New flexible models generated by gamma random variables for lifetime modeling

In this paper we introduce a new three-parameter exponential-type distribution. The new distribution is quite flexible and can be used effectively in modeling survival data and reliability problems. It can have constant, decreasing, increasing, upside-down bathtub and bathtub-shaped hazard rate functions. It also generalizes some well-known distributions. We discuss maximum likelihood estimation of the model parameters for complete sample and for censored sample. Additionally, we formulate a new cure rate survival model by assuming that the number of competing causes of the event of interest has the Poisson distribution and the time to this event follows the proposed distribution. Maximum likelihood estimation of the model parameters of the new cure rate survival model is discussed for complete sample and censored sample. Two applications to real data are provided to illustrate the flexibility of the new model in practice.     

Mean Time to Failure of Weighted k-out-of-n: G Systems

The purpose of this article is to develop a Monte-Carlo simulation algorithm for computing mean time to failure (MTTF) of weighted-k-out-of-n:G and linear consecutive-weighted-k-out-of-n:G systems. Our algorithm is based on the use of appropriately defined stochastic process which represents the total weight of the system at time t. These stochastic processes are explicitly defined and used along with the ordered component lifetimes to simulate MTTF of the systems with weighted components.     

略论气候与季节变化对中国古代文学创作的影响

中国古代文学与气候之间的关系密切。一年有四季,而四季气候有别;不同的气候决定了四时迥异的“物容”或物候特征;气候及物候影响着古代文学家的“感物”方式、文学表现内容。古代文学家在四时物候的感召下,创作了海量具有鲜明季节性和抒情性的文学作品,形成了具有多种普遍性和代表性的“四季”文学抒情范式。     

基督教在唐代传播之顿挫及其原因探析

基督教 (景教 )在中国唐代的传播历经顿挫 ,这种初传的顺利与惨遭禁绝 ,是多种因素相互作用的结果。对此问题的研究 ,有助于我们加深理解中西文化的差异和两者之间的相互关系     

Insurer ambiguity and market failure

A series of studies investigate the decision processes of actuaries, underwriters, and reinsurers in setting premiums for ambiguous and uncertain risks. Survey data on prices reveal that all three types of these insurance decision makers are risk averse and ambiguity averse. In addition, groups appear to be influenced in their premium-setting decisions by specific reference points such as expected loss and the concern with insolvency. This behavior is consistent with a growing analytical and empirical literature in economics and decision processes that investigates the role that uncertainty plays on managerial choices. Improved risk-assessment procedures and government involvement in providing protection against catastrophic losses may induce insurers to reduce premiums and broaden available coverage.This article is part of a larger effort supported by the National Science Foundation on The Role of Insurance, Compensation, Regulation, and Protective Behavior in Decision Making about Risk and Misfortune. We greatly appreciate the many helpful comments and suggestions by our colleagues on the project: Jon Baron, Colin Camerer, Neil Doherty, Jack Hershey, Eric Johnson, and Paul Kleindorfer. Support from NSF Grant #SES8809299 is gratefully acknowledged.     

刍议列强对洪宪帝制的态度及影响

帝制初起时 ,一战方酣 ,西方列强无暇东顾 ,对华政策大多以日本的意志为意志 ,为了争得对袁世凯政府的控制 ,列强争相怂勇袁世凯称帝。当袁世凯称帝之事呼之欲出、反对之声叠起时 ,日本为了乘中国国体变动之机扰乱中国以达其侵略之目的 ,联合西方列强出面干涉 ,劝告袁世凯延缓帝制 ,煽动中国内部叛乱 ,并对袁世凯施加经济压力。以日本为首的列强的出尔反尔是袁世凯政权走向灭亡的关键性因素之一。     

我国助学贷款政策变革中政府干预机制博弈分析

我国助学贷款政策历经多次变革形成目前以生源地信用助学贷款为主的助学贷款模式,这种变革离不开政府对助学贷款市场的干预。市场机制下,助学贷款经办银行和借款学生博弈中不可置信威胁的存在导致老机制助学贷款市场失灵。政府干预的作用是将银行信贷资金供给功能与信贷决策功能分离,并将信贷管理与决策交由县级资助中心员工负责,消除了银行拒贷威胁,市场失灵得以纠正,但借款学生道德风险仍是助学贷款政策顺利运行的重要隐患。     

关联供应链网络级联失效机理及鲁棒性研究

为了分析复杂关联供应链网络在遭遇干扰事件时的鲁棒性,研究关联网络层内和层间级联失效机理.通过随机规则生成供应链无向信息层网络和有向物理层网络,描述并分析由α、β、σ等参数表征的节点负荷、容量等网络结构特性.针对存在边流量约束的情况,提出相应的失效负荷分流策略;通过构建极大簇函数,判断关联供应链网络中经分流策略后仍具运作功能的有效节点,并依据供应链信息层网络和物理层网络间一对一匹配的关联关系,构建时变失效迭代状态方程,从而有效描述关联网络间的动态失效传递.最后,在不同参数控制下,对初始单个节点故障和多个节点故障两种情况下的关联供应链网络综合鲁棒性进行数值仿真分析.按节点度从大到小、从小到大、随机3种方式去除多个节点,结果表明在β=0.5, 1, 1.5, 2 4种参数下,按度从小到大方式去除多节点,其引发的关联网络级联失效规模较之其它两种方式大;同时发现关联供应链网络在多节点去除情况下,其级联失效较之单层网络具有明显的一级相变特性,即少量的节点移除就会导致整个关联供应链网络崩溃.     

Bayesian analysis of discrete time warranty data

Summary.  The analysis of warranty claim data, and their use for prediction, has been a topic of active research in recent years. Field data comprising numbers of units returned under guarantee are examined, covering both situations in which the ages of the failed units are known and in which they are not. The latter case poses particular computational problems for likelihood-based methods because of the large number of feasible failure patterns that must be included as contributions to the likelihood function. For prediction of future warranty exposure, which is of central concern to the manufacturer, the Bayesian approach is adopted. For this, Markov chain Monte Carlo methodology is developed.     

跨文化交际中的语用失误及其规避策略研究

在跨文化交际中,由于语用失误而导致的交际失败时有发生。这一现象产生的原因来自于交际的各个层面,如语言表层、文化、思维等。其次,作为心理认知活动,跨文化交际是一个动态选择的过程,这一过程需要交际者依据自身的认知语境系统对交际中相关信息做出对比、分析、判断,这就要求交际者通过语言对比、文化积累、思维训练等方式完善认知语境的网络系统,由此实现规避语用失误、提高语用能力的目标。