我的回复(2024-3-29 10:32):Dear Dr. Xu, Please ignore my last message asking for your e-mail address. I don't have the need to communicate with you personally anymore
Dear Professor He,
I am so sorry to disturb you again. The last message has some mistake in format. Thus I send message again. Please forgive me.
I am studying the optimal control recently. But there is a concept about conjugate point confused me. Fortunately, this concept is mentioned in your paper--“J.V. Breakwel and Ho Yu-Chi, “On the conjugate point condition for the control problem,” International Journal of Engineering Science,vol.2, issue. 6, pp. 565-579, Mar. 1965.\". However, I can not find the manuscript from the Internet. Could you please send me a copy of the manuscript? ?I would be very grateful. My e-mail address is Betty_Guoli@163.com. Best regards.
我的回复(2018-8-26 01:52):Thank you for your interest. However, 45+years ago there were no Internet and/or electronic copies of paper. Thus, the best you can do is to write to the publisher and find out what library archive their journals. BTW, as I recall my conjugate point condition can be reinterpreted as the Riccati equation of the problem has finite escape time. Hope this helps. Good luck
Dear Professor He,
It is so sorry to disturb you. I am studying the optimal control recently. But there is a concept about conjugate point confused me. Fortunately, this concept is mentioned in your paper--“J.V. Breakwel and Ho Yu-Chi, “On the conjugate point condition for the control problem,” International Journal of Engineering Science,vol.2, issue. 6, pp. 565-579, Mar. 1965.\". However, I can not find the manuscript from the Internet. Could you please send a copy of the manuscript to me ? ?I would be very grateful. My e-mail address is Betty_ty_Guoli@163.com. Be. Best regards.
我的回复(2018-8-26 04:56):Unfortunately after 40+ years, I no longer have a copy of the paper nor was electronic copy available then.
Dear Professor He, I used to follow your blog since ten years ago. It was like a window to look out, to imagine what it would be to do research in the U.S. I went to Brown University as a visiting scholar last year. Now when I read your former blogs again, I find so many familiar things. I am writing to say thank you. Thanks for keep writing blogs here. Thanks for providing so many new things to Chinese young researchers including me. Best regards.
我的回复(2018-5-25 18:13):Comment like yours makes my day. Thank you.
A Small friendly correction: You can aim for the best, say Tsinghua or Baida. These two university have: should be "two universities have. Great assay! Best wishes!
我的回复(2017-9-14 09:01):Thanks. Some old Chinese language habit ( gender, polarity, et al) still slips through even after more than half a century of living and breathing English.
I am glad to read your message on sciencenet and thank you very much for your help.
Based on the definitions of the controllable region of the input-constrained systems[1], I propose a computing method on the volume of the region and a proportional relation theorem between the volume of the region and the size of the solution space of the control laws in the controller designing is proposed and proven. According to the theorem, the bigger the volume is, the bigger the size of the solution space, and then the better the performance of the closed-loop control systems designed by the conventional control methods are. So, I think, the volume of the region is a good measure on the control ability and efficiency of the input variables to the state space and, after deeply understanding on that, the better works on the application of the volume to the system analysis and control design can be developed and expected. My two questions are as follows.
1. Whether the same or similar works have been done after 1960's? In the control ability studying, some conclusions promoting the ability has been proposed in the earlier works, such as, the distribution of the eigenvalues of the system matrix A must be uniform, the angel between the eigenvectors and the vectors of the input matrix B must tend to be orthogonal, and so on. But, as a synthetical measure on the control ability, I doesn't find the same or similar works and the theorem on the relation between the volume of the controllable region and the solution space of the control laws maybe proposed firstly.
2. If my works on the control ability are with some innovation, how to name the new measure? Considered the relation to the solution space of the control laws, whether the new measure can be named as 'controllable abundance'?
Your are a key pioneer on the state controllability and your comments and suggestions are very important to me. Thank you for help.
Best regards.
Mingwang Zhao
Wuhan University of Science and Technology
July 25, 2017
References
[1] Hu, T., Lin, Z., & Qiu, L. (2002). An explicit description of the null controllable regions of linear systems with saturating actuators. Systems & Control Letters, 47, 65-78.
I am glad to read your message on sciencenet and thank you very much for your help. An email about my questions has been sent to your email box in Harvard Univ.
我的回复(2017-6-14 02:18):Our current president seems to have no sense of shame. he tells a lie; he knows that it is a lie; he also knows that you know it is a lie; yet he goes on telling it.
我的回复(2017-4-5 11:07):I am not sure what you wanted me to say. I believe I said everything on this topic in my blog article. Also I am not sure what you mean by "我的贴上" pardon my understanding oof current Chinese usage.