10,776 research outputs found

    Combined Field Integral Equation Based Theory of Characteristic Mode

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    Conventional electric field integral equation based theory is susceptible to the spurious internal resonance problem when the characteristic modes of closed perfectly conducting objects are computed iteratively. In this paper, we present a combined field integral equation based theory to remove the difficulty of internal resonances in characteristic mode analysis. The electric and magnetic field integral operators are shown to share a common set of non-trivial characteristic pairs (values and modes), leading to a generalized eigenvalue problem which is immune to the internal resonance corruption. Numerical results are presented to validate the proposed formulation. This work may offer efficient solutions to characteristic mode analysis which involves electrically large closed surfaces

    Pricing and Warranty Level Decisions for New and Remanufactured Short Life-Cycle Products

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    Remanufacturing has become more prominent as a recovery process to mitigate the massive disposal of short life-cycle product at its end-of-use. However, remanufactured product is often perceived to be inferior to new product, and it has lower value in consumer’s willingness to pay. To increase the perceived quality of the remanufactured product, manufacturer offers a warranty, since one of the three roles possessed in warranty is being a signal to product reliability. This paper studies the pricing decisions and warranty level decision for new and remanufactured products in a closed-loop supply chain consists of a manufacturer and a retailer. The optimization modeling is performed under Stackelberg game with manufacturer as the leader. We found that higher expansion effectiveness coefficient would increase the supply chain profit. Also, there is an interval of demand’s speed of change, where the total profit would be at its highest. The optimum warranty level can be achieved regardless the initial warranty level set at the beginning of retailer’s optimization. Furthermore, the remanufactured product’s wholesale and retail prices are influenced by the expansion effectiveness coefficient

    Dynamical bandwidth adjustment of a link in a data network

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    An apparatus includes a first node configured to receive the data packets from a plurality of source nodes of the data network and to selectively route some of the received data packets to a link via a port of the first node. The apparatus also includes a link-input buffer that is located in the first node and is configured to store the some of the received data packets for transmission to the link via the port. The first node is configured to power off hardware for transmitting received data packets to the link in response to a fill level of the link-input buffer being below a threshold

    The effects of the little Higgs models on ttˉh0t\bar{t} h^0 production via γγ\gamma \gamma collision at linear colliders

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    In the frameworks of the littlest Higgs(LHLH) model and its extension with T-parity(LHTLHT), we studied the associated ttˉh0t\bar th^0 production process e+eγγttˉh0e^+ e^- \to \gamma\gamma \to t \bar t h^0 at the future e+ee^+e^- linear colliders up to QCD next-to-leading order. We present the regions of sf\sqrt{s}-f parameter space in which the LHLH and LHTLHT effects can and cannot be discovered with the criteria assumed in this paper. The production rates of process γγttˉh0\gamma\gamma \to t \bar t h^0 in different photon polarization collision modes are also discussed. We conclude that one could observe the effects contributed by the LHLH or LHTLHT model on the cross section for the process e+eγγttˉh0e^+ e^- \to \gamma\gamma \to t \bar t h^0 in a reasonable parameter space, or might put more stringent constraints on the LHLH/LHTLHT parameters in the future experiments at linear colliders.Comment: 22 pages, 25 figures, version to appear in Phys. Rev.

    Full one-loop QCD and electroweak corrections to sfermion pair production in γγ\gamma \gamma collisions

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    We have calculated the full one-loop electroweak (EW) and QCD corrections to the third generation scalar-fermion pair production processes e+eγγfi~fi~ˉ(f=t,b,τ)e^+e^- \to \gamma \gamma \to \tilde{f_i}\bar{\tilde{f_i}} (f=t,b,\tau) at an electron-positron linear collider(LC) in the minimal supersymmetric standard model (MSSM). We analyze the dependence of the radiative corrections on the parameters such as the colliding energy s^\sqrt{\hat s} and the SUSY fundamental parameters AfA_f, tanβ\tan \beta, μ\mu, MSUSYM_{SUSY} and so forth. The numerical results show that the EW corrections to the squark-, stau-pair production processes and QCD corrections to the squark-pair production processes give substantial contributions in some parameter space. The EW relative corrections to squark-pair production processes can be comparable with QCD corrections at high energies. Therefore, these EW and QCD corrections cannot be neglected in precise measurement of sfermion pair productions via γγ\gamma\gamma collision at future linear colliders.Comment: to be appeared in Phys. Rev.

    The beta function of the multichannel Kondo model

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    The beta function of the multichannel Kondo model is calculated exactly in the limit of large spin N and channel number M=gamma*N, with constant gamma. There are no corrections in any finite order of 1/N. One zero is found at a finite coupling strength, showing directly the Non--Fermi liquid behavior of the model. This renormalization group flow allows to introduce a variational principle for the entropy, to obtain the low temperature thermodynamics. Such in particular the low temperature thermodynamics of the non--crossing approximation to the Kondo model becomes accessible.Comment: 4 page

    Resting‐state fMRI detects the effects of learning in short term: A visual search training study

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    Can resting-state functional connectivity (rs-FC) detect the impact of learning on the brain inthe short term? To test this possibility, we have combined task-FC and rs-FC tested before andafter a 30-min visual search training. Forty-two healthy adults (20 men) divided into no-contactcontrol and trained groups completed the study. We studied the connectivity between fourdifferent regions of the brain involved in visual search: the primary visual area, the right poste-rior parietal cortex (rPPC), the right dorsolateral prefrontal cortex (rDLPFC), and the dorsalanterior cingulate cortex (dACC). Task-FC showed increased connectivity between the rPPCand rDLPFC and between the dACC and rDLPFC from pretraining to posttraining for boththe control group and the trained group, suggesting that connectivity between these areasincreased with task repetition. In rs-FC, we found enhanced connectivity between theseregions in the trained group after training, especially in those with better learning. Whole brainindependent component analyses did not reveal any change in main networks after training.These results imply that rs-FC may not only predict individual differences in task performance,but rs-FC might also serve to monitor the impact of learning on the brain after short periodsof cognitive training, localizing them in brain areas specifically involved in training

    Destruction of long-range antiferromagnetic order by hole doping

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    We study the renormalization of the staggered magnetization of a two-dimensional antiferromagnet as a function of hole doping, in the framework of the t-J model. It is shown that the motion of holes generates decay of spin waves into ''particle-hole'' pairs, which causes the destruction of the long-range magnetic order at a small hole concentration. This effect is mainly determined by the coherent motion of holes. The value obtained for the critical hole concentration, of a few percent, is consistent with experimental data for the doped copper oxide high-Tc superconductors.Comment: 12 pages, 2 figure

    Top quark pair production via polarized and unpolarized photons in Supersymmetric QCD

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    QCD corrections to top quark pair production via fusion of both polarized and unpolarized photons are calculated in Supersymmetric Model. The corrections are found to be sizable. The dependence of the corrections on the masses of the supersymmetric particles is also investigated. Furthermore, we studied CP asymmetry effects arising from the complex couplings in the MSSM. The CP violating parameter can reach 10210^{-2} for favorable parameter values.Comment: 26 pages, LaTex, including 12 figures in 12 eps files. submitted to Phys. Rev.
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