39,028 research outputs found

    Surveyor ejecta detector model ML 256-1 and 185-1 and Surveyor ejecta detector ground support equipment model ML 260-1 Final engineering report

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    Engineering analyses on Surveyor lunar dust particle detector instrumentation, and ground support equipmen

    What Have We Learned from Policy Transfer Research? Dolowitz and Marsh Revisited

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    Over the last decade, policy transfer has emerged as an important concept within public policy analysis, guiding both theoretical and empirical research spanning many venues and issue areas. Using Dolowitz and Marsh's 1996 stocktake as its starting point, this article reviews what has been learned by whom and for what purpose. It finds that the literature has evolved from its rather narrow, state-centred roots to cover many more actors and venues. While policy transfer still represents a niche topic for some researchers, an increasing number have successfully assimilated it into wider debates on topics such as globalisation, Europeanisation and policy innovation. This article assesses the concept's position in the overall ‘tool-kit’ of policy analysis, examines some possible future directions and reflects on their associated risks and opportunities

    Time evolution of the Partridge-Barton Model

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    The time evolution of the Partridge-Barton model in the presence of the pleiotropic constraint and deleterious somatic mutations is exactly solved for arbitrary fecundity in the context of a matricial formalism. Analytical expressions for the time dependence of the mean survival probabilities are derived. Using the fact that the asymptotic behavior for large time tt is controlled by the largest matrix eigenvalue, we obtain the steady state values for the mean survival probabilities and the Malthusian growth exponent. The mean age of the population exhibits a t−1t^{-1} power law decayment. Some Monte Carlo simulations were also performed and they corroborated our theoretical results.Comment: 10 pages, Latex, 1 postscript figure, published in Phys. Rev. E 61, 5664 (2000

    Pengukuran Index Konsistensi dalam Proses Pengambilan Keputusan Menggunakan Metode Ahp

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    Metode Analytic Hierarchy Process(AHP) merupakan salah satu metode dalam proses pengambilan keputusan. Metode ini digunakan untuk mendukung pengambilan keputusan terhadap beberapa alternatif pilihan. Proses pengambilan keputusan diawali dengan menetapkan faktor-faktor/kriteria yang mempengaruhi pengguna dalam mengambil keputusan. Pengguna memberikan prioritas terhadap sepasang kriteria (pairwise comparison). Jika setiap pasangan kriteria sudah ditetapkan skala prioritasnya, maka data prioritas tsb dimodelkan dalam sebuah matriks. Matriks akan menjalani proses normalisasi dengan menggunakan metode Eigenvector. Proses iterasi berlangsung, sampai dengan selisih nilai eigen antar hasil iterasi mencapai nilai relatif kecil (< 0.000010). Konsistensi pengguna metode AHP harus tetap terjaga agar solusi yang dihasilkan optimal. Untuk mengetahui tingkat konsistensi tsb, hasil penggunaan metode AHP akan diukur besarnya indeks konsistensi (Consistency Index). Jika rasio dengan standar Indeks Random <= 0.10 maka disimpulkan bahwa derajat konsistensinya memuaskan, artinya metode AHP menghasilkan solusi optimal. Namun jika > 0.10 maka terdapat ketidakkonsistenan dalam menentukan perbandingan yang memungkinkan metode AHP tidak menghasilkan solusi yang berarti

    Correction, improvement and model verification of CARE 3, version 3

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    An independent verification of the CARE 3 mathematical model and computer code was conducted and reported in NASA Contractor Report 166096, Review and Verification of CARE 3 Mathematical Model and Code: Interim Report. The study uncovered some implementation errors that were corrected and are reported in this document. The corrected CARE 3 program is called version 4. Thus the document, correction. improvement, and model verification of CARE 3, version 3 was written in April 1984. It is being published now as it has been determined to contain a more accurate representation of CARE 3 than the preceding document of April 1983. This edition supercedes NASA-CR-166122 entitled, 'Correction and Improvement of CARE 3,' version 3, April 1983

    Vlasov simulation in multiple spatial dimensions

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    A long-standing challenge encountered in modeling plasma dynamics is achieving practical Vlasov equation simulation in multiple spatial dimensions over large length and time scales. While direct multi-dimension Vlasov simulation methods using adaptive mesh methods [J. W. Banks et al., Physics of Plasmas 18, no. 5 (2011): 052102; B. I. Cohen et al., November 10, 2010, http://meetings.aps.org/link/BAPS.2010.DPP.NP9.142] have recently shown promising results, in this paper we present an alternative, the Vlasov Multi Dimensional (VMD) model, that is specifically designed to take advantage of solution properties in regimes when plasma waves are confined to a narrow cone, as may be the case for stimulated Raman scatter in large optic f# laser beams. Perpendicular grid spacing large compared to a Debye length is then possible without instability, enabling an order 10 decrease in required computational resources compared to standard particle in cell (PIC) methods in 2D, with another reduction of that order in 3D. Further advantage compared to PIC methods accrues in regimes where particle noise is an issue. VMD and PIC results in a 2D model of localized Langmuir waves are in qualitative agreement

    Collective multipole-like signatures of entanglement in symmetric N-qubit systems

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    A cogent theory of collective multipole-like quantum correlations in symmetric multiqubit states is presented by employing SO(3) irreducible spherical tensor representation. An arbitrary bipartite division of this system leads to a family of inequalities to detect entanglement involving averages of these tensors expressed in terms of the total system angular momentum operator. Implications of this theory to the quantum nature of multipole-like correlations of all orders in the Dicke states are deduced. A selected set of examples illustrate these collective tests. Such tests detect entanglement in macroscopic atomic ensembles, where individual atoms are not accessible.Comment: REVTEX, 4 pages with 1 figure; To appear in Phys. Rev.
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