Description:  I have a desktop that I assembled myself about 1.5 years ago. Recently it has started to freeze occasionally. I haven't noticed a particular application that triggers this to happen. I've had it freeze while just running Chrome and also when I'm multitasking and running Starcraft 2.  Symptoms:  System is completely unresponsive. Mouse won't move and Ctrl+alt+del doesn't do anything. After around 3 minutes, system unfreezes. Audio that was playing at the point when my computer froze is now played back. Eg. I was on a Skype call and the computer froze suddenly, cutting off the audio. When it unfroze a couple minutes later, I heard another 5 seconds of audio from the call that was cut off when the computer froze.  The computer seems to work fine after it unfreezes. No error messages and no critical events in the event log.  Computer components:   Gigabit Z77 motherboard Intel I5-2500K CPU Crucial M4 SSD Sapphire HD6770 video card   Running Windows 7 Pro
I installed Windows 7 in a 3-year-old machine. It installed successfully, took all drivers and running great, but every 5-6 minutes it freezes for a few seconds... 30 seconds to 1 minute, and then it comes back alive.  I checked Event Viewer, but nothing matched the frozen timeline.  I would appreciate any help on how to detect what is causing it, service or hardware.  After it comes alive, everything runs normal. I did run Task Manager and checked CPU usage, at the time it freezes just before and after that no task took more CPU or memory. It was like an idle machine.  There aren't any external USB drives or devices. It is an on-board Intel desktop board with SATA HDD, and the SATA HDD is running in absolute good mode.
In any Pythagorean triplet at least one of them is divisible by $2$, $3$ and $5$. Show that if $x$, $y$, $z$ are integers such that $x^2 + y^2 = z^2$, then at least one of them is divisible by $2$, at least one is divisible by $3$, and at least one is divisible by $5$.  I know that $x,y,z$ are sides of a right-angled triangles. If I start putting values, then I can show, but have no clue about mathematical approach.  How do I solve it mathematically, using modular arithmetic? Ethernet indicator in OSX menu bar I am using OSX 10.7  When I move between different ethernet networks (e.g., at work using ethernet on an external display, at home using thunderbolt ethernet), the ethernet does not always connect. However, I don't get immediate feedback. Instead, I connect to wi-fi. However, wi-fi is both slower and less reliable than ethernet. Thus, I'd like to know whether I am connected to ethernet or not. Of course I can go into preferences and network settings to see whether I'm connected to ethernet, but it would be better if there was some form of indicator in the status bar, just as there is for wi-fi. Thus, my question:  Is there a way of getting an indicator of ethernet connectivity in the OSX menu-bar?  Perhaps there is a free application that can do this. grouped bar chart with pgfplots ［I'm Done］ button is available after ［Save Edits］ even when nothing was edited in First Posts queue counting with max and min restrictions $$x_1 + x_2 + x_3 + x_4 = 10$$ But $x_1 \ge 1$ and $x_2 \ge2$.  Finally, $x_1&lt;6,  x_2&lt;6, x_3&lt;6$ and $x_4&lt;6$.  I started off by finding the total amount that you can get for the original equation. That would be $C (13, 3)$. Then i calculated for the cases of numbers being greater than or equal to 5. I dont know how to incorporate $x_1\ge1$ and $x_2\ge2$. Any help?  $x_1, x_2, x_3, x_4$ are all integers that could be >= 0(But $x_1$ and $x_2$ have their own restriction). Have the Linux kernel bugs that caused data loss when using a Samsung 850 Pro SSD been resolved? I just got a brand new Samsung 850 Pro SSD, and I would like to install Ubuntu 14.04 onto it.  I have read some pretty ugly stories of data loss with the 850 series SSDs when using Linux due to bugs in the kernel, as well as bugs in the TRIM operation.  I have done my research, but most of what I'm finding is very outdated. For example, see , and , as well as .  My question is, what is the current status? Have all major the bugs been worked out yet? How does apt-get really work? Okay, I understand how I may use apt-get {install|upgrade|remove} mypackages to install, upgrade, or remove binaries as well as their configuration data files and dependencies (actually, remove will only remove the binaries unless additional flags are provided).  I am not looking for how it is used as the man describes this, but high level what it is doing.  My end goal is to create a means for me to install and manage some custom software (created by a make file) on multiple remote machines, and I need to learn more about the process.  If answers to this question are based on which distribution is used, please tailor to Debian.  In addition to generally how it works, I have the following specific questions:   How does the client that is accessing the apt repository keep track of the files? Must the repository be hosted on the same operating system (i.e. can apt repository be hosted on redhat)? How are the locations to install files specified?  Is this specified by the .deb file? How is a remote machine accessing the repository?  Is it just ftp(s) or http(s)? Is the machine that is hosting the repository running special software (like gitlab for a git repository), or is it just some structured file system? How can you strip non-ASCII characters from a string? (in C#) How can you strip non-ASCII characters from a string? (in C#) Enter from password field doesn't submit SE login form On  page for a site where I don't yet have an account, if I select the "Log in using Stack Exchange" box, when I hit enter from the password form, nothing happens.  Minor, but... Zero vector of a vector space I know that every vector space needs to contain a zero vector. But all the vector spaces I've seen have the zero vector actually being zero (e.g. $\mathbf{0}=\langle0,0,\ldots,0\rangle$). Can't the "zero vector" not involve zero, as long as it acts as the additive identity? If that's the case then are there any graphical representations of a vector space that does not contain the origin? Fundamental particles identical or just differences very small? I have read that all electrons are identical and I assume the same for protons, etc. That is, all electrons are of the exact same mass and charge.  But do we really know this? Could there be slightly heavier electrons with slightly higher charge or is there a reason why such particles could not exist or would be unstable? A weak converse of $AB=BA\implies e^Ae^B=e^Be^A$ from "Topics in Matrix Analysis" for matrices of algebraic numbers. It is a well known fact that if $A,B\in M_{n\times n}(\mathbb C)$ and $AB=BA$, then $e^Ae^B=e^Be^A.$  The converse does not hold. Horn and Johnson give the following example in their Topics in Matrix Analysis (page 435). Let $$A=\begin{pmatrix}0&amp;0\\0&amp;2\pi i\end{pmatrix},\qquad B=\begin{pmatrix}0&amp;1\\0&amp;2\pi i\end{pmatrix}.$$ Then $$AB=\begin{pmatrix}0&amp;0\\0&amp;-4\pi^2\end{pmatrix}\neq\begin{pmatrix}0&amp;2\pi i\\0&amp;-4\pi^2\end{pmatrix}=BA.$$ We have $$e^A=\sum_{k=0}^{\infty}\frac 1{k!}\begin{pmatrix}0&amp;0\\0&amp;2\pi i\end{pmatrix}^k=\sum_{k=0}^{\infty}\frac 1{k!}\begin{pmatrix}0^k&amp;0\\0&amp;(2\pi i)^k\end{pmatrix}=\begin{pmatrix}e^0&amp;0\\0&amp;e^{2\pi i}\end{pmatrix}=\begin{pmatrix}1&amp;0\\0&amp;1\end{pmatrix}.$$   For $S=\begin{pmatrix}1&amp;-\frac i{2\pi}\\0&amp;1 \end{pmatrix},$ we have $$e^B=e^{SAS^{-1}}=Se^AS^{-1}=S\begin{pmatrix}1&amp;0\\0&amp;1\end{pmatrix}S^{-1}=\begin{pmatrix}1&amp;0\\0&amp;1\end{pmatrix}.$$   Therefore, $A,B$ are such non-commuting matrices that $e^Ae^B=\begin{pmatrix}1&amp;0\\0&amp;1\end{pmatrix}=e^Be^A.$  It is clear that $\pi$ is important in this particular example. In fact, the authors say what follows.      It is known that if all entries of $A,B\in M_n$ are algebraic numbers and $n\geq 2,$ then $e^A\cdot e^B=e^B\cdot e^A$ if and only if $AB=BA.$   No proof is given. How does one go about proving that? How do I get a block with data to place myself? Are you looking for how to use /setblock with blocks with data? See .  How do I get a block with data in my inventory so I can place it myself? In Java Edition, these commands work: give @s chest{BlockEntityTag:{Items:[{id:&quot;diamond&quot;,count:10b}]}} give @s sign{BlockEntityTag:{Text1:&quot;{\&quot;text\&quot;:\&quot;foo\&quot;,\&quot;bold\&quot;:true}&quot;}}  How can I do this in Bedrock Edition, where there is no access to NBT tags from commands? What is the difference between a function decorated with  and one decorated with ? How come Dropbox gets an icon in Finder sidebar? Distance between two hyperplanes I have two parallel hyper planes $$a^Tx=b_1,a^Tx=b_2$$ where $a \in \mathbb{R}^n, x \in \mathbb{R}^n ,b \in \mathbb{R}$ and I want to find the distance between the two. I have read that the distance between the two hyperplanes is also the distance between the two points $x_1$ and $x_2$ where the hyperplane intersects the line through the origin and parallel to the normal vector $\vec a$. These points are given by $$x_1=\frac{b_1}{\|a\|^2_2}a$$ and $$x_2=\frac{b_2}{\|a\|^2_2}a$$ Then the distance is $|x_1-x_2|$ but I don't really understand how we got $x_1$ and $x_2$. I was reading a  where the author mentions: "The coefficient of variation is primarily a descriptive statistic, but it is amenable to statistical inferences such as null hypothesis testing or confidence intervals. Standard procedures are often very dependent of the normality assumption and current work is exploring alternative procedures which are less dependent on this normality assumption."  The paper is from 2010. So my question is: has there been any recent "advancements" in terms of a coefficient of variation statistic that is not dependent upon the normality assumption? And, is this what one may call a non-parametric CV? fast saving single field value If you are reading this, you may have been affected by one of our post quality bans. If so, it is important that you  to understand what has happened and how to regain the permissions that you lost. While trying to ask a question, one could see:  We are no longer accepting questions from this account. See  to learn more.  Likewise, for answers:  We are no longer accepting answers from this account. See  to learn more.   Why am I getting this message? Are deleted posts taken into account too? Is a question/answer ban the same as a suspension? How do I avoid getting a question ban? How long do I have to wait before I can post again? What can I do to release the ban? How can I reactivate my account? Can I simply create a new account? I'll just ask somewhere else on the SE network, and they'll migrate my question to the correct site! Will a ban on one Stack Exchange site affect my standing on other sites in the network? Does this apply to meta sites too? My account is in good standing. Why am I still blocked? How would you handle different aspect ratios in a 2d platformer?