master project?

Posted in Books, Kids, Statistics, University life with tags , , , , , , , on July 25, 2022 by xi'an

A potential master project for my students next year inspired by an X validated question: given a Gaussian mixture density

$f(x)\propto\sum_{i=1}^m \omega_i \sigma^{-1}\,\exp\{-(x-\mu_i)^2/2\sigma^2\}$

with m known, the weights summing up to one, and the (prior) information that all means are within (-C,C), derive the parameters of this mixture from a sufficiently large number of evaluations of f. Pay attention to the numerical issues associated with the resolution.  In a second stage, envision this problem from an exponential spline fitting perspective and optimise the approach if feasible.

journal of the [second] plague year [con’d]

Posted in Books, Kids, Mountains, pictures, Travel, University life with tags , , , , , , , , , , , , , , , , , , , , , , , , , on April 24, 2021 by xi'an

Made  soba noodles with the machine, resulting into shorte-than-life noodles, due to the high percentage of buckwheat flour in the dough, still quite enjoyable in a cold salad. Also cooked a roghan josh lamb shack, along with chapatis flavoured with radish leaves [no fire alarm this time] and a vegetable dahl whose recipe I found in Le Monde the same morn. Also took advantage of the few weeks with fresh and tender asparagus sold at the local market to make salads.

Watched a few episodes of Better than Us, Лучше (чем люди), a Russian science-fiction series set in a close future with humanoid robots replacing menial workers, until one rogue version turns uncontrollable, à la Blade Runner. There are appealing aspects to the story, besides the peep into a Russian series and the pleasure of listening to Russian, about the porous frontier between human and artificial intelligence. The scenario however quickly turns into a predictable loop and I eventually lost interest. Even faster did that happen with the Irregulars of Baker Street horror series, which I simply could not stand any further (and which connection with Holmes and Watson is most tenuous).

Having registered for a vaccination to the local pharmacy, I most got surprisingly called a few days later mid-afternoon to come at once for a shot of AstraZeneca, as they had a leftover dose. And a rising share of reluctant candidates for the vaccine!, despite David’s reassurances. I am unsure this shot was done early enough to get abroad for conferences or vacations in July, but it is one thing done anyway. With no side effect so far.

Rashomon, plus 47 ronins, plus…

Posted in Books, Kids, pictures, Travel with tags , , , , , , , , , , , on January 26, 2020 by xi'an

Another chance encounter (on Amazon) led me to read a graphical novel entitled Rashōmon, by Victor Santos. Which uses the same short stories from Ryūnosuke Akutagawa as Akira Kurosawa in his superlative film, if not with the same intensity. (The very first sentences are inspired from the first pages of the book, though.) And in a second part builds upon the tale of the 47 rônins which I read last summer in Koyasan. Plus a possible appearance of Miyamato Mushashi, the great 17th Century swordsman (depicted in two wonderful novels by Eiji Yoshikawa). While this is historically impossible, since Rashōmon takes place in the 12th Century and the 47 rônins acted in 1702, the theme cementing the story is the presence of a detective named Heigo Kobayashi, who “solves” both crimes but is nonetheless outsmarted by the novel “femme fatale”… Without a clear explanation as to how she did it.

While I found the rendering rather entertaining, with an original if convoluted drawing style, I was rather disappointed at the simplistic and Westernised adaptation of the subtle stories into a detective story. Calling upon (anachronic) ninjas as if the historical setting per se was not exotic enough. And the oddly modified role of the main female character into an Hammet-like heroin kills the ambivalence that is central to both Akutagawa’s and Kurosawa’s versions.

Zen gardens of Kyoto [jatp]

Posted in pictures, Travel with tags , , , , , , , on August 22, 2019 by xi'an

hiking the Kumano Kodo Nakahechi imperial route

Posted in Mountains, pictures, Running, Travel with tags , , , , , , , , , , , , , , , , , on August 19, 2019 by xi'an

The Kumano Kodo is a network of paths of pilgrimage towards places seen as sacred by either buddhists or shintoists (or syncretists!) from the 700’s. (The Kumano Hongu Taisha shrine celebrated its 2050th anniversary last year!) Meaning for non-believers a well-established system of ancient hiking paths in the mountainous forests of the Kii peninsula, south of Osaka, Kyoto and Nara. Apart from the potential dangers of heavy rain, like massive mudslides, there is no particular difficulty in the hikes (which were done wearing braided straw shoes, the waraji sandals) and a dense network of guest-houses and bus routes makes it possible to adapt the length of the day trips to one’s speed. While this is the place of Japan with the maximum of rain, the hot temperatures actually make it more than bearable when it is a shower and not a typhoon!day one

14km, from Takijiri-oji to Chikatsuyu-Oui, 7:30 hours, 1100 positive gain, nice trail all the way, maximum temperature 32°, met two dozen hikers and two trail runners, got tired by the end, confused one minshuku guest house for another, the hosts of the first one drove us to the second and later brought me back my sandals I have left in their car, no English speaking at the second place and no Onsen but very nice bento box and a pleasant conversation with a couple of Ausso-Danish young women spending a month in Japan and four on the trail. Entire path under cover, making high heat so much more bearable! Not too much in terms of views despite following ridges and visiting tops. Plenty of huge butterflies.

day two

6km, from Doguyaba-bashi (reached by bus) back to Tsugizakura, 2:30-3:00 hours, maximum temperature 30⁰, mixed trail and road, rain spells and showers, met three other couples of hikers, arrived too early at the guest house, waited in a one-room thatched traditional tea house by the side of the road with free hōji-cha tea offered by a very nice old man (not English speaking, alas, which limited the exchanges), reached the guest house at the same time as a Canadian-Spanish couple embarked on a massive six month travel. The dinner was imperial with a whooping ten dishes, all delicate and beautiful. Plus getting our names in Japanese Kanji characters.

day three

9km, from Doguyaba-bashi (the host gave us a ride) to Hosshinmon-oji, 4 hours, 600 positive gain, maximum temperature 29⁰, heavier rain spells, first part really nice then switching to forest track due to closures, finishing detour on tar road, took the infrequent bus to Yunomine-Onsen due to the closure. A few more couples and lone hikers passed us. Stayed at a larger guest-house minshuku with its own natural onsen plus normally access to the river with swimming waterholes. Far from Hongu and Yunomine, alas. But also welcome place to wait two days for the typhoon Krosa to pass by Western Japan.

day four

14km, from Nachisan to Koguchi, 930 positive gain and 1260 negative gain!, alas cancelled as advised by local tourist office due to uncertainties on the state of the trail, took the bus instead and enjoyed a swim after a very hot day in the now quiet Kumanogawachonichi, next to a most congenial guesthouse. Very quiet place, superlative food!

day five

13km, from Koguchi to Ukegawa,  690 positive gain, 5:30 hours, maximal temperature 29⁰, sunny, very enjoyable part of the trail with many ridge walks, no road share, hardly any trace of the typhoon, and early arrival in Hongu. Met with a guest from the Yunomine-Onsen guest house hiking the other way. And very few others.