高分辨率摄像管的研究

提出了一种研究采用图案偏转轭的高分辨率摄像管的新方法。与现有的方法相比,该方法具有速度快、精度高和适用性广的特点。文中给出了该方法的数学模型和程序框图,并利用该方法的计算结果,分析了该种摄像管的电子光学特性和影响各电子光学特性参量的主要因素。     

杂交中稻超多蘖壮秧少穴高产栽培研究——Ⅱ:移栽时单株茎蘖数对生长发育及产量的影响

以汕优63和D优10号两个杂交组合在田间条件下连续两年观察了秧苗移栽时的单株茎蘖数对少穴栽培杂交中稻栽后生长发育及产量的影响。其结果表明,在10叶期栽插和每公顷本田植75.0千穴至150.0千穴的少穴栽培条件下,单株有效分蘖数和最高苗数均同移栽时单株茎蘖数呈极显著正相关;单株有效穗在移栽时单株茎蘖数为8～23苗范围与单株茎蘖数呈极显著正相关;单株产量在单株茎蘖数为8～15苗范围与单株茎蘖数呈极显著正相关。     

Amemiya's generalized least squares and tests of overidentification in simultaneous equation models with qualitative or limited dependent variables

Amemiya's generalized least squares method for the estimation of simultaneous equation modeis with qualitative or limited dependent variables is known to be efficient relative to many popular two stage estimators. This note points out that test statistics for overidentification restrictions can be obtained as by-products of Amerniya's generalized least squares procedure. Amemiya's procedure is shown to be a minimum chisquare method. The Amemiya procedure is valuable both for efficient estimation and for model evaluation of such models.     

匀变速直线运动的判断

以物体做匀变速直线运动的判断方法，对利用位移差相等（△Ｓ＝ａＴ２）来判断物体是否作匀变速直线运动进行分析，论证了位移差相等只是判断物体作匀变速直线运动的必要条件，给出了该判断的充要条件是，对验证匀变速直线运动的实验提出了采用频率可调打点计时器和对运动物体增系一个速度计等改进意见．     

Selection of Single Sampling Attributes Plan for Given Acceptable Quality Level and Limiting Quality Level Involving Minimum Risks

A table and a procedure are given for finding the single sampling attributes plan involving minimum sum of producer's and consumer's risks for specified Acceptable Quality Level and Limiting Quality Level.     

Estimation and Inference of Distributional Partial Effects: Theory and Application

This article considers nonparametric and semiparametric estimation and inference of the effects of a covariate, either discrete or continuous, on the conditional distribution of a response outcome. It also proposes various uniform tests following estimation. This type of analysis is useful in situations where the econometrician or policy-maker is interested in knowing the effect of a variable or policy on the whole distribution of the response outcome conditional on covariates and is not willing to make parametric functional form assumptions. Monte Carlo experiments show that the proposed estimators and tests are well-behaved in small samples. The empirical section studies the effect of minimum wage hikes on household labor earnings. It is found that the minimum wage has a heterogenous impact on household earnings in the U.S. and that small hikes in the minimum wage are more effective in improving the household earnings distribution.     

Minimum power-divergence estimator in three-way contingency tables

Cressie et al. (2000; 2003) introduced and studied a new family of statistics, based on the φ-divergence measure, for solving the problem of testing a nested sequence of loglinear models. In that family of test statistics the parameters are estimated using the minimum φ-divergence estimator which is a generalization of the maximum likelihood estimator. In this paper we study the minimum power-divergence estimator (the most important family of minimum φ-divergence estimator) for a nested sequence of loglinear models in three-way contingency tables under assumptions of multinomial sampling. A simulation study illustrates that the minimum chi-squared estimator is simultaneously the most robust and efficient estimator among the family of the minimum power-divergence estimator.     

The Decline and Fall of Type II Error Rates

For general linear models with normally distributed random errors, the probability of a Type II error decreases exponentially as a function of sample size. This potentially rapid decline reemphasizes the importance of performing power calculations.     

Preliminary phi-divergence test estimators for linear restrictions in a logistic regression model

The problem of estimation of the parameters in a logistic regression model is considered under multicollinearity situation when it is suspected that the parameter of the logistic regression model may be restricted to a subspace. We study the properties of the preliminary test based on the minimum ϕ -divergence estimator as well as in the ϕ -divergence test statistic. The minimum ϕ -divergence estimator is a natural extension of the maximum likelihood estimator and the ϕ -divergence test statistics is a family of the test statistics for testing the hypothesis that the regression coefficients may be restricted to a subspace.     

A Note on Sample Size Determination for Akaike Information Criterion (AIC) Approach to Clinical Data Analysis

ABSTRACT

Because of its flexibility and usefulness, Akaike Information Criterion (AIC) has been widely used for clinical data analysis. In general, however, AIC is used without paying much attention to sample size. If sample sizes are not large enough, it is possible that the AIC approach does not lead us to the conclusions which we seek. This article focuses on the sample size determination for AIC approach to clinical data analysis. We consider a situation in which outcome variables are dichotomous and propose a method for sample size determination under this situation. The basic idea is also applicable to the situations in which outcome variables have more than two categories or outcome variables are continuous. We present simulation studies and an application to an actual clinical trial.