Briefs: Information Technology
Mathematical Model of a Quantum Decision Maker

A mathematical model of a quantum analog-computing device that would simulate the human decision-making process has been developed. Like the immune-inspired- computing model described in the preceding article, this model is intended to contribute to improvement in the autonomy of robots and...

Briefs: Information Technology
IIR Filters for Postprocessing Noisy Test Data

A little-known parametric form of an infinite impulse response (IIR) filter has been found to be useful in digital postprocessing of noisy test signals. The filter equation is:

y(n) = α[x(n) + x(n – 1)] + γy(n – 1),

Briefs: Mechanical & Fluid Systems
Tests of Finger Seals

A report discusses tests of finger seals, which were described in “Pressure- Balanced, Low-Hysteresis Finger Seal” (LEW-16840), which appears on page 52 in this issue. Like a labyrinth or brush seal, a finger seal is used (typically in a gas turbine) to minimize a leakage flow along a rotating shaft. The report...

Briefs: Physical Sciences
Low-Power, Zero-Vibration Sorption Coolers

A report discusses three designs of proposed low-power, zero-vibration coolers for infrared instruments planned to be flown aboard spacecraft to perform astrophysical observations far from Earth. The designs take advantage of the radiative precooling available in the projected deep-space operational...

Briefs: Physical Sciences
Inhibited Carrier Transfer in Ensembles of Quantum Dots

A report presents an experimental study of time-resolved, temperature-dependent photoluminescence in InxGa1–x As/GaAs specimens containing In0.6Ga0.4As quantum dots (QDs) distributed at several different areal densities on a GaAs surface and...

Briefs: Electronics & Computers
Study of Amplification in Optocoupler-Equivalent Circuits

A report presents a theoretical and experimental study of amplification in electronic circuits that include combinations of discrete light sources (e.g., lightemitting diodes) and photodetectors (e.g., reverse-biased photodiodes), which combinations perform essentially the same functions...

Briefs: Physical Sciences
Area Production in Supercritical, Transitional Mixing Layers

This paper presents a study of area production in mixing layers undergoing transition to turbulence. These layers evolve from the mixing of two initially segregated counterflowing streams under supercritical conditions. The study may contribute to development of means to control area...

Briefs: Materials
Nanolaminate Mirrors With Integral Figure-Control Actuators

A report discusses the development of thin-shell curved mirrors comprised of metallic multilayer nanolaminate substrates that contain integral inplane actuators for controlling surface figure with micron-level precision. These mirrors, intended for incorporation into scientific imaging...

Briefs: Physical Sciences
Paraffin-Actuated Heat Switch for Mars Surface Applications

Missions to the surface of Mars pose unique thermal-control challenges to rover and lander systems. With diurnal temperature changes greater than 100 °C, the presence of a Mars atmosphere, and limited power for night-time heating, the thermal-control engineer is faced with a...

Briefs: Electronics & Computers

A coder/decoder system (codec) is being developed for use in a digital voice communication system in which speech is encoded as a series of frames of data and transmitted over a noisy or lossy channel. Called a...

Briefs: Electronics & Computers

Two electronic circuits that generate controlled power-turn-on and power-turn-off transients have been developed. These circuits are parts of a suite of test equipment used to...

Briefs: Photonics/Optics

The figure depicts the basic optical layouts for (1) conventional laser Doppler velocimetry (LDV) and (2) a newer method of LDV based partly on the use of two optical fibers. Whereas...

Briefs: Photonics/Optics
Stabilization and Registration of Sequential Video Images

A computational process converts a sequence of digitized video images of the same scene into stabilized, coregistered images of an area of interest within the scene. The process corrects for motion of the area of interest or of the camera (as manifested by rotation, translation, and/or...

Briefs: Photonics/Optics

Focal-plane arrays of quantum-well infrared photodetectors (QWIPs) featuring adjacent pixels sensitive to different colors have been proposed. An array of this type would make it...

Briefs: Photonics/Optics

A technique for projecting holographic images to make both still and moving three-dimensional displays is undergoing development. Unlike older techniques based on stereoscopy to give...

Briefs: Physical Sciences

An electrometer developed for measuring the triboelectric responses of soils on Mars is also potentially useful on Earth for identifying some materials via their triboelectric responses....

Briefs: Information Technology
The Complexity of the Diagnosis Problem

A report presents a study of the complexity of an algorithm that performs model-based diagnosis of a complex hardware system. [In model-based diagnosis, an algorithm detects logical inconsistencies between observational data and a description (mathematical model) of the system.] In the study, the problem...

Briefs: Mechanical & Fluid Systems
Design Concepts for the ISS TransHab Module

Twelve reports present concepts for the design of structural and functional systems, subsystems, and components of the proposed TransHab module — an inflatable, lightweight habitation module that would be used by crewmembers of the International Space Station and would serve as a prototype of...

Briefs: Physical Sciences
Characteristics of Supercritical Transitional Mixing Layers

This report describes a study of threedimensional, temporal mixing layers between different fluids initially flowing at different velocities under supercritical conditions. The study involved direct numerical simulations by use of a validated mathematical model of high-pressurefluid...

Briefs: Physical Sciences
Infrared CO2 Sensor With Built-In Calibration Chambers

A proposed infrared CO2 sensor, operated in conjunction with suitable readout, data-processing, and control circuitry, could be calibrated repeatedly during operation to compensate for changes in sensor response induced by such phenomena as aging and changes in temperature. The...

Briefs: Physical Sciences
Solid-State Potentiometric CO Sensor

A solid-state sensor was developed that measures the concentrations of one or more gases of interest in a mixture of gases. This simple solid-state sensor produces a voltage signal that is sensitive to CO concentration from percent to ppm (parts per million) levels. It was intended originally for use in...

Briefs: Physical Sciences

A relatively inexpensive Sun sensor for determining the absolute heading of planetary rovers to within ± 3° using a monochrome charge-coupled device (CCD) camera is presented....

Briefs: Electronics & Computers

A method of designing improved monolithic planar arrays of superconducting tunnel junctions (STJs) for use as photodetectors has been conceived. These arrays would be suitable for...

Briefs: Electronics & Computers
Development of Cognitive Sensors

A technical report enunciates the concept of a hierarchy of sensor classes (meaning transducers, associated circuitry, and embedded software) that have different levels of intelligence, and discusses issues pertaining to the development of sensors of the highest level of intelligence, called cognitive. The other...

Briefs: Electronics & Computers

A “smart” back-gate driver circuit has been proposed to enable the operation, at voltages higher than were previously possible, of a silicon-on-insulator (SOI) complementary metal...

Briefs: Electronics & Computers

A method of estimating the pointing error of an offset-conic-section reflector antenna equipped to receive in both right circular polarization (RCP) and left circular polarization (LCP)...

Briefs: Software
Advanced Fatigue-Crack-Growth and Fracture-Mechanics Program

The NASGRO 3.0 computer program is an advanced version of a program used by NASA and the European Space Agency for fracture-control analysis of space-system structures and other hardware. The prior version, NASA/FLAGRO 2.0, was described in “Updated Fatigue-Crack-Growth and...

Briefs: Software
Software for Sequencing Spacecraft Actions

SEQ_GEN is a component of the Sequence Subsystem computer program, which assists in generating a sequence of commands to be executed by a control computer aboard a spacecraft to perform scientific observations and supporting engineering actions in response to requests by numerous users. SEQ_GEN assists...

Briefs: Software
Program Distributes and Tracks Organizational Memoranda

Closed Loop Accounting Management System (CLAMS) is a computer program for Web-based distribution and tracking of memoranda within an organization. An item for distribution is entered by a user who has administrative access. The item is assigned to affected users, to whom e-mail messages...

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