21,886 research outputs found

    Fiber glass reinforced structural materials for aerospace application

    Get PDF
    Evaluation of fiber glass reinforced plastic materials concludes that fiber glass construction is lighter than aluminum alloy construction. Low thermal conductivity and strength makes the fiber glass material useful in cryogenic tank supports

    Applications of ISES for coastal zone studies

    Get PDF
    In contrast to the discipline- and process-oriented topics addressed, coastal zone studies are defined geographically by the special circumstances inherent in the interface between land and water. The characteristics of coastal zones which make them worthy of separate consideration are: (1) the dynamic nature of natural and anthropogenic processes taking place; (2) the relatively restricted spatial domain of the narrow land/water interface; and (3) the large proportion of the Earth's population living within coastal zones, and the resulting extreme pressure on natural and human resources. These characteristics place special constraints and priorities on remote sensing applications, even though the applications themselves bear close relation to those addressed by other elements of this report (e.g., oceans, ice, vegetation/land use). The discussion which follows first describes the suite of remote sensing activities relevant to coastal zone studies. Potential Information Sciences Experiment System (ISES) experiments will then be addressed within two general categories: applications of real-time data transmission and applications of onboard data acquisition and processing

    Optimizing qubit Hamiltonian parameter estimation algorithms using PSO

    Full text link
    We develop qubit Hamiltonian single parameter estimation techniques using a Bayesian approach. The algorithms considered are restricted to projective measurements in a fixed basis, and are derived under the assumption that the qubit measurement is much slower than the characteristic qubit evolution. We optimize a non-adaptive algorithm using particle swarm optimization (PSO) and compare with a previously-developed locally-optimal scheme.Comment: 3 pages, 2 figures, presented at 2012 IEEE Congress on Evolutionary Computation, to be published in the proceeding

    Bell's theorem without inequalities and without alignments

    Full text link
    A proof of Bell's theorem without inequalities is presented which exhibits three remarkable properties: (a) reduced local states are immune to collective decoherence; (b) distant local setups do not need to be aligned, since the required perfect correlations are achieved for any local rotation of the local setups; (c) local measurements require only individual measurements on the qubits. Indeed, it is shown that this proof is essentially the only one which fulfils (a), (b), and (c).Comment: REVTeX4, 4 page

    Quantum methods for clock synchronization: Beating the standard quantum limit without entanglement

    Get PDF
    We introduce methods for clock synchronization that make use of the adiabatic exchange of nondegenerate two-level quantum systems: ticking qubits. Schemes involving the exchange of N independent qubits with frequency ω\omega give a synchronization accuracy that scales as (ωN)1(\omega\sqrt{N})^{-1}, i.e., as the standard quantum limit. We introduce a protocol that makes use of N coherent exchanges of a single qubit at frequency ω\omega, leading to an accuracy that scales as (ωN)1logN(\omega N)^{-1}\log N. This protocol beats the standard quantum limit without the use of entanglement, and we argue that this scaling is the fundamental limit for clock synchronization allowed by quantum mechanics. We analyse the performance of these protocols when used with a lossy channel.Comment: 9 pages, 1 figure, published versio

    Aerodynamic characteristics of an NASA supercritical-wing research airplane model with and without fuselage area-rule additions at Mach 0.25 to 1.00

    Get PDF
    Transonic pressure tunnel tests at Mach numbers from 0.25 to 1.00 were performed to determine the effects of area-rule additions to the sides of the fuselage on the aerodynamic characteristics of a 0.087 scale model of an NASA supercritical-wing research airplane. Presented are the longitudinal aerodynamic force and moment characteristics for horizontal-tail deflection angles of -2.5 deg and -5 deg with the side fuselage area-rule additions on and off the model. The effects of the side fuselage area-rule additions on selected wing and fuselage pressure distributions at near-cruise conditions are also presented
    corecore