Information Technology & Software

Hybrid NN/SVM Computational System for Optimizing Designs

The NN and the SVM help each other “learn” in an iterative process.

A computational method and system based on a hybrid of an artificial neural network (NN) and a support vector machine (SVM) (see figure) has been conceived as a means of maximizing or minimizing an objective function, optionally subject to one or more constraints. Such maximization or minimization could be performed, for example, to optimize solve a data-regression or data-classification problem or to optimize a design associated with a response function. A response function can be considered as a subset of a response surface, which is a surface in a vector space of design and performance parameters. A typical example of a design problem that the method and system can be used to solve is that of an airfoil, for which a response function could be the spatial distribution of pressure over the airfoil. In this example, the response surface would describe the pressure distribution as a function of the operating conditions and the geometric parameters of the airfoil.

Posted in: Briefs, Information Sciences

DSN Beowulf Cluster-Based VLBI Correlator

Software architecture is scalable to meet faster processing needs for future data processing.

The NASA Deep Space Network (DSN) requires a broadband VLBI (very long baseline interferometry) correlator to process data routinely taken as part of the VLBI source Catalogue Maintenance and Enhancement task (CAT M&E) and the Time and Earth Motion Precision Observations task (TEMPO). The data provided by these measurements are a crucial ingredient in the formation of precision deep-space navigation models. In addition, a VLBI correlator is needed to provide support for other VLBI related activities for both internal and external customers.

Posted in: Briefs, Information Sciences, Navigation and guidance systems, Wireless communication systems, Data management, Spacecraft

Processing Electromyographic Signals To Recognize Words

The speaker need not make any sound.

A recently invented speech-recognition method applies to words that are articulated by means of the tongue and throat muscles but are otherwise not voiced or, at most, are spoken sotto voce. This method could satisfy a need for speech recognition under circumstances in which normal audible speech is difficult, poses a hazard, is disturbing to listeners, or compromises privacy. The method could also be used to augment traditional speech recognition by providing an additional source of information about articulator activity. The method can be characterized as intermediate between (1) conventional speech recognition through processing of voice sounds and (2) a method, not yet developed, of processing electroencephalographic signals to extract unspoken words directly from thoughts.

Posted in: Briefs, TSP, Information Sciences

Associative Memory Using Quantum-Inspired Resonance

The solution to a search problem in an unsorted database allows for significantly decreased weight of NASA spacecraft.

In this innovation, the retrieval of stored items from an exponentially large, unsorted database is performed by quantum-inspired resonance using polynomial resources due to quantum-like superposition effect. The model is represented by a modified Madelung equation in which the quantum potential is replaced by different, specifically chosen potentials. As a result, the dynamics attains both quantum and classical properties: it preserves superposition and entanglement of random solutions, while allowing one to measure its state variables using classical methods. Such an optimal combination of characteristics is a perfect match for quantum-inspired information processing.

Posted in: Briefs, Information Sciences, Mathematical models, Computer software and hardware, Data exchange

Bounded-Angle Iterative Decoding of LDPC Codes

Maximum undetected-error rates are reduced greatly; overall error rates are increased negligibly (at low error rates).

Bounded-angle iterative decoding is a modified version of conventional iterative decoding, conceived as a means of reducing undetected- error rates for short low-density parity-check (LDPC) codes. For a given code, bounded- angle iterative decoding can be implemented by means of a simple modification of the decoder algorithm, without redesigning the code.

Posted in: Briefs, TSP, Information Sciences

Conversion From Tree to Graph Representation of Requirements

A complete representation without duplicate nodes is generated automatically.

A procedure and software to implement the procedure have been devised to enable conversion from a tree representation to a graph representation of the requirements governing the development and design of an engineering system. The need for this procedure and software and for other requirements-management tools arises as follows: In systems-engineering circles, it is well known that requirements-management capability improves the likelihood of success in the team-based development of complex systems involving multiple technological disciplines. It is especially desirable to be able to visualize (in order to identify and manage) requirements early in the system-design process, when errors can be corrected most easily and inexpensively.

Posted in: Briefs, Information Sciences

Determining Surface Roughness in Urban Areas Using Lidar Data

An automatic derivation of relevant parameters estimates surface roughness.

An automated procedure has been developed to derive relevant factors, which can increase the ability to produce objective, repeatable methods for determining aerodynamic surface roughness. Aerodynamic surface roughness is used for many applications, like atmospheric dispersive models and wind-damage models. For this technique, existing lidar data was used that was originally collected for terrain analysis, and demonstrated that surface roughness values can be automatically derived, and then subsequently utilized in disaster-management and homeland-security models.

Posted in: Briefs, Information Sciences, Mathematical models, Lidar, Terrain, Aerodynamics

Presentation Extensions of the SOAP

A set of extensions of the Satellite Orbit Analysis Program (SOAP) enables simultaneous and/or sequential presentation of information from multiple sources. SOAP is used in the aerospace community as a means of collaborative visualization and analysis of data on planned spacecraft missions. The following definitions of terms also describe the display modalities of SOAP as now extended: In SOAP terminology,

Posted in: Briefs, Information Sciences, Trajectory control, Computer software and hardware, Data management, Terminology, Satellites

Error-Rate Bounds for Coded PPM on a Poisson Channel

It is now possible to calculate tight bounds at high SNR.

Equations for computing tight bounds on error rates for coded pulse-position modulation (PPM) on a Poisson channel at high signal-to-noise ratio have been derived. These equations and elements of the underlying theory are expected to be especially useful in designing codes for PPM optical communication systems.

Posted in: Briefs, Information Sciences, Design processes, Mathematical analysis, Communication protocols, Wireless communication systems

Biomorphic Multi-Agent Architecture for Persistent Computing

Computing systems would reconfigure themselves to continue functioning despite failures of components.

A multi-agent software/hardware architecture, inspired by the multicellular nature of living organisms, has been proposed as the basis of design of a robust, reliable, persistent computing system. Just as a multicellular organism can adapt to changing environmental conditions and can survive despite the failure of individual cells, a multi-agent computing system, as envisioned, could adapt to changing hardware, software, and environmental conditions. In particular, the computing system could continue to function (perhaps at a reduced but still reasonable level of performance) if one or more component(s) of the system were to fail.

Posted in: Briefs, Information Sciences

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