Category: Conferences

Have you Registered for INFORMS Practice?

The INFORMS Practice Conference is one of my favorite conferences. It is here that I get most of my stories for my classes and get inspired about the areas I work in. I also get inspired about Operations Research in general: it is a great field, and this conference shows the wonderful things we do.

If you haven’t been to a Practice Conference, it is nothing like the big fall conferences.  The Practice Conference is seen as a “Listener’s Conference”:  unlike the main conference where anyone can present, only invited speakers present at the Practice Conference.  The quality of talks given by invited speakers ranges from good to unbelievably amazing (in contrast with the fall conference where the lower bound is much, much, much lower).  There are very few parallel sessions (no more than 5 or 6) and there are lots of opportunities for interaction, greatly enhancing the social capital of the conference.

Unfortunately, it is not a cheap conference.  Running a conference of the quality of the Practice conference takes money.  So if you are planning to go, be sure to register by February 27 to save yourself $150 or so.

Of course, one highlight of the conference is the  Edelman Competition.

I already have my registration in!

Check out ILOG’s DIALOG blog!

I am in Minneapolis, flying back to Pittsburgh after spending a couple days in Winnipeg for a memorial service for my Mom.  My Mom’s passing has a number of effects, large and small.  On the large side, my son Alexander has lost both his gradmothers in the past six months, which makes me sad:  every kid needs plenty of grandparents to spoil them!  Now my Dad will have to pick up all the slack.

On the small side, I had to cancel a trip I was looking forwad to:  ILOG’s DIALOG conference in Orlando.  First, it is Orlando, which looks pretty sweet for a Pittsburgher in February.  Second, with all of the changes for ILOG in the past year, I was looking forward to meeting people and seeing how the optimization side of ILOG was making out.  No chance to do that, unfortunately, but ILOG has significant blog coverage of the conference, which I recommend.  Most of the guest bloggers are rules-oriented (my absence messes up the optimization covererage, I guess) but it was good to read that the plenary of Tom Rosamilia (head of WebSphere) sees how optimization fits in (from James Taylor’s blog entry):

Tom identified four essentials for survival:

  • Adapt to embrace change
  • Streamline processes to make them more dynamic and manageable
  • Optimize to allocate resources efficiently
  • Visualize to transform insight into action for faster decisions

This is not quite the way I see optimization (either it is much more than resource allocation, or resource allocation has a much broader definition than I usually give it!), but at least we hit the main points.

Michel Balinski IFORS Distinguished Lecture

The IFORS Distinguished Lecturer for the INFORMS meeting was Michel Balinski of Ecole Polytechnique and CNRS, Paris. Michel spoke on “One-Vote, One-Value: The Majority Judgement”, a topic close to my heart. In the talk, Michel began by discussing the pitfalls of standard voting (manipulation, “unfair” winners, and so on). He then spent most of his talk on a method he proposes for generating rankings and winners. For an election on many candidates (or a ranking of many gymnasts, or an evaluation of many wines: the applications are endless), have the electors (judges, etc.) rate each candidate on a scale using terms that are commonly understood. So a candidate for president might be “Excellent, Very Good, Good, Acceptable, Reject”. Then, the evaluation of a candidate is simply the median evaluation of the electors. The use of median is critical: this limits the amount of manipulation a voter can do. If I like a candidate, there is limited effect if I greatly overstate my liking: it cannot change the overall evaluation unless my evaluation is already under that of the median voter.

Michel then went on and discussed some tiebreaking rules (to handle the case that two or more candidates are, say “Very Good” and none “Excellent”). I found the tie-breaking rules less immediately appealing, but I need to think about these more.

Michel had done an experiment on this by asking INFORMS participants to do an evaluation of possible US Presidential candidates (not just Obama and McCain, but also Clinton, Powell, and a number of others). The result (on a small 129 voter sample) put Obama well ahead, but I do suspect some selection bias at work.

This work will be the basis of a book to be published at the end of the year, and there is a patent pending on the voting system (which I found a little strange: what would it mean to use a patented voting system?).

I didn’t get the URLs at the end of the talk.  If anyone got them, can you email me with them?  A quick web search only confused me more.

Thanks Ashutosh for this pointer.

Added Oct 20. Michel Balinski kindly wrote and provided the following references:

Michel Balinski and Rida Laraki, “Le jugement majoritaire : l’expérience d’Orsay,” Commentaire no. 118, été 2007, pp. 413-419.

One-Value, One-Vote: Measuring, Electing, and Ranking (tentative title), to appear 2009.

http://ceco.polytechnique.fr/jugement-majoritaire.html

Michel Balinski et Rida Laraki, A theory of measuring, electing and ranking,
Proceeding of the National Academy of Sciences USA, May 22, 2007, vol. 104, no. 21, pp. 8720-8725.

Michel Balinski et Rida Laraki, “Election by Majority Judgement: Experimental Evidence.”
Cahier du Laboratoire d’Econométrie de l’Ecole Polytechnique, December 2007, n° 2007-28

Greetings from Washington

I am at the Washington INFORMS and have just come back from the first session (on experiences with COIN-OR).  Sixty-eight parallel tracks!  Looks like there might be 5000 people at this conference.  It is amazing how big the conference has become.  I was on the INFORMS Board around 2000 when the decision was made to go from two conferences/year (a holdover from the ORSA/TIMS and TIMS/ORSA conferences before the societies merged in 1994) to just one.  At the time, we were getting 1500-1800 people per conference.  The discussion was “Maybe we could get 2400 people if we ran just one conference”.  No one was bold enough to suggest our yearly count would reach 3000-3600, let alone grow enormously!  But INFORMS is the one place to go where you know you will see most or all of your colleagues every year.  While I prefer smaller conferences, this is still a must-go-to event, simply for the mix of people to see.

Weather in Washington is beautiful and the conference hotel, while huge, seems to work, so this is shaping up to be a great conference.

On the blogging front, the ICS (INFORMS Computing Society) blog has posted from the conference, and I expect others to appear shortly.  If you are at the conference, don’t forget to drop by the COIN-OR booth (Booth 504) this evening (Sunday) around 8 to say hi to the blog-ORs!  And stop off to see Steve Baker, author of the Numerati.

Update on the blog-or-sphere get-together

I have confirmation from bloggers Laura McLay (Punk Rock Operations Research), Aurelie Thiele (Thoughts on Business, Engineering, and Higher Education), and Bill Hart (William E. Hart’s Blog) that they will be at booth 504 (the Coin-OR booth) at 8PM on Sunday at the INFORMS DC meeting (or at least will try hard to do so). If you are blogger and will be there, let me know so I can add you to the list. And if you are an adoring (or not) fan, be sure to drop by and say hi!

Update Oct 10 3PM. Ian Frommer (Green OR) will be at the Blog-OR gettogether.  Five bloggers and counting!

Meet at INFORMS?

I had meant to do something a little more formal for the blogging world at INFORMS DC, but until recently it was unclear whether I could make it to the conference (I am teaching now, and with a final exam coming up, I wanted to be sure my classes were ready). But I will be at INFORMS, and would like to meet up with the rest of the people either blogging or reading the blogs. Given the late date, why don’t we plan on an informal get-together during the Sunday reception. I will be by the “COIN-OR” booth at the Sunday reception at around 8PM. It is booth 504. It would be great to see you there!

In New York doing Mixed Integer Programming

I am in New York at Columbia University, attending the Mixed Integer Programming (MIP) workshop. This workshop series was started about 5 years ago, and has grown into a hundred person workshop/conference. It is still run pretty informally (no nametags: I guess it is assumed that everyone knows everyone else. Having just shaved off my beard, I would prefer letting people know my name rather than relying on their ability to recognize me!).

So far, the most interesting aspects have been approaches much different than current practice. Rekha Thomas of the University of Washington had a very nice talk on a variant of Chvatal Rank (called Small Chvatal Rank) which involved using Hilbert basis calculations to find normals of facets of the integer hull (you can think of this as Chvatal rank independent of the right hand side). I’m not sure if it is useful, but it certainly generated a number of neat results. Peter Malkin of UC-Davis talked about using systems of polynomial equations to prove the infeasibility of problems like 3-coloring. I have seen versions of this work before (given by coauthor Susan Margulies) and always begin thinking “this can’t possibly work” but they are able to prove a lack of 3-coloring for impressively large graphs.

One of the most intriguing talks was given by John Hooker, who is exploring what he calls “principled methods of modeling” (or formulation). John has a knack of looking at seemingly well-known approaches and seeing them in a new and interesting way. It is not yet clear that this principled approach gets you anything that is not folklore formulation tricks, but it is interesting to see a theoretical underpinning to some of the things we do.

Postscript. Now that I think about it a bit more, John did present a problem that would have been difficult to formulate without his principled approach. I’ll try to track down an explanation of that example.

Travel to South Africa

With the upcoming IFORS meeting in Sandton, South Africa, it was disheartening to see the recent violence in South Africa.  Of course, the violence against “foreigners” was not against tourists:  it was against Zimbabweans and other non-South Africans living in the townships.  Things seem to have calmed down, and here is one recent summary of the situation:

TravelHub (www.travelhub.co.za) – Xenophobia

THERE have been no further incidents of xenophobic violence reported since Sunday, May 25. South Africa is now in the process of dealing with the aftermath of the violence, notably the humanitarian crisis that has developed due to the thousands of displaced immigrants being housed in camps across the country. These people lack basic necessities such as food, blankets, toiletries and clothes. Recent reports confirm that violence between those displaced has broken out in some of these camps. Government is expected to announce its plan of action for dealing with the crisis later today (May 29).

The other major problem, which is affecting tourism, is the country’s image. Despite the calm of the last few days, countries are continuing to issue travel warnings for their citizens who plan to visit South Africa. No alerts have told travellers to avoid South Africa completely but a number of countries, including the United States, have issued warnings against travel to township areas. Yesterday Australians were told to avoid township tourism, and the general advice for visiting South Africa remained the same: exercise a high level of caution.

The Foreign and Commonwealth Office (FCO) issued a similar warning yesterday, advising travellers to avoid Gauteng townships.

The warnings acknowledge that tourists are not the targets of the recent violence, but point out that they might be caught up in surrounding violence, should it flare up again. This poses a major problem for companies involved in township tourism, who are trying to carry on business as usual and convince tourists that the townships are safe. Townships in the Eastern Cape, which had no reported incidents of xenophobic violence, Orlando West in Soweto and others that have been calm over recent weeks, should be safe to visit but it will take months, if not years, before the horrific images of the violence broadcast internationally will fade and tourists will again readily head to South Africa’s townships.

I am very much looking forward to both the conference and the side activities I have planned in South Africa.  I have even bought a new camera (DSLR: Canon EOS) with a big (300mm) lens for the safari part of my visit. I hope to see many of you there!

Some Final CPAIOR Thoughts

I have returned from Paris (my original plan was to go to Italy for IPCO, but I had to change that). Here are some thoughts from the CPAIOR conference:

  1. It is impossible to blog while being Program Chair, particularly in Europe (for me). Program Chair at the conference is the easiest job: the choices have all been made, so it is really a matter of sitting back and seeing how everything turned out. But I was nervous about the timing, since the schedule was more packed in that I had liked, so I sat near the front to provide pressure on speakers to keep to their time. Being in the front, I didn’t feel right tapping on my notebook, so I didn’t blog during the talks. But jetlag made me fall asleep anytime I was within fifty feet of a bed, so I couldn’t blog from my hotel room. Hence, just a few comments now!
  2. Pascal van Hentenryck gave a fascinating review of the history of constraint programming, based on an imaginary conversation with his advisor J.L. Lauriere describing what has happened to CP over the last 30 years (Lauriere died about 5 years ago). Lauriere wrote the pioneering paper in constraint programming back in 1978, centered around a language entitled ALICE. It was really neat to see how many of the ideas we have today are within that 1978 paper (though the 1978 paper and language structure is such that it is really hard to see how we got to where we got). I had not heard of Lauriere, but that is perhaps not so surprising: constraint programming is not my main home base, and Lauriere was perhaps best known within France. Correction added June 2.  Lauriere was on Pascal’s committe, but his adviser at the University of Namur was Baudouin Le Charlier.
  3. Francois Laburthe of Amadeus (a company like Sabre) gave the final plenary, and it complemented Cindy Barnhart’s very well. Francois talked about the business side of airline schedules: how do you show them to customers and determine the best routes for them. Companies like Orbitz and Expedia do this all the time, and I hadn’t realized how hard that it is to do. One stat of his I liked: pre-Internet, systems were designed to serve five price queries for every ticket sold. Now the number is closer to 1000. Given the number of searches I do before every trip, I can believe it!

Overall, I thought the conference went very well. Francois Fages, who was responsible for local organization among other things, chose a very nice boat on the Seine for dinner, and everything went very well in general.

In addition to Cindy Barnhart’s talk, I guess I most liked the workshop that Robin Lougee-Heimer put together on open-source solvers in CP and operations research. I was a little surprised that most open source constraint programming systems don’t do it for the community of developers. For the most part, they do it as a convenient license for distribution. Only COIN-OR really seems to be working to get a community of people working at improving code.

It was a great conference. Next year, it will be in Pittsburgh, where my colleagues John Hooker and Willem-Jan van Hoeve have to do all the work.