Friday, February 28, 2014
Signs that it's late Friday afternoon and that you're exhausted (number $x$ in a continuing series): When you're giving a problem class and it's 5:35 pm and you're utterly convinced that you have gone overtime on the class that ends at 6pm, because you think it's after 6pm and the fact that the clock blatantly says "5:35" (though in analog) just doesn't faze you or register in any way. And also number $x+1$: And also when you say you're going to erase the whiteboard as a courtesy to people who are using the room tomorrow morning ... which is in fact nobody because tomorrow is Saturday. The legend continues...
Thursday, February 27, 2014
I was watching some of the Dodger game tonight (once I was done with yet another meeting to work on the 'multilayer networks' review article), and I noticed that the Diamondbacks have a minor league player with the delightful name of Socrates Brito. I really hope that Socrates Brito makes the majors just because I am eager to enjoy the clever headlines that I am sure will result. (It's not close to as cool as the 'Hu's on first' jokes from when Chin Lung Hu reached first base safely, but it will be good nonetheless.)
Wednesday, February 26, 2014
Tuesday, February 25, 2014
I wrote the following comment on Arcane Gazebo's blog at 1:13 am on 29 August 2006: "I’ve been meaning to join Facebook for a while — if for no other reason I have their data and it’s probably relevant to my analysis to actually try the site. I’ll drop you a line when I get around to joining. (Facebook gets more traffic than google, by the way. Or it did as of some time in 2005. I assume it still does.) I am in MySpace, Orkut, and LinkedIn, but I don’t use any of them. I’ll log in when somebody requests me as a friend, but basically don’t use it. I get lots of friend-request spam from Orkut. I need to log in to change the preferences to not e-mail me when I get a new friend request. Do you actually end up doing any social networking through these sites? (I can see their use as gloried phonebooks, but I’m curious if you use them for more than that.) I was also thinking Facebook might be particularly useful for web-stalking. :)" Famous last words --- uttered 2 days before I joined Facebook. (By the way, my LinkedIn use is the same as it was then. I haven't logged into Orkut in years, and I think I logged into MySpace once or twice in the last few years because I was curious what the site looked like these days --- or maybe just for shits and giggles.)
Monday, February 24, 2014
Harold Ramis, who is best known for his role as Egon Spengler in the Ghostbusters movies, died today after being ill for several years. I hadn't realized this, but he also wrote/directed Caddyshack, Groundhog Day, and Analyze This. That's some seriously high-quality work! In his honor, it's worth pointing out that sometimes you need to cross the streams. (Tip of the cap to Scott Porter.)
Saturday, February 22, 2014
Friday, February 21, 2014
Our theory paper on core-periphery structure in networks, which we first posted on the arXiv in February 2012, is finally out in its official published form. Here are the details about the paper, which poses the problem of algorithmic detection of core-periphery structure in a particularly nice way. Title: Core-Periphery Structure in Networks Authors: M. Puck Rombach, Mason A. Porter, James H. Fowler, and Peter J. Mucha Abstract: Intermediate-scale (or "meso-scale") structures in networks have received considerable attention, as the algorithmic detection of such structures makes it possible to discover network features that are not apparent either at the local scale of nodes and edges or at the global scale of summary statistics. Numerous types of meso-scale structures can occur in networks, but investigations of such features have focused predominantly on the identification and study of community structure. In this paper, we develop a new method to investigate the meso-scale feature known as core-periphery structure, which entails identifying densely connected core nodes and sparsely connected peripheral nodes. In contrast to communities, the nodes in a core are also reasonably well connected to those in a network’s periphery. Our new method of computing core-periphery structure can identify multiple cores in a network and takes into account different possible core structures. We illustrate the differences between our method and several existing methods for identifying which nodes belong to a core, and we use our technique to examine core-periphery structure in examples of friendship, collaboration, transportation, and voting networks.
Thursday, February 20, 2014
The Dodgers' Clayton Kershaw is the best pitcher in Major League Baseball. As David Schoenfield writes, check out how batters did against Kershaw's curveball last year: "Batters hit .096 against it in 2013, with zero extra-base hits, zero walks and 80 strikeouts." Holy shit! Now that's awesome.
Sometimes, strange things happen in our Somerville mathematics presentations --- like seeing currency from the Bank of Somerville with my picture on the 10-pound note and my colleague Quentin Miller's picture on the 20-pound note. (The reason I am on the smaller denomination is probably because I am a cheap date.) (Thanks to Andrew MacFarlane for drawing these, and thanks to both him and Tim Camfield for an excellent presentation on paradoxes.)
Wednesday, February 19, 2014
A new exhibit at the British Library is paying tribute to scientific diagrams from the annals of history. That sounds way cool. I hope I get a chance to go. The exhibition called Beautiful Science: Picturing Data, Inspiring Insight, opens tomorrow and closes on 26 May 2014. This article also reminds me of Katy Börner's Atlas of Science, which I reviewed for the journal Science a few years ago. (Tip of the cap to Iain MacMillan.)
Monday, February 17, 2014
Wednesday, February 12, 2014
Well, another one of the old guard from Caltech applied mathematics is gone. I found out earlier today that Gerald Whitham died on January 26th. Gerald was one of the pre-eminent early scholars in the study of nonlinear waves, which are near and dear to my heart. I took Gerald's class AMa 98 when I was at Caltech --- that iteration of AMa 98 was the last class that he ever taught --- and that was the class that introduced me to solitons (so Whitham is the guy who showed me my first soliton). As many of you know, I have had a lot of fun in my career thinking about solitary waves (and, to a lesser extent, solitons). You can find one of those by-hand calculations in my scholarpedia entry on solitons (and related phenomena). I was Gerald Whitham's last undergraduate advisee. This was in the sense of signing my cards so that I could take my classes --- we never worked on research together, though obviously some of his research interests rubbed off on me. He retired after my sophomore year (or at least rarely ever showed up to campus after that ... this page claims that he retired in 1998, but I think it was technically 1996), and my advisor was then switched over from Whitham to Oscar Bruno. Whenever I saw Whitham to get my card signed, he would inevitably complain about how the math department kept switching back and forth for the organization of the Math 107, 108, and 109 trifecta. (These switches occurred every decade or so, as far as I can tell. When it existed, Math 107 was a general introduction to analysis and topology, and then 108ab was analysis and 109ab was geometry. In the other form, 108abc was analysis and 109abc was geometry, where I believe that Math 107 was more or less the same as Math 108a.) Update (2/22/14): Pasadena Star-News had an obituary for Whitham about a week ago.
Sunday, February 09, 2014
Some people are so talented that they can play the Super Mario Brothers soundtrack (overground, underground, and underwater --- and the sounds for things like coins, character death, super shrooms, etc) in real time while somebody else is playing the game. Now that is impressive! (Tip of the cap to Jimmy Lin.)
Saturday, February 08, 2014
Friday, February 07, 2014
Thursday, February 06, 2014
I mostly just looked at the pictures --- with only occasional forays into the accompanying text (partly because I am damn tired and have some other text that I want to read before I crash completely and partly because I think the pictures themselves are the best part) --- but this article on ASCII art and its ancestors is way cool. I enjoy both the art itself and the notion that people worked really hard to create it with whatever computational (or typing) medium that was available. Very nice! (Tip of the cap to Jimmy Lin.) Update (2/07/14): Tom Prescott has sent me a link to an ASCIImation page.
Tuesday, February 04, 2014
Sunday, February 02, 2014
Philip Seymour Hoffman was found dead in his apartment today (apparently of a heroin overdose). Hoffman was an excellent actor, and it was a virtual requirement for an indie film to include him in at least some role. (According to a rumor spread in Laemmle Theatres, some Congressman once tried to even get that made into a law.)