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SMOOTH ESTIMATION OF ROC CURVE IN THE PRESENCE OF AUXILIARY INFORMATION

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Journal of Systems Science & Complexity 2011年第5期24卷 919-944页

作者： yong zhou Haibo zhou Yunbei MA Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China School of Statistics and Management Shanghai University of Finance and Economics Shanghai 200433 China Department of Biostatistics University of North Carolina Chapel Hill NC27599-7420 USA

Receiver operating characteristic （ROC） curve is often used to study and compare two- sample problems in medicine. When more information may be available on one treatment than the other, one can improve estimator of ROC curve if the auxiliary population information is taken into account. The authors show that the empirical likelihood method can be naturally adapted to make efficient use of the auxiliary information to such problems. The authors propose a smoothed empirical likelihood estimator for ROC curve with some auxiliary information in medical studies. The proposed estimates are more efficient than those ROC estimators without any auxiliary information, in the sense of comparing asymptotic variances and mean squared error （MSE）. Some asymptotic properties for the empirical likelihood estimation of ROC curve are established. A simulation study is presented to demonstrate the performance of the proposed estimators.

关键词： Auxiliary information empirical likelihood ROC curve smooth estimation.

Proportional Mean Residual Life Model with Varying Coefficients for Length-Biased and Right-Censored Data

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Acta Mathematica Sinica,English Series 2020年第5期36卷 578-596页

作者： Da XU yong zhou Key Laboratory of Applied Statistics of MOE and School of Mathematics and Statistics Northeast Normal UniversityChangchun 130024P.R.China Key Laboratory of Advanced Theory and Application in Statistics and Data Science MOEAcademy of Statistics and Interdisciplinary SciencesEast China Normal UniversityShanghai 200062P.R.China Academy of Mathematics and Systems Sciences Chinese Academy of SciencesBeijing 100190P.R.China

Length-biased data are encountered in many fields,including economics,engineering and epidemiological cohort *** are two main challenges in the analysis of such data:the assumption of independent censoring is violated and the assumed model for the underlying population is no longer satisfied for the observed *** this paper,a proportional mean residual life varyingcoefficient model for length-biased data is considered and a local pseudo likelihood method is proposed for estimating the coefficient functions in the *** properties are investigated for the proposed *** finite sample performance of the proposed methodology is demonstrated by simulation ***,the method is applied to a real data set concerning the Academy Awards.

关键词： Length-biased data proportional hazards model mean residual life varying-coefficient model

An approach to the capsule endoscopic robot with active drive motion

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第3期12卷 223-231页

作者： Da-qiang GU yong zhou Department of Mechanical Engineering Zhejiang University Hangzhou 310027 China

Commercialized capsule-type endoscopes move passively by peristaltic waves (and gravity),which makes it difficult for doctors to diagnose the areas of interest more thoroughly and *** resolve this problem of passivity,it is necessary to find a special locomotion principle,which fits the gastrointestinal (GI) *** this paper,a legged locomotive mechanism with shape memory alloy (SMA) actuation based on the peristaltic principle is proposed,and then the structure of the locomotion mechanism is *** on the preliminary results,the design,modeling,and fabrication of an SMA microactuation concept for application in an endoscopic capsule are given,as well as the SMA spring and legged component design,which is the core section of the system *** used the pseudo-rigid-body model (PRBM) to analyze nonlinear and large deflections of the SMA legged ***,a prototype endoscope with an SMA spring and six legged components was designed and *** is 15 mm in diameter and 33 mm in total length,with a hollow space to house other parts needed for endoscopy such as a camera,a radio frequency (RF) module,and *** testing,the locomotive mechanism was effective in a plastic tube environment.

关键词： Capsular endoscopy Shape memory alloy (SMA) Microactuation Locomotion

Investigations on Left Hand Cut Contribution to Determination of κ（700） Pole

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Communications in Theoretical Physics 2007年第5期47卷 883-886页

作者： zhou Zhi-yong Department of Physics Peking University Beijing 100871 China

The uncertainties of background contributions to J = 0 partial wave πK scattering phase shifts are carefully studied. We firstly point out that the circular cuts exhibit different characters in S1/1 and S3/2 waves. While the former contributes negatively to the scattering length parameter, the latter contributes positively, i.e., has a wrong sign. This fact indicates that short range force contribu tions to the phase shift are non-negligible in the exotic channel. Nevertheless, it is verified that the κ pole will be affected only slightly with respect to the theoretical uncertainty in estimating the left hand cut contributions.

关键词： πK scattering unitarity dispersion relations κ resonance

Geometrical　Modeling　by　NURBS　Surface　and　RCS　Computing　by　Visualization　for　Complex　Targets

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Journal of Systems Engineering and Electronics 1997年第1期8卷 13-21页

作者： zhou, yong Liu, Tiejun Beijing Inst of Environmental Features Beijing China

A novel approach to compute the high frequency radar cross-section (RCS) of complex targets is described in this *** the three views or the sectional views of the target, target is geometrically modeled by non-uniform rational B-spline (NURBS) parametric surfaces using the software CNFEOV developed by oneself which constructs NURBS representation of complex target from engineering orthographic views. RCS is obtained through PO, PTD, MEC and IBC techniques. When calculating RCS of the target, it is necessary to get the unit normal vector to surface illumi- nated by radar and the value Z which is the distance from the point on the surface to radar. ln this novel approach, the unit normal vector to the surface can be obtained either by the Phong rendering model, in which the color components (RGB) of every pixel on the image are equal to the coordinate components of the normal, or by the NURBS expressions. The value Z can be achieved by software or hardware Z-buffer. The effects of the size of image on the RCS of target are discussed and the correct method is recommended. The RCS of the perfect conducting sphere, cylinder and dihedral as well as the coated cylinder, as some examples, are computed. The accuracy of the method is verified by comparing the numerical results with those obtained by using other methods.

关键词： RCS Visualization computation Geometrical modeling.

Estimated conditional score function for missing mechanism model with nonignorable nonresponse

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Science China Mathematics 2017年第7期60卷 1197-1218页

作者： CUI Xia zhou yong School of Economics and Statistics Guangzhou University Academy of Mathematics and Systems Science Chinese Academy of Sciences School of Statistics and Management Shanghai University of Finance and Economics

Missing data mechanism often depends on the values of the responses,which leads to nonignorable *** such a situation,inference based on approaches that ignore the missing data mechanism could not be valid.A crucial step is to model the nature of *** specify a parametric model for missingness mechanism,and then propose a conditional score function approach for *** approach imputes the score function by taking the conditional expectation of the score function for the missing data given the available *** procedure is then followed by replacing unknown terms with the related nonparametric estimators based on the observed *** proposed score function does not suffer from the non-identifiability problem,and the proposed estimator is shown to be consistent and asymptotically *** also construct a confidence region for the parameter of interest using empirical likelihood *** studies demonstrate that the proposed inference procedure performs well in many *** apply the proposed method to a data set from research in a growth hormone and exercise intervention study.

关键词： conditional score function empirical likelihood missing data nonignorabe nonresponse

Semiparametric Likelihood-based Inference for Censored Data with Auxiliary Information from External Massive Data Sources

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Acta Mathematicae Applicatae Sinica 2020年第3期36卷 642-656页

作者： Yue-xin FANG yong zhou School of Statistics and Management Shanghai University of Finance and EconomicsShanghai200433China Key Laboratory of Advanced Theory and Application in Statistics and Data Science MOEand Academy of Statistics and Interdisciplinary SciencesEast China Normal UniversityShanghai 200062China

Published auxiliary information can be helpful in conducting statistical inference in a new *** this paper,we synthesize the auxiliary information with semiparametric likelihood-based inference for censoring data with the total sample size is *** express the auxiliary information as constraints on the regression coefficients and the covariate distribution,then use empirical likelihood method for general estimating equations to improve the efficiency of the interested parameters in the specified *** consistency and asymptotic normality of the resulting regression parameter estimators *** numerical simulation and application with different supposed conditions show that the proposed method yields a substantial gain in efficiency of the interested parameters.

关键词： Auxiliary information Massive data Censored data Empirical likelihood Estimation equations

Two-Photon-Absorption Induced Superradiance of a New Organic Dye PSPS

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Chinese Physics Letters 2002年第5期19卷 739-741页

作者： zhou Guang-yong, Wang Dong State Key Laboratory of Crystal Materials Institute of Crystal Materials Shandong University Ji\'nan 250100

The linear and nonlinear optical properties of a new two-photon absorption (TPA) dye, trans-4-(4'-pyrrolidinyl styryl)-N-methyl pyridinium methyl sulfate (abbreviated as PSPS) is reported. Intense red superradiance with a peak located at 625nm can be observed from PSPS solution in benzyl alcohol when pumped by a focused picosecond laser beam operated at 1064nm. The lifetimes of one-photon absorption (OPA) and TPA fluorescence were measured to be 370 and 384ps, respectively. The pulse widths of OPA and TPA superradiance were 60 and 58 ps, respectively. The highest net upconversion efficiency from the absorbed pump laser to the upconverted superradiance is 8.3% at the pump energy of 0.6 mJ.

关键词： Two photon processes

Two-Photon Absorption-Induced Emission Properties of Dye HMASPS Doped Polymer

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Chinese Physics Letters 2002年第2期19卷 208-210页

作者： Wang Dong, zhou Guang-yong State Key Laboratory of Crystal Materials Shandong University Ji\'nan 250100

The 0.01M two-photon absorption dye trans-4-[p-(N-hydroxyethyl-N-methylamino)styryl]-N-methyl-pyridinium p-toluene sulfonate (HMASPS) doped polymer has been prepared. When pumped by the picosecond pulse from the pulsed mode-locked Nd:YAG laser, the polymer emits more intense upconverted fluorescence and superradiance compared to the solution sample of the dye. The two-photon pumped lasing with oscillating pulses has also been obtained. Compared to the dye in its solution state, the emission spectra of the polymer are all blueshifted. The polymer has a long upconverted fluorescent lifetime of about 4.041±0.04 ns.

关键词： Photons