I was fortunate to attend Prof. Johan van Benthem’s lecture on logic dynamics in Beida. He was one of my master thesis supervisor back in 2004, and we last met was in Liverpool in March 2009 on occasion of celebrating Wiebe’s 50th Birthday. I am a big fan of him as he has set a great example of how a researcher can be. Here are some Photos. A video clip will appear later.
题目：通用游戏竞赛的逻辑 (Logic for General Game Playing)
主讲人：阮吉
计算机科学和工程学院，新南威尔士大学，澳大利亚
时间：九月二十五日，星期天，晚上8点
地点：哲学系1层会议室
摘要：通用游戏竞赛GGP（General Game Playing）的目标是创建能自主地学习游戏规则进行游戏比赛的通用智能系统。和1997年打败人类国际象棋冠军的深蓝系统不同的是，通用游戏系统的设计者事先不知道竞赛的具体游戏，而只是被告知所有游戏是用游戏描述语言GDL（Game Description Language）所描述。GDL是一种基于规则的逻辑编程语言。自从2005年通用游戏竞赛在国际人工智能会议AAAI举办以来，已经引起了广泛的兴趣和深入的研究。GDL本身也从只能描述完全信息游戏（例如象棋）扩展到也能描述非完全信息游戏（例如扑克）。我将首先介绍如何对游戏进行描述，然后深入讨论逻辑在游戏推理和刻画中的应用，并展示一些推理复杂性结果。
http://www.phil.pku.edu.cn/cllct/ann_content.php?msgid=215
更新：现场的照片
例子
提问
来自相册：
http://www.flickr.com/photos/jiruan/sets/72157627656865185
Date: Friday, 23 September, 2011
Location: 清华新斋335
1:30-3:30 PM
Speaker: Patrick Girard
Department of Philosophy, The University of Auckland
Title: Logic in the Communities
Photo Update:
3：30- 5:30 PM
Speaker: Ji Ruan
School of Computer Science and Engineering, The University of New South Wales
Title: A Logic for Knowledge Flow in Social Networks （社交网络中的知识流的逻辑）
Abstract: In this talk, I will present a formal framework for analysing the flow of information and knowledge through social networks. More specifically, we propose a multi-agent epistemic logic in which we can represent and reason about communicative actions based on social networks and the resulting knowledge and ignorance of agents. This logic is applied to formally analyse the “Revolt or Stay-at-home” problem where social networks play an important role in agents’ knowledge acquisition and decision-making. We evaluate our work by proving some mathematical properties of our new logic, including the fact that it generalises the existing Logic of Public Announcement. (This is a joint work with Prof. Michael Thielscher)
Photo Update:
More photos:
http://www.flickr.com/photos/jiruan/sets/72157627753995408/
Title: A Logic for Knowledge Flow in Social Networks
Authors: Ji Ruan and Michael Thielscher
School of Computer Science and Engineering, The University of New South Wales, Australia
Abstract: In this paper, we develop a formal framework for analysing the flow of information and knowledge through social networks. More specifically, we propose a multi-agent epistemic logic in which we can represent and reason about communicative actions based on social networks and the resulting knowledge and ignorance of agents. This logic is applied to formally analyse the “Revolt or Stay-at-home” problem where social networks play an important role in agents’ knowledge acquisition and decision-making. We evaluate our work by proving some mathematical properties of our new logic, including the fact that it generalises the existing Logic of Public Announcement.
Accepted and presented at the 24th Australasian Joint Conference on Artificial Intelligence (AI2011), Perth Australia, December 2011.
Download:
Bibtex: (more…)
Title: Connecting Dynamic Epistemic and Temporal Epistemic Logics
Authors: H.P. van Ditmarsch, W. van der Hoek, and J. Ruan.
Abstract: We give a relation between a logic of knowledge and change, with a semantics on Kripke models, and a logic of knowledge and time, with a semantics on interpreted systems. In particular, given an epistemic state (pointed Kripke model with equivalence relations) and a formula in a dynamic epistemic logic (a logic describing the consequences of epistemic actions), we construct an interpreted system relative to that epistemic state and that formula that satisfies the translation of the formula into a temporal epistemic logic. The construction involves that the protocol that is implicit in the dynamic epistemic formula, i.e., the set of sequences of actions being executed to evaluate the formula, is made explicit. We first focus on the logic of knowledge and change that is known as public announcement logic, then generalize our results to a dynamic epistemic logic.
It is published in The Logic Journal of the IGPL.
http://jigpal.oxfordjournals.org/content/early/2011/10/27/jigpal.jzr038.refs
PDF:
http://jigpal.oxfordjournals.org/content/early/2011/10/27/jigpal.jzr038.full.pdf+html
It is an extended version of this workshop paper.
The paper was first submitted when I was still at the University of Liverpool (UK) in 2009; the revision was made when I was at the StFX University (Canada) in 2010, and finally accepted when I moved to the current University of New South Wales (Australia) in 2011.
An English-speaking friend asked me yesterday, why did you talk a lot of politics on Facebook (even sometimes in Chinese)?
Here is a simple answer: my parents and best friends are living in China, which is a high-speed train in a similar type of the ones crashed on 23 July in Wenzhou, China. What the China railway bureau (part of Chinese government) did was digging a big hole and burying the racked train at the second day.
I am not on that train right now, but what about my relatives and friends?
Above photo may not show correctly but here is a copy
