How to have productive meetings with Ph.D supervisor

I am a Ph.D. student in theoretical computer science. I meet my research supervisor once a week for around 2 hours. I prepare some of my research and try to present in front of him. I always try to make a list of theorems and claims given in the paper to discuss with him in a certain flow but most of the time he starts asking questions and then we go in other directions (which is okay from a research point of view). Due to this, it sometimes takes 2 months to read a single paper.  I always try to follow my designed plan but it rarely works. Also, I don't feel satisfied most of the time because many times I am only able to discuss 50-60 percent of what I have planned. Please help.


(Java Minecraft 1.13) How to get a fireball to shoot in the same direction as the summoning player is looking?

Right now, I'm working on a datapack that allows you to summon an enchanted carrot on a stick, which when you right click takes a fire charge from your inventory and shoots it where you are looking. I had an issue where the fireballs were flying in the wrong direction, at angles, and curving, but I fixed it, so here is what I did to get it to work, for those who have the same question as me.  My function to shoot the fireball looks like this:  #summon fireball summon minecraft:fireball ^ ^ ^1 {CustomName:"\"firewandfireball\"",direction:[0d,0d,0d],power:[0d,0d,0d],ExplosionPower:-2,life:60}  #get player and fireball data into scoreboards execute as @s store result score @s fwx run data get entity @s Pos[0] 100 execute as @s store result score @s fwy run data get entity @s Pos[1] 100 execute as @s store result score @s fwz run data get entity @s Pos[2] 100  execute as @e[name=firewandfireball] store result score @s fwx run data get entity @s Pos[0] 100 execute as @e[name=firewandfireball] store result score @s fwy run data get entity @s Pos[1] 100 execute as @e[name=firewandfireball] store result score @s fwz run data get entity @s Pos[2] 100  #subtract the two to get a momentum/velocity and put into fireball's scoreboard execute as @e[name=firewandfireball] store result score @s fwx run scoreboard players operation @s fwx -= @p fwx execute as @e[name=firewandfireball] store result score @s fwy run scoreboard players operation @s fwy -= @p fwy execute as @e[name=firewandfireball] store result score @s fwz run scoreboard players operation @s fwz -= @p fwz  #tp the fireball so it's like it's going from eye position execute as @e[name=firewandfireball] at @s run tp @s ~ ~1.62 ~  #put the subtracted value into the fireball's direction and power execute as @e[name=firewandfireball] store result entity @s direction[0] double 0.01 run scoreboard players get @s fwx execute as @e[name=firewandfireball] store result entity @s direction[1] double 0.01 run scoreboard players get @s fwy execute as @e[name=firewandfireball] store result entity @s direction[2] double 0.01 run scoreboard players get @s fwz  execute as @e[name=firewandfireball] store result entity @s power[0] double 0.01 run scoreboard players get @s fwx execute as @e[name=firewandfireball] store result entity @s power[1] double 0.01 run scoreboard players get @s fwy execute as @e[name=firewandfireball] store result entity @s power[2] double 0.01 run scoreboard players get @s fwz  #reset the scoreboards scoreboard players reset @e fwx scoreboard players reset @e fwy scoreboard players reset @e fwz execute run scoreboard players reset firewandClicks execute run scoreboard players set @e firewandClicks 0  #reset customName so fireball isn't affected by new fireballs execute as @e[name=firewandfireball] at @s run data merge entity @s {CustomName:""}   I'm using the subtraction method in  post to get velocity. This function was being run anchored at eyes, so the fireball was summoned at eye level but the subtraction of coordinates to get a velocity was using my feet's position which led to the fireball always shooting upwards. I fixed this by running the function anchored at feet, and then before adding motion (if you do it after it cancels any velocity it has) teleport it 1.62 blocks above where it was, so it appears like it comes from eye level. Finally, this function for some reason creates the fireball explosion right on target, but the fireball appears to curve way out of the way and disappear, which is probably a bug. If you replace the fireball with small_fireball (from a blaze) it appears to shoot straight on target.


Biblatex Citation with style=authoryear doesn't print bibliography

I ran into a strange problem while trying to implement a bibliography.  \usepackage[backend=biber,style=alphabetic]{biblatex} \addbibresource{Quellenverzeichnis.bib}   If style=alphabetic, a bibliography is printed and citations look for exmple like [BJS72]. As I rather want it to be author (year), I thought I need to change the style to "style=authoryear".  But the result is that the in-text citation is the full name of the article and no bibliography is printed. What am I doing wrong?  If it helps I could post my code but thats super long and I figured it might not really help as the only thing I'm changing is the style, I assume in the wrong way.   Thanks


I am using 4500 RPM motor.To be specific,this is the motor I am using . I am using Cytron MD10C motor driver to drive it.The PWM source is Raspberry pi.What is the range of frequency for PWM that I can use for this setup? Both the motor driver and the motor gets heated when a little amount of load is given.I have tried 50 to 300 Hz.


Prove that the only prime triple is 3, 5, 7

Prove that the only prime triple is $3,5,7$.  I tried proving using this method: Multiplication of $3$ jumps back and forth between being an even and an odd number. Thus goes from odd to odd over an interval max size 6, and likewise from even to even. In either case these will have the following types: (even - odd - even - odd - even - odd) and (odd - even - odd - even - odd - even), with 3 being a multiple of the first instance in the combinations. In the both combinations, the first and fourth would be divisible by three, leaving only two possible primes left (two odd numbers). Thus the only triple prime can be a combination where three is considered a prime....  However, is this a formal proof? can anybody tell me how to do a proof for this questions?


The horizontal space between margin and *align* environment

How can I remove the space between margin and align environment    \documentclass[a4paper,14pt]{article} \author{} \usepackage[fleqn]{amsmath} \usepackage[a4paper,margin=1in,left=2cm,right=1cm,top=1.5cm, bottom=1.5cm]{geometry}  \renewcommand{\baselinestretch}{1.5} \AtBeginDocument{% \setlength{\abovedisplayskip}{0pt}% \setlength{\belowdisplayskip}{0pt}% \setlength{\abovedisplayshortskip}{0pt}% \setlength{\belowdisplayshortskip}{0pt}% } \date{} \title{}  \begin{document} \maketitle normal text \begin{align*} \frac{1}{2}+\frac{2}{3}=\\ \frac{3}{6}+\frac{4}{6}= \frac{7}{6}\\ \end{align*} \end{document}


Would Druidcraft predict the use of the Control Weather spell?

If Druidcraft can predict a location's weather for the next 24 hours, would it note weird weather caused by Control Weather, such as a sudden storm at midday on an otherwise clear and cloudless day? Or would only naturally occurring weather be predicted?  I predict the matter will come up at our next game session (my friends like to exploit loopholes, but in good fun) so I'm hoping to be prepared for the inevitable. I read the answer to "", but my question is more specific than that question answers.


Are there any technical limitations as to why GPS can't have a centimetre resolution?

GPS is not very accurate. I was wondering if this is a technical or economic feasibility problem. If there are no technical barriers, GPS devices with accuracy within 1 centimetre might be possible by 2040. Am assuming this can be achieved with new generation of GPS satellites making use of millimetre wave technology, quantum radar etc Can anyone please confirm this


Good day! Сan anyone help me please? How can i create realistic coffee foam?   I am new to blender and don’t know much.  Here is my nodes.   I took a 2D cooffee foam texture from google and created a normal map at .  But i'm sure that there is an option to create more realistic foam.


Can I create a persistent live USB of Ubuntu?

I made a bootable USB drive of the downloadable Ubuntu 16.10, ran, and installed from it.  Fine.  Now after making some stock additions (like Samba, Wine, and such) I'd like to make a USB bootable copy of my particular Ubuntu.  It's still plenty small enough to fit on a stick.  Can it be done?


What is the best way to get all the divisors of a number?

Here's the very dumb way:  def divisorGenerator(n):     for i in xrange(1,n/2+1):         if n%i == 0: yield i     yield n   The result I'd like to get is similar to this one, but I'd like a smarter algorithm (this one it's too much slow and dumb :-)  I can find prime factors and their multiplicity fast enough.  I've an generator that generates factor in this way:  (factor1, multiplicity1) (factor2, multiplicity2) (factor3, multiplicity3) and so on...  i.e. the output of   for i in factorGenerator(100):     print i   is:  (2, 2) (5, 2)   I don't know how much is this useful for what I want to do (I coded it for other problems), anyway I'd like a smarter way to make  for i in divisorGen(100):     print i   output this:  1 2 4 5 10 20 25 50 100     UPDATE: Many thanks to Greg Hewgill and his "smart way" :) Calculating all divisors of 100000000 took 0.01s with his way against the 39s that the dumb way took on my machine, very cool :D  UPDATE 2: Stop saying this is a duplicate of  post. Calculating the number of divisor of a given number doesn't need to calculate all the divisors. It's a different problem, if you think it's not then look for "Divisor function" on wikipedia. Read the questions and the answer before posting, if you do not understand what is the topic just don't add not useful and already given answers.


Cycles Render without Shading (only texture and albedo)

I have a Cycles scene with textures and diffuse materials. Now, I want to render images without any "shading." So, the pixel values of the images will be just the texture and diffuse value of the surface.   How can this be achieved?  Thanks in advance!


I currently have a list of objects that have an attribute called "name" and I want to sort the list in an alphabetical order using the objects "name". The problem is that I do not know how to do this.  I've found a way to sort the list by the objects "names" but I want to convert it back to a list of objects but still keep the order of the sorted list.  players = list()  class Player(): name = None  def __init__(self, name):     self.name = name  players.append(Entity('Adam')) players.append(Entity('James')) players.append(Entity('Sebastian'))  sorted_player_names = sorted([player.name for player in players], key=str.lower)   I have tried to sort the list by the names but I do not know how to convert it back to a list of players instead of a list of names.


Show that $(x^2 + y^2) \sin\left(\frac{1}{x^2 + y^2}\right)$ is differentiable.

In this exercise one must show that $$f(x,y) = \begin{cases} 0 \text{     if } (x,y) = (0,0)\\ (x^2 + y^2) \sin\left(\frac{1}{x^2 + y^2}\right) \text{     else} \end{cases}$$ is differentiable for all $(x,y) \in \mathbb{R^2}$  In the lecture, we have proven that if all partial derivatives of $f$ exist and are continuous, then the derivative of $f(x,y)$ exists everywhere.  I start by calculating the partial derivatives of $f$ at $(0,0)$: $$\partial_xf(0,0) = \lim_{x\to0} \frac{f(x,0)-f(0,0)}{x} = \lim_{x\to0} \frac{x^2\sin({1 \over x^2})}{x} = 0$$ Similar for $\partial_y$: $$\partial_yf(0,0) = \lim_{y\to0} \frac{f(0,y)-f(0,0)}{x} = \lim_{y\to0} \frac{y^2\sin({1 \over y^2})}{y} = 0$$  We know that for all other values of $x$, $\partial_x f = 2x\sin\left(\frac{1}{x^2+y^2}\right)-\frac{2x\cos \left(\frac{1}{x^2+y^2}\right)}{x^2+y^2}$  I have tried to show that $\lim _ {x,y \to (0,0)} \partial_x f = 0$. (to show f is continuous) this however is problematic, since this limit doesn't exist. This implies that the partial derivates are not continuous at all points. Which makes this approach of proving that $f$ is differentiable useless.  How do I prove that $f$ is differentiable on all of $\mathbb{R}^2$.  I am open for all kind of suggestions. Thanks for your time.


I have installed Windows 7 with two partitions (C & D drives both have 60GB each)on my 160 GB HDD.  Now I want to install Ubuntu 14.4.2 on the unallocated remaining disk space.  Please tell me what should be the disk partition for installing Ubuntu on this Intel-i5 system having 4 GB RAM if I opt to install Ubuntu by selecting "something else" option.  Also let me know is there any mandatory % of disk space required/specification for allocation of swap,/,/user, /home, etc. Sometimes, it happens that after installing Ubuntu alongside Windows 7 as dual OS, the boot option menu did not show and can not log in to Windows OS. Tell me please how can I solve this issue


null pointer exception while retrieving from firebase

Unable to fetch data from my database all permissions are public and dependencies included. I am trying to print data to logcat, receiving NullPointerException  MainActivity.java   import android.support.annotation.NonNull; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.util.Log;  import com.google.firebase.database.DataSnapshot; import com.google.firebase.database.DatabaseError; import com.google.firebase.database.DatabaseReference; import com.google.firebase.database.FirebaseDatabase; import com.google.firebase.database.ValueEventListener;  public class MainActivity extends AppCompatActivity {      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);          FirebaseDatabase database = FirebaseDatabase.getInstance();         DatabaseReference myRef = database.getReference();         myRef.addValueEventListener(new ValueEventListener() {              @Override             public void onDataChange(DataSnapshot dataSnapshot) {                 String co2=dataSnapshot.child("co2").getValue().toString();                 String humi=dataSnapshot.child("humi").getValue().toString();                 String temp=dataSnapshot.child("temp").getValue().toString();                 Log.i("kkk","hhh"+ co2 +" "+humi +" "+temp);                 // ...             }              @Override             public void onCancelled(DatabaseError databaseError) {                 // Getting Post failed, log a message                 Log.w("p", "loadPost:onCancelled", databaseError.toException());                 // ...             }         });      } }


Kannada font not rendering after upgrading from 14.04 to 16.04

After upgrading from Ubuntu 14.04 to 16.04, Kannada text is appearing as boxes. In 14.04 they used to rendered correctly. How to correct it?  google home page screenshot (Kannada and Telugu text appearing as boxes):


"My mom told me that this store is going to be hiring a cashier soon. " -- should mom be capitalized?

I found the above sentence on a quiz. Mom should be capitalized because it is used as a  proper noun in the above sentence.


Series convergence of $\sum_{n=1}^{\infty}\frac{1}{n^3}$

I have the infinte series $\sum_{n=1}^{\infty}\frac{1}{n^3}$ which I believe converges.  As the ratio test proved inconclusive, I am trying to use the comparison test in order to prove it's convergence, but I am unsure what series to compare it to. Initially, I believed I could compare it to $\frac{1}{n^2}$ but I am also unsure how to prove that this series converges.  Is there a general method for choosing the series with which you compare your series to?


$\displaystyle\sum_{n=1}^\infty \frac{1}{n^s}$ only converges to $\zeta(s)$ if $\text{Re}(s) > 1$.  Why should analytically continuing to $\zeta(-1)$ give the right answer?


Multiple permanents entering the battlefield simultaneously and “Enter the Battlefield” effects

There are many cards that can put multiple permanents onto the battlefield simultaneously, such as , , or .  How do these interact with the following types of abilities?  As [this permanent] enters the battlefield... You may have [this permanent] enter the battlefield as... [This permanent] enters the battlefield with... When [a permanent with certain characteristics] enters the battlefield...   Justification There have been many questions already about particular instances of this situation.  This question is intended to be a canonical question and answer to all questions such as:      Note to moderators: three of these five questions have already been marked as duplicates pointing to this one.  Can we do the same for the remaining two?


Find (a,b,c) if $ax^2-bx+c=0$ have roots lying in $(0,1)$ where $a,b,c\in\mathbb{Z_+}$

Let the equation $ax^2-bx+c=0$ have distinct real roots both lying in the open interval $(0,1)$ where $a,b,c$ are given to be positive integers. Then the value of the ordered triplet $(a,b,c)$ can be   $$ a)\quad (5,3,1)\;,\quad b)\quad(4,3,2)\;,\quad c)\quad(5,5,1)\;,\quad d)\quad(6,4,1) $$   The solution given in my reference is $(5,5,1)$.   My Attempt  $$ a,b,c\in\mathbb{Z_+}\\ \alpha,\beta=\frac{b\pm\sqrt{b^2-4ac}}{2a}\in(0,1)\\ b+\sqrt{b^2-4ac}<2a\implies\sqrt{b^2-4ac}<2a-b\\ b^2-4ac<4a^2+b^2-4ab\implies-ac<a^2-ab\\ a=0\text{ (or) }-c<a-b\implies a+c>b\\ \Big[a=0\text{ (or) } a+c>b\Big]\; \&\;b^2\geq4ac $$  Does that constitute the complete condition for the given problem or am I missing something in my attempt ?


I would like to create a half-turn staircase without a landing. Is there an easy way to accomplish this without having to manually calculate and create each step individually?  Here’s an image similar to what I would like to achive:    I have found the Archimesh add-on including . While I can bend the created stairs, I haven’t found any way to get anywhere close to the image above. My stairs just always look out of shape and I don’t know how to get the outline of the staircase into a square.  I should mention that I only have very little experience with Blender modeling, so it’s well possible that I’m just missing some curve modification basics. Perhaps Archimesh is also the wrong approach for this in the first place?


How would I subtract milliseconds from long year, long month, long day, long hour, and long minute?

I'm storing time in my database by setting year, month, day, hour, and minute individually, and I would like to know the date difference between two datetimes. This is clumsy and cumbersome, and I would like to know what the best practice for doing something like this:  1/1/2016 12:00am - TimeUnit.MINUTES.toMillis(1800000) = 12/31/2015 11:30pm


I've seen commands to benchmark one's HDD such as this using dd:  $ time sh -c "dd if=/dev/zero of=ddfile bs=8k count=250000 && sync"   Are there better methods to do so than this?


I'm trying to make an app that when opened will play an audio file that is contained in the app, but i have no idea how to do it. I know this is really vague and I apologize but any help would be awesome.   This other question covers high level how to make an app, but I can't figure how to actually make the shell.      Is there a guide or sample code to show how to take an actual file and actually play it in AppleScript framework?


Domain Administrator unable to decrypt files with EFS recovery certificate

I have some files on the drive of a domain controller running Windows Server 2008 R2 which are encrypted via EFS. The user that originally encrypted the files no longer exists. When I look at the encryption details for these files it says that there is a recovery certificate for "Administrator(Administrator@MYDOMAIN)" with the certificate thumbprint "0123 4567 89AB...".  I am logged in as the above Administrator and when I open MMC and add the Certificates Snap-in I can see that I have a "File recovery" certificate with the thumbprint "0123 4567 89AB..." which is "enabled for all purposes".  I have checked the permissions on the files and the Administrator account has full access, except for the "Special permissions" box which is disabled.  Yet when I try to open, copy, or decrypt the files, I get an "Access is denied" error. E.g.  C:\Directory>cipher /d file.docx   Decrypting files in C:\Directory\  file.docx [ERR] file.docx: Access is denied.  0 file(s) [or directorie(s)] within 1 directorie(s) were decrypted.   What do I need to do to decrypt these files?


What is the difference between following sentences:   She will reach there by Monday next. She will have reached there by Monday next.


Why are my class's variables not unique for each object?

Why is it that the object b has the same variables as a and not unique ones? class FOO:        def __init__(self):          FOO.x = [3, 1]          self.y = [9, 4]        def g(self):          FOO.x[1] = FOO.x[1] + 7          self.y *= 2          return FOO.x + self.y    a, b = FOO(), FOO()  print(a.g())  print(a.g())  print(b.g())  Why do I get this output:  [3, 8, 9, 4, 9, 4] [3, 15, 9, 4, 9, 4, 9, 4, 9, 4] [3, 22, 9, 4, 9, 4]  and not this?  [3, 8, 9, 4, 9, 4] [3, 15, 9, 4, 9, 4, 9, 4, 9, 4] [3, 8, 9, 4, 9, 4]  Isn't each object unique?


How to find out what "Blog pages show at most" is set to

Under Settings > Reading, there is a field called Blog pages show at most __  posts. Since all of my queries are based off of the main query, I need to find out what's stored in that field. How would I do that, especially outside of the loop?


combinatorial proof that $\sum_{i=0}^n {n+i\choose i}\frac{1}{2^i} = 2^n$

Give a combinatorial proof that $\displaystyle\sum_{i=0}^n {n+i\choose i}\frac{1}{2^i} = 2^n$.  I'm not sure if Pascal's identity is useful here. Or perhaps there is a way involving binary strings? $2^n$ is the number of binary strings of length $n$, so if there was some way to decompose these strings into disjoint sets $B_i$ with cardinality ${n+i\choose i}\frac{1}{2^i}$, a proof using that method might work. ${n+i\choose i}$ is the number of binary strings of length $n+i$ with exactly $i$ ones, since one can choose $i$ of the $n+i$ positions to be ones in ${n+i\choose i}$ ways and make the rest zeroes in one way. Then we divide by the number of binary strings of length $i$, though I'm not sure how to deduce the combinatorial significance of this. I'm most likely thinking of this the wrong way.


How to escape @ symbol in enviroment file?

I have my /etc/environment file set up with proxy settings. It looks like this -   http_proxy="http://userName:password@proxy:port/" https_prxoxy="http://userName:password@proxy:port/"   The password contains an @ symbol which somehow seems to be conflicting with the latter @ symbol because of which I am not able to connect to the network. How do I escape the @ symbol in the password?


Using a linear polarizing filter with a DSLR

Can I use a linear polarizing filter with a DSLR camera in manual mode?


I've been struggling for a few hours on the below pre-calculus olympiad equation to which I still don't have an answer:     $$(x^2+4x+3)^x+(2x+4)^x=(x^2+4x+5)^x$$   where $x \in (-1,\infty)$.   Now, according to WolframAlpha, this has a unique solution, $x=2$, and I need to prove this for one of my student without using derivatives or any more advanced techniques.  Interesting substitutions that I've tried, but with no success:  1) $a=(x+2)-\frac{1}{x+2}, b=(x+2)-\frac{1}{x+2}$ leads to  $$(b^2-a^2)^x=(b^x-a^x)^2$$  2) $\alpha =2\arctan(x+2)$ leads to  $$(-\cos(\alpha ))^{\tan(\alpha /2)-2} + (\sin(\alpha ))^{\tan(\alpha /2)-2} = 1$$  Both of them make the solution $x=2$ easy to see, but its unicity still eludes me.


How to move objects in winForms to create animation

I am trying to create an animation of shapes created by 5 or more picture boxes moving together. The shape supposed to move from one place to another. In its way there are more picture boxes. The form has a picture background.  The code I used for this is the following:  //caculating image path             double slope = (double)(474 + 30 * squareRow - originalBoard.Location.Y) / (originalBoard.Location.X - 41 + 30 * squareCol);             int dis = originalBoard.Location.X - animArr[originalButton].Location.X;             counter = 1;              while (counter != dis)             {                 for (int k = 0; k < animArr.Length; k++)                 {                     //creating new point                     Point xy = new Point(pointArr[k].X + counter, pointArr[k].Y - (int)Math.Ceiling(slope * (double)counter));                     animArr[k].Location = xy;                     //updating image                     animArr[k].Update();                     this.Update();                 }                 if (counter + 3 > dis)                     counter = dis;                 else                     counter+=3;             }   the code has 2 issues: The shape moving extremely slow, especially when hovering over a picture box or a label. In addition, after it reaches it's destination, the form is freezing.  does anyone know why it happens and how to fix it?


Real Analysis - A sequence that has no convergent subsequence

How to prove that the sequence $\{a_n\}$ has no convergent subsequence if and only if $|a_n|$ approaches infinity? The forward direction is obvious, how to prove the other direction?


How does electron gets negative charge and proton gets positive charge?

I researched much in physics but I still do not know how does electron gets negative charge and proton gets positive charge? What is the source of this charge and energy?  How can this particles maintain their same energy state for infinite time?   why doesn't they lose all their energy in form of electromagnetic radiation and be non-existent?


How do I drop root privileges in shell scripts?

The "--up" option in OpenVPN is normally used for routing etc. And so it is processed before OpenVPN drops root privileges to run as nobody. However, I am invoking shell scripts that need to run as an unprivileged user.  How do I do that? I have studied , especially polynomial's and tylerl's answers, but I do not understand how to implement. I am working in Centos 6.5, and suid is blocked, both as "chmod u+s" and as "setuid()".  There is an OpenVPN plugin ("openvpn-down-root.so") which enables scripts invoked by the "--down" option to run as root. There could be an equivalent, such as "openvpn-up-user.so", but I have not found it.  Edit0  Per Nikola Kotur's answer, I've installed . Although the chpst command works in terminal, in the up script it fails with "command not found". What works is "sudo chpst" plus setting the proper display and language. Please see  Given that, the up script needs these four lines:  LANG="en_US.UTF-8"; export LANG GDM_LANG="en_US.UTF-8"; export GDM_LANG DISPLAY=:0; export DISPLAY sudo chpst -u user -U user /home/user/unprivileged.sh &   Edit1  Per 0xC0000022L's comment, I find that "sudo -u user" works as well as "sudo chpst -u user -U user":  LANG="en_US.UTF-8"; export LANG GDM_LANG="en_US.UTF-8"; export GDM_LANG DISPLAY=:0; export DISPLAY sudo -u user /home/user/unprivileged.sh &   I'll study man sudoers and update if/when I get sudo alone to work.


Does the value of a standard deviation have any meaning

I understand that the standard deviation corresponds deviance from the mean but does the actual value of the standard deviation have any direct meaning? For example if you have a $\sigma$ of 10, does 10 mean anything by itself? (relative to the problem)


How should previously awarded bounties be handled when a question is migrated?

The current handling of bounties when questions are migrated is somewhat inconsistent and incoherent. Active bounties are refunded to the asker prior to the question moving, which seems fine and good. Already awarded bounties are not handled as consistently, and bountiers complain about it on meta:  In , the points were simply disappeared, gone from both the offerer and the earner on both the source and destination site.  In , the bounty was initially deducted from the earner and refunded to the offerer, but then a mod stepped in to restore the bounty as previously offered and earned.   This is only going to come up more often as the SE network expands, especially as the new /review system facilitates migrating old flagged questions which would otherwise have just lingered. How should previously awarded bounties be handled during migration?


Why is the vector sampled from Gaussian or Subgaussian distribution in lattice-based cryptography?

I have known that the vector is sampled from Gaussian distribution in lattice-based cryptography because the distribution of the vector $\mod{\mathcal{P}(\mathbf{B})}$ approximates to uniform distribution.  It is proved by below lemma.     For any $s > 0$, $\mathbf{c} \in \mathbb{R}^n$, and lattice $\Lambda(\mathbf{B})$, the statistical distance between $\mathcal{D}_{s,\mathbf{c}} \mod{\mathcal{P}(\mathbf{B})}$ and the uniform distribution over $\mathcal{P}(\mathbf{B})$ is at most $\frac{1}{2} \rho_{1/s}(\Lambda(\mathbf{B})^*\backslash\{\mathbf{0}\})$. In particular, for any $\epsilon >0$ and any $s \geq \eta_{\epsilon}(\mathbf{B})$, the statistical distance is at most $\Delta(\mathcal{D}_{s,\mathbf{c}} \mod{\mathcal{P}(\mathbf{B})},\mathcal{U}(\mathcal{P}(\mathbf{B}))) \leq \epsilon/2$.   But if the vector is sampled from uniform distribution at first, the distribution of the vector $\mod{\mathcal{P}(\mathbf{B})}$ is uniform. So, I thought that Gaussian sampling is not needed for above reason, because Gaussian sampling requires large costs.  Another reason I think is that the smaller vector is preferred because almost lattice problem is about finding short vector and Gaussian variable has higher probability as closer to the center. Is it right?  If my thought is not correct, let me know the reason using Gaussian distribution in lattice-based cryptography.


Why do people who subscribe to self-refuting skeptical philosophies still argue with others?

The belief that everything is relative is obviously self-refuting, because it holds to an absolute.  However, in my experience, people who believe this (or some form of it) such as some Buddhists and atheistic materialists, or people who have an even more radical belief that permits no knowledge at all, such as nihilists, still actively resist those who suggest that there are at least some absolutes. In their discussing what reality is like and whether one idea corresponds to reality better than another idea, aren't they admitting that reality itself is an absolute and that at least one thing is absolutely knowable (a way in which reality is or is not, to which certain ideas correspond more or less closely)?  To put it another way, this very desire to show others that "some-absolute-truths-exist" is wrong seems to destroy their own "all is relative" or "nothing is knowable" positions. By taking a stance against any truth claim at all, they are making an ontological claim about what reality is not like and that this should apply globally—thus making a truth claim, admitting to at least one absolute. That seems ridiculously inconsistent, like someone going around and yelling at random passersby, "I'm not yelling at you!" and "You can't hear me yelling!"  I think that someone who believes in absolutely comprehensive global relativism (to me an impossible bit of nonsense, like square circles) has no business arguing with anyone at all. Any discussion they engage in cannot be intended to find truth together with their discussion partners, because they're either insane, lying, or the discussion was undertaken solely for their own pleasure—why else would someone who doesn't believe anything is true argue with you about whether something you think is true actually is? And pleasuring oneself in public at the expense of other people's comfort and in violation of basic human propriety (I don't know how to put this more delicately, it honestly seems like a very apt analogy) seems like a pretty reprehensible thing to do.  What kind of basis do relativists and their more extreme nihilist friends have for arguing against anything at all? And why do they seem to never, ever admit that when they do argue with others about the truth of any claim, that this is mistreatment solely in pursuit of their own offensive pleasure and amusement (since it can't be an attempt to discover truth, and their argument with the other person can't be an attempt to discredit an incorrect idea, since neither correct nor incorrect ideas exist)?


View alternate windows registry using java

I have JUnits (32 bit application) to which I want to expose 64 bit windows registries on my 64-bit windows OS.  I read that using the windows flag 'KEY_WOW64_64KEY' I can turn on 64-bit view.  Where in the registry do I go and set this flag?  But how do I do that easily in Java? Is there a way which avoids JNI and any reference to advapi32.dll?


Why is Spring called a framework and not a library?

I was wondering what could be the major difference between a library and framework. When can we use a library in our application and when can we go for a framework.


Can you cast racial spells with a spell slot?

Take for instance, a level 5 (standard) tiefling warlock. Would you be able to cast your Darkness and Hellish Rebuke spells with a spell slot? Both spells appear on the warlock spell list and could be taken as known spells by a warlock. But let's say you didn't take them as known spells with warlock. You can cast each of them once per day with your Infernal Legacy trait without expending a slot. The trait says (emphasis mine):  Infernal Legacy You know the thaumaturgy cantrip. When you reach 3rd level, you can cast the hellish rebuke spell as a 2nd-level spell once with this trait and regain the ability to do so when you finish a long rest. When you reach 5th level, you can cast the darkness spell once with this trait and regain the ability to do so when you finish a long rest. Charisma is your spellcasting ability for these spells.  Since it specifically says you can cast it once with this trait are you able to cast it with spell slots without having to take it as one of your spells known as a warlock?


I need to install ubuntu alongside with my current version of Windows in my new computer (I prefer UBUNTU but I still need windows to run some programs in my work place).  The point is that, in windows 8 I can not access BIOS as I did the first time that I installed ubuntu in my older computer.  Can somebody please provide me a detailed information about how to install Ubuntu without corrupting Windows 8  Thanks people.  Luis


Mirror modifier mirrors on different axis/axes from the selected one(s)

I have 2 objects a face and an ear. Mirror modifier works fine for the face. But when I use mirror modifier to duplicate the ear on X axis, it duplicates on Z axis. And when I use mirror modifier on Z axis it mirrors on X axis. How to correct the axis orientation?


I was wondering how to get the Classified Weapons added in the Febuary Update.


What is the origin of the phrase "Bob's your uncle"? Is it used internationally or is this just a term used in the UK?  I have often heard an extension of this phrase: "Bob's your uncle and Fanny's your aunt", can anyone shed any light on this variant?  An example of how it is used:  "Put it in the oven for 20 minutes and Bob's your uncle, your dinner will be done".


What is the expectation of the following joint CDF?

Yesterday, I asked the following question regarding copulas:     "Let's say $X=(X_1,X_2)′$, where $X\in \mathbb R^2$. What is the expectation of the copula function $C(F_{X_1}(x_1),F_{X_2}(x_2))$ - i.e. $\mathbb E_X[C(F_{X_1}(x_1),F_{X_2}(x_2))]$?"   Here, I rephrase this question in a form familiar to most:     Let's say $X=(X_1,X_2)′$, where $X\in \mathbb R^2$. What is the expectation of the joint CDF $F(F_{X_1}(x_1),F_{X_2}(x_2))$ - i.e. $\mathbb E_X[F(F_{X_1}(x_1),F_{X_2}(x_2))]$?


Proof that a derived set is closed in a $T_1$-space

Let $X$ be a $T_1$-space and $A\subset X$.   Claim: $A'$ is closed, where $A'=\{x\in X|(U\setminus\{x\})\cap A\ne\emptyset$ for all open neighbourhoods of $x\}$.  Proof: Let $x\in (A')^c$ be arbitrary.   Then $x\notin A'$ so there is an open set $U$ containing $x$ such that $U\setminus\{x\}\cap A=\emptyset.$  Since $X$ is $T_1,$ it follows that $\{x\}$ is closed and so $U\setminus\{x\}$ is open.   Thus, using the facts that $U\setminus\{x\}\cap A=\emptyset$ and $U\setminus\{x\}$ is open, we have $U\setminus\{x\}\subset (A')^c.$   And since $x\in (A')^c$ it follows that $U\subset (A')^c.$   So we have shown that for any $x\in (A')^c,$ there is an open set $U$ containing $x$ such that $U\subset (A')^c,$ and so $(A')^c$ is open.  Does this prove the claim?  EDIT: I know the claim is true. I just wanted to verify whether my reasoning was correct.


$\lim_{x\to0}\frac{\sin x - x}{x^3}$  I know it can be easily done by using Taylor expansion of sine function and L'Hopital. However, can we come up with a way to solve the limits using properties.


Vim integration for editing/posting on Stack Exchange websites

How practical would it be to have a Vim-engine running on Stack Exchange, so that a subset of Vim's features could be used for editing and posting on the website itself?  What are the greatest challenges for developing such a feature?


Should I upgrade dell dual-boot ubuntu from 12.04 to 14.04 (and maybe 16.04 and 18.04)?

I have a Dell inspiron 600m I bought in 2003 with a 40M drive and 1G of memory.  I have a dual boot system wherein I gave windows 30G and ubuntu 10G (3G free space remaining).  When I watch DVDs in windows it works okay, but it takes forever to get there (boot, load windows explorer, etc).  It's thrashing something awful.  I also run ubuntu 12.04.  It asks to upgrade to 14.04, but then gives  saying the unity3d desktop performance of 14.04 can't be hardware accelerated.  Here's the video card:  $ lspci | grep VGA 01:00.0 VGA compatible controller: Advanced Micro Devices, Inc.  [AMD/ATI] RV250/M9 GL [Mobility FireGL 9000/Radeon 9000] (rev 02)   Should I try upgrading to 14.04 in hopes of getting to 16.04 or 18.04?  Should I install some other lighter-weight linux?  Which one?  My goal would be to watch DVDs and videos online with maximum frame rate and minimal thrashing.  I can do it now, but DVDs sometimes won't decode.  I wonder if newer versions of linux have better graphics performance or DVD-playing abilities.  Or maybe they just use more memory, and would be worse.  What should I do?  EDIT: I can't watch netflix ("libavcodec may be vulnerable or is not supported, and should be updated to play video").  So, I should probably just upgrade.


Showing $\frac{d^3\underline{k}}{2\omega_{k}(2\pi)^3}$ is Lorentz invariant

Show $\frac{d^3\underline{k}}{2\omega_{k}(2\pi)^3}$ is Lorentz   invariant.      Hint: try to evaluate $\int dk_0\delta(k_0^2 - M^2)\theta(k_0)$ where $M^2 = \underline{k} + m^2$   My attempt is as follows,  $$ I = \int d^4k \delta(k_0^2 - M^2)\theta(k_0) = \int dk_0 \int d^3\vec{k}\ \delta(k_0^2 - (|k|^2 + m^2))\theta(k_0)\\ = \int dk_0 \int d^3\vec{k} \delta(k_0^2 - (|k|^2 + m^2))\theta(k_0) $$  then using $M^2 = m^2 + |k|^2 = \omega_k^2$ and $\delta(a^2-b^2) = \frac{1}{2|\omega_k|}\delta(a-b) + \frac{1}{2|\omega_k|}\delta(a+b)$ we get  $$ I = \int dk_0 \int d^3\vec{k} \Big( \delta(k_0 - \omega_k) + \delta(k_0 + \omega_k) \Big) \frac{\theta(k_0)}{2\omega_k} $$ using the property of the theta function, we get, $$ I = \int_{0}^{\infty} dk_0 \int d^3\vec{k} \Big( \delta(k_0 - \omega_k) + \delta(k_0 + \omega_k) \Big) \frac{1}{2\omega_k} $$ integrating over $dk_0$ and using the fact that $\theta(\omega_k) + \theta(-\omega_k) = 1$ $$ I = \int \frac{d^3\vec{k}}{2\omega_k(2\pi)^3} \Big( \theta(\omega_k) + \theta(-\omega_k) \Big) = \int \frac{d^3\vec{k}}{2\omega_k(2\pi)^3} $$ however, I still have an integral for $\int d^3\vec{k}$ I don't know how to loose this integral without loosing the $d^3\vec{k}$!


Wifi not working on Lenovo Ideapad 330 in Ubuntu 18.10

my wifi is not working. I followed the instructions of another post to generate a report, which is here -->   I understand this is relevant:     0: ideapad_wlan: Wireless LAN       Soft blocked: no       Hard blocked: yes   I'm getting kind of desperate :( Any help appreciated


I'm writing a website which allows users to enter some text in predefined text fields. This text gets passed on the server where a LaTeX document is created (containing the text entered by the user). The server finally returns a compiled LaTeX document (a pdf) to the user. Note: the user doesn't enter the whole tex document, only parts.  My problem: how can I make sure that the entered text will not harm my server? I.e. how to detect harmful LaTeX code?  Some examples:   The user entered an infinite loop written in LaTeX, the server can't compile the document. The user entered a shell script which will be executed from the tex file when compiling, potentially crashing my server.   Is my best alternative to blacklist any LaTeX code? Is detecting \ followed by a non-space enough to block any potentially harmful LaTeX code?


What is the difference between 'can', 'could', 'may' and 'might'?

I'm a native English speaker and I've been doing some research into English grammar for a programme I'm working on. However, on looking into modal verbs, I've only just come to appreciate how subtle and complicated they are.  What is the difference between these sentences? What possible different response might one have to each?        I can go to the cinema tonight.   I could go to the cinema tonight.   I may go to the cinema tonight.   I might go to the cinema tonight.      Granted, the first of these looks more like a statement of ability or possibility than the three that follow. But in what ways does it differ from the others, since all suggest ability and possibility? And crucially, what distinguishes the other three.  Perhaps it's a matter of tone, of context, of the speaker... The question may appear quite simple but I haven't found a satisfactory answer elsewhere.    looked quite useful in that it covered levels of confidence and certainty but it was talking about the potential state of something rather than the possibility for the person who is speaking. Are there any differences in that sense?   looked at these verbs used in question form (e.g., differences between 'Can I...?' and 'May I...?') but I'm not so interested in that for now.  Any thoughts appreciated.


How to find GCD between these two equations?

I've been trying for a couple of hours to find a way to prove the next claim:  $$\gcd(n-1,a) = \gcd(\frac{(n^a-1)}{n-1},n-1)$$  I have already proven that  $$\frac{(n^a-1)}{n-1}$$ is always divisible by $(a-1)$.  which means I can set define  $$\frac{(n^a-1)}{n-1}=\frac{c(n-1)}{n-1}=c$$  then I get :    $$  \gcd(n-1,a)=\gcd(c,n-1)$$  but that's it, I'm stuck.


i created a library with vanilla js and css, but it just work when i import the js and css, i want to use just importing the file js right now i am importing this way: <head>     <script src="../lib.js"></script>     <link rel="stylesheet" href="styles.css"> </head>  but its possible only with this? <head>     <script src="../lib.js"></script> </head>


Electric field lines forming closed loops

I have been reading about the electric field induced on a metal ring due to an increasing magnetic field directed along the axis of the ring and the electric field lines are found to form concentric circular loops. This implies that the electric field formed is not conservative. Why is it so? Are electric field due to free charges and those due to changing magnetic field two entirety different  things?  Please provide an intuitive and less mathematical explanation as I am just a high school student with knowledge of basic calculus.


How can a 80-bit floating point be used by a 32-bit system?

Since a 32bit system can't manage a 2^33 number (because the obvious 32-bit limit), how can manage a  number?   It should require "80-bit"...


How to create a variable with info that persists across runtimes

I am building a database and I want to be able to store a user input filepath and have it available as a variable even after the application is closed and restarted to prevent retyping the path with each launch.


Brain storm: Suppose we have a perfect lever, which has 0 quality, and perfect rigidity. It is long enough that can reach Proxima Centauri from the earth. Someone push one side of lever from Proxima Centauri, immediately, the person from the earth will get the force. That means the force speed is infinity. With this way, information can be transferred via the lever immediately. In real world, what the force speed will be for quality>0, and not perfect rigidity? Roughly, speed will be bigger for smaller quality lever, and speed will be bigger for high rigidity thing. My question, is there any research on this area?


How do I enable the "Universe" repository from the command line?

How do you use terminal to enable Universe source? Or any those 4 from Software Sources: Main, Universe, Restricted, Multiverse Main is on by default and Restricted is on if durring Ubuntu installation i tick Enable Restricted Formats. Answer with line where version checked so it auto detects it. Like command I know for partner but that goes to Other Software tab sudo add-apt-repository "deb http://archive.canonical.com/ $(lsb_release -sc) partner"


Let $\phi:G_1\to G_2$ be a group homomorphism. Show $\phi(g^{-1})=(\phi(g))^{-1}$.

Let $G_1$ and $G_2$ be groups and $\phi:G_1\to G_2$ be a group homomorphism. Show $\phi(g^{-1})=(\phi(g))^{-1}$ $\forall g_1\in G_1$.  So far I have:  $\phi(e)=e$ by definition, where $e$ is the identity element. Then $\phi(g_1)\phi(g_1^{-1})=\phi(g_1g_1^{-1})=\phi(e)=e$ since $\phi$ is a group homomorphism.  I know I can get $\phi(g^{-1})=(\phi(g))^{-1}$ $\forall g_1\in G_1$ from that, but I don't know HOW.  Any help/hints would be welcomed. ^_^


Short story about researchers on a strange planet, genetic mutation

I read this short story in a scifi collection a number of years ago. I think it was the title story.  A small group of between five and ten people (researchers, scientists, colonists) are (I think) cryogenically frozen and arrive on a planet with very strange life. Trees the size of skyscrapers weird animals, etc. The people live in their space ship and over many years they have genetic mutations and I think some of them die. I think there's also at least one more generation and they become more and more like the strange life on the planet.  I thought the title was "The Eternal Golden Braid", but that's the subtitle of Godel Escher Bach, so Googling is useless. I'm pretty sure it's something like that though.  There's another story in the same collection about a little golden flying saucer that comes to a man in a park and no one believes him and he goes crazy or something.


Attribute table for shapefile showing nonsense symbols on my PC

I am working with a shapefile which has several hundred rows and 10 or so columns. Usually, the cells contain data, but at the moment they are just showing nonsense symbols (attached). I have tried using the same shapefile on a colleague's computer, and it worked fine. I have also reinstalled QGIS. What is wrong?


How do I indent a particular block of code in Vim?

In  when I have to format code I choose a block of code and then press Ctrl + Shift + F.  What is the equivalent of this in Vim?  I.e., say we got the below lines of code:  function() { var test = "Hello, World!"; var test2 = "Hello, World! Again"; }   The final output I want to see is well formatted code like below:  function(){   var test = "Hello, World!";   var test2 = "Hello, World! Again"; }


What is the difference between Nginx variables $host, $http_host, and $server_name?

What is the difference between the three Nginx variables $host, $http_host, and $server_name?  I have a rewrite rule where I'm not sure which one I should be using:  location = /vb/showthread.php {     # /vb/showthread.php?50271-What-s-happening&p=846039     if ($arg_p) {         return 301 $scheme://$host/forum/index.php?posts/$arg_p/;         }   I'm looking for an answer that doesn't just say 'use ___ variable in your rewrite rule' but also explains the theoretical differences between them.


I'm using the style verbose-trad2 in biblatex. I have some bibliographical incollection items which refer to a collection item via the field crossref. The collection item has a shorttitle item which unfortunately is not being used, as you can see in this MWE:  \documentclass{article} \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc} \usepackage[style=verbose-trad2]{biblatex} \addbibresource{stack2.bib} \begin{document}   The first one\footcite{vasquez1998bajo}. \par    And then\footcite{negredodelcerro1998}. \end{document}   And the items:  @collection{MartinezRuiz1998,  editor =       {Martínez Ruiz, Enrique},  title =        {España y Suecia en la época del Barroco (1600-1660)},  shorttitle =   {España y Suecia},  year =         1998,  location =     {Madrid},  }  @InCollection{negredodelcerro1998,  author =       {{Negredo del Cerro}, Fernando},  title =        {Contradicciones en la Monarquía Católica},  pages =        {667-685},  crossref =     {MartinezRuiz1998}  }  @InCollection{vasquez1998bajo,  author =       {Vasquez Lopera, Julián},  title =        {Bajo el signo de la diplomacia etc.},  crossref =     {MartinezRuiz1998},  pages =        {761-791}  }   Is there a way to force biblatex to check whether a collection item has been already cited through an incollection item?


There are 3 colleges with $n$ students each. Any student knows $(n+1)$ students of the other colleges. Prove that there exists three students from different colleges who know each other (this doesn't have direction). A knows B implies B knows A i.e. the graph is undirected.   My work: Let the colleges be $X,Y,Z$. A student (say $a$) from college $X$ knows at least $\lfloor{\frac{n}{2} \rfloor}+1$. If one of the students that are known to $a$ in $Y$ knows a student in $Z$ and that student knows $a$ then we are done! But that is not always possible. There are too many cases. I can't take them all and become confused. Please help me.


I have a bunch of files written in mostly one programming language and also some written in others. They are in different folders, but few and targetable.  I want to make a program that says how many lines of code there are. I know I could do this for one file, just like this:  #include <iostream> #include <fstream> using namespace std;  int main() {     ifstream f("file.txt");     int n = 0, aux;     string line;     while (getline(f, line))         n++;     cout << endl << n << " lines read" <<endl;     f.close(); }   But how could I "browse" all the files and folders and read them all? Having to do it explicitly for each one of them sounds awful to me.


Is there any way to recover deleted files which may have since been overwritten?

I deleted lots of files & folders on my laptop and then I put a new files in the same folders. I need to recover the deleted files. I tried a lot of recovery software and I couldn't recover my old files.   I read that if you refill the folders with new files after deleting old ones then I can't recover them again. Is that true?   What should I do?


Proof of multiplicative inverse for polar complex numbers

Use the polar form of complex numbers to show that every complex number $z\neq0$ has multiplicative inverse $z^{-1}$.  If $z=a+bi$, then the polar form is $z=r(\cos(\alpha)+i\sin(\alpha))$.  I can do it, not using polar coordinates: If $z=a+ib$.  Since $1+0i$ is the multiplicative identity, if $x+iy$ is the multiplicative inverse of $z=a+ib$, then $(a+ib)(x+iy)=1+i0$ $\Rightarrow$ $(ax-by)+i(ay+bx)=1+i0$ $\Rightarrow$ $ax-by=1bx+ay=0$ $\Rightarrow$ $x=\frac{a}{a^2+b^2}$, $y=\frac{-b}{a^2+b^2}$, if $a^2+b^2\neq0$.  Thus, the multiplicative inverse of $a+ib$ is $\frac{a}{a^2+b^2} +\frac{-b}{a^2+b^2}$.  Now, how can I use this information to find it using $z=r(\cos(\alpha)+i\sin(\alpha))$??  I'm stuck...


I think my server was hacked - how do i know what has been changed?

I have read the following posts which didn't answered my questions: -  -  - and much more...  The server setup was this: - the Ubuntu server was after a router (Cisco EA6500) and didn't had port forward (uPNP is enabled). - the stupidest idea was to have a user called user with password user.  Today I entered on the php webeditor which connects by ssh and didn't accepted the password. I found out that the server might have been hacked.  I found the followings: - all the server files timestamps are changed to my last login date (today) - there was one cronjob /dev/shm/-   /.ICE-UNIX/update >/dev/null 2>&1  - there was an error on ubuntu start-up that said "error variable ROOT isn't set"  What I did: - recover password by recovery console - setting up a  which got  to get into ssh.    Questions: - How do i know what has been changed? - How did they get in if there was no ssh port exposure?     Later Edit:   They have left the logs intact and I found out that  and changed the   password. There were a lot of ssh login tries over the past weeks. I   have reinstalled the system, moved the port, installed a firewall and   I'm inspectting the router. It definitely has security holes. Thank   you all!


I am trying to create a cover page containing an image and the title of the report, but the image and the title appear on different pages. How can I solve this problem?  \documentclass[30pt]{report} \usepackage[a4paper,top=3cm,bottom=3cm,left=3cm,right=3cm]{geometry} \usepackage{graphicx} \begin{document}   \begin{figure}[h]      \centering \includegraphics[width=5cm]{najah.png}    \end{figure}    \title{ATLAS Detector}    \author{Fatima Shahrouj\\ Departement of physics, An-Najah National University NNU, Nablus, Palestine.}    \maketitle \end{document}


How download dropbox directory or files with command line on a linux server

I need to move a very big directory from dropbox to S3 ~250GB, but don't find an easy way to do it. (I don't have credential of dropbox it is a shared link)  1) From my browser trying to download the folder result in 'error zip to large', however I can dl the files inside this folder 1 by 1 on my workstation but it is going to be a pain plus we share the connexion at work so I wanted to use an amazon temp server to retrieve 1 by 1 the file then send them to S3.  2) Second problem the direct link that dropbox give you are not really direct link they contain the name of folder plus at the end "?dl=0&preview=1GQKV9M.vcf#"  and copying the link and then past it in another tab doesn't start any new download. As a result trying to use wget or changing dl=0 per dl=1 also result in errors.


doorstop: command not found (very simple installation instructions)

I would just like to test and try doorstop / see doorstop in action on my Ubuntu laptop.  In the instructions here  it says that if I pip3 install doorstop, doorstop should then be available on the command line. However, when I do this and then try to use doorstop on the command line I get doorstop: command not found. If I run Python3 and import doorstop (which seems to work), in Python3 I still haven't been able to use any of the commands on the doorstop website. I also haven't seen any information about this online.  Thanks, Milan  EDIT: Question solved in the comments by @steeldriver (use sudo or adjust PATH variable). You can also use doorstop in Python with the doorstop.___ syntax. :)


Color with falloff | Animation nodes 2.1 in blender 2.81a

I have these squares that spin 90 degrees when the falloff passes over them, I want them to change color from blue to magenta at the same time, I've made this array to clone one and got the color to work but it's only effecting the first one since they are all using the same material. How do I do this?  I either want to color the emission node using the falloff  OR Change color along with the 90 degrees of rotation  Rendered in cycles  I would love some help with this! :)


Mysql memory_global_total is smaller than memory usage in top

When I try top in my ubuntu the result   top - 16:03:09 up 16 days, 21:24,  2 users,  load average: 3.53, 2.72, 3.46 Tasks: 395 total,   1 running, 282 sleeping,   0 stopped,   0 zombie %Cpu(s): 10.0 us,  0.5 sy,  0.0 ni, 87.7 id,  1.7 wa,  0.0 hi,  0.0 si,  0.0 st KiB Mem : 16089320 total,   277676 free, 15396176 used,   415468 buff/cache KiB Swap: 31231996 total, 30194232 free,  1037764 used.   364724 avail Mem    PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND  3529 mysql     20   0 20.627g 0.013t   8084 S 168.2 89.2 533:45.83 mysqld  5361 root      20   0       0      0      0 I   2.0  0.0   0:01.08 kworker/u32:2  1234 user      20   0   43052   3280   2324 S   0.7  0.0   2:57.46 top  5299 user      20   0   43048   3380   2420 R   0.7  0.0   0:14.83 top  1305 root      20   0 2690104   1992   1256 S   0.3  0.0   2:02.85 snapd  2355 root       0 -20       0      0      0 I   0.3  0.0      but when I execute   SELECT * FROM sys.`memory_by_host_by_current_bytes`   the result is  "total_allocated" "313.61 MiB"   I am using Mysql 5.7.25 running on ubuntu 18.04.01 LTS


Calling Function in js by storing function name in variable

I have one function named root and at next part I am storing function name in variable (call) . I want to call function by using variable name For Example:-  (note:- not using root() using variable call's value )   call = "root";   root = function() {     name = "This is My root function";     console.log(name)  }    Can we call root function by value of variable (call) Is it possible.


Prove by induction for each integer  $n$ greater or equal to $1$, we have $$7 + 7^2 + 7^3 +···+ 7^n = \frac{7^{n+1}-7}{6}.$$


Why do DNS queries fail if the first nameserver is not recursive?

I have a Linux box (Ubuntu server 11.10) inside a Windows Active Directory domain, and is joined the domain using . The resolv.conf file looks like this:  domain mydomain.com nameserver 192.168.1.1 nameserver 8.8.8.8 nameserver 8.8.4.4   where 192.168.1.1 is the Windows DNS server for the Windows domain. 8.8.8.8 and 8.8.4.4 are Google's public DNS servers that we preferred over our ISP servers.  That setup was working properly, until we decided to disable recursion in the Windows DNS server due to some changes of our network design. I thought that will go well as we have configured it to use Google's servers next, but it seems not:  mydomain\myuser@linux-server:~$ dig google.com  ; <<>> DiG 9.7.3 <<>> google.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 55321 ;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 13, ADDITIONAL: 4 ;; WARNING: recursion requested but not available  ;; QUESTION SECTION: ;google.com.                    IN      A  ;; AUTHORITY SECTION: .                       3600    IN      NS      c.root-servers.net. .                       3600    IN      NS      d.root-servers.net. .                       3600    IN      NS      e.root-servers.net. .                       3600    IN      NS      f.root-servers.net. .                       3600    IN      NS      g.root-servers.net. .                       3600    IN      NS      h.root-servers.net. .                       3600    IN      NS      i.root-servers.net. .                       3600    IN      NS      j.root-servers.net. .                       3600    IN      NS      k.root-servers.net. .                       3600    IN      NS      l.root-servers.net. .                       3600    IN      NS      m.root-servers.net. .                       3600    IN      NS      a.root-servers.net. .                       3600    IN      NS      b.root-servers.net.  ;; ADDITIONAL SECTION: c.root-servers.net.     3600    IN      A       192.33.4.12 d.root-servers.net.     3600    IN      A       128.8.10.90 e.root-servers.net.     3600    IN      A       192.203.230.10 f.root-servers.net.     3600    IN      A       192.5.5.241  ;; Query time: 4 msec ;; SERVER: 192.168.1.1#53(192.168.1.1) ;; WHEN: Wed Jan  8 14:02:22 2014 ;; MSG SIZE  rcvd: 507   Also:  mydomain\myuser@linux-server:~$ ping google.com ping: unknown host google.com   And also I have failed squid proxy connections (which I solved using the  option inside squid configuration and neglected the internal DNS server).  Why DNS requests fails when recursion is declined by the first nameserver? Shouldn't the machine tries the next server? And what can I do if that was the expected (designed) behavior?  EDIT: NSLOOKUP gave other (success) results:  mydomain\myuser@linux-server:~$ nslookup google.com ;; Got recursion not available from 192.168.1.1, trying next server Server:         8.8.8.8 Address:        8.8.8.8#53  Non-authoritative answer: Name:   google.com Address: 173.194.67.102 Name:   google.com Address: 173.194.67.138 Name:   google.com Address: 173.194.67.100 Name:   google.com Address: 173.194.67.113 Name:   google.com Address: 173.194.67.139 Name:   google.com Address: 173.194.67.101   So is this application-dependent? Can I get that (trying next server if the first refuses recursion) to work transparently for all applications requesting name resolution, or name resolution is the responsibility of the program itself? (or am I missing something?!)...  EDIT: Also worth noting, mydomain.com is a registered and public address on the internet and is not owned by us. It's like we've set up an internal domain named apple.com, and I assure you I don't work for Apple, at least not yet ;-).


I have an ArcSDE geodatabase with different versions for each user.  How can I list each version using ArcPy?


how to automaticaly start a service in linux if it fails

An interviewer asked me this question in an interview.  He asked, suppose a service xyz stops due to any reason and you want it running all the time, what will you do so that it will start automatically


After Season 6, where does House Arryn's loyalty lie?

After Lyanna Mormont gave her speech and everyone started hooting-and-hollering, I'm not sure if anybody from the Vale (House Arryn) was voicing their agreement that Jon was the new King of the North.  Of course, the intentions of Lord Baelish are always unknown, but officially, is House Arryn:     declared as recognizing Jon as the new King of the North and ready to leave the easily defendable Vale and follow him into major combat?   declared as sympathetic to House Stark, but neutral? Going to war with any major army and risking major casualties will take convincing?  after Battle of the Bastards (BoB), the only remaining forces in the North are in the Vale? How many lesser Houses sat-out the BoB? It'd seem Jon has no army to command...   At end of season 6, does House Arryn 100% follow the King of the North? Or are they sympathetic but neutral?


Animating along a path with some rotation?

I've got a "flubber" like character model. I'm trying to animate the model along a path and add a playful rotation of the model at certain points along the path. I've successfully animated the character along the path using the 2 most common methods (a) parenting method (b) follow path constraint.   Ideally when the model descends at a point I would like to have a 360 degree spin, but Blender doesn't retain the keyframes I've placed. Is there solution for this?


Does $1^i$ and $1^{\frac{0}{0}}$ also give $1$ again?

This is the property of Real number $1$ that,  $1^n=1$ does this property only hold $\forall n \in \mathbb R$ or also $1^i=1$ and $1^{\frac{0}{0}}=1$  If it is; explain how?  I think that it should not give us $1$ again as we can't determine what is the square root of number $-1$ and similarly $\frac{0}{0}$ is indeterminate and so we can't proceed. May be I am wrong.


How to mention that we are applying as a couple?

My wife and I are applying to US universities for master's and PhD programmes. We both have a electrical engg. degree and are applying to the same department. However we would like to get into the same university. Is it possible to mention this in the application? Do universities take this into consideration when making admission decisions?


Let $(X,d)$ be a metric space and $A\subset X$ and $x\in X$. Then  $x\to d(x,A)$ is a uniformly continuous function.  If $\partial A=\{x\in X\,:\,d(x,A)=0\}\cap\{x\in X\,:\,d(x,X-A)=0\}$, then $\partial A$ is closed for any $A\subset X$.  If $A,B$ are subsets of $X$  then $d(A, B)=d(B,A)$. If the function is uniformly continuous then $d(x,y)<\delta $ implies $d(d(x,A)-d(y,A))<\epsilon$ , I can not handle the last expression. Difficulty continues for 3rd choice also. At least give me some hints. And for the 2nd choice I think it is true, as it is intersection of two closed sets. As finite intersection of closed sets closed $\partial A$ closed. And logic for former two sets closed is that the sets are preimage of closed set (singleton $\{0\}$ is closed as $\mathbb R$ is $T_1$) under continuous map. I am not very much sure about my ideas and want a verification.


Add feature to save reviews in the review queue

This is not the same as       – My suggestion focuses on adding a Save button to   allow the user to save a review they are not sure on, despite whether   they choose Looks OK, Requires Editing,   Unsalvageable or Skip.   I sometimes review questions in the review queue and often I am unable to review questions due to them being out of my area of expertise. However, when questions are in my area of expertise, I sometimes become confused as to what to choose due to the state of the question. It would be extremely useful if a Save button was available, so that I can save the review and come back to it to see what everyone else marked the question as.  This would not only allow me to review questions I would not have been able to before, but also allows me to sharpen my current skills and review the questions I would normally review even better, as I am more aware of what other people choose and what I should choose.  There could be an extra section on each user's profile, which keeps a record of each review item that they have saved, similar to this:      I have added a small, minimal demo to show what I mean:    html, body{ margin: 0; width: 100%; height: 100%; } iframe { border: none; width: 100%; height: 100%; } <iframe src="https://n4qe3.csb.app/"></iframe>     The demo is also available at . Remember that this is a minimal demo and lacks features; most of the links are also broken.


Please don't require answer votes to be cast before question votes

So now . But the way this is implemented is… bizarre. After casting 30 votes, we may cast 10 more votes on questions, regardless of what we voted on before.  I generally vote on a question and any answer it already has (if they deserve votes, of course) when I first view a page, and vote on new answers if I visit the page again later. So I tend to vote on questions a little before answers. After 30 votes, I can no longer maintain my voting habits, and the extra votes don't do me any good. (I frequently reach the cap on , where I'm very active.)  Please don't make a difference between voting on 10 questions first and then 30 other posts, and voting on 30 posts first and then 10 questions. (Yes, this means the figures may need to be adjusted.)  Or, maybe I'm voting on questions too much? I don't think I can see my voting statistics, but I have the Electorate badge on  with 1961 votes, which is probably about 30–35% on questions.


Test whether Ubuntu is vulnerable to (CVE-2016-4484)

I've been reading . Apparently I would gain root access if I hold down enter (somewhere) for 70 seconds. I tried it on a password prompt but it gave me like 3 attempts and stopped. I tried it on a tty but it didn't work also. Am I not vulnerable or am I doing it wrong?


I have a acer aspire 5315, recently put ubuntu 16 on there for development. The fan comes on on start up and going through the bios but once it boots ubuntu the fan turns off, this then causes the pc to get hot and switch off.   I have installed and ran lm-sensors and the fan isn't even listed, I have also tried sensors-detect and still nothing. I then tried installing fan control and still no joy.  Any advice would be greatly appreciated!   Thank you


Use displays on Linux machine to extend Windows Desktop

I have a Linux server with two monitors standing next to my Windows 8.1 machine. Since I won't be actually interfacing with server too much I would like to use its two monitors to extend my Windows desktop most of the time. I am thinking that getting my Windows machine to make use of 2 virtual monitors that stream their content over some remote desktop protocol to 2 viewers on my Linux machine. I basically need a free (DIY if needed) alternative to MaxiVista that has decent performance (so no ZeroDesktop). I have tried TighVNC with DFMirage but I could not get it to work right, it merely displayed the content of all my monitors in one scrollable window.  Any ideas?


Word for people who easily believe in rumors, and for a person who spreads them

Basically, I am asking for two words-   What do we call a person who spreads rumor?    And on the flip side, there will always be some people who easily believe rumors.    What do we call people who believe in rumours?   Is there a word, or phrase for both types of people?


Problem  Given Banach spaces $X$ and $Y$.  Consider a compact operator $C\in\mathcal{C}(X,Y)$.  Then weak convergence is turned into strong convergence: $$x_n\rightharpoonup x\implies Cx_n\to Cx$$ I'd like to try proving it but would need some hints.  Attempt  Denote the sup-norm by: $$F:\Omega\to E:\quad\|F\|_\Omega:=\sup_{\omega\in\Omega}\|F(\omega)\|_E$$  Weak convergence is preserved under continuous operators: $$\|l(Cx_n-Cx)\|=\|(C'l)(x_n-x)\|\to0$$ By uniform boundedness principle weak convergence implies boundedness: $$x_n\rightharpoonup x:\quad\|l(x)\|_\mathbb{N}<\infty\implies\|x\|_\mathbb{N}<\infty$$ Hence one can exploit compactness of the operator: $$(x_n)_{n\in\mathbb{N}}\text{ bounded}\implies C(x_n)_{n\in\mathbb{N}}\text{ precompact}$$ And one obtains strongly convergent subsequences.  Should I combine these now and how?


How much AWG do I need for my circuit wires knowing that the current can vary 10 to 20A with 12V supply  And what is the cheapest and safest way to join 2 wires together ?


So I have a pretty good save on my brothers Playstation, and I was wondering if anyone knows how to use a save from his playstation on to my account on my playstation. A problem that may occur is that my dad and I share a family account so he has the only plus account, but I can just use his account on my profile.  Ask if you need any more information.


I recently got Legend of Zelda: Breath of the Wild and have been trying to complete the Hyrule Compendium. I noticed in a YouTube video that Master Khoga is one of the entires, but unfortunately I already killed him. I don't know if you can revive him in some way but I really want to know if you can so I don't have to restart the game. If it matters I'm playing on the Switch version.


How to unpack a downloaded tar.bz2 archive?

I downloaded YOONO-Desktop from , and I try to install it with the following steps:  [root@localhost mpatil]# tar xfv yoono-destop-1.8.43.tar tar: yoono-destop-1.8.43.tar: Cannot open: No such file or directory tar: Error is not recoverable: exiting now [root@localhost mpatil]# tar xfv yoono-destop-1.8.43 tar: yoono-destop-1.8.43: Cannot open: No such file or directory tar: Error is not recoverable: exiting now   This file is in Desktop/Ram/Downloads. But it is showing an error like "no such file or directory". Why is it showing this error?


How to find the exact time a tweet was tweeted

So on the Twitter website, underneath the post there's a timestamp, but it's not very specific - it will just say something like Jul 10, or 11 hours ago or something like that.  Is there any way to find the EXACT time a tweet was posted?  Like to the second?  I want to avoid messing around with programming or dealing with the API if possible, but I've looked all over, and haven't been able to find anything.


I have samsung galaxy 3 (I5801). I have downloaded many APK files from internet. I have no problem in installing APK files. By default when APK file is selected it installs itself to phone memory. I want it to install application on SDCARD. I have made my phone memory full.   So my queries are   How to install APK on SDCARD? APK should install itself to SDCARD. How to move already installed application to SDCARD from phone memory?


I failed to copy/paste print screen output in my question box. How to copy/paste output of a shell command from terminal screen to askubuntu question box?


How do I install applications in Ubuntu?

How can I install applications like Google Chrome on Ubuntu?  Are there any commands to install an application?    Index of answers:


Deriving different spin Lagrangian from one equation

I'm looking at these three Lagrangian. They are the Lagrangians for spin 1 0 1/2 particles. I have been told that these equations were not 'derived' rather they were guessed and confirmed from experimental data. My question is, using hindsight, is it possible to derive all three of these equations from one equations. That is to say, we have one equation that gives us these three? The Klein-Gordon equation spin 0 $$L=c^2\partial _\lambda \phi \partial^\lambda \phi ^* -\left(\frac{mc}{\hbar}\right)^2\phi \phi^*$$ Dirac Lagrangian spin 1/2 $$L=i\hbar c \tilde\psi \gamma ^\mu \partial _\mu \psi-mc^2\tilde\psi  \psi $$ The Proca equation spin 1 $$L=-\frac{1}{16 \pi}F^{\mu \nu} F_{\mu \nu} +\frac{1}{8 \pi} \left(\frac{mc}{\hbar}\right)^2A^\mu A_\mu$$


Why Normality assumption in linear regression

My question is very simple: why we choose normal as the distribution that error term follows in the assumption of linear regression? Why we don't choose others like uniform, t or whatever?


Is there any media where magnet lose its property?


Cron runs my script but script doesn't do anything, something to do with mail error??? "got status 0x004b#012"

I have a seriously weird problem with one of the Ubuntu 10.10 web servers I administer.  I wrote a script using ruby and rake to run some tar commands and do a mysqldump of the databases.  I've installed an entry in the root users crontab like so:   0 0,12 * * * /bin/bash -l -c 'cd /my/script/path && rake backup:everything'   This is working perfectly on one of the servers.  However on the other this doesn't actually seem to execute whats in my script.  I know it's getting called for definite because when I run  grep CRON /var/log/syslog   it returns:  Mar 22 12:00:01 ServerName CRON[10273]: (root) CMD (/bin/bash -l -c 'cd /my/script/path && rake backup:everything')   However it's definitely not doing whats in that script.  When I directly run the script like this:  cd /my/script/path && sudo rake backup:everything   It works perfectly.  Also I did this in the crontab of both servers:  0 0,12 * * * /bin/bash -l -c 'cd /my/script/path && rake backup:everything >> output.txt'   (as in the script I'm doing a "puts 'backing up x folder'" every so often)  On the server where the cron job is working it creates the output.txt file and puts the expected output in there like "Beginning backup" etc.  However on the server where it isn't working it only creates the file but leaves it empty. But when I copy the command from the syslog again and run it manually:  sudo /bin/bash -l -c 'cd /my/script/path && rake backup:everything >> output.txt'   It works fine and the output is as expected.  I may be clutching at straws now but could it be anything to do with this:   CRON[10271]: (root) MAIL (mailed 55 bytes of output but got status 0x004b#012)   This appears in the syslog after every cron call.  I only really have this cron job and another small one to update the system clock, but from the looks of it none of them are working correctly.  Is an incorrect mail configuration killing my cron jobs?  Is that even possible?


How can I exclude certain contacts from silent mode?

During the night, I set my phone to silent, since even the vibrate wakes me up. Is there some way to let it still vibrate if I get a call from certain contacts?


Is it okay to contract "dog is running" to "dog's running"?

Are the following contractions okay to use:  The man's working on the roof for The man is working on the roof The dog's running behind the ball for The dog is running behind the ball


How to invoke any OSC escape sequence in GNU/screen?

I'm using rxvt (urxvt) terminal with gnu/screen and I experienced that some escape sequences does not get through screen. eg. I issue echo -e '\033]777;qwerty\007' on bare rxvt, it gets through, but within screen, it does not. This ESC + "]777;" + string + BEL sequence is, btw, an rxvt specific escape sequence which triggers a user function in an rxvt extension (plugin). I'm confused why screen eats it, why does it not just let it through? Is there a way for screen to output it in order to be captured by rxvt?


Bad substitution trying to rename extension

I'm trying to convert all wav and mp3 files to ogg files recursively with find and FFmpeg. I have made the following bash script to do so:  #!/usr/bin/env bash  # Converts samples to ogg  find samples \( -iname '*.wav' -o -iname '*.mp3' \) -execdir ffmpeg -i "$(basename "{}")" -qscale:a 6 "${$(basename "{}")%.*}.ogg" \;   This however errors in:  ${$(basename "{}")%.*}.ogg: bad substitution   How would I need to format the last substitution to make it give back the basename of the file suffixed with .ogg, and why does this not work?


Can a degree be revoked for minor misconduct?

I was wondering how possible it would be that, after graduating, the university would investigate a minor misconduct during college. By minor I mean, if found guilty the worst punishment would be / have been a semester suspension.   If you had already graduated, what are the possibilities that the punishment would include revoking your degree?


I'm working on a small project where I have to create a model (nltk) that will predict the tags from questions that may be published on Stack Overflow.  I used this link , and I was hoping there was a place that would explain more in-depth the details of the parameters.  For instance, what is "WikiPostId" in the Tags table? Most of the parameters are self-explanatory, but I fear I will miss some fine tuning.


Short story about government-mandated equality

I am trying to recall a short story I read perhaps 10 years ago. It was a story about a dystopian future where people were not allowed to have any advantage and were artificially handicapped.  What I remember so far:   Intelligent people had an implant that distracted them with a loud noise. People who were too fast were weighed down. Beautiful people were forced to wear ugly masks.


CSS for daily site access calendar on profile page fails to load over HTTPS

Google Chrome: Version 32.0.1700.107 m  This happens when displaying the profile and clicking on the number of visited days/consecutive.  .


How to correctly post a Q&A style question (i.e.self answer) without it failing minimal understanding

As I understand it Q&A style questions are  but a self answered question should be judged independently of the answer. Often after I've solved a problem I would like to share the question and answer on stack overflow (and have on a couple of occasions) but how to show "minimal understanding of the problem" is always challenging. For example I have been looking into the following question  How can I plot a straight line in the JMonkey Engine library I'm trying to plot straight lines between vertices that I specify using the JMonkey Engine 3D graphics library. So for example if I was to try to plot between: (2,0,0) (-1,0,1) (0,1,1) (1,1,1) (1,4,0) Then I would get:   This is something I do (and forget how to do) relatively often and the answer is harder to find than you'd imagine ( provides everything needed to figure it out but its spread out over several posts and isn't a complete solution on its own). Therefore I want to provide a Q&A for it but at present this question feels like it would fail the minimal understanding test  Questions must demonstrate a minimal understanding of the problem being solved. Tell us what you've tried to do, why it didn't work, and how it should work  Should I make up some imaginary problem? (Probably the final source code messed up a bit) Or mention in the question that I’m self answering to assuage some of the normal "This is not a do your work for you site" comments.


I'm trying to display Radio Group horizontally in lwc, but it seems to be not applying my custom css. HTML:  <template>     <lightning-radio-group name="radioGroup"                           label="Radio Group"                           options={options}                           value={value}                           type="radio"                           class="customRadioCls"></lightning-radio-group> </template>   JS:  import { LightningElement, track } from 'lwc';  export default class RadioGroupBasic extends LightningElement {     @track value = '';      get options() {         return [             { label: 'Sales', value: 'option1' },             { label: 'Force', value: 'option2' },         ];     } }   CSS:  .THIS .customRadioCls{     display : inline-block !important; }   In CSS I tried many variation like  .THIS.customRadioCls{         display : inline-block !important;     }   In inspect element I can display horizontally, by applying in standard class, but same is not working from css file.  .slds-form-element__control .slds-radio {     display: inline-block; }


bash variable with quotes and percentage

I want to use a time command in a script and put it into a variable (I will have to use it for many commands) so than I can modify just the single variable.  Simplified, this is how I tried it:  PROFILING="/usr/bin/time -f 'time: %e - cpu: %P'" ; $PROFILING ls /usr   I would expect that to be translated into:  # /usr/bin/time -f 'time: %e - cpu: %P' ls /usr bin  games  include  lib  local  sbin  share  src time: 0.00 - cpu: 0%   However I get this:  /usr/bin/time: cannot run %e: No such file or directory Command exited with non-zero status 127 'time:   Any suggestion?  Thanks


The privilege to participate in Meta is unnecessary

As we all know, the first privilege you earn here is to post here at Meta Stack Exchange. Now what makes this confusing is that the next privilege is to be able to post in Meta... which is also Meta Stack Exchange. This means you only need 1 rep to get a five rep privilege. What?  I suggest that this  (the five rep privilege) gets removed only for Meta Stack Exchange as it is confusing and conflicting.


Do the Lightroom lens correction tools make good lenses less important?

Lightroom has Lens Correction tools such as Distortion, Vignetting, Chromatic Abberation, etc. depending on the brand and model of lens.  Due to this feature, is it less relevant what the distortion quality is of lenses because Lightroom can correct them?  I understand a perfect lens is always better, but since it can save a huge amount of money, maybe the expense is not worth it?


Check if an object in an array of objects is null in java

i have an array of objects, i want to add objects in this array using a method named "AddProd()" .but in order to add in the right case of the array i have to know where the first empty case in the array is .  this is the Add Method :     public void AddProd(Produit p){      int notempty = 0;     int i = 0;     while(produits[i] != null){         notempty++;         i++;     }      if (notempty < 49) {         produits[notempty + 1] = p;     } }   let me explain to you first i have a while loop that checks where the first null case is. the while loop keeps incrementing (i++) till it finds an empty case .  the problem is when i run i get two errors :   Exception in thread "main" java.lang.NullPointerException     at prosit.pkg2.v1.pkg0.Magasin.AddProd(Magasin.java:27)     at prosit.pkg2.v1.pkg0.main.main(main.java:22) Java Result: 1 BUILD SUCCESSFUL (total time: 1 second)   this is (Magasin.java:27) :   while(produits[i] == null){ i think that the comparaison to null is not correct and the second error is when i  call the method in the main class .  Any solutions please and thanks .


How to test the convergence for $\sum _{n=3}^{\infty }\:\left(-\frac{1}{\sqrt{ln\left(n\right)}}\right)^{n+1}$?

How to test the convergence for $$\sum _{n=3}^{\infty }\:\left(-\frac{1}{\sqrt{\ln\left(n\right)}}\right)^{n+1}$$ Can I use the comparison test for this one? For example: $n≥\ln(n)$ $\sqrt{n}\ge \sqrt{\ln\left(n\right)}$ $-\sqrt{n}\le -\ln\left(n\right)$ $\frac{1}{-\sqrt{n}}\ge \frac{1}{-\sqrt{\ln\left(n\right)}}$ and then I use the the p series for p = 1 and say that this diverges? or can I only use this inequality for convergent? Thanks :)


When a recipe calls for a cup of chopped nuts, should they be measured before chopping or after chopping?

It seems like it would throw off recipe since you can fit more in once they are chopped?


$n \mid (a^{n}-b^{n}) \ \Longrightarrow$ $n \mid \frac{a^{n}-b^{n}}{a-b}$

How does one prove that if $n \mid (a^{n}-b^{n}) \ \Longrightarrow$ $ \displaystyle n \mid \frac{a^{n}-b^{n}}{a-b}$ where $a,b, n \in \mathbb{N}$.  What i thought of is to consider $$(a-b)^{n} \equiv a^{n} + (-1)^{n}b^{n} \ (\text{mod} \ n)$$ and if we suppose that $n$ is odd then we have, $$(a-b)^{n} \equiv a^{n} -b^{n} \ (\text{mod} \ n)$$ and since $n \mid (a^{n} - b^{n})$ we have $$(a-b)^{n} \equiv 0 \ (\text{mod} \ n) $$  I think i am far away from the conclusion of the problem, but this is what i could work on regarding the problem.


Adding the "Clear" Button to an iPhone UITextField

How do you add that little "X" button on the right side of a UITextField that clears the text?  I can't find an attribute for adding this sub-control in Interface Builder in the iPhone OS 2.2 SDK.  Note: In Xcode 4.x and later (iPhone 3.0 SDK and later), you can do this in Interface Builder.


How to restore lock screen option in settings?

My lock screen option from settings is gone, and neither Windows+L nor Ctrl+Alt+L are locking the screen - they are simply turning it off. When I move the mouse, no password is prompted for before resuming operation.  How can I restore the missing locking functionality?  Using Ubuntu 17.10.


NullPointerException While adding JLabel to JPanel

Im getting this strange NullpointerException whilst adding a JLabel to a JPanel:      loadoutAdvWeaponPanels = new JPanel[4][4];     loadoutAdvWeaponButtons = new JButton[4];     loadoutAdvPistolLabels = new JLabel[4][8];      //Init loadoutAdvPanels[0]      loadoutAdvWeaponButtons[0] = new JButton("Pistols");      loadoutAdvPistolLabels[0][0] = new JLabel("USP-S");     loadoutAdvPistolLabels[0][1] = new JLabel("P2000");     loadoutAdvPistolLabels[0][2] = new JLabel("Dual Berettas");     loadoutAdvPistolLabels[0][3] = new JLabel("P250");     loadoutAdvPistolLabels[0][4] = new JLabel("Five-SeveN");     loadoutAdvPistolLabels[0][5] = new JLabel("CZ75-Auto");     loadoutAdvPistolLabels[0][6] = new JLabel("Desert Eagle");     loadoutAdvPistolLabels[0][7] = new JLabel("R8 Revolver");      loadoutAdvWeaponPanels[0][0].add(loadoutAdvPistolLabels[0][0]);   The error occurs in the last line, but i dont know why.


To prove $(\sin\theta + \csc\theta)^2 + (\cos\theta +\sec\theta)^2 \ge 9$

I used the following way but got wrong answer $$A.M. \ge  G.M.$$ $$ \frac{\sin \theta + \csc  \theta}{2} \ge \sqrt{\sin \theta \cdot \csc \theta}$$ Squaring both sides, \begin{equation*} (\sin\theta + \csc\theta )^2 \ge 4 \tag{1}  \end{equation*} Similarly \begin{equation*} (\cos\theta + \sec\theta )^2 \ge 4 \tag{2} \end{equation*} Adding equation (1)  and (2)  \begin{equation*} (\sin\theta + \csc\theta )^2+(\cos\theta + \sec\theta )^2 \ge 8 \end{equation*} What is wrong?


I am trying to find out if it is possible for users of different Xbox's (an Xbox-360 & an Xbox One) to play Minecraft together, in the same world over the Internet.


I was reading the  class and feel confused by how the eidolon "heals"     A summoner can summon his eidolon in a ritual that takes 1 minute to perform. When summoned in this way, the eidolon's hit points are unchanged from the last time it was summoned. The only exception to this is if the eidolon was slain, in which case it returns with half its normal hit points. The eidolon does not heal naturally.   From the way I read this:   Eidolons never recover any HP from resting Eidolons do not regain HP when summoned or unsummoned unless they were killed Eidolons are resummoned with whatever HP they had remaining (provided it wasnt killed)   So my question is, is the only way to have it with full HP be the very first time its summoned or have it healed with magic?


Can two different topological spaces cover each other?

I.e. do there exist non-homeomorphic $X$, $Y$ and covering maps $f:X\rightarrow Y$, $g: Y\rightarrow X$?  I have a basic understanding of covering space theory as its taught in school.  I was inspired by this question   I have done some of the things you would do, looking at what happens to fundamental groups.  And I've tried to find counter examples by drawing  graphs.


Allow me to get notifications for new Meta posts, like mods do

I'm currently helping out on . One of the most valuable things on new beta sites, especially private/early public betas, is Meta participation - see :  Treat Meta Questions Like Gold It’s not unusual for your meta site to receive significantly less traffic than the main site. The problems begin when you meta starts to get ignored by the community and ignored by the moderators. It is particularly disturbing when users reach out in meta and starts talking about improving the site or asking for help… only to be ignored; No follow-up, only deafening silence  Because of this, Diamond mods get a notification in their inbox for each new question on their Meta, helping ensure that each meta post is addressed. However, wouldn't it be great if Diamond mods weren't the only ones that could do this? The post does say that the community needs to be seeing these questions too. As an involved user, I would really like to be notified of these new questions - it would increase the good I could do the site. How about this?:  Of course, it would be opt-in, not opt-out, and per-site. A feature like this would greatly improve the good that enthusiastic site-builders can do for the site, and would, most likely, increase the overall chances of a site's success.


Why does BLAST use Local alignment, not Global alignment? And when would a global alignment be useful?


How to edit the format of citations? E.g. author et al, where "et al" must be italic?

\documentclass[review]{elsarticle} \usepackage{lineno,hyperref} \usepackage{pdflscape} \usepackage{caption} \usepackage[singlelinecheck=off]{caption} \usepackage{longtable} \usepackage{booktabs} \usepackage{pdflscape} \usepackage[margin=2.5cm]{geometry} \usepackage{natbib} %Import the natbib package and sets a bibliography  and citation styles \bibliographystyle{agsm} \setcitestyle{authoryear,open={(},close={)}}  \begin{document} provide safe and hygienic environment to worker \citep{davim2007turning}, \section*{References} \bibliography{file} \bibliographystyle{sample} \end{document}     The reference is given in the image, where there is normal formatted "et al.", I need it in italic form.


we have a cron job that run every Saturday at 01:00 (0 1 * * 6) we want to modified to run every 2 weeks on Saturday at 01:00.  Thanks.


How to Remove Horizontal Lines From Colored Multirow Table

I am having some trouble removing the "white lines" from a colored table (where it says 3 and 4).    \documentclass{report}  \usepackage{wrapfig} \usepackage{colortbl} \usepackage{booktabs} \usepackage{multirow} \usepackage{hhline} \usepackage[table,xcdraw]{xcolor} \usepackage{graphicx}  \definecolor{lightgray}{rgb}{0.75,0.75,0.75} \definecolor{darkgray}{rgb} {0.50,0.50,0.50}  \begin{document} \begin{wraptable}[12]{r}[0cm]{5cm}     \vspace{-1cm}     \resizebox{5cm}{!}{         \begin{tabular}{c|c|c}             \hline             \textbf{Binary}    & \textbf{ICDR}      & \textbf{ETDRS}                                             \\ \hline             0                  & 0                  & No DR                                                      \\ \hline             &\cellcolor{lightgray}1                   & \cellcolor{lightgray}Very mild NPDR   \\ \hhline{~|--}              &\cellcolor{lightgray}2                   & \cellcolor{lightgray}Mild NPDR        \\ \hhline{~|--}             &\cellcolor{lightgray}                    & \cellcolor{lightgray}Moderate NPDR    \\ \hhline{~~|-}             &\cellcolor{lightgray}                    & \cellcolor{lightgray}Severe NPDR      \\ \hhline{~~|-}             &\cellcolor{lightgray}\multirow{-3}{*}{3} & \cellcolor{lightgray}Very Severe NPDR \\ \hhline{~|--}             &\cellcolor{darkgray}                     & \cellcolor{darkgray}\begin{tabular}[c]{@{}c@{}}Mild - Moderate\\ PDR\end{tabular}          \\ \hhline{~~|-}             &\cellcolor{darkgray}                     & \cellcolor{darkgray}High-Risk PDR                                                          \\ \hhline{~~|-}             \multirow{-8}{*}{1}&\cellcolor{darkgray} \multirow{-3}{*}{4} & \cellcolor{darkgray}\begin{tabular}[c]{@{}c@{}}Advanced Diabetic\\ Eye Disease\end{tabular}\\ \hhline{---}     \end{tabular}}     \caption{\label{tab:dr_classes}Sample Caption.} \end{wraptable}]  \end{document}   Any information is appreciated.


How to remove the 'tile' background in the launcher icons?

First let me show my launcher :-     I feel my launcher is made to look ugly by the 'square-tile-thing'(for the lack of a better word) thats behind the icon. I want the icons alone to be viewed(without the tile behind). So are there any ways to remove the 'square-tile-thing' ?  PS:- I am using Ubuntu 14.04 LTS with unity. By 'square-tile-thing' I mean the square that is around each icon. (See the picture above or see your own launcher!)


I have a correlated sub query, which is taking 16 Minutes to execute.  How can I convert it to join or optimize it.  SELECT SSF.SM_StockCode, SSF.ST_ItemSize FROM  Stock AS SSF      WHERE SSF.SM_StockCode = (         SELECT SM_StockCode         FROM  Stock AS SSFAI         WHERE SSFAI.ST_StockCode = SSF.ST_StockCode         ORDER BY SSFAI.ST_ItemSize ASC         LIMIT 1     ) GROUP BY SSF.SM_StockCode   UPDATE : Added Explain Plan  +----+--------------------+-------+-------+-------------------+------------------+---------+------+-------+----------------------------------------------+ | id | select_type        | table | type  | possible_keys     | key              | key_len | ref  | rows  | Extra                                        | +----+--------------------+-------+-------+-------------------+------------------+---------+------+-------+----------------------------------------------+ |  1 | PRIMARY            | SSF   | ALL   | NULL              | NULL             | NULL    | NULL | 45180 | Using where; Using temporary; Using filesort | |  2 | DEPENDENT SUBQUERY | SSFAI | index | ST_StockCode_Indx | ST_ItemSize_Indx | 9       | NULL |     1 | Using where                                  | +----+--------------------+-------+-------+-------------------+------------------+---------+------+-------+----------------------------------------------+   UPDATE : Table Structure  CREATE TABLE `Stock` (  `id` int(11) NOT NULL AUTO_INCREMENT,  `ST_StockCode` varchar(20) NOT NULL,  `SM_StockCode` varchar(20) NOT NULL,  `ST_ItemSize` decimal(18,2) NOT NULL,  PRIMARY KEY (`id`),  KEY `ST_StockCode_Indx` (`ST_StockCode`),  KEY `SM_StockCode_Indx` (`SM_StockCode`),  KEY `ST_ItemSize_Indx` (`ST_ItemSize`) ) ENGINE=MyISAM;


How do I prove that the sets x = {y}, y = {z} and z = {x} can’t exist with the axiom of regulation/foundation in ZFC?

How do I prove that the sets $x = \{y\}, y = \{z\} \text{ and } z =\{x\}$ can’t exist with the axiom of regulation/foundation in ZFC?  I’m having the damnest time trying to prove this since the sets are not assumed to be transitive sets.    I’ve tried using powersets and union operations but these have brought me no luck thus far. I’m beginning to wonder whether or not this is possible to prove.


If someone asks me "would you give me your bike", which one of the following will be the usual reply?   1- No, I won't give you my bike.   2- No, I wouldn't give you my bike.   My question is should I be using 'would' to reply as the question is asked with 'would'?


Differences of $V_1 \cup V_2$ and $V_1 +V_2$?

Let $V_1,V_2$ are subspaces of vector space  $V$ . Differences of $V_1 \cup  V_2$ and $V_1 +V_2$ ?


I need to flip/mirror the full PCB along the Y axis. Is there any option to do that in Altium Designer?  I only find info about how to mirror a single component but no the full PCB


Cannot connect to MS Access using UCanAccess

I'm using DbVisualizer Free 11.0 [Build #3077]  OS: Windows 10  OS Arch: amd64  Java Version: 1.8.0_242  Java VM: OpenJDK 64-Bit Server VM  Trying to create UCanAccess driver using the following theme:    But the current versions are different and now my Driver Manager looks like this:   Seems to be, it's ok, but when I try to connect I see the following message:    Where am I wrong? Quotes or spaces in Path? Jars versions? Jars should be placed in defined place?  Thanks a lot.


Bye Windows Defender, I need to turn you back off again

I am running Windows 10 on a fairly recent laptop. I'm using Avast (free version) as antivirus and before the update, Windows Defender was turned off as it should be in case a third party antivirus is installed.  Yesterday I received a notification of an available update for the OS. I ran the update on shut down, and this morning when turning the computer on, it completed the updating procedure in about 1 hour.   The update, as far as I can tell, restored a lot of bloatware that was installed on the PC at the time of the purchase, installed some additional Visual Studio components and some new applications, and it turned on Windows Defender.   I find this all weird since Avast was (and still is) running fine as usual, but now I have a resource hog (Windows Defender) sucking on my PC resources. Furthermore Cortana is running in the background even though I disabled it...   Why has this thing happened and how can I turn Windows Defender off? Since apparently it has not detected that Avast is running, it somehow turned itself back on again.