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    How many hours do you typically work in a week? (Private sector only)

    You should have an option for under 40, many people work (are in office) less than 40 even if paid full time. By the way - this not a comment about how much work people actually do when in office vs email and web, etc, which is a full topic on its own.
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    CERN team claims measurement of neutrino speed >c

    Although the SN1978A results do challenge OPERA's, I don't think there are enough energy-data-points for the two results to rule one another out (i.e. who knows whats happening in between, these territories just aren't measured to the necessary precision yet). It would be nice to see if MINOS...
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    Why doesn't the most common form of the hydrogen atom have a neutron?

    You are right that is the better picture. I was thinking in terms of post big bang. But as you say, everything was cooking together at the start. Incidentally do you know what the binding energy of the deuteron would have to be for the universe to be deuteron rich and hydrogen poor?
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    Why doesn't the most common form of the hydrogen atom have a neutron?

    The point I was trying to make is that protons and neutrons don't just come together and form deuterium for no reason, i.e. free protons are the norm, and bound states (such as deuterium, and heavier nucleons) are the exception.
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    Stats: How to combine the results of several binary tests

    What you are doing looks basically right, but there are lots of continuity issues. If you are doing this for something medical, and you don't really understand what you are doing, you should definitely have someone check over your results. pmsrw3 is right you are really looking to do...
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    Why doesn't the most common form of the hydrogen atom have a neutron?

    I'd argue its largely related to the condition that created the other nucleons. In stars there are lots of protons and neutrons, and the gravity is strong enough to bring them close together, where the nuclear force is notable. Outside of stars, there are many more protons than neutrons if...
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    Math Mathematics needed to be a researcher in machine learning?

    Just to add to what Chiro said, there is a semi-popular book on information theory and machine learning by Mackay you can check out. If you can pull it off adding a CS minor (or major) won't hurt you. But just to kind of reiterate, much of machine learning isn't really "machine learning"...
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    Probability of player winning a tennis match

    Ok -- here is a plot with Y % games won in green % sets won in orange % matches won in blue X % chance to win the point Sorry for the bumpiness from low sampling, but I don't have time to remake it with higher stats.
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    Probability of player winning a tennis match

    This is an example of a problem that is a hassle to analytically calculate, but trivial to simulate given an explicit value for p.
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    Math Mathematics needed to be a researcher in machine learning?

    I think you have it right -- its all statistics and applied math and computers. Very little actual analysis and even less abstract/modern algebra. Math wise focus on: Statistics, Bayesian Statistics, Linear Algebra, Optimization (both global and local), and general applied math such as...
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    1 in 10 statistic

    I'm not looking to make long drawn out back-and-forths on this, but I can, off hand, think of three people I know that are leaving/left their positions (in the last few months) and now the departments are doing candidate searches. I know through either work or family several heads of...
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    1 in 10 statistic

    That's sadly both funny and believable. Incidentally UT is hiring a new theorist as we speak. I don't know if its from replacement money or the new chair they are getting (thanks to espn), though.
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    1 in 10 statistic

    There are valid aspects to both of those points, but they aren't the full story either. 1) When a professor becomes 80 they are typically given emeritus status, which often comes with a TA salary. This frees up money for new professors. 2) Departments tend to want to fill as many slots as...
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    1 in 10 statistic

    True -- I meant something more along the lines of 1:10 going to 1:8. Admittedly, that doesn't sound super impressive, but its on order of a 20% increase, which is a meaningful increase (it its actually true!) to someone looking for a spot. Of course the bigger picture is still correct that...
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    1 in 10 statistic

    I think there is an important comment to make about people starting into the field now, compared to people currently or recently through there PhD. Many university professors are getting within about 10 years of retirement age. If you look at the demographics for many research institutions you...
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    Trying to fix this code

    The code has lots of errors. Here is a working version (other choices could have been made). It might be useful to one at a time, substitute in the errors into the working code and see why they fail. long foo(long a, int b); void goo(int &a, int b); float soo(long a, double b); bool...
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    Is there an analytical solution to the integral of a PDF?

    Just want to second this point. If B can't be decomposed by Cholesky factorization, then the answer will not be so simple. Thankfully all covariance matrices are ok. So this is step 1. Then once you are converted to independent y's, its simply a product of gaussian integrals, that is step 2.
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    Chi Squared and Gaussian Population Question

    To determine the chi-square statistic, you take the difference of your data and the theoretical curve at each bin, square it and then sum those up. In slightly more detail: First calculate what your theoretical Gaussian value should be at each histogram bin center. Then take the value of each...
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    ZZ found at LHC

    Nice. Incidentally, if you follow the link at the bottom of the article and go to the original talk, near the end of the talk (~pg20), they note the rest mass of the ZZ pair to be 200 Gev, which is in the heart of an "excluded" Higgs mass region, so probably not a Higg's sighting yet.
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    MATLAB Block diagonal matrices in MATLAB?

    I've found the Octave reference manual pretty useful. It doesn't give many examples or how-to's, but you can flip to a section and get a pretty good idea what tools are available.
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    Probability: Picking M&M's

    Ah -- so you are saying *if the bags aren't randomly filled (in the i.i.d. sense)* then it's possible that the likelihood of drawing a red goes down once you draw a blue. Yes totally agree. Edit: Sorry I thought you were just getting caught up in the bayesian inversion and not accounting for...
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    How to maximize P(Y = y*) for a negative binomial distribution

    First off, one obvious mistake on what I wrote to you before. The second term of the expression should be negative not positive (from the chain rule on the derivative of (1-p)). Maybe double check that the rest is right. If it still doesn't give a sensible answer I'll work it out...
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    How to maximize P(Y = y*) for a negative binomial distribution

    Sorry was just trying to avoid using latex. But write down your binomial dist. It should be neg_binomial = A * p^k * (1-p)^r where A won't depend on p, but will be some combinatoric. Now take the derivative with respect to p. A*k*p^(k-1)*(1-p)^r + A*r*p^k*(1-p)^(r-1) now set that equal to 0...
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    Probability: Picking M&M's

    Just to simplify life -- assume the factory that made (10) M&M's, (1) of which was red. They are put in (2) bags with (5) M&M's in each. You eat your first M&M and its blue. I assume we all agree on the next M&M being more likely to be red, yes?
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    MATLAB Block diagonal matrices in MATLAB?

    Try playing with something like... A=-k*ones(n,n) kron(eye(M),A)
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    Probability: Picking M&M's

    Which post are you considering the correct interpretation?
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    MATLAB Block diagonal matrices in MATLAB?

    Yeah, I was originally responding to the first, then saw yours, then realized you were asking a different question. Can't think off hand of something super elegant for you. This is best I can do off-hand, sorry :( blocks=blkdiag(A,B); background1=k*ones(10,10)...
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    Probability: Picking M&M's

    The bag is superfluous in this problem. So yes, original-poster, you are specifically correct, every time you don't find a red, your chance of drawing a red from a finite set that has a finite set of reds increases. This is not the same as a gambler's fallacy, where the picks are reset...
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    How to maximize P(Y = y*) for a negative binomial distribution

    Maximize/minimize = take the derivative and set it equal to zero
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