Show that the polynomial $X^5 + X^3 + \bar{1}$ in $(\mathbb{Z}/2\mathbb{Z}[X])$ is irreducible

Show that the polynomial $X^5 + X^3 + \bar{1}$ in $(\mathbb{Z}/2\mathbb{Z})[X]$ is irreducible. (Hint: if it were reducible, it would either have a root or be of the form $g(X) \cdot h(x)$, where deg$g(X) = 2$ and deg$h(X) = 3$) Recall that $\bar{a}$ is shorthand for the coset $a + 2\mathbb{Z} \space $in$ \space (\mathbb{Z}/2\mathbb{Z})[X]$ (for any $a \in \mathbb{Z}$)  This question is worth $7$ marks out of a possible $75$, this is my solution..  $f(X) = X^5 + X^3 + \bar{1}$ is irreducible in $\mathbb{Z}/2\mathbb{Z}[X]$ iff it has no roots in $\mathbb{Z}/2\mathbb{Z}$. Since $f(\bar{0}) = \bar{1}$ and $f(\bar{1}) = \bar{1}$, it follows that $f(x)$ is irreducible in $\mathbb{Z}/2\mathbb{Z}[X]$.  Would this be a sufficient answer? am I missing something?


Cable modem ping times go to thousands of milliseconds after 10 minutes of use

I have a wireless router (NetGear WNDR4500) which has a wired connection to a cable modem (Thompson DCM275).   My connection to the wireless router seems to be working fine and the traceroute and ping times are quite fast. But the connection from the wireless router to the cable modem doesn't seem to be working properly sometimes. When I turn the modem off and then on again the traceroute and ping times are fine. But sometimes after say 10 minutes or more the traceroute and ping times to the cable modem increase to thousands of milliseconds. When I turn the modem off and on again the issue goes away again.   Any ideas about what can be the issue?


How to get Ubuntuone password in Terminal

When trying to run Sudo-apt-get in terminal in Ubuntu 14.04 it asks for password. I do not remember any password. how to reset password/ solve this problem


Does Stack Overflow have a draft saving feature?

Every time I type a question in Stack Overflow , I occasionally see a "Draft Saved" string under the question area. Does this mean that Stack Overflow has a draft saving feature? If so, how is it used?


I saw a usb to firewire cable () and I was wondering if I can hookup my USB 3.0 flash disk to firewire port on PC. What drivers would be involved? Any benchmarking info much appreciated.   Thanks.


Where should I post a question about software architecture?

I have a question about software architecture. I .  Then the question got put on hold. Where should I post it?


Why isn't "Column ordering" available in my list settings?

I want to change the column order visible when viewing or editing a list item. I have accessed the "Column ordering" interface via the list settings page on other lists in the past, but it isn't visible in this list's settings.


I am not able to understand the differences between std::string and std::wstring. I know wstring supports wide characters such as Unicode characters. I have got the following questions:   When should I use std::wstring over std::string? Can std::string hold the entire ASCII character set, including the special characters? Is std::wstring supported by all popular C++ compilers? What is exactly a "wide character"?


What exactly causes the normal force and how is it related to friction?

So I've read many answers on the internet and have not yet come to understand the origin of the normal force. What I've to come to understand about the normal force, is that it is the electromagnetic repulsion between the electrons of the two surfaces which come into contact with one another(is this right?) Secondly, I've read about asperities and the formation of cold welds between the asperities I understand the cold welds are due to bonds formed between the atoms in contact at the surface.  So here there are two forces, one is the repulsion and the other is the attraction forming bonds between surfaces. Which one of them is the normal force? How exactly do any of these forces cause friction?  f1 is the force trying to move the body, but f2 is the force trying to restore the body In the picture above, suppose I am trying to move one surface over another. Bonds have already been formed between the two surfaces, so when I try to move the objects relative to one another, the bonds oppose the motion, and try to restore it back to the original position. Do I think of friction this way? Please bear in mind I'm a student still in high school so kindly explain it as if you were explaining it at a fairly non advanced level.


Open new windows in the same position as the parent window

I want Chrome to open new windows in the same position as the original window I opened the new window from. Chrome pushes new windows down and to the right a few pixels by default, but does use the same window dimensions as the parent window. This must be an application-specific implementation; opening new windows from Windows Explorer for example uses a much wider spacing for each new window. How can I configure Chrome to stop using a diagonal offset altogether?


Boot partition full and I can't purge old kernels

My /boot/ partition is full and I can't purge old kernels, I've been trying the suggestions here but no luck   dpkg -l linux-image-\* | grep ^ii ii  linux-image-4.4.0-71-generic       4.4.0-71.92  amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP ii  linux-image-4.4.0-72-generic       4.4.0-72.93  amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP ii  linux-image-4.4.0-75-generic       4.4.0-75.96  amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP ii  linux-image-4.4.0-78-generic       4.4.0-78.99  amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP ii  linux-image-4.4.0-79-generic       4.4.0-79.100 amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP ii  linux-image-4.4.0-81-generic       4.4.0-81.104 amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP ii  linux-image-4.4.0-83-generic       4.4.0-83.106 amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP ii  linux-image-4.4.0-87-generic       4.4.0-87.110 amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP ii  linux-image-4.4.0-89-generic       4.4.0-89.112 amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP ii  linux-image-extra-4.4.0-71-generic 4.4.0-71.92  amd64        Linux kernel extra modules for version 4.4.0 on 64 bit x86 SMP ii  linux-image-extra-4.4.0-72-generic 4.4.0-72.93  amd64        Linux kernel extra modules for version 4.4.0 on 64 bit x86 SMP ii  linux-image-extra-4.4.0-75-generic 4.4.0-75.96  amd64        Linux kernel extra modules for version 4.4.0 on 64 bit x86 SMP ii  linux-image-extra-4.4.0-78-generic 4.4.0-78.99  amd64        Linux kernel extra modules for version 4.4.0 on 64 bit x86 SMP ii  linux-image-extra-4.4.0-79-generic 4.4.0-79.100 amd64        Linux kernel extra modules for version 4.4.0 on 64 bit x86 SMP ii  linux-image-extra-4.4.0-81-generic 4.4.0-81.104 amd64        Linux kernel extra modules for version 4.4.0 on 64 bit x86 SMP ii  linux-image-extra-4.4.0-83-generic 4.4.0-83.106 amd64        Linux kernel extra modules for version 4.4.0 on 64 bit x86 SMP ii  linux-image-extra-4.4.0-87-generic 4.4.0-87.110 amd64        Linux kernel extra modules for version 4.4.0 on 64 bit x86 SMP   sudo apt-get update suggests I Try 'apt-get -f install' with no packages (or specify a solution).  All I get for my efforts is this:  The following packages have unmet dependencies.  linux-image-extra-4.4.0-93-generic : Depends: linux-image-4.4.0-93-generic but it is not going to be installed  linux-image-extra-4.4.0-96-generic : Depends: linux-image-4.4.0-96-generic but it is not going to be installed  linux-image-generic : Depends: linux-image-4.4.0-96-generic but it is not going to be installed                        Recommends: thermald but it is not going to be installed E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).   sudo apt-get autoremove returns  sudo apt-get autoremove Reading package lists... Done Building dependency tree Reading state information... Done You might want to run ‘apt-get -f install’ to correct these. The following packages have unmet dependencies.  linux-image-extra-4.4.0-93-generic : Depends: linux-image-4.4.0-93-generic but it is not installed  linux-image-extra-4.4.0-96-generic : Depends: linux-image-4.4.0-96-generic but it is not installed  linux-image-generic : Depends: linux-image-4.4.0-96-generic but it is not installed                        Recommends: thermald but it is not installed E: Unmet dependencies. Try using -f.


Why does the air flow faster over the top of an airfoil?

I understand the common explanation of lift, which describes the airflow over the top of the wing as moving faster than the air below the wing.  However, I don't quite understand why the air moves faster.  I've read some explanations citing a circulation effect among others, but haven't found a good, clear explanation for the exact cause.  Can someone help me out?


I'm trying to install themes with gnome tweak, and I need to install gnome-shell-extensions-user-theme because otherwise I cannot see the shell extensions tab. However, I cannot install shell extensions. I have tried to install by adding the PPA with the following:  sudo add-apt-repository ppa:webupd8team/gnome3   Then,  sudo apt-get update   Finally, when I try to install:  sudo apt-get install gnome-shell-extensions-user-theme   It gives an error:  The following packages have unmet dependencies: gnome-shell-extensions-user-theme : Depends: gnome-shell-extensions-common but it is not going to be installed E: Unable to correct problems, you have held broken packages.   I am convinced that there is a problem with the package. So I went on and tried to install the extensions from the website:   But even though I use Firefox (15.0), I cannot see the "switch" that is being mentioned to install the extension. Maybe the version of Firefox is too new.  Is there any workaround that you know of?  (By the way, I use Ubuntu 12.04, freshly downloaded and installed.)


Why could Steve Rogers move Mjolnir but not lift it?

In Avengers: Age of Ultron when the Avengers are all taking turns trying to lift Mjolnir from the coffee table, Steve Rogers is shown moving it about half an inch or so but not actually lifting it. Presumably whatever enchantment there is on Mjolnir that determines "worthiness"( "whosever wields this hammer", and all that) doesn't do grey areas i.e. someone can't be almost worthy of the power of Thor. Either they can lift the hammer or they can't. If this is as the case, why was Steve not able to lift Mjolnir completely off the table, since presumably if he can move it at all that means that he is in fact worthy?


How to Track What Is Opening Windows in Windows 10

Is there a way to view or log what applications have been opening windows in my system? I have Windows 10.  My reason for wanting to do this is that I have a really annoying issue where every hour something on my system opens a command prompt window and then immediately closes it. I've scanned with Malwarebytes and it hasn't turned up anything. I've also turned on history in Task Scheduler, but no task's run time corresponds with when it happens. I'm hoping to log all the times windows are opened to figure out what is causing this.


Where does the Null-pointer exception arise from?

After looking for hours I still can't figure out where the Null-pointer-Exception is originating. This code is supposed to compare the words from two .txt-files containing words (1 per line). The words from the "readlist.txt"-file are to be unscrambled before comparison. If a match is found the unscrambled word is appended to the output String. The problematic line is: "scrambled_words[scrambled_iterator] = scrambled_line_yup;"  Thanks for helping me in advance.  //Try any "char-combination"-method public static void iterate(char[] chars, int len, char[] build, int pos, String wordlist_line_yup, String ausgabe) {     if (pos == len) {         String word = new String(build);         if ( word.equals(wordlist_line_yup)) {             output += word+",";         }         return;     }     for (int i = 0; i < chars.length; i++) {         build[pos] = chars[i];         iterate(chars, len, build, pos + 1,wordlist_line_yup, ausgabe);     } } //main method public static void main (String[] args)throws IOException {     //Initialisiere Ausgabe String     String output = "";      //File Initialisation     File path1 = new File ("c:/users/xxx/Desktop/wordlist.txt");     File path2 = new File ("c:/users/xxx/Desktop/readlist.txt");     System.out.print(path1.exists()? "exists" : "doesnt exist");     System.out.print(path2.exists()? "exists" : "doesnt exist");      //Read the readList with scrambled words and put lines into string-array     BufferedReader scrambledreader = new BufferedReader(new FileReader("c:/users/xxx/Desktop/readlist.txt"));     String[] scrambled_words = {};           int scrambled_iterator = 0;     String scrambled_line;     while ((scrambled_line = scrambledreader.readLine()) != null) {         String scrambled_line_yup = "";         scrambled_line_yup += scrambled_line;         scrambled_line_yup.trim();         if(! "".equals(scrambled_line_yup)){             scrambled_words[scrambled_iterator] = scrambled_line_yup;             scrambled_iterator++;         }     }     scrambledreader.close();      //Read the wordList and compare to array with scrambled words     BufferedReader wordlistreader = new BufferedReader(new FileReader("c:/users/xxx/Desktop/wordlist.txt"));     String wordlist_line;     while ((wordlist_line = wordlistreader.readLine()) != null) {         String wordlist_line_yup = "";         wordlist_line_yup += wordlist_line;         wordlist_line_yup.trim();         if(! "".equals(wordlist_line_yup)){             for (String x : scrambled_words) {                     if(! "".equals(x)){                         char[] chars = x.toCharArray();                         int len = chars.length;                         iterate(chars, len, new char[len], 0, wordlist_line_yup, ausgabe);                     }             }         }     }     wordlistreader.close();      //Output in Cmd     System.out.println(output);      }   }


Polynomial: prove there is no double root

Are there other methods for this question other than contradict the double root hypothesis?


Ok ... i just installed Blender today, watched some tutorials but i got stuck at this step because on none of the tutorials has this happened :  when i select an object and i go into properties menu, under material, i have no + button to add a new one


Create a folder structure in a discussion board

How can I create a folder structure in a discussion board? I have already tried this solution:     1) Create a new Site Content Type say called 'Thread Folder' based on the  Folder Content Type with the Parent Content Type as a   Discussion (Site Actions -> Site Settings -> Site Content Types)      2) Then, go into the Discussion List Settings and add the new content   type (Add from existing site content types)         Then I create a new 'Thread Folder' and discussion in it. When click on Reply within this discussion, I cannot see item that represent root reply. How to get rid of this problem?


Evaluate $\lim_{x\to 0} \frac{a^x -1}{x}$ without applying L'Hopital's Rule.

The questions is: Evaluate $$\lim_{x\to 0} \frac{a^x -1}{x}$$ without applying L'Hopital's Rule.  Does this question fundamentally same as asking if the $\lim_{x\to 0} \frac{a^x -1}{x}$ exists? rather than straightway asking to find the limit. That means are questions (1) proving if the limit of a function exists and (2) asking what is the limit of that function, essentially same question?


I've been trying to solve the following linear congruence with not much success: $19\equiv 21x\pmod{26}$ If anyone could point me to the solution I'd be grateful, thanks in advance


I am in search of a simplified version of the derivation of  (both translational and rotational) for a rigid body (3D block) that has a body fixed frame and where the center of mass of the body is not at the center of gravity.  I can find elementary derivations for the same system when the center of mass is at the center of gravity, but not for my system in question.    I am using the derivation as background research for a rotordynamics project that I'm working on.  Any help and or references would be greatly appreciated!  :)


$(X,d)$ is  a compact metric space  and  $$f\ :\ X\rightarrow X $$  be  such  that $$d(x,y)=d(f(x),f(y))$$ Show that  $f$  is  onto .  I  have  to  show  that for  any  $y\in X$  there  exist $x\in X$  such that  $$f(x)=y.$$ How  to  begin$?$


Show ($n+1$)$2^n$ =  $\sum_{i\geq 0}^{} {n + 1\choose i}i$  algebraically.  I know $2^n$ = $\sum_{i\geq 0}^{} {n\choose i}$. But how do I manipulate the $(n+1)$ to make it look like the right side?


I need a regex for a 5 digit integer number with 2 decimals.  These would be correct:   12345.12 09856.99 45123.00   These wouldn't:   123.12 12345.6 98652


How to apply damage to entities without instant damage effect?

I want to be able to give an entity damage for a command I’m making, but instant damage effect is way too much, how do I apply other amounts of damage with command blocks?


Best practice for new content, but identical topic?

I write a new blog post each year regarding the previous year's market trends.  I still see users accessing some of these posts even though they are a couple of years old and outdated. Redirecting users doesn't make sense as I still want users to have access to the previous posts.  Canonical doesn't totally make sense because the content isn't identical, even though the topic is the same. I realize search engines can recognize newer content, but is there a best practice for these kinds of pages?  Should I do anything to connect the content or should I assume search engines will figure it all out without my help?


What is the best practise in terms of JavaScript and CSS versioning?  If we don't version then the browser could have a older cached version is z_1.0.js  Using version control will solve this issue but I don't see it used a lot on other websites?


Initializating an object with functional form actually does not call the default constructor

i'm trying to make a difference between different types of initializing objects. But I've read (middle to end of page) that if you try to call Class object(); this will not instantiate an object, rather will define a function? I tried and it is so, but I don't understand why.  Circle c;   // default constructor called Circle c(); // function declaration (default constructor NOT called) Circle c{}; // default constructor called   Here is how i tried to reproduce: class Circle {     float r; public:     Circle()     {         cout << "default constructor" << endl;     }     Circle(float r)     {         this->r = r;     } };  In main() I'm trying to instantiate an object like this Circle c() and it does not call the parameter less constructor. I was expecting seeing in console the message "default constructor". What does the syntax Circle c() does if it is not calling the default constructor? How is that a valid function declaration?


In QGIS, is it possible to save graduated styles to use on different columns?

I'm using QGIS to produce thematic maps of 9 quantities (given in 9 columns in the attribute table) which have values broadly within the same range and I would like to plot them using the same intervals using 'Graduated' style.    However, while I can save a style, it saves the column name with it. When I load the style to attempt to apply it to another column, as soon as I change the column, it resets the intervals, which is exactly what I would like it not to do. Is it possible to somehow keep the interval ranges while changing the column?


Is there a step by step checklist to check if a multivariable limit exists and find its value?

Do we rely on certain intuition or is there an unofficial general crude checklist I should follow?  I had a friend telling me that if the sum of the powers on the numerator is smaller then the denominator, there is a higher chance that it may not exists. And if the sum of powers on the numerator is higher then the denominator, most likely, it exists. Also if there is a sin or cos or e-constant, it most likely exists.  How can I know what to do at the first glance given so little time exists for me in exam to ponder? If I spend all my time on figuring out a two-path test when the limit exists, that would be a huge disaster. Is this one of those cases where practice makes perfect? Example: $$\lim_{(x,y)\to(0,0)}\frac{(\sin^2x)(e^y-1)}{x^2+3y^2}$$ Please give me a hint and where do you get the hint. Example: $$\lim_{(x,y)\to(0,0)}\exp\left(-\frac{x^2+y^2}{4x^4+y^6}\right)$$ I need a hint for this too.  Common methods I have learnt for reference: Two-Path test, Polar Coordinates, Spherical Coordinates, Mean Value Theorem using inequalities.


Six circles each of unit radius are being circumscribed by another larger circle. All the smaller circles touch each other. What is the circumference of the larger circle? I tried many things, but being a beginner I am actually out of ideas now. Like, I tried joining the centre of all the circles to find the radius of the larger circle, but even that didn't work.    The linked image shows the arrangement of the circles but all the circles are touching each other.


How to complete this uniform convergence proof by dividing the real line in appropriate segments?

I tried to solve . Much of the obvious things to try are there but don't work. After several failed attempts I arrived at this (also failed?) argument:  Let $$f_n(x)=\frac{nx}{1+n^4x^2}$$ The goal is to prove that $$F_m(x)=\sum_{n=0}^{m}(-1)^nf_n(x)$$ converges uniformly in $[0,\infty)$. I've tried the following:  First of all, for every $n\in\mathbb{N}$ and every $x\in[0,\infty)$ we have $|f_n(x)|<\frac{1}{2n}$  Given $x_0\in[0,\infty)$ and taking $f_n(x_0)$ as a function of $n$ we get that the sequence $\{f_n(x)\}_{n\in\mathbb{N}}$ starts to be decrasing when $n^4\ge\frac{1}{3x_0^2}$ or $x_0\ge\frac{1}{n^2\sqrt{3}}$. Now, for $p>q$ $$|F_p(x_0)-F_q(x_0)|=\left|\sum_{n=q+1}^{p}(-1)^nf_n(x_0)\right|$$ and we separate the following cases:  If $x_0\ge\frac{1}{(q+1)^2\sqrt{3}}$ then $\{f_n(x_0)\}_{n\ge q+1}$ is decreasing so we can use "Leinbiz's criterion proof" to get $$|F_p(x_0)-F_q(x_0)|<\left|f_{q+1}(x_0)\right|<\frac{1}{2(q+1)}$$ If $x_0\le\frac{1}{p^3\sqrt{3}}$ then $x_0<\frac{1}{n^3}$ for every $n\le p$ and we have $$|F_p(x_0)-F_q(x_0)|=\left|\sum_{n=q+1}^{p}(-1)^nf_n(x_0)\right|<\sum_{n=q+1}^p\frac{1}{n^2}<\frac{1}{q}$$ which we can make small.  If $\frac{1}{p^3\sqrt{3}}\le x_0\le\frac{1}{(q+1)^2\sqrt{3}}$ then none of the bounds i came up with tend to zero. Does someone have an idea? If this worked somehow I think it would be a neat thing to try for other problems.  Edit: Please note that when I uploaded my question, the original one already had an accepted answer. I'm not looking for a solution of that exercise but rather for some way to complete my line of reasoning. The functions $f_n$ or $F_m$ don't interest me as much as the "dividing the real line" trick and if it works here or in general for alternating sums of functions  Thanks!


Is ignoring emails acceptable in academia?

As a grad student, I just find it tremendously frustrating when emails are ignored by faculty (both at my institution and at other places). Is this acceptable? I'd be content with a simple response with one line along the lines of "I have read this email and am busy right now, will respond in X days when I can write a more detailed email." I understand that, as a first year student in my field, I'm not really in a position to request anything of anyone, but it just seems like common decency.  Instead, I never hear back, as if my email has been jettisoned off into oblivion.


I'm trying to install Ubuntu 12.04 to run in VirtualBox alongside my Win7 64bit OS, without having to dual-boot.  I added the 64-bit Ubuntu iso to my VM, and powered it up so to proceed with the installation, but it prompted me with this error:     This kernel requires an x86-64 CPU, but only detected an i686 CPU.   Unable to boot - please use a kernel appropriate for your CPU.   Why does it give me this error, seeing as I have a 64bit processor? Is there a way that I can run Ubuntu via my VM in the first place?


Why must a null hypothesis contain equality?

Using the inference of mean as an example, the null and alternative hypothesis could be  $$H_0: \mu \le 0 \Leftrightarrow H_1: \mu > 0$$  It is often argued that this makes the calculation of the $p$-value (or critical region) easier, but from my understanding the $p$-value is $P(\bar{X} > 0|H_0) \stackrel{\color{red}{?}}{=} \sup_{\theta \in H_0} P(\bar{X} > 0 | \theta )$. Since I'm taking its supremum, the $p$-value doesn't change regardless of whether the equality sign is included. The same result goes for the critical region. However, I'm not sure if my understanding is correct, and my doubt is marked with a red question mark above.  Anyway, I wonder if it's correct (I know that would be unconventional, though) to write  $$H_0: \mu < 0 \Leftrightarrow H_1: \mu \ge 0$$  If that's OK, what about its $p$-value and critical region? If that's not OK, I would be really surprised, because in that way we are changing the question ("Is $\mu$ less than or equal to zero?") to something different ("Is $\mu$ less than zero?")


HTML/CSS position div with multiple input forms in center not working

I have a simple DIV that has several input forms, and textarea inputs and a submit button. Now I would like this div to be centered in the center of the page instead of to the left how is it by default. I have tried all of the DIV centering methods I found searching but they always mess up the alignment of the text forms in the DIV when it is centered. How could I center something like this in the middle of the page?

 <input type="text"> <input type="text"> <textarea id="text1" name="textbox" rows="10" cols="100" ></textarea> </textarea> <textarea id="text2" name="textbox" rows="10" cols="100"></textarea> </textarea>
 <input type="submit">


Difference between continuous and non-continuous data .

In a dataset "survey", pulse and age are given as non-continuous data. how come these age and pulse can be non-continuous?  this is the reference link


Finding circle circumscribed in spherical triangle

Given three vectors $u,v,w \in S^2$ and the triangle $[u,v,w]$ I want to find its circumscribed circle. However, I don't know how to approach this problem. Would some one please explain?  In my understanding, one needs to somehow find the altitudes of the spherical triangle and then the point of its intersection (circumcentre)? Then what about the radius?


I'm doing a calculator, in which is asked to the user to put two numbers, and then an aritmethical operator, so a set of IFs will understand what operator it is and do the operation required: public class Calc {    public static void main(String args[]) { Scanner input = new Scanner(System.in);   System.out.print("First number: "); double num1 = input.nextDouble();  System.out.print("Second number: "); double num2 = input.nextDouble();  System.out.print("Artithemtical operator(-, +, :, x): "); String segn = input.nextLine();   if(segn == "+" ) { System.out.println(num1 + " + " + num2 + " = " + (num1 + num2)); } else if(segn == "-") { System.out.println(num1 + " - " + num2 + " = " + (num1 - num2)); } else if(segn == "x") { System.out.println(num1 + " x " + num2 + " = " + (num1 * num2)); } else if(segn == ":") {    System.out.println(num1 + " : " + num2 + " = " + (num1 / num2)); }      } }  as you can see if the input is a specific operator it will perform the specific task. It works well, it makes you put the two numbers, the operator but then it does nothing, what shall I do?


Java know in finally that exception thrown without any variable

Is there a way to know in finally that exception is thrown,  without using any extra variable as below:   boolean hasFailed = true;  try { // code       //...      hasFailed = false;   } finally {       if (hasFailed) {          // handle failure       }    }   Similarly, also without adding exception variable (using catch clause),  I didn't find  in similar questions


Installed Ubuntu 18.04.2 LTS on Jetson Nano trying to install Atom

I am trying to install Atom editor on to Jetson nano and, as far as I could determine, I selected the commands from link below to install Atom. Being that I am not an expert I am wondering how to correct the  unmet dependencies pasted below.     The issue is the following:  The following packages have unmet dependencies:  atom:i386 : Depends: libgtk2.0-0:i386 but it is not installable              Depends: libudev0:i386 but it is not installable or                       libudev1:i386 but it is not installable              Depends: libgcrypt11:i386 but it is not installable or                       libgcrypt20:i386 but it is not installable              Depends: libnotify4:i386 but it is not installable              Depends: libxtst6:i386 but it is not installable              Depends: libnss3:i386 but it is not installable              Depends: python:i386 but it is not installable              Depends: libdbus-1-3:i386 but it is not installable              Depends: libcap2:i386 but it is not installable              Depends: libxkbfile1:i386 but it is not installable              Depends: libx11-6:i386 but it is not installable              Depends: libasound2:i386 but it is not installable              Depends: libsecret-1-0:i386 but it is not installable              Depends: gir1.2-secret-1:i386 but it is not installable E: Unable to correct problems, you have held broken packages.


How to hide folders for people that have no access on Windows Home Server?

I have Windows Home Server 2011 running. I can create users and set their permissions on folders, however it would be nice to hide the folders they don't have access to anyways.   Is there a way you can do this, or manually tell a folder to be hidden for that user?


How did the Sorting Hat know what each student's thoughts and abilities were?

The hat was sorting students into houses according to - what seems to be - "what's in their head".  How is that possible? In Harry's case, he spoke to the hat, but most students just sit there silently from what I remember from the books!


Is there a way to change the Share default permission level to “Read”?

When I click “Share” as a Collection admin/site owner, I get a screen where my options are limited to Can Edit and Can View, and the permission choices are Contribute and Read, respectively.    When I click on “Share” as a user I get the default of ‘Invite people to Edit”. The drop down to modify this permission level is hidden and requires a user to click show options to modify it to read.    We have an issue where users are sharing a document but providing access to edit unknowingly. I would like modify this to default to Read to minimize providing higher access than intended.


Using arcpy.mapping.ExportToTIFF() to create dataframe geotiff

Has anyone created a dataframe geotiff using arcpy.mapping.ExportToTIFF() with satisfactory results?   My output has poor quality and the georeferencing is significantly off. This example is the geotiff at 50% transparency on top of my data. The shift between "South El Monte" is the best shift example.    Here is an example of the code:  currentMxd = arcpy.mapping.MapDocument(r"F:\Test\amp_Edit.mxd") dataFrame = arcpy.mapping.ListDataFrames(currentMxd, "Layers")[0]  arcpy.mapping.ExportToTIFF(currentMxd, r"F:\Test\outtif.tif", dataFrame, df_export_width = 46000, df_export_height = 29000, resolution = 1000, geoTIFF_tags = True)


Ubuntu Desktop login password does not work after OS reinstall

Oddly the password works in the the command line.   I've created a new account on command line and logged to the the desktop from that. However the password of my old account no longer logs to the desktop.


How to get figure caption to span multiple pages, without having to switch everything to capt-of?

I have found several questions on TeX.SE and elsewhere about making figure captions span multiple pages (e.g., ). I gather that the caption package puts the caption in unbreakable boxes.  Some answers recommend the use of the capt-of package. capt-of seems to work fine, but breaks caption instances. So it seems that using capt-of to enable long figure captions would require me to switch every single caption in my paper to capt-of, which is a burden and seems to eliminate the benefits of floating figures.  Here's a MWE (also on ) with a figure with short caption and a figure with a long captionof. I would like to be able to have both \usepackage{capt-of}  and \usepackage[font={small,sf}, singlelinecheck=false]{caption} enabled, and still have my long caption span multiple pages.  \documentclass{article}  % I can't have both caption and capt-of enabled.  % Caption alone doesn't let long captions span multiple pages.     \usepackage[font={small,sf}, singlelinecheck=false]{caption}  % Capt-of alone would require me to reformat many figures. \usepackage{capt-of}  % But enabling both breaks capt-of's ability to span captions across pages.  \usepackage{lipsum}  \begin{document}   \lipsum[1]  % I have many figures that are formatted like this. \begin{figure}[h!]    \centering    \rule{0.3\textwidth}{0.3\textheight} \caption[Short caption]{\lipsum[1]} \end{figure}  \lipsum[1-10]  % This seems to be the best way to get long captions to span multiple pages, while being styled like the above figure. \begin{centering} \sffamily    \rule{0.5\textwidth}{0.75\textheight} \captionof{figure}[short caption]{\lipsum[1-4]}    \label{figure} \end{centering}  \end{document}   Alternatively, some way to easily allow captions to span pages without having to re-format would be great.


Need help in understanding miller plateau region

Will somebody please help me to understand what is role of millet plateau region in switching of MOSFETs?


Integrate rational function $\frac{x^2}{1+x^4}$

Integrate $$\int\frac{x^2dx}{1+x^4}$$ I've factored the denominator to $(x^2-\sqrt{2}x+1)(x^2+\sqrt{2}x+1)$ and got stuck.


Can I get notifications from my favourite tags into the SE inbox?

I’ve labelled a few favourite tags here (and more on other sites). I appreciate them being highlighted on the question page.  Sometimes, however, I take breaks from Stack Exchange that can be anything between weeks and months. If any cool interesting question that uses my favourite tags happens to be asked during that time, I’m going to miss it. I don’t like that.  But I also don’t want a fixed e-mail notification for the following reasons:   When I’m active I don’t really need it, so I consider the e-mails spammy. I actively want to stay away when I’m staying away, so I don’t want e-mail notifiers in that time. I typically only check the e-mail account that is associated with SE once a day or less. I might well not have time to visit SE then and thus forget about the notification. Stack Exchange and that e-mail will be open in different browser windows, so my brain does not do well connecting them.   Rather, Stack Exchange has a beautiful feature that leads me exactly to those places that seem interesting once I log on: The comment notification inbox.* That inbox also logs information about bounties (automatically) and chat responses after fifteen minutes. It is a beautiful place to send favourite question notifications to, because it is right where I want it. With the added benefit of me actually wanting to spend time on SE whenever I log on and see that notification icon. (They don’t go bad even after three months.)  Therefore I would like to request the feature that subscriptions to tags should be possible to the SE inbox rather than e-mail.  Additional clutter could be removed by an intelligent system that realises if I opened the question within 15 minutes of it being posted and then discards it from the notifications list. This already happens with chat replies and other users’ edits to one’s posts. Furthermore, it knows who I am and doesn’t need to send me notifications of my own questions.    Notes:  *: Feel free to suggest a better name …


When should the front sprocket and back cassette be replaced.I have a 2014 Trek 520 Touring bike with 6500 miles and am planning a cross country touring trip in August.


Hi i was wondering what is the fastes workflow might be for citing in writelatex with new the Mendeley integration.   For those who are unfamiliar with writelatex and mendeley integration; writelatex generates a .bib file based on my complete Mendeley library, which is quite large. The .bib file is then placed conveniently in a project folder and linked directly to my Mendeley library. While in writelatex the .bib can be easily accessed as a popup screen, but searching within the .bib is limited to highlighting search words(meaning it does not "go-to"). After scrolling through 2000 lines i usually find the specific bibtex key i am looking for and manually type \cite{key}, but this is a very time consuming experience.   Any suggestions as to how the optimal workflow is intended?   Thanks.


I'm currently running version 14.04. Is it safe to upgrade only kernel to the recently released 3.16?


not able to run a downloaded program file in ubuntu 18.04 terminal

when I try running a program file downloaded in terminal ubuntu 18.04 by ./filename.exec Input.data as per the program user manual, it says no such file or directory, but when I do ls, ls -l , it shows the file in executable state, but still does not run...why? can anyone help me, being a newbie in bioinformatics. The program file contains executable file and input files. $ pwd /home/ubuntu/Downloads/program_directory $ file ./filename.exec Input.data ./filename.exec: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked, interpreter /lib/ld-, for GNU/Linux 2.6.15, BuildID[sha1]=41506b3ff2b0a8a1a10c2d856fc68be667a93df3, not stripped`  Input.data:                  ASCII text $ ./filename.exec Input.data bash:No such file or directory $ ldd sRNAscanner_Ubuntu10.exec | grep not     not a dynamic executable   I even tried running as root, but same response


Is there a way to get DateTime value from timestamp type column?

I need a select from table which does not have column that tells when row was inserted, only timestamp column (values like: 0x0000000000530278). Some data was imported to the table yesterday and now I need to find out what exactly was imported :(  Is there a way to do it using only timestamp info?  I found that:   Timestamp is a 8 bytes sequential Hex number, that has nothing to do with neither the date nor the time. To get the current value of timestamp, use: @@DBTS.   Perhaps there is a way to find what was timestamp value around specific time? That would help to form a select. Or maybe there is a well known solution?


the ordinary generating function of the sequence $\{\binom{3n}{n}\}$ is given by $$\sum_{n} \binom{3n}{n} x^n = \frac{2\cos[\frac{1}{3}\sin^{-1}(\frac{3\sqrt{3}\sqrt{x}}{2})]}{\sqrt{4-27x}}$$ How do I prove this?


Installing QT 5.5 On Ubuntu 14.04 LTS with error : QSslSocket: cannot resolve SSLv2_server_method

I've Downloaded qt-opensource-linux-x64-5.5.0-2.run file and tryed to install it using terminal, so I added execute permission and run it:   ./qt-opensource-linux-x64-5.5.0-2.run   But it shows:   qt.network.ssl: QSslSocket: cannot resolve SSLv2_client_method qt.network.ssl: QSslSocket: cannot resolve SSLv2_server_method   and nothing happens.  What is the problem and how I can install it?


My question is the same as .   Since the solution there demands a lot of adjustments and computations, I'd like to know if there is some new tool with a more powerful and simpler solution. Maybe some new tikz feature.  Also, one of solutions is not exactly two arrows but a single double arrow.  I'd like to move the arrows to get them parallels.  \documentclass[margin=2mm]{standalone} \usepackage{tikz}  \begin{document} \begin{tikzpicture} \tikzset{  togo/.style={-to,line width=.4pt},  tocome/.style={to-,line width=.4pt}, } \node (A) at (0,0) {$A$}; \node (B) at (2,3) {$B$}; \draw[togo] (A) -- (B); \draw[tocome] (A) -- (B); \end{tikzpicture} \end{document}


I learned my c++ from , which is an excellent website and I would recommend, but it never teaches delegates and events (among other subjects). When I try to learn those subjects I run a lot to the unary postfix ^ operator, for example "String^ str".   This operator is used much like the * for pointers and & for references, so I assume it does something in the same vain. This operator is never really explained anywhere.   Can someone explain to me what is this operator?  Thanks.  Edit: The question has been answered well in the comments. Thanks you!


Proving $N$ is infinite using another method

DEFINITION 1:  A set $S$ is finite  if there is a bijection from the set $[n]=\left\{ 1, ..., n \right\} \text{for some } n\in N$   to $S$.  A set is infinite if its not finite.   I have proved that   if $f:[n]\to N$ is an injection, then $\exists g:[n]\to rng(f)$ an Order Preserving map.  How can I use this to show $N$ is infinite?  This is not same as  since I have not used order preserving map anywhere over there.


Does deleting your profile and starting a new one violate any rules?

I have learned recently that I can delete my account and start a new one. Now there are some rules to this for example if you are in a suspension the suspension and/or ban would continue under the new accounts. Some of my SE accounts were beyond repair even by a moderator, so I deleted a couple after my question ban was over to see if it helped.  It seemed like it did.  The deletion was not automatic and had to be reviewed and approved I guess because I had to wait 24 hours. Who does that task?  Am I breaking any rules or circumventing the system (no where in the details does it give reasons or rules) or am I utilizing tools available to me by the system in the way the designer intended?  Note: I do not condone circumventing or exploiting the SE system in any way and that I only did this as a last resort to fix my accounts. I returned to Aviation.SE and asked some questions and did very well. I was also suspended but at least it wasn't for a year this time.  From moderators in Aviation.SE:  We've noticed that you deleted your old account and created a new one to circumvent the question block that the system imposed on you. Moreover you used this new account to ask several questions, many of which show that you still have not learned to use this site properly. This circumvention of the rules and disrespect of the community is not tolerated. We have temporarily suspended your account; you may return after 30 days.  Regards, Aviation Stack Exchange Moderation Team   Anti-Recidivism System Added  [...] We log data on such accounts at time of deletion, which is then referenced should a new account from the same individual be created. If the user was suspended at the time of deletion, then the new account will inherit the remainder of the original suspension. If the user was blocked from posting questions at the time of deletion, then the recreated account will be restricted to posting only one question per week until the quality of their contributions is demonstrated. [...]   I did show high quality in Aviation and this did not affect me.


How to convert sql.date to util.date so that i can set that date to JDateChooser?

I'm trying to convert sql.date which i'm getting from my sqlite database to util.date. And i want to set that date to JDateChooser. I've literally tried all possible ways but it seems i'm missing something. Can anybody tell me what's wrong?  try{     String query = "select * from SkaterInfo where reg_no = ?";     pst = con.prepareStatement(query);     pst.setInt(1, num1);     rs = pst.executeQuery();      while(rs.next()){          name = rs.getString("Name");          surname = rs.getString("Surname");          batch = rs.getInt("Batch");          cell = rs.getLong("Mobile_No");          date = rs.getDate("Birth_Date");     }       pst.close();     rs.close();  }catch(Exception a){     JOptionPane.showMessageDialog(null, "Exception"); }  java.sql.Date date1 = new java.sql.Date(date.getTime()); dateChooser.setBounds(150, 150, 150, 30); dateChooser.setDateFormatString("yyyy-MM-dd"); dateChooser.setDate(date1); frame.getContentPane().add(dateChooser);


Combinatorial proof for Stirling number of 1st kind's generating function

So I see this identity a lot but I can't find a detailed combinatorial proof for it.  $$n(n+1)...(n+k-1)=\sum_{j=0}^k \begin{bmatrix}k \\j \end{bmatrix}n^j$$ Can someone please help?


SP2013 - Can you limit the amount of items in a Site Feed?

Is there a way to limit the amount of items that show up on a Site Feed? We are using our Site Feeds as a sort of conversational wall. It seems to default showing 10 items, but I would really like to change it to show only 5. Is there any way to do this? I didn't see it in the configuration anywhere and there was no view for me to edit.


Why does Ubuntu 18.04 have 2 graphical interfaces?

When I wanted to change from the graphical interface to a non-graphical interface I used the shortcuts Ctrl+Alt+F[1-6] with the one in F1 being the graphical one by default. On the new Ubuntu, F2 is the graphical interface logged in, and F1, logged out. I don't understand this. What's the sense in having those 2?


$x^2-x+1$ has a root $\!\bmod p\,$ for infinitely many primes $p$

Prove that the equation $$x^2 - x + 1 = p(x+y)$$ has integral solutions for infinitely many primes $p$.  First, we prove that there is a solution for at least one prime, $p$. Now, $x(x-1) + 1$ is always odd so there is no solution for $p=2$. We prove there is a solution for $p=3$. If $p=3$, $y = (x-2)^2/3-1$. We get integral solutions whenever we get $x = 3m +2$, where $m$ is any integer.$\\$ We provide a proof by contradiction which is   similar to Euclid's proof of there being infinitely many primes. \Let us assume that it is is true for only finitely many primes, and name the largest prime for which the equation is true $P$.\\We set $$x = 2\cdot3\cdot5\dots P$$ $x$ is the product of all primes upto $P.\\$ Then, the term $x(x-1) + 1$ is either prime or composite. If it is prime, then we set $p = x(x-1) + 1, y = 1 - x$ and get a solution. If it is composite, we write $x(x-1) + 1 = p\times q$, where $p$ is any prime factor of $x(x-1)+1$, and $q$ is an integer, $q = (x(x-1)+1)/p$. Now, $x(x-1) + 1$ is not divisible by any prime upto $P$ since it leaves a remainder of $1$ with all of them. So, $p > P$. We set $y=q-x$ for a solution.$\\$In either case, we get a solution for a prime $p > P$, which means there's no largest prime for which this equation has solutions. This contradicts the assumption that there are solutions for only finitely many primes.  I feel like I'm missing some step. Is this correct ?


Solve the recurrence for $T(n) = T(\sqrt n) + 2$. Assume that T(n) is constant for $n\leqslant 2$.

Trying to work out the following question, but I'm stuck.. Can someone direct me please.   Using a change of variables  $$     \text{Let}\ m = \lg\ n \\      S (m) = T (2m)\\     T (2^{m}) = T (2^{m/2}) + 2 \\     S( m) = S (m/2) + 2 $$ Using Master Theorem   $$ n\ log_b a = n\ log_2 1 = n^{0} = 1\text{ and }f (n) = 2 $$  Since $ 1 < θ(2)$, case 1 applies and $S (m) = θ(\lg\ m^2), \quad\therefore T (n) \in \theta(\lg\lg{n^2}) $  or   I was also thinking about the problem like this: $$\begin{align} T(n)  &= T(\sqrt n ) + 2          = T(n^{1/2}) + 2          = T(n^{1/4}) + 4          = \cdots \\          &= T(n^{1/2^i}) + 2i          = \cdots          = T(n^{1/2^k}) + 2k\\ \end{align}$$ $$ n^{1/2^k} <=2 \\ \text{so } \log n = 1/(2^k) \\        k = \log (\frac{1}{\log n}) $$ $$ ∴ T (n) ∈ θ(\lg \lg n)\ or\ T(n)\ \in θ(\log (\frac{1}{\log n})) $$


How to rename a field in a shapefile in QGIS?

I'm attempting to rename a field in a shapefile. I select the layer, enabling editing and then apply changes, and save them. When I open the file again, it's been renamed 'field_to__1'. However this only seems to happen for certain (joined?) fields.  How can I save the field name changes in QGIS?


Replacing desktop OS with type 1 hypervisor and guest OS

I'm keen to use virtual machines as exclusively as possible in place of traditional operating systems on my desktop computers. Currently I can do this by running Linux as a host operating system, Virtualbox and then my day to day guest OS for working on within that.  I don't like having to run a full OS, with it's regular updates etc just to be able to run a virtual machine. What I'd like is for the physical computer to boot a minimal type 1 hypervisor and for that to boot directly into a guest OS of my choosing.  I'm not sure if there are any type 1 hypervisors that could do this and support graphics, USB etc although I've read Hyper-V may be able to do this..  If this isn't currently something people do, are there any up and coming projects that will allow this to happen?


Name of component on output side cable of a DC power adapter?

What is the name of this component (circled in red) of a charger?    What are the uses of this component?


How to run shell script in background while start On CentOS?

I have a shell script contain loop like this:  while true do   if ... ; then     ...   else     ...     break   fi done   I want this script to run backend while OS start. I have try to add this script into /etc/rc.d/local.rc as startup script. But OS start too long, and after OS start up, this script did not exist.  So how to add this script into backend while OS start up? And I need this script also could be start up by hand in backend. Thank you~


identify the ring $\mathbb{Z}[x]/(2x-1)$

Suppose it asks to show $\mathbb{Z}[x]/(2x-1) \cong \mathbb{Z}[\frac{1}{2}]$  Cand I do like this ? First of all elements of $\mathbb{Z}[x]/(2x-1)$ is of form $\frac{m}{2^n}+(2x-1)$ and also all elements of $\mathbb{Z}[\frac{1}{2}]$ are of form $\frac{m}{2^n}$. Now define a normal projection $\mathbb{Z}[\frac{1}{2}] \to \mathbb{Z}[x]/(2x-1)$ where $a \to a+(2x-1)$ for all $a\in \mathbb{Z}[\frac{1}{2}]$. So kernal is srt of all $a$ such that $2x-1|a \implies a=0$ so both are isomorphic.


How add a downarrow after an element with CSS?

I would like to add arrows to my sortable table on   What I tried is adding this code to the css:  table th.headerSortUp:after {    content: " &uarr;"; }  table th.headerSortDown:after {    content: " &darr;"; }   But that will not display the arrows "↑" and "↓" but the html-entities instead: "&uarr;" and "&darr;"  or even better would be the up- and downward arrow I found here:


Unzipping a .gz file without removing the gzipped file

I have a file file.gz, when I try to unzip this file by using gunzip file.gz, it unzipped the file but only contains extracted and removes the file.gz file.  How can I unzip by keeping both unzipped file and zipped file?


I'm having trouble with this piece of code:  22 for filename in "$( ls "$1" | grep ".*\.flac$" )"; do 23                 file_path="$1${filename}" 24                 ffmpeg -i "${file_path}" -f ffmetadata $HOME/metadata   Instead of a metadata file on each iteration, I'm getting this error message:     Downloads/Ariel Pink's Haunted Graffiti - Worn Copy (2005)/01   Trepanated Earth.flac ... 17 Jagged Carnival Tours.flac: File name too long   So it appears that inside the loop the $filename variable is equal the names of all FLAC files lumped together.  Of course, omitting quote marks on line 22 results in whitespace problems.  How do I make this work? I'm new to bash and very confused.


I apologize if this question is dumb, but I've looked all over for a straightforward answer, and either I can't find one or either the terms are too complex for me to understand. I have only a rudimentary knowledge of Mechanics, but I do understand basic Linear Algebra. So torque, mathematically, is the cross product of the radial distance vector and a force vector. This cross-product gives another vector that is orthogonal to both vectors and it points either outside or towards the "page" (in the context of a two-dimensional diagram). Assuming this is correct, I do not understand what it pointing in or out means. Does it even have a physical, intuitive meaning? The best answer I've been able to come up with is that it's just a mathematical convention with no actual physical meaning, meant to provide a framework within which operations between torque vectors, such as addition and subtraction, make sense. Am I correct or way off the mark here?


What is this input type or form setup called?

Couple of us arguing about this and none of us can remember what this is or would be called. Commonly seen on forms where you are moving an option from one box on the left to a box on the right and commonly has buttons in between the two boxes to move a singular option or all options. Crude visual example below (since we can't remember it enough to search for an actual example).  ------------         ------------------- | Option 1 |         | Selected Option | | Option 2 |   ->    |                 | | Option 3 |   -->   |                 | | Option 4 |   <-    |                 | | Option 5 |   <--   |                 | | Option 6 |         |                 | ------------         -------------------   What would this be called?  ...and, no, you don't have to tell me how mind-blowingly and award winning my illustration is. I am aware. :)


Best way to match an incomplete searchString with a Date format within Java

I need to match a (partial) searchstring to a Date with timestamp from the database.   I have a searchbox that allows you to search through 4 values at once. Those being: code, date, name and code2. When you input a value I make a new List with all the valid searchresults. At the moment everything works except my date, I can search on the independent numbers but when I use the following format I get a 404.  ("dd/MM/yyyy")  Now I do have a formatter in place to transform my Date from the database  (format = "yyyy-mm-dd hh:mm:ss") into a String. However I keep having the same problem. The moment I enter / into the searchbox it won't generate my list anymore and I get the 404.  And I was wondering what the best solution would be? Transform everything into a String, transform the searchstring into a Date format + 00:00:00 or change something in the searchbox so that it only looks for a date if the format matches exactly?     if (orderHeader.getCode() != null) {   orderHeaderDTO.setCode(orderHeader.getCode());  }    if (orderHeader.getOrderDate() != null) {        while (searchString.contains("/")) {       Date date = orderHeader.getOrderDate();       String dateString = DateUtil.convertDateToString(date);   if (dateString == searchString) {         orderHeaderDTO.setOrderDate(date);     }         }   able to search with the following format = "dd/MM/yyyy" & not get a 404 or a 500 error


How to transfer a file from one system to another system in a single command?

How to transfer a file from one system to another system easily?In my company employees will always ask us to transfer files from one system A to  system B and so on. What we do is first we access system A through samba and copy the required files and then we access the system B through samba and paste the files there.Is there any easy and quick way of transferring of files from one system to another system?Any GUI will be preferable, thanks in advance :)


Can an atom be split and put back together?

I had recent came across this question when unintentionally tearing a piece of my journal paper. These atoms' bonds are pulled apart when the paper is torn, but is there a way to put them back together?   Now i know that, depending on the object, the method can vary. According to an article i read  this can be done. However i wasnt given enough info on what atom they split, as they can vary per object.   Though i am not well educated in the field of quantum physics i understand in some instances this will work. Can anyone clear this up for me regarding what types of materials can undergo this.  Edit: Forgive my ignorance when i said they are obviously split. i do realize the bonds were pulled apart. i just didn't word it as so


Travelling as Tri-Citizen (3 passports).

I have citizenship for Australia, UK & Ireland, and possess a passport for each and am planning a trip for this year. Please can you help me understand the best way to travel on these if I'm travelling from Sydney to London to Dublin, then Amsterdam, London, Sydney. It's a little complicated and I'm tempted to simply travel on my AU passport only as that's where I live and my other two passports are currently blank.   Any advice would be appreciated! Thanks.


I cannot download apps from the app store. I am running Mojave and do not want to upgrade I have already tried to do the following:  Sign in and out of my app store account Delete any app store cache files Kill any app store process and tried again Reinstalled Mojave Installed from a backup Tried to install apps on a different user  Any ideas? Thanks!


Revisited: Binomial Theorem: An Inductive Proof

I'm asked to use the fact that $\begin{pmatrix}n\\r\end{pmatrix}+\begin{pmatrix}n\\r-1\end{pmatrix}=\begin{pmatrix}n+1\\r\end{pmatrix}$ to show, by induction, that $$(a+b)^n=\begin{pmatrix}n\\0\end{pmatrix}a^n+\begin{pmatrix}n\\1\end{pmatrix}a^{n-1}b+\cdots+\begin{pmatrix}n\\r\end{pmatrix}a^{n-r}b^r+\begin{pmatrix}n\\n\end{pmatrix}b^n,$$ but I'm not sure where to start. I suspect that for the inductive step I multiply both sides by $(a+b)$, but from there I'm not sure where to go.    So this is what I've got so far doing it this way:  We are given that $$(a+b)^n=\sum_{k=0}^n\begin{pmatrix}n\\k\end{pmatrix}a^{n-k}b^k$$ Let $n=1$. Clearly $$(a+b)^1=\begin{pmatrix}1\\0\end{pmatrix}a^1+\begin{pmatrix}1\\1\end{pmatrix}b^1=a+b.$$ Now let us assume that this equality holds for some arbitrary $n>1$, namely for the equality below: $$(a+b)^n=\sum_{k=0}^n\begin{pmatrix}n\\k\end{pmatrix}a^{n-k}b^k$$ We must now show that this holds for $n+1$. We do this by multiplying each side of the equality above by $(a+b)$: $$(a+b)(a+b)^n=\sum^{n}_{k=0}\begin{pmatrix}n\\k\end{pmatrix}a^{n-k+1}b^k+\sum^{n}_{k=0}\begin{pmatrix}n\\k\end{pmatrix}a^{n-k}b^{k+1}$$ Note that $$\sum^{n}_{k=0}\begin{pmatrix}n\\k\end{pmatrix}a^{n-k+1}b^k=\sum^{n+1}_{k=1}\begin{pmatrix}n\\k-1\end{pmatrix}a^{???}b^{???}$$


How to delete/edit files created by other user?

I asked client to create a sub-domain and a folder for me.  He created a sub-domain and dir ygjhazaxnv  I only have SSH access as mani user.  I put files in ygjhazaxnv folder via Git pull and the owner of all these files is mani. So far all OK.  Now the project I configured is able to create files dynamically, whatever the files are created by my project(PHP files) has owner ygjhazaxnv  Now how can I delete files created by ygjhazaxnv user when logged in as mani?  I tried to own those files via chown but error chown: changing ownership of ‘ABC’: Operation not permitted  Both ygjhazaxnv and root user lies under group www-data  Server is Amazon EC2


Can a player move the ball through the pitch while holding it tightly near his body in football?

I was wondering whether in football one can move the ball through the pitch in an unconventional way, namely by holding it:   on his forehead  between his head and shoulder between calf and thigh while jumping towards the goal by one foot   Are these things allowed?


I am having trouble seeing what is causing my error. Code is below and below that is the error message I am receiving. Thank you.      import java.util.*; import java.io.*;  public class IO {  public static void main(String[] args) throws Exception {     File inFile = new File("src/passign6/grades.txt");     File outFile = new File("src/passign6/finalgrades.txt");      try (             Scanner input = new Scanner(inFile);             PrintWriter output = new PrintWriter(outFile);) {          int[][] grades = new int[42][];         for (int i = 0; input.hasNextLine() && i < grades.length; i++) {             String line = input.nextLine();             Scanner input2 = new Scanner(line);             for (int j = 0; input2.hasNextInt() && j < grades[i].length; j++) {                 grades[i][j] = input.nextInt();             }              input.close();             output.close();         }      }  } }  Exception in thread "main" java.lang.NullPointerException at io.IO.main(IO.java:20)


How do you transfer to a new laptop from an Internal Hard Drive removed from an old laptop?

The old laptop won't work. So I'm looking to transfer data from my old laptop's hard drive, a 640 GB Momentus (I'm pretty sure the hard drive is fine),  to a new laptop.   I've researched and it looks like I'll need something like a USB to SATA/IDE cable. I've read and watched a couple of different demonstrations using different cables and sometimes using an external power supply. I'm not sure what exactly I need for my situation.   So, my question is what precisely do I need to buy in order to transfer data from my old Momentus 640 GB drive to my new HP EliteBook 8750p, and how exactly is this transfer made? From what I understand, after all of the connections have been made, it's a simple drag and drop.


run 2 or more cmd command using system() in C++

I want to do two steps in my c++ program using system().   open the folder  system("cd /d ...") run another program.exe     However, it seems like when I run step2, the folder opened in step1 is already closed. What can I do to make sure that the folder won't be closed, so that I can use another cmd call to run .exe?  Thanks!


Problem  1)  http://wayback.archive.org/web/20110615000000*/libgd.org/Documentation   When simply pasted in question or comments, this URL keeps just the first part linked ( */libgd.org/Documentation )  2)  http://wayback.archive.org/web/20110615000000*/http://libgd.org/Documentation   When simply pasted, this URL   in comments: breaks up in two ( second comment to this question ) in question: keeps first part linked ( */ )   But * is a valid URL character (  )  Workarounds  There is a workaround to adding such URL in question - just use the toolbar button in the question context box.  "Go "  In comments, the quick help box contains details on the syntax (it works).   The bug  This enquiry relates to the feature of making hyperlinks automatically just when URLs are pasted.  Related:     status-completed  status-by-design "An asterisk is not in the sanitizer's character whitelist for URLs"


Why would you declare a method as "virtual".   What is the benefit in using virtual?


If it's not possible then maybe just the Dash show/hide animations. I simply find myself waiting for animations which is pointless.


Extracting extension from filename in Python

Is there a function to extract the extension from a filename?


I am an adult, and I want to be taller. I know about many medicines which claim to treat stunted height.  Is there any truth behind these?


Implicit newline at the end of each paragraph?

In certain styles of text I define \parindent 0pt in the preamble and write the text in this manner:  paragraph 1\\  paragraph 2\\   and so forth. I wonder if there is anything I can include in the preamble for instance to modify how the end of paragraphs are interpreted so I don't have to include the \\ at the end of each?


Failure to Boot Windows 7 after Ubuntu install

My computer is a (brand new) PC notebook, without a CD drive running Windows 7. I followed this page to install from USB:   The installation went well and i am using Ubuntu now (v. 12.04 i believe)  I want to be able to dual boot Ubuntu and Win7 The problem is that the disc partitioning during the Linux install caused a problem with Windows, caused some problem with windows, and windows can no longer boot when i choose it at the GNU GRUB screen.  When i restart my computer i can successfully boot Linux, but not Windows 7. At the GRUB screen - if i run Win7 normally, it freezes, shows a blue screen, and returns back to GRUB - if i run Win7 recovery, i dont know how to access the files that i need in order to run windows again, so nothing helpful happens.  Can you please tell me what i would need to do(or link a guide) in order to run Windows again. (Windows and Linux is preferable, but if thats impossible going back to only Windows will help too)  Im guessing the easiest thing to do is just to reinstall both OS, or is there anyway to undo the partition i made during the install?  Thanks


When will Ubuntu 18.04 release and at what time?

I heard that April 26 will be the day Ubuntu 18.04 is going to be releasing its stable version.   Is it possible to know in advance at what time?


How do you make a Video File Texture in 2.81?

I cannot seem to find any updated information on this.  I am trying to make a plane that is a video file.  For the life of me I cannot figure out how.  I applied the video file as a texture, set the amount of frames and the start frame, but all that Blender will show is the first frame of the video.  It will not play it.  All I can find about this is old out dated tutorials.  I follow them as best I can considering the UI is totally different now, but nothing seems to work.  Every video file I try just shows the first frame and that is it.  What am I doing wrong?  EDIT:  Using Cycles Render Engine  Here is my node set up:


Wordpress; installed lamp, have localhost, but no login

I installed the AMP in LAMP (already on Ubuntu) for wordpress -- and upon the initial installation & completion I got the wordpress login page, logged in, saw the control panel & stuff; logged out & haven't been able to get back ever since.   When I go to localhost, I get an index page (instead of a login page). Within the /var/www directory, I have an /html dir. & within that is my /wordpress directory. I've fiddled with the 000-default.conf file in my /etc/apache2 directory & have changed the document root back & forth some – currently it’s looking at /var/www – which is giving me html as the parent directory on my localhost page (the wordpress folder is showing up under the parent & I can click to it; just leads to a blank page). I don't have a server alias (which I've seen in a couple different threads).  I know this is going to be a stupid question: but how do I get back to the login page so that I can create a site? I'd like to have a couple different sites & have seen a couple methods for doing that, but it seems like I should figure out this first.   I did the original setup on 17.04 & like 2 days later was the 17.10 upgrade. I don't know if that is important but there seem to be some issues with the upgrade over all & I've been having some issues myself.


Left Exactness of global sections functor over quasi compact sheaves

Let $0 \rightarrow E' \rightarrow E \rightarrow E''$ be a short exact sequence of quasi coherent sheaves on a scheme X. Show that the sequence $0 \rightarrow E'(X) \rightarrow E(X) \rightarrow E''(X)$ of global sections is left exact.   Considering the sequence as first a short exact sequence of abelian groups, I have managed to show that the sequence of sections must  be left exact as a sequence of abelian groups. I thought of using this and then showing that the maps are then naturally maps of $O_X$ modules. (I might be completely misunderstanding how this is supposed to work. It's the best guess I have).  I know that there is a natural functor from the category of $O_X$ -modules to the category of abelian groups. And since the sequence $0 \rightarrow E' \rightarrow E \rightarrow E''$ is a sequence of quasi coherent sheaves, we have that given an affine open $U = Spec A \subseteq X$, the sequence $0 \rightarrow E'|_U \rightarrow E|_U \rightarrow E''|_U \rightarrow 0$ is of the form $0 \rightarrow \tilde {M'} \rightarrow \tilde {M} \rightarrow \tilde {M''} \rightarrow 0$ for some short exact sequence of A-modules $0 \rightarrow M' \rightarrow M \rightarrow M'' \rightarrow 0$. But I'm not sure how to proceed.   I understand that the case for abelian groups is stronger in that it applies to a more general case. But from what I understand, it's also weaker as there is additional structure (Here, of an $O_X$ module) that it does not account for.  Any help would be appreciated.


Given that $a,b \in \mathbb{Z}$ and are nonzero. Why is it that $\frac{a}{\gcd(a,b)}$ and $\frac{b}{\gcd(a,b)}$ are coprime?

I understand the definition of coprime, which is $\gcd(\frac{a}{\gcd(a,b)},\frac{b}{\gcd(a,b)}) = 1$ or $x(\frac{a}{\gcd(a,b)}) + y(\frac{b}{\gcd(a,b)}) = 1$. I am pretty sure that I have to use the logic that $a = qb +r$ for $r = \{0,1,2,3, ..., b-1\}$ with the algorithm of Euclides this would mean that $$\gcd(\frac{a}{\gcd(a,b)},\frac{b}{\gcd(a,b)}) = \gcd(\frac{qb+r}{\gcd(a,b)},\frac{b}{\gcd(a,b)}) = \gcd(\frac{r}{\gcd(a,b)},\frac{b}{\gcd(a,b)})$$ Now given for that \gcd, I am unsure how to prove that this would mean that $\gcd(\frac{r}{\gcd(a,b)},\frac{b}{\gcd(a,b)}) = 1$.


Continuity and Intermediate Value Theorem.

$$Duplicate$$ Please disregard this post.


How to represent the state vector form of a qubit in density matrix representation?

While I'm studying state vector and density matrix. I wonder how to write qubit state as density matrix. qubit state can be represented with state vector form. But how about density matrix?


Two sides of an acute triangle are 8 and 15. How many possible lengths are there for the third side, if it is a positive integer?  I'm not sure if the word "acute" affects the problem.  If not, is the answer 15?  I tried using triangle inequality.


How fast does Tenser’s Floating Disc move to catch up to the caster?

If an obstacle is removed, how fast does TFD move to catch up to its caster?     ...follows you so that it remains within 20 feet of you. (PHB 282)


work with threading causing stack overflow

I have a very simple code with a clear task - to make 10 cars race asynchronous.  this is the code:   class Program {     static void Main(string[] args)     {         int numOfCars = 0;         const int destKm = 1000;         Random rng = new Random();         Console.WriteLine("Write the number of cars in the race");          while (!(int.TryParse(Console.ReadLine(), out numOfCars)))         {             Console.WriteLine("You must enter a valid int. Please try again");         }          Car[] cars = new Car[numOfCars];         int randomNumber;         for (int i = 0; i < numOfCars; i++)         {             randomNumber = rng.Next();             cars[i] = new Car(i, new SynchronizedRandomGenerator(0, 100), destKm);          }          Thread[] raceThread = new Thread[numOfCars];         for (int i = 0; i < numOfCars; i++)         {             raceThread[i] = new Thread(() => cars[i].Race());             raceThread[i].Start();         }           Console.ReadLine();     } }     public sealed class Car {     public SynchronizedRandomGenerator RandomGenerator { get; private set; }      public int CarId { get; private set; }      public int DestKm { get; set; }      public Car(int carId, SynchronizedRandomGenerator randomGenerator, int destKm)     {         DestKm = destKm;          CarId = carId;          RandomGenerator = randomGenerator;     }      public void Race()     {         int kmSoFar = 0;         while (kmSoFar < DestKm)         {             kmSoFar += RandomGenerator.Next();             Thread.Sleep(10);         }         Console.WriteLine($"Car {CarId} Has Finished The Race");      } }      public sealed class SynchronizedRandomGenerator {     public  int MinValue { get; private set; }      public int MaxValue { get; private set; }      Random rng = new Random();      public SynchronizedRandomGenerator(int minValue, int maxValue)     {         rng = new Random();          MinValue = minValue;          MaxValue = maxValue;     }      public int Next()     {         return rng.Next(MinValue, MaxValue);     } }   I recive exception at the line raceThread[i] = new Thread(() => cars[i].Race());   for some reason, it raise the value of "i" after it entered the loop and causing the exception. However when I'm debug and run it line by line it seems to work.


Sending HTML using mailx with postfix 2.6.6 and centOS 6.4

I'm trying to send an HTML email from our CentOS server to users. In the long run I'll be building a COBOL program that runs the command to send reports to the user.   Here are a few details.    CentOS 6.4 MAU : Mailx  MTA : Postfix 2.6.6 Postfix is running a relay through an exchange server.    As for what commands I've tried running. The one I've seen the most today has been the following.  $ mailx -a 'Content-Type: text/html' -s "Command Line Test" andyv@example.com < ./bodytext.html   After running the shown command, I get an error saying "Content-Type: text/html: No such file or directory". I'm pretty sure that after a certain update they stopped allowing -a as a flag for Content-Type designation.   I've also tried adding the 'Content-Type: text/html' to the actual bodytext.html file as the very first line. I'm kind of just at a loss for what I can do to send the HTML email. Some of the sources I've found say that mailx and postfix can't properly send HTML emails. Hopefully that's not the case, but if it is than I'd like to know what your take on other MAU and MTA technologies?


wilcox.test in R: W stat and p value seem to disagree

I have a data set with two groups of 13 people (condition: sim and con), who get a score for a task (value). They perform a number of tasks at various time points, which form columns Task and timepoint, but for the example below I have just selected a single task and timepoint for simplicity.  I want to formally compare if the distributions are different: they are not normally distributed, and on quick inspection of the raw data and on a plot they are markedly different (not 'science' I know). I am using wilcox.test as a Mann-Whitney U in R.  The problem I am having is the first time I run the test, I try to run it on the tibble, with the condition as the grouping factor, and the W/U value seem to 'disagree' - I've worked though below.  My question is: 1)Clearly there is something wrong with my formula in the first example, but I have tried reading the help and tinkering with subset, but to no avail, so shere have I gone wrong in the first attempt? (ideally I would like to run this a number of times for different Tasks, the missing column, and I don't want to manual have to pull out a vector for each condition for each Task. 2)Which W/U is correct? I would assume it the lower value (3, see below), as it 'agrees' with the p value.  Many thanks in advance.  I'm using R version 3.3.2, in R Studio, and have loaded the tidy verse package.  # A tibble: 26 x 2  condition value   <fctr>           <int>  1       sim              99  2       sim             100  3       con             242  4       con             255  5       con             194  6       sim             135  7       con             504  8       sim             131  9       sim             115 10       sim             159 # ... with 16 more rows   If I run a Mann-Whitney U test on the data:  wilcox.test(value ~ condition, data = q)   I get the follow result:  Wilcoxon rank sum test with continuity correction  data:  value by condition W = 165, p-value = 3.445e-05 alternative hypothesis: true location shift is not equal to 0   However, the U/W value seemed high (above the  on the tables when I checked manually) yet the p value would lead me to reject the null hypothesis. So I separated the tibble into two purely numeric vectors (one for each condition) and repeated the test:  qsim <- q$value[q$condition == "sim"] > qsim [1]  99 100 135 131 115 159 105  77 178 131 120 175 191 130  qcon <- q$value[q$condition == "con"] > qcon [1] 242 255 194 504 545 344 194 198 208 173 349 280  wilcox.test(qsim, qcon)      Wilcoxon rank sum test with continuity correction  data:  qsim and qcon W = 3, p-value = 3.445e-05 alternative hypothesis: true location shift is not equal to 0   The p-value is the same, but the U/W value is lower (and far more in keeping with what I would expect by visually comparing the vectors, let alone plotting them).


I have 27 inch wheels and need new inner tubes what size can I use

I have 27 x 1 1/4 inch tires on my bike and need to buy new tubes. Can I use 700c or just 27 inch?


Automatically reconnect wireless connection

The wireless connection in my house unfortunately often disappears, requiring a wireless router reboot.  Making this worse is that my ubuntu media pc, does not automatically reconnect to the wireless network when it's been gone, and then comes up about a minute later. The network in question is setup as "connect automatically" in the network settings.  If I manually select my wireless network, using the wireless icon in the topright of my screen, everything works fine, until the next time that wireless goes down.  I'm looking for a way so I don't have to remember to do this manually all the time.


Making adult decisions "is" or "are" really not fun: Which is correct?

Making adult decisions are/is really not fun.     What is the proper answer and why? My gut says "is" but I can't explain why.


If I am given some random date, then I need to check if that date really exists or not and then display true or false. I need to return false for both the dates 32-11-2010 and  31-02-2010 because the month of february doesn't contain 31st. How do we do this in Java?


Can the birthday attack be extended in this case?

Let $H:\{0,1\}^*\to\{0,1\}^n$ be a cryptographic hash function as a black-box, and suppose we have unlimited space.  As I understand, finding $x$ such that $H(x)=0$ (if such exists) would require a preimage attack, and avg. time $O(2^n)$ (linear in the size of the output). On the other hand, finding $x\neq y$ such that $H(x)\oplus H(y)=0$ could use the birthday attack, and therefore avg. time $O(2^{n/2})$.  My question is, if something better can be said for finding 3 (or more) distinct values $x,y,z$ such that $H(x)\oplus H(y)\oplus H(z)=0$. It seems clear that this could be done using less samples of $H$, but it's not clear to me if the time complexity could be improved.


Prove that the number 14641 is the fourth power of an integer in any base greater than 6?

Prove that the number $14641$ is the fourth power of an integer in any base greater than $6$?  I understand how to work it out, because I think you do   $$14641\ (\text{base }a > 6) = a^4+4a^3+6a^2+4a+1= (a+1)^4$$  But I can't understand why they had to specify that the base is greater than 6? Is that because if it's 4, then 4 will be cancelled out in the equation and if it's 6, it will be too?   Please advise.  Sorry for asking such a trivial question.


What do shiny ovals mean on Magic the Gathering cards?

I have just bought a set of Oath of the Gatewatch cards, and a few of them have a small shiny oval on the bottom center, like .  What does this mean?


Find range of $f(x)=3|\sin x|-4|\cos x|$

Find range of the function $$f(x)=3|\sin x|-4|\cos x|$$  I tried to do by using the trigonometric identities $$\sin^2x=\frac{1-\cos 2x}{2};\cos^2x=\frac{1+\cos 2x}{2}$$  So $$f(x)=3\sqrt{\frac{1-\cos 2x}{2}}-4\sqrt{\frac{1+\cos 2x}{2}}$$ but don't know how to proceed from here.


How does an Intelligence penalty affect skill points when character-building/leveling-up?

In character-building/leveling-up, you take your class's skill points and add your Int bonus.  So a Fighter gets 2 Plus their Int bonus.  Say my fighter is really smart(16) he'll get 2+3 (int bonus) or 5 points per level.  But what if my fighter is dumber than a sack hammers?  Let's say int 4.  He levels up and gets 2+int mod.  Int 4 carries a -3.  So it's 2+(-3) which equals -1.  How does a dumb fighter level up any of their skills if they have negative skill points?  Or is the int bonus only added if it's positive?


We as a community overuse the duplicate feature

When I first discovered Stack Exchange, it was in the form of Stack Overflow. It seemed like a great place...until I became a member. Apparently, my policy of "Upvote unto others as you would have them upvote unto you" is not common. Before long, I had deleted 10 questions, and my answers were an odd, faded gray. But then, a new problem came: the duplicate. Already, it seemed to me that the higher reputation users sat upon thrones of gold, dumping vats of acid upon lower reputation members while keeping themselves nice and happy.  What I think high reputation users don't realize is that every user on Stack Exchange came here for a reason. Whether that reason is to have fun on PPCG, or to get help on Stack Overflow, we all just want to be part of the fun/work/riddles. Also, even though a question may be a duplicate, it is not necessarily bad. The question might see things from another perspective, or have several unique parts. The only purpose the duplicate flag serves is to alienate new users. Of course, the obvious exception is a question that has been asked 5 times. But some question that happens to be a near duplicate of some obscure other question is not truly a pointless duplicate.  The point of all this is to just remember that every user is a person,too. Every question is a form of wonder, and wonder is an incredible thing. The fact that we as a species have the capability of asking, and learning, is extraordinary. So why would we want to mark harmless duplicates in such a rude way, as if we are robots built to thin out every remotely similar question and insult it? It is wrong.  How can we fix this? This is not a duplicate of , as that question is about how to handle duplicates.


Tracking the path of two point masses through time under the influence of gravity and with no initial velocities

Given the point mass $p_1$ at $(0,0)$ with mass $m_1$ and the point mass at $p_2$ at $(r,0)$ with mass $m_2$ how would you find the positions of $p_1$ or $p_2$ at any time. My first thought was to first solve the problem of what their positions were after some small period of time $\Delta t$. The force by gravity on $p_1$ is $F_1=\frac{Gm_1m_2}{r^2}$ and from the equation $F=ma$ substituting $\frac{v}{t}$ in for $a$ and the $\frac{d}{t}$ for $v$ the result should be $F=\frac{md}{t^2}$ we know the force on $p_1$ and its mass, as well as the time so substituting them results in $\frac{Gm_1m_2}{r^2}=\frac{m_1 d}{\Delta t^2}$ some quick algabra tells me that $p_1$ should have move a distance of $d_1=\frac{Gm_2\Delta t^2}{r^2}$. Taking similar steps brings me to find that $p_2$ travels a distance of $d_2=-\frac{Gm_1\Delta t^2}{r^2}$. From there the same process could be repeated to find the position of of $p_1$ and $p_2$ at the time $2\Delta t$ except by using $r-\frac{G(m_1+m_2)\Delta t^2}{r^2}$ for the new distance between the points. In general if $R(t)$ is the distance between $p_1$ and $p_2$ and if $D_1(t)$ is the distance that $p_1$ moves over the time $\Delta t$ at time the time $t$ then $D_1(t)=\frac{Gm_2\Delta t^2}{R(t)^2}$ and the corresponding function $p_2$ is $D_2(t)=\frac{Gm_1\Delta t^2}{R(t)^2}$. With those two equations $R(t)=\lim_{h\to\infty }\sum_{n=0}^h D_1(\frac{nt}{h})+D_2(\frac{nt}{h})$, but since $D_1$ and $D_2$ are defined that makes are self referential, is there any way out of that? Would the definition $R(t)=\int_0^t\frac{G(m_1+m_2)}{R(u)^2}du$ be equivalent or useful? Most of this work is back of the envelope stuff combined with only really a half understanding of both calculus and Newtonian Mechanics, so any pointers or advice would be greatly appreciated.


Feature rendering issue in Geoserver WMS layer at larger zoom scale

I am using Geoserver 2.15.1 version to display PostGIS data as WMS layer at client side. There will be a rendering problem in my WMS layer, some dense areas are not visible in larger scale as marked in the below snapshot. Those area are getting generated when zooming closer to the particular location.  Is there any way in GeoServer to make the features visible at all scale levels? I have tried MinScaleDenominator and MaxScaleDenominator, but no luck.


what's the grammar structure of "ought to"

I've seen many explanations that just treat ought to as a whole which equals should. but how to explain the function/role of each word separately? for example:  I ought to go now.  which role does to act there?  where to is just part of the to-infinitive to go (as a mere infinitive marker, no meaning) if so, why to-infinitive marker is required after ought, but not after should?  to is part of the phrase ought to, if so what's its function/role at all?   I have similar questions in understanding auxiliaries like have to and used to also, so how to understand this kind of structure correctly?


I am new to game design and i am creating a MMORPG that allows players to create 2d avatars that can be customized. If i had lets say a male character model (no equipment no armor). How would i handle body variation for this male model? If this has been answered please provide link. I know layering customizing for equipment and armor has but not morphing the character sprite itself.


I need to describe all numbers of the form $x^2 + 2y^2$.  So far I've reduced the problem to primes, and showed p=2 satisfies it. I've also shown that any primes mod 5 or 7 can't be a written in this form. How do I proceed to show that it holds for all primes mod 1 or 3? I think I'll need to use quadratic reciprocity somehow (only since it is the topic of the homework). I have a hunch the supplementary quadradic recprocity laws will be important.  Any help would be appreciated. Thanks!


Section numbering gone after etoolbox use?

I am using Kile 2.1 on Ubuntu 16.04. I have been trying to make corrections for my dissertation concerning the table of contents. After trying a number of options including a couple etoolbox patches I restored my custom .sty file back to the original form. Now I no longer have numbering before section headings. This is independent of the class (e.g. report or article). I have no idea what permanent change I have made. I have no idea how to correct this issue.


I'm looking to implement a phase lock in an FPGA without using any external components (other than the ADC). For simplicity locking to a simple binary pulse is adequate. The frequency of the signals is ~0.1-1% of the clock. I can't use the onboard clock PLL's because they are typically:   Not configurable (set during synthesis). Jittery. Don't support the frequency I need.   I've been sorting through the literature and found a few binary phase locked loops. Most notable a "pulse steal" design that I can post a link to if desired. I have implemented and synthesized with some success, but its jitter and lock range was not as good as advertised. I've also had success using a external DVCO, but I would prefer if I can implement everything on chip.  A digital circuit design or even a hint in the right direction would be helpful (I've been banging my head against this for a while), a proven FPGA implementation would be wonderful but not expected.   ADDED 10-27-2010   The actual DPLL design that I used has a "Random Walk Filter" as the loop filter (not the "pulse steal" described earlier, going through my notes that didn't work to well), which then drives the clock pulses to the DCO. The lock-in range is set via divider in the DCO. The sensitivity of the loop is established by varying the length of the random walk.   The paper in which this is found is cited at the end of this post. After implementing parts of it myself, I found that it was actually already implemented on OpenCores, however it turns out that in the last few months the project was deleted but I have the Verilog files saved if anyone wants them.  Yamamoto, H.; Mori, S.; , "Performance of Binary Quantized All Digital Phase-Locked Loop with a New Class of Sequential Filter," Communications, IEEE Transactions on , vol.26, no.1, pp. 35- 45, Jan 1978  doi: 10.1109/TCOM.1978.1093972  URL:


AF Nikkor 50mm 1.8 stopped being recognized by D3500

My lovely bride, of 40 years, bought me a new Nikon D3500 bundle. Loves me. I own a Nikkor AF d 50mm 1.8. Think it is about 13 years old. I have used it about 200 shots with the D3500 and worked great. Went to use it today and my D3500 says it is not recognized and the screen shows a blinking f_ _ _ in the aperture set area. The 50mm still works great on my D40. I reset my D3500 settings back to default. Any thoughts about what happened to my beautiful 50mm? I love it more than any other of my 8 lenses.


Setting up vhost on VirtualBox with Ubuntu 16.04

I am pretty new to development and this is why I am stuck at such a "beginners" problem.  I want to have a directory under /var/www/mysite with a index.html and access it via web browser on my PC (Win10 64 Bit) by typing mysite.example into it.  I don't want to publish anything into the internet with that. I only want to test and develop a site which later might be hosted.  I have created a VirtualMachine using Oracle VirtualBox and installed Ubuntu16.04 (64-Bit, also enabled Virtualization at my i5 2500 in Bios so I get these 64-Bit displayed).  Then I installed apache2, mysql and php.  ip addr show gave me an address: 192.168.178.31.   So if I type into my browser http://192.168.178.31/ I get to the apache2 default page - It works!  I created the directory /var/www/mysite and put a simple index.html for testing purpouse into it. I said sudo chown -R 775 to /var/www/.  Now I need to create a vhost so I can access to this index.html in this specific directory by typing in a specific string into my browser. But it just won't work!  I went to /etc/apache2/sites-available/ and created mysite.conf.  This is the content:  <VirtualHost *80> ServerAdmin webmaster@localhost DocumentRoot /var/www/mysite ServerAlias mysite.example </VirtualHost>   I did a2ensite mysite.conf, sudo service apache2 reload and restart  So there I am. If I type mysite.example into my browser I only get errors.  Site not reached. DNS-Server for mysite.example not found and so on (ERR_NAME_NOT_RESOLVED).


Create dynamic submenu + event triggering with append?

so I was trying to implement a submenu within a submenu on a navigation bar. The idea is to have the submenu "reports management" generates when the Report is clicked. The code as below. HTML
File &nbsp;

  JQuery  $(document).ready(function(){         var files_management = '
View Files
' +                               '
 Reports ' +                                  '
' +                                  '
' +                              '
';        var reports_management = '
Files
' +                                 '
Borrowed Files
';         $("#btnFileMgmt").click(function(){           $("#filesMgmt").append(files_management);       });        $("#btnReports").click(function(){           $("#reportsMgmt").append(reports_management);       });   But I don't understand is it the limitation or the way I using is wrong because it wouldn't generate when the Reports inside the Files is clicked.


What is the code for the elevator in FNAF Sister Location?

I was playing Five Nights At Freddy's Sister Location when I found a little number pad in the elevator. I tried several number sequences (1983, 1987, 1234, 2320245) but none of them worked. If anyone knows the number sequence that'd be very useful to me.


How to prevent accidental clicks in the Save button when saving a node?

I need to prevent accidental clicks in the Save button when a node is being saved.  I found this   which does exactly this. But the problem is that it uses javascript (jquery). Then if the user disable javascript this module is useless.  My problem is that in my website the user get points when creating nodes, so I have to prevent this in a more secure way.  How can I do this?   What do you think of these ideas?:  1) Maybe I would forbid the node being saved more than one time    programmatically instead of disabling the Save button.   2) Or better: I would allow the user to just save a new node every 5 minutes.


Does an abbreviation which is written in lowercase have to be capitalised after a period?

I must use after a period an abbreviation which is "mtDNA" (mitochondrial DNA). It is always abbreviated with the two first letters in lowercase. I'm struggling to find a rule to know whether the "m" has to be capitalised or not after a period. For example would you write :  lorem ipsum. MtDNA is very important for cells. lorem ipsum. mtDNA is very important for cells.  It appears to me more natural to have it lowercase also because I'm used to read it almost everyday.  Is there a rule that can be applied?  Best ,


particular Laptop key has no keycode (found with xev from Xorg)

that following key should be XF86AudioLowerVolume, but it has not even a defined keycode, i could assign the function of XF86AudioLowerVolume. I've used xev to find that out. I'm using debian Jessie and a Thinkpad T520.  FocusOut event, serial 32, synthetic NO, window 0x1800001,     mode NotifyGrab, detail NotifyAncestor  FocusOut event, serial 32, synthetic NO, window 0x1800001,     mode NotifyUngrab, detail NotifyPointer  FocusIn event, serial 32, synthetic NO, window 0x1800001,     mode NotifyUngrab, detail NotifyAncestor  KeymapNotify event, serial 32, synthetic NO, window 0x0,     keys:  2   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0               0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   for comparison, the output of XF86AudioRaiseVolume  KeyRelease event, serial 32, synthetic NO, window 0x1800001,     root 0x9a, subw 0x0, time 2905663, (3,321), root:(810,328),     state 0x0, keycode 123 (keysym 0x1008ff13, XF86AudioRaiseVolume), same_screen YES,     XLookupString gives 0 bytes:      XFilterEvent returns: False   any ideas?


In the early 2010s, I recall reading a trilogy of novels about 2 kids who have to keep earth's timeline from changing. In order to do this, they stayed on a loop of one day in a city (I think San Fransisco?) and if their surroundings changed in any small way, they'd know something happened in the past and messed with the timeline.  They also had some sort of bodyguard clone thing that was a man in the first book, was somehow made into a woman in the second, and both versions joined them in the last.  The only specifics I can remember about each book is that the first involves the First World War, the second involves dinosaurs. I have a vague recollection of Prince John in the third book, but nothing beyond that.  I was young when I read it, so I assume it's not very highbrow literature, just a YA fiction series or something like that.  Anyone remember this series?


Accepting a callback via REST from ScheduleOnce

I've never done anything with APIs before so this question is going to be badly asked. We use a online scheduling tool called ScheduleOnce. That tool has the ability to utilize webhooks, per this article , to notify other systems of bookings behind made. What I don't know how to do, nor find the information on apparently, is how do I listen for / consume the POST message in Salesforce? I want to create a record in a custom object whenever a booking is made in that scheduling tool. Not asking for anyone to write any code for me. I just can't seem to figure out the starting point for this. Found plenty of info on how to have Salesforce post to another system but not finding how to consume the message from another system. Thanks!


How to close the mouth of chromium for asking gnome-keyring password?

I use Ubuntu 13.10.  I don't like to put my password at each time.  How to attain the logging without password entry ?


Is there a way to programmatically deactivate Proces Builder & flows?

Is there a way to soql procesbuilder to tun activation off?  For example  List<Processbuilder> pbColl = new List<Processbuilder>();   Processbuilder pb=[SELECT status FROM Processbuilder WHERE status Active];  for(Processbuilder turnoff : pb){             turnoff.status = false;             pbColl.add(pb)} update pbColl;   If not is there a simple way to turn all activated Processes off/on?


A simple module is a semisimple module .     A module $M$ is called semisimple if every submodule is a direct summand of $M$   Since a simple module has $\{0\}$ and $M$ as its submodules so it is semisimple.  But why is  a simple ring not semisimple because a      A ring is semisimple if it is semisimple as a module over itself   How to construct such a ring?When will the result hold?


My prof gave us this definition of an Echelon system:     A system of m linear equations in n variables is called an echelon system if         m ≤ n.   Every variable is the leading variable of at most one equation.   Every leading variable is to the left of the leading variables of all lower equations.   Every equation has a leading variable.      I don't understand this definition at all.  Q1)If you have this system of equations:  $ax_1 + bx_2 + cx_3 = z$  $dx_1 + ex_2 + fx_3 = z$  its not an echelon system because of multiple equations having the same variable as the leading variable and therefore violating rule #2.  But if you switch around variables and rewrite the equation as:  $ax_1 + bx_2 + cx_3 = z$  $ex_2 + dx_1 + fx_3 = z$  It becomes an echelon system! Why would the way you write a system of equations affect its definition?  Q2)Why would point number three matter? Can't you just move around the equations so that they are in order of variables?  Q3)Why would point number four matter? If you have a equation in the system that doesn't have a leading variable can't you just disregard it? For example if you have the equation $0x = 0$ in the equation can't you just ignore it to have a echelon system since it doesn't affect the solution of the system?


When running `rm -rf`, is it possible to exclude certain subdirectories?

I routinely use bind mounts to aid in making space available in multiple locations without having to have multiple logical volumes / physical partitions / LUNs, etc.  For example, I may have a 200G LV mounted at /space. From there, I will make subdirectories like var_opt and var_log which I can then bind mount to /var/opt and /var/log, respectively.  When doing a cleanup on the 'space' directory, is it possible to exclude directories from an rm -rf running inside /space?  Example:  # pwd /space # rm -rf * {except-for-var_opt-and-var_log}   Is there a different or better (but similarly simple) way to accomplish what I'm trying to do that I haven't thought of?


After asking a question, I may be interested in quick responses and react on comments quickly. So I leave the tab open. But I always need to check back to the tab to see whether there's a "something has been added" note somewhere, either a comment to the question, or a new answer or a comment update on an answer I already read. Couldn't this also be shown in the page title so I don't need to switch tabs all the time while I'm reading something else?