I checked my etc/log/mail.log and i find huge file that contain a lot of rows like those (every sec insert 20 rows):  Jan 31 06:25:20 myservername postfix/smtp[15459]: 02ACF5FBC3: to=<xxxx@yahoo.com>, relay=mta5.am0.yahoodns.net[98.137.159.28]:25, delay=412553, delays=412501/50/1.6/0.13, dsn=4.7.0, status=deferred (host mta5.am0.yahoodns.net[98.137.159.28] said: 421 4.7.0 [TSS04] Messages from myServerIP temporarily deferred due to user complaints - 4.16.55.1; see https://help.yahoo.com/kb/post$ Jan 31 06:25:20 myservername postfix/smtp[15459]: 02ACF5FBC3: to=<xxxxxx@yahoo.com>, relay=mta5.am0.yahoodns.net[98.137.159.28]:25, delay=412553, delays=412501/50/1.6/0.13, dsn=4.7.0, status=deferred (host mta5.am0.yahoodns.net[98.137.159.28] said: 421 4.7.0 [TSS04] Messages from myServerIP temporarily deferred due to user complaints - 4.16.55.1; see https://help.yahoo.com/kb/postmaste$ Jan 31 06:25:20 myservername postfix/smtp[15463]: 08B5359448: host mta6.am0.yahoodns.net[98.137.159.28] said: 421 4.7.0 [TSS04] Messages from myServerIP temporarily deferred due to user complaints - 4.16.55.1; see https://help.yahoo.com/kb/postmaster/SLN3434.html (in reply to MAIL FROM command) Jan 31 06:25:20 myservername postfix/smtp[15463]: 08B5359448: lost connection with mta6.am0.yahoodns.net[98.137.159.28] while sending RCPT TO Jan 31 06:25:20 myservername postfix/smtp[15464]: 680715EDFD: host smtp5.opco.com[208.88.204.132] refused to talk to me: 554 5.7.1 You are not allowed to connect. Jan 31 06:25:20 myservername postfix/smtp[15453]: 97AEE58388: host mx142.netapp.com[216.240.21.19] refused to talk to me: 554 mx142.netapp.com    I never sent those mails. Is it possible that my server hacked?  How can I set that only my server(ip) can send mail?  I have checked my php files and close any possible trigger mail function. I need my server that could send and receive mail.   main.cf  smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu) biff = no  # appending .domain is the MUA's job. append_dot_mydomain = no  readme_directory = no  # TLS parameters smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key smtpd_use_tls=yes smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache smtpd_tls_security_level=may  smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination myhostname = MYDOMAIN.com alias_maps = hash:/etc/aliases alias_database = hash:/etc/aliases myorigin = /etc/mailname mydestination = $myhostname localhost.$mydomain localhost $mydomain relayhost = mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 mailbox_size_limit = 0 recipient_delimiter = + inet_interfaces = all inet_protocols = all  virtual_alias_domains = yooteam.com virtual_alias_maps = hash:/etc/postfix/virtual compatibility_level = 2


Prove that : $K(\alpha)=K(\alpha^{2})$ , $K$ commutative field

Problem :  Let $K$ be a commutative field, and $\alpha$ an   aldebraic element of $K$ of odd degree.  Proof that  :  $K(\alpha)=K(\alpha^{2})$  My simple try   Since $\alpha$ algebraic in $K$ so   $\exists F(x)=x-\alpha$ such that $d°F≥1$  and   $F(\alpha)=0$   But  I don't know how I complete this work   Please give me ideas or hints to approach it


Templated method within variadically templated class

is there any way implementing this behaviour?  template < typename... Args > class MyClass { public:     typedef std::tuple < Args... > my_tuple;       template < int n >     static int bar () { return -5; };  };   What I need is this - I have variadically templated MyClass that contains method foo which is templated by another type (in my case only integer). Is this even possible? I have found simmilar solution but only for non-variadic class.  But this can't be compiled due to bar.  EDIT: I compile on gcc 4.7.2  One should run the method like this MyClass<int, int>::bar<4>()  Could anyone possibly help me please?  Thanks in advance  EDIT2: full code  #include <stdio.h> #include <stdlib.h> #include <math.h> #include <queue> #include <set> #include <vector> #include <string> #include <cstring> #include <algorithm> #include <stack> #include <map>  template < typename... Args > class MyClass { public:     typedef std::tuple < Args... > my_tuple;       template < int n >     static int bar () { return -5; };  };  template < class A, int N > static void foo() {     A::bar < N > (); }   int main() {       foo< MyClass<int, int>, 4> ();      return 0; }   EDIT3: error  $g++ -Wall -std=c++11 -g -o test.out test.cpp test.cpp: In function ‘void foo()’: test.cpp:28:16: error: expected primary-expression before ‘)’ token test.cpp: In instantiation of ‘void foo() [with A = MyClass<int, int>; int N = 4]’: test.cpp:34:30:   required from here test.cpp:28:2: error: invalid operands of types ‘<unresolved overloaded function type>’ and ‘int’ to binary ‘operator<’ make: *** [test] Error 1


How to properly handle Infs in a statistical function?

Suppose I have a function such like:  f <- function(x){   exp(x) / (1 + exp(x)) }   it's supposed to work for any real value of x, but actually it returns NaN when x is 710 or larger. I'm wondering what's a proper way to handle this issue. I realize it's easy to make it just return 1, but maybe it's not a good behavior from a statistician's point. Does somebody have some comments or suggestions?


Which default programs can be safely uninstalled?

Which programs installed by default in Ubuntu are generally regarded as safe to uninstall?  I'm mostly thinking of things like social networking, E-mail, you know. Bonus stuff.


Does $ \sum_{n=1}^{\infty} \left(\frac{\sin(n)}{n}\left ( \sum_{m=1}^{n}\frac{1}{m} \right )\right) $ converge?

I am trying to determine whether the  $$ \sum_{n=1}^{\infty} \left(\frac{\sin(n)}{n}\left ( \sum_{m=1}^{n}\frac{1}{m} \right ) \right)  $$  converges or not. I have tried the popular tests, but all were inconclusive (so perhaps I am doing it wrong...).  I would appreciate any help and explanation on how I should solve it.  Thanks.


In ubuntu 11.04 there was a workaround using gconf-editor and setting key /apps/gnome_settings_daemon/plugins/xrandr/active to false.  However there is no such key in gconf-manager using ubuntu 11.10 (gnome 3).


How "submitted", "to appear", "accepted" papers are evaluated in a CV?

Assume a search committee is reading my CV and in the publication section they notice some of my papers are only submitted or claimed to appear in a journal (or accepted for publication in a journal). Sometimes the journal which has accepted the paper for publication lists the title of accepted articles before actually publishing them, but in the rest of cases there is no evidence to prove that the referee process of the paper is over and the journal has accepted the paper for publication. Also assume preprints of my papers are available in ArXiv. So, my questions are:   How a search committee interprets and evaluates those papers which are just submitted or are claimed to appear?  Does a search committee consider these types of publications less valuable than the published ones (assuming the same quality)?  Does a search committee refer to my preprints in ArXiv to evaluate my submitted or accepted papers?


What determines which tag is displayed as part of a question when multiple tags are present?

When posting questions to several different sites across the Stack Exchange network, I've noticed that depending on the tags that I've included as part of my question, one of these tags will sometimes be selected and added to the title of the question. As an example, if you take a look at a question that I posted on the Apple Stack Exchange site (), you'll notice that the "Cellular Carriers" tag is listed in the title of the page - despite it being the second tag listed as part of the question. What determines which tag is shown as part of the title of the question?


When should I vote to delete a question?

I've recently reached enough reputation on one of the sites to be able to cast delete votes. I am not sure when a question is supposed to be deleted as opposed to just remain closed.   What criteria should I use when deciding whether or not to cast my delete vote?


I am passing arguments to the shell script below ./script.sh pan.tgz 192.168.3.1 ABCXYZ  #!/bin/sh echo $1 $2 $3 file=$1 host=$2 key=$3  curl -kv -o ${file} 'https://${host}/api/?type=export&category=device-state&key=${key}'   but getting error curl: (6) Could not resolve host: $host


How do I ask someone his/her position in his family(among his siblings)?

I want to learn a person's order/position in his family i.e., among his siblings. So can I say:  "Where do you rank among your siblings?"  Is this usage correct? If not, can anyone provide me with some other better question?


Prove if $\lim_{x\to\ c} \ f'(x) = K$ then $f'(c) = K$

Suppose $f: (0, 1) \rightarrow {\rm I\!R}$ is continuous, with $c \in (0, 1)$, and suppose that $f'$ exists $\forall x \in (0, 1)$\{$c$}. Prove that if $\lim_{x\to\ c} \ f'(x) = K$ then $f'(c) = K$.  $$\lim_{x\to\ c} \ f'(x) = K \Rightarrow \forall \epsilon > 0, \exists \delta > 0 \text{ such that } |f'(x) - K| < \epsilon \text{ for } x \in (c-\delta, c+\delta)$$  Since $f$ is continuous and differentiable on the open interval we can use the Mean Value Theorem on $[x, c]$ where $x \in (c-\delta, c)$.   So $\exists x_1 \in (x, c)$ such that $f'(x_1) = \frac{f(x) - f(c)}{x-c}$.   By our limit definition $|f'(x_1) - K| = |\frac{f(x) - f(c)}{x-c} - K| < \epsilon$.   $$\Rightarrow \left|\frac{f(x)-f(c)}{x-c} - K\right| < \epsilon \text{ for } x \in (c-\delta, c)$$  We can use the MVT again on $[c, x]$ where $x \in (c, c+\delta)$, find an $x_2 \in (c, c+\delta)$ and get similar result.   $$\Rightarrow \left|\frac{f(x)-f(c)}{x-c} - K\right| < \epsilon \text{ for } x \in (c-\delta, c+\delta)$$  $$\Rightarrow \lim_{x\to\ c} \frac{f(x)-f(c)}{x-c} = K$$  $$\Rightarrow f'(c) = K$$  I'm not sure that I did this right - I'm not too comfortable with proofs yet (especially unfamiliar with using the MVT in proofs). I didn't use the fact that the domain of f is (0,1) which is concerning.


If Two Groups are both NONAbelian And Have same No. Of elements of each order .Are they isomorphic

I was trying to prove that S3×Z2 is isomorphic to D6 . Well there are a lot of Methods to Do so. But I was Queried that I We know If two ABELLEAN Groups have same no. Of elements of each order then they are ISOMORPHIC Also there exist a Abellean and a NONAbelian group satisfying the property but still non ISOMORPHIC. So my doubt Is -- Is it true If both are NONAbelian And Have same no. Of elements of each order then they are ISOMORPHIC


How to generate a number with Math.random() with the min inclusive and max exclusive?

I was using Math.random()*(max-min))+min but this is all exclusive. How can I make it inclusive and what is the method behind figuring this out? I tried Math.random()*(max-min))+min until I realized that it was all exclusive. I'm trying to figure out the logic behind how to make this with the min inclusive. I also tried Math. random() * (max - min + 1) + min but this makes the upper inclusive. Simply stated: How can I use Math.random() generate numbers from a minimum (inclusive) to a maximum (exclusive)?


Exporting all equations from a document as individual svg files

I'm currently a presentation based on a paper originally written in Latex. Currently, I use Kile and Ubuntu for my work.  What I'm finding is that I need a large number of the equations from the original paper scattered around the presentations (and are using them to annotate diagrams etc).  My current method of screenshots + gimp is rather slow :)  So, what I would like to do is compile the tex document and instead of creating a pdf/dvi, I would like it to spit out a number of files, which each file being one of the equations from the document, preferably in a vector format, but I will live with a PNG if I have to, so long as it's of high enough resolution.  I've had a look at a number of utilities.   The following web utility:  does more or less what I want for an individually typed equation. However, I've used a lot of mactros in equations that make it a little messy to use (for example)  \newcommand{\SkewSymmetric}[1]{\ensuremath{ \left[ #1 \right]_{\times}}}   I've had a look at pdf2svg, but it doesn't quite do what I want - I still need to crop out the equation of interest.  Is there anything else I should look at?


I've set up unattended upgrades, and wish to receive an email on every update run to make sure it's running. For whatever reason, ssmtp isn't installing so isn't an option.  How do I configure my server to use an external smtp server that uses login and ssl/tls security?  (I want to send from "noreply@example.com" on mail.example.com:465.)  No,  not asking about broken package fixing since I have default repository already. I'm asking if there's an alternative to ssmtp


How can I fix the 'empty drag box' effect on Windows Server 2008 R2?

I only have a small problem, which isn't really a problem, more of just an annoyance. When you drag a window around in Server 2008 R2, it just shows a outline, much like Windows 98. Here's a screenshot demonstrating what I'm talking about. I'm using the Desktop Experience feature, and Aero is turned on. Anyone know a way to fix this?


Where is standard American English derived from?

I have a book that explains how to speak in standard American English (American Accent Training — Barron's).    What does the term standard American English refer to?  Is there a region in the United States of America that has a pronunciation similar, or closer to standard American English (in the same way standard Italian is derived from a dialect spoken in Tuscany)?


How to redirect http requests to https (nginx)

There appear to be many questions and guides out there that instruct how to setup nginx to redirect http requests to https. Many are outdated, or just flat out wrong.   # MANAGED BY PUPPET  upstream gitlab {   server unix:/home/git/gitlab/tmp/sockets/gitlab.socket; }  # setup server with or without https depending on gitlab::gitlab_ssl variable server {   listen *:80;   server_name gitlab.localdomain;   server_tokens off;   root /nowhere;   rewrite ^ https://$server_name$request_uri permanent; } server {   listen *:443 ssl default_server;   server_name gitlab.localdomain;   server_tokens off;   root /home/git/gitlab/public;    ssl                           on;   ssl_certificate               /etc/ssl/certs/ssl-cert-snakeoil.pem;   ssl_certificate_key           /etc/ssl/private/ssl-cert-snakeoil.key;   ssl_protocols                 SSLv3 TLSv1 TLSv1.1 TLSv1.2;   ssl_ciphers                   AES:HIGH:!ADH:!MDF;   ssl_prefer_server_ciphers     on;    # individual nginx logs for this gitlab vhost   access_log  /var/log/nginx/gitlab_access.log;   error_log   /var/log/nginx/gitlab_error.log;    location / {     # serve static files from defined root folder;.     # @gitlab is a named location for the upstream fallback, see below     try_files $uri $uri/index.html $uri.html @gitlab;   }    # if a file, which is not found in the root folder is requested,   # then the proxy pass the request to the upsteam (gitlab puma)   location @gitlab {     proxy_read_timeout 300; # https://github.com/gitlabhq/gitlabhq/issues/694     proxy_connect_timeout 300; # https://github.com/gitlabhq/gitlabhq/issues/694     proxy_redirect     off;      proxy_set_header   X-Forwarded-Proto $scheme;     proxy_set_header   X-Forwarded-Ssl   on;      proxy_set_header   Host              $http_host;     proxy_set_header   X-Real-IP         $remote_addr;      proxy_pass http://gitlab;   } }   I've restarted after every configuration change, and yet I still only get the 'Welcome to nginx' page when visiting http://192.168.33.10. whereas https://192.168.33.10 works perfectly.   Why will nginx still not redirect http requests to https?   I've also tried the following configurations      listen *:80;   server_name <%= @fqdn %>;   #root /nowhere;    #rewrite ^ https://$server_name$request_uri? permanent;    #rewrite ^ https://$server_name$request_uri permanent;   #return 301 https://$server_name$request_uri;   #return 301 http://$server_name$request_uri;   #return 301 http://192.168.33.10$request_uri;   return 301 http://$host$request_uri;   The logs   tailf /var/log/nginx/access.log 192.168.33.1 - - [22/Oct/2013:03:41:39 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:24.0) Gecko/20100101 Firefox/24.0" 192.168.33.1 - - [22/Oct/2013:03:44:43 +0000] "GET / HTTP/1.1" 200 133 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:24.0) Gecko/20100101 Firefox/24.0"  tailf /var/log/nginx/gitlab_error.lob 2013/10/22 02:29:14 [crit] 27226#0: *1 connect() to unix:/home/git/gitlab/tmp/sockets/gitlab.socket failed (2: No such file or directory) while connecting to upstream, client: 192.168.33.1, server: gitlab.localdomain, request: "GET / HTTP/1.1", upstream: "http://unix:/home/git/gitlab/tmp/sockets/gitlab.socket:/", host: "192.168.33.10"   Resources


Could you help me finding some less colloquial equivalent to highlighted phrases of this speech

Today I want to be able to give you some good tips on parallel parking. It's part of your road test. It's something you need to learn. For most new drivers it's real difficult, because they're not able to judge angles. And parallel parking is all about angles. I'll take you through a typical parking, I'll take you through how I teach it , and maybe that'll help you in passing your road test. The first thing you want to do is you want to pull over over and you want to stop alongside a parked car. Typically, an inspector will give you a command to pull over, stop next to the red or blue car. You're just going to pull over, put your blinker on to the right, and pull over even with that car.     taken from a series of videos teaching driving   Why did the man use  be able in his speech? What is the difference between be able and I would like to or I want ? I mean what the listener should make of  I want to be able to give you ...  . Why did not he say I want to give you... ?  When he says I'll take you through a typical parking , I get the meaning of take one through ,It means I am going to teach you , isn't it? But my real concern is what the second I'll take you through means, while saying I'll take you through how I teach it . Perhaps it doesn't mean I will teach you that how I teach it ! , does it? The man always says the first thing you want to do . Why does not he say the first thing you should do , the first thing you need to do ? What are the diffrences in meaning? Isn't it unnatural saying you want to do ? In the last sentence he says You're just going to pull over, is the use of going to just weakening would and will? I think here it means something else. I think it means you just want to or you just start


This is a pretty open ended question and I apologize, in advance, if this is not the place for it.  But what do you recommend should be given the title of the Fundamental Theorem of Trigonometry and why?  Should we have to restrict ourselves to the planar case... I think so.


How to calculate no of homomorphism between Sn and Sm , Dn to Sm etc

Can anyone list out any general rules how to calculate the number of homomorphism between different groups like Sn to Sm, Dn to Dm etc? I have been trying to calculate the number of homomorphism through the traditional approach but its very time consuming.


Why $D_n$ is  not simple ?  i was  asking  this  question  to my professor  . My professor  said me that  $D_n$  is not simple  because  subgroup genereated by $< \frac{R_{360}}{n}>$ is  normal in $D_n$.  Actually  i didn't  understand the  meaning  Any hints/solution  will be appreciated  thanks u


I read some of the posts here about lightsaber physics, but I never found an explanation to a question someone just asked me:  When a lightsaber duel is happening, is it a useful tactic to turn off one's saber for a split second, allowing you to avoid certain obstacles (like the opposing saber)?


My rims are pretty old and I need help in buying a new ones. Can I use 26er rims for 26x1.95 tires?


What does it mean to have a Bad Quality Package (What qualities would it have to be a Bad quality package) and what happens if I install a package that has bad quality but still installs.


Was Jedi robe a uniform during the clone wars?

In a discussion I had about the possibility Jedi commiting war crimes on the grounds of being non-uniformed combatants with concealed weapon. Someone pointed out that a Jedi Robe is visibly distinguishes them from others. And the question I wanted to ask here is - does it? Because I think it's only distinct on-screen for the benefit of the viewer. Some pointers:  Jedi wearing a clone trooper armour is obviously totally fine. It distinguishes them as the members of the republic force quite clearly. Episode IV indirectly implies that a robe is a normal clothing for people to wear (Obi-Wan doesn't raise suspicion). In Episode I Qui-Gonn Jinn tries to swindle a Toydorian out of his stock using a mind-control technique. When it fails, the Toydorian specifically says something in the color of "who do you think you are, a jedi?" not realising one actually stands before him. (Though maybe Jedi are unexpected to be seen on the planet, to the point that even looking at one doesn't cross anyone's mind). There are scenes in Episode II on Coruscant where robed jedi walk in the crowd or a bar without raising suspicion. (Though maybe people are used to them. Even in a bar. Even offering Jedi some DeathSticks.) In Episode II there's like a hundred Jedi on an arena who covertly got there despite wearing an outfit. (though honestly they should be noticed just because they're not native Geonosians, so maybe it's just a movie flub). There are some scenes from Episode II I faintly recall but couldn't find them, they may have been removed during some edition alterations:   A crash-landing on the street of coruscant where Anakin tells people it's a "Jedi Business" without showing lightsaber or anything and they just all scatter, which would mean they have instantly recognised him as a Jedi (or he used a mindtrick); A scene at said bar where Obi-Wan tells Anakin to split up to avoid suspicion (meaning their robes aren't instantly recognisable);   Legends are welcome. I'm looking for an answer that would make sense in-universe.  Please note that I'm not asking if there was a rule that forced Jedi to wear a specific type of attire - I'm asking if the attire they adopted distinguishes them from the general population in a military situation in a way that would increase the likelyhood of their adversaries confusing enemy jedi with a neutral person who happened to be in a warzone.


OK simply I have the following model:   \begin{equation} \begin{aligned} x_k & = f(x_{k-1},\theta)+q_{k-1}\\ y_k & = h(x_k,\theta)+r_k \end{aligned}  \end{equation}  Using Matlab, I generated some data artificially (simulated data) with a vector of parameters $\theta = [\theta_1,...,\theta_n]$ (supposed the true parameters).  I used Gaussian filtering to calculate The log-likelihood expression:  $L(\theta) =  \sum_{k=1}^T -\frac{1}{2}\log [(2\pi)^d\vert \Sigma_k\vert] - \frac{1}{2}(y_k-\mu)^T \Sigma^{-1}_k (y_k-\mu) $  The parameters $\mu=\hat{y}_{k|k-1}$ and $\Sigma=P_{yy,k|k-1}$ are computed during the Gaussian filtering and $d$ is the observation dimension.  The simple question why the true values of the parameters do not maximize the log-liklihood? (is it possible that this happens?).


Computer crashes when trying to install ubuntu

I'm currently trying to reinstall ubuntu 16.04 back onto a partition on one of my hard drives, but whenever I select "Try Ubuntu without installing" or "Install Ubuntu" from my usb, it shows a few messages on the screen    then briefly shows the purple ubuntu loading screen (for a fraction of a second) and then my pc cycles off and then on. Anyone have some ideas as to what could be a potential cause?


I am trying to create a list and add values to it but getting nullpointer exception. Can you please assist. Below is my Java code:  acctTypeCodes = new ArrayList(); cumBalIndicators.add(new SelectItem("Y", "Y")); cumBalIndicators.add(new SelectItem("N", "N"));   Below is the error from log:  java.lang.NullPointerException     at com.jet.bean.GlAcctRefMBean.getCumBalIndicators(GlAcctRefMBean.java:185)


jquery onclick not working for dyanamically added div id

I am working with java and js.  Query is I am adding div dynamically from java code and it is getting displayed on the jsp but I want onclick event on that div id. And its not working  tried this:      $("#moreoption" ).on( "click", function() {                alert( "Goodbye!" ); // jQuery 1.3+              });    //added class instead of id and in a href     $(".moreoption" ).on( "click",'a', function() {                alert( "Goodbye!" ); // jQuery 1.3+              });   $("#dd" ).live( "click", function() {            alert( "Goodbye!" ); // jQuery 1.3+          });   Please help.


Is there in the game any indication of how many wizards or clerics or druids of each level are in the world? I look for a number of those per regular person or per village/city of x size.  Same for magic items. What kinds of people could afford magic swords in times of war or charisma/social skill enhancing items?  How common is teleportation and mind-affecting magic and who can afford protection (in the form of magic items or recruiting the help of a caster) against it?  i have seen the thread who give what percentage of the population is for each level, but i was more looking for how many for each level by settlement/group/tribe/country depending of the size of the setllement/group/tribe/country.


Can we deduce that any additive map from V to W, over the field $R$ is actually a linear transformation?

I showed as an exercise that for an additive function $T: V\to W$, if $T(u+v)= T(u)+T(v)$, then if the field is the rationals, we get that the linearity implies scalar multiplication, i.e.  $T(qv)=qT(v)$ for all q in rationals and v in V and so T is actually a linear transformation. My question is, if the field was all of R, can we conclude the same thing? I think not, but is there a way to extend this result by maybe introducing limiting procedures into the vector space? Thanks!


Difference between "did + verb" and just "verb+ed"

This is something I always get confuse with (native language German). As far as I know "did + verb" is something done and finished in the past. But isn't it the same with "verb + ed"?


Beamer presentation WITH NOTES. Warning!! "destination with the same identifier has been already used, duplicate ignored"

I hope this question is not a duplicate; I have seen people observing this same warning, but in a totally different context, like  and .  The difference is I do not use hyperref for anything, but this problem shows when I attempt to have notes included in my Beamer presentation.  Notably, this warning didn't show with texlive 2013, I am experiencing it with texlive 2015, as I just upgraded to it.  The warning is the following:     destination with the same identifier (name{Navigation2}) has been already used, duplicate ignored   And here a super simple MWE to reproduce it:  \documentclass{beamer} \mode<presentation> {     \usepackage{pgfpages}     \setbeameroption{show notes on second screen=right} }  \begin{document}  \begin{frame} \frametitle{Frame with notes 1} FIRST FRAME CONTENTS \note{     Notes for the first frame here } \end{frame}  \begin{frame} \frametitle{Frame with notes 2} SECOND FRAME CONTENTS \note{     Notes for the second frame here } \end{frame}  \end{document}   Has anybody observed this warning in the context of a Beamer presentation when hyperref is not used, but notes need to be shown? Does anybody know how to get rid of it? It appears once per slide, so it is really annoying to see soooo many warnings... Thanks!


How important is NTFS Allocation Unit Size really, in terms of read/write performance and fragmentation?

Specifically on large media drives. I'm interested in this subject because I just purchased a 8TB external hard drive (WD White Label) that is specifically going to be used to store hi-res images, music, and 1080p/4k video files. I also plan on editing some of these files as needed, so fragmentation is to be expected. My goal is to use an optimal AUS size with a good balance between speed and fragmentation prevention. Images will be the smallest files and will average around 1mb each.


How do I get rid of these wrinkles in texts

Whenever I add a curve modifier to this text object, It shows these weird wrinkles in some of the letters. If anyone has a solution the solve this, that would be greatly appreciated. This is Blender version 2.79 in cycles render.


Execution of a command locally after ssh tunneling

I have a script file ./run_app.sh which contains of the following:  ssh -L 8888:localhost:8888 ubuntu@address ./run_website.sh   # it should be executed locally   but it tries to run the second line on the remote machine. Actually, I want to run it on my pc. Any idea?


Java how to secure http connection query string URL request passing & getting sensitive data?

The following plain java code is calling some web service API:  String url = "https://my_web_service/some_function?password=my_password"; InputStream is = new URL(url).openStream(); BufferedReader rd = new BufferedReader(new InputStreamReader(is, Charset.forName("UTF-8"))); String result = readAll(rd);  //result is also sensitive data!   Does it's a safe way to transmit & get sensitive data? Assuming arguments like this not relevant:     "SSL is secure, but remember that any encryption can be broken if given enough time..."   Thanks,


Could some explain me how to send email in tabular format using shell script?

Emplyoyee Information:  Name    Age   DOB ______  ___   _________ Jones   54    06/12/1998  Allen   50    06/09/1990   I want to see the above output in a table.


How to prove that the following metrics are topologically equivalent

I have $d_p(x,y) = [\sum | x_i - y_i|^p]^{1/p}$ and $d_q(x,y) = [\sum | x_i - y_i|^q]^{1/q}$ metrics in $\mathbb{R}^n$ and I want to prove that they are equivalent. I already know that $d_{\infty}(x,y) \leq d_2(x,y) \leq d_1(x,y) \leq n d_{\infty}(x,y)$, so I thought of proving that if $p \leq q$ then $d_p(x,y) \geq d_q(x,y)$ or to make it simpler, $d_{p+1}(x,y) \leq d_p(x,y)$, but couldn't advance much


How to evaluate $ \lim \limits_{n\to \infty} \sum \limits_ {k=1}^n \frac{k^n}{n^n}$?

I can show that the following limit exists but I am having difficulties to find it. It is $$\lim_{n\to \infty} \sum_{k=1}^n \frac{k^n}{n^n}$$ Can someone please help me?


How do I convert a hex string to an int in Python?   I may have it as "0xffff" or just "ffff".


Ubuntu 20.04.1 / Desktop icons flicker when a file is deleted

I recently updated from Ubuntu 18.04.4 to 20.04.1. Now I noticed that the icons on the Desktop disappear shortly when I delete a file by pressing the Del key. There is no flickering when I delete a file in my HOME folder for example. Environment  Window manager: Gnome 3.36.3 Desktop environment: ubuntu-wayland Linux distribution: Ubuntu 20.04.1  Maybe related I also noticed that I cannot drag and drop files from the desktop into an open folder. I have to Ctrl + X and Ctrl + V the files.


Why is there a static frictional force on an object that rolls down a ramp?

It is clear that if a frictional force must exist on an object that rolls without slipping, it must a static frictional force because the contact point of the object with the ground does not move.  I know that if a ball rolls on a flat surface, once it begins rolling without slipping, the frictional force is 0. I am confused, however, about the case when a ball rolls down a ramp. For the condition of rolling without slipping to hold, there must be a frictional force on the ball up the ramp. I am confused about where this frictional force comes from if the part of the ball touching the ramp isn't actually moving. It doesn't seem to make physical sense because from the ramp's perspective, it is touching a stationary object and thus there shouldn't be a frictional force.   Help??


What is the difference between hyper-threading and multiple cores?

In a conversation with the network administator, I mentioned that my machine was a dual-core.  He told me it was not.  I brought up the task manager, went to the perfomance tab, and showed him that there are two separate CPU usage graphs.  I have a quad-core machine at home and it has four graphs.  He told there were two graphs on this particular machine because of hyper-threading.  I used to have a hyper-thread pentium 4 processor back in the day, but I never fully understood what it meant.  So what is the difference between hyper threading and dual-core?  And how do you tell which one you have?


Is the graph of a continuous function homeomorphic to its domain?

Let $f:\mathbb{R}^n\rightarrow\mathbb{R}$ be a continuous real function and we consider its graph identified by the subset:   $$\mathcal{G}(f)=\{(x,f(x))\in\mathbb{R}^{n+1}:x\in\mathbb{R}^n\}$$  of $\mathbb{R}^{n+1}$ equipped with the usual euclidean topology that induced on $\mathcal{G}(f)$ a subspace topology. Well with these condictions we demonstrate that $\mathcal{G}(f)$ is homeomorphic to $\mathbb{R}^n$. So we consider the function   $$ h:\mathcal{G}(f)\owns(x,f(x))\rightarrow x\in \mathbb{R}^n$$  since the domain of $f$ is $\mathbb{R}^n$, clearly $h$ is surjective on $\mathbb{R}^n$ and then is also injective because if $h(x,f(x))=h(y,f(y))$ then $x=y$; now to prove the assertion we have to demonstrate of that $h$ and $h^{-1}$ are continuous funcion or that $h$ is open and continuous, but unfortunately I'm not be able to do this so can someone help me?


Is this a proof of Fermat's Last Theorem where n = 3?

So I have spent some time thinking about Fermat's Last Theorem and about how to come up with a proof for certain cases of n. To begin with I took n = 3.  $$A^3 + B^3 = C^3 (A,B,C \in \mathbb {Z})( A,B,C ≠ 0)$$ We can assume that $A<B<C$. Because of this we can rewrite this as: $$A^3 + xA^3 = C^3$$ We now have three possibilities: $x$ is an integer, $x$ is an irrational, or $x$ is a fraction.  If $x$ is an integer then $x$+1 and $x$ must be cubes. The only numbers which satisfy this are $x$ = 0. However, this means $B^3 = 0$.  $x$ cannot be irrational because then $C^3$ is irrational. Therefore $x$ is a fraction.  We can represent this now as: $$A^3 + \frac{p}{q}B^3 = C^3 (p,q \in \mathbb {Z})(GCD(p,q) = 1)$$ This means $\frac{p}{q}$ is actually a cube over a cube. Therefore $p$ and $q$ are cube numbers.  However, $1 + \frac{p}{q}$ is also a cube. Therefore $\frac{p+q}{q}$ is a cube over a cube. Hence: $$\sqrt[3]{p} ,\sqrt[3]{q}, \sqrt[3]{p+q} \in \mathbb {Z}$$  We can now create another variable $v$ for $p+q$. Therefore, $$p+q = v$$ (Where $\sqrt[3]{v} \in \mathbb {Z}$)  Now we must deal with $\frac{p}{q}+1$. Since this is a cube we can write this as: $$\frac{p}{q} + 1 = \lambda^3$$ Since $p$ and $q$ are co-prime and in simplest form, $\lambda$ and $\lambda^3$ are also fractions in simplest form. Rearranging, we get: $$p = q(\lambda^3 - 1)$$  Substituting this into $p+q=v$, we get: $$q+q(\lambda^3 - 1) = v$$ $$q\lambda^3 = v$$  Since $\lambda^3$ is a fraction, we can express it as $\frac{D^3}{E^3}$. Hence: $$qD^3 = vE^3$$  However, because $v$ is a cube, $vE^3$ is also a cube. Therefore $\lambda^3$ doesn't have to be a fraction. This is a contradiction, and so there can be no integer solutions for $p$ and $q$. Subsequently, there can be no integer solutions for A,B,C in: $$A^3 + B^3 = C^3$$.  If anyone could point out the problem in this and what you think of it it would be greatly appreciated. Thank you.


Common modulus attack on RSA when the 2 public exponents differ by a single bit

This is an exam question an i have no idea how to recover the message m.   John wants to send an encrypted message to mary who has a pair of RSA keys, However, John does not know Mary's public key and so John sends an email to Mary to ask for the key. mary's email reply is intercepted by Peter who replaces Mary's public key $\{e,n\}$ with $\{e_2, n\}$ where $e_2$ is obtained by changing one bit in $e$ from $0$ to $1$. Now john encrypts a message $m$ to Mary by using $\{e_2, n\}$. As Mary cannot decrypt the message, she resends her public key to John and asks John to send the encrypted message to her again. Peter does not interrupt this time. However, Peter eavesdrops the whole communication and obtains both encrypted message (one encrypted by $\{e_2,n\}$ and one by $\{e,n\}$. Explain how Peter can recover the message $m$.  How can encryption with both $\{e_2,n\}$ and $\{e,n\}$ be used to recover the message $m$?  I did think that it is related to common module attack, but i have no idea how to prove that $\gcd(e,e_2)=1$.  Does anyone have some idea on how to recover the message?


I was just watching a video and came across the below prompt   Seems like lightening image is at the first and some big arrow like structure to display the directory path. Do you know how to do this in putty please? Thanks.


Book to read before "introduction to gauge field theory" by Bailin and Love

A teacher has recommended me to read this book in order to prepare for a project I am doing. Anyway, I feel that I should need a book in order to prepare for this one. Any suggestions?


Get joint distribution from pairwise marginal distribution

Assume we have 3 random variables $X_1,X_2,X_3$, and we know the pairwise marginal distribution $P(X_1,X_2), P(X_2,X_3), P(X_3,X_1)$, but we don't know anything else (such as conditional independence). Can we get the joint   distribution $P(X_1,X_2,X_3)$?


is it 'a usual' or 'an usual'? 'A usual' sounds more correct in my head ('Today was a usual day.') than 'an usual', but u is a vowel. Which one is correct and why?


I have to prove by cases that for any two sets $A$ and $B$  $A \subseteq B$ if and only if $A\cup(B\setminus A)=B$  I don't get what cases should I consider, I am thinking of proving it by definition of sets, subsets, and union. Can someone help me understand what is needed from me?


says that light always takes the fastest path to any point. So how can light know which is the fastest path without taking all the paths first?


Continuous function between two topological spaces: an ELEMENTARY property.

I'm reading the first chapter of a book on general topology. It has a lot of small, simple exercises on almost all pages and I try to do them all to fully understand the subject.  This one I did not manage to solve, though it's probably really simple, cause the previous ones were:  Suppose $X$ and $Y$ are topological spaces. $f:X\to Y$ is any map.    Prove that f is continuous if and only if: $$ f(\overline{A}) \subseteq \overline{f(A)}\quad  for\quad all\quad A\subseteq X  $$    I think I'll probably have to only use the open subset criterion for continuity and the definition of A-bar and that'll probably be it, but please, help me a bit. Thanks!


How to display any number to 5 decimal places

how to display any number to 5 decimal places.  for example 0.0 to 0.00000, 12.63 to 12.63000. how to display any number to length 8.  for example 12.1 to 12.10000, 2.1234567 to 2.123456


▶Let us think following limit   $ R $   which is  a real number which is finite and non-zero in the region  $ 0 < \sigma < 1 $    $$ R=\lim\limits_{  x\to\infty}x^{1-2\sigma}\frac{\frac{\sin(2\sigma)}{x^{1-\sigma}}+1-\left(\frac{x-1}{x}\right)^{1-\sigma}}{\frac{\sin(\sigma)}{x^{\sigma}}+1-\left(\frac{x-1}{x}\right)^{\sigma}}  $$  We can not split the right side as two limits. It means:  $$ \lim\limits_{  x\to\infty}x^{1-2\sigma}\cdot \lim\limits_{  x\to\infty}\frac{\frac{\sin(2\sigma)}{x^{1-\sigma}}+1-\left(\frac{x-1}{x}\right)^{1-\sigma}}{\frac{\sin(\sigma)}{x^{\sigma}}+1-\left(\frac{x-1}{x}\right)^{\sigma}}  $$  Because:   -- The limits in the right side;  if one is going to the zero , the other going to the infinity.  --Also, we can not apply L′Hospital rule to the second limit in the right side. Because we can not see the values of $\sin(2\sigma)$  and  $\sin(\sigma)$  as zero  in the region $0<\sigma<1$.  ▶ The question: Am I right,  we can not split the right side as two limits  ?


I was solving a recurrence problem which had a sequence such as $y = (1+2+4+8+...)\sqrt n$, and I wanted to find what $x = 1+2+4+8+...$ was. So consider $x = 1+2+4+8+...$ as an infinite series.  $$x-1 = 2+4+8+...$$  $$2(x)=2(1+2+4+8+...) = 2+4+8+... = x-1$$  $$2x = x-1 \Rightarrow x=-1$$  What does $x=-1$ represent? Have I made a mistake in my calculations? Of course, we expect that $x=\infty$ since the sum grows by a factor of $2$ with each term.


Convergence of the series $\sum_{n=1}^{\infty}((1/n)-\sin(1/n))$..?

Does the series $\sum_{n=1}^{\infty}((1/n)-\sin(1/n))$ converge..? Can anyone please give me a simple proof..


Angular 8 : Merging two objects in an array

I have a couple of objects inside of an array :  array1 =[{name : "Cena", age : 44},{job : "actor", location : "USA"}]   is there a way for me to merge these two objects to get something like :   array2 =[{name : "Cena", age : 44, job : "actor", location : "USA"}]   I tried looping through the elements but it is not a good option if the object is a big one, I guess. Any good solution using typescript?


Code to print column vector doesn't work in image caption

In the below example, the \spvec macro generates a column vector nicely in the main body of the document, but it won't compile in the caption.  \documentclass[a4paper]{article}  %% Language and font encodings \usepackage[english]{babel}  \def\spvec#1{\left(\vcenter{\halign{\hfil$##$\hfil\cr \spvecA#1;;}}\right)} \def\spvecA#1;{\if;#1;\else #1\cr \expandafter \spvecA \fi}  \begin{document}  A $test=\spvec{1;2}$ vector.      \begin{figure}         \centering         \textbf{IMAGE HERE}         \caption{abc... $\spvec{1;2}$}     \end{figure}  \end{document}   The error is  Illegal parameter number in definition of \reserved@a. <to be read again>                     $ l.17        \caption{abc... $\spvec{1;2}$}


Question regarding use of low voltage high current outputs

I see every day high voltage, high current; high voltage, low current. I rarely see low voltage, high current; why?  I know that I can take a high voltage, high current signal, send it through a step-down transformer and theoretically get a low voltage high current (with the same power output, of course), but I never see this done.  Can someone give me a reason as to why I wouldn't want a low-voltage high-current scenario?


I have the following text:    <:Hello  World :>  Blah Blah Blah  <:Hello  Foobar :>     And i want to match every <:Hello ... :> Tag with a regular expression (In JavaScript). So what's supposed to be matched is World and Foobar but not blah blah blah.  I tried using /<:HELLO([\s]{1,})([\s\S]{1,})?:>/gi But it matches the whole text From the first <:Hello to the last :> How can i match each tag separately?


In the following examples, the world "talk" was used as a verb and as a noun:     I look forward to talk to you more soon, enjoy your day!        I look forward to talking to you more soon, enjoy your day!   Which sentence is correct gramatically? If both are correct, what is the difference in the usage of talk vs talking in the previous two sentences?


Is "I just spent all my money" grammatically incorrect?

Lyircs of Free by Natalia Kills:     I'm free      I just spent all my money       but I rocked that like it don't cost a thing   Shouldn't it be "I've just spent all my money"? As far as I remember, our English told us to use Present Prefect in such case because of the just.


iMac beachballing for no reason — I suspect it might be faulty hardware. What can I do to work around it?

The Problem:   A couple of weeks ago, the iMac started "beachballing" regularly in normal use There is no discernible pattern to what triggered a beachball. It could be switching between windows, trying to type, using Spotlight, opening or closing an application, or even just whilst idle. Over the next few days, the hangs became so frequent it rendered the iMac effectively unusable I tried literally everything I could think of to fix it (detailed below), but to no avail The only thing that finally solved it was wiping the disk and reinstalling everything from a Time Machine backup But about a week later, the same thing began happening again. I still couldn't figure it out, so was forced to reinstall (again!) And now, yesterday, it's come back once more   I am at my wit's end. I work in IT, and rely on the iMac to be able to work from home whilst my country is in lockdown. My local Apple Store is obviously closed. Each Time Machine restoration takes almost 18 hours to complete, meaning I'm unable to work during that time (never mind the time waiting on the SBBOD to disappear).  The iMac:   2017 27-inch Retina 5K iMac macOS Catalina 10.15.4 32GB RAM 4.2GHz i7 processor Fusion Drive (APFS, comprised of a 128GB SSD + 2TB HDD) T2 security chip   What I've Already Tried:   Checking Activity Monitor during beachballing   CPU: load is usually ~20% Memory: 0 swap used, ~16GB free memory remaining  Signing out of iCloud Disabling Spotlight indexing Creating a new user account SMC reset NVRAM/PRAM reset Disk Utility First Aid Boot into Safe Mode Boot into Recovery Mode, and use diskutil verifyVolume and repairVolume Repairing Home Folder permissions Checking Console and reviewing system.log and other files   No correlation between beachballing and log entries  Running a spindump via Activity Monitor   Worryingly, spindumps don't show up — they just result in a Crash Report appearing in Console ()  Running EtreCheck   No major issues found No noteworthy minor issues found  Running DriveDx   The results for the SSD were fine The results for the HDD do look a bit concerning — .  Running Apple's hardware diagnostic test at startup   No faults found  Reinstalling macOS   My Suspicions:  I found it interesting that reinstalling macOS does NOT fix the problem, but wiping the Fusion drive, reinstalling macOS, AND restoring from a Time Machine backup in one go DOES fix it (at least temporarily).  My  seem to indicate the HDD is in a "failing" state. I don't know if this is just precautionary or if this could actually be causing it. It's hard to pin the blame on this directly, as the beachballs do not seem to correlate with disk I/O, but I can't say that for certain as I don't know enough about this area. I also would've assumed that the Apple hardware diagnostic test you can run at startup might have identified this if it really was a problem...?  So my hunch right now, in the absence of any more obvious clues, is that maybe this problem is caused by a failing HDD in the Fusion drive...? That might explain how wiping and reformatting the drive lets things work smoothly for a week or so, but after enough new sectors have been written to and data shuffled around on the disk, it starts to slow down after time. That's just a hunch!  What Next?   Do you have any other suggestions of things to check or try? Are there any other clues I might have missed? Do you think my hypothesis about the failing HDD is right?   If so, I understand the HDD in a Fusion drive is not user-serviceable... So I would assume the next best alternative would be to buy e.g. 2TB Thunderbolt drive and use that as the startup disk, instead of the Fusion drive? Is this possible? Are there any drawbacks? Any brands you'd recommend?    Thanks for reading this lengthy post. Any advice or guidance is really appreciated!  Jack


Is there something like indent for LaTeX? I have a collaborator that is using Scientific Workplace and the code it produces is totally messed up; I know I shouldn't expect miracles, but any machine support would be useful.  EDIT: This question is quite undefined without my comment to KeithB's answer; the idea is to save VC-friendly one sentence/one paragraph per text file line structure which SWT "fixes" by wrapping everything into fixed column width format.


How do I install itunes 64bits on Ubuntu 14.04 ? Using PlayOnLinux couldn't help me out to install the 64bit version of the latest itunes.


It is not difficult to prove that $0/0$ is not equal to any constant $c \ | \ c/c = 1 \ \land \ c \in \mathbb{R} \cup \mathbb{C}$.  First assume that $0/0 = c$. Consider the true equation $2\times0=0$. Based on our initial assumption, dividing the equation by zero gives $2\times0/0=0/0 \ \Rightarrow \ 2c=c$. Based on our definition of $c$, dividing the equation by $c$ gives $2=1$. However, $2 \ne 1$. $\ \therefore\ $ $0/0 \ne c.\quad\blacksquare$  Sorry for the incomprehensible spacing. Anyways, whenever I attempt to prove that $0/0 \ne 0$, I always end up arriving at $0=0$. Can someone find (or make) a proof? I couldn't find one online either.  Just some clarifications: In in the argument that ends with a box, I am attempting to prove that $0/0 \ne 0$.  Extra clarifications: This is not a duplicate. I am not asking for an intuitive proof that division by zero is nonsensical. I am asking for a concrete mathematical proof that $0/0 \ne 0$. And sorry about my previous edit, that was incorrect but I fixed it.


Difference between #include  & #include "filename"

Here is a preprocessor directive in C :  #include <filename>   we can write it in this way also:  #include "filename"   Is there any difference between these two?


According to the Equipartition Theorem, $$E_{kin}= 3/2 k_B T$$ I read that when we are keeping the wave-nature of particles in mind, we can write $$E= \pi k_B T$$  But how we can write that?


How can the script below be made to always work no matter the filenames returned by find ?  #!/bin/sh  cmds_should_always_work() {      echo "\n\n*********************************" $1     stat --printf='%n' -- "$1" || echo STATFAILED     echo "\n----------------\n"     lsattr -d -- "$1" || echo LSATTRFAILED     echo "\n----------------\n" };  for item in $(find "$1" -maxdepth 1 -mindepth 1); do cmds_should_always_work "${item}"; done   For example files in the find directory that contain a new line break this script.  Further if the find directory is named e.g. $schema, this script returns the parent directory.  How can this be avoided by the script vs. having to supply and escaped path somepath/\$schema to the script?


Yoneda-Lemma as generalization of Cayley`s theorem?

I came across the statement that Yoneda-lemma is a generalization of Cayley`s theorem which states, that every group is isomorphic to a group of permutations.  How exactly is Yoneda-lemma a generalization of Cayley`s theorem? Can Cayley's theorem be deduced from Yoneda lemma, is it a generalization of a particular case of Yoneda, or is this instead, a philosophical statement?  To me, it seems that Yoneda embedding is more canonical than Cayley's theorem because in the latter you have to choose whether the group acts from the left or from the right on itself. But maybe this is an optical illusion.


What exactly do \csname and \endcsname do? What are their job? I have glanced at the Texbook and some other books, but none of them was clear enough to me. Can anyone please give a simple example to clarify this issue?


I just downloaded the latest version of the Ubuntu live CD, and have installed it on a desktop computer (a Fujitsu Scaleo P). Once installed it seems to work perfectly, although there are some updates recommended in the Update Manager.  My problem is that, after having installed these updates and restarted the computer, I get this message on my monitor, and no Ubuntu interface is visible:  frequency out of range - please change display mode   I do not know how to change this when I can't access an interface. Is there a command that will bypass trying to boot the GUI and let me change the display mode via a CLI? I am brand new to Ubuntu and any help on this would be much appreciated.


How to clear all cache files in linux server ( RHEL 5)

How can i clear all cache and buffered files in linux server (RHEL 5) ?


Why do some Operating systems require reboots for certain tasks?

Windows always requires a reboot after updates or big programs are installed.  Linux generally does not require reboots but occasionally does.    It seems to me that the OS should be able to touch/edit anything it needs to while it's running, or at a minimum shut down a process, update it, then start it up again with minimal interruption to the user.   What is the computer doing technically that requires a reboot? Why can't it update or install programs without rebooting? Rhetorical question:  Why hasn't Microsoft or others figured out how to update/install programs without reboots?


I'm new to Java, and I can't find the way to get or choose a random object from my list products. I tried so many different ways, but is always giving me an error. public class VendingWorking {          List<Product> products= new ArrayList<>();          public void registerProducts() {         CStamp stampOne=new CStamp("1 Jan 2000", "Collectable Stamp");         CStamp stampTwo=new CStamp("1 Jan 2000", "Collectable Stamp");         CStamp stampThree=new CStamp("14 Feb 2000", "Collectable Stamp");         CCoin coinOne= new CCoin("25 Jan 2019", "Collectable coin");         Ccar carOne= new Ccar(2015, "Tin Car Toy");         Ccar carTwo= new Ccar(2018, "Tin Car Toy");                  products.add(stampOne);         products.add(stampTwo);         products.add(stampThree);         products.add(coinOne);         products.add(carOne);         products.add(carTwo);     }      public void getRandomElement(List<Product> products){          Random random = new Random();          Product index=products.get(random.nextInt(products.size()));      }       public List<Product> getRegProducts() {         return products;     } }


Stuck with creating if statement from string input

I am trying to learn Java and want it so you input your name, and if name input matches your name it will print Hello [your name], I am doing this using an if statement and make if so if the input is equal to a string equal to my name it will print hello plus the input. However it doesn't... the else statement is what confuses me because I got it to print the two value to see if they where equal and they both where... help would be appreciated thanks.  package AgeTester; import javax.swing.JFrame; import javax.swing.JOptionPane;  public class HelpSystem {  public static void main(String args[]) {   String inp = "Jono";   JFrame frame = new JFrame("Input Dialogue");    String name = JOptionPane.showInputDialog(frame, "What is your name?");    if (inp == name) {    System.out.printf("Hello", name);   } else {    System.out.println(inp + name);   }   System.exit(0);  } }


How many isomorphisms are there from $\Bbb Z_{12}$ to $\Bbb Z_{4} \oplus \Bbb Z_{3}$?  I can see that if $f$ is the isomorphism, the isomorphism is determined by the value of $f(1)$ because $f(1) = (1,1)$ and $f(k) = f(k) + f(1) = f(k) + (1,1)$.  But since $\Bbb Z_{12}$ has $4$ generators, there are $4$ different ways to set $f(1)$ equal to a generator.  Therefore there are $4$ isomorphisms.  Is this correct?


Let $n$ a natural number non zero   Prove that: $$n^5 \equiv n\mod 30$$  I have tried to use fermat theorem and little fermat i can't find any result


Is it possible to boot dual mode on old laptop?

I have an old laptop. (currently windows 7 is installed)  I would like to use that laptop as my personal server.  Is it possible to boot dual-mode(windows 7 and ubuntu 16.04) in my laptop?  My old laptop is a 64-bit machine and has Intel Pentium CPU (P6200).  Below is main specification of my laptop.   dual core processor(Intel Pentium CPU, 2.1GHz) 2GB RAM 64bit machine 1 HDD(300GB)   1) Is it possible to boot with dual-mode?  2) If it is impossible, then can I install ubuntu 16.04 desktop version?(I will remove windows 7)


Recently published paper does not cite my very relevant work

Before I start my PhD I worked in a group that researched on the application of a particular area to a particular domain. No other research group published work in this area+domain. So I can safely say that my previous group is among the first if not the first to research in the application of that particular research area on that particular domain.   Now I find a paper published at an IEEE conference where a major part of its contribution is introducing a system that does something I did in a previously published paper, and it does it in the exact same way and even gives it the same name!   I know that some conferences could accept non-novel contributions. Also the paper talks about other aspects so I find it perfectly fine that this paper has been accepted and published. But what I find annoying is that they do not cite my relevant work which was published a year earlier and fairly visible online; A simple (unpersonalized) search on Google would show up at least three links to my work.   This is the second time I face this problem, but the first time this happened it was actually by the same group I worked with before; they published a related paper without citing the paper I co-authored with them.   I try to give the maximum possible exposure to my work by making it publicly available on my personal website, ResearchGate, making sure it appears on Google Scholar, etc..   I find it worrying that my work misses citations, I am keen on improving my h-index and citations count. So my questions are:   Is there anything I can do regarding that already-published paper?  Is there anything I can do to prevent this from happening in the future?


Recently while visiting a question, I saw two users on Stack Overflow and found uncanny activity. So I visited their profile and saw that these users might be committing vote fraud.  One user is asking and accepting questions from a specific user and vice versa.   Now there is no rule against one user frequently answering another user's question, but if this happens quite frequently then I guess something might be going on.   I believe they are sock-puppets. What can I do in such a situation?


Is it possible to do a HTTP Head request solely using an XMLHTTPRequest in JavaScript?  My motivation is to conserve bandwidth.  If not, is it possible to fake it?


How can I prevent Windows from prompting to restart my computer after an update?

On XP Home how can I prevent Windows from ever trying to restart my computer after an update? XP Home has no Group Policy Editor.


Can I wield just a shield and use magic?

I play a wizard and while I am rarely hit due to being in the back I'm still paranoid I will get hit. So I was wondering if, after getting a feat to wield a shield, I can use that with one hand and use magic with the other?


blender keeps crashing when opening file

Almost finished a large interior project and suddenly when ever I open the specific file Blender keeps crashing. I've restarted my MacBook, reinstalled Blende, turned load UI off, then back on again, reinstalled Blender into a different folder. Sent the file to a friends MacBook, duplicated the file then moved it with no luck what so ever. Is there anyway of recovering the file?


Ruby equivalent to Python list comprehension

How do I write a loop like this in Ruby?  hashTable = [node(None, -1, None, None, -1) for i in range(0, tableLength)]   I already tried the following:  hash_table = [table_length.times do |x|   x = NODE.new(@key, @val, @next, @prev, @pos)   x end]   Where I'm passing the values for @key, @val... when I'm calling the class, as follows:  this = NODE.new(nil, -1, nil, nil, -1) this.read_file("alice.txt")   But it's not working.


what is the fastest way to create an empty binary file in java?

I need to create an empty binary file with given size in java. What is the fastest way to do this? I also need to update UI simultaneously. I use following code to do this. But it’s not very fast. Can everyone help me? Tnx  public static void create(String pathAndName, int fileSize) {     FileOutputStream fileOutputStream = null;     try {       fileOutputStream = new FileOutputStream(pathAndName);       int length = 10 * 1024;       byte[] buffer = new byte[length];       int len = buffer.length;       int createdSize = 0;        int percent = 0;       int lastPercent = 0;        while (createdSize < fileSize) {         createdSize += length;         if (createdSize > fileSize) {           len = fileSize - (createdSize - length);         }         lastPercent = percent;         percent = (int) (((double) createdsize / fileSize) * 100);         if(lastPercent != percent){           updateUI(percent);         }         fileOutputStream.write(buffer, 0, len);       }      } catch (Exception e) {       e.printStackTrace();     }     if (fileOutputStream != null) {       try {         fileOutputStream.close();       } catch (IOException e) {         e.printStackTrace();       }     }   }


string initialization in structures in c?

Sorry if this is a vague question. Basically, in this code,  #include<stdio.h> #include<string.h> struct string {     char arr[50]; }; int main() {     struct string one;     one.arr = "Max"; //this line     printf(" %s",one.arr);     return 0;  }   I get the error assignment to expression with array type. But replacing the 2nd line in main() with the line:  strcpy(one.arr,"Max");   I get no errors. Can you explain why?


How to create a new object instance from a Type

One may not always know the Type of an object at compile-time, but may need to create an instance of the Type.    How do you get a new object instance from a Type?


Choosing encryption algorithms and encryption protocols in military systems

Militaries use their own cryptographic algorithms, those of a private third party, or ones that are openly available.  But fear of a backdoor having been planted in publicly-available encryption protocols scares them--even though it is technically possible to analyze cryptographic primitives and establish whether or not they are dorked.   Is there any other advantage in hiding the algorithms and protocols a military uses for its systems?


I've read the books and all but what happened to Valyria? Are there any outside sources? If you think about it, the whole empire was destroyed in this apocalyptic event. The event had to be so bad that a few hundred years afterwards no one would go there. If it was a volcano it would be pretty unlikely that they'd still shun that place in my opinion. Same with an earthquake.


When I was wandering around , I suddenly saw this weird text:        At first I thought the post was like that, but after checking there is no strange thing in the second image that previously appeared in the first image:        The square inside the first picture that contain text "\text{closed quantum system" is not done by me; I already found it like that.


Proving existence of surjective $f:\mathbb{N} \rightarrow A$ implies $A$ is at most countable.

Definition of "at most countable" used: A set $A$ is at most countable iff it's finite or there exists a bijection $f:\mathbb{N} \rightarrow A$.  Problem: I want to prove that if there exists a surjective function from the set of natural numbers to a set $A$, then there exists a bijective function $f:\mathbb{N}\rightarrow A$, with the condition that $A$ is infinite (Because if it´s finite, one condition is met and the problem is over).  My approach for these kind of problems used to be creating a function that just maps from the first set to the second, making permutations as necessary. But infinity is confusing me. So this is my approach so far:  Index each set with different index numbers, both natural numbers. $x$ for naturals, and $y$ for elements in $A$. So we would get $f(x_n)=y_i$, $f(x_{x+1})=y_{i+1}$ and so on. Then create another function:  $g(x_n) = \left\{    \begin{array}{l l}     f(x_n) & \quad \text{if $\forall a<n, f(x_a)\neq y_i$}\\     h(x_n) & \quad \text{if $\exists a<n/f(x_a)=y_i$}   \end{array} \right.$  The problem we're trying to avoid here is having two elements in $\mathbb{N}$ so that $f$ maps them to the same $y$. Here, the so called "$h$" function: what should it do? Or is there another approach I should be using instead? (Like, Axiom of Choice and its equivalents).


Is (the reason ) "is his expecting otherwise" grammatically correct?

(1) "But maybe the fear in his eyes" "Is him expecting otherwise."  I understand it is not grammatically correct (indirect object) but please provide more info as to why it's not. A grammar expert said (1) is ok to use in a poem because ok to bend the rules.  Who agrees? (2) "But maybe the fear in his eyes" "Is he's expecting otherwise." seems grammatically correct but does not have the same meaning as (1) because it implies the expectation is causing the fear and I want the fear to instead be equated with being the expectation instead of caused by it (as I believe (1) does.) (3) "But maybe the fear in his eyes" "Is his expecting otherwise." Like 1, implies an equating relationship (though perhaps not as well as (1) does...) but is it grammatically correct? The grammar expert suggested using (3) but suggested I not use 2 (though he did not say it was grammatically incorrect).   I see nothing wrong grammatically with (2).  But I don't want to use 2 because it is not "poetic". So the question now is, is (3) grammatically correct? Seems to me "is his expecting otherwise" is using a possessive form (such as in "the reason is his shirt is too bright") and thus for it to be grammatically correct would have to be "the reason is his expectation is otherwise" which does not work poetically. If "is his expecting otherwise" is correct, then why is "The reason she's given up drinking alcohol is her having a baby" not correct? He / she, him /her, he / her. Is the answer something to do with there being 3 masculine pronouns and only 2 feminine? And why is there one more masculine than feminine anyway? Thanks.


Why isn't index fund investing (Bogleheads school) more commonplace?

I started investing recently, but I've been searching for information for over a year now. My main sources (listed below) favour the strategy of Jack Bogle. i.e. Choosing an index fund with good diversification and low TER and watch it grow (buy&hold).   There seems to be great consensus among them, supported by historical and recent data that points that actively managed funds offer no advantages against the indexed ones.  If actively managed mutual funds fail to consistently beat the market, why should an individual investor bother with them? They offer a dubious hope of higher returns, with the omnipresent downside of higher Total Expense Ratio.   My question is:   Why other investing strategies (cherry-picking stocks, mutual funds, etc) haven't been phased out in favour of index investing yet?


Adding a Method to an Existing Object Instance

I've read that it is possible to add a method to an existing object (i.e., not in the class definition) in Python.   I understand that it's not always good to do so. But how might one do this?


We have blacklists in place to stop traffic from known bad actors. There are plenty of resources such as the lists below but I am not finding any results for ipv6 blacklists. Does anyone know where I can find such lists?     "https://www.projecthoneypot.org/list_of_ips.php?t=d&rss=1" # Project Honey Pot Directory of Dictionary Attacker IPs     "https://check.torproject.org/cgi-bin/TorBulkExitList.py?ip=1.1.1.1"  # TOR Exit Nodes     "https://www.maxmind.com/en/high-risk-ip-sample-list" # MaxMind GeoIP Anonymous Proxies     "http://danger.rulez.sk/projects/bruteforceblocker/blist.php" # BruteForceBlocker IP List     "https://www.spamhaus.org/drop/drop.lasso" # Spamhaus Don't Route Or Peer List (DROP)     "http://cinsscore.com/list/ci-badguys.txt" # C.I. Army Malicious IP List     "https://lists.blocklist.de/lists/all.txt" # blocklist.de attackers     "http://blocklist.greensnow.co/greensnow.txt" # GreenSnow     "https://raw.githubusercontent.com/firehol/blocklist-ipsets/master/firehol_level1.netset" # Firehol Level 1     "https://raw.githubusercontent.com/firehol/blocklist-ipsets/master/stopforumspam_7d.ipset" # Stopforumspam via Firehol     "http://ipverse.net/ipblocks/data/countries/cn.zone" # Ban an entire country, see http://ipverse.net/ipblocks/data/countries/     "https://www.threatsourcing.com/ipall-free.txt"  EDIT: I see the URL to SpamHaus however that is for mail abuse. I am looking for overall abuse (e.g. DNS amplification attacks, SSH bots etc.)


QGIS: Building heights and DTM to STL (or other format that CAD can read)

I have downloaded a DTM and building heights from UK Digimaps (we have institutional access) and would like to: Export them to STL or other CAD format. Is it possible to do this in QGIS or do I need multiple programs? I haven't found any way of exporting to STL (dwg or other) yet.  Seems GlobalMapper is an option:  Isn't there a way in QGIS ?


The localisation of the ring $\mathbb{Z}$ at the prime ideal $(p)$ is PID

If $p$ is prime number, prove that $$\mathbb{Z}_{(p)}=\left\{\frac{a}{b}\in\mathbb{Q}: \text{$p$ doesn't divide $b$}\right\}$$ is a PID.  So, first step is to show that $\mathbb{Z}_{(p)}$ is an Ideal Domain and then show that every ideal in it is principal.  I know that $\mathbb{Z}_{(p)}$ is the subring of $\mathbb{Q}$ then it follows that $\mathbb{Z}_{(p)}$ is commutative. Then I'm lost what to do. Any help is appreciated :)


Approaching a master's in humanities after STEM-focused undergrad

I graduated this past year from an Ivy League university with a double major in a STEM field and Asian studies (with a focus in literature). Throughout university I felt the desire to eventually pursue a graduate degree in the humanities, but for various reasons ended up focusing much more on my STEM work. In my final year, I took some courses in religious studies that reignited my long-held interest in that field. Since graduating, I've been constantly reading books and papers on religion while working in tech. I think I'd like to pursue a master's in religious studies, both as a way to see if the field is really right for me and as a way to beef up my admittedly anemic experience in the area for the sake of a potential PhD.   But to be honest, I'm not sure of my prospects of getting into a good master's program. I feel like my lack of background will hurt my chances significantly. Although there is a little bit of overlap with my Asian studies degree (the language skills would help if I wanted to pursue Buddhist studies, for example), I'm not confident there's enough there to demonstrate adequate knowledge and interest. Furthermore, I took more than a few of my humanities classes in undergrad pass/fail since I was being pushed so heavily down the path of STEM. Should I be doing something else before applying to programs? Do I even have a shot of getting into a good program? What's the expectation for applicants coming out of undergrad? Any and all advice would be deeply appreciated!


I've been trying to import an fbx from a friend who works in modo so I could do a flip fluids simulation, the mesh comes in fine in 2.79b but there's no sign of the textures.  I can go into edit mode select the appropriate map and texture but when I exit edit mode no texture is visible in render view or in a final render. Am I missing a step here?    In 2.8 the images again have to be selected along with appropriate UV map but it does show them in the eevee but doesnt render in cycles but does in eevee.  Any idea whats going on? am I missing a step in the process?


If $S$ is an infinite $\sigma$ algebra on $X$ then $S$ is not countable

I am going over a tutorial in my real analysis course. There is an proof in which I don't understand some parts of it. The proof relates to the following proposition: ($S$ - infinite $\sigma$-algebra on $X$) $\implies $ $S$ is uncountable. Proof:  Assume: $S=\{A_{i}\}_{i=1}^{+\infty}$. $\forall x\in X: B_{x}:=\cap_{x\in A_{i}}A_{i}$. [Note: $B_{x}\in S$ $\impliedby$ ($B_{x}$ - countable intersection]. Lemma: $B_{x}\cap B_{y}\neq\emptyset \implies B_{x}=B_{y}$. Proof(of lemma): $z\in B_{x}\cap B_{y} \implies B_{z}\subseteq B_{x}\cap B_{y}$. 1.$x\not\in B_{z} \implies x\in B_{x}\setminus B_{z} \wedge B_{x}\setminus B_{z} \subset S \wedge  B_{x}\setminus B_{z} \subset B_{x}$ (contradiction:$\space$ definition of $B_{x}$) $\implies$ $B_{z}=B_{x}$ 2.$y\not\in B_{z} \implies y\in B_{y} \setminus B_{z} \space \wedge \space B_{y}\setminus B_{z} \subset S \space\wedge\space B_{y} \setminus B_{z}\subset B_{y} $(contradiction: definition of $B_{y}$) $\implies$ $B_{z}=B_{y}$ $\implies B_{x}=B_{y} \space \square$ Consider: $\{B_{x}\}_{x\in X}$. If: there are finite sets of the form $B_{x}$ then: $S$ is a union of a finite number of disjoint sets $\implies$ $S$ is finite $\implies$ there is an infinite number of sets of the form $B_{x}$. $\implies$ $|\bigcup\limits_{i\in A \subseteq\mathbb{N}}B_{x_{i}}| \geq \aleph_{0}$.(contradiction) $\square$  There are couple of things I don't understand in this proof:  Why the fact that we found a set ($B_{x}\setminus B_{z}$) in $S$ containing $x$ and is strictly contained in $B_{x}$ a contradiction ?  Why if there are only a finite number of different sets of the form $B_{x}$ then $S$ is a union of a finite number of disjoint sets and is finite ?


How to get nid as int (and not as string)

This code snippet:  var_dump(     db_query("select nid, title from node limit 1")->fetchAssoc() );   Prints this:  array(2) {   ["nid"]=>   string(4) "6247"   ["title"]=>   string(5) "test!" }   The database table node though has the following structure:  nid int(10) unsigned NOT NULL AUTO_INCREMENT ... title varchar(255) NOT NULL ...   Is there a way to make the query above return nid as an int?


Don't force sync with my oldest account on my network profile

I tend to put information on my profiles that's relevant for that particular site.  For example, my profile on Stack Overflow says what languages and technologies I'm familiar with and currently working in, my profiles on ELU and ELL say that I'm a native speaker of English and what dialects, my profile on Pets says what pets I keep and have kept in the past, etc. On sites where there's nothing specific relevant, I leave it blank.  My network profile syncs with my oldest site, which is Stack Overflow. But it just doesn't make any sense for me to have information about programming-specific stuff on the network profile.  It's already been asked , but since there has been no answer in nearly a year, I assume it's not possible. (Further,  to another question says that there is no way to leave the global one blank.)  So I'm requesting it.  Ways it could be done (in descending order of helpfulness):   Allow network profile to be edited independently (already requested ) Allow users to change which site gets synced from Allow users to delete their "about me" on the network profile   The first would be best, but it's already been suggested and not much done about it. The others would at least allow slightly more control.   is also related, but it's talking about manual sync, not automatic sync.


I usually use that said or that being said etc.  Today, for the first time in my life probably I read an email with This said.  Is This said correct? If so then why we don't commonly use it instead of that? In fact Wiktionary and macmillandictionary and many others have the phrase this said and not that said  After all, texts are written a text like so:     Lorem ipsum dolor sit amet, consectetur adipiscing elit.      That said, Lorem ipsum dolor etc..   The two paragraphs are in the same dialogue, one paragraph apart. So if this said is an option, then perhaps we should use it more commonly than that said since the events in the dialogue aren't far apart.


Let G be a nonabelian group of order 10 prove that G contains an element of order 5 and five element of order 2

Because order of element divide order of the group,the possiblility of order of element is 1,2,5,10. Frin this ,it must contains element of order 5 and 2. But I can't prove that it must gaurantee five elements of order 2 .Anyone can give a hint ?


Downloading El Capitan from public library with 100 MB limit

I don't have access to the Internet where I live and I must go to the public library to use it. Unfortunately, there is a 100 MB download limit and I must pause the download and reconnect each time. If I'm a few seconds too late, the El Capitan download automatically goes into the install program and I have to start the download all over again. I once got to 3 GB and lost it all. Is there any way I can recover the downloaded file when I connect to the Internet each time? I know it is there somewhere but the download process assumes that it has finished somehow and begins the install.


Let R[0,1] be the set of Riemann integrable functions between 0,1 by considering $f_{n}(x)=\frac{1}{\sqrt{x}}\chi _{[n^{-1},1]}(x)$ Where $\chi _{[n^{-1},1]}$ is the indicator function for if x is between $n^{-1},1$ with respect to the norm $\left \| f \right \|_1=\int_{a}^{b}\left | f(x ) \right |dx$  Edit:  I have to show this using the function $f_{n}(x)=\frac{1}{\sqrt{x}}\chi _{[n^{-1},1]}(x)$ so I don't think it's a duplicate since the other question is considering different functions and my issue is showing this function doesn't converge.  Thoughts so far  First I want to show that $f_{n}$ is Cauchy so I consider for $n>m$ $$\left \| f_{n }-f_{m} \right \|_1=\int_{0}^{1/n} 0\,  dx+\int_{1/n}^{1/m} \frac{1}{\sqrt{x}}\,dx +\int_{1/m}^{1} 0 \, dx  $$  I think this is Cauchy since as $n,m\rightarrow \infty $ then $1/n,1/m \rightarrow 0$ so $\left \| f_{n}-f_{m} \right \|_1 \rightarrow 0$ which is less than $\epsilon$   $ \forall$ $\epsilon >0$, But does this not imply $f_n$ converges to $0\in R[0,1]$  Edit: New idea Assume $f_{n}$ converges to $f$ then $\left \| f_{n}-f \right \|_1 < \epsilon $  for some $n>N\in \mathbb{N} $ and $\epsilon >0$ so $$\left \| f_{n}-f \right \|_1 =\int_{0}^{1/n} 0\,  dx+\int_{1/n}^{1} \frac{1}{\sqrt{x}}\,dx   $$   $\Rightarrow f(x)=1/\sqrt{x}$ when x is between $1/n$ and $1$ and 0 otherwise which is $\notin$R[0,1]


Global variables for all tikz drawings in a document

Sorry if this question sounds too elementary. I am new to TikZ, although I have experience with LaTeX.  Say I have multiple TikZ statements in a LaTeX document like the following:  \tikz\draw[line width=2mm] (0,0.1) -- (4,0.1);\hfill\textsc{\Large This is a block}%  \hfill \tikz\draw[line width=2mm] (0,0.1) -- (4,0.1);   I would like to define variables (e.g. line_thickness and line_width:  line_thickness = 2mm line_width = 4   that I could use in all such statements so that, if I want to change the parameters of my drawings in my LaTeX document, I could just change the value of my variables where I define them.  Is it possible to do this in TikZ?  I am interested in a relatively general solution, e.g. some of these variables may specify color, length, relative coordinates, etc. although a solution to addresses my particular problem above would already help a lot.  I have read the solutions in these threads:        but I don't know how to apply the answers to my problem.


What's the origin of "I'm down with it"?

I understand it's an expression of agreement. What exactly does it mean and where did it originate from?


I'm running Ubuntu 14.04.1 LTS & I'm having trouble opening .dmg files.  Any suggestions?


As described in the answers to , his face is not actually scarred but is rather the way that his species looks.  What species is Dryden Voss?


Is there a term for reduplication used to disambiguate categorization?

Reduplication - noun - A word formed by or containing a reduplicated element. An act or instance of reduplicating as a grammatical pattern.     Is there a term for the kind of reduplication where the two words are exactly the same but the first one narrows a category that could otherwise be interpreted more broadly?  e.g.    Do you mean Indian Indian or American Indian? It is common both in Irish English and English English. Do you mean cable television?  No, I mean television television.   To be clear, I'm not looking for a term to describe reduplication for the purpose of intensification, as in: "They have been together for a couple of weeks now".  "You mean "together together"?  That kind of reduplication has .


Javascript how to turn array of objects into object of objects without mutating original array?

I am turning an array of objects in to an object of objects. I added my question inside the code for better understanding.  var arr = [    {key : '11', value : '1100', $$hashKey : '00X' },   {key : '22', value : '2200', $$hashKey : '018' } ];  var result = {}; for (var i = 0; i < arr.length; i++) {   result[arr[i].key] = arr[i]; }   // below changes the original array (arr)  result["11"]["value"]="mike"   // below DOES NOT change the original array (arr)  result["2222"] = {key: "33", value: "deded"}  console.log(arr)   I just dont understand why. I have never assigned result to arr (thus created reference to original array), so why does original array change?  Thanks a lot!


If $\sin \theta+\cos\theta+\tan\theta+\cot\theta+\sec\theta+\csc\theta=7$, then $\sin 2\theta$ is a root of $x^2 -44x +36=0$ My own bonafide attempt.

$$ 0<\theta<\pi/2$$   and $$\sin\theta+\cos\theta+\tan\theta+\cot\theta+\sec\theta+\csc\theta=7$$   then show that $\sin 2\theta$ is a root of the equation $$x^2 -44x +36=0$$   I tried to use the above given equation of all the trigonometric ratios, though I ended up with an expression of $\sin\theta\cos\theta$.   But this too is in the form of $\sin\theta$ and $\cos\theta$ which was $\sin\theta\cos\theta=\frac{1}{6-\sin\theta-\cos\theta}$.  When I put that in the quadratic equation, it would again transform into the form of $\sin\theta$ and $\cos\theta$, and hence at last I couldn't prove the thing.  Even hints would work, as I would like to solve the question myself.


Is there any method to find value of $$\tan(1^{\circ})+\tan(2^{\circ})+\tan(3^{\circ})+\dots+\tan(89^{\circ})$$ without using calculator.  To find the same sum for sine and cosine , I used De-Movier's Theorem but here I can't see any approach working. Any suggestions?


I am from India and I applied for a skilled professional visa for Australia  with my old passport but it didn't have a spouse name on it. So I applied to add it and had issues with a new passport. I informed DIBP regarding this, but I got the visa on my old passport only. Now I have informed DIBP to update the passport details on their end... but haven't received any reply till now.   Just need to confirm if I can travel by taking along both old and new passports... in case I don't get any confirmation from DIBP regarding the update of my passport details.


I came across a statement online and have been looking for a proof :  It states that 1, 6 and 120 are the only numbers which are both triangular and factorials.  Is there any way I can prove this? This claim looks too 'big' and I've tried to prove it but  I couldn't. Can anyone help me to prove this?


Solutions of the diophantine equation $x+y+z=xyz$?

Let $x,y,z$ be 3 co-prime integers. Show that the only nontrivial solutions of: $$x+y+z=xyz$$ are only the permutations of $(x,y,z)=\pm(1,2,3)$


So I have Android app with Tabs and RecyclerView. When I run my app, it crashes.  logcat:  java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.String.length()' on a null object reference         at java.io.StringReader.<init>(StringReader.java:47)         at android.text.HtmlToSpannedConverter.convert(Html.java:442)         at android.text.Html.fromHtml(Html.java:136)         at android.text.Html.fromHtml(Html.java:99)         at com.example.app.MyRecyclerViewAdapter2.onBindViewHolder(MyRecyclerViewAdapter2.java:80)         at com.example.app.MyRecyclerViewAdapter2.onBindViewHolder(MyRecyclerViewAdapter2.java:17)        ...      at com.example.app.MyRecyclerViewAdapter2.onBindViewHolder(MyRecyclerViewAdapter2.java:80)   It points to this line of the code  listRowViewHolder.postId.setText(Html.fromHtml(listItems.getPostId())); // This line of code leads to crashing of app   If I delete this line, my app will work fine.  MyRecyclerViewAdapter2.java:      package com.example.app;   import android.content.Context; import android.content.Intent; import android.support.v7.widget.RecyclerView; import android.text.Html; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.TextView;  import com.android.volley.toolbox.ImageLoader;  import java.util.List;  public class MyRecyclerViewAdapter2 extends RecyclerView.Adapter<ListRowViewHolder> {     private List<ListItems> listItemsList;     private Context mContext;     private ImageLoader mImageLoader;     private int focusedItem = 0;  public MyRecyclerViewAdapter2(Context context, List<ListItems> listItemsList) {     this.mContext = context;     this.listItemsList = listItemsList; }  @Override public ListRowViewHolder onCreateViewHolder(final ViewGroup viewGroup, int position) {     View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.card_view_row2, null);      ListRowViewHolder holder = new ListRowViewHolder(v);      holder.itemView.setOnClickListener(new View.OnClickListener() {         @Override         public void onClick(View v) {             TextView postUrl =  (TextView) v.findViewById(R.id.postId);             String post_Id = postUrl.getText().toString();              Intent intent = new Intent(mContext, ViewPostActivity.class);             intent.putExtra("id", post_Id);             mContext.startActivity(intent);          }     });      return holder; }  @Override public void onBindViewHolder(ListRowViewHolder listRowViewHolder, int position) {     ListItems listItems = listItemsList.get(position);     listRowViewHolder.itemView.setSelected(focusedItem == position);      listRowViewHolder.getLayoutPosition();      mImageLoader = MySingleton.getInstance(mContext).getImageLoader();     listRowViewHolder.thumbnail.setImageUrl(listItems.getThumbnail(), mImageLoader);     listRowViewHolder.thumbnail.setDefaultImageResId(R.drawable.website_placeholder);      listRowViewHolder.title.setText(Html.fromHtml(listItems.getTitle()));     listRowViewHolder.date.setText(Html.fromHtml(listItems.getDate()));     listRowViewHolder.content.setText(Html.fromHtml(listItems.getContent()));     listRowViewHolder.postId.setText(Html.fromHtml(listItems.getPostId())); // This line of code leads to crashing of app }  public void clearAdapter () {     listItemsList.clear();     notifyDataSetChanged(); }   @Override public int getItemCount() {     return (null != listItemsList ? listItemsList.size() : 0); }}


A formula for determinant of symetric matrix whose off-diagonal entries are $-1$

I've tried the determinant of matrices with the form $$\left( \begin{matrix} x&-1&\cdots&-1\\ -1&x&\cdots&-1\\ \vdots&\vdots&\ddots&-1\\ -1&-1&\cdots&x \end{matrix} \right)_{n\times n}$$ i.e. with $x$ in the diagonal and $-1$ everywhere else. I've always get $$(x+1)^n-n(x+1)^{n-1}=(x+1)^{n-1}(x-n+1)$$ for various $n$ and I think it is a correct formula.  I think by induction will be a way but I don't know how. Any variant or counterexample are welcome.


What is the syntax and which namespace/class needs to be imported? Give me sample code if possible. It would be of great help.


Complex Analysis by Elias M. Stein Chap 1, Exercise 21

Show that if $|z|<1$ and m is a positive integer, one has   $$\frac{z}{1-z^{2}}+\frac{z^{2}}{1-z^{4}}+...+\frac{z^{2^{n}}}{1-z^{2^{n+1}}}+…=\frac{z}{1-z}$$   and   $$\frac{z}{1+z}+\frac{2z^{2}}{1+z^{2}}+...+\frac{2^{k}z^{2^{k}}}{1+z^{2^{k}}}+…=\frac{z}{1-z}.$$   Justify any change in the order of summation.   [Hint: Use the dyadic expansion of an integer and the fact that $2^{k+1}-1=1+2+2^{2}+...+2^{k}.$]   I tried to prove: $$z^{m}=\sum^{\infty}_{n=2^{m-1}}z^{2^{m}n}$$  which I obtained after several steps of converting fractions to series, but I don't know how to use the hint.


"No input registered" when attempting to start Ubuntu live USB

I have a desktop with Windows 10. I need to install Ubuntu or launch it using USB. But when I try to do either of those  things, I read      no input registered   Then the display is locked on the Ubuntu logo with 3 points.   CPU: ryzen 7 3700x GPU: rx 5700xt  RAM: 16gb ddr4 corsair Mobo: msi b450 a pro   What could be the problem and how can I fix it?


Object Becoming Transparent When Rendered

When I preview the render of my shot the skateboard/skateboard texture is transparent when it should be solid. The second picture is what it should(?) look like. As to how I set the scene up; I motion tracked the clip and used a floor that was generated by that. I imported the skateboard model. Using cycles render I made a new material and set the color to image texture and used the texture image that came with the model. After following a few tutorials a set up the three nodes belows. Any help is greatly appreciated.


I am trying to list all the cyclic subgroups of $S_4$, and also list two examples of proper non-cyclic subgroups of $S_4$.  Here's the general idea of what I have for the list: $S_4$, $A_4$, $\langle e\rangle$,  $\langle(1 2)\rangle, \langle(2 3)\rangle$, and so on...  $\langle(134)\rangle, \langle(234)\rangle$, and so on...  $\langle(12)(34)\rangle, \langle(13)(24)\rangle$, and so on...  $\langle(234)(23)\rangle, \langle(123)(12)\rangle$ and so on...  You get the idea. There are thirty in total by my count.   Is this $i.$ proper notation for a subgroup of $S_4$ and $ii.$ how would I find a proper non-cyclic subgroup?


sample_dir |-- cambridge |   |-- library |   `-- security |       |-- annex |       `-- parking |-- faculty |-- history.online |-- markham |   `-- annex |-- oxford |   |-- outline.doc |   `-- programming |       `-- report.pdf `-- stenton     `-- lib_arts         |-- english.txt         `-- match.doc   Your current directory is stenton. Make a copy of the file named parking (from the security directory), name it parking2, and place it in your current directory, using relative pathnames:


Gauldur's ghost is just standing there, how can I progress?

I read online that at this point during the quest Forbidden Legend the ghost of archmage Gauldur should fix the amulet, but now the dude is just standing there frozen:    The biggest problem is that I cannot even get out of the room. I only have one saved game, and, of course, it's after I killed the brothers.  I've tried rebooting the console, re-inserting the disk, closing the application - nothing is working so far. I also tried just waiting.. to no avail.  Have any of you experienced something similar?


I've always had a thirst for building a rich, engaging world with a group of friends playing adventurers who explore said world, and to that end I have always wanted to be a Dungeon Master.   But, I have a bit of trepidation in venturing into a 3.5 campaign.    My trepidation largely stems from not a lack of knowing the rules, but a lack of confidence in being able to interpret those rules to the satisfaction of my players.  3.5 is MASSIVELY complex, and just to create one unique character would take a long time for a beginner DM.  I have done small quests as part of a collective roleplaying experience before, but never anything as big as a campaign (even my quest consisted largely of just two big encounters in a sewer).    So, I'm looking for a system that takes it easy on the dungeon master.  Any setting will do, it doesn't have to be the tradtional dragons and wizards (though for my personal preference, I'd like to rule out horror settings).  My chief concern is an ease in worldbuilding and encounter creating.  I've seen questions asking for good starter systems for new players, but few that focus on making it an easier task for the DM.    Arguments that 3.5 is perfectly legitimate to start off with are accepted, provided you can prove to me that is the case. Recommendations on how to make a first campaign easier for me would also be appreciated, as well as scenarios that might be a good starting point for me (though I really want to build my own).    Would an easy game to learn for players be equally easy for a DM to learn?  Would the same system also be reasonable for a DM with inexperience making a campaign for players with lots of experience?  And would this always be the case?


I am pretty sure I saw this already on travel SE, but can't find it now. What are my navigation options with Android phone in an area without data connection? (I am in Northumberland)  EDIT: To clarify, I am looking for a turn-by-turn navigation system (mainly for driving). The suggested question is mainly about actual maps without this feature.


How to parse json in javascript having dynamic key value pair?

I want to parse a JSON string in JavaScript. The response is something like  var response = '{"1":10,"2":10}';   How can I get the each key and value from this json ?  I am doing this -   var obj =  $.parseJSON(responseData); console.log(obj.count);   But i am getting undefined for obj.count.


I have a christmas question for you. I have now tried to copy paste some elements from a document compiled in TeX. Sometimes it looks like this:     ❆t ❧❛st✱ ❛♥❞ t❛❦✐♥❣ t❤❡ r✐s❦ ❛ ❜❡✐♥❣ t♦♦ ❛❜str❛❝t✱ ■ s❤♦✉❧❞ ♣♦✐♥t ♦✉t   t❤❛t ❡✈♦❧✉t✐♦♥❛r2 ❛❧❣♦r✐t❤♠s ❛r❡ ✐♥s♣✐r❡❞ ❜2 ♥❛t✉r❡✬s ❡✈♦❧✉t✐♦♥❛r2   ♣r♦❝❡ss✳ ❚❤✐s ✐s ❛ ❣♦♦❞ ♦♣♣♦rt✉♥✐t2 t♦ ❣❛✐♥ s♦♠❡ ✐♥s✐❣❤t ❤♦✇ ❞❡❡♣❧2   ❝❛♥ t❤❛t ♠❡t❛♣❤♦r ❤♦❧❞✳ ❙♣❡❝✐❛❧❧2 s✐♥❝❡ ❧✐❢❡ ✐ts❡❧❢ ✐s ❧❡ss ❛   ♣❤❡♥♦♠❡♥❛ ♦❢ ♦♣t✐♠✐s✐♥❣ ❢✉♥❝t✐♦♥❛❧✐t2 ❜✉t ♠♦r❡ ♦❢ ❣❡tt✐♥❣ ❣♦♦❞ r❡s✉❧ts   ✇✐t❤ ✇❤❛t 2♦✉ ❛❧r❡❛❞2 ❤❛✈❡ ✇❤✐❧❡ ♥♦t ❜❡❝♦♠✐♥❣ t♦♦ s❡♥s✐t✐✈❡ t♦   ✐♥t❡r♥❛❧ ❛♥❞ ❡1t❡r♥❛❧ ✈❛r✐❛t✐♦♥✳ ❚❤✐s ❧❛st ❛s♣❡❝t ♠✉st ♥♦t st❛♥❞ ✐♥   t❤❡ ✇❛2 ♦❢ ♦❜t❛✐♥✐♥❣ ♣❤❡♥♦t2♣❡s ✇✐t❤ ❜✐♦❧♦❣✐❝❛❧ ✐♥t❡r❡st ❜✉t ✐s   r❡❧❡✈❛♥t ♥♦♥❡t❤❡❧❡ss✳   Can someone tell me, how I can do that to make my tex-document more difficult for copy-pasters?


I am a new user of Ubuntu.. What do I need to do to solve this update problem/bug?     W: Impossible de récupérer http://fr.archive.ubuntu.com/ubuntu/dists/maverick-backports/universe/binary-i386/Packages.gz  404  Not Found W: Impossible de récupérer http://fr.archive.ubuntu.com/ubuntu/dists/maverick-backports/multiverse/binary-i386/Packages.gz  404  Not Found W: Impossible de récupérer http://fr.archive.ubuntu.com/ubuntu/dists/maverick-proposed/main/binary-i386/Packages.gz  404  Not Found W: Impossible de récupérer http://fr.archive.ubuntu.com/ubuntu/dists/maverick-proposed/restricted/binary-i386/Packages.gz  404  Not Found W: Impossible de récupérer http://fr.archive.ubuntu.com/ubuntu/dists/maverick-proposed/universe/binary-i386/Packages.gz  404  Not Found W: Impossible de récupérer http://fr.archive.ubuntu.com/ubuntu/dists/maverick-proposed/multiverse/binary-i386/Packages.gz  404  Not Found E: Le téléchargement de quelques fichiers d'index a échoué, ils ont été ignorés, ou les anciens ont été utilisés à la place. slim@slim-N140:~$


Is there a theoretical maximum for refractive index?

May there be materials yet to be discovered which may have a higher refractive index than today's known materials (for wavelengths within the visible range)?  Is there a theoretical limit for the refractive index of a material?


Let G be a group and p and q be primes. Suppose |G| = pq and has only one subgroup of order p and only one subgroup of order q. Prove that G is cyclic.


Can anybody please explain the affect of multicollinearity on Decision Tree algorithms (Classification and regression). I have done some searching but was not able to find the right answer as some say it affects it and others say it doesn't.


Mobile theme 'X Answers' header doesn't take into account deleted answers

At 10k, you can start seeing deleted posts. The main web version takes this into account and displays the total number of answers (deleted and non-deleted):    However, for the mobile theme, it doesn't (same question in screenshot):    It's not that you can't see deleted posts in the mobile theme, because you can (erased all information, just showing screenshot to show the red deleted background):      So can it be made more consistent with the web version, and the correct number shown please?  BTW I was using  -- you can test the mobile theme yourself by clicking the 'mobile' link in the footer.


I am trying to control a brushed DC motor with PWM control through a MOSFET, below is the basic circuit for an idea. The PWM signal is given from a microcontroller to the gate driver IC which drives the MOSFET.   What is the nominal switching frequency? How to calculate the PWM switching frequency for this motor control circuit?         – Schematic created using


scrlttr2 & lualatex: Missing number, treated as zero

I can compile the following example with pdflatex (even though it complains about the missing babel package) , but not lualatex from TeX Live 2016:  \documentclass{scrlttr2} \begin{document} \begin{letter}{Name}     Test \end{letter} \end{document}   It results in the following error:  Class scrlttr2 Info: used language is `english'. (scrlttr2)           Supported languages are: `english', `UKenglish', (scrlttr2)           `british', `american', `USenglish', `australian`, (scrlttr2)           `canadian', `newzealand', (scrlttr2)           `german', `ngerman', `austrian', `naustrian', (scrlttr2)           `swissgerman', `nswissgermsn', (scrlttr2)           `acadian', `canadien', `francais', `french',  (scrlttr2)           `dutch', `italian', `spanish', `polish', (scrlttr2)           `croatian', `finnish', `norsk', `swedish', (scrlttr2)           `czech'. `slovak'  on input line 4.  ! Missing number, treated as zero. <to be read again>  p l.4 \begin{document}  A number should have been here; I inserted `0'. (If you can't figure out why I needed to see a number, look up `weird error' in the index to The TeXbook.)   , shown as "Missing number, treated as zero. \begin{document}" in TeXstudio.  Adding  \documentclass{scrlttr2} \usepackage{polyglossia} \setmainlanguage[spelling=new]{german}   doesn't help.