Numerical issues in threshold autoregressive modeling of time series

This paper analyses the contribution of various numerical approaches to making the estimation of threshold autoregressive time series more efficient. It relies on the computational advantages of QR factorizations and proposes Givens transformations to update these factors for sequential LS problems. By showing that the residual sum of squares is a continuous rational function over threshold intervals it develops a new fitting method based on rational interpolation and the standard necessary optimality condition. Taking as benchmark a simple grid search, the paper illustrates via Monte Carlo simulations the efficiency gains of the proposed tools.     

企业处理顾客、供销商、同业者关系的战略观点

为了可持续发展,忠诚的顾客关系建立在企业集中战略资源满足顾客合理需求的基础上,是具有真实性、价值性和持久性的营销。稳定的供销关系,对于企业保证产品和服务质量、降低原材料采购和市场拓展成本、降低市场风险具有重要意义,是互惠互利、休戚与共的关系。而基于公平合作同业者关系,可以使企业与同业者分享技能、信息、技术和市场机会,分担成本。     

我国房地产中介服务业的发展机遇和对策

本文阐述了住房新体制给房地产中介服务业带来的发展机遇,并分析了在该机遇下应采取的对策。目的在于建议政府部门对房地产中介服务业加以培育、规范和引导,以给该行业的发展营造较好的成长环境。同时,房地产中介服务业应把握机遇,努力提高自身素质,以促进城镇住房制度改革的进一步深化。     

AN EVALUATION OF PROCESS‐ORIENTED SUPPLY CHAIN MANAGEMENT FRAMEWORKS

Supply chain management (SCM) is implemented by integrating corporate functions using business processes within and across companies. Several process‐oriented frameworks for SCM have been proposed but only two of these provide sufficient detail to enable implementation. We evaluate the Supply‐Chain Operations Reference (SCOR) framework and The Global Supply Chain Forum (GSCF) framework using four criteria and identify their relative strengths and weaknesses.     

Feature selection methods involving support vector machines for prediction of insolvency in non‐life insurance companies

We propose two novel approaches for feature selection and ranking tasks based on simulated annealing (SA) and Walsh analysis, which use a support vector machine as an underlying classifier. These approaches are inspired by one of the key problems in the insurance sector: predicting the insolvency of a non‐life insurance company. This prediction is based on accounting ratios, which measure the health of the companies. The approaches proposed provide a set of ratios (the SA approach) and a ranking of the ratios (the Walsh analysis ranking) that would allow a decision about the financial state of each company studied. The proposed feature selection methods are applied to the prediction the insolvency of several Spanish non‐life insurance companies, yielding state‐of‐the‐art results in the tests performed. Copyright © 2005 John Wiley & Sons, Ltd.     

问渠何时清如许

工业文明在带给人类丰富的物质生活的同时,也使生态环境日益恶化.1987年,世界环境与发展委员会在<我们共同的未来>报告中第一次阐述了可持续发展的概念,即指经济、社会、资源和环境保护协调发展是一个密不可分的系统,既要达到发展经济的目的,又要保护好人类赖以生存的大气、淡水、海洋、土地和森林等自然资源和环境,使子孙后代能够永续发展和安居乐业.     

Should Chinese Local Governments Be Allowed to Issue Bonds?

I.IntroductionDespite China’s impressive economic growth,its fiscal sustainability has increasinglybecome one of the most watched risk indicators facing the economy.Although China’sexplicit national debtto GDP ratio israther manageable by theOECD standard,at about20 percent of GDP,given its small share of tax revenue to GDP,currently at18.5percent ofGDP,this fiscalsystem may stumble upon major challenges in themedium to long term ifChina’slargecontingent fiscal liabilitiesare als…     

Statistical Decision Problems and Bayesian Nonparametric Methods

This paper considers parametric statistical decision problems conducted within a Bayesian nonparametric context. Our work was motivated by the realisation that typical parametric model selection procedures are essentially incoherent. We argue that one solution to this problem is to use a flexible enough model in the first place, a model that will not be checked no matter what data arrive. Ideally, one would use a nonparametric model to describe all the uncertainty about the density function generating the data. However, parametric models are the preferred choice for many statisticians, despite the incoherence involved in model checking, incoherence that is quite often ignored for pragmatic reasons. In this paper we show how coherent parametric inference can be carried out via decision theory and Bayesian nonparametrics. None of the ingredients discussed here are new, but our main point only becomes evident when one sees all priors—even parametric ones—as measures on sets of densities as opposed to measures on finite-dimensional parameter spaces.     

国外物流发展状况及趋势

着重介绍了国外物流发展状况，以及国外现代物流的发展所呈现的新趋势和新特点。