On the trimmed mean and minimax-variance L-estimation in Kolmogorov neighbourhoods

We consider the properties of the trimmed mean, as regards minimax-variance L-estimation of a location parameter in a Kolmogorov neighbourhood K() of the normal distribution: We first review some results on the search for an L-minimax estimator in this neighbourhood, i.e. a linear combination of order statistics whose maximum variance in K_t() is a minimum in the class of L-estimators. The natural candidate – the L-estimate which is efficient for that member of K_t,() with minimum Fisher information – is known not to be a saddlepoint solution to the minimax problem. We show here that it is not a solution at all. We do this by showing that a smaller maximum variance is attained by an appropriately trimmed mean. We argue that this trimmed mean, as well as being computationally simple – much simpler than the efficient L-estimate referred to above, and simpler than the minimax M- and R-estimators – is at least “nearly” minimax.     

Penalized likelihood-ratio test for finite mixture models with multinomial observations

Due to the irregularity of finite mixture models, the commonly used likelihood-ratio statistics often have complicated limiting distributions. We propose to add a particular type of penalty function to the log-likelihood function. The resulting penalized likelihood-ratio statistics have simple limiting distributions when applied to finite mixture models with multinomial observations. The method is especially effective in addressing the problems discussed by Chernoff and Lander (1995). The theory developed and simulations conducted show that the penalized likelihood method can give very good results, better than the well-known C(α) procedure, for example. The paper does not, however, fully explore the choice of penalty function and weight. The full potential of the new procedure is to be explored in the future.     

在Delphi中利用IdFTP组件实现大文件上传

本文利用Delphi和Indy套件中的IdFTP组件，在Delphi下生成ActiveX控件供浏览器客户端上传文件用，上传完毕后客户端发送消息给服务器端，利用服务器端的脚本处理上传后的文件．     

地理系实验人员工作量考核初探

对实验人员工作进行量化管理是很有必要的。本文根据本院地理系实验室和实验人员的具体情况和工作特点，对各个实验室的工作进行了量化处理，以便于对实验人员的考核。     

皮尔士的逻辑人生

皮尔士早年曾受严格的逻辑训练,坚持以逻辑学为学术目标,一生热情地追求逻辑学的改进和应用。他的逻辑思想具有广阔的视野,对于逻辑学的发展作出了杰出贡献。然而,他作为一位伟大逻辑学家,长期不被人理解,只是在近几年才重新得到发现和重视。     

广东湛江红树林保护区植物群落生态研究

通过实地调查和资料分析，研究了广东湛江红树林自然保护区高桥镇核心区的红树植物区系、红树林的外貌结构、群落的类型与分布、生态系列与群落演替及其变化原因，为红树林的保护与发展提供理论依据。     

Theory & Methods: Krige,Smooth, Both or Neither?

Both kriging and non-parametric regression smoothing can model a non-stationary regression function with spatially correlated errors. However comparisons have mainly been based on ordinary kriging and smoothing with uncorrelated errors. Ordinary kriging attributes smoothness of the response to spatial autocorrelation whereas non-parametric regression attributes trends to a smooth regression function. For spatial processes it is reasonable to suppose that the response is due to both trend and autocorrelation. This paper reviews methodology for non-parametric regression with autocorrelated errors which is a natural compromise between the two methods. Re-analysis of the one-dimensional stationary spatial data of Laslett (1994) and a clearly non-stationary time series demonstrates the rather surprising result that for these data, ordinary kriging outperforms more computationally intensive models including both universal kriging and correlated splines for spatial prediction. For estimating the regression function, non-parametric regression provides adaptive estimation, but the autocorrelation must be accounted for in selecting the smoothing parameter.     

8种血清型禽大肠杆菌的生化反应及药物敏感试验分析

选取具有致病力8种血清（O1、O2、O6、O(35)、O(54)、O(55)、O(78)、O(103)）禽大肠肝菌进行生化反应及药物敏感试验，研究其生化特性及对药物的敏感性。结果表明：8种血清型大肠杆菌生化反应基本一致，所不同的是在卫予醇反应中，（O1、O2、O6、O(35)、O(105)）4种血清型大肠杆菌呈阴性；8种血清型大肠杆菌对了胶卡那霉素、痢特灵、链霉素、卡那霉素、新霉素、红霉素均呈极、高、中、低不同程度敏感，对万古霉素均不敏感；7种（除O6外）血清型大肠杆菌对氯霉素呈极敏感或高敏；6种（除O(35)、O(103)外）血清型大肠肝菌对庆大霉素呈高、中、低度敏感二种（O1、O2、O(54)、O(78)）血清型大肠杆菌对氨苄青霉素呈高度敏感；2种（O1、O2）血清型大肠杆菌对强力霉素、磺胺药、四环素呈中敏或极敏。     

理论力学课程教学改革与实践

在我校教学实践的基础上,结合国内外力学教学改革和创新,阐述了理论力学知识体系和课程教学特点,分析了该课程教学目前面临的主要问题,提出了对教学改革的一些建设性想法,通过对教学体系的进一步改革,加强学生对基础知识的理解,以及综合能力的培养,以期取得较好的教学效果。     

哈尔滨市博物馆利用对策

以哈尔滨市博物馆为研究对象，以不同人群对博物馆的使用需求和行为特征为切入点，通过分析博物馆的区位交通、周边环境及馆内存在的问题，为城市博物馆的建设与管理等方面提出建议，使博物馆能够良性发展，更好地承担起普及知识、教育大众、传承文化的责任。