Messages: 

(shared photos will be posted at a later time)

• Renyuan Zhang (Student, Colleague, Friend)

This morning, I suddenly heard from a friend that Prof. Wonham has passed away. This message made me very sad and depressed. The passed fourteen years with Prof. Wonham arose from my memories.

I first met Professor Wonham in Hangzhou, at May 2010. Before that, I have started the programming of improved algorithm of computing supremal quasi-congruence at 2009. I still remember our talk on synthesizing complexity of the computation. He was very nice to talk to me suffering my poor oral English. After the talk, we worked around the West Lake, and took several photos together. 

Then I visited Prof. Wonham at May 2011, and started a research topic on communication delay of DES under his supervision. From that time, I entered the amazing DES world and started my research life.

    From September 2011 to December 2012, I was an international visiting student in University of Toronto, and Prof. Wonham was my supervisor. He taught me not only how to formalize, solve problems scientifically, and write papers, but also how to make daily life happy. He’s and will be the light of my life. I have been always remembered that more than one years’ life under his supervision in Toronto. The following photos record several events in Toronto with Prof. Wonham.

     After I came back from Toronto, Prof. Wonham visited my work university two times, and gave two lectures titled as “50 years control research” and “The internal model principle of control theory”, at April 2015 and May 2018 respectively. That was the last time I met Prof. Wonham.

    Then, I mainly connected to Prof. Wonham through emails, and exchanged information on lives, and also the revisions and updates on TCT and TTCT. Until recently, we have discussed the revision on displaying TCT, and I told him I will send a new version to him. Unfortunately, he’ll never received another update on TCT any more. The following is the latest version of TCT I sent to Prof. Wonham.

    From 2009 to 2023, how time melts away. This fourteen years with Prof. Wonham were important in my life, and his attitude and sprit on science will guide me in my research. From him, I learned how to be a researcher, be a good teacher, and to be a happy person.

    Some words to Dear Prof. Wonham: 

    Dear Professor, Thank you for giving me helpful guidance in my life. You brought me to an amazing scientific world, and let me know the happiness of finding new methods and solutions. You also let me know how life could be. You will be there in my mind forever, your attitude and sprit will guide me in my life. May you rest in peace.

• Ziyue Ma (Xidian University, Xian, China)

Last we met in 2019 Spring, UofT. Wish you R.I.P.

• Rong Su (Former PhD student)

A great loss to the DES community and the entire control community! It is shocking to me, as Murray gave a seminar at NTU just one month ago, on April 19 at NTU, talking to young students here about how to become a successful researcher, and all audience were inspired by his wise words. As one of his former students, I was lucky to have a privilege to benefit from his wisdom and deep insights. He will be remembered by us all, and his legacy will stay with us forever. I also convey my deep condolence to Murray's family! 

• Ramakalyan Ayyagari (Colleague)

I have been influenced by Prof. Wonham's works on multivariable control, geometric control etc. since my graduate days in the 1990s. Glad that my undergrad student went on to study masters with him at Toronto in early 2000s. Hopeful to meet him some day, but now I cannot. My deepest condolences to his immediate family and to all of us who continue to be inspired by the genius. Rest in peace Murray.

• Lei Feng (Former PhD student)

Prof. Wonham is the role model for a teacher and researcher for my life.

• Lan Yang (Student)

It was my great luck to meet Prof. Wonham in China in 2015 when I began my Phd study. He taught me and encouraged me a lot during that period of time. I will never forget the enjoyment I had in knowing Prof. Wonham. 

• Murat Uzam (Colleague)

Dear Professor Wonham,  you have been a real gentleman. You have made great contributions to this world. Your memories will be in our minds all the time. Rest in peace.

• Zhou He (DES Lecture at Xidian University)

Rest in peace

• Xi Wang (Visiting PhD student)

Dear Professor Wonham, may you rest in peace. Deeply Remembering...

• Farzad Abdous (PhD student at Semnan University)

Please accept my deepest condolences for Murray's loss. What a lovely person who will be deeply missed. My heart is heavy today, and I know yours is too.

• Deguang Wang (Student)

It is my great honor and luck to be your student. Hope that you can continue to do what you love in heaven.

• Liyong Lin (Student and Collegue)

We miss you, Prof. Wonham.

• Chan Gu (Student)

Professor Wonham was my mentor, not just in academic terms. I always remember the first time I saw him, his kind smile and the walls of books behind him. During my year in Toronto, under his guidance, I not only found my academic direction, but also understood the rigor and persistence that a scholar should possess. I am very sad to hear the news of his passing. I still remember that we went to his house together to cook, drink, and chat, and he would share the flowers in his backyard and wine collection, and told us stories about his youth. Now, although he has passed away, I will never forget his teachings. His thoughts will continue to pass on. R.I.P.

• José Cury (Follower)

His life should be celebrated as being an illuminated trajectory that leave a trace of brightness!! 

• Abhra Roy Chowdhury (Student)

MY HEARTFELT CONDOLENCES TO PROF. WONHAM'S FAMILY !! MAY GOD REST HIS SOUL IN PEACE !! 

I WAS INTRODUCED TO HIS EXTRAORDINARY RESEARCH WORK THROUGH PROF. S.K NAGAR (IIT BHU). I WILL ALWAYS REMEMBER HIS EXEMPLARY RESEARCH NOTES AND DISCUSSIONS ON SUPERVISORY DES SHARED DURING HIS INDIA ( BHU VARANASI) VISIT; I EXPRESS MY SINCERE GRATITUDE TO YOU & PROF. NAGAR !!

• Christos Cassandras (Colleague)

I will always fondly remember conversations I've had with Murray. His remarkable intellect spanned topics from highly technical to broad and philosophical. He once shared with me the nasty reviewer comments he received on an early paper on Discrete Event Systems which were "predicting" that there was no future for such systems. I have since been using these reviews when talking about the history of the field.

• Yin Tong (Student)

Dear Mario, thank you so much for all the encouragement, caring, inspiration, support, wisdom, sharing, guidance, etc. for the last ten years. I'll always remember the precious and fun time we spent together. I'll always miss you. R.I.P.  Yours Toni.

• Karen Rudie (Former MASc and PhD student)

I am so saddened to hear the news of Murray's passing.   Murray Wonham was one of the greatest scholars in the field of control theory, a unique and brilliant mind.   He shaped the way I looked at research and was responsible for my career.  I will miss seeing him. My heart goes out to Anne, Marjorie and Cynthia. 

• Yu-Chi (Larry) Ho (Colleague and fellow Club 34 member (Club 34 are control theorist and engineer all born in the year 1934 consisting of Petar Kokotovic, Sanjoy Mitter, Karl Astrom, Y.C. (Larry) Ho, and Murray Wonham)

I look forward to join you on the other side in due time. Set up a Permanent Club 34 room for us. 

• Edwin Chong (Murray was my PhD advisor's PhD advisor)

Professor Wonham is an inspiration to many and will be greatly missed.

• Jan Komenda (Colleague)

It is with a deep sorrow that I have read the email message about passing of Professor Murray Wonham.

It is a great loss for the whole control community , his family, friends, and others.  He has been active until very recently, still updating his Lecture Notes, giving lectures for students, writing papers, and active at research gate.

I was lucky that I had a few occasion to talk to Professor Wonham. The last one seems to be the ceremony/workshop at CDC in Los Angeles back in December 2014 for his 80th birthday. It was a very remarkable and enjoyable event that I will always remember. Our Discrete-Event Systems community heavily relies on his pioneering work and it is likely that without his work our community would not even exist.

We are all grateful for his work with his books, Lecture notes, and so many papers that will inspire people for many decades.

May he rest in peace!

• Qinrui Chen (Student)

I am very grateful to the Prof. Wonham for teaching me about research and study, which will benefit me for life. It is my great honor and luck to be your student. We miss you so much, Prof. Wonham. R.I.P. 

• Brian Anderson (A professional admirer)

I met Murray a very limited number of times in my life, we never collaborated, or hosted visits in one or the other direction. Nevertheless I came to admire him as one of the preeminent contributors of my generation to control systems, and I associate him with some very powerful ideas (internal model principle, geometric control, discrete-event systems for example) underpinning our understanding today of control theory.  

• Steve Morse (Professional Collaborator)

I am shocked and saddened to learn of the passing of Murray Wonham. Although I have not worked with Murray for many years, we collaborated intensely early in our careers  on the development of linear geometric control theory while at the NASA Electronics Research Center in Cambridge, Massachusetts.  This was an incredibly exciting period and one which I shall cherish forever. It was plainly clear to me from the outset that Murray  was an amazingly smart and creative individual. Before I ran into him  at NASA, he had already come up with the separation principle of linear stochastic control theory and his celebrated pole placement theorem. Not willing  to rest on his laurels,  Murray went on to collaborate with many others  to establish with such highly innovative things  as the internal model principle and the  formalism for the supervisory control of discrete event dynamical systems. These and other contributions have made him a giant in the field of control system theory.

My heart goes out to Murray's  wife Ann to whom I send all the sympathy I can for  this tremendous  loss.

• Pablo Iglesias (Undergraduate advisor)

My sincerest condolences to the Wonham family.  I first met Murray in 1985 in a Signals & Systems class at the University of Toronto and it changed my life.  I loved the class and the way that he taught it. In addition to the classes, he led a two-hour problem session every other week (1/2 the class would meet one week, the other ½ the other). I would go to both.  I eventually signed up to do a Senior thesis with him and worked on an early version of his TCT (Toy Control Theory) software.  At the time, he had developed it in Prolog, but reworked it all in Pascal and made it much faster.  I ended up taking another course with him and sat in his graduate DES course.  I remember also asking him if he’d write a letter of recommendation for graduate school for me. He then took an interest and took me out to lunch a couple of times to discuss where I should apply to and go. It was at his suggestion that I ended up at Cambridge, and that turned out rather well.  We talked a number of times after. I met Marjorie in Cambridge when she was an undergraduate there.     

• (Samuel) Qing-Shan Jia (Colleague)

Professor Wonham was a giant in my field, discrete event dynamic systems (DEDS). He contributed so much to the birth and the flourish of DEDS, and in particular the supervisory control (together with Ramadge). I am truly sad to know his pass. This is a tremendous loss to our society. It is a sad day to me and to all of us. Wish Professor Wonham rest in peace. 

• Tongwen Chen (Student)

I received my MASc and PhD degrees from UofT Control Group. I took two graduate courses with Murray and studied his lecture notes on discrete-time optimal control and discrete event systems. I also studied advanced linear systems with Bruce Francis, who used Murray’s book on geometric control as the textbook. Murray’s pursuit of mathematical rigor and mathematical elegance in his work and writings has a lasting influence on my career. Murray’s legacy will continue for a long time.

• Christoforos Hadjicostis (Colleague)

I was deeply saddened to hear the news of Prof. Wonham passing away. He was a special person, very knowledgable and kind.

I had the honour and pleasure of interacting with Murray at various occasions: as a student when he visited MIT during his sabbatical leave, as a host at the University of Illinois where he delivered a series of lectures on discrete event systems, as a member of the audience in some of his lectures at Xidian University (which I happened to visit at the same time), as an editor-in-chief of JDEDS where he served for many years on the Advisory Board, and many others. In fact, we exchanged several emails last week (the last one on May 13th). It must have been very sudden, my deepest condolences to his family and friends.

Murray was a brilliant scientist and a gifted individual that inspired, and will keep inspiring, generations of researchers in discrete event systems (and not only).

It is a great loss to our community and he will surely be missed!

May he rest in peace!

• Margaret Chapman (Colleague)

Murray's office is next to mine in Galbraith. Last Friday, I saw the door open, and then on Monday, I heard about the very sad news of Murray's passing. What a wonderful human being. I hope that he is at peace, and I send my love and sympathy to him and his family and friends.

• Chuanning Wei (Student)

It is sad to hear about his passing, especially when I took his course only about half a year ago. The control community has just lost a talented, brilliant theorist, and I was lucky to be his student for several months. 

May he rest in peace.

• Geir Dullerud (Student)

It is very sad to hear of the passing of Professor Wonham.  His Systems & Signals course for junior-year Engineering Science students had a pivotal personal impact.  That Professor Wonham was a beacon of brilliance in the controls community for his research is widely appreciated, but what is perhaps less well known is how inspiring a teacher he was.  He had a unique insight and talent for determining what an analytically-interested engineering undergraduate could---and could not---process and appreciate, and the syllabus in this particular course was an extraordinary combination of mathematical precision and the bigger picture perspective of systems and signals.  I also took a senior-level course from him on optimization and optimal control, which was equally excellent, and had him as my undergraduate thesis advisor.  Memories of his research and teaching persona will continue to inspire into the future.  

• Peter Caines (Friend)

For decades we have been family friends of the Wonhams  and it is with shock and great sadness that we have learned of Murray’s death. Murray was  one of the pioneers of modern systems and control theory in the nineteen sixties and his contributions to the subject since then are too well known and too extensive to review here.  Suffice it to say that we use results due to Murray on an almost daily basis and that is the ultimate measure of their impact.  Murray’s keen intellect, creativity, scholarship (including the Greek classics) and wit were renowned.  Over the years, he  was a mentor and friend to Peter,  who engaged with Murray in countless lively technical discussions, reflections  and debates.  On a larger stage, Murray’s approach to the problems of cybernetics was an inspiration to  generations of his students and collaborators who demonstrate his influence in their own contributions to the subject.

We send our heartfelt condolences to Anne Wonham and their children, Marjorie and Cynthia,   for their profound loss at this time. -   Peter and Anne Caines   

• P. R. Kumar (Colleague)

Very sad to hear this. It is a huge loss to the community. Wish all strength to the family.

• Ali Afzalian (Colleague)

I am deeply saddened by the news of his passing and extend my sincerest condolences to you during this difficult time.

Murray was an exceptional professor. His passion for teaching and dedication to his students were unparalleled. He encouraged his students to think critically and creatively.

I will always cherish the memories I have of Prof. Wonham and the lessons he taught me. His legacy will continue to live on through the countless lives he touched.

• Eric B. Kopp (Student)

I took Discrete Event Systems with Dr. Wonham and had many fascinating and profitable discussions with him throughout my Ph.D.  He was one of the most singularly brilliant men I've met during my lifetime, not only in terms of control theory, but also formal language theory, the history of control, and a broad range of other topics. I never had a conversation with him that didn't leave my mind buzzing with thoughts and questions and ideas. This is one of the greatest things that an educator and researcher can provide to a student, and so I'm deeply grateful for the opportunity I had to learn from such an outstanding teacher. Thank you, Dr. Wonham. May God bless your family with peace in your passing.

• Ryan Leduc (Former PhD student)

I was very saddened to learn of the passing of Prof. Wonham. He was my Masters and Phd supervisor and the University of Toronto.  He started me on my path as a DES researcher, and I have no doubt that his recommendation helped get me my current position at McMaster University. 

He was a wonderful teacher and I owe him greatly for all I learned under his tutelage, and the many skills he imparted.  His research accomplishments speak for themselves, and will continue to be a benefit moving forward.

He will be missed.

• Bowie Cheung (Student)

I'll always look back fondly on my time with Professor Wonham. He taught me to think critically about work, life, and what's the meaning of time well spent. He knew how to teach high standards without being a jerk or a show off. I think he really enjoyed teaching, and I was a beneficiary of that. We'll miss you Professor!!

• Shahin Hashtrudi Zad

A true gentleman and exceptionally gifted at uncovering the secrets of control theory. He was always available to help students. You just had to "knock and enter."

My heartfelt condolences to the family of Prof. Wonham.    

• Feng Lin (Student)

When I received the heartbreaking news, I was very sad and shocked. I told Murray in January that I will visit him in Toronto in the summer. I was actually planning to visit him in July. I feel sorry for not visiting him earlier. It is too late now.

I first met Murray more than 40 years ago, in January of 1983, at his office in Galbraith Building. Since then, I have learned a great deal from him, not just on discrete event systems, but also on how to do research and to be a useful person to society.  When I first met him, I had no idea how to do research. He showed me how to think, how to formulate research problems, and how to solve them logically. He also taught me how to write good proof and good papers.  All those have benefited me greatly. He was always very kind to me and encouraged me when I had difficulties. The way he treated me has great influence on the way I treat my students. In this sense, my students also benefited greatly from him. 

Indeed, our community has lost a great person and leader, and I have lost a great teacher. Murray will live in our hearts forever. 

• Alessandro Giua (Disciple and colleague)

Murray Wonham led a remarkable life, marked by numerous scientific contributions in the area of control theory such as geometric control, the internal model principle, and supervisory control of discrete-event systems. He also nurtured diverse cultural interests, exemplified by his dedication to studying Italian in order to read Dante in its original language.

Just one week prior to his passing, Murray wrote to me, expressing his thoughts on the elusive nature of time: "Time has this awkward property of melting away, and something should certainly be done about it, but as yet I haven't figured out what." At this moment, I am confident that the Poet is offering him comfort in Paradiso, acknowledging how skillfully he harnessed time “che perder tempo a chi più sa, più spiace.” (because wasting time is more regretful for the wise man).

• Zhiyong Sun (Follower)

Prof. Wonham was once invited to visit Xi'an Jiaotong University (XJTU) of China while I was a master student studying automation at XJTU. During his visit he gave a seminar, in which he talked about his research career and some control topics. Through the eyes of a master student at that time, I only knew that "he is a big name" but was then not able to fully understand his research topics; I asked one question about his career, and he was so nice, so kind and patient to share his career story. This was my first interaction with Prof. Wonham. That seminar where he presented various control topics was like an academic seed to me, which to some extent also motivated me to pursue a PhD degree in control and join the control community.     

That seed arising from the first interaction indeed had a profound impact on my career. Later I came to Australia to start a PhD in control engineering. On several occasions I learnt some interesting and inspiring stories about Prof. Wonham from my PhD supervisor (Prof. Brian Anderson). Though I did not have the opportunity to have more interactions and establish collaborations with Prof. Wonham, his research works have always been a source of great inspiration to the young control generation like me. I still remember many exciting moments when reading his early and influential papers on pole assignment, internal model principle, etc. His book on the geometric approach for linear control has shown me the true elegance and deep thinking that has a lasting influence.  R.I.P. Prof. Wonham. 

• John Hepburn (Former PhD student, Friend)

Murray Wonham was a brilliant intellectual with an inquiring mind and he was the finest system theorist. He was dedicated to academic research and education. He made pioneering and seminal contributions to three different areas of systems control and remained active in research and teaching and publication right to the end. He was very modest. Never one to rest on his laurels, he always looked to the future of his field. He thought deeply about ideas and guiding principles in his research. He published technical books and many journal and conference papers, all of very high quality. His professional work was meticulous and his writing was precise, concise and elegant, and marked by clarity of thought and expression. He was deservedly awarded many prestigious honours.

He took teaching and the supervision of students very seriously and was very supportive in encouraging them and helping them to establish their careers. He was kind and empathetic with a high degree of integrity and sense of honour. He was a brilliant student through school and university, foreshadowing his career. As an aside, Leonard Cohen was in his class in Montreal and they would sometimes walk home together after school.  He travelled widely, especially in North America, Europe, Asia and North Africa.

He loved books and written and spoken language, both technical and natural, and the classics. He read widely including western literature and Homer in Greek, and enjoyed translating ancient Chinese poetry. He sometimes took delight in quoting from poetry and literature, le mot juste.

His maternal grandfather was a very successful financier in Montreal and built a fine house on Belvedere Road in Westmount, overlooking the city. The outer walls used granite imported from Indiana. His grandfather collected fine art, such as paintings by the famous twentieth century English maritime painter, Montague Dawson, and valuable fine classic books. Murray felt privileged to inherit the latter and enjoyed reading them, and also had the bindings beautifully restored. His grandfather also owned a property on the east side of Lake Memphremagog, originally with a house, and also a log cabin which survives. I visited some years ago, sleeping in a tent by the shore, and on a fine day with a fresh breeze, Murray took me for an exhilarating sail in his dinghy, a CL-16 if I remember correctly.

We were very good friends. We used to play vigorous games of tennis on Saturdays, and afterwards have interesting discussions on a wide range of topics. This continued past his eightieth birthday. Latterly he slowed a little and would stand in the centre of his court and chase me round my side by hitting the balls all over, deep and shallow, deuce and ad; he enjoyed watching me run them down and return them to him, while I enjoyed the exercise! We also used to meet regularly for lunch, usually at a Thai restaurant a few blocks from his home with Anne.

The world has lost a great man.

• Stéphane Lafortune (Colleague)

Murray Wonham was a giant. I am deeply saddened by his passing. His fundamental contributions to control theory span seven decades. His ground-breaking papers on discrete-event systems and their supervisory control shaped my entire academic career. The first time I met Murray was at the University of Toronto in 1986. He had invited me (by sending me a telegram!) to give a talk to his group. Over the last 37 years, I have continuously learned from his scholarship and greatly benefitted from his sound advice and support.

Merci Murray.

• Peter Ramadge (Former Ph.D. Student)

Murray Wonham will not easily be forgotten. He was a model scholar, mentor, and teacher.  He inspired others to tackle challenging topics; his feedback was always direct and incisive. It was a privilege to be his doctoral advisee. May you rest in peace, Murray.

• Ringo Chan (Student)

Every so often, I find myself searching for updates on my favorite individuals, eager to catch a glimpse of their current endeavors. On occasion, I even contemplate attending their events to relive cherished memories. Murray was undeniably one of the top names on my list.

Today, I am met with a jolt of disbelief upon learning that Murray passed away just a few months ago, which comes as a shock given his recent activity. The news has left me utterly devastated. In my despair, a flood of memories from over four decades ago inundates my mind — memories of how he not only nurtured my academic growth but also cultivated in me the ability to think independently. I recall how he offered his assistance when I faced financial struggles during my graduate studies, and how he rescued me, a young and reckless researcher, from the chaos I created at the computer center. I can still vividly remember sharing dinner in his home, alongside his wife and a young Cynthia.

Murray wasn't solely a teacher or mentor to me; he was a guiding light that consistently illuminated my path. He possessed not only remarkable brilliance but, even more uncommonly, a heart full of kindness. 

Today, with a heavy heart, I extend my condolences to his family. Though my heart aches, I am confident that a noble soul like Murray will continue his journey in the realm beyond, and his spirit will forever reside within my heart.

• Ramavarapu "RS" Sreenivas (Researcher in one his many areas)

I learned of Murray's passing during an annual conference held at my university. I have vivid recollections of our interactions when he visited my university as the Robert T. Chein Distinguished Lecturer. Murray was renowned for his significant contributions to various aspects of control theory. Our lunchtime discussions initially revolved around these subjects, but they soon expanded to encompass other interests such as music, literature, and politics. His exceptional intellect and captivating personality left a lasting impression on everyone who had the privilege of knowing him. Murray will be deeply missed by all of us. Om Shanthi, may he rest in peace.

• Chao Gu (Follower)

I had the privilege of meeting Professor Murray Wonham for the last time on May 11, 2018, the day after he finished his courses on discrete event systems at Xidian University in Xi'an, China. At his apartment, Professor Murray Wonham generously shared insights into research and academia that continue to shape my journey to this day. His scholarly excellence, visionary outlook and charismatic personality have been a constant source of inspiration.

Rest in eternal peace, Professor Wonham. Your legacy lives on.