Paralist package breaks hyperref pdf links

Something bizarre is happening with the clickable links that hyperref creates in my PDF file.  Here is an example LaTeX file:  \documentclass[12pt]{article}  \usepackage{amsmath,amsthm,paralist} \usepackage[dvipdfm, bookmarks, bookmarksdepth=2]{hyperref}  \theoremstyle{plain} \newtheorem{theorem}{Theorem}[section]  \begin{document}  \begin{theorem} \label{thm:test} \begin{enumerate}[\rm (a)] \item First thing. \item Second thing. \item Third thing. \end{enumerate} \end{theorem}  Reference to Theorem~\ref{thm:test}(a).  \end{document}   It compiles without warnings (using LaTeX), but when I then convert the DVI file to a PDF file with dvipdfm I get  ** WARNING ** PDF destination "theorem.0.1" not defined.   I can open the PDF file, but the clickable link for the theorem just doesn't do anything.  The problem seems to be the paralist package : if you remove it, then everything works just fine.  Also, if you insert a line of text between the \begin{theorem} and the \begin{enumerate} lines, then it also works fine.  What am I doing wrong here?


How to I need to treat dried green lentils?

In the attached picture you see green lentils which I want to prepare in order to make a Dal. They are obviously dried although it is not mentioned directly on the package.   My question is: Do I need to treat them like dried chickpeas? Dried chickpeas must be unpacked and then stay submerged for around twelve hours to be edible and cookable. Do i need to do the same with the lentils? One lentil has far less mass than a chickpea so I had doubts.  EDIT: I am aware of this possible duplicate but the submitter of the question has not clarified what types of lentils he wants to cook:


IEEEtran - How to include ORCID in TeX/PDF with PdfLatex

This question led to a new package:   I would like to display the ORCID id in an author list in an IEEEtran pdf, like that:  Is there a standard way to include it in an IEEEtran article with PdfLaTeX? I used two approaches from , but I failed. One is to insert the ORCID icon in the author list. I used the blow code: \author{Ali Al-Obaidi \href{https://orcid.org/0000-0000-0000-0000}{\includegraphics[scale=1]{figures/orcid_16x16.png}}}  where orchid_16x16.png is provided in the link . But the result is that the icon is not clear enough, even I replaced it with a different size. The other approach is to use the  package, like that: \usepackage{academicons} \definecolor{orcidlogocol}{HTML}{A6CE39} \author{AAA \href{https://orcid.org/0000-0000-0000-0000}{\textcolor{orcidlogocol}{\aiOrcid}}}  However, the result is like that:  And I also got two errors: "Latex Error: Encoding scheme 'TU' unknown" and "Bad character code (59865)". In the latest academicons.sty (see ), academicons use the font TU. However, it seems that the compiler PdfLateX cannot support this font. Thus, is there anyone that knows a standard way to include it in an IEEEtran article with PdfLaTeX? Please help me.


I am using blender 2.8, system Ubuntu Here is the video codec of source file H264, MPEG-4 AVC Frame rate 24    In blender, I set the output as File format FFmpeg video Encoding Container MPEG-4 Video codec H.264 Output Quality: High Quality    Why the video gets faded, or a dark shadow is formed after rendering?     Original video screenshot (screencast using Kazam):   Screenshot of video rendered by blender:   I also tried many other settings like AVI, but all are giving the same results.


I have a comp sci project:  Prompt the user to enter a word.     If the word is “Neil,” then ask the user to enter a letter. If the letter is a or b, display “Peart.” If it’s another letter, display “Xanadu.” If the word is “Geddy,” then ask the user to enter a number. If the number is odd and divisible by 9, display “Lee.” If the number is negative or equals 2012, display “YYZ.”   I typed the code for this and everything works except one thing. After I write Neil and it asks me to write a letter, if I type a or b it doesn't output Peart it outputs Xanadu.   import java.util.Scanner;  public class Rush  {      public static void main()      {        Scanner myReader = new Scanner (System.in);        System.out.print("Enter a word:" );        String word = myReader.nextLine();         if (word.equals ("Neil"))        {            System.out.print("Enter a letter: ");            String letter = myReader.nextLine();            if  (letter == "A" || letter == "a" || letter == "B" || letter == "b")            {              System.out.println("Peart");                        }            else             {              System.out.println("Xanadu");              }        }        if (word.equals ("Geddy"))        {            System.out.print("Enter a number: ");            int number = myReader.nextInt();            if (number % 2 != 0 && number % 9 == 0)            {               System.out.println("Lee");             }            if (number < 0 || number == 2012)            {                System.out.println("YYZ");            }        }      }  }


How can I transfer files from PC to Phone or vice versa without internet

I am using a cloud service (Dropbox) when I am using internet for file transfer. But how can I transfer files between my PC and my Android device without going via the Internet? and of course without using data cable.


How to take away only one of multiple items

I'm making an enchanting shop, where you click a button, it takes away your sword, gives you an enchanted one. But currently, I am using /clear to take away the sword, so if someone has more swords, it takes away all of them. How do I do this? Do you have to add a number somewhere? I am not trying to take away items with custom names, just a normal diamond sword.


Let  $(x_n)$ be a sequence in a Banach space $E$ such that $\sum_{j=1}^{\infty} |\varphi (x_j) |<\infty$, $\forall \varphi \in E'.$ Then $\sup \limits_{\|\varphi\| \leq 1} \sum_{j=1}^{\infty}|\varphi (x_j)| <\infty $.  My attempt:  For all $n \in \mathbb{N}$, define $f_n: E' \to \mathbb{K}$, $f_n(\varphi) = \sum_{j=1}^{n} \varphi (x_j)$.  ($\mathbb{K} = \mathbb{R}$ or $\mathbb{C}$)  Each $f_n$ is a continuous linear functional, since:  $$|f_n(\varphi)| = \bigg| \sum_{j=1}^{n} \varphi (x_j) \bigg| \leq  \sum_{j=1}^{n} |\varphi (x_j)| \leq \sum_{j=1}^{n} \|\varphi\|\|x_j\| =  (n \max \{\|x_j\|\} ) \|\varphi\|$$  For each $\varphi \in E'$, $(|f_n(\varphi)|)$ is bounded since $$|f_n(\varphi)|  \leq \sum_{j=1}^{n} |\varphi (x_j)| \leq  \sum_{j=1}^{\infty} |\varphi (x_j)| = M_\varphi \in \mathbb{R}  $$  By Banach-Steinhaus theorem, there exists $M>0$ such that $\sup \limits_{n \in \mathbb{N}}  \|f_n\|<M$.  For all $n \in \mathbb{N}$, we have: $$M> \|f_n\| = \sup \limits_{\|\varphi\| \leq 1} |f_n(\varphi)| =  \sup \limits_{\|\varphi\| \leq 1} \bigg|\sum_{j=1}^{n}\varphi (x_j)\bigg| $$  Then $$\sup \limits_{\|\varphi\| \leq 1} \bigg|\sum_{j=1}^{\infty}\varphi (x_j)\bigg| \leq M $$  Unfortunately, this is not  what we want to prove.   How can I fix it?


Oracle 11g installation stuck at installation

I'm trying to install oracle 11g on fedora by following  but it stuck after I click Next in step 8. The screen does not go away even after several hours. There's no log file in oraInventory folder.   What could be the possible problem? How can I debug it?


What is the easiest way to center align each row of table? I have a table column that contains an image and other cells in the same row contain text. I would like to know how to vertically center align the image and text cells. Currently each row is vertically bottom aligned. Here is my code:  \documentclass[a4paper]{article} \usepackage[margin=1.0in]{geometry} \usepackage{booktabs, caption, underscore, url, graphicx} \captionsetup{font=bf} \date{2012-03-01} \begin{document} \begin{table}[ht] \centering  \begin{tabular}{cccc} \bottomrule[2pt] A & B & V & D & E \\ \bottomrule \includegraphics[scale=0.35]{img1.eps} & 2 & 3 & 4 \\  \includegraphics[scale=0.35]{img2.eps} & 2 & 3 & 4  \\  \bottomrule[2pt] \end{tabular}  \end{table} \end{document}   Here is a quick sketch of the table I am trying to achieve:    The first column contains an image while the other columns contain a single line of text. How can the text be center aligned with the middle of the image?


how to recursively transfer folders between two remote servers on a local machine

I want to use a program like rsync or scp to recursively transfer folders from one remote server to another on the shell. I connect from one server usually via sftp and the other via ftp, but I believe I can also ftp and ftp. I have the links to the desired directories. I tried a program like ftprush in windows, but it would connect to both servers, but wouldn't initiate the transfer. How can I do this?


How to block a specific site's directory in windows?

How can I block a specific directory of a website as e.g. someSite unfortunately the hosts file is not an option since you can only block whole domains there and any "/" just destroys these rules.  This is just for my personal protection against visiting some sites too often, while i still have to be able to get to the other sites of that domain (as e.g. example.com/someOtherSite)  Would be great if someone knows a solution regarding this topic.


I want to make an arena where mobs will fight each other and a player can bet on one side or the other. For example: There are 2 skeletons in dyed armor; red and blue. Each color representing a team. When they spawn I want them to fight each and then when one dies I want it to announce which team is the winner and give the player the "money" due. I'm just not sure how to get the skeletons to attack each other without a player instigating it.


can the higgs particle interact with himself as it is the antiparticle of himself?  as we know that the every particle is the excitation of their respective fields i.e higgs of higgs field so what about the antiparticle?


User scope vs Application scope in app.config

What is the difference between the User scope and Application scope in app.config?


If almost everyone can earn money on stocks using good strategies. Why does a company shares profit or losses(or i do not know what the proper term is). What benefits company received? I came here because i cant find or not satisfied by the answers given by google.


how to determine value of a power storage capacitor in an intermittent circuit

I made a post earlier about this but apparently there weren't enough details and i didn't explain it well enough so i will try this again:  I have a circuit which runs on intervals of 0.75 seconds on/off. (for example, if i had a lightswitch/lightbulb, i turn the lightswitch on, but the bulb goes on for 0.75s then turns off for 0.75s then turns on for 0.75s etc. etc. for the entire time that the lightswitch is turned on, when the lightswitch is off, the bulb is constantly off)  This circuit (when on) runs at 12V and when i had the multimeter set to the 10A setting, it showed 0.07, so I'm guessing thats 0.07A?  This circuit is being connected to the signal coil on a relay.  This relay coil says on it 12VDC, when checking with a multimeter on the 2k ohm setting it showed 270, guessing thats 270 ohms?.  I checked with an adjustable power source and the minimum voltage that activated the coil was 6V, although it could only jump from 4.5V to 6V so that was the smallest it would switch at.  What I am trying to do is install a capacitor before the relay, so that during that 0.75 seconds of off, the capacitor discharges at a minimum 6V.  so my current problem is that if i just install that relay directly into that intermittent wire, the relay switches on/off at the same time as that wire, I need it to stay on.  To make a comparison: this circuit is kind of like the signal lights on your car, they blink on/off/on/off with some unknown time interval. Say you had a light that is able to work at 6V but typically works at 12V. I am trying to install a capacitor, so that when you turn the switch on (by your steering wheel) that light would be constantly on for the entire duration that the switch is turned on. instead of blinking on/off/on/off.


Some binaries in Unix-Linux systems like ping or mount have a long argument. For example if we write ping -h in the terminal, one of the options is:  Usage: ping [-aAbBdDfhLnOqrRUvV64]   Is this long set of characters really an argument?


Vertically align text next to image using CSS

I'm trying to vertically center the content of an inline-block and I can't figure it out. I've tried different options I've found here such as the flex and the transform but none of them worked for me. I'm probably missing something.  The idea is to have several divs (steps) with one image each on the left and some lines on the right, centered vertically.  Any help is appreciated  HTML:

1. Register
Morbi ut egestas urna, et interdum dolor. Duis fermentum orci in nisi egestas, et imperdiet mauris luctus. Praesent vulputate diam
<button>

    CSS:  .med-step-wrapper {     width: 95%;     margin: 0 auto; }      .med-step {         width: 100%;     }      .med-step-logo {         width: 33%;              display: inline-block;         padding: 3rem;     }          .med-step-logo img {         width: 100%;                 height: auto;     }         .med-step-text {         width: 66%;         display: inline-block;         font-family: 'DIN1451EngschriftRegular';     }      .med-step-text p {        }


After rebooting I need to log in each time in Chrome

If I reboot Ubuntu, then I need to log on each site and into Google Chrome account. What is the reason?  My system is Ubuntu 16.04 and Google Chrome 53.0.2785.101 (64-bit).


Why is double data type gives error in C++?

This is the C++ program I've written to get fibonacci numbers from 1 to 100.   #include <iostream> #include <vector> #include <iomanip> using namespace std;  int main() {     int n;     vector<double> f;      //adding first two fibonacci numbers to vector     f.push_back(0);     f.push_back(1);      cout<<"How many fibonacci numbers do you want : ";     cin>>n;      for(int i=0; i<n; i++)     {         if(i>1)     f[i] = f[i-1] + f[i-2];         cout<<(i+1)<<": "<<fixed<<setprecision(0)<<f[i]<<endl;     } }   All the results are correct upto 79 values but then after the 80th value is not exactly the sum of 78 and 79 values. The output is:  .... 78: 5527939700884757 79: 8944394323791464 80: 14472334024676220 ....   Here the last digit should be 1 but it shows 0, why did this happen?


This should be a common issue on this site, but I did not find the information I needed.  Why did not my images follow the sequence I tried to define?  \documentclass[11pt,fleqn]{book} \usepackage[portuguese]{babel} \usepackage[utf8]{inputenc} \usepackage{graphicx} \usepackage[]{titlesec} \usepackage[many]{tcolorbox} \usepackage{tikz} \usepackage{enumitem}  \begin{document}  %---------------------------------------------------------------------------------------- %   PARTE 1 %----------------------------------------------------------------------------------------  \part{Parte 1}  %--------------------------------------------------------------------------------------- %   Capítulo 1 %---------------------------------------------------------------------------------------  \chapter{Conhecendo o SolidWorks}  %--------------------------------------------------------------------------------------- %   Seções %---------------------------------------------------------------------------------------  \section{Introdução} Quando você abre o aplicativo SOLIDWORKS pela primeira vez, a tela que você vê é a seguinte:  \begin{figure}     \centering     \includegraphics[width=14cm]{1.png}     \caption{Tela inicial}     \label{fig:1} \end{figure}  \section{Interface do Usuário} Abra no botão Novo:  \begin{figure}     \centering     \includegraphics[width=14cm]{2.png}     \caption{Botão novo}     \label{fig:2} \end{figure}  \section{Comandos da Interface do usuário}  \begin{enumerate}     \item Barra de menus     \item Barras de ferramentas     \item Gerenciador de comandos (CommandManager)     \item Gerenciador de configurações     \item Gerenciador de propriedades     \item Filtro da árvore de projeto     \item Trilhas de seleção     \item Árvore de projeto do FeatureManager     \item Barra de status     \item Barra de ferramentas transparente     \item Painel de tarefas     \item Área de gráficos \end{enumerate}  \end{document}     1.png    2.png


I have enum like this :     enum Numbers     {         SmallerThenThree = 3,         SmallerThenFive = 5,         SmallerThenTen = 10,     }   Is it possible get item of enum by specific number? For example :   var numberFour = 4;         var enumOfNumber = (Numbers)numberFour; // There should be SmallerThenFive enum type         var numberSix = 6;         enumOfNumber = (Numbers)numberSix; // There should be SmallerThenTen enum type


So many deathclaws... How do I make them stop?

I'm apparently doing something wrong. I'm getting raided by deathclaws constantly(at least once per session), and they do some real damage to my dwellers.  The in-game hints say they are attracted by the radio and opening my vault, but I don't know if there is a way to turn the radio off while my vault is open.  How can I stop all these deathclaws from eating my dwellers, while still attracting new ones?


Google maps location inaccurate by over 200 miles

My phone keeps recording me as being over 200 miles south of where I am. I have looked up the location but it is not anywhere I have ever visited, Godalming near Epsom. When looking on my history it records me as being there more than once, however zooming in to that location it is actually just a track down a back Road. How can I prevent this?


I once had a book called Arena. Unfortunately that is a very common book title. Its cover was very similar to:    but that's a coincidence.  In the story, the main character (female), is invited to take part in an experiment. In the experiment she is transported to another world. (I'm pretty sure it was virtual reality.) The world has 3 sections:  The first section everything is fairly simple. You just have to stay on the path, and walk to the end, and insert the key into a door. But no one ever does. (The get off the path, and turn their keys into weapons etc). There is a town at the base of the wall (I think it is infinitely high, people try to climb it). Along the way there are safe houses that can be accessed with the keys.  The second area is (I think) a staging ground. There is a library and a team gathers to try and, I think cross the wasteland, and then get into a city (it was full of goblin equivalents).   The third area is the city and the wasteland. At the end, the main character makes it out, (There must be a gate at the center of the city).   One of her friends (male), was shot on the way, but she meets him back in real life but he has no memory. (Only people who legitimately escaped keep there memory). It was theorised the guys conducting the experiment must have been aliens because their technology was so advanced.  The book has at least one sequel. (I managed to hunt the book down once before when I when back to the library I first found it.) It was published during or before 2005.  On of my friends has had the exact same problem, trying to find it. (I mentioned this book I read, called "Arena", and he was like "I read a great book called Arena once, but I can't remember the author name, and there are so many others.". Eventually we worked out it was the same book.  Any help finding the author name would be appreciated.


Operation of simple FM transmitter circuit

I found the following little FM transmitter circuit among some old papers and it works pretty well, but I have a tough time understanding how the circuit operates:    I understand the trimcap and inductor form a LC tank circuit that resonates at the required frequency. I don't understand how the transistor keeps the tank "topped up". Can anyone explain the circuit's operation in detail ?


Social Login adoption vs Traditional Login

I have implemented  on my website. I am wondering how important it is to include a traditional login (email/password) system.  I believe there may be a significant percentage of potential users that are either uncomfortable or unfamiliar with social login. These users may not sign up for my site if social login is the only option.  Does anyone know of any data comparing social login vs traditional login and the corresponding adoption rate?  Is there a current best practice? Do I need to give the user an option to sign up using username/password? Or is facebook/google/openID/twitter/MS/Yahoo enough?


Cleanest way to prepare bilingual document and output only one language

I am currently preparing the presentation for my internship evaluation. As a French student evaluated by researchers that may or may not speak French, I would like to maintain two versions of my presentation, in French and in English.  I could just create two separate files but I am pretty sure that maintaining both of them would be complicated and that I would most likely forget to port corrections from any version to the other one as well. Thus, my preferred option would be to keep them in the same file (files, in fact: I have taken the habit of having separate files for each section of my documents and \include them all in at the end).  Here is a MWE showing how I managed to do it :  \documentclass{beamer}   \usepackage[T1]{fontenc} \usepackage[english, french]{babel} \usepackage{etoolbox} \usepackage{blindtext}  %\includeonlylecture{english} %\includeonlylecture{french}  \newcommand{\switch}[1]{%Use with "french" or "english" to switch between languages %Security check \ifstrequal{#1}{french}% {}% {\ifstrequal{#1}{english}%     {}%     {\PackageError{switch}{Invalid input}{Received "#1" instead of "french" or "english"}}% } \lecture{#1}{#1} \selectlanguage{#1} \ifstrequal{#1}{french}%     {%     \title{French title}     }%     {\ifstrequal{#1}{english}%         {%         \title{English title}         }%         {}%     } }  \begin{document}  \switch{english} \begin{frame} \titlepage \end{frame}  \switch{french} \begin{frame} \titlepage \end{frame}  \switch{english} \begin{frame}{English frame} \blindtext \end{frame}  \switch{french} \begin{frame}{French frame} \blindtext \end{frame}  \end{document}   By using \switch with english or french and selecting the desired output language with \includeonlylecture, I managed to only output the corresponding half of the document.  I felt the need to redefine the title at each switch because the theme I use, JuanLesPins, shows the last title specified at the top of each slide.  My question is: is there a cleaner way to do what I'm trying to do, i.e. preparing two consecutive versions of each slide in two different languages and only output one of them?


UK: Questions to NON-EU tourists prior to reaching the border

PLEASE NOTE THAT THIS QUESTION IS NOT A DUPLICATE AS SUGGESTED. This deals with information provided BEFORE reaching the border.  Are international (NON-EU/EEA/SCHENGEN) tourists generally required before entering the UK at the border (so for instance, in their visa application/interview...) to provide any information at all about the person they're visiting (both in case they're staying at this person's place, or in case they're staying in a hotel) if they're coming to the UK to visit a family member or a friend?  In case of a positive answer to the above: is this information only provided orally, informally and off-the-records, or will a record be kept?


Material design / Elevation in photoshop

Im new in material design and I want to start new design in this style. My problem is I don't know how to reproduce Elevation (z-axis). In image below i see 12 levels of Elevation, but how to create this levels in Photoshop?     Btw: I know that I have to use  Drop Shadow in Photoshop, but   what values do I set for each level of Elevation.   ()


Question from pathfinder for Olympiad mathematics 2

If $p$, $q$, $r$ are the real roots of equation $x^3-6x^2+3x+1=0$, determine the possible value of $p^2q+q^2r+r^2p$. My Attempt: $p+q+r=6     (1)$ $pq+qr+pr=3  (2)$ $pqr=-1      (3)$ Multiplying (1) and (2) and substituting (3) in it... I came close but still unable to find solution... Please Help


Why are there scenes that will not render on GPU but will render fine on CPU?

I've already tried GPU Rendering and it seem to be twice as fast as the CPU. However I have some situation where tried to render on the GPU, but it doesn't do anything. When I switch to CPU it renders.  I have some fur texture/materials using particle systems. I wonder if that causes the GPU not to render, I'm not really sure.


grep regular expression to remove packages

This is an unexpected result I get $ dpkg -l | grep linux-modules-nvidia-440-5.4.0-* rc  linux-modules-nvidia-440-5.4.0-26-generic                   5.4.0-26.30+2                               amd64        Linux kernel nvidia modules for version 5.4.0-26 rc  linux-modules-nvidia-440-5.4.0-28-generic                   5.4.0-28.32                                 amd64        Linux kernel nvidia modules for version 5.4.0-28 ... $ dpkg -l | grep linux-modules-extra-5.4.0-* rc  linux-modules-extra-5.4.0-26-generic                        5.4.0-26.30                                 amd64        Linux kernel extra modules for version 5.4.0 on 64 bit x86 SMP rc  linux-modules-extra-5.4.0-28-generic                        5.4.0-28.32                                 amd64        Linux kernel extra modules for version 5.4.0 on 64 bit x86 SMP ... $ dpkg -l | grep linux-modules-5.4.0-* rc  linux-modules-5.4.0-26-generic                              5.4.0-26.30                                 amd64        Linux kernel extra modules for version 5.4.0 on 64 bit x86 SMP rc  linux-modules-5.4.0-28-generic                              5.4.0-28.32                                 amd64        Linux kernel extra modules for version 5.4.0 on 64 bit x86 SMP ... $ dpkg -l | grep linux-image-5.4.0-* rc  linux-image-5.4.0-26-generic                                5.4.0-26.30                                 amd64        Signed kernel image generic rc  linux-image-5.4.0-28-generic                                5.4.0-28.32                                 amd64        Signed kernel image generic ... $ dpkg -l | grep linux-*-5.4.0-* $ dpkg -l | grep linux-*-5.4* $ dpkg -l | grep linux-*-5\.4* $ dpkg -l | grep linux-*-5\\.4* $ dpkg -l | grep "linux-*-5\.4*" $ dpkg -l | grep "linux-*-5\\.4*" $ dpkg -l | grep 'linux-*-5\\.4*'  As soon as I add * prior to ., grep stops matching. I would like to match any of the 4 cases (modules, etc.) What is the correct regex so I can still match the results? Among these, I would like to further filter *5.4.0-[2,3]*. But this is what I see as part of the output to $ dpkg -l | grep 5.4.0-[2,3]*  Why would lines with *5.4.0-4* match? The colorized part is what matches, which is 5.4.0- in this case, and I do not see how that matches the regex 5.4.0-[2,3]*. (I managed to remove those matches with $ dpkg -l | grep 5.4.0-[2,3][[:digit:]]*, but still I would like to understand why the unexpected matches here). Or, How can I combine matching wildcards, text, and multiple strings? e.g., something like linux- plus any of modules, image, modules-extra, modules-nvidia-440, plus -5.4.0-, plus [2,3], plus digit, plus *. Note that this is not an XY problem. The motivation is that I want to use regex to quickly filter a set of package names to remove them all at once. But in this specific question I am asking why the usage of grep I tried did not work and what is the correct way of using it.


Can't install sudo /sbin/vboxconfig to run Virtual Box

I have a very annoying problem: I want to run VB, but I can't because it needs sudo /sbin/vboxconfig . Sure, why not.   I tried to install it, and it says there's errors and that I need to do dmesg to know why. So I do that, and I have some errors that I post here:  [    1.080440] tpm_crb MSFT0101:00: [Firmware Bug]: ACPI region does not cover the entire command/response buffer. [mem 0xfed40000-0xfed4087f flags 0x201] vs fed40080 f80  [    1.080447] tpm_crb MSFT0101:00: [Firmware Bug]: ACPI region does not cover the entire command/response buffer. [mem 0xfed40000-0xfed4087f flags 0x201] vs fed40080 f80  [    1.147305] Couldn't get size: 0x800000000000000e  [   19.176447] PKCS#7 signature not signed with a trusted key  [  166.876052] PKCS#7 signature not signed with a trusted key   Does anyone knows what is it, and how to fix those problems ?  EDIT: Apparently those aren't from the command i did to get this. This is what I did:  sudo /sbin/vboxconfig  [sudo] Mot de passe de *user* :   vboxdrv.sh: Stopping VirtualBox services.  vboxdrv.sh: Starting VirtualBox services.  vboxdrv.sh: You must sign these kernel modules before using VirtualBox:   vboxdrv vboxnetflt vboxnetadp vboxpci  See the documenatation for your Linux distribution..  vboxdrv.sh: Building VirtualBox kernel modules.  debconf: DbDriver "config": /var/cache/debconf/config.dat is locked by another process: Resource temporarily unavailable  vboxdrv.sh: Failed to enroll secure boot key..  vboxdrv.sh: failed: modprobe vboxdrv failed. Please use 'dmesg' to find out why.  There were problems setting up VirtualBox.  To re-start the set-up process, run   /sbin/vboxconfig as root.  If your system is using EFI Secure Boot you may need to sign the kernel modules (vboxdrv, vboxnetflt, vboxnetadp, vboxpci) before you can load them. Please see your Linux system's documentation for more information.   EDIT 2: Okay, but how could I do that ? I'm not a frequent command user after all...


How can the machines built by Humans fire on Pandora?

I'm curious. In the movie Avatar, how can machines fire the weapons and cause explosion? Clearly, Oxygen is required to cause Fire/Flames.  How is this possible in Pandora?


Need help reading mosfet Safe Operating Area graph

Im trying to figure out the current limitations of a mosfet(SISA18ADN) I'm planning to use to check how much headroom I have.  The datasheet states Continuous Drain Current that it can handle as 12.1Amps at Ta=70degreeC during 10seconds, and 38.3Amps at Tc=25C with no time specification.  But in the Safe Operating Area graph, apparently for DC it can handle less than 0.2A at 10V..? Am I getting something wrong when reading the graph or when reading the specs?  The Safe Operating Area graph is here:


How to reference specific levels of a JSON object

I have a JSON object with the following structure:  obj = {     foo: 'bar',     data: {         hello: this.foo     } }   However, this in the 2nd level is always the Window object. How can I reference foo properly?  NOTE  I know I can put the object into a "class" and referencer the property with selfor something. This is not an option for me. The object must be a standalone JSON object.


$T\circ T=0:V\rightarrow V \implies R(T) \subset N(T)$

Question  Let $T:V \rightarrow V$ be a linear map. How do I prove that $T \circ T = T_0$ ( the zero linear map) iff $R(T) \subset N(T)$?  Attempt  \begin{eqnarray} T\circ T=T(T(v))&=&T(T(v-0))\\ &=&T(T(v)+T(-0))\\ &=&T(T(v))+T(T(-0))\\ &=&T(T(v))+T(-T(0))\\ &=&T(T(v))-T(T(0))&=&0, \end{eqnarray} so this last bit gives \begin{eqnarray} T(T(v))=T(T(0)), \end{eqnarray} which means $T(v)=T(0)=0~\forall~v\in V$, so $R(T)=0$, this zero of which is in the null space for all linear maps $T$.


private static <T> T GetPage()   {     T page = new T();     PageFactory.initElements(BrowserFactory.getWebDriver(), page);     return page; }   T page = new T() ---- says Error: cannot instantiate the type T  I am completely new to this. Can you help me why I am getting this error? Below is my C# code for the same thing and it works fine. Am not able to replicate this in Java.  private static T GetPage<T>() where T : new() {    var page = new T();    PageFactory.InitElements(Browser.Driver, page);    return page; }


Latex packages / templates for maths exercises

I'm enrolled in a mathematics course where we are supposed to return our solutions to weekly exercises as PDF files. There seems not to be any general official guidelines other than "it's legible", e.g. one can take a photo / scan handwritten text, but I want to practise my latex skills.  Could you recommend useful packages, templates and any other resources for producing good-looking and readable exercise answers?  I'm a relatively inexperienced in LaTeX.


Edit gave me double rep and shows double edit but second edit blank

I was "rolling back" a post via changing it back to it's first revision, since I can't truly roll back posts yet. As I was doing this, I submitted my edit, and then after a few seconds noticed some grammatical and spelling errors in the post. I fixed those, and resubmitted the edit. The edit had not been accepted yet. After it was accepted, I got 4 reputation from the edit. The edit history is also wacko, like this:    When clicking on the suggested button on that revision, it directs me to my first edit's suggested edit page, the 3rd revision.  is the revision history of that post. This smells like a bug to me.


When estimating parameters such as (I don't care about this specific instance particularly) Variance of a random variable X, one usually adopts , i.e. using the formula $\hat{Var}{(X)} = \frac{1}{n-1}\sum_i^n(x_i -\bar{x})^2$.  The justification given on Wikipedia and on all other sources I've found is either of the nature of:   the $n-1$ factor arises from dividing by the degrees of freedom of the residual terms the $n-1$ factor ensures unbiasedness the $n-1$ factor arises to correct from underestimating the variance if we weren't to include it   However, why does it make sense to divide by the degrees of freedom?  In general, it seems pretty common to divide parameter estimates not by $n$, the number of sample points used to calculate them, but by $df$. Why does this generally make sense?  EDIT: to clarify my question, what I'm asking is whether in a general setting dividing a an uncorrected estimate by it's degrees of freedom will produce a unbiased estimator or an estimator with desirable properties. It seems like this procedure is common but I have not seen a general proof (and don't know if it exists) of why this would work generally.   In particular, I think that the reason would be probably in terms of dimensions of subspaces or connecting back to the degrees of freedom of distributions (that seems closely related).  For individual estimates like sample variance or the MLR residual standard error $\frac{RSS}{n- k-1}$ I am aware that proofs of unbiasedness exist, but they are specific to the problem at hand.


90s sci-fi space Saturday morning show with teenagers

This was on Saturday mornings around 11, I think, circa 1995-97.  This show is NOT Hypernauts, but looks similar. There were more kids in the show, five I think, but they did have gray and different colored uniforms like Hypernauts did. No mechs. They traveled on a space ship together. I don’t why or what their mission was.  There’s only one episode I remember. At the beginning of this episode they are on some sort of port planet where they are looking at the street vendors. I think the city floating they are is either in the sky or floats ala Cloud City. One of the girl crew members is looking at a necklace for sale, but decides that she can’t afford it. The guy crew member she was with secretly trades (his harmonica?) for the necklace and gives it to her as a gift.  The rest of the episode is about these creatures that fly through the atmosphere of the planet and kind of resemble whales. They are being hunted down and harvested for this gas/chemical inside them that powers their ships (they used a similar idea for an episode of Star Wars Rebels a few years ago). The kids compare them to whales and talk about how Earth used to treat whales the way these creatures are being treated, i.e. as dumb animals. They talk about how Earth eventually realized that whales were intelligent and started treating them as equals. One kid even says something about “yeah, my dad (or uncle) had a whale lawyer once.”  The kids spend the rest of the episode trying to find a way to get these people of this planet/region to stop poaching the creatures. Eventually they find out the gas/chemical inside them is actually produced by surface vents in the planet and that the people there can harvest it from the planet surface directly. This saves the creatures from extinction and it ends on a happy note.


I have two questions about  Vacuum to vacuum transition amplitude.   Can any particle stay in $|0\rangle$? I was studying this topic from Srednicki's QFT book. He writes in eq.$(6.22)$ $$\langle0|0 \rangle_{f,h} = \int \mathcal{D}p \mathcal{D}q \, \exp \Big[i\int_{-\infty}^\infty dt (p \dot{q} - H_0(p,q) - H_1(p,q) + fq + hp \Big]$$ $$ =\exp \Big[-i  \int_{-\infty}^\infty dt H_1 \Big(\frac{1}{i} \frac{\delta}{\delta h(t)}, \frac{1}{i} \frac{\delta}{\delta f(t)} \Big) \Big]  $$  $$ \times \int \mathcal{D}p \mathcal{D}q \,\exp \Big[i\int_{-\infty}^\infty dt (p \dot{q} - H_0(p,q) + fq + hp \Big] \tag{6.22} $$   Here in the second line the arguments of $H_1$ suddenly changes from $p$,$q$ to  $\frac{1}{i} \frac{\delta}{\delta h(t)}, \frac{1}{i} \frac{\delta}{\delta f(t)}$. How can I derive this line from the first line?


Why don't electrons and protons collide inside Atom?

I was thinking of atoms. Usually atoms have same amount of electrons and protons. While electrons are negatively charged and Protons are positively charged. As we know from coulomb's law that positive and negative charge always attracts and (positive and positive) or (negative and negative) distract. So, they should collide inside atom also. I was searching on Google little bit. I found in Google that while electrons and protons come closer and closer they form mesons. While I was writing the question I found a related question to this in .  An electron can't be compared to a planet, and must instead be thought of as a kind of cloud of probability  Electron is particle and it has wavelike behavior also. Is it the reason of not to collide? I didn't get the answer of Quora. While it is particle it must have to collide. I found another related question in .  They do collide. But it's not like cars crashing and smashing each other up on the highway. Their quantum mechanical wavefunctions overlap and the electrons do in face settle in with wavefunctions that are centered on the nucleus.  If they collide than why atoms aren't vanishing? What type of collision is happening inside Atom? As I wrote earlier if they collide, they form mesons that's what I got in Google. But, I am unable to understand the collision inside Atom? What's happening right there?


How old was Harry when he left the Dursley's residence prior to the Battle of the Seven Potters?  If he had just turned 17, why leave by broom/flying vehicle instead of using a port key or Floo Powder?  2nd part of my question, why leave by magical means at night when he could have taken polyjuice potion or used his invisibility cloak and transport himself via non magical means like the tube or taxi during the day?


I have an Ubuntu 16.04 working very well on a MacBook (2010, CPE Intel Core Duo 2.4 GHz, graphic NVIDIA GeoForce 320 M), along MacOS Sierra. It is just a second computer I use, I thought I could explore the new version before upgrading my main computer.   I tried to upgrade to 18.04 but Ubuntu would hang on errors on boot. So I reinstalled 16.04 Then I tested 18.04 with an USB installation key - wich I should have done first. I get the same kind of errors. This time it loads until it even displays the background of the desktop, then displays errors in text mode and hangs.   Example of error messages of to-day (were different yesterday):  Could'nt get size: 0x8000000000...0e nouveau 0000:02:00,0: bus: MMI0 write of 0000807f FAULT at 100c18 nouveau 0000:02:00,0: bus: MMI0 write of 0000807f FAULT at 100c1c   It is not a big deal as I do not have to upgrade now.  I tested Lubuntu 18.04 from a USB key. It seems to work.


System requirements: What is the lightest impacting ubuntu flavor?

I have been looking for a Linux alternative to windows due to the OS constantly eating up my system's memory and CPU usage, and i'm somewhat familiar with Ubuntu systems, but i want to know what flavor might be the best for my light-weight system.   Here are my specs:  Acer Aspire A114-32-C1YA Processor Manufacturer  Intel® Processor Type Celeron® Processor Model N4000 Processor Speed 1.10 GHz Processor Core Dual-core (2 Core™)  Display & Graphics Graphics Controller Manufacturer Intel® Graphics Controller Model UHD Graphics 600 Graphics Memory Technology DDR4 SDRAM Graphics Memory Accessibility Shared Standard Memory 4 GB Memory Technology DDR4 SDRAM  Storage Optical Drive Type No Flash Memory Capacity 64 GB   Please let me know what flavors i should consider, thanks!


Within the last week my Windows XP workstation has begun randomly losing focus from the active window. I've seen this in multiple applications including FireFox, Notepad, Putty, Visual Studio etc. There is no application stealing the focus, instead the active window simply goes inactive and there is no active window visible. In the taskbar the application I am working in is still highlighted - so that application is active but its window does not have the focus.  This is not focus-stealing feature you are thinking of that you can configure with Tweak UI. I checked that and its not enabled and anyway that is working the way its supposed to and looks different since its configured to make the grabbing application flash in the task bar.   This looks more like some other app runs, grabs the focus and then exits. The desktop is in the same state you have when you exit the active application.  Any ideas?


I have a class like this:  public class ClassList {      public class SubClassOne {      }      public class SubClassTwo {      }  }   Now i want to have a list of all classes in my ClassList class without having to add them all by hand. Is that possible?


subfolder or subdomain - Which one is the best?

I'm creating a website for web creator, designer and video editor. I'm a multimedia integrator, so I'm doing almost everything related to media on the web or video. Whatever, on my portfolio I would like to add a photography section for my personal photos to show people that I love more than only web/video. Also, I draw a wireframe of what my photography page could look like and it will be really different from my original portfolio website I'm creating.  For example, my portfolio website has the nav menu on top, but the photography website will have the menu fixed on the left with a filter (to choose which picture you want to look at). Do you think I should put this photography section as "mywebsite.com/photogrpahy" or "photography.mywebsite.com"? I heard that sometimes SEO is weird with subdomain.  Also, thinking about adding two blogs in the futur. One for my work and one other for my travel and other personal stuffs. So I thought about :  mywebsite.com/blog ---> Work  blog.mywebsite.com ---> Travel/activities/etc.  What do you think about this?  Thank you


"We have focused our discussion on one-dimensional motion. It is natural to assume that for three-dimensional motion, force, like acceleration, behaves like a vector."- (Introduction to Mechanics) Kleppner and Kolenkow  We learn it very early in the course of our study that Force is vector; But, if I were the physicist defining the the Newton's second law (experimentally) and analysing the result F=ma, how would I determine whether Force is vector or scalar(especially in 3-D).   Actually, when I read the aforementioned sentences from the book, I wanted to  know why do the authors expect it to be natural for us to think that in 3-D "Force" behaves like a vector. I know a(acceleration ) is vector and mass a scalar and scalar times vector gives a new vector but is there another explanation for this?


If in a semigroup S,$ \ $ $ x^{k+1} = x $ for some  $k \ge 1$ and $xy^kx = yx^ky \quad  \forall x,y \in S$ then show that S is abelian.  I'm able to prove the following $\ x=x^3, \quad x^2y^2=y^2x^2=(xy^2)^2=(y^2x)^2 \ and \ x^k=x^2  \quad \forall x,y \in S$ I thought of proving  $x^2=y^2  \quad \forall x,y \in S$ and so S will have an identity element, but couldn't do it and don't know whether the approach is correct.


Book series about two men training to be wizards, whose powers come from lost tech from a crashed spacecraft

Trying to remember a series I read years ago. I believe there were three books. It was about two men who were training to be wizards and fighting other races. Later in the story, we find that their powers come from crystal injections from lost tech from a crashed spacecraft, and they are being guided by the ship's A.I..


What is the aural equivalent to the word "appear"?

Appear means to come into visual consciousness, but what word do we use to indicate a sound has come into consciousness?


Unable to understand $variable and how it works

I have this piece of code      var $slider = $('#divSlider')                     .hover(function () {                      }, function () {                      }).appendTo('div');      $('a').mouseover(function () {         $slider             .addClass('active')     });   I have the following questions:   What is $slider?  When does it appendTo div, does it happen after hovering or instantly?  In the mouseover function, $slider is used again. What does $slider contain?   Thanks


$T(n) = 2$ if $n=0$  $T(n) = 9T(n-1)-56n +63$ if $n>=1$  Repeated substitution  $k=1$  $T(n) = 9T(n-1)-56n+63 $  $k =2$  $T(n) = 81T(n-2) -560n + 1134$   $k =3$  $T(n) = 729T(n-3) -5096n + 15309$  I cant find the pattern for the n term and the integer  For now i just have  T(n) = $9^k(n-k)$


Each close vote should punish the caster by taking away some of his reputation

Oftentimes I post a question on some Stack Exchange and what happens is that 21 people think the question is helpful and informative and 3 people think it should be closed. This is extremely unfair and I know that the contrarians do it because it costs them nothing. Therefore because Stack Exchange already has a feature which punishes the caster for downvoting answers, logically speaking it should also have a feature that punishes the caster for voting to close. Maybe -10 for each vote to close.  My question is not a duplicate of  because I the author acknowledge that inquirer as having a bad idea, because it can result in some question on a cartoon upvoted and the mods prevented from doing their jobs. The mods made the correct decision in not approving that feature. But this feature doesn't prevent mods from doing their jobs. It only makes them think... a little longer before they do their job.  As @gnat pointed out, users are only punished for downvoting answers, not questions. I thank @gnat for that correction.


What is the proper way to handle data between scenes?

I am developing my first 2D game in Unity and I have come across what seems an important question.  How do I handle data between scenes?  There seems to be different answers to this:   Someone mention using , while other people told me this should be used to store other things like screen brightness and so on. Someone told me that the best way was to make sure to write everything into a savegame everytime that I changed scenes, and to make sure that when the new scene loads, get the info from the savegame again. This seemed to me wasteful in performance. Was I wrong? The other solution, which is the one I have implemented so far is to have a global game object that isn't destroyed between scenes, handling all the data between scenes. So when the game starts, I load a Start Scene where this object is loaded. After this ends, it loads the first real game scene, usually a main menu.   This is my implementation:  using UnityEngine; using UnityEngine.UI; using System.Collections;  public class GameController : MonoBehaviour {      // Make global     public static GameController Instance {         get;         set;     }      void Awake () {         DontDestroyOnLoad (transform.gameObject);         Instance = this;     }      void Start() {         //Load first game scene (probably main menu)         Application.LoadLevel(2);     }      // Data persisted between scenes     public int exp = 0;     public int armor = 0;     public int weapon = 0;     //... }   This object can be handled on my other classes like this:  private GameController gameController = GameController.Instance;   While this has worked so far, it presents me with one big problem: If I want to load directly a scene, let's say for instance the final level of the game, I can't load it directly, since that scene does not contain this global game object.  Am I handling this problem the wrong way? Are there better practices for this kind of challenge? I would love to hear your opinions, thoughts and suggestions on this issue.  Thanks


Is there a list somewhere of all the special characters I can type using the option key?

OS X lets me type special characters directly on the keyboard by holding the Option. For example: — is an em dash, “ and ” are curvy quotes, etc.  Is there a good cheat sheet listing all these keys somewhere? I tend to find myself holding option and running my hands up and down the keyboard looking for a specific character.


Can dual US/UK citizen travel with only UK passport and ESTA?

I have a 20-year-old daughter, born in the US to military British parents. She has dual nationality / both birth certificates.  Her US passport is expired and Social Security number misplaced. She needs to travel to the USA as soon as possible.  Can she travel on her British passport with an ESTA? She can't wait for 8 weeks to get new Social Security number, and then three more weeks for a new US passport.  Will she be okay with her British passport with an ESTA?


Equation to find how far into water you will sink depending on how high you jump from

I am looking for an equation to which I can plug in numbers to figure out to what depth a person will sink into water before momentum is lost and they begin to float upwards, depending on how high they jump from.  To keep it simple, I am assuming 90 degree straight fall, feet first, and the position is kept in the water until momentum is lost.


What if the GM is the one who is traditional?

In creating my character, I'm asking a lot of questions. I'm also studying the rules for my own benefit of what is expected of me. (We are all new to DW.)  I am reading a lot of stuff (much of it here on SE) about how the GM has rules they have to follow, and how many decisions are expected to be decided by the table, rather than GM fiat.  I am (perhaps prematurely) anticipating some conflict with the GM if I offer things I understand about the game but go against what might be considered traditional 'GM is God' philosophy.  As examples - if I understand them correctly:   all players are supposed to watch for things that trigger a move by other players. or a GM cannot simply make a move - say, springing a trap on a thief - without the required move occurring to trigger it.   I anticipate simply being overridden by the GM, not because his rationale makes sense but because - essentially - GMs traditionally had no constraints on their actions.  How do I resolve my understanding of game-play with the GM's idea of game-play, while avoiding the confrontational act of, say, quoting the rules to him? (This will not go well.)  Or do I play as if following the most basic player's guide: the character sheet and moves? (i.e. I don't need to know the game rules in order to play my character.)


Ubuntu 16.10: teamviewer:i386 depends on libpng12-0

I can't install teamviewer. dpkg is complaining about an unresolved dependency:  # dpkg -i teamviewer_11.0.67687_i386.deb  Selecting previously unselected package teamviewer:i386. (Reading database ... 169209 files and directories currently installed.) Preparing to unpack teamviewer_11.0.67687_i386.deb ... Unpacking teamviewer:i386 (11.0.67687) ... dpkg: dependency problems prevent configuration of teamviewer:i386:  teamviewer:i386 depends on libpng12-0.  dpkg: error processing package teamviewer:i386 (--install):  dependency problems - leaving unconfigured Errors were encountered while processing:  teamviewer:i386   apt-cache search libpng12 doesn't return any match  Could anybody help me to solve this issue?  Thanks in advance


Help me understand how the rule of divisibility for 11 is calculated

If you want to find b such that $a \equiv b \pmod{11}$, you do (assuming a has 4 digits, for example):  $$a_4*10^4+a_3*10^3+a_2*10^2+a_1*10^1+a_0*1$$  Then you calculate mod 11 for each product then add everything and do mod 11 again, like you do with other numbers.  The problem is that my theory book states that $10^k\equiv (-1)^k\pmod{11}$. I don't get this. How isn't the remainder of the division of 10 by 11 10? I thought that to calculate the remainder when your divisor is greater than the dividend, you to d*0 and your remainder is your dividend. For example, 10/11 = 0*11+10. Have I been doing it wrong?


Did Jeff Atwood join Stack Exchange again?

Well this  answered a  today, however his profile say "I no longer work at Stack Exchange". Did he join again to support Stack Exchange, or is he just a member?  I doubt because still he has a diamond.


Relating Quantum Mechanics to Classic Electromagnetism

I've been directed to a few articles, and I am sure there is a related post, but can someone explain the procedure by which we can view classic electromagnetism through quantum mechanics? Indeed we need to be able to look at any field as an ensemble of particles (photons), but how can we develop classic field theory assuming quantum mechanics?


Frame breaks inside mdframed environment with beamer class

The mdframed environment fails to break into several pages (slides) when used in a frame environment from the beamer class.  In the other hand, the boitecoloriee environment from the boites package can be broken into several pages.  Here is a document that demonstrates the issue. It should not be compiled directly into pdf because boitecoloriee uses pstricks.  \documentclass{beamer} \usepackage{xcolor,boites,boites_exemples,pstricks} \usepackage{mdframed} \usepackage{lipsum}  \begin{document}  \begin{frame}[allowframebreaks]{Using \texttt{boitecoloriee}}   \begin{boitecoloriee}     \lipsum[1-2]   \end{boitecoloriee} \end{frame}  \begin{frame}[allowframebreaks]{Using \texttt{mdframed}}   \begin{mdframed}     \lipsum[1-2]   \end{mdframed} \end{frame}  \end{document}   Maybe is there a way to fix mdframed to work in slides too. Any clues?


How to disable ellipsis autocorrect on macOS?

Every time i write ... in a text editor like TextEdit or Coda, Lion has started replacing it with a single Ellipse character, which doesn't encode to HTML. This started after I upgraded to Lion and happens across multiple programs. This persists in the latest Big Sur betas. Any idea how to stop it?


Showing a function on $[0,1]$ is the zero function

Suppose $f$ is continuous on $[0,1]$ and   $$ \int\limits_0^1 f(x) x^n d x = 0 $$   for all $n=0,1,2,...$. Then, $f(x) = 0$  I was trying to use by parts  $$ 0 = f(x) \frac{x^{n+1}}{n+1} \bigg|_0^1 - \int\limits_0^1 \frac{x^{n+1}}{n+1} f(x) dx $$  Thus,  $$ \frac{f(1)}{n+1} = \int\limits_0^1 \frac{ x^{n+1} f(x) dx }{n+1} \implies f(1) = \int\limits_0^1 x^{n+1} f(x) dx $$  but here I am stuck. Maybe my idea is not the best one? How would you approach this problem?


How does Hogwarts find candidates to attend?

How does the selection process to attend Hogwarts happen? Do they look at all the residents in the country and find the ones with magic: this seems quite time consuming to me. Do they have a process to narrow down candidates then look more closely?


I cannot remember anyone writing the letter epsilon in any other way than \varepsilon in any math class; but in LaTeX \epsilon and \varepsilon are different symbols. Do any of you know why there are two different symbols? (I.e. if \epsilon is the correct way to write the letter epsilon, why aren't mathematicians using it, and when is, according to the standards today, the correct situation to use each of the symbols?)


I deleted the "/etc/init.d/tomcat8" script ... when I re-install tomcat8, the script is not recreated ... how do I get it back?

I'm using an Amazon EC2 instance of Ubuntu 18.04. I installed Tomcat, experimented with it, and messed up the configuration. I wanted to remove tomcat completely and start over, so I did: sudo apt remove tomcat8 sudo apt remove tomcat8-admin  And manually deleted the tomcat8 directories: sudo rm -r /var/lib/tomcat8 sudo rm -r /usr/share/tomcat8  And manually deleted the start/stop script: sudo rm -r /etc/init.d/tomcat8  Then I figured I had a "clean" system and I could reinstall from scratch, so I did: sudo apt install tomcat8 sudo apt install tomcat8-admin  No errors, but it did not recreate the /etc/init.d/tomcat8 script for stop/start/restart the service. Why did it not recreate it, and how do I get it back?


I am new to programming and I have basic HTML skills. I am creating a basic web site and I have information in a paragraph and the information is separated by
 tags. I am looking to add a "copy to clipboard" button and function so that the 16 lines of information are saved to the clipboard.
 this is the 1st line
 this is the 2nd line
 ... this is the 16th line [copy to clipboard]


Algorithm faster than Newton's for calculating $\sqrt{2}$

It is well known that the iteration scheme   $$ x_{n+1} = \frac{1}{2} (x_n + \frac{2}{x_n })$$   converges to $\sqrt{2}$ very fast. More precisely, it converges quadratically. The problem is, is there any even faster algorithm? Namely, can we find another polynomial $P(x, 1/x)$ of $x$ and $1/x$ with rational coefficients, such that the iteration scheme   $$x_{n+1} = P \left(x_n , \frac{1}{x_n} \right)$$  converges even faster?   The conjecture is that no such algorithm exists. But I have no idea how to prove it.


Prove or disprove that Arg(zw)=Arg(z)+Arg(w)

I talked to my professor and they said that it can be disproven using an example, specifically using a picture to explain why it statement is false. Can anyone help me out?


Can you find an element of order 10 in $\mathbb{Z}_{31}^{*}$

I'm stuck on that question, because I'm trying to find a simple way to solve it.  I'm pretty sure there exists such elements because the group is cyclic and $|\mathbb{Z}_{31}^{*}| = 30$, hence there exists a sub-group of any order dividing $30$. So I know there is a sub-group of order $10$ and it's cyclic because any sub-group of a cyclic group is cyclic, and it's generator is an elements of order $10$.      Now, how can I proceed from here? How can one find the generator of this sub-group?


[INTRO]  In such arrangement of identical charged particles named $P_1$, $P_2$, ..., $P_n$ (In this diagram $n=5$), the electric field in the center is always zero.    The electric field is given by this equation:  $$\vec F=k\frac{q}{r^2}\hat r$$  Where $\hat r$ points to the radial direction.  If $2|n$, then the forces are obvious canceled by symetry.  If $n$ is odd, again the components of forces in the $y$ axis cancel by symetry. But for the $x$ direction the components cancel if this condition is true:  $$\sum_{c=0}^{n-1}\cos(c \theta)=0 \ \ \ \ \ \ \theta=\frac{2\pi}n$$  [END OF INTRO]  My main problem is to prove for any $n$, this relation holds:  $$\sum_{c=0}^{n-1}\cos(2\pi \frac{c}{n})=0$$


Redirection of subdomain working, but server not found error : Linode

Here is my virtual host :  <VirtualHost *:80>     ServerAdmin webmaster@localhost     ServerName policy.domain.com     ServerAlias www.policy.domain.com     DocumentRoot /policy     ErrorLog /policy/error.log     CustomLog /policy/custom.log combined     <Directory /policy/>         Options  +IncludesNOEXEC         AllowOverride None         Order allow,deny         allow from all          # redirect non www to www         RewriteEngine On  RewriteCond %{REQUEST_FILENAME} !-d RewriteCond %{REQUEST_FILENAME}.php -f RewriteRule ^(.*)$ $1.php [L]  RewriteCond %{HTTP_HOST} !^www\. [NC] RewriteRule ^(.*)$ http://www.%{HTTP_HOST}/$1 [R=301,L]        </Directory>   </VirtualHost>   I have tried various settngs, but pages at www doesn't seem to appear. Though, the php removal works well when I remove non-www to www condition. To be specific, apache is redirect non www to www but at www it shows server not found error.


When did zombies become "infected" rather than corpses raised from hell?

I am curious as to the evolution of the zombie concept. In old horror movies from the 60s and into the 80s, zombies were depicted as "true" undead beings; people who have died and been inhumed, and then mysteriously their corpses are reanimated, with no scientific explanation available.  From Dawn of the Dead (1978), the following is uttered:     Peter: Something my granddad used to tell us. You know Macumba? Vodou. My granddad was a priest in Trinidad. He used to tell us, "When there's no more room in hell, the dead will walk the Earth."    This, to me, created a feeling of uneasiness and inescapable doom. The forces of hell, or nature, or what have you, inflicted this plague on humanity and there really is no "way out" of that.  In the 90s and onwards, zombies changed. They are now "infected" with a virus or some kind of pathogen that resembles a super-charged variant of rabies. In many franchises such as Resident Evil this pathogen is the result of botched scientific experiments. Many of these types of zombies resemble "mutants" and can be extremely large, and even possess intelligence such as the character Nemesis:     The Nemesis-T Type (also known as the "Pursuer") was an experimental form of intelligent Tyrant created by the Umbrella Europe Sixth Laboratory in France under the direct administration of Umbrella Headquarters. Its purpose was to prove that a t-Virus infected creature could retain most of its intelligence and follow specific orders.    Now, I understand that fiction and storywriting is always a reflection of society and the zeitgeist, and it is quite obvious that this "new" type of zombie is very relevant to our brave new world of ebola, swine flu, mad cow disease and other epidemics, as well as relating to stem cells, DNA research, cloning and being a "modern extension" of the classic "mad scientist" story.  But, in these zombie stories, there is always a "way out"; the vaccine, the antidote, the "blow em all up routine". I am curious how the more ominous approach that I described in the beginning of my question, became replaced with the "new approach" and why it seems to have become a main-stay version of zombiism in popular media - my bottom line being that a metaphysical force that cannot be "reasoned with" is much more terrifying than genetic experiments gone awry. Why are these things even called zombies anyway?


I have 2 HDDs in my PC. Ubuntu is turning off the secondary HDD very quickly after about 15 minutes, which is short for me. I need to control this time. How can I do it?  I tried GNOME power management but did not find it useful.


Is it possible to store class data into an array in Python, then randomly pick a class from the array?

enemyArray = [Ork, Goblin]  class Ork:      name = "Mountain Dweller"`     health = 10     armor = 1     damage = 5   class Goblin:      name = "Looter"     health = 5     armor = 0     damage = 5


I'm having a discussion with my wife on .  She says we cannot have "would" in a hypothetical if statement:     If I would want to change my address, should I let you know?   She says that "would" can only occur in the second part (as in Type 2).  If this is the case, is there then no way to describe "a hypothetical situation in which I would want to change my address" as conditional?  I feel like this sentence is different from:     If I want to change my address, should I let you know?   Then again, maybe it is just that I'm confused with how we would say it in Dutch.  And what about if it is the change, not the wanting to change, that is hypothetical? In other words:     If I would change my address, should I let you know?


Modifying string value causes access violation

I have the following code: int main() {     char *input = "why isn't this possible?";     input[0] = 'W';     return 0; }  I want to modify the first value of the string, but it appears to cause an access violation on the input[0] = 'W'; line. Any ideas why this is happening. Oddly I don't recall this error happening on my old machine running Visual Studio, but happens with GCC and Pellas C.


Program slider to control camera aperture with python

I'm very new to scripting in blender, and I'm making an addon to simplify the depth of field process in Blender. I would like to put a slider in my ui panel to control the camera's aperture. I think I need to use a .prop function but I'm not sure. Can I have some help with this? Here is the code for my ui panel: def draw(self, context):     layout = self.layout     camera = bpy.data.objects['Camera']               row = layout.row()     row.label(text= "Focus", icon = "CAMERA_DATA")     row = layout.row()     row.operator("object.add_focus")     row = layout.row()     row.operator("object.remove_focus")     row = layout.row()     row.prop(camera, "dof.aperture_fstop", slider=True)  The last line is the one I don't know how to do. Here is what my UI panel looks like so far:  Thanks!


I tried to assign different materials to face - they work correctly only on Eevee rendering.  When I tried to render using Cycles - the surface always black - doesn't matter what the material or base color, only 2 properties have value - Emission and Alpha, they work correctly, face orientation is ok on this face.    And the blend file


I have a ceiling light that is controlled by two switches, however when one of the switches is off the other switch does not work.  What is the issue and how can I fix it?


Prove by induction that every positive integer is represented by some binary number?

A binary number is a string $r_mr_{m-1} \cdots r_1r_0$ where $m \in \mathbb{N}$ and $r_i \in \{0,1\}$ for $i=0,\ldots,m$. The string represents the positive integer $r_m2^m+r_{m-1}2^{m-1}+\cdots+r_12+r_0$. Prove by induction that every positive integer is represented by some binary number.  How do I prove p(x),p(k) and p(k+1). Or Strong induction?


I have a question regarding word usage when using "trio" in a sentence.   Here's an example sentence:     The trio tries to find the way but appear to be lost.   Should "tries" be in the third person, or should it remain "try"? The example will apply to other cases in which another word instead of "try" was used, but an answer to this will help clarify this for me in the future.


Google doesn't understand <> so that failed thus asking here.  What does '<>' (less than followed by greater than) mean in Excel? For example:  =SUMPRODUCT((E37:N37>0)*(E37:N37<>"")*(E37:N37))   What's happening here?


Wrongly states that I marked a question as a duplicate

This page states that I marked the question as a duplicate, but I never did:    Unlike , I don't think all the different reasons should be listed. I just don't want the statement to be false.


How to search for only folders in Windows 7 instead of folders AND files

I've had some issues with the new search function in Windows 7. The Search in Windows XP was packed with so many more options. The only option I can access now are Date Modified and Size.  Any pointers to how to get more options in the Windows 7 Search, or links to external programs that can make my life easier?


Auto ask to vote up question when we vote up answer

I read stuff a few weeks ago on Stack Overflow that it was important to vote up questions too. So, I've started doing it, each time I find the question that I was asking myself, I vote it up. But in fact, I remember to vote it up only when I vote up an answer. And, almost all the time, when I vote up an answer, I vote up the question.   So, I was wondering if it would be possible to make a system that, when we vote up an answer, asks us "Would you like to vote the question" or something like this, and we could click "yes" or "no".  Of course, it would show up only if we haven't voted up the question yet.  I think it would make me save about 2 seconds per question. I now it's not much, but as you have probably heard before, when you add this up, you realize that you save a lot of time.


How are results rounded in floating-point arithmetic?

I wrote this code that simply sums a list of n numbers, to practice with floating point arithmetic, and I don't understand this:  I am working with float, this means I have 7 digits of precision, therefore, if I do the operation 10002*10002=100040004, the result in data type float will be 100040000.000000, since I lost any digit beyond the 7th (the program still knows the exponent, as seen ).  If the input in this program is   3 10000 10001 10002   You will see that, however, when this program computes 30003*30003=900180009 we have 30003*30003=900180032.000000  I understand this 32 appears becasue I am working with float, and my goal is not to make the program more precise but understand why this is happening. Why is it 900180032.000000 and not 900180000.000000? Why does this decimal noise (32) appear in 30003*30003 and not in 10002*10002 even when the magnitude of the numbers are the same? Thank you for your time.  #include <stdio.h> #include <math.h> #define MAX_SIZE 200   int main()  { int numbers[MAX_SIZE];  int i, N; float sum=0; float sumb=0; float sumc=0;  printf("introduce n" ); scanf("%d", &N);  printf("write %d numbers:\n", N); for(i=0; i<N; i++) {     scanf("%d", &numbers[i]); }  int r=0;  while (r<N){     sum=sum+numbers[r];     sumb=sumb+(numbers[r]*numbers[r]);      printf("sum is %f\n",sum);     printf("sumb is %f\n",sumb);     r++; } sumc=(sum*sum); printf("sumc is %f\n",sumc); }


I am starting a new job on Monday. Can they screw me over somehow with the information I need to provide? Does this look sketchy to anyone else?

Congratulations! You have accepted for a trial period on the Remote Executive Manager position.  blahblahblah  During the work you use bitcoins for working with customers. It is necessary for customers. Use the services of our partners at a lower price, you can only for business purposes. Services and goods which you will buy for customers through bitcoins for low price:   Web Design; MySQL Database; Set up VoIP number; Database Servers; Stock exchange services; Hosting; Virtual private servers.   "To start working with Bitcoin, you need to fill up your wallet. We will provide you money via e-Transfer Interac system.  To do this, we need to know: Your Holder name: Your Bank name: Your Email address associated with account: Your phone number:  There is no fee to receive bitcoins, and many wallets let you control how large a fee to pay when spending.  Most wallets have reasonable default fees, and higher fees can encourage faster confirmation of your transactions.  After receiving electronic transfer, you will have to fill up your Bitcoin wallet.  We will send you 2-3 transactions through Interac system. Have you ever used electronic transfer (Interac)? Do you have online banking active? Do you have business bank account?"


This question is in relation to the specific case where $\sqrt{3} \gt \sqrt{2}$. Can we generalize this result and prove that  $\sqrt{x+1} \gt \sqrt{x}$ if $x \gt 1$. Can we also prove the more general case that $\sqrt{y} \gt \sqrt{x}$ if $0 \lt x \lt y$


Yesterday I upgraded from ubuntu 12.04 LTS to 14.04 using the update manager. Everything went smoothly. But when I restarted my laptop, it went till the login screen and as i entered my password, it prompted an error      Failed to start session   I read in some blogs and even tried to use sudo dpkg-reconfigure -a, but even that failed with some errors. I feel it does not connect to the Internet through my router when I use the recovery mode.  Can someone please help me. I have lot of data in there and don't want to install a fresh copy of ubuntu 14.04. I am using a Dell Studio 1555 laptop with ATI Mobility Radeon 4500 HD graphic card.  I ran the following command  $ sudo dpkg --configure -a  Output: dpkg: error: unable to access dpkg status area: Read-only file system


When I receive a reply on a comment or thread I created or opted into on chat channels such as  or MS Teams opened in a web browser I receive a small banner that extends from the bottom vertical pane of the screen if I'm not in that tab.  I noticed I get a push notification when using the Stack Exchange app on my iOS device when someone comments back.  Besides the inbox icon at the top right hand side of the screen, is there any feature within Stack Exchange that can alert me regardless of what browser tab I'm currently looking at like what Slack and MS Teams do?


How to for loop iterate for two variables?

I want to know how for loop is processed in below condition.  void main() {       int i,j;     For(i=1,j=1;i<=5,j<=10,i++,j++)     {         printf("%d%d",i,j);     } }   sorry for typo mistake I correct my syntax here  For(i=1,j=1;i<=5,j<=10;i++,j++)  answer of this -1122334455667788991010  How's that possible because loop for I will be iterate for only 5 times how's that possible ? I want to know how loop will be executed ?


What is the correct method of introducing the expanded form for Acronym in the bracket? is it expanded form first and then the acronym in bracket or Vica-Versa.  Also, what is the difference in introducing the acronyms to the American audience or to the British audience?


What anime features a boy with a gem or crystal that gives him powers to transform into an organic robot of some sort?

I'd like to identify this anime TV show or movie.  I saw it about 6 years ago, late night, on Cartoon Network/Adult Swim/Toonami/Boomerang, in English language.  At the beginning of the show there was these monsters that were attacking a village or a town and then this girl gave him a gem that was on her forehead. The gem bonded to him and then he fled away from the destruction. There was about 5 to 8 people that had these "gems" and they were teaching him how to use and how to transform into these bio monsters.   There were different elements: one guy had the water element. But the kid had a special type of "gem" that nobody knew what his powers or limit was. The crystal or gem was blue.


Erase and Install a fresh copy of Ubuntu to start over

I bought this hp mini off an old friend. well it has been running for quiet a while and it seems like since 2001 (that'as the recent modified dates seen on the files). This is my first laptop with Ubuntu and it seems I've made a mess with the system since then. I was just wondering if I could erase and start over with a fresh copy since is no such option to restore to factory command similar to Windows. I recently upgraded it, even-though I had no idea what I was doing and it changed from 10.04 to 12.04. But the power cord came out, and battery died while I was asleep. Regardless, I should say that the upgrade went half. Nevertheless, I logged-in finally, but now all kinds of errors pops-up as I have duplicate things going on. All I wanted is to start from scratch with fresh install. How can I achieve this??


Why are NginX and Lighttpd not affected by Slowloris?

I am investigating the vulnerability to  and I think I understand how and why this sort of attack works.  What I don't understand is why Lighttpd and NginX are not affected (according to the same article as linked above). What do they make so different?


int? version available for String.IsNullOrWhiteSpace

Our application requires int? variables. I'm often checking both to make sure not null and not 0 and it does get lengthy.  Is there an out of the box version of String.IsNullOrWhiteSpace() or String.IsNullOrEmpty() for int?  Maybe this would require an extension method?  If there even was or when someone makes one, would something like this considered bad practice?


Are all uncountable infinities greater than all countable infinities? Are some uncountable infinities greater than other uncountable infinities?

I recently finished a discrete mathematics class, and near the end of the semester, the prof (very superficially) touched on countable and uncountable infinities. His explanation of countable infinities began and ended with the example of the cardinal number set, while he explained that, for example, the set of all functions $f$ such that $f:\mathbb{R}\mapsto\mathbb{R}$ is, in fact, uncountable.  My question is threefold:   Does it make sense to say that any uncountable infinity is larger than any countable infinity? Does it make sense to say that certain countable infinities are larger than others? Finally, does it make sense to say that certain uncountable infinities are larger than others?   For example, is the set of all reals larger than the set of reals between any two integers? Can arithmetic-like rules be applied if this is true (addition of infinities makes them larger)?


How can I install Skype on 32-bit Ubuntu 14.04?

I'm trying to install Skype on Ubuntu 14.04 32-bits.  I have already tried :    downloading from the Skype website  But there is only a 64-bit version available. I have enabled Canonical partner in Other software in Software and Updates and run  sudo apt-get update sudo apt-get install skype   that returns:  Reading package lists... Done Building dependency tree        Reading state information... Done E: Unable to locate package skype  also tried :  sudo apt-get update --fix-missing sudo apt-get install skype   but I get the same problem...    Thanks for any help!


How to enter email adress pressing function key

I'm running  Kubuntu 20.10 desktop. Howto link my email address to F1 key and by pressing F1 in any application enter my email address.


Problem, uppercase header in an other language (Turkish)

The part of my MWE preamble  ....  \usepackage{fancyhdr} \pagestyle{fancy} \fancyheadoffset[LE,RO]{\marginparsep+\marginparwidth} \renewcommand{\chaptermark}[1]{\markboth{#1}{}} \renewcommand{\sectionmark}[1]{\markright{ #1}} \fancyhf{} \fancyhead[RO]{\textbf{\nouppercase{Kısım \thesection{}}\quad\textcolor{orange}{$\blacksquare$}\quad}\textit{\rightmark}\quad\quad\textcolor{blue}{\textbf\thepage}}% \fancyhead[LE]{\textcolor{blue}{\textbf\thepage}\textbf{\quad\quad\nouppercase{Bölüm{ }\thechapter\quad\textcolor{orange}{$\blacksquare$}\quad}}\textit{\leftmark}}% \fancypagestyle{plain}{% \fancyhead{} % get rid of headers \renewcommand{\headrulewidth}{0pt} % and the line } .... \renewcommand{\contentsname}{\textit{İçindekiler}} ....   No uppercase, no problem in Chapter names   but uppercase problem in headers   It doesn't İÇINDEKILER. It does İÇİNDEKİLER. As if, this problem seems like only i .  I find another same question. Does anyone know how to fix it?  Note: İ is uppercase of i and ı is lowercase of I in my language (Turkish).


Caption Error even it is outside of tabular

\begin{table}[h!]     %\centering      \begin{center}%\caption{table}{Caption text goes here}         \begin{tabular}{| l | p{6.7cm}|  p{5.7cm}|  p{4cm} | }             \toprule               Function & Equation & Derivative & Plot \\               \cmidrule(r){1-1}\cmidrule(lr){2-2}\cmidrule(l){3-3} \cmidrule(l){4-4}              Binary\\Step & $\mathnormal{f(x) = \begin{cases}                 \text{0}      &  \text{, for }x  < \text{0}\\                 x  & \quad \text{for }x \geq \text{ 0}                  \end{cases}}$ &$\mathnormal{f(x) = \begin{cases}                 \text{0}      &  \text{, for }x  \neq \text{0}\\                 ?  & \quad \text{for }x \geq \text{ 0}                 \end{cases}}$ & \raisebox{-\totalheight}{\includegraphics[width=0.2\textwidth, height=25mm]{binarystep.png}}    \\ %\cmidrule(r){1-1}\cmidrule(lr){2-2}\cmidrule(l){3-3}                 %\raisebox{-\totalheight}{\includegraphics[width=0.3\textwidth, height=60mm]{binarystep.png}} \\         %   Rectified linear unit (ReLU)         %   &               % &    \cmidrule(r){1-1}\cmidrule(lr){2-2}\cmidrule(l){3-3}         %   \raisebox{-\totalheight}{\includegraphics[width=0.3\textwidth, height=60mm]{binarystep.png}}             \cmidrule(r){1-1}\cmidrule(lr){2-2}\cmidrule(l){3-3}\cmidrule(l){4-4}             Picewise \\Linear & $\mathnormal{f(x) = \begin{cases}                 \text{0}      &  \text{, for }x  < x_{min}\\                 wx+b  &\text{, for }x_{min} \geq x \leq x_{max} \\ \text{1}      & \text{, for }x  > x_{max}                 \end{cases}}$ &$\mathnormal{f(x) = \begin{cases}                 \text{0}      &  \text{, for }x  < x_{min}\\                 w  &\text{, for }x_{min} \leq x \leq x_{max} \\ \text{0}      & \text{, for }x  > x_{max}                 \end{cases}}$ & \raisebox{-\totalheight}{\includegraphics[width=0.2\textwidth, height=25mm]{piecewise.png}}    \\             \cmidrule(r){1-1}\cmidrule(lr){2-2}\cmidrule(l){3-3}\cmidrule(l){4-4}             Bipolar & $\mathnormal{f(x) = \begin{cases}                 \text{0}      &  \text{, for }x  < x_{min}\\                 wx+b  &\text{, for }x_{min} \geq x \leq x_{max} \\ \text{1}      & \text{, for }x  > x_{max}                 \end{cases}}$ &$\mathnormal{f(x) = \begin{cases}                 \text{0}      &  \text{, for }x  \neq \text{0}\\                 ?  & \quad \text{, for }x \geq \text{ 0}                 \end{cases}}$ & \raisebox{-\totalheight}{\includegraphics[width=0.2\textwidth, height=25mm]{bipolar.png}}         %\\ \bottomrule         \\ \bottomrule         \end{tabular}     \end{center}\label{tbl:actfunc}\\ \caption-of{table}{Caption text goes here} \end{table}


Trying to automate contact deletion with SSJS

with the GDPR laws in place, it's important to have the possibility to remove contacts from Marketing Cloud. I'm trying to automate the process with existing tools and am looking for possible solutions.  Right now I'm trying to use the  from the Subscriber Object in the Core SSJ library:  <script runat="server">      Platform.Load("Core","1");      var subObj = Subscriber.Init("000-T-01-API-Delete");      var status = subObj.Remove();  </script>     The contact was created manually in Mobile Connect and exists in All Contacts. Although the query completes without errors, the contact remains in the system.  Any idea how to fix the script to perform the deletion?   I am thinking this might not be the best approach since it would be a 1 by 1 deletion of contacts performed in a loop, but I don't see an option like the API allows to tell the system to delete contacts stored in a data extension.   Any advice or ideas how to automate this process would be greatly appreciated.


Does anyone know how to create a light streak(trail) in Blender 2.8?  this following tutorial shows how to do it in an earlier version of Blender, but I could not make the smooth light streaks in the 2.8 version.  The light streaks came out as a bunch of particles, not smooth.  Thank you.


How to prevent behavior-attached functions from being attached twice?

I have a behavior that adds on to some checkboxes.  (function($) {    Drupal.behaviors.mymodule = {     attach: function (context, settings) {        $('.skip-line', context).on('change', function(){         // some code         if ( confirm(Drupal.t('Apply to all languages?')) ) {           // applying...         }       });     }   }; })(jQuery);   It works very well, but checkboxes are in AJAX-loaded part. If I reload that part of the form, clicking on them makes confirmation popup twice. Now, I know I can test inside function if it's the first time in a row it's called, but I would prefer to make sure it is added to my element only once, and thus called only once. How can I do that?


Solutions of the Pell-type equation $x^2-2y^2=-1$

I am assigned to find solutions to the Pell-type equation $x^2-2y^2=-1$. So far, I only have $(7,5), (41,29)$ and $(239,169)$.  My question is, is there a general formula to find all its solutions? Are there infinitely many solutions? If it's possible to write Mathematica code that would find its solutions, what would the code look like?  Thanks a lot.


Dual boot problem. Before I could dual boot, but now only Windows 10

My Dual boot is working now. The solution to my problem can be found in the last comment below. Thanks again for the help, @oldfred !  I had a dual boot with Windows 10 and Ubuntu 20.4 working before. When I make a fresh reinstall of Ubuntu 20.4 (this time I choose Home partition,) I lost the dual boot provide by Grabber. I thought the Ubuntu Installer would keep the Dual partition as before. The worst is that Windows 10 is starting now without the chance to boot on Ubuntu. Please help. Thank you. My system info,  My setup was as you can see on the picture:  ext4 ___Primary ___ /      ___I choose to format this partition ext4 ___ Primary ___ /Home ___I choose to format this partition In the Device for boot loader installation option, I choose the Windows Boot Manager option. ___I did NOT choose to format the partition where Windows Boot Manager was/is located  on Windows Boot Speed [Normal] or disabled on UEFI Secure Boot [Disabled] on UEFI Boot Mode [UEFI Boot] selected, instead of (BIOS legacy) I run chkdsk on windows. It is all good. I run defragmentation on windows. It is all good I've just found in my UEFI that I can run Ubuntu from my HDD. Now in order to run Ubuntu, I have to press F12 to access my UEFI and then go to HDD and press "enter." OBS.: When I click enter on my HDD, the first option is Windows; the second option is ubuntu, and the third option is Ubuntu (with capital later.) There are 2 Ubuntu options. It doesn't matter which Ubuntu option I click, the Ubuntu starts. Before I get the Ubuntu normal loading process, I get a black screen with a mesage on the top "System Boot Order Not Found." Also, I should say that my WIFI is not working. It always worded before.  My Dual boot is working now. The solution to my problem can be found in the last comment below. Thanks again for the help, @oldfred !


Sorry not very good with the whole JSON thing, from the json below, how would I output the title?    So far i've got:  <?php       $url ="http://en.wikipedia.org/w/api.php?action=query&list=search&format=json&srsearch=world%20cup";       $json = file_get_contents($url);       $wiki = json_decode($json, TRUE);        var_dump($wiki);     ?>


Why does the value of the penalized ridge is divided by 2 in GLMNET?

If you look at , it shows that it solves for the gaussian case:  But why does it divide the value of $\parallel \beta \parallel_2^2$ by 2?


Dimension of local ring as vector space over $\mathbb C$

I want to know what the dimension of each of the local ring $\mathbb C[x,y]_p/(y^2-x^7,y^5-x^3)$ is, where $p\neq (0,0)$ over $\mathbb C$-vector space. I know the dimension of it in the origin point, but I don't know other cases.


Can I add Ubuntu in Windows Boot Manager using Windows 10?

I'd like to boot into Ubuntu using the Windows Boot Manager on Windows 10 using UEFI. Can I do this? Thanks a lot.


Prove that $x^3+y^3+z^3-3xyz=1$ defines a surface of revolution

Prove that the equation $x^3+y^3+z^3-3xyz=1$ defines a surface of   revolution and find the analytical equation of its axis of revolution.   I think that I need to apply Euler's formula, so that I get rid of the third-grade polynomial there: $x^3+y^3+z^3-3xyz=1 \Leftrightarrow (x+y+z)(x^2+y^2+z^2-xy-xz-yz)=1$ but then I stuck on how to prove it defines a surface of revolution.  The textbook notes that: $f(x,y,z)=0$ defines a surface of revolution around the axis with equation $\frac{x-x_0}{a}=\frac{y-y_0}{b}=\frac{z-z_0}{c}$ if and only if it can be written as a polynomial of $(x-x_0)^2+(y-y_0)^2+(z-z_0)^2$ and $ax+by+cz$. Any hint for that one?


Were there any Vulcans serving on the Enterprise D?

In the TNG episode , Worf ends up being the only viable donor available to save the life of an injured Romulan.      Crusher: "Worf, you are the only one who can save his life."   Worf: "Then he will die."   Surely a Vulcan would be a superior match for obtaining vital bodily fluids. And with a crew compliment of 1,014 members there wasn't a single Vulcan serving on the Enterprise-D?      Worf: "There is a substance within my cells which you need to survive."   Patahk: "Then you've come to hear me beg for my life?"   Worf: "No."   Patahk: "I would rather die than pollute my body with Klingon filth!"


I have a directory with a bunch of log files. Something like this:  data170213.log data170214.log data170215.log data170216.log   I'm interested in looking at the last entries of the most recent file and following it. If I know the most recent file is data170216.log, I can do that with  tail -f data170216.log   The problem is, I don't know what the name of the most recent file in the directory is. I can identify it though with  ls -1r *.log | head -1   What I can't work out is how to send the result of the command ls -1r *.log | head -1 to the command tail -f [FILE]  I tried the following, unsuccessfully  tail -f < ls -1r *.log | head -1


Weird thing in references/bibliography page

I'm writing my thesis but I have a huge problem. I'm using BibTeX to make the bibliography, but when I run my project,in the references page of my pdf created file I have beside the number of the record (I'm using plain style) a label with the record's key name I don't know why there is this label, and I want to hide it. How can I do?  In my main .tex file I use:   \usepackage{cite}      %---------------------BEGIN BIBLIOGRAFIA----------------------------      \newpage      \nocite{*}      \bibliographystyle{plain}      \bibliography{bibliography}      %---------------------END BIBLIOGRAFIA------------------------------   And in bibliography.bib I have (at the moment) only one record:  @article{jor:1,  author = {Andreas Jordan and Regina Scholz and Peter Wust and Horst Fakhling and Roland  Felix},  title = {Magnetic fluid hyperthermia ({M}{F}{H}): Cancer treatment with AC magnetic field induced excitation of biocompatible superparamagnetic nanoparticles},  journal = {Journal of Magnetism and Magnetic Materials},  year = 1999,  volume = {201},  pages = {413-419}  }


When rendering my mirrored object, why does a line appear down the middle?

As said in the title, rendering my helicopter thing has a line down the middle, where it mirrored. Will this be a problem when exporting, or better, is there a way to fix it?    You can see the line down the cockpit. Please help :(


What are some real world places that call for delegates?  I'm curious what situations or patterns are present where this method is the best solution.  No code required.


What is the correct inflation pressure for hybrid road/city bike?

I have a road bike and I got a flat tire probably after going back on the road from the sidewalk very carefully. I guess I pinched my tire.   I usually inflate my tires to 7 bars. Is it enough and can I avoid this kind of issues with a higher pressure?  I also discover that I can replace my tires with some with Kevlar on it. Is it a good alternative?


Is there a list of all typos in Hoffman and Kunze, Linear Algebra?

Where can I find a list of typos for Linear Algebra, 2nd Edition, by Hoffman and Kunze? I searched on Google, but to no avail.


MOSFET always slightly on (with Pulldown) and other strange behaviour

I'm trying to control my RGB LED strip with my arduino, using IRLZ34N MOSFETs according to this schematic         – Schematic created using   I tried it out, everything worked. I soldered it to a circuit board just like that, except for that I used 4 copper wires on the Arduino connections. Everything worked, I unplugged the copper wire from the Arduino and checked back ~3 Days later, then this happened:  The strip was slightly glowing, even when the gates of the MOSFETs are directly connected to ground. Connecting a Gate to +5v made that color glow fully though. That's pretty much my problem, some deeper examining got me those Results:  I desoldered the mosfets and my multimeter reads a resistance of ~290;310;350Ω between Drain and Source. Another strange behaviour is that the conduction seems to go from 0-100% really fast. My LED strip goes from the constant "slightly on"-State to 100% brightness in a matter of some mV. Also strange is that this happens at ~4.7V on the Gate, while my fully functional IRLZ34N gives the strip 0-100% brightness at around 1.5-2V. I also tried to shorten Gate-Source and Gate-Drain, booth changed nothing. So my conclusion was that I probably destroyed the MOSFETs, but still the question is: How? Because I want to do the setup again (of course with new MOSFETs) but without killing the MOSFETs.


Is there a way to synchronize two windows 7 computers (like Dropbox but this time for the entire OS preferences*)?  *Wherever possible.


Construction of a triangle-free graph of chromatic number $1526$

I found this exercise in Bollobas: Modern Graph Theory "Construct a triangle-free graph of chromatic number 1526"  It is added not to use results from the chapter about Ramsey Theory.   Now my qestions:  (1) Is there a nice way to construct such a graph?  (2) If yes then what is so special about this specific graph?  My ideas:  Grötzsch's theorem states that every triangle-free planar graph may be 3-colored, so we know that we can exclude planar grpahs and focus on non-planar graphs.  I read something about the Mycielskian on   I think this is the key to the solution but I do not see how to follow a concrete construction.


I am trying to check if value exists in a string array. The below one works but when I tried the next code block, it failed.  bool exixts; string toCheck= "jupiter";  string[] printer = {"jupiter", "neptune", "pangea", "mercury", "sonic"};  if(printer.Contains(toCheck)) {     exists = true; }   How can I check for trim and case sensitivity?  I tried this  bool exixts; string toCheck= "jupiter   ";  string[] printer = {"jupiter", "neptune", "pangea", "mercury", "sonic"};  if(printer.Contains(toCheck.Trim(),StringComparison.InvariantCultureIgnoreCase))) {     exists = true; }


I have created node there path is "content/book/book-name-alias". Where I have override a node using view page "content/book/%" where  contextual filter using "Node Id".  When I have request a page using "book/content/9" a node will override but same node "book/content/book-name-alias" it is not working.  How to override a node using an alias?


Substitution Cipher vs. Permutation Cipher

What is the difference between Substitution Cipher and Permutation Cipher?  In a substitution cipher I have seen that there is a random choice of 26 alphabet characters for encryption and decryption and that it can't be broken by brute force attacks because the sample space for key encryption is 2**88 which is very large. Hackers can use frequency analysis to get the encrypted message.   What about permutation cipher, then? What is this and why it comes under poly-alphabetic and substitution comes under mono-alphabetic?


New to math SE. I'm working through a  but am still trying to wrap my head around methods of proving things. They've given a couple of very simple statements to prove, but beyond the intuitive notion of "if A is a subset of B and B is a subset of C then A is a subset of C" (I'm picturing marbles in my head, which is attaching incorrect context to the notion) I can't see strictly speaking what the proof is.  The only axiom given so far is the  which I don't think applies because it implies A ⊆ B and B ⊆ A (which isn't stated. It has also given me the subset definiton A ⊆ B iff x ∈ A ⇒ x ∈ B. But again, beyond intuition, I don't know how to get there. Can anyone point me in the right direction?


If a PC's ability score increases due to an item, does it increase the corresponding modifier for the ability score or any skills/attacks?

I'm a new DM. One of the PCs obtained , which raise the Strength score of the creature wearing and attuned to them to 19. Does this increase the modifier or any of the skill checks or damage rolls as well?  I'm not sure how having higher Strength is helpful if it doesn't.


A discontinuous function such that $f(x + y) = f(x) + f(y)$

Is it possible to construct a function $f \colon \mathbb{R} \to \mathbb{R}$ such that $$f(x + y) = f(x) + f(y)$$ and $f$ is not continuous?


Problem (1.8) A Path to Combinatorics Solution Verification.

Problem (1.8): There are ten girls and four boys in Mr. Fat's combinatorics class. In how many ways can these students sit around a circular table such that no boys are next to each other.   My Attempt: Total number of ways in which both boys are girls can be arranged on a circular table is $13!$ and the number of ways in which any two boys can be together is $2!*12!$. Therefore the answer is $13!-2*12!=11*12!$. Is this answer correct? I am asking this because I am confused about the exact meaning of the line "no boys are together." Does this mean that no two/three/four boys are together?   Note: Meanwhile I have made another attempt on the problem. We can place the $10$ girls on the circular table in $9!$ ways. Then we are left with $10$ spots which need to be filled with $4$ boys. This can be done in $P^{10}_4$ ways. Thus, the number of ways is $9!P^{10}_4$.


How to install Turbo C++ in ubuntu 16.04

I tried to install turbo c++ using the methods given on this site but every time I run dos box emulator on my Ubuntu 16.04 after typing mount c ~ then I typed C: and then when I typed cd Turbo C++ 3.2.2.0 (the file name which was in my case)  it showed error and said:  try Turbo (sorry space is not included b/w turbo and C)C~1   and again after typing Turbo C~1 it said   unable to change to: Turbo (sorry space is not included b/w turbo and C)C~1   Please help me because I am waiting to see the blue screen of turbo C++ and my coding back!


How do I remove duplicates when using the random sort?

I have created a view where I am displaying the the node title and a logo (a cck field). In the arguments I have passed the taxonomy term name.  In the result a node is displaying 2 or 3 times; I already checked the distinct checkbox in the Query settings but that also does not work. I have used the random sort, which seems to cause the duplicates; when I remove the random sort, it works fine.  How can I avoid the duplicates without disabling the random sort?


How to hide "Start" button in Windows 8.1?

Does anybody know how to hide this "Start" button in Windows 8.1 so that the task bar looks like it did in "old" Windows 8?


Prove that the sequence $b_n=\left(1+\frac{1}{n}\right)^{n+1}$ is decreasing

Prove that the sequence $$b_n=\left(1+\frac{1}{n}\right)^{n+1}$$ Is decreasing.  I have calculated $b_n/b_{n-1}$ but it is obtain: $$\left(1-\frac{1}{n^2}\right)^n \left(1+\frac{1}{n}\right)^n$$ But I can't go on.  Any suggestions please?