32,376 research outputs found

    Information Storage in Black Holes

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    The information loss paradox for Schwarzschild black holes is examined, using the ADS/CFT correspondence extended to the M6(4,2)M_6 (4,2) bulk. It is found that the only option compatible with the preservation of the quantum unitarity is when a regular remnant region of the black hole survives to the black hole evaporation process, where information can be stored and eventually retrieved.Comment: 5 pages Latex file, no figures. A honourable mention in the 2005 GRF essay competitio

    Smooth Approximation of Lipschitz functions on Riemannian manifolds

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    We show that for every Lipschitz function ff defined on a separable Riemannian manifold MM (possibly of infinite dimension), for every continuous ϵ:M→(0,+∞)\epsilon:M\to (0,+\infty), and for every positive number r>0r>0, there exists a C∞C^\infty smooth Lipschitz function g:M→Rg:M\to\mathbb{R} such that ∣f(p)−g(p)∣≤ϵ(p)|f(p)-g(p)|\leq\epsilon(p) for every p∈Mp\in M and Lip(g)≤Lip(f)+r\textrm{Lip}(g)\leq\textrm{Lip}(f)+r. Consequently, every separable Riemannian manifold is uniformly bumpable. We also present some applications of this result, such as a general version for separable Riemannian manifolds of Deville-Godefroy-Zizler's smooth variational principle.Comment: 10 page

    ADP correspondence system: Unsolicited proposal evaluation tracking application

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    A complete description of a correspondence control system, designed to be used by non-ADP clerical personnel is provided. In addition to operating instructions, sufficient design and conceptual information is provided to allow use or adaption of the system in related applications. The complete COBOL program and documentation are available

    Advanced beaded and tubular structural panels

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    A program to develop lightweight beaded and tubular structural panels is described. Applications include external surfaces, where aerodynamically acceptable, and primary structure protected by heat shields. The design configurations were optimized and selected with a computer code which iterates geometric parameters to satisfy strength, stability, and weight constraints. Methods of fabricating these configurations are discussed. Nondestructive testing produced extensive combined compression, shear, and bending test data on local buckling specimens and large panels. The optimized design concepts offer 25 to 30% weight savings compared to conventional stiffened sheet construction

    An analytical study of electric vehicle handling dynamics

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    Hypothetical electric vehicle configurations were studied by applying available analytical methods. Elementary linearized models were used in addition to a highly sophisticated vehicle dynamics computer simulation technique. Physical properties of specific EV's were defined for various battery and powertrain packaging approaches applied to a range of weight distribution and inertial properties which characterize a generic class of EV's. Computer simulations of structured maneuvers were performed for predicting handling qualities in the normal driving range and during various extreme conditions related to accident avoidance. Results indicate that an EV with forward weight bias will possess handling qualities superior to a comparable EV that is rear-heavy or equally balanced. The importance of properly matching tires, suspension systems, and brake system front/rear torque proportioning to a given EV configuration during the design stage is demonstrated
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