Beginner's issue with if statement
How do I compare strings in Java?
Best book of topology for beginner? I am a graduate student of math right now but I was not able to get a topology subject in my undergrad... I just would like to know if you guys know the best one.. Switching between one and two monitors When running my MBP, I attach an external monitor, a keyboard and trackpad to it so I have two separate desktops which are contiguous; like it's a "fancy" desktop.   Back in the day on Mavericks, it behaved properly: when I unplugged the external monitor to, say, take the laptop into a meeting, it would just put all of the desktops separately on the built in display, roughly preserving which window stayed on which desktop so all you'd have to use was a run a restore tool like Display Maid to restore your window positions when you plug your external monitor back in. This was handy because you didn't have to manually clean up your desktop when done.   Now, with El Cap, it would seem that when you unplug the external monitor, it used the monitor count of whichever screen had the most desktops and merges the windows from the two "combined desktops" into one desktop in a way that seemed to be random, which is clumsy.   Worse, setting back Display Maid to restore the original configuration automatic doesn't work like it used to - previously it saved positions on all desktops in one action, but now it does it one screen at a time and forcing you restore eech desktop separately, which is tedious. It would seem that Display Maid is not great software anymore.  Is there some other utility out there that must work better so you can restore how your windows and desktop setup was as it was before you unplugged the external monitor. Any ideas? Adding Basemaps from Google or Bing in QGIS $\mathbb Z[i]/ \langle 1+2i \rangle \cong \mathbb Z_5$ Paging Lucene's search results I am using Lucene to show search results in a web application.I am also custom paging for showing the same. Search results could vary from 5000 to 10000 or more. Can someone please tell me the best strategy for paging and caching the search results? How can I determine which process owns a hotkey in Windows? Given a hotkey, how can I find which program owns it? How do I change my login provider(s)? I no longer use the service that I originally used to register, and would like to change the service I use to log in, or at least add a second account.  Is this possible? How do I change my login provider or associate a backup method to log in?     For more information, see "" in the . Is there any way to check whether a file is locked without using a try/catch block?    Right now, the only way I know of is to just open the file and catch any System.IO.IOException. SE Android app for tablet has bad formatting on feed When I open a window to air out the room, how does the smell disperse? Let's say I'm in a room with some kind of noxious stink, possibly of flatulent nature.  The quickest way to right the world that comes to mind is to open a window.  When I open a window, how do the stank particles leave the room? How to disable the touchpad? I want my touchpad to be disabled when I use my mouse. How can I do that? touchpad-indicator has stopped working on 11.10. It used to work on 11.04. Gnome3 is not a solution as I don't like it and find it buggy. Aside from the repetitive appearance of the black cat, I can't remember seeing any living animals, either inside the Matrix simulation or in Zion.  How come? Is there an in-universe explanation? nvidia-libopencl1-331 has to be removed before installing WINE A closed subset of an algebraic group which contains $e$ and is closed under taking products is a subgroup of $G$ A closed subset of an algebraic group which contains $e$ and is closed under taking products is a subgroup of $G$.   Denote this set as $X$. If the condition of $X$ being closed is dropped, this statement does not hold. The set of nonzero integers in $\mathbb{G}_m$ over $\mathbb{C}$ is a counterexample.  It suffice to prove that for any $x \in X$, $x^{-1}X = X$. As $X$ is closed under taking products, it is clear that $X \subseteq x^{-1}X$. In order to prove the inverse inclusion, the closedness of $X$ (under Zariski topology) must be used.   Let $\phi: G \rightarrow G, y \mapsto x^{-1}y$ is a homoemorphism of $G$ as an algebraic variety. So $x^{-1}X = \phi(X)$ is a closed subset of $G$ containing $X$. But Why are they equal?  Thanks very much. How to rotate the curve but not the axes? Is it a problem if a UK visa was issued but not used? Last year, my wife and I were issused 6-month visieor visas for the UK. She did not travel with me and, therefore, didn't use her visa. I am currently applying for a visitor visa for my daughter and myself.  Will the fact that my didn't use her visa have any negative affect on our new application? I'm asked to used induction to prove Bernoulli's Inequality: If $1+x&gt;0$, then $(1+x)^n\geq 1+nx$ for all $n\in\mathbb{N}$. This what I have so far:  Let $n=1$. Then $1+x\geq 1+x$. This is true. Now assume that the proposed inequality holds for some arbitrary $k$, namely that $$1+x&gt;0\implies (1+x)^k\geq 1+kx,~\forall~k\in\mathbb{N}\setminus\{1\}$$ is true. We want to show that the proposed inequality holds for $k+1$. Thus multiplication of $(1+x)$ on each side of the above inequality produces the following result: $$(1+x)(1+x)^k\geq (1+kx)(1+x)\implies (1+x)^{k+1}\geq 1+x+kx+kx^2\cdots\cdots\cdots$$  I'm not sure where to go from here. I have a Red Hat Enterprise Linux server (7.5 x86_64). I have OpenSSH version 7.4. I was asked to upgrade it to a later version for security reasons: Nessus states that . However the Red Hat software and downloads does not have the latest package RPM.  I found some clues on where to get the latest package for OpenSSH. I found , however, I do not know on how to upgrade it and trust this website. I do not want the SSH and other configuration to be modified by the ugrade.  I did find links but however they are not useful, for example .  I would like to know how to upgrade OpenSSH without using yum. I'd like to estimate the correlation between:  An ordinal variable: subjects are asked to rate their preference for 6 types of fruit on a 1-5 scale (ranging from very disgusting to very tasty) On average subjects use only 3 points of the scale.  A continuous variable: the same subjects are asked to quickly identify these fruits, which results in an mean accuracy for the 6 fruits.   Is Spearman rho the best method to analyze these data and/or are there other good methods I could consider? Advantages of parallel over serial connections As far as my understanding goes, parallel data connections are faster than serial at the same frequency. However, when you increase the frequency in parallel you start getting bits 'cross-talking' and getting transferred onto the next bus. Serial however, since it's only a single bus line, can have the frequency increased to make it faster than parallel without a problem. Also, surely parallel is more expensive as it uses more lines.  So my question is, what actually is the benefit of using a parallel data connection over a serial one? Are there any? If not, why do we still use parallel connections?