Author: xi'an

Le Monde puzzle [#1111]

Another low-key arithmetic problem as Le Monde current mathematical puzzle:

Notice that there are 10 numbers less than, and prime with 11, 100 less than and prime with 101, 1000 less than, and prime with 1111? What is the smallest integer N such that…

unimaginable scale culling

Despite the evidence brought by ABC on the inefficiency of culling in massive proportions the British Isles badger population against bovine tuberculosis, the [sorry excuse for a] United Kingdom government has permitted a massive expansion of badger culling, with up to 64,000 animals likely to be killed this autumn… Since the cows are the primary […]

Le Monde puzzle [#1110]

A low-key sorting problem as Le Monde current mathematical puzzle: If the numbers from 1 to 67 are randomly permuted and if the sorting algorithm consists in picking a number i with a position higher than its rank i and moving it at the correct i-th position, what is the maximal number of steps to […]

two positions at UBC

A long-time friend at UBC pointed out to me the opening of two tenure-track Assistant Professor positions at the Department of Statistics at the University of British Columbia, Vancouver, with an anticipated start date of July 1, 2020 or January 1, 2021. The deadline for applications is October 18, 2019. Statistics at UBC is an […]

the three i’s of poverty

Today I made a “quick” (10h door to door!) round trip visit to Marseille (by train) to take part in the PhD thesis defense (committee) of Edwin Fourrier-Nicolaï, which title was Poverty, inequality and redistribution: an econometric approach. While this was mainly a thesis in economics, meaning defending some theory on inequalities based on East […]

email footprint

While I was wondering (im Salzburg) at the carbon impact of sending emails with an endless cascade of the past history of exchanges and replies, I found this (rather rudimentary) assessment  that, while standard emails had an average impact of 4g, those with long attachments could cost 50g, quoting from Burners-Lee, leading to the fairly […]

open reviews

When looking at a question on X validated, on the expected Metropolis-Hastings ratio being one (not all the time!), I was somewhat bemused at the OP linking to an anonymised paper under review for ICLR, as I thought this was breaching standard confidentiality rules for reviews. Digging a wee bit deeper, I realised this was […]

R puzzle

Can you guess the meaning of the following R code
“?”=`u\164f8ToI\x6Et`;’!’=prod;!{
y<-xtabs(~?readLines())}%in%{
z<-y[1]}&z>T##&[]>~48bEfILpu
If not (!), the explanation is provided in Robin’s answer to a codegolf …

9 pitfalls of data science [book review]

I received The 9 pitfalls of data science by Gary Smith [who has written a significant number of general public books on personal investment, statistics and AIs] and Jay Cordes from OUP for review a few weeks ago and read it on my trip to Salzburg. This short book contains a lot of anecdotes and […]

dodging bullets, IEDs, and fingerprint detection at SimStat19

I attended a fairly interesting forensic science session at SimStat 2019 in Salzburg as it concentrated on evidence and measures of evidence rather than on strict applications of Bayesian methodology to forensic problems. Even though American administrations like the FBI or various police departments were involved. It was a highly coherent session and I had […]

likelihood-free inference by ratio estimation

“This approach for posterior estimation with generative models mirrors the approach of Gutmann and Hyvärinen (2012) for the estimation of unnormalised models. The main difference is that here we classify between two simulated data sets while Gutmann and Hyvärinen (2012) classified between the observed data and simulated reference data.” A 2018 arXiv posting by Owen […]

Japan’s Kumano Kodo pilgrimage [book review]

When preparing our hiking trip to the Kumano Kodo pilgrimage route, I was extremely pleased to find a dedicated guidebook that covered precisely the region we wanted to explore and provided enough background material to make the walk sound feasible. However, once I found the Kumano Travel reservation website, run most efficiently by the Tanabe […]

Nature tidbits

Before returning a few older issues of Nature to the coffee room of the maths department, a quick look brought out the few following items of interests, besides the great cover above: France showing the biggest decline in overal output among the top 10 countries in the Nature Index Annual Tables. A tribune again the […]

research position in Bristol

Christophe Andrieu is seeking a senior research associate (reference ACAD103715) at the University of Bristol to work on new approaches to Bayesian data science. The selected candidate would work with Prof. Christophe Andrieu (School of Mathematics) and Prof. Mark Beaumont (Life Science) on new approaches to tackle Bayesian inference in complex statistical models arising in […]

Le Monde puzzle [#1109]

A digital problem as Le Monde current mathematical puzzle: Noble numbers are such that they only involve different digits and are multiple of all their digits. What is the largest noble number? Hmmmm…. Brute force? Since the maximal number of digits is 10, one may as well try: k=soz=9 for (t in 1:1e3){ sol=1 while […]