Estimation of the scale matrix of a multivariate t-model under entropy loss

This paper deals with the estimation of the scale matrix of a multivariatet-model with unknown location vector and scale matrix to improve upon the usual estimators based on the sample sum of product matrix. The well-known results of the estimation of the scale matrix of the multivariate normal model under the assumption of entropy loss function have been generalized to that of a multivariatet-model. The paper is based on the first author’s unpublished Ph.D. dissertation ‘Estimation of the Scale Matrix of a Multivariate T-model’, University of Western Ontario, Canada. Present address: School of Mathematics and Statistics, The University of Sydney, NSW 2006, Australia.     

Economic Integration: Systemic Measures in an Input–Output Framework

Countries are linked through trade and for their mutual benefits they often group together. Consequently, trade blocs are formed in some form or another, examples of which are the EU, EFTA, ASEAN, NAFTA, and SAARC. Depending upon the form and the nature of the grouping, trade relations among countries obviously vary across the trade blocs. The pattern and the volume of trade of the participating countries are different and thus cause different impacts on the growth and development of the countries concerned. Also, the nature of integration changes over time. To examine the strength of integration within trade blocs, systemic measures of integration hitherto not available are formulated in an input–output framework. The measures are used, as a case study, to assess the inter-temporal variations in the degree of integration of SAARC.     

The Price-Volatility Feedback Rate: An Implementable Mathematical Indicator of Market Stability

Geometric analysis of iterated cross-volatilities of asset prices is adopted to assess the stability of the (risk-free) measure under infinitesimal perturbations. Perturbations of asset prices evolve through time according to an ordinary linear differential equation (hedged transfer). The decay (feedback) rate is explicitly computed through a Fourier series method implemented on high frequency time series.     

Structure and Location of Innovative Activity in the Italian Economy, 1981–85

An ‘innovative activity matrix’ is established from a recent ISTAT/CNR survey of innovation. After specifying the particularities of an innovative activity matrix in comparison with other flow matrices, we show that it is asymmetrical and clustered in parts of economic space. The structure of the innovative activity matrix is similar to that of the domestic and import requirement but not the capital flow matrix. Strong correlations indicate the following: that input–output analysis is useful for identifying the location of innovative activities in economic space; that it can be analyzed in an economically meaningful way; that its location is structured; and that, furthermore, it is structured in ways which are statistically related to economic activity. The paper ends with suggestions for the examination of possible causal relationships.     

Minimax character of the two-sample χ2-test

Abstract  We consider the problem of testing equality of the mean vectors of two multivariate normal populations when covariates are present and the covariance matrix is known. As an application of the H unt -S tein theorem it is shown that the χ²-^-test of level a maximizes, among all level a tests, the minimum power on each of the contours where the χ²-^-test has constant power. A corollary is that the χ²-^-test is most stringent level a .     

基于GE矩阵的环保企业技术创新战略选择

在经济全球化进程不断加快和环境问题日益严重的今天，环保企业传统的竞争模式已经被知识技术竞争所取代，技术创新战略在环保企业的发展中成为提升企业核心竞争力、实现企业可持续发展的基础。本文对环保企业在技术创新过程应用GE矩阵确定创新领域和选择创新战略进行了分析，给出了环保企业在面临技术创新的内外部环境变化和市场竞争不断加剧时如何选择最优战略的基本分析方法。并针对中国环保企业的特点提出环保企业技术创新战略的建议。     

企业剩余资源与大战略集合模型——对多元化战略的一个新解释

在关于企业多元化战略的理论中,大战略集合模型从企业外部环境的角度对企业为何多元化、何时多元化给出了一种解释。文章首先分析了此模型在解释上的局限性。作为改进,在模型中加入了“企业剩余资源”这一来自企业自身的因素,并将剩余资源分为“暂时过剩”和“永久过剩”资源     

800Mbps准循环LDPC码译码器的FPGA实现

本文提出了一种适用于准循环低密度校验码的低复杂度的高并行度译码器架构.通常准循环低密度校验码不适于设计有效的高并行度高吞吐量译码器.我们通过利用准循环低密度校验码的奇偶校验矩阵的结构特点,将其转化为块准循环结构,从而能够并行化处理译码算法的行与列操作.使用这个架构,我们在Xilinx Virtex-5 LX330 FPGA上实现了(8176,7154)有限几何LDPC码的译码器,在15次迭代的条件下其译码吞吐量达到800Mbps.     

南宁市土地-社会核算矩阵的构建

在经济增长日益受到土地资源供给量和环境承载力的严重制约背景下,将资源、环境问题纳入综合的社会经济分析框架中,全面分析外部冲击或政策变动所造成的影响对如何科学地调控土地资源非常重要.在传统社会核算矩阵的基础上引入土地资源方面的核算账户,基于2005年相关数据构建南宁市土地-社会核算矩阵,对土地利用对社会经济的影响分析中纳入对资源与环境问题的刻划,从宏观角度对土地利用与社会经济影响进行分析,建立了一个具有较强通用性的分析工具,为政府部门采取有效的土地资源调控政策提供决策依据.     

Sectoral Comovement,Monetary Policy Shocks,and Input–Output Structure

The comovement of output across the sector producing nondurables (i.e., nondurable goods and services) and the sector producing durables is well established in the monetary business cycle literature. However, standard sticky‐price models that incorporate sectoral heterogeneity in price stickiness (i.e., sticky nondurables prices and flexible durables prices) cannot generate this feature. We argue that an input–output (I–O) structure provides a solution to this problem. Here, we develop a two‐sector model with an I–O structure, which is calibrated to the U.S. economy. In the model, each sector’s output affects those of the others by acting as an intermediate input. This connection between the sectors provides a channel through which sectoral comovement is induced.