近似方法

In the numerical simulation, the new formulation not only remedies the boundary deficiency problem in the original SPH but also more efficiently repairs the truncated integral in kernel approximation caused by discontinuity and eliminates the errors from particle inconsistency in discontinuous region.

比较不同SPH方程近似二次函数的结果，新方法不仅改进了传统SPH方法存在的边界缺陷问题，同时在非连续区域内也能更有效地修复由非连续引起的核近似截断积分和消除粒子不一致性所造成的误差。

In the paper we use the method of perturbation to find the analytical solutions of St.

论文提出用参数展开的方法去找圣维南方程的分析解；对向定常流区推进的单向波问题给出了解的一级近似和二级近似的普遍表示式；在论文的末尾还讨论了这个方法的适用范围。

Most of previous segmentation approachs make use of the surface curvatures or the approximative polynomial coefficients which are very sensitive to noise, but the mathematical morphological operations are robust, so another main advantage of our scheme is its good noise immunity.

以前的大多数分割方法都使用表面的曲率或近似多项式的系数，表面的曲率或近似多项式的系数的计算对噪声很敏感，而数学形态学运算具有较好的抗噪声性，因此我们的方法的另外一个优点是它具有良好的抗噪声性能。

Then we represent and realize an automated generalization method based on the multi-scale representations above, the multi-scale representations may be continues between the scales and backwardly.

提出并实现了基于上述多尺度表达的自动综合方法。基于实例讨论了获取多尺度上的数据近似表示，以及通过阈值的设置来补充相应的细节信息以获取介于两级尺度之间的补充近似表示，从而实现更好的综合效果的方法。

By time-varying filtering, we realize the signal selectivity and interference suppression, especially for the signals with time-varying power spectrum. It is shown herein that conventional eigenstructure based methods are lower dimensional special case of the time-frequency subspace fitting method. The closed-form array response estimation algorithms for blind source separation in wireless communication is also developed in the dissertation by exploiting the data structure of second-order statistics of the array output in the presence of multipath. The proposed method achieves array response estimation with little constraint on signal property and propagation environment such as scatters or angular spread. Moreover, the array utilized here can be of arbitrary geometry and even uncalibrated. Since the closed-form solution is obtained, no misconvergency may occur and large amount of computation can be saved. The equivalent feed model and corresponding optimization designation are proposed to realize the downlink multi-user selective transmission. By coherent and non-coherent superposition of the electromagnetical field, multiple beams can be formed using a single array, so that each co-channel user signal is transmitted in each beam and will not interfered with each other. The proposed system scheme implements the digital beamforming and the channel allocation in the base band, therefore is suitable for the utilization of the radio software technology. The feasibility and effectiveness of the proposed model are proved by the RF experiment.

在窄带条件下，GSC－SSF方法还可以提高阵列的虚拟孔径，从而提高估计的性能；可以证明，Cyclic DOA 和SC-SSF方法可看作该方法的特例或近似； 3、提出了二维GSC－SSF方法和宽带谱相关DOA矩阵方法，利用信号的循环平稳特性解决了宽带条件下二维 DOA 估计问题，并具有阵元数少、计算量较小的特点； 4、提出了时频子空间拟合和宽带时频DOA估计算法，将联合时频分析的理论和方法引入到阵列信号的空间谱估计研究中，利用时变滤波实现信号选择性测向和干扰抑制，特别适合于谱时变信号；可以证明传统特征结构法可看作是时频子空间拟合方法的特例； 5、提出了多用户环境下阵列响应的估计方法——CARE方法，该方法对信号结构和传播参数（主要是散射源分布与角度散布）的约束较少，适用于各种几何结构的阵列甚至未校准的阵列，能够直接得到阵列响应的闭式解，因此计算量小、稳健性好，不存在收敛问题； 6、提出了针对多用户下行选择性发送的阵列等效激励模型、优化设计方法及其系统实现方案，通过空间场的相干叠加与非相干叠加使得单一阵列能够形成多个波束，并保证各波束内的用户信号各不相同且相互干扰最小；其系统方案具有在基带实现数字波束成形、信道分配并便于软件无线电实现的特点，其有效性已得到外场实测数据的证实。

Then, according to phase space reconstruct technique from one-dimensional and multi-dimensional time series, the quantitative criterion and rule of system chaos which combine neural network, analyses, computations and sort are conducted on EEG signals of five kinds of human consciousness activities. The author finds that statistic results of the determinism computation in time series indicate that chaos characteristic may lie in human consciousness activities, and central tendency measure is consistent with phase graph, so it may become one division way of attractor; approximate entropy of different subjects exists discrepancy; correlation dimension and Lyapunov exponent of different consciousness activities indicate that attractors of human activities are all fractional; nonlinear quantitative criterion and rule, which unites neural network, can distinguish different styles of consciousness activity in principle, and the result of sortation takes on that consciousness activity type of arithmetic is distinguished more easily than that of abstract.

采用一维与多维时间序列相空间重构技术和系统混沌的定量判据准则，结合神经网络，对五种思维作业方式的脑电信号进行了分析、计算与分类，发现确定性计算的统计结果表明人类的意识活动中可能蕴含混沌特性，中心趋向测量(Central Tendency Measure，CTM)与相图吻合较好，可作为EEG吸引子的区分方法之一；功率谱分析反映出单个受试者的各种意识形态的差异很小，但是不同意识活动谱中的活跃频段还是略有差异的；个体之间的近似熵存在差异，同种状态下近似熵大的人可能具有更好的创新性；关联维数和Lyapunov指数的计算结果表明大脑的运动落在具有分维的奇怪吸引子上；非线性量化方法与神经网络相结合，可对人脑思维活动进行较好的分类，并且从分类结果来看数理计算类思维活动较抽象类思维活动有着更好的区分度。

A method to make Credal network approximation inference is proposed by computing the joint probability distribution and posterior probability of variables through the above operators.Furthermore its arithmetic is developed by SQL statement.Its validity and efficiency can be showed in the application case.

提出利用上述操作计算Credal网络中各结点联合概率分布和后验概率的方法，从而实现了Credal网络的近似推理，并给出了该近似推理的SQL语言实现算法，算例结果表明该方法是有效的。

The approach to calculating the gliding angle and flight time of each segment was given.The procedure for approaching the whole glide trajectory was described.Two examples show that the differences in the gliding range and flight time between the approximate solution and the...

文中算例结果表明，该近似求解方法计算得到的滑翔航程和滑翔时间与实际值相差很小，航程误差率约为0.7%，时间误差率约为0.6%，因此该方法在近似小初始滑翔角的长航时远程纵向滑翔飞行时是有效的、可行的，尤其针对航程在地球半圈以上的滑翔飞行轨迹。

In this paper, firstly, the theory and the discretization schemes of LBIE and the concepts of MLS and GMLS are introduced; secondly, LBIE method is applied to solve the thin plate-bending problems and four typical examples are given to demonstrate the applicability and validity of the method. The results obtained from numerical examples agree well with the exact solutions and have an excellent rate of convergence.

本文首先介绍了无网格局部边界积分方程方法的理论基础和离散步骤，以及移动最小二乘近似法和广义移动最小二乘近似法等概念；其次将该方法初步应用于计算薄板的弯曲问题，建立了完整的积分公式，求解了四个典型算例，结果同精确解非常接近，且收敛快。

Moreover, we discuss the relationship between the residual norm of the quasi-refined approximate eigenpair and that of the refined eigenpair, and the quasi-refined biorthogonalization Lanczos algorithm is given. Some numerical experiments are carried on, and the results illustrate that the newalgorithm is superior to the classic one. 2.We propose the semi-refined biorthogonalization Lanczos method which is based on the refined projection idea.

将精化投影方法的思想和拟精化思想相结合，提出了拟精化双正交Lanczos方法，建立了拟精化近似特征对和精化近似特征对对应的残量范数之间的关系，给出了拟精化双正交 Lanczos算法，并进行了数值实验，具体算例表明，该算法比双正交Lanczos算法优越； 2。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。