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Changes in work values across the regions of China 期刊论文  OAI收割
Asia Pacific Journal of Management, 2018, 卷号: 35, 期号: 1, 页码: 145-179
作者:  
Ralston, David;  Egri, Carolyn;  Karam, Charlotte;  Li, Yongjuan;  Fu, Pingping
  |  收藏  |  浏览/下载:18/0  |  提交时间:2019/06/14
Parameter optimization of passive dynamic walking biped with knees (EI CONFERENCE) 会议论文  OAI收割
2012 2nd International Conference on Materials Science and Information Technology, MSIT 2012, August 24, 2012 - August 26, 2012, Xi'an, Shaan, China
作者:  
Zhang P.
收藏  |  浏览/下载:21/0  |  提交时间:2013/03/25
A method to find the optimized parameter values of passive dynamic walking biped is presented. The effects of biped physical parameters on the stability property of passive gaits are studied by simulation experiments. The chosen parameters include the mass distribution  length of leg and slope angle. The stability property of passive walking limit cycles is used as criterion of optimization calculation  including the orbital stability described by eigen-values of linearized Poincare map and the global property described by size of attraction region. The simulation results show how the stability of limit cycle varies when physical parameters of the passive biped change. The work is useful to explore the inherent property of passive dynamic walking and can be used as an important instruction in the mechanical design of biped robots based on principle of passive dynamic walking. (2012) Trans Tech Publications  Switzerland.  
Low drive-voltage and high-bandwidth electro-optic modulators based on BaTiO3 thin-film waveguides (EI CONFERENCE) 会议论文  OAI收割
Science and Technology of Dielectrics for Active and Passive Photonic Devices - 210th Electrochemical Society Meeting, October 29, 2006 - November 3, 2006, Cancun, Mexico
Sun D. G.; Fu X. H.; Liu Z. F.; Ho S. T.; Wessels B. W.
收藏  |  浏览/下载:45/0  |  提交时间:2013/03/25
We investigated electro-optic modulator structures to target low drive voltage  high-speed modulation  and small device size with c-axis grown BaTiO3/MgO ferro-electric thin films. In this study  the calculations are focused on the ideal thin film with a quadratic relation between the half-wave drive voltage V and the interaction length L in the electro-optic modulation case we obtained in previous work. With the quadratic electro-optic modulating relation and the optimal rib waveguide structure of BaTiO3/MgO thin films  the frequency-voltage-size performances for 2.5GHz  10GHz  40GHz  and 100GHz modulation bandwidths have been obtained under half-wave drive voltages of 0.8V  1.6V  3.0V and 4.8V  respectively  for the ideal film with r51=730 pm/V at 1550nm wavelength  where both the phase velocity matching condition and the conductor induced microwave attenuation are considered. The required device lengths to achieve these four typical values of modulation bandwidth are 3.3 mm  0.8 mm  0.4 mm and 0.2 mm  respectively. With the c-axis grown BaTiO3/MgO crystal thin films and the quadratic electro-optic modulating relation  an electro-optic coefficient of reff=180 pm/V for the c-axis grown BaTiO3/MgO ferro-electric thin films was measured  which is relatively far from the ideal value of r51=560 pm/V. copyright The Electrochemical Society.