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随机森林的变量捕获方法在高维数据变量筛选中的应用 被引量:17
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作者 宋欠欠 李轶群 +1 位作者 侯艳 李康 《中国卫生统计》 CSCD 北大核心 2015年第1期49-53,共5页
目的探讨随机森林(RF)的变量捕获方法在高维数据变量筛选中的应用。方法通过模拟实验和实际数据分析,对两种变量捕获(vh.md,vh.vimp)和逐步剔除方法(var SelRF)进行比较,并通过选入变量的数目、模型预测错误率(PE)和受试者工作特征曲线... 目的探讨随机森林(RF)的变量捕获方法在高维数据变量筛选中的应用。方法通过模拟实验和实际数据分析,对两种变量捕获(vh.md,vh.vimp)和逐步剔除方法(var SelRF)进行比较,并通过选入变量的数目、模型预测错误率(PE)和受试者工作特征曲线下面积(AUC)对其进行评价。结果模拟实验表明,在变量具有联合作用、交互作用和弱独立作用情况下,变量捕获方法均明显优于var SelRF方法和全变量VIMP排序方法;实际数据分析结果表明,变量捕获方法筛选变量结果稳定,并能够保证良好的预测效果。结论变量捕获方法适用于高维数据的变量筛选,具有实用价值。 展开更多
关键词 随机森林 变量筛选 变量捕获
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Scheme for Implementation of Ancillary-Free 1→3 Optimal Phase-Covariant Quantum Cloning with Trapped Ions
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作者 YANG Rong-Can LI Hong-Cai LIN Xiu HUANG Zhi-Ping XIE Hong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第6期1499-1501,共3页
We propose a simple scheme for the implementation of the ancillary-free 1→3 optimal phase-covariant quantum cloning for x-y equatorial qubits in ion-trap system. In the scheme, the vibrational mode is only virtually ... We propose a simple scheme for the implementation of the ancillary-free 1→3 optimal phase-covariant quantum cloning for x-y equatorial qubits in ion-trap system. In the scheme, the vibrational mode is only virtually excited, which is very important in view of decoherence. The present proposal can be realized based on current available technologies. 展开更多
关键词 ancillary-free phase-covariant quantum cloning trapped ions
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Influences of Uncaptured Electron on Energy Conversion of Photon Compton Scattering in High Power Laser-plasma
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作者 ZHENGJing-hua HAOXiao-fei HAODong-shan 《Semiconductor Photonics and Technology》 CAS 2004年第4期285-288,共4页
Using the single particle theory and the non-flexibility collision model of electron and photon, the influence of the uncaptured electrons on the energy conversion efficiency of multi-photon nonlinear Compton scatteri... Using the single particle theory and the non-flexibility collision model of electron and photon, the influence of the uncaptured electrons on the energy conversion efficiency of multi-photon nonlinear Compton scattering in the extra stationary laser-plasma is investigated. It shows that in extra stationary laser-plasma,the uncaptured electrons make the Δω of the scattering frequency of the multi-photon Compton fall down with the increases of the incident radiation electron speed,the materials of the incident collision of electron and photon, and the number of the photons which work with the electrons at the same time. Under the modulation of the uncaptured electrons to the laser field, the energy conversion efficiency between electrons and photons will fall down with the increase of the electron incident radiation speed, using the low-power electrons for incident source, the loss can be efficiently reduced. 展开更多
关键词 Photon Compton scattering Energy conversion Captured electron LASER-PLASMA
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