检索结果-南通市图书馆

Influence of the Electrical Vehicle Charging on the Grid Harmonic

在线全文

学校读者我要写书评

暂无评论

Journal of Electronic Science and Technology 2017年第1期15卷 99-105页

作者： Cheng-Long Xia Yong-duan song Yang Luo School of Energy Science and Engineering University of Electronic Science and TechnologyChengdu 611731China

This paper described the impact of the electrical vehicle（EV） charging on the grid harmonic. In view of the randomness of the EV charging process, the harmonic admittance matrix method and superposition method were used to build the single and multiple EVs charging simulation model. By using Matlab as a simulation tool, we analyzed harmonic currents of single and multiple EVs chargers. The results show that the harmonic ratio is beyond the scope of the national harmonic standard. Finally a parallel hybrid active filter（PHAPF） was introduced for governance of *** experimental results show that net side harmonic currents are significantly reduced by using the PHAPF and meet the national standard GB/Z17625.6-2003 regulations limit.

关键词： harmonic superposition charging currents governance regulations battery impedance rectifier beyond

Noether＇s Theorem of Nonholonomic Systems in Optimal Control

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2016年第4期32卷 875-882页

作者： Ping-ping CAI duan song Jing-li FU Institute of Mathematical Physics Zhejiang Sci-Tech University Hangzhou 310018 China Eastern Liaodong University Shenyang 118000 China

In this paper, we extend Noether＇s theorem to nonholonomic constraints systems in optimal control. We present a systematic way to calculate conserved quantities along the Pontryagin extremals for optimal control problems with nonholonomic constraints, which are invariant under the parameter groups of infinitesimal transformations that change all （time, state, control） variables. Meanwhile, the Noether equalities corresponding to the conservation laws are given. Then, we obtain a new version of Noether＇s theorem to optimal control systems. An example is given to illustrate the application of these results.

关键词： nonholonommic system symmetry conservation law Noether's theorem optimal control

Face Detection under Complex Background and Illumination

在线全文

学校读者我要写书评

暂无评论

Journal of Electronic Science and Technology 2015年第1期13卷 78-82页

作者： Shao-Dong Lv Yong-duan song Mei Xu Cong-Ying Huang School of Energy Science and Engineering University of Electronic Science and Technology

For face detection under complex background and illumination, a detection method that combines the skin color segmentation and cost-sensitive Adaboost algorithm is proposed in this paper. First, by using the characteristic of human skin color clustering in the color space, the skin color area in YC b C r color space is extracted and a large number of irrelevant backgrounds are excluded; then for remedying the deficiencies of Adaboost algorithm, the cost-sensitive function is introduced into the Adaboost algorithm; finally the skin color segmentation and cost-sensitive Adaboost algorithm are combined for the face detection. Experimental results show that the proposed detection method has a higher detection rate and detection speed, which can more adapt to the actual field environment.

关键词： Adaboost cost-sensitive learning face detection skin color segmentation

构造Birkhoff动力学函数的Santilli第二方法的简化

在线全文

学校读者我要写书评

暂无评论

物理学报 2014年第14期63卷 193-197页

作者：宋端辽东学院影像物理教研室丹东118001

研究力学系统Birkhoff动力学函数的构造方法.Santilli第二方法是目前构造Birkhoff动力学函数时常用的方法之一,但研究发现其计算公式存在冗余项.通过具体的证明得到了简化的Santilli第二方法,从而为自伴随系统Birkhoff动力学函数的构造... 详细信息

研究力学系统Birkhoff动力学函数的构造方法.Santilli第二方法是目前构造Birkhoff动力学函数时常用的方法之一,但研究发现其计算公式存在冗余项.通过具体的证明得到了简化的Santilli第二方法,从而为自伴随系统Birkhoff动力学函数的构造提供了更为简洁的计算公式.举例说明结果的应用.

关键词： Birkhoff系统 Birkhoff动力学函数 Santilli第二方法

Efficient One-pot Synthesis of 12-Aryl-8, 9, 10, 12- tetrahydrobenzo [a]anthen-11-ones Under Solvent-free Conditions

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2013年第1期29卷 82-86页

作者： JIA Xu-dong HAN song-yang duan Hai-feng LIN Ying-jie CAO Jun-gang LIANG Da-peng WUMao-cheng Department of Organic Chemistry College of Chemistry Jilin University Changchun 130012 P. R. China

Multi-component condensation of 2-naphthol, aromatic aldehydes, and cyclic 1,3-dicarbonyl compounds catalyzed by ionic liquid [NSPTEA][HSO4] was accomplished for the synthesis of a series of 12-aryl-8,9,10,12- tetrahydrobenzo[a]xanthen-11-ones under solvent-free conditions. High yields, ease recovery, short reaction time and reusability of catalyst are significant advantages. ZrOC12＂8H20 was also found to act as an effective catalyst towards this transformation.

关键词： Aldehyde Ionic liquid ZrOCI28HzO Multi-component reaction Solvent-free condition

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

智能群体环绕运动控制

物理学报 2014年第14期63卷 40-48页

作者：段敏高辉宋永端重庆大学自动化学院智慧系统与新能源技术研究院重庆400044

自然界中,鸟类迁徙、鱼类群游等群体智能运动具有一定的规律.例如,鸟类迁徙以领导者和跟随者模式的直线运动为主,鱼类中以环绕运动为主.自然界的这种群体直线运动与环绕运动具有十分重要的理论研究价值和广泛的工程应用前景.本文针对群... 详细信息

自然界中,鸟类迁徙、鱼类群游等群体智能运动具有一定的规律.例如,鸟类迁徙以领导者和跟随者模式的直线运动为主,鱼类中以环绕运动为主.自然界的这种群体直线运动与环绕运动具有十分重要的理论研究价值和广泛的工程应用前景.本文针对群体环绕运动进行研究,考虑个体只能获取局部目标信息这一特性,设计均值估计器进行群体目标状态估计,建立环绕运动算法,确保实现群体圆形编队且保持队形.通过李雅普诺夫理论分析,证明每个个体在有限时间内能获取所有目标平均位置信息,且能基于群体圆形编队队形进行目标环绕和追踪,队形随目标状态变化.有关结果通过仿真得到进一步验证.

关键词：智能群体环绕运动分布式估计

在线全文

学校读者我要写书评

暂无评论

目标跟踪算法在光照突变条件下的应用

应用科学学报 2011年第6期29卷 592-597页

作者：袁雪宋永端北京交通大学智能系统与再生能源中心北京100044

为了保证光照突变条件下运动人体跟踪的正确性与持续性,提出可用于光照突变条件的目标跟踪算法.首先自动检测光照突变状态,当发生光照突变时,摄像机通过曝光补偿使光照突变前后的图像亮度保持一致.然后基于可持续跟踪Mean-Shift算法对... 详细信息

为了保证光照突变条件下运动人体跟踪的正确性与持续性,提出可用于光照突变条件的目标跟踪算法.首先自动检测光照突变状态,当发生光照突变时,摄像机通过曝光补偿使光照突变前后的图像亮度保持一致.然后基于可持续跟踪Mean-Shift算法对光照突变前后的运动人体进行跟踪.实验结果表明,该算法在光照突变条件下可以对运动人体实现准确而持续的跟踪.

关键词：光照突变人体跟踪曝光补偿 Mean-Shift算法

在线全文

学校读者我要写书评

暂无评论

肺良恶性肿块的CT误诊分析

中国介入影像与治疗学 2012年第10期9卷 732-735页

作者：宋段赤峰学院附属医院CT/MR室内蒙古赤峰024000

目的探讨肺良恶性肿块的CT征象,分析CT误诊的原因。方法收集经病理及临床、影像学随诊证实的肺癌患者87例及同期CT误诊的良性肿瘤43例,分析其影像学表现及CT误诊原因。结果 87例肺癌中,CT正确诊断46例,误诊41例;误诊和确诊的肺癌在分叶... 详细信息

目的探讨肺良恶性肿块的CT征象,分析CT误诊的原因。方法收集经病理及临床、影像学随诊证实的肺癌患者87例及同期CT误诊的良性肿瘤43例,分析其影像学表现及CT误诊原因。结果 87例肺癌中,CT正确诊断46例,误诊41例;误诊和确诊的肺癌在分叶征、毛刺征、胸膜凹陷征及淋巴结肿大、浅/深分叶征象的出现率的差异有统计学意义(P均0.05)。依据分叶征、毛刺征、血管集束征、支气管气相和胸膜凹陷征分为3个等级,将肺癌出现上述征象0～1个为不典型(等级1),2～3个为较典型(等级2),4～5个为典型(等级3),误诊和确诊肺癌在等级上差异有统计学意义(χ2=12.548,P=0.002)。结论导致CT误诊肺良恶性肿块,既有征象不典型、技术检查不足等原因,也有诊断医师对征象把握不准、经验不足等主观因素。

关键词：肺肿瘤结核,肺体层摄影术,X线计算机误诊

Duration of Human Immunodeficiency Virus Infection at Diagnosis among New Human Immunodeficiency Virus Cases in Dehong, Yunnan, China, 2008-2015

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2018年第16期131卷 1936-1943页

作者： Ai-Hua Li Zun-You Wu Zhen Jiang Jennifer M. McGoogan Yan Zhao song duan National Center for AIDS/STD Control and Prevention Chinese Center for Disease Control and Prevention Beijing 102206 China Department of Epidemiology University of California Los Angeles California USA Dehong Prefecture Center for Disease Control and Prevention Mangshi Yunnan 678400 China

Background： On diagnosis of human immunodeficiency virus （HIV） infection, a person may have been infected already for many years. This study aimed to estimate the duration of HIV infection at the time of diagnosis. Methods： Newly diagnosed HIV cases in Dehong, China, from 2008 to 2015 were studied. Duration of infection at the time of diagnosis was calculated using the first CD4 cell count result after diagnosis and a CD4 depletion model of disease progression. Multiple linear regression analysis was used to investigate the associated risk factors. Results： A total of 5867 new HIV cases were enrolled. Overall, mean duration of infection was 6.3 years （95% confidence interval [CI]： 6.2, 6.5）. After adjusting for confounding, significantly shorter durations of infection were observed among participants who were female （beta： -0.37, 95% CI： -0.64, -0.09）, Dai ethnicity （beta： -0.28, 95% CI： -0.57, 0.01 ）, and infected through injecting drug use （beta： -1.82, 95% CI： -2.25, -1.39）. Compared to the hospital setting, durations were shorter for those diagnosed in any other settings, and compared to 2008, durations were shorter for those diagnosed all years after 2010. Conclusion： Although the reduction in duration of infection at the time of diagnosis observed in Dehong was significant, it may not have had a meaningful impact.

关键词： China Delayed Diagnosis Human lmmunodeficiency Virus Infection