Sebastian Pokutta's Blog

Mathematics and related topics

Archive for August 2009

Interesting things to read…

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I just came back from the ISMP in Chicago and as I didn’t write a single line about it (I feel guilty :S), I at least wanted to share a few interesting links with you.

  1. Terry Tao’s talk on mathematics and the internet [pdf]
    (Source: Michael Nielsen’s Blog)
  2. The impact factor’s Matthew effect: a natural experiment in bibliometrics
    “Using an original method for controlling the intrinsic value of papers–identical duplicate papers published in different journals with different impact factors–this paper shows that the journal in which papers are published have a strong influence on their citation rates, as duplicate papers published in high impact journals obtain, on average, twice as much citations as their identical counterparts published in journals with lower impact factors. The intrinsic value of a paper is thus not the only reason a given paper gets cited or not; there is a specific Matthew effect attached to journals and this gives to paper published there an added value over and above their intrinsic quality. “
    (Source: Michael Nielsen’s Blog)

  3. US Top All-Time Donors 1989-2008
    Slightly off-topic but I actually have to admit that I was surprised 😉
    (Source: Michael Nielsen’s Blog)
  4. The Status of the P Versus NP Problem (L. Fortnow)
    A nice summary about P Versus NP, why it is so hard and about potential consequences if the question would be settled.
  5. The Arms Race in High Frequency Trading (R. Bookstaber)
    “A second reason is that high frequency trading is embroiled in an arms race. And arms races are negative sum games. The arms in this case are not tanks and jets, but computer chips and throughput. But like any arms race, the result is a cycle of spending which leaves everyone in the same relative position, only poorer. Put another way, like any arms race, what is happening with high frequency trading is a net drain on social welfare.”
  6. Stockmeyer’s Approximate Counting Method (R.J. Lipton)
    Great blog post on approximate counting.
  7. Multitasking Muddles Brains, Even When the Computer Is Off (Wired)
    On the perils of preemptive multi-tasking and just quickly checking emails yet again… 😉
  8. Goldman and High Frequency Trading (R. Bookstaber)
    related to 5. above.
  9. Not with a Bang but a Whimper – The Risk from High Frequency and Algorithmic Trading (R. Bookstaber)
    related to 5. above.


Written by Sebastian

August 30, 2009 at 8:40 pm

Rejecta Mathematica – your paper just got an extra life

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A few weeks ago The Economist ran an article (thx for the pointer) on Rejecta Mathematica, an open access journal that offers an outlet for papers that do not necessarily fit well into any other journal or have been rejected for various other reasons. From The Economist article:

PAUL LAUTERBUR, the father of magnetic-resonance imaging, had his seminal paper rejected when he first submitted it to Nature. Peter Higgs, eponymous predictor of physics’s missing boson, faced similar trouble with Physics Letters. But Lauterbur went on to win a Nobel prize for his work, and Dr Higgs is an odds-on favourite to get one soon. A good, rejected paper, then, is by no means an oxymoron.

And that observation is the basis of Rejecta Mathematica, an open-source academic journal that recently went online. As its name suggests, the new journal publishes only papers that, like Lauterbur’s and Dr Higgs’s, have been previously submitted to, and rejected by, others. With Annals of Mathematics, one of the best, denying entry to more than 300 last year alone, Rejecta could be busy.

The inaugural issue from July 2009 is available here. Don’t miss out on the letter from the editors in that issue which provides insight into the why, who, how, and when. From the letter:

First, there is ample evidence that in the traditional review process, significant (even Nobel prize-winning) research is occasionally overlooked and groundbreaking work is some-times actively shunned [2–4]. Perhaps this is most dramatically illustrated in the fact that at least “36 future Nobel Laureates encountered resistance on [the] part of scientific journal editors or referees to manuscripts that dealt with discoveries that on [a] later date would assure them the Nobel Prize” [5]. While it would be presumptuous for us to assume that we can spot significant work that others may have missed, we can provide a venue to introduce rejected work to the community and  increase the chances that its value will be appreciated sooner rather than later.

Second, there is also evidence that a research community can derive value from a centralized repository of rejected papers, even when (and perhaps especially when) the results are either incorrect or not significant enough to warrant consideration for a ma jor international prize. Rejecta Mathematica can benefit authors looking for feedback on their work, wanting to warn the community against false starts (i.e., the classic “null results” that never see the light of day, only to be repeated by others) [6, 7], or wanting to illuminate the occasional vagaries of the peer review process to enhance accountability and scientific integrity [8]. Our journal can also benefit readers who want access to “minor results” that may be useful but not publishable in isolation. Indeed, Rejecta Mathematica has existed in folklore for many years as a fictitious place to send papers that were never to see the light of day, and the concept of a formal repository for rejected papers hoping to be discovered and revived (called Rejuvenatable Mathematics) has also been proposed [9].

Written by Sebastian

August 18, 2009 at 8:05 pm

Mario AI Competition 2009

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Yesterday I learned about the Mario AI Competition 2009 (thx for the pointer). The goal of the competition is to provide an agent that automatically navigates through a version of the Mario game:

This competition is about learning, or otherwise developing, the best controller (agent) for a version of Super Mario Bros.

The controller’s job is to win as many levels (of increasing difficulty) as possible. Each time step (24 per second in simualated time) the controller has to decide what action to take (left, right, jump etc) in response to the environment around Mario.

We are basing the competition on a heavily modified version of the Infinite Mario Bros game by Markus Persson. That game is an all-Java tribute to the Nintendo’s seminal Super Mario Bros game, with the added benefit of endless random level generation. We believe that playing this game well is a challenge worthy of the best players, the best programmers and the best learning algorithms alike.

Sounds like a perfect application for some optimization and in fact Robin Baumgarten programmed an agent partly based on the A* algorithm. Check out the video below to see how fast the agent is actually moving through the levels:

A comment on the youtube video: “So I undestand correctly: da computer will play video games for us, so we have more free time? Way cool.”

Written by Sebastian

August 14, 2009 at 10:34 pm