GMM tests for the Katz family of distributions

Generalized method of moments (GMM) is used to develop tests for discriminating discrete distributions among the two-parameter family of Katz distributions. Relationships involving moments are exploited to obtain identifying and over-identifying restrictions. The asymptotic relative efficiencies of tests based on GMM are analyzed using the local power approach and the approximate Bahadur efficiency. The paper also gives results of Monte Carlo experiments designed to check the validity of the theoretical findings and to shed light on the small sample properties of the proposed tests. Extensions of the results to compound Poisson alternative hypotheses are discussed.     

烟草硫氧还蛋白基因NtTRX-hl的克隆和功能分析

从烟草中克隆了硫氧还蛋白基因NtTRX-hl并推导出其氨基酸序列,系统进化关系分析表明,NtTRX-hl与小麦、大麦、拟南芥等多种植物的TRX蛋白有很高的同源性.构建高效表达载体,诱导表达重组菌得到分子大小为22.26 kD的融合蛋白,与推测的分子量一致.用胰岛素和二硫苏糖醇作底物进行酶活性测定表明,Nt-TRX-hl具有活性.采用生物信息学的方法和工具分析了NtTRX-hl蛋白的生化参数和亚细胞定位,预测了该蛋白的高级结构.     

Implied Preference for Seismic Design Level and Earthquake Insurance

Seismic risk can be reduced by implementing newly developed seismic provisions in design codes. Furthermore, financial protection or enhanced utility and happiness for stakeholders could be gained through the purchase of earthquake insurance. If this is not so, there would be no market for such insurance. However, perceived benefit associated with insurance is not universally shared by stakeholders partly due to their diverse risk attitudes. This study investigates the implied seismic design preference with insurance options for decisionmakers of bounded rationality whose preferences could be adequately represented by the cumulative prospect theory (CPT). The investigation is focused on assessing the sensitivity of the implied seismic design preference with insurance options to model parameters of the CPT and to fair and unfair insurance arrangements. Numerical results suggest that human cognitive limitation and risk perception can affect the implied seismic design preference by the CPT significantly. The mandatory purchase of fair insurance will lead the implied seismic design preference to the optimum design level that is dictated by the minimum expected lifecycle cost rule. Unfair insurance decreases the expected gain as well as its associated variability, which is preferred by risk-averse decisionmakers. The obtained results of the implied preference for the combination of the seismic design level and insurance option suggest that property owners, financial institutions, and municipalities can take advantage of affordable insurance to establish successful seismic risk management strategies.     

论英语语言课程设计中的需求分析

界定需求要从目标和目的两个方面进行,这两个方面是我们发展测试、材料、教学活动、评价策略的基础。因此需求分析是语言课程建设不可分割的一部分。本文重点介绍了英语语言课程设计中需求分析的方法及步骤。目的在于强调需求分析的重要性,以及需求分析对于教师改进教学方法、提高教学效果、提高学生学习的主动性和积极性的重要意义。     

Ethnic patterns in the phonetics of Montreal English

Most North American cities no longer display strong ethnic differentiation of speech within the European‐origin population. This is not true in the English‐speaking community of Montreal, Canada, where English is a minority language. Differences in the phonetic realization of vowels by Montrealers of Irish, Italian, and Jewish ethnic origin are investigated by means of acoustic analysis. A statistical analysis of ethnic differences in formant frequencies shows that ethnicity has a significant effect on several variables, particularly the phonetic position of /u:/ and /ou/ and the allophonic conditioning of /æ/ and /au/ before nasal consonants. The unusual tenacity of ethnophonetic variation in Montreal English is explained in light of the minority status of English, and the social and residential segregation of ethnic groups in distinct neighborhoods, which limits their exposure to speakers of Standard Canadian English who might otherwise serve as models for assimilation.     

ASSESSING CONGRUENCEAMONG DISTANCE MATRICES: SINGLE-MALT SCOTCH WHISKIES REVISITED

A test of congruence among distance matrices is described. It tests the hypothesis that several matrices, containing different types of variables about the same objects, are congruent with one another, so they can be used jointly in statistical analysis. Raw data tables are turned into similarity or distance matrices prior to testing; they can then be compared to data that naturally come in the form of distance matrices. The proposed test can be seen as a generalization of the Mantel test of matrix correspondence to any number of distance matrices. This paper shows that the new test has the correct rate of Type I error and good power. Power increases as the number of objects and the number of congruent data matrices increase; power is higher when the total number of matrices in the study is smaller. To illustrate the method, the proposed test is used to test the hypothesis that matrices representing different types of organoleptic variables (colour, nose, body, palate and finish) in single‐malt Scotch whiskies are congruent.     

绿色供应链管理动力/压力影响模型实证研究

文章借鉴国外文献及国内环保专家的意见设计问卷进行调研,通过因子分析识别出中国制造企业绿色供应链管理的压力/动力和实践的主要因子.对因子进行相关分析和回归分析,根据数据结合国内外相关情况探讨动力/压力是如何影响绿色供应链管理实践,提出中国制造企业绿色供应链管理的动力/压力影响模型.     

对近年来我国建设用地扩张的分析

着眼近年来我国的建设用地面积增长扩张的现状,分析了造成建设用地扩张的原因,指出城镇人口的增加、经济发展的需求、征地制度的实施和经济利益的驱动是建设用地扩张的主要因素。总结出建设用地过度扩张,会对我国粮食安全和生态安全构成威胁。由此提出严格控制利用土地谋利益,避免建设用地过度扩张。     

东北地区产业结构调整实证分析与对策研究

以1995～2004 年的统计数据为基础,对东北三省1995～2004年产业结构的变化情况进行了初步分析,主要从产值结构的比较、就业结构的比较以及黑龙江、吉林、辽宁三省产业结构的的技术经济分析等三大方面对东北三省的产业结构调整进行实证研究,从而对东北老工业基地经济的快速增长提供理论依据.     

再谈扩大英语词汇量的途径

词汇的记忆是英语学习中的一大难点,英语水平的高低很大程度上取决于词汇量的大小,对于学习者来说,明确词汇的学习是提高英语水平的关键.本文试从学习者的学法角度对英语词汇量扩大的途径略作探讨.