Janusz A. (John) Brzozowski

University of Waterloo


Janusz A. (John) Brzozowski was one of the earliest researchers in theoretical computer science in Canada. He received the B.A.Sc. and M.A.Sc. degrees in electrical engineering from the University of Toronto in 1957 and 1959, respectively, and the M.A. and Ph.D. degrees in electrical engineering from Princeton University in 1962. He began his academic career in 1962 as Assistant Professor in the Department of Electrical Engineering at the University of Ottawa. In 1965-1966 he was Visiting Associate Professor at the University of California, Berkeley. In 1967 he joined the University of Waterloo as Professor of Computer Science. He formally retired from Waterloo in 1996, but continues to visit his office to collaborate with colleagues and students.

He is well known for his fundamental contributions to several areas of theoretical computer science. He has worked on many topics including the theory of asynchronous circuits, testing and simulation of digital circuits, VLSI models, specification of software modules, multi-valued logic, and algebra, but his most important area is the theory of automata. His method of derivatives of regular expressions has been generalized and applied to new problems. His minimization algorithm by double reversal is well known and often cited. His hierarchy of star-free languages has led to extensive new research on this topic. Recently he made substantial contributions in the area of descriptional complexity of regular languages and finite automata. He is the co-author of Digital Networks (Prentice-Hall, 1976) and Asynchronous Circuits (Springer-Verlag, 1995). He has also authored or co-authored 91 journal papers and 98 conference papers.

Dr. Brzozowski has supervised student research for 55 years, and continues to do so. At last count he has supervised 15 Ph.D. students, 28 Master’s theses and projects, and a large number of undergraduate research projects (28 students in the past 17 years). He has a particularly well-deserved reputation for engaging Waterloo’s best undergraduates in research. Several of his graduate and undergraduate students won awards for their research, and many have gone on to leading academic and industrial positions.

Dr. Brzozowski has been a significant contributor to the building of computer science at Waterloo and in Canada. He was chair of the department for seven years, 1978-1983 and 1987-1989, and contributed substantially to its current size and stature. He was also a leader in the development of computer science in Canada and around the world, through the Canadian Computer Science Chairs Committee, and the Computing Research Association.

In 1974-75 he was Visiting Professor at the University of Paris under the Canada-France exchange program. In 1984 he held a research fellowship at Kyoto University from the Japan Society for the Promotion of Science. He received a Certificate of Appreciation from the Computing Research Association in 1992. On retirement from Waterloo in 1996 he was named Distinguished Professor Emeritus. In 2001 the Catholic University of Lublin, Poland awarded him a Medal of Merit. In 2005, not only Dr. Brzozowski, but also two of his former Ph.D. students, were named Canadian Pioneers in Computing by IBM Canada. In 2015 a one-day international conference in honour of his 80th birthday was held in Waterloo to recognize his many research accomplishments. A multi-author book entitled The Role of Theory in Computer Science, Essays Dedicated to Janusz Brzozowski was published in 2017 by World Scientific.