Major research activity
We aim at the construction of intelligent systems that can perform what humans do in fast and correct manners. Our systems have symbolic representations based on computational logic or computational algebra, and reasoning mechanism on these representations.
Research activities in our laboratory cover both theoretical and practical aspects. We are currently studying the following project themes:
1. Study on qualitative spatial reasoning
In qualitative spatial reasoning, we represent spatial data such as figure, picture and movie, not numerically using coordinates or size of objects, but symbolically such as relative positional relationships of objects. It can reduce memory size and computational complexity. This approach can be applied to many fields including robot navigation and automatic window placement. We are studying various types of qualitative spatial representations and also their applications.
2. Study on system verification techniques
System verification techniques based on a formal method can greatly improve verification process as which are very important and most costly in the system development. We make a model for a target system, give a specification to be satisfied in a logical or an algebraic form, and verify that the system satisfies the specification using a computational tool. We have applied this technique to electronic money, ships’identification systems, and multi-car elevators.
3. Study on argumentation-based system
Argumentation is a kind of dialogue but has logical grounds. There are wide application areas of argumentation-based systems: supporting a smooth progress of a meeting and negotiation, legal justification and verification in assurance cases. In practical argumentation, we often find phenomena in which attendants' knowledge change, as an argumentation proceeds, which causes generating a new counter-argument. We focus on such a dynamic aspect of an argumentation and formalize a system.
Major relevant publications
- Takahashi,K., "PLCA: A Framework for Qualitative Spatial Reasoning Based on Connection Patterns of Regions", Qualitative Spatio-Temporal Representation and Reasoning: Trends and Future Directions, S.Hazarika(ed.), Chapt 2, pp.63-96, IGI Publishers，May, 2012.
- Ghourabi,F. and K.Takahashi: "Formalizing the Qualitative Superposition of Rectangles in Proof Assistant Isabelle/HOL," Seventh International Conference on Agents and Artificial Intelligence (ICAART15), pp.530-539, January, 2015.
- Sekizawa,T., T.Toyoshima, Koichi Takahashi and Kazuko Takahashi, "Probabilistic Symmetry Reduction for a System with Ring Buffer", IEICE Transactions on Information and Systems, Vol.E94-D, No.5, pp.967-975, May, 2011.
- Okuno,K. and K.Takahashi. "Argumentation System with Changes of an Agent's Knowledge Base", 21st International Joint Conference on Artificial Intelligence (IJCAI09), pp.226-232, July, 2009.
- Takahashi,K. and Y. Nambu. "A Semantics for Dynamic Argumentation Frameworks," Eighth International Workshop on Argumentation in Multi-Agent Systems (ArgMAS 2011), pp.66-85, LNCS 7543, Springer-Verlag, July, 2012.