Accurate computation of single and product moments of order statistics under progressive censoring

An accurate procedure is proposed to calculate approximate moments of progressive order statistics in the context of statistical inference for lifetime models. The study analyses the performance of power series expansion to approximate the moments for location and scale distributions with high precision and smaller deviations with respect to the exact values. A comparative analysis between exact and approximate methods is shown using some tables and figures. The different approximations are applied in two situations. First, we consider the problem of computing the large sample variance–covariance matrix of maximum likelihood estimators. We also use the approximations to obtain progressively censored sampling plans for log-normal distributed data. These problems illustrate that the presented procedure is highly useful to compute the moments with precision for numerous censoring patterns and, in many cases, is the only valid method because the exact calculation may not be applicable.     

Inference and Decision Making for 21st-Century Drug Development and Approval

ABSTRACT

The cost and time of pharmaceutical drug development continue to grow at rates that many say are unsustainable. These trends have enormous impact on what treatments get to patients, when they get them and how they are used. The statistical framework for supporting decisions in regulated clinical development of new medicines has followed a traditional path of frequentist methodology. Trials using hypothesis tests of “no treatment effect” are done routinely, and the p-value < 0.05 is often the determinant of what constitutes a “successful” trial. Many drugs fail in clinical development, adding to the cost of new medicines, and some evidence points blame at the deficiencies of the frequentist paradigm. An unknown number effective medicines may have been abandoned because trials were declared “unsuccessful” due to a p-value exceeding 0.05. Recently, the Bayesian paradigm has shown utility in the clinical drug development process for its probability-based inference. We argue for a Bayesian approach that employs data from other trials as a “prior” for Phase 3 trials so that synthesized evidence across trials can be utilized to compute probability statements that are valuable for understanding the magnitude of treatment effect. Such a Bayesian paradigm provides a promising framework for improving statistical inference and regulatory decision making.     

丹巴土司制度发展历史考证

丹巴位于“藏彝走廊”的核心区域，其对汉藏民族关系、中央政权与边疆地区的稳定均具有重要影响。自忽必烈时期开始丹巴即开始实行土司制度直至新中国成立，研究丹巴的土司制度发展历史对梳理“藏彝走廊”民族关系及社会发展历史具有重要作用。本文对丹巴土司制度的发展历史进行了考证，并对其境内的四个土司的管辖范围、权力地位进行了梳理，以期对该地区历史发展研究提供一些参考与借鉴。     

从《了凡四训》到《训儿俗说》——关于袁了凡及其家风家训的思想史考察

袁了凡（袁黄）以其《了凡四训》闻名于世，该书亦被当作训子家书。其实，了凡所作家训并非《了凡四训》，而是《训儿俗说》。作为王龙溪（王畿）的及门弟子，了凡在思想上是阳明后学的一分子，其人生轨迹属于典型的儒家士大夫，其日常修持及著述呈现三教汇通的思想特色。了凡家风淳朴，家学深厚，以儒为宗，兼收并蓄，强调道德主义，注重积德行善，具有出世情怀，对其人格产生深刻影响。     

"指标困局":农村贫困治理的实践与反思

在国家的扶贫实践中，地方政府的行为策略是影响扶贫绩效的关键变量。通过对精准扶贫政策实践的调研发现，中央政府不断升级的治理手段为重构央地关系创造了条件，地方政府对国家扶贫理念转型认知的偏差以及在形成路径依赖之后的策略行为不仅容易产生对总体局势的误判，还为后期的政策困局埋下了伏笔。在此背景下，地方扶贫工作遭遇“指标困局”，即地方政府很难实事求是去识别贫困户，只能在既有的指标约束下进行精准识别，扶贫工作陷入了反复识别，却仍难实现精准的怪圈。     

人工智能辅助地方立法的应用与规制

我国地方立法权随着2015年《立法法》的修改扩至所有设区的市，随之掀起地方立法热潮。但目前地方立法的质量普遍不高，存在诸多问题，人工智能技术的应用能为地方立法开辟新路径。基于互联网及大数据的人工智能，能被应用于资料检索、立项论证、立法公开与意见征集、辅助草案起草、立法后评估与备案审查。与此同时，当人工智能被应用于地方立法工作时，需要确立“辅助原则”，规范人工智能地方立法程序的选用标准，限制人工智能地方立法程序的算法，以此来规制人工智能带来的不利影响。     

Probabilistic population projections for countries with generalized HIV/AIDS epidemics

In 2015, the United Nations (UN) issued probabilistic population projections for all countries up to 2100, by simulating future levels of total fertility and life expectancy and combining the results using a standard cohort component projection method. For the 40 countries with generalized HIV/AIDS epidemics, the mortality projections used the Spectrum/Estimation and Projection Package (EPP) model, a complex, multistate model designed for short-term projections of policy-relevant quantities for the epidemic. We propose a simpler approach that is more compatible with existing UN projection methods for other countries. Changes in life expectancy are projected probabilistically using a simple time series regression and then converted to age- and sex-specific mortality rates using model life tables designed for countries with HIV/AIDS epidemics. These are then input to the cohort component method, as for other countries. The method performed well in an out-of-sample cross-validation experiment. It gives similar short-run projections to Spectrum/EPP, while being simpler and avoiding multistate modelling.     

Risk Modeling of Interdependent Complex Systems of Systems: Theory and Practice

The emergence of the complexity characterizing our systems of systems (SoS) requires a reevaluation of the way we model, assess, manage, communicate, and analyze the risk thereto. Current models for risk analysis of emergent complex SoS are insufficient because too often they rely on the same risk functions and models used for single systems. These models commonly fail to incorporate the complexity derived from the networks of interdependencies and interconnectedness (I–I) characterizing SoS. There is a need to reevaluate currently practiced risk analysis to respond to this reality by examining, and thus comprehending, what makes emergent SoS complex. The key to evaluating the risk to SoS lies in understanding the genesis of characterizing I–I of systems manifested through shared states and other essential entities within and among the systems that constitute SoS. The term “essential entities” includes shared decisions, resources, functions, policies, decisionmakers, stakeholders, organizational setups, and others. This undertaking can be accomplished by building on state‐space theory, which is fundamental to systems engineering and process control. This article presents a theoretical and analytical framework for modeling the risk to SoS with two case studies performed with the MITRE Corporation and demonstrates the pivotal contributions made by shared states and other essential entities to modeling and analysis of the risk to complex SoS. A third case study highlights the multifarious representations of SoS, which require harmonizing the risk analysis process currently applied to single systems when applied to complex SoS.     

China’s Choice of Analytical Models for Its Anti-Monopoly Law

Modern analytical models for anti-monopoly laws are a core element of the application of those laws. Since the Anti-Monopoly Law of the People’s Republic of China was promulgated in 2008, law enforcement and judicial authorities have applied different analytical models, leading to divergent legal and regulatory outcomes as similar cases receive different verdicts. To select a suitable analytical model for China’s Anti-Monopoly Law, we need to consider the possible contribution of both economic analysis and legal formalism and to learn from the mature systems and experience of foreign countries. It is also necessary to take into account such binding constraints as the current composition of China’s anti-monopoly legal system, the ability of implementing agencies and the supply of economic analysis, in order to ensure complementarity between the analytical model chosen and the complexity of economic analysis and between the professionalism of implementing agencies and the cost of compliance for participants in economic activities. In terms of institutional design, the models should provide a considered explanation of the legislative aims of the law’s provisions. It is necessary, therefore, to establish a processing model of behavioral classification that is based on China’s national conditions, applies analytical models using normative comprehensive analysis, makes use of the distribution rule of burden of proof, improves supporting systems related to analytical models and enhances the ability of public authorities to implement the law.     

朱熹和孟子解读舜之“怨慕”的不同逻辑

对于舜之“怨慕”,朱熹作出了不同于孟子的解读。这是基于心学、理学内在逻辑的不同。孟子作为私学之儒,和孔子一样,是主张士君子的阳刚人格的,并且从性向善的人性论出发,协调义与利、公与私的关系,而以君臣父子关系都属对待关系;依此,将舜之“怨慕”解读为舜对父母的既怨又慕。朱熹则作为官学之儒,以所谓“气质之性”协调理学先驱荀子的性向恶论,以二歧化思维把天地之性、天理绝对化,以公去私,视君臣父子关系则为下对上的绝对服从关系;依此解读,舜之“怨”只能是自怨。