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关于特定幸福立方数列 被引量:1
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作者 韩迪 《郑州大学学报(理学版)》 CAS 北大核心 2012年第3期20-21,25,共3页
针对特定幸福立方数的一些问题进行研究,并对这些问题进行推广和延伸,给出了一般特定幸福k次方数的结论.
关键词 特定幸福立方 初等方法 特定幸福k次方
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Censored Composite Conditional Quantile Screening for High-Dimensional Survival Data
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作者 LIU Wei LI Yingqiu 《应用概率统计》 CSCD 北大核心 2024年第5期783-799,共17页
In this paper,we introduce the censored composite conditional quantile coefficient(cC-CQC)to rank the relative importance of each predictor in high-dimensional censored regression.The cCCQC takes advantage of all usef... In this paper,we introduce the censored composite conditional quantile coefficient(cC-CQC)to rank the relative importance of each predictor in high-dimensional censored regression.The cCCQC takes advantage of all useful information across quantiles and can detect nonlinear effects including interactions and heterogeneity,effectively.Furthermore,the proposed screening method based on cCCQC is robust to the existence of outliers and enjoys the sure screening property.Simulation results demonstrate that the proposed method performs competitively on survival datasets of high-dimensional predictors,particularly when the variables are highly correlated. 展开更多
关键词 high-dimensional survival data censored composite conditional quantile coefficient sure screening property rank consistency property
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一种新的卫生管理方法——危险性方法
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作者 王济东 《中国医院管理》 1983年第6期56-57,共2页
1981年世界卫生组织“危险性方法”特别工作组,介绍了他们正在部分发展中国家采用的一种新的卫生管理方法——危险性方法。现将其原理及步骤简单作一介绍。在社会人群中。
关键词 危险性因素 管理方法 卫生保健 卫生服务 组织管理 卫生人员 卫生工作 特定数 培训计划 保健系统
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Attenuation of wave propagation in a novel periodic structure 被引量:2
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作者 郑玲 李以农 A.BAZ 《Journal of Central South University》 SCIE EI CAS 2011年第2期438-443,共6页
A novel periodic mount was presented. A theoretical model was developed to describe the dynamics of wave propagation in the novel periodic mount. The model was derived using Hamilton's energy conservation principl... A novel periodic mount was presented. A theoretical model was developed to describe the dynamics of wave propagation in the novel periodic mount. The model was derived using Hamilton's energy conservation principle. The characteristics of wave propagation in unit cell were analyzed by transfer matrix formulation. Numerical examples were given to illustrate the effectiveness of the periodic mount. The experiments were carried out to identify the predications of the theoretical model. The obtained results show that the experimental results coincide with the prediction of theoretical model. No pass bands appear in the overall frequency range measured when waves propagate in the longitude direction of the periodic mount. These dramatic results demonstrate its potential as an excellent mount in attenuating and isolating vibration transmission. 展开更多
关键词 periodic structure vibration isolation passive mount
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Selective harmonic elimination method for wide range of modulation indexes in multilevel inverters using ICA
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作者 Ali Ajami Mohammad Reza Jannati Oskuee +1 位作者 Ataollah Mokhberdoran Hossein Shokri 《Journal of Central South University》 SCIE EI CAS 2014年第4期1329-1338,共10页
Selective harmonic elimination(SHE) in multilevel inverters is an intricate optimization problem that involves a set of nonlinear transcendental equations which have multiple local minima. A new advanced objective fun... Selective harmonic elimination(SHE) in multilevel inverters is an intricate optimization problem that involves a set of nonlinear transcendental equations which have multiple local minima. A new advanced objective function with proper weighting is proposed and also its efficiency is compared with the objective function which is more similar to the proposed one. To enhance the ability of the SHE in eliminating high number of selected harmonics, at each level of the output voltage, one slot is created. The SHE problem is solved by imperialist competitive algorithm(ICA). The conventional SHE methods cannot eliminate the selected harmonics and satisfy the fundamental component in some ranges of modulation indexes. So, to surmount the SHE defect, a DC-DC converter is applied. Theoretical results are substantiated by simulations and experimental results for a 9-level multilevel inverter. The obtained results illustrate that the proposed method successfully minimizes a large number of identified harmonics which consequences very low total harmonic distortion of output voltage. 展开更多
关键词 selective harmonic elimination DC-DC converter imperialist competitive algorithm(ICA)
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优选法简介
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《煤炭科学技术》 CAS 1974年第2期56-59,共4页
什么叫优选法在生产斗争和科学实验中,为了获得优质、高产、低耗等效果,需要通过做试验的办法来寻找有关因素的最佳点。选择最佳点的试验方法很多,但是对于某一具体问题来说究竟用什么方法好呢?这就是优选法所要解决的问题。所谓优选法... 什么叫优选法在生产斗争和科学实验中,为了获得优质、高产、低耗等效果,需要通过做试验的办法来寻找有关因素的最佳点。选择最佳点的试验方法很多,但是对于某一具体问题来说究竟用什么方法好呢?这就是优选法所要解决的问题。所谓优选法,就是一种根据生产和科研中不同的试验项目。 展开更多
关键词 最佳点 试验范围 试验方法 陡度法 爬山法 分批试验法 特定数 平行线法 对分法 用碱量
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