The maximum likelihood estimators of the parameters of the gamma distribution are always positively biased

Several authors have conjectured, on the basis of their numerical work, that the maximum likelihood estimators of the shape and scale parameters of the Gamma distribution are positively biased. It is proved that their conjecture is always true.     

社会发展需要大学生培养信息意识

信息闭塞长期阻碍经济的发展,人们越来越认识到信息的重要性。本文通过对信息及信息意识的剖析,提出增强大学生信息意识的三条措施。     

信息传递与中国传统官僚的政治心理——以马戛尔尼访华为中心

本文从信息传递的角度对马戛尔尼访华事件进行重新的解读,认为这一历史事件之所以呈现如此的面貌,与双方信息传递的效率和准确性有关,中英双方在信息传递的过程中均存在模糊、欺骗和不及时等问题。就中方信息传递的过程而言,这些问题的出现与中国传统官僚的政治心理密切相关,中国传统官僚在忠君和明哲保身思想的双重考虑下,往往会故意或不故意对信息的内容进行改动。这些改动既是历史事件的主要内容,同时也是重要的决定因素。     

大学毕业生搜集就业信息的原则和方法

就业信息搜集是大学生择业的第一步 ,它直接关系到择业最终能否实现。搜集就业信息的关键在于遵循正确的原则与掌握适当的方法。毕业生在搜集就业信息时 ,只要按照准确真实、适用针对、系统连续与计划条理原则 ,采用地毯式访问、连锁介绍、中心开花和供需见面等方法 ,就一定能获取大量有益的就业信息 ,为顺利实现就业打下良好的基础。     

ORDER SELECTION IN ARMA MODELS USING THE FOCUSED INFORMATION CRITERION

This paper develops a new approach for order selection in autoregressive moving average models using the focused information criterion. This criterion minimizes the asymptotic mean squared error of the estimator of a parameter of interest. Simulation studies indicate that the suggested criterion is quite effective and comparable to the Akaike information criterion, the corrected Akaike information criterion and the Bayesian information criterion in autoregressive moving average order selection. The use of the focused information criterion for the simultaneous selection of regression variables and order of the error process in a linear regression model with autoregressive moving average errors is also considered.     

科技英语疑问句的信息功能探析

句子的功能所实现的交际任务是传递信息。根据话语信息传递和语言交际功能理论原则,通过甄选科技英语相关例证作为分析语料,从英语的科技文体视角探析了疑问句在科技英语信息推进中的五大作用,同时指出了解这些相关作用的必要性。     

Splines for financial volatility

Summary.  We propose a flexible generalized auto-regressive conditional heteroscedasticity type of model for the prediction of volatility in financial time series. The approach relies on the idea of using multivariate B -splines of lagged observations and volatilities. Estimation of such a B -spline basis expansion is constructed within the likelihood framework for non-Gaussian observations. As the dimension of the B -spline basis is large, i.e. many parameters, we use regularized and sparse model fitting with a boosting algorithm. Our method is computationally attractive and feasible for large dimensions. We demonstrate its strong predictive potential for financial volatility on simulated and real data, and also in comparison with other approaches, and we present some supporting asymptotic arguments.     

辩证地看待信息网络技术在医学领域的作用

信息网络技术正逐步改变着我们的生活和工作方式,作为现代科学重要组成部分的现代医学,信息网络技术必将对它产生积极而深远的影响,我们应该辩证地看待信息技术在医学中的作用,这样才能正确有效地利用它为医学服务.     

MULTIPLE-RECORD SYSTEMS ESTIMATION USING LATENT CLASS MODELS

Capture–recapture methods (also referred to as 'multiple-record systems') have been widely used in enumerating human populations in the fields of epidemiology and public health. In this article, we introduce latent class models into multiple-record systems to account for unobserved heterogeneity in the population. Two approaches, the full and the conditional likelihood, are proposed to estimate the unknown population abundance. We also suggest rules to diagnose identifiability of the proposed latent class models. The methodologies are illustrated by two real examples: the first is to count the undercount of homelessness in the Adelaide central business district, and the second concerns the incidence of diabetes in a small Italian town.     

高校信息公开制度化探析

文章针对高校信息公开存在的问题,提出推进高校信息公开制度化的建议：以法律为准绳推进高校信息公开;建立健全高校信息公开机构;创新高校信息公开管理机制;以学校网站为建立和完善信息公开渠道。