Between stability and higher-order asymptotics

We discuss the effects of model misspecifications on higher-order asymptotic approximations of the distribution of estimators and test statistics. In particular we show that small deviations from the model can wipe out the nominal improvements of the accuracy obtained at the model by second-order approximations of the distribution of classical statistics. Although there is no guarantee that the first-order robustness properties of robust estimators and tests will carry over to second-order in a neighbourhood of the model, the behaviour of robust procedures in terms of second-order accuracy is generally more stable and reliable than that of their classical counterparts. Finally, we discuss some related work on robust adjustments of the profile likelihood and outline the role of computer algebra in this type of research.     

Estimation and interpretation of models of absolute risk from epidemiologic data,including family-based studies

Absolute risk is the chance that a person with given risk factors and free of the disease of interest at age a will be diagnosed with that disease in the interval (a, a + τ]. Absolute risk is sometimes called cumulative incidence. Absolute risk is a “crude” risk because it is reduced by the chance that the person will die of competing causes of death before developing the disease of interest. Cohort studies admit flexibility in modeling absolute risk, either by allowing covariates to affect the cause-specific relative hazards or to affect the absolute risk itself. An advantage of cause-specific relative risk models is that various data sources can be used to fit the required components. For example, case–control data can be used to estimate relative risk and attributable risk, and these can be combined with registry data on age-specific composite hazard rates for the disease of interest and with national data on competing hazards of mortality to estimate absolute risk. Family-based designs, such as the kin-cohort design and collections of pedigrees with multiple affected individuals can be used to estimate the genotype-specific hazard of disease. Such analyses must be adjusted for ascertainment, and failure to take into account residual familial risk, such as might be induced by unmeasured genetic variants or by unmeasured behavioral or environmental exposures that are correlated within families, can lead to overestimates of mutation-specific absolute risk in the general population.     

语言多样性、信息获取与分析师盈余预测质量

考察了语言多样性对分析师盈余预测质量的影响,以及这种影响如何因员工教育水平的不同而变化.基于中国上市公司的实证检验结果显示,语言多样性显著降低了分析师盈余预测质量,但是随着公司员工受教育水平提高,语言多样性对分析师盈余预测质量的负面影响有所减弱.进一步研究发现,分析师与CEO间的校友关系增强了员工教育水平对语言多样性与分析师盈余预测准确性之间关系的正向调节作用.研究结论一定程度上丰富了分析师私有信息获取及其影响机理以及社会关系等方面的文献,而且还可帮助投资者、监管者等利益相关方更好地理解分析师行为,促进资源合理配置,增强资本市场的有效性等方面具有一定的启示意义.     

钢管自动跟踪及在线自动定长切割控制器的软硬件设计

采用单片机实现了焊管机生产线钢管自动定长切割的控制，并使其具有结构小、功能强控制精度高等优点；介绍了控制器的软硬件设计思想和设计方法．     

刑事搜查立法精密化比较研究

刑事搜查制度既关系到刑事侦查权的正当行使,又关系到被搜查人的人权保护,各国立法者都要在打击犯罪和保障人权之间进行艰难的价值选择,因此西方法治国家的立法者设计了一套精密科学的机制。然而我国关于刑事搜查制度方面的立法粗糙,人权保障不足。借鉴域外经验对我国刑事搜查制度予以全面改造,才是明智之举。     

Who Is the Boss and Who Is Not? Accuracy of Judging Status

We investigated whether people were accurate at judging other people's status, what behavioral and appearance cues they relied on when assessing status, whether the way those cues were used was accurate, and whether target gender affected any of the results. Targets (N = 48) were university employees (faculty and staff) who were photographed while interacting with a coworker. One sample of perceivers (66 females, 42 males) rated the relative status of the two people in the photograph to each other, and another sample (60 females and males) rated each target in the photograph on status. Additionally, an array of behavioral and appearance cues of targets in the photograph was assessed. Results showed that (1) people were able to assess status in others, (2) the cues they used to assess female and male targets were somewhat different, and (3) how much people relied on specific cues corresponded to how status was expressed in these cues.     

多传感器系统的灵敏度、选择性与精度

对多传感器系统预处理部分的灵敏度、选择性、精度及分离性作了全面分析，并引用矩阵范数证明了估计精度和分离性的上界。这些上界揭示了精度和分离性与设计阵的条件数［Ｃｏｎｄ（Ｂ）］以及设计阵偏离值δＢ和随机变量ε之间的关系。这表明，欲提高多传感器系统的估计精度，可通过控制Ｃｏｎｄ（Ｂ）、δＢ和ε来实现     

关于双销定位中工件转角定位精度的研究

本文就削边销及其配合孔的直径与工件最大转角误差的关系进行了分析计算。结果表明：对于有较高转角定位精度要求的工件，在保证原有孔、销配合精度不变的前提下，适当加大削边销与其配合孔的直径，可以减小转角误差，提高定位精度；对于转角定位精度要求一般的工件，加大削边销与其配合孔的直径，可在不降低转角定位精度的情况下，成倍地增加销间公差，从而使夹具易于制造，降低了夹具的制造成本。     

伪距差分GPS定位误差分析

提出了ＧＰＳ测量误差模型，并在此基础上第一次给出了伪距差分ＧＰＳ的ＲＭＳ误差表达式。这个误差表达式揭示了影响伪距差分ＧＰＳ定位精度的误差源及其影响大小。分析表明，不同于ＧＰＳ直接定位，伪距测量随机误差已是伪距差分ＣＰＳ的主要误差源之一。