Archive for Canada

Panch at the helm!

Posted in pictures, Travel, University life with tags , , , , , , , , , , , , on January 8, 2020 by xi'an

Reading somewhat by chance a Nature article on the new Director of the National Science Foundation (NSF) nominated by Trump (and yet to be confirmed by the Senate), I found that his name Sethuraman Panchanathan was the name of a friend of my wife 30⁺ years ago when they were both graduate students in image processing at the University of Ottawa, Department of Electrical Engineering… And looking further into the matter, I realised that this was indeed the very friend we knew from that time, with whom w shared laughs, dinners, and a few day trips together around Ottawa! While this is not the ultimate surprise, given that science administration is usually run by scientists, taken from a population pool that is not that large, as exemplified by earlier cases at the national or European level where I had some acquaintance with a then senior officer, it is nonetheless striking (and fun) to hear of a friend moving to a high visibility position after such a long gap. (When comparing NSF and ERC, the European Research Council, with French mathematician Jean-Pierre Bourguignon as current director also appearing in a recent Nature article, I was surprised to see that the ERC budget was more than twice the NSF budget.) Well, good luck to him for sailing these highly political waters!

start of 2020

Posted in Kids, Mountains, pictures, Travel with tags , , , , , on January 1, 2020 by xi'an

tea tasting at Van Cha

Posted in Kids, pictures, Travel with tags , , , , , , , , , , , , , on December 26, 2019 by xi'an

This recent trip to Vancouver gave me the opportunity of enjoying a Chinese tea tasting experience. On my last visit to the city, I had noticed a small tea shop very near the convention centre but could not find the time to stop there. This round I took advantage of the AABI lunch break to get back to the shop, which was open (on a Sunday), and sat for a ripe Pu-Ehr tasting. A fatal if minor mistake in ordering, namely that this was Pu-Ehr withing a dried yuzu shell, which gave the tea a mixed taste of fruit and tea, as least for the first brews. And remaining very far from the very earthy tastes I was expecting. (But it reminded me of a tangerine based Pu-Ehr Yulia gave me last time we went to Banff. And I missed an ice climbing opportunity!)
This was nonetheless a very pleasant tasting experience, with the tea hostess brewing one tiny tea pot after another, including a first one to wet and clean the tea, with very short infusion times, and tea rounds keeping their strong flavour even after several passes. In a very quiet atmosphere altogether, with a well-used piece of wood (as shown on top) in lieu of a sink to get rid of the water used to warm and clean pots and mugs (and a clay frog which role remained mysterious throughout!).
At some point in the degustation, another customer came in, obviously from a quite different league as he was carrying his own tea pancake, from which the hostess extracted a few grams and processed most carefully. This must have been an exceptional tea as she was rewarded by a small cup of the first brew, which she seemed to appreciate a lot (albeit in Chinese so I could not say).
As I was about to leave, having spent more time than expected and drank five brews of my tea, plus extra cups of a delicate Oolong, hence missing a talk by Matt Hoffman to which I was looking forward!, I discussed for a little while with this connoisseur, who told me of the importance of using porous clay pots and not mix them for different teas. Incidentally he was also quite dismissive of Japanese teas, (iron) teapots, and tea ceremony, which I found in petto a rather amusing attitude (if expected from some aficionados).

no dichotomy between efficiency and interpretability

Posted in Books, Statistics, Travel, University life with tags , , , , , , , , , , , , on December 18, 2019 by xi'an

“…there are actually a lot of applications where people do not try to construct an interpretable model, because they might believe that for a complex data set, an interpretable model could not possibly be as accurate as a black box. Or perhaps they want to preserve the model as proprietary.”

One article I found quite interesting in the second issue of HDSR is “Why are we using black box models in AI when we don’t need to? A lesson from an explainable AI competition” by Cynthia Rudin and Joanna Radin, which describes the setting of a NeurIPS competition last year, the Explainable Machine Learning Challenge, of which I was blissfully unaware. The goal was to construct an operational black box predictor fpr credit scoring and turn it into something interpretable. The authors explain how they built instead a white box predictor (my terms!), namely a linear model, which could not be improved more than marginally by a black box algorithm. (It appears from the references that these authors have a record of analysing black-box models in various setting and demonstrating that they do not always bring more efficiency than interpretable versions.) While this is but one example and even though the authors did not win the challenge (I am unclear why as I did not check the background story, writing on the plane to pre-NeuriPS 2019).

I find this column quite refreshing and worth disseminating, as it challenges the current creed that intractable functions with hundreds of parameters will always do better, if only because they are calibrated within the box and have eventually difficulties to fight over-fitting within (and hence under-fitting outside). This is also a difficulty with common statistical models, but having the ability to construct error evaluations that show how quickly the prediction efficiency deteriorates may prove the more structured and more sparsely parameterised models the winner (of real world competitions).

midnight run

Posted in Running, Travel with tags , , , , , , , , on December 8, 2019 by xi'an

Prairie chair

Posted in pictures, Statistics, University life with tags , , , , , , , , , , , on October 2, 2019 by xi'an

Today is the launching day of PRAIRIE, one of the four Instituts Interdisciplinaires d’Intelligence Artificielle (3IA) supported by the French government. Taking place in Paris Dauphine, with Yann Le Cun as guest speaker. I have been fortunate to be endowed with one of these chairs for the coming years, along with my CEREMADE colleagues Laurent Cohen and Irène Waldspurger.

NeurIPS without visa

Posted in pictures, Statistics, Travel, University life with tags , , , , , , , , , , , , , on September 22, 2019 by xi'an


I came by chance upon this 2018 entry in Synced that NeurIPS now takes place in Canada between Montréal and Vancouver primarily because visas to Canada are easier to get than visas to the USA, even though some researchers still get difficulties in securing theirs. Especially researchers from some African countries, which is exposed  in the article as one of the reasons the next ICLR takes place in Addis Ababa. Which I wish I could attend! In the meanwhile, I will be taking part in an ABC workshop in Vancouver, December 08, prior to NeurIPS 2019, before visiting the Department of Statistics at UBC the day after. (My previous visit there was in 1990, I believe!) Incidentally but interestingly, the lottery entries for NeurIPS 2019 are open till September 25, to the public (those not contributing to the conference or any of its affiliated groups). This is certainly better than having bots buying all entries within 12 minutes of the opening time!

More globally, this entry makes me wonder how learned societies could invest in ensuring locations for their (international) meetings allow for a maximum inclusion in terms of these visa difficulties, but also ensuring freedom and safety for all members. Which may prove a de facto impossibility. For instance, Ethiopia has a rather poor record in terms of human rights and, in particular, homosexuality is criminalised there. An alternative would be to hold the conferences in parallel locations chosen to multiply the chances for this inclusion, but this could prove counter-productive [for inclusion] by creating groups that would never ever meet. An insolvable conundrum?