Properties of the weighted log‐rank test in the design of confirmatory studies with delayed effects

Proportional hazards are a common assumption when designing confirmatory clinical trials in oncology. This assumption not only affects the analysis part but also the sample size calculation. The presence of delayed effects causes a change in the hazard ratio while the trial is ongoing since at the beginning we do not observe any difference between treatment arms, and after some unknown time point, the differences between treatment arms will start to appear. Hence, the proportional hazards assumption no longer holds, and both sample size calculation and analysis methods to be used should be reconsidered. The weighted log‐rank test allows a weighting for early, middle, and late differences through the Fleming and Harrington class of weights and is proven to be more efficient when the proportional hazards assumption does not hold. The Fleming and Harrington class of weights, along with the estimated delay, can be incorporated into the sample size calculation in order to maintain the desired power once the treatment arm differences start to appear. In this article, we explore the impact of delayed effects in group sequential and adaptive group sequential designs and make an empirical evaluation in terms of power and type‐I error rate of the of the weighted log‐rank test in a simulated scenario with fixed values of the Fleming and Harrington class of weights. We also give some practical recommendations regarding which methodology should be used in the presence of delayed effects depending on certain characteristics of the trial.     

师德建设在学风建设中的作用

高等学校加强师德建设和学风建设是全面贯彻党的教育方针的根本保证,是适应新时期发展的需要,是高等学校自身发展的需要,是学生成长和成才的需要。建设优良的学风关键在于建设一支优秀的教师队伍,而建设一支优秀的教师队伍的关键在于提高教师的道德水平。     

立足高起点发展新方向培养应用型复合型人才——对我院法学专业教学的认识及建议

我院法学专业培养目标是为社会培养应用型、复合型人才 ,针对实际情况 ,作者提出应改革教学内容 ,优化课程体系 ;改革教学方法 ,完善教学手段 ;提高教师业务水平 ,加强学术梯队建设等建议。     

孔子的富贵观及其现代价值解读

孔子的富贵观是其思想体系的重要组成部分。孔子关于世人应否追求富贵,怎样处理富贵与道义的关系,以及富裕之后还当如何等问题在《论语》中都有论述。孔子的这些论述,对当代人们创业致富,以义求利,以及坚持经济建设与精神文明建设两手抓,仍然具有启迪作用和借鉴价值。     

高校师德建设的思考

师德建设事关高校办学方向和人才培养质量。在新时期客观分析师德建设状况,加强和改进师德建设是全面贯彻党的教育方针的重要保证,是培养社会主义事业建设者和接班人的必然要求。     

建设学习型教师队伍

在知识经济时代,学习的重要性不言而喻。教师作为一个传播文化知识的职业群体,自觉学习乃至终身学习是他们的职业需要。构建学习型教师队伍不仅可以帮助教师个体成长和发展,而且还能使教师个体和教师群体以及学校组织同步发展。本文简要论述了建设学习型教师队伍的意义,提出构建学习型教师队伍和学习型组织的具体策略。     

论审美理念系统的价值阶位

审美理念系统,以其特有的知识形式反映着人类审美价值的阶位需求。文中论述了人类最有代表性的五种阶位需求,认为虽然它们都反映一定的审美本质,但从生命与价值超越角度考虑,它们的内在思想特色和精神追求,还存在着很大的区别。     

Uncertainty Analysis for Computer Model Projections of Hurricane Losses

Projecting losses associated with hurricanes is a complex and difficult undertaking that is wrought with uncertainties. Hurricane Charley, which struck southwest Florida on August 13, 2004, illustrates the uncertainty of forecasting damages from these storms. Due to shifts in the track and the rapid intensification of the storm, real-time estimates grew from 2 to 3 billion dollars in losses late on August 12 to a peak of 50 billion dollars for a brief time as the storm appeared to be headed for the Tampa Bay area. The storm hit the resort areas of Charlotte Harbor near Punta Gorda and then went on to Orlando in the central part of the state, with early poststorm estimates converging on a damage estimate in the 28 to 31 billion dollars range. Comparable damage to central Florida had not been seen since Hurricane Donna in 1960. The Florida Commission on Hurricane Loss Projection Methodology (FCHLPM) has recognized the role of computer models in projecting losses from hurricanes. The FCHLPM established a professional team to perform onsite (confidential) audits of computer models developed by several different companies in the United States that seek to have their models approved for use in insurance rate filings in Florida. The team's members represent the fields of actuarial science, computer science, meteorology, statistics, and wind and structural engineering. An important part of the auditing process requires uncertainty and sensitivity analyses to be performed with the applicant's proprietary model. To influence future such analyses, an uncertainty and sensitivity analysis has been completed for loss projections arising from use of a Holland B parameter hurricane wind field model. Uncertainty analysis quantifies the expected percentage reduction in the uncertainty of wind speed and loss that is attributable to each of the input variables.     

综合实践活动课程实施的问题与对策

教师的课程理论素养较差,与综合实践活动课程实施的要求不相适应;综合实践活动课程的实施缺乏相关的制度保障和社会支持,是综合实践活动课程实施中存在的主要问题.解决问题的对策是:加强对教师的培训,提高教师实施综合实践活动课程的能力;完善学校相关教研、培训及管理等制度,为综合实践活动课程的实施提供制度保障;建立良好的社会支持和保障系统,充分利用各种资源,为综合实践活动课程的实施创造更好的条件.     

教师话语标记语与课堂语境

在话语交际中,说话人为了实现交际目的,不仅要传递基本信息,还要用恰当的语言手段和语言成分来传达语用信息,构建语篇语境。话语标记语是说话人明示话语意图的手段,是听话人推导话语意义的标识。课堂语境具有很强的可构建性,教师话语标记语对课堂语境的构建起着重要的作用。