I've checked each stick individually in the computer, by itself, to verify that the RAM was all in working condition.  I have 2 sticks of 4gb RAM and 2 sticks of 3gb RAM.  I'm not sure which are being detected and which aren't.  Any advice would be much appreciated.  system specs (AS SHOWN)  Windows Edition: Windows 7 Home Premium processor: AMD Athlon II X4 620 Processor 2.60GHz Installed Memory (RAM): 6.00GB (3.25GB usable) System Type: 32-bit Operating System  Everything I've seen related to the subject is in regards to the amount of usable RAM being less than the amount installed. This is not my main issue, I have 14GB of RAM (2 sticks 2X2G DDR3, 2 sticks 3x1G DDR3), and only 6GB is shown as installed, with only 3.25GB of that usable.
I recently upgraded my computer's RAM to 4&nbsp;GB. My 32-bit Windows installation shows only 3574&nbsp;MB of the memory. How can I make Windows use the full amount of RAM?
How to calculate the signal-to-noise ratio (SNR) in an image? I am working with an image X, I apply the "adaptive median filter" in it and I get the image Y. I'd like to measure the SNR in both in order to evaluate the quantity of noise deleted.   I know the formula to calculate the SNR is:   SNR = Psignal / Pnoise  but I don't know how to get these values from both images I have. I was thinking in substract the image X from Y and get the noise value. But I am not sure about the method. Does the derivative of a continuous function goes to zero if the function converges to it? Physicist here. I am puzzled by a question: looking at a continuous function $g :\mathbb{R} \rightarrow \mathbb{R}$ that goes to zero at infinity, I am interested in the behavior of its derivative $\beta = g'$. Precisely, does it go to zero too? By writing on paper it looks like: $$ \beta(+ \infty)=\text{lim}_{x\rightarrow \infty}\text{lim}_{h\rightarrow 0} \frac{g(x+h)-g(x)}{h}$$ And if I can invert the two limits, I get what I expect: $\beta(+\infty)=0$, so I was curious about the hypothesis behind this permutation. Is the requirement of continuity enough? Thanks. Are black hole regarded as baryonic matter in cosmology? Black holes do not have any property as baryonic or non-baryonic matter, as is stated by the no-hair theorem. Regarding conventional theories, in different models of cosmology, like Lambda-CDM, are black holes regarded as baryonic matter, and does the black hole matter significantly affect the baryonic density? Short description of the scoping rules? What exactly are the Python scoping rules?  If I have some code:  code1 class Foo:    code2    def spam.....       code3       for code4..:        code5        x()   Where is x found?  Some possible choices include the list below:   In the enclosing source file In the class namespace In the function definition In the for loop index variable Inside the for loop   Also there is the context during execution, when the function spam is passed somewhere else. And maybe  pass a bit differently?  There must be a simple reference or algorithm somewhere.  It's a confusing world for intermediate Python programmers. The case of the bleeding monospace font! Suppose that $(s_n)$ converges to s. Prove that $(s_n^2)$ converges to $s^2$ I am really struggling with my proofs class, I don't really understand how to prove a statement like this, or what the epsilon is standing for..  Suppose that $(s_n)$ converges to s.  Prove that $(s_n^2)$ converges to $s^2$ directly without using the fact that $lim(s_nt_n)=st$  Suppose that $(s_n)$ converges to s. Then, since $(s_n)$ is convergent, there exists an $M_1$ such that $|S_n|&lt;M_1$, for all $n\in \!\,\mathbb{N} \!\,$. Let $M=M_1+|S|$ (I don't completely understand this step...). Then given $ε&gt;0$, there exists N such that n>N implies that $|s_n-s|&lt;ε/M$. Thus for n>N, we have $|s_n^2-s^2|=|s_n-s|*|s_n+s|&lt;(ε/M)(M)=ε$. Hence, $s_n^2$ converges to $s^2$. The set of integers $n$ expressible as $n=x^2+xy+y^2$ Let $S$ be the set of integers $n$, such there exist integers $x,y$ with $$n=x^2+xy+y^2$$   Is the implication $$a,b\in S\implies ab\in S$$ true? If yes, how can I prove it?  I worked out $$n\in S\iff 4n\in S$$ and $$n\in S\iff 3n\in S$$ I tried two approaches. The first is to express $$(a^2+ab+b^2)(c^2+cd+d^2)$$ in the form $$f^2+fg+g^2$$ with polynomials $f,g$ with integer coefficients. I however could not find suitable $f$ and $g$. The second approach is based on $$x^2+xy+y^2=\frac{(2x+y)^2+3y^2}{4}$$ If we have $n=x^2+xy+y^2$ , we have $u^2+3v^2=4n$ for some integers $u,v$ with equal parity. The main problem of this approach is to consider the equal parity. Any ideas ? What is the population of the Star Wars Galaxy? Why is the Yang-Mills gauge group assumed compact and semi-simple? What is the motivation for including the compactness and semi-simplicity assumptions on the groups that one gauges to obtain Yang-Mills theories?  I'd think that these hypotheses lead to physically "nice" theories in some way, but I've never, even from a computational perspective. really given these assumptions much thought. How to "grep" for line length in a given range? Subtracting from a specific column Calculating $\int_{|z|=2}\frac{e^{1/z^2}}{1-z}dz$ Find the value of $\displaystyle\int_{|z|=2}\frac{e^{1/z^2}}{1-z}dz$   The first idea I had was to apply Cauchy's integral formula. But can this be done? $e^{1/z^2}$ is not holomorphic on the interior of $|z|=2$. Still, if we would apply this we would obtain:  $\displaystyle\int_{|z|=2}\frac{e^{1/z^2}}{1-z}dz=-2\pi ie$.  Another way I think, is to apply the residue theorem. For $1-z$ has a simple zero at $z=1$ and $e^{1/1^2}\neq 0$, then the residue of $e^{1/z^2}/(1-z)$ at $z=0$ is $-e$. Again we obtain $2\pi iRes(g;0)=-2\pi ie$, where $g=\frac{e^{1/z^2}}{1-z}$.  But again, it seems to me this is not right because $g$ has two singularities, at $z=1$ and $z=0$. What we might do about $z=0$? The answer is not $-2\pi i e$? Move object in inches instead of feet? Whenever I move an object in blender in unit mode(Imperial), it always make it in feet. For example, if I type G Y 12, it will move 12 feet. How can I make it move 12 inches instead? What is some good free software for doing physics calculations?  I'm mainly interested in symbolic computation (something like Mathematica, but free). What is the expected value of the number of die rolls necessary to get a specific number? Given a discrete random number generator, such as a six-sided die, what is the expected value of the number of rolls necessary to roll a specific number (e.g. a six)?   I think the result should be given by E$\langle$rolls$\rangle$ = $\frac{1}{6}\sum_{n=0}^\infty{(\frac{5}{6})^n(n+1)}$, but I don't know how to calculate the convergence of that sum.  Also, how do I calculate the variance? How do you find all $n$ such that $\phi(n)|n$ When installing Wine on 64-bit Ubuntu 12.04, both 64-bit support and 32-bit support get installed. If I run wine foo.exe where foo.exe is a 64-bit-aware installer, it thinks it's on 64-bit Windows. This would be fine if this mode didn't fail, but in my case, it does (yet the Wine database suggests the app I'm trying to install should work, presumably as a 32-bit app).  How do I tell Wine (and Winetricks) to use Wine in 32-bit-only mode? Finding critical points (extrema) directly without using eigenvalues If we have a function $f: \mathbb R^3\rightarrow \mathbb R$ of the form:  $$f(x)=(a_1x_1^2+a_2x_2^2+a_3x_3^2)e^{-x_1^2-x_2^2-x_3^2}$$  where $a_1&gt;a_2&gt;a_3&gt;0$.   We can find the critical points by:  $$\frac{\partial f}{\partial x_1} =2x_1e^{-x_1^2-x_2^2-x_3^2}(a_1-a_1x_1^2-a_2x_2^2-a_3x_3^2)=0$$  And solving symmetrically for $x_2$ and $x_3$. We get critical points: $(0,0,0) , (\pm 1,0,0) , (0,\pm 1, 0) , (0,0,\pm 1)$   We could determine the nature of them by looking at the eigenvalues of the Hessian, but is there a way to just analyse it directly? Obviously $(0,0,0)$ is a strict global minimum, but I can't quite see that the other points are. Any pointers/hints would be appreciated. A real solution to ambiguous tags Introduction Even within a site's relatively focused range of topics (it's unlikely anybody on SO will think  refers to the solar system's star), some tags are inherently ambiguous. There are currently two unsatisfying options:  Declare that the tag is only to be used for one of the possible meanings, write a tag wiki explaining it, and link from there to the newly created tags for the other meanings, and keep cleaning up the tag whenever someone ignores the tag wiki popup explaining the tag. Use alternative tags for all meanings (e.g. cd-command and compact-disk, instead of cd), and keep removing the undesired tag whenever it pops up again. And it will. The  is not deterring users from creating unnecessary or redundant tags.  Blacklisting tags is a complicated ritual occurring once in a blue moon, at most, and involves a dragon, a team member, and sacrifices to be burnt. It also makes those other, unambiguous tags not easier to discover, if it were applied to ambiguous tags. I don't consider this to be a viable option in this case. Proposal Here's the proposed : Just like a tag can be declared a synonym of another tag, basically changing all references to the synonym to references to that other, canonical tag, it should be possible to make it a disambiguation tag (or ambiguous tag) for multiple other tags. It's a logical progression from &quot;You entered a term with the same meaning as this other term&quot; to &quot;You entered a term with the same meaning as one of these other terms, please choose the correct meaning&quot;. Use of the tag should force the user to choose one of the alternatives presented:  &quot;, did you mean  or ?&quot; &quot;, did you mean , , or ?&quot; &quot;You entered 'vm', did you mean  or ?&quot; &quot;You entered 'sas', did you mean  or ?&quot; &quot;You entered 'kvm', did you mean  or ?&quot; &quot;You entered 'mono', did you mean  or ?&quot; &quot;You entered 'dsl', did you mean  or ?&quot;  Not all of these examples might be good (I'm not sure e.g. about the first two SO examples), but that's not really the point here anyway — they should just convey how this could be used. Note how some of these tags would probably never be used if users had to type them, and yet everything shorter is ambiguous. This could probably be mostly solved by extending the synonym/tag wiki excerpt dropdowns shown when a user enters the tags, proposing the alternatives for an ambiguous tag entered by the user (like a synonym suggestion, but with multiple options). If ignored, the user could still be shown an error message like with blacklisted tags, but by designing the selection dialog well, it should be possible to prevent that in most cases.  Related topics   This topic is related, but the user seems to have accepted the inclusion of tag wiki excerpts in the tag suggestions drop-down as sufficient.   This requires extensive discussion and team involvement (i.e. the status quo)   This topic has no real solution, except manual retagging. I flagged a post and (choose one)   my flag was marked as helpful, yet nothing was done my flag was marked as declined, yet the post was deleted/edited/closed   Why?