Constructing and evaluating core inflation measures from component‐level inflation data

This paper undertakes a comprehensive examination of 10 measures of core inflation and evaluates which measure produces the best forecast of headline inflation out‐of‐sample. We use the Personal Consumption Expenditure Price Index as our measure of inflation. We use two sets of components (17 and 50) of the Personal Consumption Expenditure Price Index to construct these core inflation measures and evaluate these measures at the three time horizons (6, 12 and 24 months) most relevant for monetary policy decisions. The best measure of core inflation for both sets of components and over all time horizons uses weights based on the first principal component of the disaggregated (component‐level) prices. Interestingly, the results vary by the number of components used; when more components are used the weights based on the persistence of each component is statistically equivalent to the weights generated by the first principal component. However, those forecasts using the persistence of 50 components are statistically worse than those generated using the first principal component of 17 components. The statistical superiority of the principal component method is due to the fact that it extracts (in the first principal component) the common source of variation in the component level prices that accurately describes trend inflation over the next 6–24 months.     

试论词义术语化流程中的转换机制及语义特征

本文从分析科技术语的基本特点入手,深入讨论了术语体系中兼容语词的语义特征及其转换机制。从而为揭示词义术语化流程的基本规律提供了重要的依据。     

Error rates in quadratic discrimination with constraints on the covariance matrices

In multivariate discrimination of several normal populations, the optimal classification procedure is based on quadratic discriminant functions. We compare expected error rates of the quadratic classification procedure if the covariance matrices are estimated under the following four models: (i) arbitrary covariance matrices, (ii) common principal components, (iii) proportional covariance matrices, and (iv) identical covariance matrices. Using Monte Carlo simulation to estimate expected error rates, we study the performance of the four discrimination procedures for five different parameter setups corresponding to standard situations that have been used in the literature. The procedures are examined for sample sizes ranging from 10 to 60, and for two to four groups. Our results quantify the extent to which a parsimonious method reduces error rates, and demonstrate that choosing a simple method of discrimination is often beneficial even if the underlying model assumptions are wrong.The authors wish to thank the editor and three referees for their helpful comments on the first draft of this article. M. J. Schmid supported by grants no. 2.724-0.85 and 2.038-0.86 of the Swiss National Science Foundation.     

酚醛树脂泡沫材料的填充改性及其性能研究

用氢氧化铝粉末对泡沫酚醛树脂材料进行填充改性,并对其主要性能进行研究．结果表明,填充改性能提高酚醛泡沫材料的抗压强度,其导热系数随温度和密度的升高而增大,泡沫材料在深冷情况下表现出优异的绝热性能．同时对酚醛泡沫材料的燃烧性能进行了考察,其临界氧指数高达４７,在高于１５０℃环境温度中有自燃的危险,１５０℃以下可安全使用．     

高硅沸石中二元物系表面扩散系数的预测

用动力学蒙特卡罗（Kinetic Monte Carlo，KMC）方法模拟客体分子单组分及双组分混合物在高硅沸石（Silicalite）分子筛中的扩散，与分子动力学（Molecular Dynamics，MD）方法的模拟结果及Maxwell-Stefan（M-S）方程计算对比说明KMC方法的合理性，而由真实的体系性质获得正确的跳跃频率值及合适的晶格模型是获得正确计算结果的关键，且一旦由单组分研究获得正确的跳跃频率值及晶格模型，便可直接移用至多组分体系的KMC模拟中。     

典型受载铁磁构件的数值模拟和磁特性

研究了铁磁构件在受载状态下表面产生漏磁的磁记忆现象,对含小孔平板进行了有限元分析,实测了受拉伸载荷时的漏磁场值.结果表明,应力集中对构件的磁特性有显著影响,在应力引起的小范围塑性变形区域存在有效的磁记忆信号,采用磁记忆方法对设备承载铁磁构件由应力集中造成的早期损伤进行检测是可行的.     

小麦RIL群体中籽粒蛋白质组分的分离与主要品质性状的相关分析

利用普通小麦重组自交系群体为材料,研究了小麦籽粒蛋白质组分在后代群体中的分离和分布,同时对籽粒蛋白质组分与其它主要品质指标的关系进行了研究.结果发现籽粒蛋白质组分在群体后代中表现为微效多基因控制的数量性状,相对亲本的性状变异较大.醇溶蛋白和谷蛋白相对含量与湿面筋含量、SDS沉降值之间呈显著正相关,与硬度呈正相关.清蛋白、球蛋白相对含量与湿面筋含量、SDS沉降值和硬度呈负相关.     

基于微元件键合图库的微机电系统动态建模与仿真

为了更好地支持微机电系统(MEMS)TopDown设计流程,针对MEMS仿真中的多能量域与非线性特点,采用键合图场元件与结型结构设计并实现了一个集中参数表达的MEMS键合图仿真元件库,同时基于该元件库提出了一种MEMS动态系统建模与仿真方法.采用参数化仿真模型与结构化体系构建的元件库,为MEMS设计流程中的概念设计阶段与系统级设计阶段的快速建模与仿真提供了方便,同时元件库内的所有元件均与MEMS器件级设计中的结构特征具有映射关系,这为用户需求空间功能原理空间结构空间之间的设计空间映射提供了方便.通过一个静电间隙执行器的系统建模过程与仿真结果,验证了利用该元件库进行建模与仿真的有效性.     

湖北省经济可持续发展动态分析

搜集了湖北省1998～2002年国民经济发展的有关数据，按照可持续发展的要求，建立了经济可持续发展的多层次指标体系；借助基于主成分分析的建模方法，就实现湖北省经济、资源、环境之间协调发展的问题进行了研究，建立了湖北省经济、资源、环境可持续发展的数学模型，并利用统计软件SPSS和EXCEL对模型进行了求解，对模型的结果进行了分析和讨论．     

电氧化法处理高浓度酚钠废水

为了改善强碱性废水的可生化性,采用电氧化法处理高浓度酚钠废水.结果表明：电氧化法对废水的色度和S（重铬酸钾化学耗氧量）具有良好的去除效果,电解过程中余氯的产生对色度和S的去除有决定性作用.实验确定的高浓度酚钠废水电氧化处理条件是：电流密度为714 A/m^2、电压为10 V、电解时间为30min,采用中和→电氧化→生化工艺去除色度和S.