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Vaidotas Zemlys
Attended Vilnius University
Lived in villeneuve d'ascq
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Vaidotas Zemlys

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15 years between submission and publication. Surely this is some record.
 
I'm on the editorial board of Combinatorica. Whether I should be is another matter, since it is a journal owned by Springer, one of the big commercial publishers. But I am, and as a result I have a free subscription to the journal. Today I found the latest issue in my pigeonhole, and the last paper in the issue was a paper by Csaba Tóth, entitled, "The Szemerédi-Trotter theorem in the complex plane." 

This paper is remarkable for two reasons. One, which provokes this post, is that at the beginning of the paper it says, "Received December 1999, Revised May 16 2014." So the paper is coming out over 15 years after it was submitted. Doubtless this isn't a record, but it's still a pretty big gap. I noticed it because my first reaction on seeing the title was, "But I thought this had been done a long time ago."

The other reason is the result itself. The Szemerédi-Trotter theorem states that if you have n points and m lines in the plane, then the number of incidences (that is, pairs (P,L) where P is a point in your collection, L is a line in your collection, and P is a point in L) is at most C(n + m + n^{2/3}m^{2/3}). This slightly curious looking bound is best possible up to the constant C and is more natural than it looks.

The known proofs of the theorem relied heavily on the topological properties of the plane, which meant that it was far from straightforward to generalize the result to lines and points in the complex plane (by which I mean C^2 and not C). Indeed, it was an open problem to do so, and that was what Tóth solved.

If you're feeling ambitious, there is also a lovely conjecture in the paper. Define a d-flat in R^{2d} to be an affine subspace of dimension d. Suppose now that you have n points and m d-flats with the property that no two of the d-flats intersect in more than a point. Is it the case that the number of incidences is at most C(n + m + n^{2/3}m^{2/3})? The constant C is allowed to depend on the dimension d but not on anything else. Note that even for d=2 this would be a new result, since Tóth's theorem is the special case where the d-flats are complex lines.

I should say that I haven't checked whether there has been any progress on this conjecture, so I don't guarantee that it is open. If anyone knows about its status, it would be great if you could comment below.

#spnetwork  DOI: 10.1007/s00493-014-2686-2
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Pirmasis MIDI GameJam'as įvyko! Sukurta 11 žaidimų.
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Awesome.
 
#Mathematics hits mainstream media

Though perhaps a fairer description of Cedric Villani would be the Oscar Wilde of French mathematicians. One of his typically hyperbolic (!) statements: "Languages were invented all around the world; technology was invented many times. Mathematics was developed once and collectively. Your culture cannot be complete if you don’t have at least a glimpse of what is mathematical reasoning." But a Frenchman who quotes Rudyard Kipling must be worth reading.
Mathematics, Villani says, is “the most hidden of all fields.” Credit Photograph by Ed Alcock / eyevine / Redux
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+Audrius Radzevičius​ Siūlau savo humanitaro skilsus patestuot ant šio uždavinuko :)
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An attempt to devise a transfinite version of the Cheryl birthday puzzle.

I won't describe the original puzzle here -- just Google it if, by some miracle, you haven't seen it already. Let us define a logic puzzle of this sort to be of level N if it requires you to consider a chain of length N of the type "I know that you know that I know that you know ... etc." Then a level-omega puzzle would be one that requires you to consider a chains of length N for arbitrarily large N. That's what I've tried to devise below. I do not guarantee that I have succeeded -- I may have made a silly mistake.

Cheryl presents Albert and Bernard with the following set of pairs of positive integers. For even n, let r=n^2, s=(n+1)^2 and let A(n) be the set that consists of the pairs (1,r), (r,r), (r,r+1), (r+1,r+1), (r+1,r+2), and so on up a staircase until you reach the point (s-1,s-1). For odd n, take instead the pairs (r,1), (r,r), (r+1,r), (r+1,r+1), (r+2,r+1), ... , (s-1,s-1). So, for example, A(1) consists of the points (1,1), (2,1), (2,2), (3,2), (3,3), while A(2) consists of the points (1,4), (4,4), (4,5), (5,5), ... , (8,8).

Cheryl then tells Albert the x-coordinate of a special point and tells Bernard the y-coordinate. Albert and Bernard then have the following conversation.

Albert: I don't know which point Cheryl has chosen.

Bernard: Even now you've told me that, I don't know which point she has chosen.

Albert: Even now you've told me that, I don't know which point she has chosen.

Bernard: Even now you've told me that, I don't know which point she has chosen.

and so on and so on. Eventually Cheryl gets bored and says, "Hey, can we talk about something else now? You're never going to work out the answer."

At that point Albert and Bernard both say, "Ah, now I know which point you've chosen." What was the point?
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Sveikinimai!
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2014 m. Lietuvos mokslo premija apdovanoti Matematikos ir informatikos fakulteto Tikimybių teorijos ir skaičių teorijos katedros mokslininkai prof. dr. Ramūnas Garunkštis ir prof. habil. dr. Antanas Laurinčikas už darbų ciklą „Dzeta funkcijos. Universalumas, nuliai ir momentai (1999–2013)“.
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1. Every 40 seconds, a child goes missing in the U.S.

2. When a child goes missing, the first 3 hours are the most crucial in finding the child safely. Approximately 76.2% of abducted children who are murdered are dead within three hours of the abduction

Question. 200 children are missing. 100 of them were not found after 3 hours. How many of them are dead?
Missing people facts, including international statistics, laws, profiles, and more.
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Roger :-)
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Sometimes the cavalier attitude of people amazes me. I am new to surgery, I want to operate appendix and I found the youtube video, but I still am lost. How do I proceed? :) Apply to medical school, do not try to do it? Is it possible at all to help in such situation?
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Help Timothy Gowers with this important query :)
 
If you Google Pietro Boselli you find him described as the hottest mathematician in the world, a title he qualifies for by being a fashion model and a lecturer at UCL at the same time. However, it turns out that he is not quite a mathematician in the sense I would understand it: his PhD is in engineering and his maths lectures are not, I think, to mathematics students. So has anyone ever been both a fashion model (I would allow former fashion model here) and the author of a paper published in a reputable mathematical journal? I couldn't find anything by Boselli on arXiv.
Twenty-six-year-old maths lecturer and PhD student Pietro Boselli describes himself as 'nerdy', but the internet would beg to differ.
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This is "mathcrastination"—I have real work to do, but instead I'm procrastinating by playing around with silly math. Yesterday I posted some unusual looking nth roots that I found: https://plus.google.com/+DavidRicheson/posts/cQJhJnPsh1A Then a friend sent me this one √(91125)=9√(1125). Very cool! So I've spent the last hour looking for some other similar equalities. Here are a few. I'm sure there are more, but I have to get back to my real work . . .
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Kalbėdamas apie ekonominę situaciją Rusijoje, V.Putinas kvietė pažvelgti, kokių problemų turi JAV ir Eurozona. Prezidentas kalbėjo apie dideles ES valstybių skolas, teigė nežinantis, kaip ES lyderiai sugebės visa tai suvaldyti.
„Pažiūrėkite į JAV. Valstybės skola ten didesnė nei bendras vidaus produktas. Padėtis tragiška, – aiškino Rusijos lyderis. – Jų skola gąsdinanti, ne tik pačiai Ameriką, bet ir viso pasaulio ekonomiką“.

Įdomumo dėlei pasiieškojau Rosneft skolos ir pajamų. Paskutiniam ketvirčiui skola maždaug lygi pajamoms. Tai galėtų dabar Putinas pasiaiškinti, kodėl viena didžiausių Rusijos kompanijų seka blogosios JAV pėdomis :) I am not holding my breath for that :)
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Ketvirtadienį Rusijos prezidentas Vladimiras Putinas surengė jau tradicija tapusį klausimų ir atsakymų maratoną. Lyderis jau 13-ąjį kartą per televiziją atsakinėja į gyventojų klausimus. Tiesiogiai transliuojamos laidos pirmieji klausimai susiję su ekonomika, tačiau užsienio žiniasklaida laukia komentarų dėl krizės Ukrainoje bei įtemptų santykių su Vakarais. Daug žmonių iš anksto pateikė klausimų ekonominėmis temomis, sakė Kremliaus atstovas Dmit...
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Delfi pasirodo paėmė lenteles iš www.u-multirank.eu tik nepasižiūrėjo kad jos pagal abėcėlę išrūšiuotos. True story, go check for yourself: http://www.u-multirank.eu/#!/forstudents?trackType=student&sightMode=undefined&section=subject&simpleMapping=true
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Gyveni ir mokaisi..
"Kompiuterių mokslus, pasirodo, geriausia studijuoti Alytaus kolegijoje, KTU arba Klaipėdos valstybinėje kolegijoje.
Ketvirtoje vietoje reitinguojama Šiaulių valstybinė kolegija, penktoje – Socialinių mokslų kolegija, šeštoje – VGTU, septintoje – VU, aštuntoje – Vilniaus kolegija, devintoje – VDU."
http://www.delfi.lt/news/daily/education/sumaise-kortas-aukstosioms-mokykloms-reitingai-kurie-nustebins.d?id=67685882
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Lietuvos aukštųjų mokyklų siūlomos studijų programos ir vėl buvo įvertinos pasauliniu lygmeniu. Tiesa, šį kartą rezultatai nustebino net nuolat reitingavimo sistemas stebinčius specialistus – gauti duomenys kardinaliai skiriasi nuo iki tol skelbtų Lietuvoje.
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Aha pakeitė, nes aš parašiau jiems laišką :) Gaila straipsnio print screeno nepadariau. Bet taip dabartinis kriterijus irgi neaiškus.
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Some scientists develop a new time series forecasting method. They write an article and helpfully include the forecasting perfomance statistics based on some subset of freely available real time series. From these statistics it is clear that their proposed method performs slightly worse than MA and simple exponential smoothing together with ARIMA give RMSE about two times smaller than their method.  The question is, how can this article pass peer review and get published?

I also add link to sciencedirect:http://www.sciencedirect.com/science/article/pii/S0925231213009028
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Have him in circles
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villeneuve d'ascq - vilnius - klaipėda - girionys
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  • Vilnius University
    B. Sc in applied mathematics, 1998 - 2002
  • Vilnius University
    M. Sc in mathematics, 2002 - 2004
  • Université des Sciences et Technologies de Lille
    Ph. D in applied mathematics, 2005 - 2008
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