数控程序轮廓描述的实现

介绍ＳＩＮＵＭＥＲＩＫ８１０／８２０系统１６种轮廓描述指令及本文作者推导的分解算法．包括１６种基本的模式、转换为直线或圆弧插补的数学推导、以及Ｃ语言程序实现等．     

一类非线性算子方程组的选代求解

在Ｂａｎａｃｈ空间上，利用锥理论与迭代方法研究了一类非线性算子方程组解的再在性与唯一性，推广了文［１］的主要结果，并给出了应用。     

回归分析在短跑教学中的应用

针对教学中学生100m跑的具体情况,采用逐步回归分析方法建立了回归方程;在此基础上,分别以各相关因素、100 m跑成绩作为因变量与自变量建立了多项式回归方程,并依据正态分布理论制定了各因素平衡发展的标准.上述方法在指导短跑教学中取得了较好的效果.     

一类单周期的S_3~1(△_(mn)~((2)))插值

样条函数在 CAGD 上有着广泛的应用。本文继续[1]、[2]的工作,主要讨论了平面矩形区域在Ⅱ型三角剖分下的一类单周期二元三次插值样条的存在性和唯一性。给出了单周期样条空间的维数,并着重讨论了单周期样条插值的逼近度。     

关于中值定理“中间点”的渐近性质

文［１］给出了当区间长度趋于无穷大时Ｌａｇｒａｎｇｅ中值定理＂中间点＂的渐进性质。本文首先减弱了文［１］中主要定理的条件，从而改进了文［１］中的结果，然后给出积分中值定理当区间长度趋于无穷大时＂中间点＂的渐近性质．     

Asymptotic expansion of the nonnull distribution of likelihood ratio statistic for testing multisample sphericity

Asymptotic expansion of the nonnull distribution of the likelihood ratio statistic for testing muitisample sphericity in q multinormal populations is derived for the alternatives close to the null hypothesis.     

全微分法在IRR敏感性分析中的应用

内插法求解IRR敏感性分析存在三个不足之处 :计算量繁琐、作图不严谨和缺乏可靠的评价标准。在诸因素变动幅度不大的条件下 ,代之以全微分法是一个理想的选择。为此 ,推出了全微分法求解的一般步骤 :求出基本方案的IRR值、画含未知数的现金流量图或表、建立IRR的隐函数、在原点作全微分、求出IRR与诸因素的近似线性关系、画敏感性分析图表、根据偏导数做出敏感性评价等。通过实例分析 ,进一步说明 :在给定的条件下 ,全微分法不但能够圆满解决上述三个问题 ,而且能够同时解决内插法所难以对付的IRR多因素敏感性分析     

Nonlinear voxel-based modelling of the haemodynamic response in fMRI

A common assumption for data analysis in functional magnetic resonance imaging is that the response signal can be modelled as the convolution of a haemodynamic response (HDR) kernel with a stimulus reference function. Early approaches modelled spatially constant HDR kernels, but more recently spatially varying models have been proposed. However, convolution limits the flexibility of these models and their ability to capture spatial variation. Here, a range of (nonlinear) parametric curves are fitted by least squares minimisation directly to individual voxel HDRs (i.e., without using convolution). A ‘constrained gamma curve’ is proposed as an efficient form for fitting the HDR at each individual voxel. This curve allows for spatial variation in the delay of the HDR, but places a global constraint on the temporal spread. The approach of directly fitting individual parameters of HDR shape is demonstrated to lead to an improved fit of response estimates.     

Smoothing parameter selection methods for nonparametric regression with spatially correlated errors

When spatial data are correlated, currently available data‐driven smoothing parameter selection methods for nonparametric regression will often fail to provide useful results. The authors propose a method that adjusts the generalized cross‐validation criterion for the effect of spatial correlation in the case of bivariate local polynomial regression. Their approach uses a pilot fit to the data and the estimation of a parametric covariance model. The method is easy to implement and leads to improved smoothing parameter selection, even when the covariance model is misspecified. The methodology is illustrated using water chemistry data collected in a survey of lakes in the Northeastern United States.     

大整数分解的多个多项式二次筛法及其微机实现

通过讨论Silverman提出的多个多项式二次筛法（MPOS），提出了MPQS的计算步骤，并在486微机上实现了MPQS．