Archive for Hawaii

ellis unconference [not in Hawai’i]

Posted in pictures, Running, Travel, University life with tags , , , , , , , , , , , , , , , , , , , , , , , , , , , , , on July 26, 2023 by xi'an

As ICML 2023 is happening this week, in Hawai’i, many did not have the opportunity to get there, for whatever reason, and hence the ellis (European Lab for Learning {and} Intelligent Systems] board launched [fairly late!] with the help of Hi! Paris an unconference (i.e., a mirror) that is taking place in HEC, Jouy-en-Josas, SW of Paris, for AI researchers presenting works (theirs or others’) presented at ICML 2023. Or not. There was no direct broadcasting of talks as we had (had) in CIRM for ISBA 2020 2021. But some presentations based on preregistered talks. Over 50 people showed up in Jouy.

As it happened, I had quite an exciting bike ride to the HEC campus from home, under a steady rain, crossing a (modest) forest (de Verrières) I had never visited before, despite it being a few km from home, getting a wee bit lost, stopped by a train Xing between Bièvre and Jouy, and ending up at the campus just in time for the first talk (as I had not accounted for the huge altitude differential). Among curiosities met on the way, “giant” sequoias, a Tonkin pond, Chateaubriand’s house.

As always I am rather impressed by the efficiency of AI-ML conferences run, with papers+slides+reviews online, plus extra material as in this example. Lots of papers on diffusion models this year, apparently. (In conjunction with the trend observed at the Flatiron workshop last Fall.) Below are incoherent tidbits from the presentations I attended:

  • exponential convergence of the Sinkhorn algorithm by Alain Durmus and co-authors, with the surprise occurrence of a left Haar measure
  • a paper (by Jerome Baum, Heishiro Kanagawa, and my friend Arthur Gretton) on Stein discrepancy, with an Zanella Stein operator relating to Metropolis-Hastings/Barker since it has expectation zero under stationarity, interesting approach to variable length random variables, not a RJMCMC, but nearby.
  • the occurance of a criticism of the EU GDPR that did not feel appropriate for synthetic data used in privacy protection.
  • the alternative Sliced Wasserstein distance, making me wonder if we could optimally go from measure μ to measure ζ using random directions or how much was lost this way.

\mathbb E[y|X=x] = \mathbb E\left[y\frac{f_{XY}(x,y)}{f_X(x)f_Y(y)}|X=x\right] = \frac{\mathbb E\left[y\frac{f_{XY}(x,y)}{f_Y(y)}|X=x\right]}{f_X(x)}

as (a) densities are replaced with kernel estimates, (b) the outer density may be very small, (c) no variance assessment is provided.

  • Markov score climbing and transport score climbing using a normalising flow, for variational approximation, presented by Christian Naesseth, with a warping transform that sounded like inverting the flow (?)
  • Yazid Janati not presenting their ICML paper State and parameter learning with PARIS particle Gibbs written with Gabriel Cardoso, Sylvain Le Corff, Eric Moulines and Jimmy Olsson, but another work with a diffusion based model to be learned by SMC and a clever call to Tweedie’s formula. (Maurice Kenneth Tweedie, not Richard Tweedie!) Which I just realised I have used many times when working on Bayesian shrinkage estimators

[A]ABC in Hawai’i

Posted in Statistics with tags , , , , , , , , on April 6, 2023 by xi'an

Nature snippets

Posted in Statistics with tags , , , , , , , , , , , , , on October 1, 2019 by xi'an

In the August 1 issue of Nature I took with me to Japan, there were many entries of interest. The first pages included a tribune (“personal take on events”) by a professor of oceanography calling for a stop to the construction of the TMT telescope on the Mauna Kea mountain. While I am totally ignorant of the conditions of this construction and in particular of the possible ecological effects on a fragile altitude environment, the tribune is fairly confusing invoking mostly communitarian and religious, rather than scientific ones. And referring to Western science and Protestant missionaries as misrepresenting a principle of caution. While not seeing the contradiction in suggesting the move of the observatory to the Canary Islands, which were (also) invaded by Spanish settlers in the 13th century.

Among other news, Indonesia following regional tendencies to nationalise research by forcing foreign researchers to have their data vetted by the national research agency and to include Indonesian nationals in their projects. And, although this now sounds stale news, the worry about the buffoonesque Prime Minister of the UK. And of the eugenic tendencies of his cunning advisor… A longer article by Patrick Riley from Google on three problems with machine learning, from splitting the data inappropriately (biases in the data collection) to hidden variables (unsuspected confounders) to mistaking the objective (impact of the loss function used to learn the predictive function). (Were these warnings heeded in the following paper claiming that deep learning was better at predicting kidney failures?)  Another paper of personal interest was reporting a successful experiment in Guangzhou, China, infecting tiger mosquitoes with a bacteria to make the wild population sterile. While tiger mosquitoes have reached the Greater Paris area,  and are thus becoming a nuisance, releasing 5 million more mosquitoes per week in the wild may not sound like the desired solution but since the additional mosquitoes are overwhelmingly male, we would not feel the sting of this measure! The issue also contained a review paper on memory editing for clinical treatment of psychopathology, which is part of the 150 years of Nature anniversary collection, but that I did not read (or else I forgot!)