For Lie algebra $L$ with root $\alpha$, show that if $x \in L_{\alpha}$ then ad$x$ is nilpotent

For Lie algebra $L$ with root $\alpha$, show that if $x \in L_{\alpha}$ then ad$x$ is nil-potent. So $L_\alpha= \{x \in L : [h,x] = \alpha(h)x$ for all $h \in H \}$ where $H$ is a Cartan subalgebra of $L$. My thoughts: Given $x \in L_\alpha$ I have seen that there exists $y \in L_{-\alpha}$ s.t. span$\{x,y,[x,y]\} \cong sl(2,\mathbb{C})$. Now I'm pretty sure this isomorphism can be chosen so that $x \rightarrow e$ where $e$ is the $2 \times 2$ matrix with a $1$ in the upper left and $0$ elsewhere, and I saw some stuff when I classified the irreducible modules of $sl(2,\mathbb{C})$ that eventually $e^n(x)$ will be zero... This all being said, this exercise is before I learned about how span$\{x,y,[x,y]\} \cong sl(2,\mathbb{C})$ so this information should be unnecessary... I'd appreciate some help on this one.. Thanks!


I don't understand the concept of different sizes of infinity.

The argument to prove that there are different sizes of infinity is by saying .. no matter how many decimal numbers you write you can always come up with new one different from all others listed already.So, there is no one-one correspondence between natural numbers and decimal numbers. But, every time you come up with new one, you can add that new one to the list and correspond that to a natural number(which can go to infinity). So, again we have one-one correspondence and same cardinality and Hence same size of infinities. Please can someone help me what is wrong with my argument and what am I missing? It seems like the original argument is relying on the assumption that list of natural numbers end somewhere and we come up with a new decimal number to disprove one-one correspondence.


Why did FIPS become the AES Standard . What is wrong with Twofish and Serpent?

Why did FIPS become the AES Standard . What is wrong with Twofish and Serpent ? Is there a security vulnerability in Twofish / Serpent ? How do thy work ? As far as i know Twofish and Serpent are used in Some modern encryptions .  Sorry for the dumb question . I am only 16 and I dont really know much about Cryptography .


How to grant application access for Facebook account

Good day to all!  I've been trying to use Empathy for Facebook chat for quite some time now but whenever I try to enable it, I get the "Applications can no longer access your Facebook online account blah, blah, blah..." and so I tried going to Online Accounts and then grant access.  But whenever I click the button to grant access, it reverts back to "off" after maybe three seconds. What's happening and how can I solve this?  P.S. I already tried using Pidgin but I still get the same error.  Sometimes I get the "authorization failed" error as well.  Also, I can log into my FB account using my web browser.


Will having a "mr" in the given name of my ticket cause any problems?

On my passport Given name is Castiel  and last name is Black.  On the ticket my given name is Castielmr and the title field is blank. So it is printed as Castielmr Black  I cant remove the mr now from the booking website of qatar airline. My travel agent did the booking.


How to make a silver letter with a gold stroke like this one

Is anyone able to help me make a lowercase letter "n" like the attached?


Manga where the protagonist need to solve girl's quests

Can someone tell me the manga in which the protagonist is teleported to an alternative world where he needs to make the girls fall in love with him, then he gains some skills like an invisible sword. Then, when he finishes these "quests", he will be able to bring one of them to the real world. He has the ability to save and load like checkpoints of games.


Is there an adjective that means "every two days", i.e. is to a day as biennial is to a year?


Asymmetrical encryption with multiple sufficient key-pairs

I have the following requirement: There are N public/private RSA key pairs. The encrypted data must be decryptable by any of the private keys alone, but not by any other key. For encryption, the server knows and may utilize all the public keys for encryption if the scheme requires so. Does such a scheme exists?


Just seen someone has created this silly tag:   Should it/can it be removed?


is it safe to keep database connections open for long time

I have a .net client application which is connected to a remote database. Is it safe to keep a single connection open for the lifetime of the client (hours)? Does the answer hold if I have multiple (10 or 100) clients running?


Expected number of balls chosen from bag, I throw out everything in the bag with numbers less than the ball's

I am mainly confused about my reasoning/solution  Problem: I have a bag of numbers ranging from $1,2... n$. I randomly choose a number and then I throw out all numbers less than that. Then I keep choosing numbers until I've found the largest one. What's the expected number of things I have chosen?  My Argument: I expect on average to have chosen a number of $n/2$ on each pick. Hence, everytime I choose a number, I expect to discard half of them. Hence, the $E(X) = \log_2(n)$  Note that I devised this problem as an equivalent one while trying to solve the "cluster of cars on one long road" question. If this is not equivalent, please let me know but I am confident that it is. As a result of this equivalency, I know my solution is incorrect. However, I cannot pinpoint where the issue arises.


Tensor product of $\mathbb{Q}$ with an infinite product

How can I prove that the tensor $\mathbb{Q} \otimes \left( \prod_n \mathbb{Z}/n\mathbb{Z} \right)$, where the product is taken over all the positive integers $n$, is not trivial?


How long is it okay for a baby to remain on just breastfeed?

My daughter is now one and half year old and still refuses to eat anything. She seem to be satisfied by mother's milk itself.  Is it okay to remain on breastfeed alone this long, or should we try avoid/stop breastfeeding so that she tries/takes other food?


How do I make all links open in Chromium or Chrome's incognito mode?

How do I configure Ubuntu or Xubuntu such that when I click on a link, Chromium/Chrome opens in "Incognito mode"?


What is the simplest way to display unordered list items inline and also keep the bullets in Chrome?

I have a similar issue to the one described . I have an unordered list where the li tag has the display:inline property. Now the list items are being displayed one after the other on the same line, but the bullets are missing. I'd like to know the simplest way to have my elements show up both inline and with bullets. In  the top answer says it's correct to create a new question if the technology changed. The question linked is older than Chrome, with the top answers expected to account for IE7. There have been changes in web standards since then as well. Consequently, I think the technology has changed significantly enough to warrant another question. It is likely enough that the answer to this question is different from what was posted on the previous question that even if it happens to be there some confirmation is required.


How do I troubleshoot a Windows freeze or slowness?

A machine is described as being "really slow" or "freezing". How can I troubleshoot/resolve this issue? What should be the first steps to take?


How to sync bookmarks across Google Chrome and Mozilla Firefox bookmarks?  As I currently understand, Google Chrome puts bookmarks separately from Google Bookmarks, which is accessible in Firefox by using Google Toolbar for Firefox. Right?  So, how should I synchronize my browsers? I use Google Chrome as my primary browser.  It works good and bookmarks are synchronized across a number of computers I'm using.


Does it make sense to speak of probability of a hidden outcome? (context: confidence intervals)

My question is concerning the frequentist approach to probability. Assume that you tossed a coin but don't see the outcome. Does it make sense to say that it shows head with a probability of 0.5? Or doesn't it make sense to say that because it either is or is not heads?  I would argue that it does make sense because otherwise you would not be allowed to e.g. speak about the probability of your opponent in poker holding a certain combination of cards (he either has them or not...) which is clearly nonsensical. This would mean that at the end what counts is not whether something is or is not but your  about the fact. But perhaps this is an axiomatic issue?  This would also have profound consequences for the interpretation of confidence intervals. You are  that there is a 95% probability that e.g. the true mean is within the interval because it either is or is not - so no probability here.   But in case you are allowed to speak of probabilities of hidden outcomes you would also be allowed to say that the true mean is within the confidence interval with 95% probability. Or am I mistaken?


I have a programming problem and I've forgotten some of my math rectangle formulas. I have to make a program that creates a rectangle that isn't parallel to the X and Y axis, I assume this means a diagonal rectangle in the first quadrant of a Cartesian graph.  My inputs are the following:    coordinates of the vertex closest to the X axis and the origin angle the long side makes with relation to the X axis. area of the rectangle length of the long side   The outputs expected are the following:   length of the short side,  coordinates of all the rest of the rectangle's vertices.   Given these input how do I calculate the output mentioned?


How to get a homomorphism from $\mathbb{Z}\to G$, for $G$ a non-trivial group?

Let $G$ be a group.  If $G$ is non-trivial, then there exists a non-trivial homomorphism from $\mathbb{Z}\to G$.  How would one prove the above statement?


(and everyone else's) is slightly misleading. Underneath my main account, it shows my Physics.SE badges and my total network rep. To me, it looks as if I have 13k rep on Phy.SE (w00t!)--which I don't.  Anyone think that it should be slightly clearer which is which?


I need to convert black paths in image below to constant width lines. What strategy I should follow?


Prove that $\prod_{n=2}^∞ \left( 1 - \frac{1}{n^4} \right) = \frac{e^π - e^{-π}}{8π}$

The question  Prove that: $$\prod_{n=2}^∞ \left( 1 - \frac{1}{n^4} \right) = \frac{e^π - e^{-π}}{8π}$$    What I've tried  Knowing that: $$\sin(πz) = πz \prod_{n=1}^∞ \left( 1 - \frac{z^2}{n^2} \right)$$ evaluating at $z=i$ gives $$ \frac{e^π - e^{-π}}{2i} = \sin(πi) = πi \prod_{n=1}^∞ \left( 1 + \frac{1}{n^2} \right)$$ so: $$ \prod_{n=1}^∞ \left( 1 + \frac{1}{n^2} \right) = \frac{e^π - e^{-π}}{2π}$$  I'm stucked up and don't know how to continue, any help?


"I let him do it" and "I allow him to do it", why exactly does one require 'to'?

I let him do it.   and     I allow him to do it.   Why does the latter require to?  What are the "rules" of using to with an infinitive? When is it necessary?


I'm trying to get different band names, but then i type  $Band = "Azuolas" and $Band="Ąžuolas" I gate both at the same time. how can I fix this?  $band =$_POST['band_name']; $sql= "SELECT  Band FROM Songs WHERE Band='".$band."' "; $query_run =mysqli_query($con, $sql); while($mysqli_fetch_assoc =mysqli_fetch_assoc($query_run)){ echo $mysqli_fetch_assoc['Band']."<br>"; }


How Do I Reset A Manual Installation Of Windows Subsystem For Linux?

Related:   When installing a WSL distribution outside of the Microsoft Store (for example on a restricted network, see linked), many of the standard means of interacting with that distribution are not available.  In my example, when I go through Settings > Apps and Features, the distro is not shown in the list and the management features are not available.  If I get my manually installed linux instance into a bad state, what is the correct way to reset it and bring it back to a fresh install?  Edit:  Examples of a 'bad state' encountered thus far include a BSOD during an 'apt-get update', leading to an unrecoverable state.  Also, performing multiple configuration changes to troubleshoot a problem, removing or disabling services and installing other packages without keeping close track of what was changed, with a desire to "start fresh" to test if the solution arrived at does in fact work on its own..


How can I design a 4-to-16 decoder using two 3-to-8 decoders and 16 two-input AND gates?

I have an idea of how to get started, but not sure where to go from there.  Since I am using two 3-8 decoders to develop a 4-to-16 decoder, I want to use 4 inputs out of the two 3-8 decoders.  So I'll use all three of the first and the first of the second, and connect the last two inputs to ground, since they won't be used.  Any pointers on where to go from here are appreciated.


Whose laws should I obey in no man's land

Theoretically when you are past border control on an airport you are into no man's land. In that situation whose laws do I obey ?


Extract Values from records with max/min values

I posted a question earlier and got a great answer but realize I went about my logic the wrong way.  Given a table like this:  Name|ValueA|ValueB1|ValueB2 Bob |     1|    200|    205 Bob |     2|    500|    625 Bob |     7|    450|    850 Bob |     3|    644|    125 Ann |     4|    120|    120 Ann |     8|    451|    191 Ann |     9|    145|    982   I originally was trying to get the max/min values for each unique names and ended up with  Create TableA as (Select Name,Max(ValueA),Min(ValueA),Max(ValueB1,Max(ValueB2) Group by Name)   but this gave me (naturally) the high/low for each of A, B1, B2 e.g.   Bob|1|7|200|644|205|850   What I am looking for are the B1 and B2 values for the each of the lowest and highest A values per unique name in other words in the above I need   Bob|1|7|200|205|450|850 Ann|4|9|120|120|145|982   which gives me the high and low A values and the B1 and B2 for values contained in the high and low A Value records.  (This is NOT a duplicate question. My last question asked and answered how to pull the high and low values for three different fields for a given unique name into a new table.  This turns out to not be what I needed although the first question successfully was answered (and marked as such). What I need are the values for two fields from the high and low values of another field for a given name. If you look at the question you will see this is so and the solutions are in fact different)


How to set MultiLookupField in Workflow 2013

I'm working on SharePoint 2016 OnPremise, Workflow 2013 and I'm trying to set a MultiLookupField with one ore more values. I tryied to set 1;#2;#3;#4 and 1;#;#2;#;#3;#;#4, or for one single item 1;#;# and 1;#. Then I tryied to add the correct lookupValue 1;#Test1 and 1;#Test1;#2;#Test2;#3;#Test3 but nothing worked. The Worklows tells the following error:  An unexpected 'PrimitiveValue' node was found when reading from the JSON reader. A 'StartObject' node was expected.   I already read post like  and , they did not help.  A possible solution would be to create a WF2010 and start it from the current WF, but I'd avoid the need of a second WF...


$$E=\frac{1}{\sin10^\circ}-\frac{\sqrt3}{\cos10^\circ}$$  I got no idea how to find the solution to this. Can someone put me on the right track?  Thank you very much.


Whats is happening to Audit system today?

I came across the below scenario twice today.  Image 1    Image 2


How can I enable JRE on Firefox in Ubuntu 18.04?

I'd like to run Supermicro IPMI console which requires JRE but each time I get this error in Firefox:  You need the latest Java(TM) Runtime Environment. Would you like to update now?   I've downloaded and installed java on /usr/local/java/jre1.8.0_261 and in terminal I get # java -version java version "14.0.2" 2020-07-14 Java(TM) SE Runtime Environment (build 14.0.2+12-46) Java HotSpot(TM) 64-Bit Server VM (build 14.0.2+12-46, mixed mode, sharing)  But after restarted firefox I still can not access JRE. There are some old similar questions  which suggested installing icetea plugin. I did that sudo apt-get install icedtea-8-plugin, but the problem persists. I have also followed  old instructions but it did not work The  says: Starting with Firefox Version 52 (released in March 2017), Firefox has limited support for plug-ins, and therefore will not run Java. Use the Java Control Panel to find the installed Java version. How to find the installed Java version  So I suppose a lot have been changed since Firefox 52 and we need a new instruction if such integration is possible at all. My current firefox is 80.0.1 (64-bit) Really appreciate your hints to resolve this annoying problem.


Get angle of point in circle with center $(0, 0)$.

I have a circle with a centre at position $(0, 0)$ and I have a point in the circle at $(-5, 2)$. How can I get the angle of the point towards the centre?  I thought to use the theorem Al Kashi (law of cosines) but we need an another point to form a triangle but I don't have it.  Thanks, your help will be appreciated.


Given $A\sim \operatorname{Bin}(n,p), B\sim \operatorname{Bin}(n,q), p\geq q$ show $\Pr[A\geq k] \geq\Pr[B\geq k]$ for all $k$.

My intuition as to why the statement is true is that the binomial distribution with the higher probability will always have more weight 'further right' if you were to plot it, however I can't turn this notion into a proof.   An equivalent statement is that $$\Pr[A = 0] + \cdots + \Pr[A = k - 1] \leq \Pr[B = 0] + \cdots + \Pr[B = k - 1].$$ All this is saying is that the binomial distribution with the lower probability as more weight 'further left'. Inductive arguments seem to go nowhere...   Any help would be much appreciated.


Why does the zoom sometimes stop at a point?

I often find that I can zoom in to a point, but then cannot zoom any more, even when there is a lot of room to zoom to the meshes on the scene.   This is particularly annoying in the following scenario:  I often land up left clicking on the scene and the 3D cursor shifts there. I use Shift+C to shift the 3D cursor back to the origin. However, this also centers the view on the cursor and shifts the view to show all objects, and sometimes this zooms things way out – at this point, if I try to zoom in, I can zoom in to a point (using the pinch/zoom on trackpad), but then it stops zooming in.   How do I zoom in after that? Is there anything else I am doing wrong in this case?


Experience Cloud Not Displaying User Profile Information

I added the User Profile component to content in Experience Cloud and checked the Properties per Salesforce Help. I get an error "This component has no data. We can't load the User Profile component because it's not supported by any data. Once you add data, reload Experience Builder to see your component." As the System Administrator and builder/member of the site, I would expect to see my data as the running user. Why can't Experience Builder detect it? User Id in Properties is {!recordId}. What else am I missing?


Are there any reasons to avoid using white text on a black background?


What is the ideal class group of the ring $\mathbb{R}[x,y]/(x^2+y^2-1)$?

I would like to find the ideal class group of $\mathbb{R}[x,y]/(x^2+y^2-1)$. The motivation of this question comes from totally outside of algebraic number theory -- I was playing around with , i.e. curves parametrized by $x=A\sin(t+t_0),y=B\sin(\alpha t)$. In the book Mathematical Methods of Classical Mechanics, Arnold claims that when $\alpha$ is rational, such curves are actually algebraic, and left the proof of that claim as an exercise. My main idea to prove this was just to analyze the associated ring $\mathbb R[\cos t,\sin t]\cong\mathbb R[x,y]/(x^2+y^2-1)=:A$. As a finite integral extension of $\mathbb R[x]$, it must be a Dedekind domain, but I strongly suspect that it is not a PID. Is there any clear way to calculate the ideal class group here?


What is wrong with this demonstration regarding the sum of all naturals?

If , then the  must have a fault, but I can't find it.  Assuming $1+2+3+\cdots = -\frac{1}{12}$ (1) is true. Adding $0$ on both sides: $0 + 1+2+3+\cdots = 0 -\frac{1}{12}$ (2) Subtracting (2) from (1), we get, $1+1+1+1+1+1+\cdots=0$ (3) Adding $0$ on both sides again,  $0+1+1+1+1+1+\cdots = 0 + 0$ (4) Now subtracting (4) from (3) we get, $1=0$, which is  a contradiction. Obviously our assumption that $1+2+3+4+\cdots = -\frac{1}{12}$ is wrong.  There is some error in the steps above, but I cannot find it. What is it?


Can a concentration spell be cast without actually concentrating on it for an "instant" effect?

The book says:     Concentration. Some spells require you to maintain concentration in order to keep   their magic active. If you lose concentration, such a spell ends.   So what happens if, for example, you are already concentrating on a spell, and cast Witch Bolt without concentrating. Would you get the initial arc of blue energy, or would it not even go off?  I am asking if you can cast a spell that says concentration without concentrating for an immediate effect. This would be useful to avoid interrupting your existing concentration. In essence, if you are concentrating on thing A (doesn't have to be a spell since other things need concentration), can you cast a concentration spell getting an immediate effect without losing concentration on thing A?  Since the definition of concentration is to keep the spell active (meaning it is already active) I would think that you would get the initial effect (if it had one) without the need to concentrate on it.


Is assignment in if conditions a bad practice?

In Java, it's allowed to have assignment in a if condition, meaning we can have code like this: List<T> result; if ((result = getResultFromA())) == null) {   result = getResultFromB(); } return result;  Which I think is equivalent to: List<T> result = getResultFromA() if (result == null) {   result = getResultFromB(); } return;  I know the second one is more readable, but I'm wondering if there is any difference in terms of efficiency or performance? Is the first style a bad practice? I would appreciate any ideas. Update: Thanks for all these great ideas. Actually the question should be: which of these two syntaxex should be followed? Apart from readability, is there any other reason why we prefer the second style?


Is it possible to write few equations, number them automatically, and also describe the equations with some text?  I am unble to write some text in the \begin{equation} part  This is my case  \documentclass{standalone} \usepackage{amsmath} \begin{document} \begin{equation} Description of the equation 1                          eq1             (1) Description of the equation 2                          eq2             (2) \end{equation} \end{document}   Edit after applying the solutions below -   the additional problems are all equations should be aligned and all texts should be aligned and if possible numbering can be controlled / reset.


Convert function to synchronous from asynchronous

I've created this function, however when it runs on the website it's designed for it is returning undefined. I did some quick Googling and found that because it's an asynchronous function, it completes and returns the data before the server can respond. I'm stumped however on how to convert it to a synchronous function.   Here is my code:  render_SC = function() {       var SC_url;     $.get(Dubtrack.room.player.activeSong.url, function(f) {         SC_url = f.data.songInfo.images.thumbnail.replace('large','original');     });     return SC_url; }; console.log(render_SC());   Thanks in advance for all your responses. :)


How to Use Batch File - Simple Application to Restart Audio Drivers

I want a batch file to open CMD and run "net stop audiosrv", then "net start audiosrv", then kill CMD. I am having problems with a bunch of things including   It's not waiting It is opening a new CMD It's not closing   Here is the code I wrote myself. I've never done any coding before and got this from what I did now/combining it with other things I've seen on here.  start cmd.exe /k "net stop audiosrv"  wait 10  start cmd.exe /k "net start audiosrv"      TASKKILL /IM cmd.exe   I don't really think it matters but I'm running Windows 7 Ultimate Service Pack 1 - 64 bit


Prevent application launch if already running

My app needs to check and see if it is already running when launching so it doesn't open a second time. I have a system tray icon that can make the application visible = False. Works great. However, I need to make sure the user looks at the system tray for the notifyicon if the app is already running.  Private Sub mainWindowSmall_Load(sender As Object, e As EventArgs) Handles MyBase.Load         Dim p() As Process         p = Process.GetProcessesByName("TSC Tool Box")         If p.Count > 0 Then             MessageBox.Show("The TSC Tool Box is already running. Check System tray!", _             "Warning !!!", MessageBoxButtons.OK, _             MessageBoxIcon.Error, MessageBoxDefaultButton.Button2)             Me.Close()         Else             totalOnLoad()         End If     End Sub   VB.NET | winforms


I would generally consider fields to not be substances, since substances are generally associated with matter. I know that energy is not a substance. Are electromagnetic waves a substance?


I tried to prove this with Valli's equation: $\frac{sinx}{x} = \prod(1-\frac{x^{2}}{(n\pi)^{2}})$ and use $\frac{d(ln(sin(x)))}{dx} = i + \frac{2i}{e^{2ix}-1}$.  Maybe it's better to use Taylor's transform?  The ended result: $\zeta(2n) = (-1)^{n+1}\frac{B_{2n}(2\pi)^{2n}}{2(2n)!}$


No sound in Ubuntu 13.04, only Dummy output device listed

My sounds suddenly stopped playing on Ubuntu 13.04 64bit. I can only see Dummy output device in the Sound Settings and no sound is played during testing.  I can get the sound temporarily working by killing one of the strange processes, but I have to repeat the same after reboot  jan@jan-HP-Desktop:~$ ps -ef|grep pulseaudio 112       1405     1  0 09:38 ?        00:00:00 /usr/bin/pulseaudio --start --log-target=syslog 112       2132  1405  0 09:38 ?        00:00:00 /usr/lib/pulseaudio/pulse/gconf-helper jan       2575     1  0 09:39 ?        00:00:00 /usr/bin/pulseaudio --start --log-target=syslog jan       2597  2575  0 09:39 ?        00:00:00 /usr/lib/pulseaudio/pulse/gconf-helper jan       3160  2975  0 09:40 pts/2    00:00:00 grep --color=auto pulseaudio  jan@jan-HP-Desktop:~$ sudo kill 1405   Is there a permanent solution for this problem?


Blender does not display objects's shape

I'm new to Blender, I just started learning a couple days ago. I have one question about the preview. My Blender seems to not displaying anything in Material Preview mode, even though I edited the objects' material. As you can see in the second picture, the first picture you can clearly see the objects in Solid mode. Is it that something is wrong with Blender or did I edit something I'm not supposed to ? I'm using Blender 2.83 as well as 2.91 Sorry for my bad English :).


How do I create an .exe for a Java program?

Possible Duplicate:          I'd like to create a Windows .exe for a Java program. Previously, I've used JEXECreator for this, but it's not entirely satisfactory because:   The executable sometimes works on the machine on which it was created but not on others. The program is commercial; if you use the trial version, it adds a nag screen to your application.   I don't need the generated .exe to work if Java is not installed on the target machine (in fact, I think this is impossible).  Any recommendations?


How can I check if the request is a post back in PHP, is the below ok?  if (isset($_POST["submit"]))   where submit is the name of the <input type="submit" />


How do i sync Xbox 360 Offline Achievement (Not connected to xbox live) that i completed to my xbox live account?

Unfortunately i was playing gta 5 story mode campaign and then i finished the "FROM BEYOND THE STARS" Achievement where you had to collect all 50 spaceship parts and after i finished it i noticed that i was disconnected from xbox live and i did not get the achievement but i completed it :(  i even checked my SocialCLub account and the achievement was still locked. So how can i sync it to xbox live? note that i DID completed the achievement. please help me out! thanks. also it happened to another achievement in gta 5! Thanks.


What should I do with question that has been answered on another site?

I have review the following question and answer    My New question:  As part of community what should I do when I find questions that have been answered on another site?


Can anyone help me to figureout what is this error & how to remove the packages that are causing this error? "I am new to to ubuntu"

This happened when I was trying to download "OpenFOAM v7 CFD(Computational Fluid Dynamics)" on ubuntu 20.04 LTS. Also if any one knows how to install it please help.  sudo apt update Ign:1 http://dl.openfoam.org/ubuntu focal InRelease Hit:2 http://archive.ubuntu.com/ubuntu focal InRelease                                                                               Ign:3 http://old-releases.ubuntu.com/ubuntu focal-security InRelease                                                                 Err:4 http://dl.openfoam.org/ubuntu focal Release                                                                                404  Not Found [IP: 35.179.33.128 80] Err:5 http://old-releases.ubuntu.com/ubuntu focal-security Release                                             404  Not Found [IP: 91.189.88.153 80] Err:6 http://kr.old-releases.ubuntu.com/ubuntu/pool/universe/o/openfoam/openfoam_4.1+dfsg1-2_amd64.deb focal InRelease Could not resolve ‘kr.old-releases.ubuntu.com’ Err:7 http://in.old-releases.ubuntu.com/ubuntu focal InRelease                           Could not resolve ‘in.old-releases.ubuntu.com’ Err:8 http://in.old-releases.ubuntu.com/ubuntu focal-updates InRelease Could not resolve ‘in.old-releases.ubuntu.com’ Err:9 http://in.old-releases.ubuntu.com/ubuntu focal-backports InRelease Could not resolve ‘in.old-releases.ubuntu.com’ Reading package lists... Done E: The repository 'http://dl.openfoam.org/ubuntu focal Release' does not have a Release file.  N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'http://old-releases.ubuntu.com/ubuntu focal-security Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details


Sequence sum question: $\sum_{n=0}^{\infty}nk^n$

I am very confused about how to compute  $$\sum_{n=0}^{\infty}nk^n.$$  Can anybody help me?


Now here's what I want to do - I have a lot of Movie DVD's and Bluerays.  I want to copy some of them to my HDD.  In Windows I know how to do this,  but not in Ubuntu.  With Windows u use a DvD Ripper,  what can u use in Ubuntu ?  I would be glad for a solution - thanx !!!


exclude specific commands from saving into history

I want to exclude some specific commands from saving into zsh history.  for e.g: exclude mpv/mpc commands from saving into zsh history regardless of setting HIST_IGNORE_SPACE or not.  I found an answer  but it does not work when I test it.


I'm able to read CONSTRAINTS in the Information Schema, but how can I get all parameters associated with that CONSTRAINTS to get a full CONSTRAINTS definition by using SQL ? For example,  SELECT * FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS    This will give me list of CONSTRAINTS, but let say, I got a CONSTRAINTS FOREIGN KEY  "user_role_id" and its full definition (via pgAdmin) is  ALTER TABLE app.user ADD CONSTRAINT user_role_id FOREIGN KEY (role_id) REFERENCES app.role (id) MATCH SIMPLE ON UPDATE CASCADE ON DELETE CASCADE;   So how do I get this definition by just writing SQL that give me all those options associated with that CONSTRAINTS?


In The Forest of the Dead, the Doctor says   In a later episode, River says that it took a lot of convincing but he told her his name. This doesn't seem like the true reason.  What is this single reason that he would tell her his name? Is it their marriage?


Absolute path of files in Blender (with Python)

Functions such as os.path.exists(image.filepath) fail when Blender uses relative paths, This seems to be because Blender uses // prefix for relative paths, unlike the more conventional ./.  How can standard Python filesystem functions be used correctly on Blender paths?


How do I subtract multiple shapes at one time using the shape builder tool in Illustrator? Is there another tool I can use?

I am creating a logo and placed a Vintage overlay on top of it (white shapes). Is there a fast way for me to subtract those shapes from my logo using the shape builder tool instead of doing it one by one? It is taking FOREVER to load every time I erase one shape. Is there another tool that would work better? Thank you in advance!


If I write this line of code  \subsection{Ranger \( n \) boules distinguables dans \( M \) boîtes}   I obtain an error over the second \)  (./Probabilité.toc  ./Probabilité.toc:8: LaTeX Error: Bad math environment delimiter.   while if I write  \subsection{Ranger $ n $ boules distinguables dans $ M $ boîtes}   everything is ok.   Why? \(\) has problems with TOC?


PHP - How to extract achor href of specified linked image?

How would i extract anchor href of given HTML, based on image src?  Example:       In this case i would need to get link of linked image with src of 2.gif. That would be anchor that has href http://iwantthis.com


I am curious if there is a way to get the vertex of a parabola without calculus?  I know the calculus approach has you take the derivative set to $0$ (for $0$ slope) so if $f(x) = ax^2 + bx + c$ then $f'(x) = 2x + b$ so $0 = 2x + b$ implies $x = -\frac{b}{2a}$ with $y$ coordinate $f(-\frac{b}{2a})$.  But how would we get the vertex without calculus?


I'm a brand new player and I want to clarify my attack sequence as simple as possible. I'm a level 1 Rogue, so I have 1d8 "hit dice" according to the rules.  How does that affect me if I'm making attacks with my daggers? What would my attacks look like? For a main hand and off hand, as far as I know it's 1d4 + 3  for main and 1d4 for off hand, does this sound correct? Where does the hit die fit into it?  My DEX mod is +3 and proficiency is +2.


Prove nonexistence of a countable basis.

Let us consider space $R = \mathbb{R}^{\mathbb{N}}$ of infinite sequences of real numbers. I have to prove two claims:   Let $a_i=(0,0,\ldots,1,0,0,\ldots)$; $1$ at i-th place. Then $B=\cup_{i=1}^{\infty}a_i$ is not a basis of $R$. It can proved with the Zorn lemma that there is basis in $R$. Prove that there is no countable basis in $R$.   My attempt:   Let us consider sequence $A=(1, 1, \ldots)$ (all $1$). Since linear combination is by definition finite then it is clear that we can not express $A$ as finite linear combination of sequences from $B$, because any linear combination of sequences from $B$ would have only finite number of nonzero elements. Well, honestly I do not know to solve this. I think we should do something like this - assume that there is countable basis $B'$. Then we should construct a sequence that does not belong to $\operatorname{span}(B')$ explicitly or use some set-theoretic theorems about cardinalities that $\operatorname{span}(B')$ has smaller size compared to $R$. However while I am pretty sure about the approach we should take, I do not see how to execute it.   So my questions are:   Is $1$ is correct/make sense? How to approach $2$?   Thanks a lot for your time!


How do I increase line width in 3D Viewport?

How do I increase the line thickness displayed in the 3D Viewport? The lines are simply too thin to see easily.    I changed my theme to "Back to Black" in the user preferences, and the higher contrast helps a little bit.  I am running 1920x1080 on a 27" monitor if that makes any difference.


Does this series with alternating elements converge: $\sum_{k=10}^{+\infty}\frac{(-1)^k}{k+(-1)^k}$?

I have to investigate convergence of series $$\sum_{k=10}^{+\infty}\frac{(-1)^k}{k+(-1)^k}$$ It certainly does not converge absolutely, because it is basically a harmonic series with every two elements flipped and if harmonic series converged, or greater than series $$\sum_{k=10}^{+\infty}\frac{1}{k-1}$$ However, I do not know, how to prove convergence of this series overall. I thought about the fact, that it is basically a harmonic series(well, alternating harmonic or whatever I should call it) with every two elements flipped and if normal "alternating harmonic series" converges, then this rearangement could technically converge too. However, I am not sure if this is sufficient enough and if I can do this and I am afraid that it is not. I was considering those theorems that say "every divergent series with alternating elements can be rearranged to make arbitrary finite sum" and I am not sure if it holds with convergent series, respectively, if it holds against convergent series and infinity - that you can rearrange convergent series to make divergent...  Neverthless, there should be an easy way to prove that this sum is convergent/divergent, since it is in our textbook.  Also I thought, since it is certainly lesser or equal to $1/(k-1)$ and greater or equal to $1/(k+1)$ assigning numbers $S_1$ and $S_2$ to sums of these "alternating harmonics" and just saying that it is lower bounded by $S_2$ and upper bounded by $S_1$, since those series are convergent and have to be upper and lower-bounded too. But also, I am not sure if this is enough.


Find all functions $f$ such that  $f(f(x)f(y))+f(x+y)=f(xy), \forall x,y \in \Bbb R$  Obviously I get that $f(x)=0$ is a trivial solution, but I'm not sure as to how to go about finding any more?  Or how to know when I have found them all?


I am having difficulty in understand some code in python and would really appreciate any help on it.  condition = "{field}::{cast} {operator} {value}".format(**{     'field': field_exp(field),     'cast': cast,     'value': json.dumps(parameter).replace('"', "'"),     'operator': operator})   I cannot understand what's really happening in this statement. what does the "double colon" do? And what does format(**... mean?  Further in the code there is another line:  condition = "jsonb_typeof({field}::jsonb) is {not} null".format(**{     'field': field_exp(field),     'not': 'not' if parameter else ''})   This statement again follows similar pattern. I will really appreciate if someone could explain what's going on here.  Thank you, Asanas


Can I get SSH to use an askpass program even if it was run from a terminal?

says:  SSH_ASKPASS    If  ssh needs a passphrase, it will read the passphrase from the    current terminal if it was run from a terminal.  If ssh does not    have  a  terminal associated with it but DISPLAY and SSH_ASKPASS    are set, it will execute the program  specified  by  SSH_ASKPASS    and open an X11 window to read the passphrase.   I'd like SSH to use an askpass program even if it was run from a terminal.  On occasion, I have to connect to servers, where there's some delay in showing a password prompt (maybe due to network issues, maybe due to attempted reverse DNS lookups, …). I get annoyed and switch to something else, and forget about the attempted connection. (Insert joke about attention span of a goldfish.) When I finally get back to it, the prompt's timed out and even a correct password would just result in a closed connection.  Keys would be one solution, but not every system I use has my usual SSH keys. However, I usually use Ubuntu systems, and Ubuntu has an SSH askpass program installed by default.  If an askpass window popped up, however, I'd be immediately aware of it. That's a good enough compromise for me, if only I can get it to work.


Was the first Leto II also the Kwisatz Haderach?

By the first Leto II, I'm referring to the one born in Dune, who died during the Sardaukar raids. Additionally, I am not necessarily implying that Paul was not the Kwisatz Haderach (because that is its own discussion), I am asking, could the first son have achieved the same "terrible purpose" that Paul saw and Leto II fulfilled.  The first son had the same heritage as the second, and so should genetically be as capable as the later son.   Paul shares some prescient connection with both of them: he knows the instant the first has died, and the vision-sharing experience on the night of the second's birth. This in contrast to him not even knowing Ghanima was born.  Would the genetics alone have led him along the Golden Path?


Does the domain of the function $y=\sqrt[3]{x^3+1}$ include $x<-1$? If yes, why is Mathematica and Wolfram Alpha not plotting that part of the function?


Does gravity besides frequency change the speed of beam of light?

Does gravity besides frequency change the speed of a beam of light?For me the easiest way to grasp this possibility is the so called frame dragging where the motion of the frame affects the overall speed of an object or light.So if we presume the frame moving towards the source of gravity this should affect the speed of a beam of light when moving vertically upwards or downwards.Let say we put a mirror on a s=100 m high skyscraper and  measure the total time for the light to travel 200 m back to the emitter at the bottom of the building. So if the beam of light travels one half of the path at speed c-g' and the other half at speed c+g' the overall time should be like this: $$\ ( \frac{s}{c-g'}+ \frac{s}{c+g'})=\frac{2sc}{c^2-g'^2}>\frac{2s}{c}$$  implying that the mean speed of the beam was slower than if the beam moved horizontally. Could this be true or there were experiments that proved this is impossible?


Firefox - Websites with custom fonts not displaying

I've just upgraded to FF 57 and websites that use their own fonts have stopped displaying text.   I know this is a problem others have had, e.g. , but the solutions there have not worked. Safe mode does not help either, the problem only goes away if I uncheck the custom fonts option in Preferences.  I have custom fonts installed as well (from TexLive and and a couple more) so I'm thinking that might be the cause.   Any ideas on how to troubleshoot this?  Example from Github:


I had an interesting conversation with CuriousOne the other day about the question . I thought that wave-particle duality existed, CuriousOne thought it didn't (whether CuriousOne thought this wasn't true for both light and matter, or just matter I'm not really sure). Some of the comments were really interesting, and I wanted to know what some of the physicists here thought.   The comments on the question are just below the main question, and are just below my answer to the question (now moved to chat). Please don't close this with "not enough research" as the reason, I did look into it, but some of CuriousOne's comments left me kind of confused.   In terms of people thinking this is a duplicate: I am asking whether there is experimental evidence for electrons having a wave-particle duality (this duality being like the one light has) and whether the double-slit experiment is an example of experimental evidence for this.    Question:  Was de Broglie's hypothesis that electrons  (and other matter) have wave-particle duality correct? Does the double-slit experiment prove this, or have anything to do with this? What is some experimental evidence for de Broglie's hypothesis?  Thanks!


Is it possible to add entries to the bibliography based on keyword using Biblatex/Biber and within the document code?

I would like to print a bibliography which includes all entries with a certain keyword (and possibly some additional entries).  I know that I can filter by keyword when I print the bibliography using  \printbibliography[keyword=<keyword>]   but this will only print entries which I have cited. I could, of course, use  \nocite{*}   to add all entries to the bibliography and then print just those I want.  However, this will make my .bbl file huge as my database is enormous.  Another possibility is to use Biber or another tool to prepare a document-specific .bib file containing only those entries with the keyword. However, this would need to be recreated if additional entries with the keyword are added to my main database files.  Here's an MWE to play with, annotated to indicate the way I'd like it to work ;), and the disadvantages of the way it (almost) works.  The issue of excluding explicitly cited entries is less of an issue for me. The thing I'd really like to work around is adding the entire database contents to the .bbl.  \RequirePackage{filecontents} \begin{filecontents}{\jobname.bib} @book{new-stuff,     author          =   {Watt, Brian},     title           =   {Happy Times with Penguins},     publisher       =   {Harvard University Press},     address         =   {Cambridge, MA},     year            =   1995,     pagination      =   {section},     keywords        =   {happy}} @book{den-coll,   author                =   {Till, Jr., Dennis E.},     booktitle           =   {Penguin Land and Further North: Human Influence},     title               =   {Penguin Land and Further North: Human Influence},     publisher           =   {Oxford University Press},     year                =   2008,     address             =   {Oxford and New York},     keywords            =   {penguin, human}} @book{old-stuff,   author                =   {Harvey, Jr., Dennis E.},     booktitle           =   {Penguin Land and Further North: Human Influence},     title               =   {Penguin Land and Further North: Human Influence},     publisher           =   {Someone \& Daughters},     year                =   1567,     address             =   {Oxford},     bookpagination      =   {paragraph},     keywords            =   {penguin}} \end{filecontents} \documentclass{article} \usepackage[defernumbers=true]{biblatex} \bibliography{\jobname} \begin{document}  \cite{old-stuff}  % what I would like to work % \nocite[keyword=happy] % \printbibliography  % what does work - except that \cite{old-stuff} is ignored and, more importantly, den-coll is added to the .bbl \nocite{*} \printbibliography[keyword=happy]  \end{document}


Is the "omniscient-omnipotent-omnipresent" definition of God consistent?

is commonly defined as an  (infinite knowledge),  (unlimited power),  (present everywhere) entity.  Is there any logical  in this definition?  I have seen several paradoxes like below     Does God know what he's going to do   tomorrow? If so, could he do something   else?" If God knows what will happen,   and does something else, he's not   omniscient. If he knows and can't   change it, he's not omnipotent.      "Can 'an omnipotent being' create a   stone so heavy that it cannot lift   it?"   Do they mean that the defintion of God ( as commonly held) is logically inconsistent?


Visual Studio Solutions Folder as real Folders

I have a Visual Studio Solution. Currently, it is an empty solution (=no projects) and I have added a few solution folders.  Solution Folders only seem to be "virtual folders", because they are not really created in the Filesystem and files inside solution folders are just sitting in the same folder as the .sln file.  Is there a setting that i've overlooked that tells Visual Studio to treat Solution Folders as "real" folders, that is to create them in the file system and move files into it when I move them inside the solution into one of those folders?  Edit: Thanks. Going to make a suggestion for VS2010 then :)


Let $\zeta_7= e^{i2\pi/7}$ be the $7$th root of unity.Find the quadratic sub field of $\mathbb Q(\zeta_7)$ which can be expressed in the form $\mathbb Q(\sqrt D)$,where $D$ is an integer.  My try:let $\omega=\zeta_7+\zeta_7^{-1}\in\mathbb{Q}(\zeta_7)$ is real which is $\omega=2\cos(2\pi/7)$. Thus $K=\Bbb{Q}(\omega)$ is a proper subfield of $\Bbb{Q}(\zeta_7)$. And the polynomial $$ p(x)=(x-\zeta_7)(x-\zeta_7^{-1})=x^2-\omega x+1 $$ has its coefficients in the subfield $K$. Thus it has to be the minimal polynomial of $\zeta_7$, and $[K(\zeta_7):K]=2$.  But the problem is that what is $D?$ and how can i find that?Thank you


I have a generic list of objects in C#, and wish to clone the list. The items within the list are cloneable, but there doesn't seem to be an option to do list.Clone().  Is there an easy way around this?


numbering of sections in text disappears when using titlesec custom command

I am using the package \titlesec to transform the command \paragraph into something like \subsubsubsection. However, with the MWE displayed below, the numbering of sections, subsections and subsubsections disappears from the text. How can I keep using the custom command for subsubsubsections and still have the section numbering in the text? Thanks for your help!  \documentclass{report} \usepackage{titlesec} \titleformat{\paragraph}{\normalfont\normalsize\bfseries}{\theparagraph}{1em}{} \titlespacing*{\paragraph}{0pt}{3.25ex plus 1ex minus .2ex}{1.5ex plus .2ex}      \begin{document}  \tableofcontents   \chapter{mwe}  \section{section one}  \subsection{subsection one}  \subsubsection{subsubsection one} \paragraph{paragraph one} normal text \section{seciont two}  \subsection{subsection one}  \subsection{subsubsection one}  \end{document}


How to integrate $\int_0^{\infty}\left(\frac{\sin(x)}{x}\right)^m dx$?

How to evaluate $L(m):=\int_0^{\infty}\left(\frac{\sin(x)}{x}\right)^m dx$?  I am familiar with the case $m=1$, but what about the general one?


Is it possible that doubles are x2 FASTER than float?

I performed some benchmarking to compare doubles and floats performance. I was very surprised to see that doubles are much faster than floats.  I saw some discussion about that, for example:      Most of them said that it is possible that double and float performance will be similar , because of double-precision optimization, etc. . But I saw a x2 performance improvement when using doubles!! How is it possible? What makes it worst, is that I'm using a 32-bit machine which do expected to perform better for floats according to some posts...  I used C# to check it precisely but I see that similar C++ implementation have similar behavior.  Code I used to check it:  static void Main(string[] args) {   double[,] doubles = new double[64, 64];   float[,] floats = new float[64, 64];    System.Diagnostics.Stopwatch s = new System.Diagnostics.Stopwatch();    s.Restart();   CalcDoubles(doubles);   s.Stop();   long doubleTime = s.ElapsedMilliseconds;    s.Restart();   CalcFloats(floats);   s.Stop();   long floatTime = s.ElapsedMilliseconds;    Console.WriteLine("Doubles time: " + doubleTime + " ms");   Console.WriteLine("Floats time: " + floatTime + " ms"); }  private static void CalcDoubles(double[,] arr) {   unsafe   {     fixed (double* p = arr)     {       for (int b = 0; b < 192 * 12; ++b)       {         for (int i = 0; i < 64; ++i)         {           for (int j = 0; j < 64; ++j)           {             double* addr = (p + i * 64 + j);             double arrij = *addr;             arrij = arrij == 0 ? 1.0f / (i * j) : arrij * (double)i / j;             *addr = arrij;           }         }       }     }   } }  private static void CalcFloats(float[,] arr) {   unsafe   {     fixed (float* p = arr)     {       for (int b = 0; b < 192 * 12; ++b)       {         for (int i = 0; i < 64; ++i)         {           for (int j = 0; j < 64; ++j)           {             float* addr = (p + i * 64 + j);             float arrij = *addr;             arrij = arrij == 0 ? 1.0f / (i * j) : arrij * (float)i / j;             *addr = arrij;           }         }       }     }   } }   I'm using a very weak notebook: Intel Atom N455 processor (dual core, 1.67GHz, 32bit) with 2GB RAM.


I want to know what elements are (varimax-)rotated when I rotate after PCA and after Factor Analysis.  Let’s assume a standardized data vector $X$ of dimension $N \times q$.   In PCA, I have the formula: $F=XL$  In Factor Analysis, I have: $X=FL^T+E$  F is of dim $N \times k$, and L is of dim $q \times k$.  I obtain the loadings for PCA by applying SVD on X and reading out one of the eigenvector matrices after having sorted them according to size of their eigenvalues. To make it clear, I decide to use the two components with the largest variance. Lets call them $C_{1}$ and $C_{2}$. So the eigenvectors from the SVD are equal to the loadings which are the new axes.  For Factor Analysis, I use for simplifying reasons „Principal Component Factors“ to extract my loadings because I do not have to estimate the specific variance - it arises as the residual variance after having calculated the factors (s. Rencher 2003 p.415-421). For PCF, I apply an SVD on $X$ and multiply the values in an eigenvector  with the square root of their corresponding eigenvalues (so the main difference between the procedures at this point is only the multiplication of the eigenvectors with their eigenvalues – but still: it's Factor Analysis!). Again, I decide to retain the two factors with the largest eigenvalues. Lets call them $F_{1}$ and $F_{2}$.  I acknowledge that the factor analysis solution for the loadings is unique up to an orthogonal rotation.  Now on rotation. As far as I understand, I rotate orthogonally in PCA by multiplying the eigevectors $U_{1}$ and $U_{2}$ with an appropriate 2x2 matrix. So I rotate the axes (once more), but apparently I am still in space of the original variables, right? While my eigenvector) are still orthogonal to each other, my components (calculated as above =XL) are now correlated. I understand that this is drawback.  But what happens in factor analysis? My coordinate system is now spanned by the factors and not by the original variables, right? Somehow I lack intiution for I still haven’t estimated F.  Still, the procedure seems to be absolutely the same as before, because I rotate the loading matrix and the results seem very similar. They would be equal, I suppose, if the loadings in PCA would be multiplied by the square root of their eigenvalues, too. However, the drawback of correlated factors does not occur and I can safely rotate.  Having read @amoeba’s answer to  , my question could not be answered maybe because I could not understand what the approach for FA was.


What is the difference between "inform of" and "inform about" ?   Can you give some example sentences which clearly shows the difference.  Thanks.


Their descriptions seem pretty similar. Is a ring the same as a field except it uses abstracted versions of addition and multiplication instead of only classical addition and multiplication as in a field?   I've also already seen the proposed "other answer" and it didn't really answer my question, it was much more convoluted than necessary. Honestly all I'm looking for is a one-line answer.


Could someone help me with Bulkification?

I know everyone here is big on bulkification..but I've never done it myself. Could somebody give me some pointers on how to bulkify this Trigger? It is a basic duplicate lead trigger.  //Look for duplicate leads based on email //Populate a Dupe_Lead__c field with the Lead if found  trigger DetectDupes on Lead (before insert, before update) {     for (Lead l : Trigger.new)     //Make sure the lead has an email address     {         if (l.Email != null)         {             //Find a duplicate             String leadEmail = l.Email;             String leadId = l.Id;              Date d = system.today().addDays(-7);              List<Lead> dupeLeads = [SELECT Id FROM Lead WHERE Email = :leadEmail AND Id != :leadId AND createdDate >= :d AND Email != 'na@na.na' AND Email != 'na@na.ca' AND Email != 'na@na.com'];              //If a duplicate is found, update the Dupe_Lead__c field. There is a validation rule that will not allow the record to save if this field is populated.             if (dupeLeads.size() > 0)             {                 l.Dupe_Lead__c = dupeLeads[0].Id;             }             else             {                 l.Dupe_Lead__c = null;             }         }             else          {              l.Dupe_Lead__c = null;            }      } }


Photo filter: What is the name of this filter

This is my first post here. I am new to photography. I am amazed with some of the beautiful works people are doing. Equally I have started to love the power of filters. I jus saw the following photo:    Can some please tell, what is the name of this filter? I wonder If there is any tutorial that helps to recreate this kind of clean nice effect.  Thank you in advance.  Image source:


Did Anakin and Obi-Wan use the Force to protect themselves from the heat on Mustafar?

While duelling that close to lava, I would suspect that they would get dangerously hot and dehydrated, and possibly burned. Did they use the Force to protect themselves in some way, for example lower their body temperatures and cool the air around them while duelling?


$2 \times 2$ matrix $A$ where $\operatorname{Col}A=\operatorname{Nul}A$

Can someone provide an example of a $2 \times2$ matrix $A$ where $\operatorname{Col}A = \operatorname{Nul}A$, and explain how this is the case?   In General, under what conditions on $A$,   $\operatorname{Col}A = \operatorname{Nul}A$ holds?   Thank you!


tag:* links incorrectly when using Save And Copy Profile To All Stack Exchange Accounts

The  tag in my Stack Exchange profile links to different sites depending on where it's being viewed:  Profile on StackOverflow:  [tag:CSS] => https://stackoverflow.com/questions/tagged/css   Profile on StackExchange:  [tag:CSS] => https://stackexchange.com/questions/tagged/css   Profile on CodeReview:  [tag:CSS] => http://codereview.stackexchange.com/questions/tagged/css    I'd like to have these all link to https://stackoverflow.com/questions/tagged/css. You can ; why not add the ability to specify the site with tags? <!-- tag: stackoverflow -->[tag:css] <!--tag: meta -->[tag:feature-request]  The current behavior also cause a bug on my :    All tags send me to find a Panda aka 404 Page Not Found.


Currently I have / in /sda1, which has 732.3GB.  All I want to do is separate /home in a new partition, so that later on I can install Ubuntu 16.04 while preserving the data in /home.    The 732.3GB partition has 664.4GB being used, so I can't create a new parition for /home using Gparted, I have to somehow divide the existing partition into 2, with the new one being exclusively /home.  I don't how to explain it better, but I would really appreciate your help.


Is it possible in Blender to create a animated png vertical strip?

I want to create a png file that is an animation of fire for a Minecraft resource pack. I can render the images as separate files and painstakingly put them together in Photoshop. I would rather see if I can do that in Blender or with another tool?  Here is an example of the desired outcome. Sorry for the size.


How should answers containing just a link be flagged?

I flagged an answer as not an answer because it contained just a link (or a little more than a link), and my flag was rejected because, "flags should not be used to indicate technical inaccuracies, or an altogether wrong answer."    I was not flagging it because it was technically inaccurate, or because it was wrong. I flagged it because it was a little more than a link, and the  says:     Answers that do not fundamentally answer the question may be removed. This includes answers that are …         commentary on the question or other answers   asking another, different question   "thanks!" or "me too!" responses   exact duplicates of other answers   barely more than a link to an external site   not even a partial answer to the actual question      In which way should an answer containing just a little more than a link, or two, be flagged?


Uninformative (flat) Prior density for non-linear functions

We, bayesians, usually use non-informative priors for the parameters like  $p(\beta)\propto 1$.  Someone told me that such a flat prior is informative to some extent for non-linear functions of the parameters $\beta$. I thought this sort of prior was always uninformative for any kind of functional form.   I would appreciate some clarification on this point!


Math digits are in CM with newtxmath and fontspec (LuaLaTeX, TeX Live 2017)

This issue is not new on this site, but I’ve tried earlier solutions and neither works for me. Related questions:       My goal is to use newtxmath together with setting system OpenType fonts through fontspec. No matter in which order I load the package, the digits in math mode are rendered in Computer Modern, not Times.  % !TEX program = lualatex  \documentclass[12pt,a4paper]{article}  \usepackage{newtxmath}  \usepackage[no-math]{fontspec}  \setmainfont{Times New Roman}  \begin{document} Text: 2, Math: \(x=\sqrt{2}\) \end{document}     Per the newtxmath documentation:      As far as I can tell, newtxmath works with both [XeLaTeX and LuaLaTeX], but requires a very specific loading order and choice of   options. [...] the math options must all be loaded prior to loading and using   fontspec.   Which I’ve done right in my opinion. My packages are all up-to-date as well.  I’ve tried to adapt  for the Times font, but couldn’t make it work.


How is $\frac{\sin(x)}{x} = 1$ at $x = 0$

I have a function: $$\text{sinc}(x) = \frac{\sin(x)}{x}$$ and the example says that: $\text{sinc}(0) = 1$, How is it true?  I know that $\lim\limits_{x \to 0} \frac{\sin(x)}{x} = 1$, But the graph of the function $\text{sinc}(x)$ shows that it's continuous at $x = 0$ and that doesn't make sense.


This is a problem from Hoffman & Kunze book on linear algebra: Let V  be a finite dimensional inner-product vector space.  Let U be a self-adjoint unitary linear operator over V. Show that U(α)=β−γ, where  α=β+γ, β is in W and γ is W⊥. Here, W is a subspace of V.  Sorry for my english.


What does well-defined mean? In general or in this context (quotient group)

Youtube Clip:   The video shows that "the operation on quotient group is well-defined" by taking two elements from two different cosets and showing their composition leads to some element in one of the other cosets but I don't understand the reason why it needs to be shown since any element is in one of the cosets including $a \circ b$ (cosets partitions the group). I know that to show a function is well-defined I need to show every element can be mapped to exactly one element. But how about this. Are they conceptually the same?


User group (company) page that shows summary of all user accounts belonging to the same company/user group

For example, on LinkedIn when you say that you work for some company, then it's possible to have link to that company name that will list all employees with links to their profiles.  Is something similar possible on Stack Overflow/Stack Exchange? I.e. have a short cut to a page which displays account summary for all user who said they are working for IBM or Microsoft or myconsultingcompany.com?


Prove: $\binom{n}{0}F_0+\binom{n}{1}F_1+\binom{n}{2}F_2+\cdots+\binom{n}{n}F_n=F_{2n}$;  I was stuck with this question for a while... Help me please!!! Thanks!!!


When I open Pokemon GO all I get is a black screen and then the app closes. I have a iPod 5th gen. I've been looking forward to this game for a long time so how can I fix this?


Does pass by reference works in case of String

In java if Objects are pass by reference than in following code,  String str1 = new String("abc"); String str2 = str1; str1 = str1+"def"; System.out.println("str2 : "+str2);   Even after modifying string str1 after assigning it to string str2 I get output as str2 : "abc" instead of "abcdef" so pass by reference does not work in case of string??


How can I generate a random number within a certain range with Java?

I want to generate a random number in Java. It can be of integer, byte or float type, but all I really need it is to generate a random number. This is what I'm doing:   Generate a random number within a certain range (e.g. 5 through 20). Take the number and store it within a variable. Perform arithmetic on it.   Here's the code:  import java.util.HashMap;  public class Attack {     public static void main(String[] args) {         HashMap<String, Integer> attacks = new HashMap<String, Integer>();         attacks.put("Punch", 1);         attacks.put("Uppercut", 3);         attacks.put("Roundhouse Kick", 5);          int actionPoints = // Code for random number generation          System.out.println("A brigade integrant appeared!");         System.out.println("What do you do?");         System.out.println("1: Punch [1 AP], 2: Uppercut [3 AP], 3: Roundhouse Kick [5 AP]");         System.out.println("You have " + actionPoints + " Action Points.");         Scanner reader = new Scanner(System.in);         System.out.println("Enter a number: ");         int n = reader.nextInt();         reader.close();          if n == 1 {             System.out.println("The brigade integrant takes 2 HP of damage!");         }         else if n == 2 {             System.out.println("The brigade integrant takes 5 HP of damage!");         }         else if n == 3 {             System.out.println("The brigade integrant takes 8 HP of damage!");         }     } }


How to select rows each having all of the specified tags?

This is the table containing hytags_hyobjects that are tagged with hytags_tags                                                 Table "public.hytags"        Column        |            Type             | Collation | Nullable |                  Default                   ---------------------+-----------------------------+-----------+----------+-------------------------------------------  hytags_id           | integer                     |           | not null | nextval('hytags_hytags_id_seq'::regclass)  hytags_datecreated  | timestamp without time zone |           | not null | CURRENT_TIMESTAMP  hytags_datemodified | timestamp without time zone |           |          |   hytags_usercreated  | text                        |           | not null | CURRENT_USER  hytags_usermodified | text                        |           | not null | CURRENT_USER  hytags_hyobjects    | integer                     |           | not null |   hytags_tags         | integer                     |           | not null |   hytags_description  | text                        |           |          |   I would like to get hytags_hyobjects having all of the tag integers, such as 1, 2, 3 in hytags_tags where those values come from multiple rows. Selecting those that have either one of the tags is easy. I am looking to select those hytags_hyobjects which have all of the tags assigned.


command | grep | awk save into a variable or execute it as function

I am trying to save the value of a command into a variable but it gives an error var = `cat $1 | grep "STAN: \[$2\]" | awk -F '|' '{print $3; exit}'`   It gives me the error var: command not found


In order to compare three items I use the groupplot command. For each item I have n different criteria to compare.    Is it possible to set the color for each criteria itself? Meaning the first bar in every group goes gray, the second pink etc.. The legend than should contain the n compared criteria.  And... how do I manage to let the whole tikz-picture have a width of 0.9\textwith  \documentclass{standalone} \usepackage{pgfplots,pgfplotstable} \usetikzlibrary{pgfplots.groupplots}  \pgfplotstableread{ nr  fii faa foo a   10  15  12 b   12  18  14 c   13  19  15 d   9   13  10 e   7   11  8 f   10  15  12 }\datatable  \begin{document} \begin{tikzpicture} \begin{groupplot}     [group style={columns=3},         ybar,         ymin=0,         ymax=20,         xtick=\empty,         tickpos=both]  \nextgroupplot[xlabel=fii] \addplot [fill=blue] table [x expr=\coordindex, y=fii] {\datatable}; \nextgroupplot[xlabel=faa] \addplot [fill=green] table [x expr=\coordindex, y=faa] {\datatable}; \nextgroupplot[xlabel=foo] \addplot [fill=red] table [x expr=\coordindex, y=foo] {\datatable};  \end{groupplot} \end{tikzpicture} \end{document}


Negative SEO can harm your website rankings, that's why a rival might decide to use negative SEO techniques against you to try to penalize your website rankings, and thus obtain higher positions on Google Search results than you.  How can you prevent negative SEO prior to being attacked by a rival? Are there some special things you can do?


How to indent TOC-entries (as indexes) which have no numbers with tocbasic?

Similar to , how can I indent the chapter*-like entries to the same indent as the numbered chapters? section* work with \KOMAoptions{toc=indentunnumbered}.  The main difference to the other questions concerning indent with unnumbered chapter is related to indexes: The indentation of indexes won’t work with \addchap/\addsec etc.    \documentclass[ngerman,twoside=false,listof=totoc,listof=leveldown]{scrbook} \usepackage{imakeidx} \usepackage[style=archaeologie]{biblatex} \addbibresource{archaeologie-examples.bib} \usepackage{babel} \newcommand\tocgobble[1]{}% <- added \newcommand\tocpageseparator{\footnotesize\,\mbox{---}\,} \newcommand\tocpagenumberbox[1]{\mbox{#1}} \KOMAoptions{toc=indentunnumbered}%indent only for section* !?  \RedeclareSectionCommands[   tocraggedpagenumber,   toclinefill=\tocpageseparator,   tocindent=0em,   tocnumwidth=4em,   tocpagenumberbox=\tocpagenumberbox ]{chapter,section,subsection,subsubsection,paragraph}  \RedeclareSectionCommand[   tocentryformat=\large\scshape,   tocindent=0em,   tocnumwidth=4em,   tocpagenumberbox=\tocgobble ]{part}  \RedeclareSectionCommand[%   tocentryformat=\textbf% ]{chapter}  \makeindex[   intoc,   name=loc,    title={Locations},   columns=3,   ] \indexsetup{%   level=\section*,   toclevel=section,   noclearpage,   firstpagestyle=scrheadings,   headers={\indexname}{\indexname},     } \begin{document}   \nocite{*}   \frontmatter   \tableofcontents   \mainmatter   \part{part}   \chapter{chapter chapter}   \section{section section section}  \section{section section section}  \section{section section section}   \part{part}   \chapter{chapter chapter}   \section{section section section}  \section{section section section}  \section{section section section}   \setcounter{page}{100}   \part{part}   \chapter{chapter chapter}   \section{section section section}  \section{section section section}  \section{section section section}   \backmatter    \part{part} \index[loc]{A location}   \chapter*{Abbildungs-, Tabellen-, Tafelverzeichnis}   \addcontentsline{toc}{chapter}{Abbildungs-, Tabellen-, Tafelverzeichnis}   \listoffigures   \chapter*{\bibname}   \addcontentsline{toc}{chapter}{\bibname}   \printbiblist[%       heading=subbibintoc,%     title={Zeitschriftenabkürzungen}]{shortjournal}   \printbiblist[%     heading=subbibintoc,%     title={Reihenabkürzungen}]{shortseries}   \printbibliography[heading=subbibintoc] \chapter*{Indizes} \addcontentsline{toc}{chapter}{Indizes} \printindex[loc] \end{document}


Show that n! is equal to the recursive derangement.

Prove that An=n!, the number of permutations of n elements, and Dn, the number of permutations of n elements without fixed points, satisfy the recursive equation: Dn = (n−1)(Dn−1 + Dn−2).  I've gotten to prove that Dn satifies such recurrence. I need help showing that n! satifies it.


What is the best way to make my ears pop when landing on a plane? The hold-your-nose-and-pitch method is very painful; are there any other methods to pop ears?


I recently was pulled back into Java programming for academic purposes and I ran into something interesting during my first project.  I had to design a GUI for a storefront with buttons that did various tasks, and I noticed something weird was happening with my variables. Any CLASS VARIABLES that my buttons changed through their Actions did not need to be declared static, while any CLASS VARIABLES my main method touched had to be declared static.  Why is this? My Main Method and ActionListener Methods are all on the same level of execution. (they're all in the same class, none of them are embedded within each other)  I hope this question is not too obvious/dumb, I am trying to relearn as much about Java as possible.


How do I patch Ubuntu 14.04 for shellshock?

To know if you are vulnerable, you can run:  env X="() { :;} ; echo busted" /bin/sh -c "echo completed" env X="() { :;} ; echo busted" `which bash` -c "echo completed"   If you see "busted" then you are vulnerable.  Is there a patch yet?


The following module is missing from the file system: "post_articles"

I was given a Drupal website in the form of a Drupal database running on a website and an archive containing a Drupal installation complete with a theme. Upon uploading the installation to the server and pointing it to the database, Drupal showed me a list of missing modules errors. I have installed the modules manually, except for a "post_articles" module. I have not been able to find that module anywhere and am at loss. Here is the complete error:  User warning: The following module is missing from the file system: post_articles. For information about how to fix this, see the documentation page. in _drupal_trigger_error_with_delayed_logging() (line 1156 of drupal\includes\bootstrap.inc)  The website itself is unusable. I hope it is due to the missing module but not sure.


Now that we don't have permeating Ether anymore, why don't we consider the omnipresent Cosmic background radiation in place of it? and measure Speeds with respect to the CMBR? In that way an object moving through the space, can be said to have at least a 'kind-of' absolute velocity w.r.t Background radiation? I.O.W is that radiation stationary?


Is it possible to play games that run off of Steam, on a Linux or Unix-based OS (other than Mac OSX)?

I was wondering if it is possible to install and play Steam games like Skyrim off a Linux or Unix-base Operating System (OS), such as FreeBSD or OpenSUSE?  Update: Apart from installing through Wine, which is an emulator and would hence defeat the purpose, because it would cancel out any performance increase you might get over running through Windows. In short (as far as I am aware), running through Wine would give even less performance than running through Windows.


How to delete all emails older than a certain date in gmail?

Suppose I want to delete all emails older than year 2012 in gmail. Currently, what I do is put Before: 2012 in the search box. However using this method, I have to delete the emails 100 conversations at a time. This is time-consuming and tiring on my finger muscles. How can I delete all emails older than year 2012 in gmail in one stroke?  EDIT: The answer in the possible duplicate no longer works. I am no longer able to select all conversations. Emails have to be selected and deleted 100 conversations at a time.


Is an AR(p) process with roots inside the unit circle non-stationary?

The title pretty much says it all: is an AR(p) process with roots inside the unit circle non-stationary?


Seeking QGIS tutorials and web resources?

I wish to familiarize myself with the capabilities of QGIS up to and beyond QGIS version 3.0.   Can you recommend some good web resources and tutorials that would show me QGIS' capabilities?   I am interested in both using QGIS through its GUI and in developing applications using QGIS.


What stops water from a moon pool from filling the inside of a submarine?

In some submarines, divers can exit and enter through a moon pool, an opening in the bottom of the submarine.  We can clearly see ocean's water flowing in the moon pool, but it won't come inside.  Why so? What is stopping the water here from coming inside?


is there a way to load plugin with ajax? I want to load  plugin which supports initializing with PHP and Shortcode  [quick-chat height="400" room="default" userlist="1" userlist_position="left" smilies="1" send_button="0" loggedin_visible="1" guests_visible="1" avatars="1" counter="1"]   OR  <?php global $quick_chat; if(is_object($quick_chat) && method_exists($quick_chat, 'quick_chat')){     echo $quick_chat->quick_chat(400, 'default', 1, 'left', 0, 0, 1, 1, 1, 1); } ?>      My JS side   key = '1'; jQuery.ajax({     type : 'POST',     url : apfajax.ajaxurl,     data : {         action : 'loadMyChat',         key: key     },     dataType: "json",     success : function(data) {         jQuery("#chatModal").find(".modal-body").html(data.html);     },     error: function(MLHttpRequest, textStatus, errorThrown){             alert(textStatus);     } })      PHP Side   function loadMyChat() {     $key = $_POST['key'];     $count = 1;     $html = 2;     global $quick_chat;      //$ak = $quick_chat->quick_chat();     $ak = $quick_chat->quick_chat('300', 'default', '1', 'left', '0', '0', '1', '1', '1', '1');     die(json_encode(array(         'html' => $ak,         'count' => $count     ))); }      OUTPUT:

LOADING...

   As you see container only includes loading block, where are the other blocks? textarea and history?  Okay, one more interesting point, here is a public function for initialising chat.  public function quick_chat($height = 400, $room = 'default', $userlist = 1, $userlist_position = 'left', $smilies = 1, $send_button = 0, $loggedin_visible = 1, $guests_visible = 1, $avatars = 1, $counter = 1) {     $content = '';     ob_start();      echo '<div class="quick-chat-container" data-quick-chat-id="'.wp_generate_password(12, false, false).'" data-quick-chat-height="'.$height.'" data-quick-chat-room-name="'.$room.'" data-quick-chat-userlist="'.$userlist.'" data-quick-chat-userlist-position="'.$userlist_position.'" data-quick-chat-smilies="'.$smilies.'" data-quick-chat-send-button="'.$send_button.'" data-quick-chat-loggedin-visible="'.$loggedin_visible.'" data-quick-chat-guests-visible="'.$guests_visible.'" data-quick-chat-avatars="'.$avatars.'" data-quick-chat-counter="'.$counter.'">';         echo '
'.__('LOADING...', 'quick-chat').'
';     echo '
';      if(!isset($this->options['hide_linkhome'])){         echo '
'.__('Powered by Quick Chat', 'quick-chat').'
';     }     $content =  ob_get_contents();     ob_end_clean();     return $content; }   judging from this, my script returns everythign corectly. no js is loading or any ajax handlers are set. in my opinion the problem is data-quick-chat-id.  I did small trick like return quick_chat function on page load which is hidden and after my user sets his cookies (user and room) I request my ajax and change this div with ajax returned.  Of course it still does not work, but I didn't change change data-quick-chat-id but that's because I don't know how to change data attribute inside my data.html (returned from my ajax) before I insert it in html.  Am I going in right direction?  Just wanted to update, thanks


I have to prove:   An infinite subset of a denumerable set is denumerable.   I understand this has been asked before and I did take the time to read what was said there, but I do not understand still.   I have to prove this using other theorems about denumerable or countable sets, nothing too complex for this proof.


How can I start a remote process on a remote machine via ssh?

I want to start a shell script that resides on a remote machine. When I use  ssh user@example.com /path/to/script.sh   it needs the ssh connection to be open until the script has terminated.  But I need the script to continue to run, even after I close the ssh connection until the script finishes by itself. I just want to start a process and then forget about it.  How can I do this using ssh?  Thanks a lot!  P.S.: This is not a duplicate of .


but I don't quite understand it. Can someone explain how it works?  Example from the link:  public static void printPersonsWithinAgeRange(     List<Person> roster, int low, int high) {     for (Person p : roster) {         if (low <= p.getAge() && p.getAge() < high) {             p.printPerson();         }     } }   EDIT: question already answered here: .  EDIT 2: Oracle tutorial:


How find all ordered pairs $(m,n)$ such $\frac{n^3-1}{mn-1}$ is an integer

Question:     Find all ordered pairs $(m,n)$ where $m$ and $n$ are positive integers, such that $$\dfrac{n^3-1}{mn-1}$$ is an integer.   I know this problem is very simaler this 1994 IMO,problem 4,But My problem is different. This IMO problem is :  Find all ordered pairs $(m,n)$ where $m$ and $n$ are positive integers, such that $$\dfrac{n^3+1}{mn-1}$$ is an integer.  this problem solution can see   Thank you for you help to solve this


Sylvester's criterion for complex Hermitian

Does Sylvester's criterion work for the Hermitian matrix with coefficients in complex numbers? I found the proof for the real coefficients (), but I cannot find any proof for the complex number in general.


I've been poking around the net trying to find synonyms for "renaissance man" which indicates someone that is proficient at many skills. I was thinking "jack of all trades" but that has a negative connotation that the individual is not good at any of them, but capable. Any ideas?


I would like to make a Google account (email, youtube etc.) and it requests a mobile number. It makes sense, so it can stop robots making spam designated email accounts, but I don't own a mobile and I don't want to be forced into buying one simply to make a Google account.Is there any other form of verification that I can take?


I'm currently trying to configure our exchange 2010 to be used as a external smtp relay. What I'm trying to do is allow certain websites that we manage to send email using our exchange server smtp relay. I was told that I needed to created a receiver connector under Server Configuration>Hub Transport. After I created the receiver connector I added the following confi in which I added the website IP address in the "Receiver mail from remote servers ect" then unders Authentication I selected Externally Secured,TLS and under permissions I selected exchange servers.  I went to one of our websites and configure it with this configuration and I'm still getting "SMTP connect failed."  Can someone help me? or what is the proper way to get this to work. Multiple websites are going to be using this exchanger server SMTP relay in a secure way.


I have a raster where null values are stored as -9999. I want to change these to 0. Googling suggests this can be done in the raster calculator, but e.g. (layer name = -9999) * 0 doesn't work. And indeed other pages suggest that any formula including a null will return a null. I've also tried r.reclass, reclassify by table and by layer, but none are giving me what I need - which is simply to change -9999 values to 0.


any ubuntu touch for sony xperia t2 ultra(D5303)?

I want to install Ubuntu touch on my Sony Xperia T2 device.Any Ubuntu touch for sony xperia t2 ultra(D5303)? When will Ubuntu Touch be available for this device?


How to show the spacetime interval is invariant in general?

I understand how to derive the spacetime interval being invariant for Minkowski space, but I've never seen any derivation of it in general curved spacetime. Is the invariance just derived for Minkowski space and then postulated that it holds for all metric tensors in general relativity, or is there a proof to show it is invariant in general relativity?


Map from 2-sphere into $(\mathbb R^3, |\cdot|)$

Can you help me with this?     Let $S^2 := \{x\in \mathbb R^3:||x||_2 = 1\} \subset (\mathbb R^3, ||\cdot||_2)$  and $T:S^2 \to (\mathbb R, |\cdot|)$ be a continuous map. Since $S^2$ is compact, $T$ attains its maximum $T_{max}$ and its minimum $T_{min}$.   Is there a value $T\in]T_{min},T_{max}[$ that is assumed at only one $x_0\in S^2$?      I think I have to use the fact that the image of a connected space under a continuous function is connected again, but I don't know how. Can you help?


Is it necessary to standardise data sets before performing PCA?

My data sets are a combination of numerical and categorical data. The categorical data are inputted in a one-hot encoding manner. I would like to ask if it is necessary to standardise the data sets first here before performing PCA? If so, what would be a good way to standardise the data set?


Can a worm eat its way through a $3\cdot3 \cdot3$ cube divided into $27$ cubelets if it starts in the center cube?

I'm an eighth grader working with a graduate student on some math over the summer. He presented me with the following question: We have a cube formed of 27 small, congruent cubes. A worm sits in the central cube, and has the goal of going through every small cube exactly once. It can get from one cube to an adjacent cube only through the midpoint of the face; it cannot travel diagonally. Can this be accomplished?  After several attempts at this problem, I have been unable to find a method of solving it, and am currently trying to restrict the possibilities by figuring out which cube or class of cube (corner, center of a face, etc.) the worm has to finish its task in.   Before writing this question, I looked into the wood worm in a cube () problem that has already been asked here, but that problem had not in fact been given a clear answer and was closed for lack of important details.  I have been introduced to Hamiltonian Paths and Circuits, but these concern paths starting at a vertex of a graph; not the center.


When referring to a car, we tend to say "in the car".     "I am in the car"   but when it comes to plane, the sentence is either     "I am on the plane" or "I am in the plane".   The term      "on"   would suggest being on top of something. "I am on the chair".  while the term      "in"   is referred to being inside something. "I am in the basement"  Is it incorrect to say "on" when saying "I am on the plane" ?


The function $f$ is convex when:  $$f(tx+ (1-t)x', ty + (1-t)y') ≤  tf(x,y) + (1-t)f(x', y')$$  for all numbers $0≤t≤1$ and all pairs of points $(x,y)$ and $(x',y')$ in the domain of $f$ (the whole of $R^2$)  How would I interpret this geometrically? Also what is an example of a convex function whose graph is not a plane?


I just want to know the difference between this two symbols and what are the semantic meaning ?? And what is the difference betwwen this two formulas ????  A → B ⊢ ¬B → ¬A  A → B ⊨ ¬B → ¬A


how do you prove the existence super natural

How can you prove the existence of super-natural being ?


How to install the hmcpset package for LyX Mac with MacTex?

I've been trying for several days to get this to work, but i haven't been successful yet. I'm new to latex and I don't have a very good idea of what I'm doing, which is why I'm using LyX.   I put the hmcpset.cls file in the directory /usr/local/texlive/texmf-local/tex/latex/Max's classes. I think the MacTex distribution uses TEX Live Utility for managing packages, so that's where I'm looking to find hmcpset. But hmcpset doesn't show up in available packages inside TEX LIVE.  Is there a way to let TEX Live know where I put a new .cls files?  Once TEX Live, or whatever the package manager is, knows where the .cls file is, will I be able to use the hmpcpset class in LyX?


How to measure time with time/times comand

I have a scrip with a while. On that while i would like to measure the time that the content of it takes to run, in miliseconds, something like this:  while condition; do     #begin measure time at begining     instructions     #end measure time at end     echo "$end-$begin" done   I can't use date +%s.%N because my machine doesnt have it, so i need to use either time or times comand. Any idea how to?  thanks


Windows disappeared from GRUB after reinstalling Ubuntu

I used to have a dual boot with Windows 7 and Ubuntu 14.04. I wanted to update the latter to 18.04, so I made a bootable USB with Rufus and made the replacement. The Ubuntu installer itself told me that it had identified Ubuntu 14.04 in the computer, and it asked me whether I wanted to uninstall it to install the newer version. I clicked on this option, and then when I tried to boot with Ubuntu in the GRUB menu, a shell appears:  Gave up waiting for root device. Common problems:   — Boot args (cat /proc/cmdline)     — Check rootdelay= (did the system wait long enough?)     — Check root= (did the system wait for the right device?)   — Missing modules (cat /proc/modules; ls /dev) ALERT! /dev/disk/by-uuid/<long-number-i-wont-type> does not exist.    Dropping to a shell!   BusyBox v.1.21.1 (Ubuntu 1:1.21.0-1ubuntu1) built-in shell (ash)    Enter 'help' for list of built-in commands.    (initramfs)   To solve this, I ran from the Live USB the Boot Repair tool. After doing this, when I turn on the computer, the GRUB just shows Ubuntu. Namely, I can't access to Windows anymore, because the screen that lets me select the OS doesn't show it now. The Ubuntu booting was solved, though, but I would like to have the previous GRUB menu back.  The files are still there I believe, because I can see the Windows partition from my Ubuntu.  Here is  I performed before the issue appeared.  Is there any way to do this?


Installing from source - do I need to keep the extracted tarball directory

If I'm installing from source, do I need to keep the extracted tarball directory?  So if I download the git tarball. I then do:  tar -xvzf git.tar.gz   This will create a git.x.x. directory, into which I cd, then run ./configure etc. Once I'm done with this process, and git, or whatever is installed, do I need to keep the original git.x.x extracted directory, or is that just used for compiling the program?  I'm somewhat confused by all the directories, and folders used for programs.


Back in Europe I have a N64 console. As I am currently living in Japan, I find myself tempted to buy some old N64 games in Japanese. However, the articles about the N64's region locking usually assume Japanese games on an American console...  My question thus is: Can you play a Japanese N64 Game on a European console?


Why there are only 5 modal verbs in English

Modal is a type of auxiliary verb. The complete list of them are:   Can/could/be able to May/might Shall/should Must/have to Will/would   Another (unnamed?) category of verbs is these 3:   Have Be Do   All other verbs are your normal "actions" and are used by themselves as far as I can tell (i.e. "I read the book", just one verb).  My question's first part is, is this all of the modal/helper verbs? Are there any more? What is the complete list?  The main part of the question though is, why these are considered verbs in the first place. Here's why I'm asking that.     (1) I might go to the store.   (2) I possibly go to the store.   (3) I might possibly go to the store.   (4) I should could go to the store.   (5) I should have used to be going to the store.   So (1) is saying "possibly go to the store" basically. But you can't use "possibly" as a verb (2). It is an adverb it looks like (3).  Then, (4), you can't do either. But technically if you break down the meaning, it is a valid thing to say, saying essentially "I should go to the store and I could go to the store.".  Number (5) is just to show this is the max number of verbs I can seem to cram into a sequence.  Why do only these 5 or 8 verbs allow for this direct composition? Why aren't there 100's that have this same feature? What is so special about these?  In my head, I have quite a hard time visualizing these 5 as "actions". It is hard to visualize "may" as an action. Or "should" as an action. So why are they considered actions?  Are there any other areas of research that treats these in novel ways, provides different perspectives, etc.?


Why does a for-loop not require explicitly specifying the set of values of the loop variable?

I read a command from   Why can  $ bash -c 'for f do echo "$f";done' bash a b c a b c   output the same as  $ bash -c 'for f in "$@"; do echo "$f";done' bash a b c a b c   ?   Why does a for-loop not require  explicitly specifying    the set of values of the loop variable, as in "$@" and ; ?   Thanks.


Can anyone suggest some basic book for Hyperbolic manifolds?   What is this area about?


What is the difference between these bits of code

I am just experimenting with some things in python, and one of my problems required a funny solution of changing a / to a //. What's the difference?  def is_multiple(number=None, m=None): # m representing times table     if not number or not m:         return False     if isinstance(m//number, float):         return False     return True print(is_multiple(4, 12)) # returns True   def is_multiple(number=None, m=None): # m representing times table     if not number or not m:         return False     if isinstance(m/number, float):         return False     return True print(is_multiple(4, 12)) # returns False   I would expect both to work the same, can someone explain the difference? Thanks :)


Genitive of Sunrise: Sunrise' or Sunrise's

I just don't like 'Sunrise's' very much. I want to write "Sunrise' breaking light over the plains" but I'm not sure if it should really be "Sunrise's breaking light over the plains." Whaddaya think?


Children's sci-fi/fantasy with black blobs and why cats stare at walls

I am trying to find the name and author of a children's fantasy/sf book. The plot involves people who are simply disappearing from the world. Usually they come to some decision and mysteriously tell their family they are leaving, and soon after they simply cannot be found.  The protagonist (I think a boy) discovers that the family cat can see strange black blobby creatures that are invisible to everyone else. (This is why cats stare at things we cannot see.) I think the cat decides to "leave" as well. Finally, the boy discovers that the blob creatures are the connection to another world where everything is rural. He and his family step into the other world. The story ends with a description of how they farm the blob things.  I think the author is female.


Is it "a hour-long drive" or "an hour-long drive"?

In the following context, which usage is correct, or are both of them OK?   After a hour-long drive, they arrived at Chinatown. After an hour-long drive, they arrived at Chinatown.   Your help is greatly appreciated!


How to align text at right top besides of an image?

I've tried for hours to find a solution for this fairly simple layout. The closest I've got is: \begin{minipage}{.25\textwidth}     \includegraphics[width=\textwidth]{res/server.jpg} \end{minipage} \begin{minipage}{.75\textwidth}     \begin{flushright}         asdasd\\         asdasdasdasdasddsa     \end{flushright} \end{minipage}  .. which produces something like:  How to move the text up to the top line? I've seen many solutions with tables and boxes. Is there a simple way to do it with minipage? With [t] alignment of the minipage \begin{minipage}[t]{.25\textwidth}     \includegraphics[width=\textwidth]{res/server.jpg} \end{minipage} \begin{minipage}[t]{.75\textwidth}     \begin{flushright}         some text\\         some more text     \end{flushright} \end{minipage}   With \vspace{0pt} \begin{minipage}[t]{.25\textwidth}     \vspace{0pt}     \includegraphics[width=\textwidth]{res/server.jpg} \end{minipage} \begin{minipage}[t]{.75\textwidth}     \vspace{0pt}     \begin{flushright}         some text\\         some more text     \end{flushright} \end{minipage}


Neural Network is not predicting the results

I am testing the backpropagation algorithm for a multilayer perceptron. My net architecture have 3 neurons with sigmoid as activation function. My data is came from a linear regression problem, but I'm just trying to implement the regression with neural networks. The problem is, my net is not predicting the values. As far as I know, a neural network can approximate a huge number of functions beacuse of its non-linearity, but in this case, is a linear problem. Should it be easier to it to predict the results? Below I write the code: I'm using Python 3 with Anaconda 3.6 environment.  import matplotlib.pyplot as plt import numpy as np from scipy import stats import random  random.seed(1)  def sigmoid(x):     return 1./(1 + np.exp(-x))  def sigmoid_(x):     return sigmoid(x)*(1-sigmoid(x))  income = np.array([685, 683, 526, 662, 536, 627, 520, 423,           343, 513, 462, 383, 460, 517, 454, 448,           1076, 970, 722, 681, 814, 800, 782, 775,           689, 731, 1499])  income_ = income/np.max(income)  scholarship = np.array([5.7, 6, 4.5, 4.9, 4.7, 5.5, 4.5, 3.9,                3.6, 4.5, 4.3, 3.5, 4.1, 4.6, 3.7, 4,                6.8, 7.1, 5.7, 5.4, 6.3, 6.4, 6, 5.4,                5.5, 5.7, 8.2])  scholarship_ = scholarship/np.max(scholarship)  w1 = np.random.uniform(0.5, 1.5, size = (3, 1)) w2 = np.random.uniform(0.5, 1.5, size = (1, 3)) b1 = np.random.uniform(0.5, 1.5, size = (3, 1)) b2 = np.random.uniform(0.5, 1.5, size = (1, 1))  eta = 0.05 emax = 1e-7  epoch = 30 E = 0  for i in range(epoch):       E_ = E      for j in range(len(income)):         i1 = np.dot(w1, np.array([[scholarship_[j]]])) + b1         y1 = sigmoid(i1)         i2 = np.dot(w2, y1) + b2          dW2 = np.dot((income_[j] - i2), sigmoid_(i2))         w2 += eta*dW2*y1.T         b2 += eta*dW2          dW1 = np.dot(dW2, w2).T * sigmoid_(i1)         w1 += eta*dW1*np.array([scholarship_[j]])         b1 += eta*dW1      E = []      for k in range(len(income)):         i1 = np.dot(w1, np.array([[scholarship_[k]]])) + b1         y1 = sigmoid(i1)         i2 = np.dot(w2, y1) + b2         E.append((income_[k] - i2[0][0])**2)      E = sum(E)/(2*len(E))      if abs(E_ - E) <= emax:         break      print('Error: ', E, ' at epoch: ', i)  nn = []  for l in range(len(income)):         i1 = np.dot(w1, np.array([[scholarship_[l]]])) + b1         y1 = sigmoid(i1)         i2 = np.dot(w2, y1) + b2         nn.append(i2[0][0])  plt.plot(scholarship_, income_, 'ro', scholarship_, nn, 'bo') plt.show() plt.plot(income_, nn, 'yo') plt.show()   And the resulting graphs are:    The red points are the x data with y data, the blue one are the x data with the net predicts


What is preferred hashing/algorithm that new websites can be used ?php

basically, most of the new websites does not have a big amount of money (that includes me) for doing a high-standard-level-like password hashing, I read a lot says that other password algorithms/hashing uses a lot of memory in GPU or big-sized hashes? Currently I am using sha256, $str, $salt type of hashing, one of the website posted an article that what I am using is not recommended, I also PBKDF2 alot, but when I read how to do it. It includes sha256/mcrypt_create_iv/md5 etc. I do not understand. So can you give me, what does new websites need for that is low-budget and lowe-sized methods  IS THIS CODE SAFE? I MEAN NOT THAT UNSAFE? is this is okay? is this weak ?  <?php class Hash {     public static function make($string, $salt = '') {     return hash('sha256', $string . $salt); }  public static function salt($length) {     return mcrypt_create_iv($length); }  public static function unique() {     return self::make(uniqid());  }   }  please give me advices and opinions THANK YOU!