Information Technology & Software

Maximum-Likelihood Template Matching

This algorithm features a robust measure of matching and an efficient search technique.

An improved algorithm for detecting gray-scale and binary templates in digitized images has been devised. The greatest difference between this algorithm and prior template-detecting algorithms stems from the measure used to determine the quality or degree of match between a template and given portion of an image. This measure is based on a maximum-likelihood formulation of the template- matching problem; this measure, and the matching performance obtained by use of it, are more robust than are those of prior template-matching algorithms, most of which utilize a sum-of-squared-differences measure. Other functions that the algorithm performs along with template matching include subpixel localization, estimation of uncertainty, and optimal selection of features. This algorithm is expected to be useful for detecting templates in digital images in a variety of applications, including recognition of objects, ranging by use of stereoscopic images, and tracking of moving objects or features. (For the purpose of tracking, features or objects recognized in an initial image could be used as templates for matching in subsequent images of the same scene.)

Posted in: Briefs, TSP, Information Sciences, Mathematical models, Imaging, Imaging and visualization, Imaging, Imaging and visualization, Performance upgrades

Fast Algorithms and Circuits for Quantum Wavelet Transforms

These theoretical building blocks could be used to implement a variety of quantum algorithms.

Fast algorithms and the first complete and efficient circuits for implementing two quantum wavelet transforms have been developed in theory. The significance of this development within the overall development of quantum computing is the following: In principle, the algorithms and circuits constitute instructions for implementing the transforms by use of primitive quantum gates; the circuits in this case are analogous to circuit-diagram-level descriptions of classical electronic circuits that perform logic functions.

Posted in: Briefs, TSP, Information Sciences, Mathematical models, Architecture, Integrated circuits, Architecture, Integrated circuits

Software for Analyzing Root Causes of Process Anomalies

Root Cause Analysis (RoCA) is a computer program that assists analysts in understanding the root causes of process anomalies. As used here, “process anomalies” includes incidents that have caused, or that can potentially cause, injuries to personnel, damage to facilities, abnormal costs, or delays in processing. RoCA could be used, for example, in industry to investigate anomalies in production and by government agencies and airlines in investigating airplane accidents. Older software developed to aid such investigations offers limited capabilities for mapping the contribution of each root cause to a given process anomaly. Unlike the prior software, RoCA not only identifies root causes of process anomalies but also supports the identification of trends over multiple anomalies.

Posted in: Briefs, TSP, Information Sciences, Analysis methodologies, Computer software and hardware, Risk assessments

Ex — Software for Numerical Computation in Native Oberon

“Ex” is the name of a library of software modules from which one can rapidly develop prototype or production versions of efficient numerical-computation application programs in the Native Oberon programming environment. Mathematical constructs that can be represented and processed by use of Ex modules include both integer and non-integer rational, real, and complex numbers; vectors; matrices; and the arithmetic, algebra, and calculus of the aforementioned quantities.

Posted in: Briefs, TSP, Information Sciences, CAD, CAM, and CAE, Mathematical models, Data management

Maximum-Likelihood Scheme for Tracking an Optical Source

Subpixel resolution should be possible, even in a high-disturbance environment.

A fine-pointing scheme that involves correlation of images and maximum-likelihood estimation has been proposed to enable tracking of optical sources. This scheme is intended for implementation in the pointing-control system of an imaging instrument (e.g., a telescope equipped with an image detector) to provide a capability for highly stable and accurate pointing to a specific area within a moving target, even under conditions that ordinarily give rise to pointing jitters. Such conditions include motion of the target relative to the instrument, instability of the platform that supports the instrument-aiming mechanism, and turbulence in the atmosphere or other optical medium. In the original intended application, the scheme would be implemented in a ground station for tracking a laser that would be part of an optical communication aboard a distant spacecraft. Other potential applications include stabilization of images for video cameras and precise pointing of lasers in military, industrial, and surgical settings. This scheme is expected to make it possible to achieve subpixel resolution in a high-disturbance environment.

Posted in: Briefs, TSP, Information Sciences, Calibration, Mathematical models, Optics, Vibration, Reliability

Quantum Superluminal Transmission of Random Messages

Messages that would not convey information could be useful for deception.

In a proposed communication scheme, quantum entanglement and quantum nonlocality would be utilized to effect instantaneous transmission of randomly chosen messages to remote locations. Although the messages would not convey any information, they might nevertheless be of some value under circumstances in which deception and secrecy are of more importance than are the specific contents of the messages.

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

Goal-Based Fault Tolerance for Spacecraft Systems

A report discusses the concept of goal-based fault tolerance as implemented in NASA’s Mission Data System (MDS), which is a developmental architecture for unified flight, test, and ground software that is intended to be adaptable to a variety of next-generation deep-space missions. In goal-based fault tolerance, unlike in prior approaches to fault tolerance, it is not assumed that faults that necessitate deviations from prescribed sequences of commands will occur infrequently; instead, it is assumed that unpredictable conditions, including faults, can arise at any time, and fault tolerance is incorporated as an intrinsic feature of every aspect of system design in a unified approach to ensuring robust system behavior.

Posted in: Briefs, TSP, Information Sciences, Failure modes and effects analysis, Architecture, Computer software and hardware, Spacecraft

Remote Agent as Applied to the Deep Space 1 Spacecraft

A report presents updated information about the Remote Agent — a reusable artificial-intelligence software system that was described in “A Remote Agent Prototype for Spacecraft Autonomy” (NPO-19992), NASA Tech Briefs, Vol. 21, No. 3 (March 1997), page 106. This system was conceived to enable spacecraft to operate robustly with minimal human supervision, even in the face of hardware failures or unexpected events. It also is expected to offer similar benefits for communication networks, chemical plants, and other complex systems on Earth.

Posted in: Briefs, TSP, Information Sciences, Artificial intelligence, Computer software and hardware, Spacecraft

Multirover Coordination Based on Contract Net Protocol

NASA’s Jet Propulsion Laboratory, Pasadena, California

A computer program coordinates operations of multiple cooperating rovers (small exploratory robotic vehicles deployed from a lander spacecraft), each of which is equipped with computer hardware and software that schedule the tasks assigned to it. The program implements a contract net protocol — a type of coordination protocol commonly used in distributed artificial intelligence. In a contract net protocol, a manager announces a task to a set of contractors, each contractor bids for the task, and the manager awards the task to the contractor with the best bid. In the present program, the lander (manager) incrementally transmits tasks to each rover (contractor). Upon receiving a task, a rover tries to fit the task into its current schedule. If the rover can do so, it bids the total distance it would have to travel to complete all of its tasks (including the newly inserted one). Rovers that fail to fit the task into their schedules within a time limit do not participate in the auction. Upon receiving all bids, the lander awards the task to the rover with the smallest bid.

Posted in: Briefs, Information Sciences, Computer software / hardware, Computer software and hardware, Computer software / hardware, Computer software and hardware, Robotics

External Data and Attribute Hyperlink Programs for Promis•e®

External Data and Attribute Hyperlink are computer programs that can be added to Promis•e®, which is a commercial software system that automates routine tasks in the design (including drawing schematic diagrams) of electrical control systems. The programs were developed under the Stennis Space Center's (SSC's) Dual Use program to provide capabilities for SSC's 3 MCS configuration management system, which uses Promis•e®. The External Data program enables the storage and management of information in an external database linked to a drawing. Changes can be made either in the database or on the drawing. Information that originates outside Promis•e® can be stored in custom fields that can be added to the database. Although this information is not available in Promis•e® printed drawings, it can be associated with symbols in the drawings, and can be retrieved through the drawings when the software is running. The Attribute Hyperlink program enables the addition of hyperlink information as attributes of symbols. This program enables the formation of a direct hyperlink between a schematic diagram and an Internet site or a file on a compact disk, on the user's hard drive, or on another computer on a network to which the user's computer is connected. The user can then obtain information directly related to the part (e.g., maintenance, or troubleshooting information) associated with the hyperlink.

Posted in: Briefs, Information Sciences, CAD / CAM / CAE, CAD, CAM, and CAE, Electrical systems, Electrical systems, Human machine interface (HMI), Automation

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