Convert long filename to short filename (8.3) using cmd.exe
Get DOS path instead of Windows path
Gravitational waves and time With jQuery, how do I find out which key was pressed when I bind to the keypress event?  $('#searchbox input').bind('keypress', function(e) {});   I want to trigger a submit when ENTER is pressed.  [Update]  Even though I found the (or better: one) answer myself, there seems to be some room for variation ;)  Is there a difference between keyCode and which - especially if I'm just looking for ENTER, which will never be a unicode key?  Do some browsers provide one property and others provide the other one? Deriving Schrodinger equation from Klein-Gordon QFT with the definition $\psi(\textbf{x},t)\equiv \langle 0|\phi_0(\textbf{x},t)|\psi\rangle$ In the book "Quantum Field theory and the Standard Model" by Matthew Schwartz, , the position space wavefunction is defined as   $$\psi(x)=\langle 0|\phi(x)|\psi\rangle, \tag{2.82+2.83}$$  where $|\psi\rangle$ is any state in the Fock space. Then he uses the equations (i) $\partial_t^2\phi_0=(\nabla^2-m^2)\phi_0$ (i.e., the Klein-Gordon equation for the free massive scalar field $\phi_0(\textbf{x},t)$) and (ii) $[H,\phi_0]=-i\partial_t\phi_0$ to derive Eq. 2.85, in following 3 steps:  $$i\langle 0|\partial_t\phi_0(\textbf{x},t)|\psi\rangle=\langle 0|\int \frac{d^3\textbf{p}}{(2\pi)^3}\frac{\sqrt{\textbf{p}^2+m^2}}{\sqrt{2\omega_\textbf{p}}}(a_p e^{-ip\cdot x}-a^\dagger_p e^{ip\cdot x})|\psi\rangle\\ =\langle 0|\sqrt{m^2-\nabla^2}\phi_0(\textbf{x},t)|\psi\rangle.\tag{2.85}$$  This equation is used to successfully derive the Schrodinger equation in quantum mechanics for the state $\psi(\textbf{x},t)\equiv \langle 0|\phi_0(\textbf{x},t)|\psi\rangle$.   The first equality follows from differentiation of $\phi_0(x)$ w.r.t $t$. How does the second equality follow from the first? How are the inputs (i) and (ii) are utilized to derive the second equality from the first? Is it true that the operator $$i\partial_t\sim\sqrt{m^2-\nabla^2}~?$$ If yes, what is the use of doing the middle step? I'm including \usepackage{hyperref} so that each instance of \ref (as well as each page number in the index and the table of contents) automatically links to that page.  When I'm viewing the document (in ) and I click a link, I jump to the linked page.  Is there any easy way to go "back" to where I was before I clicked the link?  (And is the answer any different when using Adobe Acrobat reader?) Hibernate is disabled, hiberfil.sys gets recreated at each boot I have Windows 7 running on a small (40GB) partition, with 4GB ram. This means that the hiberfil.sys file created by Hibernate takes up a significant portion of the available diskspace. I would like to remove it.  I am aware that I can disable Hibernate and remove hiberfil.sys by entering powercfg -h off in an elevated command prompt. This works -- the file is immediately removed, and after doing so, the HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Power\HibernateEnabled key is (correctly) set to 0.  However, the next time I reboot the PC, hiberfil.sys returns from the dead, Hibernate is reenabled, and that registry key has returned to 1.  I'm pretty much at my wits' end with this. Almost everything I can find online related to removing the hiberfil.sys file simply suggests using powercfg to turn off hibernation, and that appears to work for just about everyone. But it just keeps coming back for me! (Like a vampire, sucking up my disk space.) I did find  from someone who seems to have had the same issue, but none of the suggestions there worked for the original poster (or for me). Still, I have tried everything listed there, including:   Disabling hybrid sleep Disabling Hibernate through the command prompt, through the Power Options GUI, and through both (in both orders) Manually changing the HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Power\HibernateEnabled key Pretty much everything else I can think of!   I do want to reiterate that I have no problem removing the file -- that works great. It just comes back after every reboot. I'm about ready to throw in the towel and just run a script on login to disable Hibernate each time, even though that seems like a crazily hacky "solution" . . . but I was hoping someone here could suggest something else, first. How do I contact other users? Ubuntu non LTS to LTS in the future I have some problems with this exercise. I don't know if it can be done. Consider the polynomial $ x^n - a \in \mathbb{Q} $ Can I compute the Galois group of this over $\mathbb{Q}$? Maybe having a nice "basis.  The splitting field is given by $\mathbb{Q}(\zeta_n,\alpha)$ , where $\zeta_n$ is a primitive root of unity , and $\alpha$ is some number such that $\alpha^n = a $. Well first of all, I want a $\underline{"good basis"}$ for the splitting field. In the sense that the minimal polynomials, of the adjoined elements, are different (in this case the computation of the galois group is very simple).  For example one easy case, it's when $a&gt;0$, then $(a)^{\frac{1}{n}} \in \mathbb{R}$ , so clearly the minimal polynomial of $(a)^{\frac{1}{n}} , \zeta_n$ are distincs, and I'm done. If $n$ is odd then , it's also easy, since one root it's also real, for example $x^3-3 $, the real root is $ \root 3 \of { - 3}  =  - \root 3 \of 3  $ , so I can consider the splitting field as $\mathbb{Q}(-\root 3 \of 3 , \zeta_3 )=\mathbb{Q}(\root 3 \of 3 , \zeta_3 )$. The difficult case is when $n$ is even and $a&lt;0$ , for example  $x^8+20$ or $x^4+20$ in some cases as in the second, there are particular cases since there exist algorithms for the Galois group of quartics, but in general. It can be done?  $\underline{Remark}$ I'm searching a $\underline{"good basis"}$ for the splitting field. In the sense that the minimal polynomials, of the adjoined elements, are different since in this case the computation of the galois group is very simple. Thomson et al. provide a proof that $\lim_{n\rightarrow \infty} \sqrt[n]{n}=1$ in . It has to do with using an inequality that relies on the binomial theorem:  I have an alternative proof that I know (from elsewhere) as follows.  Proof. \begin{align} \lim_{n\rightarrow \infty} \frac{ \log n}{n} = 0 \end{align} Then using this, I can instead prove: \begin{align} \lim_{n\rightarrow \infty} \sqrt[n]{n} &amp;= \lim_{n\rightarrow \infty} \exp{\frac{ \log n}{n}} \newline &amp; = \exp{0} \newline &amp; = 1 \end{align}  On the one hand, it seems like a valid proof to me. On the other hand, I know I should be careful with infinite sequences. The step I'm most unsure of is: \begin{align} \lim_{n\rightarrow \infty} \sqrt[n]{n} = \lim_{n\rightarrow \infty} \exp{\frac{ \log n}{n}} \end{align} I know such an identity would hold for bounded $n$ but I'm not sure I can use this identity when $n\rightarrow \infty$. Question: If I am correct, then would there be any cases where I would be wrong? Specifically, given any sequence $x_n$, can I always assume: \begin{align} \lim_{n\rightarrow \infty} x_n = \lim_{n\rightarrow \infty} \exp(\log x_n) \end{align} Or are there sequences that invalidate that identity?  (Edited to expand the last question) given any sequence $x_n$, can I always assume: \begin{align} \lim_{n\rightarrow \infty} x_n &amp;=  \exp(\log \lim_{n\rightarrow \infty} x_n) \newline &amp;=  \exp(\lim_{n\rightarrow \infty} \log x_n) \newline &amp;=  \lim_{n\rightarrow \infty} \exp( \log x_n) \end{align} Or are there sequences that invalidate any of the above identities? (Edited to repurpose this question). Please also feel free to add different proofs of $\lim_{n\rightarrow \infty} \sqrt[n]{n}=1$. Solve $$\int \limits_{0}^{\infty} \frac{\cos(x)}{\cosh(x)} dx$$ without complex integration.  This integral can be very easily solved with contour integration, but how can you solve it without taking a tour in the complex plane? Can't boot Ubuntu or Windows 8 after Ubuntu 64-bit install on Samsung series 7 Windows 8 laptop, error "All boot options are tried." I have a Samsung Chronos 7 laptop (NP770Z5E) pre-installed with Windows 8, and I wanted to install Ubuntu 13.04 alongside it, so I can dual boot. Here is what I've done:  Updated BIOS to lastest version (P04ABU) using Samsung Updater Reduced Win8 partition by half, I left the others untouched Created a bootable USB stick using  and a Ubuntu 13.04 64-bit image Disabled FastStartup on Win 8 Disabled Fast BIOS Mode Boot Mode changed to CSM OS  Update:  Also disabled Secure Boot (I had to disable it in order to select CSM OS)  After that I saved the BIOS settings, and shut down the computer. I plugged in the USB drive, powered the computer on, entered the BIOS and tried to change the boot order. Oddly, there was only one option in the boot order screen, the USB drive (HDD didn't show up in the boot priority screen). I ignored that and installed Ubuntu. I've created 3 partitions from the unused spaced left: a 8GB swap, a 100MB BIOS boot partition, and the rest to ext4, mounted in /. Boot loader installed on /sda. After a reboot, this message appears:  All boot options are tried. Press &lt;F4&gt; key to recover with factory image using Recovery or any other keys for next boot loop iteration.  So I went to the BIOS to change the boot device priority, and the list is empty! Enabling Secure Boot and Fast BIOS had no effect. I used the Ubuntu Live USB to check the disk contents, I can see the Ubuntu and Win 8 partitions. I've used Boot Repair (using the Recommended Repair), with no avail, the Boot Repair log is here:  Boot Repair showed me a message about the system being a&quot;EFI system&quot;. I suppose that means that I should have checked out the advanced settings. I don't know how to proceed. I don't know if it's a good idea to &quot;recover with factory image&quot; since I have modified the original partitions. Maybe I need to experiment with Boot Repair's advanced settings. Which other nations are there in Attack on Titan world aside Eldia and Marley? In the Attack on Titan wikia they often mention other nations aside Eldia and Marley which supposedly have more advanced technology than this 2 nations. Which other known nations are there in Attack on Titan world aside Eldia and Marley and why are they more advanced than Marley when only Eldia is supposed to be isolated from the world? Project point onto line in Latitude/Longitude Given line AB made from two Latitude/Longitude co-ordinates, and point C, how can I calculate the position of D, which is C projected onto D.  Diagram: How can I create a product key for my C# application? How can I create a product key for my C# Application? I need to create a product (or license) key that I update annually.  Additionally I need to create one for trial versions.  Related: The 'nofollow' attribute is set in user profile website link... why? I understand that from an SEO perspective it is beneficial for Stack Overflow to have the  on the website link for user profiles. Especially if people will just create an account to get a backlink. What I think however, is that contributing members of Stack Overflow should be awarded with this backlink. I think that if someone contributes and has some decent reputation, then they should not have nofollow set on their website link in their user profile. Considering the amount of users that are backlinking to Stack Overflow with flair, I really think that Stack Overflow should hook us up with some search engine love. The two causes for the factor 2 in Coriolis effect While reading this document on Coriolis effect , I saw the followig sentence     Two kinematic effects each contribute half of the Coriolis acceleration: relative velocity and the turning of the frame of reference.    And this is the reason why Coriolis term has that factor $2$. Unfortunately it does not specify anything about this two causes. Does anyone have some further explanation for how "relative velocity" and "turning of the frame" actually give rise to the Coriolis term? How to properly denoise renderings? Since the Denoise feature was added to Blender I only use the default setting with it and it really does the work. But sometimes the denoise is noticable on some of my renders. How can I overcome the blurred effect? Denoising for me is a big help because my system is quite aged. Web-mapping with editing capabilities? Compare the statistical significance of the difference between two polynomial regressions in R So first of all I did some research on this forum, and I know   questions have been asked but they usually haven't been answered properly or sometimes the answer are simply not detailed enough for me to understand. So this time my question is : I have two sets of data, on each, I do a polynomial regression like so :  Ratio&lt;-(mydata2[,c(2)]) Time_in_days&lt;-(mydata2[,c(1)]) fit3IRC &lt;- lm( Ratio~(poly(Time_in_days,2)) )   The polynomial regressions plots are:    The coefficients are :  &gt; as.vector(coef(fit3CN)) [1] -0.9751726 -4.0876782  0.6860041 &gt; as.vector(coef(fit3IRC)) [1] -1.1446297 -5.4449486  0.5883757    And now I want to know, if there is a way to use an R function to do a test that would tell me whether or not there is a statistical significance in the difference between the two polynomials regression knowing that the relevant interval of days is [1,100].  From what I understood I can not apply directly the anova test because the values come from two different sets of data nor the AIC, which is used to compare model/true data.  I tried to follow the instructions given by @Roland in the related question but I probably misunderstood something when looking at my results :  Here is what I did :   I combined both my datasets into one.  f is the variable factor that @Roland talked about. I put 1s for the first set and 0s for the other one.  y&lt;-(mydata2[,c(2)]) x&lt;-(mydata2[,c(1)]) f&lt;-(mydata2[,c(3)])  plot(x,y, xlim=c(1,nrow(mydata2)),type='p')  fit3ANOVA &lt;- lm( y~(poly(x,2)) )  fit3ANOVACN &lt;- lm( y~f*(poly(x,2)) )   My data looks like this now :    The red one is fit3ANOVA which is still working but I have a problem with the blue one fit3ANOVACN the model has weird results. I don't know if the fit model is correct, I do not understand what @Roland meant exactly.  Considering @DeltaIV solution I suppose that in that case :  The models are significantly different even though they overlap. Am I right to assume so ? How do I get Skyrim to recognize I don't have a follower anymore?