I am extremely new to latex and I have to submit a project report in my college. The college has provided us with a template which we have to use for generating the report. It contains too many packages and other things which I am not familiar with. As I a extremely short on time, I need some help to fix the subsection numbering issue.   The packages included are:  \documentclass[oneside,a4paper,12pt]{book} %\usepackage{showframe} %\hoffset = 8.9436619718309859154929577464789pt %\voffset = 13.028169014084507042253521126761pt \usepackage{fancyhdr}  \fancypagestyle{plain}{%   \fancyhf{}   \fancyfoot[CE]{Pune Institute of Computer Technology, Department of Computer Engineering 2016-17}   \fancyfoot[RE]{\thepage} } \pagestyle{fancy} \fancyhead{} \renewcommand{\headrulewidth}{0pt} \footskip = 0.625in \cfoot{} \rfoot{}  \usepackage[]{hyperref} \usepackage{tikz} \usetikzlibrary{arrows,shapes,snakes,automata,backgrounds,petri} \usepackage{titlesec} \usepackage{tabularx}  \usepackage[nottoc,notlot,notlof,numbib]{tocbibind} \usepackage[titletoc]{appendix} \usepackage{titletoc} \renewcommand{\appendixname}{Annexure} \renewcommand{\bibname}{References}  \setcounter{secnumdepth}{5}  \usepackage{float} \usepackage{subcaption} \usepackage{multirow}  \usepackage[ruled,vlined]{algorithm2e}  \begin{document} ....   after some pages of acknowledgments and abstract, this comes  \tableofcontents \listoffigures  \listoftables  \mainmatter  \titleformat{\chapter}[display] {\fontsize{16}{15}\filcenter} {\vspace*{\fill}  \bfseries\LARGE\MakeUppercase{\chaptertitlename}~\thechapter} {1pc} {\bfseries\LARGE\MakeUppercase} [\thispagestyle{empty}\vspace*{\fill}\newpage]  ....   Then comes first chapter  \setlength{\parindent}{11mm} \chapter{Synopsis} \section{Project Title}  blah blah blah... \section{ Project Option } blah blah blah...   The PDF output that I see is (I use TexStudio in ubuntu 16.04)   The numbering is correctly displayed in the table of contents but it is not displayed in the chapters. I have uploaded all the info I felt that will be necessary to understand the problem. If you want anymore info, please feel free to ask for it. Thank you.

After reinstalling TeXLive distribution (install-tl-20160318, Ubuntu 14.04), a issue occurs with the updated version of the titlesec package: the section numbering is lost.  What could it be missing? Is there a modification I have not seen?  Below is a MWE comparison of the two versions. The prevtitlesec package is a reinstall of the previous version (2011/12/15).  \documentclass{book} \usepackage[margin=2cm,a4paper]{geometry} %\usepackage{prevtitlesec}% 2011/12/15 version \usepackage{titlesec}% 2016/03/15 version \usepackage{lipsum}  \begin{document}  \chapter{Title of the first chapter} \lipsum[1] \section{A test section} \lipsum[4] \subsection{A test subsection} \lipsum[4] \subsection{A test subsection} \lipsum[4]  \end{document}   titlesec package 2011/12/15:    titlesec package 2016/03/15:


How can I write a script that is shell independent? I want to be able to run one script which will run in ksh, sh and bash.  For example: If I have a line in my script like whence ls which will run in ksh and not in sh, I want to be able to have something like  if (ksh) then whence ls if (sh) then whereis ls   Can I use $SHELL value or is there any other way?

As per my knowledge, to determine the current shell we use echo $0 in the shell. Rather I want my script to check in which shell it is running. So, I tried to print $0 in the script and it returns the name of the script as it should. So, my question is how can I find which shell is my script running in during runtime?


If you have a symmetric matrix, is it orthogonally diagonalizable? Or is the converse only true?

Can someone point me to a paper, or show here, why symmetric matrices have orthogonal eigenvectors? In particular, I'd like to see proof that for a symmetric matrix $A$ there exists decomposition $A = Q\Lambda Q^{-1} = Q\Lambda Q^{T}$ where $\Lambda$ is diagonal.


I just made a figure with text I had compiled in LaTeX and arrows added later:    Is it possible to have some text connected by diagonal arrows like above, all in LaTeX code?

Can anyone help me in giving commands for commutative diagrams in LaTeX ? It doesn't seem to appear properly in the LaTeX guides that I have. A command for a simple triangular diagram with arrows associated to maps would be good enough, or maybe some appropriate reference.


Can you help me how can i find all endomorphisms between (Q,+) and (Q,+).Which of them are automorphisms?

Find all the group homomorphisms from $(\mathbb{Q}, +)$ into $(\mathbb{R}, +)$.  My attempt:  If $\mathbb{Q}$ were a cyclic group, I could tell that any homomorphism will be determined by the image of generator. But here $\mathbb{Q}$ is not a cyclic group, so there's no generator. All one can say is that:   if $f$ is a homomorphism then $f(0)=0$.   But this doesn't help me to solve this problem. So how should it be tackled?


A similar question was asked  but the answer refers to something called , which only claims to preview files with no extension.  I need something that will show previews of files with extensions that are unknown to the Finder.  They are all plain-text files.  And, it needs to run on Lion (10.7).  To clarify: I'm not looking for a default QL for any unknown extension, but rather for one that will preview certain specific extensions (e.g., .sps, .fort) as plain text.

I'm a programmer, and I find Mac's QuickLook a really great feature for quickly becoming familiar with a particular code base.  Basically, I open up a Finder window in the directory where my code files are, I push the spacebar (to evoke QuickLook), and then I arrow key up/down/left/right through all the files and scroll within QuickLook as needed.  The problem that I run into are files with no extension and files with unknown extension.  How can I convince the Mac to attempt to QuickLook these files as text files (which they usually are).  Also, it's really nice how QuickLook automatically colors the code based upon the type of code it thinks it is.  How can I extend the types of code files that the Mac recognizes?  For instance, I want to be able to QuickLook the code in a *.html.erb file or a *.js.erb file.


A few weeks ago I ordered this  USB wifi stick from Amazon.de.  I have a DUAL boot with both windows 10 and Ubuntu 18.04 OS on my desktop computer. The driver works directly on the windows OS without any installation whatsoever.  On ubuntu however, it doesn't recognize the adapter at all as it keeps saying "No Wi-Fi Adapter Found" in the settings.   I got a CD-rom and a small instruction manual for installation of the driver for each platform. The instructions refer to the driver download link in case the CD-rom is futile, which I used.  The url is https : // bit.ly / 2IXCf8i (without spaces).  This installation provides a folder with installation instructions of its own and a LINUX folder with three subfolder options: RTL8811 RTL8812 and RTL8814. I'm not sure what the chipset of this adapter is though, so I tried to install them all. But everytime I try to install them, I get an error as follows: cc1: some warnings being treated as errors scripts/Makefile.build:284: recipe for target   cc1: some warnings being treated as errors scripts/Makefile.build:284: recipe for target '/home/****/20190622/LINUX/RTL8814/RTL8814AU_Linux_v4.3.21.1_24835.20171031/driver/rtl8814AU_linux_v4.3.21.1_24835.20171031/core/rtw_cmd.o' failed make[2]: *** [/home/****/20190622/LINUX/RTL8814/RTL8814AU_Linux_v4.3.21.1_24835.20171031/driver/rtl8814AU_linux_v4.3.21.1_24835.20171031/core/rtw_cmd.o] Error 1 Makefile:1614: recipe for target '_module_/home/****/20190622/LINUX/RTL8814/RTL8814AU_Linux_v4.3.21.1_24835.20171031/driver/rtl8814AU_linux_v4.3.21.1_24835.20171031' failed make[1]: *** [_module_/home/****/20190622/LINUX/RTL8814/RTL8814AU_Linux_v4.3.21.1_24835.20171031/driver/rtl8814AU_linux_v4.3.21.1_24835.20171031] Error 2 make[1]: Leaving directory '/usr/src/linux-headers-5.0.0-37-generic' Makefile:1699: recipe for target 'modules' failed make: *** [modules] Error 2   The same thing happens either via sudo make or sudo ./install.sh.  I'm not sure how to proceed at this point, as I feel I've tried all the possibilities till now. Does anyone know how to install the driver for this USB wifi adapter?   Let me know if I need to post any more info.

On Ubuntu 19.04 I had current rtl8812au (AC1200) and rtl8814au (AC1750) dkms drivers for my USB wireless dongles installed and running fine. They both broke after I upgraded to Ubuntu 19.10. I've been able to find a replacement/newer rtl8812au driver that works with kernel 5.3 on Ubuntu 19.10. I haven't been able to find a replacement/newer rtl8814au driver that works with kernel 5.3 on Ubuntu 19.10. Github.com has a number of rtl8814au drivers available, even some that proport to compile with kernel 5.2. I believe that I've tried about 6 different rtl8814au drivers from github, but none of them work, even though some of them do compile with kernel 5.3. Does anybody know of a working rtl8814au driver that works with kernel 5.3 on Ubuntu 19.10?


I have some data about the $\{noise,~ size,~ speed,~ length,~ width\}$ of cars. I have performed SVD, and I want to reconstruct my data using only the first 2 principal components.  I subtracted mean from data and then did  [U,S,V] = svd(matrix,0)   in matlab  If I am right the first 2 columns of V would be the first 2 principle components can anyone help me reconstruct the data please.  also my data is originally a $14 \times 5$ matrix

Principal component analysis (PCA) can be used for dimensionality reduction. After such dimensionality reduction is performed, how can one approximately reconstruct the original variables/features from a small number of principal components?  Alternatively, how can one remove or discard several principal components from the data?  In other words, how to reverse PCA?    Given that PCA is closely related to singular value decomposition (SVD), the same question can be asked as follows: how to reverse SVD?


Backdrop: A horror-themed campaign that heavily draws upon the Lovecraft mythos, using the Dungeons & Dragons 5th Edition ruleset.  Situation: The party has encountered a story arc inspired by the American folktale of the . An NPC is currently pregnant with an aberration; the party has used various magical abilities to successfully divine the gestating creature's true nature. Thanks to previous incidents being recorded in the town's charter, the party knows that giving birth to this creature will be fatal to the NPC and the creature itself will be dramatically more difficult to deal with.  The party has access to high level arcane magic (but not the Wish spell) and wants to find a way to safely separate the NPC from the aberration growing within her. Even in its current state the aberration could pose a threat if disturbed via surgery. The idea has been posed to try using a spell that targets only the NPC, specifically the Banishment spell - sending the mother to a harmless demiplane while the aberration can be collected and dealt with, without risking harm to the NPC.  With the above details in mind, could the  spell (or something similar) be used to separate the NPC from the aberration, such as by banishing just one or the other, while adhering more or less to Rules as Written?  "" covers a similar topic, but the circumstances are different in that this is not a creature that has been swallowed; the creature is actively growing inside the NPC.

Using the D&D 5e RPG system. We'll use a  and the spell  as an example. What, if anything, occurs when you attempt to cast such a spell on a creature that is currently pregnant?  The spell specifies the following:     You attempt to send one creature that you can see within range to   another plane of existence. The target must succeed on a Charisma   saving throw or be banished. If the target is native to the plane of   existence you’re on, you banish the target to a harmless demiplane.   While there, the target is incapacitated   Does the spell take effect and if so does it bring the as yet unborn creature(s) with the mother? Possible complications include, beyond the spell only targeting a single creature, that it must also be a creature that you can see. The supposition is that being inside another creature would provide those inside with .     A target with total cover can't be targeted directly by an attack or a   spell, although some spells can reach such a target by including it in   an area of effect. A target has total cover if it is completely   concealed by an obstacle


Does Ubuntu work on laptops, and if so, which download do I choose?

I'm thinking about installing Ubuntu Desktop, but I don't know what flavor is the best for my system. What are the minimum and recommended hardware requirements? What kind of CPU? How much memory? Should I have Hardware Acceleration? What flavor should I use?  This is an attempt of a canonical answer. My answers have the "official  requirements", the recommended are a mix of official sources and opinion based (along with the answer it's told the source). You can comment or edit if you feel that the information is obsolete or incomplete. It is a good rule of thumb that any system capable of running Windows Vista, 7, 8, x86 (Intel) OS X will almost always be a lot faster with any Ubuntu flavor even if they are lower-spec than described below.


I am wondering how to make a filesystem as a non-root user, using GNOME 3 (openSUSE Leap 42.3).  ~> fallocate -l ### part.bin # Create a sparse file on disk ~> #sudo mkfs -t FSTYPE part.bin # Requires root; how can I do this without root privileges?   I am assuming this is possible because of the implications of .  Though sudo can give root privileges to only certain executables, I am looking for a pure non-root solution, requiring no superuser privileges.

I'd like to create a filesystem image as a non-root user, the problem I'm facing is that the way I'm currently doing it, it needs a mount and as a non-root can't do a mount.  This is what I'm now doing:  #!/bin/sh  IMG="app.ext4" LBL="PIHU_APP" MNT="/mnt/PIHU_APP" APP="/home/buildroot/board/arctura/PIHU_APP/application"  #64MB: dd if=/dev/zero of=$IMG bs=4096 count=16384  mkfs.ext4 $IMG e2label $IMG $LBL  mkdir -p $MNT mount -o loop $IMG $MNT cp -r $APP $MNT sync umount $MNT   I have full root access, so I can setup/prepare anything, but the script will be executed from a non-root account.  However, I have a feeling there may be a better way that might not even need mounting, but I'm not sure..


I was doing this problem on , and as I was trying to simplify the formula, I arrived at the above conclusion. But now that I think of it, I actually arrived at that conclusion by mistake. Here are my workings. $$ GCD\bigl(( LCM(a,b) , LCM(a,c)\bigr)  \\\\=> a \times GCD\left( \frac{b}{GCD(a,b)} , \frac{c}{GCD(a,c)} \right) \\\\=> \frac{a \times GCD(b,c)}{GCD\bigl( GCD(a,b) , GCD(a,c)\bigr)} \\\\=> \frac{a \times GCD(b,c)}{GCD(a,b,c)} \\\\=> \frac{a \times GCD(b,c)}{GCD\bigl(a, GCD(b,c)\bigr)} \\\\=> LCM\bigl(a , GCD(b,c)\bigr) $$ I suspect that the third line is wrong since $GCD(hi,jk) != GCD(hj) \times GCD(ik)$. I know the final formula is correct since my submission was accepted. So what is the correct way to arrive at the conclusion?

is $\operatorname{lcm}(a,\gcd(b,c))=\gcd(\operatorname{lcm}(a,b),\operatorname{lcm}(a,c))$? it should be true for positive integers because the commutative algebra by Atiyah says addition, intersection on the ideals of $\mathbb{Z}$ is distributive. how should i solve it?


I think that a color is intangible and a paint (thing) is concrete but a color (property) is abstract. Isn’t ‘color’ itself an abstract noun? I cannot imagine a red color but only a red-colored thing.

Whenever I think of a concrete noun, I think of something that can be perceived by the five senses.   I was wondering, if I could see a particular practice taking place, as in a series of football drills, would the word 'practice' be a concrete noun?  I can also see a 'lesson' taking place, so would that also be a concrete noun?   Also, are sounds concrete nouns too? I can hear a 'bang', so would it be classed as a concrete noun?  Thanks in advance for any answers to clarify this.


I am trying to open a select element by the following code but with no luck.    $("#surveyno-select").trigger('mousedown'); <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>  <select id="surveyno-select" class="form-control" onchange="loadquery(this)" selectionorder="4">   <option value="-1">Please Select a Surveyno</option>   <option value="1">1</option>   <option value="10">10</option> </select>

Is it possible to use JavaScript to open an HTML select to show its option list?


i have a text like this:
Hi this is a text and i wan't to add a class to some words which are here
   And I wan't to add class ".red" to this words: "some","here","add", for example. How can I make this with jQuery? The easier the code the best it is.

I basically need to highlight a particular word in a block of text. For example, pretend I wanted to highlight the word "dolor" in this text:
     Lorem ipsum dolor sit amet, consectetuer adipiscing elit.

     Quisque bibendum sem ut lacus. Integer dolor ullamcorper libero.     Aliquam rhoncus eros at augue. Suspendisse vitae mauris.
  How do I convert the above to something like this:
     Lorem ipsum dolor sit amet, consectetuer adipiscing elit.

     Quisque bibendum sem ut lacus. Integer dolor ullamcorper     libero. Aliquam rhoncus eros at augue. Suspendisse vitae mauris.
  Is this possible with jQuery? Edit: As  , this is quite possible without jQuery - but I was hoping there might be a special method of jQuery which would let you do selectors on the text itself. I'm already using jQuery heavily on this site, so keeping everything wrapped up in jQuery would make things perhaps a bit more tidy.


I have changed my shell from bash to zsh and set it as default in Ubuntu 20.10 and now every time I run the command su i get this: su Password: (entered correct password) su: Authentication failure  Does Anyone knows why?

It's very weird that after switching to zsh from bash, I can't access root.  I normally use 'su' to login as root after I login as a normal user (username is normalusername) with less privileges. And it was always nice. But after switching root shell from bash to zsh, when I try to login via su, I got:  normalusername@(none):~$ su Password: (enter the correct password) Cannot execute zsh: No such file or directory   When I access root directly via ssh from my Mac, I got:  localhost:~ myname$ ssh -lroot 106.186.120.20 root@106.186.120.20's password: (enter the correct/incorrect password) Permission denied, please try again.   No matter whether I entered the correct password, it comes again and again.  So I intentionally entered a wrong password with "su" from a normal user, I got:  normalusername@(none):~$ su Password: (entered a wrong password and pressed enter) (pressed enter) su: Authentication failure   After entering the incorrect password I didn't see anything, I typed enter twice and then got the su: Authentication failure result.  I tried for many times and the conclusion is:   If I enter the correct password, it will tell me that "Cannot execute zsh: No such file or directory" If I enter the incorrect password, it will not showing up anything until I hit enter for 2-6 times.   It seems to be an indication that I didn't just forget the "correct password". But how can I access root anyway?  The entry in /etc/passwd is  root:x:0:0:root:/root:zsh


I need to simplify: $\sum_{k=1}^n ({n \choose k}k^2 )$.  My first idea was to get rid of the square and use known identities to proceed. This is what I did  $$\sum_{k=1}^n( {n \choose k}k^2) = \sum_{k=1}^n( \frac n k {n-1 \choose k-1}k^2) = \sum_{k=1}^n {n-1 \choose k-1} nk = n \sum_{k=1}^n {n-1 \choose k-1} k = \\ n \sum_{s=0}^n \left({n-1 \choose s}(s+1) \right)$$ Now, the only thing that stops me here is the $s+1$ factor. Is there a way to dispose of it, or maybe to change it to $s$?

I know that $$\sum_{k=0}^n \binom nk k^2=2^{n-2}(n^2+n),$$ but I cannot find a way how to prove it. I tried induction but it did not work. On wiki they say that I should use differentiation but I do not know how to apply it to binomial coefficient.  Thanks for any response.  (Presumptive) Source: Theoretical Exercise 1.12(b), P18, A First Course in Pr, 8th Ed, by S Ross


I have a VERY small site and recently I've been trying to make it more secure, I used to store my passwords in plain text.  I think Im doing it right, but as a "hobby" programmer I wanna make sure so I ask you, the professionals  When a user register I do: password_hash($their_password, PASSWORD_DEFAULT) and store that in the 'password' column in the users table. I use PASSWORD_DEFAULT as that seems the best according to php.net.     Note that this constant is designed to change over time as new and stronger algorithms are added to PHP."   Sounds good!  And the Login part (very simple):  if (count($_POST) > 0) {  $username = trim($_POST['username']); $password = trim($_POST['password']);  $query = $db->prepare("SELECT password FROM users WHERE username = ?"); $query->execute(array($username)); $row = $query->fetch();  if (password_verify($password, $row['password'])) {     echo "Correct password";     // create session... } else {     // wrong password }   Maybe I should check if the username exists first but other than that what do you think?

It is currently said that MD5 is partially unsafe. Taking this into consideration, I'd like to know which mechanism to use for password protection.  This question,   suggests that hashing multiple times may be a good idea, whereas  suggests using salt.  I'm using PHP. I want a safe and fast password encryption system. Hashing a password a million times may be safer, but also slower. How to achieve a good balance between speed and safety? Also, I'd prefer the result to have a constant number of characters.   The hashing mechanism must be available in PHP It must be safe It can use salt (in this case, are all salts equally good? Is there any way to generate good salts?)   Also, should I store two fields in the database (one using MD5 and another one using SHA, for example)? Would it make it safer or unsafer?  In case I wasn't clear enough, I want to know which hashing function(s) to use and how to pick a good salt in order to have a safe and fast password protection mechanism.  Related questions that don't quite cover my question:


Do you recommend I take a course in Abstract Algebra before or after a course in Linear Algebra? I have never taken any abstract mathematics courses before. So this would be my first one.

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


I have one object like this  let ob1 = { 'item_data':{   'stack':{     'purchase':'12345',     'order':'22222'    }   } }   and another object like this  let ob2 = {   'stack':{     'purchase':'444444'    }  }   The resultant object should look like this  result = {   'item_data':{     'stack':{       'purchase':'444444',       'order':'22222'      }    }  }   The code is in a nodejs application. I am wondering if there is any javascript library to do this kind of merge/replace objects in server side js.  Thanks for helping.

I need to be able to merge two (very simple) JavaScript objects at runtime.  For example I'd like to:  var obj1 = { food: 'pizza', car: 'ford' } var obj2 = { animal: 'dog' }  obj1.merge(obj2);  //obj1 now has three properties: food, car, and animal   Does anyone have a script for this or know of a built in way to do this?  I do not need recursion, and I do not need to merge functions, just methods on flat objects.


I am very confused about how to think about the . How can we relate the concept of expectation value to the Bloch sphere? If my state lies in let's say $yz$ plane how can we say that expectation value around $x$ is 0. I can understand that we take the projections and because of the equal probability of projection onto the positive and negative axis, we get a 0. My question is how can a vector living in $yz$ plane can even be projected on $x$-axis?

It is usually said that the points on the surface of the  represent the pure states of a single 2-level quantum system. A pure state being of the form: $$ |\psi\rangle = a |0\rangle+b |1\rangle $$ And typically the north and south poles of this sphere correspond to the $|0\rangle$ and $|1\rangle$ states. Image: ("Bloch Sphere" by Glosser.ca - Own work. Licensed under CC BY-SA 3.0 via Commons - )    But isn't this very confusing? If the north and south poles are chosen, then both states are on the same line and not orthogonal anymore, so how can one choose an arbitrary point $p$ on the surface of the sphere and possibly decompose it in terms of $0,1$ states in order to find $a$ and $b$? Does this mean that one shouldn't regard the Bloch sphere as a valid basis for our system and that it's just a visualization aid? I have seen decompositions in terms of the internal angles of the sphere, in the form of: $a=\cos{\theta/2}$ and $b=e^{i\phi}\sin{\theta/2}$ with $\theta$ the polar angle and $\phi$ the azimuthal angle. But I am clueless as to how these are obtained when $0,1$ states are on the same line.


I have a MacBook Pro with macOs Catalina and an Azerty (FR) keyboard. I'm using an external Azerty keyboard (PC type, not Mac). My keyboard setting is "French - PC" and works well for everything but the numerical pad: the dot is displayed as a comma. Is there any way to change the locale (and having this dot being a dot) while keeping the "French - PC" keyboard layout?

I wonder how to edit the following two files, so that I can change the system keyboard layout. It seems they are binary resource files, but I'm not sure.  /System/Library/Keyboard\ Layouts/AppleKeyboardLayouts.bundle/Contents/Resources/AppleKeyboardLayouts-B.dat  /System/Library/Keyboard\ Layouts/AppleKeyboardLayouts.bundle/Contents/Resources/AppleKeyboardLayouts-L.dat   I could use  to create a custom layout, but I would like to know how Ukelele reads the current layouts, and more over whether it is posible to edit the system layout directly.


How can I clone an arrayList with the following structure:  List<empItem> empList = new ArrayList<empItem> ();   I need to create a clone in such a way that i need to modify the empItem without affecting the original?  Yes the same scenario has an answer already. But since the post is Outdated , i am looking for any fresh / latest way ..

How can I clone an ArrayList and also clone its items in Java?  For example I have:  ArrayList<Dog> dogs = getDogs(); ArrayList<Dog> clonedList = ....something to do with dogs....   And I would expect that objects in clonedList are not the same as in dogs list.


I am an Indian Citizen traveling to Dublin.  My Irish visa does not have BIVS endorsement as it was issued in a center outside India.  I am flying into Dublin, staying there for a few days and then departing Dublin to London with a 12 hour stopover in London before my connection to Mumbai.  Can I pass border control in London using my Irish Visitor visa (no BIVS endorsed) for my 12 hour layover or do I need to get a UK Visitor Transit visa?

Is there a website or some other way to find out if I need a transit visa for a short stop in the UK on my way somewhere else? Ideally this should give me the answer for all nationalities, and take into account any other visas I may have.


I recently started using the Nikon f and I’m unsure about what settings are supposed to be used with 400 speed film!

I know digital cameras have ISO options, and that ISO is the camera's sensitivity to light, but if you set  higher ISO then you can get a noisy image. I also know there are two other camera options, shutter speed and aperture.   What is the relationship of between them? Is there any equation, or something like that?  For example, if I set the ISO to 640, then how should I set the shutter speed and aperture?


(cross-posted from math.stackexchange.com)  I found after publication of an article that a chunk of it was duplicated in a previous article written by someone else, and I'd like to know if I should take some action, like write a corrigendum just to add the other paper as another citation.  Perhaps some journals have a formal process to deal with this?  In my field, pure mathematics, it sometimes happens that people publish the exact same theorem, but the methods are distinct enough that the reviewer of the later paper views it as publishable because of its methods.  In my case, only one of four theorems in my paper duplicates earlier work, but the methods I use, while looking slightly different, would certainly be considered essentially the same as the earlier paper.  I suppose the best answer might simply be, "contact your journal and ask".  On the other hand, I have seen many times a result claimed as "independently" discovered in multiple papers, and I don't recall seeing a corrigendum or something in those cases.  Perhaps a notation on the research page of my website is sufficient?    As a follow-up, in mathematical publishing/culture, where is the line drawn between saying a result was "independently" discovered by multiple people and crediting all of them, as opposed to give priority to the one who was first?  Crediting all authors who gave substantially different proofs makes sense to me.  But what if two proofs use essentially the same idea?  (This question differs from     in that the both results, original and duplicate, have already published.)

I am a researcher in Mathematics and I have recently found that it has been published a paper X whose main result is a (very) special case of a result of mine, which has been published more than an year ago. From the journal log, I can also see that paper X has been submitted after my paper has been published.  However, the author of the paper X was not aware of my previous result, indeed she did not cite my paper.  I am wondering if it would be possible to make the journal of paper X acknowledging my priority on the result, and in such a case how to do so.  I have often seen journals publishing short notes with the title "Acknowledgement of priority", in which it is explained that a published result was already proved by someone else, but I have no idea of how it works.  Thanks for help.  UPDATE: I wrote to the author of the paper and I have got no response.


Specifications  RHEL version: Red Hat Enterprise Linux release 8.2 (Ootpa) Kernel version: 4.18.0-193.14.3.el8_2.x86_64  The issue I was facing Yesterday I started a SSH session to a RHEL8 machine, added a user (including myself to test first) to the wheel group with the usermod -a -G wheel <username> command. This command, as expected, ran successfully. However when I wanted to test my new privileges with e.g sudo whoami, it failed and gave me the following error:  user is not in the sudoers file.  This incident will be reported.  This was obviously not true, because I did groups and verified that I, and the user was in fact added to the wheel group. There were no restrictions nor any modifications made to the sudo rights or the wheel in the sudoers file. What I tried I was overly confused of what the cause of this was, but later found out that a new login session with the command su -l <username> solved the issue without any additional commands or changes made. Therefore, concluded with that it's giving a false negative. What I don't understand is that the only difference from a real SSH login session and a similar login environment provided by su -l <username> is this according to the .  clears all the environment variables except TERM and variables specified by --whitelist-environment  initializes the environment variables HOME, SHELL, USER, LOGNAME, and PATH  changes to the target user's home directory  sets argv[0] of the shell to '-' in order to make the shell a login shell   Which leads me to believe that there must be something wrong with my session? Which I later got my colleague to test on another machine. The result of that was negative. It shouldn't be. My question and curiosities What I am wondering is how could this happen? This didn't just happen to me, it happened to my colleague as well from a different machine with a SSH session to the same RHEL8 machine. At a glance, I can only assume that there was an outdated session I was accessing, even though these sessions was just started. And as far as I've tested, the only solution was to kill the session in any way or open a new login session. What could be the exact cause of this? Because I am genuinely curious and is happy to provide with more information.

I changed permissions of a file (chmod g+w testfile) and running ls -l testfile gives:  -rwxrwxr-x 1 user1 user1 0 2011-01-24 20:36 testfile   I then added a user to that group ("/etc/group" has user1:x:1000:user2 line), but am failing to edit that file as user2. Why is this so?


I have started a PHP script via browser and due to a loop error the script continues to be executed even after closing the browser. I am noticing it since the script is logging error messages to my logfile (path known).  We have a Apache server where many developers work together and the user is nmdev. So how can I find out what process it the one running and logging to my logfile?  ps -afe | grep php53 gives me many processes of today like:  nmdev 26518 24151 0 11:51 ? 00:00:00 /opt/xxx/yyy/apache-php5/bin/httpd -k start

I'm trying to find a reliable way of finding which process on my machine is changing a configuration file (/etc/hosts to be specific).  I know I can use lsof /etc/hosts to find out what processes currently have the file open, but this doesn't help because the process is obviously opening the file, writing to it, and then closing it again.  I also looked at lsof's repeat option (-r), but it seems to only go as fast as once a second, which probably won't ever capture the write in progress.  I know of a couple tools for monitoring changes to the filesystem, but in this case I want to know which process is responsible, which means catching it in the act.


Recently I bought a Magic Mouse from Apple & I want to enable the middle click to use it  in some apps like Chrome, Safari etc.   The native configuration include only left and right click, but is there any way to enable the middle click?  Thanks in advance.

I'm currently using the old Apple Mighty Mouse and I configured clicking on the trackball as a "middle click" that's been very handy for opening links in new tabs, closing tabs, etc. However, the mouse is starting to show its age and I've been looking at Apple's Magic Mouse and Magic Trackpad, and I'm wondering - do either of these support the "middle click" operation? If not, is there a gesture or a multi-finger click that can be used for the same things (i.e. opening new tabs, etc)?


i have a problem with conditions of typed text in prompt. I want to add conditions for prompt. Case A : If you type nothing in prompt - it will alert that you have inserted nothing.  and opens prompt again until you type the number in. Case B: if you type text - it will alert that you haven't inserted number. and opens prompt again until you type the number in as in case A Case C: if you type number (What is essential, because it is a script which calculate the cubic equal) - it continues the script. This script only finds out when you type nothing and press enter - It will alert you that you havent typed anything - BUT it will tell you even if you type number in - Which totally breaks the script. And I also don't know how to define number in JS - How to find out when someone types in prompt for example "Word" - that is not a number, so again it suppose to tell you that you havent inserted number. var a = prompt('Zadejte hodnotu a v kvadratické rovnici ax2 + bx + c = 0'); if (a == "") do { alert('Nezadali jste žádné číslo, zadejte ho prosím'); a = prompt('Zadejte hodnotu a v kvadratické rovnici ax2 + bx + c = 0'); } while (a = "something"); var b = prompt('Zadejte hodnotu b v kvadratické rovnici ax2 + bx + c = 0'); if (b == "") do { alert('Nezadali jste žádné číslo, zadejte ho prosím'); b = prompt('Zadejte hodnotu b v kvadratické rovnici ax2 + bx + c = 0'); } while (b = "something"); var c = prompt('Zadejte hodnotu c v kvadratické rovnici ax2 + bx + c = 0'); if (c == "") do { alert('Nezadali jste žádné číslo, zadejte ho prosím'); c = prompt('Zadejte hodnotu c v kvadratické rovnici ax2 + bx + c = 0'); } while (c = "Something");  Thanks a lot!

I'm hoping there's something in the same conceptual space as the old VB6 IsNumeric() function?


I am moving 2 rows from a table called allCooks to one row in a table called recipeChallenge (cookAAA against cookBBB in a pizza challenge) Each match already has an ID, and this is the row I want to UPDATE  I am doing the update twice, once for cookAAA and then for cookBBB To update the matchID with cook A...(i-ve left the php variables in)  "UPDATE `recipeChallenge` AS v1,          `allCooks` AS v2      SET v1.`cookAAAID` = v2.`cookID`,          v1.`cookAAAName` = v2.`cookName`    WHERE     v1.`matchID`='" .$matchID."'          AND v2.`cookID`= '" .$cookAID."'";   and then for cook B  "UPDATE `recipeChallenge` AS v1,          `allCooks` AS v2      SET v1.`cookBBBID` = v2.`cookID`,          v1.`cookBBBName` = v2.`cookName`    WHERE     v1.`matchID`='" .$matchID."'          AND v2.`cookID`= '" .$cookBID."'";   The table recipeChallenge is updating, but the second update is ALSO creating a new matchID and row in the recipeChallenge table. Why?

I have a database with account numbers and card numbers. I match these to a file to update any card numbers to the account number, so that I am only working with account numbers.   I created a view linking the table to the account/card database to return the Table ID and the related account number, and now I need to update those records where the ID matches with the Account Number.  This is the Sales_Import table, where the account number field needs to be updated:  LeadID  AccountNumber 147         5807811235 150         5807811326 185         7006100100007267039   And this is the RetrieveAccountNumber table, where I need to update from:  LeadID  AccountNumber 147         7006100100007266957 150         7006100100007267039   I tried the below, but no luck so far:  UPDATE [Sales_Lead].[dbo].[Sales_Import]  SET    [AccountNumber] = (SELECT RetrieveAccountNumber.AccountNumber                            FROM   RetrieveAccountNumber                            WHERE  [Sales_Lead].[dbo].[Sales_Import]. LeadID =                                                  RetrieveAccountNumber.LeadID)    It updates the card numbers to account numbers, but the account numbers gets replaced by NULL


I'm trying to make a match 3 game in C++ and I want to make a best move method to show the player the ideal position to move to get the most amount of points.   The rules of the game are as follows:   Pairs of objects adjacent vertically and horizontally can be swapped. You can only swap objects when this will result in a match being created. A match happens when there are 3 or more objects of the same kind adjacent vertically or horizontally. objects that match are removed from the board. objects above a gap will keep fall down until all gaps are filled. New matches made by objects falling into place will be removed with the process repeating until there are no matches left. Points are awarded based on the number of objects removed. The best move for a given board is the one that removes the most objects .   However, I'm stumped for ideas on how to implement such a method. Can anyone give me some ideas on how I can do it?   If you've made a match 3 game, and have implemented a similar method; how did you do it?

Is there a known good way to have a "computer" opponent play a Match 3 game? It doesn't have to be fancy, or even considered fair. If the AI always takes the best move on the board that would be OK with me. Note that a valid move is one that doesn't make a match.  Edit: What I am currently doing is a brute force approach. I look at every tile on the board, and see what the best move that tile can do. I add it to a collection and give it a score (based on how many it will match 3 or 4). Once I have traversed the entire board I use the move with the  best score. In the event of a tie I pick one.  If a 5 match combo is found I short circuit out to that one. 5 is the highest combo you can get)  I may not be able to improve it, but it feels like this should have been solved already.


Well, this is embarrassing. I feel like I just realised I don't know a loyal colleague's name after working with them for 10 years. "Hey, er... *cough!*, thanks for that great job you did on setting my aliases this morning..."  What do the letters rc signify in .bashrc, .kshrc, etc.?  If you know, please cite sources.  Even if you don't know, I'd also welcome unfounded assumptions, suggestions or alternatives if they're marked as such.

In these and other applications what does the "RC" stand for?


Question: Suppose that a and b belongs to an integral domain.   If $a^{m}=b^{m}$ and $a^{n}=b^{n}$, where m and n are positive integers that are relatively prime, prove that a=b.   Well, m and n are relatively prime so gcd(m,n)=1 holds. In fact, from the fact that the gcd of any positive integers: gcd(m,n)=1=ms+nt for some integers s,t.   Raising the element a to ms+nt: $a^{ms+nt}=a$  A good bit of hint here would be helpful.  Thanks in advance.

Let $D$ be an integral domain and let $a^m=b^m$ and $a^n=b^n$ where $m$ and $n$ are relatively prime integers, $a,b \in D$.   How do I show $a=b$?


I learned about this in college, but have since forgotten over the decades. An example is an anthropologist who has learned about a tribe but has never actually visited and studied the tribe first hand.

What is a word or phrase that means a speaker (or writer) is talking about something they know very little about, but they think they know more than they do?  An example: If you read diet message boards, you get dozens of people saying ‘Eat 6 small meals a day,’ or ‘Eat 3 big meals, but don’t snack,’  or ‘Eat more/less protein/carbs/fat.’ Each person is sure they are knowlegable enough to give good advice, but real experts(dieticians or researchers, for example) are rare.  I want a word to describe this attitude.  Bullshit is close, but someone bullshitting usually knows they aren’t an expert, they just want to convince the listener they are.  Also, I’d prefer something politer than bullshit.


Let Y be an ordered set in the order topology. Let $f,g: X \rightarrow Y$ be two continuous function.  Show that the set {$x | f (x) \leq g (x) $} is closed in $X$. Any help would be appriciated. Thanks.

Suppose $Y$ be an ordered set in the order topology. Let $f, g: X \to Y$ be continuous. How to show that the set $\{x| f(x) \leq g(x)\}$ is closed?  This is a excercise from munkres. Maybe trying to show that the set $f(\{x| f(x) > g(x)\})$ is open is suffice. But I could not figure out the connection between this set and the continuity of the two functions.Could you give a hint?  Thanks.


Let $(𝑎_𝑛)$ $𝑛≥0$ be a strictly decreasing sequence of positive real numbers, and let $𝑧∈ℂ$, $|𝑧|<1.$ Prove that the sum $𝑎_0+𝑎_1 𝑧+𝑎_2𝑧^2+⋯+𝑎_𝑛𝑧^𝑛+⋯$ is never equal to zero.  Is it valid to say that since the series converges absolutely, we may take derivatives which then implies it is holomorphic. Holomorphic implies the existence of a convergent Taylor series and by the uniquety of the Taylor series, the polynomial being $0$ implies $a_n$ is $0$, a contradiction?

Let $(a_n)_{n \geq 0}$ be a strictly decreasing sequence of positive real numbers , and let $z \in \mathbb C$ , $|z| < 1$. Prove that the sum $a_0 + a_1z + a_2z^2 + \cdots + a_nz^n +\cdots $ is never equal to zero.


While I am developing the Python code, I found I used to use single quotation marks all the time, but some experienced programmers used double quotation marks more often. I couldn't find the difference between them, could anyone help to give me some examples if there is a difference? Or is it just a personal preference? For example: class TextBox(UIControl):     def draw(self):     print('TextBox')  class TextBox2(UIControl):     def draw(self):         print("TextBox")  class TextBox and TextBox2 seems like have no difference while running. Thanks for your help!

According to the documentation, they're pretty much interchangeable.  Is there a stylistic reason to use one over the other?


In my dataset, I have 2 labels, positive and negative. Most samples belong to only one class, either positive or negative. A small fraction of samples take both labels i.e. both positive and negative. Thus, making it a  classification problem. Usually, this could be solved in many different ways including  or using multi-label classifiers. My question is, can I consider the samples that take both labels as a third class and consider this as a multi-class classification problem with 3 classes?  As far as I understand, this method is not preferred in multi-label classification scenarios where the no. of individual labels is large. That is, if $n$ is the no. individual labels, then a sample could take any of the $2^n-1$ combination of labels. Hence for large $n$, opting for a multi-class classification (with $2^n-1$ classes) could be a bad idea. But, in my case $n=2$, which is a trivial case. Hence, I am considering multi-class classification as an option. Please advise on this and let me know if I am right. Also, if possible please point to literature where such trivial case of multi-label classification problems are dealt with.

I have a classification problem with 2 classes (positive and negative). Usually, in such classification problems, all the samples will be labelled either 'positive' or 'negative'. In my dataset, some of the samples possess a combination of both positive and negative characteristics. Formally, if the dataset is $x$, then,      $x=x_1 \cup x_2 \cup x_3$   where $x_1$ is the set of all positive samples, $x_2$ is the set of all negative samples and $x_3$ is the set of samples that contain the characteristics of both the classes. As far as I could think of, this situation could be handled in 2 ways,   Ignore $x_3$ (samples that contain characteristics of both classes) and treat the problem as a traditional binary classification. Label the samples in $x_3$ with both labels (positive & negative) and consider this as a multi-label classification problem.   I wish to follow the second option, as it is more natural choice. The reason being, ignoring some samples from the dataset gives me a feeling of manipulating the dataset artificially which may affect the performance of the classifier in the real world scenario. In this context, I have the following questions,   Is it correct to treat this a multi-label classification problem. If so, is the intuition which is explained in the previous paragraph correct? Is there any other learning paradigm that can handle this scenario? If so, please provide reference to relevant literature.


I have the following script :  echo  'Please select type file , the name of the input file and the name of the output file:       a.plain ( please press a ) <input_file> <output_file>;      b.complex ( please press b ) <input_file> <output_file>;'  read one two three echo $#  if  [ $# -ne 3 ]; then    echo "Insufficient arguments !"    exit 1; else    echo "Number of passed parameters is ok" fi   $# always outputs 0 , the read command provides the correct variables when I am using $one , $two and $three later in the script    Thank you.

I'm trying to create an if else statement to verify that the user has entered something. If they have it should run through the commands, and if not i want to echo a help statement.


I have looked through the available HTML and JS materials in print, and online, concerning the problem of "disabling the enter key" or at least eliminating the default of submitting a form when the enter key is pressed.  My web page needs to ignore form submission until the appropriate button is pushed.  For that matter, I would like to ignore any enter key depression while inside my form. I can send code samples if needed.  I am new to this site and new to web development (Html-CSS-JS-JQ).  I am an old linear programmer so please be merciful on your explanation.  MANY thanks in advance.

How do you prevent an ENTER key press from submitting a form in a web-based application?


Why byte[] comparison differs from hex comparison? I am computing a hash value of the same string with return type of byte[]  byte[]  hash1 = md5sum('3078RUR26') byte[]  hash2 = md5sum('3078RUR26')   I get  [B@7852e92 and [B@4e25154f respectively.  However, if I use the same function and do bitwise Integer.toHexString on hash1 and hash2 afterwards, I get 5ddff3704bc83a675f3f51671da9c2c for both statements. Why?

In Java, arrays don't override toString(), so if you try to print one directly, you get the className + '@' + the hex of the  of the array, as defined by Object.toString():  int[] intArray = new int[] {1, 2, 3, 4, 5}; System.out.println(intArray);     // prints something like '[I@3343c8b3'   But usually, we'd actually want something more like [1, 2, 3, 4, 5]. What's the simplest way of doing that? Here are some example inputs and outputs:  // Array of primitives: int[] intArray = new int[] {1, 2, 3, 4, 5}; //output: [1, 2, 3, 4, 5]  // Array of object references: String[] strArray = new String[] {"John", "Mary", "Bob"}; //output: [John, Mary, Bob]


I'm trying to prove that an ellipsoid defined by $$E:=\{(x,y,z) \mid \frac{x^2}{a^2} + \frac{y^2}{b^2} + \frac{z^2}{c^2} \le 1 \}$$ with $a,b,c \gt 0$   is convex, but I'm having trouble with it. I tried with the definition of convexity, but I reach a point of $$ \lambda \left( \frac{x_1^2}{a^2} + \frac{x_2^2}{b^2} + \frac{x_3^2}{c^2} \right) + 2 \lambda ( 1 - \lambda) \left( \frac{x_1y_1}{a^2} + \frac{x_2y_2}{b^2} + \frac{x_3y_3}{c^2} \right) + (1 - \lambda)^2 \left( \frac{y_1^2}{a^2} + \frac{y_2^2}{b^2} + \frac{y_3^2}{c^2} \right) \le 1 $$  and I don't know how to proceed from there (or even if it's right). I think that there might be another (easier) way to do this, but i can't come up with it, so if someone could help me with this proof I'll be really grateful $:)$

I know what an ellipsoid is, but I do not know how to approach how to prove that one is convex. Any advice would be greatly appreciated.


I have downloaded the NBI ascii file data from . Now I am not able to convert it into a shapefile. The ASCII file has a latitude longitude column. I understand that it can be imported in a GIS software using X,Y values. But I am not able to make out whether the latitude longitude is in DMS or decimal degrees.  I am posting a sample here.  Sample Latitude: 40454200 Sample Longitude: 122190700  If there is any other way of converting it, I would like to know.

I need to convert lat/long that is expressed as degrees, minutes, and seconds in the data into decimal degrees. For example, in the data, they are listed as N335042.06 in the Latitude column, and W86031.04 in the Longitude column. I have done this problem before where I created a script which converted DMS to DD, and vice-versa, so I guess I could use bits from that. But the problem I'm having is how to ignore (for lack of a better word) the 'N' and 'W' in the data? Can I skip them? And DMS are listed all together without any symbols or spaces.  Can I use len(), range(), split() to specify what part to read from the value? For example, can do the following?  N335042.06 where, 33 = degrees 50 = minutes 42.06 = seconds ...?  I came across  ESRI article, but it's in VB. Will probably use it as a reference but some of the terminology/syntax is different from Python.  Final code that works!   # Pre-logic def latDD(x):   D = int(x[1:3])   M = int(x[3:5])   S = float(x[5:])   DD = D + float(M)/60 + float(S)/3600   return DD  # Expression latDD(!Latitude!)


Is there a way to check and see what version of the .NET framework is available on a machine, without manually digging through the registry, etc.?  Ideally, from C++. How can this be solved it?

A similar question was asked , but it was specific to .NET 3.5. Specifically, I'm looking for the following:   What is the correct way to determine which .NET Framework versions and service packs are installed? Is there a list of registry keys that can be used? Are there any dependencies between Framework versions?


I'm running 13.04 on my laptop. My laptop has a tendency to run really hot - to the point of thermal shutdowns if left unattended for a long period of time. I don't know if that's relevant. the mouse cursor flickers constantly. Sometimes it disappears altogether. The flickering is about 1Hz at rest, but as I do things or type it increases in frequency. It looks like every time the system registers a keypress it flickers. How can i fix this or diagnose what is causing this?

I installed Ubuntu today and since the first start up I have a problem with the mouse cursor.  It starts randomly disappearing and flickering a lot.  I have searched for a solution on Google and here but didn't find anything.


"An opportunity for a complete positive transformation of your child for which you have always aspired for".   The above sentence appears on the board of a private primary school. I think the writer has made a redundancy in use of preposition. The sentence should correctly read as follows:     "An opportunity for a complete positive transformation of your child which you have always aspired for."    or:     "An opportunity for a complete positive transformation of your child for which you have always aspired."

This is a tooltip in an application:     Identifies the site name to which the GL code belongs to.   Can I say that it is incorrect to use "to" twice here and we should remove 1 of them?  Other examples:       Identifies the vendor to which the port speed is associated with.   Provides the vendor to which the milestone is associated with.   (They are both tooltips, too)  The repetitions here are incorrect, aren't they? Please confirm.


I have limited the download speed on my nginx site with this option:  limit_rate 350k;   Is it possible to do this only if the file size is larger then 10Mb? Thank you.

I am using nginx/1.11.11 compiled from the source with the mp4 module and I am serving video files from 300MB size up to 8GB.  I am thinking of implementing a throttle system similar to google's drive. If the size of the file is big set a larger the limit_rate and if the file size is small set a smaller limit_rate. The problem is I can't find a way to get the size of the served file.  My default.conf file looks like this:  server {     listen       80;     server_name  _; # change this for your server     root /var/www;     index index.php;     client_max_body_size 5G;     proxy_read_timeout 60000000;      # handle requests to the API     location ~ /api/v2/(.+)$ {         if (!-e $request_filename) { rewrite ^/api/v2/(.*) /api/v2/index.php?_page_url=$1 last; }         fastcgi_pass   127.0.0.1:9000;         fastcgi_index  index.php;         fastcgi_param MOD_X_ACCEL_REDIRECT_ENABLED on;         fastcgi_param  SCRIPT_FILENAME   $document_root$fastcgi_script_name;         include        fastcgi_params;     }      # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000     location ~ \.php$ {         if (!-e $request_filename) { rewrite ^/(.*) /index.php?_page_url=$1 last; }         fastcgi_pass   127.0.0.1:9000;         fastcgi_index  index.php;         fastcgi_read_timeout 180000000;         fastcgi_param MOD_X_ACCEL_REDIRECT_ENABLED on;         fastcgi_param  SCRIPT_FILENAME   $document_root$fastcgi_script_name;         include        fastcgi_params;     }      location / {         if (!-e $request_filename) {                 rewrite ^/(.*) /index.php?_page_url=$1 last;         }     }     location /files/ {         root /var/www;         aio threads;         internal;         mp4;         limit_rate_after 5m;         limit_rate 400k;     }      # these locations would be hidden by .htaccess normally     location /core/logs/ {         deny all;     }


I am a big fun of ubuntu.  I recently bought a tonbux tablet 10 inch with android.  I have tried to install ubuntu on it but I don't seem to be able to unlock the device, has anyone tried this before on a tonbux tablet?

With the announcement of the Ubuntu Phone OS I'd like to know what phone (and tablet) models are supported at this time.  Note from foss & Oli: We are making this the master question for all future "Will this work on <insert random tablet/phone/device here>?!" questions


Does windows have any decent sampling (eg. non-instrumenting) profilers available?  Preferably something akin to Shark on MacOS, although i am willing to accept that i am going to have to pay for such a profiler on windows.  I've tried the profiler in VS Team Suite and was not overly impressed, and was wondering if there were any other good ones.  [Edit: Erk, i forgot to say this is for C/C++, rather than .NET -- sorry for any confusion]

I'm looking for a profiler to use with native C++. It certainly does not have to be free, however cost does factor into the purchase decision. This is for commercial work so I can't use personal or academic licensed copies. The key features I'm looking for are:  Process level metrics Component level metrics Line-level metrics Supports Multi-threaded code Usability Cost Visual Studio 2005 Professional support required (VS 2008 Professional support highly desirable)  I've used Intel's VTune and Compuware's Devpartner Performance Analysis Community Edition. VTune seemed very powerful but it has a steep learning curve. It also is very "modular" so you have to figure out what parts are you need to buy. DevPartner PACE was pretty easy to use and provides all of the key features however it's only a 45-day trial. The licensed version (DevPartner for Visual C++ BoundsChecker Suite) is about $1400 a seat, which is doable but a bit high imo. What are some good profilers for native C++ and WHY?  See also:


My friend told me a wrong proof which involves differentiation, but I cannot point out where he has been wrong.  $x^2 = x + x + x + … + x$ (total $x$ terms)  ${\frac d {dx} x^2} = {\frac d {dx} (x + x + x + … + x)}$  $2x = 1 + 1 + 1 + … + 1$ (total x terms of 1)  $2x = x$  $2 = 1$  Can someone points out where is wrong?

Consider the following:   $1 = 1^2$ $2 + 2 = 2^2$ $3 + 3 + 3 = 3^2$   Therefore,   $\underbrace{x + x + x + \ldots + x}_{x \textrm{ times}}= x^2$   Take the derivative of lhs and rhs and we get:   $\underbrace{1 + 1 + 1 + \ldots + 1}_{x \textrm{ times}} = 2x$   Which simplifies to:   $x = 2x$   and hence    $1 = 2$.     Clearly something is wrong but I am unable pinpoint my mistake.


my batch file is ProcessMe.bat  the Command is this  ProcessMe   -color  blue    -type  high    --size  large    --tag  gift   the parameters order is not fixed  ProcessMe     -type  high  --tag  gift  --size  large  -color  blue      ProcessMe     --tag  gift   -color  blue   --size  large   -type  high  ProcessMe     --size  large    -type  high  -color  blue   --tag  gift      and parameters are coming in the same format single - and double --  I want to read these parameters in my .bat file  I tried these but non worked  echo %--size%  echo %-size%  echo %size%  echo --size  echo -size  echo size  echo %--size  echo %-size  echo %size   how can I get parameters values in .bat file?!

I need to pass an ID and a password to a batch file at the time of running rather than hardcoding them into the file.  Here's what the command line looks like:  test.cmd admin P@55w0rd > test-log.txt


I'm trying to write my first (extremely simple) gnome extension. The documentation and API docs seem a bit lacking, so I'm having a bit of trouble. Most tutorials show how to add a button with a dropdown menu to the top bar, by instantiating a PanelMenu.Button, overriding _init, and then passing it to Main.panel.addToStatusArea. However, I'm looking for something simpler, and I can't find how to do it. Can I simply add a plain button to the top bar (with no dropdown menu), such that, when I click it, it executes a bash command? What class should I instantiate to do this?

How do I create a button on my taskbar along with the time and stuff that performs a specific task? I wanted to be able to disable and enable my keyboard with the help of a keyboard shortcut, but I realized that once I disabled my keyboard with a shortcut, I wouldn't be able to use the keyboard to enable it again. So, I want a button on my taskbar that does this for me with the click of a button, thus not requiring my keyboard. Thanks.


Prove that the Lagrangian Density $\mathscr{L}$, which generates a given set of Euler-Lagrange equations, is not unique.     Hint 1:  Adding a divergence to $\mathscr{L}$ does not alter the   Euler-Lagrange equation.   Attempt: Let $\mathscr{L´}=\mathscr{L}+\sum_{k}\frac{\partial f_k}{\partial x_k}$  Where $$\mathscr{L}=\mathscr{L}\big(x_k, \varphi_j, \frac{\partial \varphi_k}{\partial x_k}\big)$$ $$f_k=f_k(\varphi_j)$$ $j=1,...,m$ indexes the dependent field variables.  $k=1,...,n$ indexes the independent variables.     Hint 2: Then prove that: $$\frac{\delta \mathscr{L´}}{\delta \varphi_j}=\frac{\delta \mathscr{L}}{\delta \varphi_j}$$   Attempt: Now we define $$\frac{\delta \mathscr{L}}{\delta \varphi_j}=\frac{\partial \mathscr{L}}{\partial \varphi_j}-\sum_{l} \frac{\partial}{\partial x_l} \frac{\partial \mathscr{L}}{\partial (\partial \varphi_j/\partial x_l)}$$    But i can´t keep following the hints to get the proof done:

Greiner in his book "Field Quantization" page 173, eq.(7.11) did this calculation:     ${\mathcal L}^\prime=-\frac{1}{2}\partial_\mu A_\nu\partial^\mu A^\nu+\frac{1}{2}\partial_\mu A_\nu\partial^\nu A^\mu-\frac{1}{2}\partial_\mu A^\mu\partial_\nu A^\nu $   $\space\space\space\space=-\frac{1}{2}\partial_\mu A_\nu\partial^\mu A^\nu+\frac{1}{2}\partial_\mu[A_\nu(\partial^\nu A^\mu)-(\partial_\nu A^\nu) A^\mu]$        The last term is a four-divergence which has no influence on the field equations. Thus the dynamics of the electromagnetic field (in the Lorentz gauge) can be described by the simple Lagrangian        ${\mathcal L}^{\prime\prime}=-\frac{1}{2}\partial_\mu A_\nu\partial^\mu A^\nu$     Yes, if it is a four-divergence of a vector whose 0-component doesn't contain time derivatives of the field, indeed according to the variational principle this four-divergence will not influence the field equation.  And actually I calculated the time-derivative dependence of 0-component of $[A_\nu(\partial^\nu A^\mu)-(\partial_\nu A^\nu) A^\mu]$, in which only $[A_0(\partial^0 A^0)-(\partial_0 A^0) A^0]$ could possibly contain time-derivative, which vanishes fortunately, so whatever the general case it doesn't matter in this present case.  But how can he seem to claim that it holds for a general four-divergence term,The last term is a four-divergence which has no influence on the field equations?  EDIT: I only assumed the boundary condition to be $A^\mu=0$ at spatial infinity, not at time infinity. And the variation of the action $S = \int_{t_1}^{t_2}L \, dt$ is due to the variation of fields which vanish at time, $\delta A^\mu(\mathbf x,t_1)=\delta A^\mu(\mathbf x,t_2)=0$, not having the knowledge of $\delta \dot A^\mu(\mathbf x,t_1)$ and $\delta \dot A^\mu(\mathbf x,t_2)$, which don't vanish generally, so the four-divergence term will in general contribute to the action, $$\delta S_j=\delta \int_{t_1}^{t_2}dt\int d^3\mathbf x \partial_\mu j(A(x),\nabla A(x),\dot A(x))^\mu =\delta \int_{t_1}^{t_2}dt\int d^3\mathbf x \dot j^0 =\int d^3\mathbf x [\delta j(\mathbf x, t_2)^0-\delta j(\mathbf x, t_1)^0]$$ which does not vanish in general!


I have been writing a shell script that needs to know if the system one is on is, in fact, Debian-based. Now I have seen  question, but its answers weren't so helpful. I am aware of checking /etc/os-release and the output of lsb_release, likewise I know that checking if rpm or dpkg commands exist is another way of checking whether one's distribution is Red Hat or Debian-based, respectively. All these methods have flaws though. There are hundreds of different Debian-based distros (including those based on Ubuntu, which is in itself based on Debian) and checking whether the NAME field in /etc/os-release, or the Distributor ID in the output of lsb_release -a matches any of the hundreds of known Debian-based distributions would take forever. Checking whether the commands dpkg and rpm exist aren't fool-proof either as some people install other distribution's package managers for various different reasons. For example, on my Ubuntu machine I have RPM installed, partly because sometimes I use the Open Build Service's OSC command, which in some cases requires RPM.   So in short I want a simple and fast way of checking (with certainty) whether the distribution my script finds itself on is Debian-based or not.  Is this possible?  EDIT: As people seem to be implying, by voting to close this question, that /etc/debian_version is present on all Debian-based systems. Does anyone have proof of this?

I am trying to write a script which works based on the knowledge that each Linux Mint release was based on a particular Ubuntu release.  However, I do not want to install Linux Mint to verify that, but instead let the users of the script test it, if they need it.  Can I rely on the presence of /etc/debian_version, though? I am doing this in order to detect Debian and its derivatives. It works reliably on Debian and Ubuntu, but does Linux Mint have this file?  Note: I am aware of lsb_release and I am using that in order to figure out more details later on. But the existence of /etc/debian_version is a way to make assumptions about certain things before even checking for and invoking lsb_release.


I have a question that is the opposite of : since upgrading to Windows 10 version 1809 on my machine, the "Run" box has stopped caching the commands I type.  Previously, and on other machines, I hit Windows+R to open the "Run" box, where I type a command to execute. The next time I open the Run box, previous commands appear there and can be found by scrolling or starting to type.  Now, on this machine, the Run box always comes up empty and I have to type all commands completely each time.  Does anyone know how to re-enable that cache?  In my searches, I have found many pages talking about how to clear this cache, but none to help me enable it.

There is a similar post to this but does not work with my system. The previous suggestion was to turn on Start > Settings > Personalisation > Start > Show most used apps. Unfortunately, that option is set to Off and greyed out.  HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\RunMRU does not show the list either. it is empty.    I was running Windows 10 version 1703, and recently updated to the Redstone 3 Preview build 16170.  Any other suggestions?


I am downloading textures from online and I have found where to plug most of the on a principled shader from online. There is a map called mask, and after further research I am unsure what this does or how to apply it through a principled shader.  To be clear: I am still unsure that textures the mask would be mixing, as a mask doesn’t seem to be applicable to the other textures.  Textures downloaded from cc0 textures

I created some texture maps in MindTex to use in Blender, but I can't figure out how to properly hook them up. The maps I have:  - Diffuse  - Normal  - Height   - Specular   - Gloss   - Self Illumination  - Reflection  - Ambient Occlusion   MindTex (left) vs. Blender (right)  As you can clearly see it's a pretty big difference.  is my material node setup in Blender. In the examples I don't actually use self illumination or reflection images, but including this in the answer would be helpful.


I make this mayonnaise based sauce that my friends all rave over and I wanted to make a large batch, can it (which I've never done before) and give it out as a gift. I'm nervous about giving away something without understanding how long it can be preserved in the refrigerator.  The sauce has 1 part white wine vinegar, 1 part water and 6 parts mayonnaise, in addition to minced garlic and other spices. Any ideas on how long this might last, or where I can find better literature about preserving in general?

How do I know if a given food or ingredient I have is still good, or if I should discard it?  How can I best preserve a food or ingredient?     This broad question is intended as a "general reference" question to quickly answer many how long will food keep for? questions. Please feel free to edit this question to expand and clarify as needed.


I've choosed to upgrade from Windows 7 to Windows 8. When I started up my computer, I saw GRUB and i could choose between Windows 7 and Edubuntu 12.04. But now, when I start up computer, it's just booting Windows 8! (I haven't formatted or anything like that) Please help me!

I installed Windows 7, which ate Ubuntu's boot file. When starting up the computer, it now goes straight to Windows, without giving me the option of booting Ubuntu.   How can I get Ubuntu back?


We came across the more general form of faradays law in my EM lecture:  $\oint E \cdot \,dl=-\frac{\partial}{\partial t}(\int B \cdot dA)$  Pretty sure this is me misunderstanding magnetic fields in circuit theory, but in the case of a DC circuit, B is constant and so the rhs of the equation is 0, which gives KVL, the sum of the potential differences in a closed loop = 0. If the currents are varying, so will the magnetic fields they generate. In which case I can't see why in AC circuits KVL holds as the RHS no longer = 0. Can someone explain where my  reasoning has gone wrong.  Edit:  I am more specifically asking where my reasoning has gone wrong. I am already aware that it is valid under ideal circuit theory as an approximation to what really happens.

I'm having some difficulty with understanding why KVL (Kirchhoff voltage law) is valid when considering an AC circuit. I mean, the system is by definition not in steady state, right? That in turn means that the change in current causes a change in the magnetic field, which is manifested within the electric potential. I realize the potential is still defined and thus a line integral over a crossed curve of ALL of it's component should be zero.   However, what I often see (for, say, RLC circuits with an AC emf) is total disregard to the time varying components of the electric potential. Only the emf of the different components are considered and their sum is said to be zero. How can that be? What about the "second" part of the potentials?


I would like to be able to pipe all bash terminal commands through a certain command (for no good reason other than to play a prank on someone). I just want to pipe the stdout of any executed command into a predetermined program without doing anything special.  For example: If that predetermined program was cowsay  echo "Hello World"   should output   _____________ < Hello World >  -------------         \   ^__^          \  (oo)\_______             (__)\       )\/\                 ||----w |                 ||     ||   How can I achieve this? (Some of the fun programs I'd like to use to play pranks on others include rev, cowsay, and lolcat)

I'd like to edit my .bashrc so that every command executed on the shell is piped to something, for example:   $ sudo apt update   _________________ < sudo apt update >  -----------------     \   ^__^      \  (oo)\_______         (__)\       )\/\             ||----w |             ||     ||   I have managed something rather similar, but not entirely:  $ bash $ exec > >(cowsay) $ echo "Hello AU!" $ exit  _______ < Hello AU! >  -------     \   ^__^      \  (oo)\_______         (__)\       )\/\             ||----w |             ||     ||   It is not the desired result, as it only happens after exiting the current shell.  It's mainly for fun/learning purposes.


As a C++ newbie, I am just discovering iterators. I realize that one can use either an int or an iterators for loop through any container. Consider for example  #include <iostream> #include <vector>  int main() {     std::vector<int> v;     v.push_back(1);     v.push_back(4);     v.push_back(8);      std::cout << "i is an int: ";      for (int i = 0; i<v.size();i++)     {        std::cout << v[i] << " ";     }     std::cout << std::endl;      std::cout << "i is an iterator: ";     for (std::vector<int>::iterator i = v.begin(); i!=v.end();i++)     {        std::cout << *i << " ";     }     std::cout << std::endl; }   which outputs  i is an int: 1 4 8                                                                                i is an iterator: 1 4 8     Generally speaking,   is there any advantage of using one or the other method? Is one faster than the other one? When should I use an int and when should I use an iterator?

Take the following two lines of code:  for (int i = 0; i < some_vector.size(); i++) {     //do stuff }   And this:  for (some_iterator = some_vector.begin(); some_iterator != some_vector.end();     some_iterator++) {     //do stuff }   I'm told that the second way is preferred. Why exactly is this?


I want to connect my home ubuntu server with ssh from remote. So i bought static ip address from my provider. But i don't know how to set up it correctly.  I have done something like that in /etc/netplan/50-cloud-init.yaml  network:   version: 2   renderer: networkd   ethernets:     enp0s5:      dhcp4: no      addresses: [<my_ip>/24]      gateway4: <my_ip>      nameservers:        addresses: [8.8.8.8,8.8.4.4]   And after  sudo netplan apply   But it haven't work for me. (Sorry if it is a dumb question)

let's imagine i am at school with an android phone. I have a computer at home and that computer has a virtual machine working on it. here is the scenario, client and virtual client has ssh-client and ssh-server both and they can communicate each other in the local network.  when i want to connect to my virtual client from school by android phone through internet there must be an ip address.  the problem is virtual machine and client has the same public ip. so how do i connect one of the two machines?


In Episode IV: A New Hope when Commander Tagge is talking about the Rebellion gaining support in the senate Grand Moff Tarkin enters as says     The Imperial Senate will no longer be of any concern to us. I've just received word that the Emperor has dissolved the council permanently. The last remnants of the Old Republic have been swept away.   This got me thinking, considering that Palpatine would've had anyone oppose him killed and Jar Jar didn't seem all that enthusiastic about allowing the Grand Army of the Republic which became the groundwork for the Imperial Army what happened to Jar Jar after the Senate became "no more"?

I know there are questions about Jar Jar’s age and relevance in the films already, but I was under the impression that when all the Jedi were killed between 3 and 4 that he had been murdered as well. Am I wrong? Or do we not know?


I was studying about alternating current, and I stumbled upon RMS. I clearly cannot understand what it means, the only thing my textbook says is: RMS current $I$ is related to the peak current $i_m$ by $ I=0.707 i_m$  Why are we multiplying AC current by $0.707$?  Are there any sort of things I've missed learning?

What makes it a good idea to use RMS rather than peak values of current and voltage when we talk about or compute with AC signals.


In order to  address traffic jam and reduce carbon footprint In order to  address traffic jam and to reduce carbon footprint  Which one is correct?

I googled it but I couldn't find the answer... maybe I didn't seek it in the proper way. My question is if "to" must be repeated in sentences such as the following ones:   In the past, women used to do the housework and to take care of children.  The aim of this meeting is to control their progress and to discuss the new working plan.    If I had to bet, I would omit the second to... But I am not sure about it.


I've decided to make an online game; the server sends packets of information to the client application, which is going to simulate what it gets from the server. The client makes a part of the design of the game, and sends the new state back to the server for processing.  The clients can send fake information to the server, and inform the server that I've done the task successfully, without trying. Assume a Counter-Strike game; the client may send a fake packet to the server and tell the server that I've defeated someone. How can I avoid this violation?

I am almost complete developing a small indie-style multiplayer game. While I intend to allow people to cheat in single-player, this is obviously not acceptable in multi-player. Does anyone know of any ways to help stop the average Joe from using something like Cheat-Engine to modify parts of the game? I currently plan to have the client upload a MD5 hash of each setting file the game uses (stored as an XML) to the game server for verification every few seconds, but is there anything I can do to stop things like memory-editors, etc?


I recently discovered that I don't need to enter my password to log into Serverfault after successfully logging out.  I'm not sure this is as secure as intended.  Steps to repeat (using Firefox 25.0.1) - Log in using stackexchange credentials - Log out - Log in using the stackexchange button without credentials - Successfully logged in without typing anything...  Is this just me?

I want to log out of Stack Overflow or any Stack Exchange site, but always it shows me logged in!  How do I log out of this site?  Note: I have yet to register; the site currently always shows my name and default email. I wish to log out so that I may start a new session!


Find a formula for the $n$th term of the sequence   $$1,2,2,3,3,3,4,4,4,4,\ldots.$$   Let $x_n$ denote the $n$th term of the sequence. If $$1+2+\cdots+m < n \leq 1+2+\cdots+m+(m+1)$$ then $x_n = m+1$. Is this a formula or not?

I've a series in which the nth term repeats n times. For example see this : 1, 2, 2, 3, 3, 3, 4, 4, 4, 4, ...    So the question which I want to ask is that is there any way (like a formula) to get the kth term from the series  (say 2000th term) except direct finding each and every term. I also request to tell the derivation. Note: This is not my HW question  (although it may look like! ), I rather prefer doing them by myself.


How can I extract the ip address and the country and put them individual in a string without any quotes or any other characters which are present in the text by using the next command:  info_ip=`wget --tries=1 --timeout=10 -qO- http://ipinfo.io/?callback=callback; echo`   Now I'm looking to filter the data for ip and country  $ip = ?  $country = ?  ipinfo.io currently returns something like:  /**/ typeof callback === 'function' && callback({   "ip": "198.51.100.123",   "hostname": "host.example.com",   "city": "Example City",   "region": "Example Region",   "country": "XY",   "loc": "12.3456,-1.2345",   "postal": "XXX",   "org": "ASXXXX Example Organisation" });

How can I extract the ip address and the country and put them individual in a string without any quotes or any other characters which are present in the text by using the next command:  info_ip=`wget --tries=1 --timeout=10 -qO- http://ipinfo.io/?callback=callback; echo`   $ip = ?  $country = ?


I followed the mainstream instructions for installing Ubuntu 16.10 alongside windows 10. After installing Ubuntu I restarted my computer to get the GRUB menu to choose which OS to boot. Everything is fine. Booted Ubuntu 16.10 and then I wanted to test Windows as well, so I shut the pc down and turned on again to find the same menu but this time I chose Windows. When I turned it on again, it just ignored grub and went straight to booting Windows.   EDIT: Windows 10 fast start and hibernation are disabled, Secure Boot is disabled; my notebook is a Sony Vaio SVE151J11X  EDIT2: through admin prompt on windows i just ran:  bcdedit /set {bootmgr} path \EFI\ubuntu\shimx64.efi   now everything is fine. Thanks

I've just upgraded to Windows 10 from Windows 8.1 on my partitioned laptop that has Ubuntu 14.04 installed. Grub no longer appeared on boot so I ran boot-repair from an Ubuntu liveUSB. This didn't seem to have any effect. I've checked and secure boot is still disabled. Log from boot-repair:  So what's next?  Update: I've attempted to use chroot to update grub from my Ubuntu partition. update-grub runs successfully finding both linux and windows boot manager but the process still doesn't have any effect. grub-install complains that it cannot find EFI directory (but I have mounted everything correctly).  Update2: Just discovered that running efibootmgr after chroot into ubuntu shows ubuntu as not being in the boot order at all. I manually changed the order and rebooted to discover that the bootorder was reset. I run in windows: bcdedit /set {bootmgr} path \EFI\ubuntu\shimx64.efi But this has no effect either even after reporting 'Operation Successful'.


I have a set of input fields, some of them have labels associated, some not:  <label for="bla">bla</label> <input type="text" id="bla" />  <label for="foo">bla <input type="checkbox" id="foo" /> </label>  <input ... />   so, how can I select the associated label for each input, if it exists?

Let's say I have an html form.  Each input/select/textarea will have a corresponding <label> with the for attribute set to the id of it's companion. In this case, I know that each input will only have a single label.  Given an input element in javascript — via an onkeyup event, for example — what's the best way to find it's associated label?


MKV Video files are not paying properly.  SM player  only plays the audio, not the video.  Please hep.

I am having a problem while playing .mkv files. Every time I play a .mkv file, the audio can be heard but video cannot be seen. The only way to see the video if I actually right click on it or put a window in front of it and it displays one part of the video but not all.    The link of the picture above basically describes what I am saying. While I was trying to take the screenshot, the window for the screenshot disappeared and displayed part of the video. I hope someone could help me on this. Thank you!   EDIT: I was running Unity 2D when I have the problem but when I run Unity 3D, it works. So I need to make this work on 2D. Please help.


In my Chrome on Ubuntu 16.04 LTS, Devanagari fonts are not displayed correctly.    How can I correct it?

When I typed the title I was directed to another question "". My experience is somewhat different than discussed there. The display is correct in LibreOffice and Text Editor but not in browser search results page. Again if you click the link with incorrect display the actual website displays correctly. I experimented with copying the incorrectly displayed lines and pasted in text editor and it displayed correctly.   This problem seems to be only in Debian/Ubuntu and distros based on them. I have tried a few other distros like Fedora, Manjaro and Solus and everything is displayed correctly in them.


I have a dictionary of values read from two fields in a database: a string field and a numeric field. The string field is unique, so that is the key of the dictionary.  I can sort on the keys, but how can I sort based on the values?  Note: I have read Stack Overflow question here  and probably could change my code to have a list of dictionaries, but since I do not really need a list of dictionaries I wanted to know if there is a simpler solution to sort either in ascending or descending order.


I have a SharePoint Sub site , I want to take the back up of the Sub site and want Restore in to another Sub site of different Site collection, The site collection is belongs to different web application.  Is it Possible through Power shell Command?.  Please Help Me

Are there any SharePoint tools out there that copy all of the content from one site collection to another?  We need to get one site from our site collection and all of the lists and libraries and all of the items on those lists to an entirely new site collection. Are there any good tools out there for this? We also thought a PowerShell script could be viable, does that seem like it may work?  Thank you for your help.


Solve the following integrals:  $$ \int_0^{\frac{ \pi }{2}} \frac{\sin^{1395}x}{\sin^{1395}x + \cos^{1395}x}\ dx $$  And it does not follow a specific pattern.

Evaluate the integral $$\int^{\frac{\pi}{2}}_0 \frac{\sin^3x}{\sin^3x+\cos^3x}\, \mathrm dx.$$  How can i evaluate this one? Didn't find any clever substitute and integration by parts doesn't lead anywhere (I think).  Any guidelines please?


I have a get request being sent to my Django project with a list of parameters. GET /site/login? _name=bill&_last_name=Smith&_favorite_food=wings  I need to get each parameter and it's value.  What would be the best way to do this?  I know that in Django you can do print(request.data) but I need the parameters.

I am currently defining regular expressions in order to capture parameters in a URL, as described in the tutorial. How do I access parameters from the URL as part the HttpRequest object? My HttpRequest.GET currently returns an empty QueryDict object. I'd like to learn how to do this without a library, so I can get to know Django better.


My laptop is a HP Notebook - 15-ac173tx having Realtek RTL8723BE/RTL8188EE 802.11b/g/n Wireless LAN Drivers.  I can not work with my wifi properly as it drops once in a while, and also I can't log into a wifi network if the wifi router is in another room even if I connect to a wifi network really close to my lap the signal strength of the wifi is really low.  Please help me to fix this issue asap.

I have a HP 14-AN001NA laptop. It came with Windows 10 installed on which the Wi-Fi worked fine anywhere in the house.   However I removed Windows 10 and installed Ubuntu 16.04 instead and since I have had terrible Wi-Fi anywhere aside from about three foot away from the router. I don't know if it's relevant but my Wi-Fi is not called wlan0 but wlo1 for some reason (I didn't change it).  When running lspci -knn | grep Net -A3     I get the following output:  05:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter [10ec:b723] DeviceName:   Subsystem: Hewlett-Packard Company RTL8723BE PCIe Wireless Network Adapter [103c:81c1] Kernel driver in use: rtl8723be Kernel modules: wl, rtl8723be


I am using Jquery to shown and hide an overlay on the web page.  In my scenario, I am showing an overlay menu and currently close the overlay when an item within the menu is clicked (click event detected and then overlay closed).   $('#menu a').click(function(){ $('.overlay').hide(); });   Nice and simple!  I now have a requirement that I want to hide the overlay when anywhere on the screen is clicked other than the menu item (for convenience).  Here's an example:    $('.overlay').click(function(){     // pseudo code   if (isDivClicked == false){      $('.overlay').hide();   } });   Is there a way to see if the clicked area is the overlay but NOT the div shown (with the menu items).  Thanks in advance!

I have some HTML menus, which I show completely when a user clicks on the head of these menus. I would like to hide these elements when the user clicks outside the menus' area.  Is something like this possible with jQuery?  $("#menuscontainer").clickOutsideThisElement(function() {     // Hide the menus });


(This is a question from a friend of mine who is a secondary school mathematics teacher --- I am posting it on his behalf.)  My question is about the standard deviation.  I was talking to a colleague about why the standard-deviation is the square-root of the sum of squares, rather than just the sum of the absolute values.  I've though about it while ago but got stuck at "its useful for further calcuations, just a manufactured measure when variance is the most used", etc.  Could you shed any light on the matter for a couple of inquisitive teachers?

In the definition of standard deviation, why do we have to square the difference from the mean to get the mean (E) and take the square root back at the end? Can't we just simply take the absolute value of the difference instead and get the expected value (mean) of those, and wouldn't that also show the variation of the data? The number is going to be different from square method (the absolute-value method will be smaller), but it should still show the spread of data. Anybody know why we take this square approach as a standard?  The definition of standard deviation:  $\sigma = \sqrt{E\left[\left(X - \mu\right)^2\right]}.$   Can't we just take the absolute value instead and still be a good measurement?  $\sigma = E\left[|X - \mu|\right]$


I have found the convergence domain, which is $$|z|<1$$ now for this domain I am trying to calculate the series $$\sum_{n=0}^\infty n(n+1)z^n $$

How can I find to what this sum converges to?  $$\sum _{n=1}^{\infty} n(n+1)x^n$$   I proved that it converges when  $$|x| < 1$$  but no idea how to find what it sums to.


I want smartdiagram to use the color of the preceding box also for the arrow, instead of the box it is leading to. Therefore in this image:  I want the green arrow to be red, the blue one to be green, the orange one to be blue and the red one to be orange. How can I achieve this? Here is my MWE: \documentclass[border=3mm]{standalone}  \usepackage{smartdiagram}  \tikzset{     every shadow/.style={         fill=none,         shadow xshift=0pt,         shadow yshift=0pt} }  \tikzset{module/.append style={top color=\col,bottom color=\col}}  \smartdiagramset{%     module shape=rectangle,     text color=white,     border color=none, }  \smartdiagramset{set color list={red,green,blue,orange}}  \begin{document} \sffamily \smartdiagram[flow diagram:horizontal]{elem1,elem2,elem3,elem4} \end{document}

The smartdiagram package appears to have a default convention that an arrow in a circular diagram takes the colour of the destination block. Is there a way to choose instead the colour of the source block as the colour of the arrow. For instance, in this example  \documentclass{article} \usepackage{tikz} \usepackage{smartdiagram} \begin{document} \smartdiagramset{set color list={red!50,orange!50,green!50}} \smartdiagram[circular diagram:clockwise]{Red,Orange,Green} \end{document}   I want the arrow from "Red" to "Orange" to be red instead of orange. In other words, I want to advance all arrow colours one step clockwise.  Is there a single key or other simple option to do this? If there isn't might I suggest it through this forum please?


I recently upgraded from 16.04 to 18.04, and I think something went wrong with the upgrade. When I run sudo apt-get install -f, it tries to upgrade udev, but then I get repeated messages about "unsafe symlinks" and this error message:  dpkg: error processing package systemd (--configure):  installed systemd package post-installation script subprocess returned error exit status 1 Errors were encountered while processing:  systemd E: Sub-process /usr/bin/dpkg returned an error code (1)   I was getting a similar message about systemd-shim earlier, but managed to fix it. I also had a problem with incorrect /etc/apt/sources.list, but I think that's fixed as well.  I was getting various error messages during the upgrade process, and at the end I had to "destroy" something instead of finishing the upgrade properly (unfortunately I don't remember exactly what happened.) Any ideas as to what's going on?

I know it has been asked many times before but none of those solutions helped me.  Every time I am running sudo apt upgrade I get this error.  dpkg: error processing package systemd (--configure):  installed systemd package post-installation script subprocess returned error exit status 127 Errors were encountered while processing:  systemd E: Sub-process /usr/bin/dpkg returned an error code (1)   And sudo dpkg --configure -a returns     Setting up udev (237-3ubuntu10.28) ... /var/lib/dpkg/info/udev.postinst: 108: /var/lib/dpkg/info/udev.postinst: addgroup: not found dpkg: error processing package udev (--configure):  installed udev package post-installation script subprocess returned error exit status 127 Setting up systemd (237-3ubuntu10.28) ... /var/lib/dpkg/info/systemd.postinst: 123: /var/lib/dpkg/info/systemd.postinst: addgroup: not found dpkg: error processing package systemd (--configure):  installed systemd package post-installation script subprocess returned error exit status 127 dpkg: dependency problems prevent configuration of libnss-systemd:amd64:  libnss-systemd:amd64 depends on systemd (= 237-3ubuntu10.28); however:   Package systemd is not configured yet.  dpkg: error processing package libnss-systemd:amd64 (--configure):  dependency problems - leaving unconfigured dpkg: dependency problems prevent configuration of libpam-systemd:amd64:  libpam-systemd:amd64 depends on systemd (= 237-3ubuntu10.28); however:   Package systemd is not configured yet.  dpkg: error processing package libpam-systemd:amd64 (--configure):  dependency problems - leaving unconfigured Errors were encountered while processing:  udev  systemd  libnss-systemd:amd64  libpam-systemd:amd64   I don't think it's safe to remove systemd package all together. Any help is appreciated and I am on Ubuntu 18.04.


Let $\emptyset = A \subset \mathbb R $ where A is bounded above, and A has a supremum that is not contained in A. Prove the existence of an $(x_n)_{n\in\mathbb N}$ in A such that $\lim_{n->\infty}$ $x_n = supA$.  I'm guessing we can construct an example with the information given. I have been playing around with the idea the that we can order A such that $a_i \leq a_j$ for all $i \leq j$ and define $(x_n)_{n\in\mathbb N}$ such that $x_l = a_l$ for all $l \in \mathbb N$. Hence $x_i\leq x_j$.  I also believe, the actual definition of the limit will have to come in, but here I do not know how to continue.  Any help is appreciated.

Given a sequence of real numbers, $\{ x_n \}_{n=1}^{\infty}$, let $\alpha =$ limsup$x_n$ and $\beta = $ liminf$x_n$.   Prove that there exists a subsequence $\{ x_{n_k}\}$ that converges to $\alpha$ as $k \rightarrow \infty$.   Not sure how to start this without since I'm not given that the subsequence is bounded..


/dev/tcp is often mentioned in many sources, and I think I saw it in Ubuntu not so long ago. Now, in Debian Jessie, I can't find it. The same with /dev/udp.  tomasz@E4200:/dev$ ls agpgart          dm-1     hidraw3       network_latency     sda2      tty11  tty24  tty37  tty5   tty62    vcs2   vfio autofs           dm-2     hpet          network_throughput  sda5      tty12  tty25  tty38  tty50  tty63    vcs3   vga_arbiter block            dm-3     hugepages     null                sg0       tty13  tty26  tty39  tty51  tty7     vcs4   vhci bsg              dm-4     initctl       port                shm       tty14  tty27  tty4   tty52  tty8     vcs5   vhost-net btrfs-control    dm-5     input         ppp                 snapshot  tty15  tty28  tty40  tty53  tty9     vcs6   watchdog bus              dri      kmsg          psaux               snd       tty16  tty29  tty41  tty54  ttyS0    vcs7   watchdog0 char             fb0      kvm           ptmx                stderr    tty17  tty3   tty42  tty55  ttyS1    vcsa   xconsole console          fd       log           pts                 stdin     tty18  tty30  tty43  tty56  ttyS2    vcsa1  zero core             full     loop-control  random              stdout    tty19  tty31  tty44  tty57  ttyS3    vcsa2 cpu              fuse     mapper        rfkill              tomas-vg  tty2   tty32  tty45  tty58  uhid     vcsa3 cpu_dma_latency  fw0      mcelog        rtc                 tty       tty20  tty33  tty46  tty59  uinput   vcsa4 cuse             hidraw0  mem           rtc0                tty0      tty21  tty34  tty47  tty6   urandom  vcsa5 disk             hidraw1  mqueue        sda                 tty1      tty22  tty35  tty48  tty60  vcs      vcsa6 dm-0             hidraw2  net           sda1                tty10     tty23  tty36  tty49  tty61  vcs1     vcsa7   Has it moved somewhere? (And why?) Does this apply to all Linuxes?  To make it complete, I'm on:  Linux E4200 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt25-2+deb8u3 (2016-07-02) x86_64 GNU/Linux   UPDATE   doesn't answer my question.  This answer:     When you used /dev/tcp/74.125.225.19/80 in a pipe, bash attempted to   run a command named /dev/tcp/74.125.225.19/80 and reported an error   because that file didn't exist.   doesn't tell me much about /dev/tcp. Neither the  linked.  I gather from the first answer to my question that /dev/tcp is a "virtual" folder. Please post a link that explains this. And if you know, please answer if this has always been so.

When I try to run the following command:  echo -e "GET / HTTP/1.1\n\n" | /dev/tcp/74.125.225.19/80   I get the following error message:  bash: /dev/tcp/74.125.225.19/80: No such file or directory   The following command works perfectly, so the problem involves how I'm using /dev/tcp:  echo -e "GET / HTTP/1.1\n\n" | nc 74.125.225.19 80   I'm in Ubuntu 13.04, so the capability should be on my system. What am I doing wrong? What are the rules for using /dev/tcp properly?


Because order of element divide order of the group,the possiblility of order of element is 1,2,5,10. Frin this ,it must contains element of order 5 and 2. But I can't prove that it must gaurantee five elements of order 2 .Anyone can give a hint ?

This is almost a duplicate of the following questions (but, read further):      But, I wasn't able to apply the proof to my case of a group of order 10 and an element of order 5.  In my case, if I try a proof by contradiction, I'm left with the fact that every element in $G$ is of order 2, but if I divide them into subgroups, every subgroup is of order 2, and has one unique element.  I also tried other methods to prove the theorem, but couldn't come up with anything meaningful.  I'm a beginner in the field, and am not familiar with theorems such as Cauchy's or Sylow's theorem (I'm aware of Lagrange's theorem). Therefore, please try to provide a simple answer, thanks!