查询词典 necessary condition

Moreover, based on the symmetric Rouche's theorem, a necessary and sufficient condition for the Hurwitz stability of the convex combinations of polynomials is proposed. This condition is simple and can be easily applied to the Hurwitz stability analysis of the convex combinations of polynomials.

而且基于对称Rouche定理给出了多项式凸组合Hurwitz稳定的一个充要条件，该充要条件直观简明，用于分析多项式凸组合的Hurwitz稳定性十分方便。

By combinatory counting process to enumerate data of work condition of each generators, thus makes sure the searching and solver in optimal condition.3. Set up the power equilibrium equation and flow equilibrium equation according to the slack variable. It is not necessary to adjust the optimization any more and guarantee the optimal precision of the solution.4. Digitalize the composite characteristic curve, such as the digital input and accurate extraction of data during the performing.The above mentioned is an expanding for optimal performing of hydropower station in theory. It has good engineering applicability.

在水轮机专业领域和水电站运行领域主要成果是：(1)用人工智能的方法解决了水电站机组间负荷动态最优调度问题，且用数学方法严格证明了解的最优性；(2)用组合计数对并联机组的每个组合工况进行无遗漏枚举，从而保证搜索策略的作用范围和解的最优性；(3)利用松弛变量建立了功率平衡方程和流量平衡方程，使优化结果不再需要二次调节，保证了解的优化精度；(4)综合特性曲线的数字化，包括曲线的数字化输入和在程序运行过程中对曲线信息的精确提取。

The author believes that the demand is only a necessary condition for high prices, not sufficient condition.

笔者认为，需求是唯一的一个必要条件高价格，而不是充分条件。

However, insist on only a necessary condition for success, rather than a sufficient condition for success.

然而，坚持只是成功的必要条件，而不是成功的充分条件。

A necessary and sufficient condition for the existence of guaranteed cost control is derived. Furthermore, it is shown that this condition is equivalent to the solvability of a system of linear matrix inequalities, and its solution provides a parameterized representation of guaranteed cost controllers. Based on that, the design of the optimal guaranteed cost controller is formulated as a convex optimization problem, which can be solved by the existing convex optimization techniques.

通过采用线性矩阵不等式的方法，导出了存在保性能控制律的一个充要条件，进而，证明了该条件等价於一组线性矩阵不等式的可解性问题，并用这组线性矩阵不等式的可行解给出了保性能控制律的一个参数化表示。

This paper gives the definition of the trivial solution to the high degree congruence x^ n = a, presents one sufficient and necessary condition for the congruence to have solutions, derives and proves one new judgment condition complementarily.

这篇文章给出了高阶同余方程 x^ n = a平凡解的定义，介绍了高阶同余方程有解的一个充要条件，补充推导和证明了另一个充要条件。

Since the lengths of the line segments and the angles between line segments are treated as representation parameters, it is convenient to construct energy function and to deal with displacement and length constraints. Based on this advantage, a parametrical model for human body is proposed, which can easily produce human body models with different feature sizes. The above method is just suitable for polylines. Therefore, a generic deformation method for both discrete curves and surfaces is presented. The energy function is constructed by analyzing the relationship of the points before and after deformation. Together with the displacement constraints, the deformation problem is converted to a convex quadratic programming. A necessary condition for constraint points and a sufficient condition for the uniqueness of solution are given. The proposed method can be combined with skeleton-driven animation to control the deformation.

将线段长度与线段之间的角度作为表示参数，既有利于能量函数的构造，又便于处理位移约束和长度内蕴约束条件，利用这一优势，将其应用于三维人体的参数化建模，可以方便地产生具有不同特征尺寸参数的人体模型，由于这种方法只适用于折线变形，具有较大局限性，因此，本文进一步提出一种较通用的离散曲线曲面变形方法，通过分析变形前后的位置关系来构造能量函数，再加上位移约束条件，将变形问题转化为一个凸二次规划问题，并且给出了约束点应满足的必要条件及模型解唯一的充分条件，这种方法还可以与骨架驱动变形的思想相结合，能更好的控制变形。

Li reduces the surface tension of aluminum luquid obviously, increases the ratio and rate of heterogeneous nucleation, which is the necessary condition of the formation of fine grains. However, a large amount of unmelted Al3Sc, Al3Zr TiAl3 particles dispersively distribute in the luquid metal along the edge of the molten pool, which is the sufficient condition of the formation of fine grains.

Li显著地降低了铝液表面张力，大大提高了异质形核率和形核速率，是细晶层产生的必要条件；而熔池边缘液态金属中弥散均匀分布大量未熔化的Al_3Sc、Al_3Zr和TiAl_3质点，则是细晶层产生的充分条件。

Under the conditions of q=2, G is a finite group of order mn ,where both m and n are odd prime numbers, the splitting is μ-1 , the necessary condition and sufficieat condition for the existence of such duadic codes are presented.

考虑q＝2，G为mn阶非阿贝尔群且劈分为μ－1的duadic码存在的充分条件和必要条件。

It is demonstrated that existence of inflection point on velocity profile is a sufficient condition, but not a necessary condition for flow instability, for both inviscid and viscous flows.

它表明存在速度剖面拐点充分条件，但不是必要条件流不稳定，都粘和粘性流动。

The witness also told the jury at the Royal Courts of Justice in London that he saw a paparazzo fighting with a member of the public who was trying to stop him taking pictures in the minutes before the emergency services arrived.

他还告诉在伦敦皇家法庭的陪审团，在急救服务到来之前，他当时看见一个狗仔队正和一群阻止他拍照的人打架。

The entire N／C program on a tape is made up of an accumulation of these successive data blocks.

纸带上的整个数控程序由这些连续数据单元连接而成。