查询词典 positive definite

Based on the rules and the facts that covariance matrix is positive definite symmetric matrix, new split-and-merge methods are proposed and the improvements for the SMEM algorithm are designed.

最后在Ueda等人的利用分离合并过程来改善EM算法的思想启发下，具体从用于高斯混合体模型的EM算法出发，得到了一类新的分离合并EM算法，同Ueda等的比较，后者的分离合并方法是一种启发性的过程，前者则是在一定理论指导下的推出的。

Positive definite matrix ; \ inverse matrix ; \ Schur complement of matrix

正定矩阵；逆矩阵；矩阵的Schur补

Based on quadratic PEk method, quadratic EPEk method is advanced and itsconvergences are discussed by the conditions of the symmetric positive definite and thepositive-definable Matrix.

基于二次PE_k方法的基础之上，文章提出了二次PE_k方法的外推迭代一二次EPE_k方法，并讨论了其在对称正定和可正定化条件下的收敛性。

Based on the relationship between matrix and symmetric matrix global exponential stability of the discrete-time neural networks model and the result of exponential convergence rate were obtained by using the characteristics of eigenvalues of a positive definite matrix and introducing a proper factor.

针对带有边界约束的凸二次规划问题，利用离散神经网络模型的建模原理，构造了一个神经网络模型。利用矩阵与对称矩阵的关系和正定矩阵特征值的性质，通过引入一个适当的因子，得到了该离散型神经网络模型是全局指数稳定性和指数收敛率的结果。同时分析了该结果的优越性和存在的不足，提出了解决的3种方法，最后给出了实例说明本方法取得结果的实用性

If A is a symmetric positive definite matrix, then the quadratic form x~ TAx can be written as a sum of squares. Equivalently, A is a sum of rank one matrices VV~T.

若A是对称正定矩阵，则二次型x~ TAx 能写成平方项的和，即A是秩为1的矩阵VV~T的和。

It is found that energy density of static sphere symmetry of gravitational field is negative in the sphere coordinates and their energy density is positive definite in the Cartesian coordinates. This result shows that Einstien-Tolman expression of the energy-momentum pseudo tensor in the Cartesian coordinates have reasonable property.

在球坐标系和直角坐标系下我们用Einstien-Tolman表述计算球对称静态引力场的能量密度，发现在球坐标系下能量密度为负，而在直角坐标系下能量密度为正；这样的结果显示了Einstien-Tolman表述在直角坐标系下有其合理性。

We calculate the energy-momentum pseudo-tensor of relic gravitational wave of both the polarized states by Riazuelo-Uzan expression of the energy-momentum pseudo tensor in the Cartesian coordinates, we can see that energy density and momentum densities of relic GWs are dependent on cosmic scale factor and square of the amplitudes,. At the same time, the energy density of relic GWs is positive definite, the momentum densities components have reasonable physical behavior,and their values are independent on the directions.

我们还用Riazuelo-Uzan表述在直角坐标系下对双极化态的遗迹引力波的能量动量赝张量进行计算，发现双极化态的遗迹引力波的能量张量密度与他们的振幅的平方和宇宙学尺度因子有关，他们的能量密度是正定的，大小跟传播方向无关，即遗迹引力波在宇宙学尺度上是各项均匀同性的。

In chapter 3, we presented a dual method for solving positive definite quadratic programming with box constraints.

在第三章，我们提出了一种解决具有边界约束的正定二次规划问题的对偶方法。

In chapter 2, we presented a method for solving positive definite quadratic programming with coupled-block structure.

在第二章，我们提出了一种解决具有原方块角形结构正定二次规划问题的分解协调算法。

When the diffusion matrix is symmetric and locally uniform positive definite, we prove that the solution tends to the thermal equilibrium state exponentially in L〓 norm and relative entropy.

当扩散矩阵对称且局部一致正定时，利用熵方法证明了其解在L〓或相对熵意义下指数衰减到热平衡状态，并且能明确的计算出收敛速率。

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。