Keiji Hirata

DepartmentComplex and Intelligent Systems
Specialized FieldsMusic Informatics (Computational Music Theory), Smart City (Demand Responsive Public Transportation), Medical ICT (IT Support for Family Caregivers Caring for Depressed Family Members)
Subjects in Charge
Academic BackgroundUniversity of Tokyo, Graduate School of Information Engineering
DegreeDoctor of Engineering
Personal Historyreceived degree of Doctor of Engineering from University of Tokyo in 1987. He joined NTT Basic Research Laboratories in 1987 (later changed to NTT Communication Science Laboratories), was engaged in the Fifth Generation Computer System Project for 1990 to 1993, and moved to Future University Hakodate as professor in 2011. His research interest includes music informatics (computational music theory), smart city (demand-responsive transportation), ICT support for depression. In NTT, he headed a research project of video communication system, t-Room. He is the first chairperson of SIGMUS (special interest group of music and computer) of IPJS (Information Processing Society of Japan) in 1993 to 1995, is the editor in chief of Digital Practice from 2010 to 2015. He is the board member of IPSJ, in 2005 to 2007 and 2011 to 2013 and a IPSJ fellow.
Starting Time of EmploymentApril, 2011.

Research Contents

I am engaged in the following three research topics: music informatics, smart city and medical ICT.

(1) Music informatics
I am interested in understanding and using a media of music from the informatics point of view. In reality, the goals include reconstructing the music theory that has the history of over 400-years as a computational system and building applications utilizing the music as a target of computation. In general, a music theory is described in a natural language and is not defined precisely using equations and diagrams. While we possess a computer which enables intelligent computing, a music theory is difficult to be translated into a program because of its ambiguity.

If a music theory would be correctly programmed, we could not only compensate the incomplete parts in a music theory but also further develop the parts. Such a reconstructed music theory enables a computer to correctly understand music. Then, a computer can properly work in more variety of situations, and I can build more practical musical services so that a user's intention is properly reflected into an output. For example, the services include melodic authoring tools melody/rhythm/harmony generators, performance renderers, ubiquitous musical environment, and musical games. Moreover, around us, besides music, there are phenomena in which events occur along the temporal axis (temporal events); for example, temporal events include meeting, story, gesture, dance, and watching a painting. I think that a music theory can be used to understand temporal events and build an application system for temporal events.

(2) Smart city
Secondly, using ICT, the goal is to make the public transportation systems such as bus, taxi and tram available in Hakodate city more comfortably. The final goal of the project (sponsored by JST/RISTEX, term: 2012 October to 2015 September) is substituting demand-responsive transportation vehicles for all of buses and taxies in the current Hakodate city; demand-responsive transportation means the one without fixed routes nor time tables. The research issues in the project include not only developing necessary technologies but also leading people toward using the technologies. Hence, the project comes to be related to various research fields such as simulation, optimization problem, mathematical modeling, ubiquitous network, user interface, and Serviceology. My colleagues and I have to utilize these technologies and knowledge into an integrated system. In 2015, my colleagues and I actually plan to conduct the wide-area experiment for feasibility study in Hakodate city.

(3) Medical ICT
Among the several social problems, depression can be considered primary because it degrades not only the QOL of a patient itself but also the productivity of our modern society. At the same time, depression leads people around a patient (family caregivers, colleagues in offices, and friends) to face a difficult situation and degrades their productivity, too. While a patient is cured by a doctor, it has not been considered serious to take care of the people around a patient and to preserve their QOL. By using ICT , my colleagues and I promote a research to encourage and support the people around a patient.

Attractive Factors of My Research

(1) Music informatics
It is said that there is no cultures without music. Although music is closely related to a human being, there are still many unknowns about music. In this research, I investigate the substance of music, then approach to what a human is, what human intelligence is. At present, a computer is the most powerful experimental tool among tools human beings have invented. By enabling a computer to listen to and compose music, we will be able to step forward to revealing the substances of music.

(2) Smart city
Many social problems have been caused by the isolation of the place of technologies being created from that used. From now on, I think scientists and engineers should be engaged in developments taking into account the place of technologies being used. Since the Internet is progressed and disseminated, the circulation of information and materials is also progressed; it enables us to handle and resolve the social problems in reality. I believe that the result of this research will contribute to making the Hakodate citizens happy, which is a mission of Future University of Hakodate, too.

(3) Medical ICT
The advances in ICT has been enhancing the functionalities of machines and, at the same time, reducing manufacturing costs. Being always online enables us to work and have amusement anytime, anywhere; the social bond emerged and strengthened makes our life and work richer. I think the people who most benefit from being always online include those around a depression patient.


(1) Music informatics
My colleagues and I have named as computational music theory the music theory that is reorganized from the informatics point of view [1]; my colleagues and I provide a theoretical background and the relevance with natural language, formalize music theory GTTM (generative theory of tonal music), and introduce several application systems.

My colleagues and I proposed the formalization of musical structure based on human musical cognition in the GTTM fashion for the first time in the world [2]. The paper gave the computational background to the operations of melodic synthesis and transformation, which allows the algebraic operations applied to melodies as in the arithmetic [3]. Moreover, my colleagues and I showed that music can be analyzed like a natural language by implementing an automatic melodic-structure analyzer.

My colleagues and I translated a great work covering the whole knowledge of computer music composition [4]. Since the publication, the original and translated books have been often referred to as a standard text of computer music and/or music information processing.

(2) Smart city
In October, 2012, I joined the project in which all of taxies and buses in Hakodate city are to be made fully responsive [5]. My colleagues and I will make a simulation based on the real survey data of buses and taxies, and conduct an experiment in which real buses and taxies are used; by repeating the simulation then the real-world experiment, we will create the service to reinvigorate the flows of people and materials in the city step by step and my colleagues and I verify the effects.

(3) Medical ICT
To clarify the difficulties that the family caregivers of a depression patient face unavoidably and preserve their QOL, my colleagues and I made a proposal of a ICT support [6]. My colleagues and I interviewed the people who had experienced the care of a depression patient and discover the contradiction and dilemma that the family caregivers have

Major Books and Papers

[1] Keiji Hirata, Satoshi Tojo, Masatoshi Hamanaka, Yuzuru Hiraga: On the computational music theory, IPSJ, Guidepost running articles (1)~(5), Vol.49, No.7~11 (2008) in Japanese.

[2] Satoshi Tojo, Keiji Hirata, Masatoshi Hamanaka: Computational Reconstruction of Cognitive Music Theory. New Generation Computing 31(2): 89-113 (2013)

[3] Keiji Hirata, Satoshi Tojo, Masatoshi Hamanaka, Algebraic Mozart by Tree Synthesis, Proceedings of Joint ICMC and SMC 2014, pp.991-997 (2014)

[4] Tatsuya Aoyagi, Naotoshi Osaka, Keiji Hirata, Yasuo Horiuchi, Masataka Goto, Takafumi Hikichi, Saburo Hirano, Toshiaki Matsushima: Computer Music -- History, Technology and Art, Tokyo Denki University Press (2001) in Japanese.

[5] Hideyuki Nakashima, Hitoshi Matsubara, Keiji Hirata, Yoh Shiraishi, Shoji Sano, Ryo Kanamori, Itsuki Noda, Tomohisa Yamashita, Hitoshi Koshiba: Design of the Smart Access Vehicle System with Large Scale MA Simulation. Keynote Talk in MASS2013 (The 1st International Workshop on Multiagent-based Societal Systems)

[6] Naomi Yamashita, Hideaki Kuzuoka, Keiji Hirata, Takashi Kudo: Understanding the conflicting demands of family caregivers caring for depressed family members. CHI 2013: 2637-2646

Message to Students

・ A university is something like a BBQ restaurant offering as much as one can eat for a standard charge. Once you pay an entrance fee and a tuition, you will be able to learn as much as you want afterward.

・ Since there is no faculty who teaches useless knowledge/skill, what you have learned is certainly useful for something in the future. The more you learn, the more ingenious you leverage what you have learned.

・ A faculty is something like an electric assist bicycle. As long as a student does not start pedalling, an electric assist bicycle does not move forward.

・ However, once a student presses the pedals of an electric assist bicycle, surely a faculty assists the student. I would like you to find a theme or a goal so that you come to want pedalling.