3,005 research outputs found

    Hypersonic Research Vehicle (HRV) real-time flight test support feasibility and requirements study. Part 2: Remote computation support for flight systems functions

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    The requirements are assessed for the use of remote computation to support HRV flight testing. First, remote computational requirements were developed to support functions that will eventually be performed onboard operational vehicles of this type. These functions which either cannot be performed onboard in the time frame of initial HRV flight test programs because the technology of airborne computers will not be sufficiently advanced to support the computational loads required, or it is not desirable to perform the functions onboard in the flight test program for other reasons. Second, remote computational support either required or highly desirable to conduct flight testing itself was addressed. The use is proposed of an Automated Flight Management System which is described in conceptual detail. Third, autonomous operations is discussed and finally, unmanned operations

    Automated flight test management system

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    The Phase 1 development of an automated flight test management system (ATMS) as a component of a rapid prototyping flight research facility for artificial intelligence (AI) based flight concepts is discussed. The ATMS provides a flight engineer with a set of tools that assist in flight test planning, monitoring, and simulation. The system is also capable of controlling an aircraft during flight test by performing closed loop guidance functions, range management, and maneuver-quality monitoring. The ATMS is being used as a prototypical system to develop a flight research facility for AI based flight systems concepts at NASA Ames Dryden

    On the maximal Sobolev regularity\ud of distributions supported by subsets of Euclidean space

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    Given a subset EE of Rn\R^n with empty interior and an integrability parameter 1<p<1<p<\infty, what is the maximal regularity sRs\in\R for which there exists a non-zero distribution in the Bessel potential Sobolev space H^{s,p (\R^n) that is supported in EE? For sets of zero Lebesgue measure we show, using results on certain set capacities from classical potential theory, that the maximal regularity is non-positive, and is characterised by the Hausdorff dimension of EE, improving known results. We classify all possible maximal regularities, as functions of pp, together with the sets of values of pp for which the maximal regularity is attained, and construct concrete examples for each case.\ud \ud For sets with positive measure the maximal regularity is non-negative, but appears more difficult to characterise in terms of geometrical properties of EE. We present some partial results relating to the latter case, namely lower bounds on the maximal Sobolev regularity supported by certain fat Cantor sets, which we obtain both by capacity-theoretic arguments, and by direct estimation of the Sobolev norms of characteristic functions. We collect several results characterising the regularity that can be achieved on certain special classes of sets, such as dd-sets, boundaries of open sets, and Cartesian products, of relevance for applications in differential and integral equations

    Two-dimensional and relativistic effects in lower-hybrid current drive

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    From an automated flight-test management system to a flight-test engineer's workstation

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    The capabilities and evolution is described of a flight engineer's workstation (called TEST-PLAN) from an automated flight test management system. The concept and capabilities of the automated flight test management systems are explored and discussed to illustrate the value of advanced system prototyping and evolutionary software development

    Interpolation of Hilbert and Sobolev Spaces:\ud Quantitative Estimates and Counterexamples

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    This paper provides an overview of interpolation of Banach and Hilbert spaces, with a focus on establishing when equivalence of norms is in fact equality of norms in the key results of the theory. (In brief, our conclusion for the Hilbert space case is that, with the right normalisations, all the key results hold with equality of norms.) In the final section we apply the Hilbert space results to the Sobolev spaces Hs(Ω)H^s(\Omega) and H~s(Ω)\tilde{H}^s(\Omega), for sRs\in \mathbb{R} and an open ΩRn\Omega\subset \mathbb{R}^n. We exhibit examples in one and two dimensions of sets Ω\Omega for which these scales of Sobolev spaces are not interpolation scales. In the cases when they are interpolation scales (in particular, if Ω\Omega is Lipschitz) we exhibit examples that show that, in general, the interpolation norm does not coincide with the intrinsic Sobolev norm and, in fact, the ratio of these two norms can be arbitrarily large

    The use of an automated flight test management system in the development of a rapid-prototyping flight research facility

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    An automated flight test management system (ATMS) and its use to develop a rapid-prototyping flight research facility for artificial intelligence (AI) based flight systems concepts are described. The ATMS provides a flight test engineer with a set of tools that assist in flight planning and simulation. This system will be capable of controlling an aircraft during the flight test by performing closed-loop guidance functions, range management, and maneuver-quality monitoring. The rapid-prototyping flight research facility is being developed at the Dryden Flight Research Facility of the NASA Ames Research Center (Ames-Dryden) to provide early flight assessment of emerging AI technology. The facility is being developed as one element of the aircraft automation program which focuses on the qualification and validation of embedded real-time AI-based systems

    Signals for Vector Leptoquarks in Hadronic Collisions

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    We analyze systematically the signatures of vector leptoquarks in hadronic collisions. We examine their single and pair productions, as well as their effects on the production of lepton pairs. Our results indicate that a machine like the CERN Large Hadron Collider (LHC) will be able to unravel the existence of vector leptoquarks with masses up to the range of 22--33 TeV.Comment: 15 pages and 5 figures (available upon request or through anonymous ftp), revtex3, IFUSP-P 108

    Indirect Collider Signals for Extra Dimensions

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    A recent suggestion that quantum gravity may become strong near the weak scale has several testable consequences. In addition to probing for the new large (submillimeter) extra dimensions associated with these theories via gravitational experiments, one could search for the Kaluza Klein towers of massive gravitons which are predicted in these models and which can interact with the fields of the Standard Model. Here we examine the indirect effects of these massive gravitons being exchanged in fermion pair production in \epem annihilation and Drell-Yan production at hadron colliders. In the latter case, we examine a novel feature of this theory, which is the contribution of gluon gluon initiated processes to lepton pair production. We find that these processes provide strong bounds, up to several TeV, on the string scale which are essentially independent of the number of extra dimensions. In addition, we analyze the angular distributions for fermion pair production with spin-2 graviton exchanges and demonstrate that they provide a smoking gun signal for low-scale quantum gravity which cannot be mimicked by other new physics scenarios.Comment: Corrected typos, added table and reference
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