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中国民族团结的发展在经历了隋唐的第二次大整合之后,在宋辽西夏金元时又进入第二次大冲突时期。  相似文献   
23.
通过对藏族大学生在识记不同语言材料时表现出不同效果的分析,从信息加工的角度阐述了母语是识记的基础,是识记表象建立的关键,母语所反映的认知取向决定了识记的侧重点。  相似文献   
24.
王昱 《青海民族研究》2007,18(2):124-127
该文对西汉元鼎年间所设的西平亭的性质、设立时间、位置及其与东汉建安年间所设的西平郡的位置和相关方位做了简要考证,针对不同意见,提出了西平亭与西平郡在方位上有凭依关系,位置在西宁明清城恒之内的学术观点。  相似文献   
25.
回族群众在花儿会上,不同于日常世俗生活的表现说明,花儿会是回族社会生活中二元结构下的特定时空。在这个特定时空里,回族群众完成了角色转换,以弥合现实生活和精神心理上的矛盾。  相似文献   
26.
本文介绍了黑龙江省杜尔伯特蒙古族自治县农转牧发展情况、存在的问题及对策。  相似文献   
27.
One of the objectives of personalized medicine is to take treatment decisions based on a biomarker measurement. Therefore, it is often interesting to evaluate how well a biomarker can predict the response to a treatment. To do so, a popular methodology consists of using a regression model and testing for an interaction between treatment assignment and biomarker. However, the existence of an interaction is not sufficient for a biomarker to be predictive. It is only necessary. Hence, the use of the marker‐by‐treatment predictiveness curve has been recommended. In addition to evaluate how well a single continuous biomarker predicts treatment response, it can further help to define an optimal threshold. This curve displays the risk of a binary outcome as a function of the quantiles of the biomarker, for each treatment group. Methods that assume a binary outcome or rely on a proportional hazard model for a time‐to‐event outcome have been proposed to estimate this curve. In this work, we propose some extensions for censored data. They rely on a time‐dependent logistic model, and we propose to estimate this model via inverse probability of censoring weighting. We present simulations results and three applications to prostate cancer, liver cirrhosis, and lung cancer data. They suggest that a large number of events need to be observed to define a threshold with sufficient accuracy for clinical usefulness. They also illustrate that when the treatment effect varies with the time horizon which defines the outcome, then the optimal threshold also depends on this time horizon.  相似文献   
28.
In this paper, we study the joint Laplace transform and probability generating function of some random quantities that occur in each environment state by the time of ruin in a Markov-modulated risk process. These quantities include the duration spent in each state, the number of claims and the aggregate amount of claims that occurred in each state by the time of ruin. Explicit formulae for the joint transforms, given the initial surplus, and the initial and terminal environment states, are expressed in terms of a matrix version of the scale function. Moments and covariances of these ruin-related quantities are obtained and numerical illustrations are presented. The joint transform of the duration spent in each state, the number of claims, and the aggregate amount of claims that occurred in each state by the time the surplus attains a certain level are also investigated.  相似文献   
29.
The aim of this study is to compare performances of commonly cointegration tests used in literature in terms of their empirical power and type I error probabilty for various sample sizes. As a result of the study, it has been found that some tests are not appropriate in testing cointegration in terms of empirical power and type I error probability. As a result of simulation study, λmax test for any values of ρ and sample sizes have been found most appropriate test in conclusion.  相似文献   
30.
Smoothed Gehan rank estimation methods are widely used in accelerated failure time (AFT) models with/without clusters. However, most methods are sensitive to outliers in the covariates. In order to solve this problem, we propose robust approaches based on the smoothed Gehan rank estimation methods for the AFT model, allowing for clusters by employing two different weight functions. Simulation studies show that the proposed methods outperform existing smoothed rank estimation methods regarding their biases and standard deviations when there are outliers in the covariates. The proposed methods are also applied to a real dataset from the “Major cardiovascular interventions” study.  相似文献   
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