Archive for ISBA 2022

keep meetings hybrid

Posted in Statistics, Travel, University life with tags , , , , , , , , , , , , , , , , , , on September 30, 2022 by xi'an

I was reading the latest ISBA Bulletin and the tribune by ISBA President Sudipto Banerjee celebrating the return to the physical ISBA World meeting, along with worries about participants who caught COVID there. (Unfortunately, one good friend of mine experienced symptoms that went beyond the mild cold-like ones I zoomed through a few days ago.) This particular issue of creating a COVID cluster [during coffee breaks?!] provides [me with] one further argument for my supporting hybrid and multimodal meetings on a general basis. Which should [imho] appear in the proposals for the 2026 and 2028 World Meetings (deadline on 31 October)…(The 2024 meeting in Venezia will certainly involve hybridicity! As will BayesComp in Levi.) Discussing the topic with others in some scientific committees recently made me realise this was not such a shared perspective, from reasons varying from worrying about balancing the budget, to zoom fatigue, to the added value of informal interactions. Still, there also are reasons for hybridising our meetings, from reduced travel impact, to more inclusiveness,  on geographical, diversity, affordability, seniority grounds. Holding hybrid conferences with multiple regional mirrors allows for a potentially higher degree of interaction and local input.  And a minimal organisational effort.

the strange incident of the bottle in the fridge

Posted in Statistics with tags , , , , , , , , , , , , , on September 1, 2022 by xi'an

a journal of the plaid [shirt] year [#2]

Posted in Books, Kids, Mountains, pictures, Running, Travel, University life with tags , , , , , , , , , , , , , , , , , , , , , , , , , on August 3, 2022 by xi'an

Read Kawabata’s Sound of the Mountain, which I also found in a Montréal bookstore. At first, I thought it was connected to the masterpiece House of Sleeping Beauties,  which I read eons ago, as dreams are also central to that (mostly) domestic and familial story, but this was quite another, more personal, and poignant reflection on aging and the irreversibility of time. As well as an unsuspected window into immediate post-war Japan. (With the realisation that abortion was completely acceptable then.) Also spotted Greg Bear’s Darwin’s Children in my Canadian cabin, which I started and finished later with a Kindle version. As I was unaware of a sequel to the fabulous Darwin’s Radio. Overall, I was almost as enthusiastic about it as I was with the first book, but obviously suffering from an academic bias as the author engages into speculative population genetics, which may prove too much for non-academics… (Imho, the end is wasted, though.) And (binge) read January Fifteenth on the flight back (leaving too early to sleep!), which is a short novel whose only speculative aspect is the move (by the US Government) to a universal basic income (UBI) for all individuals, and the consequences on several women’s live. This was indeed a very quick read, presumably due to the high proportion of dialogues, with (variably) interesting characters that avoid a direct take on the concept, but somewhat charicaturesque nonetheless. The implementation of the scheme is rather vaguely described: January 15 is the calendar day people pick their yearly UBI and they have to do it in person to avoid been coerced or scammed into transferring it to someone else. As someone rather interested in this societal propsal, this book did not modify my views on the concept or on its practical aspects, but shed light on some potential consequences of (one version of) it.

Had a great time in a Lac-Saint-Jean cabin, with direct access to the lake. Albeit requiring the emergency purchase of a neoprene swimming suit, as the temperature of the lake was rather low for extended swimming without it. But otherwise, having a swell time every morning, often running and swimming and biking. Before hiking. (The last week, farther south, next to a much smaller lake I could easily cross, did not require the suit!) Also appreciated very much the almost flat véliroute des Bleuets (blueberries) that run all around the lake (even though some sections are alas shared with cars). Has for instance an uninterrupted 15K connection to the nearest (genuine) bakery+cheese-mongery! Made an attempt at kouign amann, but using the wrong type of both flour and cassonade, plus an unknown oven and the poor substitute of baking soda for yeast predictably failed the experiment, even though the outcome was eatable (and eaten within a few days).

As usual (!), did not spot much wildlife, beyond groundhogs, pikas, squirrels, beavers and muskrats in our rental’s lake, moose tracks here and there, and a few Virginia deer in the Mauricie National Park. (Which made me realise that national and regional [Québec] parks co-existed in the area.) Had a few traditional hikes, reconnecting with Deet to keep mosquitoes and black flies at bay.

Watched nothing at all! In part due to my wife often borrowing my laptop for its Netflix connection, in part due to my early sleep caused by earlier rise, as light comes before 5am in this part of Québec we were staying, which made an ideal opportunity for very early run, swim, and… Biometrika editing!

a journal of the plaid [shirt] year

Posted in Books, Kids, Mountains, pictures, Travel, University life with tags , , , , , , , , , , , , , , , , , , , , , , , , , on August 1, 2022 by xi'an

Read The priory of the orange tree, bought in one of the many Montréal bookstores [where I could have purchased many more books!] This fantasy novel was a Goodread fantasy recommended read, plus a NYT best-seller and nominated for some fantasy award, but I am quite surprised by the enthusiastic support. Indeed, I found the book had a very shallow and predictable scenario, with most of the tropes of the genre (e.g., ninja-like fighters, heroes uncovering long-lost magical artefacts, , super-evil entity about to return to life/power, a few predestined characters saving the Universe). Unrealistic events, all-too-convenient coincidences, with little efforts put in the construction of the world, of the magical rules, or of the political structure there. The second half was particularly bad.

Enjoyed very much my week in the Plateau part of Montréal, with the green spots in from of every house, the density of shops (and not only restaurants), and the fantastic network of BiXi stations that made travelling around so easy and essentially free! (Glad I brought my 661 helmet from home, even though it attracted many questions during the conference!). And lived essentially on (Saint-Viateur) bagels and (Kinton) ramens. With a funny linguistic incident when I ordered a bagel [which I pronounced bah-gael in the Parisian way] in a bakery and was offered a baguette!

Watched The Chase, an improbable but funny Korean film about a grumpy old man uncovering a serial killer, helped by a former cop escaped from a psychiatric facility. Given that the heroes were mostly senior citizens, this made for a welcome major change from the series I usually watched. Also came by chance upon the 2003 Japanese anime Tokyo Godfathers, which I found amazing, despite my rare foray into anime! A most unconventional Christmas movie, to watch in July or any other month.

day five at ISBA 22

Posted in Mountains, pictures, Running, Statistics, Travel, University life with tags , , , , , , , , , , , , , , , , , , , , , , , , , , , , on July 4, 2022 by xi'an

Woke up even earlier today! Which left me time to work on switching to Leonard Cohen’s song titles for my slide frametitles this afternoon (last talk of the whole conference!), run once again to Mon(t) Royal as all pools are closed (Happy Canada Day!, except to “freedom convoy” antivaxxxers.) Which led to me meeting a raccoon by the side of the path (and moroons feeding wildlife).

Had an exciting time at the morning session, where Giacomo Zanella (formerly Warwick) talked on a mixture approach to leave-one-out predictives, with pseudo-harmonic mean representation, averaging inverse density across all observations. Better than harmonic? Some assumptions allow for finite variance, although I am missing the deep argument (in part due to Giacomo’s machine-gun delivery pace!) Then Alicia Corbella (Warwick) presented a promising entry into PDMP by proposing an automated zig-zag sampler. Pointing out on the side to Joris Bierkens’ webpage on the state-of-the-art PDMP methodology. In this approach, joint with with my other Warwick colleagues Simon Spencer and Gareth Roberts, the zig-zag sampler relies on automatic differentiation and sub-sampling and bound derivation, with “no further information on the target needed”. And finaly Chris Carmona presented a joint work with Geoff Nicholls that is merging merging cut posteriors and variational inference to create a meta posterior. Work and talk were motivated by a nice medieval linguistic problem where the latent variables impact the (convergence of the) MCMC algorithm [as in our k-nearest neighbour experience]. Interestingly using normalising [neural spline] flows. The pseudo-posterior seems to depend very much on their modularization rate η, which penalises how much one module influences the next one.

In the aft, I attended sort of by chance [due to a missing speaker in the copula session] to the end of a session on migration modelling, with a talk by Jason Hilton and Martin Hinsch focussing on the 2015’s mass exodus of Syrians through the Mediterranean,  away from the joint evils of al-Hassad and ISIS. As this was a tragedy whose modelling I had vainly tried to contribute to, I was obviously captivated and frustrated (leaning of the IOM missing migrant project!) Fitting the agent-based model was actually using ABC, and most particularly our ABC-PMC!!!

My own and final session had Gareth (Warwick) presenting his recent work with Jun Yang and Kryzs Łatuszyński (Warwick) on the stereoscopic projection improvement over regular MCMC, which involves turning the target into a distribution supported by an hypersphere and hence considering a distribution with compact support and higher efficiency. Kryzs had explained the principle while driving back from Gregynog two months ago. The idea is somewhat similar to our origaMCMC, which I presented at MCqMC 2016 in Stanford (and never completed), except our projection was inside a ball. Looking forward the adaptive version, in the making!

And to conclude this subjective journal from the ISBA conference, borrowing this title by (Westmount born) Leonard Cohen, “Hey, that’s not a way to say goodbye”… To paraphrase Bilbo Baggins, I have not interacted with at least half the participants half as much as I would have liked. But this was still a reunion, albeit in the new Normal. Hopefully, the conference will not have induced a massive COVID cluster on top of numerous scientific and social exchanges! The following days will tell. Congrats to the ISBA 2022 organisers for achieving a most successful event in these times of uncertainty. And looking forward the 2024 next edition in Ca’Foscari, Venezia!!!


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