Archive for Japan

神々の山嶺 [the summit of the gods]

Posted in Books, Kids, Mountains, pictures with tags , , , , , , , , , , , on February 19, 2017 by xi'an

The summit of the gods is a five volume manga created by Jiro Taniguchi, who just passed away. While I do not find the mountaineering part of the story realistic [as in the above stripe], with feats and strength that seem beyond even the top himalayists like Reinhold Messner, Pierre Beghin, Abele Blanc, or Ueli Steck (to name a few), I keep re-reading the series for the unique style of the drawing, the story (despite the above), and the atmosphere of solo climbing in the 1970’s or 1980’s, especially as a testimony to Japanese climbers, as well as the perfect rendition of the call of the mountains… Reading Taniguchi’s obituaries over the weekend, I realised he was much more popular in France, where he won a prize for his drawing at the BD Festival in Angoulême in 2005, than in Japan.

走ることについて語るときに僕の語ること [book review]

Posted in Books, Running with tags , , , , , , , , , , , on April 19, 2014 by xi'an

The English title of this 2007 book of Murakami is “What I talk about when I talk about running”. Which is a parody of Raymond Carver’s collection of [superb] short stories, “What we talk about when we talk about love”. (Murakami translated the complete œuvres of Raymond Carver in Japanese.) It is a sort of diary about Murakami’s running practice and the reasons why he is running. It definitely is not a novel and the style is quite loose or lazy, but this is not a drawback as the way the book is written somehow translates the way thoughts drift away and suddenly switch topics when one is running. At least during low-intensity practice, when I often realise I have been running for minutes without paying any attention to my route. Or when I cannot recall what I was thinking about for the past minutes. During races, the mind concentration is at a different level, first focussing on keeping the right pace, refraining from the deadly rush during the first km, then trying to merge with the right batch of runners, then fighting wind, slope, and eventually fatigue. While the book includes more general autobiographical entries than those related with Murakami’s runner’s life, there are many points most long-distance runners would relate with. From the righteous  feeling of sticking to a strict training and diet, to the almost present depression catching us in the final kms of a race, to the very flimsy balance between under-training and over-training, to the strangely accurate control over one’s pace at the end of a training season, and, for us old runners, to the irremediable decline in one’s performances as years pass by… On a more personal basis, I also shared the pain of hitting one of the slopes in Central Park and the lack of nice long route along Boston’s Charles river. And shared the special pleasure of running near a river or seafront (which is completely uncorrelated with the fact it is flat, I believe!) Overall, what I think this book demonstrates is that there is no rational reason to run, which makes the title more than a parody, as fighting weight, age, health problems, depression, &tc. and seeking solitude, quiet, exhaustion, challenge, performances, zen, &tc. are only partial explanations. Maybe the reason stated in the book that I can relate the most with is this feeling of having an orderly structure one entirely controls (provided the body does not rebel!) at least once a day.  Thus, I am not certain the book appeals to non-runners. And contrary to some reviews of the book, it certainly is not a training manual for novice runners. (Murakami clearly is a strong runner so some of his training practice could be harmful to weaker runners…)

the devotion of suspect X

Posted in Books with tags , , , , , on April 13, 2013 by xi'an

“Ah, an adherent of Erdös, I see”

I read this book (I bought along with the House of Silk in Oxford) over a wee more than a day: it reads fast and it reads well! Really really well. The devotion of suspect X is a Japanese detective story where the reader knows the true murder story from the start and waits for the police to uncover the culprits, except there is a twist in the story. And another twist in the twist. And yet another one…

“That guy might be a genius mathematician, but he’s certainly a novice murderer.”
“They are the same thing,” Yokawa stated simply. “Murder probably comes even easier to him.”

The main characters are three graduates from the Imperial University in Tokyo: one in sociology (who acknowledged only visiting the library twice), one in physics who is still working as a researcher there and one in mathematics, who left the academic system to teach bored high school students—while still working on his free time on the Riemann conjecture. The X in the title is actually related with the mathematician, who handle the murder as a maths equation and the murderer as an unknown X.

“For instance, I give them a question that looks like a geometry problem, but is in fact an algebra problem.”

The book starts somehow sedately but, as the personalities of the mathematician and the physician unfold, it gets more and more gripping, to the point I could not let go (and was glad of my battery giving up during the flight to Montpellier so that I could keep reading!). I also appreciated very much the depiction of the Japanese society in the novel and found myself visualising the characters in some parts of Kyoto I visited last year (although the story takes place in Tokyo). The harsh condition of single women in this society is also well-exposed and central to the story.

“He had calculated that it would take him roughly another twenty years to complete his work on this particular theory. Possibly even longer. It was the kind of insurmountable problem worthy of an entire lifetime’s devotion. And of all the mathematicians in the world, he was in the best position to crack it.”

There are a few imperfections, of course, like the final scene which is both “necessary” and clumsy. Or the uncovering of the (brilliant) last twist by the physicist. But the plot holds solidly as a whole and makes me want tore-read the book again, to reanalyse every situation with the knowledge of the “full” truth. (I also disliked the connection with Stieg Larsson made on the front cover:  it differs very very much from Millenium in that the central female character Yasuko remains a victim throughout the book without ever taking over. There is no political perspective to be found in The devotion of suspect X.) The book was adopted into a movie, I wonder how well it translates…

quick impressions from Japan

Posted in pictures, Running, Travel with tags , , , , , , , , , on July 9, 2012 by xi'an

Just like last year trip to Shanghai was my first visit to China, this trip to Kyoto was my first time in Japan. I found the experience so exhilarating that I am already considering a trip back next year! (Especially since I could have lost all of my Kyoto pictures with my hard drive!) The mix of tradition and modernity, of history and high-tech, of chaotic architecture and smooth interactions, of rice fields in the shade of high-rises and of houses in the shade of expressways; all those snapshots, caught from the train as much as from the few hours I spent exploring the modern part of the city, are starting to blur already and I feel a need to go beyond to get a broader and deeper perspective on this fascinating country! Continue reading

Kant, Platon, Bayes, & Le Monde…

Posted in Books, Statistics, University life with tags , , , , , , , , , , , , on July 2, 2012 by xi'an

In the weekend edition of Le Monde I bought when getting out of my plane back from Osaka, and ISBA 2012!, the science leaflet has a (weekly) tribune by a physicist called Marco Zito that discussed this time of the differences between frequentist and Bayesian confidence intervals. While it is nice to see this opposition debated in a general audience daily like Le Monde, I am not sure the tribune will bring enough light to help to the newcomer to reach an opinion about the difference! (The previous tribune considering Bayesian statistics was certainly more to my taste!)

Since I cannot find a link to the paper, let me sum up: the core of the tribune is to wonder what does 90% in 90% confidence interval mean? The Bayesian version sounds ridiculous since “there is a single true value of [the parameter] M and it is either in the interval or not” [my translation]. The physicist then goes into stating that the probability is in fact “subjective. It measures the degree of conviction of the scientists, given the data, for M to be in the interval. If those scientists were aware of another measure, they would use another interval” [my translation]. Darn… so many misrepresentations in so few words! First, as a Bayesian, I most often consider there is a true value for the parameter associated with a dataset but I still use a prior and a posterior that are not point masses, without being incoherent, simply because the posterior only summarizes what I know about the  parameter, but is obviously not a property of the true parameter. Second, the fact that the interval changes with the measure has nothing to do with being Bayesians. A frequentist would also change her/his interval with other measures…Third, the Bayesian “confidence” interval is but a tiny (and reductive) part of the inference one can draw from the posterior distribution.

From this delicate start, things do not improve in the tribune: the frequentist approach is objective and not contested by Marco Zito, as it sounds eminently logical. Kant is associated with Bayes and Platon with the frequentist approach, “religious wars” are mentioned about both perspectives debating endlessly about the validity of their interpretation (is this truly the case? In the few cosmology papers I modestly contributed to, referees’ reports never objected to the Bayesian approach…) The conclusion makes one wonders what is the overall point of this tribune: superficial philosophy (“the debate keeps going on and this makes sense since it deals with the very nature of research: can we know and speak of the world per se or is it forever hidden to us? (…) This is why doubt and even distrust apply about every scientific result and also in other settings.”) or criticism of statistics (“science (or art) of interpreting results from an experiment”)? (And to preamp a foreseeable question: no, I am not writing to the journal this time!)

Awata Sanso dinner (Kyoto)

Posted in pictures, Travel with tags , , , , on July 1, 2012 by xi'an

Continue reading

ISBA 2012 [#3]

Posted in Statistics, Travel, University life with tags , , , , , , on June 29, 2012 by xi'an

A third and again very intense day at ISBA 2012: as Steve Scott said, “we are  getting Bayes-ed out”… It started for me with Robert Kohn’s particle filter session, where Julien Cornebise gave us programming recommendations to improve our code, performances, and overall impact of our research, passionately pleading for an object oriented approach that would make everything we program much more portable. Scott Sisson presented a new approach to density estimation for ABC purposes, using first a marginal estimation for each component of the statistic vector, then a normal mixture copula on the normal transforms of the inverse cdfs, and Robert concluded with a extension of  PMCMC to eliminate nuisance parameters by importance sampling, a topic we will discuss again when I visit Sydney in two weeks. The second session of the morning was ABC II, where David Nott spoke about the combination of ABC with Bayes linear tools, a paper Scott had presented in Banff last Spring, Michael Blum summarised the survey on the selection of summary statistics discussed earlier on the ‘Og, Jean-Michel spoke about our (recently accepted) LDA paper, acknowledging our initial (2005) misgivings about ABC (!), and Olie Ratmann concluded the session with a fairly exciting new notion of using a testing perspective to define acceptable draws. While I clearly enjoyed the amount of “ABC talks” during this meeting, several attendees mentioned to me it was a bit overwhelming… Well, my impression is that this conveyed high and loud the message that ABC is now truly part of the Bayesian toolbox, and that further theoretical exploration would be most welcomed.

The afternoon session saw another session I was involved in organising, along with Marc Suchard, on parallel computing for Bayesian calculations. Marc motivated the use of GPUs for a huge medical dataset, showing impressive gains in time for a MAP calculation, with promises of a more complete Bayesian processing. Steve Scott gave the distributed computing version of the session, with Google requirements for a huge and superfast logistic regression, Jarad Niemi went into the (highly relevant!) details of random processors on GPUs and Kenichiro McAlinn described an application to portfolio selection using GPUs. (The topic attracted a huge crowd and the room was packed!) I am sorry the parallel session on Bayesian success stories was taking place at the same time. As it related very much to our on-going project with Kerrie Mengersen (we are currently waiting for the return from  selected authors). Then it was time for a bit of joint work, along with a succulent macha ice-cream in Kyoto station, and another fairly exhausting if quality poster session.

I am sorry to miss the sessions of Friday (and got “flak” from Arnaud for missing his lecture!) as these were promising as well. (Again, anyone for a guest post?!) Overall, I come home exhausted but richer for the exchanges and all I learn from a very good and efficient meeting. Not even mentioning this first experience of Japan. (Written from Kansai Osaka airport on a local machine.)