How would it be if a SE site is created on Bangla (=Bengali) language?

Bangla (Eng. Bengali) is a language common in Bangladesh and part of India (West Bengal) with a rich history of literature and cultural heritage.   How would it be; if on  site is opened for discussion about question and answer about Bengali language? The functions like tagging etc. and main portion of the question and answers will be basically written in English (so that everyone can understand and participate) but users will be allowed to quote in Bengali; with an English transcript of pronunciation and an English translation.  Initially the site would include all aspects of Bengali language; such as starting from Literature, riddles, metaphor-cracking through grammar, spelling, etymology, pronunciation, translation etc. to typing softwares, encoding types, problems in encoding, fonts, optical character recognition, etc.   Later on, if the site can survive and cross the beta stage; then further branching can be decided.   Update: The proposal has been submitted at


Why does Windows 7 install 64 bit apps in the Program Files (x86) folder? Can I change the behaviour?

I've been using the 64-bit version of Windows 7 since the CTP and have run into a few problems with applications that get installed in the C:\Program Files (x86) folder. What's the purpose of having 2 separate Program Files directories anyway?  Every program I've installed has gone into the C:\Program Files (x86) folder. It doesn't seem to matter if the app is 32 or 64 bit. Why don't 64-bit apps get placed in C:\Program Files?  Is there a way to change the default to be C:\Program Files instead? Would it mess anything up if I just put everything into C:\Program Files?   If indeed there is some benefit to having a separate folder for 64 bit apps, it seems like the more sensible default would have been to use C:\Program Files for x86 apps and create a new C:\Program Files (x64) folder for the new 64-bit apps. This would help maintain backwards compatibility. I work as a software developer and some of my projects contain path references to libraries under C:\Program Files. Now those references are broken on the Windows 7 machine that has placed them in C:\Program Files (x86). I even tried to change the target location in the installer to be C:\Program Files, but that was ignored and the app went into C:\Program Files (x86) anyway.  This is very frustrating because I need to share source code between 32 and 64 bit machines and I don't want to have to mess with some configuration file that sets the path to these libraries differently on different machines.  Edit regarding environment variables: (Using only default English values of variables for simplicity.) On a 64-bit machine %ProgramFiles% will be C:\Program Files while the brand new variable %ProgramFiles(x86)% will be C:\Program Files (x86). So, if you have a 32-bit program that needs to find the folder path that it would be installed under, it would need to check to see if it was running on a 32-bit or a 64-bit version of Windows in order to know which environment variable to use. Any 32-bit apps that were written without this consideration would need to be updated in order to work correctly on a 64-bit machine. So even using environment variables, the backwards compatibility is broken.  Also, %ProgramFiles(x86)% doesn't exist on 32-bit versions of Windows. If it did, then 32-bit apps could just always use that environment variable and wouldn't need any conditional logic based on which OS they're running on.


My son has modified a car that he considers to be capable to do things that it shouldn't or more-so that he uses it for purposes it shouldn't withstand but does. He can't remember the word he thought of that totally describes this conundrum, if you will. It shouldn't, but it does. I suggested sin but he scoffed! Do-able but not do-able. Impossibly possible.


I am wondering how you would make use of lowercase numbers in a document? Specifically, are there any packages that introduce these?


I have a doubt concerning a question about the Monty Hall Three-Door Puzzle, in probability. I found this problem in Rosen's "Discrete Mathematics and Its Applications".     The Monty Hall Three-Door Puzzle: Suppose you are a game show contestant. You have a chance to win a large prize. You are asked to select one of three doors to open; the large prize is behind one of the three doors and the other two doors are losers. Once you select a door, the game show host, who knows what is behind each door, does the following. First, whether or not you selected the winning door, he opens one of the other two doors that he knows is a losing door (selecting at random if both are losing doors). Then he asks you whether you would like to switch doors. Which strategy should you use? Should you change doors or keep your original selection, or does it not matter?   First of all, before I ask my specific doubt:  I understand that the best strategy is switching doors, because the probability that the initially chosen door is incorrect is high (2/3); therefore, it is most probably not the winning door. So, after the host opens a door (which he knows is a losing door), the probability that the prize is in the other closed door (and not in the initially chosen one) is higher (2/3).  Now, the specific question which I want to ask (found in Rosen's book):     Explain what is wrong with the statement that in the Monty Hall Three-Door Puzzle the probability that the prize is behind the first door you select and the probability that the prize is behind the other of the two doors that Monty does not open are both 1/2, because there are two doors left.   When the contestant chooses one door (before the host opens a door), the probability that it has the prize is 1/3. But, when the host opens one door (that he knows is a loosing door), the possibilities of where the prize can be are reduced by one, because now the contestant knows that the prize can only be either on the chosen door, or on the closed door. So, it seems reasonable to think that the probability that the prize is in any one of the two remaining doors is 1/2.  But this reasoning is apparently wrong. Can any one help me understand why?  Thank you in advance.


How would I say?      I have gone to the cinema twenty times this year   Or I better say:     I have been to the cinema twenty times this year


Regarding identical copies of gedit files

When ever I save a gedit file in a directory, two copies of it get saved with identical content. Ex: If the gedit file is named as file_name and saved in Home directory then when u ls the Home directory you get file_name and file_name~ in the list. When the file command is run against them I get ASCII text, with very long lines for both of them when I view their contents using the less command they seem to largely contain identical content. The ~ file is a copy of the file when it was saved for the penultimate time. Can someone please help me in understanding as to why such a file (the file with a trailing ~ mark in its name ) is created?


How can I exclude one specific post from a WP_Query query? (For example, show all posts apart from a post with the ID 278)  I've tried the post__not_in argument but it just removes all posts..  Any help would be great.  Here is my current query  <?php     $temp = $wp_query;     $wp_query= null;     $wp_query = new WP_Query(array(         'post_type' => 'case-study',         'paged' => $paged,     ));     while ($wp_query->have_posts()) : $wp_query->the_post(); ?>   Thanks


Prove, that the multiplicative group of a finite field is cyclic.

I have almost completed the proof, I have shown, that there exists an element of order e, where e is min{n:$g^n=1$} and $g\in G$ where $G$ is the multiplicative group of a finite field. Now I noticed, that the polynomial $x^e-1$ is solved by all $g\in G$. I am finished if I can show, that e=q-1 where q=$|G|$. However I only know that q-1$\leq$e. My idea is, that if q-1 <e, e >min{n:$g^n=1$}, so e has to be q-1 wich means $G$ is cyclic. Is the reasoning for q-1=e sufficient?


Windows 8 constantly plays the Device Connect sound

On my PC, Windows 8 keeps playing the Device Connect sound (Windows Hardware Insert.wav) - a slightly discordant sequence of 3 notes. This is at least every 1-2 minutes, but can be up to every ten seconds.  This happens even after I've unplugged everything.  There's nothing in the Event Viewer about this, and there are no highlighted devices in the Device Manager. What can I do to figure out what the problem is?  (I'm hoping there's some information I can get out of Windows. I don't particularly want to go through some trial-and-error process of disabling/uninstalling devices, or similar.)


How to Separate Bands Through ModelBuilder

Q1: I have a .tiff file containing 365 bands. Each band represents a daily variable. I want to separate each band and save as a single .tiff file. In the end, I want to have 365 individual .tiff files.  Q2: And since these are daily data, is there are a way to make them monthly if you can share your model.  How do I do this?   I am using ArcGIS 10.0.


Prove that $\cos (A + B)\cos (A - B) = {\cos ^2}A - {\sin ^2}B$

$$\cos (A + B)\cos (A - B) = {\cos ^2}A - {\sin ^2}B$$  I have attempted this question by expanding the left side using the cosine sum and difference formulas and then multiplying, and then simplifying till I replicated the identity on the right. I am not stuck. What's bothering me is that the way I went about this question seemed like a rather "clunky" method. I'm just curious if I've missed some underlying pattern that could have made it easier to reproduce the identity on the right.  The way I did it:  $$\begin{array}{l} \cos (A + B)\cos (A - B)\\ \equiv (\cos A\cos B - \sin A\sin B)(\cos A\cos B + \sin A\sin B)\\ \equiv {\cos ^2}A{\cos ^2}B - {\sin ^2}A{\sin ^2}B\\ \equiv {\cos ^2}A(1 - {\sin ^2}B) - (1 - {\cos ^2}A){\sin ^2}B\\ \equiv {\cos ^2}A - {\cos ^2}A{\sin ^2}B - {\sin ^2}B + {\cos ^2}A{\sin ^2}B\\ \equiv {\cos ^2}A - {\sin ^2}B\end{array}$$


I added one conflicting repository by   sudo add-apt-repository ppa:obsproject/obs-studio   and now I would like to remove the repository in my Debian 8.1.  I cannot find it in /etc/apt/sources.list.   How can you remove the repository in Debian 8.1?


Entire function with vanishing derivatives?

Let $f:\mathbb{C}\rightarrow\mathbb{C}$ be an entire function. And assume that at each point, one of it's derivatives vanishes.  What can you say about $f$?  A hint suggests that $f$ must be a polynomial.


I have a question for our theoretic SuperUsers. How much knowledge and which fields of physics you have to know to start studying string theory? I am now on QFT, after I think I'll start study Supersymmetry or maybe special cases of QED. How much more should I know to start Strings? :)


What's the strangest corner case you've seen in C# or .NET?

I collect a few corner cases and  and would always like to hear more. The page only really covers C# language bits and bobs, but I also find core .NET things interesting too. For example, here's one which isn't on the page, but which I find incredible:  string x = new string(new char[0]); string y = new string(new char[0]); Console.WriteLine(object.ReferenceEquals(x, y));   I'd expect that to print False - after all, "new" (with a reference type) always creates a new object, doesn't it? The specs for both C# and the CLI indicate that it should.  Well, not in this particular case. It prints True, and has done on every version of the framework I've tested it with. (I haven't tried it on Mono, admittedly...)  Just to be clear, this is only an example of the kind of thing I'm looking for - I wasn't particularly looking for discussion/explanation of this oddity. (It's not the same as normal string interning; in particular, string interning doesn't normally happen when a constructor is called.) I was really asking for similar odd behaviour.  Any other gems lurking out there?


Best Timer for using in a Windows service

I need to create some windows service which will execute every N period of time. The question is: Which timer control should I use: System.Timers.Timer or System.Threading.Timer one? Does it influence on something?    I am asking because I heard many evidences to non correct work of System.Timers.Timer in windows services. Thank you.


What will be the total work done by friction on the system (man+boat)?

As I am seeing this,  the man and boat will have different displacement from ground frame,  so there should be a net work done by friction .  The books says,  total work done by friction is zero when friction is static and internal to system. Please explain..


Any traceless $n\times n$ matrix with coefficients in a field of caracteristic $0$ is a commutator (or Lie bracket) of two matrices. What happens when the field has positive caracteristic?  When trying to reproduce the proof I have in the caracteristic $0$ case for the positive caractersitic case, I run into two problems:   multiples of the identity may have trace $=0$. a matrix may have a spectrum equal to the whole field.      Are all traceless matrices commutators? If not, for which $n\in\mathbb{N}\setminus\lbrace 0  \rbrace$ and fields $k$ does it still hold? EDIT given a traceless matrix $M$, I want to know wether there are two matrices $A,B$ with $M=AB-BA$.


The mobile web is very limited and is lacking lots of features that are available in the desktop (full site) version. Why is that? What is the reasoning? Some example of the things I can't do on mobile web theme:  I can't watch the number of votes for and against  To create a description before it you need to flip through by hand, you can't enter its name in the search   It's inconvenient to check edits. You need to go to the tags, participants or ask a question. Only after it does the edit button appear  I can't really look at the result of the edit or response. Available only during question assignment  Can't run the code from a snippet  Can't edit the profile  I can't change the tracking label


I need to do an  request in JavaScript. What's the best way to do that?  I need to do this in a Mac OS X dashcode widget.


Click event with .on is not firing over appended elements

My problem is, that even when I use .on, the click event over added div with class added does not triggers. This is my script from page.   $(".added").on("click", function () { alert("halo") });  $("#nextAdress").on("click",function (event) {     event.preventDefault();     $("#trainerRegistrationFields").append('
adsa
'); }   Can you please help me so the click event will trigger also on the dynamically added element with class added?   Tahnk you in advance


what does the length of arrows represent in the correlation circle plot in pca analysis?

I want to know that in PCA analysis or FAMD the lengths of arrows in correlation circle plot(which can be plotted by bellow code) is equal to which parameter(coefficient estimates,cos2,contribution,...) while their coordinates represent their loadings?   fviz_pca_var(res.pca)   res.pca is the result of fitting PCA analysis on our data.  Any help would be greatly appreciated.


Please check the output of the following code:     double r1 = 10 * 0.39;     double r2 = 3.9;     System.out.println(r1);     System.out.println(r2);  I got the following output:     3.9000000000000004     3.9  Why this happened?? any feedback?


How realistic is the use of red yarn hub and spokes in crime television shows

I refer to a shot that occurs quite often in crime shows...    There is the victim at the hub and spokes of red yarn that connect the suspects. How realistic is this in modern detective work?  I have read these articles:         All of which suggest in a vague and noncommittal way that this technique is more about narrative exposition for the television viewer rather than a detective's tool. Can someone confirm and explain?


Prove an isomorphism between this two algebraic objects

I want to prove that $\bar{K}[V]/M_p \simeq \bar{K}$ where $K$ is a field, $\bar{K}$ is its algebraic closure and $$\bar{K}[V]=\bar{K}[x_1,...,x_n]/I_V,$$ where $I_V$ is the ideal attached to a variety, so it is prime, and $$M_p=\{f \in \bar{K}[V] : f(p)=0\}.$$  The thing is that I think that there is something wrong with this, because Can one mod out more than once?.  My intuition tells me that in $\bar{K}[V]/M_p$ we are killing all the polynomials that vanish in the variety so I was trying to use this to map a polynomial to its coefficients in $\bar{K}$ and doing this the other way around to get a bijection, but I think there has to be a better way since I am not quite sure that this will work.  Can someone help me with this issue?  Thanks in advance.


$f$ defined on $[1,\infty )$ is uniformly continuous. Then $\exists M>0$ s.t. $\frac{|f(x)|}{x}\le M$ for $x\ge 1$.  I know f uniformly continuous $\implies \forall\varepsilon > 0s.t.\forall x,y\in [1,\infty)$, $$|f(x)-f(y)|<\varepsilon \space\space\forall |x-y|<\delta$$  By Mean value theorem, $\exists c\in (x,y)\forall x,y\in [1,\infty)$ such that   $$\frac{f(x)-f(y)}{x-y}=f'(c)$$  $$\frac{|f(x)-f(y)|}{|x-y|}=|f'(c)|<M$$ for some $M>0$  $$|f(x)-f(y)|<M|x-y|<M\delta $$  How can I get an expression for $|f(x)|/x$?


I'm learning about Real Analysis, specifically accumulation points of a sequence, and need some help with this problem:      Show that the set of accumulation points of the sequence $a_n = \sin{n}$ is the closed interval $[-1, 1]$.     My thoughts:   Obviously we have $-1 \leq \sin{n} \leq 1 \forall n \in \mathbb{N}$.   The set $a_n$ will be of the form  $a_n = \{\sin1, \sin2, \sin3, ...\}$.   Given $l \in [-1, 1]$ we want to show that there exists a subsequence  $\{a_{n_k}\}$ such that $a_{n_k} \rightarrow l$ as $k \rightarrow \infty$.    This problem is different from the problems I'm used to solve in the sense that instead of finding the accumulation points of a sequence I need to prove that the accumulation points of a sequence is a closed interval and I don't know how to approach this.


Can anyone help me with this NullPointerException and explain how to stop this issue from occurring in the future?

I am getting a NullPointerException on the following code on the 2nd line of the snippet. I've tried looking it up online but can't fix it. If anyone could please help me it would be greatly appreciated! for (int j=1;j<12;j++) {         while (!topCard.getCardDetails().toString().equals("")) {             hand1[j-1] = (String) topCard.getCardDetails();         }             topCard = topCard.getNextCard();         removeCard(topCard);         topCard = topCard.getNextCard();


How to find all dependent (dependency walker) packages before installing a .deb file?

When installing Ubuntu Core 13.10 according to the instructions at , step 5 says that Ubuntu 12.04 "Precise Pangolin" development kernel requires the 'wireless-crda' package. This wiki suggest to have a look at . However the  doesn't even mention the 'wireless-crda' package at all.   After reading the Ask Ubuntu articles for 'download +kernel +packages +deb', ,  and "" I still don't know how to figure out all dependent packages.  Update#1  The answers from    1. apt-cache showpkg linux-image-3.11.0-18-generic  doesn't output a 'wireless-crda' dependency:  Reverse Depends:    linux-image-3.11.0-18-generic:i386,linux-image-3.11.0-18-generic   linux-signed-image-3.11.0-18-generic,linux-image-3.11.0-18-generic 3.11.0-18.32   linux-image-virtual,linux-image-3.11.0-18-generic   linux-image-generic,linux-image-3.11.0-18-generic   linux-image-extra-3.11.0-18-generic,linux-image-3.11.0-18-generic Dependencies:  3.11.0-18.32 - initramfs-tools (2 0.36ubuntu6) module-init-tools (2 3.3-pre11-4ubuntu3) dpkg (2 1.10.24) fdutils (0 (null)) linux-doc-3.11.0 (16 (null)) linux-source-3.11.0 (0 (null)) linux-tools (0 (null)) linux-headers-3.11.0-18-generic (0 (null)) grub-pc (16 (null)) grub-efi-amd64 (16 (null)) grub-efi-ia32 (16 (null)) grub (16 (null)) lilo (2 19.1) hotplug (3 0.0.20040105-1) hotplug:i386 (3 0.0.20040105-1) linux-image-3.11.0-18-generic:i386 (0 (null))  Provides:  3.11.0-18.32 - redhat-cluster-modules linux-image-3.0 linux-image kvm-api-4 ivtv-modules fuse-module  Reverse Provides:   2. dpkg -I linux-image-3.11.0-18-generic_3.11.0-18.32_amd64.deb  also doesn't output a 'wireless-crda' dependency:  Depends: initramfs-tools (>= 0.36ubuntu6), module-init-tools (>= 3.3-pre11-4ubuntu3)  Recommends: grub-pc | grub-efi-amd64 | grub-efi-ia32 | grub | lilo (>= 19.1)  Suggests: fdutils, linux-doc-3.11.0 | linux-source-3.11.0, linux-tools, linux-headers-3.11.0-18-generic  Conflicts: hotplug (<< 0.0.20040105-1)  Provides: fuse-module, ivtv-modules, kvm-api-4, linux-image, linux-image-3.0, redhat-cluster-modules   When installing the kernel through apt-get install linux-{headers,image}-generic there is a depending 'wireless-crda' package.  Question:  How to find out - before actually installing the Ubuntu kernel .deb file - all dependent packages that need to be installed?


What kinds of verbal complement does the verb "request" accept and require?

This verb has me a bit confused. I cannot submit my report personally and therefore have to resort to sending it by post. Now I need a polite way to ask to do this.    I request that I send my report via post. I request that I be able to send my report via post.  I request the ability to send my report via post.  I request to send my report via post.   Which one of these is correct?  While I am here can you say We all request to change the swimming timetable, or do you have to have a you after the verb request like We all request you to change the swimming timetable even when he will not be doing the changing?


While playing Diablo 3 today, I encountered an Elite monster named Nemisis several times. He popped up very randomly. I noticed he had a rune-like symbol under his name as well.He popped up twice in Act 1(I don't exactly remember what I was doing those times) and once in Act 2 (right before I went into the Witch's Den to fight her). He showed up probably a few hours in between his spawns. After being pulverized by him the first two times, the next time he showed up I was able to kill him. But an even stranger thing happened when I was about to kill him, as he had several shadows of myself attacking as well. He ended dropping a good bit of loot including a legendary item. What I want to know is his characteristics, like those rune-like symbols were, what triggers him to pop up, and anything else that would be helpful to know.


Definition of embedded submanifolds of $\mathbb{R}^n$.

In general, when someone defines a manifold he defines the concept of topological manifold and then the concept of compatible smooth charts, atlases,... If I understand it correctly the Whitney embedding theorem sais that every manifold can be embedded in $\mathbb{R^n}$ (I guess with the canonical smooth structure?) for some natural number $n$, so we could instead of defining manifolds just define embedded submanifolds of $\mathbb{R^n}$. Also, this is the takeaway I get from . But then What would be this precise definition of an embedded submanifold of $\mathbb{R}^n$? If I consider the definition of an embedded submanifold  I think I get that a subset $S\subset \mathbb{R}^n$ is an embedded submanifold if for every $x\in S$ we have a diffeomorphism $U\xrightarrow{\phi}\mathbb{R}^n$ (here $U\subset\mathbb{R}^n$ is open) such that $\phi(U\cap S)=\phi(U)\cap(\mathbb{R}^{(n-k)}\times\{0_{\mathbb{R}^k}\})$. Is that how it is defined? Because in some notes I see the (except for open submanifolds) :  definition : Let $M$ be a subset of a linear space $E$. We say $M$ is a smooth embedded submanifold of $E$ if : For a fixed integer $k\ge 1$ and for each $x\in M$ there exists a neighborhood $U$ of $x$ in $E$ and a smooth function $h:U\to \mathbb{R}^k$ such that (a) If $y$ is in $U$, then h(y) = 0 if and only if $y\in M$;and (b) rank Dh(x) = k  Are these two equivalent?


Show that the series $\sum_\text{p prime}\frac{1}{p}$ is divergent

Show that the series $$\sum_\text{p prime}\frac{1}{p}$$ is divergent.   I know that $\sum_{p=1}^\infty \frac{1}{p}$ is a p-series with $p=1$, it is a Harmonic series and is divergent, but in this case $p$ are only the prime numbers. Is it still valid?


It is revealed that the Maesters have acess to Valyrian Steel when Maester Luwin shows Bran his Valyrian steel link. We are told that when Maesters learn a new skill, they forge a new link, I assume this  is literal.   Marwyn the Mage, also has a Rod, ring and mask of Valyrian Steel. I assume the mask and ring would be reforged every time a new arch maester is appointed.  These pieces of evidence show that the Citadel does have a seemingly large stockpile of Valyrian steel and that perhaps, they have someone who can rework it. Tywin says that there are only three living smiths capable of doing so. Is there any direct reference to a stockpile of Valyrian Steel in the Citadel or a Maester who knows who to rework it?


How can I make a GameObject attach (or "stick") to another GameObject after collision? The problem: I want the GameObject to attach after collision even if it changes scale.  What I have tried:  protected Transform stuckTo = null; protected Vector3 offset = Vector3.zero;  public void LateUpdate() {     if (stuckTo != null)         transform.position = stuckTo.position - offset; }   void OnCollisionEnter(Collision col) {     rb = GetComponent<Rigidbody>();     rb.isKinematic = true;      if(stuckTo == null         || stuckTo != col.gameObject.transform)         offset = col.gameObject.transform.position - transform.position;      stuckTo = col.gameObject.transform; }   This code makes a GameObject attach perfectly after collision. But when that GameObject changes scale (while it's attached), it visually no longer looks attached to whatever it collided with. Basically, this code makes the GameObject stick with only the original scale at the moment of the collision. How can I make the GameObject always stick to whatever it collided with? And with whatever scale it has during the process?


Minecraft Keeps crashing everytime I try to load it

---- Minecraft Crash Report ---- // Ouch. That hurt :(  Time: 1/3/17 2:57 AM Description: Initializing game  org.lwjgl.LWJGLException: Pixel format not accelerated     at org.lwjgl.opengl.WindowsPeerInfo.nChoosePixelFormat(Native Method)     at org.lwjgl.opengl.WindowsPeerInfo.choosePixelFormat(WindowsPeerInfo.java:52)     at org.lwjgl.opengl.WindowsDisplay.createWindow(WindowsDisplay.java:247)     at org.lwjgl.opengl.Display.createWindow(Display.java:306)     at org.lwjgl.opengl.Display.create(Display.java:848)     at org.lwjgl.opengl.Display.create(Display.java:757)     at org.lwjgl.opengl.Display.create(Display.java:739)     at bes.ap(SourceFile:600)     at bes.an(SourceFile:436)     at bes.a(SourceFile:383)     at net.minecraft.client.main.Main.main(SourceFile:124)  A detailed walkthrough of the error, its code path and all known details is as follows:  -- Head -- Thread: Client thread Stacktrace:     at org.lwjgl.opengl.WindowsPeerInfo.nChoosePixelFormat(Native Method)     at org.lwjgl.opengl.WindowsPeerInfo.choosePixelFormat(WindowsPeerInfo.java:52)     at org.lwjgl.opengl.WindowsDisplay.createWindow(WindowsDisplay.java:247)     at org.lwjgl.opengl.Display.createWindow(Display.java:306)     at org.lwjgl.opengl.Display.create(Display.java:848)     at org.lwjgl.opengl.Display.create(Display.java:757)     at org.lwjgl.opengl.Display.create(Display.java:739)     at bes.ap(SourceFile:600)     at bes.an(SourceFile:436)  -- Initialization -- Details: Stacktrace:     at bes.a(SourceFile:383)     at net.minecraft.client.main.Main.main(SourceFile:124)  -- System Details -- Details:     Minecraft Version: 1.11.2     Operating System: Windows 10 (amd64) version 10.0     Java Version: 1.8.0_25, Oracle Corporation     Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation     Memory: 50486592 bytes (48 MB) / 151265280 bytes (144 MB) up to 1060372480 bytes (1011 MB)     JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M     IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0     Launched Version: 1.11.2     LWJGL: 2.9.4     OpenGL: ~~ERROR~~ RuntimeException: No OpenGL context found in the current thread.     GL Caps:      Using VBOs: Yes     Is Modded: Probably not. Jar signature remains and client brand is untouched.     Type: Client (map_client.txt)     Resource Packs:      Current Language: ~~ERROR~~ NullPointerException: null     Profiler Position: N/A (disabled)     CPU:


How do I find the sum of $\sum\limits_{k=1}^\infty{\frac{k}{2^{k+1}}}=1$?

As shown in the title, how do I find the sum of:  $$\sum\limits_{k=1}^\infty{\frac{k}{2^{k+1}}}=1$$


Why is RSA encryption key based on modulo $\varphi(n)$ rather than modulo $n$?

While calculating RSA encryption key we take modulo $\varphi(n)$ rather than modulo $n$. I can’t understand why it’s done this way.


prove that $f:X\rightarrow Y$ is surjective if and only if $f(f^{-1}(C))=C$

I need help with proving this:  $f:X\rightarrow Y$ is surjective if and only if $f(f^{-1}(C))=C$  $C\subseteq Y$  Thanks.


"Though the number of women's welfare societies are growing." "Though the number of women's welfare societies is growing."  Which one is correct? I found this sentence in GMAT question book.


Disable "automatic maintenance" in Windows 8

I'm running a few VMs, and suddenly I noticed my CPU fan was spinning louder than usual. I tracked it down to Windows 8 doing some "automatic maintenance":      How can I turn this completely off? I found a way to set the time, but not a way to turn it off completely.


How to prove a cross is not locally homeomorphic to an euclidean space?

Consider the subset $X = \{(x, 0) \mid -1 \lt x \lt 1\} \cup \{(0, y) \mid -1 \lt y \lt 1\} \subset \Bbb R^2$. It's just two open segments intersecting at $(0, 0)$.  How do you show that $X$, equipped with the subspace topology of $(\Bbb R^2, \lvert \lvert \cdot \rvert \rvert_2)$, is not locally homeomorphic to an euclidean space because of the point $(0, 0)$ ?


Can I still use a metal box if the cover plate mounting holes are stripped?

The metal double-gang box (40 yrs old) is stripped where you place the 8/32 screws. I should have replace the box in the beginning. It took me an hour or so to put a nut on both of these screws from within (not touching any wires) behind the stripped holes to hold the screws. Do most electricians replace the box or get the next size screws up (10/32)?


How to prove that $R/I \otimes_R M \cong M / IM$

Possible Duplicate:          In  the following claim was mentioned:  $R/I \otimes_R M \cong M / IM$  So I tried to prove it. Can you help me finish my proof? Thanks!    We recall that $M \otimes_R -$ is a covariant right-exact functor that it is exact if $M$ is flat and we observe that the following is an exact sequence: $$ 0 \to IM \xrightarrow{i} M \xrightarrow{\pi} M / IM \to 0$$  $R/I$ is an $R$ module since $R/I$ is a subring of $R$ closed with respect to multiplication from $R$ but it is not necessarily flat hence we only get exactness on one side:  $$  (R/I) \otimes_R IM \xrightarrow{id \otimes i} (R/I) \otimes_R M \xrightarrow{id \otimes \pi} (R/I) \otimes_R M / IM \to 0$$  Then $$ \mathrm{Im(id \otimes \pi)} = (R/I) \otimes_R M / IM  \cong (R/I) \otimes_R M / \mathrm{Ker} (id \otimes i) $$  so we want to show two things:   (i) that $\mathrm{Ker} (id \otimes i) = \{0\}$. To this end let $r + I \otimes im \in (R/I) \otimes_R  IM $ and assume $ id \otimes i(r + I \otimes im ) = r + I \otimes im = 0 + I \otimes 0$. I'm not sure how to proceed from here.   (ii) and that $M /IM \cong (R/I) \otimes_R M / IM $  Can you help me? Thanks.


What are the possible integer values for $x,y,z$ if $792|\overline{5x36y98z2}$?

So the question is  Let $x,y, z$ Be digits so that the 9-digit number  5$x$36$y$98$z$2 is divisible by 792.  1) Without calculating $x$ and $y$, explain why z = 3 or 7.  2) WIthout calculating $x$, show that y = 0 or 9.  3) FInd all combinations of $x, y, z$


Operator Theoretic Perspectives on Bayesian Inference

On the Wikipedia page for conjugate prior there is a , which describes a metaphor where observation of data is seen as a "linear operator" on the space of probability distributions, with conjugate priors as an eigenvector. Unfortunately, this section has no inline citations.  Does anyone know of any good references on the subject?


Prove that $\phi (2^n-1)$ is a multiple of $n$ for any $n>1$.  I'm not really sure how to start this proof.


difference between \prime and `'` in math mode

I believed that \prime is the appropriate code to insert a prime in math mode and assumed that it would be equivalent to type '. I find that  \prime inserts an ugly, large prime, whereas the ' produces something ok. Is there an explanation?  \documentclass{article}  \begin{document}  $a'_{i}$ dürfen zu $x'_{i}$ nur  $a\prime_{i}$ dürfen zu $x\prime_{i}$ nur  \end{document}


PS1='$(pwd)' why this works and why is this different from PS1=$(pwd)

Why when I enter this command the prompt changes to my directory?  PS1='$(pwd)'   I am using single quotes, which means no interpolation , a.k.a echo '$(pwd)' ——→ $(pwd)  Furthermore, say that we clarified why this works... why is it functioning differently from PS1=$(pwd) ? (no quotes at all)  By different I mean that if I use the quotes then the prompt will keep changing to my current directory as I navigate through the terminal. But if I don't use quotes, then the prompt will always remain the directory that I was in when I first entered the command PS1=$(pwd)  why?


I have to implement a threadsafe logging mechanism in C++ under Windows and I want to use the streams library.  I wanted to know if anyone could give me some advice regarding doing this and what would be the best way?  The logging messages will most likely be a few lines long each time, so I'd probably need to write them to a buffer first and then flush to file?  This logging should be fairly fast and not affect the performance of the application too much when its used, so I was thinking of doing the actual writing to the file in its own thread.  Is that a good idea?  Any advice and hints are appreciated.


How to avoid Exif data rotating images automatically during approval selection?

I've been doing some digging, but so far with no results. I'm currently looking for a way of forcing or letting the admin to dictate the orientation of an image. I came across an issue where some user uploaded content looked correct upon initial upload, but when the admin began the approval process, the files hidden orientation data changed it from a vertical to a horizontal orientation. Now mind you I know that I could simply re-save that file, pull down the submitted post data and re-upload with the correct image, but I'm trying to be as efficient as possible in the event someone outside myself is administrating the content one day.   Has anyone come across a module that could help force orientation away from EXIF content or other data?   Thanks in advance!


Error while finding java version on ubuntu

I recently messed up badly in eclipse, so was doing some digging to update/fix jdk.  While executing java -version to find Java version on my Ubuntu 12.04, i get the below error and even on following sudo apt-get install <selected package> for any of the packages, the problem persists!!     The program 'java' can be found in the following packages:  *   default-jre  * gcj-4.6-jre-headless  *   openjdk-6-jre-headless  * gcj-4.5-jre-headless  *   openjdk-7-jre-headless Try: sudo apt-get install    Can any one tell me what does this mean and what is needed to be done to correct it, couldn't find much on internet about this!!  PS : i have executed sudo apt-get install openjdk-7-jre-headless and it tells that :     openjdk-7-jre-headless is already the newest version. 0   upgraded, 0 newly installed, 0 to remove and 0 not upgraded.   so jre is there somewhere....what's the bug then?????  Why asking this question because eclipse is throwing this error and i need to fix jre/jdk to run it but i am total noob in this!!     A Java Runtime Environment (JRE) or Java Development Kit (JDK)   must be available in order to run Eclipse. No Java virtual machine was found after searching the following locations:   /usr/lib/eclipse/jre/bin/java java in your current PATH     so


Is it possible to use kernel PCA for feature selection?

Is it possible to use kernel principal component analysis (kPCA) for Latent Semantic Indexing (LSI) in the same way as PCA is used?  I perform LSI in R using the prcomp PCA function and extract the features with highest loadings from the first $k$ components. By that I get the features describing the component best.  I tried to use the kpca function (from the kernlib package) but cannot see how to access the weights of the features to a principal component. Is this possible overall when using kernel methods?


Keyboard focus on first file in Windows explorer?

When i open windows explorer, I usually navigate it with keyboard most of the time. My biggest annoyance is when I open a folder, and in it I want to open the first folder or file in the list. For this, I have to press the down arrow key, and the up arrow to get the focus on that file/folder. How could I make Explorer, automatically focus on the first file, so once i open the folder, I can just click enter and it opens?


If $1,a_1,a_2,...,a_{n-1}$ are the $n$ roots of unity, then how can we find the value of $$(1-a_1)(1-a_2)...(1-a_{n-1}) \space ?$$    My Approach: If $n=2$ , then $1,-1$ are the roots of unity $\therefore (1-a_1)=(1-(-1))=2$ for $n=3 \space :$  $1,\omega,\omega^2$ are the roots of unity $\therefore (1-a_1)(1-a_2)=(1-\omega)(1-\omega^2)$ $\quad \quad \quad =1-\omega^2 -\omega +1=3$ so we conclude for $n$ the value $(1-a_1)(1-a_2)...(1-a_{n-1}) \space = n$    but i want a direct process to evaluate $(1-a_1)(1-a_2)...(1-a_{n-1}) $ (without generalisation),so how can i do so?


The current process for self-deletion of a user account has several problematic aspects, both in the process itself and in the end result. Some of these issues are:   The process requires manual intervention of a mod or SE employee, leading to delays and sometimes mistakes. It is more complicated than it has to be, which can lead to the impression that SE is imposing some rather arbitrary-looking restrictions and steps one has to take. This can give the impression that the user isn't really in control of his private data at SE. It is irreversible once the account is deleted, although an account can be partially reconstructed with a lot of manual effort from an SE developer. There is no real protection against mod/SE employee errors, if an account is deleted in error, there is no easy way to undo the damage. Because it is manual, it consumes the time of SE employees that have to deal with it  (unless  is used), removing useful voting information and annoying users that lose reputation that way.   I'm proposing an alternative way of handling self-deletion that would be automated, and also reversible to some extent, while still being pretty much a hard-delete (and not a soft-delete that would be problematic with respect to user privacy). The process would work roughly like this:   The user clicks a "delete profile" button in his profile. There should be a way to indicate if you want to delete all profiles on all SE sites, only on this site and a way to select multiple sites from a list where the profile should be deleted. It is verified that the user has true access to the account in some way (confirmation mail?) and not just someone that found the unlocked computer of the user. A countdown until deletion is started (I'd go with 48h, but that could be different). The timer shouldn't be too long, but long enough to correct mistakes and leave users a bit of time to reconsider. Alternative options would be to enable users to override the countdown if they really want to nuke their account immediately. Another option would be to soft-delete the account immediately, and make the countdown only for hard-deletion of the user data. Upon deletion, the posts of the user and his votes are transferred to a newly created blank account, the original account itself is hard-deleted with all the remaining data it contains. The dummy account that holds the user's data should be flagged in some way as deleted, so that the profile links will be disabled, the profile won't be accessible and it won't appear in any user lists.  The user receives a private code that can be used to claim ownership of the account. Other ways are not possible as all private information is removed about the account. This allows for an automatic way of reclaiming most of the important parts of a deleted account. The ability to restore a deleted account might have to be somewhat restricted to avoid misusing it to get rid of the account history. It is more meant as an additional safeguard so that account reconstruction is more easily possible in rare cases. Such additional safeguards might be necessary as the deletion itself would be automatic and without oversight from SE or moderators.   I personally think that the information which posts and votes were connected to a (now anonymized) account is not sensitive enough that it would have to be removed on account deletion. My idea is that this would be close enough to a hard-delete that it satisfies any privacy concerns, but still allow reassociation of posts with a recovered account. The partial reversibility would alleviate concerns about removing the manual oversight by mods and SE employees over the account deletion process.


I have a folder and it has some xls files of same format in it. I don't know number of files or their names. I want to merge all of them. So how would i know the names of those files dynamically so that i can write further logic to merge them.


Concatenating two variables with an underscore

I need to concatenate two variables to create a filename that has an underscore. Lets call my variables $FILENAME and $EXTENSION where filename is read from a file.  FILENAME=Hello EXTENSION=WORLD.txt   Now...  I have tried the following without success:  NAME=${FILENAME}_$EXTENSION NAME=${FILENAME}'_'$EXTENSION NAME=$FILENAME\\_$EXTENSION   I always get some kind of weird output. Usually the underscore first.  I need it to be  echo $NAME Hello_WORLD.txt


Remove the annoying comment auto-anchor links

I am noticing this behaviour since today only. When I post a new comment, the browser window is scrolled down to the comment I just added. Previously, this scroll-down behaviour was reset once the animation for new comment fade effect was finished.  The same happens when I click on show more comments button.  Is this a ninja feature being incorporated? If so, it is very annoying.


Does exception handling hurts the performance of code?

Does exception handling hurts the performance of the code in terms of execution speed? Does it have any drawback? What precautions one must take when using exception handling in code?


Selection from layer panel in Illustrator

Lets say I have selected a bunch of objects in the layer panel (as shown in the following capture), is there a way to select the corresponding path without having to click on each circle individually holding the command key?


Polynomial factors from sum of polynomials with known factors

Say I know the linear factors of polynomials A and B.  For instance, if they were cubic I could express them as A(x) = (ax + b)(cx + d)(ex + f) and B(x) = (gx + h)(ix + j)(kx + l).  Are there any circumstances under which I can take advantage of knowing these original factors if I want to compute the linear factors of the polynomial A + B?


If you roll 5 standard 6 sided dies, what's the probability that you will get at least three 2s?  I imagine it would be 1 - P(0 twos) - P(1 two) - P(2 twos), but I don't know how to calculate the probability of these.


In a circuit, if voltage is established at both terminals, then how can components use up this voltage?

Suppose we use a 9V battery.  Then the voltage between these two terminals is 9V. In other words, it would take 9 J of energy to move +1C of charge from the (+) to the (-) terminal by the electric field established by the battery.  So exactly how can electrical components "reduce" this voltage?  How can we say that the potential difference between a resistor connected to a battery is 9V?  This would obviously imply that the voltage would have to "move" in the circuit, such that right before the resistor, the potential is 9 V.  Then after the current passes the resistor, the potential at this point immediately after the resistor, it is somehow 0 V.  But this is wrong by definition, because it is +9V at the + terminal of the battery, and 0V at the - terminal of the battery.    I am confused?


Word for concept of degrees of definition

Is there a name for the concept that some words have different degrees of precision, and that misalignment or ambiguity over the intended precision easily leads to misunderstanding? Some examples, but please note that I'm not trying to be particularly accurate with these definitions, but instead offered for purpose of drawing the point that there are two senses with differing levels of precision, and this ambiguity of precision if not addressed could lead to confusion/argument.  In colloquial usage the word "chemical" generally refers to dangerous substances, more likely liquid, usually man-made, and differentiated from "natural"; while in scientific usage a "chemical" is pretty much anything made of atoms — arsenic is a naturally occuring chemical substance, as even is gold.   A scientific "theory" is more narrowly defined than the colloquial usage, and particularly so as with a conspiracy "theory".   Today, armour scholars define "mail" as it was defined in the Middle Ages — consisting of a "fabric" of interlocked metal rings that form a strong, flexible, mesh armour. (The word "mail" being derived through the Old English mayle, the French maille, and Italian maglia, from the Latin macula, which refers to the mesh of a net). This definition of mail was not the one used by Victorian scholars though. They used the word in a more general sense — to describe any sort of metallic body armour (i.e. "mail" is "armour", and thus a need to invent the term "chain mail"). [cribbed from ]  So, similar to how a synecdoche refers to parts/whole of a thing, but different in that here the differentiation is by precision. Also,  polysemy is too broad, as it encompasses any alternatives of definition and not specifically two senses which are similar in topic/direction but otherwise disagree in terms of precision. (Doesn't have to be a single word)  Update: it would appear the closest sense has to do with Semantic Broadening and Semantic Narrowing.


When I connect to my server (ubuntu server 10.10), I get this:  name@server-name.belkin ~>   How can I remove ".belkin"?


Reviewing a question on Stackoverflow and reputation

Recently I could check it that the minimum reputation for reviewing - review first question/answer has been increased to 500.  Is there any hard thumb rule that defines the relevancy of reputation with review.


Understanding what a differential is (Why can physicists multiply both sides by dx?)

I've just finished my first semi-rigorous run through single variable calculus, where I tried proving most of the results using epsilon-delta proofs. I'm just not sure that I'm understanding the meaning of differentials properly. I learned that the derivative with respect to a variable was an operator, meaning it 'took in' a function and 'outputted' a function that has a value of $\lim_{h\to 0} \frac{f(x+h)-f(x)}{h}$ at all values of x where $f$ is differentiable. Based on this definition, $\frac{dy}{dx}$ is a function of x. I also learned that when integrating or finding the antiderivative with respect to x, the dx within the integral represented the infinitely small width of an interval in a partition of a Darboux or Reimann sum. When solving differential equations with separation of variables or integrating using u-substitution, I've seen people say things like 'multiply both sides by dx' or 'bring dt to the other side',  especially in physics. This doesn't sound right, because I'm not sure how multiplying a function ($\frac{dy}{dx}$) by an infinitesimal (dx) gives another infinitesimal. So I'm wondering if this is this just a notational shortcut for the chain rule, or saying things like $\frac{dy}{dx} dx = dy$ has some mathematical meaning.


"Notable questions" badge page and search report different numbers for questions with 2.5K views

On Travel-SE, there are currently  awarded. However, when one uses the search interface with views:2500, . The two numbers should be equal, and it's difficult to explain the difference with caching issues.   As the number of views is ever-increasing (as we all know, it's impossible to un-see things, unfortunately), this seems like a bug. Or perhaps I'm doing something wrong?  Also, some questions which should qualify don't appear on the search page. See , for example.  None of these questions are closed or deleted: views:2500 closed:yes and views:2500 deleted:yes return 0 results.  Eeeek?


Switch between the keyboard layouts of the Xserver/xorg?

I had added up English(US), Belgian(alternative), Tamil Keyboard layouts using the GUI.  How do I easily switch between these three layouts from terminal?


Is it possible to make these changes with one reflow?

I've been reading some guides and results that google throws at me but I am still not sure how to go about to reduce the following changes to one single reflow.  var el1 = document.getElementById("one"); var el2 = document.getElementById("two"); var el3 = document.getElementById("three"); var variable1 = getSomeDynamicValue();  function doChanges() {   el1.style.cssText = "width: " + variable1 + "px;";   el2.style.cssText = "top:50px; left: 50px; position: fixed;";   el3.style.cssText = ""; }  doChanges();   As I understand, cssText causes a reflow, so with this code there will be three reflows? Or does it depend on other circumstances?  Edit: The articles and similar post's don't really give a definitive answer to  my question. Is it possible? Which is the method?


Trying to network mount a new exfat 6Tb hard drive for network windows 10 access, all instructions tried but still 'no such file or directory' error

I've looked at all previous posts and tried many suggestions/things, but I still can't mount my new hard drive to enable network access (via smb and for windows 10). Basically this is for my windows computers to use as backup location. I've tried a ton of different fstab stuff and all I ever get is this error: mount error(2): No such file or directory here is my fstab entries for this drive (the drive mounts locally no problem I can transfer files). UUID=BEE3-E4B0 /media/abemd/Ububak01   auto nosuid,nodev,nofail,x-gvfs-show 0 0  //192.168.0.107/share /media/abemd/Ububak01 cifs credentials=/home/abemd/.smbcredentials,iocharset=utf8,gid=1000,uid=1000,file_mode=0777,dir_mode=0777 0 0  I have made a proper .smbcredentials file and chmod 600 as others suggested. Of course I have latest cifs and samba installed. Ubuntu version 20.04 lts. I've been trying to figure this out for a week now and sheesh!! I've done this before no problem, I feel like I'm missing something obvious and stupid. It's driving me crazy. Thanks for any help. p.s. here is the result of 'mount' for this drive: /dev/sdc on /media/abemd/Ububak01 type fuseblk (rw,nosuid,nodev,relatime,user_id=0,group_id=0,default_permissions,allow_other,blksize=4096,x-gvfs-show)


\documentclass[letterpaper]{article}  \usepackage[T1]{fontenc} \usepackage[sc,osf]{mathpazo}  \begin{document}  How do I type ® under mathpazo?  \end{document}   This piece of code interprets    I thought it was about encoding, so I make \usepackage[T1]{fontenc} to \usepackage[utf8]{inputenc}:  \documentclass[letterpaper]{article}  \usepackage[utf8]{inputenc} \usepackage[sc,osf]{mathpazo}  \begin{document}  How do I type ® under mathpazo?  \end{document}   I get nothing:    I would like to have the number, alphabet and equation under mathpazo but how do I type special character like ®? Do we have encoding other than fontenc and inputenc?


I'm working on a site that has been hacked through SQL Injection (at first glance only db entries are corrupted with cross-site scripting) the potential vulnerability I found after looking at the code is that there's a lot of mysql_query call whose inputs are not escaped at all.  The good old :  $query = "SELECT * FROM mytable where name LIKE '%".$_GET['name']."%'"; /*HACK HERE*/ mysql_query($query, $connection);   Nevertheless I can't find how can we do something cool from that injection vulnerability (by cool I mean something like an INSERT or an UPDATE). I've tried to build a statement like this one :  SELECT * FROM mytable where name LIKE '%' AND WHERE id IN (INSERT INTO secondtable (id,description) VALUES (15, 'Fifteenth description');--%'   No success. I guess that the INSERT has nothing to do here.  I'm escaping all user's inputs in the code right now but I've not really get how hackers have penetrated this site, then I'm not 100% sure that my fix will do the job. Any brilliant suggestions ?  Thanks


Show that $Y_1$ and $Y_2$ are independent $N(0, 1)$-distributed random variables.

The random variables $X_1$ and $X_2$ are independent and $\mathcal N(0, 1)$-distributed.     Set     $$Y_1=\frac{X_1^2-X_2^2}{\sqrt{X_1^2+X_2^2}} $$ and      $$Y_2=\frac{2X_1\cdot X_2}{\sqrt{X_1^2+X_2^2}} $$         I want to show that $Y_1$ and $Y_2$ are independent $\mathcal N(0, 1)$-distributed random variables.    My idea was to define $X_1$ and $X_2$ as functions of $Y_1$ and $Y_2$, find the Jacobian and use the fact that we know the joint distribution of $(X_1,X_2)$ to find $f_{Y_1,Y_2}$. If the density $f_{Y_1,Y_2}$ turns out to be multivariate normal with a covariance matrix being diagonal (uncorrelated), then we know that $Y_1$ and $Y_2$ are independent and normally distributed. Am I correct?  If yes, then I need help finding the Jacobian. I have a hard time defining $X_1$ and $X_2$ as functions of $Y_1$ and $Y_2$ and dealing with the fact that the transformation has to be bijective.   And of course, any other approach would be appreciated as well. Thanks


I have installed windows 8, and I need to get updated drivers for my HP2311x.   Oddly, there are two very different product support pages at hp.com for this model number:    and     ...though the pictures of a monitor on each page look identical (and just like my monitor, of course.)  Could these be actually the same product?? If not, how can I tell whether I have an LED, or an LED backlit LCD monitor. I bought this quite a long time ago; the packaging and receipt are gone.


I have installed Ubuntu 17.10 on my machine yesterday.  It had a launch bar/dock at the left of the screen yesterday. But not remembering what I had done yesterday, I somehow realized that I made dock disappear.  It now looks like in the screenshots:      How will I bring Ubuntu dock back to actual desktop?


How much more net energy do I use walking up hill?

I have a question regarding work done / energy done. Say a $70\mathrm{kg}$ man walked $100\mathrm{m}$ on a horizontal surface as a constant speed, is it correct to assume the energy done by this man would be: $$\text{Energy} = \text{force}\cdot\text{distance}=70\cdot9.81\cdot100=68,670\text{ joules}$$ Where the force is just the weight of the man. Then say he walks another $100\mathrm{m}$, but this time he ascends $10\mathrm{m}$ and descends $10\mathrm{m}$ during the walk. To calculate the energy would you then have to add in energy done against gravity, so: $$\text{Total energy}=(\text{force}\cdot\text{distance})+(m\cdot g\cdot h)=(70\cdot9.81\cdot100)+(70\cdot9.81\cdot10)=86,670+6,867=75,537\text{ joules}$$


Total space of a finite rank locally free sheaf, Vakil's 17.1.4 & 17.1.G

If $X$ is a scheme and $\mathcal{F}$ is a locally free sheaf of rank $n$, then in Vakil's book the total space of $\mathcal{F}$ is defined to be $Spec(\text{Sym}^\bullet \mathcal{F}^\vee)$, the relative spectrum of the sheaf of algebras. The total space is a rank $n$ vector bundle, which is easy to see, just take any open subset $U$ such that $\mathcal{F}|_U$ is trivial, then we have  \begin{equation} Spec(\text{Sym}^\bullet \mathcal{F}^\vee|_U) \cong \mathbb{A}_U^n \end{equation}  In Ex. 17.1.G, it claims that $\mathcal{F}$ is isomorphic to the sheaf of sections of the total space $Spec(\text{Sym}^\bullet \mathcal{F}^\vee)$. It is easy to see that the sections of $Spec(\text{Sym}^\bullet \mathcal{F}^\vee)$ on $U$ is isomorphic to $\mathcal{O}_U^n$, i.e. when $U$ is affine, say $U=\text{Spec}(A)$, then we have $\text{Sym}^\bullet \mathcal{F}^\vee|_U \cong A[x_1,\cdots,x_n]$ and the sections is in one to  one bijection with the $A$-map $A[x_1,\cdots,x_n] \rightarrow A$, which is determined by the values of $x_i$, thus it is isomorphic to $A^n$.   However, I could not show the transition functions are actually the same. If the transition functions for $\mathcal{F}$ is $T_{ij}$ with respect to the affine open cover $U_i$, then the transition function for $\mathcal{F}^\vee$ is $(T_{ij}^t)^{-1}$, the inverse of transpose. It seems to me that the transition function for the vector bundle $Spec(\text{Sym}^\bullet \mathcal{F}^\vee)$ is actually $(T_{ij}^t)^{-1}$. How could the transition function for the sheaf of its sections be the same as that of $\mathcal{F}$, i.e. $T_{ij}$?


Adding a line to Windows hosts file: PermissionError: [Errno 13] Permission denied

I would like to add a line in my Windows hosts file via Python with this code:  fh = open("C:\Windows\System32\drivers\etc\hello.txt", "w") fh.write("new line") fh.close()   But I get this error:  PermissionError: [Errno 13] Permission denied: 'C:\\Windows\\System32\\drivers\\etc\\hello.txt'  It doesn't work even if my antivirus is disabled.  I don't know how to write a file as an administrator on a Windows machine.


Why do I get "I don't deserve this" when attempting to relocate?

I finished the mission where Lilly's little brother takes me to all of these bases, and so I tried to relocate. However it says 'I don't deserve this'   Why does it say that and how can I relocate then?


Is it acceptable to write: A person can develop their talent. or a person can develop their uniqueness?  In this case the person is used as a general term, not a specific person.


Taxonomy of statistical methods and bayesian techniques

I was wondering if there was a document or a website that shows how statsitical techniques relate to each other and when to use each of them. I'm an engineer and every time I need to use a certain model (for bayesian inference for example), I have to go throw a lot of papers and websites to find what really applies to my problem. Should I use Conditional random fields, Deep Gaussian processes, recursive bayesian models, ... ?  A statistician might know his way around these techniques and instantly know what to use, but I don't seem to find a book or a website that translates the "math" in simpler terms, something like : if you have this stuation, you should use this model (don't get me wrong I love a good model and I'm ready to go through its details if necessary), but for someone who has basic understanding of PCA, factor analysis and LDA, going through methods like CRF, GP, HMM, .. without knowing if it's really what's you're looking for can be really tiring ..   So back to my question, I would like to know if there was some kind of "taxonomy" of statistical tools (something like this ()) but for statistical analysis, inference and bayesian models not for machine learning.   Any suggestion is much appreciated.  Thanks for all of you !


If someone from the royal family was to inherit the Founding Titan, then the predecessors' and future successors' memories would transfer to him/her as well.   But,     Eren's father steals the Founding Titan and then passes it down to Eren.   So, are the memories gone? Or will they come back if a true member of the royal family      retrieves the Founding Titan back?


Create my own high-gluten flour by mixing vital wheat gluten and bread/AP flour?

Has anyone had success with giving their bread or all-purpose flour an extra gluten kick by adding vital wheat gluten?  I would like to know what ratio to mix the the two ingredients with, or perhaps some hints at a formula that can help me accomplish this, assuming it is feasible (i.e. mixing will produce a close substitute for high-gluten flour).  I'm also interested in any quality differences with this mixed approach vs. just using high-gluten flour in recipes.  You can assume I'm using King Arthur bread flour and King Arthur vital wheat gluten (or analogously King Arthur AP flour and vital wheat gluten), and that I'll be baking bread with the flours.  Note: this related question () mentions mixing, but doesn't go into details on ratios, etc.


Many people refer to Android versions by "codenames" rather than version numbers (e.g. Android "Gingerbread"). What are the names of the various versions of the Android OS, and how are these names chosen?


Saving project with data source path as relative in QGIS?

Is there an option in QGIS to save the project with the data source being a relative path?  I don't see the option here. QGIS Wroclaw1.7.3


My camera will not follow the object it is constrained to

I have a camera here that is constrained to look at an empty object. It is also following along a path. I have follow unchecked on the path but when the camera reaches a turn it flips on its side regardless if i'm using follow or not. I locked the Y rotation of it which didn't help one bit. Does anyone have any ideas what to do about this?     When it takes a shit ^^^^^


Cheese webcam app doesn't see webcam in 64-bit ubuntu 16.04

When I run the  app it shows nothing (see below) instead of picture from my webcam.    However guvcview (a webcam viewer app) recognizes my webcam and I see the picture from it.


Text to Speech shortcuts with two languages

I use Mac's Text to Speech function a lot. Under Settings > Speech > Text to Speech I also have set a "Key" for quick access.   Since I also want Text to Speech to read German and OS Lion offers Voices for other languages, I would like to have a second shortcut for German.   Does anyone know where I can set this? Or is the only way to constantly change the System Voice before I want a German text to be read? (And then reset the voice to Alex for English texts)? And what about French text?   What options exist for this general problem?


Is the proof of the following exercise correct?     Let $(X,\tau)$ be a connected topological space, $Y\subset X$ connected and $U\subset X\setminus Y$ clopen. Prove that $ Y \cup U$ is connected.   Proof  As $Y$ is connected, $X\setminus Y$ is still connected.  As $U\subset X\setminus Y$ is clopen and $X$ is connected (there is only one clopen set, namely $X$), we must have this $U=X$.  And finally $Y\cup U=Y\cup X=X$ is connected.


How does one attack a two-time pad (i.e. one time pad with key reuse)?

My question might appear the same as the question , but actually I did read all the answers and none of them helped me with the details I need.  I am new to cryptography and my problem is with two time pad attacks on OTP. The problem I had in my course was that I have 10 ciphertexts encrypted with the same key $K$. I am then given another ciphertext that I should decrypt.  I know that XOR-ing two ciphers gives me the XOR of their original messages.  My question is what is the correct thing to do after that?  I tried to take 3 ciphertexts $C_1, C_2$ and $C_3$.  Then get $S_1 = C_1 \oplus C_2  \oplus $' ', also get $S_2 = C_1 \oplus C_3 \oplus$ ' '.  After that I compared all corresponding characters in $S_1$ and $S_2$,  and if $S_1[i] = S_2[i]$ then I calculate $S_1[i] \oplus C_2[i]$ to get $K[i]$.  I tried this on paper before coding and it worked, but I might be missing something.  Is this the right approach? Why does it work?


Getting java.lang.NullPointerException while entering data into database in jsp using ojdbc

I am trying to register new users to my database using jsp. When i do i get this error java.lang.NullPointerException   From this page i enter the variable to the database  <%@page import="storage.data"%> <%             String ps="";             String v_name="";                v_name =request.getParameter("vname");              ps=request.getParameter("pass");               data dt=new data();                 out.println(v_name + ps);                 try{                      dt.st=dt.cn.createStatement();                     out.println("1");                     String insert="insert into voters values(myseq_voters.nextval,'"+v_name+"','"+ps+"',sysdate)";                     out.println("2");                     dt.st.executeUpdate(insert);                     out.println("3");                         //response.sendRedirect("adduser.jsp?usad="+1);                 }                 catch(Exception ex){                 out.println(ex);                 } %>   And this is my code to connect it to the database  package storage; import java.sql.*;   public class data {          public Connection cn;         public Statement st;         public ResultSet rs;          public data()         {             try{                  Class.forName("oracle.jdbc.OracleDriver");                 //cn=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:XE","mustafadb","111");                 //jdbc:oracle:thin:@localhost:1521:XE [system on Default schema]                 cn=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:XE","voter_db","111");             }             catch(Exception ex){}         } }


In  (2017), Logan seems to be dying from sort sort of ailment, that prevents him to heal properly and seems to be decaying his body in a way that wasn't happening in any of the other films his character appears in.  I don't recall that this is being explained in the film. The Wikipedia page only mentions "adamantium poisoning" and "his healing factor fading", but it is not backed up with citations, so I would love to get an in-depth answer for this question, maybe using excerpts from the comic or original source material.  What is happening to Logan?


Is there a way to call a function in another Python module without explicitly stating the function name?

I'm designing a program in Python to handle the calculation of key performance indicators (KPIs) for an industrial application. The results are calculated from raw process data, which in the program is stored in a NumPy matrix.  I wanted to keep the actual calculation procedures separate from the main program, which handles the other heavy lifting, like fetching the relevant raw data. There are multiple real-life "units" for which the KPIs can be calculated, so each of them has their own Python file containing the specific implementations of the KPIs. A for-loop in the main program module calculates all the KPIs for all the units in succession.  So what I do is as follows:  1) Import the calculation file for the unit under calculation this round:  print("Importing calculation module '{}.py'...".format(file_name)) try:     module = __import__(file_name) except ImportError:     status = "Error: no plant file defined." else:     print("Done.")   2) Pass the imported module to a function, which determines, which KPI function to call in the module:  def CalculateKPI(KPIToCalculate, raw_data, kpi_module):      status = ""     kpi_result = []      not_defined = "Error: Calculation method not defined for this KPI."      print("Calculating KPI values... ")      if(KPIToCalculate == "SupportFuelUsage"):         try:             kpi_result, status = kpi_module.SupportFuelUsage(raw_data)         except AttributeError:             status = not_defined     elif(KPIToCalculate == "Lambda"):         try:             kpi_result, status = kpi_module.Lambda(raw_data)         except AttributeError:             status = not_defined     elif(KPIToCalculate == "PrimaryAirRatio"):         try:             kpi_result, status = kpi_module.PrimaryAirRatio(raw_data)         except AttributeError:             status = not_defined      ... As many ELIF forks as there are possible KPIs, close to 200      else:         status = "Error: Function CalculateKPI does not contain if-statement for this KPI."         return kpi_result, status      print("Done.")      return kpi_result, status   It does work. However, this seems like a very bulky and crude way of doing this, and in the long term will likely be a nightmare to manage.  So basically, what I'm asking is: is there any way of determining the function to call in the module based on the variable "KPIToCalculate" alone, and not have to list each possible function separately?


My cycle seems to have this problem, that whenever I change the gear it starts changing from the second sprocket.  Whenever I start from gear one it starts from the second biggest sprocket, though it goes up to the smallest sprocket (6th one) it doesn’t climb back to the first biggest sprocket ever.   What's the issue with it?  The bike is a new one (~5 months). Since I brought it and I am facing the same issue ever since.  Is it really an issue, or is everything fine?   Thank you.


I know that operators in quantum mechanics act on states (kets, assumed to be normalized), and return another state. So, an operator such as $\hat{p}$ when acted on a ket $|\psi\rangle$ will give me another ket $|\phi\rangle$. Thus, $$\hat{p}|\psi\rangle = |\phi\rangle.\tag{1}\label1$$ Also, $\langle x|\psi\rangle =\psi(x)$ if $x$ is the position. Now, since $\psi(x)$ is a complex number, what I don't understand is how can the operator $\hat{p}$ cat on $\psi(x)$? How does the expression $\hat{p}\psi(x)$ make sense if $\psi(x)$ does not lie in the domain of the operator/function $\hat{p}$? And how does $\hat{p}\psi(x) =\langle x|\hat{p}|\psi\rangle$?


My quetion is - how I can enter "new line" symbol using android voice input? For example I tyr to create shopping list using Evernote and voice, but to create new item in list I must switch to keybord, and press enter. How to do that using only my voice?


What settings, especially shutter speed, should I use for stage performances?

In particular, lower light.  I will be shooting plays and other stage performances.  Low light.  Really not good light at all until their lights are upgraded.  I know I can't expect miracles, but how can I calculate what shutter speed to use to stop the subjects?  I can't see good enough to tell if the subject is blurred on the LCD screen.  Everything looks good on a screen that small.  I'm thinking of buying a Nikon D90, if that matters.  Don't know what ISO I'd need.  The subjects will be from 15 - 40 feet away, but mostly 15 - 20.  I cannot use flash.  Lens will be 1.8 - 2.8 (either a prime or a Tamron zoom).  Typically children, but some are older high school kids.  I don't know how far I need to be or what focal length is needed at a give distance to fill the frame with a 6'tall person.  Those are all the variables I know.  Thanks for any advice.


Relatively prime integers and order of an integer

Let $a$ and $n$ be natural numbers with $(a,n)=1$. Then there exists a natural number $k$ such that $a^k≡1 \pmod n$.  I am using Number Theory Through Inquiry which does not offer much in the way of help solving theorems. The previous theorems are meant to set up proofs for the ones that follow, but I can't quite get this one.


How to add separate "list of symbols" when "list of abbreviations" is already produced by glossaries?

My University's dissertation class uses glossaries to produces a "LIST OF ABBREVIATIONS". I want to use it to produce a second list, a simple "LIST OF SYMBOLS".  Can this be done with glossaries? How to do it?    Here is how my current jumble of latex files uses glossaries. First, the .cls file includes a \RequirePackage[nonumberlist, nopostdot]{glossaries}. Then, I add some lines to the preamble of the main.tex file:  \newacronym{fpga}{FPGA}{Field-Programmable Gate Array} \newacronym{lqr}{LQR}{Linear Quadratic Regulator}   Then when I use \gls{fpga} and \gls{lqr} in my document, it does a fantastic job of inserting text and generating a list of abbreviations.  After digging through my jumble of files, I found that main.tex calls lists.tex which has the following code:  \phantomsection \addcontentsline{toc}{chapter}{LIST OF ABBREVIATIONS} \begingroup \pagestyle{loastyle} \makeatletter \let\ps@plain\ps@normal \makeatother \vspace{0.07in} \printglossary[style=grizz_glossary] \addtolength{\textheight}{0.85in} \newpage \endgroup   It then goes back to .cls with this:  % Glossary \newglossarystyle{grizz_glossary}{ \renewcommand{\glossaryname}{\vspace*{0.2in}LIST OF ABBREVIATIONS}  % put the glossary in the tabular environment:    \renewenvironment{theglossary}%      {\noindent\begin{longtable}{p{1.13in}p{4.37in}}}{\end{longtable}}%    % have nothing after \begin{theglossary}:    \renewcommand*{\glossaryheader}{}%    % have nothing between glossary groups:    \renewcommand*{\glsgroupheading}[1]{}%    \renewcommand*{\glsgroupskip}{}%     \renewcommand*{\glossaryentryfield}[5]{           \glstarget{##1}{##2}\hfill & ##3\hfill \vspace{12pt}\\  }    }   I also need to run some perl, with the command makeglossaries main to get this to generate right.  What do I need to change? The documentation for glossaries is super involved, and some hints would help.  Related questions:   seems related but is very complicated, and requires hyperlinks.   is close, but different enough that I don't know what to do.  Edit:  As suggested by @EladDen in the comments,  provides some valuable clues, but it is far too complicated. A good answer there is integrated and produces two lists from one set of data. I want to produce two separate lists from two separate data sets.  Spectifically, the "List of Abbreviations" will look like this:  FPGA    Field-Programmable Gate Array LQR     Linear Quadratic Regulator  Whereas the "list of symbols" will look like this:  m       Mass F       Force a       Acceleration  Again, I want to emphasize that they will come from a completely difference dataset. Perhaps there is a command \newsymbol in glossaries?


How to prove that distance between two neighboring primes can be arbitrarily large? Thanks for help, John


How to trick a particular command into thinking it is a different date?

How can I execute a command making it believe that is on a different date than system one?  For instance, if I have this script:  #!/usr/bin/env bash     date +"%B %d, %Y"   It prints the actual date: march 13, 2014   But I would like it to print a different date, on the future or past, without changing the system date.  If I wasn't clear enough, I want a command line tool like .    I do not want to use a different script (it was just an example). I do not want to set a cronjob. I do not want to change my general system date. Only change the date that apply to the command to run.


Prevent RegExpt from returning matched string that is not between parenthesis

I want to match all the emails that are after the text "Email: "  However, when using match, the matches return the whole string: Email: demo@example.com.  Isn't there a way to just return the text matched by the parenthesis within the regular expression? (.*?) I just want to get the email address: demo@example.com  This is what I got so far:  var regex = new RegExp('E-mail:\\s(.*?)
', 'mg'); var matches = document.body.innerHTML.match(regex);   And yeap, I know using exec on a loop can retrieve on an array just the email. But I would have to manually create the loop and get what I want:  var regex = new RegExp('E-mail:\\s(.*?)
', 'mg'); var allMatches = []; while( matches = regex.exec(document.body.innerHTML)){     allMatches.push(matches[1]); } console.log(allMatches);


Textures and colors not imported from OBJ file when using Cycles render

I'm trying to import a bunch of models from OBJ files (with their MTL files) to a blender scene that I have. When using Blender Render the materials and textures are imported successfully. But when using Cycles Render the material names are imported, but not their actual data.  This behavior is also noted by   Is there a workaround for this? I prefer to use Cycles for my rendering (for using GPU devices, and node control).


hillshade and slopeshade geotiffs fail to convert to new projection using gdalwarp

I'm trying to convert my three DEM products (colour, hillshade and slopeshade; the latter two generated using gdaldem) from EPSG:4326 -> EPSG:3857 using gdalwarp, via the command:  gdalwarp -of GTiff -s_srs epsg:4326 -t_srs epsg:3857 -co "tfw=yes" {src} {dst}   This works fine for the colour geotiff, but the resulting hillshade and slopeshade geotiffs now appear blank.  Sample output from gdalinfo for the slopeshade geotiff is below, with links to the original and converted files at the bottom.  gdalinfo before:  Driver: GTiff/GeoTIFF Files: slopeshade_dem.tif Size is 4557, 3577 Coordinate System is: GEOGCS["WGS 84",     DATUM["WGS_1984",         SPHEROID["WGS 84",6378137,298.257223563,             AUTHORITY["EPSG","7030"]],         AUTHORITY["EPSG","6326"]],     PRIMEM["Greenwich",0],     UNIT["degree",0.0174532925199433],     AUTHORITY["EPSG","4326"]] Origin = (-121.460761599999998,38.583444700000001) Pixel Size = (0.000000654597323,-0.000000654598826) Metadata:   AREA_OR_POINT=Area Image Structure Metadata:   INTERLEAVE=PIXEL Corner Coordinates: Upper Left  (-121.4607616,  38.5834447) (121d27'38.74"W, 38d35' 0.40"N) Lower Left  (-121.4607616,  38.5811032) (121d27'38.74"W, 38d34'51.97"N) Upper Right (-121.4577786,  38.5834447) (121d27'28.00"W, 38d35' 0.40"N) Lower Right (-121.4577786,  38.5811032) (121d27'28.00"W, 38d34'51.97"N) Center      (-121.4592701,  38.5822740) (121d27'33.37"W, 38d34'56.19"N) Band 1 Block=4557x1 Type=Byte, ColorInterp=Gray   Mask Flags: PER_DATASET ALPHA  Band 2 Block=4557x1 Type=Byte, ColorInterp=Alpha   gdalinfo after:  Driver: GTiff/GeoTIFF Files: slopeshade_dem.tif Size is 4088, 4105 Coordinate System is: PROJCS["WGS 84 / Pseudo-Mercator",     GEOGCS["WGS 84",         DATUM["WGS_1984",             SPHEROID["WGS 84",6378137,298.257223563,                 AUTHORITY["EPSG","7030"]],             AUTHORITY["EPSG","6326"]],         PRIMEM["Greenwich",0],         UNIT["degree",0.0174532925199433],         AUTHORITY["EPSG","4326"]],     PROJECTION["Mercator_1SP"],     PARAMETER["central_meridian",0],     PARAMETER["scale_factor",1],     PARAMETER["false_easting",0],     PARAMETER["false_northing",0],     UNIT["metre",1,         AUTHORITY["EPSG","9001"]],     EXTENSION["PROJ4","+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +wktext  +no_defs"],     AUTHORITY["EPSG","3857"]] Origin = (-13520950.132675198838115,4662178.034760829061270) Pixel Size = (0.081230547006284,-0.081230547006284) Metadata:   AREA_OR_POINT=Area Image Structure Metadata:   INTERLEAVE=PIXEL Corner Coordinates: Upper Left  (-13520950.133, 4662178.035) (121d27'38.74"W, 38d35' 0.40"N) Lower Left  (-13520950.133, 4661844.583) (121d27'38.74"W, 38d34'51.97"N) Upper Right (-13520618.062, 4662178.035) (121d27'28.00"W, 38d35' 0.40"N) Lower Right (-13520618.062, 4661844.583) (121d27'28.00"W, 38d34'51.97"N) Center      (-13520784.097, 4662011.309) (121d27'33.37"W, 38d34'56.19"N) Band 1 Block=4088x1 Type=Byte, ColorInterp=Gray Band 2 Block=4088x1 Type=Byte, ColorInterp=Undefined   Links to the slopeshade file before conversion (in EPSG:4326):    Links to the slopeshade file after conversion (in EPSG:3857):


Zooming to selection in arcpy.mapping and only seeing selected features?

I selected data by using select layer by attribute, then I need to only select these selection and zoom in to the selection.  my code is this, it can zoom in base on the scale I set, but I see other adjacent polygon that has other Code_No, why?  Layer = arcpy.mapping.ListLayers(mxd, "lyr", df)        arcpy.SelectLayerByAttribute_management(lyr, "NEW_SELECTION", "Code_NO = '%s'"%mycodeNo)            df.extent = lyrLayer1.getSelectedExtent() df.scale *= 2


A problem of a discrete group of smooth isometries acting discontinuously on a smooth manifold.

Suppose that a smooth manifold $M$ is a metric space and that $\Gamma$ is a discrete group of smooth isometries acting discontinuously on $M$. Show that the action is necessarily properly discontinuous.   Discontinuous means: each $x \in M$ has a neighborhood $U$ such that $\{h \in \Gamma ; hU \cap U \neq \emptyset\}$ is finite.  And properly discontinuous means both discontinuous and if $x,y \in M$ are not in the same orbit, then there are neighborhoods $U, V$ of $x,y$ such that $U \cap \Gamma V = \emptyset$.  Anyone can solve this problem? Thanks.


None of the objects I'm working with have a stroke on them, however all of them display an outline that shows up through other objects in illustrator. It looks as though I'm in preview mode with colors turned on? I can't figure out how to turn this setting off, help!


How to make a textbox that only accepts number and decimal points in c#?

How to make a textbox that only accepts number and decimal points in c# ?  looking for something very simple if anyone knows please help !


Every well-ordered set is isomorphic to a unique ordinal

I'm following a proof in Jech's book that every well ordered set is isomorphic to a unique ordinal and hitting a point where I'm not sure why a certain move is justified. He writes      Proof. The uniqueness follows from Lemma 2.7. Given a well-ordered set $W$,    we find an isomorphic ordinal as follows: Define $F(x) = \alpha$ if $\alpha$ is isomorphic    to the initial segment of $W$ given by $x$. If such an $\alpha$ exists, then it is unique.    By the Replacement Axioms, $ F(W) $ is a set. For each $x \in W$, such an $\alpha$ exists (otherwise consider the least $x$ for which such an $\alpha$ does not exist). If $\gamma$ is the least $\gamma \not\in F(W)$ then $F(W) =\gamma$ and we have an isomorphism of $W$ onto $\gamma$.   I've filled in all the details of this proof for myself up to the point where he assumes the class of ordinals not in the image of the function has a least element. Since this isn't a set, I'm not sure what can justify this. I could try to prove that every nonempty class of ordinals has a least element but that seems so substantial that it's hard to imagine it was a detail intentionally omitted. Am I missing something simple?


Simple poisson regression for a death rate

I am trying to regress the death rate for a particular cause of death for 25-30 year olds. My dependent variable of interest is the crude rate, i.e., y = number of deaths of 25-30 year olds/number of people 25-30 year old in a county. If I were to run this as a Poisson regression, would I run this on the count of deaths of 25-30 year olds (the numerator) on my regressors, and include the log of the denominator (number of people 25-30) as a regressor as an offset? Is the idea thinking of the link function, let deaths = number of  25-30 year olds dying from the cause, and n = the number of 25-30 year olds \begin{align}  \newcommand{\deaths}{{\rm deaths}} \frac{\deaths}{n} &= e^{x'\beta}  \\[5pt] \deaths   &= ne^{x'\beta}  \\[5pt] \deaths   &= e^{x'\beta + \ln(n)} \end{align} and this last equation is Poisson link function?


I have searched and find this:  In classical logic, why is $(p \Rightarrow q) = T$ if $p = F$ and $q = F$?  Is the only way to prove that is not  a tautology by having $T \to F$, which gives $F$?


Example of Riemann integrable $f: [0,1] \to \mathbb R $ whose set of discontinuity points is an uncountable and dense set in $[0,1]$

Give example of a function $f:  [0,1] \to \mathbb R $ which is integrable ( Lebesgue or Riemann , if possible , both) but whose set of discontinuity points is  an uncountable set and dense in $[0,1]$ ?


set theoretic function, products of sets (product versus Cartesian product)

Regarding the products of functions in axiomatic set theory, two textbooks which I am reading (Halmos; Hrbacek/Jech) have said the following:   "There is a natural one-to-one correspondence between [the Cartesian product] and a certain set of families. Consider, indeed, any particular unordered pair $\{a,b\}$, with $ a\neq b$, and consider the set $Z$ of all families $z$, indexed by $\{a,b\}$ such that $z_a \in X$ and $z_b \in Y$. If the function $f$ from $Z$ to $X \times Y$ is defined by $f(z) = (z_a, z_b)$, then $f$ is the promised one-to-one correspondence. The difference between $Z$ and $X \times Y$ if merely a matter of notation."  Hrbacek/Jech said as much, but reversed the bijection: they considered   "...a canonical one-to-one correspondence between ordered pairs and 2-tuples that preserves first and second coordinates. Define $\delta((a_0, a_1)) = \{(0, a_0), (1, a_1)\}$; then $\delta$ is a one-to-one mapping on $A_0 \times A_1$ onto $\prod_{0\leq i<2} A_i$ and $x$ is a first (second, respectively) coordinate of $(a_0, a_1)$ iff $x$ is a first (second, respectively) coordinate of $\{(0, a_0),(1,a_1)\}$."   (I had to change their notation a bit: the function maps to 2-term sequences, with each term a "coordinate.")  This is my question: in Halmos' case, how did we order the coordinates? I can see how we could remove the second coordinates from each ordered pair in the family systematically (put $\beta = \{ \bigcup_{x \in \{z_i\}} ( \bigcup_{x \in (i,z_i)} (i,z_i) - \bigcap_{x \in (i,z_i)} (i,z_i)): (i,z_i) \in f \}$), but I do not see how to reorder them into a new pair which recovers the order of the Cartesian product, since the index set was unordered. I like the H/J version, but want to see it made invertible.


cannot change screen size from 640x480 after 14.04 installation on VirtualBox OSX

After installing Ubuntu 14.04 guest on VirtualBox running on a Max OSX host, I am stuck with 640x480 screen resolution. Adding guest additions again doesn't help. Previous Ubuntu installations are fine with bigger resolution. The 'Detect Displays' button on the 'Display Settings' Settings screen is not reachable, because 640x480 is too small. I could not find a /etc/X11/xorg.conf file to configure manually.


How do I cash a USD cheque in Europe, quickly?

I'll receive a USD cheque shortly. I prefered payment by money transfer, but all attempts to do so - i.e. SWIFT/IBAN, Payoneer, transferwise - failed. Now I will receive a cheque by mail.  I contacted my bank and they say that they can cash a cheque for me, given a (prob hefty) fee. The bank employee was so kind to warn me, that in case of a cheque the funds are cashed, but reserved until the legal reimbursement period ends, which apparently is between 3 and 6 months.   Is there really no quicker way to receive payments by cheque and have access to the funds quickly?


How can the following table be created in LaTeX

I have asked this question , and asking it once again, as it was marked as duplicate, although it is different from the links that were pointed to be the same as the question.  So, how can I create a table that looks like the following using LaTex?    Thanks.


I had an issue where every time I put my bike in gear 3, it would just keep "skipping". By this I mean that it wouldn't stay in gear 3; the chain would go onto it, then fall onto gear 4, then go back onto it, then back on 4.  Some Googling showed me that I might need to adjust the rear derailleur. So I set about doing this today by first putting my bike onto the biggest cog and adjusting it so the derailleur was in line with the cog. Then I shifted it down to the smallest one and did the same thing (I think I got a bit confused between this and changing the screws to line these two up with something).  Anyway, as luck would have it, this fixed the problem of the skipping however I now can't shift into gears one or two (the two biggest cogs). Like I literally can't flick down the gear lever to put it into these gears.  What could be the issue? I would love some advice.  Thanks


The  treatment of circular apertures yields a diffraction pattern of circles, with the first minimum (dark ring) at an angular radius of $\theta$ where $\sin(\theta)=1.22\lambda/b$, where $b$ is the diameter of the circular aperture.     But this same result is extrapolated to lenses, to calculate its limit of resolution. But in the case of lenses, there is no opaque material which blocks of the light coming out from everywhere except the aperture.      In the absence of this opaque obstacle, how can diffraction take place,   since according to the , the wavefront which would   produce the secondary wavelets still extends everywhere and not just   to a confined region, which is how the diffraction pattern arises, by   confining secondary sources to a finite region or confining it from an   "edge" till infinity?* In other words, Why does putting a circular lens in the path of plane wavefornt produce the same effect as allowing only a circular portion of that wavefront to propagate?      And even if there is diffraction, will the same formulae apply? will   not the presence of light elsewhere change the case?


Is there a way to create a Color ID map in Blender?

All of the most powerful texturing applications require a color ID map (Substance Designer, Substance Painter, Quixel DDO). I've been using a Maya plugin called Nightshade Blockout to export color maps for use in these programs. Nightshade may be one of the most-used plugins for texture artists abroad, simply because it's referred and linked by those giants.      I would hope it's as simple as assigning a material color and baking the texture, but it's safe to assume such a map wouldn't come with edge padding (extending the boundaries of each color island by a certain number of pixels, to hide seams during the texturing process).   If there is a Blender workflow/plugin for this, I would love to know about it!  Thanks for reading,  Allen


$25 w(w-1)y''+(14-15w)y'+y=0$ - Gauss's Hypergeometric equation

I would like to solve the equation $(x^2-x-6)y''+(5+3x)y'+y=0$ near the singular point $x=3$. I think we have to solve this problem in considering the Gauss's hypergeometric equation on the form $$x(1-x)y''+[c-(a+b+1)x]y'-aby=0.$$  I got $t(t-(-5))y''+(14+3t)y'+y=0$ with the change of variable $t=(x-3)$. Thereafter, with the appropriate change of variable $w=\frac{t-A}{B-A}=\frac{t}{-5}$, I obtain $25 w(w-1)y''+(14-15w)y'+y=0$, but how could solve this equation?


What's the runtime (in Big O notation) for Array reversal (java)?

What's the runtime (in Big O notation) for Array reversal for the below java code?  void reverse(int[] array){    for(int i=0;i<array.length/2;i++){      int other = array.length-i-1;      int temp = array[i];      array[i] = array[other];      array[other] = temp;    } }


How do I give Ubuntu more space (when installed inside Windows 7 (via wubi))?

I had installed Ubuntu inside Windows XP but then I formatted XP and installed Windows 7.   EDIT1: I used Wubi for the same. I want to know which one of the two will solve my problem? creating a virtual disk or resizing root? Also is resizing root possible as the 4GB ext4 partition is already in a NTFS format Hard Drive partition.  At the time of installation I had allocated only 4GB of space to Ubuntu. I want to increase that size as I keep getting a low disk space notification.   I have surfed through a lot of similar questions but this is not a duplicate.  Because I want to know a little about the file systems. In order to solve my problem,do I have to increase the size of root.disk? Or will it be solved by creating a virtual disk?  Also I want to know the difference between creating a virtual disk and just increasing disk space of root.I'm new to Ubuntu so I don't know how the file systems function.  EDIT2:I have created a virtual disk of 10gb ,but I'm still getting the same notification.Is there anyway to install all further applications on the virtual disk I created?


Updating HTML Without Removing Event Listeners

Here is the HTML part:
      More Details

Text Here

   When you click on More Details, the HTML changes to this:
      More Details

Text Here

   This happens because I use a script that includes this code (let's call it toggle-script for future reference):  $(".deploy-toggle-3").click(function() {     $(this).parent().find('.toggle-content').slideToggle(200);     $(this).find('em strong').toggleClass('toggle-3-active-ball');     $(this).find('em').toggleClass('toggle-3-active-background');     return false; });   So far so good. Now, for various reasons, I want to make an AJAX call and update the HTML. I do this using the following script:  function createHTML() {     let content =          '
 ' +         '
 ' +         ' {14} ' +         '  ' +         '
 ' +         '
{15}
 ' +         '
 ' +         '
 '     ;      return content.format(         // In here I replace the {14} and {15} with what I want     ); }  let my_content = createHTML();  $("#my-container").html(my_content);   While it does replace the HTML correctly, I have noticed that it removes the Event Listener from the More Details element. This means that, if you click on it, it does not run the toggle-script. Reading the JQuery DOC, I found this:     jQuery removes other constructs such as data and event handlers from   child elements before replacing those elements with the new content.   My temporary fix is to re-include the toggle-script after running the .html() function.  1) Can someone explain if what I described is the case indeed? Or what exactly is going on?  2) Is there a way to deal with this more effectively than my temporary solution? Ideally, a way to not remove the Event Listeners in the first place.   3) Is the way I am updating the HTML optimal? Is there a better way to do this and why?


Layer's resizing when I copy a layer to a different document? I don't want this to happen.

I am working on converting a large map into a booklet format.  I am making selections of 4 inches by 7 inches then copying them to make a new layer.  When I drag this new layer into a new document it is increasing in size.  How to I make the sizing consistent between layers?


Suppose that we have a commutative ring $R$ and an exact sequence of graded R-modules $$0\rightarrow M'\rightarrow M\rightarrow M''\rightarrow 0$$ It is true that we have an exact sequence of graded R-modules $$0\rightarrow\text{S}^{\bullet}(M')\rightarrow\text{S}^{\bullet}(M)\rightarrow\text{S}^{\bullet}(M'')\rightarrow 0$$ where $\text{S}^{\bullet}(-)$ denotes the symmetric algebra? Thank you for your time.


When someone's account is deleted, reputation is updated accordingly, and vote count is not updated everywhere

I tried looking up information about this and couldn't find anything, so I decided to post this. Basically, if you look over my profile on Personal Finance & Money Stack Exchange, you will notice that I have an answer with a given amount of upvotes, let's say N. And then, when you look at my profile from another community, on Meta for example, that same answer will appear in Top Network Posts with N+1 votes. It also shows N+1 when I check my Top Answers on the Stack Exchange network profile. The reason is because, at some point, I had received N+1 upvotes on that answer, and the account of one of them was deleted, as explained by the reputation change. It seemed to have updated everything, except these two places. I think the same would apply for downvotes too, but I don't want to make assumptions. Is this a known minor bug?


Format an external hard disk to FAT32, only option showing is NTFS

I am trying to format an external hard disk to FAT32 (I need it to work with some hardware that expects it to be in FAT32). When I am trying to format it via Windows the only option get is to format it to NTFS.  When I am trying to format one of my own partitions (on the hard disk that is running the OS) I can do it only in NTFS while another partition my OS can format in both NTFS and FAT32.  What can cause such a behavior and how can I format the external hard disk to FAT32?


Why teach linear algebra before abstract algebra?

Is there a reason why most undergraduate curriculums put linear algebra before abstract algebra?  I'm asking this because personally it seems to be much easier to understand the architecture behind linear algebra as supposed to simply solving problems after a course in abstract algebra.


I am looking for some help with the following question. How do I prove that the series  $\displaystyle  \sum_{n=1}^{\infty} \frac{n}{(n+1)!}$ converges, and then how would I find its sum?    I see that this series $a_n$ converges if the sequence of partial sums $s_n$ converges.  So $s_n = \frac{1}{2} + \frac{1}{3} + \frac{1}{8} + \frac{1}{30}+... + \frac{n}{(n+1)!}$  I see that $\lim\limits_{n\to\infty}\frac{n}{(n+1)!}= 0 $ as $(n+1)!$ approaches infinity faster than $n$


Why isn't Harry Potter punished for using magic outside of Hogwarts in Prisoner of Azkaban?

At the very start of the movie adaptation of Prisoner of Azkaban, Harry attempts the spell Lumos Maxima in his bedroom. He then inflates his Aunt Marge and makes her float in the air.  How come he is doing this outside of Hogwarts as an underage wizard? The Trace is clearly still on him!  I understand the quote by the Minister for Magic, Cornelius Fudge, "Oh, come now, Harry. The Ministry does not send people to Azkaban for blowing up their aunts." But isn't that pretty much saying that casting any smaller spell is something that an underage wizard or witch can get away with?


I have just installed gcc 4.7 from ppa repository. Ubuntu 12.04 already comes with 4.6. When I use command:  gcc --version   It tells me it is 4.6.3 to be exact.  I have no idea of how to launch the 4.7 compiler. In fact, I wouldn't mind erasing the former version and stay with 4.7 only (I guess that wouldn't be a problem).  How can I fix this?