2) subtree mutation
子树变异
1.
Experimental result shows that the convergent efficiency of Genetic Programming could be improved if subtree mutation is conducted and the models with the best fitness are brought into the evolution.
试验结果表明 ,在遗传操作中执行子树变异操作 ,将性能好的模型结构引入到进化中 ,可以提高遗传程序设计的收敛速
3) Tea plant mutation
茶树变异
4) transformed query tree
变异查询树
1.
Secondly,the transformed query trees derived by .
首先,通过模式重写策略,将原始查询树改写为多种XML DTD(文档类型定义)下的重写查询树,从而解决了XML数据的多样性带来的查询语义缺失问题,接着,利用基本变异操作得到的变异查询树对XML数据树完成精确嵌入,可将XML近似查询的问题转变为多棵变异查询树的精确查询问题,并给出了基于XML数据统计的相似度计算模型和Top-K问题求解的优化算法。
5) These trees were quite variable.
这些树变异很大。
6) orientation-singularity
姿态奇异
1.
The orientation-singularity expression of the Stewart platform is deduced by using unit quaternion which can avoid singularity when using Euler angles to represent the orientation of rigid body, and then the algorithm of orientation-workspace of the manipulator at a certain position is proposed.
基于单位四元数描述的刚体姿态,避免了欧拉角等描述刚体姿态的奇异性问题,推导出Stewart机构处于给定位置时的姿态奇异解析表达式,并提出了该机构处于给定位置时的姿态工作空间算法,通过计算机仿真给出该机构处于一给定位置时姿态奇异轨迹和姿态工作空间的三维可视化描述。
2.
Based on the unit quaternion representation of orientations of the 6/6-SPS Stewart manipulator,an analytical expression that represents the orientation-singularity locus of the manipulator at a fixed position is derived and examples are given to illustrate the result.
基于单位四元数表示并联机构动平台的姿态,推导出当6/6-SPS型Stewart并联机构动平台处于固定位置时机构姿态奇异轨迹的解析表达式,并通过计算机仿真给出姿态奇异轨迹的三维可视化描述。
3.
Unit quaternion is used to represent the orientation of rigid body,orientation-singularity expression of the Stewart platform at a given position is deduced,and the singularities caused by Euler angles are avoided.
以单位四元数描述刚体的姿态,避免了欧拉角描述刚体姿态的奇异性问题,推导出Stewart机构处于给定位置时的姿态奇异表达式。
补充资料：美姿姿
1.同"美孜孜"。
说明：补充资料仅用于学习参考，请勿用于其它任何用途。
参考词条