Sir or Mr with first name only
Can "Mr", "Mrs", etc. be used with a first name?
Drupal is fast at develop, but the performance is so poor.  It is hard to reach 50 request per second.  And there are so many SQL queries in a simple web page.  If you test the request time of a form submit in Drupal.org it will always take seconds to finish.  How do you improve the speed of your web site? Got this problem from a friend and would like some pointers if anyone has any.  Fill an $n \times n$ matrix with the symbols $\{a,b,c,d\}$ subject to the following:     Only the symbol $a$ appears to the left or above an $a$    Only the symbol $b$ appears to the right or above a $b$    Only the symbol $c$ appears to the left or below a $c$    Only the symbol $d$ appears to the right or below a $d$     Here are some examples of a valid fillings: $$\left( \begin{matrix} a &amp; a &amp; b  &amp; b \\ a &amp; a &amp; b &amp; b \\ c &amp; c &amp; c &amp; d \\  c &amp; c &amp; c &amp; d  \end{matrix}\right) $$  $$\left( \begin{matrix} a &amp; a &amp; a  &amp; a &amp; a &amp; b  &amp; b \\ a &amp; a &amp; a  &amp; a &amp; a &amp; b  &amp; b \\ a &amp; a &amp; a &amp; d &amp; d &amp; d &amp; d \\  a &amp; a &amp; a &amp; d &amp; d &amp; d &amp; d\\a &amp; a &amp; d &amp; d &amp; d &amp; d &amp; d\\c &amp; c &amp; d &amp; d &amp; d &amp; d &amp; d\\  c &amp; c &amp; d &amp; d &amp; d &amp; d &amp; d  \end{matrix} \right) $$  What I have done: We'll it is clear to me that the $a$'s (for example) make up a sort of Young Diagram just by the property above. But there is more to the problem than that. If your YT for $a$ is just a square, then you might have a reversed (right justified) YT available to place for the $b$'s. Details like this seem to make this a tricky problem for me. I am intrigued by this problem and I just thought I'd share it here in case there is some easy way to do this counting problem that I've never heard of.  Thanks, I have a stupid self-answered question. Should I accept my own answer? was genuine at the time, but I realised that  gave the right advice, but required me to restart my Linux (which wasn't mentioned in the solution).  It's a bit of a  question and  points to me not deleting it.  But it seems hugely self-aggrandizing to accept my own answer. Should I? How to disable system beep for non-privileged user I was wondering if $\mathbf{A}\times\mathbf{C}=\mathbf{B}$ and $\mathbf{A}\cdot{\mathbf{C}}= p$, is it possible to express C in terms of A, B, and p?  Note: A, B, C are vectors and p is a scalar.  Sorry if this question has been asked before. If so, can anyone give me a link to it? Skins that cannot be in mystery gifts? Yesterday I had a discussion with some of my friends while playing league. It was about the contents of the mystery gifts and while I said there are restrictions, they were convinced that you can get absolutely every skin from a gift (including victorious, and really old ones).  Now while I'm pretty sure that there are restrictions (Triumphant ryze for example), I'm not really sure on which skins they affect.   What about the victorious, riot, legacy, pax and completely removed skins (Rusty BC, Black Ali, Urf WW)? Can you get those with a mistery gift or is it impossible to get those right now? Photoelectric Effect - Dependence of current on frequency We all know that the amount of current flowing b/w the plates is independent of the frequency. If I were to ask why doesn't it depend then you'd probably say that it depends on the number of electrons rather than the frequency or you might show me a current vs frequency graph.  But here is my theoretical argument. Electric current is defined as the amount of charge flowing through a point/space/wire per unit time. Let I be current due to photo electrons ejected by photons of some frequency. Now if I would increase the frequency, the kinetic energy of the ejected electron would increases, therefore it will move faster and therefore contribute more current (charge will through the same point many times per unit time) . Thereby, giving a net current greater than I.  What is wrong with my argument?  After thinking a lot, I came up with a possible reason. However fast the electrons may move, but when they hit the metal plate, they would lose their velocity and start moving in drift velocity. Now there is a problem with this argument. If this were to be true then I should expect to see a big chunk of extra electrons getting stuck at the anode.  If my reasoning was correct, then why can't I see a big charge buildup at the anode. Why do stars flicker? Why do stars flicker and planets don't? At least this is what I've read online and seen on the night sky. I've heard that it has to do something with the fact that stars emit light and planets reflect it. But I don't get it, isn't this light, just "light"? What happens to the reflected light that it doesn't flicker anymore?  I was thinking that it has to do something with Earth's atmosphere, different temperatures or something (if this has any role at all). What does \s! do? What happened to this user's rep, badges, and name? This user is only displaying 56 rep.   But surely (s)he has much more than that.        The user has also never given out any bounties.  Also, badges are missing: Get the real width and height of an image with JavaScript? (in Safari/Chrome) Is there an online course in Mathematical Methods for Physics, Covering Matrices and Vector Analysis? I am taking a course in Mathematical Methods for physicsPhysics (Junior Level).   We are working from   > Mathematical Methods for physicists, George B.Arfken .    I just need online resources covering ( Matrices, Determinants, Vector Analysis, Tensors and differential forms and Vector spaces...etc) to study and understand from. There's something funky about some titles in revision histories here on Meta Stack Exchange How can I copy one side of a rig to the other? Objects disappear when looking through camera Name of mean absolute error analogue to Brier score? Yesterday's question  got me curious about probability scoring. The  $$\frac{1}{N}\sum\limits _{i=1}^{N}(\text{prediction}_i - \text{reference}_i)^2$$ is a mean squared error measure. Does the analogous mean absolute error performance measure $$\frac{1}{N}\sum\limits _{i=1}^{N}|\text{prediction}_i - \text{reference}_i|$$ have a name, too? Let $G$ be a finite group and $F$ a field with $\mathrm{char}(F)=0$ or coprime to $|G|$. Let $V$ be a $FG$-module in a way that every $ FG$-homomorphism $ f : V \to V $ is given by $f(x)= \lambda x $. Then $V$ is irreducible.   I already managed to proof this by contradiction, using Maschke's Theorem. We can  write $V$ as $U\oplus W$ and get a $FG$-homomorphism $\pi:U\oplus W \to U\oplus W$, $\pi (u+w)=u$, then $\pi(u+w)=\lambda (u+w)=u $ then either $U$ or $W$ are trivial and thus $V$ is irreducible.  My question is if this statements still holds if the characterictic of $F$ divides the order of $G$, since I only used this fact in my proof to use Maschke's theorem. Could someone please provide an explanation for the origin of ? (Ideally someone who I have been speaking with on the h-bar)  Any advanced maths beyond basic calculus will most probably leave me at a loss, though I do not mind a challenge! Please assume little prior knowledge, as over the past few days I have discovered that much of my understanding surrounding the process as virtual particle pairs is completely wrong. What is the command to open the shutdown dialog? A sequence includes $a_p=\sqrt2$, $a_q=\sqrt3$, $a_r=\sqrt5$ for some $1\leq p<q<r$. Can these be terms of an arithmetic progression? harmonic?