"Dynamical Clustering of Exchange Rates"

This paper is another one of those papers that my collaborators and I submitted to a journal a long time ago (in this case, in spring 2009) that has only now appeared in final form. Hence, although it's a new paper in some sense of the word, it certainly doesn't feel new. Here are some details:

Title: Dynamical Clustering of Exchange Rates

Authors: Daniel J. Fenn, Mason A. Porter, Peter J. Mucha, Mark McDonald, Stacy Williams, Neil F. Johnson, and Nick S. Jones

Abstract: We use techniques from network science to study correlations in the foreign exchange (FX) market during the period 1991–2008. We consider an FX market network in which each node represents an exchange rate and each weighted edge represents a time-dependent correlation between the rates. To provide insights into the clustering of the exchange-rate time series, we investigate dynamic communities in the network. We show that there is a relationship between an exchange rate’s functional role within the market and its position within its community and use a node-centric community analysis to track the temporal dynamics of such roles. This reveals which exchange rates dominate the market at particular times and also identifies exchange rates that experienced significant changes in market role. We also use the community dynamics to uncover major structural changes that occurred in the FX market. Our techniques are general and will be similarly useful for investigating correlations in other markets.



Note: I know I have brought this one up before in my blog and it did appear online after dealing with page proofs a couple of months ago, but it now has page numbers, etc.

The Innocence of Youth

I just overheard one of the new Somerville freshers mentioning how he was planning to only work from 9 to 5 and see how that works for him.

Ah, the innocence and naivety of youth!

While I was there, my thought process went as follows: Try to keep a straight face. Try to keep a straight face. Try not to burst out laughing. Try to keep a straight face. Try to keep a straight face. Try to keep a straight face.

A Geometry Theorem and Interpretative Dance

Here is an excellent entry for the 'Dance Your PhD' contest that illustrates a new theorem from geometry.

(Tip of the cap to Kreso Josic. [Note: Kreso has accents in his name, but I don't feel like looking up the html codes for them today.])

Yup. I've Done That. :)

Well, I didn't use experimental equipment---as depicted in this comic strip (well, comic panel)---but when I was in graduate school, I did take advantage of being a seminar-series organizer and thereby having access to a video projector by bringing my Nintendo 64 to campus for the purpose of playing big-screen Mario Kart. :) So I highly approve of this comic strip!

The Birthday Problem with Johnny Carson

Steve Strogatz writes about "the birthday problem" and Johnny Carson's attempt to discuss it on "The Tonight Show" in 1980 in his latest article in the New York Times.

A Short Baseball Round-Up

The regular season ended yesterday.

I watched a bunch of the Rangers-Athletics game, and the Rangers finished their implosion with a wretched game yesterday that allowed Oakland to leapfrog them for the AL West title. Texas is still a wildcard team, which---with the new format this year---really is much worse than winning a division (and that is why I like this change).

Baltimore has made the postseason as the other AL wildcard team.

Miguel Cabrera won the first hitters Triple Crown since 1967 (making it the first in my lifetime), though Mike Trout deserves the MVP by a mile over Cabrera. It is extremely awesome that Cabrera got the Triple Crown---which one gets by leading a league or tying for a league lead in each of homeruns, RBIs, and batting average---but his season still comes nowhere close to the one Trout had. Trout will obviously win the AL Rookie of the Year Award---his season was probably the best rookie season ever---but he deserves the MVP as well (and, again, nobody else is anywhere close).

As expected, adding a second wildcard and making the battle between wildcard pairs in each league 1 and gone (i.e., a one-game playoff for a chance to advance to a Division Series) has really improved things massively.

The Red Sox fired Bobby Valentine today. I am shocked. SHOCKED, I say :) That marriage was doomed from day 1. (Additionally, the Red Sox finished in last place in an utterly disastrous season. It was their worst season in a very long time.)

(Sorry for not putting links to player stats and articles and so on, but I am feeling really overwhelmed right now and need to get back to other things, so I'm going to forego them this time.)

Quote of the Day: Cardinality Edition

I uttered this gem today: There are infinitely many methods, more than half of which have not yet been discovered.

I accidentally made this comment earlier today, and this is perhaps one of the most brilliant things I've ever said. (I guess I was just channelling my inner Yogi Berra?)

In the UK applied mathematics community, such things are sometimes called "colemanballs".

What Happens in Glasgow Stays in Glasgow

I am currently in Glasgow to visit University of Strathclyde's math department.

You know you're in Scotland when you hear comments like "I'll put that in a wee plate for you."

Update (7/01/14): I think I neglected to post my pictures from Glasgow.

Headline: Math Professor Strips Naked and is Escorted to the Hospital by Police

Greg Fricke posted this article on my timeline about a Michigan State University mathematics professor who stripped naked in class and started cussing madly.

Greg used this text with the post: I'm comforted by the knowledge that, when you go crazy, you at least will not strip naked (and the profanity laced rants will certainly be much more creative and snarky).

Notice the use of the word "when" rather than "if". When he posted that on my timeline, the first thing I did was open up the article and see if the dude is somebody I know (he isn't).

Clearly, I am a ticking time bomb. (And also a GOLDEN GOD!!!!) And, yes, if I ever truly go off the deep end, I definitely plan to keep my clothes on.

D4D Challenge

Do you want to study a huge mobile phone data set? Well, if you write a 250-word abstract quickly and you get chosen as one of the lucky winners (based on your proposal), then here's your chance.

This is a very cool idea, and I like the idea of this kind of challenge very much. If one or more of my group members or collaborators wants to do this, then I will help him/her/them, but when there are too many cooks stirring the pot (as there are with mobile phone data), I usually steer myself towards other research directions. I do have a paper that uses data from the NetFlix Prize competition, but my collaborators and I studied used the data to study human dynamics and generative/rewiring mechanisms for networks for their own sake rather than practical things.

(Tip of the cap to Lada Adamic.)

Acronyms and "Sophistication"

Fun Fact: If you give something an acronym, it will sound more sophisticated even when it really isn't.

Some examples: DNS for "directed numerical simulations", ROI for "region of interest", and AUC for "area under the curve".

Scientists are very good at this, by the way. :)

The Golden Ratio

Steve Strogatz's latest piece in the New York Times discusses the golden ratio. I didn't like this article as much as many of his other ones, but I suspect that that is an issue of personal subject preference and nothing more.

Congratulations to Dr. Joseph Schaeffer!

It is once again my pleasure to announce the successful thesis defense of one of my good friends. Welcome to the club, Dr. Joe Schaeffer, who unsurprisingly had a very smooth defense of his thesis (which is in the broad area of computational biology)! I'm not putting in more details on the topic just because I'll probably get tons of things wrong if I do, and I would be relying mostly on his paper in SIAM Review that predates tons of stuff in the thesis.

My congratulations might have worked better if I didn't have a bit of a screw up with Joe's phone number, but that is a rather small glitch in the scheme of things.

Update (9/29/12): I'm not sure how I managed to forget to write this, but Joe's PhD is from Caltech and his supervisor is Erik Winfree. So those of you who want to find out more about the work in that lab now have a place to look. :)

Postdoc Opening in My Lab

We have reposted the advertisement for a 3-year (technically, 34-month) postdoctoral position at University of Oxford to study multiplex networks:

https://www.maths.ox.ac.uk/node/19782


This is the same position I circulated a couple of months ago, but we had to take the advertisement down for bureaucratic reasons before. It's back up and applications are due by Friday 26 October, with a start date for as soon as possible thereafter.

The position is in the Mathematical Institute, and the successful candidate will be part of my group.

Please circulate far and wide. :)

The Perfect Valentine's Day Gift

Yup, arranging your partner's funeral ("Surprise!") is the perfect Valentine's Day gift. At least "overwhelmed" seems like an accurate reaction to such a gift.

I suppose I should have held this in until February. :)

"Mason, what do you really think?"

Quote of the day: "Mason, what do you really think?"


Granted, I have gotten numerous variants of this over the years. (Technically, today's quote was probably a slightly variant of this.) And I would venture to guess that anyone who doesn't understand this doesn't know me very well at all.
There is also a particular scene from Buffy that might come to mind.

RIP Herbet Lom (1917-2012)

Herbert Lom died today. He is best known for his role as (Former) Chief Inspector Dreyfuss in the Pink Panther films. My eye has started twitching uncontrollably in his honor.

(Tip of the cap to Steve Van Hooser.)

"Political Moneyball"

Here is a exceptionally cool visualization of political donation networks.

(Tip of the cap to Peter Mucha and someone else who I can't remember.)

Today's Rant: Passive Voice

The subject of today's rant is passive voice

Before going on, let me first acknowledge that passive voice is sometimes necessary. That said, what the fuck? It is used way too often in science. :)

Alright, so now that I've gotten that bit of irony out of the way, what's so bad about it? As far as I can see, there are basically three things wrong with passive voice. I'll illustrate them using an imaginary sentence in a scientific paper that might start with the phrase "An experiment was conducted..." You can fill in something from your favorite discipline to complete the sentence.

(1) It lessens clarity, and that's already a cardinal sin. Who conducted the damn experiment? Was it you? Was it the janitor? Was it done by the authors of the paper you cited a couple of sentences before this one? (D'oh... there goes clarity. Now we don't even know if the experiment was original or not.) Maybe it was done by a bunch of fluffy bunnies?

(2) It dehumanizes science. I suppose I can't make this argument in quite the same compelling manner as I can about clarity, but (seriously) it does do this. You put a human face on science by indicating your ownership of the work, and I think that science (and scientists!) needs all of the humanization it can get. So write it loudly and proudly: "I conducted the fucking experiment!" At least then we know who did the work! (As an exercise, see if you can make an appropriate change at the page proof stage of an article to try to get this exact phrasing in print.)

(3) It's bad writing. In most of its guises, passive voice is just an ugly use of language. Isn't that reason enough to try to minimize how much you use it? (Again, I want to acknowledge that sometimes passive voice really does provide the most parsimonious answer to your phrasing problems, but at least try to find another solution first.)



Here's another question: How in Hell did things get this way? Did a bunch of scientific gods get up one morning and decide that passive voice was somehow the right way to present scholarship? (Because it's really not...) Did the rampant use of passive voice in science just evolve slowly? Anyway, passive voice is bad writing and should be used sparingly. I go through great pains to try to get my students [and other coauthors... :) ] to unlearn such fallacies, and you should do that too. Scientific writing can also be good writing, so let's try doing that, ok?

Corollary: Just as annoying as the unnecessary preponderance of passive voice in science is the use of passive voice to avoid taking responsibility for mistakes. All too many times, I have seen a phrase along the lines of "A mistake was made" coming from the person who made the mistake in question. That's really a bunch of bullshit and a sleazy way to attempt to shirk responsibility. Just admit "I made a mistake." and be done with it---lose the sidestepping bullshit!

This rant was brought to you by the letters A, B, and C, and by the number ε > 0.

Why Your Friends Have More Friends Than You Do

What? You don't believe me? Just read the discussion in Steve Strogatz's latest article in The New York Times. By the way, this idea was one of the modules in our outreach efforts on networks for school kids last spring. That was one of the modules that needed some improvement, and Steve's article gives me some ideas of how to do it.

(Tip of the cap to Mariano Beguerisse Díaz.)