and intrusion prevention. Ames Research Center, Moffett Field, California A software-based innovation called Mesh was developed that provides a single sign-on capability to the built-in public key authentication mechanism of Secure Shell (SSH) using system call interposition. Mesh is a secure, lightweight grid middleware. Each Mesh installation is dedicated to serving a particular virtual organization (VO), which is defined to be a dynamic collection of individuals, institutions, and resources. Mesh allows individuals in one VO to execute SSH remote commands on Mesh-accessible resources within other cooperating VOs using a single Mesh SSH private key generated at the local VO.

Posted in: Briefs

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Delay Tolerant Networking Contact Graph Routing MACHETE Model

NASA’s Jet Propulsion Laboratory, Pasadena, California This simulation environment of Contact Graph Routing that uses the QualNet network simulator leverages the previously developed space communication models. This software models the Contact Graph Routing (CGR) system proposed for future NASA missions and used in DINETl and DINET2 experiments. It runs inside the QualNet network simulator. This protocol model can assist NASA network designers who wish to use Delay Tolerant Networking protocols with Contact Graph Routing.

Posted in: Briefs, TSP

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JavaGenes Data Optimization

Ames Research Center, Moffett Field, California JavaGenes is a general-purpose software program that implements several different data optimization techniques. The program is intended for problems that have no gradient, comparing genetic algorithms with stochastic hill climbing and simulated annealing to generate optimal design solutions. JavaGenes can create many different data structures, and describe problems in a variety of ways.

Posted in: Briefs, TSP, Mathematical/Scientific Software, Simulation Software

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A Large-Eddy Simulation Model of the Atmospheric Boundary Layer

The model includes the interaction of various physical processes, including turbulence, clouds, precipitation, and radiation. NASA’s Jet Propulsion Laboratory, Pasadena, California The atmospheric boundary layer is the lowermost layer of the atmosphere and is host to a plethora of physical processes that significantly affect weather, climate, and air quality. In many applications, detailed information about the boundary layer is required at high temporal and spatial resolution. The main purpose of the current model is to provide accurate and finely resolved inspace and time predictions of the atmospheric boundary layer. High-resolution predictions of the boundary layer are typically pertinent in the development and evaluation of weather and climate models, in fundamental studies of atmospheric dynamics including clouds and precipitation, the dispersion of pollutants, and the development of remote sensing instruments.

Posted in: Briefs, Electronics & Computers, Simulation Software

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Advanced Rolling Mechanics Analysis (AROMA) 1.0

Lyndon B. Johnson Space Center, Houston, Texas AROMA uses a boundary-element formulation to calculate normal and shear pressure distributions and sub-surface stresses for elastic bodies in contact. In addition to handling static normal and sheer loading, it also solves the contact problem for rolling elements such as bearings, traction drives, and wheel-to-rail interfaces. AROMA is a powerful and flexible tool for studying the tractive forces that arise during rolling in combination with kinematic effects, such as creepage and spin that are related to rolling element alignment. This GUI-based tool was developed in MATLAB, and can run within the MATLAB environment or as a standalone application.

Posted in: Briefs, Measuring Instruments

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