I have only a Chinese version yet: #lvba #greendam
当GFW遭遇微博客（1）
In this first article, I try to analysis the huge impact of the uprising of micro-blogging services towards the Great Firewall (GFW), which is created by the Chinese government to censor the Chinese Internet. My website was blocked by the GFW from August 2008 to May 2009, so during that period, the users from China mainland could not directly access my website. Whenever they tried to connect to any page in jiruan.net, their web browsers would get a “The Connection Has Been Reset” error message.
I will argue that the micro-blogging services are making the GFW more difficult to stop the information flow to Chinese people. I believe that this is the very reason that recently Chinese government requested all the pc vendors in China install a censorship software called “Green Dam + Youth Escourt” by 1st July.
Title: Model Checking Knowledge Dynamics of Multi-Agent Systems
- Time: 3PM, 29 May 2009
- Location: Seminar room in the Centre for Logic and Information at StFX.
- Talk Slides: available upon request.
Abstract:
In this talk, I will first briefly introduce Model Checking and Multi-Agent Systems (MAS), then focus on two frameworks on modelling knowledge dynamics of MAS. The first is Dynamic Epistemic Logic, which is reasoning about knowledge and actions, and the second is Temporal Epistemic Logic, which is reasoning about knowledge and time. Then I will give a comparison of three state-of-the-art model checkers for MAS (DEMO, MCK and MCMAS) by verifying a communication protocol for Russian Cards Problem. Finally I will discuss with the audience about the possible ways of modelling the interactions in Health Care Services & Work-flows.
(Some work was jointly done with H.P van Ditmarsch, W. van der Hoek, and R. van der Meyden)
References:
- Chapter 6 of my PhD Thesis.
This Russian Cards Problem originated at the Moscow Math Olympiad 2000. Maybe you could try to solve it before the talk.
From a pack of seven known cards two players each draw three cards and a third player gets the remaining card. How can the players with three cards openly inform each other about their cards, without the third player learning from any of their cards who holds it?
I plan to give four talks about my research, in the Center for Logic and Information. The first two will be kept more introductory, and the remaining two will be more advanced. Here is my first talk given on last Friday.
Solving Sum-and-Product Riddle Using Public Announcement Logic
- Time: 2:30PM, 22 May 2009
- Location: Seminar room in the Centre for Logic and Information at StFX.
- Talk slides: stfx_talk1_snppal09 (1.3Mb)
- Some photos: flickr album
Abstract:
Here is the Sum-and-Product Riddle:
Adam says to S and P: I have chosen two integers x, y such that 1 < x < y and x + y ≤ 100. In a moment, I will inform S only of s = x + y, and P only of p = xy. These announcements remain private. You are required to determine the pair (x, y).
He acts as said. The following conversation now takes place:
i. P says: ‘I do not know it.’
ii. S says: ‘I knew you didn’t.’
iii. P says: ‘I now know it.’
iv. S says: ‘I now also know it.’Determine the pair (x,y).
Reference:
H.P. van Ditmarsch, J. Ruan, L.C. Verbrugge, Sum and Product in Dynamic Epistemic Logic.
We got 26 degrees today in Antigonish.
It is strange that we suddenly have such a warm day. But it is nicely warm and I like it.
I was waring a sweater when I go to my office in the morning. Now I have through it away.
Available now online:
PhD Thesis: Reasoning about Time, Action and Knowledge in Multi-Agent Systems
