何毓琦的个人博客分享 http://blog.sciencenet.cn/u/何毓琦 哈佛(1961-2001) 清华(2001-date)

留言板

facelist

您需要登录后才可以留言 登录 | 注册


[232]程宗明  2017-9-14 06:57
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!
博主回复(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.
[231]许培扬  2017-9-13 10:25
何院士   您好。得知您和您夫人在北京,我们特别高兴,我们去看望您们。我的手机13901205407       请您告诉我们在哪里相聚?
[230]赵明旺  2017-7-25 21:16
I have sent the email to your mail box in Harvard Univ,  ho@seas.harvard.edu, in morning. Please receive the email form the mail box. Thank you.
博主回复(2017-7-26 19:29)BTW, please ignore my last comment. It wad sent by mistake.
博主回复(2017-7-26 05:11)Many thanks.  But please read the first sentence of anyone of my blogs first.
博主回复(2017-7-25 22:27)I have just replied.
[229]赵明旺  2017-7-25 07:09
Dear Prof. Ho,

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.
[228]赵明旺  2017-7-22 12:19
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.
[227]赵明旺  2017-7-22 07:14
Prof. Ho, 我从读硕士开始一直学习您的最优控制、离散时间摄动分析等方面著作和文章,受益匪浅。现有一问题请教。对线性离散和连续系统,通过已有的定义能控域(即所有能控状态构成的几何体)的工作,我建立了计算任意N步(或有限时间T、无限时间等)能控域在n维空间的体积的方法,用此体积作为控制能力的一个测度,并证明这个体积与控制设计中控制律(control law)的解空间大小的正比关系。因此这个体积大,即控制设计的解空间大,设计控制器就可能达到更好的性能。我想把这个能控域的体积命名controllable abundance(控制丰富性或充裕性),并进一步研究其在系统分析和控制中的应用。但由于能控性方面工作是上个世纪60年代的工作,许多文献查找不易。您是能控性工作的重要的开拓者,不知您能否告诉我是否已经有类似或相关工作?这个工作该如何进一步发展下去?打扰了,谢谢!    学生:赵明旺
博主回复(2017-7-22 09:13)I have difficulty reading technical Chinese. Please write to me in English via an e- mail with your questions. I'll see if I can help
[226]LairdUnlimited  2017-6-13 06:36
http://blog.sciencenet.cn/blog-3226978-1060427.html   Prof. Ho, I am starting to follow 45th POTUS cabinet as well as 115th US Congressional hearings closely... cheers!
博主回复(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.
[225]魏焱明  2017-6-6 01:42
you may be interested in this article:
创新发明--可用于直升机的蹬伞式或百叶窗板式推进桨
http://blog.sciencenet.cn/blog-2339914-1058615.html
Also some papers may interest you in this full collection.
http://vixra.org/author/yanming_wei
博主回复(2017-6-6 01:54)Thank you for the references.
[224]LairdUnlimited  2017-4-15 23:01
I like American's traditional woman's college...https://en.wikipedia.org/wiki/Women%27s_colleges_in_the_United_States
[223]何毓琦  2017-4-5 20:57
Thank you for the notification.
[222]tianjilei  2017-4-5 17:42
http://blog.sina.com.cn/caigoubaokao
推荐阅读
[221]王毅翔  2017-4-5 10:08
何院士 是否可以在我的贴上 发表一下 您的看法?
博主回复(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.
[220]王毅翔  2017-4-4 10:33
地址:http://blog.sciencenet.cn/blog-2649160-1043519.html
-- 请何院士指证
博主回复(2017-4-4 21:34)Thanks for your further writing on this subject.
[219]吴中祥  2017-2-12 18:47
没有找到你的回复,请发到我的“博客”或“短消息”。谢谢!
博主回复(2017-2-12 21:32)Did you receive it now?
[218]吴中祥  2017-2-12 09:40
   你好!
http://blog.sciencenet.cn/blog-226-1032716.html
请予指正、讨论!
祝新年快乐!
  
博主回复(2017-2-12 13:06)Dear Prof. 吴中祥
Greetings. Unfortunately this is not my expertise area and I am not able to comment intelligently. Many thanks. YCHo
[217]吴中祥  2017-2-12 09:37
   你好!请予指正、讨论!
  
[216]魏焱明  2016-9-28 04:47
歡迎砥礪我的新作
我發動了科學史上的秋收起義--碩果累累的金秋 http://blog.sciencenet.cn/blog-2339914-1005320.html
[215]LairdUnlimited  2016-9-27 02:47
Just finished reading your article 'On election to IFAC'.  There is a delay in peer recognition apart from public recognition in scientific fields of inquiry, is it not?  How many truly peerless scientists left almost nothing but relics and mystery to this world we inherit, apart from Saints recognized oddly under Catholic and Apostolic Church? I am trying to locate reference to this iconic imagery. http://nunia.sdf-us.org/trans/RG/lbdbpajcelegiabd.jpg  Any idea, if this is linked to St. Olga of Kiev or not?  curious.
博主回复(2016-9-27 20:35)Thank you. But I'll let my article stand as it is.
[214]sslv123  2016-8-20 08:49
数学揭示量子纠缠与一种暗物质有直接关系,请何教授考虑下物理实验室是否要证实这种暗物质的存在,这种暗物质一旦被证实存在,对数学也会造成较大影响。请查看http://bbs.sciencenet.cn/thread-3093226-1-1.html
博主回复(2016-8-20 11:16)I am no expert in this topic and cannot really comment.
[213]scienceusa  2016-8-12 15:52
何老师,您好!欢迎加我的微信 。微信号 :cc_cl_lcy_czx_chz_18
谢谢关注
博主回复(2016-8-13 01:48)I am an technological dinosaur. You have to explain 微信号 to me.

Archiver|手机版|科学网 ( 京ICP备14006957 )

GMT+8, 2017-11-19 01:41

Powered by ScienceNet.cn

Copyright © 2007-2017 中国科学报社

返回顶部