Justification for the way s is computed in DSA?

I am sorry if this is a naive question but is there any justification for the way that s is computed in the DSA signature algorithm:  $$ s = k^{-1} * (rx + m) $$  This looks to me like a very arbitrary combination of $k$, $r$, $x$ and $m$. Is this just one particular way that's found to work or does it actually have some kind of structure/reason behind it that I am missing?


how to convert bytes to string in Python 3

I want to write a function that returns a string, not bytes.   the function:  def read_image(path):     with open(path, "rb") as f:         data = f.read()     return data image_data = read_image("/home/user/icon.jpg")   How to convert the value image_data to type str. If convert to string successfully, how to reconvert the string to bytes.


Is there a way to print a snapshot of a job that's in the background to standard output?

If I have a job that's running/paused in the background, is there a way of printing a snapshot of its activity to standard output?


Asserting that Atheism and Theism are both faith based positions

I am recently testing an assertion that I have concluded namely that atheism is a faith based position just like theism is a faith based position.  The reason I arrived at this conclusion is that theists have no proof that God actually exists. It's purely a matter of faith. Yes, there maybe strong implicit proof that God exists in their opinion (scriptures, history, etc) but there is no concrete proof of God's existence. In my view, atheists also suffer from the same problem of providing a proof of their position. Specifically that they cannot prove that God is non-existent.  The typical rebuttal I get is that the burden of proof is on the theists. But I view this as a cop out and they hide behind the wall of burden of proof which is just a bias in the debate.  Given the above, I claim that both atheism and theism are positions based on faith. Would it be incorrect to claim that?


there was windows 8 before on my laptop and the wifi was working without a trouble. After I ve  installed Ubuntu 14.04 the wifi connection is not visible (there is the icon available on the upper panel, but no wireless option visible).  Thank you in advance for help. MB


Is there any application that provides a color picker for the screen?  For example: after starting the application the mouse is transformed into a color picker. Clicking anywhere on the screen it will detect the pixel color.


Contents section number and name clashing. Want to increase spacing

I am using Roman Numerals for the contents page however this is clashing with the section title as shown in the image. Is it possible to increase the spacing between these two?  Many thanks in advance.


How do I replace this cast iron toilet flange?

I have a big old gawd awful cast iron (at least I think it's cast iron, the house was built in 1940) toilet flange that is in sorry shape.  See?   There will never be a better time to replace it - as we have the floor above and ceiling below it open, and it desperately needs it, obviously.    I have never done anything with cast iron before, however, and do not know how I should proceed.  Should I break the pipe back on the long straight stretch and connect to pvc using a rubber connector like this?    Or should I focus on just trying to replace the flange (which seems much more difficult to me...)  I know cast iron is hard to cut - is a grinder going to be more effective at cutting this stuff?  (Huge mess for the kitchen below :( - but I can hang trash bags or something underneath I suppose...)      UPDATE 5 Nov 2012  The end result:


Postgres: How is SET NOT NULL "more efficient" than CHECK constraint

In , it says     A not-null constraint is functionally equivalent to creating a check constraint CHECK (column_name IS NOT NULL), but in PostgreSQL creating an explicit not-null constraint is more efficient.   I'm wondering   What exactly does it mean by "more efficient"? What are the detriments of using CHECK (column_name IS NOT NULL) instead of SET NOT NULL?   I want to be able add a NOT VALID CHECK constraint and validate it separately (so the AccessExclusiveLock is only held for a short period of time for the adding of the constraint and then a ShareUpdateExclusiveLock is held for the longer validation step):  ALTER TABLE table_name   ADD CONSTRAINT column_constraint   CHECK (column_name IS NOT NULL)   NOT VALID; ALTER TABLE table_name   VALIDATE CONSTRAINT column_constraint;   Instead of:  ALTER TABLE table_name   ALTER COLUMN column_name   SET NOT NULL;


How can I find out how many lines a text file contains without viewing it?

How can I find how many lines a text file contains without opening the file in an editor or a viewer application? Is there a handy Unix console command to see the number?


Is opening a new credit card worth the potential impact?

I'm trying to decide whether or not I should open up a second credit card. The primary reason is to have a backup credit card in case my only (and oldest) card is cancelled/eliminated for any reason. Length of credit history is 15% of your credit score, and I do not want to put all of my eggs in one basket. The second reason is to simply get a credit card with better rewards.  Currently, I pay my credit card off in full every month, and have done this for the past several years. I also have a car loan and a student loan (I'm not sure how these factor into my credit score). My credit score is 760+.  I'm aware that opening a new credit card can temporarily hurt your credit score by being a "hard pull" against your credit score, but what I'm more concerned about is that the second credit card will cut my "average length of credit history" in half. As an example, if my current credit card has been open for 10 years and I open up a brand new card - my "average length of credit history" will plummet from 10 years to 5. Is this a reasonable fear?  Aside from that, is my rationale valid for wanting a second credit card? Or is it safe to ride out one credit card for life?


Proving the set of points at which a function diverges to $\infty$ is countable

Let $f\colon\mathbb{R}\to\mathbb{R}$. Prove that the set    $$\{x \mid \mbox{if $y$ converges to $x$, then $f(y)$ converges to $\infty$}\}$$ is countable.   My book told me to consider  $g(x)=\arctan(f(x))$, then it said "it is easy to see the set is countable." But I still can't understand what it mean.


hyperref is pointing always to the first page of the document

I am typing my thesis in LaTeX. I used hyperref. Two papers are in the bibliography. Paper no 1 is cited in the first page and paper no 2 is cited in the 2nd page.   When I am clicking the red coloured number below the paper number 1 in the bibliography it is pointing wrongly to the title page of the document. But there is NO PROBLEM with paper no 2. Please help me. I want the paper number 1 to point the correct page.  Also in my document, I don't want "Chapter 0, Synopsis". I want only "Synopsis" i.e. no mention of chapter 0 mark. This I want only for this chapter not in the later chapters. I also want synopsis to occur in the content of the document. Please help me to figure out this.  I am attaching my .tex code below.  \documentclass[12pt, reqno, a4paper]{book}  \usepackage{fancyhdr}%, setspace}  \usepackage[pagebackref]{hyperref} \hypersetup{      colorlinks = true, linkcolor = red,      citecolor   = blue,      urlcolor    = blue, }   \begin{document}  \begin{titlepage} \begin{center} {\bf Title page} \end{center}  \end{titlepage}     \pagestyle{plain} \pagenumbering{roman} \addtocounter{page}{1}   %\thispagestyle{empty}  $\textnormal{ }$ \vspace{9cm}  \begin{center} {\bf \Large{To my Parents}} \end{center}   {\Large \tableofcontents}  \pagestyle{fancy} \renewcommand{\chaptermark}[1]{\markboth{\chaptername\ \thechapter.\ #1}{}} \renewcommand{\sectionmark}[1]{\markright{\thesection\ #1}} \renewcommand{\headrulewidth}{0.1pt} \renewcommand{\footrulewidth}{0.1pt} \fancyhf{} \fancyhead[LE,RO]{\bfseries\thepage} \fancyhead[LO]{\bfseries\rightmark}  \fancyhead[RE]{\bfseries\leftmark} \lfoot{Anjan Gupta, TIFR, Mumbai.}     \pagenumbering{arabic} \setcounter{chapter}{-1}  % to start Chapter numbers from 0  \chapter{synopsis} \setcounter{page}{1} In \cite[Theorem 4.1]{cr} it is shown that this is indeed true in the absolute case.  \newpage  we shall now use the result \cite{sfmaa}  \begin{thebibliography}{VAST}  \bibitem{cr} Paper 1.  \bibitem{sfmaa} Paper 2.  \end{thebibliography}  \end{document}


Can't connect to dedicated video card using vga_switcheroo

So I have an Intel 5500 as integrated GPU and AMD R5 M430 as Dedicated (Discrete) GPU, I installed Oibaf's Drivers and vga_switcheroo and I want to switch to the Dedicated GPU, forever.  Here's the output for sudo cat /sys/kernel/debug/vgaswitcheroo/switch 0:IGD:+:Pwr:0000:00:02.0 1:DIS: :DynOff:0000:0d:00.0  And when I do sudo echo OFF > /sys/kernel/debug/vgaswitcheroo/switch which is connecting to the Dedicated GPU, I get this error bash: /sys/kernel/debug/vgaswitcheroo/switch: Permission denied  How can I connect to the Dedicated (AMD) GPU, and do I need to connect everytime I reboot my laptop?


Sudo PM2 command not found but works without

I have a PM2 process for my NodeJS server and it crash after few minutes. I read somewhere I need to run PM2 as root to not crash. So I do : debian@vps:~$ pm2 start server [PM2] Applying action restartProcessId on app [server](ids: [ 1 ]) [PM2] [server](1) ✓ [PM2] Process successfully started ┌────┬────────────────────┬──────────┬──────┬───────────┬──────────┬──────────┐ │ id │ name               │ mode     │ ↺    │ status    │ cpu      │ memory   │ ├────┼────────────────────┼──────────┼──────┼───────────┼──────────┼──────────┤ │ 1  │ server             │ fork     │ 991  │ online    │ 0%       │ 13.8mb   │ └────┴────────────────────┴──────────┴──────┴───────────┴──────────┴──────────┘ Current process list running is not in sync with saved list. App app differs. Type 'pm2 save' to synchronize. debian@vps:~$ pm2 stop server [PM2] Applying action stopProcessId on app [server](ids: [ 1 ]) [PM2] [server](1) ✓ ┌────┬────────────────────┬──────────┬──────┬───────────┬──────────┬──────────┐ │ id │ name               │ mode     │ ↺    │ status    │ cpu      │ memory   │ ├────┼────────────────────┼──────────┼──────┼───────────┼──────────┼──────────┤ │ 1  │ server             │ fork     │ 991  │ stopped   │ 0%       │ 0b       │ └────┴────────────────────┴──────────┴──────┴───────────┴──────────┴──────────┘ Current process list running is not in sync with saved list. App app differs. Type 'pm2 save' to synchronize.  debian@vps:~$ sudo pm2 start server sudo: pm2: command not found  So I can't run it as root?


I have a text file :  20160906000001     // header with dateTime = 20160906 and code = 000001 name0100000152255  // body with name = name01 and reference = 00000152255 name0200000152256  // body with name = name02 and reference = 00000152256 name0300000152257  // body with name = name03 and reference = 00000152257   and class :  public class file {     public header header { get; set; }      public List<body> body { get; set; } }  public class header {     public string dateTime { get; set; }      public string code { get; set; } }  public class body {     public string name { get; set; }      public string reference { get; set; } }   I want to create a instance of my class file from the text file :    property datetime in header have always 8 chars property code in header have always 6 chars property name in body have always 6 chars property reference in body have always 11 chars   What is the best way to do this?


Why is the Laplacian of $1/r$ a Dirac delta?

How does one show that $\nabla^2 1/r$ (in spherical coords) is the Dirac delta function ? Intuitively, it would seem that the function undefined at the origin and I'm not able to construct a limiting argument that avoids this problem.


A short question today about the usage of "be" without using "to" in front of it.  Here is an example of each situation: 1. "He requested that the new car be fast." 2. "He requested for the new car to be fast."  Are these both correct, or is example 1 a bit funny?


I have an Early 2015 MacBook Pro Retina, which I hard-restarted earlier (holding the power button) due to a software crash. It turned off just fine but refused to turn back on again (no backlight, no drive noise, nothing). I thought I remembered a fairly high battery percentage, but to be sure I connected it to power and tried again, unsuccessfully. I left it for a while, then tried an SMC reset with the adapter connected.   This seemed to work, since the power indicator light turned green for a few seconds (which makes sense). This somewhat fixed the issue in that the machine actually showed signs of life when I tried turning it back on, but it would just display a black screen with the red/white low battery symbol and the lightning bolt underneath it.   I left it charging for a while and then had to disconnect it for about an hour to take it with me. When I plugged it back in, it actually powered on and booted up successfully. However, the battery indicator is now perpetually at 0%, and the battery info is rather disturbing:  Battery Information:  Model Information:    Manufacturer: SMP   Pack Lot Code:    0   PCB Lot Code: 0   Firmware Version: 702   Hardware Revision:    1   Cell Revision:    3217  Charge Information:    Charge Remaining (mAh):   0   Fully Charged:    No   Charging: No   Full Charge Capacity (mAh):   1708   Health Information:   Cycle Count:  564   Condition:    Replace Now   Battery Installed:    Yes   Amperage (mA):    0   Voltage (mV): 8421   I've also tried an NVRAM reset, with no change. I read somewhere that doing an SMC reset while booted up and logged in solved similar problems in some cases, but that seems a bit risky as far as my data is concerned.  I'd really appreciate any ideas - thank you!  EDIT  I should also mention that the charger light isn't doing anything unusual (i.e. not turning on when the charger is connected). Also, the machine is noticeably slower than when everything was working normally.


Problem  I am trying to draw a tree diagram with forest package. I have multiline children including the \texttt command and a one-line child with normal text. This results in a misalignment among the children, as you can see from the picture below.    I would like all children to be top-aligned. How can I achieve that?  MWE:  % Class \documentclass[10pt]{article}  % Forest package \usepackage[edges]{forest}  %Defining the styles used in trees \tikzset{standard/.style={align=center,text width=3cm,rounded corners=2pt},     wide/.style={align=center,text width=4.2cm,rounded corners=2pt},     narrow/.style={align=center,text width=2cm,rounded corners=2pt} }  % Document \begin{document}     \begin{figure}[hbt!]         \centering         \begin{forest}             for tree={%                 %               grow'=0,                 l sep=0.5cm,                 s sep=0.1cm,                 minimum height=0.8cm,                 minimum width=2cm,                 draw%             },             forked edges,             [\texttt{Parent} object, standard                 [\texttt{AStandardChild} object, standard]                 [\texttt{VeryVeryVeryLongChild} object, wide]                 [Other, narrow]             ]         \end{forest}     \end{figure} \end{document}   Attempted solution  I tried to use some additional for tree options inspired by . In this attempt I need to force the line break (\\) of the long tree elements because that would not happen automatically. The misalignment is reduced but it is still present.    MWE:  % Class \documentclass[10pt]{article}  % Forest package \usepackage[edges]{forest}  %Defining the styles used in trees \tikzset{standard/.style={align=center,text width=3cm,rounded corners=2pt},     wide/.style={align=center,text width=4.2cm,rounded corners=2pt},     narrow/.style={align=center,text width=2cm,rounded corners=2pt} }  % Document \begin{document}     \begin{figure}[hbt!]         \centering         \begin{forest}             for tree={%                 %               grow'=0,                 l sep=0.5cm,                 s sep=0.1cm,                 minimum height=0.8cm,                 minimum width=2cm,                 parent anchor=south, child anchor=north, align=center, base=top,                 draw%             },             forked edges,             [\texttt{Parent} object, standard                 [\texttt{AStandardChild}\\object, standard]                 [\texttt{VeryVeryVeryLongChild}\\object, wide]                 [Other, narrow]             ]         \end{forest}     \end{figure} \end{document}


I have often written sentences in the following form which combines a statement with a question, separated by a semicolon. For example,      I understand you have received payment for my order; will it ship by Monday?   Is this use of the semicolon correct, and is the semicolon commonly used in questions?


SpiceJet flight Goa to Hyderabad cancelled but no refund

I booked four SpiceJet tickets for my return journey Goa to Hyderabad for 15th Dec 2014.  That day at 9:45 AM I got an SMS "flight cancelled and call us for reschedule". Everybody knows that SpiceJet people never pick up and talk to customers. So I couldn't reschedule. I booked a bus and came back to Hyderabad along with my family, travelling the whole night with lots of pain with my little kids. SpiceJet spoiled our vacation joy.  Now on the SpiceJet site they don't mention anything about a refund.    Do I get my ticket money refunded? Do I need to do any thing for that? Will they automatically process a full refund to my card/account? Can I put a case in a consumer forum for the inconvenience/pain caused?


How to run a script directly when double clicked?

To execute a script, I have to:   Write the script Make it executable Double click it, which shows this window:   Click the "Run" button.    How can I execute the script directly, without showing the dialog?


I'm struggling with my model (below), since despite some hyperparameters tuning i always end with a sudden rise of the loss function and then a 'infinite" plateau. My hypothesis were: -learning rate and local minima issue? i tried several (1e-3,1e-4) -Optimizer issue? i tried SGD for example -Too complex model? i removed some layers or neurons -Metric issue? i tried MAE Among theses hypothesis and perhaps others, which one seems the most likely ? I looked for differents curve patterns but didn't find this one.  timeseries = Input(shape=(1536,2), name='timeseries') #1536 time steps, and 2 features features = Input(shape=(22,), name='features')  #22 features  y=LSTM(256)(timeseries) #256 y=Dropout(0.20)(y) y=Flatten()(y)  x=Dense(28, activation='relu')(features) #14 x=Dense(14, activation='relu')(x) #14 x=Dense(14, activation='relu')(x) #7  #z = concatenate([x, y]) z=Concatenate(axis=1)([x,y]) z=Dense(64, activation='relu')(z) #64 z=Dense(64, activation='relu')(z) #64 x=Dense(32, activation='relu')(x) #32 x=Dense(16, activation='relu')(x) #16 z=Dropout(0.40)(z)  outputP = Dense(1, activation='softplus')(z) outputR = Dense(1, activation='softplus')(z) outputC = Dense(1, activation='softplus')(z)  modelLSTM256NN = Model(inputs=[timeseries,features], outputs= [outputP,outputR,outputC]) opt = Adam(lr=1e-3) #1e-3  modelLSTM256NN.compile(optimizer=opt, loss='mse')  Thanks!!


Prove that $ k[x,y]/(x^3 - y^2)$ is not a UFD.

I want to prove that: the integral domain $k[x,y]/ (x^3 - y^2)$ is not normal and find its integral closure in its field of fractions. I know that I will use the idea that $UFD \implies$ normal and hence not normal means not $UFD$ so what I should show is that $k[x,y]/ (x^3 - y^2)$ is not a UFD and I have read a hint here  to consider $x = (y/x)^2.$but I can not see how that will show that it is not a UFD. could someone elaborate this to me please? Also, what is the field of fraction of this integral domain? I know that a unique factorization domain is an atomic integral domain in which factorization to irreducibles is unique (up to associates). And a commutative ring is atomic if each $r \in R$ is a finite product of irreducibles in R. Also, a ring $R$ is a normal ring if $R$ is an integral domain that is integrally closed in $\operatorname{frac}(R).$ And $R$ is integrally closed in a commutative ring $S$ iff the integral closure of $R$ in $S$ (int($R$)) equals $R$. And int($R$) consists of all $x \in S$ that is integral over R. And note that an element is integral over $R$ if there exists a monic polynomial $f(x) \in R[x]$ such that $f(x) = 0.$


How do I manually install Adobe Flash player for Chromium?

I'm using Xubuntu 16.04.1  For external reasons I cannot use apt-get.  I downloaded flash_player_ppapi_linux.x86_64.tar.gz and have extracted it but I don't know where to put each of the files, the readme does not have instructions.  In the archive are a few legal text files, the readme, libpepflashplayer.so and manifest.json.


Where can I find the source code of Ubuntu?

I would like to know where to find the source code of Ubuntu. I'd like to see how far it is "open source".


Why is rendered viewport faster than rendering individual frames?

When I'm using rendered viewport it initially takes a while before rendering starts, but once it does, I can freely move around and rendering a new view happens almost instantaneously. When on the other hand I'm rendering a movie, for each frame Blender takes a significant amount of time before rendering even starts, usually doing the following:  Synchronizing object, Updating images, Updating meshes, Updating Scene BVH, Packing BVH,  Why does it do this? And is it possible to disable this to increase movie rendering speed?


Generalization of convolution operation?

In integral transforms, convolution is defined by $$ (f*g)(t)=\int_{-\infty}^\infty f(\tau)g(t-\tau)\mathrm d\tau $$ satisfying the commutative, associative property, and $$ \mathcal F\{f*g\}=\mathcal F\{f\}\cdot\mathcal F\{g\} $$ where $\mathcal F\{\cdot\}$ denotes Fourier transform. Previously, I thought this operation is only dedicated to this property, but when I began learning other branches of mathematics, I found other operations that resembled convolution: For instance, the product of two power series satisfies $$ \sum_{n\ge0}a_nx^n\cdot\sum_{k\ge0}b_kx^k=\sum_{m\ge0}\left(\sum_{0\le r\le m}a_rb_{m-r}\right)x^m $$ Likewise, the product between two Dirichlet series also produces a similar pattern: $$ \sum_{n\ge0}{f(n)\over n^s}\cdot\sum_{k\ge0}{g(k)\over k^s}=\sum_{m\ge0}{1\over m^s}\left[\sum_{d|m}f(d)f\left(\frac md\right)\right] $$ Since this phenomenon occurs in many parts of mathematics, I wonder whether there is a more-abstract, more-generalized algebraic structure that can be extracted from these formulae.


I have the following code that I run on my Terminal.  LC_ALL=C && grep -F -f  genename2.txt hg38.hgnc.bed > hg38.hgnc.goi.bed   This doesn't give me the common lines between the two files. What am I missing there?


I like to go get coffee while the computer starts. However we have a policy that says the screen must be locked when away.  How can I make sure that the screen locks immediately after logging in?


Slow image review after long exposure shot

When I use the Bulb function for long exposure shots on my Canon 60D, I find the Image Review afterwards takes for ever to appear...  the camera displays 'busy' for nearly as long as the exposure took.  It does not seem right.  Any suggestion re settings?


Does a lecturer need to cite their teaching material?

My lecturer uses powerpoints as a teaching material. During the first class she told me that we are using a book as resource for our class. But one day I realised that some parts are not from the book. So the question is: should she provide the reference she use? IMO, she should tell us what she is basing her teaching on.


How to solve the problem that "File `pdftexcmds.sty' not found. \RequirePackage{pdftexcmds}[2018/01/30]"?

Coding:  \documentclass{ctexart}  \usepackage[style=numeric, backend=biber]{biblatex}  \addbibresource{test.bib}  \begin{document}     \cite{hubert_how_1990}      \parencite{_tex_2019}      \supercite{_xml-tex-pdf_201}      \printbibliography  \end{document}   Log File:  ! LaTeX Error: File `pdftexcmds.sty' not found.  Type X to quit or <RETURN> to proceed, or enter new name. (Default extension: sty)  Enter file name:  ! Emergency stop. <read *>   l.37 \RequirePackage{pdftexcmds}[2018/01/30]                                             ^^M *** (cannot \read from terminal in nonstop modes)   Platform: TexLive2019，Windows10 64bit  Compiler: XeLaTeX, Bibliography Tool: Biber


Problem: Let $A$ be a $2\times 2$ real matrix with exactly one eigenvalue $\lambda \in \mathbb{R}$, but that $A \not= \lambda I $, show that there exists an invertible matrix $P$ such that    $$ P^{-1}AP = \pmatrix{\lambda&1\\0&\lambda}$$   What I have at most:   Firstly, if $\lambda \in \mathbb{R}$ is an eigenvalue, then $(A - \lambda I )\mathbf{v} = 0$ for a nonzero vector $\mathbf{v} \in \mathbb{R}^2$. And if $A - \lambda I \not = 0 $, this means the eigenspace of $\lambda$ is precisely of dimension $1$.   Therefore, exists $\mathbf{t}$ such that and $\mathbf{t}$ and $\mathbf{v}$ are linearly independent, and $A \mathbf{t} \not= \lambda \mathbf{t}$. So $A \mathbf{t} = \alpha \mathbf{v} + \beta \mathbf{t} $. where $\alpha \not= 0$ (since otherwise $\beta$ would be an eigenvalue). Giving,  $$ A \frac{\mathbf{t}}{\alpha} = \mathbf{v}  + \beta \frac{\mathbf{t}}{\alpha}$$  Thus, letting  $$P = \big[ \mathbf {v} \quad \frac{1}{\alpha}\mathbf{t} \big]$$ where they are column vectors, yields   $$ P^{-1}AP = \pmatrix{\lambda&1\\0& \beta/\alpha}$$  What am I missing - may someone give a hint? Thank you!   edits: Thank you for the solutions. (Also made minor edits as in the comments.)


Is PermitRootLogin without-password a secure method?

I have read a lot of documentation on disabling root user login via ssh for security reasons. I have set in /etc/ssh/sshd_config  PermitRootLogin no   If I disable root login then boot need to assume user name and password also.  If I set   PermitRootLogin without-password   Then it is secure to do this. If I use my sshkey is it secure? Please explain.


Make a USB flash drive readable but not copyable

I want to protect my USB flash drive in general so these files and directories are readable but not copyable so no one can make a copy of these files in my USB flash drive.  Is that possible?


I want the title to be in the font small capital but want them to be bold at the same time


why are outgoing text message bubbles colorful?

Why are speech bubbles either blue or green for outgoing messages and not for incoming messages?   For example, in whatsapp, the outgoing messages are green. In iMessage, they are blue. I don't think I've ever seen a messaging app where the outgoing message bubbles are grey and the incoming ones are coloured. Is there a reason for this?


"Simple problem" to find order of a product in a Group

Let a and b be elements of a group, with $a^2 = e, b^6 = e $ and $ ab =b^4  a $ . Find the order of ab, and express its inverse in each of the forms $a^mb^n$ and $b^ma^n?$  Though it seems very simple I'm unable to find a power such that $(ab)^x =e$. Please help.  Im all confused with this problem.  PS: to put  in context, this question was asked for  maths optional UPSC IAS  exam in India


So I recently installed the kde packages, running the command apt install kde-full for installing the kde desktop environment, after test it a while I realize I didn't want it anymore so I remove the packages like this apt remove kde-full, but I notice that some packages and applications remains and weren't completely removed.  I am on Debian 8 distribution. I recently turned to the linux world so any help will be appreciated.  [Edit]  I also tried tasksel --list-task:  u desktop   Debian desktop environment u gnome-desktop GNOME u xfce-desktop  Xfce u kde-desktop   KDE u cinnamon-desktop  Cinnamon u mate-desktop  MATE u lxde-desktop  LXDE u web-server    web server u print-server  print server u ssh-server    SSH server i laptop    laptop   Some packges listing with synaptic-package-manager:    aptitude why kde-base-artwork output:  aptitude why kde-base-artwork i   kdeartwork         Depends kscreensaver (>= 4:4.14.2-1)       i A kscreensaver       Depends kde-workspace-bin                  i A kde-workspace-bin  Depends kde-workspace-data (= 4:4.11.13-2) i A kde-workspace-data Depends kde-base-artwork


A type-I superconductor can expel almost all magnetic flux (below some critical value $H_c$) from its interior when superconducting. Light as we know is an electromagnetic wave. So what would happen if we shine a light deep into a type-I superconductor? Suppose the magnetic field of the light is significantly lower than $H_c$.  And what about type-II superconductors?


Using grep -E and regular expressions I need to find words containing all of a group of characters in no particular order. For instance a word containing all vowels (aeiou) however the vowels can appear in the word in any order.


Can (or should) two voltage regulators be connected in a parallel configuration.

I have two 5 volt voltage regulators that I would like to connect to a 9 volt source in a parallel configuration.  Is this advisable, problematic, or even commonly done?    I have tested this configuration and noticed that one of the regulators gets hotter than the other.  Why is this?


Since there already seem to be ways to do this with user-specific CSS: why not have a couple of base themes for the sites? I'd like to see a theme like the dark flair that is available.  Getting into the more unlikely, what about a way for users to choose their own colors? I know this site is more for questions and the like, but customizability never hurt anyone :P


Can't install mysql properly (won't start?)

I have issues installing mysql,  sudo apt-get update sudo apt-get install mysql-server   I also tried:  sudo dpkg -P mysql-server-5.1 mysql-server sudo apt-get install mysql-server   I get the following error:  Job for mysql.service failed because the control process exited with error code. See "systemctl status mysql.service" and "journalctl -xe" for details. invoke-rc.d: initscript mysql, action "start" failed. ● mysql.service - MySQL Community Server    Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)    Active: activating (auto-restart) (Result: exit-code) since Mon 2017-05-15 14:43:06 CEST; 5ms ago   Process: 22585 ExecStartPost=/usr/share/mysql/mysql-systemd-start post (code=exited, status=0/SUCCESS)   Process: 22584 ExecStart=/usr/sbin/mysqld (code=exited, status=1/FAILURE)   Process: 22576 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SUCCESS)  Main PID: 22584 (code=exited, status=1/FAILURE)       CPU: 485ms  maj 15 14:43:06 XPS-13-9350 systemd[1]: mysql.service: Unit entered failed state. maj 15 14:43:06 XPS-13-9350 systemd[1]: mysql.service: Failed with result 'exit-code'. dpkg: error processing package mysql-server-5.7 (--configure):  subprocess installed post-installation script returned error exit status 1 dpkg: dependency problems prevent configuration of mysql-server:  mysql-server depends on mysql-server-5.7; however:   Package mysql-server-5.7 is not configured yet.  dpkg: error processing package mysql-server (--configure):  dependency problems - leaving unconfigured No apport report written because the error message indicates its a followup error from a previous failure.                                                                                Processing triggers for systemd (232-21ubuntu3) ... Processing triggers for ureadahead (0.100.0-19) ... Errors were encountered while processing:  mysql-server-5.7  mysql-server E: Sub-process /usr/bin/dpkg returned an error code (1)   If I type mysql I get:  ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)   It seems to have semi-installed as if I do mysql -u root -p I get the password prompt, but nothing happens.  I tried starting it using sudo service mysql start but I got this error message in mysql.service:  $ systemctl status mysql.service  ● mysql.service - MySQL Community Server    Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)    Active: activating (start-post) (Result: exit-code) since Mon 2017-05-15 14:24:24 CEST; 13s ago   Process: 13333 ExecStart=/usr/sbin/mysqld (code=exited, status=1/FAILURE)   Process: 13317 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SUCCESS)  Main PID: 13333 (code=exited, status=1/FAILURE); Control PID: 13334 (mysql-systemd-s)     Tasks: 2 (limit: 4915)    Memory: 1.8M       CPU: 353ms    CGroup: /system.slice/mysql.service            └─control              ├─13334 /bin/bash /usr/share/mysql/mysql-systemd-start post              └─13397 sleep 1  maj 15 14:24:24 XPS-13-9350 systemd[1]: Starting MySQL Community Server... maj 15 14:24:26 XPS-13-9350 systemd[1]: mysql.service: Main process exited, code=exited, status=1/FAILURE


When I type 4.1-0.1 into the javascript console in my browser (Chrome), or anywhere else in my code, it always returns the number 3.9999999999999996. I have also tried this in Firefox, and got the same result. I don't know if this is only my computer, or if this applies to all javascript, or if it's something simple I am overlooking. Also, sorry if this is a duplicate. I couldn't find any other situations like this, but I might not have been looking for the right thing.


Calculating number of elements commmuting with $\sigma\in S_{10}$

let $S_{10}$ denote the group of permutations on ten symbols ${1,2,3,....,10}$.Then how do we calculate number of elements of $S_{10}$ commuting with the element $\sigma=(1\ 3\ 5\ 7\ 9)$?


Admin Hook After Post Status Filter Above The Posts Table

I'm looking for a hook/other solution to add a button after the post status filter.  The closest hook I found is "restrict_manage_posts" but I need to hook after the status filter.


"edit tags" button does not disappear as normal

This morning I went to a question where the edit tags button was hidden, however I went over it with my cursor, though I didn't click it, it became visible. However even when I moved my cursor off it it still stayed there. And it seems to be the case that all questions I now visit on AskUbuntu have it visible all the time which is strange because normally it stops being visible after I move my cursor away from it.  I do not currently have 10k+ on any other sites in the SE network so cannot check whether or not they are affected.  I am running Ubuntu GNOME 16.04 with GNOME 3.20 and Firefox 47.


What is tricky about proving the Nielsen–Schreier theorem?

The Nielsen–Schreier theorem states (in part):     Let $F$ be a free group, and $H\le F$ be any subgroup. Then $H$ is isomorphic to a free group.   I have seen the topological proof of this theorem using the correspondence between coverings and subgroups of the fundamental group. This has always struck me as using rather strong theory for what it is being used to prove (though I do appreciate the beauty of the argument).   In my head, I see the following (loose) argument:      Let $H$ be a subgroup of $F$, and assume that $H$ is not free. Then there exists some nontrivial relation $h_1h_2\dots h_n = 1$. But then this is also a nontrivial relation in $F$ implying that $F$ is not free, which is absurd. Thus $H$ is free.   Clearly, there must be some problem with this. What are the stumbling blocks here? An issue I see is that the exact notation a relation has always seemed a little vague to me (some reduced word equal to the identity?), but that doesn't seem like it ought to be a large enough problem to invalidate the argument.


SEO domain advice: sol-spl.com vs sol-spanish.com

I'm taking Spanish lessons from a school that uses a domain name sol-spl.com (not the actual domain), where sol is the name of the company, and spl stands for "Spanish private lessons".  I was thinking that it might be much better for their search rankings if they used the domain sol-spanish.com, since every search for spanish lessons is going to use the keyword spanish, and spl isn't likely to be used.  Will switching domains like this likely have a positive impact on their search rankings, and is it a reasonable thing for me to advise them to do?


I want to upgrade my ubuntu 17.10 to 18.04 from terminal of ubuntu.  I've tried using commands  sudo apt-get update  sudo apt-get upgrade  sudo apt-get dist-upgrade  All the above commands executed successfully. But when I checked it using the command.  sudo lsb_release -a But it didnt work.


I would try to make it as clear as possible. I have a relay, and it has five pins( NC, NO, C, and coil) like any basic relay.    Now, I want to apply a logic - when the input (I would say it BMS from now) is 230V ( the mains supply is on) the alarm system should not buzz ( the alarm work at 230V mains supply) and when the input(BMS) is cut off (0V) the alarm system should start buzzing. In short, the alarm should start when the input is 0V and should turn off when the input is 230V mains. I realized the best way I can achieve is by using a relay and 2 different mains supply. The BMS will control the coil of the relay. The second power supply mains will be connected to the NC pin of the relay. And the alarm (hooter) will be connected to the C or common pin of the relay. Now, we consider two cases.   Case 1:  The second power supply is On and BMS is also on.   When this is the case, the Coil of relay is high as we have connected BMS to the relay coil.  So, NO and C of the relay will be connected to each other. We have nothing connected in the NO pin so the C pin would be low and the alarm will not start. Exactly what we want.   Case 2: The second power supply is On and BMS is cut-off  In this case, the coil of the relay will be cutoff so NC and C of the relay will be connected to each other. The second power supply is connected to the NC pin and as it is shorted to C of the relay, it will start the alarm as it will receive the supply voltage from the second power supply. So, when the BMS is cut-off, the alarm starts. Still, exactly the case we want.   The problem is that the BMS will always be on usually and the relay will always be in the switched state( NO and C of the relay will be connected). It will be only when the BMS is cut-off the relay will come to normal state( NC and C of the relay are connected).   Now, coming to my question. As the relay will be in the switched state forever ( NO AND C is always connected), will it damage my relay? Will the self-life of the relay decrease in that case? I hope you got my question. If it will damage my relay, please read further. If not, I would not look for alternatives.   Please help if you have any alternative for achieving the same thing.   If there is any other way of the same functioning ( the alarm should start when the BMS is cut-off) without using relay or using relay but with different connections, please do let me know. I am open for suggestions and please do help. Thanks for reading as I know I wrote a whole story here. Thank you.


package for making the script in MiKTeX colorful

I uninstalled my MiKTeX and now after re-installing the software, my scripts in the environment of the MiKTeX are not shown by colors.  I use TexWorks IDE.  for example, when you write \usepackage{} it is shown fully black while it used to be shown in blue color.  Entire the text is black. As another example, comments used to be shown in Green.  Which package should I install or which settings should I change in Texworks to do so?


Prove: Use the triangle inequality to prove that for all $x, y, | |x| − |y| | ≤ |x − y|$     Proof:       If $x ≥ 0$ and $y ≥ 0$, then both sides of the   inequality are the same.      Also if $x ≤ 0$ and $y ≤ 0$ then both sides of the   inequality are the same.       Assume $x ≥ 0$ and $y ≤ 0$ then $|x| = x$, and $|y| = −y$, and so:      $||x|| = ||x − y + y|| ≤ ||x − y + y|| ⇒ ||x−y||≤||x − y||$      and      $||y|| = ||x − y − x|| ≤ ||x − y|| + ||x|| ⇒ −(||x||−||y||) ≤ ||x − y||$   How do I approach this? Is this a good start?  Update:  I feel the following approach is a little bit more clear.     Proof:      Case $x≥0$ and $y≥0$: We have both sides equal each-other      Case $x≤0$ and $y≤0$: We also have both sides equal each-other      Case $x≥0$ and $y≤0$: Then $|x|=x$, and $|y|=−y$, and so   $||x|| = ||x − y + y|| ≤ ||x − y + y|| ⇒ ||x−y||≤||x − y||$      Case $x≤0$ and $y≥0$: Then $|x|=-x$, and $|y|=y$, and so   $||y|| = ||x − y − x|| ≤ ||x − y|| + ||x|| ⇒ −(||x||−||y||) ≤ ||x − y||$      QED


I have an attributes table, where I want a unique name for each attribute in order to prevent confusion between potentially similar attributes.  In terms of the table design, the way I see it, there are at least two realistic options.   Have an autoincrement int PK, with an additional unique-constraint placed on the column that holds the name data. Drop the integer autoincrementing PK, and just use the name as the primary key, it will by definition then have a unique constraint.   This attributes table will be joined all round the place, like say many thousands of products each having one or more attributes associated with them.  I am wondering if there is any disadvantage to #2 over #1?, like the indexing costs of adding new attributes down the path, or, are joins slower. What is the best practice?  I suspect #1 is the best option from performance, but #2 has advantages for readability of the data (ie pk:product_weight is more intuitive than pk:2)  Database is MySql, and, I am writing code using a SqlAlchemy/Python ORM abstraction layer, with migrations etc...


How to filter members of more than one list with LINQ?

I'm new to LINQ and I'm a little out of my depth here. I tried searching on MSDN and here without success. I feel there's probably a one-liner LINQ query for this that I'm incapable of finding.   Basically, I have a class called Student and a class called University. Each university holds a Student[] array. A student can be a member of multiple universities.   I also have an array of universities. The job is to construct a LINQ query that outputs an array of all students enrolled in more than one university.   I can easily get a union of all the different Student[] arrays across the universities via  University[] universities //initialize //fill universities with data Student[] bigListOfStudents = universities.SelectMany(b => b.Students).ToArray();   And then I would just need to grab all the elements of bigListOfStudents which appear in the array more than once. The opposite of .Distinct(). Wat do?  edit: to clarify, here are the basic Student and University classes. Jmbag is a unique student ID and is used to compare then, as in the Equals(Student s) override method, also to generate hash codes, and subsequently to permit LINQ queries.   class Student {     public string Name { get; set; }     public string Jmbag { get; set; }     public Student(string name, string jmbag)     {         Name = name;         Jmbag = jmbag;     }     public enum Gender     {         Male, Female     }      public static bool operator ==(Student student1, Student student2)     {         return student1.Jmbag == student2.Jmbag;     }      public static bool operator !=(Student student1, Student student2)     {         return student1.Jmbag != student2.Jmbag;     }      public override bool Equals(object obj)     {         if (GetType() == obj.GetType())         {             Student tempStudent = (Student)obj;             if (Jmbag == tempStudent.Jmbag)             {                 return true;             }         }         return false;     }      public override int GetHashCode()     {         int hash = 0;         foreach(char c in Jmbag)         {             hash += c.GetHashCode();         }         return hash;     } }   class University {     public string Name { get; set; }     public Student[] Students { get; set; } }


Typo in elections page - space needed before "Nominations close"

I just found a typo in the Elections page:   This election is currently in the nomination phase.Nominations close in 6 days                                                    ^^                         ^^                                                   I need a space here!!      |                                                                              |                                              also a final dot here wouldn't hurt


I write because I can’t use the plugin “Geotag and Import photos”. My version is 2.18.13 Las Palmas and it runs on WIN 7 Home. First of all, when I click on “Import photos” and specify the path to photos, I obtain the following error message:   The details are:  File "C:/Users/Emazza/.qgis2/python/plugins\geotagphotos\importphotosdialog.py", line 88, in selectPhotosDir             self.loadTags(dirName)           File "C:/Users/Emazza/.qgis2/python/plugins\geotagphotos\importphotosdialog.py", line 125, in loadTags             with et:           File "C:/Users/Emazza/.qgis2/python/plugins\geotagphotos\exiftool.py", line 179, in __enter__             self.start()           File "C:/Users/Emazza/.qgis2/python/plugins\geotagphotos\exiftool.py", line 162, in start             stderr=devnull)           File "C:\OSGeo4W\apps\Python27\lib\subprocess.py", line 711, in __init__             errread, errwrite)           File "C:\OSGeo4W\apps\Python27\lib\subprocess.py", line 948, in _execute_child             startupinfo)         WindowsError: [Error 2] Impossibile trovare il file specificato   The pointer begins to rotate as if it is working; nevertheless, I can still use the software. Even if I succeed to insert the output shapefile, I can’t see any EXIF tag.   I already installed Exiftool and I can’t understand which is the problem. Any suggestions for these two problems?


How can I see my nvidia quadro 6000 in 2.80, 2.81 CUDA?

I bought my computer two years ago. In 2.79 or earlier I can see my quadro 6000 listed in the CUDA settings but now, starting with 2.80 I cannot see it. Is there any way to fix this problem? I am using Windows 10 and I already updated my driver, but still, no change.  Thank you!


What is the safest way to move the iTunes Library from one hard drive to another?

This may happen later with my iMac, but right now it is happening for my iTunes on PC.  The PC had 60GB of partition to install Windows 7, and right now it is down to about 2GB of free space.  All iTunes purchases, including Music and Movies, are downloaded to  C:\Users\mike\Music\iTunes\iTunes Media\Music  C:\Users\mike\Music\iTunes\iTunes Media\Movies   which will make the C: drive have less and less free space.  (and C: will be more healthy if it has at least a couple of GB of free space).  What is the safest, most proper way to migrate all the media to an external hard drive J: ?  On J:, the path might be:  J:\iTunes\iTunes Media\Music   or  J:\iTunes Media\Music   My guess is that we can change the folder in iTunes, but won't iTunes go to that folder or create it, and find nothing, and index everything wrong?  So, should an exact copy of C:\Users\mike\Music\iTunes\iTunes Media be made as J:\iTunes Media first (probably 30GB of files copying), and then start iTunes and change the preference for the folder to the J: one?  Is there a standard or official method to do this?


I've got a Blu-ray drive and I'd like to be able to use it to watch movies under Ubuntu.


Warning message: glm.fit: fitted probabilities numerically 0 or 1 occurred ? What does it mean and how to fix it?

All,  I have a dataset that contains more than 45k rows and 2 columns. Below is dput() of first 50 rows. One thing to consider is that category  column contains 34 factor of different levels. I am using Logistic regression model to predict the category based on other two columns. Below is my model. However, I am getting warning in my model. I Googled the warning, and found that there might be linear relationship between my DV(Dependent Variable) and IV (Independent Variable). I am not sure how to deal with this warning. Some post suggested to perform Log transformation, but not sure How to perform in my model. Being a newbie to R if you could provide an explanation of how to deal with the warning that will be great.  > dput(droplevels(head(new_df1, 10))) structure(list(category = structure(c(1L, 5L, 7L, 8L, 9L, 10L,  2L, 3L, 4L, 6L), .Label = c("", "baking", "canned", "crackers",  "DELI", "dessert", "MEAT", "NUTRITION", "PASTRY", "PRODUCE"), class = "factor"),      quantity = c(5L, 27L, 3L, 1L, 29L, 94L, 70L, 20L, 12L, 122L     ), sales_value = c(11.6, 86.83, 13.46, 2, 52.4, 133.75, 160.15,      38.81, 29.91, 208.75)), row.names = c(NA, 10L), class = "data.frame") > dput(droplevels(head(new_df1, 50))) structure(list(category = structure(c(1L, 5L, 20L, 21L, 24L,  27L, 2L, 3L, 4L, 6L, 7L, 8L, 10L, 11L, 12L, 13L, 14L, 15L, 16L,  17L, 18L, 19L, 22L, 23L, 25L, 26L, 28L, 1L, 5L, 20L, 21L, 24L,  27L, 2L, 3L, 4L, 6L, 7L, 8L, 9L, 10L, 11L, 12L, 13L, 15L, 16L,  17L, 18L, 19L, 22L), .Label = c("", "baking", "canned", "crackers",  "DELI", "dessert", "drinks", "drug", "ethnic", "food", "food add-ons",  "frozen dessert", "frozen food", "frozen meat", "fruit", "health",  "household", "instant dinner", "meat", "MEAT", "NUTRITION", "other",  "packaged foods", "PASTRY", "personal care", "produce", "PRODUCE",  "seasonal"), class = "factor"), quantity = c(5L, 27L, 3L, 1L,  29L, 94L, 70L, 20L, 12L, 122L, 81L, 1L, 78L, 82L, 30L, 7L, 1L,  33L, 5L, 56L, 4L, 66L, 5L, 45L, 37L, 36L, 3L, 1L, 41L, 2L, 18L,  20L, 115L, 83L, 32L, 24L, 118L, 72L, 2L, 1L, 73L, 92L, 44L, 16L,  21L, 1L, 57L, 1L, 68L, 14L), sales_value = c(11.6, 86.83, 13.46,  2, 52.4, 133.75, 160.15, 38.81, 29.91, 208.75, 204.38, 3.99,  128.27, 193.84, 56.27, 11.75, 1.5, 41.59, 33.51, 140.42, 7, 170.11,  14.08, 84.93, 111.53, 33.62, 2.07, 2.99, 125.34, 4.45, 46.33,  42.91, 132.35, 181.04, 51.64, 59.91, 260.86, 189.15, 12.68, 1.09,  115.18, 210.44, 111.53, 31.4, 25.16, 2.29, 142.57, 2.5, 179.86,  59.28)), row.names = c(NA, 50L), class = "data.frame")   My model  fit_glm = glm(category~.,new_df1,family = 'binomial')   Warning:  Warning message: glm.fit: fitted probabilities numerically 0 or 1 occurred


Does Ubuntu store sudo password in cache?

If we fire a command with sudo in terminal, it asks for password for the first time and if we fire another command with sudo immediately in same terminal, it won't ask for password again. Why is it so ?  Does Ubuntu store the sudo password for sometime in cache? Can anyone else (another program/malware) use that password during that time span ?


How to convert a string to Boolean ?   I tried using the constructor Boolean("false"), but it's always true.


Is there a word for saying "um" or "uh", etc, during speaking?  Or a word for "um" and "uh", etc?


Why doesn't unix filesystem store creation time of a file?

Is there any historic reason? Stat stores last accessed time, last modified time and last changed time , but not the creation time! Isn't that important information.   I can't understand why the developers would leave out such an important piece of information. Some filesystems do store the data, as pointed in this . But clearly the importance of this information has been downplayed. Why is it so?  Note:  stat -c %W <filename>   Returns 0 in my system (fedora 22).


Shadows from illustrator to photoshop and vice versa

I'm working on the design of a new app. Ideally I could swap from illustrator to photoshop and vice versa since each has its advantages. This works out very well (I use shapes / vectors) except for one thing. Shadows! When I export to psd, the element with shadows from illustrator become images, not shapes. When importing the psd from photoshop, the shadowed elements become images (to trace). Anyone who knows a proper solution to this?


Simple Homebased "Super-kind-of" Computer

Well something similar to that.  Got an ancient desktop running a ubuntu-based distro and an equally ancient macbook.  Would like to connect and utilize both their computing capability for day-to-day tasks, you know like browsing, gaming, coding, movies, etc.  Have heard of cluster computers, which look good but most of them suggest a similar hardware. And also read that they can actually get counter-useful because of the way the master node would task the sub-nodes, so lot of wasteful energy consumption of the sub-nodes if the master dont delegate. But I only have a vague idea.  Question is, a desktop and a laptop, with different hardware, can it be made to work in tandem, elegantly and for normal tasks? And how?  Desktop specs (Elementary OS, 32-bit) 1. Intel Pentium Dual Core  CPU  E2180  @ 2.00GHz 2. 1GB RAM SDRAM (yeah, its that old!) 3. 160GB SATA Disk 4. Intel Corporation 82945G/GZ Integrated Graphics Controller  Laptop specs (Snow Leopard, 32-bit?) 1. Intel Core 2 Duo  CPU  @ 2.16GHz 2. 2GB 667MHz DDR2 RAM 3. 250GB SSD 4. Intel GMA 950 64MB  PS - Of course, will put in Ubuntu-based distro in both. PPS - There should be a solution, right? PPPS - A step-by-step would be cool.  EDIT -  Have read many threads, and they all state the accessing the RAM of a different machine is too costly. So there can be a scenario where the RAM is shared as one and only the CPU is "clustered" as such. OR maybe putting a big RAM in one of the machine, whichever is easier.


Suppose that $Tr(A^n) = 0$ for all integer $n>0$.  I have to prove that $A$ is nilpotent.  I can see it's true for little $n$ but i do not know how to prove that for all integer $n$. Any idea please?


$f\in K[t]$ is irreducible if and only if $G$ $(\Gamma(L:K))$ acts transitively on the roots of $f$.

Let $K$ be a field, $f\in K[t]$ separable over $K$, $L$ the splitting field of $f$ over $K$, and $G=\Gamma(L:K)$. I need to prove that $f$ is irreducible if and only if $G$ acts transitively on the roots of $f$.   I was able to show one direction, that $f$ irreducible implies $G$ acts transitively on the roots. I'm stuck on the other direction of implication; supposing $G$ acts transitively on the roots of $f$. Any guidance or a point in the right direction would be much appreciated!


'In a very long time' vs 'for a very long time'

I was watching friends lately and on that show Ross said "I haven't had sex in a very long time". I wonder why he didn't said "I haven't had sex for a very long time" although 'in a very long time' sounds more native and correct but why not he used  'for a very long time '.   So, this is my question when do we use 'in a very long time' and when do we use 'for a very long time'.


Is an identity card issued to a non-citizen an acceptable document to travel within the EU?

Suppose an EU citizen is resident of another member state and gets issued a national identity card identical to the ones citizens get there. (If that is not concrete enough to answer the question, assume a Finnish citizen who is a temporary resident in Estonia.)    This is an Estonian ID card issued to a Finnish citizen. The ones for Estonian citizens look exactly the same, just with a different entry at "citizenship" and without a small remark on the back side specifying the type of residence. I know that this is the old model that isn't valid anymore but I couldn't find an example of the new card.  If one carries no other identity document into a country which is neither the issuer nor the country of citizenship,   Is it possible to cross the border from outside the EU? Is it allowed to cross Schengen borders? Does this satisfy the requirements to carry an ID imposed by some member states, e.g. Portugal? Is it possible to get on board of an airplane in countries where a valid ID is required for this, e.g. Spain?   In short, can such a card be used just as if it had been issued to a citizen?  I know that technically you can enter the EU even without any identification at all as an EU citizen but that comes with a lot of hassle. I'm interested in how well this works in practice. Is such an identity card assumed a valid document that is waved through?    such a card as an identity document but not a travel document. Which consequences does this have for the holder?


The following code excerpt is responsible for a cryptic MSVC++ compiler error:  template<class T> class Vec : public vector<T>{   public:     Vec() : vector<T>(){}     Vec(int s) : vector<T>(s){}      T& operator[](int i){return at(i);  }     const T& operator[](int i)const{ return at(i);} };  ...   The error:  test.cpp(5) : error C2143: syntax error : missing ',' before '<'   test.cpp(12) : see reference to class template instantiation 'Vec<T>' being compiled   How do I fix this?  ---Edit---  Some context:  I am trying to compile code essentially copy and pasted from The C++ Programming Language. I don't yet even understand this code completely. The purpose, however, is to implement a vector type that will throw an exception when some code attempts to access an item out of the vector's range instead of just returning incorrect values.


If $\gcd(a, b) = 1$ then $\gcd(ab, a+b) = 1$?

In a mathematical demonstration, i saw:  If $\gcd(a, b) = 1$ Then $\gcd(ab, a+b) = 1$  I could not found a counter example, but i could not found a way to prove it too either. Could you help me on this one ?


Why there are two speeds written on the CPU?

When looking on the details of some of Intel’s CPU, it looks for example like this:     Intel® Core™ i7-6500U CPU @ 2.50GHz 2.59 GHz   What is the meaning of each speed rate?


In the Last Jedi,       Holdo ran the Raddus into the First Order fleet at light-speed,  doing massive damage.    Why has no-one thought of this before?  Fit a light-speed drive to a cheap ship, and make your own super missile. You could even fill it with a warhead for added damage. Why is it not a standard tactic?   Not only do you have incredible tactical speed advantage (compare this to the slow projectiles as the FO fleet shot at the Raddus, and it even looks faster than energy bolts), but it seemed to ignore the shields.


I have a few questions about the verb 'to languish.'   In the OED, it suggests that this word must be used for a living thing. Couldn't it be used metaphorically for something like an idea or a literary genre that has a kind of "life?" Most usage suggests that languish cannot have an object. Can't languish be used with a prepositional phrase (with an object of course), for instance? Can something languish into a pale imitation of itself? This usage (languish into) was more common 200 years ago but has almost died out according to ngram. Any ideas on why?   Any clarification would be greatly appreciated!  (I posted this in the wrong place at first, apologies for repost)


Define a literal Javascript object so a property referenced directly calls a function and not its sub-ordinates

I want to define a literal object in Javascript so that, for example:  myObject.foo()   returns an anonymous function, but   myObject.foo.bar()   returns a different anonymous function, and  myObject.foo.status   equals some string, etc.  Assume I'm starting with something like:  var myObject = {     foo: {         bar: function () { ... },         status: "someString"     } }   How would I modify this accordingly?  Is it proper syntax to add a static reference like:  myObject.foo = function() { ... }   My guess is that, if valid, that would override the definition of foo entirely.  Is there an elegant way to achieve this?  I am creating a literal object that maps directly to a REST API URL so there is consistency between the URL and its object reference.  For example, if the relative URL for a particular API call is myObject/foo and another is myObject/foo/bar, then I would like the JS functions to be myObject.foo() and myObject.foo.bar(), respectively.


How can I typeset in landscape in PlainTeX

I would like to have output turned 90 degrees so I could print envelopes and spread sheets. I use TeX (not LaTeX) and ocular on linux.


Do we only have to have a deallocation when we have an allocation in C++?

I have this example from an official site: char* variable1; variable1=getenv ("PATH"); if (variable1!=NULL) {  printf("variable1=%s",variable1); } //Shouldn't this be here to avoid memory leak? //delete variable1;  Or we can say that the pointer variable get its value in an equation and there is no need for deallocation because there is no allocation?


How can I handle vertical alignment of `div`?

I'm practicing publishing of  How can I handle vertical alignment of div?      .header {   background: rgba(0, 0, 0, 0) linear-gradient(135deg, rgb(6, 68, 161) 0%, rgb(56, 205, 255) 100%) repeat scroll 0% 0%;   height: 668px; }  .header__nav {   padding: 20px; }  .header__nav__logo {   float: left; }  .header__nav__logo {   padding: 6.5px 20px 6.5px 0;   display: inline-block;   margin-left: -20px; }  .header__nav__logo img {   width: 150px;   height: 36px; }  .header__nav__list {   overflow: hidden;   float: right;   margin-right: -20px; }  .header__nav__list li {   float: left; }  .header__nav__list li a {   padding: 20px;   display: inline-block;   color: white; }  .header__nav__list__button {   background-color: #eb4336;   border-radius: 3px; }  .header__main {   text-align: center;   color: white;   background-color: green; }  .header__main__title {   font-size: 50px; }  .header__main__intro {   font-size: 20px;   margin-top: 20px;   margin-bottom: 10px; }  .header__main__button {   background-color: #eb4336;   border-radius: 5px;   padding: 15px 50px;   font-size: 20px;   margin-top: 20px;   display: inline-block; }  .header__main__signin {   margin-top: 10px; }  .contents {   background-color: yellow; }  .footer {   background-color: blue; } <!DOCTYPE html>      <meta charset="UTF-8">   <meta name="viewport" content="width=device-width, initial-scale=1.0">   <meta http-equiv="X-UA-Compatible" content="ie=edge">   <link rel="stylesheet" href="default.css">   <link rel="stylesheet" href="style.css">   <title>Project Management Software</title>

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     Contents
        Footer           I wanna div of green space to align vertically in the blue background except nav bar. How can I handle this?? I searched solutions and tried lots of things, but I failed. Many solutions suggest display: table-cell for vertical alignment, but it didn't work.


refused visitor visa how can we prove he is genuine and will return home

My fiance applied for a UK visitor visa in December and was refused on paragraph 4.2 (a) and (c). We want to reapply, but how can we prove his circumstances have changed and that he is a genuine visitor and will return to his country. He has a job to go back to as well as a house that he has paid the rent up until next year for, isn't that sufficient to show economic ties to his country and enough to show he will go back?  They said his bank statement showed inconsistent deposits that he didn't prove where they came from, although it stated in his application that a large portion of that was deposited by his mum to go toward his MBA.  Does he need to get her bank statement and a letter from her confirming this, this time as the money is still in his account?  Also he had a professional do his last application and she put me as a family friend which she shouldn't have.  We want to put that I am his fiance on this application.  Is there a way to do that without it causing issues?


I want to solve the following problem:  Suppose that $X$ and $Y$ are two independent, Gaussian variables, with mean zero and common variance $\sigma^2$. Let $R^2 = X^2+ Y^2$ and $Z = \arctan (X/Y)$. I know that in this case $R^2$ has an exponential distribution and $Z$ has a uniform distribution. However, are $R$ and $Z$ independent from each other?


htaccess www to non-www and non-SSL to SSL

I want to redirect all HTTP requests to HTTPS as well as redirect all www requests to non-www.  The reason for this is that I want SSL to be forced and I am currently unable to support SSL on my www subdomain.  This solution needs to support all combinations of HTTP, HTTPS, www and non-www. The best solutions I have found so far supports all combinations except www and HTTPS at the same time.  Thank you for your time. :)  EDIT: Just to explicitly state it once again, to avoid any more incorrect duplication suggestion: I want to redirect from www to non-www not the other way around. I also want to force SSL at the same time.


windows 7 becomes unberable slow, what could I do?

I'm using windows 7 professional edition, 32 bits. At the beginning it's quite OK, but not it becomes unbearably slow: it takes around 31 minutes to start up!  After I typed in the windows id and password, it still takes more than 10 minutes to really log in. Seeing the "welcome..." page, I pressed Ctrl + Alt + Delete and popped out the Task Manager, however, the CPU usage is only 1% and Memory usage is 34%.  These are the details:  Processes: 78 CUP Usage: 1% Physical Memory: 34%  Physical Memory (MB) Total:      2942 Cached:     798 Available:  1743 Free:       1005  Kernel Memory (MB) Paged:      248 Nonpaged:   58  System Handles:    18306 Threads:    916 Processes:  77 Up Time:    0:00:35:40 Commit (MB):    1263/5882   Then I go to check the services running, also could not find any suspicious services. Below are the running ones:  AtherosSvc Background Intelligent Transfer Service Base Filtering Engine Check Point Device Auxiliary Framework Check Point ESME Client CNG Key Isolation COM+ Event System Computer Browser Cryptographic Services DCOM Server Process Launcher Desktop Window Manager Session Manager DHCP Client Diagnostic Policy Service Diagnostic Service Host Diagnostic System Host Distributed Link Tracking Client DNS Client Extensible Authentication Protocol Function Discovery Resource Publication Group Policy Client IKE and AuthIP IPsec Keying Modules Intel(R) Capability Licensing Service Interface Intel(R) Dynamic Application Loader Host Interface Service Intel(R) Management and Security Application Local Management Service Intel(R) Management and Security Application User Notification Service IP Helper IPsec Policy Agent Machine Debug Manager McAfee Framework Service McAfee McShield McAfee Task Manager McAfee Validation Trust Protection Service Multimedia Class Scheduler Net Driver HPZ12 Netlogon Network Connections Network List Service Network Location Awareness Network Store Interface Service Offline Files Plug and Play Pml Driver HPZ12 Power Print Spooler Program Compatibility Assistant Service Remote Procedure Call (RPC) Remote Registry RPC Endpoint Mapper Security Accounts Manager Security Center Server Shell Hardware Detection SSDP Discovery Superfetch System Event Notification Service Task Scheduler TCP/IP NetBIOS Helper User Profile Service Validity VCS Fingerprint Service Windows Audio Windows Audio Endpoint Builder Windows Event Log Windows Firewall Windows Font Cache Service Windows Management Instrumentation Windows Modules Installer Windows Search Windows Time Windows Update WinHTTP Web Proxy Auto-Discovery Service Wired AutoConfig WLAN AutoConfig Workstation ZAtheros Bt and Wlan Coex Agent ZAtheros Wlan Agent   As the notebook is under the protection of McAfee and "Check Point Endpoint protection", it's unlikely this is caused by virus.  Since the browser is not even started, the slowness is not caused by the plug-ins.  The "heavy" softwares I installed are Oracle database client, Microsoft SQL Server 2014 Express Edition (but disabled), and Microsoft Visual Studio 2013 Express Edition.  It shall not be a hardware issue. My notebook is a Dell Vostro, with 4 Intel Cores of i5-3337U @ 1.80 GHz and 4 GB RAM. And at the beginning it runs ok.  What could be the reason and what can I do?


Finding a set which has non-full outer measure on every interval, and so does its complement.

I've been struggling with this exercise, and was hoping someone here might be able to point me in the right direction.  Question. Let $m^*$ denote the Lebesgue outer measure on $[0,1]$. Show that there exists $A \subseteq [0,1]$ s.t. for every interval $I \subseteq [0,1]$ we have   $m^*(A \cap I)<m^*(I)$, $m^*(A^\complement \cap I)<m^*(I).$     EDIT: I guess I misunderstood the conditions, and this is indeed a duplicate. Apologies.


Camera body vs lenses - which is more important technically?

I am writing an article for a case study, explaining which one is more important in Photography, either the camera body or the lenses, and in which, one has to invest more? This is a technical question.  Maybe we will be looking at the advantages of its element.   Could you please help me?


adjective order: "long boring report" or "boring long report"?

A long boring annual report   A boring long annual report       which of the above is right?  I learnt the adjective order of DOSA SCOMP, which means the adjective order should be as below:        determiner, opinion, size, age, shape, color, origin, material, purpose   the answer is      a long boring annual report   but that seems to be against the DOSA SCOMP Does anyone know the reason?


Finding a PDF of a sum of random variables

The following is given: $$X,Y\ \textit{are independent}$$ $$X∼exp(1),Y∼exp(2)$$ $$Z=e^{−X}+e^{−2Y}$$ And I want to find: $$f_Z(1)=?$$ As a part of my solution I do the following: $$Z=U+V$$ where $$U=e^{−X},V=e^{−2Y}$$ Using one dimensional transformation we get: $$U∼Uni(0,1),V∼Uni(0,1)$$ Since we know that X,Y are independent we can assume the same for U,V. In order to calculate $f_Z$ im using a convolution integral : $$\int_{-\infty}^{\infty} f_U(u) \cdot f_V(z-u)du = \int_{0}^{1} 1 \cdot 1du = 1$$ According to the solution this is not $f_Z$, could you point out where I was wrong?


Why was the flag declined, even though the answer was deleted?

I had flagged  as not an answer. The flag was declined by a moderator stating this reason      declined - flags should not be used to indicate technical inaccuracies, or an altogether wrong answer.   So I thought that I might have wrongly flagged the answer, and thus moved on. But later today, I just happened to stumble upon that answer again and I see that it was deleted after all by a moderator. Why was my flag declined in that case? Is there something which I'm missing about the flags and moderator deletion?  Note - Since the answer under discussion was deleted by a moderator already, it can be seen only by users with 10k+ reputation on Stack Overflow.


Can I use "US-American" to disambiguate "American"? If not, what can I use?

Based on , I wonder: as an alternative to USAian (which is very nonstandard) is it OK to use  to more clearly indicate "inhabitant of the USA"?  According to , this phrase has grown in usage since the 1960's.  The problem I'm trying to solve is that American can relate to either an inhabitant of the American continent(s), or an inhabitant of the United States of America. (In fact, the one Brazilian person I know does refer to himself as American, or at least would like to be able to do so.)  I'm looking for a word that specifically means "inhabitant of the United States of America".  I can see that in German, 'US-Amerikaner' is certainly not uncommon (see e.g. Wikipedia). Also, see also the Wikipedia article .   Alternatively, if it turns out that "American" always means an inhabitant of the USA, what word can be used for inhabitants of the continent?


jQuery on click event working in one instance, not working in another

I'm working to learn javascript by building a basic fruit shopping page where fruits displayed at the top of the screen can be clicked on and added to a "cart" at the bottom of the screen. Once a fruit is in the cart, clicking an image should remove it from the cart.  Clicking to add an image is working fine, but clicking to delete the image is not, even though the code is basically the same.  Using debugger and some console.logs, I've identified that the click event is the issue, as opposed to the function associated with it.  I've tried changing the html selectors to see if that were the issue, as well as changing the order of the functions in the document.ready statement.  $(document).ready(function() {     renderInventory();     addFruitOnClick();     removeFruitOnClick();     render(); });   This code is working to add fruits to the cart:  function addFruitOnClick () {     $("#inventory img").on("click", function(event) {         OWNED_FRUIT.push(event.target.id);         render();     }) }   This code is not working to remove fruits from the cart:  function removeFruitOnClick () {     $("#cart img").on("click", function(event) {         OWNED_FRUIT.splice(parseInt(event.target.id, 10), 1);         render();     }) }   Here's the relevant html:


Word meaning a job someone is installed in where they don’t do anything

I’m looking for a word I’m struggling to remember that refers to a job or role which is inconsequential and usually created in order to install someone in a company, not based on their merit.  An example would be creating a vague new role for a friend’s son. The word I’m looking for refers to the actual job itself - it’s a noun that would replace the ‘job’ (e.g “they put so and so’s cousin in a ____”).   I believe the word may not be a strictly formal or technical word but I don’t think it was slang.


Finding the equation of the circle passing through two points $(4,4)$ and $(-2,-2)$ with radius $4$

After solving using Sim Eq, obtained are $h=1$ and $k=1$, but I could not prove it as I did not get the exact radius $4$. My radius would always slightly run such as $18$ or $15$. Is there a step I miscalculated or skipped?


How do we see an object fall into a Black hole in gravitational waves?

If an object emitting light falls into a black hole, the conventional wisdom is that an observer (at infinity) will never actually see it fall in - they will see it moving slower and slower as it approaches the horizon and then eventually freeze at the horizon, making the time of "falling in" to be infinite for the outside observer.  During BH mergers we can actually see one BH "fall into" another one in a finite time. Why does the same thing not happen with gravitational waves?


How to hide some, but not all, subsections from table of contents, without losing in-document subsection numbering?

I'm using \tableofcontents. I'd like to hide some, but not all, subsections from the contents, but I don't want to lose the subsection numbering within the document itself. (So I can't use \subsection*{}.) Is there an easy way to do this? If not, could someone provide a clever solution?  In my case, if I want to suppress a single subsection within a section, then I want to suppress all the subsections in that section. I don't need the flexibility to both suppress and incorporate subsections within a single section.  Here's a MWE:  \documentclass[11pt]{article}  \usepackage{amsmath} \usepackage{amssymb} \usepackage{graphicx} \usepackage{fancybox} \usepackage{fancyhdr} \usepackage[margin=1in]{geometry} \usepackage{hyperref} \usepackage{cleveref}  \begin{document}  \tableofcontents  \section{Section} \subsection{To be included in TOC} \subsection{Also to be included in TOC}  \section{Another Section} \subsection{Not to be included in TOC}  \section{Another Section Redux} \subsection{Not to be included in TOC}  \end{document}


Why is my validation loss always larger than my epoch loss

I am training a CNN and it seems no that matter what I do my validation loss is always much greater than my training loss. To my understanding, this should mean my model is always overfitting my data set. INFORMATION: My model is built in Keras running on tensorflow=1.14. My model is a binary cross-entropy. I Have a data set of about 2500 tagged photos. My tensor board:


Travel from Indonesia to India via Bangkok(DMK)

I will be reaching DMK by Indonesia Air Asia and have a connecting flight to India in Thai Air Asia. Layover is 9 hrs.  Please help me out if I will need a transit visa in Thailand.  PS: I have an Indian passport. I do not intend to leave Bangkok airport and my tickets were purchased under one booking number.


df -h   gives:  Filesystem                         Size  Used Avail Use% Mounted on  udev                               3.9G     0  3.9G   0% /dev tmpfs                              799M   81M  718M  11% /run /dev/mapper/buildingbase--vg-root  287G   27G  246G  10% / tmpfs                              3.9G     0  3.9G   0% /dev/shm tmpfs                              5.0M     0  5.0M   0% /run/lock tmpfs                              3.9G     0  3.9G   0% /sys/fs/cgroup /dev/vda1                          472M  466M     0 100% /boot /dev/vdb1                          2.0T  647G  1.4T  32% /mnt/bigstorage tmpfs                              799M     0  799M   0% /run/user/1000   my kernel  uname -r  4.4.0-72-generic   And than my installed kernels...  dpkg -l | tail -n +6 | grep -E 'linux-image-[0-9]+'   as you can see NO OLDER KERNELS :-{  ii  linux-image-4.4.0-72-generic       4.4.0-72.93                                amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP ii  linux-image-4.4.0-75-generic       4.4.0-75.96                                amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP ii  linux-image-4.4.0-78-generic       4.4.0-78.99                                amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP ii  linux-image-4.4.0-79-generic       4.4.0-79.100                               amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP ii  linux-image-4.4.0-81-generic       4.4.0-81.104                               amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP ii  linux-image-4.4.0-83-generic       4.4.0-83.106                               amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP ii  linux-image-4.4.0-87-generic       4.4.0-87.110                               amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP ii  linux-image-4.4.0-89-generic       4.4.0-89.112                               amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP ii  linux-image-4.4.0-91-generic       4.4.0-91.114                               amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP ii  linux-image-4.4.0-92-generic       4.4.0-92.115                               amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP   How can I clean up /boot?  Of course   sudo apt-get autoremove   is not working... not enough space


Accessing .VDI Image from Ubuntu VirtualBox

I have Ubuntu 11.04 installed in VirtualBox 4.0.10 on a Windows Vista Home Premium  32-bit host. I have a hard disk that I have added to the SATA Controller on the VirtualBox (a .VDI image). My question is, how can I access the files within that hard disk?   Thank you.


Why should the minimal class be avoided?

In a comment to my , Peter Grill said that he read that the minimal class should not be used for a Minimal Working Example. I wonder why, and which class should I use instead?  BTW: Is it preferable to use article or scrartcl, i.e. the standard classes or the ones form the KOMA-Script bundle?


How to get the list of all posts I've upvoted via the API?

I'm looking for a way to get the list of all my upvotes on Stack Overflow, however after looking through the , seems there is no way to achieve that.  And I know I can view my upvotes in votes tab, however I'm looking for an official API to query the list.


Do cantrips gained through Pact of the Tome use Charisma or their default stat?

Pact of the Tome gives Warlocks access to any 3 cantrips. The feature doesn't specify whether the cantrips use the default stat (my guess), or whether they use Cha (to make the feature more useful/avoid MAD).  Contrast the omission with Magic Initiate, which explicitly calls out the stats, according to the class. So, which is it?


How to uninstall older version (15.04) of Ubuntu and install newer(18.04)

I have installed  Ubuntu version 15.04  on my laptop which already had windows 10 by partitioning the disk  I have not yet stored any files in Ubuntu but found the installation process incomplete and is incompatible to install some softwares  So I need to install Ubuntu version (18.04) which is downloaded and files are extracted into bootable pen drive Pls help me out


How will I make this /media/De Soft/mongodb/bin PATH variable permanent?  Everyone is saying "export PATH=$PATH:media/De\ Soft/mongodb/bin to your ~/.profile, or .bashrc, or .zshenv depending on your shell".   I don't know what is ~/.profile, or .bashrc, or .zshenv. What do they do actually?  How will I add export PATH=$PATH:my/path to my .profile/.bashrc/.zshenv?   I'm using 64 bit Ubuntu 14.04 LTS with default terminal.


About the proposition2.1.11 of Analysis I by Terrence Tao

I'm confused about why this proposition is true if this property is not true at all.  $Proposition$  2.1.11.  A certain property $P(n)$ is true for every natural number n.  Proof. We use induction. We first verify the base case $n = 0$, i.e., we prove $P (0)$. (Insert proof of $P (0)$ here). Now suppose inductively that n is a natural number, and $P(n)$ has already been proven. We now prove $P$(n++). (Insert proof of $P(n++)$, assuming that $P(n)$ is true, here). This closes the induction, and thus $P(n)$ is true for all numbers n.   Thanks.


I have a file with those data :   PAS_BEGIN_0009999     T71_MANUFACTURER_4=98     T71_COLOR_ID_7=000     T71_OS_7=08 PAS_END_0009999  PAS_BEGIN_0009996     T72_VAS_SERVICE_IDENTIFIER_6=     T72_ORDER_NB_7=0003     T72_TECHNOLOGY_7=01 PAS_END_0009996  TPV_BEGIN     PAS_20819001=3600000  TPV_END   How can I simply isolate content betweenPAS_BEGIN_0009996 and PAS_BEGIN_0009996  Here is a link for the example :   It finds something, but my python code doesn't find anything..  if re.match("PAS_BEGIN_0009999([\S\s]*)PAS_END_0009999", line):     data.append(line)     print(line)   Can anyone help me on this ? Thanks


Soundness vs completeness, am I understanding? And proving soundness?

Soundness: $a \vdash b \implies a \vDash b$, i.e. if we can prove something, it will also be true. We don't want a system where we start out with something true and dedice something false. However it is conceivable that even if our system is sound, maybe it's quite incomplete/limited regarding what we can express, which is why we also would like...  Completeness: $a \vDash b \implies a \vdash b$, i.e. if we can show something is true, it's also provable. We want to be able to prove all true statements. However it is conceivable that even though we can prove all true statements, maybe it also proves false ones as well, which is why we'd also like the soundness property from before.  Do I have the right idea?   If so, how would I begin to prove soundness? If we are already given $a \vdash b$ I'm not sure what all we must iterate over in e.g. propositional logic to show that we always get true statements. Especially since it seems possible I could pick a false $b$ that contradicts.


I found a problem with an application on Ubuntu.   Questions :   How do I best report the issue?  What sort of information should I provide?


Why does it open my old project every time I create new file after reinstalling Blender?

Every time I create new file this file keeps opening:


Convert columns to rows without using pivot

I have been assigned to get the data in required format from two tables. TableStaff : STaffID | Staff Name -------------------- 1      | John  2      | Jack  and TableLead LeadID | LeadValue | LeadStaus | StaffID ----------------------------------------   1    | 5000      | New       | 1   2    | 8000      | Qualified | 1   3    | 3000      | New       | 2  As you will notice StaffID is the foreign key to  TableStaff. I have to represent the data in following format StaffID | StaffName | NewLeadCount | QualifiedLeadCount  ------------------------------------------------------- 1       | John      |  1           |   1 2       | Jack      |  1           |   0  What I have tried: SELECT      count([LeadID ]) as LdCount ,      'New' as StageName   FROM      [dbo].[TableLead]  where      [LeadStaus] = 'New'  UNION  SELECT      count([LeadID ]) as LdCount ,      'Qualified' as StageName  FROM      [dbo].[TableLead]  where      [LeadStaus] = 'Qualified '   Any NULL spots should be replaced by 0. Can anyone show me the right direction to approach the problem? Without using pivot (because of its restrictive nature).


I want the following code to show only rounded numbers by two decimals . . .    public class Main {      public static void main(String[] args) {          double gross = 4322.12d;         double tax = 397.04d;          double net = gross - tax;         double fee = gross * 0.30d;         double vat = fee * 0.20d;         double takeHome = net - (fee + vat);          System.out.println("Gross Refund £" + gross);         System.out.println("Tax Deducted £" + tax);         System.out.println("Net Refund £" + net);         System.out.println("Our Fee £" + (fee + vat));         System.out.println("Funds remaining after deductions £" + takeHome);      }  }


If you delete a question with a positive score will your reputation go down? If so, how long does it take?

If you delete a question with a positive score will you get reputation back? Basically what I'm asking is, suppose you have a question with a score of 22, and I delete the question. Would I lose reputation? If so, how long does it take  for it to re-calculate the reputation?


Greatest common divisor of $X^n-1$ and $X^m-1$

Let $f=X^n-1$ and $g=X^m-1$ be two polynomials. Show that: $$\left(f,g\right)=X^{\left(n,m\right)}-1,$$ where $\left(a,b\right)=$ greatest common divisor of $a$ and $b$.


I'd like to redirect output from this command:  ps -eo pid,comm,cmd,start,etime | grep -i qtcreator > file.txt  When I try it, I've also output command grep -i example  2018 qtcreator       qtcreator                   08:11:50    01:05:00 <br> 5513 grep            grep -i qtcreator           09:16:50       00:00   How can I resolve this problem?


Animate polygon shapefile using QGIS time manager

I am looking for a way to use the QGIS plugin "Time Manager" to animate a polygon shapefile. I have a polygon shapefile that has a field of population per year for each feature and I want the plugin to display the data year by year.  COUNTY_NAME / 2001_POP / 2002_POP / 2003_POP  Madison / 1500 / 2000 / 3000  Guilford / 1500 / 3000 / 4500  I have found tutorials that explains how to do it with a point layer, such as , but none with polygons. Any idea?


How do I file feature request bugs on Launchpad?

I've seen on Bugzilla bug request for enhancements, is there anything similar for Launchpad?


Proving there is no rational number such that square of it is equal to 2.

I start the proof by assuming there is $m/n \in Q$, expressed in lowest terms, such that $$(m/n)^2=2$$  My textbook tells me to derive a contradiction by showing $m,n$ are both even.  Here's how I did it.      $(m/n)^2=2$      $m^2/n^2=2$      $m^2=2n^2$      Hence, $m^2$ is even and $m$ must be even. Then, $m^2=2k$ for some   integer $k.$ Plugging $m^2$ back to the equation,       $(2k)^2/n^2=2$      $4k^2=2n^2$       $n^2=2k^2$      Hence, $n^2$ is even so as $n.$ Therefore, it contradicts $m/n$ are in   lowest terms.   Is this right way to prove this? I feel I am doing wrong because I am plugging back the equation I got from the equation to the same equation.


Showing that $\frac{f(x)-f(x-h)}{h} \le f'(x) \le \frac{f(x+h)-f(x)}{h}$ given that f' is increasing

We are considering that $h > 0$. I just don't really know how to approach this question; it seems that by taking the limit of the inequality as h goes to 0, each part of the inequality is going to be equal to $f'$, but I don't really understand why the fact that $f'$ is increasing is relevant to finding a solution to this question (and how to answer the question based on that constraint).


What is the best way to sort the results of a sql query into a random order within a stored procedure?


Travel from USA to India - Transit Visa requirement?

I am traveling from seattle to bangalore via london airport. Do i require transit visa, if my current US visa (h1b) expired? I have valid canadian visitor visa, would that suffice or still i need to have transit visa for UK?


Future plans for the Stack Exchange iOS app beta version

I’m using Stack Exchange iOS app 1.7.0.1 beta and it expires shortly:        Latest stable version in the AppStore is 1.6.6 was released about 4 months ago.   What are the future plans of Stack Exchange team about the iOS app?  Will we see new beta in the next week?


I put an article on the Arxiv, submitted it, it got cited before being accepted, and now is accepted with minor revisions. Some of the minor revisions can be implemented elegantly be referencing the article that cited the preprint version of the article.  Is it oke to do so? Or should this circular referencing be avoided?


Distribution of Product of Random Variables with one being the normal distribution.

Let $X$ and $Z$ be independent, with $X\sim N(0,1)$, and with $\textbf{P}(Z=1)=\textbf{P}(Z=-1)=\frac{1}{2}$. Let $Y=XZ$ (i.e., $Y$ is the product of $X$ and $Z$).   (a) Prove that $Y\sim N(0,1)$.  (b) Prove that $\textbf{P}(|X|=|Y|)=1$.   (c) Prove that $X$ and $Y$ are not independent.   (d) Prove that $\textbf{Cov}(X,Y)=0$.  (e) It is sometimes claimed that if $X$ and $Y$ are normally distributed random variables with $\textbf{Cov}(X,Y)=0$, then $X$ and $Y$ must be independent. Is that claim correct?   My Work: (a) Is really where I am a little stuck. In order to show that $Y\sim N(0,1)$, I want to show that they have the same distribution laws. Thus, I want to show that $\mathcal{L}(Y)=\int_{-\infty}^\infty \frac{1}{\sqrt{2\pi}}e^{-\frac{t^2}{2}}\textbf{1}_B(t)\lambda(dt)$ given that $\mathcal{L}(X)=\int_{-\infty}^\infty \frac{1}{\sqrt{2\pi}}e^{-\frac{t^2}{2}}\textbf{1}_B(t)\lambda(dt)$.   However, I don't know how to go about that. Another approach I have considered is to show that for any Borel measurable function $f:\mathbb{R}\to\mathbb{R}$,$\space$ $\textbf{E}(f(X))=\textbf{E}(f(Y))$ for which each is well defined. Which approach do you think is better and How should I start. Any help will be appreciated.


I have a definition:  \newcommand{\arnold}{Arnold Schwarzenegger}   When I refer to it by:  \arnold is a   it is rendered as:   Arnold Schwarzeneggeris a    In order to have a space in front of "is" I would need to write  \arnold\ is a   Is there some other shorter way?


Function pointers that hold more functions

I am trying to create a function:  int func(int a, int b) { if (a == b) return 1; else return 0; }   Then I would like to create a function pointer like:  int (*ptr)(int, int);   How can I assign dynamically ptr to allow for it to hold, for example, 10 different function calls?  ptr[0] = func(1, 1); ptr[1] = func(1, 0); ... ptr[9] = func(0, 0);   So that I can call function inside FOR loop via pointer like:  int result = 0; for (int i = 0; i < 10; i++)     result += ptr[i]; printf ("%d\n", result);


I Used Shift + L to select all objects in common.. how do I apply a material to all of those now?

I did Shift + L to select objects with the same default material, but now how do I apply a material to all of those?  It will only apply a material to the original one I wanted to compare the other objects with.


Confusion about calculating electrostatic energy using the electric field

Recently I learned that electrostatic potential energy of a system of charges can be calculated like so:  $$E = \int \frac{1}{2} \epsilon_0 \mathbf E^2 dV.$$  However, for a system of two point charges Q1 and Q2, we have  $$E = \int \frac{1}{2} \epsilon_0 (\mathbf E_1 + \mathbf E_2)^2 dV = \int_{}^{}\frac{1}{2}\epsilon_0 \mathbf E_1^2 dV + \int_{}^{}\frac{1}{2}\epsilon_0 \mathbf E_2^2 dV + \int_{}^{}\frac{1}{2}\epsilon_0 * 2 \mathbf E_1 \cdot \mathbf E_2 dV$$  from which we subtract the first two terms because they are already properties of the charges themselves.  Question:  Why do we not need to do something like this for charge distributions? Aren't charge distributions made up of many many little charges of magnitude $e$? Even if we treat the charge distribution as perfect continuous, won't there be infinitely infinitesimal charges?


Apache server config: how can I disable the certificate/SSL handshake on the WWW version only?

Serving a apache website via https:// => how can I disable the certificate/SSL handshake on the WWW version only?  Hi we use SSL on the  version of our website  Now I would like to disable the SSL connection on the  version of our website  SO the result is:    => SSL handshake  => no SSL handshake => and htaccess rewrites are executed   question: Can this be done?  ps. I am asking because nowadays more websites move to https, not realizing that directing non-www to www traffic (and vice versa) is a little more difficult - because the handshake occurs before the htaccess (rewrite) directives .. the solution is ofcourse an extra certificate ... but a better solution would be to do find a solution to just redirect the traffic ...   Appreciate your help


How to create a playlist form a list of links (not from bookmarks)?

I have something like that  how do I convert this to a YouTube playlist?


#include<stdio.h> int main() {     union emp;     union emp{     int age;     char name[2];     };     union emp e1={512};     printf("%d,%d,%d",e1.age,e1.name[0],e1.name[1]);     return 0; }   Here ive tried to craete a union and initialize its 1st member i.e "int age". As per my knowledge ANSI C compilers support this. My question is why i am getting an output like "512,0,2". If i replace 512 with 513, 514 and 768 i get the following oytputs. "513,1,2", "514,2,2", "768,0,3", Now i can see that the e1.name[0] is storing (the number)%256 and e1.name[1] is storing (the number)/256. It would be greatly appreciated if it is explained that why and how this happens. Thank you all.


While I was trying to install wifi drivers in ubuntu 18.04, i was getting this error:  modprobe: ERROR: could not insert 'rtl8723be': Required key not available   I followed procedure given in   Unable to figure the reason for the error. Any solution to this problem will be appreciated.


Do Indians need transit visa to stay in Jeddah for 13 hours?

I am travelling to USA in December from India (Indian citizen) through Saudia Airlines. Unfortunately, I have a layover period of 13 hours in Jeddah. Even though I dont have any plans to leave airport do i still need to apply for a transit visa?


Potential Difference across an ideal short circuited cell

It was my friend who asked me this question first. Suppose we have an ideal cell and a wire of resistance zero.Suppose we short circuit the cell using the wire(although we know ideal cells and zero resistance wires are not practically possible). Would there be a potential difference across the wire . I think it ought to be there ; but my friend points to me that no potential difference exist across a zero resistance wire. Please help me.


I''ve downloaded tar file from oracle server but I don't know how to install it on my ubuntu linux system. Could you please provide step by step details on how to install it? Thanks


How do I switch between keyboard layouts?

I want to switch between English and another language.  I have tried Lubuntu and it was easy, I figured it out from the friendly menus. But in Ubuntu everything is so cryptic.


I’ve read about hash and HashMap coming from here:   In particular:  //Depends only on account number @Override public int hashCode() {     final int prime = 31;     int result = 1;     result = prime * result + accountNumber;       return result; }   Why the hash code is calculated with prime * result + accountNumber and not only from accountNumber  What meaning has the fixed value prime * result?  Why not just prime (result value is 1 so prime time 1 is prime)?


Using cURL command-line tool on Mac, how does one fetch stock data which comes back *without* commas?

The below script is not working.   cd desktop/quoteUpdate while true do  curl-o quotes.txt -s "http://download.finance.yahoo.com/d/quotes.csv?s=goog,aapl&f=sl1"  sed -i '.bak' 's/,/ /g' quotes.txt echo UPDATED: date sleep 10 done   When I try and run the executable I get this error and no txt file is created in my desktop folder.  UPDATED: Wed 14 Jan 2015 15:33:30 GMT      /Users/chrisdorman/Desktop/quoteUpdate/runNow: line 4: curl-o: command not found     sed: quotes.txt: No such file or directory


"Install alongside" option missing. How do I install Ubuntu beside Windows using "Something Else"?

Whenever I startup from the LinuxLive USB, and try to install Ubuntu 12.04, it only gives me two options instead of the usual 3 or 4. My options are "Replace Windows 7 with Ubuntu" and "Something Else". Whenever I go into "Something else", it looks extremely confusing. How do I install it side-by-side while using the "Something else" section? These are my partitions.   /dev/sda /dev/sda1 ntfs (104Mb, System Required Partition) /dev/sda2 ntfs (1000097Mb, Windows 7 Partition)   Or should I try reinstalling my installer on a CD rather than USB and maybe then it will have the "Install alongside" function?


Need help remembering title of 80s-era sci fi anime featuring car combat with Star Wars inspired characters

Been trying to track down some of my old favorites from the 80s era of anime, one that has refused to show up in search after search has brought me here with the hope that someone might know of it.  Details: Sci-fi anime series (viewed on American TV early weekday mornings) during the 80s. Heroes drove cars and enemies were cars, with the heroic cars being high-tech and each unique, and enemies being some organic spore-based grow-on-demand instant cars. One of the latter had a bola style weapon, forget the others.  Characters were quite obviously modelled after Star Wars 4, I forget what their cars were capable of except in one case:  -"Han" owned the starship they traveled on, "Luke" was main character (?), "Ben" and "Leia" rode in the same car, which had a drill for going underground.  As far as what year the title was aired, I can't say for certain, around the mid 80s I can say confidently.