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User: john83

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Comments · 469

  1. Re:8 bits to the byte silly on Voyager 1 Beyond Solar Wind · · Score: 4, Informative

    Yes, there are, but SMS uses a reduced character set and so seven bits per character. It's 140 bytes to represent 160 characters. That's my understanding at least, backed up by a cursory google. I could of course be wrong.

  2. Re:Data transfers on Voyager 1 Beyond Solar Wind · · Score: 5, Interesting
    From here,

    The total cost of the Voyager mission from May 1972 through the Neptune encounter (including launch vehicles, radioactive power source (RTGs), and DSN tracking support) is 865 million dollars.

    and

    A total of five trillion bits of scientific data had been returned to Earth by both Voyager spacecraft at the completion of the Neptune encounter.

    That's $0.001384 per bit. There are 1120 bits in an SMS message. That's about $1.55 per SMS. Not exactly cheap, but then Vodafone don't have coverage beyond Pluto.

  3. Re:Nice headline on Computer Defeats Human At Japanese Chess · · Score: 1

    I mean, a chess computer has no concept of a plan,

    That really depends on the program, now doesn't it? I'd be very surprised if the programs didn't cache some of their computations to immediately generate the countermove if the opponent moves as expected, and use the reminder of their turn to further simulate future moves. After all, it's an obvious optimization, and that's what plans are - now I do this, then he does that, then I respond with this move, and so on.

    That's not what I'm talking about. I am a club player of moderate ability - I would have no hope against a modern chess programme like Fritz on a basic PC (even on that hardware, it's at least comparable to a top-50 player). However, I can look at a position and decide that to win, I need to, say, get my knight to a particular outpost, and drive home a passed pawn and promote it. A computer doesn't think like this.

    and even Kasparov or Topalov or whoever can only calculate a handful of positions a second.

    I wouldn't be too sure of that. A brain is basically a massively parallel computer, simulating the likely events in your immediate vicinity all the time - and in the case of humans, using abstract thought to simulate far away places as well. It's likely that there are hundreds, if not thousands, of plans that are considered subconsciously but rejected because of some obvious flaw, freeing the conscious mind to only examine the most promising ones in detail.

    I was talking about brute force computation, which has been measured. I forget the precise result, but I think you're talking something like 3 or 5 positions a second. Those players, and even I derive most of our ability from pattern recognition, while the computer is powerful because it performs an (optimised) search on a tree of possible continuations. There's a fundamental difference in how humans and computers play chess.

  4. Re:Shogi - chess on steroids on Computer Defeats Human At Japanese Chess · · Score: 1

    Swap chess, a minor variant of chess, has a similar concept. Two pairs of players face off. On each team is one player with white pieces, and one with black pieces. Any piece they capture, they hand to their team mate, who can place it on the board at any time in lieu of a move.

  5. Re:Nice headline on Computer Defeats Human At Japanese Chess · · Score: 1

    Draughts has only been solved on the 8x8 board, and the best programmes for the 10x10 version caught up with the top humans a few years back.

    It's interesting to speculate about how the advancement of playing software might hint at how tactics and strategy are balanced for the various board games. I mean, a chess computer has no concept of a plan, and even Kasparov or Topalov or whoever can only calculate a handful of positions a second. Of course, the most interesting part of that problem is how to pose the question.

  6. Re:Sounds like beamforming on High-Tech Microphone Picks Voices From a Crowd · · Score: 1

    To be honest, I'm not clear on how it scales. I've only seen presentations on this sort of thing for, say, two mikes and maybe five speakers. The thing about background noise is that it has to be filtered out somehow, or what you get is essentially white noise. Maybe localizing the sound helps in that regard. I don't really know.

  7. Re:Sounds like beamforming on High-Tech Microphone Picks Voices From a Crowd · · Score: 1

    Beamforming is only possible where you have as many microphones as sources. This is more probably some sort of blind source separation algorithm - calculating the pseudo-inverse of a mixing matrix based on assumptions about speech.

  8. Re:``Security?'' What? on "Super Monkey" Security Force Used At Commonwealth Games · · Score: 1

    Except in American airports.

  9. Re:Alzheimer on Terry Pratchett's Self-Made Meteorite Sword · · Score: 1

    That's right. Sadly, it's already severely limited his ability to type, so he now prefers to dictate. However, he remains lucid for the moment. Long may that last.

  10. Re:Don't sit down = Immortality on Sit Longer, Die Sooner · · Score: 1

    the researchers found that women who sit more than 6 hours a day were 37 percent more likely to die than those who sit less than 3 hours; for men, long-sitters were 17 percent more likely to die

    You know... I'm pretty sure everyone is 100% likely to die...

    It's probably a quote or a rephrasing from the paper. In that case "during the period of the study" is implied.

  11. Re:Noise/Light Sensitivity/Optics on Canon Unveils 120-Megapixel Camera Sensor · · Score: 1

    It's an interesting question. Pixels return an intensity value proportional to the mean intensity over their surface, so I'd imagine you could average groups of 2x2 or 3x3 (etc.) pixels to trade resolution for sensitivity. Alternatively, you could up the gain on each pixel, which as Greymist points out would reduce your signal to noise ratio.

  12. Re:Depth of Field on Why Bad 3D, Not 3D Glasses, Gives You Headaches · · Score: 1

    That's refocussing by post-processing, not infinite depth of field. In each of their processed photos, there are objects in and out of focus.

    As an aside, I've not read their paper, but that device has to have a large number of pixels per microlens, meaning it's significantly lower resolution than an equivalent camera without microlens, something they've ignored in their comparison photos.

  13. Re:What is up with this site lately? on Xfire Purchased, Team Leaving · · Score: 1

    I'm a much more recent arrival at slashdot than that. An engineering PhD, I also come here for the technical focus and for the commentary. The community really shows its knowledge base in topics in computer science, astronomy and maybe particle physics, and its passions in copyright and other areas of IP, privacy and human rights. When the stories drift away from those areas, the comments can be fairly inane.

  14. Re:Depth of Field on Why Bad 3D, Not 3D Glasses, Gives You Headaches · · Score: 1

    Call me back when they fix the depth of field issue. The whole scene needs to be in focus so that when my eyes aren't looking at precisely what the director wants, my eyes don't try to focus on something that can't be focused on.

    I'm unclear: is this a problem you have specifically with 3D, or with cinema in general? Every imaging system has limited depth of field. What you're asking for is technically impossible except in animated films.

  15. Re:But put this in pespective on What's Wrong With the American University System · · Score: 1

    The argument that professors are more interested in publishing than teaching is true. The problem is, research brings in big money to universities too, and it's massively overemphasised in most places when they're employing a new professor or promoting internally. Lots of professors are passionate about teaching, but they're under stress to put most of their time into other things. As for tenure, it's not perfect, but I don't think it's that big a deal.

  16. Re:A great user experience awaits in 2030 on Google Nabs Patent To Monitor Your Cursor Movement · · Score: 3, Interesting

    I do recall seeing an interview in which a Google executive (I forget which one) was asked about patents. He replied that Google was only interested in defensive patents. Of course, that statement isn't exactly binding, but even the links you've given claim that Google has never sued anyone for patent infringement.

  17. This sort of nonsense is depressingly common on Scientists Create Equation For a Perfect Handshake · · Score: 1

    I haven't read TFA, and won't. These "Boffins discover equation for ____" stories are almost always marketing. Here's an example: http://www.badscience.net/2007/09/clarion-communications-respond-on-the-rigged-jessica-alba-wiggle/

  18. Re:Stealing the power of the gods again... on Saturn's Moon Prometheus Spawning Moonlets · · Score: 1

    This time he's getting lots more eaten by the eagle than just his liver.

    Yeah. Don't you just hate it when that happens?

    (Wonder how many people are going to get your reference to Greek mythology...)

    And I wonder how many more think it's a reference to Terry Pratchett's The Last Hero.

  19. Re:CPU speed determines req. radiation amount? on GPUs Helping To Lower CT Scan Radiation · · Score: 1

    I think it's being driven by recent work which suggest risks associated with the scans are a bit higher than previously thought. There's a perceived medical need to reduce the radiation. I'm afraid I can't put my finger on a citation though.

  20. Re:The key to not getting beaten up as a nerd on Nerds Still More Likely To Get Bullied · · Score: 1

    I was top of my class in maths and thereabouts at everything else, and I was terrible at making friends - very introspective and unsocial. I only really learned decent social skills in college. I never really got picked on though. I have no idea why. Decent schools helped, but they didn't help others, so I really don't think it's as simple as nerd = bullied. Maybe people don't think that, but it's the impression I get from popular culture and comments here on stories like this.

  21. Re:Analogue vs Digital on Pixel Inventor Goes Back To the Drawing Board · · Score: 1

    ... Everyone likes using images like these during the debate, but given enough resolution (bits), the closer the digital audio will be to its original analogue (electrical) source.

    Ironically, both images are in fact digital. Lossy compression, too.

  22. Re:Charles Mackay on Fark Creator Slams 'the Wisdom of Crowds' · · Score: 5, Informative

    Interestingly, there are four copies on Google books, and every one of them has pages omitted as they're from recent editions. What the hell, Google? Thankfully, Project Gutenberg has a few versions, e.g. this one.

  23. Re:more importantly on Firefox 4.0 Beta Candidate Available · · Score: 1

    What are you people doing that causes Firefox to have such horrible stability problems? I leave Firefox open for literally days at a time, with anywhere between 10-25 tabs open, and I have no stability problems.

    My guess is that they're all secretly myspace users.

  24. Re:LaTeX, Arxiv and Why the Hell Not? on Best Way To Publish an "Indie" Research Paper? · · Score: 5, Informative

    The above amounts to good advice, but I have one thing to add. If you're still interested in publishing in an academic journal, use something like Google Scholar to find recent articles about algorithms like yours. That will give you (a) an idea of what journals publish on that subject and hence what researchers in that area read, (b) examples of published articles in that field to use as a stylistic template and (c) some idea of which academics are active in the area, which could be useful if you'd like to either recommend reviewers (as many journals ask you to when submitting) and possibly contact one of them for advise. (Though if the advise is that your idea is rubbish, ignore them - they may be right or they may just be dismissing you without giving your idea due consideration, or have another angle).

    Finally, if you'd like some help from a postdoc in a completely different field, send me a message, and I'll proof read whatever you've got and advise you on dealing with reviewers and the like.

  25. Re:Where's the applications? on Fermilab Experiment Hints At Multiple Higgs Particles · · Score: 4, Informative

    When Einstein wrote about the stimulated emission of light in 1917 (The paper is called "Zur Quantentheorie der Strahlung"), there was (a) no example of it known in nature (still isn't, I think) (b) no known way to produce it and (c) no known application. Welcome to LaserFest