差

In chapter 6, we study the dimension of a code associated with a difference set and we also study how to construct Ramanujan graph by using difference sets, we obtain:(1) let q≡1 (mod 4) be a prime power, p be a prime such that p｜〓, then the p-rank of the quadratic residue partial difference set in the finite field GF is 〓.

在第六章中，我们研究差集对应的码的维数及用差集构造Ramanuian图，得到了：（1）设q≡1（mod 4）是素数幂，素数p｜〓，则GF中的二次剩余部分差集的p-秩是〓。

The noninformative prior of the standard deviation of error terms was introduced for Bayesian analysis. Then, given the prior density of the random coefficients in the degradation path model, the Markov Chain Monte Carlo method was adopted to generate samples of joint posterior distribution of random coefficients and unknown standard deviation.

为了处理未知的误差项方差，引入相应的标准差的无信息先验分布，并进一步结合退化轨道模型中随性参数的先验分布，利用马尔可夫链蒙特卡罗方法得到随机参数及误差项标准差的联合后验分布的采样值，进而实时预测产品在未来一段时间内的可靠度。

According to the characteristics presented by armed helicopters during cruising or searching for ground targets, this paper has established the mean-square deviation stationary random model of helicopter tracks. It is an important method to decorrelate the measure noise by estimating the parameters of the color noise online. Kalman filtering and forecasting have been made with helicopter tracks. The simulated study has been carried out on helicopter tracks under the condition of color noise. It is very difficult to get an accurate and reliable prediction when the data is very limited. The paper make use of the theory of grey system to resolve the problem of prediction of helicopter tracks, establishing the GM model of grey systems and the cumulative residual error model of n degree, then correcting the GM forecast model. In the period of sampling, GM model and residual error model have been established on line to improve prediction precision.

结合武装直升机在巡航或搜索地面目标的特点，给出直升机航迹模型为协方差平稳随机模型，在线估计有色噪声参数，对测量噪声去相关，对直升机航迹进行卡尔曼滤波与预估，最后对有色噪声条件下的航迹进行了仿真研究；在数据非常有限的情况下，准确地预测又很困难，本文提出了用灰色系统理论解决直升机航迹预测问题，建立了灰色系统GM预测模型和n次累加残差模型并对GM预测模型进行修正，在每个采样期间内，实时在线建立GM预测模型和残差模型以提高预测精度。

According to third-order aberration theory, the conditions of the absence of aberrations were analyzed, and the influences to the remaining high order aberrations of the system caused by the change of the relative aperture of the primary mirror, the position of the corrector and the different combination of the positive and negative lens in the corrector were investigated.

根据像差理论分析了消像差的条件，研究了主镜的相对孔径变化、校正板在次镜后的位置变化以及无光焦度校正板的正负透镜的不同组合形式对系统高级残余像差的影响。

Results the parameter estimates and it's stability of linear regression models is associated with the variation of explanatory variable between and within level 2units,and the relationship of parameter estimates and it's stability between linear regression models and variance component model is associated with level 2 residual variance or intatra-unit correlation.

结果 线性回归模型参数估计以及估计的稳定性与自变量在水平2单位间和水平2单位内的变异大小有关，线性因归模型与方差成分模型参数估计及其稳定性的关系与水平2残差方差或单位内相关系数大小有关。

Since in some instance, the variance of response variable might be changeable along withthe alteration of explanatory variable, in the procedure of model constructing, a fixedeffects model should be considered firstly, then the random effects model or randomcoefficient model when necessary. The best fit model should be chosen by comparing thealterations of between-study variance and residual variance, as well as their relationshipswith covariates.

基于各研究中因变量与自变量间的曲线形状可能存在较大差异，建模时可依次考虑固定效应模型、随机效应模型和带协变量的随机系数模型，并观察研究水平的方差与残差方差的变化，以及与协变量的关系，从而选择最优模型。

The first one is to generate the circle for each borderline segment of the component by considering the segment length and the prescribed tolerance value. If this is not the case, the borderline segment will be equally divided into halves until the obtained circle satisfies the tolerance value over the whole borderlines of the component. The basic idea of the last two algorithms aims at covering the domain occupied by the component as much as possible. The circle generation is carried out sequentially from salient angle to the sector formed by the salient angle till the uncovered borderline segments of the component. Particularly, the three-step algorithm with gap allows that the generated circles are distributed with gap along the component contour.

二分法利用组件各边长度和设置的容差大小得到该边的候选包络圆，若该圆不满足组件所有边的容差要求，则将该边不断地对分，直至所得到的包络圆满足各边的容差要求；三步划分法和带间隙的改进三步划分法则以组件区域为划分对象，依次对组件多边形凸顶角、凸扇形区和多边形各边剩余线段划分包络圆，且带间隙的改进三步划分法则允许包络圆在组件边界上以适当的间隙分布。

R2 The adjusted R2 is 1 minus the ratio of sample variance of the OLS residuals (after correcting the degrees of freedom) to the sample variance of y.

调整过的R2是1减去OLS残差的样本方差与y的样本方差之比。

Estimation of parameters for general liner functional model with singular covariance. First, the Rao decomposition of the sample variance and the known singular measure error variance are presented and then the square measure error with singular variance and the standardized condition are got.

首先讨论了样本协方差与已知的奇异度量误差方差的Rao分解，给出了含有奇异方差广义逆的二次度量误差和模型的标准化条件，证明了二次度量误差与广义逆的选取无关。

Based on the Seidel sums formulae of thin lens, four types of NIM thin lenses free from partial primary aberrations are designed with specific parameters and given redundant aberration coefficients.

通过对单块负折射率介质薄透镜的像差特性分析，我们提出了四种只有利用到负折射率介质才具备的可消除部分初级像差的单块薄透镜系统，并给出了相关的系统结构参数和冗余的初级像差表达式。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失