2,602 research outputs found

    Design of a fault tolerant airborne digital computer. Volume 2: Computational requirements and technology

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    This final report summarizes the work on the design of a fault tolerant digital computer for aircraft. Volume 2 is composed of two parts. Part 1 is concerned with the computational requirements associated with an advanced commercial aircraft. Part 2 reviews the technology that will be available for the implementation of the computer in the 1975-1985 period. With regard to the computation task 26 computations have been categorized according to computational load, memory requirements, criticality, permitted down-time, and the need to save data in order to effect a roll-back. The technology part stresses the impact of large scale integration (LSI) on the realization of logic and memory. Also considered was module interconnection possibilities so as to minimize fault propagation

    Equidistribution Rates, Closed String Amplitudes, and the Riemann Hypothesis

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    We study asymptotic relations connecting unipotent averages of Sp(2g,Z)Sp(2g,\mathbb{Z}) automorphic forms to their integrals over the moduli space of principally polarized abelian varieties. We obtain reformulations of the Riemann hypothesis as a class of problems concerning the computation of the equidistribution convergence rate in those asymptotic relations. We discuss applications of our results to closed string amplitudes. Remarkably, the Riemann hypothesis can be rephrased in terms of ultraviolet relations occurring in perturbative closed string theory.Comment: 15 page

    Symposium: THE MULTINATIONAL ENTERPRISE AS GLOBAL CORPORATE CITIZEN

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    The word globalization finds its way into many commentaries these days, in different ways and different connotations. Sometimes it is thought to be beneficial, and sometimes it\u27s thought to be harmful. We have here today four people highly qualified to talk about this topic. The focus on the multinational enterprise, which is one of the terms that\u27s used for a company that does business in many jurisdictions, is the focus of today\u27s discussion, and whether and how multinational enterprises function as global corporate citizens

    Antiresonances in Molecular Wires

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    We present analytic and numerical studies based on Landauer theory of conductance antiresonances of molecular wires. Our analytic treatment is a solution of the Lippmann-Schwinger equation for the wire that includes the effects of the non-orthogonality of the atomic orbitals on different atoms exactly. The problem of non-orthogonality is treated by solving the transport problem in a new Hilbert space which is spanned by an orthogonal basis. An expression is derived for the energies at which antiresonances should occur for a molecular wire connected to a pair of single-channel 1D leads. From this expression we identify two distinct mechanisms that give rise to antiresonances under different circumstances. The exact treatment of non-orthogonality in the theory is found to be necessary to obtain reliable results. Our numerical simulations extend this work to multichannel leads and to molecular wires connected to 3D metallic nanocontacts. They demonstrate that our analytic results also provide a good description of these more complicated systems provided that certain well-defined conditions are met. These calculations suggest that antiresonances should be experimentally observable in the differential conductance of molecular wires of certain types.Comment: 22 pages, 5 figure
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