At a movie theatre, $m+n$ people stand in line to buy tickets. The ticket price is \$5. Suppose $m\geq n$, and $m$ of those people only has \$5 bills and the remaining $n$ people only has \$10 bills. At the beginning, no change is available at the ticket counter. It is desirable to arrange the order of these $m+n$ people in the line so that nobody needs to wait for change when buying the ticket, or exchange bills among each other. In how many ways can this be done?  Sorry for the lack of mathjax and the simplicity of this problem because I am just learning combinatorics.

My interest in combinatorics was recently sparked when I read about the many things that the Catalan numbers count, as found by Richard Stanley. I picked up a copy of Brualdi's Combinatorics, and while browsing the section on counting sequences I found a nice little puzzle that has definitely puzzled me.     Let $m$ and $n$ be nonnegative integers with $n\geq m$. There are $m+n$ people in line to get into a theater for which admission if $50$ cents. Of the $m+n$ people, $n$ have a $50$-cent piece and $m$ have a $\$ 1$ dollar bill. The box offices opens with an empty cash register. Show that the number of ways the people can line up so that change is available when needed is   $$ \frac{n-m+1}{n+1}\binom{m+n}{m}. $$     I first noted that the first person to enter must be one of the $n$ with a half-dollar. Now the register has a half-dollar change. The second person can be either a person with a half-dollar or a dollar. In the first case, the register will now have two half-dollars, in the second case, the register will now have one dollar bill. So it seems to me that when one of the $n$ people with a half-dollar enters, the number of half-dollars in the register increases by $1$, and when one of the $m$ people with a bill enters, the number of half-dollars decreases by $1$ but the number of bills increases by $1$.   I tried to model this by looking at paths in $\mathbb{Z}^2$. The $x$-axis is like the number of half-dollars, and the $y$-axis is the number of bills. You start at $(0,0)$, and you can take steps forward $(1,0)$ or backwards diagonally $(-1,1)$ corresponding to who enters, but you must always stay in the first quadrant of the plane without crossing over the axes. The goal is to make $m+n$ moves, and I figured maybe the number of such paths is counted by $\frac{n-m+1}{n+1}\binom{m+n}{m}$, but I'm not sure how to show this. I don't know if this observation simplifies the problem at all, as I don't know how to finish up. I'd be happy to see how this problem is done, thank you.


I was copy/pasting some commands into CMD (Windows 7) and accidentally pasted in an entire cmd history (from the Select All command). This included something along the lines of  Y:/>database.mdb   Which executed and apparently wrote Y:/ is not a recognized command over database.mdb. I've tried Recuva, but It didn't find the file. It wasn't really deleted, which is why I suppose it didn't work. Is there any way to get the file back? I have a backup, but it isn't as recent as I would like.

I just wrote an extensive essay, ironically the last one of my academic career, and then, for the first time in my life, saved over it with an empty document by accident.  Is all hope lost?  Is there any way to restore it to its last version?


I have Ubuntu 12.10 on my laptop, no Windows.  I have my system disks and tried to do a system recovery and it won't allow me.  I've tried creating a boot disk and doing the "try ubuntu" and installing the OS uninstaller.  My laptop freezes up in this process.  Any other suggestions on how to remove ubuntu and reinstall my windows vista again?

I have absolutely no experience with Linux, and I desperately need to get my computer back up and running again with Windows.  How do I remove Ubuntu and reinstall Windows?    Editor's note: many of the answers are about removing Ubuntu from dual-boot but keeping Windows (which is a bit complicated), while other answers are about removing Ubuntu from single-boot (which is easy: basically just format the disk while installing Windows). The question as written is ambiguous between dual-boot or single-boot.


Is there a rule or pattern to describe where someone comes from? Some examples of places, with the word to describe people from that place:  New York / New Yorker London / Londoner Toronto / Torontonian Paris / Parisian Boston / Bostonian Brazil / Brazilian Mexico / Mexican Vancouver / Vancouverite  There are -er suffixes, -ian suffixes, -an suffixes, and -ite suffixes. Possibly others that I could remember. Is there a general rule for determining which suffix to use when you see the name of a place for the first time?

Are there specific rules / conventions at play when creating demonyms? Or are they merely formed organically over time - the most popular winning out?  There are many suffixes to choose from, but I cannot find concrete guidelines as to which is proper to use in which instance.


My D80 has a greenish tint effect (shutter count at approx 46000) in it's viewfinder which goes away if i use it long enough constantly looking through the viewfinder. The weird thing is my other eye starts to see things in green tint when i use it for viewfinder instead. I don't keep my both eyes during shooting (neither when it comes to shooting certain devices) for easier manual focus but this was a interesting effect. The other thing i find weird is that my left eye feels exhausted if i keep both of my eyes open. So, is this normal? What are these called.

Possible Duplicate:          How does the eye perform the equivalent of white balance? Why is the camera not able to replicate it?


Actually I have type D multiple entry visa issued by Greece and valid for 3 months. I'm a little bit confused: is it a Schengen visa? Does it allow me to enter the Schengen area?  I have been emailing many EU embassies: some say I can travel with that visa, some say I can't, and that I have to get another visa to visit the Schengen area. What is the correct answer?

I have requested for a French long term (Type D) student visa from a consulate in India. It's a national Type D visa and not a Schengen visa. My question is that can we still go to other Schengen countries on this visa? If not then can we get a Schengen visa from a consulate in France?


I just installed a Ubuntu 11.10 box and I'm trying to figure out how to set the timezone to UTC. I have it set to London at the moment, but UTC doesn't appear to be an option.  Help?

Currently when I execute the date command from bash I get the following displayed  Thu May 17 12:21:00 IST 2012  Below is my timezone config based on executing dpkg-reconfigure tzdata     Current default time zone: 'Europe/Dublin'   Local time is now: Thu May 17 12:32:52 IST 2012.   Universal Time is now: Thu May 17 11:32:52 UTC 2012.     Any idea how I change from IST to UTC/GMT?


I have seen this said multiple times where (1) the cosine of the angle between the random variables (on a vector space) is equal to the correlation coefficient, and (2) the claim if random variables are orthogonal then their correlation coefficient is zero. I don't think (1) is true unless the random variables are centered? Is (2) true even without centering?

According to some articles (e.g. ) correlation is just a centered version of cosine similarity. I use the following code to calculate the cosine similarity matrix of the column vectors of a matrix X (slightly modified from ):  cos.sim <- function(ix)  {   A = X[,ix[1]]   B = X[,ix[2]]   return(t(A)%*%B/sqrt(sum(A^2)*sum(B^2))) }    n <- ncol(X)  cmb <- expand.grid(i=1:n, j=1:n)  C <- matrix(apply(cmb,1,cos.sim),n,n)   My question  Which modifications of the code above are needed to get the correlation matrix cor(X) instead of the cosine similarity matrix. I guess the changes are minimal but I can't see them at the moment.


$encrypted_pass = hash("sha256", $password. "randomSalt");   If not, what is a very good method to encrypt PHP passwords (without having to install additional plugins or modules, so I prefer simple methods)?  Thanks.

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:


In Mac HD Storage it shows 65 GB under Documents but the list in Large Files only shows a fraction of that. I need to delete files to get my Time Machine Backup running again. How can I do this if I can't see where the problem is?

Every few days I get notices on my MacBook that it's running or run out of hard drive space. Curiously, restarting the computer will enable me to recover gigabytes of space (this past time, it was able to recover about 2.2GB). However, I can't identify anything in my personal activity that consumed that space.  It's possible that it's a rogue iTunes podcast or a huge software update that my Mac is automatically downloading - would either of these reclaim the space upon a restart?  One possibility that I can think of is that FileVault has some sort of disk leak, allocating but not freeing files. Does this make sense? Is there a tool that I can run to determine where this space is going? Assuming it is FileVault, should I try to disable it? What's the best way to turn of FileVault on a nearly full computer?


I have never used Archipack add-on before. When ever I try to add any element (window, door, stair, fence..) aside from wall, from the add mesh menu. A blank window appears on the screen and I can not add anything from the addon apart from a wall.  I am doing something wrong? How can I add element from the free Archipack add-on for Blender?

I haven't tried Archipack previously but anyways, after going like this: and when I click on Windows it shows up this black patch in middle of the viewport: I tried Wall and it worked well as it added a wall type mesh, but in this case windows aren't showing up, that black patch covers my viewport..


Prove that if $M \in M_{n,n}(F)$ can be written in the form   $M=\begin{pmatrix} A & B\\ O & C \end{pmatrix}$, where $A$ and $C$ are square matrices, then $\det(M)=\det(A)*\det(C)$   I am not sure the rigorous way of proving, and I see some proof goes by block matrix, which is something not yet learned about.   My idea is constructing a triangular matrix, then by cofactor expansion, we lead to a linear combination of the form of the determinant. Is that doable?  Another thing is should I separate by cases, when the matrix is invertible or when not invertible?

I have encountered an statement several times while proving determinant of a block matrix.      $$\det\pmatrix{A&0\\0&D}\; = \det(A)\det(D)$$   where $A$ is $k\times k$ and $D$ is $n\times n$ matrix. How to prove this?  Thanks in advance.


I'm trying to write a Python 3 function that will filter a list and pop() all items that are a string. But when I try to write the following function: def filter_list(l):     for i in l:         type_item = type(l[i])         if type_item == "class str":             l.pop(i)     return l  I get an error saying: File "/home/codewarrior/solution.py", line 3, in filter_list     type_item = type(l[i]) TypeError: list indices must be integers or slices, not str  I believe that the return of this method is not a str, but I haven't found any documentation that tells me how I can check if the return is a string or not. Thank you!

What is the best way to check whether a given object is of a given type? How about checking whether the object inherits from a given type?  Let's say I have an object o. How do I check whether it's a str?


Is there a way I can use a model input in QGIS modeler to amend the parameters of a SQL query. For example I want a model input (string) to allow me to pick the name of someone I am searching for in a database. In the example below the name is 'Tim'  I know I can change between a 'value', 'pre calculated value', 'model input' and 'algorithm output' but none of these seem to allow me to change a specific parameter within the script.

I'd like to insert an input variable (integer) in a query SQL (@variable) using the algorithm postgresql execute sql in the graphical modeler of QGIS. For example, in this kind of query INSERT INTO table2 SELECT * FROM table1 WHERE ID = @variable;  where I should insert the variable in the input panel of the modeler and click play to do the query. I used pre-calculated value but with no success. Any suggestion?


Prove if $2^k - 1$ is prime, then $k$ is prime.   using the fact that for positive integers $m,n$:  $2^m -1 \vert 2^{mn} - 1$   so $2^{mn} - 1 = (2^m - 1)k$ some $k$ (**)  for contrapositive, suppose $k = k_1k_2$  now we w.t.s. $2^{k_1k_2} - 1$ is composite as well  Can I show this using (**) letting $m,n$ be $k_1,k_2$?  And that's all I need to do ?

I understand the idea of the proof. I just want to make sure I wrote my proof well.  Suppose $n$ is not prime. Then $\exists x,y \in \mathbb{Z}$ such that $n = xy$.  $2^{xy} - 1 = (2^x)^y - 1$  $ = (2^y - 1)(2^{y(x-1)} + 2^{y(x-2)} + ... + 2^{y} + 1)$  Since $2^{n} - 1$ is divisible by $2^y - 1$ it must be that $2^n - 1$ is not prime. Contradiction. Thus $n$ must be prime.  How does this look?


Recently, I read a lot about "Speculative Realism" being the (not that) new kid in town. But what does "speculative" or "speculation" exactly mean in the domain of philosophy? What exactly distinguishes a speculative position from a non-speculative? And what are examples of this and that (beside of the SR)?

From Loux's: Metaphysics: A Contemporary Introduction.     The metaphysical theories of the rationalists, by contrast, were   anything but conservative. In their hands, metaphysics results in   abstract speculative systems far removed from any recognizably   commonsense picture of the world. Here, one has only to skim the works   of a thinker like Spinoza or Leibniz to appreciate the extravagance of   rationalist metaphysics.   I'm still in the beginning of the book and I've read this in the introduction, so what's so speculative in rationalists metaphysics?


I’ve been trying to animate a blowing skull, but, when i try to add the active rigid body dynamic, it stars from keyframe 1, when what i want is to start it in the keyframe 267.

I've been trying to make a wrecking ball smash through a figure of sorts, not really sure what exactly but I made an example. The problem I'm having is that the figure does indeed fall apart, but I would like it to stay put together until the ball hits it. I achieved this by using Cell Fracture on the figure and just using Rigid Body. Again, I just need a way for the figure to stay still until hit by the ball, and then have all of its pieces come apart.


How can I take any given path in bash and convert it to it's canonical form, dereferencing any symbolic links that may be contained within the path?  For example:  ~$ mkdir /tmp/symtest ~$ cd /tmp/symtest/ /tmp/symtest$ mkdir -p foo/bar cat/dog /tmp/symtest$ cd foo/bar/ /tmp/symtest/foo/bar$ ln -s ../../cat cat /tmp/symtest/foo/bat$ cd ../../ /tmp/symtest$ tree . |-- cat |   `-- dog `-- foo     `-- bar        `-- cat -> ../../cat  6 directories, 0 files   How can I get the full canonical path of /tmp/symtest/foo/bar/cat (i.e: /tmp/symtest/cat)?

Given an absolute or relative path (in a Unix-like system), I would like to determine the full path of the target after resolving any intermediate symlinks. Bonus points for also resolving ~username notation at the same time.  If the target is a directory, it might be possible to chdir() into the directory and then call getcwd(), but I really want to do this from a shell script rather than writing a C helper. Unfortunately, shells have a tendency to try to hide the existence of symlinks from the user (this is bash on OS X):  $ ls -ld foo bar drwxr-xr-x   2 greg  greg  68 Aug 11 22:36 bar lrwxr-xr-x   1 greg  greg   3 Aug 11 22:36 foo -> bar $ cd foo $ pwd /Users/greg/tmp/foo $   What I want is a function resolve() such that when executed from the tmp directory in the above example, resolve("foo") == "/Users/greg/tmp/bar".


I am having a hashMap which stores my values like that:  {10997=Event [Numb=0007449001, date=07.02.2008], 10998=Event [Numb=0007449001, date=08.04.2008], ...   As you can see the key is a integer and the value is an Event Object which has a numeric value and a date, which is saved as a String.  I want to compare the numeric value of the map to another value with an if statment.  I tried:  if(numericVal==eventMap.get(i).toString()) {   However that does not really work. How to get the value easily out of the HashMap and of the Object?  I appreciate your answer!  UPDATE  By easily I mean performance orientated, because I have to process a lot of values.

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


Why does the command chmod 6754 correspond to the file permissions rwsr-sr-?  I understand that Read = 4, Write = 2, and Execute = 1, but what value does the s (setuid) permission or the dashes have?

Sometimes I see chmod commands that use four octal digits instead of three -- what is the optional first digit for? For example, chmod 777 is equivalent to chmod a+rwx; what's the same command for chmod 2777?


Q: If $M$ be the maximum value of $$72\int_0^y \sqrt{x^4+(y-y^2)^2}dx$$ for $y\in [0,1]$, then find $\frac{M}{6}$ $$$$ A: $4$  My first thoughts involved differentiating it and equating it to zero, but since the integrand is dependent on the upper bound, I'm unable to do so. Then I thought of actually integrating it, and the trying to find its maximum value, but the $x^4$ is throwing me off track; had it been $x^2$ I'd be able to carry out my thoughts. But since it isn't I'm stuck. Thanks in advance.  Edit: My question is a teeny bit different from ; the solutions there use multivariable calculus, while I'm looking for a solution involving single variable calculus, as I encountered this one while studying for an exam whose syllabus doesn't involve multivariable calculus. Edit 2: Since a user pointed out that this is a possibile duplicate, I edited the question body to show how my question is different from that one, yet the question was marked duplicate.

Find the maximum value of $72\int\limits_{0}^{y}\sqrt{x^4+(y-y^2)^2}dx  $ for $y\in[0,1].$  I tried to differentiate the given function by using DUIS leibnitz rule but the calculations are messy and I tried to solve directly by integrating it but that also is not working.Can someone please help me in solving this question?


I was recently introduced to LaTeX but I cannot find any resources online for beginners like me. I need a how-to kind of a resource for basic functionality. Pardon my vagueness. I currently have no knowledge of it but I am willing to learn.

Which book (free or otherwise) was the most useful to you when you started learning LaTeX?  I am frequently asked this question by friends who want to learn LaTeX, and I recommend the book which got me started, , but I feel that there might be better options around.  Also see .


I have read numerous answers to similar questions, but I'm still stuck.  Here's my approach:  All elements in $\langle 3+i \rangle$ have the form $(a+bi)(3+i)=(a-b)+i(a+3b)= 2p + i 4q$, for $p, q\in \mathbb{Z}$, which implies that all other elements are not in $\langle 3+i \rangle$. But aren't there infinitely many such elements?  Can you please clarify what I'm not seeing in this problem?

A very basic ring theory question, which I am not able to solve. How does one show that    $\mathbb{Z}[i]/(3-i) \cong \mathbb{Z}/10\mathbb{Z}$. Extending the result: $\mathbb{Z}[i]/(a-ib) \cong \mathbb{Z}/(a^{2}+b^{2})\mathbb{Z}$, if $a,b$ are relatively prime.   My attempt was to define a map, $\varphi:\mathbb{Z}[i] \to \mathbb{Z}/10\mathbb{Z}$ and show that the kernel is the ideal generated by $\langle{3-i\rangle}$. But I couldn't think of such a map. Anyhow, any ideas would be helpful.


I recently got banned from SoftwareEngineering.StackExchange.com. The point of this post is not to get the ban lifted, or to argue with the negative scores of my posts. It is to discuss the ban system and whether or not it could be improved.  The thing is, that even though I recently got the ban, the two posts that (most likely) caused the ban are more than three years old (see the screenshot). According to the guidelines the ban can be lifted by improving the score of negative received posts or simply by waiting six months. Since the posts are so old that no one will ever see them, the only real option is to wait for six months.   So here are my two points:   Could the system be improved so that the ban occurs sooner after the negative received posts. Improving the feedback loop, would (probably) lead to faster reactions improving poor questions, leading to higher quality content. I am aware that this might be a technically difficult thing to implement though. Make the ban period start from the date, where the users latest poor post was submitted, rather than the users latest post (even if that was well received). This would seem like a more "fair" way of doing things, but it would possibly prevent a more poor questions, as the "time-to-think" period would occur immediately after the problematic post(s) and not years later, where the quality of the posts already increased (at least in my case).   And again, I have no hopes or expectations for my own account with this post. It is meant to discuss the system, not me personally.  What do you think?

The  mentions that it's possible to post one more question after a six-months waiting period and if the question is good enough, the question ban can be lifted:     If you're unable to improve your existing questions, you'll get the chance to ask one new one 6 months after your last question. If that question is positively received, you may be able to continue asking questions; if not, then the ban will be reinstated.   What is positively received in this context? Is it enough if the question has a zero score and is not closed? Or does it have to have a positive score?  How long does the system wait after posting this new question to evaluate this criteria and possibly lift (or reinstate) the question ban?


We have a document template that we're building that looks like this:        When we click Print, the Preview window appears, and we see (note the additional whitespace at the top and left of the blue sidebar):        This Preview is what we see on the physical paper copies as well. Is there a setting that should be changed to prevent this? The left bar and the line below "Document Title" are both in the header, but "Document Title" is not.

I often get told by Word 2013 that, on trying to print, my margins are outside the printable area of the paper. Does this mean that the printer applies a 'margin' to the paper to which it cannot print, e.g. a cheap printer can only print within 2cm of the physical edges of a piece of A5 paper? So the margins I set in word must all be greater than or equal to 2cm. When I choose to Fix the margins, my margins are decreased to 2cm where necessary?  I am trying to replicate a document printed on slightly smaller than A5 paper, and print it on an A5 page size. I assume my margins of e.g. 0.6cm are outside of the printer's 'margin' for A%, say 0.8cm, and I get the complaint.   How could I remedy this? Physically centre the original document on a real A5 page and measure my Word margins from the edge of the A5?


I was trying to prank a friend, and accidentally created the loop on myself, and now I'm stuck. I don't know where the command block is, and it's on MC Realms. I used the command /tp @a -0 -0 -0. The Realm World is a flatworld, so I'm suspended over the void. Please help!!! I'm stuck, and I have an infinite timer going on somewhere.

I set a command block to /tp. It was supposed to activate only if you had 0 time left, and to activate the command block with a hopper clock to keep giving it power.   But it is not checking if you have 0 time left, so it keeps teleporting me. I can't get close enough to the command block to break it, so I'm stuck in a neverending teleport loop.  Any ideas?


I have a module where there is a file upload which accepts any file but it should only process csv files. If there is someother file then it should say invalid file.  I have written a code but even when I upload a CSV file it doesnt recognise it as a CSV file. My code is   if($_FILES['file']['type'] != "application/vnd.ms-excel"){    die("This is not a CSV file."); }

This is a question you can read everywhere on the web with various answers:  $ext = end(explode('.', $filename)); $ext = substr(strrchr($filename, '.'), 1); $ext = substr($filename, strrpos($filename, '.') + 1); $ext = preg_replace('/^.*\.([^.]+)$/D', '$1', $filename);  $exts = split("[/\\.]", $filename); $n    = count($exts)-1; $ext  = $exts[$n];   etc.  However, there is always "the best way" and it should be on Stack Overflow.


I want to know the origin of the cross product And his relationship with' Groupe compact'

Most questions usually just relate to what these can be used for, that's fairly obvious to me since I've been programming 3D games/simulations for a while, but I've never really understood the inner workings of them... I could get the cross product equation as a determinant of a carefully-constructed matrix,   but what I want to ask is... How did the dot and cross product come to be? When were they "invented"? Some detailed proofs? Did someone say: "Hey, wouldn't it be nice if we could construct a way to calculate a vector that is perpendicular to two given operands?"  Basically, how/why do they work?  I would appreciate explanations, links to other explanations, other web resources... I've been searching the Internet lately for explanations, but most of them are on how to use it and nothing that really gives substance to it.


The examples come below.   Sussex's Case's anus's   How do I pronounce them?

Possible Duplicate:           My name is Greg — this is Greg 's post.  If my name ended with an 's', I am aware of the proper apostrophe usage (James → James'), but how should this be pronounced?  Phonetically, am I Jameses best friend or James best friend?


I created a java class and written logic for password and confirm password in the class. while calling the class in another class by creating class object, it is showing null pointer exception.  public class Verify_password {     WebDriver driver;     String pwd = "password";     String confirm_pwd = "password";     String wrong_pwd="yogesh";     public void password_match(){         //Password = confirm password         driver.findElement(By.id("encrypted_pwd")).clear();         driver.findElement(By.id("confirm_pwd")).clear();         driver.findElement(By.id("encrypted_pwd")).sendKeys(pwd);         driver.findElement(By.id("confirm_pwd")).sendKeys(confirm_pwd);         driver.findElement(By.id("submit-btn")).click();         if(pwd ==confirm_pwd){             System.out.println("Password Match");         }         else{             System.out.println("Password doesn't Match");         }     }   Calling this class to another class by:  Verify_password password1 = new Verify_password(); password1.password_match1();   Can someone verify and confirm that is it okay or not?  Thanks

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


Recently my site's index.php file was replaced with some malicious javascript code.  I really don't know how it was added to the page.  Today when I tried to download the file via FTP, my local anti-virus software gave me a warning. I presume this means it was not uploaded from my computer.  Is there any way to install anti-virus software on my VPS (running CentOS 5 and Cpanel/WHM)?  Also what is mod_security. Will it be helpful in future?

This is a  about Server Security - Responding to Breach Events (Hacking)   See Also:                  Canonical Version I suspect that one or more of my servers is compromised by a hacker, virus, or other mechanism:   What are my first steps? When I arrive on site should I disconnect the server, preserve "evidence", are there other initial considerations? How do I go about getting services back online? How do I prevent the same thing from happening immediately again? Are there best practices or methodologies for learning from this incident? If I wanted to put a Incident Response Plan together, where would I start? Should this be part of my Disaster Recovery or Business Continuity Planning?   Original Version       2011.01.02 - I'm on my way into work at 9.30 p.m. on a Sunday because our server has been compromised somehow and was resulting in a    attack on our provider. The servers access to the Internet   has been shut down which means over 5-600 of our clients sites are now   down. Now this could be an FTP hack, or some weakness in code   somewhere. I'm not sure till I get there.      How can I track this down quickly? We're in for a whole lot of   litigation if I don't get the server back up ASAP. Any help is   appreciated. We are running Open SUSE 11.0.            2011.01.03 - Thanks to everyone for your help. Luckily I WASN'T the only person responsible for this server, just the nearest. We managed   to resolve this problem, although it may not apply to many others in a   different situation. I'll detail what we did.      We unplugged the server from the net. It was performing (attempting to   perform) a Denial Of Service attack on another server in Indonesia,   and the guilty party was also based there.      We firstly tried to identify where on the server this was coming from,   considering we have over 500 sites on the server, we expected to be   moonlighting for some time. However, with SSH access still, we ran a   command to find all files edited or created in the time the attacks   started. Luckily, the offending file was created over the winter   holidays which meant that not many other files were created on the   server at that time.      We were then able to identify the offending file which was inside the   uploaded images folder within a  website.      After a short cigarette break we concluded that, due to the files   location, it must have been uploaded via a file upload facility that   was inadequetly secured. After some googling, we found that there was   a security vulnerability that allowed files to be uploaded, within the   ZenCart admin panel, for a picture for a record company. (The section   that it never really even used), posting this form just uploaded any   file, it did not check the extension of the file, and didn't even   check to see if the user was logged in.      This meant that any files could be uploaded, including a PHP file for   the attack. We secured the vulnerability with ZenCart on the infected   site, and removed the offending files.      The job was done, and I was home for 2 a.m.            The Moral   - Always apply security patches for ZenCart, or any other CMS system for that matter. As when security updates are released, the whole   world is made aware of the vulnerability.   - Always do backups, and backup your backups.   - Employ or arrange for someone that will be there in times like these. To prevent anyone from relying on a panicy post on Server   Fault.


I have an iPad running iOs 7.x  I want to install an app which requires iOs 8.0 or newer. But for compatibility reasons I can't install iOs 9.x yet, as it may break some existing app.  Is there a way to install iOS 8 from iOS 7 ?  P.S. If it's possible I'd rather not to downgrade, that is I would like to install directly iOs 8 instead of installing 9 and then downgrading to 8 somehow.

I'm trying to downgrade my iPhone from the current iOS to an older one, as per .  But every time I try, I always receive this error:     The iPhone could not be restored. This device isn't eligible for the requested build.     I have tried many times with and without DFU mode. Any ideas regarding this?


I'm using Firefox 38 on vista. (Error still present now in FireFox 42 on vista.) On  (or any beta site) the error does not show up, however here and on SO (or anywhere with the new design) the "Markdown Editing Help" button in the post editor looks like this, if it pushed off the right edge. Do note it happens on the post editor for both questions and answers.

Just posted a bug report, and found another one :p    (lame hand-drawn cursor coz windows doesn't capture the real cursor)  Oh yeah, I'm on Firefox.


Does anybody know the hotkey combination to rotate a group of vertices 45° in edit mode without deforming the cylinder shape? I forgot this important tool, I remember that I could constrain the axes with the Alt key.    BTW see below the screen shot to understand better what I would like to achieve:

I'm trying to make a pistol with a hammer thingy on the back. I've been struggling to make the back perfectly aligned like the red line in the 3rd image. Any help would be appreciated.


When I made alt b this red box outliner showed up and no matter what I do I couldn't get rid of what should I do. I restarted blender and nothing has changed.

In the 3d viewport I am using a border region to only render things inside the selected region. I did this with CtrlB. I cannot get rid of the region. How can I make the border disappear?


If I want the picture I render to be 300 ppi when I open it in photoshop. How to set up in Blender?  Thank you very much for help.

Is there a way to output for Print. I want to save in a higher DPI than the default 72dpi say 300dpi that's a good quality for printed pieces. I tried downloading an add-on but don't know if I am installing it correctly it isn't showing up but the bar in python is green. I'm using the 2.69 version of Blender. If no such feature exists what size have any of you found best for print quality. Thank you


I try to get some dependency stuff on pacman automated via python. What I want to issue in the shell (and get output from) is:  pacman -Si [a_package] | grep Conflicts | awk -F: '{print $2}'   So this is my python code:  getconflicts1 = "pacman -Si" getconflicts2 = "| grep Conflicts | awk -F: '{print $2}'" pkgs = # an example package list for x in range (1,2):     getconflicts = getconflicts1 + pkgs[x] + getconflicts2     process2 = subprocess.Popen(getconflicts.split(), stdout=subprocess.PIPE)     conflicts = process2.communicate()[0]     print(conflicts)   However pacman says "invalid option -- F" when I use the python program, whereas issueing the command in the shell directly works.  This:  print(getconflicts.split())   gives me:  ['pacman', '-Si', 'frameworkintegration', '|', 'grep', 'Conflicts', '|', 'awk', '-F:', "'{print", "$2}'"]   I'm kinda new to python and subprocesses in python even more, so do you have a hint on how to do that correctly?

How do I execute the following shell command using the Python  module?  echo "input data" | awk -f script.awk | sort > outfile.txt   The input data will come from a string, so I don't actually need echo.  I've got this far, can anyone explain how I get it to pipe through sort too?  p_awk = subprocess.Popen(["awk","-f","script.awk"],                           stdin=subprocess.PIPE,                           stdout=file("outfile.txt", "w")) p_awk.communicate( "input data" )   UPDATE:  Note that while the accepted answer below doesn't actually answer the question as asked, I believe S.Lott is right and it's better to avoid having to solve that problem in the first place!


I could have sworn this story was by James White, but I can't ID it if it is.    Basic premise, story opens with a guy waiting for a starship to arrive.  It had been sent out decades before as part of a search to track down an alien race that had left traces on an extra-solar planet.  This was the only race we had found evidence of.  All other ships had returned with no success.  This ship was the last.  Ship comes in, crew exits.  They either didn't find anything or they found the other race's home planet and they were extinct.  (Don't remember.)  Humanity is alone in the universe.  Only distinctive element I recall is one of the crew had memorized the Bible during the round trip.

I think this grim little short story is by Lester del Rey, but I'm not sure. I'm pretty sure it was published in the 1940s/50s.   The story: Earth's very last starship is coming home after searching the galaxy for life. Exploration began with high hopes due to the discovery of a Martian civilization which, for reasons unknown, died out. The crew of this last starship, however, has discovered what the Martians discovered; life is a freak that exists on only Earth and Mars - there is no life anywhere else in the Universe. The Martian race lost its will to live after that, and now it seems the same is going to happen to humanity.


Here is how it appears in "rendered view":   Here it is when rendered:

Anyone knows why the preview (left bottom) looks different than the render (bottom right)?  What i tried to achieve is something like   i dont know what is going on?!


I got a computer from my office and ordered IT to wipe it all from Windows OS. Now how can I get Ubuntu OS on this computer?

I would like to see a full how-to guide on how to install Ubuntu.


Iam trying to solve this problem , i can visualize graphically it is not possible. iam trying to do the proof by contradiction. if f:(0,1) to [0,1] is a continuos onto function  then i have to prove that f can never be 1-1 . so iam letting that if f is 1-1 then either f is strictly increasing or strictly decreasing function. so case (1) if f is strictly increasing function then there exits some t in (0,1) such that f(t)=0 , so for x lesser than t f(x)k , f(x) <0 which is also not possible .so f can't be 1-1 . My method is right ??? is there is any alternative approach then plz tell

Does there exist a continuous bijection from $(0,1)$ to $[0,1]$? Of course the map should not be a proper map.


I am refreshing my page every 25 seconds using Javascript.But another Javascript for click function works fine before page refresh whereas after page refresh it doesnot work.  HTML:

     //Set of Functions      Play Now!

   Javascript:        Before refresh, link opens in new window whereas after execution of refresh script, link opens in new tab instead of new window.

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


What happens when you delete the entire C:/Users/Username/AppData folder?  I haven't used my Windows boot in a while and want to make space on my harddrive. But if I decide to use Windows again, I don't want all the programs to be broken.  I don't care if the program settings return to defaults, but I'd like to keep my Firefox and Chrome saved passwords on the Windows boot.

Well well well...my computer keeps on eating whatever free space is available in the hard drive. It doesn't care whether the free space is in kb,KB,MB or GB. It happens only in the C drive where my OS & other program files are installed.  I used a software Windir Stat or something like that (I don't remember the name exactly) to analyze the usage of space by various programs.  In my C drive, there's a folder named AppData with loads of useless files. I don't know whether they are useful or not? Are they useful?  I was thinking about deleting the contents of that folder. I visited  for more info. WHich folder should I delete???


In my addon (Blender 2.8) I would like to have a hotkey that changes the value of a Property (to be exact: a BoolProperty which is a part of a PropertyGroup). I have found a way of doing this for an Operator, but I can't figure it out for the Property. Properties  as a possible space_type for new keymaps, but it wasn't enough info to get me going. How can I achieve this? The code I have right now does not work (i.e. the hotkey 1 is not executed): import bpy  class FP_PT_user_panel(bpy.types.Panel):     bl_idname = "FP_PT_user_panel"     bl_space_type = "VIEW_3D"     bl_region_type = "UI"     bl_label = "Test Prop"      def draw(self, context):         layout = self.layout         col = layout.column(align=True)         col.prop(context.scene.brush_properties, 'is_smooth_brush', text='[1]Smooth brush', toggle=True, icon="BRUSH_SMOOTH")   class BrushProperties(bpy.types.PropertyGroup):     def smooth_brush_handler(mod, context):         # some other stuff here #          for a in [a for a in bpy.context.screen.areas if a.type == 'VIEW_3D']:             a.tag_redraw()      is_smooth_brush: bpy.props.BoolProperty(default=False, update=smooth_brush_handler)   addon_keymaps = [] classes = (     FP_PT_user_panel,     BrushProperties, )   def register():     for cls in classes:         bpy.utils.register_class(cls)      bpy.types.Scene.brush_properties = bpy.props.PointerProperty(type=BrushProperties)      kcfg = bpy.context.window_manager.keyconfigs.addon     if kcfg:         km = kcfg.keymaps.new(name='3D View', space_type='VIEW_3D')         items = []         addon_keymaps.append((km, items))         kmi = km.keymap_items.new("wm.context_toggle", type='ONE', value='PRESS')         kmi.properties.data_path = "scene.brush_properties.is_smooth_brush"         items.append(kmi)   def unregister():     for cls in classes:         bpy.utils.unregister_class(cls)      km, items = addon_keymaps.pop()     for i in items:         km.keymap_items.remove(i)     addon_keymaps.clear()      del bpy.types.Scene.brush_properties   if __name__ == "__main__":     register()

I have a self made checkbox in a script. Now I want to create a hotkey in the Input manager to toggle it.  What I have done so far is to create a keymap item with wm.context_toggle. But I cannot get the Context Attribute to work. I grab the one from my script, the Python term in the tooltip. Which is WindowManager.deselect_bool and with that I get an error that the "Object has no attribute WindowManager".  What is the proper Context Attribute term here? Is it even possible to do it this way? If not, what is the proper way to assign a toggle hotkey for my custom checkbox?  Script:  import bpy from bpy.props import BoolProperty  class LayoutDemoPanel(bpy.types.Panel):     bl_label = "Demo Panel"     bl_space_type = 'VIEW_3D'     bl_region_type = 'UI'      def draw(self, context):         layout = self.layout          wm = context.window_manager # Our bool is in the windows_manager         layout.prop(wm, "deselect_bool") # Our checkbox  def register():     bpy.types.WindowManager.deselect_bool = bpy.props.BoolProperty(     name="Checkbox", description="A checkbox", default = False)     bpy.utils.register_module(__name__)  def unregister():     del bpy.types.WindowManager.deselect_bool # Unregister our flag when unregister.     bpy.utils.unregister_module(__name__)  if __name__ == "__main__":     register()


I tell a story to a friend. I want to say that I was in Rome for the third time. Do I need to use be or go? I know the difference like in this example:  - She has just been to the shop. She brought some cakes. (she is here now)  - She has just gone to the shop. She will back soon. (she is not here now)  I get confused when it happened in the past. Could anyone help me? Thank you.  The question is about the two sentences:      It was the third time I had been to Rome   or      It was the third time I had gone to Rome.   I speak in the  past. I tell the story from a past point of view. In the past I wasn't back when I spoke. What does that change? What is the meaning of the two forms?

Both are in the present perfect, but one uses the verb 'to go' and the other 'to be'. Is there a rule for this?  Is there any chance that the differences between "I have been" vs. "I have gone", are differences in English dialect (I don't know if this is the right word).  Edit Could I say that North American English speakers use "I have gone", and maybe U.K speakers say "I've been"? Or vice versa.


I was trying to simulate an animation of fluid flowing from one cup to another, but after baking the domain, there is this strange shape that stretch all the way out of the cup, and I wasn't sure what had caused it.  Tried turning up the resolution but the domain still stretched far off the cup into a line or something. Please help?   Screenshots:      Thanks :)

Here you can see an animation of my fluid sim. The inflow is that small black circle.    For some reason, the fluid flows in from the space between the inflow and one edge of the domain...    Here are a couple other views showing the domain and inflow windows.      How might I go about fixing this?  Additional notes:    I get "No active UV layer found in the object" when I bake via the render panel (not when I bake via the physics panel). I don't know if this is significant or not. Object scales are all at 1.0x, 1.0y, 1.0z.


Suppose to draw a sample of $n$ observations from $X \sim \mathcal{N}(0,\sigma)$, with observations outside the interval $(-c,+c)$ censored; $c$ is known and one can conveniently set $c=1$, for example.   If $m$ observations are $x_1,x_2,...,x_m$, and the other $n-m$ observations in the sample are censored, which is the ML estimator for $\sigma$ (or any other good estimator for it, giving priority to a closed form solution than to efficiency)?

In general we maximize a function   $$ L(\theta; x_1, \ldots, x_n) =  \prod_{i=1}^n f(x_i \mid \theta) $$  where $f$ is probability density function if the underlying distribution is continuous, and a probability mass function (with summation instead of product) if the distribution is discrete.  How do we specify the likelihood function if the underlying distribution is a mixture between a continuous and a discrete distribution, with the weights on each depending on $\theta$ ?


I reviewed a post in the Super User First Post queue and thought it sounded familiar.  I searched for the subject and found a previous post with the same question.  I then  added a comment recommending they search for previous questions and gave them a link to the duplicate question and answers.  Since the audit changed the name of the user, there was no way for me to know otherwise.  So why would I fail then?

I recently received this rather amusing message while reviewing a user's first post:  Congratulations! This was only a test, designed to make sure you were paying attention. This post has already been removed, but thanks for taking time to leave feedback for the author.   What is the purpose of this test? How does the audit work? What happens if I fail? Why was the system expecting me to negatively review a good post, or positively review a bad post? A review is obviously an audit. Should I report it? Do review audits count toward the Reviewer badge? Do robo-reviewers dream of electric sheep?


Is there any example of a function which is discontinuous on $\mathbb{R}$

Do you know examples of nowhere continuous functions, besides the Dirichlet function and its modifications?


I'm building a lighting fixture using big led panels.   The LED panel says it requires 7 amps @ 12 volts, but the power supply I have is only rated to 4 amps @12 volts.   What will happen? Will it damage the power supply, or just not light up all the way?

Power supplies are available in a wide range of voltage and current ratings.  If I have a device that has specific voltage and current ratings, how do those relate to the power ratings I need to specify?  What if I don't know the device's specs, but am replacing a previous power supply with particular ratings?  Is it OK to go lower voltage, or should it always be higher?  What about current?  I don't want a 10 A supply to damage my 1 A device.


If a indestructible creature is a 3/3 and I block that creature with a 2/2 then I give the indestructible creature a -1/-1 will the indestructible creature die?

Can I hit a 4/4 indestructible creature with a  (3 damage) and give it -1/-1 with  to kill it? (Does it matter which way around I cast those?)  I read  here and it says, damage is removed in cleanup step, so it should be on the creature still after both spells.     702.12. Indestructible   702.12a Indestructible is a static ability.   702.12b A permanent with indestructible can’t be destroyed. Such permanents aren’t destroyed by lethal damage, and they ignore the state-based action that checks for lethal damage (see rule 704.5g).   702.12c Multiple instances of indestructible on the same permanent are redundant.


When I call the constructor, the program gets a StackOverflowException.  public class User{     public User(string email, string pass){         this.email = email;         this.pass = pass;      }     public string email{         get => email;         set => email = email;     }     public string pass{         get => pass;         set => pass = pass;     } }   Process is terminating due to StackOverflowException.

I know java and would normally put in getter/setter methods. I am interested in doing it in C# with the following code, but it throws a StackOverflow exception. What am I doing wrong?  Calling Code  c.firstName = "a";   Property Code    public String firstName; {     get     {         return firstName;     }     set     {         firstName = value;     } }


A non-profit organization is selling tickets to an event. I suggested they add an opportunity to make a tax-deductible donation line along with the ticket purchase, like:     2 Tickets .... $45      Make a donation!      Your tax deductible donation blah blah      Suggested donation       [$10] [$20] [$50]   They liked the idea but insist that the buyer fill in a dollar amount instead of clicking the suggested amounts cause     Its not about what is easy. Its about stewardship of relationships and   this is not the place to make a formal "ask". We're simply offering   the opportunity in case they have the money or the inclination to   donate to us.   I don't understand their point. From a "sales" point of view, I would think being able to just click a button is more enticing while entering a value is just more work on the user's part.

A coworker forwarded me some feedback she had come across during an annual giving network discussion regarding website design for online giving websites:     I'm jealous of this  even better is their main page  which features not a click to give button, but rather, a box to start writing in the amount of your gift!    On our own website, we have a prominent "Donate" button that brings users to a form, which starts with an introduction about what the donation will be used for.  Additional fields on the form make it clear to the donor the level of control they have over what the donations would be earmarked for.  I'm concerned that if we implemented a system where the dollar amount was the first thing entered, before any context would be given, that no matter how convenient it seemed, it might discourage potential donors.  It would also seem to eliminate the possibility of upselling to a larger donation amount, if the first step is to put the amount of the donation.  Is it better to start with a dollar amount, or provide more context for the donation before asking for a specific amount?  Will one strategy yield a higher conversion rate, or potentially a higher donation amount?   If it is relevant, our donor demographic is generally affluent senior citizens, with very few of our donors being under the age of 50.


I need to prove the following fact: if $L$ is a finite-dimensional Lie algebra over field of characteristic $0$, $Rad(L)$ is its radical, and $N$ is the maximal nilpotent ideal in $L$, then $[L,Rad(L)] \subseteq N$. It's obvious that $[L,Rad(L)]$ is a solvable ideal in $L$, but I can't see how to prove its nilpotency. I found a proof in Bourbaki's book, but it's rather long and uses representation theory. Is there an easier way to prove it?

Suppose L is a finite dimensional Lie Algebra over an algebraically closed field of characteristic zero. I want to show that $[L,rad(L)]$ is nilpotent.  I was given a hint that all operators of the form $ad_{[L,rad(L)]}(x)$ are nilpotent which proves this result via Engel's Theorem. I am, however, unclear on how one shows this. I assume Lie's Theorem is used, but I can't figure out how.


I have a site where some pages are "virtual".  The path is :   internal_node/XYZ   where  * internal_node/% is defined in a hook_menu() * XYZ is a number  my "internal_node" callback  call an external service using XYZ like argument, get soma data and display this data to the user. All works without problem. And all is legal.   Now I want to add all "interal_node" links to my google's sitemap.  I have installed xmlsitemap, but this module create a google sitemap for only all internal drupal node and my "internal_node" are not a drupal node.   So, how can I add link to xmlsitemap ?   Thanks.

I have a module with a page callback handler for the path "products". So if the user navigates to products/apples then the module presents a page about our apples, and if they go to products/oranges then etc. These pages include detail about the various products.  I would like XML Sitemap to be populated from my module. After all, it's my module that knows what products exist, their descriptions etc.  Any hook or anything I can use for that?


Imagine a wedding invitation which ends with the following sentence:     To round off the weekend celebrations, please join us for lunch.   Would it be more, less, or equally correct to say:     To round off the weekend's celebrations, please join us for lunch.

In the following is it better to use a possessive noun with an apostrophe or an attributive noun without an apostrophe?     The following list details the assumptions that have been made in   conjunction with the Dell Company’s staff.   Or      The following list details the assumptions that have been made in   conjunction with the Dell Company staff.   Assume Company is the name of a company, such as Dell.


So, I've been playing minecraft for a while. I stopped playing for a few weeks, and when I get back on in singleplayer creative and in servers it sometimes lets me break blocks and sometimes doesn't.   Why is it doing this? And how can I fix it? I've tried everything I can think of. Resetting my laptop, relogging into minecraft, moving sensitivity up. I don't know what else to do, and yes, my controls are correct. It's left click to break a block. But sometimes it will break and sometimes not.

I'm playing on a Survival world with cheats on, "easy" difficulty, and at night in-game. I didn't have a sword or anything to make a sword with, and I was starving, so I switched to Creative to give myself a stack of food and a bed to set my spawn point. When I switched back to Survival, I couldn't destroy or place blocks. I'm on single player, and my Internet is fine, and I can destroy blocks still if I switch to creative. I've tried resetting the button one, and reloading the map, and it still doesn't work. I've even tried deleting everything I gave myself in Creative. This happened before on a different world and I ended up deleting it.  This only happens on this world. How do I fix it?  If I know I'm in the correct game mode, what else can cause this?  Are there different causes in multiplayer?


I have created an ItemAdded event receiver that is supposed to process new documents/files after they've been added to any document library in the farm - i.e., I'd like the event receiver to automatically monitor all document libraries across the farm, both already existing and those that will be created in the future.  The problem is, if I set the event receiver feature scope to "Farm", I get an error in VS2010 when I try to deploy:     The Project Item cannot be deployed through a Feature with Farm   scope.   How can I deploy event receiver for the entire farm, if possible at all? (Because if it isn't possible, that pretty much renders the entire concept of event receivers useless to me...).

For some security reasons on one of our farm level solutions, we need to limit some actions using Event Receiver-FileMoving event. However, as known, event receivers can be deployed only by Site or SiteCollection level features. Since the solution that provides the main functionality is on farm scope, we need to be able to apply this event receiver to each and every document library there is.  I thought of creating a site level feature for the event receiver, and then enable it on all sites via FeatureActivated event of the farm scoped feature. But it doesn't cover new sites being added after the feature is activated. And since there is no setting for Site level features to "default enable", it doesn't work.  Then I found out  event, where I can enable the feature as soon as it's added. But, from what I understand, it's also site(SPWeb) scoped, so new web applications and site collections are not covered.  So, any ideas how I can make a farm scoped solution to deploy FileMoving event throughout the farm?  Sharepoint 2010/2013 Enterprise edition


I have read that "it" is not used to refer to human, but I encountered the following within a grammar textbook without any explanation:  There's someone at the door. Can you go and see who it is?  Is it grammatically correct to use "it" to refer to people?

Your phone is ringing and your daughter picked up the phone but she hasn't answered the call. Then do you ask her:     Who is it?   or      Who are they?   And when she tells you, would she say:     I don't know who it is"   or     I don't know who they are?   If none of the above isn't natural, then what is it?


I'm having an issue with getting the correct character encoding for data being POSTed which is built up from multiple sources (I get the data as a single POST variable). I think they're not in the same character encoding...  For instance, take the symbol £. If I do nothing to the character encoding I get two results:  a = Â£ and b = £  I've tried using various configurations of iconv() like so;  $data = iconv('UTF-8', 'windows-1252//TRANSLIT', $_POST['data']);   The above results in a = £ and b = �  I've also tried utf8_encode/decode as well as html_entity_decode, as I think there's a possibility that one of the pound symbols are being generated using html_entities.  I've tried setting the character encoding in the header which didn't work. I just can't get both instances to work at the same time.  I'm not sure what to try next, any ideas?

I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1.  Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur?  This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2.


I want to write this belongs to symbol in latex like this  x belongs to R^M. that you normally see in papers. Suggestions?

I know what my symbol or character looks like, but I don't know what the command is or which math alphabet it came from. How do I go about finding this out?


Could you please give a short explanation of whether there is a significant difference between the following thread implementations:  // Method 1 Thread aThread = new Thread() {     @Override     public void run()     {         // do some work     } };  aThread.start();  // Method 2       Thread bThread = new Thread(new Runnable() {     @Override     public void run()     {         // do some work     } });  bThread.start();   I tried to find similar questions in stackoverflow, but couldn't succeed. Sorry, if it is already discussed before.

From what time I've spent with threads in Java, I've found these two ways to write threads:  With implements Runnable:  public class MyRunnable implements Runnable {     public void run() {         //Code     } } //Started with a "new Thread(new MyRunnable()).start()" call   Or, with extends Thread:  public class MyThread extends Thread {     public MyThread() {         super("MyThread");     }     public void run() {         //Code     } } //Started with a "new MyThread().start()" call   Is there any significant difference in these two blocks of code ?


When I used INotify with /etc/mtab or /proc/mounts, it doesn't detect changes when things mount or unmount, even though /etc/mtab and /proc/mounts both have changed when I check manually. Why is this, and how can I track mounting and unmounting things?

I have written a small 'daemon' in bash that will switch to the headphones if they are detected, and if not, switch to an external USB speaker with PulseAudio.  What I'm looking for is some way to get notification of changes on the file /proc/asound/card0/codec#0, just like inotifywait does on real files (considering files under /proc to be as "pseudo-files").  I find my code a bit insane, because it runs sleep 1 with awk for the whole day, that is 86400 times a day :)  while sleep 1; do     _1=${_2:-}     _2=$(awk '/Pin-ctls/{n++;if(n==4)print}' '/proc/asound/card0/codec#0')      [[ ${_1:-} = $_2 ]] ||         if [[ $_2 =~ OUT ]]; then             use_speakers         else             use_internal         fi done   What I'm looking for is something like (this example doesn't work):  codec=/proc/asound/card0/codec#0 while inotifywait $codec; do     if [[ $(awk '/Pin-ctls/{n++;if(n==4)print}' $codec) =~ OUT ]]; then         use_speakers     else         use_internal     fi done   This way the commands inside the loop would be run only when there are real changes on the $codec file.


There are few different formats I have seen so far:   With quotes and brackets:  PATH="/usr/local/bin:${PATH}"  With quotes only:  PATH="/usr/local/bin:$PATH"  None:  PATH=/usr/local/bin:$PATH    Export all the same:  export PATH   Which is the correct/preferred way?

I'm wondering where a new path has to be added to the PATH environment variable. I know this can be accomplished by editing .bashrc (for example), but it's not clear how to do this.  This way:  export PATH=~/opt/bin:$PATH   or this?    export PATH=$PATH:~/opt/bin


I want to come out the back of a spigot at a 90 degree angle - e.g. from this , To this  However, when you screw the two all the way together, you'll end up with a (seemingly?) arbitrarily oriented elbow. That is, say for example a pipe was coming up from the bottom, but when you screwed the elbow to the spigot the elbow ended up pointing up, which wouldn't work. It would seem reasonable to be able to control the direction that you come out, How would you do this?

I'm an electrical engineer, working on repairing a somewhat complicated pneumatic system, but I figured this would probably be the best place to ask. This is probably a very basic question to anyone who works in plumbing, but I couldn't find anything about it online. When you have right-angle pipe fittings, the kind with NPT threads that you screw together, how do you control what angle they screw in to? If you just screw two things together, the relative angle between them will be essentially random as it depends on the exact angle of where the thread starts and how far the threads engage. But we need to put in pipe at specific angles to align fittings to other parts of the system, so how does one actually do that?


Show that the following integral: $$ \int_{-\infty}^{\infty} \frac{1}{x^4 + 1} \,dx = \frac{\pi}{\sqrt{2}}. $$ I know this is $\pi/\sqrt{2}$ which I was found with Mathematica. I think I could utilise the substitution $t = x^2 + 1$ or $t = 1/x$, but I can't seem to make an approach because the integral is quite different from what I have been dealing with. Is there a better approach?

Can anyone give me a hint to evaluate this integral?  $$\int_0^\infty \frac{dx}{1+x^4}$$  I know it will involve the gamma function, but how?


I have this code which gets the current date and converts it to word format.  import datetime  days={'0':'Monday','1':'Tuesday','2':'Wednesday',       '3':'Thursday','4':'Friday','5':'Saturday',       '6':'Sunday'}  months={'1':'January','2':'February','3':'March','4':'April',         '5':'May','6':'June','7':'July','8':'August',         '9':'September','10':'October','11':'November','12':'December'}  currentDay=datetime.date.weekday(datetime.datetime.now()) currentMonth=datetime.date.today().month currentDate=str(datetime.date.today().day) if currentDate[:1]=="1":suffix="st" elif currentDate[:1]=="2":suffix="nd" elif currentDate[:1]=="2":suffix="rd" else:suffix="th" dateString=("{} the {}{} of {}".format(     days[str(currentDay)],currentDate,suffix,months[str(currentMonth)]))   output for today,  >>>Wednesday the 4th of January   how would I about turning a user input in the format DD/MM/YYYY to the word format?

This is my code:  import datetime today = datetime.date.today() print(today)   This prints: 2008-11-22 which is exactly what I want.  But, I have a list I'm appending this to and then suddenly everything goes "wonky". Here is the code:  import datetime mylist = [] today = datetime.date.today() mylist.append(today) print(mylist)   This prints the following:   [datetime.date(2008, 11, 22)]   How can I get just a simple date like 2008-11-22?


This is what I get when I hit render (I've now tried unselecting crop and boarder with the same result):    This is what I want to render:    This is the first time I've made something using blender however so I'm sure I'm making some basic mistake.  To be clear, in the pictures the rendered one is what I get whenever I hit render, the other picture is what I've "made" and am trying to get rendered to a PNG file but nothing I do or can find shows me how to get the whole image, and I keep getting the same small blurry square instead of the full scene pictured.  When I use camera view this is what I see which seems to be the source of the problem:

Often I want to just point the camera to an object or a specific area in my scene to get an idea of how it'll look in the render. What's the most painless hassle-free way to do this in blender?  A quick search on the blender wiki does not lend itself to easy look-up due to all the noise in the search result.  This question could probably be broken down into these two main questions:   How do I point a selected camera to the current 3d-cursor location in the scene? How do I point the selected camera to the currently selected object(s) in the scene?


firstly I cloned my own repo from github, because i wanna amend the last commit, so i type "git commit --amend" and push to github, but some errors occur. Some guys said that the operation doesn't allowed by github, unless make another commit, Is that true?  and how can i amend the last commit on github?

When I've worked a bit with my source code, I did my usual thing commit and then I pushed to a remote repository. But then I noticed I forgot to organize my imports in the source code. So I do the amend command to replace the previous commit:  > git commit --amend   Unfortunately the commit can't be pushed back to the repository. It is rejected like this:  > git push origin To //my.remote.repo.com/stuff.git/  ! [rejected]        master -> master (non-fast forward) error: failed to push some refs to '//my.remote.repo.com/stuff.git/'   What should I do? (I can access the remote repository.)


I have configured dovecot and postfix...Email server works fine.. (Webmail and outlook both works..)  I have created users using unix command ..  usreadd -s /sbin/nologin myuser   But i have a concern, if i want to login to webmail or outlook I have to use myuser instead of myuser@mydomain.com.  For the time being im using, only user name as below..    If i use myuser@mydomain.com it says its invalid user both webmail and outlook..  I tried googling .. no luck.. yet.. kindly some one please shed a light..   10-master.conf is   #default_process_limit = 100 #default_client_limit = 1000  # Default VSZ (virtual memory size) limit for service processes. This is mainly # intended to catch and kill processes that leak memory before they eat up # everything. #default_vsz_limit = 256M  # Login user is internally used by login processes. This is the most untrusted # user in Dovecot system. It shouldn't have access to anything at all. #default_login_user = dovenull  # Internal user is used by unprivileged processes. It should be separate from # login user, so that login processes can't disturb other processes. #default_internal_user = dovecot  service imap-login {   inet_listener imap {     #port = 143   }   inet_listener imaps {     #port = 993     #ssl = yes   }    # Number of connections to handle before starting a new process. Typically   # the only useful values are 0 (unlimited) or 1. 1 is more secure, but 0   # is faster. <doc/wiki/LoginProcess.txt>   #service_count = 1    # Number of processes to always keep waiting for more connections.   #process_min_avail = 0    # If you set service_count=0, you probably need to grow this.   #vsz_limit = 64M }  service pop3-login {   inet_listener pop3 {     #port = 110   }   inet_listener pop3s {     #port = 995     #ssl = yes   } }  service lmtp {   unix_listener lmtp {    # mode = 0666   }    # Create inet listener only if you can't use the above UNIX socket   #inet_listener lmtp {     # Avoid making LMTP visible for the entire internet     #address =     #port =    #} }  service imap {   # Most of the memory goes to mmap()ing files. You may need to increase this   # limit if you have huge mailboxes.   #vsz_limit = 256M    # Max. number of IMAP processes (connections)   #process_limit = 1024 }  service pop3 {   # Max. number of POP3 processes (connections)   #process_limit = 1024 }  service auth {   # auth_socket_path points to this userdb socket by default. It's typically   # used by dovecot-lda, doveadm, possibly imap process, etc. Its default   # permissions make it readable only by root, but you may need to relax these   # permissions. Users that have access to this socket are able to get a list   # of all usernames and get results of everyone's userdb lookups.  # unix_listener auth-userdb {  #   mode = 0600  #   user = postfix  #   group = postfix  # }     #Postfix smtp-auth   unix_listener /var/spool/postfix/private/auth {   mode = 0666   user = postfix   group = postfix   }    # Auth process is run as this user.   #user = $default_internal_user }  service auth-worker {   # Auth worker process is run as root by default, so that it can access   # /etc/shadow. If this isn't necessary, the user should be changed to   # $default_internal_user.   #user = root }  service dict {   # If dict proxy is used, mail processes should have access to its socket.   # For example: mode=0660, group=vmail and global mail_access_groups=vmail   unix_listener dict {     #mode = 0600     #user =      #group =    } }   Results for  dovecot -n  # 2.0.9: /etc/dovecot/dovecot.conf # OS: Linux 2.6.32-042stab093.4 x86_64 CentOS release 6.6 (Final) auth_mechanisms = login plain disable_plaintext_auth = no mail_location = maildir:~/Maildir mbox_write_locks = fcntl passdb {   driver = pam } service auth {   unix_listener /var/spool/postfix/private/auth {     group = postfix     mode = 0666     user = postfix   } } ssl_cert = </etc/pki/tls/certs/mycert.crt ssl_key = </etc/pki/tls/private/mycert.key userdb {   driver = passwd }

I have Dovecot v2.0.11 installed on a FreeBSD server and the user lookups for incoming email addresses are failing, but lookups for system users is successful.  Dovecot is setup to use system users, so my dovecot.conf has   userdb {   driver = passwd }   and  passdb {   driver = passwd }   I have auth debug enabled.  For example, I have a user called webmaster, and using doveadm user for "webmaster" works as follows:  #doveadm user webmaster userdb: webmaster   system_groups_user: webmaster   uid       : 1020   gid       : 1020   home      : /home/webmaster   However using doveadm user to lookup webmaster@myregisteredname.com fails as follows:  # doveadm user webmaster@myregisteredname.com userdb lookup: user webmaster@myregisteredname.com doesn't exist   This is resulting in incoming mail for webmaster@myregisteredname.com to bounce with an "unknown user" error.    Here's the failure logged in /var/log/maillog:  Apr 16 20:13:35 www dovecot: auth: passwd(webmaster@myregisteredname.com): unknown user   Here's the failure logged in /var/log/debug.log:  Apr 16 20:13:35 www dovecot: auth: Debug: master in: USER       1       webmaster@myregisteredname.com  service=doveadm Apr 16 20:13:35 www dovecot: auth: Debug: passwd(webmaster@myregisteredname.com): lookup Apr 16 20:13:35 www dovecot: auth: Debug: master out: NOTFOUND  1   The users and their home directories were imported from another server and the users were setup using the vipw tool.  I'm sure there's someting I missed on the import that's not "linking" the system user with the dovecot lookup.    Any ideas about what that something may be?  EDIT: Using BillThor's advice, I updated dovecot.conf as follows:  #doveconf -n passdb userdb passdb {   args = username_format=%n   driver = passwd } userdb {   args = username_format=%n   driver = passwd }   However, now, doveadm user fails in a different fashion:  #doveadm user webmaster@pantronx.com doveadm(root): Error: userdb lookup(webmaster@myregisteredname.com): Disconnected unexpectedly doveadm(root): Fatal: userdb lookup failed for webmaster@myregisteredname.com   And, it no longer works for users without a domain:  #doveadm user webmaster doveadm(root): Error: userdb lookup(webmaster): Disconnected unexpectedly doveadm(root): Fatal: userdb lookup failed for webmaster   When I get the above messages, the following is in /var/log/maillog:  Apr 17 17:30:02 www dovecot: auth: Fatal: passdb passwd: Unknown setting: username_format=%u Apr 17 17:30:02 www dovecot: master: Error: service(auth): command startup failed, throttling


I have seen that when we make some search in google there is a left display of information sometimes in a box in Google. Please what Meta enables the left display of information on google like in the picture below  ?

What I am referring to is say you search for . You can see on the sidebar of the results page all of the company's wiki information.  My current website does not show my company's wiki page. I am trying to figure out if there is a certain time limit for Google to show the wiki page or if some other validation is required for it to show that is documented?


Logo and image on the same row.But padding top only the issue.Check the fiddle.
Twitter
   The issue is the text below the image. So I want to place into the middle of the image. Padding style not working on that

Why won't vertical-align: middle work?  And yet, vertical-align: top does work.   span{   vertical-align: middle; }
      Doesn't work.


Let $\varphi: M_2(\mathbb{Z})\to \mathbb{Z}$ be a ring homomorphism. Then $\varphi$ is necessarily trivial.  My reasoning:  Suppose not. Then $\varphi(I)=1\implies \forall A\in M_2(\mathbb{Z}),\exists A^{-1}\in M_2(\mathbb{Z})$ such that $\varphi(I)=\phi(A)\phi(A^{-1})=\phi(A)\phi(A)^{-1}=aa^{-1}$. However, only $1$ and $-1$ have multiplicative inverses in $\mathbb{Z}$. Hence, if $A\ne I$, then $\phi(A)^{-1}$ may not exist. This implies that $\phi$ must be trivial (that is, map everything to $1$). [For if $\phi(A)=0$ for all $A\ne I$, then $\phi(A)^{-1}$ admits division by $0$].  Do you think this is correct?

I have the following problem:  Is it possible to construct ring homomorphism from $M_2(\mathbb Z)\to \mathbb Z$, or in other words, a homomorphism from ring of all $2\times2$ matrices over the integers into integers?  I tried determinant, trace and mapping that maps matrix to it's element in the position $(1,1)$ but none of that obviously works, which led me to believe there might not be such a homomorphism. Determinant doesn't work because it is obviously not a linear map.  Trace doesn't work because it doesn't respect multiplication.  And the mapping to the position $(1,1)$ also doesn't work because $$\begin{pmatrix}1&1\\1&1\end{pmatrix}\begin{pmatrix}1&1\\1&1\end{pmatrix}=\begin{pmatrix}2&2\\2&2\end{pmatrix}.$$


I noticed this minor UX bug on the ongoing : Each candidate in an SE election page has three buttons next to their candidacy - 1st choice, 2nd choice and 3rd choice. However, the Open Source SE elections just have two candidates, so having a "3rd choice" doesn't serve any useful function.  Definitely not the most important bug in the world, but I figured I might as well report it.  Screenshot:

There are two candidates in the . There are still buttons for three choices. Since it's single transferable vote, you don't actually need the second or third choices, but this isn't terribly obvious from the page, given that the buttons are still there, and the help on the side says you have three votes.  Mostly this is just a little ugly, but it might be more friendly if it dealt with it, especially for any relatively new users voting in their first moderator election!


ETFs trade just like stocks, so I wonder how come questrade lets customers trade ETFs for free whereas they charge commission on stock trading? Any guesses? Furthermore, only buying is free but selling is not, which is all the more confusing.  Do they mark up the spread? Or are ETFs so liquid that the broker can afford not to charge a fee. I can ask the broker of course, but usually they say 'customer loyalty, customer appreciation etc.' and things like that.

I just noticed TD Ameritrade has program where you can trade from a list of ETFs with zero fees.  Sounds like it could save me a bit of money, but my cynical side wonders how they make money off such a program...  Is it a loss leader? (They entice me to have an account there, and then make money off the other trades I make?)  Or do they simply want to grow the size of their asset base -- what is the mechanism by which they make money on the funds that I have in my account?  Edit: in case it wasn't clear in the original question above, this is an ongoing program for free ETF transactions -- not a one-time deal for some number of free trades when you open an account. I have had an account there for years and I'm eligible to participate -- it's not a program explicitly designed just to gain new accounts.


For example, I believe the following to be acceptable:  "I've had no issues in the past with this client"  However, the following is what I'm unsure of:  "I've $16 in my bank account."  I've definitely heard this before (though admittedly very rarely). Is this wrong? Or is it acceptable? If acceptable, is it considered to be informal? What dialect is this from primarily?

I feel uncomfortable saying sentences like the following:    "I've a car" instead of "I have a car" "They've a great time" instead of "They have a great time" "He's a pen" instead of "He has a pen" etc   I ask this because I read this sort of thing in a book.  Are they correct? And what is the rule? Can you use such forms in a formal setting?


On stackexchange.com there is a .  Except that the list does not include all sites.  Today I was reminded of , which is not listed there.  I had forgotten about this site.   is not listed there either, but that's not a Q&A site.  Which other sites exist that are part of Stack Exchange but not listed on stackexchange.com?

I wanted a list of sub-domains of Stack Exchange that are not mentioned over here   Some of the sub-domains I found which were not mentioned are       Are there any other which are not mentioned?    Mentions by , ,             Other mentions below which are not mentioned in "All Sites" but are mentioned in the drop down menu on the top left of the Stack Exchange website         Any other website that's left out ?


I'm on a ship in the Canadian Arctic and trying to link up to a wireless network that has been set up on a Windows 7 laptop, this is connected to the satellite system.  My MacBook Pro shows the signal under device when I click on the wireless symbol on the top right tool bar.  When I click on it and it connects with a check mark, all I get at the top is a greyed out computer network icon symbol.  What do I need to do under wireless network connections to make this work?  Here a couple of pics to show you what I am looking at.enter image description here  Thanks, Captain Marc

I'm trying to share my wired ethernet connection from my Windows 7 laptop with my MacBook Pro (running 10.6.5). I've just set it up to be an open network; no encryption. I'm pretty sure I set up the ad hoc network correctly, it's broadcasting, and I can connect to the network on the mac.   The catch is that the network shows up under the "Devices" part of the menu, rather than the main networks area. I can't browse to any websites, nor connect to the Windows box via samba. The IP assigned is a 169.254 one.  Is there some setting somewhere that I missed to get this to work correctly? Do I need to manually set this up some how? Here are my network settings:


I walk into a store and ask the clerk: "Do you have any diet Dr Pepper?" The clerk answers, "We have regular Dr Pepper."  Searching for a description of this type of response, I've found a lot of material on question dodging. But in this case, the respondent doesn't intend to dodge the question or avoid answering it.   I repeat, this isn't question dodging, evasion, or obfuscation like a politician might engage in. In those cases, the politician doesn't want to answer the question, and knows he isn't answering the question.  In this case, the respondent knows the answer to the question, and thinks he is providing it sufficiently. In his mind, his response logically implies an answer to the question posed, but that logic is bad/does not follow.    I find this type of answer extremely annoying. Basically the respondent is implying an answer to my question and making me decode his response, when he could instead just answer my question directly. The problem with this type of response in general is that I would be expected to take future actions/make future decisions as if I have the information I requested, when I really don't.  Descriptions of this type of answer that I've found are "non-answer" and "non-response," but I was just wondering if there was an explicit name for this horrible communication tic.

Take an example:  Me : Where can I find the best pizza in the city?   Friend:1000s of people are dying of hunger and all you care about best pizza.  In this case he does reply to my question but it doesn't help me.  Is there a word/group of words to express this?


I have a command like python abc.py -p 'File Path' -c 'File path'.

I want to know if I can pass an argument with an alias command.  for example:  alias d="dmesg|grep -iw usb|tail -5"    Now d will print the last 5 lines. If I want to use d to print a different number of lines, I have to make change in the alias command declaration of d again.  Is there any way I can modify the declaration of an alias so that I don't have to retype the declaration to change the number of lines. Like incorporating passing the number of lines as an argument while declaring alias for d? Or is there some other method to solve this?


I'm trying to run GParted, but it says that I need root privileges. How do I get them for Ubuntu 15.10?

I installed gparted to use for partitioning my hard drive so ubuntu is my only os but when I tried to run gparted, it told me that i have to be root but i am root as far as i know how do i know for sure i haven't even signed on as guest because i am still setting stuff up most other apps ask for confirmation i type in my password and on i go but gparted doesn't have that prompt how do i become root


Suppose that two inertial reference frames 'A' and 'B' are moving relative to each other with a constant velocity. According to special relativity, from the frame of 'A', time runs slowly for 'B'. But from the frame of 'B', time actually runs slowly for 'A'! What's happening here?Isn’t this an apparent contradiction? What am I missing? As far as I am concerned, there was a philosopher named Herbert Dingle who asked this same question in the lifetime of Einstein. I have been surfing the internet for a couple of days, but still hadn’t find any satisfying answer. No textbook seems to address this question! Note that it is different from the so called 'Twim paradox'. There is no acceleration involved here.

Suppose we have two twins travelling away from each other, each twin moving at some speed $v$:    Twin $A$ observes twin $B$’s time to be dilated so his clock runs faster than twin $B$’s clock. But twin $B$ observes twin $A$’s time to be dilated so his clock runs faster than twin $A$’s clock. Each twin thinks their clock is running faster. How can this be? Isn’t this a paradox?


First, I use TeXstudio and I have MikTeX 2.9.    I tried to make TeXstudio automatically install it but it gives me an error saying it cannot find polynom.sty. At this point I go around the internet trying to find a solution and I find it. In a few words, I have to install the package manually by first downloading the files from CTAN, which I did, and then open the two files .dtx and .ins with my editor and compile them, which I did but that gives me this error:    Could not start Default Compiler:PdfLaTeX:   pdflatex.exe -synctex=1 -interaction=nonstopmode "polynom".tex.     I also ended up with a texput.txt saying this:    This is pdfTeX, Version 3.14159265-2.6-1.40.16 (MiKTeX 2.9) (preloaded format=pdflatex 2016.4.15)  28 MAR 2017 15:30   entering extended mode   **polynom.tex  ! Emergency stop.   <*> polynom.tex  *** (job aborted, file error in nonstop mode)   Here is how much of TeX's memory you used:   2 strings out of 493634   17 string characters out of 3141299   52604 words of memory out of 3000000   3491 multiletter control sequences out of 15000+200000   3640 words of font info for 14 fonts, out of 3000000 for 9000   1025 hyphenation exceptions out of 8191   0i,0n,0p,1b,6s stack positions out of 5000i,500n,10000p,200000b,50000s !  ==> Fatal error occurred, no output PDF file produced!   I don't really understand what's the problem. Can someone help me?

I recently installed MiKTeX with the texmaker editor and cannot figure out how to update the packages. When I attempt to use the subfigure package with the following preamble  \documentclass[a4paper,12pt]{article} \usepackage[english]{babel} \usepackage{graphicx} \usepackage{subfigure}   I then get a prompt to install a new package, which I then set to the online directory at ctan. I then get the following error:   ! LaTeX Error: File `subfig.sty' not found.Type X to quit or <RETURN> to proceed,or enter new name. (Default extension: sty)Enter file name:! Emergency stop.<read >   How do I properly install packages to miktex? I'm absolutely confused. Thanks in advance for any help.


I am trying to identify tenses from complex sentences. but I am not sure what counts as a tense. so my question is probably: What counts as a tense? what is the bare minimum for something to be called a tense? can it exist without a subject? Thanks beforehand

Do we have 16 tenses in English?  With   future present past future in the past   in these forms   simple continuous perfect perfect continuous   Can we manipulate these together to create English tenses? For example, "present perfect" or "future perfect continuous"?


for a science project at university I have the task to create a web application based on Geoserver. The data is already stored, I have to visualize it now on the web for different users. Each user can only see certain layers.  I only have basic programming skills but experience in Drupal.   Would Cartaro be a good solution for this?

I want to start working on a web map at work to map some of our statistics by city.    I have an idea, but I'm not exactly sure where to start.   Are there any definitive resources that provide step by step guidance on how to do this?


I am using a Lenovo Legion Y720 laptop with a discrete GTX 1060 GPU. I can connect to an external monitor but there is no option to chose HDMI as output source for the speakers. Only the internal speakers are listed. I tried with a laptop without a discrete GPU and it worked. As far as I can see bumblebee is a dead project. What is the alternative for Nvidia Optimus now on Ubuntu 18.04? I am using the Nvidia proprietary drivers, version 390, but it has only caused me problems like overheating (90+ celcius), screen tearring and now this HDMI problem.

I am running kernel v4.13.0-36-generic on Ubuntu 17.10 on an HP Omen 15. I have a hybrid NVIDIA Optimus graphics card. I dual-boot Windows 10, which can play audio from the same external monitor over the same HDMI cable I am attempting to use in Ubuntu. I can see video on my external monitor in Ubuntu.  I have tried , but in the former no HDMI audio device appears, and in the latter all HDMI devices show up as unplugged.  I have had the most success using the proprietary nvidia-384 driver installed via the Additional Drivers tab of Software & Updates. Using this driver I am able to see video on my external monitor, play audio through my laptop speakers, and boot reliably.  I have tried using nvidia-387 and nvidia-390 from  with , but I can't even boot or see video on my external monitor reliably using these drivers. I observed that /etc/bumblebee/xorg.conf.nouveau and /etc/bumblebee/xorg.conf.nvidia detected my GeForce GTX 1050 Ti as a discrete graphics card, which I believe is incorrect, but am unsure how to override these settings to indicate that my graphics card is a hybrid.    I installed , but after rebooting was stuck in a boot loop, so I ran sudo nvidia-uninstall.      I disabled Secure Boot.  I tried using kernel v4.15.4, but only found it even more difficult to boot reliably.  I tried . I do not know how to switch from hybrid to dedicated graphics mode as the author of that solution suggests though, so that may be why it didn't work for me.  $ aplay -l **** List of PLAYBACK Hardware Devices **** card 0: PCH [HDA Intel PCH], device 0: ALC295 Analog [ALC295 Analog]   Subdevices: 1/1   Subdevice #0: subdevice #0 card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0]   Subdevices: 1/1   Subdevice #0: subdevice #0 card 0: PCH [HDA Intel PCH], device 7: HDMI 1 [HDMI 1]   Subdevices: 1/1   Subdevice #0: subdevice #0 card 0: PCH [HDA Intel PCH], device 8: HDMI 2 [HDMI 2]   Subdevices: 1/1   Subdevice #0: subdevice #0 card 0: PCH [HDA Intel PCH], device 9: HDMI 3 [HDMI 3]   Subdevices: 1/1   Subdevice #0: subdevice #0 card 0: PCH [HDA Intel PCH], device 10: HDMI 4 [HDMI 4]   Subdevices: 1/1   Subdevice #0: subdevice #0  $ lspci 00:00.0 Host bridge: Intel Corporation Xeon E3-1200 v6/7th Gen Core Processor Host Bridge/DRAM Registers (rev 05) 00:01.0 PCI bridge: Intel Corporation Skylake PCIe Controller (x16) (rev 05) 00:02.0 VGA compatible controller: Intel Corporation Device 591b (rev 04) 00:04.0 Signal processing controller: Intel Corporation Skylake Processor Thermal Subsystem (rev 05) 00:14.0 USB controller: Intel Corporation Sunrise Point-H USB 3.0 xHCI Controller (rev 31) 00:14.2 Signal processing controller: Intel Corporation Sunrise Point-H Thermal subsystem (rev 31) 00:16.0 Communication controller: Intel Corporation Sunrise Point-H CSME HECI #1 (rev 31) 00:17.0 SATA controller: Intel Corporation Sunrise Point-H SATA Controller [AHCI mode] (rev 31) 00:1c.0 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #1 (rev f1) 00:1c.4 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #5 (rev f1) 00:1c.5 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #6 (rev f1) 00:1c.6 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #7 (rev f1) 00:1f.0 ISA bridge: Intel Corporation Sunrise Point-H LPC Controller (rev 31) 00:1f.2 Memory controller: Intel Corporation Sunrise Point-H PMC (rev 31) 00:1f.3 Audio device: Intel Corporation Device a171 (rev 31) 00:1f.4 SMBus: Intel Corporation Sunrise Point-H SMBus (rev 31) 01:00.0 3D controller: NVIDIA Corporation GP107M [GeForce GTX 1050 Mobile] (rev a1) 03:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS522A PCI Express Card Reader (rev 01) 04:00.0 Network controller: Intel Corporation Wireless 7265 (rev 61) 05:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 15)   A big thank you to anyone who made it to this point. Any suggestions would be greatly appreciated.


Today one of our PCs got infected with nasty CryptoLocker trojan crap.  The PC was a Windows XP machine with up-to-date NOD32 a/v. As you probably know the virus encrypts your file with an 2048 bit RSA public key and only the bad guy has the private key. So... they ask for 1.16 BTC or 500 EUR as a ransom via TOR.  I glanced through google results I saw some of the resources mentioning that it encrypts the files and then deletes the original ones. So, is it possible to recover those deleted files using some recovery tools like "Recuva"? Maybe some Linux magic? Or have they thought of that too and the data loss is permanent?   Some of the search results say, that they could have left the private key behind in %appdata% folder or that kind of stuff, though I seriously doubt it :)  Please share your experience if you had that happen to you and you managed to recover or if you have any suggestions. Any help is appreciated!  PS. I can't physically access the machine as of right now as it didn't get shipped from branch office yet, so can't really try anything. Just want to prepare for the good or the bad.

My MS Office files and pdf files has been encrypted by some ransomware in my pc which was running window XP. I removed the ransomware,formated the OS and put windows 7, but my files are still encrypted. Is there any way of decrypting it as it very important files and i dont have a backup of these files. Some one pls help me out of this mess.


It seems to be forbidden (based on a meta question) but I don't see that in the Help. If it is, why?   Can this feature be added?

I don’t know if this is a bug or is this how the images work, hosted on imgur. It basically adds a query string. I added a profile pic as gif but it doesn’t work as how gif images work. If I goto the image url it works fine.  My Profile:   Image URL on profile:   Actual animated image Url without Query String (working):   Is this how images hosted on imgur work or is this something else?


How to get these details:  I have tried to get this by following method FirebaseAuth firebaseAuth = FirebaseAuth.getInstance(); long joineDate = firebaseAuth.getCurrentUser().getMetadata().getCreationTimestamp(); String joined_on_date = String.valueOf(joineDate); joined_on.setText(joined_on_date);  But that looks like this:  So how to display it in date format No the question linked doesent answer my question when I get those date from firebase it shows some random numbers which I dont know in which form it is.

How to format correctly according to the device configuration date and time when having a year, month, day, hour and minute?


I am using Opera 37.0 on Ubuntu 15.10 (64 bit). Opera shows that the Flash Player needs to be updated. I cannot find any option of updating the plugin. Tried Prefrence-- but there is no advnaced settings.

I'm trying to install Flash for Opera latest version on Ubuntu 16.10 but everything I have found and tried failed. It works fine however on Firefox and Chrome. Has anybody been able to successfully make it work? Thanks a lot.


Please keep in mind that I am only a beginner when it comes to trigonometry. I understand that sine is opposite/hypotenuse, cosine is adjacent/hypotenuse and that tangent is opposite/adjacent. My questions is that when you input sin(B)=AC/Hypotenuse (when hypotenuse and B is given to us). What does the calculator do to get the answer.

Sine $\theta$ = opposite/hypotenuse   Cosine $\theta$  = adjacent/hypotenuse   Tangent $\theta$  = opposite/adjacent      In order to calculate the sine or the cosine or the tangent I need to know $3$ sides of a right triangle. $2$ for each corresponding trigonometric function. How does a calculator calculate the sine, cosine, tangent of a number (that is actually an angle ?) without knowing any sides?


Suppose $f$ is an analytic function on a domain $D$. Then I need to show that $\overline {f(\bar z)}$ is also analytic.  Here is what I did -   Suppose $f(z) = u(x,y) + iv(x,y)$ where $u$ and $v$ are real functions of $x$ and $y$ and $z = x + iy$. Now $f(\bar z) =  u(x,-y) + iv(x,-y) $ and then $\overline {f(\bar z)} = u(x,-y) - iv(x,-y) $.   To show that a function is analytic, I need to verify that it satisfy Cauchy-Riemann Equations. I differentiated $\overline {f(\bar z)}$ and checked that it actually satisfies these equations. But here is my doubt - Being analytic means that the function if complex differentiable. Now here to check for analyticity, I am differentiating my function without proving that it's actually analytic. So is this the right way to do it?

I'm doing a bit of self study, but I'm uncomfortable with a certain idea. I want to show that $f(z)$ is analytic if and only if $\overline{f(\bar{z})}$ is analytic, and by analytic I mean differentiable at each point. Here $f$ is a complex valued function.  What I do is write $f(z)=u(x,y)+iv(x,y)$, where $u$ and $v$ are real functions of two variables. Then $\overline{f(\bar{z})}=u(x,-y)-iv(x,-y)$.  These two forms look very similar, in the sense the one function being differentiable should immediately imply the other is differentiable, since the only thing really changing might be a $-$ sign popping out due to the chain rule.   How can I more rigorously express that $f(z)$ is analytic iff $\overline{f(\bar{z})}$ using this? Many thanks.