Im currently able to detect an item in a players inventory and it is only active if the player is holding it while pressing the button that activates the chosen item. But I've been trying to get a chained, conditional, Always active block after it to remove the item after pressing the button. Is it possible to do so?

I'm messing around with command blocks, and I'm wanting to try and make an XP vending machine. My idea is if you click a button with a Diamond in your hand, 1 diamond gets removed and you get x amount of XP.  Is this possible using command blocks? If so, what commands would I need to look at? I already know /xp myAmount @p, it's just the checking/removing of items I can't seem to get.


I deleted my documents and downloads folder. How can I get them back. I don't want them to be like any other folder, I would like it to be like how it used to be where it shows on the side of the filesystem. Any idea on how i can get it back like that.

I removed the original Downloads folder in the home directory and created a new one with the same name, but the down arrow icon on the new Download folder now disappeared. Could someone please tell me how to restore that icon?   In addition, from the image above we see "Downloads" disappears also in "Places" category in the left panel. I think it should be there originally. If after restoring the down arrow icon, the "Downloads" is still not in "Places" category, I would also like to ask you to help me put "Downloads" back to "Places". Thank you.  PS: I am not using any theme.


the graph of continuous function $f:\Bbb{R}\to \Bbb{R}$ has measure $0$.  the graph of measurable function $f:\Bbb{R}\to \Bbb{R}$ is measurable. it can also be shown it has measure 0:   But could you show me an example of:   (noncontinuous) function with graph of positive measure? (nonmeasurable) function which has nonmeasurable graph?   Thanks in advance.

Let $f:R^n \rightarrow R^m$ be any function. Will the graph of $f$ always have Lebesgue measure zero?  $(1)$ I could prove that this is true if $f$ is continuous.  $(2)$ I suspect it is true if $f$ is measurable, but I'm not sure. (My idea was to use Fubini's Theorem to integrate the indicator function of the graph, but I don't know if I'm using the Theorem properly).  If $(2)$ is incorrect, what would be a counterexample where the graph of $f$ has positive measure?  If $(2)$ is correct, can we prove the existence of a non-measurable function whose graph has positive outer measure?


I have a following code,          var options = {             'x': 250,             'isVirtual': true,           }   var arr[0] = {          'y': 250,                 }   i need to add the options keys(instance) to arr[0].. how to add?  my expectation output is,  arr[0] = {           'x': 250,           'isVirtual': true,           'y': 250,    }

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


I am from the former soviet union, and I have just got my green card after a few years ago.  I am still stateless and have applied for a refugee travel document which may or may not come through.  My question is, if I get my Refugee Travel Document, do I still need a schengen visa?  I just need to go to Germany for about a week for training for my job.  That's all.

I just want to double check to make sure I won't run into any issues at the border of entry.  I'm a permanent resident of the USA with a green card and I have a travel document issued by the USA (I-571). Will I have any issues traveling around in the Schegen countries?  Do I need a visa? Do I have to pay any fees?


I got an assignment from which nothing is clear for me.  I have the following logistic regression formula:    and what I am struggling in understanding how to do is to the to prove that this equation is true for binary logistic regression with one continuous predictor.  What should I do? Should I plug inside some values and solve it? Moreover, I don't understand what does pie stands for, what does it denotate?

What is the difference between linear regression and logistic regression?  When would you use each?


I remember reading this novel ten or more years ago. The prologue had the narrator reminiscing of Tokyo Bay and condoms floating onto the shore. The protagonist seems to be an immortal or incredibly long-lived human with powers to create or morph planets to his liking. There appear to be numerous similar individuals of different alien races who travel around the Galaxy, creating hospitable worlds. I think one of the worlds had silicon-based life on it.

I read this at least 20 years ago, and I believe it was originally published in the '60s.   The main character is a human, but somehow "inherits godhood" from an alien, whose species is very long lived. IIRC this is one of the old-style god thingies, i.e. "god of thunder" not "omniscient omnipotent omnipresent transcendent being".  The plot somehow revolved around identifying and fighting some enemy which, I believe, was in turn a member of the alien species who acted as the avatar of the opposite god in the alien pantheon.  The only thing I remember for sure is that the enemy was identified as "green green" or "gringrin" (sadly, I read this in translation so I am not sure what the original meant)


I have this bowl of sodium polyacrylate (Insta-Snow) that has been drying out for a few weeks.  At this point it consists of solid pieces ranging in size from 3 or 4 mm across to much smaller ones that form a fine powder. I can stir them around and mix them but if I hold the bowl at a slight angle and shake it for few seconds they sort themselves out with the smallest particles at the higher part of the bowl and the largest ones at the bottom.  The behaviour reminds me of seeing sand grains sorted on a beach by the action of waves.  How does this self sorting happen?  EDIT   If I put the particles in a cylindrical cup and shake them they sort themselves the opposite way with the largest particles on top but in the bowl it's the finest particles on top.  This seems to be a case of the reverse Brazil nut effect.  Clearly interactions between the particles and the container are part of the explanation.     I'm not sure what tags apply - feel free to edit.

Most of the time when I mixed different nuts in a bowl, I observed that the big Brazil nuts were always on top while the small peanuts settled near the base. No matter how you take it, if the big nuts are put at the bottom and then the small nuts are poured, then also after some time the big ones will come to the top. Will not the gravity attract those big nuts more and eventually will they not remain at the base? But it doesn't happen!   I googled it and found the term Brazil-nut Effect but couldn't find any proper explanation. What is the physical explanation for this effect?


My advisor obligate me to put her name first author name in my publication. What are the possible pros and cons of this order? What should I do if my advisor insists on being first author, in violation of my field's conventions? My field is IT.

When you look at a paper, what order to you assume the authors are in? Most important/most work done first or alphabetical? In my group we usually use alphabetic order, but I've been wondering if that might create a misleading impression with lots of people.  On a related note, would you expect the name of a PhD student to be always first on publications related to her/his work?


<form action="http://PasswordCheck/check.php" method="post" onsubmit="loadSyncPost();return false" id="my-form">         userName: <input type="text" id="username" name="userName">
         password: <input type="password" id="pass" name="password">         <input type="submit">     </form>
         tests  So I have this form that I want to submit and track the response from the PHP server to validate the password is correct, so I have this loadSyncPost function. Its not finished yet but the issue is, is that its showing that its undefined, and pulling up this error message: loadSyncPost is not defined at HTMLFormElement.onsubmit However, it is clearly defined. And if it was not defined there, I moved the script<> to before the form, and it still was pulling up that it is not defined. I'm wondering if its because I am trying to use AJAX and the function is inside the jquery function because I don't wait the page to reload when it occurs. What am I missing? Thank you guys

What is the scope of variables in javascript? Do they have the same scope inside as opposed to outside a function? Or does it even matter? Also, where are the variables stored if they are defined globally?


Let p be a prime number which is not equal to 2. Prove that if there exists an integer a such that $a^2 \equiv −1 \text{ (mod p) then }  p ≡ 1 \text{ (mod 4)}$  I am not sure how to solve this one. I know $p|a^2 + 1$, but I can't figure out how to relate this to p modulo 4.

Assume: $p$ is a prime that satisfies $p \equiv 3 \pmod 4$  Show: $x^{2} \equiv -1 \pmod p$ has no solutions $\forall x \in \mathbb{Z}$.  I know this problem has something to do with Fermat's Little Theorem, that $a^{p-1} \equiv 1\pmod p$. I tried to do a proof by contradiction, assuming the conclusion and showing some contradiction but just ran into a wall. Any help would be greatly appreciated.


I would like to know of a quick way to auto align LaTeX code where appropriate, similar to the ctrl + i keyboard shortcut used in MATLAB after highlighting a bunch of code that isn't aligned correctly.

I've been using Texmaker for ~5 years now and prefer it over other editors because of its flexibility.   Is there a way to auto-indent LaTeX code in TeXmaker so that the code becomes more manageable ?


I don't need to enumerate much about Voldemort's killings. He sometimes kills randomly (for example, recall the scene from the movie where just after Harry destroys the Diadem, Voldemort gets weakened for a moment. When a random death eater merely asked if his master was okay, Voldemort replied : "Avada Kedavra!" ) We also know the fact that killing rips the soul apart:  "But how do you do it?" "By the act of evil—the supreme act of evil. By committing murder. Killing rips the soul apart. The wizard intent upon creating a Horcrux, would use the damage to his advantage   (Horcruxes, Half-Blood Prince)  So we do incur damage when we murder. Slughorn also mentions that too much ripping is not too good:  "Merlin's beard Tom!" yelped Slughorn. "Seven! Isn't it bad enough enough to think of killing one person? And in any case...bad enough to divide the soul...but to rip it into seven pieces..." -Horace Slughorn (Horcruxes, Half-Blood Prince)  We see evidence that too much ripping is too bad in book 6:  His features were not those Harry had seen emerge from the great stone cauldron almost two years ago: They were not as snakelike, the eyes were not yet scarlet, the face not yet masklike, and yet he was no longer handsome Tom Riddle. It was as though his features had been blurred; they were waxy and oddly distorted, and the whites of the eyes now had a permanently bloody look, though the pupils were not yet the slits that Harry knew they would become. He was wearing a long black cloak and his face was as pale as the snow glistening on his shoulders. (Lord Voldemort's request, Half-Blood Prince)  I find Slughorn's point contradictory here. If Voldemort killed much more than the other wizards:  "As far as I know — as far, I am sure, as Voldemort knew — no wizard had ever done more than tear his soul in two" -Albus Dumbledore(Horcruxes, Half-blood Prince)  Why didn't his soul divide each time he killed? Here's another line that tells us that only certain deaths made the cut for a Horcrux:  "He seems to have reserved the process of making Horcruxes for particularly significant deaths" -Albus Dumbledore(Horcruxes, Half-blood Prince)  Does that mean his soul only ripped when he intended to make a Horcrux? According to  article on HP fandom, The circumstances of the murder also mattered. Snape's soul would not be divided under the circumstances of Dumbledore's murder, because of Dumbledore's intention:  It should be noted however, that killing in and of itself seems not to have the same consequences to a soul as committing deliberate murder  Voldemort hardly ever killed "deliberately" (Like how Snape kills Dumbledore) If the murders like those of James and Lily Potter are considered "delibrate", I don't see how they wouldn't hurt the soul. Killing here is purely of the evil intentions Voldemort has. Hence, I conclude that the soul must be damaged. Splitting your soul would also make it highly unstable. According to :  In fact, Voldemort's soul was so unstable that by the time he created five Horcruxes, it split on its own when his Killing Curse rebounded the first time, which caused the fragment to be removed from him and attached to Harry.  So why isn't his soul much more damaged than it should be?  EDIT: To make it clear, what I'm asking is, WHY is Voldemort strong enough even though his soul is so badly wounded? Does the soul have temporary regenerative properties to heal itself for the trivial murders Voldemort had done?

I think that we have it well-established (regardless of whether or not one sees this as flawed logic) that Harry is not a Horcrux.  A Horcrux has to be made intentionally, and the recipient is cursed and classified as an "evil object," etc.  Neither of which is true for Harry - so, as stated by JKR herself, Harry is not a Horcrux as such.  But the fact remains that murder can, in fact, accidentally create something that shares a key property of the Horcrux: the soul splits, attaches itself to the nearest recipient, and lingers inside.  As it does in Harry's case.  So my question is: is this only true for wizards?  A Muggle cannot utilize a spell to create a Horcrux.  But, if a Horcrux-like object / being can be created accidentally through murder without intentional Horcrux-creating spells, can this also happen in the case of a Muggle committing murder?    Can a Muggle commit murder, have their soul split, and have the piece of the soul inadvertently attach itself to something nearby without any Horcrux-creating spell being cast?


I have a 250 gb HDD running Ubuntu 16.04 and I want to migrate its contents over to a new 250 gb SSD.  I found  which gives pretty detailed instructions for doing do.  First I wanted to ask if this is a good and up-to-date set of instructions, since I don't really know who wrote it and it was posted 5 years ago.  Assuming it is, I'm curious about a couple of things.  For one, this is a pretty complicated set of steps.  Why can't I just image the existing HDD (say, with DD) and restore it to a blank SSD?  Also the instructions say that after moving things over I have to reinstall Grub.  Why do I need to do this if grub is already installed on the HDD?

My current situation is:   One hard disk Dual boot Ubuntu 11.04 and Windows 7. Partitions:  100MB Windows System thingy 144GB Main Windows 160GB Ubuntu 4GB Swap 12GB System Restore stuff    Now I want to install an 80GB SSD and move Ubuntu to it. AFAIK I need to:   Shrink the 160GB Ubuntu partition to 80GB Copy it over to the SSD Change fstab to mount the SSD as /   How do I do the second? And what do I need to do about Grub?


I am learning grammar and I feel some confusion between the usage of can I and could I. Is there some rule I should use?

When should I use can? When should I use could? What is right under what context?


Prove that the Taylor series about the origin of the function $[\log(1-z)]^2$ is given by    $$\sum_{n=1}^{\infty} \frac{2H_{n}}{n+1} z^{n+1}$$   where    $$H_{n} = \sum_{j=1}^{n}\frac{1}{j}$$   is the $n$-th partial sum of the harmonic series.   (Hint: Write $\log(1-z)$ as a power series for $|z| < 1$ and use Cauchy products for $[\log(1-z)]^2$)   I've been working on this question since last night and I've been trying to follow the hint and look at the derivative of $\log(1-z)$ and then integrate that, but all attempts have been futile.   Really lost here...

I'm having some trouble proving that the Taylor series about the origin of the function $[Log(1-z)]^2$ to be $$\sum_{n=1}^\infty \frac{2H_n}{n+1}z^{n+1}$$ where $$H_n = \sum_{j=1}^n \frac{1}{j}$$  So far, I've been trying to use the definition of Log(1-z) = log|1-z| + iArg(1-z). I've also noted that the Taylor expansion for log|1-z| = $\sum_{k=0}^\infty \frac{-z^{k+1}}{k+1}$ from integrating the geometric series $\sum_{k=0}^\infty z^k$ given |z|<1.  Because log|1-z| = $\sum_{k=0}^\infty \frac{-z^{k+1}}{k+1}$ converges for |z|<1, I've tried to use this for the Cauchy product of [Log(1-z)]^2   $$[Log(1-z)]^2 = Log(1-z) Log(1-z)$$ $$=\left(\sum_{i=0}^\infty \frac{-z^{i+1}}{i+1}\right)\left(\sum_{j=0}^\infty \frac{-z^{j+1}}{j+1}\right)$$ $$=\sum_{n=0}^\infty \sum_{k=0}^n\frac{-z^{k+1}}{k+1} \frac{-z^{n-k+1}}{n-k+1}$$ $$= \sum_{n=0}^\infty \sum_{k=0}^n\frac{z^{n+2}}{(k+1)(n-k+1)}$$  Really lost here, so any clues would be helpful! Thank you in advance.


I wanted to install python-pip so i ran sudo apt install python-pip and got this error  Reading package lists... Done Building dependency tree        Reading state information... Done You might want to run 'apt --fix-broken install' to correct these. The following packages have unmet dependencies:  libgcc1:i386 : Depends: libc6:i386 (>= 2.2.4) but it is not going to be installed  libgcrypt20:i386 : Depends: libc6:i386 (>= 2.28) but it is not going to be installed  libgpg-error0:i386 : Depends: libc6:i386 (>= 2.28) but it is not going to be installed                       Recommends: libgpg-error-l10n:i386  libidn2-0:i386 : Depends: libc6:i386 (>= 2.4) but it is not going to be installed  liblz4-1:i386 : Depends: libc6:i386 (>= 2.4) but it is not going to be installed  liblzma5:i386 : Depends: libc6:i386 (>= 2.17) but it is not going to be installed  libunistring2:i386 : Depends: libc6:i386 (>= 2.7) but it is not going to be installed  python-pip : Depends: python-pip-whl (= 18.1-5) but it is not going to be installed               Recommends: python-all-dev (>= 2.6) but it is not going to be installed               Recommends: python-setuptools but it is not going to be installed               Recommends: python-wheel but it is not going to be installed E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).    it says Try "apt --fix-broken install" so I did that and got this  Reading package lists... Done Building dependency tree        Reading state information... Done Correcting dependencies... Done The following additional packages will be installed:   libc6:i386 Suggested packages:   glibc-doc:i386 locales:i386 The following NEW packages will be installed:   libc6:i386 0 upgraded, 1 newly installed, 0 to remove and 42 not upgraded. 88 not fully installed or removed. Need to get 0 B/2578 kB of archives. After this operation, 12.7 MB of additional disk space will be used. Do you want to continue? [Y/n] y debconf: DbDriver "config": /var/cache/debconf/config.dat is locked by another process: Resource temporarily unavailable (Reading database ... 269716 files and directories currently installed.) Preparing to unpack .../libc6_2.30-0ubuntu2.1_i386.deb ... debconf: DbDriver "config": /var/cache/debconf/config.dat is locked by another process: Resource temporarily unavailable dpkg: error processing archive /var/cache/apt/archives/libc6_2.30-0ubuntu2.1_i386.deb (--unpack):  new libc6:i386 package pre-installation script subprocess returned error exit status 1 Errors were encountered while processing:  /var/cache/apt/archives/libc6_2.30-0ubuntu2.1_i386.deb E: Sub-process /usr/bin/dpkg returned an error code (1)   I tryied also running sudo apt-get install -f didn't work  So what shall I do? Ubuntu 19.10

I'm trying to install the flashybrid but when I enter the apt-get install flashybrid command, I get this error:  root@user-desktop:/home/user# apt-get install flashybrid Reading package lists... Done Building dependency tree Reading state information... Done flashybrid is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 1 not fully installed or removed. After this operation, 0B of additional disk space will be used. debconf: DbDriver "config": /var/cache/debconf/config.dat is locked by another process: Resource temporarily unavailable Setting up flashybrid (0.15+nmu2) ... debconf: DbDriver "config": /var/cache/debconf/config.dat is locked by another process: Resource temporarily unavailable dpkg: error processing flashybrid (--configure): subprocess post-installation script returned error exit status 1 Errors were encountered while processing: flashybrid E: Sub-process /usr/bin/dpkg returned an error code (1)   I also tried this one to find what is already using that file:  root@user-desktop:/home/user# lsof | grep /var/cache/debconf/config.dat lsof: WARNING: can't stat() fuse.gvfs-fuse-daemon file system /home/user/.gvfs Output information may be incomplete. dpkg-prec 4672 root 4rW REG 8,6 39658 1697827 /var/cache/debconf/config.dat   But I don't know how to fix this.


On average, how many times must a 6-sided die be rolled until a 6 turns up twice in a row?  This  a question from "a collection of dice problem", the original explanation I couldn't understant. Can someone explain it from the expectation (sum of an infinite series) point of view?

Basically, on average, how many times do you have to roll a fair six-sided die before getting two consecutive sixes?


I think we commonly use these words every day but we are not clear which word is correct.

.  But I saw a lot of people wrote "I play tennis everyday".   Is "I play tennis every day" the right way?


Is it possible to make circuitikz draw battery-symbols like this:

I'm attempting to draw a battery (using the battery1 component) that includes positive and negative signs at the appropriate ends. A  that was answered here (using version 2.4) shows exactly what I mean:    Only, of course, I want to be using a battery1 symbol instead. So, I have my code as follows:  \usepackage[americanvoltages,fulldiodes,siunitx]{circuitikz} \begin{document} \begin{circuitikz}     \draw (0,0) to [battery1=\SI{9}{V}] (3,0)                 to [pC,v=$v_C$] (6,0); \end{circuitikz} \end{document}   And I end up with this:    Notice the lack of +/- signs (I know how circuits work so I don't need to be actually shown these signs, but for the sake of copying my class notes diagrams I want these signs to be included in my latex diagram).  In either case, I think it may have something to do with the version of Circuitikz I'm using because I'm using the latest version (I believe, 0.3.0) but in the previous question linked above, they were using 2.4 and it worked out for them.  I would really like to find a way to add +/- without having to manually add it with Tikz or something, i.e. just have it naturally part of the component without having to add nodes or extra Tikz code etc. If that's not possible, then I'll have to settle for that as a last result.   Thank you for your help!  EDIT: I should also mention that I've tried using battery1, v=$9V$ instead of battery1=\SI{9}{V} and to no avail (the +/- signs still don't show up).


I would like to know how the author got  $\frac{\sum_{k=1}^{n}\frac{1}{k}}{\ln(n)} \longrightarrow 1$  from $ \sum_{k=1}^{n}\frac{1}{k} =\ln(n)+\lambda+o(1)$    $$\frac{\sum_{k=1}^{n}\frac{1}{k}}{ln(n)}=1+\frac{\lambda}{ \ln(n)} +o(\frac{1}{\ln(n)})$$  when n goes to infinity we got that   $$ \frac{\sum_{k=1}^{n}\frac{1}{k}}{ln(n)}=1+o(0)$$

I'm not completely new to convergent series and sequences, but proving the above gave me some troubles. Would appreciate some help :) Show that: $$\lim_{n\to\infty} \frac{\sum\limits^n_{k=1} \frac{1}{k}}{ \ln(n) } = 1$$


I recently upgraded Ubuntu, and now whenever I restart my computer I have no internet. To get internet I have to edit my /etc/resolv.conf file.  It shows this when I load the file.  # Generated by NetworkManager nameserver 127.0.1.1   To get internet I have to add another nameserver, so I chose Google's, and now it looks like this:  # Generated by NetworkManager nameserver 127.0.1.1 nameserver 8.8.8.8   How to I get it so that I have internet when I restart?

I upgraded my laptop to new Ubuntu distribution 17.10 this afternoon/evening and since then I cannot connect to the internet.  I have tried both wired and wireless connections, but the icon in the status bar shows a question mark over the connection icon whichever method I've tried. I originally thought it was a wireless problem (it's a Realtek RTL8833EE card) so tried to connect via Ethernet to download the latest driver but find I can't connect with wire either.  I had a similar problem last week with 17.04 which I resolved somehow but I can't find exactly what I did.  Please can I have some suggestions as to what I should try to troubleshoot.  EDIT: I have tried the question (and the answer) here:    both by adding a line  [main] dns=dnsmasq   under /etc/NetworkManager/NetworkManager.conf, and by checking the resolvconf.service via  $ systemctl status resolvconf   which is NOT showing an error like  resolvconf[623]: /etc/resolvconf/update.d/libc: Warning: /etc/resolv.conf is not a symbolic link to /run/resolvconf/resolv.conf   I have confirmed that /etc/resolv.conf is a symbolic link to /run/resolvconf/resolv.conf


I remember fighting and shooting everything as Duke spouted one liners he borrowed from Bruce Campbell.  What prevented the dancing girls &  Duke Nukem from morphing during crisises that made him our last, crass hope for mankind?

In Duke Nukem: Manhattan Project, it can be seen that G.L.O.P.P. (Gluon Liquid Omega-Phased Plasma) mutates alligators, rats, pigs etc. into giant monsters. But, when I (Duke) am attacked with green-colored GLOPP by some monsters, only my health point is affected and I don't see any sign of mutation. Why? Duke doesn't wear any kind of armor to protect his DNA from exposure.


I want to calculate a customer age based on his birth date.   public List<ProductView> GetProductsByStoreAndCategoryID(string storeId, string categoryId) {     Authenticate();     int _storeId = Convert.ToInt32(storeId);     int _categoryId = Convert.ToInt32(categoryId);      //selecting customerid     var _customerId = (from cs in context.customerstores.Where(cs => cs.StoreId == _storeId && cs.IsDefault.Equals(true)) select cs.CustomerId).FirstOrDefault();      //getting customer date of birth for calculating age and excluding regulated product from the list     var _DateOfBirth = (from c in context.customers.Where(c => c.CustomerId == _customerId && c.IsBlocked.Equals(false)) select c.DateOfBirth).FirstOrDefault(); }   Here I am getting the date of birth, after that I want to calculate age based on that date of birth. How to do that?

Given a DateTime representing a person's birthday, how do I calculate their age in years?


I am moving my bathroom exhaust fan from its current location to 2 feet farther, over the shower cabin. I need to extend existing wire for this. I can't fish new wire because existing wire has been secured to joist/studs with nail/staples. As per code I have to splice wire into junction box and it has to be accessible. So I have to install this box in ceilling and hide it with cover plate. I found  which mentions some NEC exception which allows  this product called "Tyco NM splices". Does this exception apply to my case? NEC language is sometimes hard to interpret.

Is there a way without using junction boxes to simply splice in additional length of 12/2 NM-B cable? Can I use twist caps?  I'm putting in a dog door and as it so happens, there is some 12/2 right in the way of the location I've chosen. There's no additional slack in the cable, and I don't want to rip up more drywall than I have to. I'm tempted to just cut it and splice in an additional foot or two with twist caps to get it out of the way. I don't know if this is safe or legal. Do I need to get junction boxes? Attached some pictures for fun.  Also, there is a 1-gang electrical outlet box that is going to the outside. I'm moving that up a bit.


Hi so i am making a small sort of physics engine, but if your fps is really slow the physics will update slower and objects will move slower. How do i make the speed of objects greater if the fps is lower so that on a computer with 5 fps the object will land at the same time as on a 60 fps computer? (just with that slow framerate)

Should a game loop be based on fixed or variable time steps?  Is one always superior, or does the right choice vary by game?  Variable time step  Physics updates are passed a "time elapsed since last update" argument and are hence framerate-dependent.  This may mean doing calculations as position += distancePerSecond * timeElapsed.  Pros: smooth, easier to to code  Cons: non-deterministic, unpredictable at very small or large steps   example:  while( game_is_running ) {     prev_frame_tick = curr_frame_tick;     curr_frame_tick = GetTickCount();     update( curr_frame_tick - prev_frame_tick );     render(); }   Fixed time step  Updates might not even accept a "time elapsed", as they assume each update is for a fixed time period.  Calculations may be done as position += distancePerUpdate.  The example includes an interpolation during render.  Pros: predictable, deterministic (easier to network sync?), clearer calculation code  Cons: not synced to monitor v-sync (causes jittery graphics unless you interpolate), limited max frame rate (unless you interpolate), hard to work within frameworks that assume variable time steps (like  or )   example:  while( game_is_running ) {     while( GetTickCount() > next_game_tick ) {         update();         next_game_tick += SKIP_TICKS;     }     interpolation = float( GetTickCount() + SKIP_TICKS - next_game_tick )                     / float( SKIP_TICKS );     render( interpolation ); }   Some resources     —allegedly a reason  is frame-locked to 60fps? Flixel requires a variable timestep (I think this is determined by Flash) whereas  allows both types.  suggests it uses constant time steps.


I was able to post  on recently closed question (take a look at posting answer time and closing time).    I started writing answer before question was closed.  Then info about closing was shown disabling "Post Your Answer" button, so I clicked on info to reload page. From curiosity went "back" in my browser and previously cached version of question was loaded enabling "Post Your Answer" button. After captcha validation I found my answer posted.   Is this bug or feature? Why there is no server side mechanism to check if question is closed while posting answers?

Question:   Answer:   The question was closed at 11:57:57 (according to the hover-over-"x-mins-ago" bar) and the answer was posted at 12:16:35. It's a fairly lengthy answer, so it's possible that it was started to be written before it was closed but I swear I've started to answer a question then I got a banner along the top saying "this question has been closed" and the answer was no longer post-able.


I have this , but the seasoning that I created with  is very brittle and flakes off easily into my food. I have not been using anything acidic in the pan, so I think I just need to start from scratch.  Most information on seasoning is geared towards cast iron. I want to know what temperatures can I use with the carbon steel pan without it warping. Can I strip the old seasoning with a self-cleaning cycle or is that too hot? What temperature should I use during the reseasoning?

After reading , I want to try to re-season a skillet with flaxseed oil; I'm fairly certain I did a terrible job when I seasoned the skillet several years ago. Is it possible to do this with steel wool or vinegar? (I don't have a self-cleaning oven, so that method is out.)


I am having issue upgrading my Kubuntu from 19.04 to 20.04. I have tried to find a solution, but nothing seems to be working for me. W test@test:~/Document$ [sudo] password for name:   Checking for a new Ubuntu release Your Ubuntu release is not supported anymore. For upgrade information, please visit: http://www.ubuntu.com/releaseendoflife  Please install all available updates for your release before upgrading.  Can someone help me to upgrade Kubuntu?

I am currently using Ubuntu 10.04. I know there is a 10.10 release, but can I upgrade directly to 11.04? Could you walk me through the steps please?


Currently following a tutorial for Blender, as I'm still relatively new to it. Ran into an issue where I realized that the actual selection/pivot point of the object, in particular, was moved away from the object. Don't know how to fix this, currently on Blender 2.9x.  This is what happens when I tell the two parented objects to snap to cursor, which is at World Origin. Object is rotated around this point too. I'd appreciate any help I could get.

So, I'm working creating a lamp... yes, newbie here.  After modeling for a bit, I noticed that my point of origin was no longer the center of my object:    How to I reset an object origin point to the center of it's geometry?


Is it possible, via command line (shell command), to check for properties of a file (like when I right click on a file via Nautilus).  Specifically, given an mp3 audio file, I would like to know how I can extract the info related to title and artist from the audio section of its properties.

Is there a way to read the mp3 tags of a file from the shell? Something like:  mp3tags MyFile.mp3 author should output the author-tag of an mp3-file.


I often read the definition of event horizon of a black hole as the region where the escape velocity is bigger than the speed of light. However this would imply that if you're inside the event horizon you can -in theory- escape from black hole with constant acceleration (non-ballistic trajectories), like you can escape from the Earth's gravity with constant thrust without reaching escape velocity.  However I know that inside the event horizon, space-time is bended and distorted so every path only leads to singularity. So is the general definition of event horizon stating that it's the boundry where escape velocity is > speed of light wrong?  For example  Even in Encyclopeadia of Britannica defines event horizon as:     Event horizon, Boundary marking the limits of a black hole. At the event   horizon, the escape velocity is equal to the speed of light. Since general relativity states that nothing can travel faster than the speed of light, nothing inside the event horizon can ever cross the boundary and escape beyond it, including light.

Can someone please explain what the  of a black hole is? I mean is it the actual surface of the black hole or is it the point of no return where light can no longer escape?


I'm having some trouble proving the following proposition:  Let $a,c \in \mathbb Z\setminus\{0\} $ and $k \in \mathbb Z$, then:$$\gcd(a,ak+c)=\gcd(a,c)$$  If $D_a$ and $D_c$ are the set of all numbers that devide $a$ and $c$ respectively I was able to prove that, if $\lambda := \gcd(a,ak+c)$ then $\lambda \in D_a \cap D_c$, but now, I can't arrive at the conclustion that $\max(D_a \cap D_c) = \lambda$. How can I conclude this proof?

Given: $a = qb + r$. Then it holds that $\gcd(a,b)=\gcd(b,r)$. That doesn't sound logical to me. Why is this so?    Addendum by LePressentiment on 11/29/2013: (in the interest of  and averting a duplicate)  What's the intuition behind this result? I only recognise the proof and examples solely due to algebraic properties and formal definitions; I'd like to apprehend the result naturally.


I am an undergraduate student in the field of information technology. Recently I worked on an academic project under a supervisor. We want to publish it. My question is: Does the person who submits the manuscript to a journal become the corresponding author of that paper? That is, if my supervisor submits the manuscript, will he become the corresponding author by default? Can’t he refer the correspondence to me?

Problem  This question was triggered by the comments on , but comments and answers on   confirm the existence of conflicting ideas.  There seem to be two prevalent interpretations of the word corresponding author:   The corresponding author is the one who corresponds the (unpublished) paper to the journal, i.e., who performs the technical process of submitting the paper, is available for requests on the review and publishing processes, and so on. The corresponding author is the one who corresponds on the (published) paper with anybody who likes to do so, e.g., because they found an error or like some clarification.   What I found out so far  Until today, I was only aware of the first interpretation, which was confirmed by my experience: For all papers I submitted, I automatically became the corresponding author and cannot remember that I could choose one of my co-authors for this role. Some of these journals do not even indicate a corresponding author to the reader. Also, there already is a way to indicate that an author is available for questions on the paper (interpretation 2): stating the e-mail address.  On the other hand, other journals do indicate corresponding authorship, which makes little sense for interpretation 1. Also, the value put into this role by some funding agencies for its  makes more sense for interpretation 2 (not that I completely agree with it).  Looking for some guidelines from publishers covering multiple fields, I found the following  from Elsevier¹, which kind-of covers both interpretations:     Clearly indicate who will handle correspondence at all stages of refereeing and publication, also post-publication.   While there are other questions on this site touching this issue, they focus on consequences of the interpretation, such as , , or .  Actual question  What is the explicit meaning of the word corresponding author? Interpretation 1 or 2 as listed above, both, something else, or is this an extreme example of  and the answer depends on the field or publisher? Please answer only if you have more to offer than personal experience and individual journal guidelines. In particular, please address the possibility of a varying meaning.     ¹ which is separate for each journal, but seems to be identical in content for many journals


I know $I_{\text{rms}}$ produces the same energy over time as if the current were DC. I am asking the reason why it works. The main focus of this question is highlighted below which makes it different from similar questions.(why we take mean of square then take root instead of taking mean of absolute value of current.    Let's say the AC current is $I=\sin(t)$ for this case where $t=\omega \tau$ where $\tau$ is time in seconds. This is done to make the question simpler.  Let's say we have graph of $\sin(t)$. It's average is zero so we square: $\sin^2(t)$. Now be careful! we take average of $\sin^{2}(t)$ and then we take root. Why don't we take the absolute value $|\sin(t)|$ first and then take the mean, which will give us the answer 0.637I not 0.707I.    That will actually mean that in the formula $P=IV$ we will use $I=I_{avr}$ not $I=I_{rms}$ where $I_{avr}=\langle|\sin(t)|\rangle$.

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


I was asked to create command which generates one word in terminal, if internet connection is absense, and another one, if it present. For doing that it seems that I need "if" and "else" syntaxis. Is it possible to provide such syntaxis in terminal?

I am trying to pull logs and doing few others things directly. written a small line BASH but not working. I am sure thats with IF Condition.    sed -rne '/21:25:07/,/21:50:07/ p'  server.log.2015-04-21 > /tmp/filename.log ; du -sh  /tmp/filename.log ;  if [`du -sh  /tmp/filename.log` -gt 0] then gzip /tmp/filename.log ;


I want to upgrade my computer from Ubuntu 10.04. But when I go to open the Update Manager, it says that my version is old (as if I didn't already know that) and that I need to update, but the manager won't run. I honestly have no idea what to do from this point, so any help would be greatly appreciated!

Recently I have installed an older version of Ubuntu on my old machine. Whenever I try to install any software, I get an error saying it couldn't be found:  $ sudo apt-get install vlc Reading package lists... Done                Building dependency tree        Reading state information... Done     E: Couldn't find package vlc


I currently have a plugin in the global WordPress plugin directory that I'd like to remove. It is currently broken, outdated, and I do not intend to provide continuing support for it. To spare people the heartbreak of installing it, I'd like to remove it.  Unfortunately Google is flooded with how to remove plugins installed on WordPress sites, so that makes it hard to find a clear answer for this.

I wanted to create a WP plugin. So I requested and my request was approved by WordPress.org But I don't want to develop that plugin anymore. How can I delete the repository forever or request its deletion.


There are different methods which are proposed for initialization of K means, but is there any literature that lists the merits and demerits of each one.(some sort of survey)  Most popular one is i guess k-means++ but why is it better than farthest point method ?

I am interested in the current state of the art for selecting initial seeds (cluster centers) for K-means.   Googling leads to two popular choices:   random selection of initial seeds, and, using the KMeans++ selection technique:    Are there any other promising methods that anyone here is aware of, which might not be as popular?


I'm wondering if it will be possible to install vmware server on a hyper-v image?  Currently I get an error when trying to install.  Setup cannot continue becuase microsofts hyper-v is being used. Please disable it, reboot and start the VMWare Server installation again.

Can VMWare ESX or ESXi be installed and used inside a virtual machine?  It can be installed inside VMWare Workstation or Server, but then it doesn't work; the main symptoms are:   It runs REALLY slowly. It lets you create VMs, but when powering up them it gives an error stating "You may not power on a virtual machine in a virtual machine".


How to prove that formula for Fibonacci numbers are always integers, for all $n$:  $$ F_n = \frac{\varphi^n - \psi^n}{\sqrt{5}} $$ where, $\varphi = \frac{1 + \sqrt{5}}{2}$ and $\psi = \frac{1 - \sqrt{5}}{2}$.  I know how to prove that $F_n$ is rational, but what about integer?

For each $n$ consider the expression $$\frac{1}{\sqrt{5}}\left[\left(\frac{1+\sqrt{5}}{2}\right)^{n}-\left(\frac{1-\sqrt{5}}{2}\right)^n\right]$$  I am trying to prove by induction that this is an integer for all $n$.  In the base case $n=1$, it ends up being $1$.   I am trying to prove the induction step:   if $\frac{1}{\sqrt{5}}\left[\left(\frac{1+\sqrt{5}}{2}\right)^{n}-\left(\frac{1-\sqrt{5}}{2}\right)^n\right]$ is an integer, then so is $\frac{1}{\sqrt{5}}\left[\left(\frac{1+\sqrt{5}}{2}\right)^{n+1}-\left(\frac{1-\sqrt{5}}{2}\right)^{n+1}\right]$.   I have tried expanding it, but didn't get anywhere.


Why is $$\sqrt{7 + 2\sqrt{10}} = \sqrt2 + \sqrt5 $$  I can't seem to prove it so can someone help me out in doing so if it is possible.   And if it can't be proven, is there and explanation to why this is so?

I am looking for a way to easily discover how to go from a nested root to a sum of roots.  For example,   $$\sqrt{10-2\sqrt{21}}=\sqrt{3}-\sqrt{7}$$  I know that if I set $\alpha=\sqrt{10-2\sqrt{21}}$, square both sides, I get  $$\alpha^2=10-2\sqrt{21}$$  Now I recognize that we have a situation where $10=3+7$ and $21=7\cdot 3$, so I can immediately see that we have  $$\alpha^2=10-2\sqrt{21}=3-2\sqrt{21}+7=\sqrt{3}^2-2\sqrt{3}\sqrt{7}+\sqrt{7}^2=(\sqrt{3}-\sqrt{7})^2$$  My question is, it this the only way to approach this problem?  This approach mirrors basic algebra 1 methods of factoring quadratics, but I was curious to know if thre are other techniques that can be used to quickly deduce that a nested radical can be simplified to the sum of two radicals.  Mathematically, suppose $a,b,c,m,n,r,s\in\mathbb{N}$.  Is there a way to quickly determine $m,n,r,s$ in the equation  $$\sqrt{a\pm b\sqrt{c}}=m\sqrt{r}\pm n\sqrt{s}$$


95% of the area under the standard normal distribution lies within 1.96 standard deviations away from the mean (0).  This 1.96 number is used to construct 95% confidence intervals.  I was just wondering... how is this 1.96 value derived?  Looking at the standard normal distribution, I know the following statement is true:  $$\dfrac{1}{\sqrt{2\pi}}\int_{-\infty}^{-z}e^{-x^2/2}dx=\dfrac{1}{\sqrt{2\pi}}\int_{z}^{\infty}e^{-x^2/2}dx=0.025$$  Where z = 1.96.  These areas are equal to 0.025 because they represent the leftover areas under the standard normal distribution below -1.96 and above 1.96, which adds up to 5% or 0.05.  I want to know how I can mathematically show that z = 1.96.    I tried differentiating both sides with respect to z so I could make use of the fundamental theorem of calculus and solve for z to show that it had to equal 1.96, but that didn't work out for me... kept getting an undefined answer for z.  Am I going about this the right way?  Or is there a better way to explicitly show that z = 1.96?  This is just something I've been curious about regarding z scores.

I am working my way through , where the author states that     "there is no closed form expression for the normal cumulative density   function"   but does not provide any further details as to why this is the case, simply saying that the alternative is to write it in terms of the error function.  Is there some way to intuit why  the Normal Distribution can not be expressed as a closed form function?


I am doing the following summation: $$ \sum{\frac{\theta^{n}}{n(n+1)}}, n=1,2, \ldots, 0<\theta<1 $$ I tried to use the technique $\sum\frac{1}{n(n+1)} = \sum(1/n)-(1/(n+1))$, but didn't know how to continue to deal with the $\theta^n$. Any hint or help?

My partner is tutoring a Civil Engineering student in maths. Conveniently, I am a civil engineer so when any maths that's confusing comes up, I can usually help out. However, we are having a problem with the summing of power series, one area where I am sorely lacking.  After spending two hours on a question, we still cannot solve it and are always left with a $k$. Admittedly, I don't fully know what I am doing.     Evaluate $\displaystyle \sum_{k=1}^\infty\frac{x^k}{k(k+1)}$.   We do know that the answer is $1 + \dfrac{1-x}{x}\ln (1-x)$.  Any hints or help in the direction to go would be very much appreciated.


When buying flights tickets usually buying a one-way flight is very expensive, comparing to flights that have return. In many airline websites there is not an option for planing a whole big trip with many stops.  Let's say I want to travel from Tel Aviv to Paris, Paris to Stockholm and then from Stockholm to Tel Aviv.  In the Norwegian airline website there isn't an option for this type of things. In addition, if I want to take Tel Aviv - Paris flight and Paris - Stockholm flight I will need to pay them separately as one-way trip.  How do I resolve this problem? How do I plan this type of flights? How do I do it traveling with Norwegian airline if there isn't the option on their website? I tried with ElAl airline and it is very expensive for taking a one-way flight at their website (for example Tel Aviv - Paris is very expensive one-way trip).

It seems like one-way tickets are always more expensive than buying round-trip. But what if I have two destinations? For example I would like to go on the following itinerary this March:  London --> Austin --> Rio de Janeiro --> London  At the moment the cheapest way to do this seems to be:  London --> Austin --> Rio de Janeiro --> Austin --> London  but that seems a bit ridiculous. Is there not a way to just buy a series of one way tickets that would follow the first itinerary? Please keep in mind, my main concern is price.


Please redirect to an HTTPS connection by default on stackoverflow.com  To illustrate the problem, please see the screenshot below where a man-in-the-middle attack is being used to forge responses from Stack Overflow and inject advertisements.    A wildly crude estimate of the financial cost of this attack is as follows:   Xfinity hotspots / All Wifis in the US = 1.5m/77m = 2% SO revenue = $2m in 2010 * 5x growth = $10m per year 50% of ad clicks will be on the injected ad (because it is more interactive and new) 20% of visitors in the US   LOST REVENUE IS $20,000 PER YEAR DUE TO COMCAST ALONE    Sources for numbers above

So it looks like Stack Exchange now supports HTTPS (to some extent). Which is awesome! But there are a few problems, the main one being that some content is delivered over the CDN, which is plain HTTP. This causes browsers to complain about "unsecured content":


I tried ls ?[0-9]* ,  this matches all files in current directory, but also expands any directories in my current directory as  and matches the files in any sub directory. I want * to match only to current directory.   ---- Program output -------------------------------- f1 f2 g2t g3t  d2:  d4:  --- Expected output (text)--- d2 d4 f1 f2 g2t g3t   Here d2 and d4 are directories, while others are files. I want them to be listed as d2 and d4 and not as d2: and d4:

I have a directory called selenium_IDE  if I do   ls sel*    I get to see directories that are in it, e.g.  $ ls sel* HAPPY              HAPPY_PLUS_OPTIONS SAD                SAD_PLUS_OPTIONS   but not the directory itself, i.e. selenium_IDE/  I tried using -d1 (depth 1) which has worked for me in the past on some system.  It does work in that it shows the selenium_IDE directory but also shows a error  here on OSX  $ ls sel* -d1 ls: -d1: No such file or directory selenium_IDE: HAPPY              HAPPY_PLUS_OPTIONS SAD                SAD_PLUS_OPTIONS


I have created music using drums and guitar, but I do not know in which category does my music falls in. Is it jazz, pop or any other. Also if in future I create a music with a violin in addition, does the genre of music change?

I listen to many songs and I always wonder how the genre of a song is determined. Is it by listening to the song, or by the song's info like the artist, year released and so on?


I've looked everywhere and cannot seem to figure this out. My issue is that I am trying to use the 'enum' for rank that is in my database but keep getting errors.  What I have below I'd like to be able to display in a specific div depending on what rank a member is.  This is what I have so far, where am I going wrong?  If someone could shed some light on if this is even correct or what I need to do to make this work, I'd greatly appreciate it.  PHP:  class Rank {   // If no value is given during object construction this value is used   const __default = 1;   // Our enum values   const Registered       = 1;   const Legend           = 2;   const Inactive         = 3;   const Greenhorn        = 4;   const FullMember       = 5;   const JuniorAdmin      = 6;   const SeniorAdmin      = 7;   const Leader           = 8;   const Founder          = 9;   const OriginalFounder  = 10; }  $registered     = new Rank(Rank::REGISTERED); $legend         = new Rank(Rank::LEGEND); $inactive           = new Rank(Rank::INACTIVE); $greenhorn          = new Rank(Rank::GREENHORN); $fullmember     = new Rank(Rank::FULLMEMBER); $junioradmin        = new Rank(Rank::JUNIORADMIN); $senioradmin        = new Rank(Rank::SENIORADMIN); $leader         = new Rank(Rank::LEADER); $founder            = new Rank(Rank::FOUNDER); $originalfounder    = new Rank(Rank::ORIGINALFOUNDER); $fail              = 1;  function responsibilities(Rank $rank) {   if (Rank::REGISTERED == $rank) {     echo "Post something about being a registered member.\n";   } elseif (Rank::LEGEND == $rank) {     echo "Post something about being Legend.\n";   } elseif (Rank::INACTIVE == $rank) {     echo "Post something about being Inactive./n";   } elseif (Rank::GREENHORN == $rank) {     echo "Post something about being a Greenhorn./n";   } elseif (Rank::FULLMEMBER == $rank) {     echo "Post something about being a Full Member./n";   } elseif (Rank::JUNIORADMIN == $rank) {     echo "Post something about being a Junior Admin./n";   } elseif (Rank::SENIORADMIN == $rank) {     echo "Post something about being a Senior Admin./n";   } elseif (Rank::LEADER == $rank) {     echo "Post something about being a Leader./n";   } elseif (Rank::FOUNDER == $rank) {     echo "Post something about being a Founder./n";   } elseif (Rank::ORIGINALFOUNDER == $rank) {     echo "Post something about being an Original Founder./n";   } }  responsibilities($registered); responsibilities($legend); responsibilities($inactive); responsibilities($greenhorn); responsibilities($fullmember); responsibilities($junioradmin); responsibilities($senioradmin); responsibilities($leader); responsibilities($founder); responsibilities($originalfounder);  responsibilities($fail);   HTML:
<?php echo $rank ?>

I know that PHP doesn't yet have native Enumerations. But I have become accustomed to them from the Java world. I would love to use enums as a way to give predefined values which IDEs' auto-completion features could understand. Constants do the trick, but there's the namespace collision problem and (or actually because) they're global. Arrays don't have the namespace problem, but they're too vague, they can be overwritten at runtime and IDEs rarely know how to autofill their keys without additional static analysis annotations or attributes. Are there any solutions/workarounds you commonly use? Does anyone recall whether the PHP guys have had any thoughts or decisions around enumerations?


So for a hydrogen atom, an electron at n=1 would require 13.6eV of energy to be excited to the infinite energy level, so thats ionization. Is the work function the energy to overcome the attraction between the ionized electron and the nucleus?

In a particular textbook, the work function of a metal (in the context of the photoelectric effect) is defined as:     the minimum amount of energy necessary to remove a free electron from the surface of the metal   This sounds similar to ionisation energy, which is:     the amount of energy required to remove an electron from an atom or molecule in the gaseous state   These two energies are generally different. For instance, Copper has a work function of about 4.7eV but has a higher ionisation energy of about 746kJ mol-1 or 7.7eV.  I've sort of figured it's because the work function deals with free electrons whilst ionisation is done with a valence electron still bound within the atom. Is the difference due to the energy required to overcome the attraction of the positive nucleus?


i have htc wildfire 3  i can not scan qr code for whatsApp web  i see the "OK, got it" button , no problem with that  but it seems camera keep scanning but not getting anything any idea how to fix that ? every thing is updated already

Why I can't scan the Whatsapp QR?   I reinstalled WhatsApp  I already have the WhatsApp Web Option  I put it to scan but it just doesn't scan it. I Installed a QR Scanner app and it works perfectly. I uninstalled the QR Scanner app to see if that was the issue and still doesn't work.   My phone is a Samsung Galaxy Ace.


I am working on a complex configuration of magnets and every time I make an experiment something unforseen happens. Now I believe I could speed up the development by sitting down and calculating the configuration in all scenarios. My question is however: Is there any software that can help me to calculate the forces between magnets. I am already working with AutoDesk as my CAD software.

Is there easily-available* software to simulate coils, solenoids, and other magnetic and electromagnetic devices?  I'd like to play around with some design ideas, such as Halbach arrays, but physics simulators like SketchyPhysics don't seem to have the laws of electromagnetism implemented.  (*"Easily-available" means "not cost prohibitive.")


How can I merge a semicircle with two parallel lines? I want to have the leftmost point of the semicircle to bind with the leftmost line in the illustration below, and I'd like the rightmost point of the semicircle to be bound to the rightmost line simultaneously:    I'm using Illustrator (16.0.3).

I'm new to Adobe Illustrator and I wanted to accomplish this task. How do I remove the inner lines in my drawings? I tried with all the pathfinders effect but it keeps removing my tangent lines (the lines connecting both my circles).    It works like a charm as I followed the selected's answer guide:  Here it is.


Background:   Summary of that thread: "Can we change the 5 second limit on up votes?" Status: "Declined." My interpretation of the reason: An altered time limit might lead to more noise in the signal, the very thing the mechanism is designed to avoid.  My take is this:  The problem is not the time limit, the problem is the failure message behavior.  I believe the "you can't upvote on a comment again so soon" message's BEHAVIOR is complete overkill, though I understand the necessity for the underlying time limit mechanism.  Problems with the current error:   Brings up a popup. Displays the most visually noisy red error I have yet seen on the site, total overkill. Remains open until you manually click to close it. Provides no indication of when the functionality will actually be available again.   All just to tell you that you're being a bit too eager in your non-value-changing upvoting.  So I argue that the problem isn't the mechanism, it's the presentation, and I think that we can propose something better and much less annoying.  What alternatives can we come up with?

I quite often will read a thread of comments, and want to vote up a few of them. I vote one up, read the next few comments, vote up another and get a *giant red box*.  I've seen that "You can only submit a comment vote every 5 seconds" box far too often. Can I vote for 12 comments per minute, rather than 1 comment every 5 seconds?


I recently tried installing LaTex on my Ubuntu 13.10 system. The installation failed but I can't remember the error-messages. After the failed installation the memory cache was quite full and the system was running slow. I therefore restarted the system. However, after reboot, the screen turns black with only the mouse pointer showing after I have typed in my password and hit enter on the login screen.  The weird things is that Guest Session login is seamless, but I cant access anything from there.

I am trying to boot Ubuntu on my computer.  When I boot Ubuntu, it boots to a black screen.  How can I fix this? Table of Contents:


claims that  Contractions The contraction of there is is there's.  There's a good song on the radio. There's only one chocolate left in the box.  You cannot contract there are.  There are nine cats on the roof. There are only five weeks until my birthday.   So, can we not say There're nine cats on the roof?

Q: "Do you have any juice?"   A: "Yes, there's some in the fridge."   Sounds perfectly fine to me, but:     Q: "Do you have any towels?"   A: "Yes, there's some in the closet."   Does not.  I asked for towels - plural - so wouldn't "Yes, there're some in the closet," in which there are is turned into a contraction be the correct way to say it?  Spellcheck, however, doesn't like "there're", and I think I'm the only person I've ever heard use the word "there're".  Even folks who I know say "there are" shorten it to "there's" when possible.  Am I saying it wrong, or are both forms acceptable?


The core of the problem is already in the title but I feel as i should add some more details.  I was doing some mathematics and, if there are no logical flaws or mistakes of any other nature (it seems that there are none) I managed to prove some result that, again, if it is proved with no errors, would, I believe, enrich the field in which it belongs.  Of course, I immediately started to think about arXiv.org and I decided that I want to submit an article there, but, when I was reading help section, there stands this, written:     Note: It is a violation of our policies to misrepresent your identity or institutional affiliation. Claimed affiliation should be current in the conventional sense: e.g., physical presence, funding, e-mail address, mention on institutional web pages, etc. Misrepresentation of identity or affiliation, for any reason, is possible grounds for immediate and permanent suspension.   But, as you are aware by now, I do not belong to any institution and as such, am not affiliated with any, I am just an amateur that among all fields thinks about mathematics the most. So, I have stumbled upon this cautious note quoted above and do not know what to do.  So, I decided to write to all of you here to see what can be done in this case of mine. I am not 100% sure that among all sites this is the one most suited for this problem of mine (for example, I could have written this on MO Meta or MSE Meta) but surely I will try to welcome opinions and help, even if they do not resolve this issue that I am faced with.  What should be done?  EDIT: This is not a complete duplicate of the question mentioned in such a way as this one is a duplicate of that one because the body of the question mentioned goes like this:  "Assume you have already completed your undergrad and have been working for a number of years. Does one need to be part of a university or a learning institution to publish papers?"  But, I did not complete my undergrad and I am working for a number of years (independently). so, there are some similiarites but the question is not exactly the same, although answers seem to fit well.


I wanted to install a software and they ask me to choose the 32bit version or the 64bit version. My PC is 32bit OS, x64 based processor, Windows 8.1 and I have no clue what I should choose. I will mostly appreciate a simple "choose this one". I know many people have great knowledge here, but a technical explanation will be wasted on me. Than you!

i know this question has been asked a lot on superuser, but i am stuck as i have checked with different applications, windows system information, vmware processor x64 processor utility, cpu-z, securable, registry entry..and i am getting different results. i have windows 8 32-bit.  windows system information  System Type X86-based PC  System Properties    vmware guest64check    cpu-z    Securable    Why am i getting different results in windows system info and vmware processor utility, and what exaclty is my machine type? Will it be able to run windows 8 64-bit?  Thanks.


This is the problem I face when I boot my laptop.   Error found when loading /home/pulkit/.profile  /home/pulkit/.bashrc: line 5: alias: python: not found /home/pulkit/.bashrc: line 5: alias: =: not found /home/pulkit/.bashrc: line 5: alias: python3: not found  As a result the session will not be configured correctly. You should fix the problem as soon as feasible.   After few seconds, cursor appears and I can boot by clicking ok. Can you suggest me how to rectify this issue.  This is .bashrc file's content:

When I log in, I see the error:     bash: alias: alias: not found   If I source my .bashrc file, the message appears again.  What is causing this?


I have tried many methods and none of them worked! I tried blender render and cycles render, checked that everything was able to render, and i even tried re-doing the project all over! Anyone have anyway i can fix this? Ill add the blend file.    (File was to big for other options, so mediafire I guess)

This is meant to solve this problem once and for all. What is every reason an object isn't showing up in a render or viewport in when using the cycles render engine?


I've been tasked with creating a script to send announcement emails to clients using outlook to read their emails and they must not be able to forward them. Is there a header we can set to prevent forwarding that outlook recognizes?  This is a business requirement that has nothing to do with the actual security of the information in the email. What is required is that pressing the forward button in outlook will not work so our clients do not accidentally send forwards and are made aware it is intended that they do not forward the email.

Is it possible to prevent an email from being forwarded, or to have sensitive information automatically removed when reply-all/forward is pressed?  For example, a Google Calendar invitation includes a link to directly accept/reject the event. However, if someone clicks reply-all, and they keep the HTML formatting, the link will be shared with everyone else who received the invitation, and they can change the user's RSVP. (Specifically, the email is sent only to you, but has a "To:" header showing all invitees, so the problem remains.)  What can be done to ensure that the recipient does not accidentally share the sensitive link? Would it be possible with some MIME trickery or with a semi-standard header? Or is the best practice to refrain from including such "direct action" links when someone might be tempted to reply-all?


I am having a little trouble understanding how the protection enchantments work, so my question is, will it help any if I put Featherfalling IV on my Protection IV boots, or does that exceed the cap? All my armor is diamond and with only protection IV

Prior to 1.4.6 it was a well known fact that the protection enchantment on armor was strictly superior to the other enchantments and that simply having a few pieces with protection III/IV would max out this protection, leading to the best possible set of armor.  Now that this has , however, I'm curious to see if anyone has analysed what the optimal armor configurations now are?  Presumably it will be some combination of protection enchantments and other enchantments, going by the description of how enchantments work now on the wiki.  Or, are we forced to choose one or more types of protection to max out?  (This would be the case if there are not enough total enchantments possible to max out all areas).  If this is the case, it would be great to see some analysis of how to optimise that choice as well.  I've looked around but haven't found any good mathcrafting on this question yet.  Furthermore, beyond protection against taking damage, can someone include some explanation of the hidden utility bonuses?  For instance, Blast Protection has been described in wiki sources as reducing the knockback effects from explosions, and Fire Protection is described as reducing burn time.  Do these effects scale and max out at some enchantment level, and does Projectile Protection similarly reduce the knockback effect from projectiles?


Right now I do this …
     <?php          $blog_list = wp_get_sites();         foreach ($blog_list AS $blog) {             global $blog_id;             $currentblog = get_blog_details( $blog['blog_id'] );             echo "blogname . "'>".$currentblog->blogname."";         }     ?>
   Is it possible to list all Blogs alphabetically. How would I do that?

I want to list all sites in the multi site network in alphabetical order? Right now, the code lists by registered date  <?php // Query for getting blogs             $blogs = $wpdb->get_results( $wpdb->prepare("SELECT blog_id, domain, path FROM $wpdb->blogs WHERE site_id = %d AND public = '1' AND archived = '0' AND mature = '0' AND spam = '0' AND deleted = '0' ORDER BY registered DESC", $wpdb->siteid), ARRAY_A );              // put it in array               foreach ( (array) $blogs as $details ) {$blog_list[ $details['blog_id'] ] = $details;}             unset( $blogs );             $blogs = $blog_list;              // if is valid array             if (is_array( $blogs ) ){                     echo '
';                     $array= array();                     // reorder                     $array= array_slice( $blogs, 0, count( $blogs ) );                     for($i=0;$i<count($array);$i++){                     // get data for each id                     $blog = get_blog_details( $array[$i]['blog_id'] );                     // print it                     echo '
siteurl.'">'.$blog->blogname.'
';                     }                     echo '
';             }             ?>


I'm a bolivian citizen currently living in Bolivia until November 6th at which point I will join my family in Norway. The Norwegian visa application has been approved, I hold a Schengen visa (already stamped on my passport) to enter Norway and I am supposed to stop by the authorities having jurisdiction in Norway to get the permanent visa stamped on my passport upon arrival.   I will arrive to the UK via Heathrow and will be in transit for 2 hours before I board my flight to Oslo on the same day.   I also have a 10-year tourist visa to the US. Will I need a visa to pass through the UK? If so, which one?

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


while testing my DKIM/SPF config by using the port25.com email service, I am getting the following reply for my SPF record:  permerror (DNS void lookup limit exceeded)  However, my spf record does not have any "include":  v=spf1 mx a ip4:IP1 ip4:IP2 ip6:IP3 ~all  any idea what is going on?  When I am using , I get a pass on the SPF.  I have checked the docs at   and found this here:     "The void lookup limit was introduced in RFC 7208 and refers to DNS lookups which either return an empty response (NOERROR with no answers) or an NXDOMAIN response."   It's not doing ant DNS lookups, or is it?

I am trying to setup SPF on a server - mail works fine and validates according to mxtoolbox and other online checks but when I check it using  I get an error:  PermError SPF Permanent Error: Void lookup limit of 2 exceeded   I am aware of a limit of 10 lookups but have not seen this error before.  SPF record is:  v=spf1 a mx ip4:IP1 ip4:IP2 ip6:IP3 include:spf-a.outlook.com  include:spf-b.outlook.com include:spf-c.outlook.com  include:spf.messaging.microsoft.com include:_spf.zdsys.com  include:spf.mail.intercom.io -all    What is the void lookup limit refering to?


I recently got accepted into PhD programs at University A,B,C, and D.  I interviewed with Professor W at University A, Professor X at University B, Professor Y at University C, and Professor Z at University D.  I chose University B.  But now I am having doubts about B  and wish to go to University A to work with Professor W.  How do I tell Professor X that I want to change my mind and work with Professor W?  I also had additional conversations with Y and Z at C and D; they were pretty helpful and gave good guidance and tips about going to A and not going to B, so I feel even stronger about my decision to attend A over B.    University C and University D are on the east coast, while A and B are on the west coast.  How should I handle this?    Will I be burning bridges with X, Y and Z at B, C and D?   I wish to do my post-doc someday at University D or maybe C so it's important to not piss off X and Y, who both know B very well since the area of research is quite small.  W also knows X Y and Z

I applied to graduate schools this year, and at the tail end of February, my first pick school sent me an email that to me, sounded like they had filled all the available TA positions. So naturally I chose my second pick school (that did offer me a TAship).  Today (April 16th), I receive an email from my first choice school saying they would like to offer me a TAship (apparently somebody declined their offer).  The graduate adviser at my second choice school had told me before that sometime she made offers to candidates in the summer, so I am thinking if I were to contact her and ask to be released from my agreement, she might be OK with that. (I realize there are formal rules that apply)  Would it be such a bad thing to ask my second choice school to release me (if they say no it will be somewhat awkward for me and if I just walk out on them, I am not sure what they can do).  TIA, GB


Is there an option to copy first 100 files from a directory to another location using the cp command? If not is there any other way to do this? Do i need to write a script?

I have a directory more than 1200+ files. How do I copy the top 1000 lines of that directory to another directory?


In the download section I see choices for versions 13.10 and 12.04. Also, I notice that 13.10 will be supported for 9 months and 12.04 LTS has support until year 2017. I have read information in this forum explaining Ubuntu support and I guess I have an idea about what all this means.   The following is the conclusion I have:   If I install a short-term support version then it is a good idea to replace it as soon as a new version comes out. If I install a long-term support version then I can keep it until the end of it. Support will be available for bugs, new hardware, new software, etc.   Am I correct?

What are the differences between an Ubuntu Long Term Support release (LTS) and a normal release?


I'm trying to map the information R prints for an ARIMA model to the coefficients in the formulas that I'm familiar with. Here's what I have so far   ar1 = $\varphi_1$, ar2 = $\varphi_2$, ... intercept = $c + \varepsilon_t$ ??? ma1 = $\theta_1$, ma2 = $\theta_2$, ... mean = $\mu + \varepsilon_t$ ??????   where an AR(p) model is defined as  $X_t = c + \sum_{i=1}^p \varphi_i X_{t-i}+ \varepsilon_t$  and an MA(q) model is given by  $X_t = \mu + \varepsilon_t + \sum_{i=1}^q \theta_i \varepsilon_{t-i}$  Note: I have read , but it doesn't discuss the "intercept" and "mean" parameters.

suppose for a time series, the auto.arima output is:  ARIMA(1,0,1) with non-zero mean   Coefficients:          ar1     ma1  intercept       0.7456  0.2775   767.7463 s.e.  0.0804  0.1197     0.1072   It is specified in help file of arima function that definition used for this function is  X[t] = a[1]X[t-1] + … + a[p]X[t-p] + e[t] + b[1]e[t-1] + … + b[q]e[t-q]   and if we include mean(m),  this formula applies to X - m rather than X.  My questions are:  (1)  For the model considered above, what will be the arima equation?    (a) X[t] =  767.7463 + 0.7456*X[t-1] + 0.2775*e[t-1]    or    (b) X[t] =  195.3258 + 0.7456*X[t-1] + 0.2775*e[t-1],   where constant term is achieved by 195.3258 = 767.7463*(1-0.7456).  (2) How to interpret this constant term if we have more than one AR coefficient?  e.g. ARIMA(2,0,2) with non-zero mean   Coefficients:           ar1      ar2     ma1     ma2  intercept       -0.0124  -0.6945  0.3629  0.9414    -0.1288 s.e.   0.1172   0.1132  0.0598  0.1270     0.0636   (3) What should be the ARIMA equation in presence of drift term?  e.g. ARIMA(1,1,0) with drift           Coefficients:          ar1   drift       0.3307  0.3981 s.e.  0.0946  0.1463


I want to render 3D objects and grease pencil animation over an image sequence i have in the Video sequence editor, Is there a way to make the video sequence editor become the background video for the 3D view?

I have a bit of live-action footage that I would like to incorporate into a scene done with Grease Pencil to. Think of a newscaster talking about something and the live-action video is in a smaller window on the screen. Where the newscaster and set are done in Grease Pencil and the video they're talking about is live-action. I've brought the live-action footage into the video sequencer and I will be editing the live-action footage with pauses. The live-action footage will not fill the screen. it will only take up about 25% of one part of the screen.  Is there a way to see the video from the video sequencer in the Grease Pencil view? It would be helpful to be able to see the video sequencer video while working on the character in Grease Pencil.  If not, is there a workflow that would help with this?   Thanks, Jim


What is a better solution to make gaps between active areas of menu items or place them close to each other? I'm asking just about active areas of links not about visual styles.   For example, maybe gaps help to aim on touch devices. Is it not good when cursor switches between pointer and normal when it hovers on menu?  Live demo

I have already looked at these:        None of these tell us for certain what is the minimum spacing required between two click targets on Desktops while being compliant to WCAG AA. Either I am missing the term that is being used to define this in WCAG Guidelines or this is not defined yet. If this is not defined yet then how much space (in pixels) should I be keeping between two click targets?  Also if possible please guide on the minimum size required for related UI Elements such as Buttons, input boxes, radio and check boxes and Links for being AA Compliant on Desktops.


My question is about citing. I found two sectences that were cited in a review article (first sentence[1], extra information about it[2]. Second sentence [3]). And after that i found the original references and read them. (I didn't need ref [2], i just remove it and didn't talk about it)  At the end, i changed the places of them (flipped...1-3 to 3-1). Also i paraphrase them and added some words on them. Because in review article some parts of them were missing. But i gave reference to the original sources not to review article. So, is it considered to be plagiarism in introduction part?   Note: The primary sources are not previous studies on my local research area. They are like descriptions on that field. One of them is reasons of illness and the other one is statistical numbers of sport. Actually i gave the statistical number a bit different like "more than 150 m" instead of "180 m" and I was specific like "who are older than 20 years old". And also for reasons of illness, i gave different reference for ref1 but ref3 kept constant. To be specific; reasons of illness can be described by a doctor easly.   Here, total number of sentences is two.  For example in following link; we see that APA style says that we need to give original reference.   murdoch university;  apa style blog;   So what about my question's answer? I just obeyed to rule of APA and after i finished my thesis, i learnt that my situation might be considered as plagiarism for 2 citationss? and my M.Sc. degree can be revoked later?

I'm currently writing a paper on a certain topic for which a review article was recently published. Of course, I want to contrast my new approach to existing techniques. For that purpose, I have identified the relevant prior work with the help of the above-mentioned review article.  However, in my current version, I simply reuse the whole block of citations from the review article with no change at all. I have consulted each reference individually and they do seem appropriate for citation.   Is taking a pre-existing block of citations and using it in my own manuscript considered plagiarism?


I am looking for a shapefile of Assam showing district-wide boundaries. I have searched in the net but I have not been able to locate one for Assam, even though shapefiles for India are available.   Can anyone suggest where I can obtain such a file?

I am looking for Indian city/village points and village/Taluk boundaries for India.  A perfect example what I am looking for is  for the State of Haryan, produce by  .  Till now I am little lost, can some body point me in right direction and share some sources from where I can get this data for commercial purpose.  Just for update for all who are following  I have found  that Survey of India has "Village Bdy.Database (#42)". This is exactly what i am looking but till today no response from them.  Any body have some idea how to purchase this layer from them.


Prove by mathematical induction:  $\sum_{i=0}^{n}{n \choose i} = 2^n ; n \ge 0$  Step 1: n = 0  ${0 \choose 0}=2^0$  Step 2:  for n = k   $\sum_{i=0}^{k}{k \choose i} = 2^k$  assumption: for n = k+1   $\sum_{i=0}^{k+1}{k+1 \choose i} = 2^{k+1}$  Step 3:  $\sum_{i=0}^{k+1}{k+1 \choose i} = \sum_{i=0}^{k}{k \choose i} + {k+1 \choose k+1} = 2^k+1$  Assumption:  $2^{k+1}$   Result of mathematical induction:  $2^k+1$  Is that correct or is somewhere the mistake ?

Prove by induction that for all $n \ge 0$:  $${n \choose 0} + {n \choose 1} + ... + {n \choose n} = 2^n.$$  In the inductive step, use Pascal’s identity, which is:  $${n+1 \choose k} = {n \choose k-1} + {n \choose k}.$$  I can only prove it using the binomial theorem, not induction.


I seem to remember  Simple vs continuous Past vs present (no future tense, that's present) Perfect vs "normal"  Okay, if we multiply that, we got 2*2*2=8 tenses in English.  Am I correct?  For example, say I want to express I kick a cat in 8 tenses I will got:  Simple past imperfect tense  I kicked a cat.  Simple past perfect tense  I had kicked a cat  Simple present tense  I kick a cat  Simple present perfect tense  I have kicked a cat  Continuous past imperfect tense  I was kicking a cat  Continuous past perfect tense  I had been kicking a cat  Continuous present tense  I am kicking a cat  Continuous present perfect tense  I have been kicking a cat  Am I correct here? Only 8 tenses right?

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


following compiles fine with g++:  struct acounter {    long static counter;    void static create() {  //reset or create the counter     counter=0;   }    void static count() {   //the counter changes its internal value.     counter=counter + 1;   }     };   int main(int   argc,  char *argv[] ){    //compiles and executes!   //do some random stuff...   return 0; }   The problem is: as soon as I add "acounter::create();" or "acounter::count();" to the main loop, I get an error:      undefined reference to `acounter::counter'   But I defined "counter" and even initialize it. What is the problem?  (P.S. I can only use static functions as I have to deal with callbacks later - the idea is to use the whole struct only on its global scope without creating instances.)

Can anyone explain why following code won't compile? At least on g++ 4.2.4.  And more interesting, why it will compile when I cast MEMBER to int?  #include <vector>  class Foo {   public:       static const int MEMBER = 1;   };  int main(){       vector<int> v;       v.push_back( Foo::MEMBER );       // undefined reference to `Foo::MEMBER'     v.push_back( (int) Foo::MEMBER ); // OK       return 0; }


Is there any totally ordered field with cardinality larger than the continuum? If such field exist, please give an example (an simple one if possible).

On the top of my head, I cannot think of any fields of cardinality more than that of the reals. (It is known that the process of algebraic closure does not increase the cardinality of an infinite field.)  What is the simplest way to give an example of a field (and an ordered field) of a specific cardinality $\alpha$?  I see there is the "Field" of surreal numbers, but it is a proper class rather than a set (and hence do not have a cardinality as such). However, there seems to be some modified construction which gives proper fields with the cardinality of some strongly inaccessible cardinal.


I watched a film around 2005 that involved modern soldiers (possibly American) who are being stalked and killed one by one in a forest or jungle. The look and feel is similar to Predator - big GI's with vests, bulging muscles and heavy weaponry. However, it's not a humanoid they are fighting but a sort of infestation of large vines that attack by wrapping around victims and sucking all the fluid out them - leaving sort of emaciated and discoloured husks.   The soldiers stumble across a few 'dehydrated' bodies that confuses and terrifies everyone ("What the hell could have done that!?" etc), and the threat is later revealed where you see a soldier killed gruesomely in front of everyone - I'm sure there is a moment where he is trapped and people try to rescue him, but as they get close he dies horribly. I was quite young and the imagery has stuck with me for a long time - it was quite dramatic in that creepy bad visual effects way like the end of Raiders Of The Lost Ark.  I distinctly remember a scene where a soldier successfully blows up a bunch of the 'vines' with a grenade launcher - it might have been a rotating barrel grenade launcher or an under slung one on an M16 or similar.   The plot might have involved an abandoned research station where Bad Things Happened(TM) that led to the current events, but I might just be confusing similar plots now so I'm not sure about that point.   There may also have been a female researcher who acted as the foil to all the big muscly soldier types and who was interested in studying and finding out what was going on rather than just blowing everything up.   I watched this late at night on a Sky box with hundreds of channels - it could have been anywhere to be honest.  I'm unsure how old the film was but at the time I thought it was likely from the 90s. It may have been a feature film, a straight to TV film or part of a series I was unfamiliar with.

I remember a group of people (soldiers?) stuck in a jungle and attacked by two different sorts of aliens. One looked a lot like the Xenomorphs from the Alien movies, very bestial. The other was a humanoid armored creature  like in Predator films which I remember had a jetpack, and might have had a thrown weapon that looked like a fanged frisbee. I distinctly remember the jetpack bit happened on a bridge.  After that, my memory gets very fuzzy right up until the end credits which featured the aliens (both? Maybe just the Xenomorph ones) on a talk show. I vaguely remember TV Tropes mentioning this, and that vague memory suggests it was originally a Swedish movie.  I would have watched it on TV somewhere between 1994 and 1998, possibly on a premium cable channel as I think I watched it while at All State Choir, where they bunked us up in hotels and frequently forgot to shut down the premium channels.  I'm pretty sure that the English title had the word "Alien" in it, and I think it was just a two word title.  Trish Ling clued me in that the talk show bit is from a totally different movie than the first movie, which is the one I was really looking for, so I've struck out those bits.


Let $a_1,\dots,a_d,b_1,\dots,b_d$ be positive real numbers. Then $$ \prod_{i=1}^d a_i+\prod_{i=1}^d b_i \le \prod_{i=1}^d (a_i^d+b_i^d)^{1/d}$$ and equality holds if and only if $\frac{a_i}{a_j}=\frac{b_i}{b_j}$.     Is there a nice proof for this fact? Is there some geometric interpretation?   I know a proof based on an application of Holder's inequality which seems rather miraculous to me. The idea is to define $f_i:\{0,1\} \to \mathbb{R}$, by $f_i(0)=a_i,f_i(1)=b_i$, and to endow the domain $\{0,1\}$ with the counting measure. The generalized Holder's inequality then states that  $$\prod_{i=1}^d a_i+\prod_{i=1}^d b_i\le\|  \prod_{i=1}^d f_i\|_1 \leq \prod_{i=1}^d \|f_i\|_d=\prod_{i=1}^d (a_i^d+b_i^d)^{1/d}$$  and equality holds if and only if $\frac{f_i}{f_j}$ is constant, i.e. $\frac{a_i}{a_j}=\frac{b_i}{b_j}$. Somehow, I feel that it's weird to use an "abstract" measure-theoretic inequality, applied to such a degenerate case (finite measure space with the counting  measure).     Are there other, "more elementary" proofs?   Even the case where $a_i=c$ are constant does not seem trivial to me: i.e. why  $$ c^d+\prod_{i=1}^d b_i \le \prod_{i=1}^d (c^d+b_i^d)^{1/d}$$ and equality holds if and only if $b_1=b_2=\dots=b_d$.  I tried using the generalized Young's inequality for multiple products, which states that $$ \prod_{i=1}^d a_i \le \frac{\sum_i {a_i^d}}{d}.$$ (This is in fact the AM-GM inequality in disguise.)  This implies  $$ \prod_{i=1}^d a_i+\prod_{i=1}^d b_i \le \frac{\sum_i {a_i^d}+{b_i^d}}{d} \ge \prod_{i=1}^d (a_i^d+b_i^d)^{1/d}$$  but the direction of the last inequality (also by AM-GM) is opposite to the one we would like to have.  Of course, we can always mimic the (inductive) proof of the generalized Holder inequality, but this does not seem enlightening to me.

consider positive numbers $a_1,a_2,a_3,\ldots,a_n$ and $b_1,b_2,\ldots,b_n$. does the following in-equality holds and if it does then how to prove it  $\left[(a_1+b_1)(a_2+b_2)\cdots(a_n+b_n)\right]^{1/n}\ge \left(a_1a_2\cdots a_n\right)^{1/n}+\left(b_1b_2\cdots b_n\right)^{1/n}$


I am trying to write a file containing the "\b" character as a string, but when open the file it is omitted.  Here is my code:  with open('proof.tex','w') as archivo:     archivo.write('''\documentclass[12pt, a4paper]{article} \begin{document} $S=\sum ^{100}_{i=0}a_{i}\left( x\right) $ \end{document}''')   And here is the text generated in the output file:  egin{document} $S=\sum ^{100}_{i=0}a_{i}\left( x\right) $ \end{document}

I have a string that contains both double-quotes and backslashes that I want to set to a variable in Python. However, whenever I try to set it, the quotes or slashes are either removed or escaped. Here's an example:  >>> foo = 'baz "\"' >>> foo 'baz ""'   So instead of baz "\" like I want I'm getting baz "". If I then try to escape the backslash, it doesn't help either:  >>> foo = 'baz "\\"' >>> foo 'baz "\\"'   Which now matches what I put in but wasn't what I originally wanted. How do you get around this problem?


I have a image of width:300px, height:400px;  My container size is  width:168px, height:208px;  I want to display only a part of the image so that it can fill the container.   like:  Suppose top left corner is 0px 0px bottom right corner is 300px 400px of the original image.  I want to display picture from 10px 0px(top-left) to 200px 208px(bottom-right) such that it fits in the container.   How to do this in css?

Let's say I want a way to display just the the center 50x50px of an image that's 250x250px in HTML. How can I do that. Also, is there a way to do this for css:url() references?  I'm aware of clip in CSS, but that seems to only work when used with absolute positioning.


I am using ArcMap 10.3 and while using Share As > Map Package, I was trying to save the package to disc. There were no errors when I used Analyze. So I hit the Share button and after a little bit of work, the “Save Map Document” pop up window came up. Immediately after saving it I got a “packaging error_general function failure”  First, here at StackExchange, a similar issue was resolved using the Check Geometry function. However, after checking both my layers' geometry, I didn't find any errors.   Second, searching online I found that another user fixed this problem when two feature classes were using the same data source. I deleted one of the layers that I wasn’t using to make sure the data was being drawing from only one table, but I'm still having the problem.  It seems this broad error can indicate a variety of problems.   How do I troubleshoot to figure out why I’m getting this error?   It would be easier if it was a geoprocessing tool creating the issue.

Have some problems with sharing my map on ArcGIS Online:  As a student, I am now working with my master thesis and I use ArcGIS Online as a workflow based sharing network. I work locally on my computer and share my work with my supervisor via ArcGIS Online. My supervisor downloads the .mpk file and gives me feedback on my work.  This has worked fine until now. Today I was going to send my updated work and I get the error message:     Error Packaging - General function failure.   I do exactly the same as before, as follows: log in with my ArcGIS Online account (in arcmap), click File --> Share As, Map Package, overwrite my previous file and hit Share. The analyze process reports no problems. After a while I get the message      Packaging Error - General function failure.    What to do?  I'm running ArcGIS 10.1 SP1 for Desktop.


So I'd like to do something along the line:  \mybox{Some content on the first line \\ some content on the second line \\ and this boxes border are fitting the content}   So I want a box around content which actually fits the content and also respects things like line breaks. How can I do that?

I am trying to have two lines in inside \fbox but is not working. Below is my code  \documentclass{beamer} \usepackage{vietnam} \begin{document} \begin{frame} \frametitle{Exhaustive Search} {\centering\fbox{ One billion searches per second $\Rightarrow 36 yrs \newline All this to recover only $10$ bits !}} \end{frame} \end{document}   Update:


I am trying to read a .tab file but getting a NullPointerException error.  Exception in thread "main" java.lang.NullPointerException     at project.FTAFileReader.<init>(FTAFileReader.java:37)     at project.FTAFileReader.main(FTAFileReader.java:103)   Please find the code below  public FTAFileReader(){      try {             BufferedReader buffer;             buffer = new BufferedReader(new FileReader("event_trace.tab"));                                  buffer.readLine(); //Skips the first line of the file.              String currentstr;             while((currentstr=buffer.readLine().trim()) != null){                 String[] column = currentstr.split("\\s+");                           if(column.length>0){                     //hostID.add(Long.parseLong(column[0]));                     eventID.add(Integer.parseInt(column[0]));                     componentID.add(Integer.parseInt(column[1]));                     nodeID.add(Integer.parseInt(column[2]));                     platformID.add(Integer.parseInt(column[3]));                     nodeName.add(Double.parseDouble(column[4]));                     eventType.add(Integer.parseInt(column[5]));                     eventStartTime.add(Long.parseLong(column[6]));                     eventStopTime.add(Long.parseLong(column[7]));                     eventEndReason.add(Integer.parseInt(column[8]));                                      }                             }         }          catch (IOException e) {             e.printStackTrace();             System.out.println("The simulation has been terminated due to an IO error");         }        }   Any help will be highly appreciable. Thanks in advance.  Yogesh Sharma

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


Is there a function $f\colon \mathbb{R} \to\mathbb{R} $ such that $ f(f(x)) = -x$ ?

I've been perusing the internet looking for interesting problems to solve. I found the following problem and have been going at it for the past 30 minutes with no success:     Find a function $f: \mathbb{R} \to \mathbb{R}$ satisfying $f(f(x)) = -x$ for all $x \in \mathbb{R}$.   I am also wondering, can we find $f$ so that is continuous?  I was thinking of letting $f$ be a periodic function, and adding half the period to x each time. I had no success with this, and am now thinking that such a function does not exist.  Source:


Which git can I find the gnome on ubuntu 18.04 and see the source code of the applications?

I am assuming that all application installed through apt-get are open source; but for those that are available in that manner, where can I get the source code for these applications as well as update them?   I have a couple applications I use regularly that aren't being actively developed any longer and I would like to add features. Where would I go to get the rights to update these applications?  In this case specifically, I am referring to the hellanzb package


I have DXF files from Gerber which I want to import in Blender for 3D simulation. How can I do that?

I am a noob with blender. Please be as specific as possible. College students have been doing this for me, but I am unable to understand them.


I'm a terribe novice when it comes to electronics and I've got a question: I have a simple circuit including a photocell that regulates current (I hope this terminology is correct). It works as it should: The more light, the more current flows.  Now I am looking for some opposite device: A schematic / device / photocell (?) that increases its resistance the more light is applied.  Is there something like that? I'd be gracious for any help.  edit details:  I'm quite sure that what I'm doing is a total no-go, but somehow it's working anyhow (i'd be glad for any tip you guys have :)).. My super-simple (dangerous?) circuit consists of a 9V battery and a power-led. in between their connection I simply placed a photocell. As mentioned, I'd like this photocell to work in opposite of its current function: Power-led should become brighter if I "close up" the photocell.   thanks a ton so far!

How can I have a LED either on or off (not in between) depending on night or day with basic electronics? I have created the circuit below, but it only shines and in darkness it dims.    The photo-resistor is about 3kΩ when light shines and about 1MΩ when dark.  I want my LED to shine at night and be off at day.  What is the simplest way I can achieve this?


I am using Python script to load a mesh from .obj format file. It output some information when it loading. I want to disable the output. How can I do?

Every time the bpy.ops.remove_doubles() operator is used, it outputs to my terminal (where I called Blender from).  How can I suppress this output?  The code is:  bpy.ops.object.mode_set(mode='EDIT') bpy.ops.mesh.select_all(action='TOGGLE') bpy.ops.mesh.remove_doubles()   and the undesired output is:     Info: Removed 48 vertices