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At least 109 records · Page 6

Short constraint length rate 1/2 'quick-look' codes

Quick-look nonsystematic convolutional codes have the property that the information sequence may be recovered from the encoded sequence in straightforward fashion and with a minimum of error amplification. In this concise paper we investigate their relevant characteristics for constraint lengths less than eight and rate 1/2 and obtain a number of interesting and practically useful results. In particular, for the best of these codes, we derive their free distance and error amplification, their decoded bit error probability when used over the binary symmetric channel in conjunction with Viterbi decoding, and show how they can be employed to measure the channel bit error rate.

Helgert, H. J.↗

QUICK-GEOMETRY, a rapid response method for mathematically modeling configuration geometry

The philosophy, development, and various applications of the QUICK-GEOMETRY system were outlined. This system provides a practical method for developing the geometry models that are essential to the operation of computer-based design and manufacturing systems. Of particular interest are the various methods for modeling surface geometry that are used by aerodynamic analysis codes.

Vachris, A. F., Jr.↗

Quick-disconnect coupling/filter

Two-part coupling system for hose lines combines both connection and filter in one fitting. Flared fittings make coupling less prone to leakage, and reduced number of components speeds operation. These features may make coupler useful with liquid-bulk carriers, where materials (e.g., milk, cooking oil, and liquid sugar) must be transferred quickly from vehicle to storage facility.

Jankowski, F.↗

Quick look analysis of an emergency separation for ALT captive-inert flight 1

Emergency separation capability for the landing configuration of ALT Captive Inert Flight Number One was investigated. The quick look analysis confirms emergency separation capability under nominal conditions for the ALT landing configuration. The recommended emergency separation procedure under those conditions is not applicable to all ALT configurations.

Glenn, G. M.↗

Quick-and-easy shear-load testing

Device for applying shear loads to test specimens can be attached and removed without damaging specimen surface. Because it is quick, clean, and inexpensive, method is expected to be useful in commercial testing laboratories for applying shear loads to smooth surfaces on which there is no provision for conventional attachments and which could be easily damaged.

Gustafson, J. A.↗

Quick-connect threaded attachment joint

Joint is self-aligning and tightens with only sixty-five degrees of rotation for quick connects and disconnects. Made of injection-molded plastics or cast or machined aluminum, joint can carry wires, tubes, liquids, or gases. When two parts of joint are brought together, their shapes align them. Small projections on male section and slots on female section further aid alignment; slight rotation of male form engages projections in slots. At this point, threads engage and male section is rotated until joint is fully engaged.

Lucy, M. H.↗

A quick response four decade logarithmic high-voltage stepping supply

An improved high-voltage stepping supply, for space instrumentation is described where low power consumption and fast settling time between steps are required. The high-voltage stepping supply, utilizing an average power of 750 milliwatts, delivers a pair of mirror images with 64 level logarithmic outputs. It covers a four decade range of + or - 2500 to + or - 0.29 volts having an output stability of + or - 0.5 percent or + or - 20 millivolts for all line load and temperature variations. The supply provides a typical step setting time of 1 millisecond with 100 microseconds for the lower two decades. The versatile design features of the high-voltage stepping supply provides a quick response staircase generator as described or a fixed voltage with the option to change levels as required over large dynamic ranges without circuit modifications. The concept can be implemented up to + or - 5000 volts. With these design features, the high-voltage stepping supply should find numerous applications where charged particle detection, electro-optical systems, and high voltage scientific instruments are used.

Doong, H.↗

Vulnerability of Quick Disconnect Connectors to Carbon Fibers

Unprotected quick disconnect electrical connectors were exposed to fibers of 3mm, 7mm, and 12mm lengths. The average exposure to failure was determined. Results indicate that when the fiber length divided by the airgap is less than one, multiple fibers are required to bridge the gap, and the exposure time to failure rises rapidly.

Meyers, J. A.↗

Quick-look decoding schemes for DSN convolutional codes

Decoding schemes are proposed for the tracking systems of the galileo project. Quick look decoding schemes requiring only shift registers are given for the DSN (7, 1/2) and (7, 1/3) convolutional codes. These schemes are used when the communication channel is error free. The schemes decode the data, symbol errors, and the lack of node syncronization.

Greenhall, C. A.↗

Processing of on-board recorded data for quick analysis of aircraft performance

A system of independent computer programs for the processing of digitized pulse code modulated (PCM) and frequency modulated (FM) data is described. Information is stored in a set of random files and accessed to produce both statistical and graphical output. The software system is designed primarily to present these reports within a twenty-four hour period for quick analysis of the helicopter's performance.

Michaud, N. H.↗

Quick mixing of epoxy components

Two materials are mixed quickly, thoroughly, and in precise proportion by disposable cartridge. Cartridge mixes components of fast-curing epoxy resins, with no mess, just before they are used. It could also be used in industry and home for caulking, sealing, and patching. Materials to be mixed are initially isolated by cylinder wall within cartridge. Cylinder has vanes, with holes in them, at one end and handle at opposite end. When handle is pulled, grooves on shaft rotate cylinder so that vanes rotate to extrude material A uniformly into material B.

Dunlap, D. E., Jr.↗

Report on JANNAF panel on shotgun/relative quickness testing

As the need for more energetic solid propellants continues, a number of problems arises. One of these is the tendency of high energy propellants to transition from burning (deflagration) to detonation in regions where the propellant is present in small particle sizes; e.g., in case bonding areas of a motor after a rapid depressurization causes a shear zone at the bond interface as the stressed propellant and motor case relax at different rates. In an effort to determine the susceptibility of propellants to high strain rate break up (friability), and subsequent DDT, the propulsion community uses the shotgun/relative quickness test as one of a number of screening tests for new propellant formulations. Efforts to standardize test techniques and equipment are described.

Gould, R. A.↗

Passive Optical Sample Assembly (POSA) for STS-1 quick look post-mission report

A passively deployed array of contamination-sensitive samples was mounted and flown in the cargo bay of the space shuttle Columbia during the first orbital flight test. A similar unit was mounted in a different location in the cargo bay at Dryden Flight Research Center during the postflight operations there prior to the ferry flight return of Columbia to Kennedy Space Center. The samples in both POSA arrays were subjected to a series of optical and analytical measurements prior to delivery for installation in the cargo bay and after retrieval of the flight hardware. A quick-look summary of the results of a comparison of the series of measurements is presented.

Linton, R. C.↗

The hammer QSD-quick stop device for high speed machining and rubbing

A quick stop device (QSD) was designed for use in orthogonal machining and rubbing experiments. QSD's are used to obtain chip root samples that are representative of the deformation taking place during dynamic (actual) cutting conditions. These 'frozen' specimens are helpful in examining the plastic deformation that occurs in the regions of compression and shear which form the chip; the secondary shear at the tool-chip interface; and the nose ploughing/flank rubbing action which operates on the newly machined surface. The Hammer QSD employs a shear pin mechanism, broken by a flying hammer, which is traveling at the same velocity as the workpiece. The device has been successfully tested up to 6000 sfpm (30.48 m/sec).

Black, J. T.↗

A quick-look decoder with isolated error correction and node synchronization

It is noted that in a low-noise environment, a simple inversion circuit can be used for quick-look decoding of a convolutional code. An improvement in the bit error performance of the raw inversion circuit is effected by a simple pattern-recognition technique operating on the syndrome stream, which is also used to acquire node sync.

Greenhall, C. A.↗

Quick-Disconnect Fastener

Proposed quick-disconnect fastener for two or more parts resists shear loads and torque. Device centers parts to be joined, clamps and tightens them into single unit. Potential applications for removable fastener include holding parts for welding, brazing, soldering, riveting, and gluing. Other possible uses are for attaching removable panels and panels with poor access on one side and plugging leaks in pressure vessels.

Palmer, L. W.↗

STS-2 Induced Environment Contamination Monitor (IECM): Quick-Look Report

The STS-2/induced environment contamination monitor (IECM) mission is described. The IECM system performance is discussed, and IECM mission time events are briefly described. Quick look analyses are presented for each of the 10 instruments comprising the IECM on the flight of STS-2. A short summary is presented.

Miller, E. R.↗

STS-3 Induced Environment Contamination Monitor (IECM): Quick-look report

The STS-3/Induced Environment Contamination Monitor (IECM) mission is described. The IECM system performance is discussed, and IECM mission time events are briefly described. Quick look analyses are presented for each of the 10 instruments comprising the IECM on the flight of STS-3. Finally, a short summary is presented and plans are discussed for future IECM flights, and opportunities for direct mapping of Orbiter effluents using the Remote manipulator System.

Miller, E. R.↗