泡沫增强聚合物体系配方研究

在分析了聚合物驱提高采收率技术在实际应用中的局限性基础上,提出了采用就地起泡形成泡沫的泡沫增强聚合物体系以减小聚合物沿大通道窜流的问题。为了有效确定该体系的配方,实验中采用了均匀设计实验方法安排实验,并运用DPS数据处理软件对实验数据进行了二次多项式逐步回归处理,找出了影响该体系性能的主要因素。     

物流金融中季节性存货质押融资质押率决策

物流金融创新模式下的存货质押融资业务能有效解决供应链上的资金瓶颈,具有很大发展空间,但风险控制水平的滞后严重制约了业务的成长.本文针对基于统一授信的物流金融创新模式中季节性存货质押融资业务的核心风险控制指标——质押率展开研究,首先考虑统一授信模式的特征及成本收益结构,借鉴贸易融资中“主体+债项”的风险评估思路,构建融资...     

On smoothness of Tukey depth contours

The smoothness of Tukey depth contours is a regularity condition often encountered in asymptotic theory, among others. This condition ensures that the Tukey depth fully characterizes the underlying multivariate probability distribution. In this paper we demonstrate that this regularity condition is rarely satisfied. It is shown that even well-behaved probability distributions with symmetrical, smooth and (strictly) quasi-concave densities may have non-smooth Tukey depth contours, and that the smoothness behaviour of depth contours is fairly unpredictable.     

Uniform consistency rate of kNN regression estimation for functional time series data

In this paper, we investigate the k-nearest neighbours (kNN) estimation of nonparametric regression model for strong mixing functional time series data. More precisely, we establish the uniform almost complete convergence rate of the kNN estimator under some mild conditions. Furthermore, a simulation study and an empirical application to the real data analysis of sea surface temperature (SST) are carried out to illustrate the finite sample performances and the usefulness of the kNN approach.     

生命的困境与心灵的自由——庄子的人生哲学

庄子人生哲学的根本宗旨是实现对构成生命困境的必然性因素 (“命”)的超越 ,达到个体生命心灵的绝对自由 (“逍遥”)。庄子将人生所面临的生死、时势、情欲等困境概括为一种必然性范畴———“命”。而作为“逍遥哲学”的开创者 ,庄子找到了三种超越生命困境、实现心灵自由的途径 :安命、齐物、体道     

村委会职能立法的基本情况及存在的问题——以立法条文为分析对象

当前为村委会设置职能的法律既有国家统一立法也有地方立法。通过分析发现：统一立法所反映的村委会性质有所差异,在不同立法中不能保持恒定;指导及协助关系不仅存在于乡、镇政府与村委会之间,还存在于村委会与众多主体之间;立法中的某些职能设置没有充分考虑村委会的适格性问题,从而使村委会无法胜任。各省《村组法》实施办法中的职能规定,主要是大量重复《村组法》的内容,虽然在实施方式、方法以及步骤上起了一些具体化的作用,但并不普遍,尚未实现统一立法的“本土化”。在使村委会的职能具体化以及可操作化这一问题上,其他地方性法规以及部门规章做得比《村组法》实施办法成功得多,但它们在这一过程中增加了村委会的工作量,同时也强化了行政机构对村委会的控制。     

分贷统还合同的法律性质与违约风险化解

分贷统还合同为政府通过合约统一贴息实现了扶贫资金的公司化运作,有效地发挥财政扶贫资金的整体效益,但也产生了合同法律性质认定争议大、合同履行易受政策变化影响;户贷企用导致贷款用途和资金安全存在风险,公司分红还款系统性违约等弊端,如公司经营不善,贷款亏空,一旦出现系统性违约,不仅影响农村社会稳定和政府公信力,司法机关亦将面临纠纷批量涌入的现实问题。为趋利避害,分贷统还合同有必要在综合衡量扶贫目的、公司盈利及扶贫责任和银行资金安全的基础上,调整户贷企用政策,甄别债权类型,考虑违约的具体情势,从实操层面化解分贷统还合同违约风险。     

Trend estimation of multivariate time series with controlled smoothness

This paper extends the univariate time series smoothing approach provided by penalized least squares to a multivariate setting, thus allowing for joint estimation of several time series trends. The theoretical results are valid for the general multivariate case, but particular emphasis is placed on the bivariate situation from an applied point of view. The proposal is based on a vector signal-plus-noise representation of the observed data that requires the first two sample moments and specifying only one smoothing constant. A measure of the amount of smoothness of an estimated trend is introduced so that an analyst can set in advance a desired percentage of smoothness to be achieved by the trend estimate. The required smoothing constant is determined by the chosen percentage of smoothness. Closed form expressions for the smoothed estimated vector and its variance-covariance matrix are derived from a straightforward application of generalized least squares, thus providing best linear unbiased estimates for the trends. A detailed algorithm applicable for estimating bivariate time series trends is also presented and justified. The theoretical results are supported by a simulation study and two real applications. One corresponds to Mexican and US macroeconomic data within the context of business cycle analysis, and the other one to environmental data pertaining to a monitored site in Scotland.     

A powerful and efficient algorithm for breaking the links between aliased effects in asymmetric designs

Fractional factorial (FF) designs are no doubt the most widely used designs in experimental investigations due to their efficient use of experimental runs. One price we pay for using FF designs is, clearly, our inability to obtain estimates of some important effects (main effects or second order interactions) that are separate from estimates of other effects (usually higher order interactions). When the estimate of an effect also includes the influence of one or more other effects the effects are said to be aliased. Folding over an FF design is a method for breaking the links between aliased effects in a design. The question is, how do we define the foldover structure for asymmetric FF designs, whether regular or nonregular? How do we choose the optimal foldover plan? How do we use optimal foldover plans to construct combined designs which have better capability of estimating lower order effects? The main objective of the present paper is to provide answers to these questions. Using the new results in this paper as benchmarks, we can implement a powerful and efficient algorithm for finding optimal foldover plans which can be used to break links between aliased effects.