钢筋混凝土叠合梁的斜截面承载力灰关联分析

为了经济合理地设计叠合梁，应用灰色系统理论，对均布荷载下钢筋混凝土叠合梁的斜截面积承载力及其关联因素进行关联度分析。结果表明，对叠合梁斜截面承载力影响最大的是预制梁混凝土强度等级，其次是叠合层混凝土强度等级、叠合特征参数αｈ，影响最小的是叠合特征参数αｍ。     

An alternative definition of individual bioequivalence

Several definitions of individual bioequivalence of two formulations of a medical treatment (drug) have been proposed recently. These definitions attempt to adapt the criterion of average bioequivalence, which would be deficient if substantive treatment heterogeneity were present. In some of the proposed definitions, relatively large differences of means can be compensated by differences in the measurement-error variances. We propose a definition based on a simple latent-variable model which overcomes this anomaly and need not involve the U.S. Food and Drug Administration's 80/125 rule. Our approach is based on a moment-matching estimator of the discrepancy between the outcomes underlying the subjects' responses. The distribution of this estimator is a linear combination of independent χ² variates; asymptotically, it can be approximated by a normal distribution. Evidence of individual bioequivalence corresponds to rejecting the hypothesis that the discrepancy is greater than a specified threshold. The approach is illustrated by reanalysing two bioequivalence trials.     

Mean squared error of the empirical best linear unbiased predictor in an orthogonal finite discrete spectrum linear regression model

The mean squared error (MSE) of the empirical best linear unbiased predictor in an orthogonal finite discrete spectrum linear regression model is derived and a comparison with the MSE of the best linear unbiased predictor in this model is made. It is shown that under weak conditions these two mean square errors are asymptotically the same.     

双层组合梁应力分析与试验研究

对由两种材料组合而成的梁的弯曲正应力计算方法进行了研究，发现由于连接件剪切面上存在较大的剪力，使上下层梁同时受弯矩和轴力的共同作用。在建立合理假定的基础上。提出了完全刚性连接和自由叠舍两种极端情况下的弯曲正应力计算方法，并制作了钢-铝两种材料楔块连接、自由叠合两种形式的双层组合梁进行了试验验证，结果表明理论分析与实验结果吻舍较好。     

部分相干高斯—谢尔模光束在负色散介质中的光谱特性

文章利用由部分相干光理论及张量方法推导出的部分相干高斯—谢尔模(GSM)光束在介质中的传输公式,计算分析了部分相干GSM光束在负色散介质中的演化特性.研究结果表明,部分相干GSM光束在负色散介质中传输时会出现光谱分裂和频移现象.     

FDI与湖南产业结构关系的实证研究

对湖南的产业结构和三次产业利用FDI的现状进行了分析,利用1983～2006年的统计数据,运用协整分析技术、误差修正模型和Cranger因果关系检验,对FDI与产业结构变动之间的关系进行了实证研究.结果表明,FDI与产业结构变动之间存在正向的协整关系,FDI是产业结构变动的重要原因;在短期FDI偏离了产业结构的长期均衡水平,但短期波动对长期均衡的回调速度较快.进而,就模型得出的结论提出了若干建议.     

中国健康保险市场规模实证分析

健康保险是中国医疗保障制度的重要组成部分,健康保险市场规模的扩张使得保险在中国能够更好地发挥经济补偿功能、资金融通功能与社会管理功能。本文借鉴前人的研究成果,利用国内生产总值、社会与个人卫生支出以及健康险保费收入的历年数据,构建误差修正模型(ECM),并寻找社会与个人卫生支出同健康险保费收入之间的数量关系,进而预测分析国内健康保险市场的发展规模、空间及方向。     

大学生英语写作错误归因

写作一直是大学英语教学中的一个难点,也是学生学习英语时最头疼的问题。文章分析了大学英语写作中的典型错误,对其成因进行了初步探究,并提出了一些提高英语写作水平的几点建议。     

浅析华南快速三期春岗立交钢箱梁吊装施工

文章通过对华南快速三期春岗立交钢箱梁现场吊装施工进行分析和总结，特别是对临时支撑的稳定性和安全性进行了受力计算和分析，并结合实际施工过程提出了一些应注意的问题。     

Cross Validation Calibration Based Shrinkage – Revisited for the Construction of Prognostic Indices

The use of shrinkage methods for the construction of prognostic indices has been paid increasing attention in the literature on medical statistics in the last years. One approach for the construction of a shrinkage factor is cross validation calibration as suggested by van H ouwelingen and le C essie (1990). We investigate this approach in more detail. First we try to clarify why shrinkage factors constructed by cross validation calibration tend to be smaller than 1. Second we explain why use of this shrinkage factor can result in an improvement of the average prediction error. Third we investigate the possible gain for constellations relevant in medical research by means of a simulation study, focusing on the dilemma, that the improvement on average has to be paid by distinct deteriorations for some patients. Finally we conclude that it is necessary to rethink the choice of loss functions in constructing prognostic indices before recommendations about the use of shrinkage methods can be made.