二次形式

Utilizequadratic form and Perron value of bottleneck matrices, we study how the algebraic connectivityof a weighted tree changes under shifting its branches and changing its edge s weights and obtainmore entire information about algebrai.

利用代数连通度的二次型形式和瓶颈矩阵的Perron值，我们研究了当迁移或改变分支和变动一些边的权重时树的代数连通度的变化，得到了比过去更多的关于赋权树的代数连通度的结论。

During the Voronoi tessellation on a planar point set composed of massive points, a technical scheme of dynamic data-exchange between hard disk data file and internal memory structural array designed so, that the limitation of computer internal memory storage need not be considered and the construction of massive Voronoi cells as many as hundreds thousant in number was effectively implemented.

在对"海量"点组成的平面点集进行Voronoi划分时，设计"硬盘数据文件－内存结构体数组"之间动态的数据交互方案，避开计算机内存的限制，有效实现了数十万Voronoi晶胞集合体的构造，存储Voronoi图几何信息的数据最后以文本文件的形式输出，方便Voronoi图在工程实际中的应用与二次开发。

But this may result to the control quality decline. In this paper, on the basis of fast algorithm, we used the quadratic programming form to constraint the control variable in the whole time domain.

本文在快速算法的基础上，采用二次规划的形式，对整个预测时域的控制量加以约束限制，满足约束条件，控制效果良好，且节约了计算量。

A fitting method that simultaneously fits specific quadric forms to both surface and contour data at object limbs or creases is presented.

本文所提供的方法，乃是经由将线条及表面的资料，同时调适，使得以匹配二次曲面形式的一种技巧。

Quadric surfaces are the simplest curved surfaces and are widely used in CAD/CAM or solid modeling.

二次曲面作为表示形式最简单的一种曲面，在CAD／CAM以及立体造型中有非常广泛的应用。

By using testing functions to make comparative research on the precision of approximate models which were built by RBF under the condition of different sample amounts and different kernel function types, a conclusion was drawn: the model quality built by Reciprocal Multiquadric RBF as kernel function was highest when the sample amout was big, and the model quality built by Gaussian RBF as kernel function was highest when the sample amount was small.

运用测试函数对在不同样本数量与不同核函数形式下所建立的近似模型的精度进行对比研究，得出逆多二次函数与高斯函数作为核函数分别在大样本和小样本情况下精度最高的结论，并验证了径向基函数近似模型方法能够兼顾效率与精度。

Secondly, the problem of observer design for Lipschitz switched nonlinear systems is considered. By proposing a proper switching strategy and utilizing Schur complement formula and the related notion of LMI, we design a quadratically stable observer which can be used for both finite and infinite switched nonlinear systems. The main result is given in the form of linear matrix inequality. Simulations validate the correctness of the presented algorithms. The simplicity of the design algorithm makes it easy to be carried out.

通过设计适当的切换策略，利用Schur补公式和线性矩阵不等式的相关知识，给出了一种全局二次稳定的观测器的设计方案，这种方案适用于有限和无限切换系统，主要结果以线性矩阵不等式的形式给出，通过仿真实例验证了所提方案的正确有效性，该部分设计思路简单、易实现。

In the specific quantum numbers configuration of holon-isospin excitation where the excited momentum approach to the ground state, the dispersion relations can be expected as a quadratic dispersion, so we can define the effective mass of the spin wave excitation.

在激发能动量接近基态的特殊的isospin 量子数选取下，可以把色散关系看成为二次函数的形式，由此得到了有效质量与能隙、激发态动量的关系。

The terminal sliding mode controller is designed by using unit vector style; the switching function of the terminal sliding mode is designed by the quadratic optimal control theory.

采用单位向量控制形式的最终滑动模态控制器，并采用二次型最优控制理论设计最终滑动模态的切换函数。

First, based on quadratic model and Perrys conjugacy condition, two new formulas of the main parameter β_k of conjugate gradient method are proposed.

第一，本文基于二次模型及Perry提出的共轭性条件，导出共轭梯度法的主要参数β_k的两种新形式。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。