Back in May, I gave my PhD dissertation talk, which is the second-to-last major milestone in getting a PhD. The last one is actually writing it. I think most EECS PhD students give their talk and then file in the written dissertation a few days afterwards. I had a summer-long gap, but the long wait is finally over. After seven (!) years at UC Berkeley, I have finally written up my PhD dissertation and you can download it here. It’s been the ride of a lifetime, from the first time I set foot at UC Berkeley during visit days in 2014 to today. Needless to say, so much has changed since that day. In this post, I discuss the process of writing up my dissertation and (for fun) I share the acknowledgments.

The act of writing the dissertation was pretty painless. In my field, making the dissertation typically involves these steps:

1. Take 3-5 of your prior (ideally first-author) papers and stitch them back-to-back, with one paper as one chapter.

2. Do a find-and-replace to change all instances of “paper” to “chapter” (so that in the dissertation, the phrase “In this paper, we show…” turns to “In this chapter, we show …”.

3. Add an introduction chapter and a conclusion chapter, both of which can be just a handful of pages long. The introduction explains the structure of the thesis, and the conclusion has suggestions for future work.

4. Then the little (or not so little things, in my case): add an acknowledgments section at the beginning, make sure the title and LaTeX formatting all look good, and then get signatures from your committee.

That’s the first-order approximation to writing the PhD. Of course, the Berkeley Graduate Division claims that the chapters must be arranged and written in a “coherent theme” but I don’t think people pay much attention to that rule in practice.

By the way, I am legitimately curious: how much money does ProQuest actually make from selling PhD theses? Does anyone pay for a dissertation??? A statistic would be nice to see.

I did pay for something that is probably a little more worthwhile: printed copies of the dissertations, just so that I can have a few books on hand. Maybe one day someone besides me will read through the content …

Well, that was how I filed in the dissertation. What I wanted to do next here was restate what I wrote in the acknowledgments section of my dissertation. This section is the most personal one in the dissertation, and I enjoy reading what other students have to say. In fact, the acknowledgments are probably the most common part of theses that I read. I wrote a 9-page acknowledgments section, which is far longer than typical (but is not a record).

Without further ado, here are the acknowledgments. I hope you enjoy reading it!

When I reflect back on all these years as a PhD student, I find myself agreeing to what David Culler told me when I first came to Berkeley during visit days: “you will learn more during your years at Berkeley than ever before.” This is so true for me. Along so many dimension, my PhD experience has been a transformative one. In the acknowledgments to follow, I will do my best to explain why I owe so many people a great debt. As with any acknowledgments, however, there is only so much that I can write. If you are reading this after the fact and wish that I had written more about you, please let me know, and I will treat you to some sugar-free boba tea or keto-friendly coffee, depending on your preferred beverage.

For a variety of reasons, I had one of the more unusual PhD experiences. However, like perhaps many students, my PhD life first felt like a struggle but over time became a highly fulfilling endeavor.

When I arrived at Berkeley, I started working with John Canny. When I think of John, the following phrase comes to mind: “jack of all trades.” This is often paired with the somewhat pejorative “master of none” statement, but a more accurate conclusion for John would be “master of all.” John has done research in a wider variety of areas than is typical: robotics, computer vision, theory of computation, computational geometry, human computer interaction, and he has taught courses in operating systems, combinatorics, and social justice. When I came to Berkeley, John had already transitioned to machine learning. I have benefited tremendously from his advice throughout the years, first primarily on machine learning toolkits when we were working on BIDMach, a library for high throughput algorithms. (I still don’t know how John, a highly senior faculty, had the time and expertise to implement state-of-the-art machine learning algorithms with Scala and CUDA code.) Next, I got advice from John for my work in deep imitation learning and deep reinforcement learning, and John was able to provide technical advice for these rapidly emerging fields. As will be highlighted later, other members of his group work in areas as diverse as computer vision for autonomous driving, video captioning, natural language processing, generating sketches using deep learning, and protein folding — it sometimes seems as if all areas of Artificial Intelligence (and many areas of Human Computer Interaction) are or were represented in his group.

I also was fortunate to work with Ken Goldberg, who would become a co-advisor and who helped me transition into a full-time roboticist. Ken is a highly energetic professor who, despite being a senior faculty with so many things demanding of his time, is able to give some of the most detailed paper feedback that I have seen. When we were doing serious paper writing to meet a deadline, I would constantly refresh my email to see Ken’s latest comments, written using Notability on his iPad, and then immediately rush to address them. After he surprised me by generously giving me an iPad midway through my PhD, the first thing I thought of doing was to provide paper feedback using his style and to match his level of detail in the process. Ken also provides extremely detailed feedback on our research talks and presentations, an invaluable skill given the need to communicate effectively.

Ken’s lab, called the “AUTOLab,” was welcoming to me when I first joined. The Monday evening lab meetings are structured so that different lab members present on research progress in progress while we all enjoy good food. Such meetings were one of the highlights of my weeks at Berkeley, as were the regular lab celebrations to his house. I also appreciate Ken’s assistance in networking across the robotics research community at various conferences, which has helped me feel more involved in the research community and also became the source for my collaboration with Honda and Google throughout my PhD. Ken is very active in vouching for his students and, like John, is able to supply the compute we need to do compute-intensive robot learning research. Ken was also helpful in securing academic accommodations at Berkeley and in international robotics conferences. Much of my recent, and hopefully future, research is based on what I have learned from being in Ken’s lab and interacting with his students.

To John and Ken, I know I was not the easiest student to advise, and I deeply appreciate their willingness to stick with me over all these years. I hope that the end, I was able to show my own worth as a researcher. In academic circles, I am told that professors are sometimes judged based on what their students do, so I hope that I will be able to continue working on impactful research while confidently acting as a representative example for your academic descendants.

During my first week of work at Berkeley, I arrived to my desk in Soda Hall, and in the opposite corner of the shared office of six desks, I saw Biye Jiang hunched over his laptop working. We said “hi,” but this turned out to be the start of a long-time friendship with Biye. It resonated with me when I told him that because of my deafness, I found it hard to communicate with others in a large group setting with lots of background noise, and he said he sometimes felt the same but for a different reason, as an international student from China. I would speak regularly with him for four years, discussing various topics over frequent lunches and dinners, ranging from research and then to other topics such as life in China. After he left to go to work for Alibaba in Beijing, China, he gave me a hand-written note saying: “Don’t just work harder, but also live better! Enjoy your life! Good luck ^_^” I know I am probably failing at this, but it is on my agenda!

Another person I spoke to in my early days at Berkeley was Pablo Paredes, who was among the older (if not the oldest!) PhD students at Berkeley. He taught me how to manage as a beginning PhD student, and gave me psychological advice when I felt like I was hitting research roadblocks. Others who I spoke with from working with John include Haoyu Chen and Xinlei Pan, both of whom would play a major role in me getting my first paper under John’s primary supervision, which I had the good fortunate to present at UAI 2017 in Sydney, Australia. With Xinlei, I also got the opportunity to help him for his 2019 ICRA paper on robust reinforcement learning, and was honored to give the presentation for the paper in Montreal. My enthusiasm was somewhat tempered by how difficult it was for Xinlei to get visas to travel to other countries, and it was partly his own experience that I recognized how difficult it could be for an international student in the United States, and that I would try to make the situation easier for them. I am also honored that Haoyu later gave a referral for me to interview at Waymo.

In November of 2015, when I had hit a rough patch in my research and felt like I had let everyone down, Florian Pokorny and Jeff Mahler were the first two members of Ken Goldberg’s lab that I got to speak to, and they helped me to get my first (Berkeley) paper, on learning-based approaches for robotics. Their collaboration became my route to robotics, I am forever grateful that they were willing to work to me when it seemed like I might have little to offer. In Ken’s lab, I would later get to talk with Animesh Garg, Sanjay Krishnan, Michael Laskey, and Steve McKinley. With Animesh and Steve, I only wish I could have joined the lab earlier so that I could have collaborated with them more often. Near the end of Animesh’s time as a PhD student, he approached me after a lab meeting. He had read a blog post of mine and told me that I should have hung out with him more often — and I agree, I wish I did. I was honored when Animesh, now a rising star faculty at the University of Toronto, offered for me to apply for a postdoc with him. Once COVID-19 travel restrictions ease up, I promise that I will make the trip to Toronto to see Animesh, and similarly, to go to Sweden to see Florian.

Among those who I initially worked with in the AUTOLab, I want to particularly acknowledge Jeff Mahler’s help with all things related to grasping; Jeff is one of the leading minds in robotic manipulation, and his Dex-Net project is one of the AUTOLab’s most impactful projects, and shows the benefit of using a hybrid analytic and learned model in an age when so many have turned to pure learning. I look forward to seeing what his startup, Ambi Robotics, is able to do. I also acknowledge Sanjay’s patience with me when I started working with the lab’s surgical robot, the da Vinci Research Kit (dVRK). Sanjay was effectively operating like a faculty at that time, and had a deep knowledge of the literature going on in machine learning and robotics, and even databases (which was technically his original background and possibly his “official” research area, but as Ken said, “he’s one of the few people who can do both databases and robotics”). His patience when I asked him questions was invaluable, and I often start research conversations by thinking about how Sanjay would approach the question. With Michael Laskey, I acknowledge his help in getting me started with the Human Support Robot and with imitation learning. The bed-making project that I took over with him would mark the start of a series of fruitful research papers on deformable object manipulation. Ah, those days of 2017 and 2018 were sweet, while Jeff, Michael, and Sanjay were all in the lab. Looking back, there were times on Fridays when I most looked forward to our lab “happy hours” in Etcheverry Hall. Rumor has it that we could get reimbursed by Ken for these purchases of corn chips, salsa, and beer, but I never bothered. I would be willing to pay far more to have these meetings happen again.

After Jeff, Michael, and Sanjay, came the next generation of PhD students and postdocs. I enjoyed my conversations with Michael Danielczuk, who helped to continue much of the Dex-Net and YuMi-related projects after Jeff Mahler’s graduation. I will also need to make sure I never stop running so that I can inch closer and closer to his half-marathon and marathon times. I also enjoyed my conversations with Carolyn Matl and Matthew Matl, over various lab meetings and dinners, about research. I admire Carolyn’s research trajectory and her work on manipulating granular media and dough manipulation, and I look forward to seeing Matthew’s leadership at Ambi Robotics, and I hope we shall have more Japanese burger dinners in the future.

With Roy Fox, we talked about some of the most interesting topics in generative modeling and imitation learning. There was a time in summer 2017 in our lab when the thing I looked forward to the most was a meeting with Roy to check that my code implementations were correct. Alas, we did not get a new paper from our ideas, but I still enjoyed the conversations, and I look forward to reading about his current and future accomplishments at UC Irvine. With our other postdoc from Israel, Ron Berenstein, I enjoyed our collaboration on the robotic bed-making project, which may have marked the turning point of my PhD experience, and I appreciate him reminding me that “your time is valuable” and that I should be wisely utilizing my time to work on important research.

Along with Roy and Ron, Ken continued to show his top ability in recruiting more talented postdocs to his lab. Among those who I was fortunate to meet include Ajay Kumar Tanwani, Jeff Ichnowski, and Minho Hwang. My collaboration with Ajay started with the robot bed-making project, and continued for our IROS 2020 and RSS 2020 fabric manipulation papers. Ajay has a deep knowledge of recent advances in reinforcement learning and machine learning, and played key roles in helping me frame the messaging in our papers. Jeff is an expert kinematician who understands how to perform trajectory optimization with robotics, and we desperately needed him to improve the performance of our physical robots. With Minho, I enjoyed his help on getting the da Vinci Surgical Robot back in operation and with better performance than ever before. He is certainly, as Ken Goldberg proudly announced multiple times, “the lab’s secret weapon,” as should no doubt be evident from the large amount of papers the AUTOLab has produced in recent years with the dVRK. I wish him the best as a faculty at DGIST. I thank him for the lovely Korean tea that he gave me after our farewell sushi dinner at Akemi’s! I took a picture of the kind note Minho left to me with the box of tea, so that as with Biye’s note, it is part of my permanent record. During the time these postdocs were in the lab, I also acknowledge Jingyi Xu from the Technical University of Munich in Germany, who spent a half-year as a visiting PhD student, for her enthusiasm and creativity with robot grasping research.

To Ashwin Balakrishna and Brijen Thananjeyan, I’m not sure why you two are PhD students. You two are already at the level of faculty! If you ever want to discuss more ideas with me, please let me know. I will need to study how they operate to understand how to mentor a wide range of projects, as should be evident by the large number of AUTOLab undergraduates working with them. During the COVID-19 work-from-home period, it seemed as if one or both of them was part of all my AUTOLab meetings. I look forward to seeing their continued collaboration in safe reinforcement learning and similar topics, and maybe one day I will start picking up tennis so that running is not my only sport.

After I submitted the robot bed-making paper, I belatedly started mentoring new undergraduates in the AUTOLab. The first undergrad I worked with was Ryan Hoque, who had quickly singled me out as a potential graduate student mentor, while mentioning his interest in my blog (this is not an uncommon occurrence). He, and then later Aditya Ganapathi, were the first two undergraduates who I felt like I had mentored at least somewhat competently. I enjoyed working and debugging the fabric simulator we developed, which would later form the basis of much of our subsequent work published at IROS, RSS, and ICRA. I am happy that Ryan has continued his studies as a PhD student in the AUTOLab, focusing on interactive imitation learning. Regarding the fabrics-related work in the AUTOLab, I also thank the scientists at Honda Research Institute for collaborating with us: Nawid Jamali, Soshi Iba, and Katsu Yamane. I enjoyed our semi-regular meetings in Etcheverry Hall where we could go over research progress and brainstorm some of the most exciting ideas in developing a domestic home robot.

While all this was happening, I was still working with John Canny, and trying to figure out the right work balance with two advisors. Over the years, John would work with PhD students David Chan, Roshan Rao, Forrest Huang, Suhong Moon, Jinkyu Kim, and Philippe Laban, along with a talented Master’s student Chen (Allen) Tang. As befitting someone like John, his students work on a wider range of research areas than is typical for a research lab. (There is no official name for John Canny’s lab, so we decided to be creative and called it … “the CannyLab.”) With Jinkyu and Suhong, I learned more about explainable AI and its application for autonomous driving, and on the non-science side, I learned more about South Korea. Philippe taught me about natural language processing, summarizing text, and his “NewsLens” project resonated with me, given the wide variety of news that I read these days, and I enjoyed the backstory for why he was originally motivated to work on this. David taught me about computer vision (video captioning), Roshan taught me about proteins, and Forrest taught me about sketching. Philippe, David, Roshan, and Forrest also helped me understand Google’s shiny new neural network architecture, the Transformer, as well as closely-related architectures such as OpenAI’s GPT models. I also acknowledge David’s help for his work getting the servers set up for the CannyLab, and for his advice in building a computer. Allen Tang’s master’s thesis on how to accelerate deep reinforcement learning played a key role in my final research projects.

For my whole life, I had always wondered what it was like to intern at a company like Google, and have long watched in awe as Google churned out impressive AI research results. I had applied to Google twice earlier in my PhD, but was unable to land an internship. So, when the great Andy Zeng sent me a surprise email in late 2019, after my initial shock and disbelief wore off, I quickly responded with my interest in interning with him. After my research scientist internship under his supervision, I can confirm that the rumors are true: Andy Zeng is a fantastic intern host, and I highly recommend him. The internship in 2020 was virtual, unfortunately, but I still enjoyed the work and his frequent video calls helped to ensure that I stayed focused on producing solid research during my internship. I also appreciated the other Google researchers who I got to chat with throughout the internship: Pete Florence, Jonathan Tompson, Erwin Coumans, and Vikas Sindhwani. I have found that the general rule that others in the AUTOLab (I’m looking at you, Aditya Ganapathi) have told me is a good one to follow: “think of something, and if Pete Florence and Andy Zeng like it, it’s good, and if they don’t like it, don’t work on it.” Thank you very much for the collaboration!

The last two years of my PhD have felt like the most productive of my life. During this time, I was collaborating (virtually) with many AUTOLab members. In addition to those mentioned earlier, I want to acknowledge undergraduate Haolun (Harry) Zhang on dynamic cable manipulation, leading to the accurately-named paper Robots of the Lost Arc. I look forward to seeing Harry’s continued achievements at Carnegie Mellon University. I was also fortunate to collaborate more closely with Huang (Raven) Huang, Vincent Lim, and many other talented newer students to Ken Goldberg’s lab. Raven seems like a senior PhD student instead of just starting out, and Vincent is far more skilled than I could have imagined from a beginning undergraduate. Both have strong work ethics, and I hope that our collaboration shall one day lead to robots performing reliable lassoing and tossing. In addition, I also enjoyed my conversations with the newer postdocs to the AUTOLab, Daniel Brown and Ellen Novoseller, from whom I have learned a lot of inverse reinforcement learning and preference learning. Incoming PhD student Justin Kerr also played an enormous role in helping me work with the YuMi in my final days in the AUTOLab.

I also want to acknowledge the two undergraduates from John Canny’s lab who I collaborated with the most, Mandi Zhao and Abhinav Gopal. Given the intense pressure of balancing both coursework and others, I am impressed they were willing to stick around with me while we finalized our work with John Canny. With Mandi, I hope we can continue discussing research ideas and US-China relations over WeChat, and with Abhinav, I hope we can pursue more research ideas in offline reinforcement learning.

Besides those who directly worked with me, my experience at Berkeley was enriched by the various people from other labs who I got to interact with somewhat regularly. Largely through Biye, I got to know a fair amount of Chinese international students, among them include Hezheng Yin, Xuaner (Cecilia) Zhang, Qijing (Jenny) Huang, and Isla Yang. I enjoyed our conversations over dinners and I hope they enjoyed my cooking of salmon and panna cotta. I look forward to the next chapter in all of our lives. It’s largely because of my interaction with them that I decided I would do my best to learn more about anything related to China, which explains book after book that I have on my iBooks app.

My education at Berkeley benefited a great deal from what other faculty taught me during courses, research meetings, and otherwise. I was fortunate to take classes from Pieter Abbeel, Anca Dragan, Daniel Klein, Jitendra Malik, Will Fithian, Benjamin Recht, and Michael I. Jordan. I also took the initial iteration of Deep Reinforcement Learning (RL), back when John Schulman taught it, and I thank John for kindly responding to questions I had regarding Deep RL. Among these professors, I would like to particularly acknowledge Pieter Abbeel, who has regularly served as inspiration for my research, and somehow remembers me and seems to have the time to reply to my emails even though I am not a student of his nor a direct collaborator. His online lecture notes and videos in robotics and unsupervised learning are among those that I have consulted the most.

In addition to my two formal PhD advisors, I thank Sergey Levine and Masayoshi Tomizuka for serving on my qualifying exam committee. The days leading up to that event were among the most stressful I had experienced in my life, and I thank them for taking the time to listen to my research proposal. I also enjoyed learning more about deep reinforcement learning through Sergey Levine’s course and online lectures.

I also owe a great deal to the administrators at UC Berkeley. The ones who helped me the most, especially during the two times during my PhD when I felt like I had hit rock bottom (in late 2015 and early 2018), were able to offer guidance and do what the could to help me stay on track to finish my PhD. I don’t know all the details about what they did behind the scenes, but thank you, to Shirley Salanio, Audrey Sillers, Angie Abbatecola, and the newer administrators to BAIR. Like Angie, I am an old timer of BAIR. I was even there when it was called Berkeley Vision and Learning Center (BVLR), before we properly re-branded the organization to become Berkeley Artificial Intelligence Research (BAIR). I also thank their help in getting the BAIR Blog up and running.

My research was supported initially by a university fellowship, and then later by a six-year Graduate Fellowships for STEM Diversity (GFSD) which was formerly called the National Physical Science Consortium (NPSC) Fellowship. At the time I received the fellowship, I was in the middle of feeling stuck on several research progress. I don’t know precisely why they granted me the fellowship, but whatever their reasons, I am eternally grateful for the decision they made. One of the more unusual conditions of the GFSD fellowship is that recipients are to intern at the sponsoring agency, which for me was the National Security Agency (NSA). I went there for one summer in Laurel, Maryland, and got a partial peek past the curtain of the NSA. By design, the NSA is one of the most secretive United States government agencies, which makes it difficult for people to acknowledge the work they do. Being there allowed me to understand and appreciate the signals intelligence work that the NSA does on behalf of the United States. Out of my NSA contacts, I would like to particularly mention Grant Wagner and Arthur Drisko.

While initially apprehensive about Berkeley, I have now come to accept it for some of the best it has to offer. I will be thankful of the many cafes I spent time in around the city, along with the frequent running trails both on the streets and in the hills. I only wish that other areas of the country offered this many food and running options.

Alas, all things must come to an end. While my PhD itself is coming to a close, I look forward to working with my future supervisor, David Held, in my next position at Carnegie Mellon University. Throughout the time when I was searching for a postdoc, I thank other faculty who took the time out of their insanely busy schedules to engage with me and to offer research advice: Shuran Song of Columbia, Jeannette Bohg of Stanford, and Alberto Rodriguez of MIT. I am forever in awe of their research contributions, and I hope that I will be able to achieve a fraction of what they have done in their careers.

In a past life, I was an undergraduate at Williams College in rural Massachusetts, which boasts an average undergraduate student body of about 2000 students. When I arrived at campus on that fall day in 2010, I was clueless about computer science and how research worked in general. Looking back, Williams must have done a better job preparing me for the PhD than I expected. Among the professors there, I owe perhaps the most to my undergraduate thesis advisor, Andrea Danyluk, as well as the other Williams CS faculty who taught me at that time: Brent Heeringa, Morgan McGuire, Jeannie Albrecht, Duane Bailey, and Stephen Freund. I will do my best to represent our department in the research area, and I hope that the professors are happy with how my graduate trajectory has taken place. One day, I shall return in person to give a research talk, and will be able to (in the words of Duane Bailey) show off my shiny new degree. I also majored in math, and I similarly learned a tremendous amount from my first math professor, Colin Adams, who emailed me right after my final exam urging me to major in math. I also appreciate other professors who have left a lasting impression on me: Steven Miller, Mihai Stoiciu, Richard De Veaux, and Qing (Wendy) Wang. I appreciate their patience during my frequent visits to their office hours.

During my undergraduate years, I was extremely fortunate to benefit from two Research Experiences for Undergraduates (REUs), the first at Bard College with Rebecca Thomas and Sven Andersen, and the second at the University of North Carolina at Greensboro, with Francine Blanchet-Sadri. I thank the professors for offering to work with me. As with the Williams professors, I don’t think any of my REU advisors had anticipated that they would be helping to train a future roboticist. I hope they enjoyed working with me just as much as I enjoyed working with them. To everyone from those REUs, I am still thinking of all of you and wish you luck wherever you are.

I owe a great debt to Richard Ladner of the University of Washington, who helped me break into computer science. He and Rob Roth used to run a program called the “Summer Academy for Advancing Deaf and Hard of Hearing in Computing.” I attended one of the iterations of this program, and it exposed to me what it might have been like to be a graduate student. Near the end of the program, I spoke with Richard one-on-one, and asked him detailed questions about what he thought of my applying to PhD programs. I remember him expressing enthusiasm, but also some reservation: “do you know how hard it is to get in a top PhD program?” he cautioned me. I thanked him for taking the time out of his busy schedule to give me advice. In the upcoming years, I always remembered to work hard in the hopes of achieving a PhD. (The next time I visited the University of Washington, years later, I raced to Richard Ladner’s office the minute I could.) Also, as a fun little history note, when I was there that I decided to start my (semi-famous?) personal blog, which seemingly everyone at Berkeley’s EECS department has seen, in large part because I felt like I needed to write about computer science in order to understand it better. I still feel that way today, and I hope I can continue writing.

Finally, I would like to thank my family for helping me persevere throughout the PhD. It is impossible for me to adequately put in words how much they helped me survive. My frequent video calls with family members helped me to stay positive during the most stressful days of my PhD, and they have always been interested in the work that I do and anything else I might want to talk about. Thank you.