基于DOCSIS的冲突解决算法的研究

研究了基于DOCSIS规范的冲突解决算法棗二进制指数后退,提出了一种全新的逆向二进制指数后退算法,对两种算法进行了仿真实验,仿真结果表明逆向二进制指数后退算法比二进制指数后退算法有较小的接入延迟特性。     

菲涅尔区平面反射器的焦散区场

菲涅尔区相位修正平面反射器具有类似于旋转抛物面的聚焦特性。本文用物理光学方法分析了平面波入射时其焦散区场的分布并给出了数伍计算结果。重点探讨了入射波倾斜时其焦散区场的相应变化，为该类反射面的实际应用提供了理论依据。     

On the detection of clustering and anisotropy using binary data from a lattice patch

A method i s suggested for detecting spatial pattern of disease data on a rectangular lattice. One first classifies all pairs of points by their distance and orientation of separation and then counts the number of pairs of points in each distanceorientation type for which both points show the disease. A log-linear model is proposed for these counts. Methods of fitting to it are suggested that furnish tests of clustering and of anisotropy. Empirical sarnpling results show that the tests are reasonably powerful against certain alternatives and verify that nominal levels of simificances are approximately correct. The method is given in detail for a single four by five plot and is then adapted for combining data from many such plots. Examples are given of such counts and of the calculations used to analyze them.     

论归化与异化之统一

归化与异化之争由来已久,很多人不是支持异化反对归化,就是支持归化反对异化.归化与异化都只是一种翻译的策略,并没有好坏与优劣之分,归化与异化并不是完全对立的概念,应该消除它们之间对立的观念,因为归化与异化永远同时并存.     

A Semiparametric Binary Regression Model Involving Monotonicity Constraints

Abstract.  We study a binary regression model using the complementary log–log link, where the response variable Δ is the indicator of an event of interest (for example, the incidence of cancer, or the detection of a tumour) and the set of covariates can be partitioned as ( X ,  Z ) where Z (real valued) is the primary covariate and X (vector valued) denotes a set of control variables. The conditional probability of the event of interest is assumed to be monotonic in Z , for every fixed X . A finite-dimensional (regression) parameter β describes the effect of X . We show that the baseline conditional probability function (corresponding to X  =  0 ) can be estimated by isotonic regression procedures and develop an asymptotically pivotal likelihood-ratio-based method for constructing (asymptotic) confidence sets for the regression function. We also show how likelihood-ratio-based confidence intervals for the regression parameter can be constructed using the chi-square distribution. An interesting connection to the Cox proportional hazards model under current status censoring emerges. We present simulation results to illustrate the theory and apply our results to a data set involving lung tumour incidence in mice.     

平方数的位数和函数的2个性质

设正整数n的二进制表达式为n=∑i≥0εi（n）2^i，这里最（n）=0或1，i≥0，定义二进制位数和函数为s（n）=∑i≥0εi（n）．设s（n）=κ，证明了s（n^2）≤κ（κ＋1）／2，并且证明了几乎所有满足s（n）=κ的正整数n都满足s（n^2）≤κ（κ＋1）／2，i≥0从而给出了｜{n〈2^N：s（n）=κ，s（n^2）=m}｜的一个确切分布．     

On Deconstruction of the Binary Opposition in Guests of the Nation

Guests of the N ation w ritten by the Irish w riter Frank O ’C onnor is the most magnificent short story,in w hich a tragedy about the killing betw een friends is depicted.In this story,many different pairs of binary opposition are used to present the theme and the characters vividly,w hich makes the plot more attractive.T his study attempts to analyze the phenomena of the binary opposition in the story based on the theory of deconstruction to deconstruct the individuals’feelings of the absurdity and void of the meaningless w orld.     

Some aspects of the design and analysis of cluster randomization trials

Trials which randomize intact social groups, or clusters, to different interventions are becoming increasingly widespread. Although statistically less efficient than trials which randomize individuals, such designs are often preferred from a practical or ethical point of view, particularly in the evaluation of health care or educational strategies. We discuss selected issues that arise in the conduct of such trials, including the choice of design, ethical implications, sample size estimation and approaches to the analysis. The discussion is closely tied to methodological issues that have arisen in a recent evaluation trial of a new antenatal care programme, as sponsored by the Special Programme of Research, Development and Research Training in Human Reproduction of the World Health Organization.     

News about Members

In this article a natural extension of the beta-binomial distribution is developed. Forced binary choice situations are modeled such that each individual has a probability p of knowing the correct answer. (This probability is distributed f(p) across the population.) Hence each individual will guess at the correct answer with probability 1 – p. The observable random variable R, the total number of correct answers (both by knowing and guessing) out of k trials has a rather complicated distribution. However, when f(p) is distributed beta with parameters m and n, the distribution P(r; k, m, n) can be expressed in terms of the well-known Gaussian hypergeometric function. This distribution has implications for true-false tests, taste tests, and virtually every other forced binary choice situation.     

Dynamic Analysis of Recurrent Event Data with Missing Observations, with Application to Infant Diarrhoea in Brazil

Abstract.  This paper examines and applies methods for modelling longitudinal binary data subject to both intermittent missingness and dropout. The paper is based around the analysis of data from a study into the health impact of a sanitation programme carried out in Salvador, Brazil. Our objective was to investigate risk factors associated with incidence and prevalence of diarrhoea in children aged up to 3 years old. In total, 926 children were followed up at home twice a week from October 2000 to January 2002 and for each child daily occurrence of diarrhoea was recorded. A challenging factor in analysing these data is the presence of between-subject heterogeneity not explained by known risk factors, combined with significant loss of observed data through either intermittent missingness (average of 78 days per child) or dropout (21% of children). We discuss modelling strategies and show the advantages of taking an event history approach with an additive discrete time regression model.