Why is my LCD stop to work correctly when my pump is running?
Why does connecting a high-current device to my digital circuit cause weird behavior?
What reputation do you need on Stack Overflow to receive an invite to Careers? Parse v. TryParse What is the difference between Parse() and TryParse()?  int number = int.Parse(textBoxNumber.Text);  // The Try-Parse Method int.TryParse(textBoxNumber.Text, out number);   Is there some form of error-checking like a Try-Catch Block? How can I prove: if $p $ is prime and $n>1$, then $ p^{\frac1n} $ is irrational? Integration of $\frac {1}{1+\sin x}$ For $\int \frac {1}{1+\sin x} \mathrm{d}x$, my calculus textbook told me to multiply the integrand by $\frac {1- \sin x}{1- \sin x}$ to obtain: $$ \int \frac{1-\sin x}{1-\sin^2 x} \mathrm{d}x= \int \frac{1-\sin x}{\cos^2 x} \mathrm{d}x$$  From here, it is a matter of breaking up the integral to two very trivial integrals, $\int \sec^2x \mathrm{d}x$ and $\int \sec x \tan x \mathrm{d}x$, which are easily found via commonly known rules.  My question is whether there exists a way of finding $\int \frac {1}{1+\sin x} \mathrm{d}x$ without having to perform the multiplication by $1- \sin x$ in the numerator and denominator. Renaming attributes/fields in shapefile attribute table using QGIS I would like to rename some fields in my attribute table:  Like rename &quot;XRF_N3&quot;in something else. It seems quite a easy issue but I don't find any information about how can I do that. braces on the sides of an easybmat matrix I created the following matrix with , and I would like to add at the bottom (respectively right) something like an underbrace (resp. "rightbrace") under each of the two blocks, together with a number specifying the number of columns (resp. rows) of the block. This amounts to two braces on the bottom and two on the right, and each brace should have a number below (resp. at the right) of it.  I did not find anything about that on the easybmat manual. I think I see how to do the braces with the  package, but then I am not able to create the block structure of the matrix in the first place.  \documentclass{article} \usepackage{easybmat} \begin{document} \[  M(z)= \left[ \begin{BMAT}[5pt]{c|c}{c} \begin{BMAT}[5pt]{c:c:c}{ccccccc} &amp; &amp; \\ &amp; &amp; \\ &amp; &amp; \\ v_1 &amp; \dots &amp; v_m \\ &amp; &amp; \\ &amp; &amp; \\ &amp; &amp; \end{BMAT} &amp; \begin{BMAT}{c}{c|c} \begin{BMAT}[5pt]{c:c:c}{ccc} &amp; &amp; \\ w_1(a) &amp; \dots &amp; w_n(a) \\ &amp; &amp; \end{BMAT} \\ \begin{BMAT}[10pt]{c}{c} B(z) \end{BMAT} \end{BMAT} \end{BMAT}  \right] \] \end{document}     This is more or less what i wish: How can I pad a String in Java? Is there some easy way to pad Strings in Java?  Seems like something that should be in some StringUtil-like API, but I can't find anything that does this. I have a computer with a video card that has no Linux support.  I discovered this issue while trying to use a persistent usb to boot from.   I found that I can boot like that if I change options and edit so as to add nomodeset there (see ).  Also, editing the syslinux.cfg file from my live persistent USB and adding nomodeset in a line there made this setting automatic for booting from the persistent USB.  Can I make a similar edit for proper install from the same live USB?  Is it possible to edit something on the live USB in order to install the SO from it,  -- that is: having automatically the nomodeset setting already there when the installation starts?  My problem is that in order to install I think I already have to have added nomodeset or I'll see nothing on my display. I need a way to be sure that nomodeset it's permanent from the start. Following , this is how we correctly make the r sound:   Let the throat vibrate since it is voiced. Round the lip a little. Raise the tip of the tongue towards the hard bump behind the upper front teeth,  but do not let the tip of tongue touch the bump. This also makes the center of the tongue go down. The back part of the tongue is raised because you pull it into a tight ball Fold and raise the sides of the tongue so they touch the upper side-teeth.   If we follow the above requirement, our tongue should have an s shape when we pronounce the r sound as depicted in the following sketch:    Is it possible to raise the tip while raising the back and lowering the center of the tongue when making an r sound?   How do native speakers make an r?  P.S. My tongue is very short anyway! In the King James version of the Bible there is a verse like this:     The Lord is my strength, and my fortress, and my song. And He is become my salvation.   Is it still feasible to use "is become" instead of "has become" and what is the semantic difference? Not sure this is something which people will know on here are not.    We currently have a BI setup where we have Integration services on one SQL instance and the data warehouse database on a separate SQL Instance.    My question is, as no users physically connect to the Integration services SQL instance and it is purely used to execute package from the integrations service catalog via SQL agent, do we need to License every user i.e. Cal's for that SQL instance.  Basically i'm wanting to know if I could utilize SQL 2016 for an integration services instance and use features like Json manipulation etc and then load this data into the 2014 version instance...but what level of licensing will I need? How do I configure internet connection for Terminal on Ubuntu 14.04? I've installed on Ubuntu 14.04 and with I've Broadband connection setup, Browser connection is OK,  but Terminal not connection via internet, when command type "sudo apt-get update" by terminal then showing me Error, see screenshot, How I can fix this ? Find all functions $f:\mathbb{N_{0}} \rightarrow \mathbb{N_{0}}$ satisfying the equation $f(f(n))+f(n)=2n+3k,$ for all &amp; $n\in \mathbb{N_{0}}$, where $k$ is a fixed natural number.  A friend of mine suggested me to use recurrence relation. While it is unfortunate that I have problems understanding recurrence relation. Please refer information to understand difference equation, homogeneous equation &amp; auxillary equation.  Thanks in advance! Kindly don't down vote for not showing my attempt. I am seriously not able to understand the question and the process suggested to use. Random operators Let $(\Omega, \mathcal F,P)$ be a probability spaces and $H$ be a Hilbert space. By a random operator $A$ from $H$ to $H$ we mean a linear continuous mapping from $H$ into the Frechet space $L_0^H (\Omega, \mathcal F,P)$ of all $H$-valued random variables. My question is: How Can we define $|A|$ and the adjoint $A^*$? Had it not been vs If it were not for Will wolves attack and kill ocelots in Minecraft? I know they kill sheep. I just don't want my cats being eaten. Is a Schengen visa/transit visa required for a transit flight through two Schengen airports? When should I use an em-dash, an en-dash, and a hyphen? I generally know how to use a hyphen, but when should I use an en-dash (–) instead of an em-dash, or when should I use a hyphen (-) instead of an em-dash (—)? I have a list of tuples like this:  [ ('a', 1), ('a', 2), ('a', 3), ('b', 1), ('b', 2), ('c', 1), ]   I want to iterate through this keying by the first item, so, for example, I could print something like this:  a 1 2 3 b 1 2 c 1   How would I go about doing this without keeping an item to track whether the first item is the same as I loop around the tuples? This feels rather messy (plus I have to sort the list to start with)... Using notify-send with cron I am using Arch Linux with KDE/Awesome WM. I am trying to get  notify-send to work with cron.   I have tried setting DISPLAY/XAUTHORITY variables, and running notify-send with "sudo -u", all without result.  I am able to call notify-send interactively from the session and get notifications.  FWIW, the cron job is running fine which I verified by echoing stuff to a temporary file. It is just the "notify-send" that fails to work.  Code:  [matrix@morpheus ~]$ crontab -l * * * * *  /home/matrix/scripts/notify.sh  [matrix@morpheus ~]$ cat /home/matrix/scripts/notify.sh #!/bin/bash export DISPLAY=127.0.0.1:0.0 export XAUTHORITY=/home/matrix/.Xauthority echo "testing cron" &gt;/tmp/crontest sudo -u matrix /usr/bin/notify-send "hello" echo "now tested notify-send" &gt;&gt;/tmp/crontest  [matrix@morpheus ~]$ cat /tmp/crontest testing cron now tested notify-send  [matrix@morpheus ~]$    As you can see the echo before &amp; after notify-send worked. Also I have tried setting DISPLAY=:0.0   UPDATE: I searched a bit more and  needs to be set. And after hardcoding this using the value I got from my interactive session, the tiny little "hello" message started popping up on the screen every minute!   But the catch is this variable is not permanent per that post, so I'll have try the the named pipe solution suggested there.   [matrix@morpheus ~]$ cat scripts/notify.sh #!/bin/bash export DISPLAY=127.0.0.1:0.0 export XAUTHORITY=/home/matrix/.Xauthority export DBUS_SESSION_BUS_ADDRESS=unix:abstract=/tmp/dbus-BouFPQKgqg,guid=64b483d7678f2196e780849752e67d3c echo "testing cron" &gt;/tmp/crontest /usr/bin/notify-send "hello" echo "now tested notify-send" &gt;&gt;/tmp/crontest   Since cron doesn't seem to support notify-send (at least not directly) is there some other notification system that is more cron friendly that I can use?