Ji Ruan - Jimagine » Talk

Johan’s Lecture in Beida

Ji — Thu, 29 Sep 2011 01:34:15 +0000

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.

He came from Tinghua Campus on his bike (a typical dutch way)

Here is the complete album:

http://www.flickr.com/photos/jiruan/sets/72157627784013200/

我将在北大的学术报告：通用游戏竞赛的逻辑 (星期天 25-09-2011) 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...
My coming up seminar at Tsinghua University (Friday 23-09-2011) Date: Friday, 23 September, 2011 Location: 清华新斋335 1:30-3:30 PM Speaker:...

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我将在北大的学术报告：通用游戏竞赛的逻辑 (星期天 25-09-2011)

Ji — Wed, 21 Sep 2011 01:30:35 +0000

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

My coming up seminar at Tsinghua University (Friday 23-09-2011) Date: Friday, 23 September, 2011 Location: 清华新斋335 1:30-3:30 PM Speaker:...

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My coming up seminar at Tsinghua University (Friday 23-09-2011)

Ji — Tue, 20 Sep 2011 13:16:18 +0000

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)

Reference Link.

Photo Update:

More photos:
http://www.flickr.com/photos/jiruan/sets/72157627753995408/

Conference paper: A Logic for Knowledge Flow in Social Networks Title: A Logic for Knowledge Flow in Social Networks Authors: Ji Ruan...

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My Coming talk in Liverpool: Connecting Dynamic Epistemic and Temporal Epistemic Logics For Multi-Agent Systems

Ji — Sun, 06 Dec 2009 00:48:11 +0000

Title: Connecting Dynamic Epistemic and Temporal Epistemic Logics For Multi-Agent Systems

Abstract:

I will 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. The results presented are from a joint work with Dr. Hans van Ditmarsch, and Prof. Wiebe van der Hoek. In the end, I will share some latest thoughts on an extension of Multi-Agent Systems framework with a social network connecting agents.

Updated: Talk photo album

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StFX Logic Talk 2: Model Checking Knowledge Dynamics of Multi-Agent Systems

Ji — Fri, 29 May 2009 13:34:04 +0000

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?

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StFX Logic Talk 1: Solving Sum-and-Product Riddle Using Public Announcement Logic

Ji — Thu, 28 May 2009 16:34:56 +0000

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:

In this talk I will present a joint work with H. van Ditmarsch and R. Verbrugge. I will first introduce the problem we want to solve: the Sum-and-Product Riddle. Then I will present how to model the Sum-and-Product riddle in a modal logic called public announcement logic. This logic contains operators for knowledge, but also operators for the informational consequences of public announcements. The logic is interpreted on multi-agent Kripke models. The riddle is then implemented and its solution verified in the epistemic model checker DEMO. The results are compared with other work in epistemic model checking and the complexity is experimentally investigated for several representations and parameter settings.

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.

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Ji Ruan - Jimagine » Talk

Johan’s Lecture in Beida

我将在北大的学术报告：通用游戏竞赛的逻辑 (星期天 25-09-2011)

My coming up seminar at Tsinghua University (Friday 23-09-2011)

My Coming talk in Liverpool: Connecting Dynamic Epistemic and Temporal Epistemic Logics For Multi-Agent Systems

StFX Logic Talk 2: Model Checking Knowledge Dynamics of Multi-Agent Systems

Title: Model Checking Knowledge Dynamics of Multi-Agent Systems

Abstract:

References:

StFX Logic Talk 1: Solving Sum-and-Product Riddle Using Public Announcement Logic

Solving Sum-and-Product Riddle Using Public Announcement Logic

Abstract:

Reference: H.P. van Ditmarsch, J. Ruan, L.C. Verbrugge, Sum and Product in Dynamic Epistemic Logic.

Reference:
H.P. van Ditmarsch, J. Ruan, L.C. Verbrugge, Sum and Product in Dynamic Epistemic Logic.