Professor Emeriti Alfred Lehman
May 2006 Alfred (Al) Lehman, Professor Emeritus, passed away on May 8, 2006.
Al received his PhD from the University of Florida in 1954 and joined the Departments of Computer Science and Mathematics at the University of Toronto in 1965. Although Al didn't publish many papers, he was a very deep and brilliant researcher. He supervised two PhD students, Tim Walsh and Greg Heil. In 1991 he received the prestigious Delbert Ray Fulkerson Prize for his work in the late 1970s on width-length inequalities. This belated recognition arose from Manfred Padberg's discovery that Al had solved in great generality an open problem that had arisen from the work of Robertson and Seymour. He is survived by his wife, June Mines. He was truly a kind and gentle genius.
From Professor Derek Corneil:
"Soon after Al arrived at the University of Toronto, I took his graduate course on Graph Theory. Many times during mathematical conversations with Al in the intervening years, he would comment "of course, you remember that from my course". I never had the heart to tell him that my memory wasn't in the same league as his. Despite deteriorating health, Al was a regular attendee at a broad range of Computer Science and Mathematics seminars. Having known him for over 40 years, I cannot remember Al arriving at, or leaving, a seminar early!"
[news.utoronto.ca]
Professor Kenneth C. Sevcik
October 2005
Ken's work in performance evaluation has been called "an exemplar of experimental computer science." He was a founder of the field of computer system performance. He made influential contributions to both the theory and practice of computer system performance evaluation. His seminal work on queueing network models has had a lasting impact on industrial practice and provides a foundation for much of the performance research that has followed it. Database researchers know him for his work on grid files, an early multidimensional indexing technique that remains on the required reading list in most Ph.D. programs, and for his extensive work on database system performance. He was an early member of the ACM SIGMETRICS Board of Directors, the premier organization for the promotion of research in performance analysis. In 2004, he received the SIGMETRICS Achievement Award in recognition of a career devoted to sustained, long-lasting, and high-impact contributions to computer system performance evaluation in the technical, leadership, and mentoring dimensions. In his career at the University of Toronto, he graduated over 50 M.Sc. and 20 Ph.D. students in performance evaluation, parallel processing and database systems. His students have in turn produced a large and distinguished family tree that includes more than 200 Ph.D. offspring as of 2004.
Writing in connection with Ken's 60th birthday celebration in 2004, four of his early students said, "Ken managed to be our friend as well as our advisor, without letting either of those relationships interfere with the other. This is at the heart of the immense respect we have for him, both professionally and personally. In the final tally, how well one has done as an advisor is reflected in how much one's students have learned. We owe Ken a terrific debt for the lessons he gave us about performing and leading research, and about how to lead our lives."
Ken was an exceptional mentor, an exceptional academic, and a man of profound wisdom. He leaves a tremendous hole in our University and our hearts.
[news.utoronto.ca]
Professor Alberto Mendelzon
June 2005
It is with great sadness that we report that Professor Alberto Mendelzon passed away on June 16 after a two year struggle with the illness that finally took his life. Alberto, originally from Argentina, received his Ph.D. from Princeton in 1979 and joined the University of Toronto in 1980. Alberto was an international leader in database theory. His work was inspired by the intriguing problems that lie at the heart of understanding how data can be modeled, managed, and queried in computer systems. He established fundamental and influential results in the theory of data management with many applications that only came decades later. For example, his work provided the basis for languages used to search the web. The volume of these applications is a testament to the truly foundational nature of his research.
He was one of our most prolific researchers, who published some 110 refereed articles in journals, conference proceedings and books. He supervised 31 M.Sc. students and 17 Ph.D. students. The volume of research funding he brought to the University is impressive. He also served the database research community by editing journals, organizing conferences, and in many other ways.
In 2003, Alberto became the first Chair of the then newly created Department of Computer and Mathematical Sciences at UTSC, a position he had to resign from only a few months later due to the onslaught of his illness. This did not slow down his research productivity or teaching, he kept up the pace of his work until the very last days.
[news.utoronto.ca]
Professor Raymond Reiter
September 2002 Raymond Reiter, professor of Computer Science at the University of Toronto, fellow of the Royal Society of Canada, and winner of the 1993 Research Excellence Award of the International Joint Conference on Artificial Intelligence, died on September 16, 2002. Reiter, known throughout the world as 'Ray,' made foundational contributions to artificial intelligence, knowledge representation and databases, and theorem proving. Among many other things, he was the prime mover in the Cognitive Robotics initiative that led to a whole new program of research.
From Fiora Pirri, Geoffrey Hinton, and Hector Levesque:
"Ray dedicated his life to his research with the wonder of a child, the fearlessness of an explorer, the precision of a mathematician, and the tirelessness of a researcher who found shallowness and confusion intolerable. He leaves a legacy of groundbreaking, deep insights that have changed the course of AI."
Professor Tom Hull
August 1996 Tom Hull died suddenly on August 15, 1996, in his 75th year. He had for nearly 20 years struggled with a less than perfect heart, but managed to enjoy life and contribute his full share to the Department he was so instrumental in building. Tom was Chair from 1968 to 1975, and during that time he master-minded the major growth of the department's faculty. In fact, many of the Ph.D. students he persuaded to come to UofT are now senior faculty at DCS.
Tom's main research interest for many years was in the numerical solution of ordinary differential equations, but later in accurate and efficient implementations of complex elementary functions, polynomial root-finding algorithms, and programming language facilities (especially precision control and exception handling) for numerical computing.
He received many honours, among them Fellow of the Royal Society of Canada, Fellow of the Association for Computing Machinery, and was awarded an honorary doctorate from Dalhousie University. He was a Professor Emeritus of the Computer Science Department. Tom was a scholar and researcher to the end, having just finished his last research paper the day he died.