A class of semiparametric transormation frailty models with application to estimating treatment effects and heterogenity in aids clinical traials

Muitivariate failure time data are common in medical research; com¬monly used statistical models for such correlated failure-time data include frailty and marginal models. Both types of models most often assume pro¬portional hazards (Cox, 1972); but the Cox model may not fit the data well This article presents a class of linear transformation frailty models that in¬cludes, as a special case, the proportional hazards model with frailty. We then propose approximate procedures to derive the best linear unbiased es¬timates and predictors of the regression parameters and frailties. We apply the proposed methods to analyze results of a clinical trial of different dose levels of didansine (ddl) among HIV-infected patients who were intolerant of zidovudine (ZDV). These methods yield estimates of treatment effects and of frailties corresponding to patient groups defined by clinical history prior to entry into the trial.     

对学生学业成绩实施标准分处理与定比例淘汰制初探

根据教育统计学的思想 ,改革现行的学生学业成绩管理办法 ,将竞争激励机制引入教学管理过程中 ,提出了对学生学业成绩实施标准分处理与定比例淘汰的新的成绩管理模式 ,从而使长期以来形成的“60分万岁”的不良现象 ,基本上得到了解决。     

Probabilistic Reliability Modeling for Oil Exploration & Production (E&P) Facilities in the Tallgrass Prairie Preserve

The aging domestic oil production infrastructure represents a high risk to the environment because of the type of fluids being handled (oil and brine) and the potential for accidental release of these fluids into sensitive ecosystems. Currently, there is not a quantitative risk model directly applicable to onshore oil exploration and production (E&P) facilities. We report on a probabilistic reliability model created for onshore exploration and production (E&P) facilities. Reliability theory, failure modes and effects analysis (FMEA), and event trees were used to develop the model estimates of the failure probability of typical oil production equipment. Monte Carlo simulation was used to translate uncertainty in input parameter values to uncertainty in the model output. The predicted failure rates were calibrated to available failure rate information by adjusting probability density function parameters used as random variates in the Monte Carlo simulations. The mean and standard deviation of normal variate distributions from which the Weibull distribution characteristic life was chosen were used as adjustable parameters in the model calibration. The model was applied to oil production leases in the Tallgrass Prairie Preserve, Oklahoma. We present the estimated failure probability due to the combination of the most significant failure modes associated with each type of equipment (pumps, tanks, and pipes). The results show that the estimated probability of failure for tanks is about the same as that for pipes, but that pumps have much lower failure probability. The model can provide necessary equipment reliability information for proactive risk management at the lease level by providing quantitative information to base allocation of maintenance resources to high-risk equipment that will minimize both lost production and ecosystem damage.     

英语语用失误分析及对策

从分析语用失误的分类出发,着重分析了日常语用失误的成因,并着重探讨了在英语教学中,如何培养学生的语用能力及如何避免因文化差异而带来的跨文化语用失误,以期减少或防范跨文化交际中的语用失误。     

数控机床可靠性分析方法

利用故障频次主次图、故障比重比主次图及危害度的综合分析方法,对所采集的某系列加工中心现场故障信息进行了统计分析,找出了其可靠性的薄弱环节,进一步明确了加工中心可靠性工作的改进方向,为其他机电产品的可靠性研究提供了较实用的方法。     

公示语的语用翻译

公示语是常见于公共场所为公众提供信息服务的一种特殊文体。笔者认为语用等效是适用于公示语翻译的原则,根据此原则,分析了武汉市部分公示语翻译中的语用失误现象,并提出公示语翻译中的语用策略。     

多奈哌齐对慢性心力衰竭患者心功能、心室重构的影响

目的探讨使用乙酰胆碱酯酶抑制剂-多奈哌齐对慢性心衰患者的心功能以及心室重构的影响。方法慢性心衰患者60例,随机分为治疗组(28例) 和对照组(32例)。两组均给予目前常规治疗,治疗组用加多奈哌齐5mg／d。对比观察6个月至一年后两组心功能改变情况;心脏超声检查左房内径(LA)、左心室收缩末期内径(LVESD)、左心室舒张末期内径(LVEDd)、室间隔厚度(1VSD)、左室后壁厚度(LVPWD)、左室射血分数(EF)、短轴缩短率(FS),对比两组指标的前后差异(Δ值)有无统计学意义。结果①治疗组在使用多奈哌齐后,心功能改善明显优于对照组(心功能分别为2．14±0．71和2．62±0．77,P<0．05)。②心超检查的各项指标除了LA以外,其余指标的△值,两组间存在显著差异,多奈哌齐组均优于对照组(LVEDd为-0．28±0．198和0．055±0．154;IVSD为-0．0214±0．0778和 0．0447±0．0119,P<0．01);(LVESD为-0．073±0．325和0．267±0．329;LVPWD为 -0．00625±0．104和0．0564±0．0679;EF为4．836±5．65％和0．973±7．96％及FS 为3．525±3．505％和0．769±6．7％,P<0．05)。结论慢性心衰患者在常规治疗基础上加用乙酰胆碱酯酶抑制剂-多奈哌齐能改善心功能,抑制心室重构。     

商务谈判口译语用失误浅析

中国加入世贸组织后 ,我国的对外贸易及对外经济、技术合作日益频繁。作为对外经济交流的重要手段 --商务谈判 ,其作用及面临的挑战也就不言而喻了。要想在对外经济合作中成为真正的赢家 ,除了研究谈判策略等内容之外 ,尤其要研究口译中存在的问题。口译是一种面对面的跨文化交际活动 ,了解、避免跨文化语用失误对口译来说有特别重要的意义     

翻译与隐含的语用用意

翻译与隐含的语用用意@李丽$三峡大学外国语学院!湖北宜昌443002~~     

The outcomes of a longitudinal study of non‐organic failure‐to‐thrive

Individuals who had failed‐to‐thrive for non‐organic reasons received psychosocial intervention which was tailor‐made to their particular needs during childhood. Their progress was followed up over 20 years later, including their physical growth and social and cognitive functioning. Not all clients showed the same outcomes. The quality of the parental relationship and the reason for the growth‐faltering were found to be related to the outcomes at 20 years. Unless they experienced a positive and sustained change in their life or circumstances, individuals who had experienced abuse showed poorer outcomes than those whose growth‐faltering had been thought due to neglect, lack of parenting or feeding dif?culties. Abuse tended to be a contributing factor to growth‐faltering more frequently in families where the parents were observed to have a poor relationship with each other. However, a signi?cant change in the quality of care given to the child and the emotional environment experienced by them resulted in positive outcomes 20 years later despite experiencing abuse during childhood. Copyright © 2003 John Wiley & Sons, Ltd.