1,619 research outputs found

    Investigation of temporal variations of winds

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    Nighttime observations of upper atmospheric wind data to determine physical properties of atmospher

    Observations of chemical releases from high flying aircraft

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    Barium and lithium vapors were released from sounding rockets in the thermosphere and observed from aboard the NASA Convair 990 at an altitude of 40,000 ft. The purpose of the releases was to (1) check out observational and operational procedures associated with the large high altitude barium release from a Scout rocket (BIC); (2) develop an all-weather technique for observing chemical releases; (3) evaluate methods of observing daytime releases, and (4) investigate the possibilities of observations from a manned satellite. The initial analysis indicates that the previous limitations on the usage of the vapor release method have been removed by the use of the aircraft and innovative photographic techniques. Methods of analysis and applications to the investigation of the thermosphere are discussed

    Numerical evaluation of the incomplete airy functions and their application to high frequency scattering and diffraction

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    The incomplete Airy integrals serve as canonical functions for the uniform ray optical solutions to several high frequency scattering and diffraction problems that involve a class of integrals characterized by two stationary points that are arbitrarily close to one another or to an integration endpoint. Integrals of such analytical properties describe transition region phenomena associated with composite shadow boundaries. An efficient and accurate method for computing the incomplete Airy functions would make the solutions to such problems useful for engineering purposes. Here, a convergent series solution form for the incomplete Airy functions is derived. Asymptotic expansions involving several terms were also developed and serve as large argument approximations. The combination of the series solution form with the asymptotic formulae provides for an efficient and accurate computation of the incomplete Airy functions. Validation of accuracy is accomplished using direct numerical integration data

    Foundations of Social Media Marketing

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    The Social Media have changed the power structures in the marketplace; evidence points to a major power migration taking place and to emergence of a new breed of powerful and sophisticated customer, difficult to influence, persuade and retain The paper outlines the nature, effects and present status of the Social Media, underlying their role as customer empowerment agents. It explains their aptitude and possible roles as part of the corporate Marketing strategy and identifies different ways of engaging them as marketing tools. The paper proposes two possible Social Media marketing strategies: a. The passive approach focusing on utilizing the Social Media domain as source of customer voice and market intelligence. b. The active approach i.e. engaging the Social Media as direct marketing and PR channels, as channels of customer influence, as tools of personalizing products and last but not least develop them as platforms of co-operation and customer-generated innovation. Finally the paper identifies future research directions around this new element of the marketing landscap

    Optimal Bond Trading with Personal Taxes: Implications for Bond Prices and Estimated Tax Brackets and Yield Curves

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    The assumption that bondholders follow either a buy-and-hold or a continuous realization trading policy, rather than the optimal trading policy,is at variance with reality and, as we demonstrate, may seriously bias the estimation of the yield curve and the implied tax bracket of the marginal investor. Tax considerations which govern a bondholder's optimal trading policy include the following: realization of capital losses, short term if possible; deferment of the realization of capital gains, especially if they are short term; changing the holding period status from long term to short term by sale of the bond and repurchase, so that future capital losses may be realized short term; and raising the basis through sale of the bond and repurchase in order to deduct from ordinary income the amortized premium. Because of the interaction of these factors, no simple characterization of the optimal trading policy is possible. We can say, however, that it differs substantially from the buy-and-hold policy irrespective of whether the bondholder is a bank, a bond dealer, or an individual. We obtain these strong results even when we allow for transactions costs and explicitly consider numerous IRS regulations designed to curtail tax avoidance.

    Study of the dynamics and ionization of the upper atmosphere Final report

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    Wind effects on nighttime E region ionization layer distributio

    Investigation of the time variation of sporadic-E layers Final report

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    Analysis of wind and electron density profiles of E-region obtained from Nike-Apache rockets launched 22 Feb. 196

    KAPow: A System Identification Approach to Online Per-Module Power Estimation in FPGA Designs

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    In a modern FPGA system-on-chip design, it is often insufficient to simply assess the total power consumption of the entire circuit by design-time estimation or runtime power rail measurement. Instead, to make better runtime decisions, it is desirable to understand the power consumed by each individual module in the system. In this work, we combine boardlevel power measurements with register-level activity counting to build an online model that produces a breakdown of power consumption within the design. Online model refinement avoids the need for a time-consuming characterisation stage and also allows the model to track long-term changes to operating conditions. Our flow is named KAPow, a (loose) acronym for ‘K’ounting Activity for Power estimation, which we show to be accurate, with per-module power estimates as close to ±5mW of true measurements, and to have low overheads. We also demonstrate an application example in which a permodule power breakdown can be used to determine an efficient mapping of tasks to modules and reduce system-wide power consumption by over 8%

    Higher Education Marketing: A Study on the Impact of Social Media on Study Selection and University Choice.

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    The importance of the Internet as commercial platform is by now universally recognized, and businesses increasingly adopt online marketing channels at the cost of traditional ones. The social media, being second generation (Web 2.0) internet applications, allow interaction, one-to-one communication, customer engagement, and user generated content. The interest of higher education institutions in social media as part of the marketing toolkit is increasing, but little is known about the potential of these channels in higher education marketing strategies. Even less is known about the role of social media as influencers of future students in the choice of study and university. This article presents the results of a study identifying the role and importance of social media on the choice of future students for a study and university in comparison with the traditional university marketing channels in the Netherlands. The study identifies and describes three market segments among future students based on their use of the social medi

    Creative tools for producing realistic 3D facial expressions and animation

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    Creative exploration of realistic 3D facial animation is a popular but very challenging task due to the high level knowledge and skills required. This forms a barrier for creative individuals who have limited technical skills but wish to explore their creativity in this area. This paper proposes a new technique that facilitates users’ creative exploration by hiding the technical complexities of producing facial expressions and animation. The proposed technique draws on research from psychology, anatomy and employs Autodesk Maya as a use case by developing a creative tool, which extends Maya’s Blend Shape Editor. User testing revealed that novice users in the creative media, employing the proposed tool can produce rich and realistic facial expressions that portray new interesting emotions. It reduced production time by 25% when compared to Maya and by 40% when compared to 3DS Max equivalent tools
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