December 2002

Briefs : Electronics & Computers
Photodiode CMOS Imager With Column Feedback Soft Reset

A proposed complementary metal oxide/semiconductor (CMOS) photodiode integrated-circuit imaging device of the active-pixel-sensor (APS) type would include column feedback sub-circuits that would make it possible to reduce readout noise (thereby making it possible to image at lower light...

Briefs : Electronics & Computers
Digital Flash X-Ray Imager for Quantitative Physiology

An optoelectronic/digital flash x-ray imaging system has been invented for use in quantitative physiological studies and general radiology. The system could be implemented in a relatively compact, lightweight apparatus suitable for use aboard a spacecraft as well as on Earth. Applications...

Briefs : Electronics & Computers
High-Frame-Rate CCD Camera Having Subwindow Capability

A custom high-speed charge-coupled-device (CCD) camera that features a capability for real-time readout from multiple regions of interest (subwindows) within its field of view is undergoing development. The camera was designed initially as a means of tracking a remote laser beacon in a...

Briefs : Electronics & Computers
Interface System for Downlinking Digital TV Signals From Spacecraft

A system of interface electronic circuitry that includes a data packetizer and a data depacketizer has been developed to enable the downlinking of both standard- and high-definition television (SDTV and HDTV) signals from a space shuttle or the International Space Station. The...

Briefs : Electronics & Computers
Stereoscopic Vision System Tracks Objects in Real Time

A stereoscopic machine-vision system offers a capability for robust tracking of objects in three dimensions (3D). The system is suitable for use in a variety of robotic applications. The system hardware includes a pan-tilt-verge camera and aiming mechanism assembly and a board that holds...

Briefs : Electronics & Computers
High-Efficiency Ultraviolet CCD Video Camera for Biology

A high-efficiency, high-frame-rate ultraviolet (UV) charge-coupled device (CCD) camera that is especially well suited for biological and defense applications was developed. This is the first high-frame rate camera using delta-doped CCDs, which is suitable for biological imaging having high...

Briefs : Electronics & Computers
Data Acquisition and Control Systems Laboratory

The Data Acquisition and Control Systems (DACS) Laboratory is a facility at Stennis Space Center that provides an off test-stand capability to develop data-acquisition and control systems for rocket-engine test stands. It is also used to train new employees in state-of-the-art systems, and provides...

Briefs : Electronics & Computers
Geography-Based Routing in an Ad Hoc Communication Network

The best-effort geographical multi-hop routing (BEGHR) protocol routes packets of data in an ad hoc digital radio-communication network on the basis of the current geographical positions of all the network nodes. This protocol was conceived especially for application to a network, (1)...

Briefs : Information Technology
Characteristics of Dynamics of Intelligent Systems

An investigation of nonlinear mathematical models of dynamics has led to the selection of characteristics that could be useful for distinguishing mathematically between the behaviors of (1) intelligent or living systems and (2) nonliving systems. As contemplated here, an intelligent or living...

Briefs : Information Technology
Coupled-Layer Architecture for Advanced Software for Robots

The title "Coupled Layer Architecture for Robotics Autonomy" (CLARATy) refers to a software architecture for robots that has been proposed to (1) improve the modularity of robotic-system software while (2) tightening the coupling between autonomy and control software...

Briefs : Materials
Polymer Electrolytes for Rechargeable Lithium Batteries

Polymeric electrolytes for rechargeable lithium-based electrochemical cells and batteries would be made by blending and complexing cyanoresins with lithium salts, according to a proposal. In particular, polymeric electrolytes for separators, carbon-composite anodes, and cathodes would be...

Briefs : Software
Software for Monitoring Performance of Other Software

Performance Logging Services (PLS) is a software utility that tracks the performance of another program in terms of statistics of timing and use of memory buffers. The monitored program must utilize either the UNIX or the VxWorks operating system. PLS can monitor performance requirements in...

Briefs : Software
Software for Multidisciplinary Analysis With Parallelization

HiMAP is an advanced, portable software system that implements highly modular, parallel computation of the possibly nonlinear, coupled behaviors of aeroelastic and other complex systems that comprise subsystems, each of which is modeled by use of software formulated within a separate...

Briefs : Software
ICAN/JAVA: Integrated Composite Analyzer Recoded in Java

The Integrated Composite Analyzer (ICAN) computer program, originally written in the FORTRAN language, has been completely recoded in Java to make it more widely usable. Whereas the original ICAN could be executed on only a limited number of platforms, ICAN/JAVA is compatible with almost...

Briefs : Software
Software for Onboard Autonomy of a Three-Spacecraft Mission

A system of software has been designed to enable autonomous operations of the three University-built miniature spacecraft of the Three Corner Sat mission, scheduled for launch in 2003. The main software subsystems and their functions are the following:

Briefs : Software
Software for Mobile Data-Communication Networks

Mobile Router is operating system code residing in a network router allowing the router to provide mobile-ipv4 functionality for any attached nodes. Mobile Router enables the entire network to roam. It is no longer necessary for every node in the network to run mobile Internet Protocol (IP)...

Briefs : Software
Runge-Kutta Circular-Advection-Problem Solver

Release 3.0 of the Multi-Stage Runge-Kutta Circular Advection Solver is a computer program that solves the circular-advection problem by use of a general m-stage Runge-Kutta scheme (for m = 1, 2, and 4) on a Cartesian (x,y) grid with optimized coefficients. [The circular-advection problem, ¶u/¶t =...

Briefs : Software
Software Optimizes Piping System for Sewage Treatment Plant

A $90 million AUS (Australian dollar) upgrade ($49 million USD) to the Cronulla Sewage Treatment Plant in Southern Sydney, Australia, was undertaken to meet the requirements of a growing population and to add advanced sewage treatment processes including ultraviolet disinfection. During...

Briefs : Manufacturing & Prototyping
Micromachining of a Mesoscale Vibratory Gyroscope

A micromachining-based fabrication process has been proposed for low-volume production of copies of a mesoscale vibratory gyroscope. The process would include steps of photolithography, metallization, deep reactive-ion etching (RIE), Au/Au thermal-compression bonding, and anodic bonding. In the...

Briefs : Manufacturing & Prototyping
Deforming Fibrous Insulating Tiles To Fit Curved Surfaces

A curved tile of refractory silica-fiber-based or alumina-fiber-based thermal-insulation material can be formed from an initially flat billet in a process that includes pressing against a curved mold surface during heating. The mold or tile curvature can be concave or convex. Curved tiles...

Briefs : Mechanical & Fluid Systems
Optimization of Orientations of Spacecraft Reaction Wheels

A report presents a method of optimizing the orientations of three reaction wheels used to regulate the angular momentum of a spacecraft. The method yields an orientation matrix that minimizes mass, torque, and power demand of the reaction wheels while maximizing the allowable duration...

Briefs : Physical Sciences
Compact System Detects Potentially Explosive Gas Mixtures

The figure depicts selected aspects of a "smart" microelectronic-based hazardous-gas-detection system that simultaneously measures concentrations of hydrogen and oxygen. Unlike conventional gas-leak-detection systems built around mass spectrometers, this system is not restricted...

Briefs : Physical Sciences
Scanning Thermography

Scanning thermography is a noncontact, nondestructive technique that makes it possible to find defects hidden inside structural components in a variety of settings. Scanning thermography can be used to perform inspections of objects that may have large areas and a variety of shapes and that are found in a variety of...

Briefs : Physical Sciences
Ultrahigh-Vacuum Arc-Jet Source of Nitrogen for Epitaxy

An arc-jet source of chemically active nitrogen atoms has been developed for use in molecular-beam epitaxy (MBE) to grow such III-V semiconductors as nitrides of gallium, aluminum, and indium. This apparatus utilizes a confined arc to thermally excite N2 and to dissociate...

Briefs : Physical Sciences
Lightweight Mirrors for Orbiting Earth-Observing Instruments

A report discusses selected aspects of a continuing program to develop thermally stable, lightweight mirrors for planned Earth-observing spaceborne instruments. These mirrors are required to retain precise concave or convex surface figures required for diffraction-limited optical...

Briefs : Motion Control
Fail-Safe Electromagnetic Motor Brakes

Fail-safe electromagnetic motor brakes are undergoing development for use in joints of robot arms. The brakes are needed for both static holding and emergency stopping. In the present context, "fail-safe" signifies that a brake disengages (that is, allows motion) when electric power to the brake is turned...

Briefs : Mechanical & Fluid Systems
Three-Degree-of-Freedom Parallel Mechanical Linkage

Figure 1 depicts a mechanical linkage that converts rotational motion about three base joints (A, B, and C) to translational motion of an end effector (D) in three dimensions. The linkage is fully forward- or back-driveable: It can be driven by motors at joints A, B, and C to obtain a desired...

Briefs : Motion Control
Releasable Conical Roller Clutch for Knee Brace

A compact conical roller clutch can be either (1) engaged to obtain both positive locking against rotation in one sense and freewheeling in the opposite sense or (2) disengaged to obtain free rotation in both senses. This clutch was devised to enhance the functionality and increase the durability...