27,229 research outputs found

    Theoretical and subjective bit assignments in transform picture

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    It is shown that all combinations of symmetrical input distributions with difference distortion measures give a bit assignment rule identical to the well-known rule for a Gaussian input distribution with mean-square error. Published work is examined to show that the bit assignment rule is useful for transforms of full pictures, but subjective bit assignments for transform picture coding using small block sizes are significantly different from the theoretical bit assignment rule. An intuitive explanation is based on subjective design experience, and a subjectively obtained bit assignment rule is given

    A comparison of measured and theoretical predictions for STS ascent and entry sonic booms

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    Sonic boom measurements have been obtained during the flights of STS-1 through 5. During STS-1, 2, and 4, entry sonic boom measurements were obtained and ascent measurements were made on STS-5. The objectives of this measurement program were (1) to define the sonic boom characteristics of the Space Transportation System (STS), (2) provide a realistic assessment of the validity of xisting theoretical prediction techniques, and (3) establish a level of confidence for predicting future STS configuration sonic boom environments. Detail evaluation and reporting of the results of this program are in progress. This paper will address only the significant results, mainly those data obtained during the entry of STS-1 at Edwards Air Force Base (EAFB), and the ascent of STS-5 from Kennedy Space Center (KSC). The theoretical prediction technique employed in this analysis is the so called Thomas Program. This prediction technique is a semi-empirical method that required definition of the near field signatures, detailed trajectory characteristics, and the prevailing meteorological characteristics as an input. This analytical procedure then extrapolates the near field signatures from the flight altitude to an altitude consistent with each measurement location

    Two techniques for digital filter design

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    Digital controllers, one using a special-purpose computer and the other using a combination of digital and analog techniques, are designed around /1/ computers that simulate the transfer function and interface with the system, and /2/ analog and digital circuits, converters, amplifiers, constant multipliers, and delay lines that form a digital filter

    A study of various synthetic routes to produce a halogen-labeled traction fluid

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    Several synthetic routes were studied for the synthesis of the compound 1, 1, 3-trimethyl-1, 3-dicyclohexyl-2 chloropropane. This halogen-labeled fluid would be of use in the study of high traction lubricants under elastohydrodynamic lubrication conditions using infrared emission spectroscopy. The synthetic routes included: dimerization of alpha-methylstyrene, methanol addition to alpha-methylstyrene, a Wittig reaction, and an organometallic approach. Because of steric hindrance and competing reactions, none of these routes were successful

    Solar radius measurements

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    Preliminary results of measurements made during 1979-1980 are discussed. Variability in the radius measurements of 0.4 pi is found, of unknown origin

    Correlation of predicted and measured sonic boom characteristics from the reentry of STS-1 orbiter

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    Characteristics from sonic boom pressure signatures recorded at 11 locations during reentry of the Space Shuttle Orbiter Columbia are correlated with characteristics of wind tunnel signatures extrapolated from flight altitudes for Mach numbers ranging from 1.23 to 5.87. The flight pressure signature were recorded by microphones positioned at two levels near the descent groundtrack along the California corridor. The wind tunnel signatures used in theoretical predictions were measured using a 0.0041-scale model Orbiter. The mean difference between all measured and predicted overpressures is 12 percent from measured levels. With one exception, the flight signatures are very similar to theoretical n-waves

    MARGINAL PRICE OF LAKE RECREATION AND AESTHETICS: AN HEDONIC APPROACH

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    Efficient allocation of water requires knowledge of water's value in both consumptive and nonconsumptive uses. This study estimates the marginal value of water in lake recreational and aesthetic (RA) use. An hedonic price equation (employing the Box-Cox functional form) indicates lake front location, distance to lake, and scenic view are significant RA characteristics of housing. Water front properties command a premium price for the private access they offer. Beyond the water front, the marginal RA price falls rapidly with increasing distance, becoming asymptotic to some minimum. Twenty-two percent of housing price is found to be attributable to the RA component.Aesthetic, Box-Cox, Hedonic, Housing, Lake, Nonmarket, Recreation, Water, Resource /Energy Economics and Policy,

    National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program, 1989, volume 1

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    The 1989 Johnson Space Center (JSC) National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program was conducted by Texas A and M University and JSC. The 10-week program was operated under the auspices of the ASEE. The program at JSC, as well as the programs at other NASA Centers, was funded by the Office of University Affairs, NASA Headquarters, Washington, D.C. The objectives of the program, which began nationally in 1964 and at JSC in 1965, are: (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate an exchange of ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of participants' institutions; and (4) to contribute to the research objective of the NASA Centers

    RECREATIONAL AND AESTHETIC VALUE OF WATER USING HEDONIC PRICE ANALYSIS

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    Historically, water allocation focused on quantities demanded by consumptive uses. As quantity demand grows, efficient allocation among consumptive and nonconsumptive uses becomes more critical. This hedonic approach provides information regarding recreational and aesthetic (RA) value for a central Texas lake. The model indicates several statistically significant RA characteristics of housing; proximity is the most important. Waterfront properties command a premium, but marginal RA price falls rapidly with increasing distance. Marginal RA values are estimated for selected water levels and are found to have a lower marginal price per acre-foot than many agricultural uses.Demand and Price Analysis, Resource /Energy Economics and Policy,

    Sanctions for E-Discovery Violations: By the Numbers

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    This Article reviews our comprehensive survey of written opinions from cases in federal courts prior to January 1, 2010, involving motions for sanctions relating to the discovery of electronically stored information (ESI) We analyzed each case for various factors, including date, court, type of case, sanctioning authority, sanctioned party, sanctioned misconduct, sanction type, sanctions to counsel, if any, and the protections provided from sanctions by Federal Rule of Civil Procedure 37(e) The survey identified 401 sanction cases and 230 sanction awards and showed that sanction motions and awards have increased over time, particularly in the last five years Sanctions against counsel are rare but are also increasing Sanction motions have been filed in all types of cases and in courts across the country Failure to produce ESI is the most common basis for sanctions Courts have used a variety of different rules, statutes, and powers to sanction parties for e-disco very violations, including Rule 37 and the inherent power of the court, and courts impose many different sanction types on e-discovery violators, including the severe sanctions of dismissal, default Judgment, adverse jury instructions, and sizeable monetary awards Rule 37(e) has not provided broad protection from such sanction
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