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排序方式: 共有266条查询结果,搜索用时 15 毫秒
1.
中德电信政策比较分析   总被引:1,自引:0,他引:1  
在 WTO的背景下 ,我国电信业面临着开放的压力。文章通过对比中德电信的开放过程 ,从中得出启示和借鉴 ,为我国电信业的发展提出一些建议  相似文献   
2.
癌症基因组计划是当前研究热点,存在诸多伦理、法律及社会问题,如何有效地保障基因组研究参与者的知情同意是值得关注的内容。信息披露(disclosure)作为知情同意的第一要素具备深厚的伦理基础,然而与传统医学研究相比,癌症基因组研究由于其目的与内容的特殊性,研究中信息披露的内容和标准尚存在诸多伦理问题,需要深入探讨。  相似文献   
3.
Of the 324 petroleum refineries operating in the U.S. in 1982, only 149 were still in the hands of their original owners in 2007. Using duration analysis, this paper explores why refineries change ownership or shut down. Plants are more likely to ‘survive’ with their original owners if they are older or larger, but less likely if the owner is a major integrated firm, or the refinery is a more technologically complex one. This latter result differs from existing research on the issue. This paper also presents a split population model to relax the general assumption of the duration model that all refiners will eventually close down; the empirical results show that the split population model converges on a standard hazard model; the log-logistic version fits best. Finally, a multinomial logit model is estimated to analyze the factors that influence the refinery plant's choices of staying open, closing, or changing ownership. Plant size, age and technology usage have positive impacts on the likelihood that a refinery will stay open, or change ownership (rather than close down).  相似文献   
4.
本文采用基于ARMA模型适用于小样本的最优预测的建模方法,来分析政府采购和经济增长之间的因果关系。研究结果表明政府采购和经济增长之间存在非对称、单向因果关系,即政府采购对经济增长的影响不显著,而经济增长对政府采购具有促进作用。因此,从政府采购影响路径的角度分析认为,在后金融危机时代应该采取一些可行的措施扭转政府采购对经济增长的不显著状况。  相似文献   
5.
Single cohort stage‐frequency data are considered when assessing the stage reached by individuals through destructive sampling. For this type of data, when all hazard rates are assumed constant and equal, Laplace transform methods have been applied in the past to estimate the parameters in each stage‐duration distribution and the overall hazard rates. If hazard rates are not all equal, estimating stage‐duration parameters using Laplace transform methods becomes complex. In this paper, two new models are proposed to estimate stage‐dependent maturation parameters using Laplace transform methods where non‐trivial hazard rates apply. The first model encompasses hazard rates that are constant within each stage but vary between stages. The second model encompasses time‐dependent hazard rates within stages. Moreover, this paper introduces a method for estimating the hazard rate in each stage for the stage‐wise constant hazard rates model. This work presents methods that could be used in specific types of laboratory studies, but the main motivation is to explore the relationships between stage maturation parameters that, in future work, could be exploited in applying Bayesian approaches. The application of the methodology in each model is evaluated using simulated data in order to illustrate the structure of these models.  相似文献   
6.
Classifying several regression models fitted on a dataset is one of the most problems in data analysis. In other words, scientists are interested in comparing several regression models that can be used for a dataset. In this paper, an approach will be used to compare and classify several dependent regression models. Then the performance of the proposed method is investigated using simulation study and real example.  相似文献   
7.
旨在探讨《心经》中独特的女性形象以及张爱玲写此文的深层原因。生活在父权制社会下,男性凝望世界中的女性,渴望直接与男性对话,从而产生异样感情,特殊的母女关系经历了分裂到张扬再到重组的过程,表现出女性在与男性相抗衡的过程中的绝望与疯狂,也隐含作者内心深处的希望。  相似文献   
8.
In this article, the statistical inference for the Gompertz distribution based on Type-II progressively hybrid censored data is discussed. The estimation of the parameters for Gompertz distribution is obtained using maximum likelihood method (MLE) and Bayesian method under three different loss functions. We also proved the existence and uniqueness of the MLE. The one-sample Bayesian prediction intervals are obtained. The work is done for different values of the parameters. We apply the Monto Carlo simulation to compare the proposed methods, also an example is discussed to construct the Prediction intervals.  相似文献   
9.
本次股权分置改革是非流通股股东通过市场交易的方式来购买其所持股票的流通权的过程,然而双方就支付价格进行讨价还价时,流通股股东处于明显的弱势地位。为了推动股权分置改革继续顺利进行,证券监管机构要进一步完善投票表决制度,切实保护流通股股东的权益。  相似文献   
10.
Randomized response models deal with stigmatizing variables appearing in health surveys. Additive and subtractive scrambling in split sample and double response yield unbiased mean and sensitivity estimators of high precision. The split sample method is protective of privacy. The double response method is as protective only conditionally. To achieve the maximum efficiency, the scrambling variables must be similar to each other and the probability of obtaining a true response must be as large as possible. The randomized response procedures yield more efficient estimates of the average total number of classes missed by university students.  相似文献   
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