Archive for Midlands

BNP12

Posted in pictures, Statistics, Travel, University life with tags , , , , , , , , , , , , on October 9, 2018 by xi'an

The next BNP (Bayesian nonparametric) conference is taking place in Oxford (UK), prior to the O’Bayes 2019 conference in Warwick, in June 24-28 and June 29-July 2, respectively. At this stage, the Scientific Committee of BNP12 invites submissions for possible contributed talks. The deadline for submitting a title/abstract is 15th December 2018. And the submission of applications for travel support closes on 15th December 2018. Currently, there are 35 awards that could be either travel awards or accommodation awards. The support is for junior researchers (students currently enrolled in a Dphil (PhD) programme or having graduated after 1st October 2015). The applicant agrees to present her/his work at the conference as a poster or oraly if awarded the travel support.

As for O’Bayes 2019, we are currently composing the programme, following the 20 years tradition of these O’Bayes meetings of having the Scientific Committee (Marilena Barbieri, Ed George, Brunero Liseo, Luis Pericchi, Judith Rousseau and myself) inviting about 25 speakers to present their recent work and 25 discussants to… discuss these works. With a first day of introductory tutorials to Bayes, O’Bayes and beyond. I (successfully) proposed this date and location to the O’Bayes board to take advantage of the nonparametric Bayes community present in the vicinity so that they could attend both meetings at limited cost and carbon impact.

ghost town [book review]

Posted in Books, Kids, Travel, University life with tags , , , , , , , , , , , on November 7, 2015 by xi'an

During my week in Warwick, I bought a book called Ghost Town, by Catriona Troth, from the campus bookstore, somewhat randomly, mostly because its back-cover was mentioning Coventry in the early 1980’s, racial riots, and anti-skinhead demonstrations, as well as the University of Warwick. And Ska, this musical style from the 1980’s, inspired from an earlier Jamaican rhythm, which emerged in Coventry with a groups called The Specials. (And the more mainstream Madness from Camden Town.)  While this was some of the music I was listening to at that time, I was completely unaware it had started in Coventry! And Ghost Town is a popular song from The Specials.  Which thus inspired the title of the book..

Enough with preliminaries!, the book is quite a good read, although more for the very realistic rendering of the atmosphere of the early 1980’s than for the story itself, even though both are quite intermingled. Most of the book action takes place in an homeless shelter where students just out of the University (or simply jobless) run the shelter and its flow of unemployed workers moving or drifting from the closed factories of the North towards London… This is Margaret Thatcher’s era, no doubt about this!, and the massive upheaval of industrial Britain at that time is translated into the gloomy feeling of an impoverished Midlands city like Coventry. This is also the end of the 1970’s, with (more) politically active students, almost indiscriminatingly active against every perceived oppression, from racism, to repression, the war in Ireland (with the death of Bobby Sand in Maze prison, for which I remember marching in Caen…), but mostly calling for a more open society. Given the atmosphere at that time, and especially given this was the time I was a student, there is enough material to make the book quite enjoyable [for me] to read! Even though I find the personal stories of both main protagonists somewhat caricaturesque and rather predictable. And, maybe paradoxically, the overall tone of the (plot) relationship between those two is somewhat patronising and conservative. When considering that they both can afford to retreat to safe havens when need be. But this does not make the bigger picture any less compelling a read, as the description of the (easy) manipulation of the local skinheads towards more violent racism by unnamed political forces is scary, with a very sad ending.

One side comment [of no relevance] is that reading the book made me realise I had no idea what Coventry looks like: none of the parts of town mentioned there evokes anything to me as I have never ventured farther than the train station! Which actually stands outside the ring road, hence not within the city limits. I hope I can find time during one of my next trips to have a proper look at down-town Coventry!

chain event graphs [RSS Midlands seminar]

Posted in pictures, Statistics, University life with tags , , , , , , , , , , on October 16, 2013 by xi'an

img_1836Last evening, I attended the RSS Midlands seminar here in Warwick. The theme was chain event graphs (CEG), As I knew nothing about them, it was worth my time listening to both speakers and discussing with Jim Smith afterwards. CEGs are extensions of Bayes nets with originally many more nodes since they start with the probability tree involving all modalities of all variables. Intensive Bayesian model comparison is then used to reduce the number of nodes by merging modalities having the same children or removing variables with no impact on the variable of interest. So this is not exactly a new Bayes net based on modality dummies as nodes (my original question). This is quite interesting, esp. in the first talk illustration of using missing value indicators as a supplementary variable (to determine whether or not data is missing at random). I also wonder how much of a connection there is with variable length Markov chains (either as a model or as a way to prune the tree). A last vague idea is a potential connection with lumpable Markov chains, a concept I learned from Kemeny & Snell (1960): a finite Markov chain is lumpable if by merging two or more of its states it remains a Markov chain. I do not know if this has ever been studied from a statistical point of view, i.e. testing for lumpability, but this sounds related to the idea of merging modalities of some variables in the probability tree…