ON THE INDEPENDENCE OF THE SAMPLE MEAN AND TRANSLATION-INVARIANT STATISTICS FOR MATRIX NORMAL DISTRIBUTIONS

We present an explicit characterization of the joint dependency structure of an n×p matrix normal random matrix such that the p-dimensional sample mean vector is independent of all translation invariant statistics.     

Uncertain Numbers and Uncertainty in the Selection of Input Distributions—Consequences for a Probabilistic Risk Assessment of Contaminated Land

Risks from exposure to contaminated land are often assessed with the aid of mathematical models. The current probabilistic approach is a considerable improvement on previous deterministic risk assessment practices, in that it attempts to characterize uncertainty and variability. However, some inputs continue to be assigned as precise numbers, while others are characterized as precise probability distributions. Such precision is hard to justify, and we show in this article how rounding errors and distribution assumptions can affect an exposure assessment. The outcome of traditional deterministic point estimates and Monte Carlo simulations were compared to probability bounds analyses. Assigning all scalars as imprecise numbers (intervals prescribed by significant digits) added uncertainty to the deterministic point estimate of about one order of magnitude. Similarly, representing probability distributions as probability boxes added several orders of magnitude to the uncertainty of the probabilistic estimate. This indicates that the size of the uncertainty in such assessments is actually much greater than currently reported. The article suggests that full disclosure of the uncertainty may facilitate decision making in opening up a negotiation window. In the risk analysis process, it is also an ethical obligation to clarify the boundary between the scientific and social domains.     

An Inquiry into Liberty,Slavery, and Thomas Jefferson’s Place in American Memory

Abstract

This article presents a guided inquiry into Thomas Jefferson’s place in American memory. It centers on Jefferson’s liberty-based articulations and his involvement in slavery, which are paradoxical when juxtaposed. Evocative primary sources and competing secondary sources ground the inquiry. Discipline-specific strategies direct students through the stages of inquiry. Close reading, text-based writing, and informed action intertwine with history literacy, historical thinking, and historical argumentation. Discussion focuses on logical curricular extensions.     

寡头企业价格领先竞争的均衡性

首先介绍完全信息时双寡头垄断的企业价格决策的静态模型,得到伯川德均衡;然后介绍完全信息时双寡头垄断的企业价格决策的动态模型,得到价格领先的寡头竞争模型均衡解;最后分析了后者的局限性,得到在理性假设的前提下价格领先的寡头竞争模型的均衡解不是一个稳定状态,完全信息时双寡头价格决策的动态博弈的结果必然最终趋近于静态博弈的结果。     

我国独立董事独立性的两个问题

独立性是独立董事制度赖以建立和存在的基础。影响和制约我国独立董事独立性的因素主要有独立董事制度缺乏法律明确定位、独立董事任职条件不严密、选任程序不合理、行权不畅、报酬问题以及任期问题。应当明确独立董事的法律定位、建立独立董事控制下的专业委员会、确立独立董事采取公告与回避制度、充分发挥声誉激励作用、建立独立董事自律组织自律规范独立董事行为以及营造良好的外部环境和机制。     

Power and perceptions in participatory monitoring and evaluation

This paper examines the assumptions that commonly underpin the design of participatory monitoring and evaluation (PM&E) within development programmes through the examination of a case study of a large rural development programme in Uganda. This case study reveals a mismatch between programme assumptions and participant perceptions, which stymied the implementation of PM&E. In this case, PM&E was based on the assumptions that programme and participant goals were compatible, participants were willing to volunteer and engage themselves for the greater good of their communities, and information sharing and communication was fairly free and open. However, farmers within the programme felt that the bureaucratic and accountability requirements of the programme were not their concern, and were acutely aware of power differences between farmers and programme officials, and between farmers of varying status. The key lesson to be drawn from this case is the need for a heightened awareness of power dynamics and political factors in the design of PM&E.     

Introduction: decolonising the “undecolonisable”? Portugal and the independence of Lusophone Africa

In 2015, Lusophone Africa celebrated 40 years since independence. Portuguese colonies in Africa became independent in the aftermath of two orders of interlinked events. The first was the fierce-armed opposition to the colonial order – through the action of nationalist movements and nationalist thinkers such as Amílcar Cabral – which escalated after 1960 when French and English colonies in Africa were achieving independence. The second was the Carnation Revolution, in 1974, which, despite having taken place in Lisbon, had powerful reverberations across Portuguese Africa. Here, I argue that the Carnation Revolution was a by-product of the emergence of nationalist movements in Africa, when it became apparent that popular uprisings there could not be won by conventional armed struggle. Or, to put it slightly different, anticolonial struggle in Africa opened the way not only for the end of Portuguese rule on the continent, but also for the demise of dictatorship in Portugal itself.     

Misspecifications of the Normal Distribution

Incorrect statements about the normal distribution are discussed and illustrated with counterexamples.     

Examples of Uncorrelated Dependent Random Variables Using a Bivariate Mixture

A particular mixture of bivariate distributions is used to present examples of dependent uncorrelated random variables and independent random variables. A necessary and sufficient condition for the independence for such a bivariate distribution is given.