Archive for migrants

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!!!

 

more border policing won’t save lives

Posted in Kids, Travel with tags , , , , , , on November 26, 2021 by xi'an

It is just shocking that the widespread reaction to an increasing number of migrants’ deaths (whether at sea or in the Belarus wetlands) is a call for more policing… And for criminalising NGOs that bring basic help to those stranded in liquid or terrestrial no man’s lands. The EU should act to give migrants and asylum seekers just-as-basic rights, rather than delegating its border control to non EU countries with abyssal human right records and accepting that its member states breach asylum laws and deny the victims their humanity.

and it only gets worse [verbatim]

Posted in Kids, pictures, Travel with tags , , , , , , , , , , , , , , , , , on July 9, 2019 by xi'an

“Increasing export capacity from the Freeport LNG project is critical to spreading freedom gas throughout the world by giving America’s allies a diverse and affordable source of clean energy” M. Menezes, US Secretary of Energy

“NASA should NOT be talking about going to the Moon – We did that 50 years ago. They should be focused on the much bigger things we are doing, including Mars (of which the Moon is a part)” DT,, 7 June

“I just met with the Queen of England (U.K.) [sic], the Prince of Whales [re-sic]” DT, 13 June

“[Sarah Sanders] is going to be leaving the service of her country and she’s going to be going  (…) She’s a very special person, a very, very fine woman, she has been so great, she has such heart, she’s strong but with great, great heart, and I want to thank you for an outstanding job.” DT, 13 June

“…when I asked, ‘How many will die?’ ‘150 people, sir’, was the answer from a General. 10 minutes before the strike I stopped it, not … proportionate to shooting down an unmanned drone.” DT, 21 June

“The reason we have tragedies like that on the border is because that father didn’t wait to go through the asylum process in the legal fashion and decided to cross the river and not only died but his daughter died tragically as well,” K. Cuccinelli, head of US Immigration and Citizenship Services, 28 June

“If Japan is attacked, we will fight World War III. But if we’re attacked, Japan doesn’t have to help us at all. They can watch it on a Sony television.” DT, 24 June

art brut [no!]

Posted in pictures, Statistics, Travel with tags , , , , , , , , , , , , on June 27, 2019 by xi'an

deaths at sea and a workshop

Posted in pictures, Statistics, Travel, University life with tags , , , , , , , , , , , , , , , on May 9, 2018 by xi'an

For several years, actually from the beginning of the Syrian revolution, I have been looking for data and for statisticians working on migrant deaths resulting from crossing the Mediterranean. With very little success, either because the researchers I met had poor and fragmented data, or because the agencies I contacted showed no (good) will into returning these statistics. Frontex being the most blatant example. I thus read with a lot of interest this article “Uncounted: Invisible Deaths on Europe’s Borders” which analyses the reasons for not producing statistics on the deaths at sea linked with desperate migrants crossing the sea in ill-suited boats.

In connection with this pressing issue, Kerrie Mengersen, Pierre Pudlo and myself organise next November a small workshop on Young Bayesians and Big Data for social good, at CIRM, Marseille, France. It will take place on the weekend before our main conference, Bayesian statistics in the Big Data era, that is, on 23-26 November 2018. Registration is free (and on site accomodation is cheap) but the number of attendees is limited, so apply asap! Senior participants include at this stage Tamara Broderick (MIT), Julien Cornebise (Element AI, TBC), David Corliss (Peace Work), Ruth King (Edinburgh), Cody Ross (UCSD, TBC), and the workshop aims at bringing participants to work together on methodological challenges and characteristic datasets. The outcome of the workshop will be presented at the beginning of the Bayesian statistics in the Big Data era, conference, on Monday 26 November.

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