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
As a former student of the ILLC, I am very happy to see that the ILLC has launched a blog-based webportal for the research community of logic and rational interactions, called loriweb.org. Here is a snapshot:
The ILLC has finally made an attempt going from web1.0 to web2.0, which means more dynamics and interactions!
However, I noticed that there is an important element missing on loriweb’s front page. It is a link to the RSS feed. What is RSS?
RSS (Rich Site Summary) is a format for delivering regularly changing web content. Many news-related sites, weblogs and other online publishers syndicate their content as an RSS Feed to whoever wants it.
More details of RSS: http://en.wikipedia.org/wiki/RSS_(file_format)
Why RSS is important?
RSS solves a problem for people who regularly use the web. It allows you to easily stay informed by retrieving the latest content from the sites you are interested in. You save time by not needing to visit each site individually. You ensure your privacy, by not needing to join each site’s email newsletter. The number of sites offering RSS feeds is growing rapidly and includes big names like Yahoo News.
Actually, since the loriweb is using the popular wordpress software (good choice!), it has an RSS feed by default: http://loriweb.org/?feed=rss2. So I subscribed to it using my Google RSS Reader. But then I found this problem. The loriweb RSS feed only outputs an abstract of the content. For example, here is a snapshot of the loriweb in my Google Reader:
You have to click on the article in order to read it fully.
And this is what you see from the blog of Terence Tao, a well-regarded mathematician:
In this case I can read all his articles without leaving the my reader. The difference is small if you only subscribe to a few blogs, but very noticeable when you
subscribe to dozens of blogs, which may have 1000+ new articles every week.
So my suggestions to the webmaster of loriweb.org are as follows:
- add a link to the RSS feed in the front page
- output the full text in the RSS feed.
It is very easy to set in wordpress: login as admin, and find the Settings section, and choose the Reading subsection, then you can see the following: just make sure Full text is chosen (this view is based on version 2.7.1)
Cheers, Ji
The USA White House launched its strategy to reform the government in the Web 2.0 age. In this post:
http://www.whitehouse.gov/blog/09/05/01/WhiteHouse/, it gives the information channels through which white house is reaching its citizens. These channels include:
- Whitehouse.gov
- Facebook.com/WhiteHouse
- MySpace.com/WhiteHouse
- Twitter.com/WhiteHouse
- Flickr.com/WhiteHouse
- Vimeo.com/WhiteHouse
- YouTube.com/WhiteHouse
- iTunes (videos & podcasts)
I would say this government is leading toward the right way. Well, my government, the Chinese government, is still using a communist version of web 1.0 tools. You see, my blog is still blocked from China Mainland. What a shame.
