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基于随机抽样一致性算法的运动标定方法 被引量:2
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作者 杨硕 李素华 高峰 《现代制造工程》 CSCD 北大核心 2017年第10期115-120,共6页
在邦定设备运动标定过程中收集到的对位平台旋转中心的样本数据包含有各种干扰,以至于利用其进行推导时过程复杂、结果精度低且鲁棒性不高。为了解决以上问题,提出一种基于随机抽样一致性算法的简单方法,该方法的构建基于样本数据分布... 在邦定设备运动标定过程中收集到的对位平台旋转中心的样本数据包含有各种干扰,以至于利用其进行推导时过程复杂、结果精度低且鲁棒性不高。为了解决以上问题,提出一种基于随机抽样一致性算法的简单方法,该方法的构建基于样本数据分布密度模型,该模型进行一定次数的迭代筛选后,其最优解集合可进行精确推导。试验表明,在使用随机选取的10组样本数据的计算中,本方法平均计算时间为697.6s,标定精度在7.2pixel以内,并且有7组数据的结果均满足10pixel的像素精度要求。整个标定结果达到国外同类型设备的先进水平,能够完全满足设备运行的要求。 展开更多
关键词 邦定设备 运动标定 随机一致抽样 样本数据分布密度的模型
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基于SLIQ决策树算法的研究 被引量:3
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作者 张华成 《现代计算机》 2009年第10期54-56,83,共4页
提出一种改进的SLIQ决策树分类算法,克服原有SLIQ算法需要大量计算决策树每个节点的吉尼指数(GINIIndex)的缺点。一是给出数据分布密度的基本概念,并在GINI指标的基础上利用数据分布密度差改进SLIQ;二是将SLIQ算法应用到综合评价中去。... 提出一种改进的SLIQ决策树分类算法,克服原有SLIQ算法需要大量计算决策树每个节点的吉尼指数(GINIIndex)的缺点。一是给出数据分布密度的基本概念,并在GINI指标的基础上利用数据分布密度差改进SLIQ;二是将SLIQ算法应用到综合评价中去。实例结果表明,算法改进后,寻找最佳分裂方案的GINI指标的个数大大减少,缩减计算量,降低排序成本和寻找最佳分裂点的代价,简化决策树的规模。 展开更多
关键词 SHQ 数据分布密度 评价
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Calculation of One-Valued Control Limits by Control Chart of Angles 被引量:2
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作者 李元生 方英 朱险峰 《Journal of China University of Mining and Technology》 2001年第2期229-230,共2页
The data we use to express angle or direction are entitled directional data. In a plan right angled coordinate system the traditional control chart can’t solve the quality control problem which the characteristic val... The data we use to express angle or direction are entitled directional data. In a plan right angled coordinate system the traditional control chart can’t solve the quality control problem which the characteristic value is angle. This paper analyses and calculates the one valued control limits by control chart of angles. 展开更多
关键词 control chart ANGLE directional data
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Improved model and 3D simulation of densification process for iron powder 被引量:5
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作者 宋毅 李元元 +2 位作者 周照耀 郑振兴 陈普庆 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第8期1470-1475,共6页
A new model for describing the compaction process of iron powder was proposed based on the continuum hypothesis and elliptical yield criterion.To simulate the densification behaviour,the constitutive model was impleme... A new model for describing the compaction process of iron powder was proposed based on the continuum hypothesis and elliptical yield criterion.To simulate the densification behaviour,the constitutive model was implemented in Marc computer program.For the relationship between load and displacement,different models were compared and the influence of the parameters in the constitutive equations was determined by means of simulation and experiments.The density distribution of a balancer was measured and simulated.The results show that the parameterηadopted plays a modification role for the load-displacement curve,and compared with other models the present model fits better with the experimental data in the later stage of the compaction process mainly due to the different parameters A and B.The friction on the contact surface contributes to the inhomogeneous density distribution under large deformation of the workpiece.The comparison between the simulation and experimental data indicates that this model can be used to predict the powder compact process precisely and effectively. 展开更多
关键词 powder compaction SIMULATION IRON density distribution constitutive model
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