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pacome delva

Can Google Predict the Stock Market? - ScienceNOW - 2 views

news.sciencemag.org/...-google-predict-the-stock.html

stock_market google

shared by pacome delva on 15 Nov 10 - No Cached
  • Luís F. Simões on 15 Nov 10
     
    in related news: Twitter Mood Predicts The Stock Market "An analysis of almost 10 million tweets from 2008 shows how they can be used to predict stock market movements up to 6 days in advance" http://www.technologyreview.com/blog/arxiv/25900/ http://arxiv.org/abs/1010.3003
  • ...1 more comment...
  • LeopoldS on 16 Nov 10
     
    not overly impressive: "The Google data could not predict the weekly fluctuations in stock prices. However, the team found a strong correlation between Internet searches for a company's name and its trade volume, the total number of times the stock changed hands over a given week."
  • Francesco Biscani on 16 Nov 10
     
    Likewise, I can predict the statistical properties of white noise :-)
  • nikolas smyrlakis on 18 Nov 10
     
    the problem is that usually the google search queries and the twitter updates happen after a crisis for example. I dont really think that people all over the world suddenly realised that Lehman would collapse and started googling it like crazy before it collapsed. More likely they did it afterwards.
santecarloni

[1010.3437] Dynamical mass generation via space compactification in graphene - 0 views

arxiv.org/1010.3437

technology science PHY

shared by santecarloni on 27 Oct 10 - No Cached
  • santecarloni on 27 Oct 10
     
    Is it really possible?
  • ...2 more comments...
  • Luzi Bergamin on 27 Oct 10
     
    The affiliation is Saudi Arabia and Marocco, not countries famous for their contributions to physics... But nonetheless, yes this is possible, to me it even looks very plausible! But you should know that the term "mass" in this context just means a certain parameter in the dynamical equations and only has a loose relation to what we usually call "mass" in the macroscopic world.
  • LeopoldS on 27 Oct 10
     
    ok - admit that I only read the abstract but to me the seems to be a little bit of magic happening ... even if "mass is only a certain parameter in the dynamical equations" ... I assume it still bears some "heavy" consequences in terms of their speed, interactions etc, no? and assuming that you gradually bend such a structure from a 2D to a 1D one ... does it "gain" mass gradually? all very strange to me ...
  • santecarloni on 28 Oct 10
     
    I think the problem is in the boundary conditions... the issue is that if you use and infinite sheet or a cylinder in the equations you always take cyclic boundary condition. If this guys are right then the mass of the quasi-particles in a crystal depends on its topology... this is a major thing...
  • Luzi Bergamin on 28 Oct 10
     
    BINGO!! It's almost like good ol' Kaluza-Klein...
Isabelle DB

Evidence for a Collective Intelligence Factor in the Performance of Human Groups - 2 views

www.sciencemag.org/...686

intelligence team talking women

shared by Isabelle DB on 05 Nov 10 - No Cached
  • Isabelle DB on 05 Nov 10
     
    What do you think of this one ?
  • ...2 more comments...
  • Luzi Bergamin on 05 Nov 10
     
    Great! Women perhaps are not more intelligent as individuals, but now at least they have more collective intelligence... Interesting research topic, though, but I doubt that any of these results can be generalized to real live situations.
  • Isabelle DB on 05 Nov 10
     
    Maybe by passing the message to ensure some men understand it would be their interest to have (more) women in their teams ? No problem at the ACT, this maybe why it works so well ? :-))
  • Luzi Bergamin on 05 Nov 10
     
    Well, that's perhaps the reason, why meetings were always so f... boring while I was at ACT :D
  • sreejanag on 08 Nov 10
     
    Lots more resources on collective intelligence: http://cci.mit.edu/
Francesco Biscani

Pi Computation Record - 4 views

bellard.org/pi2700e9

inf

shared by Francesco Biscani on 06 Jan 10 - Cached
  • Francesco Biscani on 06 Jan 10
     
    For Dario: the PI computation record was established on a single desktop computer using a cache optimized algorithm. Previous record was obtained by a cluster of hundreds of computers. The cache optimized algorithm was 20 times faster.
  • ...6 more comments...
  • Ma Ru on 06 Jan 10
     
    Teeeeheeeeheeee... assembler programmers greet Java/Python/Etc. programmers :)
  • Dario Izzo on 07 Jan 10
     
    And he seems to have done everything in his free time!!! I like the first FAQ.... "why did you do it?"
  • nikolas smyrlakis on 07 Jan 10
  • LeopoldS on 07 Jan 10
     
    did you read any of the books he recommends? suggest: Modern Computer Arithmetic by Richard Brent and Paul Zimmermann, version 0.4, November 2009, Full text available here. The Art of Computer Programming, volume 2 : Seminumerical Algorithms by Donald E. Knuth, Addison-Wesley, third edition, 1998. More information here.
  • LeopoldS on 07 Jan 10
     
    btw: we will very soon have the very same processor in the new iMac .... what record are you going to beat with it?
  • Francesco Biscani on 08 Jan 10
     
    Zimmerman is the same guy behind the MPFR multiprecision floating-point library, if I recall correctly: http://www.mpfr.org/credit.html I've not read the book... Multiprecision arithmetic is a huge topic though, at least from the scientific and number theory point of view if not for its applications to engineering problems. "The art of computer programming" is probably the closest thing to a bible for computer scientists :)
  • Francesco Biscani on 08 Jan 10
     
    "btw: we will very soon have the very same processor in the new iMac .... what record are you going to beat with it?" Fastest Linux install on an iMac :)
  • Juxi Leitner on 08 Jan 10
     
    "Fastest Linux install on an iMac :)" that is going to be a though one but a worthy aim! ""The art of computer programming" is probably the closest thing to a bible for computer scientists :)" yep! Programming is art ;)
pacome delva

Condensation transition in networks and other complex systems - 4 views

nuweb.neu.edu/...Condensation.html

phy bio complex_networks

shared by pacome delva on 15 Jan 10 - Cached
  • pacome delva on 15 Jan 10
     
    I like this work... it mixes physics, networks and biology ! Anyone heard about her ? Here's an interesting paper found on this website: http://nuweb.neu.edu/gbianconi/condensation.pdf
  • ...3 more comments...
  • Francesco Biscani on 15 Jan 10
     
    Eh... Barabasi is really milking the golden cow :) It seems interesting, even if I don't remember enough from my statistical mechanics classes to truly understand it without a major effort. Maybe you could make a layman's science coffee about it?
  • pacome delva on 15 Jan 10
     
    yeah i could if there's enough interest...? do u know Barabasi ?
  • Francesco Biscani on 15 Jan 10
     
    He's quite well known for his work on scale-free networks: http://en.wikipedia.org/wiki/Albert-L%C3%A1szl%C3%B3_Barab%C3%A1si He's applying them for everything and the kitchen sink :) We have a Barabasi-Albert network topology implemented in PaGMO...
  • Dario Izzo on 16 Jan 10
     
    We worked on this with Luzi a few years back ... while the analogy is original and interesting it fails to capture the dynamics of a network, e.g. if a network has hubs that grow and shrink .... Luzi worked on an extended model to solve this issue, but, if I remember correctly, he got stuck in a computationally very hard problem .... We intended to develop and use the extended model to define relevant characteristic of the ESA network formed by mail exchanges.....
  • nikolas smyrlakis on 18 Jan 10
     
    ...but then the CMS YGT didn't really like the project
Joris _

NASA will miss Congressional deadline for asteroid tracking - Science Fair - USATODAY.com - 0 views

blogs.usatoday.com/...ine-for-asteroid-tracking.html

MAD NEO

shared by Joris _ on 25 Jan 10 - Cached
  • he panel finds the 2005 order to find 90% of Earth-threatening asteroids 460 feet or larger infeasible,
  • No method for diverting asteroids has been experimentally demonstrated
  • Options include a "gravity tractor" orbiting slow-moving objects and tugging them off course with tidal tugs, a "kinetic" impact of a heavy spacecraft into an asteroid, or a nuclear explosion
  • ...1 more annotation...
  • Unlike the dinosaurs, we are smart enough to do the math and figure out the answer that modest resources should be dedicated to the problem
    • Joris _
      Joris _ on 25 Jan 10
       
      "we are smart enough" is a completely subjective comment. Reading the article it does not give the same impression :|
pacome delva

RHIC nets strange antimatter - 0 views

physicsworld.com/...41917

strange_antimatter collider

shared by pacome delva on 08 Mar 10 - Cached
  • The antihypertriton – consisting of an antiproton, an antineutron and an antilambda particle – is the heaviest antinucleus yet produced and opens up a new realm of strange antinucluei. It could also shed light on a number of problems in astrophysics and cosmology, including the dominance of matter over antimatter in the universe.
Luís F. Simões

Russian Physicists Solve Radio Black-Out Problem for Re-Entering Spacecraft  ... - 1 views

www.technologyreview.com/...26222

radio communications re-entry plasma military

shared by Luís F. Simões on 05 Jan 11 - No Cached
  • When spacecraft return to Earth, one of the tensest parts of the mission is the radio black out that occurs as the vehicle re-enters the atmosphere. Travelling at hypersonic speeds of between Mach 8 and 15, the spacecraft heats and breaks down molecules in the atmosphere causing a plasma to form. It is this plasma sheath that prevents radio communication.
  • Ref: arxiv.org/abs/0704.3103: Communication Through Plasma Sheaths
Luís F. Simões

Kaggle: Crowdsourcing Data Modeling - 2 views

www.kaggle.com/aboutus

crowdsourcing competition data mining statistics data database

shared by Luís F. Simões on 05 Jan 11 - No Cached
  • Kaggle is an innovative solution for statistical/analytics outsourcing. We are the leading platform for data modeling and prediction competitions. Companies, governments and researchers present datasets and problems - the world's best data scientists then compete to produce the best solutions. At the end of a competition, the competition host pays prize money in exchange for the intellectual property behind the winning model.
LeopoldS

A Biological Solution to a Fundamental Distributed Computing Problem | Science/AAAS - 3 views

www.sciencemag.org/...183.abstract

BIO science

shared by LeopoldS on 18 Jan 11 - No Cached
  • LeopoldS on 18 Jan 11
     
    .... sounds interesting
Luís F. Simões

Polynomial Time Code For 3-SAT Released, P==NP - Slashdot - 0 views

science.slashdot.org/...me-Code-For-3-SAT-Released-PNP

INF computer science mathematics algorithm complexity P=NP?

shared by Luís F. Simões on 20 Jan 11 - No Cached
  • "Vladimir Romanov has released what he claims is a polynomial-time algorithm for solving 3-SAT. Because 3-SAT is NP-complete, this would imply that P==NP. While there's still good reason to be skeptical that this is, in fact, true, he's made source code available and appears decidedly more serious than most of the people attempting to prove that P==NP or P!=NP. Even though this is probably wrong, just based on the sheer number of prior failures, it seems more likely to lead to new discoveries than most. Note that there are already algorithms to solve 3-SAT, including one that runs in time (4/3)^n and succeeds with high probability. Incidentally, this wouldn't necessarily imply that encryption is worthless: it may still be too slow to be practical."
  • Luís F. Simões on 20 Jan 11
     
    here we go again...
  • Luís F. Simões on 28 Feb 11
     
    slashdot: "Russian computer scientist Vladimir Romanov has conceded that his previously published solution to the '3 SAT' problem of boolean algebra does not work."
Joris _

What the strange persistence of rockets can teach us about innovation. - 5 views

www.slate.com/...all

technology innovation space politic MAD

shared by Joris _ on 04 Feb 11 - No Cached
  • Joris _ on 04 Feb 11
     
    If I could write, this is exactly what I would write about rocket, GO, and so on... :) "we are decadent and tired. But none of the bright young up-and-coming economies seem to be interested in anything besides aping what the United States and the USSR did years ago. We may, in other words, need to look beyond strictly U.S.-centric explanations for such failures of imagination and initiative. ... Those are places we need to go if we are not to end up as the Ottoman Empire of the 21st century, and yet in spite of all of the lip service that is paid to innovation in such areas, it frequently seems as though we are trapped in a collective stasis." "But those who do concern themselves with the formal regulation of "technology" might wish to worry less about possible negative effects of innovation and more about the damage being done to our environment and our prosperity by the mid-20th-century technologies that no sane and responsible person would propose today, but in which we remain trapped by mysterious and ineffable forces."
  • ...4 more comments...
  • Ma Ru on 04 Feb 11
     
    Very interesting, though I'm amused how the author tends to (subconsciously?) shift the blame to non-US dictators :-) Suggestion that in absence of cold war US might have abandoned HB and ICBM programmes is ridiculous.
  • Luís F. Simões on 04 Feb 11
     
    Interesting, this was written by Neal Stephenson ( http://en.wikipedia.org/wiki/Neal_Stephenson#Works ). Great article indeed. The videos of the event from which this arose might be equally interesting: Here Be Dragons: Governing a Technologically Uncertain Future http://newamerica.net/events/2011/here_be_dragons "To employ a commonly used metaphor, our current proficiency in rocket-building is the result of a hill-climbing approach; we started at one place on the technological landscape-which must be considered a random pick, given that it was chosen for dubious reasons by a maniac-and climbed the hill from there, looking for small steps that could be taken to increase the size and efficiency of the device."
  • Joris _ on 04 Feb 11
     
    You know Luis, when I read this quote, I could help thinking about GO, which would be kind of ironic considering the context but not far from what happens in the field :p
  • LeopoldS on 05 Feb 11
     
    Fantastic!!!
  • LeopoldS on 05 Feb 11
     
    Would have been nice if it were historically more accurate and less polemic / superficial
  • pacome delva on 14 Feb 11
     
    mmmh... the wheel is also an old invention... there is an idea behind but this article is not very deepfull, and I really don't think the problem is with innovation and lack of creative young people !!! look at what is done in the financial sector...
Ma Ru

IEEE Trans. Evolutionary Computation - Special Issue on Differential Evolution - 3 views

ieeexplore.ieee.org/...tocresult.jsp

inf optimisation differential evolution evolutionary computation

shared by Ma Ru on 03 Mar 11 - No Cached
  • Ma Ru on 03 Mar 11
     
    Dario - perhaps worth giving a look to be up-to-date... There's even an article "Improving Classical and Decentralized Differential Evolution with New Mutation Operator and Population Topologies". They quote our CEC paper, but not the ParCo.
  • ...1 more comment...
  • Ma Ru on 03 Mar 11
     
    Don't know if you have full text access, so here goes the quote: "Recently, Izzo et al. designed in [27] a heterogeneous asynchronous island model for DE. They considered five islands and five DE strategies (DE/best/1/exp, DE/rand/1/exp, DE/rand-to-best/1/exp, DE/best/2/exp, and DE/rand/2/exp), and studied five distributed DEs using the same DE strategy in all the islands, and a heterogeneous model with one different DE strategy in every island. As a result, the heterogeneous model is not outstanding, but performs as well as the others."
  • Joris _ on 03 Mar 11
     
    Isn't it a bit a paper-killing quote?
  • Ma Ru on 03 Mar 11
     
    :) It's in the context of a review of the work that's been done about DE with island model in general, they don't evaluate. Pity they didn't refer to the ParCo article on topologies, as it was a bit more extensive and more focused on the method (as they do in the article) rather than on the problem (as was our CEC paper, if I recall well).
Nicholas Lan

Betting on Green - 5 views

www.economist.com/18304172

technology economics innovation

shared by Nicholas Lan on 16 Mar 11 - No Cached
  • Nicholas Lan on 16 Mar 11
     
    breakthroughs vs. accelerated deployment in climate change mitigation technologies.
  • ...2 more comments...
  • LeopoldS on 17 Mar 11
     
    interesting guy indeed ... "Forget today's green technologies like electric cars, wind turbines, solar cells and smart grids, in other words. None meets what Mr Khosla calls the "Chindia price"-the price at which people in China and India will buy them without a subsidy. "Everything's a toy until it reaches that point," he says. I also like this one since its a bit like ACT topic selection: ""I am only interested in technologies that have a 90% chance of failure but, if they do succeed, would change the infrastructure of society in some radical way," he says." should we propose SPS to him ? :-)
  • LeopoldS on 17 Mar 11
     
    one more: ""I never compute returns. If you start forecasting cash flows, you lose innovation, you lose instinct. You average yourself down to mediocrity." "I've had many more failures than successes in my life," admits Mr Khosla. "My willingness to fail gives me the ability to succeed."
  • Nicholas Lan on 17 Mar 11
     
    indeed. puts me in mind of the often reinvented private ACT idea. actually there's a bunch of interesting looking articles on his website. http://www.khoslaventures.com/khosla/papers.html . No sps in the solar one as far as i can tell :) found this bit intriguing too in that, albeit presumably out of context, it doesn't make sense ""The solution to our energy problems is almost the exact opposite of what Khosla says," declares Joseph Romm, who is the editor of Climate Progress, an influential climate blog, and a senior fellow at the Centre for American Progress Action Fund, a think-tank. "Technology breakthroughs are unlikely to be the answer. Accelerated deployment of existing technologies will get you down the cost curve much more rapidly than a breakthrough."" found this seemingly not very well considered piece (to be fair a blog post) by the guy http://climateprogress.org/2010/07/02/is-anyone-more-incoherent-than-vinod-khosla/ . maybe he's written some more convincing stuff in this vein somewhere.
  • Ma Ru on 25 Apr 11
     
    "Mr Khosla (...) is investing over $1 billion of his clients' money in black swans" Well, with his own money his approach might be a little different :-)
Luís F. Simões

Coding for Outer Space - A Programming Contest | Google Lunar X PRIZE - 1 views

www.googlelunarxprize.org/...er-space-a-programming-contest

programming competition

shared by Luís F. Simões on 24 May 11 - No Cached
LeopoldS and Joris _ liked it
  • This weekend, programmers from all over Europe will be gearing up to compete in the 5'th Catalysts Coding Coding Contest (CCC'11). This year, the theme is Astronautics.
  • The competition is also open to online participants.
  • Individuals or teams of up to three people will be given a series of challenging problems that must be solved as quickly as possible.
  • ...2 more annotations...
  • As a contestant, you must conceive of a proper solution and produce the correct output in order to advance to the next level. How you get there is completely up to you. You may use any computational means at your disposal.
  • Online contestants will not be eligible for prizes – they compete for glory alone.
  • LeopoldS on 25 May 11
     
    who is interested in following this a bit closer?
Joris _

Let's Reconstitute Humans From Genomes Launched Into Space! and Other Ambitious Proposa... - 0 views

www.popsci.com/...military-and-public-darpa-says

technology darpa

shared by Joris _ on 17 Jun 11 - No Cached
  • Fragmented human genomes could be shipped toward the stars and reconstructed upon their arrival,
  • to spur the monumental technology advances that would be required for such a feat. So the 100-Year Starship is more like a thought experiment than a construction project.
  • “The crux, to us, is inspiration of research — not just in solving the physics-based problems. It’s across all of the domains
  • Joris _ on 17 Jun 11
     
    disruptive!
Christos Ampatzis

Academic publishers make Murdoch look like a socialist - 4 views

www.guardian.co.uk/...c-publishers-murdoch-socialist

science

shared by Christos Ampatzis on 02 Sep 11 - No Cached
  • Christos Ampatzis on 02 Sep 11
     
    Who are the most ruthless capitalists in the western world? Whose monopolistic practices make Walmart look like a corner shop and Rupert Murdoch a socialist? You won't guess the answer in a month of Sundays. While there are plenty of candidates, my vote goes not to the banks, the oil companies or the health insurers, but - wait for it - to academic publishers.
  • LeopoldS on 11 Sep 11
     
    fully agree ... "But an analysis by Deutsche Bank reaches different conclusions. "We believe the publisher adds relatively little value to the publishing process … if the process really were as complex, costly and value-added as the publishers protest that it is, 40% margins wouldn't be available." Far from assisting the dissemination of research, the big publishers impede it, as their long turnaround times can delay the release of findings by a year or more." very nice also: "Government bodies, with a few exceptions, have failed to confront them. The National Institutes of Health in the US oblige anyone taking their grants to put their papers in an open-access archive. But Research Councils UK, whose statement on public access is a masterpiece of meaningless waffle, relies on "the assumption that publishers will maintain the spirit of their current policies". You bet they will. In the short term, governments should refer the academic publishers to their competition watchdogs, and insist that all papers arising from publicly funded research are placed in a free public database. In the longer term, they should work with researchers to cut out the middleman altogether, creating - along the lines proposed by Björn Brembs of Berlin's Freie Universität - a single global archive of academic literature and data. Peer-review would be overseen by an independent body. It could be funded by the library budgets which are currently being diverted into the hands of privateers. The knowledge monopoly is as unwarranted and anachronistic as the corn laws. Let's throw off these parasitic overlords and liberate the research that belongs to us."
  • Christos Ampatzis on 12 Sep 11
     
    It is a really great article and the first time I read something in this direction. FULLY AGREE as well. Problem is I have not much encouraging to report from the Brussels region...
andreiaries

YouTube - Mission 3 computer animation - 0 views

www.youtube.com/watch

technology youtube

shared by andreiaries on 14 Oct 09 - Cached
  • andreiaries on 14 Oct 09
     
    ARCA is the romanian google X prize competitor.
  • ...1 more comment...
  • andreiaries on 14 Oct 09
     
    They'll probably launch the concept this month. It doesn't look very realistic, but I like the stage separation.
  • Joris _ on 17 Oct 09
     
    I like the 4 stage system. But how did they solve the plume issue ?
  • andreiaries on 19 Oct 09
     
    The plume issue is not that difficult. I think they used something similar on Apollo LES. The problem is stabilizing the entire system, which is extremely difficult. The entire system will most likely plummet down after the solar balloon phase (which is the only phase they tested before). At least they are not using government money :).
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