10,444 research outputs found

    Digital data reformatter/deserializer

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    A method and apparatus is presented for reformatting and de-serializing a serially-received sequence of data words, each consisting of a fixed number of binary data bits. A block of nm bits is serially fed into a shift register or serially-connected group of shift registers. In lieu of the(nm-1)th shifts, the bits are rearranged within the shift register in parallel fashion, according to a prescribed scheme. Shifting then continues, until the first bit of each data word appears in the last bit position in the shift register, at which time that data word is shifted in parallel into an output buffer stage, from which it is outputted in parallel, after a fixed delay

    Drawn to the Sea: Charles Bradford Hudson (1865-1939), Artist, Author, Army Officer, with Special Notice of His Work for the United States Fish Commission and Bureau of Fisheries

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    The biography of Charles Bradford Hudson that follows this preface had its seeds about 1965 when I (VGS) was casually examining the extensive files of original illustrations of fishes stored in the Division of Fishes, National Museum of Natural History, Smithsonian Institution. I happened upon the unpublished illustration of a rainbow trout by Hudson and was greatly impressed with its quality. The thought occurred to me then that the artist must have gone on to do more than just illustrate fishes. During the next 20 years I occasionally pawed through those files, which contained the work of numerous artists, who had worked from 1838 to the present. In 1985, I happened to discuss the files with my supervisor, who urged me to produce a museum exhibit of original fish illustrations. This I did, selecting 200 of the illustrations representing 21 artists, including, of course, Hudson. As part of the text for the exhibit, Drawn from the Sea, Art in the Service of Ichthyology, I prepared short biographies of each of the artists. The exhibit, with an available poster, was shown in the Museum for six months, and a reduced version was exhibited in U.S. and Canadian museums during the next 3 years

    The Impact of User Effects on the Performance of Dual Receive Antenna Diversity Systems in Flat Rayleigh Fading Channels

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    In this paper we study the impact of user effects on the performance of receive antenna diversity systems in flat Rayleigh fading channels. Three diversity combining techniques are compared: maximal ratio combining (MRC), equal gain combining (EGC), and selection combining (SC). User effects are considered in two scenarios: 1) body loss (the reduction of effective antenna gain due to user effects) on a single antenna, and 2) equal body loss on both antennas. The system performance is assessed in terms of mean SNR, link reliability, bit error rate of BPSK, diversity order and ergodic capacity. Our results show that body loss on a single antenna has limited (bounded) impact on system performance. In comparison, body loss on both antennas has unlimited (unbounded) impact and can severely degrade system performance. Our results also show that with increasing body loss on a single antenna the performance of EGC drops faster than that of MRC and SC. When body loss on a single antenna is larger than a certain level, EGC is not a “sub-optimal” method anymore and has worse performance than SC

    The Impacts of Contract Type on Broker Performance: Submarket Effects

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    Rutherford et al. (2001) develop and empirically test a model that analyzes the effect the type of listing contract, either exclusive agency (EA) or exclusive right to sell (ERTS), has on the performance of the agent/broker. This paper extends the work of Rutherford et al. (2001) and looks at differences between housing submarkets delineated by price. The results show a selling price discount associated with both broker-effected and owner-effected sales for lower-priced houses with EA contracts. For higher-priced houses, there is no price advantage to an EA-listing if the broker achieves the sale, but if the owner sells the house, there is a modest price premium associated with the sale. The primary implication of the results is that owners of lower-priced houses should be wary of alternative listing arrangements, namely exclusive agency contracts.

    Influence of Hydrolytic and Chemical Treatment on the Mechanical Properties of Aramid and Copolyaramid Fibers

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    Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Commercial PPTA fibers ( Kevlar 49® and Twaron 1055®) and copolyaramid fibers (Trevar®) are subjected to various hydrolytic and chemical treatments. Tensile mod ulus, tensile strength, and elongation at break are measured, and mechanical property deterioration is compared. Copolyaramid fibers show improved hydrolytic stability and chemical resistance compared to PPTA fibers. The time dependence of degradation pro cesses can be described by two decreasing exponential functions. WAXS measurements detect only slight differences in the crystalline structure and superstructure of the treated fibers. Thus, the main origin of mechanical degradation is the destruction of intercrys talline links such as tie molecules or tie crystallites

    Potential on Using Cultural Syndromes for Explaining Differences in Attitudes in Northern and Southern EU Countries

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    Nowadays, it is more realistic to view the development of a new technology as a result of a complex social system of interactions and decisions. Understanding the public's range of views on biotechnology is important for decision makers, in order to be able to anticipate potential acceptance problems or, one step further, to take consumer or public desires and concerns into account so that desirable applications can be developed. Previous work from the same research group, using data from Eurobarometer surveys, was trying to explore the attitudes of the European consumers towards genetic modification of food. Emerging differences in attitudes towards genetically modified food have not been explained adequately in most cases using only sociodemographic variables. In addition strong national differences lead to the idea that cultural differences should also be taken into account, despite the difficulties in formulating specific hypotheses that can be tested empirically. In this paper, in an effort to approach culture in a more clear way, we try to track down and analyse the specific units (customs, traditions, beliefs, and other social norms) that comprise cultures. The notion of cultural syndromes as approached by Triandis is tackled. Furthermore applying data from the European Social Survey (ESS) to Schwartz's value system, our objective is to validate empirically the potential utilisation of Schwartz values to further explain existing differences in attitudes towards GM food among European countries. Further research can lead to a deeper and more precise understanding of cultural differentiation as well as to a more valid cross-cultural theory of attitude formation.attitudes towards genetically modified food, attitude formation, cultural differentiation, cultural syndromes, Consumer/Household Economics,

    Noiseless Quantum Circuits for the Peres Separability Criterion

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    In this Letter we give a method for constructing sets of simple circuits that can determine the spectrum of a partially transposed density matrix, without requiring either a tomographically complete POVM or the addition of noise to make the spectrum non-negative. These circuits depend only on the dimension of the Hilbert space and are otherwise independent of the state.Comment: 4 pages RevTeX, 7 figures encapsulated postscript. v5: title changed slightly, more-or-less equivalent to the published versio
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