2,560 research outputs found

    Data catalog series for space science and applications flight missions. Volume 4A: Descriptions of meteorological and terrestrial applications spacecraft and investigations

    Get PDF
    The National Space Science Data Center (NSSDC) provides data from and information about space science and applications flight investigations in support of additional studies beyond those performed as the principal part of any flight mission. The Earth-orbiting spacecraft for investigations of the earth and its atmosphere is discussed. Geodetic tracking data are included in this category. The principal subject areas presented are meteorology and earth resources survey, and the spacecraft selection is made according to those subjects. All experiments on board the spacecraft are described. No attempt is made to reference investigations that are related to the above disciplines, but that are described in other volumes of this series

    The transmission or scattering of elastic waves by an inhomogeneity of simple geometry: A comparison of theories

    Get PDF
    The extended method of equivalent inclusion developed is applied to study the specific wave problems of the transmission of elastic waves in an infinite medium containing a layer of inhomogeneity, and of the scattering of elastic waves in an infinite medium containing a perfect spherical inhomogeneity. The eigenstrains are expanded as a geometric series and the method of integration for the inhomogeneous Helmholtz operator given by Fu and Mura is adopted. The results obtained by using a limited number of terms in the eigenstrain expansion are compared with exact solutions for the layer problem and for a perfect sphere. Two parameters are singled out for this comparison: the ratio of elastic moduli, and the ratio of the mass densities. General trends for three different situations are shown

    S-Lemma with Equality and Its Applications

    Full text link
    Let f(x)=xTAx+2aTx+cf(x)=x^TAx+2a^Tx+c and h(x)=xTBx+2bTx+dh(x)=x^TBx+2b^Tx+d be two quadratic functions having symmetric matrices AA and BB. The S-lemma with equality asks when the unsolvability of the system f(x)<0,h(x)=0f(x)<0, h(x)=0 implies the existence of a real number μ\mu such that f(x)+μh(x)0, xRnf(x) + \mu h(x)\ge0, ~\forall x\in \mathbb{R}^n. The problem is much harder than the inequality version which asserts that, under Slater condition, f(x)<0,h(x)0f(x)<0, h(x)\le0 is unsolvable if and only if f(x)+μh(x)0, xRnf(x) + \mu h(x)\ge0, ~\forall x\in \mathbb{R}^n for some μ0\mu\ge0. In this paper, we show that the S-lemma with equality does not hold only when the matrix AA has exactly one negative eigenvalue and h(x)h(x) is a non-constant linear function (B=0,b0B=0, b\not=0). As an application, we can globally solve inf{f(x)h(x)=0}\inf\{f(x)\vert h(x)=0\} as well as the two-sided generalized trust region subproblem inf{f(x)lh(x)u}\inf\{f(x)\vert l\le h(x)\le u\} without any condition. Moreover, the convexity of the joint numerical range {(f(x),h1(x),,hp(x)): xRn}\{(f(x), h_1(x),\ldots, h_p(x)):~x\in\Bbb R^n\} where ff is a (possibly non-convex) quadratic function and h1(x),,hp(x)h_1(x),\ldots,h_p(x) are affine functions can be characterized using the newly developed S-lemma with equality.Comment: 34 page

    On QCD and Effective Locality

    Full text link
    In a recent paper it was shown how quark scattering in a quenched, eikonal model led to a momentum-transfer dependent amplitude expressed in terms of Halpern's functional integral; and how the requirement of manifest gauge invariance converted that functional integral into a local integral, capable of being evaluated with precision by a finite set of numerical integrations. We here prove that this property of "effective locality" holds true for all quark processes, without approximation and without exception.Comment: Expanded and Revised in REVTeX 4.1, 14 pages, follow-on work of Eur. Phys. J. C65, pp.395-411 (2010) or arXiv:0903.2644v2 [hep-th

    Analytic, Non-Perturbative, Gauge-invariant QCD: Nucleon Scattering and Binding Potentials

    Full text link
    Removal of the quenched approximation in the mechanism which produced an analytic estimate of quark-binding potentials, along with a reasonable conjecture of the color structure of the nucleon formed by such a binding potential, is shown to generate an effective, nucleon scattering and binding potential. The mass-scale factor on the order of the pion mass, previously introduced to define transverse imprecision of quark coordinates, is again used, while the strength of the potential is proportional to the square of a renormalized QCD coupling constant. The potential so derived does not include corrections due to spin, angular momentum, nucleon structure, and electroweak interactions; rather, it is qualitative in nature, showing how Nuclear Physics can arise from fundamental QCD.Comment: 25 pages, 3 figures in REVTeX. The fifth of a series on Non-Perturbative QCD (Eur. Phys. J. C65, 395 (2010) or arXiv:0903.2644 [hep-th], arXiv:1003.2936 [hep-th], arXiv:1103.4179 [hep-th] and arXiv:1104.4663 [hep-th].
    corecore