载波相位平滑GPS伪码伪距的研究

分析了全球定位系统接收机可获取的观测量。给出了载波相位平滑伪码伪距的一个递归算法结构。讨论了平滑算法初值的设定和构造伪距前向预测值，并对各种情况进行了统计分析。文中还给出了平滑算法的性能评估，结论表明载波相位平滑技术可大大改善伪距观测精度。改善程度与该算法中的权重因子和递归时间密切相关     

克隆技术对人类社会的影响

本文分析了克隆技术对社会发展的积极作用和消极影响 ,分析了“Clone”技术的必然发展趋势 ,预言了“Clone”技术对人类社会的深层影响及对策 ,提示人类应用该项技术时要趋利避害     

从网络小说看网络文学基本特征

网络文学已登上二十一世纪中国文学的大雅之堂。从最能体现网络文学基本特征的网络小说进行探析 ,认为网络文学的基本特征为 :情感表达的宣泄性 ;著读交流的迅捷性 ;叙事结构的随意性 ;语言表达的能动性等。     

基于主动网的SYN攻击防御

针对目前传统网防御TCP同步泛滥攻击的服务器主机、路由器过滤、防火墙方法的局限性,利用主动网的动态特性,提出一种基于主动网的同步泛滥防御机制,并通过仿真实验将它与传统网环境下的防火墙防御进行了性能比较和分析,结果表明主动网技术为同步泛滥攻击提供了良好的防御性能。     

《金属材料与热处理》教法探究

对如何在《金属材料与热处理》课堂教学中培养提高学生的学习能力,从动力、基础及主要环节与关键问题等方面作了粗浅的研究与探讨。     

“换词求雅”的修辞作用及衔接功能

“换词求雅”作为一种消极修辞手段,在避免重复、增加文章的文体色彩方面起到了积极的作用。不仅如此,作为一种衔接手段,“换词求雅”也在保证语篇的衔接与连贯上发挥着不可替代的作用。本文通过对这种辞手段的应用原则及分类方法的阐述,试图表明“换词求雅”并不是为了语言花哨的目的而存在的,无论从修辞还是语法意义角度上看,这一修辞方法的作用都是其他方法难以替代的。     

双长链双季铵盐化合物的发展概况

双季铵盐类化合物作为一代新型的阳离子表面活性剂,在过去的二十几年中,有了长足的发展.人们合成了上百种的化合物,并研究了它们的物化性能、抗菌活性以及在相转移催化和模拟生物膜方面的作用.本文是对双季铵盐类化合物的发展的综述.     

An analytic method for randomized trials with informative censoring: Part 1

Consider a randomized trial in which time to the occurrence of a particular disease, say pneumocystis pneumonia in an AIDS trial or breast cancer in a mammographic screening trial, is the failure time of primary interest. Suppose that time to disease is subject to informative censoring by the minimum of time to death, loss to and end of follow-up. In such a trial, the censoring time is observed for all study subjects, including failures. In the presence of informative censoring, it is not possible to consistently estimate the effect of treatment on time to disease without imposing additional non-identifiable assumptions. The goals of this paper are to specify two non-identifiable assumptions that allow one to test for and estimate an effect of treatment on time to disease in the presence of informative censoring. In a companion paper (Robins, 1995), we provide consistent and reasonably efficient semiparametric estimators for the treatment effect under these assumptions. In this paper we largely restrict attention to testing. We propose tests that, like standard weighted-log-rank tests, are asymptotically distribution-free -level tests under the null hypothesis of no causal effect of treatment on time to disease whenever the censoring and failure distributions are conditionally independent given treatment arm. However, our tests remain asymptotically distribution-free -level tests in the presence of informative censoring provided either of our assumptions are true. In contrast, a weighted log-rank test will be an -level test in the presence of informative censoring only if (1) one of our two non-identifiable assumptions hold, and (2) the distribution of time to censoring is the same in the two treatment arms. We also extend our methods to studies of the effect of a treatment on the evolution over time of the mean of a repeated measures outcome, such as CD-4 count.     

Early experiences of mentoring: Design and use of multimedia materials for teaching OR/MS

The MENTOR project, based at the University of Strathclyde, is producing multimedia computer based learning materials with the aim of improving both the effectiveness and the efficiency of teaching Operational Research/Management Science in higher education. The process of development has been carefully designed to encourage ownership of and commitment to the materials amongst lecturing staff in Universities, with the aim of ensuring widespread use. The paper outlines this process of development and design of materials. Experiences in introducing students to the use of these materials as an integrated part of a Management Science class are reported. Feedback from students has been very positive but also indicates the need for ongoing support and direction.     

Limit theorems for dependent Bernoulli variables with statistical inference

We consider a class of dependent Bernoulli variables where the conditional success probability is a linear combination of the last few trials and the original success probability. We obtain its limit theorems including the strong law of large numbers, weak invariance principle, and law of the iterated logarithm. We also derive some statistical inference results which make the model applicable. Simulation results are exhibited as well to show that with small sample size the convergence rate is satisfying and the proposed estimators behave well.