Ok, so I have a Dell XPS that I bought around 2011.  About two weeks ago, it started behaving strangely during the boot load. First of all, it makes some weird clicking noises. When that happens, I know the computer won't boot at all.  It also displays this message:  Intel UNDI, PXE-2.1 (build 083) Copyright (C) 1997-2000 Intel Corporation  This product is covered by one or more of the following patents: US5,307,459, US5,434,872, US5,732,094, US6,570,884, US6,115,776 and US6,327,625   After turning it on and off many times, it boots like nothing ever happened.   After booting successfully the first time this happened, I backed up all my data and made a fresh Ubuntu 14.04 install. At first, it looked like everything was back to normal, but after a few boots, it started behaving the same way again.  I also attempted to use boot-repair, but it didn't work.   Does anyone know what's going on? Thanks in advance.
I've run across (personally or by proxy) a bunch of storage media that exhibited physical problems during their life. Hard disks, solid state drives and other flash storage media all fail after some time. The situation is worse with USB flash drives and flash cards because of the large amount of suppliers with inferior flash cell and flash controller quality.  How can I reliably detect if a storage drive suffers from physical damage?  Note that this question isn't about file system integrity (which can be checked with ).
Can't finish registration in Stackoverflow.ru I have an account on Stack Overflow and also on Russian Stack Overflow. I can ask questions on Russian Stack Overflow, but it always displays the phrase "Finish registration". I have tried logging in by different methods — Facebook, Google, etc. — but it still says that my registration is not finished. Can someone help me with it? or explain what I should do there to finish the registration?  P.S: I can't write questions in Meta Russian Stack Overflow because it says that my registration is not finished.  P.S.S: I have already tried "Click the "register" link at the top of the page." it brings to the login page with the phrase "Finish signing up by using any of the following options:". I have already tried all options there. I also can't merge them because they already linked. Some of the git commands have many options, and it would often be useful to search through them for the one I need - I was just looking for the option which controls the TAB width in git-gui, but there are about 200 completions for git config. An obvious workaround is to copy all the completions into an editor and search through them, but I'd rather do  [something] | grep tab   There are no man or info pages for compgen, help compgen doesn't even explain its own options, and there's no auto-complete for compgen (how's that for irony?).  PS:  doesn't work.  PPS: This is not a question about git-gui - The  was elsewhere.  PPPS: This is not about auto-completing commands, only command parameters. Keyboard macro to change default audio device Windows 7, Logitech G110 keyboard  2 audio devices (headphones and speakers)  I am hoping to find a quick way to macro a key to switch to headphones, and a key to switch to speakers.  Anyone have a good program or anything of that nature?  EDIT:  Using AHK to try and get this task working as hoped is sadly not doing the trick.  I have included a screenshot of my audio set, as well as a screenshot of my script as it sits now.    I have also tried to uncheck "show disabled devices" and modified the script to be Down 1, and Up 1 respectively.  It will work for one device, but it refuses to switch to the secondary. I recently found out that the expectation of a random variable $X$ in a probability space $(\Omega, \mathcal F,  \mathbb P)$, $\mathbb E(X)$, is just the term used in probability theory for the measure of the function $X$; i.e.:  $$ \mathbb E(X)=\mathbb P(X) $$  or, for a real-valued random variable $X:\Omega\to\mathbb R$:  $$ \mathbb E(X)=\int_\Omega X(x)\mathbb P(dx) $$  The thing is, I am also familiar with the definition of the expectation of a random variable $X:\Omega\to\mathbb R$ with probability distribution function $f$ to be:  $$ \mathbb E (X)=\int_\mathbb R xf(x)dx $$  Here, the integral is with respect to the Lebesgue measure on $\mathbb R$.    We can define the function $f$ in the following way: we have $F(x)=\int_\mathbb R f(x)dx$, where $F(x)=\mathbb P(X^{-1}((-\infty,x]))$.    I can't see any way to show that these two definitions are equal to one another.  The only transformation between integrals with respect to different measures that I know is that $\mu(f^{-1}(g))=\mu(g\circ f)$, which gives that $\mathbb E(g)=\mu_X(g)$, where $\mu_X$ is the image measure $\mathbb P\circ X^{-1}$, but that doesn't seem to help.  Why can we write $\mathbb E(X)=\int_\mathbb R xf(x)dx$?  Why are these two definitions consistent? Prove that $\sum_{r=1}^nr(r+1)=\frac{n(n+1)(n+2)}{3}$ using induction $$\sum_{r=1}^nr(r+1)=\frac{n(n+1)(n+2)}{3}$$  could you help me with how exactly I work this out? Automatic reboot after ubuntu freeze? How Can I Do It? Solutions for INSERT OR UPDATE on SQL Server Assume a table structure of MyTable(KEY, datafield1, datafield2...).  Often I want to either update an existing record, or insert a new record if it doesn't exist.  Essentially:  IF (key exists)   run update command ELSE   run insert command   What's the best performing way to write this? Matryoshka words Where do I put item tags on items inside a chest or your inventory? I am making a Minecraft Mini Game adventure map, and one of the levels has a /setblock command, I am using the command in a way to spawn an item in a chest (Wooden Button) I need the wooden button to have CanPlaceOn tag so it can be placed on a log. I have tried this command: setblock 294 5 -1251 minecraft:chest 0 replace {Items:[{Count:1,Slot:0,id:minecraft:wooden_button,CanPlaceOn:[log]}]}` Suppose Alice chooses a random Prime $p$ and a random private Key $a \in \mathbb{Z}^*_p$. By accident, she also chooses a random number $g \in \mathbb{Z}^*_p$, which is not a generator of $\mathbb{Z}^*_p$ and therefore  $$\langle g\rangle \subset \mathbb{Z}^*_p$$  as opposed to $\langle g\rangle = \mathbb{Z}^*_p$, which would yield a valid key. Alice then computes $A \equiv g^a \pmod{p} $ and publishes the Tuple $(p,g,A)$ as her public key.  Bob now encrypts a message $M$ using Alices public key by computing  $$C_1 = g^b \pmod{p}$$ $$C_2 = M \cdot A^b \pmod{p}$$  Is it possible for an attacker (Eve) to distinguish a “real” ciphertext $(C_1,C_2)$ from a random ciphertext $(Z_1,Z_2) \stackrel{$}{\longleftarrow} \mathbb{Z}^*_p$ with significant advantage (say $Adv \geq \frac12$)?    Edit: I guess it should be enough to show, that the ciphertext cannot be random, if  $$\langle g \rangle \neq \langle C_1 \rangle \quad(\text{or $Z_1$, respectively})$$  But how can Eve check for this property efficiently? Can someone point me in the right direction here?    Edit: A real-world situation where this flaw occurred Measuring accuracy of a logistic regression-based model How do I get attention for old, unfixed bug reports and feature requests without official responses here on Meta? given the 2 PDE  $$ \Delta u-au_{tt}+u_{t}=0$$  and $$ \Delta u + Du*Df=0 $$  here $ \Delta u $ is the Laplacian $ Du= grad(u) $ is the gradient and * means scalar product $u_{t} = \frac{\partial u}{\partial t}$  my doubt is what term should i include to get the linear part of the equations $ u_{t} $ and $Du*Df $ from the Euler Lagrange equations in $ R^{n} $ thanks I have some lines. I want to draw perpendicular lines at the start and end of the lines, on both sides of the lines.  Can somebody help me in Python?  I am using ArcGIS. Optimum Bone To Water Ratio For Pork and Beef Stocks I am tinkering with my stock recipes.   For pork stock I have been using 8 cups of water over a roasted trotter, a roasted backbone section with about 4 inches of rib attached, and a 1/4 inch slab of roasted pork belly.   For the beef stock I have been using 8 cups of water over an equivalent amount of roasted beef bones (knuckles and backbone/rib).   This gives a very flavorful stock and, for cost reasons, I want to determine how much I can reduce the concentration (by adding more water) without reaching too watery a taste.   Does anybody have any guidance on this topic? How do you link to applications in the Android market? When posting app links, I'm always using a link on Cyrket or AppBrain -- becuase I can't get a link to anything in the official Android Market.  But I have seen some links out there for use w/ Android itself ( ''market://'' protocol ):  market://details?id=de.schildbach.oeffi   (as seen @ )  Is it possible to web-link to apps in the Market so that a non-Android user can link to the appropriate Market page in a non-Android web browser? So, somehow over the weekend, my 1GB USB flash drive has managed to become write-protected.  There is no switch on the stick, so I'm concluding that something has corrupted at some point.  Obviously I can't format it or remove.  The output from dmesg | tail is:  Buffer I/O error on device sdb1, logical block 328168 lost page write due to I/O error on sdb1 sd 73:0:0:0: [sdb] Unhandled sense code sd 73:0:0:0: [sdb] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE sd 73:0:0:0: [sdb] Sense Key : Data Protect [current] Info fld=0x0 sd 73:0:0:0: [sdb] Add. Sense: Write protected sd 73:0:0:0: [sdb] CDB: Write(10): 2a 00 00 05 08 00 00 00 01 00 Buffer I/O error on device sdb1, logical block 328200 lost page write due to I/O error on sdb1   I think the second and final lines are a giveaway to corruption, but I don't know how to interpret this output.  Could someone help to see if this output gives any indication?  I usually eject the drive before removing it, but I may have been lax once or twice.  The data isn't critical, it's just bugging me.  Any suggestions on how to fix it (if the drive even can be) would be greatly appreciated. Rotate whole animation by 90 degrees I make my animation and now I realized that its pointed in wrong direction I used -y (native blender) as direction but I need to be pointed at x axis so what would be the easiest way to rotate whole animation, to switch -y with x :) Is there a way to determine the device running an application. I want to distinguish between iPhone and iPod Touch, if possible. How do I sort custom objects alphabetically in an array in Java?