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After 35 years as a faculty member in Georgia Tech’s H. Milton Stewart School of Industrial and Systems Engineering (ISyE), A. Russell Chandler III Chair – and now Institute Emeritus Professor – George Nemhauser has retired. Summarizing all that Nemhauser accomplished throughout his 60-year-long academic career is a near-impossible task, as he developed theory and applications that shaped and energized the field of operations research (OR).

A true leader, he also served his profession by dedicating his time to professional organizations, mentoring doctoral students, and working with Institute and Stewart School leadership to attract top research faculty and students. It is not an overstatement that Nemhauser’s presence at the Institute contributed to ISyE and Georgia Tech’s trajectories to, respectively, the top industrial engineering school and one of the top public universities in the U.S.

Nemhauser’s own rise as an operations researcher was meteoric. After finishing his dissertation at Northwestern University under the tutelage of OR pioneer Jack Mitten, he was hired by Johns Hopkins University, which had an outstanding OR program at the time. From there he went to Cornell University’s prestigious Department of Operations Research and Industrial Engineering (ORIE) for 15 years, where he was School Chair from 1977 to 1983 and held an endowed chair.

His research, which primarily concerns large mixed-integer programming problems and their applications, has earned him several major optimization awards: He is the first person to receive the Lanchester Prize twice (1977, 1989); the inaugural recipient of the Khachiyan Prize (2010); the John von Neumann Theory Prize (2012); and international recognition from the Canadian Operations Research Society via the Harold Larnder Prize (2012). He also received the Philip McCord Morse Lectureship (1992) for his teaching contributions, and the George E. Kimball Award (1988) in recognition of his many years of service to INFORMS. 

“George built his reputation from his research – coming at OR from both theory and application – and through his engagement with colleagues in the field,” noted John Jarvis, retired ISyE professor and former school chair. “He founded Operations Research Letters and served as president of the Operations Research Society of America [1981], which were distinguishing contributions.”

Andrew Schaefer, Rice University Noah Harding Chair and professor of computational and applied mathematics and one of Nemhauser’s doctoral students (Ph.D. IE 2000), concurred. 

“A significant amount of the field of integer programming’s success is due to the fact that George cared deeply about the theory,” he explained. “But he was also able to see how the theory, computation, and applications all fit together and thus developed techniques that are useful everywhere – such as his work with sports and airline scheduling. Through George’s leadership, integer programming has been at the forefront of all OR research, and in the late 1990s, ISyE was way ahead of the rest of OR in terms of integrating real-world problems into the field.”

Given Nemhauser’s reputation for unrivaled work in OR, it’s perhaps not surprising that when Nemhauser left Ithaca, New York for Atlanta and ISyE at Georgia Tech, this move generated bemusement among his colleagues.

At the time, Georgia Tech’s standing was that of a highly regarded regional school. Then-President Joseph Petit had come from Stanford University with the goal of making Tech a top research institution and raising its national – even international – stature. In line with this, ISyE alumnus Russ Chandler (IE 1967), who had just endowed the first ISyE chair as part of the Institute’s first-ever capital campaign, and ISyE School Chair Mike Thomas, who had been one of Nemhauser’s first Ph.D. students at Johns Hopkins, wanted to bring in a renowned professor. Nemhauser fit the bill.

“Russ basically told Mike, ‘Let’s get the best person we can, independent of research area,’” remembered Professor Emeritus Gary Parker. “Armed with the resources of the A. Russell Chandler endowment, Mike had the foresight and inclination to invite George to consider Georgia Tech and all that he could accomplish here.”

Nemhauser’s arrival at the Institute caused its would-be peer institutions – Berkeley, Stanford, MIT, and Cornell – to take notice, and his presence catalyzed other prominent engineering academicians to take Georgia Tech seriously as a place to conduct research and teach. One such was Ellis Johnson, a world-renowned expert in integer programming. He joined Georgia Tech’s faculty in 1995 as a member of the National Academy of Engineering – ISyE’s second after Nemhauser, who had been elected in 1986 and was the Institute’s first sitting faculty member to be so honored.

Nemhauser’s insistence that elevating the Institute’s other colleges alongside the College of Engineering would uplift Georgia Tech’s standing as a whole influenced the organization of the College of Computing and the reorganization of the Colleges of Business and Science. Math also deserved a special focus, because, Nemhauser said, “We can’t produce the best engineers in the country without a solid mathematical foundation.”

“With George urging us on,” Jarvis recalled, “we worked to more closely connect the School of Mathematics and ISyE. OR and math go hand-in-hand as courses of study.”

A substantial by-product of this effort was Nemhauser’s role as a principal founder of the Algorithms, Combinatorics, and Optimization (ACO) Program, a doctoral program jointly supported by ISyE, the School of Mathematics, and the College of Computing. The ACO program is still only one of two such degree programs in the U.S. and remains a model for outstanding interdisciplinary programs at Georgia Tech.

And of course, while Nemhauser was impacting Georgia Tech, he was simultaneously helping to shape ISyE. He successfully shepherded the separation of the School’s doctoral and master’s programs, which allowed top-notch graduate students to be directly admitted to the Ph.D. program. The challenge of accomplishing this cannot be overstated, Parker explained, as others in ISyE’s past had attempted this in vain.

Nemhauser’s tireless efforts to promote ISyE – and the elite faculty and students who came to Atlanta in his wake – eventually led to the Stewart School’s graduate programs being ranked No. 1 by U.S. News & World Report for the first time in 1990. The undergraduate program followed five years later, and both programs have held the topmost position ever since.

“George is remembered by many as ISyE’s greatest champion, well-regarded for being supportive but stern,” said Cornell ORIE School Director Mark Lewis (Ph.D. IE 1998). “If he said it, you knew that he had thought through each angle so that the School would continue to thrive.”

“A prominent ISyE professor once told me,” Jarvis recalled, “that given the caliber of OR faculty who were attracted to ISyE because of George, ISyE has long been considered the centroid of the optimization universe.”

Just as important as his vision for what ISyE and Georgia Tech could become has been Nemhauser’s role as a generous faculty mentor to the more than 70 graduate students he advised. 

Schaefer noted that Nemhauser modeled a singular approach to research, which in combination with the considerable time he spent thinking about dissertation topics for his students, set them up for career success.  

“You know how it was said of Wayne Gretzky that he saw where the puck would be rather than where it actually was? That’s George as an advisor. He saw where the OR field was going, what problems would be studied 5-10 years into the future, and those innovative problems were what he advised his students to work on,” said Schaefer. “In my case, George suggested that I look at this very new and interesting field called stochastic integer programming, which maybe had three papers written on it at the time. These days, the field has almost limitless demand in terms of its applications, the problems it can address. 

“Given George’s foresight,” Schaefer continued, “this meant that when his students completed their dissertations, we often had already spent five years thinking about a problem that other OR practitioners were just beginning to consider. Many of us have tried to emulate this and give our own students similar opportunities.”

Pam Vance (BChe 1986, MSOR 1989, Ph.D. IE 1993), currently a managing director at fintech company Qontigo, said that Nemhauser modeled for her how to approach mathematical problems with “endless energy, curiosity, and tenacity. George taught me optimization, of course, but he also taught me how to sell ideas – whether on the page or standing in front of an audience. He was always supportive of me and my goals, one of my greatest champions.”

As a young faculty member at ISyE, MIT Chancellor Cynthia Barnhart co-advised Vance with Nemhauser. 

“George was an incredible mentor,” she recalled. “He invited me to take on a co-supervisory role with some of his students, which meant I had access to the best students, because they wanted to work with him. I had the opportunity to both learn how he did research and how he advised students. George had a style that was very respectful of the students – he was teaching them, yes, but he was also learning from them. It was especially rewarding to do research with him – he was very collaborative, devising projects that involved several faculty and students. It was a chance to learn from others and how differently people can approach problems. 

“But you can’t just talk about George the teacher or George the researcher. He’s also a personality with a strong sense of fun. He and Ellen [Nemhauser’s wife] are very generous, and they invited people to their home and to share in their interests: wine, travel, hiking, art, and good conversation. He is one of my favorite professors in the world – because of his excellence, certainly, but also because of his collaborative and generous style,” Barnhart added.

In 2015, five years before his retirement, Nemhauser was honored by Georgia Tech with the Class of 1934 Distinguished Professor Award, which is the Institute’s highest faculty award. It is given to a current professor who has made significant, long-term contributions that have brought widespread recognition to the professor, to their school, and to the Institute.

“Almost all the awards I have received have been from my profession,” Nemhauser said at the time. “This is the Georgia Tech award. This means a lot to me because it connects directly to Georgia Tech.”

He announced his retirement to the faculty and staff of ISyE via email. 

“These many years at Tech have been a wonderful time for me,” he wrote. “It was thrilling to be a participant in ISyE’s ascent to be the No. 1 school in industrial engineering and operations research.  … We built what I believe was the best optimization group in the country, if not the world. … When I left Cornell to join the faculty at Tech, my Ivy League colleagues thought I had gone off my rocker. But it turned out to be one of the best decisions I made in my life thanks, in part, to the colleagues I had the opportunity to work with at Tech.” When news of his retirement became widely known, tributes from colleagues and past students poured in from around the world. (You can read these below.)

Currently, Nemhauser is still co-advising three Ph.D. students and plans to continue a few research projects. (There is a departmental joke that Stewart School faculty members don’t actually leave when they retire from the School.) He is part of a large group of ISyE professors who are submitting an NSF grant related to machine learning, artificial intelligence, and optimization. He and his wife, Ellen, have traveled extensively throughout the years, and they plan to resume their regular trips to New York City once the Covid-19 pandemic is over, and it is safe to do so.

As for his work’s significance for the field of operations research, those who know Nemhauser best expect that to continue. 

Schaefer said, “What makes George so remarkable is his breadth as much as his depth. I think we will be revisiting his technical ideas for years to come. Concepts George came up with decades ago are having implications for current research; for example, the ideas in the paper for which he won the 1977 Lanchester Prize are being widely examined in data science and machine learning circles today. [It discussed locating bank accounts so as to optimize ‘float.’] His impact goes far beyond optimization and OR.”

ISyE Leo and Louise Benatar Early Career Professor and Associate Professor Alejandro Toriello, another Nemhauser advisee (Ph.D. IE 2010), noted, “When I teach my Ph.D. logistics class, I discuss a paper of George’s from the late 90s that puts forward a technique to deal with very very large, complicated integer programming problems. Over the course of his career, George pioneered using integer programming as a means for useful industrial applications – the airline and sports scheduling, for example. The methodology had a reputation that it could only be used for small problems, but he put a lot of effort into showing it can do so much more. George had ideas that have continued and furthered his influence in the field.”

When Chandler was asked for his reflections about the professor who for so long occupied the chair he endowed, he said, “All I can say is that there are very few faculty selections that have had a greater impact on the reputation of a school – and even a university – than that of George Nemhauser. We knew he was outstanding, but little did we realize how much his presence would attract other top faculty members. Soon the ISyE School at Georgia Tech would become No. 1 in the world, and it remains that way 25-plus years later! George was the catalyst, and we will all miss him, but we will remain on top because the foundation has been firmly laid, beginning with him.”   

George Nemhauser will be honored with a retirement celebration in Atlanta in fall 2021. You can read a Q&A conducted with him shortly before his retirement here.

More about George Nemhauser

• From Shakespeare Ave in the Bronx to North Ave in the ATL (authored by ISyE Professor Emeritus Gary Parker and Professor Dave Goldsman)
• INFORMS Biographical Profile: George Nemhauser
• Nemhauser Honored with Class of 1934 Distinguished Professor Award: ISyE Professor Hits Home Run with Top Honor
• NemFest: Celebrating Optimization Legends George Nemhauser and Arkadi Nemirovski
• Mathematics Genealogy Project
• 75 Years of Industrial Engineering at Georgia Tech: A Brief History
• ISyE’s National Academy of Engineering Members

Well-Wishes for George Nemhauser from Colleagues, Students, and Friends

George has been and continues to be an inspiration and role model for me since my early days as his doctoral student at Georgia Tech. His impressive wealth of knowledge and experience has made him a natural attraction as an advisor for students. That is, of course, not surprising for the giant of operations research. What is really special about George is his genuine warmth, humility, and wit that put everyone in the room with him at ease and led to unhindered discussions and creativity. George’s vision, research, and passion for integer programming have spread all over the world through his books, papers, and students and have been transformative in numerous optimization-based technologies that are now ubiquitous. Thank you, George, for inspiring us over the years, and congratulations on a richly deserved retirement! – Alper Atamturk, Professor, University of California-Berkeley 

I feel privileged to have worked with George. I am most impressed and humbled by how much he cares about his students as people, and how he values and focuses on each individual's strengths as opposed to their weaknesses. He told me once that his students are like his family, and I truly felt this in working with him. As a world-renowned researcher and expert in our field, he still takes the time to engage with his students and serve undergraduate and graduate education. His legacy in our field will certainly live on through this contribution. Best of luck in retirement, George! – Kelly Bartlett, Commercialization Program Manager, Dematic

I will be forever grateful to George for many things, not least his enormous contributions to the field I love: integer programming. But for me personally, George means much more. First, I owe my entire career to George. Nearing the end of my Ph.D., which was in nonlinear programming, I attended a conference in Singapore in 1991. Among my vivid memories of that event was George’s workshop on integer programming. It was electrifying, and I decided then and there to make my career in that field. The conference dinner was on a boat – a harbor cruise – where I had the chance to talk to George and also met Ellen for the first time. At that time, I started talking to George about the possibility of a postdoc at Georgia Tech. After a detour to Waterloo, in Canada, I took up the postdoc at Georgia Tech in 1994 – with George as my advisor – for a most amazing year. It started in a similar way to many of the postdocs and faculty colleagues that George brought to Atlanta: with a stay in the lovely apartment atop the garage, in the midst of Ellen’s gorgeous garden, in their house at Villa Drive. 

Such a warm and personal welcome was a big part of being a close colleague of George. George always liked to have fun. There was never much separation for George between friends, “work,” and family: All were mixed together in a heady brew of excellent food, great wine, incredible art, outstanding integer programming, and wonderful conversation. And for me, in around May that year, came the second major life event that I owe to George: Through his student Pam Vance and her husband, I met my first husband, an Atlanta-born Georgia Tech graduate. He and I were married in George and Ellen’s garden the following year, thanks to their incredible generosity. And later that year, George gave my career a great kickstart by visiting Australia for three months during my first year as an assistant professor at the University of Melbourne. 

Fast forward many years, which included fun and rewarding collaboration with George in the early years and catching up at the occasional conference in later years, and I can credit George with a third major life event: my second husband, Martin Savelsbergh, whom I would never have known if it hadn’t been for George – though I think it came as a big surprise to all of us when Martin and I became a couple in 2009! I don’t think many people can claim George had such a profound impact on their life as I can: a life-time career and two husbands! But that is George, who never does anything by halves (only integers!).  – Natashia Boland, Fouts Family Professor, ISyE

It was my real honor and cherished experience working with George during my Ph.D. study at Georgia Tech. It was an enjoyable and exciting moment. George's vision of research and mentorship inspired and nurtured me, not only for my dissertation work, but also for my whole career. Although this happened 15 years ago, George's instructions were vivid and as if it just happened yesterday. Additionally, my most gratefulness to George is his encouragement to me for an academic job. Before my graduation, due to various reasons such as no interest or no tradition, there were no Chinese graduates from George Tech ISyE going to U.S. academia. His encouragement strengthened my confidence to make it happen. This experience is unforgettable, and the most significant asset George gave me is confidence. Thank you, George. I wish you good health and happiness always. -- Yongpei Guan, George and Rolande Willis Endowed Professor, University of Florida

George is a man with big wisdom. He has given me simple but life-changing advice. For example, when I felt uncertain about my future before graduating, he told me that the most important thing is to “follow your heart.” From then on, whenever I face difficult decisions in my life, I always ask what I want from the bottom of my heart. Looking back, I have no regret on any of the decisions I made. George has also impacted me in many ways as a scholar. Hiswork is mostly motivated by solving problems in practice, such as political districting, airline scheduling, network design, and integer programming in general. I adopted this problem-driven principle early in my own research. When I became an assistant professor, I made sure that any topic I chose came from the need of solving a practical problem. My recent move into industry is further driven by my interest to see how large-scale optimization problems are tackled in practice.

Last but not least, George has a great sense of humor and brings lots of laughter to work. One time I was having a weekly meeting with George and Shabbir Ahmed, and I was trying to complete a proof on the whiteboard. One equation read as E=mc. At that moment, Bill Cook walked by. Without saying a word, he picked up the marker and added a superscript 2 to the letter c. Immediately, George raised his arm and cheered, “We found it!” Everyone burst into laughter. – Qie He, Applied Scientist, Amazon

When I needed to put together a proposal for the Transdisciplinary Research Institute for Advancing Data Science at Georgia Tech, I consulted George, and he offered numerous good suggestions. He also shared several of his past relevant experiences, both positive and negatives ones. This was extremely helpful for us to finally win that project from the National Science Foundation. Thank you, George! – Xiaoming Huo, A. Russell Chandler III Professor, ISyE

We used George’s book in my integer programming class when I was a Ph.D. student at Carnegie Mellon. I remember going through the book line by line and learning a lot in the process. It had been a great honor to meet him, a legend, in person (dinner at a French restaurant) during my interview for a faculty position in ISyE, and then to become colleagues. – Pinar Keskinocak, William W. George Chair and Professor, ISyE

George, you were a superb adviser; I could have not asked for a better one. My memorable graduate study is exclusively attributed to your guidance, passion, and great personality. I cannot think of a person more deserving retirement than you. Sincere congratulations to all of your achievements and a fantastic career. – Diego Kalbjan, Professor, Northwestern University

George Nemhauser and Ellis Johnson, both my Ph.D. advisors, have taught me that any problem, no matter how hard, can be solved if you have a right mind and determination. I’m forever grateful for their teaching, as this has become my guiding principle. – Ladislav Lettovsky, Director of Sales Support AirCentre & AirVision, Sabre Airline Solutions

What a privilege it is to have been a student of Dr. Nemhauser! There are far too many pleasant memories and impressions etched in my mind while I was his Ph.D. student.  A few that stand out are his attention to detail, his passion for basketball, and his love for wine. It was rare for George to miss a home game, but, whenever he did, his Ph.D. students often received his tickets. This is how I got indoctrinated as a basketball zealot. And I vividly recall sitting on the steps at George’s house late one evening as a party was winding down, but the wine was still flowing. As if George read my mind, he said, “Anuj, when you understand great wine, it does not have to be expensive.” After spending a fortune over the past three decades, I have still not succeeded in acquiring George’s flair in wine selection.

I do not believe I was the only student that George called late at night to go over the edits in the dissertation page by page. When I graduated, George presented me Dr. Seuss’s book entitled “Oh, the Places You’ll Go!” and claimed that I would learn more from that book than I did from him. I believe that is the one time you were incorrect, George, for I have learnt a lot more from you. George, you are an inspiration and an example of why academia is respected. I want to wish you the very best as you enter the exciting phase of retirement and “Oh, the places you’ll go!” – Anuj Mehrotra, Dean, School of Business, George Washington University

Like so many of his former students, I will always be grateful for George's guidance and support during my studies and subsequent career. The role he played in my growth as a scholar, an academic, and an operations research professional cannot be overstated. But what I will also always remember about George is the interest he took in his students and others on a personal level. I always appreciated his friendliness and the fact that he was down-to-earth in his interactions with people. 

There is one memory in particular that I will always remember with fondness: One evening George had an extra ticket to the Yellow Jackets home basketball game, and he had the thoughtfulness to come to the graduate students' office to see if any of us who were there wanted to go with him. It was my good fortune to join him. This was the era of Matt Harpring and Alvin Jones; Georgia Tech won that night, which made the evening that much more enjoyable. I will never forget celebrating and high-fiving my advisor as the Jackets surged to victory. I have great memories of times with George after finishing my Ph.D., too. For example, I was fortunate to spend a lot of time at CORE in Louvain-la-Neuve, Belgium during my academic career, and George made a few visits that overlapped with my time there. I always appreciated how good-natured he was when teased about the fact that he had not quite mastered the local language during the years that he spent there.

I am grateful for the impact that George has had on my life, and I wish him and his family all the best in retirement. -- Andrew J. Miller, Marketing Senior Data Scientist, UPS

During my time as a Ph.D. candidate, I thought I would be happier if there were no weekly meetings. Now, I truly miss those meetings with Dr. Nemhauser. He was always kind and warmhearted – I can still remember his comforting words after my first failed job interview. It was indeed a great honor and privilege to be his student. -- Byungsoo Na, Associate Professor, Korea University

Working with George as co-examiners of more than 50 Senior Design projects has been no less than a gift. I will miss the endless hours of presentations, meetings, laughter, and the pure joy and pride we felt at the end when our students get out. – Dima Nazzal, Director of Professional Practice, ISyE

I can think of only very few researchers whose academic contributions are as interweaved with their field of study as George’s are to integer programming. From developing its theory, to leading progress in computation, to expanding the set of its applications, George has contributed to all aspects of integer programming. Over the course of his storied career, he has been a steadfast force instrumental in the truly exceptional transformation of a budding research field into one that is fantastically successful and has revolutionized practice. 

George’s contributions are personal to me as one of the students he advised towards a doctoral degree. I remember that my first days in Atlanta were filled with enthusiasm at the idea that I would spend the next years studying integer programming.  I had grown passionate about the field from the classes Laurence Wolsey taught at UCL. I felt excited, fortunate, and honestly a bit intimidated that George had agreed to be my advisor. From these early days, I remember the crushing heat of  Atlanta’s summer, the seemingly uncountable lanes of I75 hedging campus, and the disorientation that came from abandoning the idea that continuous variables would ever be called x, while integer variables would ever be called y. 

Over the next four years, my life as a researcher fully formed. George was instrumental in this transformation. He did so patiently as my first attempts at proving results led me irremediably back to reinventing wheels long known to him. He did so kindly when my writing in English lacked structure and was riddled with imprecisions and flowery ramblings. He did so reassuringly by nudging me back towards more promising research avenues when I was going astray. I appreciated that he took time for me whenever I needed it, and that he took the time to teach me the craft and art of research and not only its science. From George, I learned to be precise, organized, and rigorous, and got pushed to aim higher. His guidance was present throughout my PhD studies, from the day I started to, the day I graduated: having skipped the rehearsal and being the first PhD student hooded (thanks to receiving an ACO degree), I wandered across the stage aghast; George pointed me to where I needed to stand, gestured me to spin, hooded me, patted me on the back, and send me on my way. Over the years, I have found his advice and guidance, in small and large matters, to be invaluable and his willingness to help to be enduring. 

I believe I speak for all of his students when I say there is no word to accurately capture the profoundly positive influence George had on our academic and personal developments. As George enters retirement, I hope that he knows how impactful the effort and dedication he put in developing the potential of his students have proven to be.  Accrued over several academic generations, these efforts have helped pushed the boundaries of integer programming across many dimensions, all from a blueprint that was George’s. The research he set in motion keeps expanding and keeps on transforming the world of optimization.  I certainly hope that I will contribute to it by being as good an advisor to my students as George was to me.  For all you did for me and for the field, George, thank you. – Jean-Philippe Richard, Professor, University of Minnesota

George Nemhauser and Ellis Johnson, both my Ph.D. advisors, have taught me that any problem, no matter how hard, can be solved if you have a right mind and determination. I’m forever grateful for their teaching as it has become my guiding principle. One of my fondest memories of George Nemhauser happened in our last meeting before I submitted my first peer-reviewed research paper. Writing the paper had been a long and painstaking process, and we were both exhausted. In the meeting, Dr. Nemhauser had found a grammatical error I had made by incorrectly using the word ’which’ instead of the word ‘that.’ He explained the grammar rule, which he had learned himself in a similar meeting with one of his co-authors. Now, whenever my students make this frequent grammar error, I relate the story of my meeting with George. I wish Dr. Nemhauser all the best in his retirement, which I am sure he will enjoy. – Jay Michael Rosenberger, Professor, University of Texas Arlington

George, thank you for your contributions to our community. I, for one, am eternally grateful for whatever stroke of luck guided my application your way. Thank you for taking a chance on me. I am often conflicted when asked who my supervisor is. It can be both a gift and a burden. A gift that has taught me so much and opened so many doors. A burden because I fear I will never measure up to the expectation of said student. Thank you for taking me under your wing – this Kiwi never had any. Sincerely and always your student – Faram Roze, Partner, EnWeave Pte. Ltd.

Besides his direct contributions to Georgia Tech and optimization, George made tremendous contributions through his integer programming books that educated generations of engineering students, including chemical engineers like myself who were drawn into optimization after reading George’s textbooks. George’s contributions to the field will remain strong even after his retirement! – Nick Sahinidis, Gary C. Butler Family Chair and Professor, ISyE

Over his long career George has inspired many. The publication of the book he wrote with his long-time friend and colleague Laurence Wolsey, which has become known simply as “Nemhauser & Wolsey,” inspired me to seek a visiting position at Georgia Tech to learn from and collaborate with one of the fathers of integer programming. Luckily, George agreed to host me; I asked him after he had had a few glasses of wine at an IBM-organized workshop in Garmisch-Partenkirchen, which may have helped. Regardless, my visit in the academic year of 1989-90 was a success and turned into a long and productive research collaboration and friendship that is still ongoing. After my year as visitor and before I joined ISyE as a faculty member, I visited George regularly and always stayed in the “apartment above the garage” of his house on Villa Dr. I fondly remember the outdoor breakfasts I had there: fresh fruit, wonderful bread, great company and conversation. George and Ellen were always there to make my stays as enjoyable as possible. As a result, when offered to join IBM Yorktown Heights Research Lab and to join Georgia Tech, the choice was easy – and one that I never regretted. – Martin Savelsbergh, James C. Edenfield Chair and Professor, ISyE

George was often outspoken, but he was never quarrelsome. He led. When he arrived at Georgia Tech, the core first-year Ph.D. program consisted of M.S. level courses. In less than two years, George had successfully led the creation of the same Ph.D. core structure we have today. He recruited and mentored both Ph.D. students and faculty. Several times, he challenged the administration on behalf of intellectual quality. He often won these battles, and in the two major ones he lost, time proved him to have been correct. – Craig Tovey, Professor, ISyE 

I've worked with George on both research and through a sports scheduling company we founded. I am constantly amazed at his energy, enthusiasm, and creativity. I hate to think where the world of sports scheduling optimization would be if George hadn't taken an interest in it. My own research and personal life have been tremendously enhanced by working with George. – Michael Trick, Harry B. and James H. Higgins Professor of Operations Research and Dean, Carnegie Mellon University Qatar

Being a young graduate student halfway across the world, I knew about what a legend George Nemhauser is for the OR community and his contributions to this field. I am certain this is the case for thousands of young brilliant minds studying OR somewhere on this earth. Among the young admirers, I have been lucky enough to take his class, to be advised by him, and to get to know him in person. It was these moments that made me understand that you can never portray a true legend wholly on paper, by their accomplishments. These little moments complete the perception you have of George and glorify it even more. I will always be grateful for all those little moments. -- Ezgi Karabulut Türkseven, Faculty Member, Sabancı University

Just after my Ph.D., I started to work on a normal form for system of linear constraints over nonnegative variables that would identify all variables who were fixed to a single value. I wanted to show that this normal form would be preserved under pivoting. I found this old book by Garfinkel and Nemhauser (1972) that contained a beautiful result that I could use (guess what). You can still buy the book for $967 on Amazon. It took me another 10 years to meet George, and another 15 to have a joint NSF grant with him. Together with us on that grant, we had a young, incredibly smart, and friendly assistant professor. His name was Shabbir Ahmed, and obviously everyone on that grant did great work on stochastic optimization. (The grant also had Michel Goemans and Eli Upfal as co-PIs). I mention this because it highlights one of the most amazing qualities that George possesses: He is always open to new ideas and to work with and mentor (young) people from many disciplines. – Pascal Van Hentenryck, A. Russell Chandler III Chair and Professor, ISyE

Dear George,  I hope you have a wonderful retirement! Your work and guidance has shaped generations of researchers, and I am very proud and thankful to be one of them. The first time we met was in November 2002 at the IV ALIO/EURO Workshop on Applied Combinatorial Optimization in Pucon, Chile. I double-checked the abstract for your talk there, and yes, as I recalled, you did talk about SOS2 sets and piecewise linear functions, so you truly have been pointing me in the right research directions since even before I started my Ph.D.! Thanks again for everything, my heartfelt congratulations and best wishes. – Juan Pablo Vielma, Research Scientist, Google

It has been a pleasure knowing you, George, and benefiting from your guidance over the years I've been at Georgia Tech, especially while I was ISyE school chair. Thank you for generously sharing your time and experience with me, as well as all of the others on our faculty you have mentored. Your contributions to ISyE and Georgia Tech have been remarkable. I wish you all the best as you segue into retirement, which I hope you will find enjoyable. – Chip White, Schneider National Chair in Transportation and Logistics and Professor, ISyE

Congratulations, George! All the best in your retirement. –Jill Hardin Wilson, Charles Deering McCormick Distinguished Professor of Instruction, Northwestern University

As a student at ISyE, one long-tenured faculty member stood out as being the best teacher in the department, and that faculty member was George. his practice of lecturing without using notes was impressive, but so too was his passion for students and the subject matter, and his ability to explain complex topics. All the best to you and your family as you transition to retirement following a long and extremely impactful career. I hope that you remain healthy and are able to pursue activities you enjoy. –Erick Wikum, Analytics Consultant, Wikalytics

George Nemhauser is a role model as a scholar and colleague. I do not need to repeat his many major intellectual and practical contributions in optimization and his impacts to the operations research profession. After being his ISyE colleague for 17 years, I have seen very admirable things about him. He has an absolute and uncompromising insistence on the quality of work and recruit. More amazingly, George is willing to express this insistence in public discussions, even to the point of “offending” people. In my opinion, it is this trait that helps maintain the high and uncompromising quality and No. 1 ranking of the ISyE. His retirement will leave a big hole in our collective intellectual portfolio. – Jeff Wu, Coca-Cola Chair Professor in Engineering Statistics, ISyE