Saint-Chély d’Aubrac [jatp]
Posted in Mountains, pictures, Travel with tags Aubrac, Auvergne, bell of the lost, domerie, estive, hiking, hiking trail, jatp, knight hospitalers, knight order, pilgrims, Saint-Chély d'Aubrac, Santiago de Compostela, Way of Saint James route, winter light on January 27, 2024 by xi'an
all over the moon [or not]
Posted in pictures, Travel with tags Arthur C. Clarke, DNA, human remains, moon, moon mission, Najavo Nation, NASA, Peregrine Mission 1, religions, space, space mission, the dog on the Moon on January 26, 2024 by xi'an
High diddle diddle,
The Cat and the Fiddle,
The Cow jump’d over the Moon,
The little dog laugh’d to see such Craft,
And the Dish ran away with the Spoon.
Read about the cumulated non-sense of a commercial company sending human remains (incl. some DNA of Arthur C. Clarke) to the Moon by a commercial mission, along with NASA scientific experiments, and of the Navajo Nation objecting to it for religious reasons. Wasting energy, time, room (albeit less than 70g) for vanity purposes (at $12,000 per gram) is evidently absurd, almost to the scale of launching a Tesla into space. But such is calling upon religious beliefs to control what can fly to the Moon and what cannot is equally absurd, especially when considering that the whole Moon lander is contaminated with all sorts of material, including DNA. But there may be a dog (on the Moon) since the mission failed.
salut, c’est Lenoir !
Posted in Books, Kids, Travel with tags Bernard Lenoir, Black Session, cassette, feedback, France Inter, indie rock, Joy Division, Les Inrockuptibles, memories, nostalgia, obituary, pop culture, Radio France, radio show, souvenirs on January 25, 2024 by xi'an
The death of Claude Villers a few days ago, a mythical radio presenter, reminded me of Feedback, the fabulous rock and pop show of his accomplice Bernard Lenoir on France Inter, to which I listened most evenings while in high school then uni, with live concerts like Joy Division’s and my religiously taping my favourite groups on cassettes. Until it got terminated. He returned to the national public radio for Black Sessions / C’est Lenoir, with a memorable studio concert of The Cure in 2004. Chapeau, Lenoir!
the academic integrity flow chart
Posted in Kids, pictures, University life with tags academic integrity, academic misconduct, dissertation, flowchart, module leader, plagiarism, simulations, survey, University of Warwick on January 24, 2024 by xi'an
This year, I received a summer project dissertation at Warwick (among several I supervised) that was a direct aggregation of three main papers on the project topic, including advanced simulations that were clearly beyond the reach of a summer project. Especially when the perpetrator only attended a very few supervision sessions among those I proposed.
With the help of a colleague we found rather easily the three papers, which had been rewritten to some extent into the project, while keeping the plan of the originals. And then I later a fourth paper corresponding to the numerical illustrative component of the project, which was the original reason for suspecting foul play. With graphs redrawn! Meaning that a plagiarism detector was only achieving an 18% agreement with the available literature, but still flagging plagiarism as “highly likely.”
I thus referred the case to the colleague in charge of academic integrity in the department. 
And this initiated a very involved process summarised by the attached flowchart… Starting with the academic conduct panel, which also concluded at plagiarism.
combining normalizing flows and QMC
Posted in Books, Kids, Statistics with tags Arianna Rosenbluth, arXiv, Illya Sobol, importance sampling, inverse cdf, John Halton, MCM 2023, Metropolis-Hastings algorithm, mostly Monte Carlo seminar, normalizing flow, Python, quasi-Monte Carlo methods, scrambling, Sobol sequences on January 23, 2024 by xi'an
My PhD student Charly Andral [presented at the mostly Monte Carlo seminar and] arXived a new preprint yesterday, on training a normalizing flow network as an importance sampler (as in Gabrié et al.) or an independent Metropolis proposal, and exploiting its invertibility to call quasi-Monte Carlo low discrepancy sequences to boost its efficiency. (Training the flow is not covered by the paper.) This extends the recent study of He et al. (which was presented at MCM 2023 in Paris) to the normalising flow setting. In the current experiments, the randomized QMC samples are computed using the SciPy package (Roy et al. 2023), where the Sobol’ sequence is based on Joe and Kuo (2008) and on Matouˇsek (1998) for the scrambling, and where the Halton sequence is based on Owen (2017). (No pure QMC was harmed in the process!) The flows are constructed using the package FlowMC. As expected the QMC version brings a significant improvement in the quality of the Monte Carlo approximations, for equivalent computing times, with however a rapid decrease in the efficiency as the dimension of the targetted distribution increases. On the other hand, the architecture of the flow demonstrates little relevance. And the type of RQMC sequence makes a difference, the advantage apparently going to a scrambled Sobol’ sequence.
Xi'an's Og 