查询词典 finite

In this paper we investigate the dynamical properties of continuous mapson a class of hereditarily decomposable chainable continua and the structure ofthe inverse limit space using a piecewise monotone continuous map with zerotopological entropy on a finite graph as a single bonding map.

本文研究了一类遗传可分可链连续统上连续自映射的动力性质并且对有限图上逐段单调且具有零拓扑熵的连续自映射的逆极限空间的拓扑结构进行了较为细致的刻画。

Hence we can map ELOTOS to RPPM according to the trace equivalence. We describe the qualitative properties with deterministic timed automaton . The key of our qualitative model checking algorithm is how to map continuous time to finite intervals by constructing equivalence classes.

该算法构造等价类的思想是：通过触发事件剩余延迟时间与DTA中时钟时间值或其它事件的剩余延迟时间值的相互关系将连续时间映射到有穷个加了标志变量的时间区间，标志变量表示这种相互约束关系。

Conley index; prime isolated invariant set; bifurcation point; discontinuity dynamical systems; finite piecewise continuous map; coding; rigorous computer assisted proof; chaos; Ikeda map

基础科学，数学，动力系统理论Conley指标；素孤立不变集；分支点；间断动力系统；有限分片连续映射；编码；计算机严格辅助证明；混沌； Ikeda映射

Firstly, this paper investigated roundly the basic theory of the ambient vibration method, analyzed systematically the main methods of ambient vibration identification, and discussed their advantages and disadvantages. Then we established the finite element model of structural dynamics and test model and analyzed their mutual relation, improved MUSIC method and correlation function method in the harmonic identification, and gave the subspace method and correlation function method based on continuous model, which is multi-harmonic retrieve technique. And then, this paper also puts forward least-squares method to estimate directly structural physical and modal parameters; this approach replaced the derivative operator in the continuous time model with an equivalent approximation, and estimated the physical parameters of structures by the least-squares method. And then, we discussed the approximation methods of derivative and their convergence. Finally, this paper researched the modal parameters of a frame structure by the simulation and test. The results demonstrated that subspace method, correlation function method and the least-squares method are effective and stable respectively.

全面地研究环境振动识别方法的基本理论，系统地分析环境振动识别方法的主要方法，讨论它们的优点和不足；建立结(来源：6666AB44C论文网www.abclunwen.com)构动力学的有限元模型和试验模型，分析有限元模型与试验模型之间的相互关系；改进谐波识别中的MUSIC识别方法和相关函数识别方法，给出大型结构模态识别的连续型的子空间分解识别方法和相关函数识别方法，这个方法是多元谐波识别方法；提出直接识别结构的物理参数和模态参数的最小二乘方法，这个方法利用导数的近似值代替导数值，并运用最小二乘方法识别结构的物理参数，讨论导数近似值的选择方法，分析算法的收敛性；通过仿真计算和模型实验，研究高层框架结构的模态参数识别，验证子空间分解识别方法、相关函数识别方法和最小二乘识别方法的有效性，算法的稳定性；从理论和试验两个方面分析和研究噪声对识别精度的影响，影响识别精度的因素，以及部分模态成分的模态参数不能够被识别的原因。

Take the method of "subarea" and "conjunction" to segment the whole request model to three parts. Making use of boundary continuousness between medium and lining structure at stress and displacement, construct a wave function that can satisfy the stress boundary condition at horizontal surface by the scattering of SH-waves in circular part. And then, availing of the wave function, conjoin the circular part into the semi-circular hollow space at common boundary. The problem can be reduced to solve the question that can only meet the condition of "conjunction". Finally, the solution of the problem can be summarized to a series of algebraic equations and solved numerically by truncating the finite terms of the infinite algebraic equations.

采用"分区"与"契合"的方法，将整个求解区域分割成三部分，利用介质与衬砌结构在边界上的应力、位移的连续性，构造一个可以自动满足水平界面上应力边界条件的圆域对SH波散射的波函数；再利用这一波函数将圆域与半圆形凹陷半空间的"公共边界"进行"契合"，将问题简化成对一个只需满足'契合'边界条件的散射问题的求解；最终归结为对一组无穷代数方程组的求解问题，利用截断有限项的方法对其进行计算。

The finite-element method can be regarded as an extension of the displacement method to two-and-three-dimensional continuum problem.

有限单元法可以看作是位移法对二维和三维连续体问题的推广。

The discrete element method and the finite element method have their own advantages and weaknesses. Basically, the DEM was developed for predicting the failure problems accompanying with the transition from continuum to non-continuum media. However, it is not accurate to calculate the problem of continuum media. The FEM may forecast the failure area of the material reasonably, while it is hard to calculate the failure process in brittle media. Therefore it becomes a good choice to combine the two methods to construct a hybrid model.

离散元法和有限元法等数值计算方法各有其优势，同时也都存在不足之处：离散元法适于处理由连续介质向非连续介质转化的破坏问题，但对于连续体计算结果精度不高；有限元法适于预测材料破坏的区域，但难以直接用于计算脆性材料破坏过程，因此将两种方法结合可以形成一种较好的混合模型。

When the stress and displacement fields in a specimen are calculated by finite element method, the stress intensity factors K and K of mixed-mode crack can be obtained immediately by a contour integral.

此方法与积分路径的选择无关，用有限元法计算出远离裂纹尖端的位移场和应力场，就可通过计算绕裂端的围线积分，精确地给出混合型裂纹的应力强度因子KⅠ和KⅡ的数值解。

With the development and application of the finite element analysis software, higher demand is suggested for quality and efficiency of post-processing. Contour map drawing is especially important for engineering design analysis and improvement.

随着有限元分析软件的开发和应用，对计算成果后处理的质量和效率提出了更高的要求，特别是等值线图的绘制对于工程设计的分析与改进尤为重要。

Contrapositive cam engine ; piston ; temperature field ; finite element methodFEM

对置式凸轮发动机；活塞；温度场；有限元方法

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。