Archive for Navy

climbing encounters

Posted in Mountains, pictures, Travel with tags , , , , , , , , , , , , on August 28, 2020 by xi'an

A nice if easy climbing morn on Éperon de Bouchier (à ne pas confondre avec Crochet de Boucher!) a week ago with a local guide, François, who happened to be a formidable character (even conditioning on him being guide). He left school at 14 to become a car mechanic, join the French Navy at 16, caught tuberculosis on a Navy basis, was sent to the Alps for recovery, caught a fatal and definite mountain attraction while there, got training supported by the Navy for an higher mechanic degree, took qualification courses to become a French mountain guide, started being interested in learning techniques and abilities through his training ski schools, experimented new teaching methods with kids from the Marseille suburbs,  eventually joined a Master in biomechanics and ergonomy at Orsay and ended up with a thesis on the topic, worked with French ski federation and a French ski brand, and is still guiding, training and researching despite having passed the retirement age! A wonderful chance encounter, with the facility of the route making chatting not an issue. (Except that some puritan ayatollah had recently removed most of the bolts, which did not make things harder in the end but exhibited an absurd degree of self-righteousness on a route that easy…)

And then an even more rewarding climb today with another local guide, Cathy, who gave me a great and profitable climbing lesson for over three hours, allowing me to reach a higher climbing level than I had previously achieved on an outside route. With a high degree of pedagogy and support. I ended up fairly tired, but exhilaratedly so!

bitcoin and cryptography for statistical inference and AI

Posted in Books, Mountains, pictures, Running, Statistics, Travel, University life with tags , , , , , , , , , , , , on April 16, 2018 by xi'an

A recent news editorial in Nature (15 March issue) reminded me of the lectures Louis Aslett gave at the Gregynog Statistical Conference last week, on the advanced use of cryptography tools to analyse sensitive and private data. Lectures that reminded me of a graduate course I took on cryptography and coding, in Paris 6, and which led me to visit a lab at the Université de Limoges during my conscripted year in the French Navy. With no research outcome. Now, the notion of using encrypted data towards statistical analysis is fascinating in that it may allow for efficient inference and personal data protection at the same time. As opposed to earlier solutions of anonymisation that introduced noise and data degradation, not always providing sufficient protection of privacy. Encryption that is also the notion at the basis of the Nature editorial. An issue completely missing from the paper, while stressed by Louis, is that this encryption (like Bitcoin) is costly, in order to deter hacking, and hence energy inefficient. Or limiting the amount of data that can be used in such studies, which would turn the idea into a stillborn notion.