Archive for Facebook

Der Kunst ihre Freiheit [and the scare of the nude]

Posted in Books, pictures, Travel with tags , , , , , , , , , , , , , on February 17, 2018 by xi'an

A poster campaign advertising for several exhibits of modernist painters in Vienna, including major paintings by Egon Schiele, has met with astonishing censoring from the transport companies posting these advertisements. (And by Facebook, which AIs are visibly too artificial and none too intelligent to [fail to] recognise well-known works of art.) Not very surprising, given the well-known conservatism of advertising units in transportation companies, but nonetheless appalling, especially when putting these posters against the truly indecent ones advertising for, e.g., gas guzzling machines and junk food.

major confUSion

Posted in Books, pictures, Statistics with tags , , , , , , , , on November 19, 2016 by xi'an

crossing the Seine in RER C near Maison de la Radio, Nov. 09, 2012In a recent evening talk-show on France Inter, the French national public radio, the debate was about the [bad] surprise election of the donald and the fact that the media had missed the result, (self-)blaming a disconnection with the “real” country. One of the discussants, Julia Cagé, Professor of Economics at Science Po’, started the discussion with the amazing confusion [at 5’55”] between the probability that Hillary Clinton would win [evaluated at 84% on the last day] and the percentage of votes in her favour [which was around that figure in Manhattan]…

On a related if minor theme, my post on Flaxman et al.’s early [if preliminary] analysis of the said election got so many views that it became the most popular post for 2016! (If not competing with Ross Ihaka’s call to simply start over with R!)

And yet another related entry today in Libération, blaming the disastrous result partly on the social media and their algorithms (again!) that favour items of information (or dis-information) from the same perspective and do not rank those items by their reliability… The author of the tribune is an econometrician at Essec, but there is no methodological content in this ideological entry that seems to call for a super-monitor which would impose (how?) diversity and (which?) ranking on social media. A post-truth era, for sure! Shifting the blame from the deplorable voters themselves to anything else…


Posted in Kids, pictures, University life with tags , , on May 31, 2014 by xi'an


Advances in scalable Bayesian computation [day #3]

Posted in Books, Mountains, pictures, R, Statistics, University life with tags , , , , , , , , , , on March 6, 2014 by xi'an

polyptych painting within the TransCanada Pipeline Pavilion, Banff Centre, Banff, March 21, 2012We have now gone over the midpoint of our workshop Advances in Scalable Bayesian Computation with three talks in the morning and an open research or open air afternoon. (Maybe surprisingly I chose to stay indoors and work on a new research topic rather than trying cross-country skiing!) If I must give a theme for the day, it would be (jokingly) corporate Big data, as the three speakers spoke of problems and solutions connected with Google, Facebook and similar companies. First, Russ Salakhutdinov presented some  hierarchical structures on multimedia data, like connecting images and text, with obvious applications on Google. The first part described Boltzman machines with impressive posterior simulations of characters and images. (Check the video at 45:00.) Then Steve Scott gave us a Google motivated entry to embarrassingly parallel algorithms, along the lines of papers recently discussed on the ‘Og. (Too bad we forgot to start the video at the very beginning!) One of the novel things in the talk (for me) was the inclusion of BART in this framework, with the interesting feature that using the whole prior on each machine was way better than using a fraction of the prior, as predicted by the theory! And Joaquin Quinonero Candela provided examples of machine learning techniques used by Facebook to suggest friends and ads in a most efficient way (techniques remaining hidden!).

Even though the rest of the day was free, the two hours of exercising between the pool in the early morning and the climbing wall in the late afternoon left me with no energy to experiment curling with a large subsample of the conference attendees, much to my sorrow!

interacting particle systems as… facebook

Posted in Books, Statistics, University life with tags , , , , , on October 8, 2013 by xi'an

Among the many interesting arXived papers this Friday, I first read David Aldous’ “Interacting particle systems as stochastic social dynamics“. Being unfamiliar with those systems (despite having experts in offices down the hall in Paris-Dauphine!), I read this typology of potential models (published in Bernoulli) with a keen interest! The paper stemmed from a short course given in 2012 in Warwick and Cornell. I think the links exhibited there with (social) networks should be relevant for statisticians working on networks (!) and dynamic graphical models. Statistics is not mentioned in the paper, except for the (misleading) connection with statistical physics, but there is obviously a huge potential for statistical inference, from parameter estimation to model comparison. (As pointed out by David Aldous, there is usually “no data or evidence linking the model to the asserted real-world phenomena”.) The paper then introduces some basic models like the token, the pandemic and the averaging process, plus the voter model that relates to Kingman’s coalescent. A very nice read opening new vistas for sure (and a source of projects for graduate students most certainly!)

MCMski IV (homepage)

Posted in Mountains, pictures, Statistics, Travel, University life with tags , , , , , , , , , , , , , , , , , on October 23, 2012 by xi'an

I have rewritten the text on the home page of the MCMSki IV website. Feel free to comment! I also want to signal the creation of a Facebook page.

The next MCMSki meeting, MCMSki IV, will be held in Chamonix Mont-Blanc, France, from Monday, January 6 to Wednesday, January 8, 2014. As for the previous MCMSki meetings, it jointly supported by the IMS (Institute of Mathematical Statistics) and ISBA (International Society for Bayesian Analysis), as the first meeting of the newly created BayesComp section of ISBA. It will focus on all aspects of MCMC theory and methodology, including related fields like sequential Monte Carlo, approximate Bayesian computation, Hamiltonian Monte Carlo. In contrast with the earlier meetings, it will merge the satellite Adap’ski workshop into the main meeting by having parallel (invited and contributed) sessions on those different themes. A call for proposals of sessions and talks is available here. There will be also opportunities for presenting one’s work at plenary and well-attended evening poster sessions.

In terms of location, after an excursion to Utah, MCMSki IV is back in the Alps, on the French side of Mont-Blanc, and Chamonix offers a wide range of outdoor and indoor activities during the breaks, with all levels of skiing available. The meeting will take place at the Conference Centre le Majestic (Centre des Congrès – Le Majestic) in Chamonix Mont-Blanc. (With a large population of English expatriates living there, Chamonix is very easy to handle for English speakers. The lodging capacities are both diverse and plenty.)