59,029 research outputs found

    Optimal design application on the advanced aeroelastic rotor blade

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    The vibration and performance optimization procedure using regression analysis was successfully applied to an advanced aeroelastic blade design study. The major advantage of this regression technique is that multiple optimizations can be performed to evaluate the effects of various objective functions and constraint functions. The data bases obtained from the rotorcraft flight simulation program C81 and Myklestad mode shape program are analytically determined as a function of each design variable. This approach has been verified for various blade radial ballast weight locations and blade planforms. This method can also be utilized to ascertain the effect of a particular cost function which is composed of several objective functions with different weighting factors for various mission requirements without any additional effort

    Effect of atmospheric turbulence on propagation properties of optical vortices formed by using coherent laser beam arrays

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    In this paper, we consider the effect of the atmospheric turbulence on the propagation of optical vertex formed from the radial coherent laser beam array, with the initially well-defined phase distribution. The propagation formula of the radial coherent laser array passing through the turbulent atmosphere is analytically derived by using the extended Huygens-Fresnel diffraction integral. Based on the derived formula, the effect of the atmospheric turbulence on the propagation properties of such laser arrays has been studied in great detail. Our main results show that the atmospheric turbulence may result in the prohibition of the formation of the optical vortex or the disappearance of the formed optical vortex, which are very different from that in the free space. The formed optical vortex with the higher topological charge may propagate over a much longer distance in the moderate or weak turbulent atmosphere. After the sufficient long-distance atmospheric propagation, all the output beams (even with initially different phase distributions) finally lose the vortex property and gradually become the Gaussian-shaped beams, and in this case the output beams actually become incoherent light fields due to the decoherence effect of the turbulent atmosphere.Comment: 10 pages, 5 figure

    Quantum state engineering with flux-biased Josephson phase qubits by Stark-chirped rapid adiabatic passages

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    In this paper, the scheme of quantum computing based on Stark chirped rapid adiabatic passage (SCRAP) technique [L. F. Wei et al., Phys. Rev. Lett. 100, 113601 (2008)] is extensively applied to implement the quantum-state manipulations in the flux-biased Josephson phase qubits. The broken-parity symmetries of bound states in flux-biased Josephson junctions are utilized to conveniently generate the desirable Stark-shifts. Then, assisted by various transition pulses universal quantum logic gates as well as arbitrary quantum-state preparations could be implemented. Compared with the usual PI-pulses operations widely used in the experiments, the adiabatic population passage proposed here is insensitive the details of the applied pulses and thus the desirable population transfers could be satisfyingly implemented. The experimental feasibility of the proposal is also discussed.Comment: 9 pages, 4 figure

    Strategic Trade Policy in Bargaining over Managerial Delegation Competition

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    In this paper, we assess the influence of the generalized Nash bargaining model on strategic trade policies. In particular, how the trade policy and the bargaining process over managerial contract are strategically connected within the context of bargaining over the sales delegation model is analyzed. We explore the policy impacts in two different models: the export rivalry model and the import-competing model, and show that the introduction of managers' bargaining process leads to a decrease in the export subsidy and optimal tariff in different models.Bargaining Delegation

    Strong decays of heavy baryons in Bethe-Salpeter formalism

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    In this paper we study the properties of diquarks (composed of uu and/or dd quarks) in the Bethe-Salpeter formalism under the covariant instantaneous approximation. We calculate their BS wave functions and study their effective interaction with the pion. Using the effective coupling constant among the diquarks and the pion, in the heavy quark limit mQm_Q\to\infty, we calculate the decay widths of ΣQ()\Sigma_Q^{(*)} (Q=c,bQ=c,b) in the BS formalism under the covariant instantaneous approximation and then give predictions of the decay widths Γ(Σb()Λb+π)\Gamma(\Sigma_b^{(*)}\to\Lambda_b+\pi).Comment: 41 pages, 1 figure, LaTex2e, typos correcte

    Nonconical theory of flow past slender wing bodies with leading-edge separation

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    Nonconical theory of flow past slender wing bodies with leading edge separatio

    Generation of nonclassical photon states using a superconducting qubit in a microcavity

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    Based on the interaction between the radiation field and a superconductor, we propose a way to engineer quantum states using a SQUID charge qubit inside a microcavity. This device can act as a deterministic single photon source as well as generate any Fock states and an arbitrary superposition of Fock states for the cavity field. The controllable interaction between the cavity field and the qubit can be realized by the tunable gate voltage and classical magnetic field applied to the SQUID.Comment: 4 page

    High efficiency tomographic reconstruction of quantum states by quantum nondemolition measurements

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    We propose a high efficiency tomographic scheme to reconstruct an unknown quantum state of the qubits by using a series of quantum nondemolition (QND) measurements. The proposed QND measurements of the qubits are implemented by probing the the stationary transmissions of the dispersively-coupled resonator. It is shown that only one kind of QND measurements is sufficient to determine all the diagonal elements of the density matrix of the detected quantum state. The remaining non-diagonal elements of the density matrix can be determined by other spectral measurements by beforehand transferring them to the diagonal locations using a series of unitary operations. Compared with the pervious tomographic reconstructions based on the usual destructively projective (DP) measurements (wherein one kind of such measurements could only determine one diagonal element of the density matrix), the present approach exhibits significantly high efficiency for N-qubit (N > 1). Specifically, our generic proposal is demonstrated by the experimental circuit-quantumelectrodynamics (circuit-QED) systems with a few Josephson charge qubits.Comment: 9pages,4figure
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