挠性转子动不平衡量的极大似然估计

本文提出利用模态参数识别技术进行挠性转子动平衡的方法。为了计及平衡过程中测试数据的误差,对动不平衡量采用极大似然估计。本文给出计算机模拟的几个实例以论证此种方法,并提出加速收敛的措施。计算结果表明此法效果是鸿意的。     

Confidence interval estimation of the difference between paired AUCs based on combined biomarkers

In many diagnostic studies, multiple diagnostic tests are performed on each subject or multiple disease markers are available. Commonly, the information should be combined to improve the diagnostic accuracy. We consider the problem of comparing the discriminatory abilities between two groups of biomarkers. Specifically, this article focuses on confidence interval estimation of the difference between paired AUCs based on optimally combined markers under the assumption of multivariate normality. Simulation studies demonstrate that the proposed generalized variable approach provides confidence intervals with satisfying coverage probabilities at finite sample sizes. The proposed method can also easily provide P-values for hypothesis testing. Application to analysis of a subset of data from a study on coronary heart disease illustrates the utility of the method in practice.     

A lower bound for the centred L 2-discrepancy on combined designs under the asymmetric factorials

The foldover is a useful technique in the construction of two-level factorial designs for follow-up experiments. To search an optimal foldover plans is an important issue. In this paper, for a set of asymmetric fractional factorials such as the original designs, a lower bound for centred L ₂-discrepancy of combined designs under a general foldover plan is obtained, which can be used as a benchmark for searching optimal foldover plans. All of our results are the extended ones of Ou et al. [Lower bounds of various discrepancies on combined designs, Metrika 74 (2011), pp. 109–119] for symmetric designs to asymmetric designs. Moreover, it also provides a theoretical justification for optimal foldover plans in terms of uniformity criterion.     

Composite quantile regression for varying-coefficient single-index models

ABSTRACT

The varying-coefficient single-index model (VCSIM) is a very general and flexible tool for exploring the relationship between a response variable and a set of predictors. Popular special cases include single-index models and varying-coefficient models. In order to estimate the index-coefficient and the non parametric varying-coefficients in the VCSIM, we propose a two-stage composite quantile regression estimation procedure, which integrates the local linear smoothing method and the information of quantile regressions at a number of conditional quantiles of the response variable. We establish the asymptotic properties of the proposed estimators for the index-coefficient and varying-coefficients when the error is heterogeneous. When compared with the existing mean-regression-based estimation method, our simulation results indicate that our proposed method has comparable performance for normal error and is more robust for error with outliers or heavy tail. We illustrate our methodologies with a real example.     

Testing non-nested log-linear models with pseudo estimator

As the number of random variables for the categorical data increases, the possible number of log-linear models which can be fitted to the data increases rapidly, so that various model selection methods are developed. However, we often found that some models chosen by different selection criteria do not coincide. In this paper, we propose a comparison method to test the final models which are non-nested. The statistic of Cox (1961, 1962) is applied to log-linear models for testing non-nested models, and the Kullback-Leibler measure of closeness (Pesaran 1987) is explored. In log-linear models, pseudo estimators for the expectation and the variance of Cox's statistic are not only derived but also shown to be consistent estimators.     

Smoothing techniques via the bezier curve

Although the Bezier curve is very popular in the area of computational graphics it has rarely been used by statisticians. In this paper we develop methods and techniques for use of the Bezier curve in estimation of density and regression function. Also, asymptotic mean integrated square error for both estimators are derived. Comparisons with kernel estimator are conducted using simulation.     

Nonparametric estimation of quantile functions for randomly right censored data

In this paper we compare four nonparametric quantile function estimators for randomly right censored data: the Kaplan–Meier estimator, the linearly interpolated Kaplan–Meier estimator, the kernel-type survival function estimator, and the Bézier curve smoothing estimator. Also, we compare several kinds of confidence intervals of quantiles for four nonparametric quantile function estimators.     

“西部中国”与“中国民族学”——《西部中国民族学文库》序

在中国民族分布格局中,少数民族多集中在西部。民族学在中国发展的过程中,其重要特色之一就是重视中国各民族社会,特别是少数民族社会、历史与文化的研究。中国多民族社会的现实为民族学提供了广阔的田野,但该学科在加强实证研究以扩大其社会影响力的同时,不要忽略学理上的支撑,需要在实证研究中体现学科规范。     

论网络犯罪对刑事侦查与证据制度的冲击

网络犯罪是伴随着20世纪全球因特网（Internet）的开通而大量产生的,由于计算机及信息网络技术的发展变得形式多样,有的犯罪性质极其恶劣,对人类生产和生活造成巨大的潜在威胁,已经呈现出社会化的发展趋势。本文将结合网络犯罪的发展态势及特征,针对刑事侦查与证据制度在网络犯罪狂潮冲击下受到的挑战与面临的问题,分析、探索刑事法律如何应对网络犯罪的冲击。     

研究性学习方法在大学语音教学中的应用

语音学习是外语学习中不可或缺的关键性环节 ,由于中小学英语教育中师资、教学设施等诸多因素 ,和学生对语音学习认知上的误区 ,使本应在中学就应过的语音关 ,延续至大学。因此 ,大学教师必须搞好英语语音教学 ,应从指导学生从认知和学习策略上切入 ,加强语音教学 ,使学生真正过好语音关