Unit Roots,Level Shifts,and Trend Breaks in Per Capita Output: A Robust Evaluation

Determining whether per capita output can be characterized by a stochastic trend is complicated by the fact that infrequent breaks in trend can bias standard unit root tests towards nonrejection of the unit root hypothesis. The bulk of the existing literature has focused on the application of unit root tests allowing for structural breaks in the trend function under the trend stationary alternative but not under the unit root null. These tests, however, provide little information regarding the existence and number of trend breaks. Moreover, these tests suffer from serious power and size distortions due to the asymmetric treatment of breaks under the null and alternative hypotheses. This article estimates the number of breaks in trend employing procedures that are robust to the unit root/stationarity properties of the data. Our analysis of the per capita gross domestic product (GDP) for Organization for Economic Cooperation and Development (OECD) countries thereby permits a robust classification of countries according to the “growth shift,” “level shift,” and “linear trend” hypotheses. In contrast to the extant literature, unit root tests conditional on the presence or absence of breaks do not provide evidence against the unit root hypothesis.     

SOJOURN TIMES IN NON-HOMOGENEOUS QBD PROCESSES WITH PROCESSOR SHARING

We study sojourn times of customers in a processor sharing queue with a service rate that varies over time, depending on the number of customers and on the state of a random environment. An explicit expression is derived for the Laplace–Stieltjes transform of the sojourn time conditional on the state upon arrival and the amount of work brought into the system. Particular attention is paid to the conditional mean sojourn time of a customer as a function of his required amount of work, and we establish the existence of an asymptote as the amount of work tends to infinity. The method of random time change is then extended to include the possibility of a varying service rate. By means of this method, we explain the well-established proportionality between the conditional mean sojourn time and required amount of work in processor sharing queues without random environment. Based on numerical experiments, we propose an approximation for the conditional mean sojourn time. Although first presented for exponentially distributed service requirements, the analysis is shown to extend to phase-type services. The service discipline of discriminatory processor sharing is also shown to fall within the framework.     

High-order extensions of the Double Chain Markov Model

The Double Chain Markov Model is a fully Markovian model for the representation of time-series in random environments. In this article, we show that it can handle transitions of high-order between both a set of observations and a set of hidden states. In order to reduce the number of parameters, each transition matrix can be replaced by a Mixture Transition Distribution model. We provide a complete derivation of the algorithms needed to compute the model. Three applications, the analysis of a sequence of DNA, the song of the wood pewee, and the behavior of young monkeys show that this model is of great interest for the representation of data that can be decomposed into a finite set of patterns.     

性别变更权的宪法思考

随着我国变性人的增多,变性人已经形成一个不容忽视的社会群体。随之而来的法律问题也日益突出,其中首要的就是宪法问题。自由赋予了人存在的理由,必然也可以给予"易性癖"者以享有性别变更权的自我空间。性别变更权虽然不属于公民的基本权利,但却应当是公民人格权中的一项重要的权利。对于变性人,只要他们变性后的性别得到了法律肯定,就应该与其他同性别的公民一样,在人格上能平等享有宪法和法律所赋予的权利和自由。     

以尖团分混考察影响方言变异的语言因素

从分尖团到不分尖团,是汉语方言发展演变的大趋势。无锡方言尖团音似分又混的现象初露端倪,表明它正处在由分到混的初始阶段。它所体现出的参差不齐的语音现象,正是我们考察这一发展进程的活化石。本文采用随机抽样调查的手段,结合变项规则分析法来考察与无锡市区方言精组尖音字的变化相关的语言因素,从而揭示出方言在和普通话接触之下是如何逐渐向普通话靠拢的。     

管理会计变化的制度研究及其理论应用

文章首先回顾了西方管理会计变化研究的结构理论和制度理论,揭示了管理会计稳定性和变化阻力的根源;运用管理会计研究的结构理论和制度理论的框架,对山东东阿阿胶集团公司应用ERP的案例进行了剖析。认为管理会计变化的结构理论和制度理论对解释我国企业管理会计变化过程及其成败具有理论指导意义。     

中国艺术观念中的"幻"学说

幻是中国艺术观念中的一个大问题,中国艺术有从幻境界入门的思想,表达了追求生命真实的审美理想。本文从幻化、幻有、幻相三个方面探讨这一问题,对中国艺术中与此相关的一些观念作了梳理,     

从庸众到战士——论西方大众文化理论中受众观的嬗变

西方大众文化理论中的受众现有一个嬗变的过程,这一过程大致可以划分为这样四个阶段:马修·阿诺德以及利维斯主义者的文化精美主义受众观,法兰克福批判理论的单向度受众现,以斯图亚特·霍尔为代表的多元性受众观,约翰·费斯克以及德塞图等的抵抗性受众观.受众从庸众到游击战士的发展表明受众在大众文化研究中的地位明显提高,同时也从另一个方面显露出大众文化的性质、功能的改变,对于受众观的嬗变过程的分析有助于理解这点.     

高职院班主任工作观念的转变

在高等职业教育中班主任教育和管理工作观念应随形势的变化而进行观念的更新,同时班主任的个人素质也应相应的提高,以适应不断发展的形势。