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


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


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


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


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


Multivariate Time Series Search Capability to Identify Complex Patterns in Large Datasets

Ames Research Center, Moffett Field, California There exist many datasets that can be viewed as multivariate time series, such as the daily high temperature at a locality, sensor recordings in diagnostic systems and scientific data, and music and video recordings. These time series reside in large repositories, and there is often a need to search for particular time series exhibiting certain types of behaviors. Many current approaches to time series search are too slow on large repositories, or constrain the range of possible queries.

Posted in: Briefs, Data Acquisition, Mathematical/Scientific Software


NGDCS Linux Application for Imaging-Spectrometer Data Acquisition and Display

NASA’s Jet Propulsion Laboratory, Pasadena, California A simple method of controlling recording and display of imaging spectrometer data in (airborne) flight was needed. Existing commercial packages were overly complicated, and sometimes difficult to operate in a bouncing plane. The software also was required to keep up with the imaging data rate, while still running on commodity hardware and a desktop operating system. Finally, the software needed to be as robust as possible — repeating a flight because of lost data is sometimes impossible, and always expensive.

Posted in: Briefs, Displays/Monitors/HMIs, Data Acquisition