分布参数

When the underlying error term for tobit model is known to be normally distributed and homoskedasticity, maximum likelihood estimation is consistent and asymptotically normally distributed.

半参数估计是一种参数和非参数估计的混合，比相应的参数模型更能一致的估计参数，而且比非参数模型估计更精确，其优点是无需假定误差项分布，所以它对非正态和异方差是稳健的。

The data analysis shows that: 1 different texture parameters have a clear scattered distribution, 2 the main direction of texture is the direction represented by the maximum parameter of Gauss-MRF parameters, and 3 for those samples basing the same main direction, the finer the texture is, the greater the corresponding parameter is, and the smaller the other parameters are; and the higher the order of Gauss-MRF is, the more clearly the texture is described.

数据分析表明，各不同纹理特征参数之间具有明显的分布性；Gauss-MRF参数值最大的参数所表示的纹理集聚为向为纹理的主方向；对于纹理主方向相同的样本，纹理越细致，其相应参数越大，而其他参数越小；Gauss-MRF阶数越高，纹理描述越细致：在2阶Gauss-MRF模型情况下，弦切纹理的B1参数大于径切纹理的B1；弦切纹理的B2、B3、B4分别小于径切纹理的B2、B3、B4。

The model uses the Pearson distribution system to simulate the backscattering distribution of ocean surface on SAR imagery. In the Pearson distribution system, four distributions including the Pearson distributions of typeⅠ,Ⅲ,Ⅳ and Ⅵ are employed.

模型使用Pearson分布系统模拟SAR图像海洋背景散射分布， Pearson分布系统由4种参数分布组成，包括Pearson I分布、Ⅲ分布、Ⅳ分布和Ⅵ分布。

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。

By analysing and calculating the variations in distribution of axis direction contact force and contact pressure on screw thread, the influence of errors of pitch and taper of casing screw threads to the properties of resisting pull and sealing liquid and gas are studied. Based on the result obtained through analysis, a reasonable tolerance distribution for pitch and taper is proposed.

最后，本文通过分析计算内外螺纹不同的螺距、锥度参数配合时，轴向载荷及接触压力在螺纹上分布的变化，研究了套管螺纹的螺距、锥度参数误差对套管螺纹接头的拉伸和密封性能的影响，并依据分析结果提出了二参数公差带的合理分布。

The numerical calculation shows that the space distibution of the electromagnetic field in each sub-micro-layer changes with the varing transmission depth in the relief grating, the space distribution in each sub-micro-layer is uniformer than that in isotropic grating and the optical parameters of the anisotropic relief grating and the incident beam have a large impact on the space distribution of the electromagnetic field in relief grating and so on.

数值计算表明，光波场光强的空间分布随透射深度的变化而变化，各向异性介质光栅体内光波场的空间分布相对各向同性介质要均匀，光栅材料的性质参数和光束的入射参数对光波场光强的空间分布有较大的影响等。

For exponential distribution, the acquired estimate expression is the same as the result obtained by other method in reference [8]; for Weibull distribution, the author prove that γ satisfies a non-linear equation and λ is afunction of y; for lognormal distribution, a iterative algorithm for parameter estimation is proposed, which is the expansion of some results in Wolynetzs Ph.D. thesis.

对指数分布，得到的估计表达式与文献[8]中使用其他方法得到的结果相同；对Weibull分布，论文证明了参数γ满足一个非线性方程，而λ则可以直接由含有γ的表达式求出；对对数正态分布，论文给出参数估计的迭代算法，这可以看成是Wolynetz博士论文结果的推广。

A frame image of a video frequency sequence is read into a postpositional memory zone, and staring position and size information of a tracked object is obtained in the frame, then distribution statistical information of a target signature is extracted to build a gauss mixed model as an object template, a mean vector and a covariance matrix in gauss mixed distribution are used to describe the position and the size of the object, then the next frame image of the video frequency sequence is read into the postpositional memory zone. In a new frame video frequency image, a parameter estimation method is used to obtain object gauss mized model parameters in the current frame in iterative computation and find candidate template similar to the object template, and the final model parameters obtained in iteration are used to update the tracking window for realizing self-adaption of the tracked window.

将视频序列的一帧图像读入缓存区，获得该帧中被跟踪目标的初始位置和尺寸信息，然后提取目标特征的分布统计信息建立高斯混合模型作为目标模板，用高斯混合分布的均值向量和协方差矩阵描述目标的位置和尺寸，再将视频序列下一帧图像读入缓存区，在新一帧视频图像中利用参数估计方法迭代计算当前帧中目标高斯混合模型参数找到与目标模板最相似的候选模板，利用迭代得到的最终模型参数更新跟踪窗口实现跟踪窗宽的自适应。

The random errors of main factors in flood regulation process are identified; and combining flood forecast, the randomnesses of main parameters such as initial reservoir level, inflow flood, outflow flood, etc., are analyzed. By using the first order second moment method and theoretic distribution, the random distributions of parameters are described then the routing process of a certain preflood limit water level is random, which can well reflect the random preflood influences in actual regulation.

对防洪调度过程各主要相关参数进行了随机误差识别，结合洪水预报对起始水位、人库洪水、泄流等主要参数的随机性进行分析，应用一次二阶矩法和相应的理论分布函数描述事件的随机分布，对应某一汛限水位的调洪过程不再是一确定过程，而是具有随机分布特性，反映了实际防洪调度中各随机因素的影响作用。

A multi-distance measurements method is employed in this paper. A single parameter fitting method and a double parameters (reduced scattering coefficient and amplitude factor) fitting method on the basis of the least square Newton fitting algorithm is used to derive the optical parameters respectively. For the finite-thickness homogenous tissue, it can be concluded that the rest terms in expressions of diffusion reflectance and transmittance for the corresponding tissue geometries that subtract the exponential term contained source-detector distance depend on the detected position weakly.

在多程测量的基础上，使用单参数最小二乘牛顿法拟合方法和双参数（约化散射系数、幅度因子）最小二乘牛顿法拟合方法，得到有限厚均匀组织的反射率分布和透射率分布公式中除去包含测量位置的指数项的其它部分对测量位置皆具有弱依赖性的结论，并对拟合结果进行了分析讨论；而对于有限厚平板状双层组织，可根据对反射测量结果及透射测量结果进行拟合所得的约化散射系数间的差异及常数因子的正负判断双层组织的可能结构分布。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。