Today my friend and coauthor Judith Rousseau is delivering a Bayesian lecture at the ICM in Philadelphia. Congrats!
Judith Rousseau’s talk at the International Congress of Mathematicians
Posted in Statistics, University life with tags Bayesian inference, conference, Hawkes processes, ICM 2026, International Congress of Mathematicians, Judith Rousseau, Philadelphia, Université Paris Dauphine on July 25, 2026 by xi'anbothsidesism in Nature
Posted in Books, Kids, Running with tags bothsidesism, doping, drug testing, East Germany, Enhanced Games, GDR, Nature, Paris 1924 Olympics, Paris Marathon, World Anti-Doping Agency, World record on July 24, 2026 by xi'anIn its 21 May issue, Nature prints two columns back to back, “Can the ‘steroid Olympics’ show the sporting community how to support athletes better?” by April Henning and “The Enhanced Games miss the point: science can clean up sport“, by Kim Wolff. They are both about the so-called “Enhanced Games” that were to take place a few days later, on 24 May, in Las Vegas (where else?!), with competitions in swimming, athletics, and weightlifting, and no drug test. With only one World record unofficially broken at the event. (Fortunately no one died. So far.)
The first column argues that those games are exposing how many elite athletes are struggling with financial, physical and psychological issues. And how the current anti-doping system, built around the agency WADA (whose French branch is located in the town next to mine) is getting it wrong… The second one is warning about the impact of this deregulation on athletes’ welfare and integrity. Especially when the impact of most drugs on health is unknown, esp. in the long run (!). The author is thus calling for improved anti-doping protocols, rather than a return to the 1980’s GDR State-sanctioned doping. I find it terrible that Nature brings those two opposite points with no balancing towards the reasonable one, while no scientific argument in favour of live testing came out of the first column. Terrible.
BNP15 a Bergamo [28 June – 02 July 2027]
Posted in Mountains, pictures, Statistics, Travel, University life with tags Bayesian nonparametrics, Bergamo, BNP15, conference, ISBA, Italia, Italy, Milano, seminar, Università degli studi di Bergamo on July 23, 2026 by xi'anbroken random generators
Posted in Statistics with tags Bayes theorem, games, mathematical puzzle, posterior expectation, posterior mean, The Riddler, uniform distribution on July 22, 2026 by xi'anNothing exciting or catastrophic here! Just a Friday afternoon puzzle entry on the successor to The Riddler (which I had not visited for a long while)… The first riddle reads as follows:
A random number generator on my calculator should generate random numbers between 0 and 1. But my suspicion is that the calculator is “tanked,” meaning it only generates random numbers between 0 and some value 0 < a < 1. Beyond that, I have no knowledge regarding the value of a. At the moment, it’s equally likely to be any value from 0 to 1. As an experiment, I ask the calculator to generate one random number. It produces a value of exactly 0.5. Based on this result, what can I expect the value of a to be, on average?
This is a direct (Bayesian) calculation of a posterior expectation when a given x=0.5 (a Uniform (0,a) realisation) is distributed as 1/(a log(2)) over (½,1), with expectation 1/(2 log(2)), about 0.72.
The added riddle just modifies the conditioning event (bringing it closer to Bayes experiment):
A second calculator is similarly “tanked.” As before, every value of a between 0 and 1 is equally likely at first. A friend generates one random number and only reveals that it’s somewhere between 0 and 0.5. On average, what can I expect the value of a to be?
This is also a direct (Bayesian) calculation with a Bernoulli output z, with probability min(0.5,a)/a, which results in a posterior expectation of a equal to 3/(4*(1+log(2))), about 0.44. And… I happened to get selected for my (correct) answer to this question!
a journal of the Hugo year (ter)
Posted in Books, Kids, Mountains, pictures, Running, Travel, University life, Wines with tags action movie, Black Plague, book reviews, COVID-19, Daniel Defoe, fantasy, FBI, fish liver, Game of Thrones, grilled eel, hitsumabushi, Hugo Awards, Journal of the Plague Year, kindle, LAcon V, locked room mystery, rhubarb, Russian invasion, samosa, science fiction, Stand Up To Trump, tournament, trilogy, Ville de Marseille, world building on July 21, 2026 by xi'anRead part of another Hugo best novel contender, Death of the Author by Nnedi Okorafor, which is about a writer getting suddenly famous for an original novel of (voluntarily) rusty robots, but this was too much of an infinite mirror (and too little speculative fiction) that I gave up a third of the way, before anything speculative happened…. And the Hugo (hopeful) novella The Summer War by Naomi Novik, nice tale à la Grimm if not particularly deep. And another Hugo nominated novel The Incandescent by Emily Tesh, a magical boarding school à la Harry Potter, enjoyable enough if missing in villeins besides demons! However, the constant whine of the head teacher about her duties, the glorification of the English boarding school model, and the fixation on the A levels and on getting to Oxford are weighting down my vote… And the Hugo novelette The Girl That My Mother Is Leaving Me For by Cameron Reed, with little appeal. Lots of books, thanks to this long-lasting spell of jetlag!
Cooked cold soba noodles for the week in Nagoya, And (alas!) enjoyed eels in the local histumabashi format. Alas because I discovered afterwards that eels are dramatically threatened to extinction. Given that the fisheries rely on wild eels for the most part.
Watched the whole season of A Knight of the Seven Kingdoms in the plane to Tokyo, set in the Game of Thrones universe and quite engaging, even though the (edge) knight’s naïvety is exaggerated, while the scenario shifts suspend belief way too much and too often. The absurd brutality of medieval jousts and tournaments is rendered in strongest terms (but I did not faint!). Reminding me of Scott’s Last Duel.
Xi'an's Og