查询词典 iterative method for eigenvalue problems

But it demands the higher computational accuracy. Time-dependent LU-SGS method and close coupled full implicit finite volume scheme are used. The AUSMPW+ based on the three-order MUSCL difference scheme is used for the inviscid operator, and the maximum eigenvalue splitting method is used to convert matrix operation to algebraic operation in order to shorten the computing time.

运用时间相关的LU-SGS方法，采用强耦合的全隐式有限体积进行离散，其中无粘对流项采用三阶MUSCL型差分的AUSMPW+格式，并应用最大特征值分裂，将矩阵运算转化为代数运算，大大缩短了计算时间。

Mode matching method and expanded boundary condition method used in eigenvalue problem are also investigated.

其次讨论模式匹配法和扩展边界条件法，与边界积分方程法比较，它们用于分析多个目标有其优越性。

Methods The matrix transformation method and matrix eigenvalue analysis method.

方法矩阵变换与矩阵特征值分析方法。

This method combines the advantages of the QR eigenvalue algorithm and the Prony method. And

了QR特征值分析算法和Prony分析方法的优势，可以很容易在现有程序中实现。

To explain the computable of correlated noise attenuation by wavelet analysis; to give adaptive wavelet shrinkage algorithm on basis of threshold. We discuss three thresholds'choice; namely eigenvalue, unbiased risk estimator and hitograph method. We give comesponding experiments'analysis and comparison. It shows that our method is reliable.

阐述了小波分析去相关噪声的可行性；给出了基于阀值的自适应小波收缩法，讨论了三种阀值的选取；论述了特征值法，无偏的风险估计与直方图法，给出了相应的实验分析与比较，说明了该方法是可行的。

The distribution of gear's contact stress, root stress, and contact engagement line in the engagement situation of gear pairs, were obtained on the base of explicit integration method. 3. Adopting the method of system matrix, the torsional vibration differential equation of general shafting was gained. The simple harmonic forms of excitation torque under the normal combustion or piston flameout of in-line engine and v-type engine were analysed. The decoupled algorithm of free vibration and forced vibration and the solution to the vibration damper's energy of resistance and the off-resonance calculation were studied. The sensitivity formulations of the natural frequency and vibration mode to physical parameters of system were derived by solving the eigenvalue problem. These sensitivity formulations provided the theoretical base for the dynamic modification of structure.

运用系统矩阵法建立了轴系的扭振微分方程，并对直列和V型发动机在正常发火和气缸熄火工况下的激振力矩进行了详细的简谐分析；基于精确方法推导了自由振动和强迫振动的解耦算法，给出了能量法计算中的减振器阻尼功求解和非共振计算方法；并研究了曲轴系扭振非线性分析中的变惯量问题，得到了单缸转动惯量的精确求解公式以及变惯量和固有频率的关系式；最后，从特征方程和振型正交性出发，推导了固有频率和振型对轴系转动惯量和刚度等物理参数的灵敏度，为扭振系统的结构动力学修改提供了理论基础。

Schur-Rayleigh-Ritz accelerated subspace iteration method: Schur-Rayleigh-Ritz accelerated subspace iteration method was applied to the gyroscopic eigenvalue problem.

2Schur-Rayleigh-Ritz加速的子空间迭代法将Schur-Rayleigh-Ritz加速的子空间迭代法应用于陀螺特征值问题。

Time-Frequency analysis method is applied to the analysis of PEC signals with the aim of discriminating the occurrence of corrosion from the simultaneous variations of lift-off, smoothed pseudo Wigner-Ville distribution is used to get the signal spectrum map. The method of extracting the lowest energy area as the classification eigenvalue is proposed, and a good classification result is acquired.

采用时频分析的方法对同时出现腐蚀缺陷和提离变化的情况进行了识别，利用平滑的伪Wigner-Ville分布得到了信号的谱图，提出了提取谱图中最低能量区域面积作为特征量进行识别的方法，取得了较好的识别效果。

In the process of smart structure's uncoupled properties recognition, the new recognition method which is combined by initial-value search method and nonlinear Alternating iterative Method has been established.

在智能结构的非耦合物性识别中，建立了由初值搜索法与非线性交错迭代法；相组合的新的物性识别统一性解法。

At the same time, combining with the actual condition of delivery pipeline of our country and some prevalent leak detection and location methods, this paper raised a method, which is based on wavelet analysis and negative- pressure-wave to detect and locate the leakage. Jobs in the paper are as follows:As affected by gas density, pressure, specific heat and pipe material, the velocity of negative-pressure-wave improved depending on the energy conservation. At one time, taking the affection of velocity of gas flow, the location formula was modified in some degree.When locating the leaks with location formula, the iterative approach algorithm was adopted as a new method to increase the location accuracy level of system.Multi-scale decomposition and reconstruction of wavelet transform is utilized to filter the noise of negative-pressure-wave, which was brought by leakage. With the capacity to detect the signal singularity fast and accurately, wavelet transform was used to catch the break point of pressure signal. The work improved the accuracy of At in location formula, accordingly improved the location accuracy.Wavelet is a suitable tool for signal analysis. The distinct character is that the mother-wavelet is of optional. That means choosing different mother-wavelet will get different analysis result. So we studied how to choose mother-wavelet and its scale for signal singularity detection. The method is to choose a wavelet by regularities of the wavelet and the signal.Finally, a plan, which bases on SCADA system for inspection and detection of natural gas leakage, is proposed in the article.

其中，主要进行了以下几方面的工作：针对泄漏产生的负压波在管道中的传播速度受媒介的密度、压力、比热及材质等因素的影响，而非声波在空气中传播的速度，本文利用能量守恒原理，对其进行了修正；考虑到管内气体流速对压力波速的影响，对原始的负压波定位公式进行了一定程度的改进，并在利用定位公式进行泄漏点定位时采用逐步迭代逼近算法，提高了系统的定位精度；利用小波变换的多分辨率分解和重构技术，对采集到的管道发生泄漏时产生的负压波信号进行了降噪处理；并利用小波变换技术对信号奇异点的快速、准确的识别能力，对经上述消噪后的负压波信号进行了奇异点捕捉，精确捕捉的结果提高了定位公式中上下游站点采集到的负压波奇异点的时间差△t的精度，从而进一步提高了定位的精度；考虑到小波变换是一种基波可变的信号分析工具，也就是说，不同的小波基波对信号分析的结果将有很大差别，这势必影响最终的处理结果，因此，我们又对比分析了本课题中小波基及尺度的选择问题，依据规则性系数相似性原理对母小波的选择进行了探索性研究；最后，还提出了基于SCADA的泄漏检测与定位系统的软件开发构想及系统的嵌入方案。

Nowadays, most of research are to build a transmutative Petri Nets through adding controlling place sets, controlling arc sets and controlling policy to the basic Petri Nets, while the Controlled Petri Nets could be used to argue many controlling theory problems conveniently and to induce many logically and physically supervisory and solve the Event Feedback Controlling Problems and State Feedback Controlling Problem in DEDS supervisory theory.

目前大多数的研究表现为在变形后的受控Petri网基础上，利用各种方法求得各种逻辑型、结构型控制器，解决DEDS监控理论中的事件反馈控制问题与状态反馈控制问题。

On one hand, there are discussions with the works council and union about extension of short time working up to the end of September.

一方面，有讨论，工程理事会和联盟关于延长工作时间短至9月底。