event fired by a future loaded element
jQuery .on function for future elements, as .live is deprecated
If $p$ and $q = 2p + 1$ are both odd primes, show that $-4$ and $2(-1)^{(1/2)(p-1)}$ are both primitive roots modulo $q$.   I cannot get heads nor tails of how to even start this let alone finish it When did UX start being called UX? When did people start talking about User Experience as a role/domain similar to the way that it's used today?  The earliest reference I can find is the Norman, Miller, Henderson CHI 95 piece on Apple's set up (Donald Norman, Jim Miller, Austin Henderson: What You See, Some of What's in the Future, And How We Go About Doing It: HI at Apple Computer. Proceedings of CHI 1995, Denver, Colorado, USA)  Anything earlier?  [Edit - after @Andrew's nice answer we have 1993 as an earlier date     "I invented the term because I thought Human Interface and usability   were too narrow: I wanted to cover all aspects of the person's   experience with a system, including industrial design, graphics, the   interface, the physical interaction, and the manual." - Don Norman   ]  (I'm writing a talk on communities of practice relating to UX - and want to get my time lines right ;-) How is using a transformer for isolation safer than directly connecting to the power grid? How is using a 1:1 transformer safer than using the mains straight off? Is it because you can limit the current coming from the transformer whereas straight from the mains its not current limited? I fail to see how its "safer" when playing with electricity is dangerous. Could someone please explain why it is considered safer to be isolated by a transformer. Cardioid in coffee mug? Characterizing all mobius transformations from unit disk to itself. All answers to this problem involve the following process:   Pick a point $a$ in the unit disk such that $T(a)=0$. Then, $T(a^*)=\infty$ if $a^*$ is the symmetric point $a^*=\frac{1}{\bar{a}}$ of a. Clearly, such a transformation is of the form $T(z)=\frac{z-a}{1-z\bar{a}}$. We might as well place a constant C in there: $T(z)=C\frac{z-a}{1-z\bar{a}}$. Then, most answers magically jump to replacing $C=e^{i\theta}$ in the formula and claiming the job is done.  Why does a function built so that it sends a point inside the unit disk to zero, and its symmetric point to $\infty$, be the one that preserves the unit disk? What's the motivation behind approaching this problem in that manner? Could one proceed bruteforce: with $|\frac{az+b}{cz+d}|&lt;1$ and arrive at the same function? For some reason this seems to me like somebody pulled a rabbit out of a hat. Once given the formula, I understand why it does the job, but why would somebody think that choosing a point inside the disk and building a function that sends it to zero create a mobius transformation that does the job? Change ViewPager animation duration when sliding programmatically Make clear which profile data is visible to whom Generating a separate pdf file of tables and figures from a latex file? Is it possible to generate a PDF of figures and tables of a paper from LaTeX itself?  I saw Journals and Conferences asking for a separate file of tables and figures.  In  question, questioner proposed a method that uses \usepackage{endfloat} to push all the figures and tables to the last pages and then use a PDF editor to cut the last pages of PDF. This is a solution but not a good one. LaTeX should be able to do this by its own.  What I have in mind is to compile the LaTeX file and it generates a complete PDF output and beside that a separate file that contains all the figures and tables of former PDF. Efficiently select beginning and end of multiple contiguous ranges in Postgresql query I've got about a billion rows of data in a table with a name and an integer in the range 1-288.  For a given name, every int is unique, and not every possible integer in the range is present--so there are gaps.  This query generates an example case:  --what I have: SELECT * FROM ( VALUES ('foo', 2),               ('foo', 3),               ('foo', 4),               ('foo', 10),               ('foo', 11),               ('foo', 13),               ('bar', 1),               ('bar', 2),               ('bar', 3)      ) AS baz ("name", "int")   I'd like to generate a lookup table with a row for each name and sequence of contiguous integers.  Each such row would contain:  name   --  the value of the name column start  --  the first integer in the contiguous sequence end    --  the final value in the contiguous sequence span   --  end - start + 1  This query generates example output for the above example:  --what I need: SELECT *  FROM ( VALUES ('foo', 2, 4, 3),               ('foo', 10, 11, 2),               ('foo', 13, 13, 1),               ('bar', 1, 3, 3)      ) AS contiguous_ranges ("name", "start", "end", span)   Because I have so many rows, more efficient is better.  That said, I only have to run this query once, so it isn't an absolute requirement.  Thanks in advance!  Edit:  I should add that PL/pgSQL solutions are welcome (please explain any Fancy Tricks--I'm still new to PL/pgSQL). I am working to build a reinforcement agent with DQN. The agent would be able to place buy and sell orders for a day trading purpose. I am facing a little problem with that project. The question is "how to tell the agent to maximize the profit and avoid the transaction where the profit is less than 100$".  I want to maximize the profit inside a trading day and avoid to place the pair (limit buy order, limit sell order) if the profit on that transaction is less than 100$. The idea here is to avoid the little noisy movements. Instead, I prefer long beautiful profitable movements. Be aware that I thought using the "Profit &amp; Loss" as the reward.  "I want the minimal profit per transaction to be 100$" ==> It seems this is not something that is enforceable. I can train the agent to maximize profit per transaction, but how that profit is cannot be ensured.  At the beginning, I wanted to tell the agent, if the profit of a transaction is 50 dollars, I will remove 100 dollars, then It becomes a penalty of 50 dollars for the agent. I thought it was a great way to tell the agent to not place a limit buy order if you are not sure it will give us a minimal profit of 100$. It seems that all I would be doing there is simply shifting the value of the reward. The agent only cares about maximizing the sum of rewards and not taking care of individual transactions.   How to tell the agent to maximize the profit and avoid the transaction where the profit is less than 100$? With that strategy, what guarantee that the agent will never make a buy/sell decision that results in less than 100 dollars profit? Does the sum of reward - # transaction * 100 can be a solution? Suppose $f$ and $g$ are continuously differentiable functions such that $f(x) = g'(x)$ and $g(x) = f'(x)$ and that any product of $f, f', g$ and $g'$ is commutative for all $x ∈ R$. Show that $ f^2 − g^2 = C $ for some real constant C  I have actually no clue how to solve this, and would be really greatfull for all the help i can get Is it okay to vectorize this image to make a poster out of it even though the image is not Creative Commons or anything like that? I'm not using any part of the image directly and only going to use it as a guide to make my own SVG version.  This is the image:    Here is .  It says that it is CC licensed but the original NatGeo one isn't, I don't think.  I don't plan to make money off it or anything, I just want a nice poster and the quality of the original isn't that good. As you can see, objects are falling down when I run the game. Ground is unable to stop those obstacles. Obstacles are rapidly traveling through y axis. I tried by freezing y axis. And, unchecked Use Gravity. I tried by checking Is Kinematic also. But, if I freeze y axis. Than, obstacles completely freeze through y. If there was no ground than the objects don't fall. Same thing happen when I unchecked Use Gravity. I want those obstacles to move if Player hit them. How to stop those obstacles from falling down?   Info : $\chi(G)+\chi(G')\leq n+1$ How to prove, that the sum of chromatic numbers of graph and it's complement is smaller then the number of vertices incremented by one?  $\chi(G)+\chi(G')\leq n+1$  The notes from my classes say to color the first graph using sequential algorithm with vertices ordered by their degrees (the ones with lowest appear first). We would get $k_1$ colors, then we color the graph $G'$ in the backwards order and get $k_2$ colors, and the sum $k_1+k_2$ in my notes is magically smaller than $n+1$, but I just don't see why... I want to know if there is another way to solve the equation:  $$(x+1)^y-x^z=1$$  for positive integers $x,y,z$ greater than $1$ without using the Catalan identity. Does exist? By now I only know that $x\mid y$. Why do we use residuals to test the assumptions on errors in regression? Suppose that we have a model $Y_i = \beta_0 + \beta_1X_{i1} + \beta_2X_{i2} + \dots + \beta_kX_{ik} + \epsilon_i$.  Regression has a number of assumptions, such as that the errors $\epsilon_i$ should be normally distributed with mean zero and constant variance. I have been taught to check these assumptions using a normal QQ plot to test for normality of the residuals $e_i = Y_i - \hat{Y}_i$ and a residuals vs. fitted plot to check that the residuals vary around zero with constant variance.  However, these tests are all on the residuals, not the errors.  From what I understand, the errors are defined as the deviation of each observation from their 'true' mean value. So, we can write $\epsilon_i = Y_i - \mathbb{E}[Y_i]$. These errors cannot be observed by us. *  My question is this: how good of a job do the residuals do in mimicking the errors?   If the assumptions appear to be satisfied on the residuals, does this mean they are satisfied on the errors too? Are there other (better) ways to test the assumptions, like fitting the model to a testing dataset and getting the residuals from there?    * Furthermore, does this not require that the model is specified correctly? That is, that the response really does have a relationship with the predictors $X_1, X_2,$ etc. in the way specified by the model.  If we are missing some predictors (say, $X_{k+1}\ \text{to}\ X_p$), then the expectation $\mathbb{E}[Y_i] = \beta_0 + \beta_1X_{i1} + \beta_2X_{i2} + \dots + \beta_kX_{ik}$ would not even be the true mean, and further analysis on an incorrect model seems pointless.  How do we check whether the model is a correct one? Are DSLRs a dying breed, making now the time to switch to a mirrorless camera system? Why would Littlefinger want this person dead? How to position the paper's authors' addresses on the front page (maketitle)? When I use the following code for the title page of a paper (please see below), the authors' addresses and emails appear on the last page of the paper. However I need them to appear on the first-title page (after the authors' names before the abstract). How can I do this?  \documentclass [reqno, 12pt ]{amsart} ... \begin{document}  \title[paper]{Nice paper}  \author{Me} \address{University} \email{mmm@lala.com} \thanks{.} \author{my friend} \address{Institute} \email{kkk@lala.edu} \thanks{.}  \date{\today} \keywords{XXX }  \begin{abstract} Lalala \end{abstract}  \maketitle How to prove that 2017 divides $1^{2017}+2^{2017}+\dots+2017^{2017}$? How can I prove that $2017 \mid 1^{2017}+2^{2017}+\dots+2017^{2017}$? I tried proving it with the use of modulo, however it was to no avail. Afterwards, I  tried researching, for possible theorems, that may help, but that bore no fruit, either. Can you guys please help me proving it, as I am stuck? Thanking you in advance.