Today marks Paul Rubin‘s retirement. To celebrate this special day in O.R.’s history, a few of us put together a nice collection of stories at http://paulsretirement.wordpress.com/ (very special thanks to go Mary Leszczynski). My personal contribution is here. If you know Paul, make sure to check it out! If you don’t know Paul…nah, everyone knows Paul.
Category Archives: People
By now, most people are aware of the latest Internet meme Texts from Hillary which is, by the way, hilarious. You’re also probably aware that Bill Cook created an iPhone App that allows one to solve traveling salesman problems (TSP) on a mobile phone! If you like optimization, you have to give this App a try; and make sure to check out the Traveling Salesman book too!
Inspired by Texts from Hillary I finally figured out the “real” reason why Bill Cook created the App. Here it is:
I was talking to my wife the other day recalling how much fun she has while overhearing words from some of my research-related phone calls. We started to think about what comes to people’s minds when they hear an OR-related term whose definition is not obvious to them. I’m not talking about obscure and technical mathematical terms such as a “contrapolymatroid“, but terms at which a non-expert would actually be able to take an educated guess, such as “large-neighborhood search“. So I made a list of ten such terms and asked three friends (named A, B, and C) to define them to the best of their ability. The only rule was that they had to do it on the spot, off the top of their heads; no Googling allowed. Because none of them have training in OR, some of the answers turned out to be pretty interesting.
1. A global constraint.
A) All the stuff in the world that’s holding us back.
B) All the factors that prevent the open market from being truly open: laws, politics, foreign/domestic policy, national borders, etc.
2. Complementary slackness.
A) A dude who hangs out in a bar with no job, but complements the decor and vibe perfectly.
B) An equal and opposite reaction to whatever sectors are experiencing growth in the marketplace.
C) Time off from performing a task or responsibility granted by a superior or by oneself.
3. An odd cycle.
A) When you get your period unexpectedly; or that cycle on the washing machine that no one ever uses.
B) An economic cycle (quarter, fiscal year, etc.) which displays characteristics unlike the ones that preceded or succeeded it. In other words, in a sustained period of economic growth, it’s the one segment that shows recession.
C) A phenomenon with awkward tendencies and characteristics that is repeated every so often.
4. A spanning tree.
A) A tree that creeps from your neighbor’s yard to yours. Usually makes a huge mess in yours.
B) Has something to do with Ethernet networks.
C) A rather large plant with either a long branch span or time span on planet Earth.
5. A cutting plane.
A) A wood working tool that both cuts and planes.
B) No freaking clue.
C) A slice that intersects a 3D object in order to provide another viewpoint.
6. A shadow price.
A) The hidden cost of owning things. Like the extra cost of owning and maintaining a house or a luxury car.
B) The true representative value of goods and services, compared to the value dictated by the supply/demand of the marketplace.
C) A value for an item or service which can be obtained but that requires the buyer to perform an extensive search.
7. A comb inequality.
A) When you have a better comb than I do.
C) Inadequacies that persist despite efforts to eliminate them.
8. Duality gap.
A) The gap between personalities in someone with multiple personality disorder.
B) Again no idea.
C) A two-faced abyss. In other words, an alternative that may seem unfortunate but that possesses some advantages.
9. A feasible region.
A) The region where it is possible for you to live given your income, wants, and available houses.
B) Sounds like agriculture. Sorry, I got nothing.
C) An area or scope which could be a viable alternative for several purposes.
10. The first-fail principle.
A) When you get to repeat a class the first time you fail it, if approved by your high-school principal.
B) The idea that early adopters in a new sector of the market who fail will provide secondary adopters guidance through their failure. Not literal guidance, of course, but the secondary adopters will come into the marketplace and make decisions based upon others’ prior failures.
C) If you fail miserably the first time, don’t try again.
The first lesson I learned from this very non-scientific experiment is: if you’re at a party and somebody asks you what you do, you’re probably better off using an example. For instance: “Do you ever wonder how hurricane paths are estimated? That’s what I do.” You’d of course replace “hurricane paths” with your favorite problem. If the example comes before “scary” words, I believe the end result will be much better. If things go well, the ideal reaction by other person will be: “That’s so cool! What kind of training do you need to do that?” From that point on, you proceed to convince them that math is cool.
Secondly, the amusing nature of the answers above notwithstanding, this experiment got me thinking about how to make OR more visible and accessible to the general audience. That’s one of the goals of the INFORMS Public Information Committee (PIC), of which I’ve recently become a member. We already have some ideas and initiatives lined up, but I’m open to your comments and suggestions. Feel free to send me your thoughts by e-mail or via the comments section below. By the way, if you feel like doing this experiment with your own friends, feel free to send me their answers and I’ll add them to the bunch.
There were sub-freezing temperatures, there were snow flurries, there was a hail storm, and there was a tornado watch. No, I’m not claiming that my visit to Pittsburgh last week was as full of adventures as Bilbo Baggins’s journey, but it was very nice indeed.
I had the great pleasure of being invited by John Hooker and Willem-Jan van Hoeve to give a talk at the Operations Research seminar at the Tepper School of Business. Since John, André Ciré, and I are working together on some interesting things, I took the opportunity to spend the entire week (Mon-Fri) at CMU; and what a joy it was.
The Tepper School was kind enough to have a limo service pick me up from, and take me back to, the airport. I guess this is how the top business schools roll. It’s a great way to make a speaker feel welcome. Besides, my driver turned out to be an extremely friendly and easy-to-talk-to fellow. Thanks to him (and his knowledge of off-the-beaten-path roads), I managed to catch my return flight. Otherwise, a cab driver would have sat through miles of Friday rush hour, and I’d certainly have missed the flight.
I walked to campus every day and actually enjoyed the few minutes of cold weather (wow! I can’t believe I just said that!). Stopping at the Kiva Han to grab an almond biscotto and a small coffee, right across the street from Starbucks, was a daily treat. Walking around campus brought back great memories from my PhD-student days. It’s nice to see all the improvements, and all the good things that remain good. Upon leaving Miami, I had the goal of having Indian food for 10 out of my 10 meals (excluding breakfast). Although I managed to do it only 4 times, I’m pretty happy with my gastronomic adventures in Pittsburgh. The delicious semolina gnocchi served at Eleven is definitely praiseworthy.
Work-wise, it was a very productive week. We had interesting ideas and conversations. I’m very grateful to all of those who took time off their busy schedules to meet with me, be it to catch up on life, talk about research (including some excellent feedback on my talk), or both. Thank you (in no particular order) to Alan Scheller-Wolf, Javier Peña, Michael Trick, Egon Balas, Sridhar Tayur, Masha Shunko, Valerie Tardif, Lawrence Rapp, and of course John and Willem. Many thanks also go to André, David, and all the other PhD students who joined me for lunch on Friday. I really enjoyed meeting all of you and learning a bit about your current projects.
I noticed that John got rid of his chalk board and painted two of his office walls with some kind of glossy white-board paint. It’s pretty cool because it allows you to literally write on your wall and erase everything with a regular white-board eraser. Now I want to do the same in my office! (My white board is pretty small.) But I’m not sure if they’ll let me. Gotta check on that!
Overall, it was an awesome week and I hope I can do this again some time.
(a) I was sharing a room with graduate students and I was motivated by rubbing elbows with hard-working people.
(b) I spent two weeks thinking about a single problem.
(c) I felt at ease wearing shorts, a T-shirt and a hoodie to go to work.
(d) Seeing old friends and being in my undergraduate department brought me memories of the “good old times”.
(e) All of the above.
This whole experience made me think of a related topic. Everyone has their productivity trigger. Some little thing that you do that improves your performance, or some place to which you go that awakens the genius inside you. When I was an undergrad student, I remember spending long hours on my way to and from school (long walk + bus ride) thinking about homework problems. Often, my best ideas would come to me during the commute. Later in life, I gathered more substantial evidence that good ideas come to me when I think about a problem as I walk (increased blood flow to the brain?). I should do that more often.
I wonder if anyone out there has a quirk of this sort. What is it that you do that fuels your creative mind? I’m willing to try new methods!
During the first two weeks of May, I’ll be visiting the Institute of Computing (IC) at the University of Campinas (UNICAMP) in Brazil. That’s where I got my BS and MS degrees before coming to the US. I’ll be working on some fun integer programming stuff with my former Master’s advisor Cid de Souza. (Cid spent a year visiting the Tepper School while I was doing my PhD there.)
Despite being a CS department, IC hosts some of the OR people at UNICAMP (the others are spread around in the Math and EE departments). I’m looking forward to working with Cid again, visiting the city of Campinas and seeing some old friends. I’m wondering if I should stop by to see my mother, who lives 2 miles away from campus and whom I haven’t seen in almost 2 years…hmm…such a dilemma… :-)