Kunihiko Hiraishi Professor
School of Information Science（Department of Information Science・Theoretical Information Science）
B.E., M.E. and Ph.D.from Tokyo Institute of Technology (1983,1985,1990)
Fujitsu Laboratories LTD (1985)
Formal modeling and analysis of concurrent systems, discrete event systems, and hybrid systems
concurrent systems, discrete event systems, hybrid systems
Modeling and analysis of discrete event systems and hybrid systems
A discrete event system (DES) is a dynamic system such that the state of the system changes only at discrete instances of time instead of continuously. DESs arise in the domains of manufacturing, robotics, vehicular traffic, logistics, and computer and communication networks. We are studying modeling and analysis of DESs by means of various kinds of formal models, such as automata-based models, graph models, algebraic models, and logical models. We are also interested in hybrid systems, which are systems with both continuous dynamics and discrete dynamics.
Efficient analysis and verification of concurrent systems
In the analysis of concurrent systems, there are several problems that do not happen in sequential systems. For example, the size of the state space often increases exponentially in the size of the model. This phenomenon is called state space explosion and it makes the analysis very difficult. We are studying efficient analysis and verification techniques for such systems.
Modeling of complex processes in nursing and cargiving services
In 2010, JST/RISTEX in Japan started a new R&D program ``Service Science, Solutions and Foundation Integrated Research Program''. "Innovation for Service Space Communication by Voice Tweets in Nursing and Caring" is one of the selected projects by the above program. The aim of the project is to develop a stress-free information assisting system based on smart voice messaging. By providing voice messaging environment optimized for current situation of nurses, the system helps nurses in their cooperation, knowledge sharing, and making work records, and as a result the system reduces various kinds of stresses associated with their work. To estimate current situation of nurses, it is important to have detailed process models that described working schedules and how they behave in various situations. Moreover, computer simulation based on the process models is useful for quantitative evaluation of the system. In this article, we first clarify problems to be solved toward the modeling of nursing and caregiving processes, and give solutions to them.
- Modeling and Design of Networked Control Systems Using a Stochastic Switching Systems Approach，Koichi Kobayashi and Kunihiko Hiraishi，IEEJ Transactions on Electrical and Electronic Engineering，9，1
- A Petri Net-Based Approach to Control of Boolean Networks，Koichi Kobayashi and Kunihiko Hiraishi，Workshop on Computational Complexity Analysis and Algorithm Design for Combinatorial Optimization Problems，2012/12
- Application of Interval Methods to Sampled-Data Control of Uncertain Piecewise Affine Systems，Koichi Kobayashi and Kunihiko Hiraishi，SICE Journal of Control, Measurement, and System Integration，5，3，184-189，2012/05
◇Lectures and Presentations
- On Analysis of a Class of Timed Continuous Petri nets and Its Applications，Kunihiko Hiraishi，SICE Annual Conference 2010，Taipei，2010/8/18-21
- DES Technology: Toward Dependable Embedded Control Systems，Kunihiko Hiraishi，ICROS-SICE2009，Fukuoka, Japan，2009/8/18-8/21
- Formal Approaches to Model-Based Development of Real-Time/Hybrid Systems，Kunihiko Hiraishi，SICE 2008, Workshop on Model-Based Development of Embedded Systems，Chofu, Japan，2008/08/19
◇Academic Society Affiliations
- IEEE Computer Society，1993-
- International Conference on Application and Theory of Petri Nets and Concurrency，Steering comittee member(2008-)
- IFAC Technical Committee 1.3 on Discrete Event and Hybrid Systems，member(2008-)