http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Jing Wei,Ruizhi Shu,Datong Qin,Teik C. Lim,Aiqiang Zhang,Fanming Meng 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.17 No.9
Multi-source driving transmission systems, in which the gear assembly is driven by multiple induction motors, are extensively used in new energy, aerospace, marine engineering, and in other fields. The multi-source driving system faces an even-load distribution problem, i.e., torque or speed synchronization issues. In this study, the synchronization characteristics of a multi-source driving transmission system under an impact load at different load change rates are studied. An accurate electromechanical coupling dynamic model of the system considering the flexible shafts, support bearing and meshing gear pair is established by applying virtual equivalent shaft elements. By considering the time-varying meshing and the coupling effects of the dynamic electric motor and the speed, torque and stator current synchronization characteristics are investigated using this model. Computational results show that the influence of the load change rate on the speed synchronization characteristics of the system is minor, but has a significant influence on the torque and stator current synchronization characteristics. The stator current root mean square value (RMS) can be chosen as a feedback signal to monitor the synchronization characteristics of the system. The proposed research provides the theoretical basis for the formulation of the synchronization control strategy for multi-source driving transmission systems.
Bandwidth-Related Optimization in High-Speed Frequency Dividers using SiGe Technology
Chao-Zhou Nan,Xiao-Peng Yu,Wei-Meng Lim,Bo-Yu Hu,Zheng-Hao Lu,Yang Liu,Kiat-Seng Yeo 대한전자공학회 2012 Journal of semiconductor technology and science Vol.12 No.1
In this paper, the trade-off related to bandwidth of high-speed common-mode logic frequency divider is analyzed in detail. A method to optimize the operating frequency, band-width as well as power consumption is proposed. This method is based on bipolar device characteristics, whereby a negative resistance model can be used to estimate the optimal normalized upper frequency and lower frequency of frequency dividers under different conditions, which is conventionally ignored in literatures. This method provides a simple but efficient procedure in designing high performance frequency dividers for different applications. To verify the proposed method, a static divide-by-2 at millimeter wave ranges is implemented in 180 ㎚ SiGe technology. Measurement results of the divider demonstrate significant improvement in the figure of merit as compared with literatures.
Bandwidth-Related Optimization in High-Speed Frequency Dividers using SiGe Technology
Nan, Chao-Zhou,Yu, Xiao-Peng,Lim, Wei-Meng,Hu, Bo-Yu,Lu, Zheng-Hao,Liu, Yang,Yeo, Kiat-Seng The Institute of Electronics and Information Engin 2012 Journal of semiconductor technology and science Vol.12 No.1
In this paper, the trade-off related to bandwidth of high-speed common-mode logic frequency divider is analyzed in detail. A method to optimize the operating frequency, band-width as well as power consumption is proposed. This method is based on bipolar device characteristics, whereby a negative resistance model can be used to estimate the optimal normalized upper frequency and lower frequency of frequency dividers under different conditions, which is conventionally ignored in literatures. This method provides a simple but efficient procedure in designing high performance frequency dividers for different applications. To verify the proposed method, a static divide-by-2 at millimeter wave ranges is implemented in 180 nm SiGe technology. Measurement results of the divider demonstrate significant improvement in the figure of merit as compared with literatures.
Zou, Jun,Fu, Donghui,Gong, Huihui,Qian, Wei,Xia, Wei,Pires, J. Chris,Li, RuiYuan,Long, Yan,Mason, Annaliese S.,Yang, Tae‐,Jin,Lim, Yong P.,Park, Beom S.,Meng, Jinling Blackwell Publishing Ltd 2011 The Plant journal Vol.68 No.2
<P><B>Summary</B></P><P>Interspecific hybridization is a significant evolutionary force as well as a powerful method for crop breeding. Partial substitution of the AA subgenome in <I>Brassica napus</I> (A<SUP>n</SUP>A<SUP>n</SUP>C<SUP>n</SUP>C<SUP>n</SUP>) with the <I>Brassica rapa</I> (A<SUP>r</SUP>A<SUP>r</SUP>) genome by two rounds of interspecific hybridization resulted in a new introgressed type of <I>B.?napus</I> (A<SUP>r</SUP>A<SUP>r</SUP>C<SUP>n</SUP>C<SUP>n</SUP>). In this study, we construct a population of recombinant inbred lines of the new introgressed type of <I>B.?napus</I>. Microsatellite, intron‐based and retrotransposon markers were used to characterize this experimental population with genetic mapping, genetic map comparison and specific marker cloning analysis. Yield‐related traits were also recorded for identification of quantitative trait loci (QTLs). A remarkable range of novel genomic alterations was observed in the population, including simple sequence repeat (SSR) mutations, chromosomal rearrangements and retrotransposon activations. Most of these changes occurred immediately after interspecific hybridization, in the early stages of genome stabilization and derivation of experimental lines. These novel genomic alterations affected yield‐related traits in the introgressed <I>B.?napus</I> to an even greater extent than the alleles alone that were introgressed from the A<SUP>r</SUP> subgenome of <I>B.?rapa</I>, suggesting that genomic changes induced by interspecific hybridization are highly significant in both genome evolution and crop improvement.</P>