Archive for variational autoencoders

Nature tidbits [28 Aug 25]

Posted in Books, Kids, pictures, Travel, University life with tags , , , , , , , , , , , , , , , , , , , , , , , , on September 24, 2025 by xi'an

A nice cover (and a used pun) on the cover of this issue of Nature. That (reminded of trees from the Guadeloupean rainforest and) which refers to the rich microbiomes found in trees, with a partition between sapwood and heartwood. Along

  • an editorial call for “hazardous” research, namely the relevance of studies on urban gullies that endanger surrounding populations and have unpredictable dynamics, albeit scientists alone cannot provide solutions.
  • a Columbian study on how the microbial communities acting during the fermentation of cocoa and could be controlled towards finer chocolat).
  • the alas now usual articles on the impacts of Trump.2.0 on science and academia, with US Minister of Health Kennedy launching a call for finding the environmental cause of autism. When most researchers blame primarily genetics and associate the rise in cases with a rise in detection and awareness. And pointed out at the earlier drop in NIH funds for autism research, the overall balance being negative.
  • plus a useful debunking of five quantum theory myths! Along with the story of a 2020 Science paper by Vaitiekėnas et al. on Majoranas that raised enough questions for Science to publish an expression of concern, now lifted after the publication of a long correction.
  • (a video of) rappelling robots diving into a lava tube!!
  • a Verne-esque proposal to create a lunar biodepository, a (dubious imho) mix between Noah’s Ark and the (unscientific) faith in cryogeny
  • a more sobering call for more frequent data inputs (forcing datasets) to calibrate climate models, with no mention made of statistics or machine learning…
  • an operative “mind-reading” device… with a protection password (and a 74% efficiency)!
  • two research articles on AI unification of cognitive theories.
  • Another one on the (revolutionary) construction of an optical encoder-decoder network towards generating images.

mostly M[ay]C

Posted in Books, Statistics, Travel, University life with tags , , , , , , , , , , , , , on May 22, 2024 by xi'an

With the details from the second speaker:

Adaptive MCMC sampling using a Metropolized PDMP sampler combined with a No-U-Turn criterion

Augustin Chevallier, Université de Strasbourg

Adaptivity in MCMC algorithms is hard to achieve. In Hamiltonian Monte Carlo, for example, it is possible to tune the path length using the No-U-Turn sampler, but the numerical step size cannot be adapted; it can only be tuned. We propose here a new class of algorithm based on Metropolizing a numerical approximation of a PDMP sampler. Like HMC, these samplers require two parameters: a numerical step size and a path length. Unlike HMC, both parameters can be adapted. This paves the way for more robust sampling algorithms, especially for difficult target densities.

 

 

mostly MC [April]

Posted in Books, Kids, Statistics, University life with tags , , , , , , , , , , , , , , , , , , , , , , , , , on April 5, 2024 by xi'an

All About that Bayes stroll

Posted in pictures, Statistics, University life with tags , , , , , , , , , , , , , on February 9, 2024 by xi'an

For all Bayesians and sympathisers in the Paris area, an incoming All about that Bayes seminars¹ by Elisabeth Gassiat (Institut de Mathématiques d’Orsay) on 13 February, 16h00, on Campus Pierre & Marie Curie, SCAI:

A stroll through hidden Markov models

Hidden Markov models are latent variables models producing dependent sequences. I will survey recent results providing guarantees for their use in various fields such as clustering, multiple testing, nonlinear ICA or variational autoencoders.


¹Incidentally, I came across an unrelated All about that Bayes YouTube video, a talk given by Kristin Lennox (Lawrence Livermore National Laboratory). And then found out a myriad of talks or courses using that pun.

accronyms [CDT lectures]

Posted in Books, Statistics with tags , , , , , , , , , , , , , , , on May 16, 2022 by xi'an

This week, I gave a short and introductory course in Warwick for the CDT (PhD) students on my perceived connections between reverse logistic regression à la Geyer and GANS, among other things. The first attempt was cancelled in 2020 due to the pandemic, the second one in 2021 was on-line and thus offered little possibilities for interactions. Preparing for this third attempt made me read more papers on some statistical analyses of GANs and WGANs, which was more satisfactory [for me] even though I could not get into the technical details…