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首先对1980—2013年全国年度GDP数据进行消除趋势分析(DFA),发现GDP时序具有长记忆性,表明当前GDP值用来预测未来一段时间内的GDP值具有可行性,在此基础上利用具有非线性和强泛化能力特点的支持向量回归机(SVR),建立SVR预测模型,得到了较好的预测效果.  相似文献   
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There is finally precise information about the reform in endowment insurance to abolish the"double-track system".On December 23,2014,Mr.Ma Kai,Vice Premier of the State Council,delivered a work report on behalf of the State Council at the 12th Session of the Standing Committee of the Twelfth National People’s Congress about the progress made in comprehensively advancing the establishment of urban  相似文献   
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冯梦龙在《新列国志》的创制过程中,发挥《左传》“借言作断”之法:一方面,将春秋义理融入人物话语,明白显豁地反映历史真相,寄寓是非论断;一方面,借鉴《左传》中“君子曰”的模式,以髯翁、髯仙、史官、史臣等身份进行讽咏,或出以己意,或引经据典,以有诗或无诗的评论,增加内涵与意趣。他力图经史融合,藉由小说实现儒家道德伦理的大众教化,提升了列国小说的品格,确立了《新列国志》在列国小说演进过程中的典范意义。  相似文献   
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On Thanksgiving and Collective Memory: Constructing the American Tradition   总被引:1,自引:0,他引:1  
Relying on the approach by Maurice Halbwachs who argued that collective memory is based on contemporary interests and concerns, this article shows how Thanksgiving has changed over time in accordance with the ideas of the day. Aspects of the analysis support Barry Schwartz's theory that commemoration reflects the historical past. Similar to the pilgrims' celebration, many people commemorate Thanksgiving by, for example, feasting and praying. But in contrast to Schwartz's thought, this paper also shows that there are other elements of traditions that have minimal connection with the original event. Forms of commemoration like the Macy's Day Parade challenge the idea that commemoration and celebration contain some connection to the initial occasion. In general, the findings lend support to historical research and theories that implement social constructionist approaches.  相似文献   
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1.环境整治对经济发展的影响 我们生活的地球,正面临着人口、资源、生态与环境如何协调发展的重大挑战.人口爆炸、粮食紧缺、生态破坏、环境污染、经济危机等社会问题,一个又一个的危机,不仅使人类已有的文明成果黯然失色,而且使人类的未来也越来越充满艰险.  相似文献   
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陕北方言的疑问句和普通话的疑问句不同 ,只有是非问句、特指问句和选择问句三种 ,且结构格式也不一样。是非问句通常用类似于正反问的“体标记 否定词”格式表示 ;选择问句是在选择项之间嵌入“是”字 ,并于选项末缀体标记 ;特指问句则表现为一系列不同于普通话的特殊疑问代词的使用。同时三种问句格式在语义、语用方面也和普通话的相应形式有一些差别  相似文献   
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Children may be more susceptible to toxicity from some environmental chemicals than adults. This susceptibility may occur during narrow age periods (windows), which can last from days to years depending on the toxicant. Breathing rates specific to narrow age periods are useful to assess inhalation dose during suspected windows of susceptibility. Because existing breathing rates used in risk assessment are typically for broad age ranges or are based on data not representative of the population, we derived daily breathing rates for narrow age ranges of children designed to be more representative of the current U.S. children's population. These rates were derived using the metabolic conversion method of Layton (1993) and energy intake data adjusted to represent the U.S. population from a relatively recent dietary survey (CSFII 1994–1996, 1998). We calculated conversion factors more specific to children than those previously used. Both nonnormalized (L/day) and normalized (L/kg-day) breathing rates were derived and found comparable to rates derived using energy estimates that are accurate for the individuals sampled but not representative of the population. Estimates of breathing rate variability within a population can be used with stochastic techniques to characterize the range of risk in the population from inhalation exposures. For each age and age-gender group, we present the mean, standard error of the mean, percentiles (50th, 90th, and 95th), geometric mean, standard deviation, 95th percentile, and best-fit parametric models of the breathing rate distributions. The standard errors characterize uncertainty in the parameter estimate, while the percentiles describe the combined interindividual and intra-individual variability of the sampled population. These breathing rates can be used for risk assessment of subchronic and chronic inhalation exposures of narrow age groups of children.  相似文献   
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Summary.  Non-ignorable missing data, a serious problem in both clinical trials and observational studies, can lead to biased inferences. Quality-of-life measures have become increasingly popular in clinical trials. However, these measures are often incompletely observed, and investigators may suspect that missing quality-of-life data are likely to be non-ignorable. Although several recent references have addressed missing covariates in survival analysis, they all required the assumption that missingness is at random or that all covariates are discrete. We present a method for estimating the parameters in the Cox proportional hazards model when missing covariates may be non-ignorable and continuous or discrete. Our method is useful in reducing the bias and improving efficiency in the presence of missing data. The methodology clearly specifies assumptions about the missing data mechanism and, through sensitivity analysis, helps investigators to understand the potential effect of missing data on study results.  相似文献   
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