Reference request on multivariate statistics

I am taking a course on multivariate statistics and I enjoy it pretty much. But I feel the course focuses too much on procedures and not on answering "why" some things are the way they are.  So let me be more specific. The course is about: - Exploratory and confirmatory factor analysis - Principal Component Analysis - Cluster Analysis - MANOVA - Canonical Correlation Analysis - Discriminant Analysis - Logistic Regression  We are currently following the book "Applied Multivariate Techniques" by Subhash Sharma. I would like to read a book which explains "why" things are the way they are. For example, instead of just saying "We apply the following test", I would like to know what the test statistic means and how we found it. I hope this makes sense.  It can be very mathematically rigorous, I don't mind. It doesn't have to be very proofy (although that would be neat!), but I would like to get to know "why" and not only "how".


Alert when terminal program finishes running?

I am running Xubuntu 15.04, but maybe this question has a general solution for all Ubuntu flavours.   I usually leave long computations running in a terminal window, which may take from a couple of minutes, to hours, or days. It would be nice if I could be alerted somehow when a terminal finishes executing a command. This should only be necessary for terminals which are minimized.   Is there a way to set up something like this? Ideally, the terminal window could flash, or maybe a notification show up.


How long do Space Marines live on average?  What technology lets them live longer than we are living now or does it have more to do with their psychas?


If $\sum\limits_{n=1}^\infty na_n$ converges , does $\sum\limits_{n=1}^\infty na_{n+1}$ converge?

I ask for some help with this question:  Prove or provide counter example:  If $\sum\limits_{n=1}^\infty na_n$ converges then $\sum\limits_{n=1}^\infty na_{n+1}$ also converges.  I tries this way:  If $\sum\limits_{n=1}^\infty na_n$ converges then $na_n \to 0$, therefore $a_n \to 0$.  There are 3 possible cases:  1) If $a_n >0 $ and $a_n$ is monotonic decreasing sequence then $na_{n+1}<na_n$ and $\sum_{n=1}^\infty na_{n+1}$ converges by Comparison Test.  2) If $a_n >0 $ and $a_n$ is not monotonic decreasing sequence : it is not possible that $a_{n+1}>a_n$ because in this case $a_n \to \infty$, therefore it must be $a_{n+1} \le a_n$ and $\sum_{n=1}^\infty na_{n+1}$ converges by Comparison Test.  3) If $a_n$ is sign-alternating series. There I have a problem to find a solution.  Thanks.


How does one come up with the model of torque?

In school, we learn that $T = Fd$, where $T$ is the torque, $F$ is the force perpendicular to the moment arm, and $d$ is the length of the moment arm. If I was the first physicist to come up with this model for torque, what might my train of thought be? In other words, how does one come up with this model?


What is the fraction field of $A[z]/(z^2-f)$?

Suppose $A$ is an integrally closed domain and that $f\in A$ has no repeated prime factors. Then $z^2-f$ is irreducible and $B:=A[z]/(z^2-f)$ is an integral domain. I am trying to see why $K(B)$, the fraction field of $B$, is $K(A)[z]/(z^2-f)$. In $K(B)$, we are inverting all elements of $B$ that are not contained in the ideal $(z^2-f)$. So then I think this should give us $K(B)=(A[z]-(z^2-f))^{-1}B$. Is this correct? And if so, why are the two forms of $K(B)$ equal?


How to get Amazon music to work in firefox or chrome

I have updated and installed adobe but I am receiving this message error still. And Amazon music will not stream at all, I am 100% new to Ubuntu/ Linux and just learning. Guidance much appreciated.


What's the number-theoretic significance of $561$?

In  on Hilbert's 10th problem in the March 2008 Notices of the AMS, Bjorn Poonen uses the equation  $$x^{1729}y^{1093}z^{196884} - 163xyzt^{262537412640768000} = 561$$  to suggest how deep the rabbit hole (of integer solutions to polynomial equations) goes. Clearly this is a cheeky equation. I recognize 1729 as the , 163 as the 9th (and greatest) , and 196884 as the linear coefficient in the  (and so, by Monstrous Moonshine, also 1 more than the degree of the smallest irreducible representation of the Monster group). Of course this made me curious about the others. Internet searches told me that 1093 is the smallest  and  262537412640768000 appears in the  for fast approximation of $\pi$. But all I could find out about 561 was that it's the area code of Palm Beach, FL.     What's the number-theoretic significance of 561?   Addendum: This question has been marked as a duplicate of  asking "Why is 561 the smallest Carmichael number?" This is not a duplicate of that question, since a person who has the present question (as I did when I asked it) does not know that 561 is the smallest Carmichael number.


Supress \cleardoublepage for some chapters

I am using book environment.  Between \listoffigures, \listoftables, \printglossary[glossaryname]s and appendices, I need a normal \clearpage between them (not a \cleardoublepage).   I still need to define these as chapters for document style consistensy and \cleardoublepage between normal chapters.


Nginx $document_root$fastcgi_script_name vs $request_filename

I can't notice any difference if in my config file I set   fastcgi_param  SCRIPT_FILENAME    $document_root$fastcgi_script_name;   Or:   fastcgi_param  SCRIPT_FILENAME    $request_filename;   What do they do respectively? Is one of the two better than the other?  Thanks in advance.


I have the following code:   class employee { public:     static int last_id;     ...  };   int main() {     employee::last_id=0;  }   When i try to run it it gives the following error:   Undefined symbols for architecture x86_64:   "employee::last_id", referenced from:       _main in chap7-F3IpS1.o ld: symbol(s) not found for architecture x86_64 clang: error: linker command failed with exit code 1 (use -v to see invocation) [Finished in 0.3s with exit code 1]


How to install a .exe file in Ubuntu 16.04?

I have an editor which has .exe format and i want to install it on Ubuntu 16.04. How it is possible to install this application in Ubuntu?


SQL no matching unique or primary key for this column-list

I can't find the problem. Hope someone can help me. (Translated using Google translate).


Etymology of "history" and why the "hi-" prefix?

According to , history comes from the same root as story. If they are from the same word, where does hi- come from? Is it just because of the English habit of taking names from other languages verbatim or is there something more to it?


Steam won't work on Ubuntu 15.10 64-bit "libGL error: unable to load driver:"

Whenever I click the steam app it won't start and when I try from the terminal it says:  Running Steam on ubuntu 15.10 64-bit STEAM_RUNTIME is enabled automatically Installing breakpad exception handler for appid(steam)/version(0) libGL error: unable to load driver: r600_dri.so libGL error: driver pointer missing libGL error: failed to load driver: r600 libGL error: unable to load driver: swrast_dri.so libGL error: failed to load driver: swrast   What do I do?


What is the relationship name of my sibling-in-law's sibling to me?

For example:   I have a sister named Charlotte. Charlotte is married to Martin. Martin has a brother named William.   Martin is my brother-in-law, but what is William to me?


A proof of $\int_{0}^{1}\left( \frac{\ln t}{1-t}\right)^2\,\mathrm{d}t=\frac{\pi^2}{3}$

What is the proof of the following: $$\int_{0}^{1} \left(\frac{\ln t}{1-t}\right)^2 \,\mathrm{d}t=\frac{\pi^2}{3} \>?$$


Short story about time-travelling cop/agent-of-justice from future checking on criminal exiled to our present

Trying to locate a sci-fi story I read in the '90s, and the story is probably written in '50s-'70s.  Paraphrasing, might have fudged details, but the essence follows.  The narrator A is a cop from the future, arriving in our time to check on B, a (political?) enemy-of-the-state / criminal, also from the future, who has been exiled to our time as punishment. In the years that B has been here, he has settled down, made a life, has a wife, kids, etc, and despite being an anachronism in his mind, has found happiness.  A and B talk about things for a bit.    The story ends with A revealing to B, to B's dismay and horror, that A is here to impose the real punishment now, a second exile for B, uprooting him from the life he has painstakingly built for himself.    The story ends with A saying something to the reader like "I sent him back to a small village in Eurasia (?) in the __th century, 3 years  before Genghis Khan (/ Attila the Hun?) ransacked the region."    [Update 01:] Mark Olson has identified it as "My Object All Sublime" by Poul Anderson.  He found the story in this .  (I was clearly muddled on story specifics.)


How do you turn off browser suggestions on html input

How do you turn this off browser suggestions on html input?


How do I remap my Tab key on startup? - Ubuntu 20.04

My tab key doesn't work properly, so I'm trying to remap it to the grave/tilde key right above it. I have already found out the command to map it - xmodmap -e "keycode 49 = Tab"  but it reverts back to the original when I restart my computer. How do I stop this from happening? I'm using Ubuntu 20.04.


Students expelled from Hogwarts, breaking of wands, and complete education

Related to this question:  and   TL;DR - 1a) Do we know of any other students that were actually expelled?  TL;DR - 1b) What constitutes a complete education? Do all children have to pass OWLS and NEWTS?  The only example I can remember is: Hagrid. He was fully expelled, wand broken and everything.  It is also my recollection that the wand is broken because without a completed education the wizard will end up being a danger to the public by not performing spells properly.  However we see the following:   Fred and George left the school voluntarily so there was no official to confiscate and break their wands. They end up opening their joke shop.   Same goes with Harry and Ron so they can pursue the Horcruxes. They end up working as Aurors directly after the war. Hermione leaves but goes back and completes her education.    This leaves the following questions:   Since Fred and George did not finish, why did the Ministry not show up at the shop to confiscate and break their wands?  Same with Harry and Ron. Why when they went to work for the Ministry was nothing said or done?   Harry and Ron are the HEROS so I am guessing that no one would want to enforce the law in their cases. Kingsley actually recruited them to head up the new Auror department.   Fred and George, however, leave before the end of the war in a time where the Ministry is corrupt. So it would stand to reason that they would be targets.  We also know that many children are home-schooled throughout the world. So there must be some standard that the Ministry would deem acceptable to not go break the wands of all the wizards that are home-schooled.   It almost seems to that this is just a setup for Hagrid's character and role, plus a background threat to Harry whenever it convenient for the plot...     Edit to account for Fantastic Beasts and Where to Find Them:  We know that Newt Scamander was expelled from Hogwarts, but he definitely still has his wand!


In what order should I watch The planet of the Apes franchise?

Basically, I ended somewhere on the reboot film made in 2001. I would like to get back to Planet of Apes series and watch it again.  With Star Wars franchise, there is famous order of how should one watch the series. Is there something similar with The Planet of Apes series?


Im trying to get the URI for the captured image from camera I why am i getting the exception as java.lang.NullPointerException: uri ,  here is my code.  Uri selectedImage = data.getData();   file = new File(URI(selectedImage));   public String URI(Uri contentUri)  {         Cursor cursor = null;  try  {     String[] proj = {MediaStore.ACTION_IMAGE_CAPTURE};       cursor=getActivity().getContentResolver().query(contentUri,proj,null,null,null);       intcolumn_index=cursor.getColumnIndexOrThrow(MediaStore.ACTION_IMAGE_CAPTURE);             cursor.moveToFirst();             return cursor.getString(column_index);         } finally {             if (cursor != null) {                 cursor.close();             }         }     }


$R^2$ for least absolute deviation regression

I know that $R^2$  is for the least square regression. Is there an analogous measure of fit to $R^2$ in LAD (Least Absolute Deviations) regression?  Here I am concerned with the "fitting quality".


How to do email address validation using Javascript (without JQuery)?

I'm trying to do an email address validation for an input text field, however, it must only submit if the entry is not null and has the @ char in it  Example 1 is the one that works, however, it excludes the need for the @ char  function emailvalidation() { var x=document.forms["input"]["email"].value;  if (x==null || x=="") {     alert("Input email address, please!"); return false }   Example 2 which does not work, but is how I imagine it would be written      function emailvalidation() { var x=document.forms["input"]["email"].value; var email = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/;  if (x<>null || x<>"" && x.value.match(email)) {     alert("Input email address, please!"); return true } else {     alert("Input email address, please!"); return false } }   Anyone have any ideas? Thank you though, preferably without JQuery! Thanks!


Same files in home folder and on desktop

Whenever I create a new file in my home directory the same file also appears on my desktop, when I remove the file from the desktop, the same file also get removed from my home directory. What can I to do to fix this issue?


The  click event is not working when data added by jQuery ajax

Here is the mvc webgrid codes:  @grid.GetHtml(                 displayHeader: false,                 htmlAttributes: new { id = "Grid1" },                  tableStyle: "webgrad4",                 columns: new[] {               gridRight.Column(columnName: "Dept_ID", header: "Dept ID"),               gridRight.Column(columnName: "Inv_ID", header: "Inv ID"),                    gridRight.Column(columnName: "Inv_NAME", header: "Inv Name"),                     gridRight.Column(columnName: "U_ID", header: "User ID"),                      gridRight.Column(columnName: "SEC_ID", header: "SEC ID")                     })   and this javascript codes:  $(document).ready(function () {     $('#Grid1 tr').click(function () {     alert("test");         $(this).addClass('selectRow');         var rowId = $(this).closest("tr").find("td:first").html();         var rowId2 = $(this).closest("tr").find("td:nth-child(2)").html();         $("#RightRecID").val(rowId);         $("#RightRecID2").val(rowId2);         $("#RightGridID").val("Grid1");         $('#Grid1 tr').not(this).removeClass('selectRow');     }); });   The above codes are working well when the data is loaded to webgrid in default. but after the following ajax codes generating the data of table rows and appended to the webgrid, the clicking event is not working.   $.each(response, function (j, dataval) {       $("#Grid1").append('
' + (dataval.DEPT_ID == null ? "" : dataval.DEPT_ID) + '	 + ' + dataval.Inv_ID + '	 +' + dataval.Inv_NAME + '	' +             (dataval.U_ID == null ? "" : dataval.U_ID) + '	 ' + (dataval.SEC_ID == null ? "" : dataval.SEC_ID) + '
');         pageCount = dataval.PageCount;           });   I also tried to add the id of the ajax added tr like this:    $.each(response, function (j, dataval) {       $("#Grid1").append('
' + (dataval.DEPT_ID == null ? "" : dataval.DEPT_ID) + '	 + ' + dataval.Inv_ID + '	 +' + dataval.Inv_NAME + '	' +             (dataval.U_ID == null ? "" : dataval.U_ID) + '	 ' + (dataval.SEC_ID == null ? "" : dataval.SEC_ID) + '
');         pageCount = dataval.PageCount;      });   and then created a simple test for the above codes:  $(document).ready(function () {     $('#newRowID').on('click', function () {         alert("test1");     });   The click event doesn't trigger the alert at all, from F12 key debug, I can see the id "newRowID" is added, but it can not be recognized, are there any other way to resolve this issue? thanks  edited: eventually, the table rows created by ajax dynamically should use the same codes as the click event of default table data like this:  $(document).ready(function () { $('#newRowID').on('click', function () {     alert("test1");     $(this).addClass('selectRow');     var rowId = $(this).closest("tr").find("td:first").html();     var rowId2 = $(this).closest("tr").find("td:nth-child(2)").html();     $("#RightRecID").val(rowId);     $("#RightRecID2").val(rowId2);     $("#RightGridID").val("Grid1");     $('#Grid1 tr').not(this).removeClass('selectRow');  });


How to address a professor in person at US universities?

At US universities, how should one address a professor while talking to him or her? In my home country, we usually address the professors as either "sir" or "madam" while talking about our queries in person.   What's the norm at US universities?


phpmyadmin not working due to missing mbstring extention

I upgraded my Ubuntu 14.04 to 16.04. But my phpmyadmin has error  The mbstring extension is missing. Please check your PHP configuration.   I searched somewhere but no solution on Ubuntu. Please help me. I'm using apache2


How do I merge two columns into one column steps?

When I save the table after I set up the classifcation and then ArcGIS save it as a INFO file and then you have two columns that you want to merge into one. Is there a better way to do that ? What I want to get the columns from FROM and TO merge into One column. These are the feet Elevation numbers.  Here is the screenshot


Invent Binary Operator $*$ on Reals that Can Create $+$, $-$, $\times$, $\div$

Exact Question: Invent a single binary operator $*$ such that for every real numbers $a$ and $b$, the operations $a + b$, $a - b$, $a \times b$, $a \div b$ can be created by applying $*$ (multiple times), starting with only $a$'s and $b$'s  From my interpretation, you can apply $*$ recursively some number of times with carefully selected parameters to produce the desired outcome.  I thought the operator should be a combination of $a - b$ and $a \cdot b^{-1}$ Since $-$ and $\div$ can produce $+$ and $\times$ respectively  Please do not tell me the full answer. Give me a hint to point me towards the right path


When I try to ask a question, I receive the message:     Oops! Your question couldn't be submitted because:      Sorry, we are no longer accepting questions from this account.   And strangely when I logged in on Ubuntu everything was fine. What's the problem?


"She's the author of" or "She's author of"? - which one is correct?

What's the difference in the usage of the article "the" with the word "author"? Why is the article "the" left in the second sentence?     She's the author of "The Power of Glamour," "The Future and Its   Enemies" and "The Substance of Style."       She's author of the new book,   “The Intimidation Game: How the Left is Silencing Free Speech.”


Does uncountable summation, with a finite sum, ever occur in mathematics?

Obviously, “most” of the terms must cancel out with opposite algebraic sign.  You can contrive examples such as the sum of the members of R being 0, but does an uncountable sum, with a finite sum, ever occur naturally as part of a larger scenario (eg, proof of a theorem, or preparation for a definition)?


This query is executed many times as part of an application, but runs slow:  SELECT [c2], [c1], [c5], [c4], [c3], [c6]   from [MyBigTable]  where [c7] = 1    and [c3] in ('a','b','c','d','e')    and [c4] is not NULL   It takes routinely more than 3 seconds, which is already bad, but sometimes the IN has 250 arguments, and the query takes more than one minute. This is the estimated execution plan:    Table has 11 millions rows.   In about 11% of rows [c3] and [c4] are both not null. In about 88% of rows [c3] is null and [c4] is not null. In only 0.4% of rows [c3] is not null and [c4] is null. Both [c3] and [c4] can never be null at the same time. [c7] is 1 in 97% of cases   There is a nonclustered index on [c3], [c4], [c7], [c8] (in order) including [c2], [c5], [c6]  Every time the query has to be run, the PHP code prepares a SQL statement, executes once and discard. I am discussing with the coders whether this can be improved, but I don't hold my breath.  What can I do to improve the performances of the query?  Could a conditional index, "WHERE [c7]=1 AND [c4] is not NULL" seriously improve the situation?


Number of Integer Solutions for a Liner Equation

The total number of integer pairs ($x$,$y$) satisfying the equation $x+y=xy$ is ....... $?$ Now I have solved this question by assuming the values of $x$ and then finding out the value of $y$ and I came with the solution set of $[(2,2),(0,0)]$  and I was not able to find any other solution set. Is my answer correct? Also in what way mathematically we can arrive at the correct answer without missing out any of the other possibilities. Please clarify!


On which Stack Exchange site should I post this question?

I have a question regarding marriage. I am not able to find the right Stack Exchange site. Please help.  I am 18. I have several points, like I get angry on small things and many more. I will list them. I need advice: Should I marry or live single?


Cancellation of booking (without credit card) from booking.com

I booked a room from booking.com just for the visa. The room that I booked didn't require a credit card information and I did the booking without reading the conditions.  Now I noticed that 320 CAD is required for cancellations. I sent several emails to booking.com but no one replied so far.  Did anyone face such a situation before? How could they take the money without credit card info?


Number of ways in which a composite number can be resolved into 2 coprimes?

for example 210 = 2*3*5*7,number of relative primes is 2*(4-1) =8,please help me derive this result.here's my try = 4C0+4C1+4C2+4C3+4C4=2*4 .Since nCr = nCn-r we decide this by two.4C0 couples with 4C4 ,4C1 couples with 4C3 but 4C2 is left.The idea I apply is that when we select r objects out of n,n-r are automatically selected.


How soon can I re-enter the US after my previous visit?

I entered the USA on a Visa Waiver Program (VWP) on 1 July 2012 and stayed until 16 Sep 2012 (78 days).  On what date in 2013 will I be able to travel to USA again under VWP?


How can I make an Echo (or any Object) invisible?

An Echo knight's echo is an object, which makes it hard to turn invisible, as invisibility and greater invisibility only affect creatures.  What options, from any non-homebrew source, allow you to turn an object (thats not being worn or carried by an invisible creature) invisible in 5e?


I have two iterators, a list and an itertools.count object (i.e. an infinite value generator). I would like to merge these two into a resulting iterator that will alternate yield values between the two:  >>> import itertools >>> c = itertools.count(1) >>> items = ['foo', 'bar'] >>> merged = imerge(items, c)  # the mythical "imerge" >>> merged.next() 'foo' >>> merged.next() 1 >>> merged.next() 'bar' >>> merged.next() 2 >>> merged.next() Traceback (most recent call last):     ... StopIteration   What is the simplest, most concise way to do this?


Invalid expression error 000358 when using in_memory workspace?

with an SQL Selection Expression against a geometry property like length fails when the source feature class is in an . An otherwise identical model works just fine when the feature class source is in a regular workspace (file-gdb).  ERROR 000358: Invalid expression Shape_Length = 0 Failed to execute (Layer of Zero Length Lines).   I'm using ArcGIS Desktop 10.3.1 but don't believe the issue to be version specific.  Fail:    Success:


Descriptor for people in an over 50 heterosexual relationship

What is the best way to describe a relationship, or the two people in a relationship, who are heterosexual, non-married on purpose, but exclusive and committed, and over the age of 50, where “boyfriend” and “girlfriend” do not sound appropriate.


Proving seemingly obvious equations with measure theory

I want to prove very simple equations, but am having some trouble because I have no clue.  Definition of Conditional Probability is given as follows:  Definition $E(Y|X)$ is a conditonal expectation of $Y$ given $X$ if it is a $\sigma (X)$-measurable random variable and for any Borel set $S \subseteq R$, we have $E(E(Y|X)1_{X \in S})=E(Y1_{X \in S})$  I want to solve those two problems based on above definition.   Suppose $X$ and $Y$ are independent.   (a) Prove that $E(Y|X)=E(Y)$ with probability 1.  (b) Prove that $Var(Y|X)=Var(Y)$ with probability 1.  (c) Explicitly verify the following theorem.(with $\mathcal{G}=\sigma (X)$ in this case)  Theorem: Let $Y$ be a random variable, and $\mathcal{G}$ a sub-$\sigma$-algebra. If $Var(Y)<\infty$, then $Var(Y)=E(Var(Y|\mathcal{G}))+Var(E(Y|\mathcal{G}))$   Let X and Y be jointly defined random variables.   (a) Suppose $E(Y|X)=E(Y)$ with probability 1. Prove that $E(XY)=E(X)E(Y)$  (b) Give an example where $E(XY)=E(X)E(Y)$, but it is NOT the case that $E(Y|X)=E(Y)$ with probability 1.  1.  For this part, I think I could deal with this by myself if I understand how to prove (a). So please help me with just (a).  In order to prove that $E(Y|X)=E(Y)$ with probability 1, I need to show that  \begin{equation} E(E(Y|X)1_{X})=E(E(Y)1_{X}). \end{equation}  if $X$ and $Y$ are independent.  From the above definition, conditional expectation $E(Y|X)$ is defined such that $E(E(Y|X)1_{X \in S})=E(Y1_{X \in S})$.  So maybe it suffices to show that $E(Y1_{X \in S})=E(E(Y)1_{X \in S})$. But it looks too obvious. My guess is that there is more educated way of showing why $E(Y1_{X \in S})=E(E(Y)1_{X \in S})$ holds if $X$ and $Y$ are independent.  2.  I can do (b) on my own. So for (a), "$E(Y|X)=E(Y)$ with probability 1" means that $E(E(Y|X)1_{X})=E(E(Y)1_{X})$. But, how can I prove $E(XY)=E(X)E(Y)$ with that information? I know how to prove this equation with integral sign or summation sign. But how does information about a.s. convergence give any implication about that equation?


calculating aperture and shutter speed inversion

I'm taking a manual photography class, using my canon rebel t5. Any tips on how to calculate aperture and shutter speeds easily? (I know they have to be inverted).  After I meter my photo (set at -0-). And Set ISO at 200 (this is all set by the instructor) If my aperture is F11...and shutter speed is 1/60...and I am instructed to move my aperture to F22...how do I calculate the correct shutter speed to correspond? (My camera moves in thirds)


Preferred method to exchange USD to CAD?

I don't do much traveling outside of the US but in a few weeks I will be driving from NYC to Canada.  I am not sure what the best method would be to convert USD to CAD.  Should I convert before I enter Canada?  Hit up an ATM once I get there using my Chase card?  Any tips/suggestions would be greatly appreciated.


Some malware remains after factory reset

I have a MicroMax Canvas Doodle 4 Smart Phone with Android 5.0, purchased in November 2015. It came with a lot of bloatware, probably including some app named "9Apps", which keeps suggesting apps for me to try out. I always cancel it. While watching YouTube videos, I get some advertisements for some app or the other. Again I never click or install those.  Unfortunately, in touch-phones, it is possible to accidentally tap the wrong button and install malware unintentionally. Also, a friend installed CleanMaster to "help" me, but it looks suspicious to me.    After about 6 months of usage, some malware got installed and it used to show random advertisements at odd times. It was tolerable for some time, but the frequency of advertisements increased, and there was a possibility that I might have unknowingly installed some more apps "suggested" by the malware.    About 6 months back, anytime I would connect to wifi, "SystemUI" would automatically download a whole lot of apps : BatterySaver, Duplicate WhatsApp, web browsers, games, Pro*n downloaders, . . . Also, Phone would become hot and battery would drain-out quickly. Crashes & Reboots were common.    I tried to uninstall all unknown apps, but either system would say that it could not disable system apps, or it would reinstall these apps at next wifi connect.  I tried a factory reset last week, but it was hanging on the next reboot. After repeating the factory reset, I got to the main screen, where I could see the Default Apps, but I got some popups like "WhatApps has stopped running" and "System update in Progress". Moreover, most of the unwanted apps are now shown as Default System Apps. Clearly, malware is still in control.    How can I get rid of this malware ? How can I reset the system to the real factory settings ?  I went to recovery mode and selected "root integrity check" : It shows 66 new files, 2 modified files, and 2 lost files. It does not provide a way to resolve these issues.


Show that in a topological space $\partial\partial A \subset \partial A$

I have the following task:      Show that in topological space $\partial\partial A \subset \partial A$,   where $\partial A$ denotes the set of boundary points of $A$, that is   $\partial A = \overline{A}\;\setminus\;A^o$, where $\overline{A}$ is   the closure of $A$ and $A^o$ is the set of interior points of $A$.   Give an example of $A$ such that $\partial \partial A \neq \partial  A$.   I tried to solve this but I resulted in equality $\partial \partial A = \partial A$, I'm not sure where I went wrong. Here's what I tried:   By the definition of $\partial A$ we have $\partial A\;\cup A^o = \overline{A}$, that is $A^o$ is the open complement of $\partial A$ in $\overline{A}$. Now  $$\partial \partial A = \overline{\partial A}\;\setminus\; (\partial A)^o = \overline{\partial A}.$$  Now because $\partial A$ is closed in $\overline{A}$ then $\partial A$ is the smallest closed set containing $\partial A$, that is $\overline{\partial A}=\partial A$, so  $$\partial \partial A = \overline{\partial A}=\partial A,$$  that is $\partial \partial A = \partial A$   I know I did a mistake in some point...


How to switch between intel and AMD graphics card?

I'm on Ubuntu 14.04 using a ZBook 14 which has Intel® Haswell Mobile graphics and an AMD FirePro M4100. Using the open-source radeon driver, how can I switch between the intel and the AMD card?  I'm using 14.04 so instructions for 13.10 and below don't apply.


Do all universities have a minimum required GPA for graduate school application?

I am a senior undergraduate (electrical) engineering student, exceedingly interested in physics. 4 years ago when entering university, for some reasons (better: illusions) I chose engineering as my major, while I was interested (and also really knowledgeable) in physics . Soon after the first semester I realized that I've decided wrong, and I must have chosen physics.  Since our university is a technical institute and does not have a strong physics department I decided to study physics on my own, without changing my major.But I took and passed the basic graduate physics courses (advanced quantum mechanics, advanced statistical mechanics, electrodynamics I & II), have done a few research projects and had a paper published (maybe 1 more in the future). I have explored lots of research areas in physics and I think I have a good potential for doing research.  While concentrating on physics, I was inattentive to EE courses. Today, while searching for graduate programs, I saw that some schools require a minimum GPA, usually 3. I just calculated my GPA and found out that it is 2.95!   Do all universities have a GPA threshold?  Since I'm changing my major and also have a good GPA in graduate physics courses, is there any way I can compensate for my (very) low electrical engineering GPA? (like by taking subject GRE, etc.) If I first (somehow) get a masters degree in physics and then apply for a PhD, can I throw away this electrical engineering GPA in my PhD application ?   Any other suggestion is warmly appreciated.


Why does the unstable vortex of the stargate not destroy the SGC iris?

As the title says, why doesnt the iris get destroyed?


How to calculate the effective resistance of this circuit

How do I calculate the effective resistance of this circuit? Using only the two formulas: $$\frac{1}{R_{Total}}  = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} + \cdots$$ and $$R_{Total} = R_1 + R_2 +R_3$$ I know how to calculate current and voltage using the node voltage method and thus derive the resistance. but I'm wondering how do I get the resistance using strictly only the two resistance formula?


Notation Question: What does $\vdash$ mean in logic?

In a "math structures" class at the community college I'm attending (uses the book Discrete Math by Epp, and is basically a discrete math "light" edition), we've been covering some basic logic.  I've been reading some of the logic questions on here to get used to notation, etc.  However, when I came across the question , I didn't understand what the $\vdash$ symbol means.  It's not in Discrete Math by Epp, nor is it in my mom's old logic book from when she went to college.  Wikipedia's  page says it means "can be derived from" when used in a logic context.  However, that doesn't make any sense in the above question, as there is nothing on the left of the $\vdash$.  So, what does $\vdash$ mean, especially in the context of the question linked above?


How to store a pointer to SubClass object in a BaseClass pointer array?

I am trying to create a BaseClass array that stores SubClass objects. Below are the follow steps I use to do this:   I create a BaseClass array. I create a new SubClass object to be stored in the array. I call the printSelf() function of that object in the array. The method incorrectly calls the BaseClass function, not the SubClass function.   The error here is that the object stored in the BaseClass array is of a BaseClass object. I need it so that the BaseClass array stores an object of type SubClass.  The problem is designed such that if there were to be multiple SubClasses (i.e. SubClassA, SubClassB, SubClassC...) they would all be stored in a single array.  I've tried various other solutions on StackOverFlow. None so far have provided a solution as to why creating a SubClass object will not store its class type properly in a BaseClass array.  class BaseClass {     public: void printSelf() { cout << "This element is a BaseClass." << endl; }; };  class SubClass : public BaseClass {     public: void printSelf() { cout << "This element is a SubClass." << endl; }; };  class House {     public: House();     private: BaseClass* subClassArray[1]; };  House::House() {     subClassArray[0] = new SubClass;     subClassArray[0]->printSelf(); }  int main() {     House houseMain; }   I expect the output to be "This element is a SubClass."   Instead, the output I am receiving is "This element is a BaseClass."


Can one “manually override” BibTeX's choice of citation keys by adding a field to the entry? II

There a previous question on this subject   Let me recall it. There are sometimes one wants to edit BibTex's choice  of citation key. For example, for a paper by Freyd, Hoste, Lickorish, Millet, Ocneano and Yetter someone may want to cite [HOMFLY] instead of [FHL+95]. This was solved in above's question by the command  shorthand = {NewLabel}   so that the cite is labelled as [NewLabel].  My problem is getting this on a concrete example. I am using \bibliographystyle{amsalpha} and I am writing  @book{SGA6,  shorthand = {SGA6},  title = {Th\'eorie des intersections et th\'eor\`eme de {R}iemann-{R}och},  series = {Lecture Notes in Mathematics},  volume  = "225",  note = {S{\'e}minaire de G{\'e}om{\'e}trie Alg{\'e}brique du Bois-Marie 1966--1967 (SGA 6)},  publisher = {Springer-Verlag, Berlin-New York},  year = {1971}, }   However, I am getting instead of [SGA6] and I don't know why.  Does anyone know how to solve this?  Thank you very much for your help.


Qt Quick UI templates missing from Qt Creator's New File or Project dialog

After following the  on the  page, everything seems just fine.  All the Ubuntu specific stuff is there, but when I try to create a new project using the Qt Quick 2 UI template, it's just missing. There are almost no templates available.  I'm on Ubuntu 12.10 64-bit, clean install.    This is how my New File or Project dialog looks like.


Is there a way to get OSX style file previews in the file browser?

In the default file browser of Mac OS X, pressing space will preview the file in question.  Is there already something similar that I haven't found, or is there a way to add the functionality to Ubuntu?


How small does a hole in a cup have to be to hold water without dripping?

I am creating a drain that lets water in but keeps pieces of plastic out. I need to know the size of a standard water droplet.


Is there a way to have the Windows 8 start screen displayed on both monitors?

I have 2 monitors, when I open the start screen it does only open on 1 monitor. Is there a way to have the start screen displayed on both monitors at the same time (like an extended start screen)?


What's the reference frame for displacement when calculating work?

I know that one way to calculate work is force*(displacement in the direction of the force). But what reference frame does that displacement value come from? One where the object starts at rest?  Here's an example to clarify. Imagine two identical rockets in space, each with the same amount of fuel. At $t=0$, the first rocket is at rest in the observer's reference frame, and the second rocket is already moving forward at some speed. They both start their engines and burn out all of their fuel, exerting identical, constant forces. When their engines stop, the second rocket has traveled farther than the first, despite both having burned the same fuel and therefore done the same work/energy.  So in that situation, what reference frame would you use for each rocket to measure its displacement? The two rockets do indeed do the same amount of work, right? Am I misunderstanding something?


I am having trouble with the following proof:   Prove that for every three positive real numbers a, b, and c that   $(a+b+c)*(\frac{1}{a} + \frac{1}{b} + \frac{1}{c}) \ge 9$.  I have tried to directly prove this but all I get are dead ends.


$1+2+3+4+5+\dotsb =\frac{-1}{12}$ Is this true in real domain? Can you tell where this series is used?

In our sequence and series class, my teacher wrote this series and asked if it makes any sense. We all were saying "this makes no sense at all." But when I Googled it, the whole world knows it. So what exactly this series define? Some say string theory uses this series. Can someone explain it?


How to access the road graph plugin in python?

I am developing a few scripts in Python for QGIS 1.8 to automate some geo-tasks and one of them would be to calculate the shortest distance from a hospital to each building in a town.  I would like to take advantage of the already existing Qgis plugin but, as it is a C++ plugin, I am not sure whether it is possible to access it from Python? Is there a binding or a trick for that?  If not, any further advice would be appreciated! As the base data is OpenStreetMap data stored in a PostGIS DB, I may also try with pgRouting. But the QGIS plugin would be my favourite choice if possible.  PS: this question is close to this one:  but I believe it's still different enough to be worth a new thred.


Can't find where to change add primitive operator properties

Though I am new to Blender, I am not new to modeling. Still there is one thing I am not finding in Blender 2.8 beta, and it's frustrating the hell out of me.  How the heck do I change the properties of a primitive during creation.  In Blender 2.79 I see the option to do this, during creation, in the bottom left corner of the screen, but I do not see it in 2.8.  For example, with the selector icon chosen, which seems to be the default upon opening, I go to Add > Mesh > Cylinder. The cylinder shows up on the screen, but I cannot find the properties to change the number of vertices/facets, the radius, the height, etc.  Am I doing something wrong?  Thank you,  Jim


exit doesn't terminate the script when error is called..  output  Error: Could not resolve localhost after exit   script  #!/bin/sh  resolve_ip (){     if [ -z "$1" ]; then         host="localhost"         ip=$(dig +short myip.opendns.com @resolver1.opendns.com)     else         host="$1"         ip=$(dig +short $1)     fi      if [ -z "$ip" ]; then         error "Could not resolve $host"     fi      echo "$ip" }  error (){     (>&2 echo "Error: $1")     exit 1 }  master_host='google.com'  if [ "$(resolve_ip)" = "$(resolve_ip $master_host)" ]; then     error "some error" fi  echo "after exit" exit


If $p, q, r$ are the roots of $x^3 -x+1=0$, what is $p^5 + q^5 + r^5$?

Can someone please help us solve this equation. It was on our college entry exam, but no one managed to solve it. The problem is:     Let $p,q,r$ be the roots of $x^3 -x+1=0$.  Then $p^5+q^5+r^5 = ?$   Correct answer was $-5$, but no one managed to solve this problem. We tried different methods, but none came up with a solution. Any help is appreciated.


How can I implement dialog trees into my game?

What is the best way to implement a dialog tree system in my game? I want an NPC to give the player different sets of responses, some which may only appear when the Player has an item or a previous event has occurred.


Can I use a DSL Modem with built-in wireless router with a cable modem?

I recently moved from DSL to Cable. I have a 'dumb' cable modem, but a 'smart' DSL modem (two actually). What I would like to do is to connect the cable modem to one of the lan ports of the DSL modem (the internet port of the DSL modem is a DSL line obviously) and have it act as the DHCP and wireless router.  The modem in question is an ActionTec GT784WN.  The closes answer I've found seems to be , but it seems to be discussing using the modem/router as a wireless access point instead of as a router.


At a microscopic level, how does friction come into exist?

The simplest answer is that the protuberances on the rough surfaces have inelastic collisions on each other and thus have a macroscopic tendency to impede motion.    Is there any more comprehensive and complete theory about how friction rises?   Is f=μN a theoretical conclusion or an approximate experimental result?   Why is the magnitude of friction LINEARLY proportional to the normal force exerted on the contact surface?


We have just received this email regarding my partners UK visitor visa application. I know that we should just wait the 3 days for him to collect his passport to see the outcome, but I can’t help but wonder if this email means he has been rejected? I’ve been doing some research and I’ve came across forums where people have said they have received different worded emails based on the outcomes of their visa applications.   I just want to get everybody’s comments or experiences...


Should I vary input field lengths in a single page checkout form?

I am currently designing a single page checkout form.  I would appreciate some feedback on the lengths of my input fields.    In the Billing and Shipping sections, I have staggered the length of the fields, trying to keep the size of the input field relative to the size of the expected input.   However, in the Payment section, all the input fields are of the same length.  Do you think this breaks the consistency of the form since the Billing and Shipping sections have staggered lengths for input fields?  Should I try to vary the lengths of the inputs in the payment section so that it looks more like the other sections?


What the symbol $\subseteq$ represents generally?

My book says that $\subset$ is used to represente any subset, proper or improper, needing in this case to show the anti symmetric property of sets. ($A = B \iff A \subset B \, \, \wedge \,\, B \subset A)$  And $\subseteq$ is used specifically to represent improper subsets. (In other words, $A \subseteq B \iff A = B) $  But i saw so many articles using $\subseteq$ and not $\subset$ then i am kinda suspicious about this definition.  If this definition is correct, why $\subseteq$ it's so used? Just because it helps to prove the equality betwen the sets?   Thanks for the help.


In Windows 7 you can drag a window to each side to split to 2 screens, can you get 4 with multiple monitors?

As the question states... In Windows 7 with a single screen, you can drag a window to the right and a window to the left to maximize them both at half the screen, letting you quickly and neatly see two windows simultaneously.  If I have 2 monitors, is there a way to do this with 4 windows, where each monitor gets 2 windows split across each screen?


Light emitting material in Eevee doesn't cast light on surfaces?

Bit of  noob, so forgive me in advance.  Working in Eevee in 2.81, I can't get an emission shaded material to cast light onto a surface. I've got bloom enabled, and the emitting surface illuminates plenty of bloom effect, but the material doesn't cast light onto anything else. my other surfaces catch illumination from other lights just fine.  I'm just using an emission shader node and material output - that's all.  I'm used to building light sources out of objects in Cycles - what am I missing?


Is it possible to change the default encoding in notepad?

On windows 7 (x64), the default option, for saving text files in notepad is ANSI. One can select other encoding from the combo box, however, I'd like this option to be the default.


Principal Ideal Domain $R$ and ideal $J\neq 0$ so that that $R/J$ have a finite number of ideals.

Let $R$ a un Principal Ideal Domain(PID) and $J\neq 0$ a ideal of $R$. Show that $R/J$ have a finite number of ideals.


In Ubuntu 13.04, whenever I decrease brightness, it still stays at its highest, and won't decrease. What's the fix?   Info  13.04, using Gnome Environment, but its Ubuntu 13.04.  Dell Inspiron  Also, cannot get updates at ALL   "Failed to get repository information."  Sudo apt-get update also gives errors at end.


HeapSize limit reached in an unexpected behaviour

i just made a test, to see how much data i can put in a string before i reach the the heapsize limit and i get an unexpected behaviour   string  csvFile = '"XXXXXXX","XXPX XXRXXXX","XXPX BP","XLXXXXR","XXXXVXXX PRXXXDXXXX","XXPX XXXXVXXX","XDRXXXDXX LXGXLX","XXXXRX XXLX","LXXXX XX","DXXX XXXZXX XXXXVXXX","DXXX XXXX XXXXVXXX","XXDXXX BP","XXDXXX XXXXXLX","PXRXXXX XVX","DXXXXXXXZXXXX","XXXX XXRXXXXRX","XXGXXXX XXRXXXXRX","DXXX DX XXXXXXX","LXXGX DX XXXXXXX","PXD","XXXXX XXXXRXXXXXLX","XXXX RXXXPXXX","XXDXRXZZX RXXXPXXX","PRXVXXXXX RXXXPXXX","XXXXXX RXXXPXXX","XXP RXXXPXXX","XXXXRX XXLXXXXX 1","XXXXRX XXLXXXXX 2","XXXXRX XXX","XXDXRXZZX XXXXL","XXDXRXZZX XXRXXXXRX","XXXXXX XXRXXXXRX","PRXVXXXXX XXRXXXXRX","XXP XXRXXXXRX","XXXXX XLXXXXX","XXDXXX PRXXXXX","DXXX XXXXXZXXXX","XXPX DXXXXXXXX","XHXXVX XXXXXRX","DXXX XXXXXXXXX XXXXXRX","DXXX XXXDXXZX XXXXXRX","XXPXRXX XXXXLX","XXPXRXX RXXXDXX XXXXDXXX","PRXXXXXXXXXXXXXXZXXXX PRXXXXXXXXXX","DXXX PRXXXXXXXXXXXXXXZXXXX PRXXXXXXXXXX"';  string  csvFile2='',csvFile3; system.debug(limits.getLimitHeapSize()); system.debug(limits.getHeapSize()); for(integer i=0;i<3618;i++){ csvFile2+='\n'+csvFile; }   system.debug(1.0*limits.getHeapSize()); system.debug((1.0*limits.getHeapSize())/limits.getLimitHeapSize()*100);   with 3618 iteraction i get    Heap size 3001245.0 Which correspond to ~50% of the heap size limit in the Synchronous context   but if i go to 3619 iteractions in the for, i get the error "Apex heap size too large: 6001368".... which surprise me a lot...   I'm not getting out why this behaviour is occurring. Do you have any similar experience? There is a reason for this?  Seems more about limits on strings, in effect the string csvFile2 overcome 3M characters... but i dont know


What is the best way to select the apparel size?

I'm redesigning my filters and product page of an online apparel store. Do you think I should display all sizes and use radio button or using a drop down menu to select the size ?


I'm wondering how to give subnumberings like "2a" and "2b" for separate floats.  I know both the subfigure and subcaption packages do the subnumbering but they demand the subfigures be in a single figure environment.  For example, I'd be happy if I could find an environment subfigures like this:  \begin{subfigures} \begin{figure}   A figure comes here.   \caption{\label{first}Caption text.} %--> Fig.1a \end{figure} \begin{figure}   Another figure.   \caption{\label{second}Caption text.} %--> Fig.1b \end{figure} \end{subfigures}   It's basically the same as AMS LaTeX's subequations environment.  The reason why I want to do this is that I can't decide how I should group my figures until much later in my writing process.  If I had an environment like the above, all I would have to do is to cut&paste figure environments or delete or add subfigures environments in order to reorganize my figures.  Since what I want is very similar to the subequations environment, I guess I can make my own subfigures environment after enough hacking, but I'm not much versed in TeX coding and am wondering if there is already a solution available.  Thanks for your help.  Ryo  Edit: Thank you all for your responses.  Mico asks: ‘Should the individual figure environments within a (still to be designed) subfigures environment be allowed to "float" and possibly end up on different pages . . . ?’ — Yes.  I just want separate floats to be numbered in the way I want and that's all.  Of course, if there be an option that controls the placement of the grouped figures, that would be a nice addition.


Is there a way to prevent installs/updates to litter my hard drive with cryptic folders?

Often I find guid-like folder names spread around on my hard drives. Is there a way to prevent this from happening? I think they might come when I install various programs or while updating them (seems like windows update does it too).   I find it very annoying. Especially when some of them won't be deleted because of security stuff. Doesn't Windows have a dedicated temp folder for these cases? Why can't they use that? Or at least clean up after themselves...


What evidence do we have that CMB is the result of the Big bang?

I got the main picture repeated over and over again about why if there's a Big bang we indeed should see the CMB with this feature. In this question I'm asking something different: what independent evidences do we have that the CMB is really related with what the Universe was 400k years after the Big bang and not just related with what the Universe is now or just related with something else we don't yet know? What are the effective evidences that is the result of the Big bang as it is usually described?   If the list is too long I would also appreciate one or two references.


I'm having difficulty correctly displaying Special Characters in our PHP application. The Special Characters are being displayed as "?" in most cases. I believe this has to do with the cURL operation.  We store our content in a Content Management System which we return via cURL. When I return our content via CMS, the Special Characters change to �. When I use mb_convert_encoding on these keys, it displays the Special Character as "?". How can I correctly display Special Characters? Any help would be appreciated!  Content Management System:   Zürich Airport   Result Output - using cURL (Before mb_convert_encoding):   Z�rich Airport   Page Output (After mb_convert_encoding):   Z?rich Airport   Code:      $curl = curl_init();     curl_setopt($curl,CURLOPT_HTTPHEADER,array(         'Content-type:application/json'     ));     curl_setopt($curl,CURLOPT_POST,true);     curl_setopt($curl,CURLOPT_POSTFIELDS,json_encode(array(         'contentKeyName' => $prefix,         'langCode' => $language,         'rollSetiForExperiments' => false     )));     curl_setopt($curl,CURLOPT_RETURNTRANSFER,true);     curl_setopt($curl,CURLOPT_TIMEOUT,10);     curl_setopt($curl,CURLOPT_URL,$endpoint);      $response = new stdClass();     $response->response = curl_exec($curl);     $response->headers = curl_getinfo($curl);     $response->error_number = curl_errno($curl);     $response->error_message = curl_error($curl);      curl_close($curl);      $result = $response->response; // If I echo $result, Special Characters are outputted as �      $result = mb_convert_encoding($result,'utf-8'); // Changes � to ?    Desired Output:   Zürich Airport


Collecting baggage in different countries through different airlines

Long story short..I am flying from New York to Dubai with Delta and Dubai to Mumbai with Air India.   How do I obtain my baggage and recheck the baggage with Air India without having to go through customs? I am not planning on obtaining UAE visa..


How is uniq not unique enough that there is also uniq --unique?

Here are commands on a random file from :  wget -qO - http://pastebin.com/0cSPs9LR | wc -l 350 wget -qO - http://pastebin.com/0cSPs9LR | sort -u | wc -l 287 wget -qO - http://pastebin.com/0cSPs9LR | sort | uniq | wc -l 287 wget -qO - http://pastebin.com/0cSPs9LR | sort | uniq -u | wc -l 258   The man pages are not clear on what the -u flag is doing.  Any advice?


Why am I (low rep user) able to downvote questions/answers on this community?

I am a low reputation user (103 points)  on this community. However, I am able to downvote questions and answers. I thought I needed 125 points for downvoting. On other communities, I need 125 points for downvoting but not on this one, why?


Is there any connection between the symbol $\supset$ when it means implication and its meaning as superset?

A rather old-fashioned symbol for logical implication is $\supset$ (see ). For example $p \supset q$ means $p \implies q$ or $p \rightarrow q$ in more recent notations.  Is there any semantic connection between using the symbol to show implication and using it to represent subset/superset relationships?  I can see a connection myself but the problem is I see it in the opposite direction ($\subset$ instead of $\supset$). For example, I see $x \in A \implies x \in B$ is (somewhat) equivalent to $A \subset B$. Therefore, if I had to reuse the subset/super set symbol for logical implication, I would have used $p \subset q$ to denote $p \implies q$. Is there any historical or semantic reason for using $\supset$?


Performing find and replace in QGIS field calculator?

I'm trying to replace selected string values in an attribute table, eg. "Text1" for "Text2" (QGIS 1.8.0), patriculary for those rows with NULL values. I have been trying to use the replace expression (and any other that I have found) with no luck.  Are there any wildcard characters that I may be able to use in future?


System broken after I ran sudo apt-get purge 7.0.*

By mistake I ran   sudo apt-get purge 7.0.*     instead of   sudo apt-get purge PHP 7.0.*   Now my system is not opening. What to do now?  I updated the system but still no progress.


I'm studying password encryption algorythms. I know the existence of bcrypt, scrypt, and varients, but I want to chanllenge myself on this question and that's why I came up with this algorythm in PHP:  $secret = md5( uniqid( mt_rand(), true ) ); // Length is 32 $passwd = 'qwert123'; $hash = $secret . hash( 'sha256', $secret + $passwd );   Since secret is randomly determined and added at the front of the password hash, I could verify the password input like this:  $secret = substr( $hash_from_db, 0, 32 ); $hash_from_db === $secret . hash( 'sha256', $secret + $input_from_user );   What do you think about this implementation? I would do like to receive some feedback about it. Thank you.


I know that we should use \dotsc with a comma and \dots if there is no comma.  But what if I have a comma on the right side and no comma on the left side, for example in   Pr[X_i | X_{i+1}, ... ]   Which one should I use?


How to delete an invincible 0 byte file?

I have a file whose size is 0 bytes. When I try to remove it an error message appears, saying "Could not find file".  Here is the list of things I've tried to delete the file:   Rebooted Reset folder options Cleaned the registry with CCleaner Using the del command Replacing it with a different file   The dir command gives this information about the file:  25.06.2011 21:06 0 STALKER   File properties:    How can I remove it?


Give $3$ examples of a field extensions which are neither normal nor separable.

Here   $1)$ $F=\Bbb F_2(x)$ and consider $K=F(x^{1/6})$. Now $K/F$ is neither normal nor separable.  $2)$ Let $k$ be field of characteristic $2$, let $F=k(x,y)$, let $S=F(u)$, where $u$ is a root of $t^2+t+x$, and let $K=S(\sqrt{uy})$ then $K/F$ is not separable I have proved. How to prove $K/F$ is not normal? I think considering $min(\sqrt{uy},F)$ I have to show this does not split over $K$. But how to prove?  $3$ What is the $3$rd example?


A continuously differentiable map is locally Lipschitz

Let $f:\mathbb R^d \to \mathbb R^m$ be a map of class $C^1$. That is, $f$ is continuous and its derivative exists and is also continuous. Why is $f$ locally Lipschitz? Remark Such $f$ will not be globally Lipschitz in general, as the one-dimensional example $f(x)=x^2$ shows: for this example,  $|f(x+1)-f(x)| = |2x+1|$ is unbounded.


Why create clk and clk NOT with 2 inverters instead of 1?

I see many circuits use this topology   Why dont we use just only one inverter like this:   Thanks very much!


Estimate the population variance from a set of means

I have a set of measurements which is partitioned into M partitions. However, I only have the partition sizes $N_i$ and the means $\bar{x}_i$ from each partition. Because all measurements are assumed to be from the same distribution, I believe I can estimate the mean of the population, $\bar{y}$, and standard deviation of the mean, $\sigma_{mean}$: $$ N=\sum_{i=1}^M N_i $$ $$ \bar{y} = \frac{1}{N}\sum_{i=1}^MN_i\bar{x}_i $$  $$ \sigma_{mean}=\sqrt{\frac{1}{N}\sum_i N_i(\bar{x}_i-\bar{y})^2} $$  My questions:   Am I right in my assumptions, that the mean $\bar{y}$ can be computed as above?  How can I find the standard deviation for the population, given only the means?  I read that the standard deviation of the population and standard deviation of the mean is related with $$ \sigma_{mean}=\frac{\sigma}{\sqrt{n}} \mbox{[1]} $$ where $n$ is the number of samples used in the computation of $\bar{x}_i$. So is it actually as simple as just multiplying $\sigma_{mean}$ with $\sqrt{n}$ if $n$ for all means are the same?   If it's that simple, what do I do if each $\bar{x}_i$ is computed using a different number of samples?    [1]


Evaluate the improper integral $ \int_0^1 \frac{\ln(1+x)}{x}\,dx $


Contradiction of total energy of a system?

I consider a situation in a system in which an observer is sitting in body of mass $M$ and another observer in a body of mass $2M$, both moving with velocity $v$ towards each other. If observers in each body consider themselves at rest and the other one is in motion, total energy calculated by the first observer is $\frac{2M(2v)^2}{2}$ but for the second observer it is $\frac{M(2v)^2}{2}$ which is half of the first. How am I getting different total energy of system at same instant?


I have a requirement to convert two list into a dictionary. Just wondering if there is an easiet and pythonic way of doing it.  i can acheive that using the code below but wanted to know if this is the right way of doing it  a = ['1.1.1.1','1.1.1.2'] b = ['225.1.1.1','225.1.1.2'] d = {} for i,j in enumerate(a):     d[j]= b[i]  print(d)


Incorrect context Runtime Error on calling .poll() method via command line

I'm trying to get a python based audio visualisation script to work in blender via command line interface. Here's the code   When I run the following in blender 2.66 on Ubuntu 14.04  blender -b -noaudio -P myscript.py  I get the following error  File "/home/random9/myscript.py", line 66, in <module> bpy.ops.anim.keyframe_insert_menu(type='Scaling') File "/usr/share/blender/2.79/scripts/modules/bpy/ops.py", line 189, in __call__ ret = op_call(self.idname_py(), None, kw)  RuntimeError: Operator bpy.ops.anim.keyframe_insert_menu.poll() failed, context is incorrect   in [line number 66]  bpy.ops.anim.keyframe_insert_menu(type='Scaling')  How do I resolve this error?  I've been going through  and it suggests that I should be able to figure out what context an operator needs simply by seeing how it’s used in Blender and thinking about what it does.  Any help is appreciated.


Unix find a file and then prompting to delete

I'm currently learning Unix and have come across a question in a book that I'm trying to solve.  I'm trying to write a script that asks a user to enter a file name. Then, the script needs to check for file existence. If the file does not exist, that script should display an error message and then exit the script. If the file exists, the script should ask if the user wants to delete the file:   If the answer is yes or y, the script should remove the file. If the answer is no or n, the script should exit from the script. If the answer is neither yes nor no, the script should display an error message and exit from the script.   This what I have written so far but have come across with a few errors:  #!/bin/bash  file=$1  if [ -f $file ]; then echo read -p  "File $file existes,do you want to delete y/n" delete case $delete in n)    exit y) rm $file echo "file deleted";; else echo "fie $file does not exist" exit fi   If anyone come explain where I have gone wrong it would be greatly appreciated


Which of the following is grammatical?          To see my stuff at your grocery is a great source of pride!    Seeing my stuff at your grocery is a great source of pride!       The verb "to see" is the subject, so I suppose that using "to see" is the right way... but it sounds so strange to me.


How can I burn a windows 10 iso to an usb stick?

Can somebody help me trought teamviewer? I have ubuntu mate 20.04


Subject-Verb Agreement in "Neither" Comparison (see example)

I am not sure about the form of the verb that follows "neither". Should it be a singular or plural verb?  For example:     Admittedly, being a celebrity is not easy, but neither are being many other professionals who, unfortunately, receive much less compensation.    P.S. I came across another sentence on the Internet that says "Being single is not easy, but neither is being married."  Here, the verb following "neither" is singular. So, may I ask what is the rule here?


LaTeX package "titling", titles with hard line breaks, and \MakeUpperCase

I have a document with a title that is spread over several lines using hard line breaks. To configure the title formatting, I use the titling package with code adapted from its documentation:  \documentclass{article}  \usepackage{titling} \pretitle{\begin{center}\LARGE\sffamily\bfseries} \posttitle{\par\end{center}\vskip 0.5em}  \title{Higgelty Pigglety Pop! \\ or \\ There Must Be More to Life}  \begin{document} \maketitle \end{document}   …and it works perfectly.  I now want the title additionally to be in all caps and therefore change the \pretitle command:  \pretitle{\begin{center}\LARGE\sffamily\bfseries\MakeUppercase}   …and I get the following error message:  ! Use of \@icentercr doesn't match its definition. <argument> \def  l.12 \maketitle   This only happens with a title that includes hard line breaks.  What does this error message mean? How can I fix it?


Can we use media9 to show a video on a PDF but the video is not embedded to the PDF?

I have video tutorials that I want to show in my presentation with beamer class. I don't want the video files get embedded to the PDF because they will make the PDF size very very huge.  If you know how the videos can be played on the HTML with a reference rather than embedding the video file to the HTML file, I want something like this to be applied to my PDF presentation. I just want to reference the video URL from my PDF presentation.   Shortly speaking, can we use media9 to show a video on a PDF but the video is not embedded to the PDF?  Uploading those videos to a web server might be difficult for me because internet connection is very slow and sometimes not available in the presentation room. :-)


How do I display the user login in a popup?

When menu item "Login" is clicked, I want to display the login form as a popup. How can I achieve this?  I have looked into the following but with little luck. (Let me know if the answer is below and I am missing it.)   modules: Overlay paths, Popup, Ajax login/register Code: hook_admin_paths_alter()   Any help will be great. I am looking for a clean pop up option that I can theme too.


So I have two arrays and I want to merge them into one array by adding the values with the same key together.  array &a     Array     (         [0] => 4         [1] => 10         [2] => 3         [3] => 10         [4] => 7     )   array &b     Array     (         [0] =>          [1] => 1         [2] => 2         [3] => 2         [4] => 2      )   I expect the resulting array as   Array     (         [0] => 4         [1] => 11         [2] => 5         [3] => 12         [4] => 9      )


Is it possible to view an atom? What would it look like?    Would it resemble a traditional atomic diagram?


Screen Tearing while scrolling chrome xubuntu

Scrolling through pages with lots of images cause a distortion about 2/3 down the screen. I've tried enabling/disabling smooth scroll and in chrome. I've also tried toggling compositor settings on device. I'm not really sure what the best bet solution here is. I'm at a loss, any help would be appreciated!  Here's a device info dump:   -Computer-   Processor        : 4x Intel(R) Core(TM) i5-5200U CPU @ 2.20GHz Memory       : 8075MB (3935MB used) Operating System     : Ubuntu 16.04.1 LTS User Name        : nick-bbytes (Nick-BBytes) Date/Time        : Mon 06 Feb 2017 01:03:12 PM EST   -Display-   Resolution       : 3840x1080 pixels OpenGL Renderer      : Mesa DRI Intel(R) HD Graphics 5500 (Broadwell GT2) X11 Vendor       : The X.Org Foundation   -Multimedia-   Audio Adapter        : HDA-Intel - HDA Intel HDMI Audio Adapter        : HDA-Intel - HDA Intel PCH   -Input Devices-   Lid Switch Sleep Button Power Button AT Translated Set 2 keyboard Video Bus USB Optical Mouse USB-HID Keyboard USB-HID Keyboard ETPS/2 Elantech Touchpad HDA Intel PCH Mic HDA Intel PCH Headphone HDA Intel HDMI HDMI/DP,pcm       : 3= HDA Intel HDMI HDMI/DP,pcm       : 7= HDA Intel HDMI HDMI/DP,pcm       : 8= Asus WMI hotkeys USB2.0 HD UVC WebCam   -SCSI Disks-   ATA Micron_M600_MTFD


Where can I leave luggage in Frankfurt, either airport or train station?

I need to find a place to leave my luggage in lockers for 2 days in Frankfurt, either the airport (Terminal 1) or at the train station. I have to go by train to Stuttgart for 2 days without luggage. The luggage is 5 bags, 28 inches.


Why is my husband's iphone now getting my call history

Why is My husband's iPhone getting my call history?


I realise it's probably an outdated form, but this exchange (from Master and Commander) makes me wonder:     Captain: Killick! Killick there! What do you have for us tonight?      Cook: Which it's soused hog's face.      Captain: Eh?      Cook: Which it is soused hog's face!      Captain: My favourite. My favourite.   I really don't understand, from a grammar point of view, how those words go together as a (correct) sentence. Can someone please elucidate?


When normalization is counter-productive

Could you give me general examples of when normalization is not used properly and affects badly the classification accuracy, or when it is not needed?


using awk command to compare the two files and print all the columns then missing display as NA

File 1:  123, 234 345, 789 678, 900   File 2  123, abc 345, dnc   Desired output (all columns in file1 and missing value in file two as NA):  123,234,abc 345,789,dnc 678,900,NA


I have a textarea that when hovered, I would like the caret to follow the cursor. It would be like if I clicked the textarea every time I moved my mouse. Here is my current js:  $("textarea").on("mousemove", function() {     $(this).trigger("click"); });   I don't want to move the mouse, but the caret in the textarea.    Update   similar but  how I can use mouse's co-ordinates to set the carets position using this method. If I receive X:120 Y:244 how can I use this method to set the caret


Folder keeps changing back to read-only. What permissions setup causes this in Windows?

I think I'm going crazy. Every time I create a folder it automatically is set to readonly, but I can still then rename the folder or add folders to it. If I attempt to uncheck the readonly flag it becomes checked again when I next open the folder properties. What the heck? Could my IT dept really have set up a policy like this somehow? If so, how?  Seems crazy that Windows would even do this -- no errors when I uncheck read-only and hit ok but the change fails.  Also, it is the halfway checked state -- greyed out and checked, but uncheckable.


Supposing someone says they have a sample of insulanium with the following properties:   If you make a thermos out of insulanium, it will keep a drink hot or cold forever. If you put your hand on a sheet of insulanium, it won't feel hot or cold, because no heat is exchanged with your hand. A sheet of insulanium looks like a mirror at all frequencies, because it neither absorbs nor emits radiation.   Is such a material possible? Could you use the above properties of insulanium to design an experiment that would break the laws of physics?


Is there a way to get a description for each command or app that "apt-get install" can install?

When we type in emacs in Ubuntu's Terminal, it will show a list of apps or commands we can install.  I am not so interested in what it is particularly for emacs, but want to find out if there is a way to get a one line or longer description of each of the commands?  Such as  <some-command> emacs   and it will show  emacs24   The GUI version of emacs jove      A simplified version of emacs (non GUI) [...]


Proving that $2^{2\cdot 3^{n-1}}\equiv 1+3^n\pmod{3^{n+1}}$ for every natural $n$

Prove that $2^{2\cdot 3^{n-1}}\equiv 1+3^n\pmod{3^{n+1}}$ for every natural $n$   Of course, should be done by induction. Base case ($n=1$) is easy.  I got stuck with the step:  Let's assume that it's right for $n$. Then,  $$2^{2\cdot 3^{n-1}} = 1 + 3^n \pmod{3^{n+1}}$$  We want to evaluate $$2^{2 \cdot 3^n} \pmod {3^{n+2}}$$  I think we can somehow utilize the fact that $2,3$ are coprime and reduce $3^{n+2}$ to $3^{n+1}$.   I'd be glad for help on that.  Thanks!


Coding a plugin on WordPress; when should I sanitize?

I am developing a custom plugin on WordPress for a client. Just a simple question: when I am using update_post_meta() and update_user_meta(), do I need to use the WordPress sanitization functions? I was under the impression that I don't, since the documentation says that $meta_key and $meta_value should be raw.  Are there any other instances / WordPress features in a plugin wherein I will need to sanitize my data?


How was this blurry background, sharp motorbike effect achieved?

In this photo nominated as , the background seems to blur while the rider is sharp. Wouldn't this normally be the other way?  How was this done?


Javascript event for table cell generated by AJAX

I am printing rows in a talbe as follows. when btnDes cell is clicked, I am able to captuer the variable from the java script.  When the same table is printed via AJAX, same javascript code is not able to capture the event and variables.  Can somebody tell me how to do this?  $counter = 0; while ($row = $db->getAssocArr($results)) {           ?> <form action="form.php" method="post" id="form-<?php echo $counter; ?>" enctype="multipart/form-data">
 <?php echo $row['name']; ?> <input type="hidden" value = "<?php echo $row['projId']; ?>" name="projId"/> 	 Design |
 </form> <?php         $counter++;     }   java script  designBtn = document.getElementsByName("btnDes");        for (var i = 0; i < designBtn .length; i++) {         designBtn [i].id = i;                    designBtn [i].onclick = fdesign;                 }


What is the significance of Lie groups $SO(3)$ and $SU(2)$ to particle physics?

I was hoping someone could give an overview as to how the Lie groups $SO(3)$ and $SU(2)$ and their representations can be applied to describe particle physics?  The application of Lie groups and their representations is an enormous field, with vast implications for physics with respect to such things as unification, but I what specifically made these groups of physical importance and why there study is useful.  I have just started studying these two groups in particular, but from a mathematical perspective, I'd very much appreciate understanding some sort of physical motivation.


I want to set my linux machine box 12 hours format,how to set it ,please advise  I am able to display with #date +%r,but wanted to set it permanently


Show that the function $f: S \to \mathbb R$ given by $$f(x,s,t):=-\ln(st - ||x||^2)$$ is convex on $$S := \left\{(x,s,t) \in \mathbb R^n \times \mathbb  R \times \mathbb R: \frac{\|x\|^2}{s}<t, s>0, t>0 \right\}$$   $-\ln(x)$ is a convex monotonic decreasing function, hence we can use composition by showing the inner part is concave. Also we know $-||x||^2$ is concave and $st$ is neither convex nor concave on $S$. Also in $S$ we have $st>||x||^2$ but I was unable to show the convexity of the function as a whole


Can I use a visa in my old passport that was previously reported as stolen?

This is my issue: I was robbed and my passport was stolen with my ATM cards. I went to the nearest police station to make a police report and an affidavit as I was advised to get a new passport before proceeding to the consular office. Which I did within a few days. A day after I got the new passport, I got a call from the police that my passport has been recovered along with the other stolen items.  So I went to the immigration office and told them that my passport had been recovered and asked if I need to go to the embassy again. I was told that I don’t need to go the embassy as all they will need to do is to cancel my old passport without tampering with my US valid visa on it, since I got a new passport and was told that I will need to hold both my new passport and old passport while traveling.  So I want to ask if this is right and won’t give me a problem at the US port of entry? Thanks.


When applying regex to a multiline string, I realize the regex may be correct according to rubular.com. The problem is that somehow it is not working against multiline text.  Question is, I attempted to do "item.strip()" and no change in behavior.  s = """ #if route rate 230.207.200.1', '', '    (50.50.50.11,230.207.200.1)', """ for item in s:      match = re.findall(r'([0-9].[0-9].[0-9].[0-9],.........)', s)  if match:     print('match')


How to calculate age in T-SQL with years, months, and days

What would be the best way to calculate someone's age in years, months, and days in T-SQL (SQL Server 2000)?  The datediff function doesn't handle year boundaries well, plus getting the months and days separate will be a bear.  I know I can do it on the client side relatively easily, but I'd like to have it done in my .


Right now, I have 0 votes left on PPCG.  However, Vox Populi says I have voted 33 times.  Is this a bug?


User profile picture not rendering correctly

On  question, 's user profile picture does not render correctly for me. It renders like this:        It seems that only the 32px version is rendering incorrectly:              This question was also raised in the past, but it was  although it is now still broken.


How to evaluate if my Apache needs another server and/or load balancer?

I have an Apache web application which is serving ~2k Requests Per Minute. The current infrastructure includes two servers, one acting as Apache + database, and the second one just database.   I'm trying to evaluate the added value from moving the Apache to its own server and/or maybe even a couple of small instances and a load balancer.  How can I perform such evaluation? I'm using New Relic for server monitoring and seeing most (~70%) of the app server time spent is in PHP.


Number of solutions of $x_1+2x_2+\cdots+kx_k=n$?

Suppose $n$ be a given positive integer. Then the Diophantine equation $x=n$ has only $1$ solution. Just by inspection, I found that the Diophantine equation $x+2y=n$ has $\left\lfloor \dfrac{n}{2}+1\right\rfloor$ non-negative solutions for $(x,y).$ Also, according to  the Diophantine equation $x+2y+3z=n$ has $\left\lfloor \dfrac{n^2}{12}+\dfrac{n}{2}+1 \right\rfloor$ non-negative solutions for $(x,y).$  Is there any closed form for the number of non-negative integer solutions for $(x_1,x_2,\cdots,x_k)$ of $$x_1+2x_2+3x_3+\cdots+kx_k=n$$ for a given $k\in\Bbb{N}$? How can I prove these formulas rigorously?  EDIT After a very tedious calculation I found that the equation $w+2x+3y+4z=n$ has  $\left\lfloor \dfrac{n^3}{144}+\dfrac{5n^2}{48}+\dfrac{(15+(-1)^n)n}{32}+1 \right\rfloor$ solutions. This solution completely agree with the approximation given by Rus May. However still I believe that we can do something more than this.


How to prove $\big | e^{it}-1 \big |=2 \bigg |\sin \left(\frac{t}{2}\right) \bigg |$

i started by rewriting:$$\big | \cos(t)+i\sin(t)-1 \big |=2 \bigg |\sin \left(\frac{t}{2}\right) \bigg |$$$$\bigg | \frac{1}{2}(e^{it}+e^{-it})+\frac{1}2(e^{it}-e^{-it})-1 \bigg |=2 \bigg |\frac{1}{2}(e^{i\frac{t}{2}}+e^{-i\frac{t}{2}}) \bigg |$$ How do I get rid of the absolute value bars?


Stop Notepad++ warning if file has been modified from outside

How can I stop the warning that appears in Notepad++ if the file is modified from an external program or application?


How can I use biblatex in latextools for sublime text?

I am trying build this file: \documentclass{article}    \usepackage{filecontents} \begin{filecontents}{\jobname.bib} @article{einstein,   author = {Albert Einstein},   title = {the true about tree},   journaltitle = {Annalen der Physik},   year = {1905},   volume = {322},   number = {10},   pages = {891-921}  }  \end{filecontents}  \usepackage{biblatex} % \usepackage[style=abnt]{biblatex} \addbibresource{\jobname.bib}  \renewcommand*{\mkbibnamefamily}[1]{#1}%  \begin{document}  \section{Section}  \textcite{einstein} fez um bom trabalho.  As pessoas precisam de ajuda \cite{einstein}.  \printbibliography  \end{document}  I am using LatexTools package for Sublime Text and I getting this message:  Compiling /home/bismarck/exemplo/main.tex] Basic Builder: running pdflatex...done. running biber...done. running pdflatex...done. running pdflatex...done. No errors. Warnings:  /home/bismarck/exemplo/main.tex: LaTeX Warning: Overwriting file `./main.bib'. /home/bismarck/exemplo/main.tex:26: LaTeX Warning: Citation 'einstein' on page 1 undefined on input line 26. /home/bismarck/exemplo/main.tex:27: LaTeX Warning: Citation 'einstein' on page 1 undefined on input line 27. /home/bismarck/exemplo/main.tex:29: LaTeX Warning: Empty bibliography on input line 29. /home/bismarck/exemplo/main.tex: LaTeX Warning: There were   undefined references. /home/bismarck/exemplo/main.tex: Package biblatex Warning:  Please (re)run Biber on the file:(biblatex)                main(biblatex)                and rerun LaTeX afterwards.  [Done!]  My get a pdf file, but without reference page. What am I doing wrong? blg file: This is BibTeX, Version 0.99d (TeX Live 2015/Debian) Capacity: max_strings=35307, hash_size=35307, hash_prime=30011 The top-level auxiliary file: main.aux I found no \citation commands---while reading file main.aux I found no \bibdata command---while reading file main.aux I found no \bibstyle command---while reading file main.aux You've used 0 entries,             0 wiz_defined-function locations,             83 strings with 482 characters, and the built_in function-call counts, 0 in all, are: = -- 0 > -- 0 < -- 0 + -- 0 - -- 0 * -- 0 := -- 0 add.period$ -- 0 call.type$ -- 0 change.case$ -- 0 chr.to.int$ -- 0 cite$ -- 0 duplicate$ -- 0 empty$ -- 0 format.name$ -- 0 if$ -- 0 int.to.chr$ -- 0 int.to.str$ -- 0 missing$ -- 0 newline$ -- 0 num.names$ -- 0 pop$ -- 0 preamble$ -- 0 purify$ -- 0 quote$ -- 0 skip$ -- 0 stack$ -- 0 substring$ -- 0 swap$ -- 0 text.length$ -- 0 text.prefix$ -- 0 top$ -- 0 type$ -- 0 warning$ -- 0 while$ -- 0 width$ -- 0 write$ -- 0 (There were 3 error messages)


I got 1 reputation on SO meta, is it a bug?

I pinned the SO meta to the SE site switcher. I looked at my reputation and it is 1. When I go to SO meta I am not suspended or my reputation is one. Is this intended? The SO meta reputation in the site switcher should match the SO reputation.


How do I detect when a web page is loaded?

I want to write an application that detects when a page is loaded in the browser, then I should be able to insert content on top of the loaded web page? Anybody with an idea on how to do that?  Please note that I should be able to do this in any browser (Firefox/IE).  What language should I use to help me do this?  How do I detect this from an external application?  How should I integrate this with the browser?


Can I student visa holder in France exit Schengen from another country?

As a student in France with a long-term student visa, I want to go from Barcelona airport back to my country. Is it possible or do I have to exit from France only?


Switching between English and Swedish keyboard on Ubuntu 13.04

How can I switch between English and Swedish keyboard on my Ubuntu 13.04?


E.g.     If you thought that we only notice women who grace the covers of   prestigious fashion magazines, you’ve been mistaken.   or     If you thought we only notice women who grace the covers of   prestigious fashion magazines, you’ve been mistaken.   How do I know when "that" is OK to use and when not? Can anybody explain that? Are there any "tricks" how can I be sure that "that" is needed or not?


Speed of light in vacuum - is it really a constant and what is the accurate value?

Let's suppose that the speed of light would not be a constant but a function of something. As is quite clear now, universe is expanding exponentially. If the speed of light would actually be a function of this expansion, maybe in terms of cosmological constant... We would never find this out because the measure of distance (definition of meter) is now locked; meaning it is defined in terms of the speed of light! Also, in a way we know that the speed of light may indeed be a function of cosmological constant because very distant targets are escaping us faster than the speed of light? Is it hence indeed so that the speed of light just can't be measured, or defined currently by any independent means?


How do I position these two blocks next to each-other correctly?

I want to try achieve something like this image:   So far my attempt is that I have a div for the left column (that contains the image), and a div for the right column which contains the heading and the paragraph stuff. Both of them are displayed as blocks, and floated left. The left column has a fixed with of 96px since the image will be that size. The right div is a percentage width which I eyeballed (65% worked okay).  However, I don't think this is the right way to approach this without it messing up later. Am I approaching this correctly? What is the proper way to do this kind of thing?


Is it the same time, does time pass at the same pace everywhere in the universe?

According to big bang cosmology, the universe has a beginning, a definite age. Does this mean that it is the same time, that time passes at the same pace everywhere?


What is the best symbol to use for the d'Alembertian?

Normally, most people use the symbol $\Box$ to represent the  (including the linked to Wikipedia page).  Recently I wanted to use \hat\Box and \tilde\Box, but they do not render very well.    What is the "best" way to create such symbols?    Aside: The above image is rendered using my local install of pdflatex: pdfTeX 3.1415926-1.40.10-2.2 (TeX Live 2009/Debian). The symbols seem to render fine on some online services: e.g. "" produces    from   \begin{align*} \Box &= \sum_a \partial^a\partial_a \,, & \hat\Box &= \sum_a \mathcal{D}^a\mathcal{D}_a \end{align*}


How to change the value of a progress bar through your Main - Nullpointerexception error

I am trying to add a value and display it on a progress bar i have created on a jframe through my main (because i have methods left and right and i want that value to be from 1 of theses) but when i run it it gives me    Exception in thread "main" java.lang.NullPointerException    i understand that i have to initialize the "var" so I wont be getting that error but i dont really know how. (i am kind of new to java)    This is my code (there are probably unnecessary stuff here but they were created automatically through the design)    import java.io.IOException;  public class UI extends javax.swing.JFrame {  /**  * Creates new form UI  */ public UI() {     initComponents(); }   /**  * This method is called from within the constructor to initialize the form.  * WARNING: Do NOT modify this code. The content of this method is always  * regenerated by the Form Editor.  */ @SuppressWarnings("unchecked") // <editor-fold defaultstate="collapsed" desc="Generated Code">                           private void initComponents() {      p1hp = new javax.swing.JProgressBar();      setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);      javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());     getContentPane().setLayout(layout);     layout.setHorizontalGroup(         layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)         .addGroup(layout.createSequentialGroup()             .addContainerGap()             .addComponent(p1hp, javax.swing.GroupLayout.PREFERRED_SIZE, 200, javax.swing.GroupLayout.PREFERRED_SIZE)             .addContainerGap(768, Short.MAX_VALUE))     );     layout.setVerticalGroup(         layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)         .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()             .addContainerGap(469, Short.MAX_VALUE)             .addComponent(p1hp, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)             .addGap(100, 100, 100))     );      pack(); }// </editor-fold>                          /**  * @param args the command line arguments  * @throws java.io.IOException  */ public static void main(String[] args) throws IOException {       java.awt.EventQueue.invokeLater(new Runnable() {         @Override         public void run() {             new UI().setVisible(true);         }     }); // THIS IS WHAT I AM TRYING TO DO   p1hp.setStringPainted(true);   p1hp.setValue(12);   }  // Variables declaration - do not modify                      public static javax.swing.JProgressBar p1hp; // End of variables declaration    }   aside that though, i tried creating a button, which i added thoses 2 lines  and it worked fine (the code for the button isnt here)    Note1: I manually maked the progressbar static bacause if not, I would get the error    non-static variable p1hp cannot be referenced from a static context   Note2: I have read this answer:  Still not sure how to fix it    Note3: I am using Netbeans 8.2


Can I replace my domain controller with Azure Active Directory?

I currently have a small network with a few servers and about 25 client PCs. We are using Office365 and have AD synchronisation setup from our on-premise server. We also have single-sign-on setup using ADFS.  We have recently replaced all but 2 of our servers with Azure virtual machines.  The only thing we now use our internal servers for is the Active Directory and ADFS.  So - my question is this... Can I setup an Azure Active Directory, sync my on-premise directory to it, get Office365 to talk to the Azure Active Directory and then decommission my on-premise servers?  Will my local client PCs authenticate against the Azure Active Directory?  If the answer is, "Yes" - any suggestions for how to achieve this would be great. If the answer is, "No" - some information on why not would be great!  Thanks!


includes an URL with a ?, which is not correctly parsed. I think it should be.  Actually, I wanted to include the image that is autogenerated from the URL, to show a point of my answer, this did also not work.


Are there any research careers except professorship for a person holding PhD in pure mathematics?

I'm interested in mathematical research, but want to know if there are good jobs besides being a professor.  Are there any lucrative research-centric careers out there for someone with a PhD in pure mathematics?


A Live Linux Distro which is as small as possible (no X, no networking, bash)

I've been trying to find a Linux distribution to fit my needs but I need something that seems to be more minimal then "minimal" distributions (Eg: Microcore Linux) seem to provide.  I don't need X, I don't need networking, I need something that can launch a bash script, which runs a modified version of , which talks to a serial device and outputs information to a user via the normal console and nothing else. It'll be booted from read only media (Probably a disc but could also be write protected SD card) and will run on x86 platforms. It'll need to access SATA/IDE hard drives. I don't have any memory limitations but anything that isn't being used needs to be gone.  Can anyone point me in the right direction or perhaps to a tool which can build something I am looking for? I'm hoping to spend as little time as possible on altering an existing distribution so I can focus on the application itself.


Prove that $a^{(p-1)/2} \equiv 1$ (mod p) and $a^{(p-1)/2} \equiv -1 \pmod p$

I've stumbled upon this congruence very similar to Fermat's Little Theorem, but I can't seem to wrap my head around how to solve it. It goes like this:     i) Suppose $p$ is prime, $(a,p)=1$ and the congruence $x^2 \equiv a \pmod p$ has a solution $x$. Prove that $a^{(p-1)/2}\equiv 1 \pmod p$.   And the same question but with an additional condition:     ii) Suppose $p$ is prime, $p \equiv 3  \pmod 4$, $(a,p) = 1$ and the congruence $x^2 \equiv a \pmod p$ does not have a solution $x$. Prove that $a^{(p-1)/2}\equiv -1 \pmod p$.   For i: Since $x^2 \equiv a \pmod p$ has a solution, we know that $p \mid x^2 - a$, hence $kp=x^2-a$ for some integer $k$, or $a = x^2-kp$. Now this doesn't really help me much!  For ii: Similarly stumped.


Changing outlet with 3 live wires, 3 neutrals, and 1 ground. Question / seems kinda crowded?

Images:   I was going to change out this outlet.  It was previously all shoved together in a back-wire type outlet (The kind you just stab in). Was going to replace with a new side-wire outlet, but wasn't expecting 6 total wires.  For now, I've just pig-tailed the 3 live wires together, & the 3 neutral wires together, so that the next several outlets down work (crucially, the refrigerator's outlet doesn't work unless these are all connected).  Couple questions:   So I'd just pigtail in 2 more wires - 1 white wire to the 3 neutral wires, and 1 black wire to the 3 live wires, then connect those to single posts in the new outlet? Is this not...excessively crowded in that electrical box? Is that OK? Anything else I'm missing that means I'm going to burn down my house?   Thanks,


I've seen  which Microsoft put out covering how to remove SSL 2.0 on IIS 7.0 and earlier, but I can't find anything advising on how to do the same on IIS 7.5. The registry keys mentioned on that KB article are no longer in the registry.


How can I make a bigger dent in close vote reviews?

I have 40 close votes per day, which I can go through in 15-20 minutes on reviews (or much less if I filter to opinion-based/too-broad).  The current close vote queue size is 90.7k. At 4 remaining normal user votes per close that's about 362,800 total votes needed.  This means every day, I can contribute 40/362,800 = 0.011% of the total work required to take care of that queue.  That seems... low. Is there some way I can make a bigger dent?  Also, are there statistics available that show, for a given day (or on average per day), the number of new items added to the close review queue, the number of votes on questions in that queue, and the number of users who typically participate in reviews (I know there's the stats site I just don't know how to make this query)?


Is a field just a commutative ring?  My algebra professor didn't give a very wide introduction to this algebraic structure, and I did not get a real grasp of what a field is.  We're studying polynomials of $\mathbb{K}[x]$ and he keeps repeating $\mathbb{K}[x]$($\Bbb{C}[x], \Bbb{R}[x] $ or $\Bbb{Q}[x]$) are fields so they have $y$ or $z$ property, but I don't get the difference between them and a commutative ring.


I am new to this field of SEO.  My site is intended to target local customers only.  I want to generate quality backlinks for my site. Is there any tools to generate quality backlinks. Or blog sites to improve count of backlinks.  I am trying to improve my page ranking .  Any Other SEO tips also would be highly appreciated!  Thanks in Advance


Separate polygons based on intersection using PostGIS

I have a PostGIS table of polygons where some intersect with one another.  This is what I'm trying to do:   For a given polygon selected by id, give me all of the polygons that intersect.  Basically, select the_geom from the_table where ST_Intersects(the_geom, (select the_geom from the_table where source_id = '123')) From these polygons, I need to create a new polygons such that intersection becomes a new polygon.  So if polygon A intersects with polygon B, I will get 3 new polygons: A minus AB, AB, and B minus AB.   Any ideas?


Currently I have Ubuntu MATE 14.04 installed on my system. I have a Windows setup file of Counter Strike 1.6. I have installed WINE from Ubuntu Software Centre. Counter Strike 1.6 has been successfully installed on my system through WINE but when I am about to run it, it does not run, though it has been installed. Can anyone help me in fixing it?


Prove $(A+B)^2 = A^2 +2AB + B^2$ for commutative matrices

Hello i just need some help with proving that $(A+B)^2 = A^2 +2AB + B^2$ holds for commutative matrices. Maybe by induction ?


what is difference between the two comparative adjectives while used in the same sentence?

Your room is clearer than mine AND your room is more clear than mine  Comparatives like these are many used in the same fashion such as neater/ more neat-- cleaner/ more clean etc. Having been into English grammar, I find myself bemused to figure their differences, thereby left wondering if anybody could help me comprehend their contextual connotation, Thanks in advance


In an earlier question  I asked in general about the symbol table for an Apex class.  Using the Tooling API wrapper from  I am able to get part way there. But am unGodly confused.  If I go to the developer console, query editor, check the "Use Tooling API" box and run this query:  Select Id, Name, symbolTable FROM ApexClass Where Name Like '%NewCaseListController%'   I get back an ID, Name and [object Object] for the symbol table, meaning there is a symbol table object there.   But if I try the same query in Apex code in the execute anonymous window I get the error:   System.CalloutException: Web service callout failed: Unable to parse callout response. Apex type not found for element location   If I do this in Apex I can get a result back, and according to the code for the class the result should be of type ToolingAPIWSDL.QueryResult. The QueryResult should contain a member consisting of a list of sObject_x records sObject_x[], unless I am mis-reading what that means.  ToolingAPIWSDL.QueryResult result = tooley.query('select Id, Name from ApexClass WHERE Name Like \'NewCaseListController\'');   I can take the result and apparently put the sObject_x object in it like this:  List<ToolingAPIWSDL.sObject_x> objList = new List<ToolingAPIWSDL.sObject_x>(); for(Integer i = 0; i<result.records.size(); i++){     objList.add(result.records[i]); }   At least that does not throw an error and I can write:     System.debug('objList: ' + objList[0]);  And get a result, but how do I access the symbol table? Or more to the point, how can I get a list of methods and variables? I am assuming the symbolTable is the only way?


I am just wondering if my camera is an SLR camera?   It is a Panasonic Lumix DMC-FZ45.   Could you also tell me what an SLR camera is? I have read a few descriptions but still am not sure.   Thanks :)


I'm trying to add a loopcut to a filled in part of my mesh. why won't it work?


Intergrating product of multivariate normal and univariate normal to find marginal density

Suppose, $y_i|u_i\sim MN(X_i(t_i), \sigma_e^2I_{m_i})$ and $U\sim MN(0,I_p)$. Now how to find the marginal distribution of $f(y_i)=\int f(y_i|u_i)f(u_i)du_i$? Since one is multivariate normal and other is univariate normal, can we actually find the product before the integration? Or it will be a no-closed form expression? Even if it's the case, how do we come up with the no-closed form expression? $X_i(t)=\dfrac{exp[Z_i(t)]}{\int_a^dexp[Z_i(s)]ds}$ and $Z(t)= b(t)^Tc+b(t)^TAU $ So $X_i(t)$ is determined by $u_i$ via $Z_i$ Here $X_i(t)$s are functions at grid points $[t_{i1},...,t_{im_i}]$


Minimum distance from points to nearest line among multiple lines shapefile

I am new to QGIS. I am looking for any plugin or any manual method in QGIS for finding minimum distance (perpendicular distance) from a point which is part of one shapefile to nearest line among many lines which is part of another shapefile. MMQGIS is not useful for this purpose.   I used v.net.connect command.  I am getting minimum distance (perpendicular distance) from points which are part of one shapefile to nearest line among many lines which is part of another shapefile, but there is one problem. I am not identifying from the attribute table which distance belongs to which line.   In the attribute table, there 32 distance values for 32 points w.r.t nearest line. Is there any method to identify which distance value is belong to which nearest line? I want to identify the line identity in attribute table w.r.t distance value