Flexible high speed codec

The project's objective is to develop an advanced high speed coding technology that provides substantial coding gains with limited bandwidth expansion for several common modulation types. The resulting technique is applicable to several continuous and burst communication environments. Decoding provides a significant gain with hard decisions alone and can utilize soft decision information when available from the demodulator to increase the coding gain. The hard decision codec will be implemented using a single application specific integrated circuit (ASIC) chip. It will be capable of coding and decoding as well as some formatting and synchronization functions at data rates up to 300 megabits per second (Mb/s). Code rate is a function of the block length and can vary from 7/8 to 15/16. Length of coded bursts can be any multiple of 32 that is greater than or equal to 256 bits. Coding may be switched in or out on a burst by burst basis with no change in the throughput delay. Reliability information in the form of 3-bit (8-level) soft decisions, can be exploited using applique circuitry around the hard decision codec. This applique circuitry will be discrete logic in the present contract. However, ease of transition to LSI is one of the design guidelines. Discussed here is the selected coding technique. Its application to some communication systems is described. Performance with 4, 8, and 16-ary Phase Shift Keying (PSK) modulation is also presented

A Water Distribution System for Cold Regions: The Single Main Recirculation Method: An Historical Review, Field Evaluation, and Suggested Design Procedures

Students and residents of the Arctic are familiar with the many problems peculiar to the geographical area. This monograph will consider an adequate, safe, and reliable water distribution system. Water supply, together with housing, transportation, and waste disposal, are demanded when a remote area becomes established as a permanent settlement. As long as the population of the North was widely distributed in small mining camps, villages, and individual cabins, water distribution systems were not necessary, as shallow wells and nearby streams adequately served most needs. With the rapidly increasing settlement of the vast lands of the North, the population is being centered in communities rather than distributed over large areas. The world population explosion will undoubtedly contribute to increasing immigration into Arctic and sub-Arctic areas. These changes have already created a need for modern water distribution systems, a need which will become more critical with time.The research upon which this publication is based was performed in accordance with Contract No. ph 86-67-18 with the U.S. Public Health Service, Department of Health, Education, and Welfare. Lastly, the support of the Institute of Water Resources, University of Alaska is acknowledged, through an Office of Water Resources Research grant A-018-Alas

Reflection high-energy electron diffraction analysis of polycrystalline films with grain size and orientation distributions

We report a computationally efficient algorithm to calculate reflection high-energy electron diffraction (RHEED) intensities from well-textured, small-grained polycrystalline films in the kinematic limit. We also show how the intensity maps of the spots in a RHEED pattern from such a film can be quantitatively analyzed to determine the film's average grain size, as well as its in-plane orientation and texture distributions. We find that the in-plane orientation and texture distribution widths of these films can be determined to within 1 degree and that the average lateral grain size can be measured to within a fraction of a nanometer after suitable calibration of our technique

Investigation of reliability attributes and accelerated stress factors on terrestrial solar cells

Major effort during this reporting period was devoted to two tasks: improvement of the electrical measurement instrumentation through the design and construction of a microcomputer controlled short interval tester, and better understanding of second quadrant behavior by developing a mathematical model relating cell temperature to electrical characteristics. In addition, some preliminary work is reported on an investigation into color changes observed after stressing

Infrared testing of electronic components Final report, 5 Apr. 1965 - 5 Jun. 1966

Infrared radiation nondestructive test technique for electrical/electronic equipmen

Honey Bunch \u27n\u27 Me

Contains advertisements and/or short musical examples of pieces being sold by publisher.https://digitalcommons.library.umaine.edu/mmb-vp/6808/thumbnail.jp

Feasibility investigation of integrated optics Fourier transform devices

The possibility of producing an integrated optics data processing device based upon Fourier transformations or other parallel processing techniques, and the ways in which such techniques may be used to upgrade the performance of present and projected NASA systems were investigated. Activities toward this goal include; (1) production of near-diffraction-limited geodesic lenses in glass waveguides; (2) development of grinding and polishing techniques for the production of geodesic lenses in LiNbO3 waveguides; (3) development of a characterization technique for waveguide lenses; and (4) development of a theory for corrected aspheric geodesic lenses. A holographic subtraction system was devised which should be capable of rapid on-board preprocessing of a large number of parallel data channels. The principle involved is validated in three demonstrations

Effect of Virginiamycin on Growth and Carcass Characteristics of Barrows and Gilts

Antibiotics have been used as additives to swine diets for approximately 30 years. Various antibiotics have been shown to improve growth performance and efficiency of feed utilization. In addition, antibiotics have reduced low order infection. Since different organisms are sensitive to different antibiotics, the antibiotic of choice may vary depending on the organisms present. The effect of antibiotics on carcass characteristics has been less conclusive. This experiment was conducted to determine the effect of the antibiotic, virginiamycin, on performance and carcass characteristics of barrows and gilts fed separately