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71.
In this article, we propose a general class of partially linear transformation models for recurrent gap time data, which extends the linear transformation models by incorporating non linear covariate effects and includes the partially linear proportional hazards and the partially linear proportional odds models as special cases. Both global and local estimating equations are developed to estimate the parametric and non parametric covariate effects, and the asymptotic properties of the resulting estimators are established. The finite-sample behavior of the proposed estimators is evaluated through simulation studies, and an application to a clinic study on chronic granulomatous disease is provided.  相似文献   
72.
知识产权"十二五"发展规划具有多重属性与复杂性、制定组织结构多元化、地区发展不平衡及其与环境匹配较难等特点,较薄弱的知识产权基础因素与国际发展动态影响下,使得我国知识产权"十二五"发展规划实施挑战与机遇并存。  相似文献   
73.
针对阜新市创建资源枯竭转型示范市过程中不能忽视生态建设这一现实问题,采用理论分析与现实结合的方法,论述了阜新市创建示范市生态建设的哲学依据、现实基础和建设措施,表明生态建设要以生态伦理学为哲学依托对阜新创建示范市有现实意义。  相似文献   
74.
We introduce a general class of continuous univariate distributions with positive support obtained by transforming the class of two-piece distributions. We show that this class of distributions is very flexible, easy to implement, and contains members that can capture different tail behaviours and shapes, producing also a variety of hazard functions. The proposed distributions represent a flexible alternative to the classical choices such as the log-normal, Gamma, and Weibull distributions. We investigate empirically the inferential properties of the proposed models through an extensive simulation study. We present some applications using real data in the contexts of time-to-event and accelerated failure time models. In the second kind of applications, we explore the use of these models in the estimation of the distribution of the individual remaining life.  相似文献   
75.
Covariance matrices play an important role in many multivariate techniques and hence a good covariance estimation is crucial in this kind of analysis. In many applications a sparse covariance matrix is expected due to the nature of the data or for simple interpretation. Hard thresholding, soft thresholding, and generalized thresholding were therefore developed to this end. However, these estimators do not always yield well-conditioned covariance estimates. To have sparse and well-conditioned estimates, we propose doubly shrinkage estimators: shrinking small covariances towards zero and then shrinking covariance matrix towards a diagonal matrix. Additionally, a richness index is defined to evaluate how rich a covariance matrix is. According to our simulations, the richness index serves as a good indicator to choose relevant covariance estimator.  相似文献   
76.
Clinical phase II trials in oncology are conducted to determine whether the activity of a new anticancer treatment is promising enough to merit further investigation. Two‐stage designs are commonly used for this situation to allow for early termination. Designs proposed in the literature so far have the common drawback that the sample sizes for the two stages have to be specified in the protocol and have to be adhered to strictly during the course of the trial. As a consequence, designs that allow a higher extent of flexibility are desirable. In this article, we propose a new adaptive method that allows an arbitrary modification of the sample size of the second stage using the results of the interim analysis or external information while controlling the type I error rate. If the sample size is not changed during the trial, the proposed design shows very similar characteristics to the optimal two‐stage design proposed by Chang et al. (Biometrics 1987; 43:865–874). However, the new design allows the use of mid‐course information for the planning of the second stage, thus meeting practical requirements when performing clinical phase II trials in oncology. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
77.
伴随着中国改革开放的进程,转型成为社会变迁的主题和基本特征。与此相应的却是,改革日益呈现出一种“锁定”的状态。在社会转型时期出现的诸多根本性问题,并不能用过渡性的办法来解决。在国家和法律的现代化进程中,特别是构建法治政府的进程中,政府不能再像过去那样,一味运用相机决策和政策调整来处理社会利益矛盾,不能再对不同群体在基本权利上区别对待。同样,在工农、城乡、区域乃至人与自然生态之间,要实现统筹协调发展的目标,更需要加强普遍性的努力,这种普遍性努力以法治和体现法治精神的整体性政策为特征。  相似文献   
78.
入世后,我国民营外贸企业得到了迅猛的发展,目前已基本完成了"量"的积累,进入了全面转型和提升"质"的阶段。民营外贸企业要突破当前的发展困境,必须关注企业的内外部利益相关者,只有得到他们的充分理解与大力支持,才能成功实现企业的转型。  相似文献   
79.
We propose localized spectral estimators for the quadratic covariation and the spot covolatility of diffusion processes, which are observed discretely with additive observation noise. The appropriate estimation for time‐varying volatilities is based on an asymptotic equivalence of the underlying statistical model to a white‐noise model with correlation and volatility processes being constant over small time intervals. The asymptotic equivalence of the continuous‐time and discrete‐time experiments is proved by a construction with linear interpolation in one direction and local means for the other. The new estimator outperforms earlier non‐parametric methods in the literature for the considered model. We investigate its finite sample size characteristics in simulations and draw a comparison between various proposed methods.  相似文献   
80.
The use of the logit transformation on paired-comparison data in the weighted least squares analysis of response surfaces for aesthetic qualities of products is discussed. Monte Carlo simulations are employed to investigate the small sample properties of the estimators and test statistics. A secondary objective of the Monte Carlo simulations is the comparison of two transformation procedures. The simulations are of standard-item paired-compar-ison experiments in which ties are not allowed.  相似文献   
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