6,269 research outputs found

    Non-intrusive monitoring algorithm for resident loads with similar electrical characteristic

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    Non-intrusive load monitoring is a vital part of an overall load management scheme. One major disadvantage of existing non-intrusive load monitoring methods is the difficulty to accurately identify loads with similar electrical characteristics. To overcome the various switching probability of loads with similar characteristics in a specific time period, a new non-intrusive load monitoring method is proposed in this paper which will modify monitoring results based on load switching probability distribution curve. Firstly, according to the addition theorem of load working currents, the complex current is decomposed into the independently working current of each load. Secondly, based on the load working current, the initial identification of load is achieved with current frequency domain components, and then the load switching times in each hour is counted due to the initial identified results. Thirdly, a back propagation (BP) neural network is trained by the counted results, the switching probability distribution curve of an identified load is fitted with the BP neural network. Finally, the load operation pattern is profiled according to the switching probability distribution curve, the load operation pattern is used to modify identification result. The effectiveness of the method is verified by the measured data. This approach combines the operation pattern of load to modify the identification results, which improves the ability to identify loads with similar electrical characteristics

    Collapse of the vortex-lattice inductance and shear modulus at the melting transition in untwinned YBa2Cu3O7\rm YBa_2Cu_3O_7

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    The complex resistivity ρ^(ω)\hat{\rho}(\omega) of the vortex lattice in an untwinned crystal of 93-K YBa2Cu3O7\rm YBa_2Cu_3O_7 has been measured at frequencies ω/2π\omega/2\pi from 100 kHz to 20 MHz in a 2-Tesla field Hc\bf H\parallel c, using a 4-probe RF transmission technique that enables continuous measurements versus ω\omega and temperature TT. As TT is increased, the inductance Ls(ω)=Imρ^(ω)/ω{\cal L}_s(\omega) ={\rm Im} \hat{\rho}(\omega)/ \omega increases steeply to a cusp at the melting temperature TmT_m, and then undergoes a steep collapse consistent with vanishing of the shear modulus c66c_{66}. We discuss in detail the separation of the vortex-lattice inductance from the `volume' inductance, and other skin-depth effects. To analyze the spectra, we consider a weakly disordered lattice with a low pin density. Close fits are obtained to ρ1(ω)\rho_1(\omega) over 2 decades in ω\omega. Values of the pinning parameter κ\kappa and shear modulus c66c_{66} obtained show that c66c_{66} collapses by over 4 decades at TmT_m, whereas κ\kappa remains finite.Comment: 11 pages, 8 figures, Phys. Rev. B, in pres

    A highly sensitive mean-reverting process in finance and the Euler-Maruyama approximations

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    Empirical studies show that the most successful continuous-time models of the short term rate in capturing the dynamics are those that allow the volatility of interestchanges to be highly sensitive to the level of the rate. However, from the mathematics, the high sensitivity to the level implies that the coeffcients do not satisfy the lineargrowth condition, so we can not examine its properties by traditional techniques. This paper overcomes the mathematical difculties due to the nonlinear growth and examines its analytical properties and the convergence of numerical solutions in probability. The convergence result can be used to justify the method within Monte-Carlo simulations that compute the expected payoff of financial products. For illustration, we apply our results compute the value of a bond with interest rate given by the highly sensitive mean-reverting process as well as the value of a single barrier call option with the asset price governed by this process
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