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21.
Many applications of nonparametric tests based on curve estimation involve selecting a smoothing parameter. The author proposes an adaptive test that combines several generalized likelihood ratio tests in order to get power performance nearly equal to whichever of the component tests is best. She derives the asymptotic joint distribution of the component tests and that of the proposed test under the null hypothesis. She also develops a simple method of selecting the smoothing parameters for the proposed test and presents two approximate methods for obtaining its P‐value. Finally, she evaluates the proposed test through simulations and illustrates its application to a set of real data.  相似文献   
22.
虚假广告不但损害消费者的利益,更是一种典型的破坏市场竞争秩序的不正当竞争行为,应当承担行政责任。但是,我国法律对于虚假广告的行政责任立法却存在许多漏洞。为完善虚假广告的行政责任立法,必须解决虚假广告行政责任法律冲突、行政责任的构成要件及行政处罚方式等问题。  相似文献   
23.
善意取得制度意在对特定类型的非正常的利益变动,做出价值判断,进行利益衡平。那么,善意取得制度对何种类型非正常的利益变动进行衡平?又是如何进行衡平的呢?这就引出了善意取得制度的构成要件及其效力问题。笔者正是从这两方面着手对善意取得制度基础理论和实践应用提供一孔之见。  相似文献   
24.
在差异化服务机制的基础上,研究了互联网的多级带宽定价问题.通过导入广义第二价格拍卖,构造了基于差异化服务的互联网多级带宽定价模型.该模型能够有效地解决Internet拥塞问题,促进网络资源的合理利用.  相似文献   
25.
Summary.  We explore the determinants of debt, financial assets and net worth at the household level by using survey data for Germany, Great Britain and the USA. To identify which households are potentially vulnerable to adverse changes in the economic environment, we also explore the determinants of a range of measures of financial pressure: the probability that a household has negative net worth; the debt-to-income ratio; mortgage income gearing; the saving-to-income ratio. Our empirical findings suggest that the poorest and the youngest households are the most vulnerable to adverse changes in their financial circumstances.  相似文献   
26.
基于主成分分析的我国西部地区间产业结构转换能力评价   总被引:3,自引:0,他引:3  
罗吉 《统计教育》2004,(5):39-43
产业结构的演进和转换是经济发展的本质特征,也是促进经济持续稳定协调发展的关键。西部地区产业结构转换能力的地区差异十分明显,本文阐述了影响地区产业结构转换的一般因素,并通过主成分分析方法对影响西部地区产业结构转换的主要因素进行了分析,并对西部各地区产业结构转换能力、转换速度以及转换方向进行了分析评价。  相似文献   
27.
Abstract. The use of the concept of ‘direct’ versus ‘indirect’ causal effects is common, not only in statistics but also in many areas of social and economic sciences. The related terms of ‘biomarkers’ and ‘surrogates’ are common in pharmacological and biomedical sciences. Sometimes this concept is represented by graphical displays of various kinds. The view here is that there is a great deal of imprecise discussion surrounding this topic and, moreover, that the most straightforward way to clarify the situation is by using potential outcomes to define causal effects. In particular, I suggest that the use of principal stratification is key to understanding the meaning of direct and indirect causal effects. A current study of anthrax vaccine will be used to illustrate ideas.  相似文献   
28.
Not having a variance estimator is a seriously weak point of a sampling design from a practical perspective. This paper provides unbiased variance estimators for several sampling designs based on inverse sampling, both with and without an adaptive component. It proposes a new design, which is called the general inverse sampling design, that avoids sampling an infeasibly large number of units. The paper provide estimators for this design as well as its adaptive modification. A simple artificial example is used to demonstrate the computations. The adaptive and non‐adaptive designs are compared using simulations based on real data sets. The results indicate that, for appropriate populations, the adaptive version can have a substantial variance reduction compared with the non‐adaptive version. Also, adaptive general inverse sampling with a limitation on the initial sample size has a greater variance reduction than without the limitation.  相似文献   
29.
浅论教师在多媒体教学中的主体地位   总被引:2,自引:0,他引:2  
运用现代多媒体教学手段,是实现教育方法现代化的必由之路,但教师在现代多媒体教学中的主体地位是不可替代的,多媒体教学在高等教育教学中发挥的作用如何,主要取决于教师的主体地位。  相似文献   
30.
On Block Updating in Markov Random Field Models for Disease Mapping   总被引:3,自引:0,他引:3  
Gaussian Markov random field (GMRF) models are commonly used to model spatial correlation in disease mapping applications. For Bayesian inference by MCMC, so far mainly single-site updating algorithms have been considered. However, convergence and mixing properties of such algorithms can be extremely poor due to strong dependencies of parameters in the posterior distribution. In this paper, we propose various block sampling algorithms in order to improve the MCMC performance. The methodology is rather general, allows for non-standard full conditionals, and can be applied in a modular fashion in a large number of different scenarios. For illustration we consider three different applications: two formulations for spatial modelling of a single disease (with and without additional unstructured parameters respectively), and one formulation for the joint analysis of two diseases. The results indicate that the largest benefits are obtained if parameters and the corresponding hyperparameter are updated jointly in one large block. Implementation of such block algorithms is relatively easy using methods for fast sampling of Gaussian Markov random fields ( Rue, 2001 ). By comparison, Monte Carlo estimates based on single-site updating can be rather misleading, even for very long runs. Our results may have wider relevance for efficient MCMC simulation in hierarchical models with Markov random field components.  相似文献   
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