Why don't we have a social sciences site?
How can I propose a new site?
$\operatorname{Aut}(\mathbb Z_n)$ is isomorphic to $U_n$. I've tried, but I can't solve the question. Please help me prove that:  $\operatorname{Aut}(\mathbb Z_n)$ is isomorphic to  $U_n$. A Sequence converges to a limit $L \in \mathbb R$ if, and only if, an $N$-th tail of the sequences converges to $L$ for some $N \in \mathbb N$ Which is easier, pushing or pulling? It is generally assumed, from a person's perspective, that pushing a cart is more easier than pulling one. But why? Is there any difference in terms of force required to achieve the same amount of displacement?  Or is it merely human perception?  Why is it that almost all automobiles transfer torque to the back axle. But then, why do trains have engines in the front? I am fairly new to the system administration world. I've been working on an application recently and when I check my application server logs, I constantly get various IP addresses trying to ssh into my server by brute force. Here is an example of my server log:   Feb 14 04:07:20 foodwiz3 sshd[1264]: error: Could not load host key: /etc/ssh/ssh_host_ed25519_key Feb 14 04:07:21 foodwiz3 sshd[1264]: reverse mapping checking getaddrinfo for coenamor.columbiansabbatical.com [23.249.167.223] failed - POSSIBLE BREAK-IN ATTEMPT! Feb 14 04:07:21 foodwiz3 sshd[1264]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=23.249.167.223  user=root Feb 14 04:07:23 foodwiz3 sshd[1264]: Failed password for root from 23.249.167.223 port 32997 ssh2 Feb 14 04:07:23 foodwiz3 sshd[1264]: Received disconnect from 23.249.167.223: 11: Bye Bye [preauth] Feb 14 04:13:04 foodwiz3 sshd[1289]: error: Could not load host key: /etc/ssh/ssh_host_ed25519_key Feb 14 04:13:05 foodwiz3 sshd[1289]: reverse mapping checking getaddrinfo for coenamor.columbiansabbatical.com [23.249.167.223] failed - POSSIBLE BREAK-IN ATTEMPT! Feb 14 04:13:05 foodwiz3 sshd[1289]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=23.249.167.223  user=root Feb 14 04:13:07 foodwiz3 sshd[1289]: Failed password for root from 23.249.167.223 port 41562 ssh2   Is this something that is fairly normal, or should I be worried/doing something about it? How to do logistic regression subset selection? I am fitting a binomial family glm in R, and I have a whole troupe of explanatory variables, and I need to find the best (R-squared as a measure is fine). Short of writing a script to loop through random different combinations of the explanatory variables and then recording which performs the best, I really don't know what to do. And the leaps function from package  does not seem to do logistic regression.  Any help or suggestions would be greatly appreciated. Using a foreign driver's license in California when staying with a J-1 visa The choice of measurement basis on one half of an entangled state affects the other half. Can this be used to communicate faster than light? It is often stated, particularly in popular physics articles and videos, that if one measures a particle A that is entangled with some other particle B, then this measurement will immediately affect the state of the entangled partner.  For example, if Alice and Bob share an entangled pair of electrons and Alice measures her spin in the $x$ direction, then Bob's spin will also end up spinning in that direction, and similarly if she measures in the $z$ direction. Moreover, the effect will be instantaneous, regardless of the spatial distance between the two particles, which seems at odds with special relativity.  Can I use a scheme like this to communicate faster than light? Any other words that use “dis-” as an amplifying prefix? I remember hearing once about the etymology of disgruntled, probably based around a joke about how people can not be gruntled. The explanation given was that there was never a word gruntled, rather the dis‑  in disgruntled is actually a usage of the old prefix where it acts like an amplifier.   Firstly, is this true?  Secondly, are there any other words that use this prefix in this way? Area51 proposals are being advertised now all over the network? Count down in timeout is cut off The time out countdown which is flying in is missing half of the number.  Note the 33 here:        Can this be fixed please? How to filter IPv4 and IPv6 addresses? Nested regression model Read from location on console C# biblatex: Handling secondary ("quoted in") citations This question and the answer became part of a package:      How can I qoute secondary quotes which I’ve taken form another book.  Example  Jon Doe writes a book an cites Fred Bloggs in it. Now I read the book of Doe an want to cite his cite of Bloggs. So my bibliography entry must look like     Bloggs, Fred: A nice old book, 1850, p. 35. Quoted in Doe, John: A bad new Book, 2011, p. 67.   Doe’s book should not be listed separately in the bibliography.  I know that there’s a bibstring quotedin containing “quoted in” (p. 159 of biblatex’s manual) but I don’t know if theres a (predefined) way to use it …  Update  It seems that there’s no predefined way, so I decided to use userc for crossreferences like this. This works for the bibliography but not for cite commands. At the moment I create the “in text cite” manually.  It would be great to have a macro like  \QIautocite[&lt;prenote a&gt;][&lt;postnote a&gt;]{&lt;author a&gt;}[&lt;prenote b&gt;][&lt;postnote b&gt;]{&lt;author b&gt;}   that expands to the above given example.  That’s my new code, which gives the right results for bibliography and “in text cite” but the latter not automatically …  \RequirePackage{filecontents} \begin{filecontents}{\jobname.bib} @BOOKLET{autora,   title = {A nice old book},   userc={autorb},   author = {Fred Bloggs},   year = {1850}, } @BOOKLET{autorb,   title = {A bad new book},   author = {Jon Doe},   year = {2011}, } \end{filecontents}  \documentclass[ngerman]{scrartcl}  \usepackage[T1]{fontenc} \usepackage[latin1]{inputenc}  \usepackage{babel,csquotes,blindtext}  \usepackage[%     bibstyle=authortitle,     citestyle=verbose-ibid, ]{biblatex} \addbibresource{\jobname.bib}  \NewBibliographyString{bibcitedas} \DefineBibliographyStrings{german}{%   bibcitedas = {{zitiert als}{zit. als}}, }  % Put the 'quoted in text' behind the bibentry. \renewbibmacro*{finentry}{%   \ifbibliography{%     \iffieldundef{userc}{}{%       \newunit\bibstring{quotedin}\addspace\fullcite{\thefield{userc}}     }   }{}%   \finentry% }  \begin{document} \blindtext \begin{quotation}     \blindtext\footnote{\cite[36]{autora}. Zit. nach \cite[89]{autorb}} \end{quotation} \blindtext\footnote{\cite[36]{autora}. Zit. nach \cite[89]{autorb}}  \printbibliography \end{document}   Example 2  In addition to my comment (Hi @Audrey. This works fine :-) but theres a little thing …) on Audrey’s answer:  If I use the quotecite command like this  \quotecite[1]{reese}[5]{weinberg} \quotecite[1]{reese}[5]{weinberg} \pagebreak \quotecite[1]{reese}[5]{weinberg} \quotecite[1]{reese}[5]{weinberg}   the footnotes should look like       1 Reese [full cite], p. 1. Zit. nach Weinberg [full cite], p. 65   2 Ebd.   ———— page break ————   3 Rese [short cite], p 1. Zit nach Weinberg [short cite], p. 65   4 Ebd.   Everything works like expected except footnote 3 which is     3 Rese [short cite], p 1. Zit nach Weinberg [full cite], p. 65     at the moment  Update 2  Since it seems not possible to react to autocite I created a new plain command with  \DeclareMultiCiteCommand{\quoteciteplain}[\cbx@qcwrapperplain]{\cbx@quotecite}{\cbx@qcdelim}  \newrobustcmd{\cbx@qcwrapperplain}[1]{%   \global\toggletrue{cbx@isquote}%   #1%   \global\togglefalse{cbx@isquote}%   \global\togglefalse{cbx@iflastibid}%   \global\togglefalse{cbx@ifquoteepost}%   \global\togglefalse{cbx@ifquoterpost}} Making Map Book of pages with same area shown but different layers turned on/off In ArcMap a Map Book is best suited for a series of features that each get their own page. It allows you to pick a feature and generate a Map Book Page for each feature including any additional information you wish to add to each page via dynamic text, charts, etc. Is there an alternative for say a series of pages showing the EXACT same area but with different layers turned on and off? We have a Capital Improvements document that I have to create showing the City Boundaries on every page. One page has all police and fire stations listed, another shows proposed water systems, another shows expressways and highways and work being done near or on them... etc., ad nauseum. Is there some way to set this up so that I DON'T have to created a separate MXD for each Map Page of this document? Can I use a HDD on my PS3 if I have already used another on the same console? I'm thinking of changing the Hard Disk of my PS3 (Slim 120GB), but I am unsure of what will happen to the data on the one I previously had if I do this:   PS3 has some data in the HDD. I turn off PS3, change HDD, install OS on new HDD. I download some data on new HDD from PS Plus.   Let's imagine I forgot to back something up...   I turn PS3 off, change HDD back.   Can I still use the old hard drive without needing to format it again? It didn't fixed the error. So, how do I fix my GUI update?  For every software I have to install it from command line because I got same error when install software from Ubuntu Software Center. Do rogues get sneak attack damage added to attacks made outside their turn? PHB says 'once per turn,' so, it would seem that a Rogue with Sentinel, for example, could "consistently" deal Sneak attack twice per round (whether the enemy triggers an OA or the melee weapon attack provided by the Feat).  So, can rogues deal sneak attack damage with any weapon attack outside their turn? (obv. one that meets the standard requirements--finesse, adv or adj ally) Can polymorphing monsters spam their ability to effectively give themselves a massive health pool? Some creatures have an ability that lets them polymorph, such as the Couatl's Change Shape action. I am wondering if this ability could be used again whenever the form is dropped to give the creature a massive effective health pool.  For example, if the Couatl used their action to Change Shape and become a Veteran, then was hit for enough damage to kill the polymorphed form, could it then re-use the Change Shape ability to transform into a fully healed Veteran once more? Is there a specific term for a statement that uses words such that their precise meaning conveys a subtext contrary to the colloquial meaning?  For example, the joke in Men in Black:     Gentlemen, congratulations. You're everything we've come to expect   from years of government training.   where the precise use of the words conveys a sarcastic meaning (ie that the candidates are inept because that's what he's come to expect from government training).  I was going to use "irony" to describe this but then realized this is basically the opposite of irony - the use of words to convey their literal intention, when a nonliteral intention was expected.