A comparison of classification models to identify the Fragile X Syndrome

The main models of machine learning are briefly reviewed and considered for building a classifier to identify the Fragile X Syndrome (FXS). We have analyzed 172 patients potentially affected by FXS in Andalusia (Spain) and, by means of a DNA test, each member of the data set is known to belong to one of two classes: affected, not affected. The whole predictor set, formed by 40 variables, and a reduced set with only nine predictors significantly associated with the response are considered. Four alternative base classification models have been investigated: logistic regression, classification trees, multilayer perceptron and support vector machines. For both predictor sets, the best accuracy, considering both the mean and the standard deviation of the test error rate, is achieved by the support vector machines, confirming the increasing importance of this learning algorithm. Three ensemble methods - bagging, random forests and boosting - were also considered, amongst which the bagged versions of support vector machines stand out, especially when they are constructed with the reduced set of predictor variables. The analysis of the sensitivity, the specificity and the area under the ROC curve agrees with the main conclusions extracted from the accuracy results. All of these models can be fitted by free R programs.     

局部环上典型群的非双曲型

引入域上典型群的生成问题所得的成果；对局部环R上典型群生成问题研究，构造度量函数及一平延，为局部环R上典型群向域F上的典型群导入，给出典型群的非双曲型．     

翻译的政治:马儒翰与第一次鸦片战争

鸦片战争期间,中英双方都存在语言沟通的难题.但是,英方由于聘用马儒翰等人担任翻译,有效解决了政治沟通和情报收集等问题.他们充分借助马儒翰等人的中文知识,作出了合理的战略决策和军事安排.而反观中方,林则徐之后的几个主帅,出于怀疑汉人、明哲保身等心理,竟将为数不多的几个译员拒之门外,倚赖英方的马儒翰"居中翻译".在缺乏翻译的情况下,清军前线主帅根本无法摸清敌人的真实动向,更无法核对所签条约文本的准确性.结果,清政府不但丧失了战争主动权,也丧失了谈判主动权,造成了很多原本可避免的损失.     

The robust economic statistical design of the Hotelling's T2 chart

ABSTRACT

Economic statistical designs aim at minimizing the cost of process monitoring when a specific scenario or a set of estimated process and cost parameters is given. But, in practice the process may be affected by more than one scenario which may lead to severe cost penalties if the wrong design is used. Here, we investigate the robust economic statistical design (RESD) of the T² chart in an attempt to reduce these cost penalties when there are multiple scenarios. Our method is to employ the genetic algorithm (GA) optimization method to minimize the total expected monitoring cost across all distinct scenarios. We illustrate the effectiveness of the method using two numerical examples. Simulation studies indicate that robust economic statistical designs should be encouraged in practice.     

The impact of anti-Vietnam demonstrations upon national public opinion and military indicators

In an attempt to assess the national impact of anti-war protest, 15 major anti-Vietnam demonstrations occurring in the United States from 1965 through 1971 were analyzed for their effects upon Gallup public opinion survey data, American troop strength, and American munitions expenditures. While weak and short-term counterproductive effects appeared for two opinion indicators, an equally likely conclusion is that the demonstrations had little or no lasting impact whatsoever. The possible reasons for this finding, and its social implications, are discussed.     

关于网络计划技术中结点时间的求解

指出网络计划技术中求解结点时间是网络时间计算的重点．抓住结点，就可突破网络．在笔者多年实践的基础上向读者推荐一有利于读者学习和使用的简易口诀和简图．最后举例加以说明．     

毫米波高增益大功率收发组件研制

提出了一种可用于雷达的毫米波收发组件的实现方案。组件包括两个几乎完全相同的接收通道和一个发射通道,接收通道采用两次混频将毫米波信号变为50MHz中频,而发射通道则采用两次上变频将50MHz信号变为毫米波频段的信号发射出去。该文分析了收发组件的设计原理,讨论了组件方案选择,并给出了测试结果。收发组件的各项技术指标基本达到设计要求:在10MHz的工作带宽内,连续波发射功率达1W,接收机噪声系数小于4.5dB,接收通道的净增益超过100dB。     

关于房地产泡沫量的测度研究

房地产基础(内在)价值理论是评估房地产资产泡沫的依据.而只有准确评估房地产资.产的基础价值,投资者和决策者才能正确认识房地产泡沫问题.文章首先对Ramsey模型做了改进.使之更具有实用价值;接着利用改进后的Ramsey模型,测算了我国1991～2006年房地产泡沫.研究结果表明,我国房地产经历了一个由正泡沫到无泡沫负泡沫、反复循环的过程.     

GORE-TEX~与有机溶剂结合法在纺织品文物保护中的应用

部分纺织品文物在保护过程中不宜与水接触,或普通的保护方法不能满足实际操作的要求,因此需要寻找一种替代技术.本文介绍了采用微孔膜层压织物材料GORE-TEx@与有机溶剂结合法应用于纺织品文物保护的新型技术,并对GORE-TEx@材料及该新型技术的使用方案、应用方向和注意事项进行了总结.