多元线性回归方程及其应用

通过建立多元线性回归的数学模型,利用最小二乘估计得到正规方程组并进行相关性检验,从而解决相关实际问题。     

写作过程与大学生英语写作能力训练

大学生英语写作能力的提高在于教师得当的教学方法和学生的大量的写作实践,得当的教学方法会激发学生写作的积极性和创造性,同时可以减轻教师批阅压力,使师生双方受益。这种方法就是教师充分利用写作过程中的预写阶段、写作阶段和修改阶段来全面训练和培养学生的写作能力。     

20世纪中国文学思潮进程现象反观(一)

每一个时代都有自己时代所需要的历史叙述与文学观念 ,成为了学术的基本权力。 2 0世纪中国文学已经走完了它的全程 ,并完整地展现在我们的记忆与案头。纵览 2 0世纪中国社会思潮的史学进程 :从“人文主义精神”到“社会主义思潮” ,再向世纪末“现代主义理念”的嬗变演进 ,决定 2 0世纪中国文学思潮的整体走向 ,传统的“现、当代文学史”的分期理论与编史叙述的本质缺陷 ,清晰地暴露出来 ,从而有力地支撑着“2 0世纪中国文学”编史叙述的基本构想。     

Missing data and forecasting in multivariate time series: An application of the common components dynamic linear model

Summary The paper deals with missing data and forecasting problems in multivariate time series making use of the Common Components Dynamic Linear Model (DLMCC), presented in Quintana (1985), and West and Harrison (1989). Some results are presented and discussed: exploiting the correlation between series, estimated by the DLMCC, the paper shows as it is possible to update state vector posterior distributions for the unobserved series. This is realized on the base of the updating of the observed series state vectors, for which the usual Kalman filter equations can be applied. An application concerning some Italian private consumption series provides an example of the model capabilities.     

计算机公共课教学改革实践探索

在科学技术高度发达的今天 ,为了使计算机公共课教学适应时代的发展 ,教师必须转变教育观念。同时 ,针对计算机教学自身的特点 ,教师应当运用变化的教学手段和灵活多样的教学方法来进行教学     

试论企业的环境成本管理

近年来随着人们环保意识的增强,企业对环境成本的管理日趋重视。本文从环境成本的内涵入手,阐述了环境成本的管理指导思想,并提出了环境成本管理的方法。     

Local polynomial estimation of Poisson intensities in the presence of reporting delays

Summary.  The system for monitoring suicides in Hong Kong has considerable delays in reporting as the cause of death needs to be determined by a coroner's investigation. However, timely estimates of suicide rates are desirable to assist in the formulation of public health policies. This motivated us to develop a non-parametric procedure to estimate the intensity function of a Poisson process in the presence of reporting delays. We give closed form estimators of the Poisson intensity and the delay distribution, conduct simulation studies to evaluate the method proposed and derive their asymptotic properties. The method proposed is applied to estimate the intensity of suicide in Hong Kong.     

世界教育信息化发展及其经验

教育信息化是战后教育发展的最重要发展方向之一。世界教育信息化的发展经历了发端、进一步推进和迅速高涨的发展时期;在每一个阶段各国推进教育信息化的政策、措施和特点等方面都呈现出一些独自的特征。总结世界各国推进教育信息化的经验对我国教育信息化的发展具有重要的启发意义。     

Sampling Returns for Realized Variance Calculations: Tick Time or Transaction Time?

This article introduces a new model for transaction prices in the presence of market microstructure noise in order to study the properties of the price process on two different time scales, namely, transaction time where prices are sampled with every transaction and tick time where prices are sampled with every price change. Both sampling schemes have been used in the literature on realized variance, but a formal investigation into their properties has been lacking. Our empirical and theoretical results indicate that the return dynamics in transaction time are very different from those in tick time and the choice of sampling scheme can therefore have an important impact on the properties of realized variance. For RV we find that tick time sampling is superior to transaction time sampling in terms of mean-squared-error, especially when the level of noise, number of ticks, or the arrival frequency of efficient price moves is low. Importantly, we show that while the microstructure noise may appear close to IID in transaction time, in tick time it is highly dependent. As a result, bias correction procedures that rely on the noise being independent, can fail in tick time and are better implemented in transaction time.     

Bayesian analysis of elapsed times in continuous‐time Markov chains

The authors consider Bayesian analysis for continuous‐time Markov chain models based on a conditional reference prior. For such models, inference of the elapsed time between chain observations depends heavily on the rate of decay of the prior as the elapsed time increases. Moreover, improper priors on the elapsed time may lead to improper posterior distributions. In addition, an infinitesimal rate matrix also characterizes this class of models. Experts often have good prior knowledge about the parameters of this matrix. The authors show that the use of a proper prior for the rate matrix parameters together with the conditional reference prior for the elapsed time yields a proper posterior distribution. The authors also demonstrate that, when compared to analyses based on priors previously proposed in the literature, a Bayesian analysis on the elapsed time based on the conditional reference prior possesses better frequentist properties. The type of prior thus represents a better default prior choice for estimation software.