A frequentist understanding of sets of measures

We present a mathematical theory of objective, frequentist chance phenomena that uses as a model a set of probability measures. In this work, sets of measures are not viewed as a statistical compound hypothesis or as a tool for modeling imprecise subjective behavior. Instead we use sets of measures to model stable (although not stationary in the traditional stochastic sense) physical sources of finite time series data that have highly irregular behavior. Such models give a coarse-grained picture of the phenomena, keeping track of the range of the possible probabilities of the events. We present methods to simulate finite data sequences coming from a source modeled by a set of probability measures, and to estimate the model from finite time series data. The estimation of the set of probability measures is based on the analysis of a set of relative frequencies of events taken along subsequences selected by a collection of rules. In particular, we provide a universal methodology for finding a family of subsequence selection rules that can estimate any set of probability measures with high probability.     

Estimation of survival quantiles in two-stage randomization designs

In two-stage randomization designs, patients are randomized to one or more available therapies upon entry into the study. Depending on the response to the initial treatment (such as complete remission or shrinkage of tumor), patients are then randomized to receive maintenance treatments to maintain the response or salvage treatment to induce response. One goal of such trials is to compare the combinations of initial and maintenance or salvage therapies in the form of treatment strategies. In cases where the endpoint is defined as overall survival, Lunceford et al. [2002. Estimation of survival distributions of treatment policies in two-stage and randomization designs in clinical trials. Biometrics 58, 48–57] used mean survival time and pointwise survival probability to compare treatment strategies. But, mean survival time or survival probability at a specific time may not be a good summary representative of the overall distribution when the data are skewed or contain influential tail observations. In this article, we propose consistent and asymptotic normal estimators for percentiles of survival curves under various treatment strategies and demonstrate the use of percentiles for comparing treatment strategies. Small sample properties of these estimators are investigated using simulation. We demonstrate our methods by applying them to a leukemia clinical trial data set that motivated this research.     

Confidence limits and prediction limits for a Weibull distribution based on the generalized variable approach

In this article, we consider the problems of constructing confidence interval for a Weibull mean and setting prediction limits for future samples. Specifically, we construct upper prediction limits that include at least l$l$ of m$m$ samples from a Weibull distribution at each of r$r$ locations. The methods are based on the concept of generalized variable approach. The procedures can be easily extended to the type II censored samples, and they can be used to find approximate inferential procedures for type I censored samples. The proposed methods are conceptually simple and easy to use. The results are illustrated using some practical examples.     

从传播失灵看经典社会主义体制的治理困境

信息的可获得性及流通状况主导着政治活动,并对社会治理产生着广泛的影响.经典社会主义体制下的信息流通呈现出“传播失灵”的特征,“数字注水、欺上瞒下”以及“真理报无真理,消息报无消息”等现象即传播失灵的突出体现.传播失灵与经典社会主义体制相互嵌套,经典社会主义体制内蕴了传播失灵,传播失灵又强化并导致了经典社会主义体制的治理困境.对于一个庞大的国家和日益复杂的社会而言,传播通畅是实现社会治理的前提和保证,经典社会主义体制下的传播失灵降低了政治决策的科学性和社会的透明度,给政治决策、政策执行、反馈以及社会治理与社会合作等都带来了巨大的困难.传播失灵是解释经典社会主义体制困境与转型的一个新视角.     

Do Mexicans flee from violence? The effects of drug-related violence on migration decisions in Mexico

This paper attempts to identify the existence of displacement in Mexico caused by drug-related violence. We identify two types of migrants: (i) migrants moving from nonviolent to violent states, driven by better economic opportunities and less expensive cost of living at destination and (ii) migrants moving from violent to nonviolent states: they still migrate even if the cost of living at destination is more expensive and economic opportunities are lower. Our hypothesis is that for the second type, migrants are fleeing from violence, and are willing to sacrifice economic opportunities in order to gain safety. For instance, when migrants move from nonviolent to violent states, they demand a salary 25% greater in order to increase the odds of migration in 10%. On the contrary, when migrants move from violent to nonviolent states, they only demand an increase in their salary of 15%.     

How many people participated in candlelight protests? Counting the size of a dynamic crowd

The recent controversy about the size of crowds at candlelight protests in Korea raises an interesting question regarding the methods used to estimate crowd size. Protest organizers tend to count all participants in the event from its start to finish, while the police usually report the crowd size at its peak. While several counting methods are available to estimate the size of a crowd at a given time, counting the total number of the participants at a protest is not straightforward. In this paper, we propose a new estimator to count the total number of participants that we call the size of a dynamic crowd. We assume that the arrival and departure times of the crowd are randomly observed and that the number of the attendees in the crowd at a specific time is estimable. We estimate the number of total attendees during the entire gathering based on the capture-recapture model. We also propose a bootstrap procedure to construct a confidence interval for the crowd size. We demonstrate the performance of the proposed method with simulation studies and the data from Korea''s March for Science, a global event across the world on Earth Day, April 22, 2017.     

贝那普利单用与联合缬沙坦治疗老年男性轻度左室功能异常的研究

目的对比贝那普利单用与联合应用缬沙坦对老年男性轻度左室功能异常（NYHA II级）的疗效。方法59名老年男性高血压患者被随机分入单药组（贝那普利10mg/日）和联合用药组（贝那普利10mg/日＋缬沙坦80mg/日）,于治疗前和治疗28周后分别测量心脏功能指标等。结果两组基线数据的比较没有区别。联合用药组左室射血分数（ΔLVEF：5.73±2.45,3.44±1.92,P〈0.05）、左室舒张末内径（ΔLVDd：5.18±2.06,4.01±2.32mm,P〈0.05）、6分钟步行试验成绩（Δ6MWT：47.5±14.8,36.3±16.6m,P〈0.05）、生活质量评分（ΔQOL：4.82±1.88,3.61±1.96,P〈0.05）的改善比单药组更为明显。两组血压变化无差异（ΔSBP t=0.985,P=0.329;ΔDBP t=0.629,P=0.532）。结论贝那普利与缬沙坦联合应用于老年男性轻度左室功能异常患者能够改善生活质量,提高运动能力,对肾功能无不良影响。     

医疗侵权损害赔偿中的证明责任研究

全面认识和了解医疗损害赔偿诉讼中适用的证明责任分配规则,是切实保护医疗损害受害人合法权益的关键。我国法律对医疗损害赔偿诉讼案件应依据案件的具体情况,适用有限制的证明责任倒置、高度盖然性、妨碍证明理论等不同的证明责任分配规则,从而保证医疗损害案件裁决的客观与公正。     

系统状态概率矩阵在企业集群中的应用

阐述了马尔可夫决策理论中的最基本分析方法———系统状态转移概率矩阵决策法,针对企业集群的特点,运用系统状态转移概率矩阵决策法对企业集群市场的状态进行了分析,并对各种状态的未来分布趋势和分布状况进行预测,分别计算出各种类型企业的未来市场资源份额,给政府进行市场的调节提供了理论上的依据和方法上的指导。     

带干扰的双险种Cox风险模型

给出了一个较一般的风险模型即带干扰的双险种Cox风险模型,并运用鞅的方法得出了保险公司的最终破产概率ψ(u)的不等式,使得用它来研究保险公司的盈利更符合实际情况,更具有实际意义.