Dynamic component detection in a multifactor model for stock returns

Summary In this paper the factorial structure of some asset returns quoted at the Milan stock exchange is analyzed in order to detect the presence of a dynamic component. The maximum likelihood estimates of the dynamic model, for which a space-state representation and the Kalman filter were used, are compared with the estimates of the static model via the information criteria. There is no evidence of dynamic factors underlying the analyzed samples of asset returns, while one static factor seems to be relevant. Invited paper at the Conference held in Bologna, Italy, 27–28 May 1993, on ?Statistical Tests: Methodology and Econometric Applications?.     

Evaluating Weight of Evidence in the Mystery of Balkan Endemic Nephropathy

Balkan endemic nephropathy (BEN) is a chronic, progressive wasting disease of the kidneys, endemic in certain rural regions of the Balkan nations Croatia, Serbia, Bulgaria, and Romania. It is irreversible and ultimately fatal. Though this disease was first described in the 1950s, its causes have been a mystery and a source of much academic and clinical contention. Possible etiologic agents that have been explored include exposure to metals and metalloids, viruses and bacteria, and the dietary toxins aristolochic acid (AA) and ochratoxin A (OTA). AA is a toxin produced by weeds of the genus Aristolochia, common in Balkan wheat fields. Aristolochia seeds may intermingle with harvested grains and thus inadvertently enter human diets. OTA is a mycotoxin (fungal toxin) common in many foods, including cereal grains. In this study, we analyzed the weight of evidence for each of the suspected causes of BEN using the Bradford Hill criteria (BHC): nine conditions that determine weight of evidence for a causal relationship between an agent and a disease. Each agent postulated to cause BEN was evaluated using the nine criteria, and for each criterion was given a rating based on the strength of the association between exposure to the substance and BEN. From the overall available scientific evidence for each of these suspected risk factors, AA is the agent with the greatest weight of evidence in causing BEN. We describe other methods for testing causality from epidemiological studies, which support this conclusion of AA causing BEN.     

略论中国近现代社会文化背景的演变对翻译的影响

中国近现代文化背景是由鸦片战争前的封建传统文化单一模式逐步转向西方文化强势进入模式 ,然后转向当代多元共生的模式。这里分析了中国近现代历史文化背景的演变对翻译选材和翻译标准的影响 ,认为在其影响下翻译选材经历了由自然科学向社会科学、文学等所有领域逐步扩大的过程 ,翻译标准经历了由“信、达、雅” ,向“宁信勿顺”、“化境” ,而至“一定制约性 ,一定自由度”的过程 ,指出文化背景对翻译有着巨大的制约和推进作用 ,新的翻译标准应该包括“顺应社会文化背景”这一点。     

中外企业会计准则—合并财务报表的比较研究

通过对国内外现行会计准则的关键部分—合并财务报表的比较研究,可以看出不同国家在合并会计的理论和实务领域里存在着巨大的差异。提出了西方国家的合并报表理论和实务有许多东西可以借鉴。应采纳世界各国合并报表表现方法中的一切有价值的思想和最新成果,以重新优化和组合现有的合并报表理论和方法,形成自己的合并报表理论体系。     

The effects of different choices of order for autoregressive approximation on the Gaussian likelihood estimates for ARMA models

This paper investigates, by means of Monte Carlo simulation, the effects of different choices of order for autoregressive approximation on the fully efficient parameter estimates for autoregressive moving average models. Four order selection criteria, AIC, BIC, HQ and PKK, were compared and different model structures with varying sample sizes were used to contrast the performance of the criteria. Some asymptotic results which provide a useful guide for assessing the performance of these criteria are presented. The results of this comparison show that there are marked differences in the accuracy implied using these alternative criteria in small sample situations and that it is preferable to apply BIC criterion, which leads to greater precision of Gaussian likelihood estimates, in such cases. Implications of the findings of this study for the estimation of time series models are highlighted.     

美学范式:实践的生态和谐观

实践美学以马克思主义实践哲学为基础,把实践作为联系人和自然的纽带,把美的本质归结为“人的本质力量的对象化”,即美是人在对象上面的自我观照。实践美学的思想主要来源是马克思的《1844年经济学哲学手稿》,其中“自然人化”和“两个尺度”的论述对实践美学有重要的影响。今天,传统的实践观和旧有的主体性哲学范式已不尽符合现实要求。对中国当代的美学进行重释,使其理论基础由主体性哲学向主体间性哲学转换,以适应哲学和美学的未来发展趋势,是一个十分重要的课题。     

新课程标准下高中教师专业发展问题探讨

新一轮高中课程改革对教师的专业发展提出了更新教育理念、完善知识结构、提高驾驭教材能力等要求,建立以校为本的教研制度、发挥教研机构以及大学的专业引领作用是教师专业发展的有效途径,而将理论与教学实践的有机结合则是教师专业发展的根本。     

普通话水平测试中方言语调判定之我见

针对普通话水平测试过程中所遇到的区域性方言语调问题进行研究探讨,分析了方言语调的基本内涵和具体特征,然后就普通话水平测试中方言语调的判定、评分的标准和具体情况的处理,作出了原则的揭示。     

一类带有时滞的神经网络一致稳定性判别法

讨论带有时滞神经网络一致稳定性的问题,给出了状态函数与输出函数关于平衡点一致稳定、全局一致渐近稳定性等价性定理及判别方法。     

我国环境资源民事侵权责任制度之探讨

环境资源民事侵权是一种特殊侵权行为,与传统的侵权行为相比较具有显著的特点。与此相关的责任构成上实行无过错责任、因果关系推定、举证责任倒置以及多元证明标准体系,以利原告诉讼,保护自然环境与生态安全。