Dr. Nishizeki completed his Ph.D. in electrical and communication engineering, Tohoku University, in 1974. The same year, he was appointed a research associate in the Faculty of Engineering, Tohoku University. He was elevated to an associate professor in 1976 and a professor in 1988. For one year from April 1977, he stayed at Carnegie Mellon University as a visiting mathematician. When the Graduate School of Information Sciences was established in Tohoku University, he became a professor of this Graduate School with a focus on algorithm theory and research and education in information science. For two years from 2008, he operated and managed the Graduate School as its dean. In 2010, he was designated a professor emeritus by Tohoku University. From 2010 to 2015, he was a professor in the Schools of Science and Technology, Kwansei Gakuin University. From 2016 to 2018, he was an auditor for the Japan Advanced Institute of Science and Technology.His contributions to the electronics, information and communication cover a broad range of topics from algorithm theory to graph theory, circuit network theory and information security. He linked graph theory and discrete mathematics, which were previously only one field of mathematics, with problems related to main elements of information communication such as circuits and networks. He has been recognized throughout the world as a trailblazer who launched the new scientific field of graph algorithms.
In particular, he focused his attention to the fact that, while many important graph optimization problems do not have efficient solution methods (NP difficulty) for general graphs, efficient solution methods do exist for special graphs, such as tree graphs. He came up with the revolutionary idea of using structural characteristics of graphs in algorithms, giving rise to a big increase in graph algorithm research. Specifically, in his paper published in Journal of ACM in 1982, he presented a unified framework for algorithm design methods that make use of the structural characteristics of graphs, and indicated that most of the important optimization problems can be solved in a linear time for a serial-parallel graph, a graph made up of a repetition of what may be called serial connections and parallel connections in electrical circuitry. This result was accepted in the world with astonishment. Subsequently, he extended this theory into a novel computation theory on “partial k-trees” using “tree width” as a parameter, thereby achieving a conventionally unexpected, groundbreaking result. This idea has developed into a research field called “parameterized complexity theory,” which continues to be studied worldwide.
Graph drawing is a technical foundation for information visualization, which plays an important role in everyday life, such as Web analysis and car navigation. Dr. Nishizeki was the first to point out the importance of graph drawing, and his book, “Planar Graph Drawing” (published by World Scientific, 2004) is widely read throughout the world. He has also made original research in the field of information security, inventing a distributed secret sharing scheme that can realize an arbitrary access structure, and developing a secret key sharing protocol.
His achievements mentioned above have been extremely highly rated. He was designated a fellow by ACM, IEEE and IEICE. He has received numerous awards, including a FUNAI Information Science Promotion Award (2002) and a Commendation for Science and Technology from the Minister of Education, Culture, Sports, Science and Technology (2008). He has also received Best Paper Awards, an Achievement Award and a Distinguished Achievement and Contributions Award from IEICE.
Dr. Nishizeki has also involved himself in scientific community activities. In 1990, he founded the International Symposium on Algorithms and Computation (ISAAC), which is the most prestigious conference in this field not only in Japan but also in the Asia Pacific Region. For 17 years from 1992 to 2008, in his capacity as chair of its Advisory Committee, he operated and planned its conferences, thereby leading the efforts to promote learning in this scientific field in Asia. He also devoted himself to the establishment of an international conference, called Graph Drawing, and served as a member of its Steering Committee for many years.
As stated above, Dr. Nishizeki’s contributions to the electronics, information and communication field, centering on algorithm theory, has been outstanding. Therefore, we strongly recommend that he be designated as a fellow honorary member of IEICE.
