Why is SOM not being used?
(Why) Has Kohonen-style SOM fallen out of favor?
How do I install PlayOnLinux on Ubuntu? Select an area in rep graph not working on Chrome The "select an area by dragging across the lower chart" thing is not working on Chrome.  Tested with Chrome 13.0.782.220 m, works with Firefox 6.0.1 and IE 8  Quirk: For some reason, if I open an incognito window, it works. Tried clearing the cache and cookies, still not working. Citation: refer to author or paper? What is the British English way of referring to a source in-text.  Is it plural because there are two authors, like this:         X and Y (2011) describe ...   Or is it singular because you are referring to a singular source, like this:     X and Y (2011) describes...   So what I am asking is whether you refer to the source or to the authors? Is there a rule of thumb for objective questions asked out of curiosity? Proving by induction that $ \sum_{k=0}^n{n \choose k} = 2^n$ After pacman update, pacsearch is no longer installed How can one change the timestamp of an old commit in Git? The answers to  describe a way to amend previous commit messages that haven't yet been pushed upstream.  The new messages inherit the timestamps of the original commits.  This seems logical, but is there a way to also re-set the times? Local server updates for the network I have setup one computer on our network as the file server. Because Internet here in Tanzania is both slow and expensive I would like that one system to download all the updates and then the other 10 computers on the network to get those update files from the server. I'm a bit of a noobie to Ubuntu, but really want to learn how to get this working smoothly so as to help other NGOs and schools here in Tanzania. Brendon Can't Open files from a directory in python integral of $\int_{0}^{1}\frac{\ln(x^{2}+1)}{x+1}dx$ using contour integration? I have an interest in contour integration. I am not that good at it, but I enjoy learning what I can about it.  Here is a version of a rational log integral rarely encountered.  $\displaystyle \int_{0}^{1}\frac{\ln(x^{2}+1)}{x+1}dx=\frac{3}{4}\ln^{2}(2)-\frac{{\pi}^{2}}{48}$  I can do this using real methods (via double integral and substitution). I can post my workings if anyone would be interested.  My question is, can this be evaluated using contour integration due to the limits being $[0,1]$ instead of $[0,\infty)$?.  Contours may not be the most efficient way to go about it, but what is the course of action when the limits are 0 to 1 instead of 0 to infinity?. Should I assign dwellers to the storage room? I'm studying orientability of manifolds currently and I'm having trouble to prove the following: $M\times N$ is orientable iff $M$ and $N$ are orientable.   I am able to prove that the product is orientable if components are orientable (chart is $\{(U_\alpha\times V_{\beta},\phi_\alpha\times \psi_\beta):(\alpha,\beta)\in A\times B \}$, and $\det J=\det J_1 \det J_2&gt;0$ by Cauchy-Binet's theorem), but I don't know how to prove the other direction.   So why this holds: if $M\times N$ is orientable, then $M$ and $N$ are orientable?  Thanks in advance. Show that $\left| \frac{1}{x}-\frac{1}{z} \right| \le \left|\frac{1}{x} - \frac{1}{y} \right| + \left|\frac{1}{y} - \frac{1}{z} \right|$. I'm trying to prove that  $$ \left| \frac{1}{x}-\frac{1}{y} \right| $$  is a metric on $X = \mathbb R^+$.  The properties of non-negativity and symmetry are obvious (do I actually even need to prove them?), but the tricky one is, as usual the inequality property, i.e.  $$ d(x,z) \le d(x,y) + d(y,z) \text{ for any } z \in X. $$  So, ok, I have that  $$ d(x,z) \le d(x,y) + d(y,z) \\ \iff \left| \frac{1}{x}-\frac{1}{z} \right| \le \left|\frac{1}{x} - \frac{1}{y} \right| + \left|\frac{1}{y} - \frac{1}{z} \right| \\ \iff \left| \frac{1}{x} \right|- \left| \frac{1}{z} \right| \le \left| \frac{1}{x}-\frac{1}{z} \right| \le \left|\frac{1}{x} - \frac{1}{y} \right| + \left|\frac{1}{y} - \frac{1}{z} \right| $$  ...and that's about as far as I've gotten–which is to say, not very far. I also tried multiplying both sides by $ \left| \frac{1}{x}-\frac{1}{z} \right| $, but that wasn't very fruitful. If someone could point me in the right direction, it'd be greatly appreciated. Thanks. Are global variables bad? Is there a HTML opposite to ? Is there a tag in HTML that will only display its content if JavaScript is enabled? I know &lt;noscript&gt; works the opposite way around, displaying its HTML content when JavaScript is turned off. But I would like to only display a form on a site if JavaScript is available, telling them why they can't use the form if they don't have it.  The only way I know how to do this is with the document.write(); method in a script tag, and it seems a bit messy for large amounts of HTML. Why is boiling water loud, then quiet? Water in my electric kettle makes the most noise sixty to ninety seconds before the water comes to a full boil. I have been fooled many times by the noisy kettle, only to discover that the water was not yet hot enough for tea. The kettle is only at a full boil after the noise has subsided.    I have noticed the same phenomenon with many other kettles, including conventional kettles on kitchen ranges; it is not a peculiarity of this electric kettle.  Why does the boiling become quieter as the water reaches full boil? So I had been literally trying to fix my windows not being able to boot at all for more than 24 hours straight till now. I almost read every single article and troubleshooting step on the web to find a solution but nothing seems to work. I will keep it short as much as I can.  I did all of the following and it was:  "Reset this PC" gave an error "The required drive partition is missing"  "Refresh this PC" gave an error "The drive where windows is installed is locked. Please unlock and try again"  "System restore" gave an error something I don't actually remember but its like "Choose your OS and then try again"  "Automatic Repair" just failed to fix it and reverted me back to advanced options.   After all of that, I did  bootrec /fixboot bootrec /fixmbr bootrec /scanos bootrec /rebuildbcd bcdboot d:\windows (D is where I have the windows installed and C is for system reserved) bcdboot d:\windows /s c: /f ALL   All of these command prompt lines failed giving multiple errors like:  For REBUILDBCD, it said "Identified total windows installations: 1" then clicked "Y" to add it to the list and then it said "The requested system device cannot be found"  For bcdboot d:\windows it said Failure when attempting to copy boot files"   I wiped the disk multiple times using diskpart and installed fresh copies of windows on it 3 times but each time the installation will finish stage 1 (at a very slow pace) then when it restarts to continue installation, it simply won't boot (Windows logo and a spinning dot circle below forever)  I gave up and tried a totally new HDD and installed windows to it, it booted so normal and fast actually so I made sure it was not an issue with the windows.  Now I am booted from the new HDD and reformatted the old HDD and working on data recovery using easeus and it is finding my stuff luckily. It is also noticeable that the old HDD is making some noise while it is reading now as I scan for lost files.  My ultimate question is, will this HDD ever be able to used again? Even as a storage drive not as a drive I boot from? Because it is being seen through the bios boot menu and I see it in the disk management with healthy status. Can this HDD be fixed or I'm better off stop using it?  Here is a screenshot of the health status through SMART using HD Tune Pro: Maximum number of edges in a bipartite graph Prove that for a bipartite graph $G$ on $n$ vertices the number of edges in $G$ is at most $\frac{n^2}{4}$.     I used induction on $n$.    Induction hypothesis: Suppose for a bipartite graph with less than $n$ vertices the result holds true.    Now take a bipartite graph on $n$ vertices.Let $x,y$ be two vertices in $G$ where an edge exist between $x$ and $y$. Now remove these two vertices from $G$ and consider this graph $G'$. $G'$ has at most ${(n-2)^2}\over4$. Add these two vertices back.  Then the number of edges $G$ can have is at most    $$|E(G')|+d(x)+d(y)-1$$   My question is in my proof I took $d(x) + d(y) \le n$, where $d(x)$ denotes the degree of vertex $x$.  Can I consider $d(x)+d(y) \leq n$? I thought the maximum number of edges is obtained at the situation $K_{\frac n 2,\frac n 2}$ Your Mileage May Vary In the United States we have a saying, "your mileage may vary", which means "your experience may be different".  In English-speaking countries that don't use Imperial miles, is there an equivalent expression? How can I mount my partition with executive permissions using the launcher icons?