Testing for Serial Correlation: Generalized Andrews–Ploberger Tests

This paper considers testing the null hypothesis that a times series is uncorrelated when the time series is uncorrelated but statistically dependent. This case is of interest in economic and finance applications. The GARCH(1, 1) model is a leading example of a model that generates serially uncorrelated but statistically dependent data. The tests of serial correlation introduced by Andrews and Ploberger (1996, hereafter AP) are generalized for the purpose of testing the null. The rationale for generalizing the AP tests is that they have attractive properties for cases for which they were originally designed: they are consistent against all nonwhite-noise alternatives and have good all-round power against nonseasonal alternatives compared to several widely used tests in the literature. These properties are inherited by the generalized AP tests.     

AN EXTENSION OF THE EM ALGORITHM FOR OPTIMIZATION OF CONSTRAINED LIKELIHOOD: AN APPLICATION IN TOXICOLOGY

Since its introduction in the mid 1970's, the EM algorithm has found a widespread popularity for solving the likelihood equations. Several investigators have used the algorithm in a variety of problems with incomplete information to obtain maximum likelihood estimates in numerous applications. The algorithm, however, becomes inappropriate when the underlying equations are subject to some constraints. Although an extension has been proposed to derive solutions when the parameters are subject to a set of linear constraints, the evaluation of likelihood equations from incomplete data when the equations are subject to a nonlinear constraint is still an open problem. Here, we consider a mixture model, a classical example of incomplete data, and discuss the problem of maximum likelihood estimation of the model parameters when the parameters have to satisfy a nonlinear constraint. An extension of the EM algorithm based on the celebrated Lagrange multiplier will be proposed to solve the equations. An application of the methodology in animal bioassay experiments for risk assessment of toxic substances will be described and data from a toxicological experiment will be used to illustrate the results.     

基于交易成本理论的IT外包风险控制策略研究综述

IT外包在过去10年中迅速发展,但潜藏着巨大的风险.为了更好地管理风险,对现有研究成果做了全面的梳理、归纳和提炼,将风险控制策略进一步分类为2个子系统:①主要策略子系统,包括合同机制、关系治理、组织整合、控制机制和动态成本监控;②辅助策略子系统,包括引入第三方专业机构、外包决策优化、不同的管理模式、标准化工具.这2个子系统为建立企业ITOR策略研究的方法论提供了良好的基础,有助于丰富企业ITOR管理理论.     

变分迭代算法的应用

介绍了一种对求解非线性方程非常有效的方法-变分迭代算法及其发展成果．几个例子说明这种方法的有效性．     

国家利益拓展的倍增器——学习胡锦涛同志关于军事科技创新的最新论述

军事科技创新是国家利益拓展的重要技术基础，具有倍增器的作用。适应世界军事发展趋势的需要和我国国家利益发展的新要求，我们必须注重发挥军事科技创新在国家军事实力、国家科技实力、国家经济实力、国家战略能力等领域的倍增作用。其关键途径在于贯彻胡锦涛主席提出的构建军民兼容的国防科技创新体制和机制。     

Examining Links Between Sign-Out Reporting During Shift Changeovers and Patient Management Risks

This article reports on a qualitative study that investigated how various risk factors associated with the process of sign-out reporting across shifts in critical care hospital environments could lead to flawed communication and thus to increased risk of poor patient outcomes. The study was performed in two critical care hospital units: the pediatric intensive care unit (PICU) and the postanesthesia care unit (PACU). We collected data from observations of eight nurses and four resident physicians in the PICU and four nurses and four resident physicians in the PACU giving sign-out reports during their shift changes. In addition, we conducted semi-structured interviews with a separate sample of medical providers consisting of nurse managers, attending physicians, nurses, and residents from each of these two units. The issues that were addressed in these interviews included how various methods of conducting sign-outs and factors such as personality and experience could impact the effectiveness of communication during sign-out reporting. We also collected data from these medical providers on how failures in communication during sign-out reporting could lead to potentially adverse patient outcomes. The article concludes with the presentation of a modeling framework that demonstrates how the combined influences of risk factors can generate a particularly important type of failure mode in communication and how interventions can be targeted to serve as barriers to such events. A number of recommendations intended for reducing risks associated with the communication of sign-out reports are also presented.     

现代俄罗斯青年亚文化探析——消极亚文化

俄罗斯作为曾经的超级大国在现代文化领域发生了深刻的变化,青年亚文化在发展过程中也发生了质的变化,曾经被学者们忽略的亚文化日趋受到人们的关注。本文概括了青年亚文化的消极现象,它们反映了社会意识形态的变化对世纪末俄罗斯青年亚文化的影响。     

TESTS FOR SEASONAL DIFFERENCING WITH AN UNKNOWN BREAK-POINT

Some Lagrange multiplier tests for seasonal differencing are proposed; their main objective is to avoid over-differencing due to structural change. The null hypothesis is either the presence of both regular and seasonal unit roots or the presence of a seasonal unit root. Alternative hypotheses allow for stationarity around a possible structural change where the break-point is unknown. The location of the structural change is estimated using the proposed procedures, the asymptotic distribution of the test statistics under the null hypothesis is derived and some useful percentiles are tabulated. An illustrative example based on the Canadian Consumer Price Index is presented.     

企业跨国经营面临的政治风险及其防范

政治风险是企业跨国经营和海外投资必须考虑的一个重要风险问题。通过对当前企业跨国经营面临的政治风险及其表现形式的分析,并提出了政治风险的防范策略,具体包括对外直接投资前的预防性策略、经营过程中的分散性策略以及风险发生后的缓解性策略,以避免或减轻企业跨国经营过程中政治风险所带来的不利影响。     

The Financial Management of Catastrophic Flood Risks in Emerging-Economy Countries

This article examines the potential of pre- and post-disaster instruments for funding disaster response and recovery and for creating incentives for flood loss mitigation in countries with emerging or transition economies. As a concrete case, we discuss the disaster recovery arrangements following the 1997 flood disaster in Poland. We examine the advantages and limitations of hedging instruments, which are instruments for transferring the risk to investors either through insurance or capital market-based securities. We compare these mechanisms with financing instruments whereby the government sets aside funds prior to a disaster or taps its own funding sources after the event occurs. We show how hedging instruments can be designed to create incentives for the mitigation of damage to public infrastructure using the flood proofing of a water-treatment plant on the hypothetical Topping River as an illustrative example. We conclude that hedging instruments can be an attractive alternative to financing instruments that have been traditionally used in the poorer, emerging-economy countries to fund disaster recovery. Since very poor countries are likely to have difficulty paying the price of protection prior to a disaster, we suggest that international lending institutions consider innovations for subsidizing these payments.