Information Technology & Software

Evolutionary Computing Methods for Spectral Retrieval

Solutions to the inverse problem of spectral retrieval are found in a computationally efficient process.

A methodology for processing spectral images to retrieve information on underlying physical, chemical, and/or biological phenomena is based on evolutionary and related computational methods implemented in software. In a typical case, the solution (the information that one seeks to retrieve) consists of parameters of a mathematical model that represents one or more of the phenomena of interest.

Posted in: Briefs, TSP, Information Sciences

Monitoring Disasters by Use of Instrumented Robotic Aircraft

Real-time synoptic data would help in coordinating and planning responses.

Efforts are under way to develop data- acquisition, data- processing, and data- communication systems for monitoring disasters over large geographic areas by use of uninhabited aerial systems (UAS) — robotic aircraft that are typically piloted by remote control. As integral parts of advanced, comprehensive disaster-management programs, these systems would provide (1) real-time data that would be used to coordinate responses to current disasters and (2) recorded data that would be used to model disasters for the purpose of mitigating the effects of future disasters and planning responses to them.

Posted in: Briefs, Information Sciences, Disaster and emergency management, Emergency management, Robotics, Hazards and emergency management, Hazards and emergency operations, Unmanned aerial vehicles

Complexity for Survival of Living Systems

Interactions between systems and their mental images enable unlimited increase of complexity.

A logical connection between the survivability of living systems and the complexity of their behavior (equivalently, mental complexity) has been established. This connection is an important intermediate result of continuing research on mathematical models that could constitute a unified representation of the evolution of both living and non-living systems. Earlier results of this research were reported in several prior NASA Tech Briefs articles, the two most relevant being “Characteristics of Dynamics of Intelligent Systems” (NPO- 21037), NASA Tech Briefs, Vol. 26, No. 12 (December 2002), page 48; and “Self-Supervised Dynamical Systems” (NPO- 30634) NASA Tech Briefs, Vol. 27, No. 3 (March 2003), page 72.

Posted in: Briefs, Information Sciences, Mathematical models, Biological sciences

Protecting Data Signals Through Isolation

Many of us believe that if we don’t have ground loops we don’t need to isolate analog I/O signals. Yet there are five very real – and very different – reasons to isolate every one of your analog signals! If you’ve had problems on past applications, chances are you experienced one of the following:

Signal crosstalk Common-mode voltage DC common-mode rejection AC common-mode rejection Over-range and input protection issues.

Isolating power sources and sensor signals is the most effective way to address these problems; understanding how measurement inputs become corrupted in the first place will illustrate this.

Posted in: Articles, Information Sciences, Instrumentation, Amplifiers, Architecture, Communication protocols

Wireless Avionics Packet To Support Fault Tolerance for Flight Applications

A simple network interface supports fault detection and autonomous fault recovery.

In this protocol and packet format, data traffic is monitored by all network interfaces to determine the health of transmitter and subsystems. When failures are detected, the network interface applies its recovery policies to provide continued service despite the presence of faults. The protocol, packet format, and interface are independent of the data link technology used. The current demonstration system supports both commercial off-the-shelf wireless connections and wired Ethernet connections. Other technologies such as 1553 or serial data links can be used for the network backbone.

Posted in: Briefs, Information Sciences, Avionics, Communication protocols, Wireless communication systems

EOS MLS Level 1B Data Processing, Version 2.2

A computer program performs level- 1B processing (the term “1B” is explained below) of data from observations of the limb of the Earth by the Earth Observing System (EOS) Microwave Limb Sounder (MLS), which is an instrument aboard the Aura spacecraft. This software accepts, as input, the raw EOS MLS scientific and engineering data and the Aura spacecraft ephemeris and attitude data. Its output consists of calibrated instrument radiances and associated engineering and diagnostic data. [This software is one of several computer programs, denoted product generation executives (PGEs), for processing EOS MLS data. Starting from level 0 (representing the aforementioned raw data, the PGEs and their data products are denoted by alphanumeric labels (e.g., 1B and 2) that signify the successive stages of processing.]

Posted in: Briefs, Information Sciences, Computer software and hardware, Data acquisition and handling, Spacecraft

Physical Principle for Generation of Randomness

A physical principle (more precisely, a principle that incorporates mathematical models used in physics) has been conceived as the basis of a method of generating randomness in Monte Carlo simulations. The principle eliminates the need for conventional random-number generators.

Posted in: Briefs, Information Sciences, Computer simulation, Mathematical models

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

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