Information fraction estimation: Strategies for a phase 3 non-inferiority maximum duration design with time to event outcome

There is considerable debate surrounding the choice of methods to estimate information fraction for futility monitoring in a randomized non-inferiority maximum duration trial. This question was motivated by a pediatric oncology study that aimed to establish non-inferiority for two primary outcomes. While non-inferiority was determined for one outcome, the futility monitoring of the other outcome failed to stop the trial early, despite accumulating evidence of inferiority. For a one-sided trial design for which the intervention is inferior to the standard therapy, futility monitoring should provide the opportunity to terminate the trial early. Our research focuses on the Total Control Only (TCO) method, which is defined as a ratio of observed events to total events exclusively within the standard treatment regimen. We investigate its properties in stopping a trial early in favor of inferiority. Simulation results comparing the TCO method with alternative methods, one based on the assumption of an inferior treatment effect (TH0), and the other based on a specified hypothesis of a non-inferior treatment effect (THA), were provided under various pediatric oncology trial design settings. The TCO method is the only method that provides unbiased information fraction estimates regardless of the hypothesis assumptions and exhibits a good power and a comparable type I error rate at each interim analysis compared to other methods. Although none of the methods is uniformly superior on all criteria, the TCO method possesses favorable characteristics, making it a compelling choice for estimating the information fraction when the aim is to reduce cancer treatment-related adverse outcomes.     

建设用地指标和建设用地的序贯拍卖定价机制研究

现行建设用地指标定价机制未能有效反映其真实价值,使得农民缺乏复垦闲置宅基地来提供建设用地指标的意愿。针对指标和建设用地的互补性特点,以及指标价值是开发商私人信息的特征,本文构建第一价格和第二价格两种密封拍卖下的互补品序贯拍卖模型,研究建设用地指标和建设用地的定价机制。理论和仿真分析得出两种拍卖下的建设用地指标和建设用地价格,并通过对比分析得出不同目标下的最优定价机制。研究发现,两种拍卖下,竞标人的建设用地指标报价均随着土地价格增值系数增加而提高,随着竞标人数递增而降低;序贯二价下的竞标人建设用地指标及建设用地的报价均高于序贯一价;序贯二价下,持有建设用地指标的竞标人获得建设用地的概率更高。因此,地方政府可采用适当提高土地闲置费用的方法,以此提高失地农民复垦权益,激励农民复垦闲置宅基地,增加建设用地指标供给;同时,采用序贯二价拍卖,提高建设用地指标和土地的利用效率。     

Morality rules: Understanding the role of prior reputation in consequences of scansis

A favorable reputation casts positive influences over organizations’ short- and long-term development, which can be especially important when organizations grapple with unpredictable challenges such as organizational crises. Yet, keeping a good track record might also backfire to cause more reputational damages, which is often observed when organizations deal with value-oriented moral crises. Against this backdrop, drawing from the literature on crisis communication and moral psychology, we situated our study in the scansis context, a particular type of morality-focused negative situation featuring characteristics of both crisis and scandal, and explored effects of prior reputation on people’s responses to an organizational scansis. Through an online experiment (N = 293), we found severe backlash towards the scansis-stricken organization in both the control condition (i.e., no indication of reputation) and the good reputation condition, whereas such prominent difference was not observed in the bad reputation condition. The findings thus implicated the need to take the unique role of morality in scansis into account in both pertinent research and practice.     

Contrast of Compliments Between Chinese and English（英文）

Compliments and their responses are special speech actions which are broadly used in interpersonal communications.And how to give compliments and respond to them constitute a significant part of the communicative competence of every member in a speech community.Complimenting is a particularly suitable speech action to investigate in comparative studies,for it acts as a window through which we can view what is valued by a particular culture.This essay mainly analyzes and researches the differences between Chinese and English compliments,attempting to reveal the contrast between Chinese and English compliments in the aspects of expression,topics and lexical formulas.The comparative study may contribute to understand more about Chinese and English compliment cultures,and furthermore,promote the study of pragmatics and the development of intercultural communication effectively.     

Sequential estimation problems for negative exponential populations

The literature on sequential estimation problems for negative exponential populations has been reviewed here, We attempt to bring in all the published and unpublished materials known to us in a fairly coherent fashion. Both the concepts and theoretical findings are discussed.     

A two- sample partially sequential probability ratio test

A two-sample partially sequential probability ratio test (PSPRT) is considered for the two-sample location problem with one sample fixed and the other sequential. Observations are assumed to come from two normal poptilatlons with equal and known variances. Asymptotically in the fixed-sample size the PSPRT is a truncated Wald one sample sequential probability test. Brownian motion approximations for boundary-crossing probabilities and expected sequential sample size are obtained. These calculations are compared to values obtained by Monte Carlo simulation.     

Asymptotic expansions for sequential confidence levels in inverse linear regression

Non-linear renewal theory is used to derive second order asymptotic expansions for the coverage probability of a fixed-width sequential confidence interval for an unknown parameter xin the inverse linear regression model. These expansions are obtained for a two-stage sequential procedure, proposed by Perng and Tong (1974) for the construction of a confidence interval for x.     

A two-sample parametric group sequential procedure for monitoring clinical trials

A group sequential procedure is presented which allows for staggered entry of patients, random loss to followup, and utilizes the flexible boundary approach of Lan and DeMets. The proposed procedure assumes that response times are nearly exponentially distributed. An example as well as simulation studies comparing the performance of the proposed procedure with the group sequential logrank are also presented.