查询词典 jacobian

Oil film forces and its Jacobian matrix at any moment of sliding bearing with finite length is determined using finite element method based on the variational inequalities principle.

根据不等式变分原理，采用有限元离散化方法，求解有限长径向滑动轴承任一时刻的油膜力及相应的Jacobi矩阵。

The unbalance forces due to the lumped eccentric mass are treated as general forces. Meanwhile, the potential energy expression about gravity based on finite element method is presented for convenience. Based on the variational inequalities principle, the finite element is used to determine the film forces produced by fluid film bearing and damper at any moment and its Jacobian matrix with respect to location and velocity of journal and bearing house.

在第二部分中，主要应用有限元方法及Hamilton原理对所研究系统进行了建模分析，着重对质量偏心问题进行了分析处理，并对此提出了两种处理方法：一、转化为对系统动能的影响；二、将其产生的离心惯性力视为非保守的广义力，并对其表达式进行了推导，同时为分析问题方便，基于有限元离散化方法，推导了重力的势能表达式。

The fluid film bearing-flexible rotor nonlinear system with squeeze film damper is modeled practically using the finite element method and the Hamilton principle.(3) The film forces produced by fluid film bearing and squeeze film damper are determined by finite element method at any moment, and the Jacobian matrix is also determined.(4) A method for analyzing the dynamics of a large system with local nonlinearities is presented. The stability and bifurcation of the equilibrium position and the unbalance responce of a fluid film bearing-flexible rotor system with squeeze film damper are investigated based on the assumption of an incompressible lubricant together with the long bearing approximation for fluid film bearing, short bearing approximation for squeeze film damper and the"π"film cavitation model.

主要研究内容包括下面几个方面：（1）对挤压油膜阻尼器-滑动轴承-转子非线性动力系统中的非线性现象进行了机理方面的研究；（2）应用有限元方法及Hamilton原理对复杂的挤压油膜阻尼器-滑动轴承-转子非线性动力系统进行了建模分析；（3）对滑动轴承及挤压油膜阻尼器中任一时刻的油膜力及相应的Ja-cobi矩阵的确定进行了分析；（4）对一类具有局部非线性的多自由度动力系统，提出了一种可以有效地分析其动力特性的方法；（5）采用实验与理论分析相结合的方法，对挤压油膜阻尼器-滑动轴承-转子非线性动力系统的动力特性进行了分析。

Finally, we study the PLDP(n, 2) and strongly nilpotent Jacobian matrices, and we prove that if the nilpotency index of JH for a power-linear map H of degree 2 is less than 4, then JH is strongly nilpotent, and consequently the rows of JH are linearly dependent.

此外，我们特别对线性多项式2次幂映射的相关性问题进行了讨论，为此，对强幂零的Jacobi矩阵进行了研究，刻画了Gorni-Zampieri对的幂零指数之间的关系，并证明了Gorni-Zampieri对保持强幂零性。

ABSTRACT In this dissertation, fault-tolerance of redundant manipulators is thoroughly investigated. First, inherent relationship between the dexterity and fault-tolerance of single-redundancy manipulator is discussed. Both the manipulability and the relative manipulability are utilized for measuring the kinematic fault-tolerance of the manipulator with one joint failure. Furthermore, the relative manipulability is used for measuring dexterity loss resulted by one joint failure, and the relationship between the fault-tolerance measurement and null space vector of Jacobian matrix is established.

本文对冗余自由度机器人的答错性问题进行了深入的分析和迭付：首先研究了单冗余度机器人运动学灵活性与容错性之间的内在关系，提出以故障构形的可操作度和相对可操作度来度量机器人的运动学容错性，用相对可操作度来度量关节故障给机器人操作灵巧性造成的损失，并建立了容错性度量指标与Jacobian矩阵零空间向量之间的关系。

In order to locate direct singular positions, we begin by expressing the determinant of the Jacobian matrix Jx in terms of position of the center P of the moving platform. The Z and the Y coordinates of P may be chosen from the workspace, then the determinant of Jx is now a six order polynomial of X, the x coordinate of P. The direct singular positions corresponding to are obtained by solving the polynomial equation, and retaining all real roots in the workspace.

由速度分析的Jacobian矩阵Jx，将其行列式值表示成活动平台中心点P位置的函数，寻找奇异位置的方法是先假设平台高度，再假设工作空间内P点的Y座标，使Jx行列式成为P点X座标的六次方程式，求解方程式并保留在工作空间内之实根。

In this paper, the virtual relation between partial velocity, the transformation matrix and Jacobian matrix are discussed with mathematical method.

多臂机器人系统的协调任务的数学描述是约束方程，因此，多臂"协调"的力学涵义就是"约束"。

In comparison with the HD measured configuration, it can't make full use of all poles. It takes much longer time to inverse only several sounding points, and in the calculation of partial derivatives Jacobian matrix.

与高密度电阻率法测量装置对比，其对电极的利用率较低，仅几个电测深点的反演就需要很长的时间。

The impact of transfer contracts on node voltages is evaluated according to base-case Jacobian matrix and the partial derivatives of ...

定义flowgate为线路热极限和线路故障2种情况，分别计算基态潮流和考虑线路紧急故障情况下的区域间ATC值，并与线性分布因子法和重复潮流法计算结果相比较。IEEE30节点系统计算结果表明，该算法快速准确，满足在线计算和分析要求。

The DC reactive power is the only parameter to be specified in calculation, and the partial differential formulas in Jacobian matrix do not change when the DC control model changes.

计算时，只需规定换流器直流侧的无功功率，而且当直流系统控制方式发生变化后不需重新推导Jacobian矩阵中的偏导公式。

Salt is good, but if the salt becomes flat and tasteless, with what do you season it?

14：33 盐本是好的，盐若失了味，可用什么叫它再咸呢？

He reiterated that the PLA is an army of the people under the leadership of the Communist Party of China.

他重申，人民解放军是在中国共产党领导下的人民军队。