A seasonal mixed-POT model to estimate high flood quantiles from different event types and seasons

Flood events can be caused by several different meteorological circumstances. For example, heavy rain events often lead to short flood events with high peaks, whereas snowmelt normally results in events of very long duration with a high volume. Both event types have to be considered in the design of flood protection systems. Unfortunately, all these different event types are often included in annual maximum series (AMS) leading to inhomogeneous samples. Moreover, certain event types are underrepresented in the AMS. This is especially unsatisfactory if the most extreme events result from such an event type. Therefore, monthly maximum data are used to enlarge the information spectrum on the different event types. Of course, not all events can be included in the flood statistics because not every monthly maximum can be declared as a flood. To take this into account, a mixture Peak-over-threshold model is applied, with thresholds specifying flood events of several types that occur in a season of the year. This model is then extended to cover the seasonal type of the data. The applicability is shown in a German case study, where the impact of the single event types in different parts of a year is evaluated.     

Estimation of discrete survival function for error‐prone diagnostic tests

The product limit or Kaplan‐Meier (KM) estimator is commonly used to estimate the survival function in the presence of incomplete time to event. Application of this method assumes inherently that the occurrence of an event is known with certainty. However, the clinical diagnosis of an event is often subject to misclassification due to assay error or adjudication error, by which the event is assessed with some uncertainty. In the presence of such errors, the true distribution of the time to first event would not be estimated accurately using the KM method. We develop a method to estimate the true survival distribution by incorporating negative predictive values and positive predictive values, into a KM‐like method of estimation. This allows us to quantify the bias in the KM survival estimates due to the presence of misclassified events in the observed data. We present an unbiased estimator of the true survival function and its variance. Asymptotic properties of the proposed estimators are provided, and these properties are examined through simulations. We demonstrate our methods using data from the Viral Resistance to Antiviral Therapy of Hepatitis C study.     

Principal stratum strategy: Potential role in drug development

A randomized trial allows estimation of the causal effect of an intervention compared to a control in the overall population and in subpopulations defined by baseline characteristics. Often, however, clinical questions also arise regarding the treatment effect in subpopulations of patients, which would experience clinical or disease related events post-randomization. Events that occur after treatment initiation and potentially affect the interpretation or the existence of the measurements are called intercurrent events in the ICH E9(R1) guideline. If the intercurrent event is a consequence of treatment, randomization alone is no longer sufficient to meaningfully estimate the treatment effect. Analyses comparing the subgroups of patients without the intercurrent events for intervention and control will not estimate a causal effect. This is well known, but post-hoc analyses of this kind are commonly performed in drug development. An alternative approach is the principal stratum strategy, which classifies subjects according to their potential occurrence of an intercurrent event on both study arms. We illustrate with examples that questions formulated through principal strata occur naturally in drug development and argue that approaching these questions with the ICH E9(R1) estimand framework has the potential to lead to more transparent assumptions as well as more adequate analyses and conclusions. In addition, we provide an overview of assumptions required for estimation of effects in principal strata. Most of these assumptions are unverifiable and should hence be based on solid scientific understanding. Sensitivity analyses are needed to assess robustness of conclusions.     

刍议我国“网络暴民”典型事件及其特征

＂网络暴民＂是近几年网络媒体中的一个重要现象,在网络秩序并未得到有效控制的情况下,＂网络暴民＂现象一直受到极大的关注,从虚拟空间的攻击谩骂延伸到现实中的暴力行动,与＂网络暴民＂相关的负面舆论激起了人们关于虚拟社会、个人隐私以及网络媒体的理论反思。尽管它的出现有着自身的背景和原因,但这直接反映出当前网络媒体存在的问题,并在一定程度上影响着人们对网络新兴媒介的认识。＂网络暴民＂现象的特征包括伴随有个人隐私的公开、表现出言语侵扰和攻击、背后有经济利益的驱使、导致了现实影响的危害。     

What is the Point of Change? Change Point Detection in Relational Event Models

This paper presents an extension to the relational event model with change points (REM-CP) to study abrupt changes to social interaction behavior in temporal networks. A change point detection algorithm is proposed for exploring when and which network effects abruptly change, and a confirmatory approach to test the presence of a change point at a given moment. The effectiveness of the methodology was assessed with numerical simulations and NASA’s Apollo 13 mission data. The latter revealed dynamic communication behavior and identified time zones where most change points occurred, including around the time of the famous quote “Houston, we’ve had a problem.”     

国外体育经济影响研究述评

体育经济影响是近20年来国外体育经济研究的热点。本文对国外体育经济影响研究的起因、概念、方法和存在问题等进行了评述。提出完善我国体育经济影响研究的建议有：提高认识,加强我国体育经济影响研究;建立一个更全面而合理的理论框架,评估体育对区域的影响;丰富和发展体育经济影响评估的方法和工具,并建立体育影响数据库。     

鲁迅的“幻灯片事件”与终末论的精神救治

“幻灯片事件”展现了鲁迅从肉体救治到精神救治的生命抉择。在日本的医学讲堂中,鲁迅同时遭遇了肉体救治和战争屠戮的话语,从而对维新现代性产生了质疑。肉体救治并不能改变被示众的看客的看与被看的逻辑。由此,鲁迅基于一种终末论的眼光,发现了精神的救治,在死的终末意识中领会生命的价值。文艺的自觉正是基于这样一种眼光,担负起了精神救治的使命。     

生命历程理论视角下劳动力迁移对初婚年龄的影响

本文利用2012年清华大学“城镇化与劳动力移民”项目的调查数据,通过事件史方法考察劳动力迁移对初婚年龄的影响。研究发现,劳动力迁移会对初婚年龄产生推迟效应,迁移事件发生的时机和过程都会左右这一影响的具体结果。研究显示,越早实现迁移,越有助于移民进入婚姻,频繁的流动则削弱了结婚的可能性,而父亲的迁移经历同样会对子女的初婚年龄产生影响。通过对不同世代群体的比较,本文进一步发现,迁移对初婚年龄的影响程度随世代推移呈现“倒U型”趋势,这一结果与不同世代下的迁移特点及其身处情境有关。研究结果表明,劳动力移民的生命历程基于迁移发生了转轨,他们放缓了自我再生产的周期,这对人口结构和社会结构的调整具有重大意义。     

非制度化政治参与原因探究——以厦门PX事件为例

政治参与是民主政治建设的重要内容,按照政治参与主体行为是否符合政治系统的程序和制度,政治参与可分为制度化政治参与和非制度化政治参与。近年来我国公民非制度化政治参与呈现增长趋势,研究非制度化政治参与,认识其表现形式,分析其原因,寻找治理对策,对于扩大公民有序参与,构建和谐社会具有重大的现实意义。文章以厦门PX事件为例,试图从国家制度、公民文化、信息技术等方面分析非制度化政治参与的原因,并从中得出一些启示。