查询词典 estimation

Estimations of effective parameter in heterogeneous media: Firstly, we clarify the concept of the effective parameter and address the problems of parameter estimation by traditional pumping test. Secondly, we present two estimation approaches (i.e., distance-drawdown and spatial moment analyses) for Seff and Teff, which are consistent with Theis' homogeneous aquifer assumption.

本文探讨的内容主要分两大部分：(1)空间异质性孔隙介质有效参数的推估方法：主要探讨内容包括重新思考有效参数的定义及其观念，探讨传统抽水试验推估异质性含水层有效参数的一些问题，其次提出估计异质性地下水系统有效参数两个合理方法：泄降-距离曲线分析和泄降分布的空间矩分析，并以数值实例解释其合理性，文中藉由分析数值模拟的结果探讨说明该问题。

Fist, comprehensive analysis on the current study on data processing is made, and characters of Newton methods about nonlinear surveying and mapping data processing are discussed, and then new solutions to parameters estimate with multi-sources, multi-types, multi-dimension, multi-precision bynonlinear least square are presented such as PSB algorithm, digital continuation and generalized digital continuation algorithm, cone model method, tensor analysis method, GCMA(mixed algorithm of gradient method and conjugate gradient method), combining algorithm based on Newton method and gradient method and confidence region and so on, and a new fast difference iterative algorithm is proposed towards parameters estimation containing random parameters in nonlinear models, and a new solutions to nonlinear least squares surveying and mapping adjustment by parameters estimation both considering the random and nonrandom parameters is presented after studying on nonlinear data processing in deformation monitoring, and at last primary analysis on error propagation of spatial data is made and approximate error propagation formula and error analysis formula to length and area are proposed.

首先比较全面分析了目前测量数据处理理论的研究现状，讨论了牛顿类方法在处理非线性模型参数估计方面的特点，研究并给出了求解多源、多类型、多维、多精度、非线性最小二乘测量平差参数估计的若干种新方法，这包括PSB算法、数值延拓及其广义数值延拓算法、锥模型法、张量分析法、基于最速下降法和牛顿法的组合算法、基于最速下降

Burg maximum entropy spectral estimation theory of modern spectral estimation is introduced in this paper, and the PSD is simulated by VC ++.

介绍了现代功率谱估计中的Burg算法最大熵谱估计的基本原理，并采用VC++语言对功率谱密度进行了仿真。

Correlation and signal-to-noise ratio of the space sources can affect the resolution of DOA estimation of subspace algorithms. Using this relation, the algorithm changes the correlation and SNR of the equivalent sources by processing the Toeplitz matrix based on the Toep-MUSIC algorithm, so that the resolution of DOA estimation can be improved.

改进算法利用信源间相关性和信噪比对子空间类DOA估计算法分辨力的影响，在Toep-MUSIC算法基础上，通过对Toeplitz重构矩阵的处理，改变了等效信源的相关系数和信噪比，从而使DOA估计分辨力得到提高。

Based on physical characteristics, existing stochastic estimation methods of equipment sensitivity to voltage sag use subjective probability models to express the probability distribution of voltage tolerance curve of equipment in the uncertain region. But the parameter estimation needs vast sample data. These methods may result in man-made errors.

现有负荷敏感度随机估计法以电压暂降的物理特征为基础，用主观概率模型描述负荷电压耐受曲线(voltage tolerance curve，VTC)的随机分布规律，所需样本量大，在实际中难以实现且可能引入主观误差。

Based on the distributed multi-sensor track fusion system, it applies sequence disposal means, multi-sensor track fusion problem with feedback information, on the condition of correlated estimation, is studied, under the rule of minimizing the trace of estimation error covariance matrix, the corresponding fusion algorithm is proposed, also ,the analyse of the simulation is presented.

基于分布式多传感器航迹融合系统，采用序贯处理的方法，研究了相关条件下带反馈信息的多传感器航迹融合问题，在估计误差方差阵迹最小的准则下，导出了相应的融合算法，并进行了仿真分析。

The method will eventually converge to a near optimal solution and is relatively unaffected by the outliers.Ⅲ. Trilinear geometry estimation based on messy genetic algorithm: similar to the method of epipolar geometry estimation. Experiments show that it is more robust and precise than other typical methods, but takes more time to get the final result.Ⅳ.

ii基于混合遗传算法的对极几何估计：以最小的数据子集来构造染色体，利用染色体在某一位置上的基因冗余来提高遗传算法的选择能力，尽管这样会增加运算的复杂度，但却更有可能寻找到全局最优解，并且运算精度略高于中的算法。

In this paper, total logistics amounts are chosen as evaluation index, and artificial time series are designed to solve the shortness of statistical data in Chinese logistics. Spectrum estimation theory depicts time characteristics in frequency domain thus has such benefit than time domain methods. This paper evaluates the period of Chinese logistics using spectrum estimation. Stationarity of artificial series is verified, parameter sensitivity of truncation point is analyzed, six periods with different delay window are compared, and significance of period evaluated is tested.

中国物流统计数据缺乏，客观上限制了对其周期规律的研究，本文选取社会物流总额作为测度指标，设计了一种人工序列，解决了统计数据过短问题；谱估计法从频域角度揭示客观事物的时间特性，在研究时间序列周期波动方面具有时域分析法所不具备的优势，作者采用谱估计法对中国物流发展周期进行测定，检验了指标序列平稳性，分析了截断点参数灵敏度，比较了6种不同滞后窗下周期值，并检验了所测得周期的显著性。

In Chapter 2, the Balanced LS Estimation is defined for the linear model when its error covariance is positive definite or singular. The new estimation as well as the necessary and sufficient conditions is gained for its unbiasedness, efficiency and admissibility.

第2章提出了一般线性回归模型和奇异线性回归模型平衡LS估计的概念，得到回归系数β的平衡LS估计，进而探讨了这种估计的无偏性、有效性和可容许性。

Simulation results show that the system has better control performance and estimation effect , but the influence of parameters variation on speed estimation error is evident .

仿真结果表明该系统有较好的控制性能和辨识效果，但参数变化对速度辨识误差有明显的影响。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。