I used the command poweroff and unexpectedly the system went off. I didn't used sudo therefore I didn't expect computer to be turned off. Why it was possible for me to use this command without root privilege?
For some reason, I can run halt, poweroff, shutdown, and reboot as a regular user without root. How can I fix this? Is it something to do with user groups, or is it a seting somewhere?
How do I change the Google Play country? Can someone tell me how to change the country preference for Google Play? I have searched high and low but in most of the forums people ask you to go to Gmail settings -> edit profile and change the country there. But there is no place to change the country in settings! There is a something called place (which can be marked as current) but that has no impact on Google Play.  I don't want to circumvent country restrictions, I want to permanently change the country. So it's NOT a duplicate of . If you go to review a suggested edit and close the Reject dialogue box, the button at the top-right will continue to say "Rejecting...". You will not be able to continue with the review process.  I have refreshed the page, and tried clearing my cache. If I refresh the page, I can continue reviewing the edit.  I'm using Chrome Version 31.0.1650.57 m. Tracking very long shot with no points in common between first and last frame Is it possible to track an handheld shot (there is already an answer on here about tripod shots: ) that doesn't have any visible points in common between the first and the last frame? As an example, imagine a shot of someone driving in a car for thirty minutes. Obviously everything from the first couple of seconds won't be there anymore at minute 15. Why does the field of an electric dipole drop off as $1/r^3$? Electric field of a point charge drops off inverse squarely but that of a dipole varies as $1/r^3$. Why the field drops off more quickly for a dipole? Make Launchpad Appear on screen with mouse If that's not possible, then a way to trigger the Dock on the screen with mouse without moving my cursor to the bottom of the screen is also an acceptable solution (I know that the launchpad appears on the screen with Dock)  Also i did see the  about this. Currently the migration path options from SO are:   Meta.SO Serverfault SuperUser Webmasters Programmers   If we are going to be limited to 5 options, shouldn't we periodically re-evaluate which sites are most appropriate?   (10k only) indicate that the top sites for the last 90 days are:   Superuser - 564 - 5% rejected ServerFault - 278 - 10% rejected Tex - 157 - 13% rejected DBA - 144 - 2% rejected Sharepoint - 127 - 1% rejected Programmers - 126 - 26% rejected CodeReview - 100 - 3% rejected Meta.SO - 81 - 18% rejected Wordpress - 75 - 14% rejected Webmasters - 58 - 8% rejected   All these migrations for sites out of the list required a flag and a moderator to process it.  This is just extra work for the mod team!  If we had the top 5 destinations by volume as the 5 options, we would have had a net savings of 160 flags to be processed.  I suspect we will actually see these numbers change quite a bit if it's easier for users to put questions in the appropriate spot without moderator intervention.  Can we have a review of the migration path list based on migration volume?  Think of the flags! If time standard clocks and any memories about the time standard are destroyed, can we recover the time standard again? Assume the time standard clocks and any memories about the time standard are destroyed. Can we recover the time standard again exactly?  Recovering the time standard again means we can determine the date  and time that are exactly the same as the destroyed time standard clocks will show (if they are not destroyed). SQL Server: Examples of PIVOTing String data Trying to find some simple SQL Server PIVOT examples.  Most of the examples that I have found involve counting or summing up numbers.  I just want to pivot some string data.  For example, I have a query returning the following.  Action1 VIEW   Action1 EDIT   Action2 VIEW   Action3 VIEW   Action3 EDIT     I would like to use PIVOT (if even possible) to make the results like so:  Action1 VIEW EDIT   Action2 VIEW NULL   Action3 VIEW EDIT     Is this even possible with the PIVOT functionality? How to convert a HEIF/HEIC image to JPEG in El Capitan? What to do if I can't get a visa to attend a conference that accepted my paper? My work got accepted into a very good category in a very good conference in my field. Due to complicated visa issues it will be very hard for me to attend that conference.   If I don't attend the conference they are certainly going to remove my work from the proceedings.  I am worried I won't be able to claim any sort of achievement if I don't attend this conference.  Can I still add it to my CV and specify that my work got accepted in this conference in a very good category? Cannot truncate table because it is being referenced by a FOREIGN KEY constraint? Using MSSQL2005, can I truncate a table with a foreign key constraint if I first truncate the child table (the table with the primary key of the FK relationship)?  I know that I can either   Use a DELETE without a where clause and then RESEED the identity (or) Remove the FK, truncate the table, and recreate the FK.   I thought that as long as I truncated the child table before the parent, I'd be okay without doing either of the options above, but I'm getting this error:     Cannot truncate table 'TableName' because it is being referenced by a FOREIGN KEY constraint. Dealing with splits in my ground plane Whenever I'm making a cheap, 2-sided PCB, I run into this problem:    Where I have signal lines (on the top layer here) running over top of a big fat power trace (on the bottom layer).  Now, this is obviously terrible because there is no good return path on the bottom side.  For issues like this, Hott consultants has a good recommendation:    However, I wonder if a solution like the one below is also acceptable.    My intuition tells me yes, this solution is ok.  Over the break in the ground plane, the current will hop over the vias and then back down to the lower plane.  Some back of the envelope math tells me that this adds a trivial amount to the loop area, and therefore a trivial amount to the return impedance.  Can someone tell me...   How right / wrong my intuition is here about using vias? If my intuition is wrong, why? Also, if my intuition is wrong, what is the correct solution in this sort of situation (2 layer, with power traces under signal)?   For the record, these particular signal lines aren't terribly fast (500 kHz), but I would like to know how to deal with this situation when I have signals in the 5 - 10 MHz range.  Edit  Below is a screenshot of about 60% of the board.  Maybe it will help with the critique Can Button[] generate output without using Print[]? When are infinities okay? I'm a little confused about how to handle infinities in physics. On the one hand, I always here things like infinities are not physically tenable answers. GR can't answer anything about the origin of the universe because of singularities. Throw away the radial solution that gives an infinite potential when solving the Laplace equation in spherical coordinates. But then there are other times that the infinities are okay. For instance, it is usually okay to set the reference point for your potential at infinity. There are certain times in David Tong's quantum field theory lecture notes where he seems to almost to hand wave away infinities. So, philosophically, physically, and mathematically when are infinities okay, and when are they not okay? Quoting in ssh $host $FOO and ssh $host "sudo su user -c $FOO" type constructs I often end up issuing complex commands over ssh; these commands involve piping to awk or perl one-lines, and as a result contain single quotes and $'s.  I have neither been able to figure out a hard and fast rule to do the quoting properly, nor found a good reference for it.  For instance, consider the following:  # what I'd run locally: CMD='pgrep -fl java | grep -i datanode | awk '{print $1}' # this works with ssh $host "$CMD": CMD='pgrep -fl java | grep -i datanode | awk '"'"'{print $1}'"'"   (Note the extra quotes in the awk statement.)  But how do I get this to work with, e.g. ssh $host "sudo su user -c '$CMD'"?  Is there a general recipe for managing quotes in such scenarios?.. Getting video dimension / resolution / width x height from ffmpeg Say I have an embedded device which is only capable of doing HMAC-SHA1 transformations (that device is, in fact, a YubiKey).  Would it be secure to feed it like a block cipher in counter mode to get a random pad suitable as an stream cipher?  Of course, I'm talking about not repeating the counter value ever to encrypt data (so this construction would also need some random IV or treating the counter value as a nonce forever). Limit distribution of infinite sum of Bernoulli random variables Even though a question may be closed by receiving 5 close votes, the votes do not necessarily need to agree.  I think this is a good behavior, but  (which it was) and found the question was closed as "not a real question".  This is unfortunate, while I'm happy to display my username and acknowledge that I voted to close, I'd like some additional transparency.  That is, if it was a 4-1 vote for "not a real question" vs "exact duplicate" I'd be interested in seeing that level of information.  The point is to be transparent about why the question was closed, and though 5 users may agree the question needs to be closed they may not agree why.  It's important to recognize all the reasons for closure, not just the majority reason.  I'd suggest displaying this information as something like:     closed on Jun 21 at 4:26 as:         not a real question by foo, bar, baz   exact duplicate by alice, bob      Once a question has been closed I'd argue it's more important to understand the rationale than it is to worry about an extra 2 lines of text. If the votes are 2,1,1,1 perhaps keep just 2 bullets, the first showing the majority vote, the second saying "for other reasons" as a summary of the change.  The point is to aggregate the summary by reason. How can I narrow down these gaps? I am writing my curriculum vitae, but I have one question.  In the first image, there are spaces between different sections.  (Between contact and phone, between education and Seoul~~,....)  Thus, I want to narrow down these gaps.  How can I solve this problem??  \documentclass[margin,line,letterpaper,11pt]{res}  \usepackage{times}  \usepackage{enumitem}   \setlength{\topmargin}{0.1in} \setlength{\textheight}{11in}  \setlength{\textwidth}{6in} \setlength{\oddsidemargin}{-.55in}  \setlength{\evensidemargin}{-.55in}  \oddsidemargin -.25in \evensidemargin -.49in \textwidth=5.4in  \newcommand{\ts}{\textsuperscript}  \newcommand{\block}[1]{     \vspace{.1in} \section{\sc #1} }  \newcommand{\subblock}[1]{     \vspace{-.2in}\subsection*{#1} }  \newenvironment{enum}{     \begin{enumerate}[leftmargin=5mm]     \setlength{\itemsep}{1mm} }{     \end{enumerate} }   \begin{document}   \name{\sc \LARGE  }   \begin{resume}  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  \block{Contact} Phone:  \\ Email:  \\\vspace*{-6mm} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  \block{Education}  University : \\  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  \block{Other\\ Activities}  Club : \\   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  \end{resume} \end{document}