1,543 research outputs found

    Apartment Rent Prediction Using Spatial Modeling

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    This paper provides a new model to explain local variation in apartment rents by introducing the notion of a spatial process. This model differs from those in the literature by explicitly specifying spatial association between pairs of locations as a function of distance between them. Data on apartment rents for the eight markets are used to illustrate the spatial model. Results indicate signi?cant prediction improvement over traditional hedonic rent models that only include indicator variables to capture spatial effects.

    Ce-, Dy-, and Mn-Doped Luminescent Glasses for White Light Emitting Diodes Applications

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    The Effect of Nitrided Layer on Antibacterial Properties for Biomedical Stainless Steel

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    AbstractPlasma nitriding of AISI type 303 austenitic stainless steel using microwave system at various input powers was conducted in present study. The nitrided layers were characterized via scanning electron microscopy, transmission electron microscopy and Vickers microhardness tester. The anti-bacterial property of this nitrided layer was also evaluated. The analytical results revealed the hardness of AISI type 303 stainless steel could be enhanced with nitriding process. The microstructure of the nitrided layer comprised of nitrogen-expanded Îł phase. Bacterial test demonstrated the nitrided layer processed the excellent an ti-bacterial properties. The enhanced hardness and anti-bacterial properties make the nitrided AISI type 303 austenitic stainless steel the potential material in the biomedical applications

    The Intrinsic Dimensionality of Attractiveness: A Study in Face Profiles

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    The study of human attractiveness with pattern analysis techniques is an emerging research field. One still largely unresolved problem is which are the facial features relevant to attractiveness, how they combine together, and the number of independent parameters required for describing and identifying harmonious faces. In this paper, we present a first study about this problem, applied to face profiles. First, according to several empirical results, we hypothesize the existence of two well separated manifolds of attractive and unattractive face profiles. Then, we analyze with manifold learning techniques their intrinsic dimensionality. Finally, we show that the profile data can be reduced, with various techniques, to the intrinsic dimensions, largely without loosing their ability to discriminate between attractive and unattractive face

    Solar Mikheyev-Smirnov-Wolfenstein Effect with Three Generations of Neutrinos

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    Under the assumption that the density variation of the electrons can be approximated by an exponential function, the solar Mikheyev-Smirnov-Wolfenstein effect is treated for three generations of neutrinos. The generalized hypergeometric functions that result from the exact solution of this problem are studied in detail, and a method for their numerical evaluation is presented. This analysis plays a central role in the determination of neutrino masses, not only the differences of their squares, under the assumption of universal quark-lepton mixing.Comment: 22 pages, LaTeX, including 2 figure

    Intelligent tracking control of a DC motor driver using self-organizing TSK type fuzzy neural networks

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    [[abstract]]In this paper, a self-organizing Takagi–Sugeno–Kang (TSK) type fuzzy neural network (STFNN) is proposed. The self-organizing approach demonstrates the property of automatically generating and pruning the fuzzy rules of STFNN without the preliminary knowledge. The learning algorithms not only extract the fuzzy rule of STFNN but also adjust the parameters of STFNN. Then, an adaptive self-organizing TSK-type fuzzy network controller (ASTFNC) system which is composed of a neural controller and a robust compensator is proposed. The neural controller uses an STFNN to approximate an ideal controller, and the robust compensator is designed to eliminate the approximation error in the Lyapunov stability sense without occurring chattering phenomena. Moreover, a proportional-integral (PI) type parameter tuning mechanism is derived to speed up the convergence rates of the tracking error. Finally, the proposed ASTFNC system is applied to a DC motor driver on a field-programmable gate array chip for low-cost and high-performance industrial applications. The experimental results verify the system stabilization and favorable tracking performance, and no chattering phenomena can be achieved by the proposed ASTFNC scheme.[[notice]]èŁœæ­ŁćźŒç•ą[[incitationindex]]SCI[[booktype]]çŽ™æœŹ[[booktype]]電歐

    Theory of nonlinear Landau-Zener tunneling

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    A nonlinear Landau-Zener model was proposed recently to describe, among a number of applications, the nonadiabatic transition of a Bose-Einstein condensate between Bloch bands. Numerical analysis revealed a striking phenomenon that tunneling occurs even in the adiabatic limit as the nonlinear parameter CC is above a critical value equal to the gap VV of avoided crossing of the two levels. In this paper, we present analytical results that give quantitative account of the breakdown of adiabaticity by mapping this quantum nonlinear model into a classical Josephson Hamiltonian. In the critical region, we find a power-law scaling of the nonadiabatic transition probability as a function of C/V−1C/V-1 and α\alpha , the crossing rate of the energy levels. In the subcritical regime, the transition probability still follows an exponential law but with the exponent changed by the nonlinear effect. For C/V>>1C/V>>1, we find a near unit probability for the transition between the adiabatic levels for all values of the crossing rate.Comment: 9 figure

    A new method for the estimation of variance matrix with prescribed zeros in nonlinear mixed effects models

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    We propose a new method for the Maximum Likelihood Estimator (MLE) of nonlinear mixed effects models when the variance matrix of Gaussian random effects has a prescribed pattern of zeros (PPZ). The method consists in coupling the recently developed Iterative Conditional Fitting (ICF) algorithm with the Expectation Maximization (EM) algorithm. It provides positive definite estimates for any sample size, and does not rely on any structural assumption on the PPZ. It can be easily adapted to many versions of EM.Comment: Accepted for publication in Statistics and Computin

    Z0Z_0 Boson Decays to Bc(∗)B^{(*)}_c Meson and Its Uncertainties

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    The programming new e+e−e^{+}e^- collider with high luminosity shall provide another useful platform to study the properties of the doubly heavy BcB_c meson in addition to the hadronic colliders as LHC and TEVATRON. Under the `New Trace Amplitude Approach', we calculate the production of the spin-singlet BcB_c and the spin-triplet Bc∗B^*_c mesons through the Z0Z^0 boson decays, where uncertainties for the production are also discussed. Our results show Γ(1S0)=81.4−40.5+102.1\Gamma_{(^1S_0)}= 81.4^{+102.1}_{-40.5} KeV and Γ(3S1)=116.4−62.8+163.9\Gamma_{(^3S_1)}=116.4^{+163.9}_{-62.8} KeV, where the errors are caused by varying mbm_b and mcm_c within their reasonable regions.Comment: 11 pages, 5 figures, 2 tables. To be published in Eur.Phys.J.
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