I have look here in order to find an answer why the orthogonal group $O(n)$ has two path-components, given by $\det =1$ and $\det =-1$.   But what is a possible proof for that fact? I can easily show that there are at least two components (not path-components) by using the determinant-function.


Is there a general word for performing music?

If someone is performing music with an instrument, I'd say that they're playing the instrument.  If someone is performing music with their voice, I'd say that they're singing.  Is there a word that combines both of these connotations?  "In the band, there are pianists, drummers, flautists, and singers; they _____ together."  I wouldn't use perform in this context, because they're not performing in front of an audience. Practice also doesn't have the right connotation, and playing to me connotes strictly playing an instrument and wouldn't be used in the context of singing. Jamming is a relevant word, but to me connotes only certain types of musical styles. Is there a single word that would encapsulate both singing and playing an instrument?


"Sign into your account" or "Sign in to your account"?

Which is correct? Is it that you are signing "into" your account or "in to" your account?


what is difference in deportation and VRS

one of my friend travel to UK and was done 12 month prison and he availed voluntary return scheme can he go back to UK again or not.


Will we ever "find" files whose names are changed by "find"? Why not?

While answering  it struck me that it seems find, in the following example, potentially would process files multiple times:  find dir -type f -name '*.txt' \     -exec sh -c 'mv "$1" "${1%.txt}_hello.txt"' sh {} ';'   or the more efficient  find dir -type f -name '*.txt' \     -exec sh -c 'for n; do mv "$n" "${n%.txt}_hello.txt"; done' sh {} +   The command finds .txt files and changes their filename suffix from .txt to _hello.txt.  While doing so, the directories will start accumulating new files whose names matches the *.txt pattern, namely these _hello.txt files.  Question: Why are they not actually processed by find? Because in my experience they aren't, and we don't want them to be either as it would introduce a sort of infinite loop. This is also the case with mv replaced by cp, by the way.  The  (my emphasis)     If a file is removed from or added to the directory hierarchy being searched it is unspecified whether or not find includes that file in its search.   Since it's unspecified whether new files will be included, maybe a safer approach would be  find dir -type d -exec sh -c '     for n in "$1"/*.txt; do         test -f "$n" && mv "$n" "${n%.txt}_hello.txt"     done' sh {} ';'   Here, we don't look for files but for directories, and the for loop of the internal sh script evaluates its range once before the first iteration, so we don't have the same potential issue.  The GNU find manual does not explicitly say anything about this and neither does the OpenBSD find manual.


What is - if any - the difference between PhD and doctor?

In a Simpsons episode of season 25 the dialoge   Monsarno Rep: Say hello to our chief scientist. Everyone: Augh! Sideshow Bob! Sideshow Bob: Dr. Sideshow Bob. Homer: Real doctor or PhD? Sideshow Bob: PhD.   takes place. In my country there is only a doctor and I thought a PhD would be exactly that in Anglo-Saxon countries. I would like to know is there a difference in the USA between a PhD and a doctor?  Especially: What did they mean in the dialogue?  Edit: In hindsight this may be a duplicate, but originally it wasn't because I did not know that the "doctor" of the dialogue was about a medical doctor.


Can the number of suggestions in firefox's location bar be increased?

Example : you start typing the address in firefox's location bar, it gives out, uhmm, 6 suggestions. Can that number be increased (also, can it give only the title, without the actual address to save space) ?


I'm wondering something. Whenever i right click on minecraft and click open with another application, i try to find Java JDK. I have installed it for minecraft itself, but i just cant find where java is on the list of other applications. Any help?


How many times can I format a hard disk?

Is there a limit to the number of times I can format a hard disk?  I tried to find this information , but I didn't find an answer.


How can I add applications to the lxpanel application launch bar via cli?

Is there a way on LXDE toolbar to change what applications are on the quick launch part via the terminal so that it can be put in a batch file to change on multiple clients?


Proxy Blocking apt-get, Allowing wget/curl

I'm having an issue getting passed my corporate proxy server.  I had an exception put in place to allow my IP address to pass through, but haven't been able to get apt-get to work.  wget can get to the Ubuntu repos without any issues.  root@server:/tmp# http_proxy=http://<PROXY>:8080 wget http://us.archive.ubuntu.com/ubuntu/dists/precise-backports/multiverse/binary-i386/Packages.bz2 --2014-01-24 09:17:38--  http://us.archive.ubuntu.com/ubuntu/dists/precise-backports/multiverse/binary-i386/Packages.bz2 Resolving <PROXY> (<PROXY>)... x.x.x.25, x.x.x.24 Connecting to <PROXY> (<PROXY>)|x.x.x.25|:8080... connected. Proxy request sent, awaiting response... 200 OK Length: 5178 (5.1K) [application/x-bzip2] Saving to: `Packages.bz2'  100%[========================================>] 5,178       --.-K/s   in 0.001s  2014-01-24 09:17:38 (7.78 MB/s) - `Packages.bz2' saved [5178/5178]  root@server:/tmp# ll -h total 16K drwxrwxrwt  2 root root 4.0K Jan 24 09:17 ./ drwxr-xr-x 23 root root 4.0K Jan 16 14:14 ../ -rw-r--r--  1 root root 5.1K Jan 24 09:05 Packages.bz2 root@server:/tmp#   I setup my apt-conf.d proxy configurations.  root@server:/tmp# cat /etc/apt/apt.conf.d/30proxy Acquire::http::proxy "http://<PROXY>:8080"; Acquire::ftp::proxy "ftp://<PROXY>:8080"; Acquire::https::proxy "https://<PROXY>:8080"; root@server:/tmp#   apt-get still fails with a 403  Forbidden error.  root@server:/tmp# apt-get update Ign http://us.archive.ubuntu.com precise Release.gpg <...snipped excess...> Ign http://us.archive.ubuntu.com precise-backports/universe TranslationIndex Err http://security.ubuntu.com precise-security/main Sources   403  Forbidden [IP: x.x.x.25 8080] <...snipped excess...> Err http://security.ubuntu.com precise-security/multiverse i386 Packages   403  Forbidden [IP: x.x.x.25 8080] W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/precise/main/source/Sources  403  Forbidden [IP: x.x.x.24 8080] <...snipped excess...> W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/precise-security/multiverse/binary-i386/Packages  403  Forbidden [IP: x.x.x.25 8080] E: Some index files failed to download. They have been ignored, or old ones used instead. root@server:/tmp#     PROXY replaces my proxy server's FQDN


Loop cut entirely after dissolving an edge

I can still cut it entirely with the Loop cut.    Thing is, I want to get rid of that edge, I do that by dissolving it:    Now here's the problem, after that, I can't cut it entirely. I've also tried dissolving the remaining vertices but it didn't work.    So what I want to do is to cut it entirely after dissolving the edge, instead of doing it separately as you can see in the pic. Is there a way to achieve that? Did I make a wrong move?


Short sci-fi story about a group of people space travelling to a distant planet, overtaken by a second group who left after them but were faster

Does anyone know this short story I read many years ago? It's about a group of people who decided to get to a distant planet on a spaceship that isn't very advanced. Some time after they started their trip, new technology got developed that allows space travel at a much faster speed. A second group of people who set out for the same destination end up arriving a lot earlier than the first group of people.  I think this would be a good story to introduce my kids to space travel but couldn't remember the name of the book.


In algebra & polynomials, how do we prove that $$x-1 \mid x^n -1?$$


How to reorder /etc/resolv.conf at load time

I have a CentOS system that retrieves its upstream DNS servers via DHCP.  I want to run DNSMasq on this box and use it as a server to resolve some hostnames for development.  The problem is when my system starts, the upstream DNS servers are loaded into /etc/resolv.conf and THEN the DNS1 entry from my ifcfg-enp0s3 setup gets loaded.   That's a problem because when I query for the internal dev names, it tries to go out to the upstream DNS server instead of checking DNSMasq first.  I need the DNSMasq server to be at the TOP of the /etc/resolv.conf and the dhcp loaded ones at the bottom of the resolv.conf so that DNSMasq will work properly.  Any simple way to do that?


If $A,B\in \mathbb R^{n\times n}$ s.t. $AB=I$ then $BA=I$.

I want to prove that if $A,B\in \mathbb R^{n\times n}$ are s.t. $AB=I$ then also $BA=I$ (where $I$ is the identity matrix).  $$AB=I\implies BABA=BA\implies (BA)^2-BA=0\implies BA(BA-I)=0.$$  How can I conclude from here ? I know that $CD=0\not\Rightarrow C=0$ or $D=0$. So I can't continue. I also thought to do : $$BA(BA-I)=0\implies ABA(BA-I)=0\underset{AB=I}{\implies} A(BA-I)=0,$$ but it's not conclusive. Any idea ?  Edited  I can't use determinant.


bash: how for loop sorts files when iterating

What is the default behavior of for loop in terms of sorting when listing files in a directory?  e.g.  for sqlfile in *.sql; do mysql -u root -p pass < sqlfile; done   Is this documented somewhere?


The question wizard might be useful for Meta Stack Exchange too; should we give it a try?

tl;dr  Due to the special nature of Meta and the high rate of "lost souls", should we try out the Ask a Question Wizard here on Meta Stack Exchange too?  General idea  In case anyone doesn't know yet, . It guides new users towards writing better questions.  I think that such a question wizard would be useful on Meta Stack Exchange too, for three main reasons:   . There are four types of questions on Meta, each represented by the different required tags: , ,  and . Especially bug reports can often be split into a certain structure (what's wrong, how to reproduce, why I think it's wrong, examples). The same holds true for feature requests. Such a structure is ideal for a question wizard. Quite a few users  and . While the Meta community is well prepared to deal with these posts quickly, they lead to an less-than-ideal first impression by the new users and they distract the community from more important issues. Site-specific questions are often off-topic. This  since nowhere is it hinted at in the help pages (and there are a lot of old, not-yet-closed SO-specific questions from a prior era of this site) and can lead to unnecessary drama. If we add an honeypot into the wizard to catch this case (and ideally redirect them to the proper meta site), we could prevent this.   As Sonic said, there's an  new users need to read and confirm. However this doesn't really prove effective right now and we might need to try stronger tools (e.g. question wizard).  Therefore I think that we should test the Ask Question Wizard here on Meta too.  Implementation details (help welcome)  I think the wizard should have six main entry points:   I want to discuss a specific post or action from any Stack Exchange site. (-> honeypot, redirects to the appropriate per-site meta) I have a question regarding the use of Stack Exchange sites (-> support mode) I think I found a bug while using the Stack Exchange sites  (-> bug mode) I have an idea for improving the Stack Exchange sites  (-> feature request mode) I have a discussion I want to start about Stack Exchange communities or their rules  (-> discussion mode) I have some other (e.g. programming) question  (-> honeypot, redirects to )   Coming from these choices, the user would either be redirected to a landing page explaining, why this is not the right community and offering some alternative choices or they would follow the guided assistant.  For 1. the user might be asked on which site the post/action is. Maybe the system could show the three sites where the user was recently active/has the highest reputation on.  support mode would ask the user for these details:   what do you want to achieve? what have you tried? what is your current problem?   bug mode would ask the user for these details:   bug description how to reproduce the problem why do you think that this is wrong? (possibly) examples   feature request mode would ask the user for these details:   what is your goal? how do you think could this be achieved? why will the community benefit from this change? (possibly) details   discussion mode would ask the user for these details:   which rule do you want to propose/clarify (optionally) examples/why is this rule required?   Note: the above implementation details probably require some revision. Feel free to edit/suggest improvements for both wording and details.


Is there a way to setup an audible alert in response to a reply or comment?

It would be very convenient and useful to be able to be alerted by a notification sound when a question or answer has been replied to or commented on in one of the open tabs in my browser!   Does such a feature exist? If so, how do I enable it?!


Add comment link disappears after deleting a comment (mobile theme)

When using the mobile theme (e.g. mobile device), the add comment link disappears is a comment is added and deleted.  Steps to repro:   Open a post (I'm using Firefox) Add a comment Delete the added comment   Now the particular post for which the comment was added & deleted, doesn't show the add comment link.  Reloading the post makes the link appear again, however.  First step:        Second step:        And it's gone:          EDIT: This appeared to be fixed a few days back but seems to be broken again.


How can I build a Visual Studio 2010 solution from wsp?

I've inherited a site with a Sandbox Solution but no documentation nor the original solution package.  How can I extract the .wsp to get the solution?  I tried renaming it to a .cab file and extracting it and importing the solution to Visual Studio.  In both cases, I'm missing the .cs files for the Web Parts. I can only see the .webpart file and the .elements file.  Thanks for the help!


Is it possible to set environment variables needed for a separate process in Java?

I have a process I want to start from Java. The problem is that due to a mismatch between the remote desktop client and the process I want to start I need to modify the environment variables. I will not use this in production, but only for running tests. I will also just do this until this bug is fixed in the tool I use.  I do not have root access and I am using Linux RHEL7. Anyone having an idea how I can set this environment variable from Java? I should also add that I run this from an IDE.  The following answer was not very helpful due to the lack of actual examples:   and the following example was not able to set the variables in the scope I needed to set them:   I tried this,  Process p = Runtime.getRuntime().exec("setenv " + name + " " + value);   But get the following error message,  java.io.IOException: Cannot run program "setenv": error=2, No such file or directory   EDIT: Someone suggested this post,    Unfortunately I do not find any solutions in there. The process I want to start already have a Java API, which does not work in my environment. What I want is an equivalent to the linux command,  setenv NAME VALUE   for the process which java runs in.


What is the correct sentence.    I am a IT degree holder. I am an IT degree holder.


Old pulp sci-fi series from the seventies with many books

Back in the late seventies I began collecting a sci-fi series. There were just a ton of them, and they were all pretty standard pulp sci-fi hero stuff, all about the same hero and, I believe, by the same author... someone who later became famous and wrote these under a pseudonym. My mom chucked the books while I was overseas, and I can't remember what they were. I thought it was the Lucky Star series by Asimov, but those were only six books.


I am trying to get Z Pass to render but all I get is a white image. Any ideas why that happens?  I tried setting up the render layers, checked only z-pass since that's all I need but still can't get it going. I am having a similar issue when trying to output to PNG's other passes but they do show up however at least in the viewer.  Also I tried looking up for tuts on this but what I found is only for internal compositor unfortunately.   Thanks


show that the probability of the last person sitting in the right spot is $1/2$

There are $n$ seats in a classroom and $n$ students who have been assigned seats on small slips of paper. Unfortunately, the first student to enter the classroom has lost his slip, so he just chooses a seat at random and sits in it. Each of the remaining students enters one at a time and either sits in their assigned seat if it is empty or if someone is sitting in their seat, chooses a seat at random from those that are empty. For $n\geq 2,$ show that the probability that the last student to enter will sit in their assigned seat is $\frac{1}2.$  I tried a few small examples and drew some tree diagrams to list out the possibilities, and got $\frac{1}2$ each time. I did make a few obvious observations though. Firstly, if the first student sits in the right spot, everyone else will too, by the premise. There is a $\frac{1}n$ chance for this. Secondly, if the first student chooses the last person's seat, the last person won't be able to sit in their assigned seat. And thirdly, the only way the last person can sit in their assigned seat is if everyone before him/her did not choose his/her seat. We can label the students $S_1,\cdots, S_n.$ I'm not quite sure how to determine the sample space for this problem (i.e. the total set of points or possibilities to consider).


A conductor is defined as it has free electrons to move, but when non conductor attain charge, it would also have free electrons. so it should behave like a conductor or not?


How can I compute this conditional expectation given I only have access to $P(X>t)$?  I have been looking into the literature for quite sometime and have not seen something similar.  Please help!! Thank you


"as bad at English as me" vs. "as bad at English as I"

He was almost as bad at English as me. He was almost as bad at English as I.   The first one sounds better as-is, but not when you change the second one to He was almost as bad at English as I was.  Which is correct?


Does Feeblemind prevent items that raise intelligence from functioning?

From Feeblemind's spell description,     On a failed save, the creature’s Intelligence and Charisma scores become 1.   The spell's effects are listed as "Instantaneous", which leads me to my question:  Does this prevent the effects of items like Ioun Stones which add to the score, or Headbands of Intellect which set the score to 19, from going into effect, or does the spell have an ongoing magic that keeps the stats at 1 until the save is made or the Feeblemind is removed through on of the listed spells?  If it does not prevent the intelligence/charisma stats from being raised through items, are the listed effects (being unable to speak/cast spells) caused by the low scores or a separate part of the spell's effects?


I want to print the array when arr.toString() is called. How can i do that?   Integer[] arr = new Integer[10];   for(int i = 1; i <= 5; i++) {      arr[i] = (i);  }   System.out.println(arr.toString() + " " + arr.length);


Telegrams from Unknown City that Gets Destroyed by Mist

A visiting science fiction author, James D. Macdonald, showed a writing group at my school this story when I was in 7th/8th grade (around 1996-1997) and I can't remember the title or the author but it's always stayed with me and I'd love to find out more about it.    The gist of the story is that someone starts a job working for a news service, receiving telegrams or teletypes or similar written communiques. Pretty soon he starts receiving telegrams from a city that doesn't show up on any map, name kinda reminds me of Xanadu or something similar. The employee reads these telegrams as they describe a kind of mist enveloping this city; and to cut a short story short, the city is ultimately destroyed and no more word is received.    Really sorry if this is vague, doesn't leave much to go on.


Does Windows7(+) have the env or equivalent? (Env. variable for single run of application)

I'm looking for an opportunity to launch an application (eg, compilers) with specific environment variables . I want same functionality like env in Linux. env var=value application.exe  I found  but not satisfied with the decision. (because it has a lot of character in the writing which you can make a mistake )  Something changed from 2010 year ? I would be happy  not even with  builtin solutions.


Did the UA "revised" Beastmaster Ranger make it into any official source book?

There was "" pdf in the 2016 playtest material. A Beastmaster Ranger was considered the weakest class by many GMs and players, which apparently caused the need for a "revised" version. However, I've never heard how exactly the playtesting ended. Googling "ranger revised" gives me the same 2016 pdf and nothing more. What happened to the "revised" ranger from the Unearthed Arcana? Was it renamed from "revised" to something else? Was it published in any official source book, changed or unchanged? (I don't have access to all of them so I can't check it myself for now) Or was it abandoned by WoTC? This is a technical duplicate of , which was answered in 2017, but things probably changed in 2021, so that accepted answer doesn't answer the question anymore. Also, I'm asking about Beastmaster Ranger specifically, which could be changed/revised in latter source books (XGtE,TCoE, whatever) as an additional Ranger archetype.


Why is MixColumns omitted from the last round of AES?

All rounds of AES (and Rijndael) have a MixColumns step, save the last round which omits it.  DES has a similar feature where the last round differs slightly.  The rationale, if I recall correctly, was to "make the cipher appear similar in reverse as it does in the forward direction."  Why does this make AES$^{-1}$ look similar to AES?  And how does this help in implementing the block cipher?


how to enable "universe" repository in ubuntu 14.04

I'd like to install mplayer but I've been told that I got to enable "unvierse" repository, where and how can I do that ? any help will be highly appreciated


I am a sockpuppet; may I exist if I have a real purpose?

I am a sockpuppet account of . I am going to help him test the XMPP chat integration system he's building.  Am I allowed to exist? I promise to behave, and never leave Meta or Meta's chat. If so, may I please have enough rep to chat?  EDIT BY JOSH: I have drawn a freehand circle for my sock:


Rename a specific part of a lot of files

I have a bunch of files named:  Brooklyn Nine-Nine S01 E01 [H264].mkv Brooklyn Nine-Nine S01 E02 [H264].mkv Brooklyn Nine-Nine S01 E03 [H264].mkv Brooklyn Nine-Nine S01 E04 [H264].mkv Brooklyn Nine-Nine S01 E05 [H264].mkv Brooklyn Nine-Nine S01 E06 [H264].mkv Brooklyn Nine-Nine S01 E07 [H264].mkv Brooklyn Nine-Nine S01 E08 [H264].mkv ...   I want to rename them so that the space Between S01 and E08 is removed. example   Brooklyn Nine-Nine S01E08 [H264].mkv   I already found a command to remove all spaces:  IFS="\n" for file in *.mkv; do     mv "$file" "${file/[[:space:]]}" done   but I only want to remove space between Sxx and Exx.


When my web form is filled and submitted, I get redirected to a page that says:     Thank you for submitting.   but theres a red warning box there that says:     Unable to send e-mail. Contact the site administrator if the problem persists.   I think its the SMTP server, but I don't know how to fix that.


Can I use a 555 to ignore short DC pulses in simple switch circuit? Not same as usual debouncing

I have a reversing camera in my car that I wish to:   switch on whenever the reverse lights come on turn off when reverse lights go off.     Problem is, my car's computer will periodically send these short (let's say 100 ms) 12V pulses to the reverse lights to test whether they are present (simple resistance test).  These pulses are too short to light up the bulbs, but they are short enough to switch on an electronic circuit.  Q. Can I use a 555 timer to ignore those short pulses?  I know I can probably do it with a RC setup, and I realise that I'll end up have resistors and capacitors around the 555 circuit. A delay in switching on the reverse camera is OK.  Cheers!


If I flag a comment now, it puts the dialog off the page:        It is only fixed by performing one of these actions:   Maximize window (if not already maximized) Restore window (if maximized)         I am running Windows and Firefox; also I tried Firefox in safe mode. I would be interested to see what testing was done on this beforehand - as this seems like a pretty glaring error. Please and thank you.    Inspired by the answer, the following CSS worked for me. It makes me sad to have to fix Stack Exchange CSS; I would figure this community over all others would get it right. Oh well.  aside {   transform: none !important; }


for some years, I've read that it's a good idea to create a swap partition having the double space of my RAM. does it still apply today? or this isn't needed anymore?  I have a server with 8 GiB of RAM and I need to create a swap partition, and I was wondering if  16 GiB was too much.


Equivalence between derived categories preserve distinguished triangles

I have a problem: Is it true that every equivalence between derived categories preserve their distinguished triangles? Thanks very much!


Automagically externalising PSTricks and TikZ pictures

My thesis currently has a few PSTricks and TikZ pictures. It takes a while to compile over  says he has some scripts to automate externalising TikZ pictures.  I'm looking ideally for something that will automatically name sequentially all of my figures, generate the graphics for them and automagically include them. I don't mind if I have to delete them by hand to recompile them if I change the code.  For PSTricks and TikZ please =) cause currently LaTeX is spanned for each PSTricks picture to generate a PDF graphic, and TikZ compilations starts to take up time.  P.S. half way through hte thesis I discovered TikZ but don't have time to redo PSTricks graphics.


If I am in a free float environment and there is another object at rest relative to me, and then I start to accelerate towards this object, do I know I am the one who is moving, since I am the one who is feeling the acceleration? If I accelerate and then start to coast at a constant speed, can I conclude that the object did not move and that the one who was moving was me, since I felt the acceleration?


Let $d$ be a square free integer. Show that $\mathbb{Z}[\sqrt{d}]$ is an integral domain.   Here $1+0\sqrt{d}$ is identity of $\mathbb{Z}[\sqrt{d}]$. Also commutative property can be shown easily. But I can't show that $\mathbb{Z}[\sqrt{d}]$ has no zero divisor with $d$ is square free. Could you please help?


I get the following error message when trying to restore the database from backup using RMAN.  rman target /  RMAN> set dbid=130474031 RMAN> configure device type 'sbt_tape' clear; RMAN> startup nomount; RMAN> restore controlfile from autobackup; RMAN> sql 'alter database mount'; RMAN> restore database;  Starting restore at 22-DEC-15 using channel ORA_DISK_1  creating datafile fno=1 name=/opt/oracle/oradata/prod/system01.dbf RMAN-00571: =========================================================== RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS =============== RMAN-00571: =========================================================== RMAN-03002: failure of restore command at 12/22/2015 12:47:01 ORA-01180: can not create datafile 1 ORA-01110: data file 1: '/opt/oracle/oradata/prod/system01.dbf' RMAN>   EDIT  RMAN> restore database;  Starting restore at 22-DEC-15 using channel ORA_DISK_1  creating datafile fno=1 name=/opt/oracle/oradata/prod/system01.dbf RMAN-00571: =========================================================== RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS =============== RMAN-00571: =========================================================== RMAN-03002: failure of restore command at 12/22/2015 14:22:01 ORA-01180: can not create datafile 1 ORA-01110: data file 1: '/opt/oracle/oradata/prod/system01.dbf'  RMAN> exit   Recovery Manager complete. [oracle@DR-Corebank ~]$ id uid=501(oracle) gid=501(oinstall) groups=501(oinstall),502(dba) [oracle@DR-Corebank ~]$ cd /opt/oracle/oradata/prod/ [oracle@DR-Corebank prod]$ touch aaa [oracle@DR-Corebank prod]$ ls -ltr total 875772 -rw-r----- 1 oracle oinstall 298631168 Dec 22 14:22 control03.ctl -rw-r----- 1 oracle oinstall 298631168 Dec 22 14:22 control02.ctl -rw-r----- 1 oracle oinstall 298631168 Dec 22 14:22 control01.ctl -rw-r--r-- 1 oracle oinstall         0 Dec 22 14:22 aaa [oracle@DR-Corebank prod]$ pwd /opt/oracle/oradata/prod [oracle@DR-Corebank prod]$ df -h Filesystem            Size  Used Avail Use% Mounted on /dev/cciss/c0d0p3     1.1T  163G  850G  17% / /dev/cciss/c0d0p1     244M   18M  213M   8% /boot tmpfs                 7.9G     0  7.9G   0% /dev/shm /dev/mapper/mpath0    493G  248M  467G   1% /opt/oracle2/u002


Decode from ISO-2022-JP-MS to UTF-8 in PHP - IMAP

I am Using IMAP in order to check some emails( sometimes in Japanese, sometimes in English), and some of them I get the results encrypted in ISO-2022-JP. I was trying using $msg='=1B$B#77n=1B(B      =1B$B2V2&=1B(B          =1B$B%K%e!<%9$N$_=1B(B';  $utf8Msg = mb_convert_encoding($msg,'UTF-8','ISO-2022-JP-MS');  to decode the message, but it is not working. Do you guys have any suggestion on how I should proceed to decode any message(Japanese, English and so on) using IMAP? or is there a better way to read email in php? Like some method that already shows the decoded message?


Can I get a command block on Minecraft PE

I was just wondering if you could get a command block in Minecraft PE.


How is it possible that if I combine 100 Ohm resistors in different ways, I get _LESS_ resistance than original?

This is blowing my mind.  Let's say I've a bunch of 100 Ohm resistors, all identical.  How is it possible that if I combine them in parallel, I can get something that has less resistance?  Check this out:     ----100OHM--- ---|           |---    ----100OHM---   This is effectively a 50 Ohm resistor!  It was already hard for current to get through one resistor (at 100Ohms), but I combined two resistors together, and now it became easier for current to go through!  If I take ten 100 Ohm resistors in parallel:  Check this out:     ----100OHM---    ----100OHM---    ----100OHM---    ----100OHM---    ----100OHM--- ---|---100OHM--|---    ----100OHM---    ----100OHM---    ----100OHM---    ----100OHM---   This is now 5 Ohms!!!!!!!!!!!!!!!!!!!!!!! Electricity is no longer having almost any resistance, yet each of resistors is 100 Ohms. If I added even more 100 Ohm resistors, resistance would go close to 0, and current would just flow through with no resistance.  How is that even possible? If I think logically, then it could only have gotten HARDER for current to go through two resistors, but somehow it became easier.  Real life analogy:  Let's say there's a 500 pound bouncer at club entrance. It's hard to get past him right? He's strong and will resist you getting past him. Now if the club adds another bouncer at 500 pounds, it suddenly becomes EASIER to get past both of them??  There's no way it's possible!! Can anyone explain this in simple terms?


I tried to install apache2 with  sudo apt-get install apache2   Why am i seeing this   E: Type 'gpg' is not known on line 1 in source list /etc/apt/sources.list.d/sublime-text.list E: Type 'gpg' is not known on line 1 in source list /etc/apt/sources.list.d/sublime-text.list


Writing $e_1\otimes e_1+e_2\otimes e_2$ in another way

Let $V=\mathbb C^2$ with standard basis $\{e_1,e_2\}$. Are there $v,w\in V$ s.t. $e_1\otimes e_1+e_2\otimes e_2\in V\otimes V$ can be written as $v\otimes w$   Is the answer no ?  for example if $v=c_1e_1+c_2e_2$ then   $v\otimes w=c_1e_1\otimes w+c_2e_2\otimes w=e_1\otimes c_1w+e_2\otimes c_2w$ is this true ?  and by uniqueness $c_iw=e_i$ then we reach a contradiction ?  Is this always valid, no matter what $V$ is ?


How to capture a subset of a Latex document?

I would like to programmatically capture a subset of a latex document, something like:  doc = new Doc("foo.tex") node = doc.getNode("bar") print node.text   where node "bar" would be delimited by some tags, put for example in comments:  %% <bar> This the \textbf{node content} %% </bar>   How to do this?


One or two apostrophes for two subjects in the possessive case?

Which is correct: [Bonus question: should there be a question mark here instead of a colon?]     The book contains Marx and Engels' theories about the nature of   society and politics.   or     The book contains Marx's and Engels' theories about the nature of   society and politics   It seems to me that the former is more common, but I am confused here since the latter seems more logical to me (and matches what you would see in my native language Icelandic).


Young Adult novel, young man fights with spear, becomes a gladiator at some point in a demon arena

I read it sometime around 2010, it involved a young man, possibly a teenager that fought using a spear, and at some point the modern world was taken over by demons, and the nations of the world negotiated with the demons to survive. He fought as a gladiator in an arena filled with demons. It was part of a series, and for some reason I keep thinking of the spear of Cucuhlainn.


Can Windows 10 100% disk utilization be due to bad sectors? can this be solved by hard formatting hard disk?

I am in big trouble since last few weeks... I am getting 100% disk utilization on my Windows, while I can see no process is significantly using the disk. The issue is faced by many as you can see there are many many threads on this:   on  on    This is how it looks like:    100% disk usage    No process is significantly using the disk    Also I created a thread on   to ask where to find the registry key to tweak HDD driver as recommended by microsoft's site. But of no use.  I tried, stopping many services, clean boot, running process explorer to checks whats using disk the most, as suggested by many online threads. In fact, I formatted by C: drive and installed clean Windows 10. But issue came back!!!  Let me tell me something about my machine: its Dell XPS 15 L502X. Its 2011 edition. It has 16 GB RAM, quad core i7 2630QM. This machine worked perfect with Windows 7,8 and 10 for so many years but now its failing. As I told above I tried everything thats noted in various sites, but nothing helped.   Now I recalled that few months back I was trying to copy paste some big video file to pendrive and I was getting another famous error "Cannot read from source file issue". I didnt paid much attention to it. Left those video files as is. I remember I tried running chkdsk with no success. Now I started feeling that the issue was aggravated. I felt this must be due to  bad sectors. So I cut pasted all files in the drives to external hard disk using TeraCopy software. It gives list of files that failed to copy. So I deleted those files when TeraCopy was not able to move them and then recovered those files using EASEUS recovery tool. Then I hard formatted (not quick format) thinking that it will fix bad sectors. This worked for E: drive.  But while doing same for F: drive, it got all screwed. First while recovering files, I was getting . So I left those files unrecovered and went on to hard format the drive. But now after almost 5 hours its barely 30% done.   One more observation, many times after random killing of processes (mostly onedrive which had folder in F: drive), my disk utility used to come to normal after few minutes.  Q1. So should I conclude its hard disk which is culprit here?    Q2. Will this formatting of F: drive ever complete?  Q3. If completed will my machine be fixed, that is will my machine be free from 100% disk utilization?   Q4. Will my hard disk be safe to use in future for no data loss...  Q5. Should I buy new hard disk?  Q6. Does hard formatting fix bad sectors at all?  Q7. Should I do the same for C: drive too? While installing Windows I did quick format, not hard format.  Sorry for so many questions...but I have wasted many weeks on this. And no thread online is of help to me.


I have looked up reflections in java, but still don't quite understand them. I need to "swap" values of two local parameters using a reflection. Here is what I have. I know it doesn't swap the values which is why I need to use the reflection. How do I do this?  public class SwapBla { static int x = 1; static int y = 2;  public static void swap2(int x, int y)  {    int temp = x;    x = y;    y = temp;  } }


locate command doesn't locate files in /media folder

I know there is a file in /media folder, then I searched with locate command, but it doesn't locate the file. I did sudo updatedb, then locate command again, but it doesn't locate the file.   I suspect locate path environment parameter since /media folder filesystem is on a seperate hard disk from the main stuff.   Should I edit locate path environment parameter?? How do I do it? or Am I missing more??


I saw this below message on some page     We are no longer accepting answers from this account. See  to learn more   But http://goo.gl/C1Kwu is a just text. Stack Overflow is a big professional site, so can you change this text to URL (link button style) or this format below?     Sorry, we are no longer accepting questions from this account. See the  to learn more.


Fundamental group of $\mathbb{R}^3$ \ finite number of lines passing through origin.

I want to confirm my answer for this question:      Calculate the fundamental group of $X=\mathbb{R}^3\setminus \{\text{union of n lines passing through origin}\}$.   My idea is that $X$ deformation retracts onto $S^2\setminus \{\text{union of $2n$ number of points}\}$, which will be homeomorphic to $\mathbb{R}^2\setminus\{\text{union of $(2n-1)$ number of points}\}$. Hence fundamental group of $X$ is same as fundamental group of wedge of $(2n-1)$'s circles, which is free group on $(2n-1)$'s symbols. Please confirm it.


Getting the real path of the current directory when using symlinks

So I just found out that my build fails on the build server (Windows 2008 R2) because the workspace is located on a different drive using symlinks.  The build path is C:\Program Files (x86)\Jenkins\jobs\MyProjectTestBuild\workspace but it actually leads to d:\Jenkins\jobs\MyProjectTestBuild\workspace\ because C:\Program Files (x86)\Jenkins\jobs is a symlink to D:\Jenkins\jobs.  So for whatever reason, my build never terminates when running from C:\Program Files (x86)\Jenkins\jobs\MyProjectTestBuild\workspace but completes fine when running in the real location.  So the question is: How can I find out the real location of the current directory so I can cd into it before running the build script?    Edit:   I know how to check the location of a symbolic link. That is not the question. I want to know, given a path, where the real location is. No matter if there might be any symlinks down the path chain.


How to fix printed out identation when using "\n"

I'm new to Python and tried to make a simple program that prints out the Square roots of given numbers. However it prints the 3rd line with a small identation. I'd like to know what causes this.  Not sure what to do at this point. I'm still quite new to this.   import math  a = 4; b = 9; c = 16 print("Zahl\t\tWurzel") print(a, "\t\t\t", math.sqrt(a), "\n",       b, "\t\t\t", math.sqrt(b), "\n",       c, "\t\t", math.sqrt(c)) user_in = input("Bitte geben Sie eine Zahl ein: ") print("Die Wurzel ist: ", math.sqrt(int(user_in)))   Zahl        Wurzel 4            2.0   9           3.0   16          4.0


How do I stop Seahorse from asking for my password multiple times on every login?

I've set up my System to log me in automatically but for some reason I need to "unlock my keyring" x times, where x is a number much larger than one. I've read a few similar threads here and elsewhere but I've yet to find a solution to the problem.  How do I stop this from happening?  Seahorse screenshot  Note : The original title described the behaviour as "molestation" which I think is apt.


How do I achieve the effect in these photos with photoshop?

They did an awesome job of blending their website colors to the photos. I'm trying to figure out how to do the same.


How can I get the difference in days between today and a previous date?

I'm trying to get the difference (in days) between today and a previous date here: from datetime import date  today = date.today() # get today's date print("Today's date:", today) new_today = today.strftime("%Y, %#m, %Y") # convert it so that delta.days understands print(new_today)  f_date = date(new_today) l_date = date(2014, 7, 11) delta = f_date - l_date print(delta.days)  But I get an error: TypeError: an integer is required (got type str) I've read   on this, but they don't address using today's date in the calculation. What's the best way to perform this calculation?


Especially on MathOverflow, I ask much more than I answer. On some sites I haven't answered anything at all yet (mainly because of my subject skill level). Yet I feel this is unfair and I'm taking more than I'm giving, and that I'm not worthwhile to site. Am I right in this thinking, or not?


pyspark - how to delete a local directory if it already exists

i wish to delete a local directory if it already exists. below is my code:  import sys import os from pyspark import SparkContext from pyspark import SparkConf  conf=SparkConf().setAppName('pyspark') sc=SparkContext(conf=conf)  data=sc.textFile('file:///home/cloudera/Downloads/SAN_SALES_EXTRACT_TRANS_LEVEL_D0906.txt') datamap=data.map(lambda x: ((str(x.split(',')[1]).strip(),int(x.split(",")[0])),float(x.split(",")[10]))) datagrouped=datamap.reduceByKey(lambda x,y: x+y) if (os.path.exists("file:///home/cloudera/Downloads/store_perday_rev")):         os.remove("file:///home/cloudera/Downloads/store_perday_rev") else:         datagrouped.sortByKey().saveAsTextFile("file:///home/cloudera/Downloads/store_perday_rev") #for i in datagrouped.sortByKey().take(20): #       print(i)   It doesn't delete the directory. What am i doing wrong?


Gӧdel proved that FOL is complete. The arithmetical theory Q is closed under first-order logical consequence, and yet Gӧdel's theorems establish that Q is incomplete. What's the relationships between the relevant concepts involved? Why these facts are mutually compatible?


Display os x window full screen on secondary monitor using Cocoa

I'm working on a Cocoa Mac app where I need to display a window/view on a secondary monitor, full-screen.  I know how to create a window that could be dragged onto the secondary monitor, but I was wanting to programatically create the window and make it full screen on the external monitor.  Thanks for the help.


Periodically I need to help a person who has an older iPhone or iPad, and I cannot see their device. Is there a program or web page available that simulates the Settings app in different versions of iOS? I found  but there were no replies.


Why is the output of following C code 10? What I mean is why is printf giving x as output?

Compiled using GCC on a Fedora 20 Desktop, the following code outputs 10.  int x=10; int y=5; printf("%d",(y,x));


Stack overflow blog posts using wrong icon

In the Android app, I saw a blog post on "ES beta", that links to the Stack Overflow blog. I assume this is a cosmetic bug, as function is not affected.


Waiting for required medium software center

I'm trying to install the proprietary AMD drivers through Software Sources. I tick the box for fglrx-updates, and it says applying changes and fills 10% of a progress bar. It then sites there for hours (I left the computer unattended).   Trying to get this process to finish, I found that the Ubuntu software center progress tab display a message reading:      Applying Changes: Waiting for required medium   What in the world does that mean and how can I get it to move on?


Dual national planning a visit to the US

We are a Canadian-Iranian family, residing in the UAE. We have recently attended a family event in Iran with our Iranian passports. We are planning our US trip a week after our visit in Toronto. We would be entering the US through the Canadian border (Pearson Airport). Do we need to obtain a US visa?


What are effects on overhead of using list.pop(0)?

Early on in my exploration of Python, I remember being told that using pop on the first element of a list wasn't necessarily bad practice, but was less than optimal. The reason that was given was that basically a new list had to be formed to be able to re-index all of the remaining elements. This doesn't appear to be the case, however: test_list = [1, 2, 3, 4, 5]  hex(id(test_list)) Out[29]: '0x17d5b172f48'  test_list.pop(0) Out[30]: 1  hex(id(test_list)) Out[31]: '0x17d5b172f48'  Nonetheless, I'm still wordering if there is some overhead to reassigning indices to the remaining elements, or if there is some other cost to popping from any other element but the last. EDIT Honestly, the difference between popping the last and first element does not look all that trivial when working with large lists: test_list = list(range(int(1e6))) %timeit test_list.pop(0)  671 µs ± 26 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)  test_list = list(range(int(1e5))) %timeit test_list.pop(0)  The slowest run took 5.01 times longer than the fastest. This could mean that an intermediate result is being cached. 17.3 µs ± 7.91 µs per loop (mean ± std. dev. of 7 runs, 10000 loops each)  test_list = list(range(int(1e8))) %timeit test_list.pop()  91.7 ns ± 0.821 ns per loop (mean ± std. dev. of 7 runs, 10000000 loops each)


Devise a strategy for coin toss among three players

Suppose that there are 3 players and 1 fair coin.  Devise a strategy such that we can have a clear winner. The coin can be tossed any number of times and the probability of winning for each candidate must be same.


Is there a way to find out how "deep" a PHP array is?

A PHP array can have arrays for its elements. And those arrays can have arrays and so on and so forth. Is there a way to find out the maximum nesting that exists in a PHP array? An example would be a function that returns 1 if the initial array does not have arrays as elements, 2 if at least one element is an array, and so on.


Can you please tell me what is the food choice / what the food choice is? (inversion)

1a. "Can you please tell me what is the food choice for a vegetarian?"  Why is there no inversion in the example above? I mean, why did the native English speaker who wrote the example not do it like this:  1b. Can you please tell me what the food choice for a vegetarian is? or 1c Can you please tell me what the food choice is for a vegetarian?  I have been taught that, whenever we ask an indirect question, we have to switch the inverted word order in the direct question to normal sentence order as follows:    Where is the nearest hospital?(direct question)   2a. Can you please tell me where the nearest hospital is? (indirect question)   So could you please explain to me why this change in the order of words doesn't happen in the original example (written by a native speaker)?


Python-check what position it is in a list

list1 = ['physics', 'chemistry', "dog", "cat","dog"];   I want it to say if I typed in an input dog it will tell me dog is the forth one and sixth one.


Two body problem with given start positions and velocities

I am trying to program a $n$-body problem simulation. To calculate the position and velocity after a time-step I want to split it in multiple 2 body problems. Now I am stuck, trying to find the velocity and position of two bodies (ignoring all the others) after one time-step with given mass, start position and velocity.  I am able to calculate the force between the two, but I am unable to solve the differential equation $$ \ddot{\vec{r_{12}}(t)} = G M \frac{\vec{r_{12}(t)}}{|\vec{r_{12}(t)}|^3} \\ M := m_1 + m_2 \\ \vec{r_{12}(t)} := \vec{r_1}(t) - \vec{r_2}(t) $$  to calculate the position relative to each other. What is $\vec{r}(t)$ and how can I calculate it? And is there another and maybe faster way to get the positions and velocities?  Edit: As @Sofia pointed out, this was not clear: $\vec{r_1}$ and $\vec{r_2}$ are the location vectors of the two masses.


How do I put a table following the other table in a two-colmuns layout?

my page is of two columns layout and I want to put two tables in consequence on the right column like below:  text here    Table 1 goes here text here text here    Table 2 goes here text here   while I have used wraptable then Table 1 is placed accurate but Table 2 is jumped to the left column below the last text line. In case if I remove wraptable for the table 2, the two tables are covering each other (overlapping).  How can I have the two tables aligned in the right column?


Low Battery Alert for Mac OS X El Capitan

I have Macbook Air, Mac OS X El Capitan.  There is no warning box shown before the battery is near %15, like it did for Mountain Lion. So I can not notice and my computer goes sleep simply when the battery is off.  And even if it did I generally miss it because I use it external monitor attached to my Macbook Air. And because I play Spotify, I may miss the warning sound, too.  Is there warning box for low battery on El Capitan? If not, is there any utility or software that may help for external monitors and even playing music?


ubuntu 32bit 13.04 iso image for virtual box

Hello folks From where i can download 32bit for 13.04 version for my virtual box. Only 32bit. Thanks shazz


Unable to locate package vsftpd Ubuntu 17.10

I am using below command to install ftp but its showing error message: sudo apt-get install vsftpd  Error Building dependency tree Reading state information... Done E: Unable to locate package vsftpd


scp from remote Linux to local Windows with spaces in local path

To push a file from a Linux terminal to a Windows system, the following two examples work just fine.  scp /home/user.name/file.html user.name@local.ip.num:/C:/Users/user.name/test_folder/file.html  scp /home/user.name/file.html user.name@local.ip.num:"/C:/Users/user.name/test_folder/file.html"   I need to do this where the local folder has spaces and I cannot change the name,  say /C:/Users/user.name/test folder/  All of the following fail with the message scp: ambiguous target  scp /home/user.name/file.html user.name@local.ip.num:"/C:/Users/user.name/test folder/file.html"  scp /home/user.name/file.html user.name@local.ip.num:"/C:/Users/user.name/test\ folder/file.html"  scp /home/user.name/file.html user.name@local.ip.num:"'/C:/Users/user.name/test\ folder/file.html'"  scp /home/user.name/file.html user.name@local.ip.num:"/C:/Users/user.name/test\\ folder/file.html"  scp /home/user.name/file.html user.name@local.ip.num:"'/C:/Users/user.name/test\\ folder/file.html'"  scp /home/user.name/file.html user.name@local.ip.num:"/C:/Users/user.name/test\\\ folder/file.html"  scp /home/user.name/file.html user.name@local.ip.num:"'/C:/Users/user.name/test\\\ folder/file.html'"   How do I get this to work?


Sorting an array by two values using compareTo

So I am trying to sort an array using compareTo.  This is what i have now:  @Override public int compareTo(Episode other) {     return Integer.compare(episodeNummer, other.episodeNummer); }   I am now sorting only by episodenumber, but I am trying to also sort the list by season.


Prove sum of 2 little 'o is equal to the little 'o from the sum

I need to prove if   for $f(x) = o(h(x))$ and $g(x) = o(q(x))$  then $f(x) + g(x) = o(|h(x)| + |q(x)|)$  I think that this is false but I am struggling to find a counter example.


How do i create low lying smoke (similar to Zootopia), in blender

Hello Blender community,  I am a huge fan of the Disney movie Zootopia, the amount of physics and detail really drew me into 3D animation and design. Although I always had an interest in 3D technologies, designs, animation, etc. This movie really pushed me into getting into making 3D stuff, and learning Blender.  Anyway, as a learning experience, I decided to take multiple different 'animating techniques' of the movie and try to replicate in Blender.   The scene I'm trying to replicate? The Limo scene, specifically the low, lying smoke.    I have analyzed this scene many times and I have concluded on some of its properties   It lively collides, with the characters, meaning that it is not a textured material, it is most likely mesh based. It has a lower temperature value than other objects, which is why when the characters breathe, an amount of fog appears (This is because the movie was designed in the Hyperion Renderer, I don't really need this, but if you know how to make this please let me know) It is somewhat fluffy, although not cloud-like. When a mass of this smoke comes together, it makes a fluffy looking mass. It is affected by gushes of air, when Judy (the bunny) lands on the ground, a gush of air extrudes the smoke around her. Sudden movements have this effect as well.   Now I'm pretty sure that making this is in Blender is difficult or even impossible, considering that Disney has their own proprietary rendering engine named Hyperion and they can drop smoke in within a couple of clicks. And they have HUGE render-farms that can render these details.  But I just wanted to know if it is possible. As I may be getting an internship for Disney Animation, I need to know this stuff  UPDATE: So, I see that using a still frame from the movie to demand something that needs multiple frames, is pretty stupid  So feel free to study this clip:  (and if you haven't seen the movie, do yourself a favor and please have a watch)  Also, I would like to know, how to smoke kind of 'flows', the way that it lies low to the ground moving. Not just stuck in place similar to how Cycles does it.


Yesterday my brother's computer was showing ads on almost every site, the same ads in the bottom right corner with a black close button. Today, my computer started showing them. I use the same network with him but as a public network to minimize the risk of network infection. The problem is that I NEVER install software from suspicious sources. Does anyone know something about this virus? I have some screenshots for some legit sites with those ads. So my computer is infected, no suspisous Chrome extensions or addons. Any suggestions? Thanks.


The purpose of the command should be replacing any IP in file myfile.txt with the local ip of the server automatically  example:  sed -i -e 's/[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}/LOCALIP/g' myfile.txt   i want to know if it possible to use command for getting local ip address inside sed   basically i want to replace LOCALIP in my example with this command   /sbin/ip -o -4 addr list eth0 | awk '{print $4}' | cut -d/ -f1


Proving an Integral Identity with Increasing Bounds

How can I show that  $$ \lim_{A\rightarrow \infty} \int_0^A \frac{\sin(x)}{x}dx\;=\;\frac{\pi}{2}?$$ I know that can use the fact that, for $x>0$,  $$x^{-1}\;=\;\int_0^\infty e^{-xt}dt$$ but I'm not sure how to begin.


Assign multiple keyboard shortcuts for one action

I've been wondering how can I assign to multiple keyboard shortcuts to do the same action? More specifically, I want to be able to change my volume with both my headset buttons and my keyboard.  I'm able to change the volume with just one at the time: with the one I define in the 'Keyboard shortcuts' application. Is there any way?


Given an ideal $\mathfrak{a}$, Matsumura defined the height of $\mathfrak{a}$ as: $$\text{ht}(\mathfrak{a})=\inf_{\mathfrak{p}\in V(\mathfrak{a})}\text{ht}(\mathfrak{p})$$ He states that: $$\text{ht}(\mathfrak{a})+\dim(A/\mathfrak{a})\leq \dim(A)$$ Any ideas on how to show this? I know I have to use the correspondence theorem. I'm just having a hard time writting it properly with the definitions of height and dimension. Thanks in advance!


Proving the countability of algebraic numbers

I am trying to prove that algebraic numbers are countably infinite, and I have a hint to use: after fixing the degree of the polynomial, consider summing the absolute values of its integer coefficients, and setting the sum less than or equal to $m$, for each $m \in \mathbb{N}$. I am also allowed to use the fact that every polynomial has a finite number of roots. I am not sure where to begin... Perhaps after fixing the degree of the polynomials, I could try enumerating them, and after proving countability of the set that contains the roots of all polynomials of a certain degree, I could state that the union of infinitely many ($\bigcup_{n=1}^{\infty}$, $n \in \mathbb{N}$) countably infinite sets is countable, and thus the algebraic numbers are countably infinite, too, but I am not sure if this is a good approach/how to enumerate the polynomials. Thanks!


Two websites, two domains, for one brand, SEO issues?

I'm doing SEO for a new real estate company, yet the developer had surprised me with this:  The developer had created two websites with two domains for one brand:  The first domain/website:  samplehouse.com - that's where the rental and real estate listings go  The second domain/website:  samplehouseinc.com - that website has pages like "about us" "pricing" "contact us" "how it works" and basically only pages representing the brand.  When I asked the developer the reason behind two websites!! this was her response:     The website was too big to be put on one Domain. Hence the reason that   we got two domains!!!!   If you can please answer some of my concerns:    How does this affect SEO? How to notify Google about this? This will likely create confusion to some users, what do you think? Should the site be redone again using just one domain only? given the fact that the company is just starting out in a competitive niche.   Your answers are appreciated and thanks a lot in advance.


How to find whether a multiplicative group is cyclic or not

I am new to group theory, and I observed that some multiplicative mod-n groups are cyclic and some are not . For ex :   $U(8) = (1,3,5,7)$ is not cyclic , but  $U(10) = (1,3,7,9)$ is cyclic and its generators are $(1,3,9)$.  How do we find which multiplicative group is cyclic, which is not?


String Theory- Are strings the end? What are they made of?

Although I have informed myself in string theory through reading books and watching videos, I do not know or understand what superstrings are made of. History has definitely shown us that when we think something is fundemental, there is always something smaller.  What are superstrings made of? Can we go smaller than strings?


Finding my father's Royal Navy record for WWII?

I have tried many times to find a record of my father who was in the navy during WWII without success. He told me that he served in minesweepers and then on motor gun boats and ended up serving in Ceylon. I know that we have an unusual surname Duguid and that it may have been misspelt but none of the various sites list him or names spelt like Duguid. Does anyone have any idea?


Only the page number in the header, nothing else

\documentclass[a4paper, twoside, 12pt]{report} \usepackage[  a4paper,  twoside,  inner=5cm,  outer=2.5cm,  top=2.5cm,  bottom=2.5cm,  headsep=0.5cm ]{geometry} \pagestyle{headings}   I need page numbers to be at the outer corner -- \pagestyle{headings} accomplishes this perfectly, however, it also adds the name of the section, which I do not want in the header.  I tried:  \usepackage{fancyhdr}  \pagestyle{fancy}  \fancyhf{} \fancyhead[LE,RO]{\thepage}   which puts the number in the correct position, however, also produces an underlining, and does not understand the page margins (i.e. the width of the header is not the same as the width of the text).  Is there a way to avoid using the fancyhdr package, and still get the hoped result? And if I must use the fancyhdr package, how do I get rid of the underlining and set the correct width?


Should closed questions earn vote/viewcount badges?

A while ago . Today it hit 1,000 pageviews, awarding me the  out of the blue.   Is this intended behavior; should badges still be awarded for activity on questions after they are closed? It sends a confusing mixed message — "this question is off topic but you get a cookie for it" — although I can see how we might not want to penalize people out of the achievement system just because a question was closed.  I'm not concerned about the closure itself (wasn't getting the answer I needed anyway). I'm just making sure that this is by design and not a bug.


I got several .obj files from a face and i want too animate them like keyframing. However keyframing does not work since the .obj files might differ in small details. My simplest approach is: make a animation based on showing each .obj just a few miliseconds. I need to do this with python since this should be automated. (In the end someone will give me a video, i split the video in frames and get for every frame a .obj file from the face (some Machine-Learning stuff behind there) and then i rebuild the "video" but in 3d. Is this possible with the python-api from blender ? And when yes, where would i start? Thanks.


how to get whatsapp working on ubuntu 11.04?

I don't have an android phone.please help me to acess whatsapp on ubuntu.


I have in the LaTeX source file:  \usepackage{subcaption}  \captionsetup{compatibility=false}  \begin{figure}    \begin{subfigure}{0.50\textwidth}    \includegraphics[width=0.95\linewidth]{RegressionFixedObservedN4451.png}    \caption{Based on the observed data sets}    \label{fig:RegressionFixedObservedN4451}  \end{subfigure}%  \caption{Regression plot for the fixed condition of the ACT (N = 445). The  x-axis represents the natural logarithm of the absolute value of the minimum  residual score belonging to the sequence of 14 consecutive bars with the  smallest MSE. The y-axis represents the smallest MSE. The top line is the  line $y = 2x + \ln{10}$. The bottom line is the line $y = 2x-\ln{10}$. The  line exactly in between is the line $y=2x$.}  \label{fig:observedfixedcondion}  \end{figure}    and the caption is centered. But I want the caption NOT centered. How should I do this?


Does the atom get the impulse from a photon?

A photon has both impulse and energy. If it is absorbed in an atom from level E1 to E2 what happen to the impulse. Does the atom acquire the impulse of the photon? If so it would get some acceleration and this is some excessive kinetic Ek?


I was given this problem to Prove if $Q(n)=Q(2n)$ implies $9∣n$. Where $Q(n)$ be the sum of digits of $n$. I tried to use the fact that sum of digits is congruent to the number modulo $9$ but I had no luck. Any help is appreciated.


I just tried to install python 3.6 on my Ubuntu 16.04 system, and now I can't run the terminal from the launcher or from Ctrl + Alt + T. I tried to run gnome-terminal from XTerm and got the following message:  Traceback (most recent call last):   File "/usr/bin/gnome-terminal", line 9, in <module>     from gi.repository import GLib, Gio   File "/usr/lib/python3/dist-packages/gi/__init__.py", line 42, in <module>     from . import _gi ImportError: cannot import name '_gi' Error in sys.excepthook: Traceback (most recent call last):   File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 63, in apport_excepthook     from apport.fileutils import likely_packaged, get_recent_crashes   File "/usr/lib/python3/dist-packages/apport/__init__.py", line 5, in <module>     from apport.report import Report   File "/usr/lib/python3/dist-packages/apport/report.py", line 30, in <module>     import apport.fileutils   File "/usr/lib/python3/dist-packages/apport/fileutils.py", line 23, in <module>     from apport.packaging_impl import impl as packaging   File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 23, in <module>     import apt   File "/usr/lib/python3/dist-packages/apt/__init__.py", line 23, in <module>     import apt_pkg ModuleNotFoundError: No module named 'apt_pkg'  Original exception was: Traceback (most recent call last):   File "/usr/bin/gnome-terminal", line 9, in <module>     from gi.repository import GLib, Gio   File "/usr/lib/python3/dist-packages/gi/__init__.py", line 42, in <module>     from . import _gi ImportError: cannot import name '_gi'   How can I fix this error?  It should also be noted that:   My gnome-terminal file is now a python script. The gnome-terminal.real file will open the terminal as expected. python3.5 gnome-terminal will open the terminal as expected.


I have tried many different things to try to format my USB drive, but none of them work... how might I do this using the mformat commands? thanks!


Would raising the review limit help with the Close Votes queue?

We all know       , but it seems the problem is people not reviewing enough. Whenever I had time, I would go through all 40 that I was given, but by then I wanted to do more. Would raising that limit of 40 and not counting Close Votes queue votes towards your daily close vote allowance help?


Automatic forwarding of Google Apps mail

How can I ensure that any mail received or sent via our Google Apps domain, is automatically forwarded on to the domain administrators mailbox?


Where to focus when taking a portrait of 2 people?

Could someone please tell me where to focus when taking a portrait picture of a couple who are standing next to each other. Thank You


Solving an equation with least residues and roots modulo $n$

I am facing the problem of proving $z^2 \equiv 1\pmod 8$ for all odd $z\in\mathbb{N}$. What I know is that for each $z \in \mathbb{N}$, $z = m^2-1$, for $m\in\mathbb{N}$. What I also know is that in a least residue system there are the following solutions for all $z\in\mathbb{N}$. The solutions are: $$n \equiv 1,3,5,7$$ Which lead to solutions of the initial problem: $$n = 8 \cdot k + 1\\ n = 8 \cdot k + 3 \\ n = 8 \cdot k + 5 \\ n = 8 \cdot k + 7$$ where $k\in\mathbb{N}$. My question now is how I can transfer my knowledge about the solutions for all $n\in\mathbb{N}$ to the key problem where $n$ must be an odd number and the proofs needs to be done for all odd $n$. I also know that $8 = 2^3$ which leads to $$(2\;\cdot\;m\;-\;1)^2\;\equiv\;1\;\pmod 8$$ $$(2\;\cdot\;m\;-\;1)^2\;\equiv\;1\;\pmod {2^3}$$ but I do not know what this tells me right now.


I'm writing a paper now and I have the format problem as shown in the following snip   I follow the latex code for the table   \documentclass[sigconf]{acmart} \begin{table}[h] \centering \begin{tabular}{|c|c|c|c|c|} \hline    Brand & community & Neutral\_Average & Negative\_Average & Positive\_Average  \\ \hline    Apple & NEWS & 1.45 & 2.93 & 2.72 \\ \hline    Apple & Amazon & 0.069 & 0.39 & 0.71 \\ \hline    Apple & Twitter & 17.11 & 11.36 & 12.06 \\ \hline  Huawei & Amazon&0.076 & 0.20 & 1 \\ \hline  Huawei & Twitter& 13.56 & 5.3 & 10.58 \\ \hline  Huawei & NEWS&1.034 & 1.73 & 1.75 \\ \hline   Samsung & NEWS & 1.03 & 1.83 & 3.37 \\ \hline   Samsung & Twitter & 10.82 & 4.52 & 11.62 \\ \hline   Samsung & Amazon & 0.093& 0.35& 1.1 \\ \hline      \end{tabular} \caption{Average Brand Sentiment Per Community} \label{brand_senti_community} \end{table}


Uploading a 7 years old published conference paper on arXiv

I have 3 conference papers which were published around 7 years ago. However, the conference proceedings are not well indexed. If I upload a 7 year old published work on arXiv to increase the audiences, will the research community take this action positively or negatively?


Is there a browser equivalent to IE's ClearAuthenticationCache?

I have a few internal .net web application here that require users to "log out" of them. I know this may seem moot on an Intranet application, but nonetheless it is there.  We are using Windows authentication for our Intranet apps, so we tie in to our Active Directory with Basic Authentication and the credentials get stored in the browser cache, as opposed to a cookie when using .net forms authentication.  In IE6+ you can leverage a special JavaScript function they created by doing the following:  document.execCommand("ClearAuthenticationCache", "false")   However, for the other browsers that are to be supported (namely Firefox at the moment, but I strive for multi-browser support), I simply display message to the user that they need to close their browser to log out of the application, which effectively flushes the application cache.  Does anybody know of some commands/hacks/etc. that I can use in other browsers to flush the authentication cache?


Are users given back rep if another person compromises their account and uses it to post spam?

What if some person has access to someone else's Stack Exchange account (compromised credentials, open laptop, etc.) and goes ahead and posts something useless or even offensive garnering multiple downvotes and thereby negatively affecting that person's reputation?  Can the original user be awarded his rep back on an appeal/request? This is, of course, keeping in mind the question asked is not a "bad" question; mainly spam.


Request: Keep statistics on a question's HNQ appearance

Duplicate, maybe. ()     While the HNQ list creates a lot of cross-site traffic (which is wanted), it also causes issues on those sites sometimes, in particular on sites like  where the 'hotness' of some questions strongly distorts the "voting = quality" paradigm.  However, I'm not about fixing HNQ here. Instead, I'm wondering if there is a good method to find out (via query or otherwise) if a question has in the past ever been placed on the HNQ list. ( See also:  )  And if not, I would like to propose this as a general feature request. The information whether or not a question has been on HNQ is a valueable meta-info which ideally should be captured in the database.  It would allow   easy flagging of such questons in some site design (i.e. an addtional icon) easy filtering for/against such questions in the search query notification and user statistics ( see:  ) interesting analysis of the impact of HNQ in various contexts


Word to use when you don't understand a sport or video-game language

I've been trying to find this word for ages. It's on the tip of my tongue, but I can't find it. Here's a scenario:        Guy 1: Did you see that curve ball by that baseball player?     Guy 2: Yeah that was really well done!     Guy 3: I don’t understand a thing Guy 1 and 2 are saying. They are using so much _____      The blank part is a word that I can't remember.


I'm trying to learn materials, and there are so many options! I'd like to be able to compare side by side the effect of changing certain values.  Is it possible to keep old renders open?


TikZ: Node at same x-coordinate as another node, but specified y-coordinate?

In TikZ, if I have a node (A), how do I create a node (B) with the same x-coordinate as (A), but a given y-coordinate?


Here's the sentence - We Put These BFF's to the test.  Is this correct or wrong and why?


How to implement a property with a base value and a changed value?

I have a number of stats and effects in game that are subject to change, they have some kind of base value and the current value. For stats, I implemented this in a dynamic way, but for less important things, like buffs that is too much work. For buffs I have 2 properties - current and base value. For example, the shield buff action takes the base value and copies it into the current value at the start of each turn.  What is a good way to implement having the current value and base value for effects?  Right now I have a base property defined along with the modified value.  +(BuffBase*)buffWithEffectType:(kEffectType)effectType intensity:(int)intensity {     BuffBase* buff = [[BuffBase alloc] init];     buff.intensity = intensity;     buff.baseIntensity = intensity;      return buff; }   Should I refactor such code early on and replace it with some kind of tuple, like EffectValue(current,Base) where x is current and y is base?   +(BuffBase*)buffWithEffectType:(kEffectType)effectType intensity:(int)intensity {     BuffBase* buff = [[BuffBase alloc] init];     buff.intensityTuple = EffectValue(intensity, intensity);     return buff; }   Or should I start with a dictionary/map right from the start? This seems to be the easiest to expand later on, although I have to remember string keys:  +(BuffBase*)buffWithEffectType:(kEffectType)effectType intensity:(int)intensity {     BuffBase* buff = [[BuffBase alloc] init];     NSMutableDictionary* dictionary = [[NSMutableDictionary alloc] init];     [dictionary setObject:@(intensity) forKey:@"base"];     [dictionary setObject:@(intensity) forKey:@"current"];      //optional parameters for potential future expansion     [dictionary setObject:@(1) forKey:@"decay"];     [dictionary setObject:@(4) forKey:@"maxHitsBlocked"];     buff.valueDictionary = dictionary;      return buff; }


Can I move a webform to another drupal installation?

I have created a few webforms on our development server and would like to move them over to a production installation. Can I do this with node export?   I'm not concerned with migrate any user responses (as we were only testing).


What should be length of keyword using for meta keyword tag?

I want to know that what is character count limit to use Meta Keyword as per Search Engine Optimization policy  like Title should not be extend than 70 Characters or Meta Description must less than 155 characters


How can i keep the give the subject of the email using postfix in crontab?

Using MAILTO where can i give the subject of the email without using echo Test | mail -s Test xyz@example.com because if i use like this for sender to a one user it is okay if i want to add multiple user mails then for every script i have to add the mail id's which will be not good when comapare to MAILTO command.  Right now i have the script to send the mail to a user and send the STDOUT AND STDERR to logs.txt.   MAILTO="xyz@example.com,abc@example.com,rer@example.com"  25 07 * * * /usr/local/bin/curator --dry-run --config /home/itadmin/.curator/curator.yml /home/itadmin/.curator/snapshot.yml 2>&1 | /usr/bin/tee -a /home/itadmin/.curator/logs.txt   What i want is that in the MAILTO command is it possible to subject to all the users listed in that command like this MAILTO="xyz@example.com,abc@example.com,rer@example.com?subject=Mail Tested"  Thanks


How can I fix program icons that appear as a question mark in the Launcher?

In the left side of the screen there are icons: Software Center, Ubuntu One, etc. System icons can be seen but icons of the programs that I have installed can not be seen. Rather there is a "?" for the icons. How can I solve this problem?


In Russell's famous paradox ("Does the set of all sets which do not contain themselves contain itself?") he obviously makes the assumption that a set can contain itself. I do not understand how this should be possible and therefore my answer to Russell's question would simply be "No, because a set cannot contain itself in the first place."  How can a set be exactly the same set as the one that contains it? To me it seems unavoidable that the containing set will always have one more additional level of depth compared to all the sets which it contains, just like those russian matryoshka-dolls where every doll contains at least one more doll than all the dolls inside it.  Of course one can define something like "the set of all sets with at least one element" which of course would include a lot of sets and therefore by definition should also include itself, but does it necessarily need to include itself just because its definition demands so? To me this only seems to prove that it's possible to define something that cannot exist beyond its pure definition.


E: Could not get lock /var/lib/dpkg/lock-frontend. It is held by process 5200 (apt) N: Be aware that removing the lock file is not a solution and may break your system. E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), is another process using it?


bibliography with per-author numbering (and author-year sort)

I'm working on a new edition of a book which uses a very unusual style of bibliography: Entries are sorted in author-year fashion, but then numbered per author or group of authors, e.g.:  Milnor, J.:    1. Construction of universal bundles: I, Ann. Math., (2)63:272-284 (1956).    2. Construction of universal bundles: II, Ann. Math., (2)63: 430-436 (1956).    3. On manifolds homeomorphic to the 7-sphere, Ann. Math., (2)64: 399-405       (1956).    4. The theory of characteristic classes, mimeographed, Princeton University,       Princeton, N.J., 1957. Milnor, J., and M. A. Kervaire:    1. Bernoulli numbers, homotopy groups, and a theorem of Rohlin, Proc. Intern.       Congr. Math., 1958. Milnor, J., and E. Spanier:    1. Two remarks on fibre homotopy type, Pacific J. Math., 10: 585-590 (1960).   Citations are formatted as Milnor [3], and so on.  Is there any bibtex style for something strange as this? Or can this type of bibliography be created with biblatex without too much coding?


I would like to make some changes to the core toolbar module across all my sites, and I don't want to modify the actual core's css.  It looks like I should be able to override the core css found in modules/toolbar/toolbar.css by simply copying this file into my sites directory at /sites/modules/toolbar/toolbar.css.  I tried doing this, cleared the Drupal cache, but nothing happened.  What am I missing?


What is this 'view only the selected area' mode I am in, in the 3D viewport and how do I out of it?

I've managed to enter this 'view only selected area' thing in the viewport and I have no idea how to get out of it.


How long for Google to index pages after submit to index? How to check the progress?

After a revamp of our website, I have submitted an updated sitemap then fetched the homepage URL / as Google and submitted it and its direct links for indexing in Google Search Console more than 2 weeks ago.  Since then I haven't seen a change at all in total number of indexed pages.  The pages crawled per day has been consistent throughout this time but nothing to indicate the whole site has been re-crawled for indexing (I would've expected to see a spike here).  If I go to Crawl -> Sitemaps, I can see some pages have been marked as indexed but it's only a very small percentage of total number of submitted URLs and the figures haven't changed in over two weeks.  There are no sitemap errors or index errors.  Does anyone know how long it takes before I should see some movement?  And am I looking in the right place to see it, i.e. the crawl stats and total number of indexed pages in Google Search Console?  How do I know if Google has crawled the pages and decided not to index them versus not crawled them at all?


How to change the IP address of an installed printer?

I installed an HP printer from a local network. Now, for some reason, the internal address of the printer has changed from 10.0.0.3 to 10.0.0.2. I opened the printer setting, but cannot change the IP address from there:  Is there another way to change the printer's address?


How to modify the real value with a multiply operation

A simple question :  1) In Python using numpy, how to get without parisitic decimals the follwing result (true value 0.6968) ? :  >>> 0.67*(1.04) 0.6968000000000001   If I convert to string, I can find the right value :   >>> str(0.67*(1.04)) '0.6968'   2) By the way, how to control the rounding to systematically get the real value ? I saw that epsilon machine with Python (and/or Numpy) was around 2e-16.  So, I conclude that taking 16 decimals is too small and implies random values after 16th decimal or more precisely below 2e-16.  I don't want to troll but Matlab (I like also Python) doesn't produce this kind of error.


How to auto-start unprivileged lxc containers?

On Ubuntu 14.04, I have created an unprivileged container that I can manually start and stop.  But I would like this to start and stop along with the system.  I have added the following to the container's configuration:  lxc.start.auto = 1 lxc.start.delay = 5   However, the system scripts don't seem to pick unprivileged containers.  There is  related to this on linuxcontainers.org, but the solution seems to be restricted to root user.  Is there a clean way to do this for a non-root user (with root user's consent)?


Does the Mordenkainen's Magnificent Mansion spell's mansion exist on a separate plane of existence?

In particular: the  spell (PHB, p. 281) states:  [...] The creature can be anywhere on the same plane of existence as you. The spell ends if you or the target are no longer on the same plane. [...]  Can telepathy connect two characters, one inside the extradimensional dwelling created by the  spell and the other in the same plane as the portal to the magnificent mansion?


Removing overlapping polygons using QGIS

I have many polygons in a single shapefile and they are overlapping (first figure). Is there a tool in QGIS to only keep one overlapping area as the one shows in the second figure? There is a "update" function in ArcGIS but the polygons must be in separate shapefiles.


I recently received a mark-down for the following phrase:     With this regard, will you please accept the Takeover agreement on this quote so that we can proceed with the validation process?   The quality evaluator (I work with a Customer Service Team) told me that the use of a question mark in this sentence is incorrect.  Is his evaluation correct, and why?


Getting LyX to honor paper size of LaTeX class?

I'm not sure, if I'm just overlooking a simple preference setting or if what I would like to achieve is possible at all...  Anyway, I recently created a LaTeX class file (it's based on scrbook from the KOMA-Script package, but that might be beside the point) that looks like that:  \NeedsTeXFormat{LaTeX2e} \ProvidesClass{MyBook}[2016/06/03 My Book Class]  \LoadClass[ paper=17cm:22cm, DIV=12, twoside, fontsize=9pt, toc=flat ]{scrbook}  (...skipping a few more adjustments...)   I then created a LyX layout file by simply copying the contents of the original file scrbook.layout:  #% Do not delete the line below; configure depends on this #  \DeclareLaTeXClass{MyBook}  Format 35 Input scrclass.inc Input numreport.inc  Sides                   2 PageStyle               Headings  NoStyle Abstract   Style Chapter     LabelString          "\thechapter"     TocLevel 0 End   # Equations are numbered by chapter Counter equation     Within chapter     LabelString "\thechapter.\arabic{equation}" End   Style Bibliography     TopSep                4     LabelString           "Bibliography"     LabelFont       Series              Bold       Size                Largest     EndFont End   I put the files into the correct directories, reconfigured LyX and so far, everything is working perfectly.  ...well, except for the fact that LyX seems to ignore both the paper size (set as 17cm:22cm) and the margins (defined by setting DIV=12). Instead LyX always uses A4 for the paper size and standard margins (not sure how big). I'm assuming that LyX takes these from its own set of preferences, instead of honoring the class settings.  I could, of course, define the paper size and the margins in the preferences of the LyX document itself. However, I would like to give the class definition to several authors, without them having to do any further adjustments in the preferences. So, I would really prefer to define the paper size and the margins in a more central place.  Is this possible? Any help would be much appreciated. Thanks in advance!


MYSQL Server is getting restarted multiple times every 2-3 days

Mysql Server is getting restarted saying below errors. It will be grateful if someone can help me to solve this.  2017-10-04 17:07:43 3402 [ERROR] /usr/sbin/mysqld: Out of memory (Needed 1048548 bytes) 2017-10-04 17:07:44 3402 [ERROR] /usr/sbin/mysqld: Out of memory (Needed 1048548 bytes) 2017-10-04 17:07:46 3402 [ERROR] /usr/sbin/mysqld: Out of memory (Needed 1048548 bytes) 2017-10-04 17:07:48 3402 [ERROR] /usr/sbin/mysqld: Out of memory (Needed 1048548 bytes) 2017-10-04 17:07:49 3402 [ERROR] /usr/sbin/mysqld: Out of memory (Needed 1048548 bytes) 2017-10-04 17:07:51 3402 [ERROR] InnoDB: InnoDB: Unable to allocate memory of size 1065016.  2017-10-04 17:07:51 993b90 InnoDB: Assertion failure in thread 10042256 in file ha_innodb.cc line 17352   Using 32bit centos system as database server.  Tried increasing max connections, innodb_buffer_size but did not help.


Show that if $A$, $B$, and $A + B$ are invertible matrices with the same size, then   $A(A^{-1}+B^{-1})B(A+B)^{-1}=I$      What does the result in the first part tell you about the matrix $(A^{-1}+B^{-1})$?   I get the first part. Help me with the second part.


If $A<C$ is finite must $A<B,B<C$ be finite

Let $A<B<C$ be a tower of commutative rings with identity. If $C$ is finitely generated as an $A$-module, must we have the following:  1) $B$ is finitely generated as an $A$-module.  2) $C$ is finitely generated as an $B$-module. (This is trivial already as noted by user26857.)  Do 1), 2) have to hold if at least we restrict ourselves to integral domains?  Thank you.


Compute the indefinite integral  Irrational: $$\int \frac{x-1} {1 + \sqrt{x^2+2x-3}}dx$$ Help me pls. What do I need to do then? fraction isn't simplified


Should an off-topic question always be downvoted?

The upvote tooltip says:      This question shows research effort; it is useful and clear.   The downvote tooltip says:      This question does not show any research effort; it is unclear or not useful.   Sometimes, a question can show research effort, be useful, be clear, but just not in the good place. Voting to close the question and downvoting seems like a double penalty.  Should an off-topic question always be downvoted ?


InDesign CS5.5/CS6: How to work with facing pages, but retain bleed area all around each page?

I have this very real situation. I have a 68 page brochure + cover. I'm working with facing pages, which is ideal for clarity and design of the brochure. But the problem is when I need to export the brochure for the printhouse.   The printer tells me he needs each page separately (as opposed to spreads) and each page has to have its own bleed area. This makes perfect sense. But when I work with spreads in InDesign, there is no inner bleed area. What happens during export, is that whatever is on the opposing page gets included in the other page's bleed area, on the inner side at the spine.  I needed to get the job done quickly, so I did it the dirty way. I converted the facing pages document into a non-facing pages document. Then I had to reposition some elements because they got moved, especially because the left and right margin of each even/odd page, were different. So I had to prepare new master pages, for the left and right page with appropriate margins, and assign the master pages to each even/odd page. This is a terribly error prone workflow. It got the job done, the printer accepted my file. Each page got its own clean bleed area. But this is just wrong (dirty) workflow.   Is there a clean and flexible way to do this in InDesign CS5.5 or CS6? A feature that does this? What I imagine would be appropriate, is a gap between the left and right page, so that there is space for the inner bleed. Then I could keep working in facing pages layout, but have the ability to provide the inner bleed.  Edit: This is not a dupicate question. In my case, I need to have different content on the left and right pages, hence I need different inner bleeds. The other question is for when I want one image to spread accross the facing pages, it's not the same situation.


If $\epsilon=\{\}$ then what is $\bigcup \epsilon$ and $\bigcap \epsilon$?

I know that $\bigcup \epsilon$ is the union of sets that are members of collection set $\epsilon$, and $\bigcap \epsilon$ is the intersection of sets that are members of collection set $\epsilon$. But what if the set (for this question is $\epsilon$) is an empty collection of sets, what would the union and intersection be?


Why are "degrees" and "bytes" not considered base units?

From :     The SI base units and their physical quantities are the metre for measurement of length, the kilogram for mass, the second for time, the ampere for electric current, the kelvin for temperature, the candela for luminous intensity, and the mole for amount of substance.   As far as I know, a base is a unit which cannot be broken down into units other than those from the above mentioned units. However, degrees (for angles) and 8-bit  (for digital data) cannot be expressed using one or more of the base units. So, why are these two units not considered base units?


How to save a webpage as MHT archive files in Google Chrome?

I've been searching for a Google Chrome way of -How to save a webpages as MHT archive files in Google Chrome? but still no luck !! As a Chromium project, it should have been easy to figure out, but why it's still not available in Google Chrome v43.0.2357.130 m ?


Reset supervisor password on Toshiba Portégé

I want some thing "software" that can help me to remove bios password on my **Toshiba Portégé Z30-A-12T.  I still remember the user password for bios but i can't remove it.  I hope to find a software to remove user and supervisor password;  Thank you :)


How to correct Fatal error: Uncaught Error: Class 'mysqli' not found in?

I uploaded my files on a live hosting server today and upon loading the url, this error was displayed. Fatal error: Uncaught Error: Class 'mysqli' not found in /home3/maalu/public_html/php_action/db_connect.php:9 Stack trace: #0 /home3/maalu/public_html/index.php(2): include_once() #1 {main} thrown in /home3/maalu/public_html/php_action/db_connect.php on line 9 Below is my database connection. <?php     $localhost = "localhost"; $username = "maalu"; $password = "********"; $dbname = "stock";  // db connection $connect = new mysqli($localhost, $username, $password, $dbname);  // check connection if (mysqli_connect_errno($connect))  { // creation of the connection object has some other error     die("Connect failed: ".mysqli_connect_errno()." : ". mysqli_connect_error()); }  ?>  Please kindly help.


Why cant Ridge Regression benift from negative lamda?

in Rigid regression, we generally set a positive Lambda for regularization to get a less Residual. Why cant we have a negative Lambda in a regularization if we can benefit from it?


How to calculate the costs of a weapon enchantment?

For my new adventure I want to buy an Inspired Rapier and just do not get how to calculate it. I actually thought I calculate the costs of the weapon (20gp) plus the +1 enchantment (2000gp) and pay the Inspired with the +1 so instead of a +1 Rapier I have an Inspired Rapier.   Is that correct and if not, could anyone explain to me how to calculate this?


Xdotool does not minimize terminal window when using in Startup Application when pc boots?

Based on feedback in comments tried this command:   In a terminal window this works:   gnome-terminal -x bash -c "sudo ./serial"; xdotool getactivewindow windowminimize    However when running the command in Startup Program the xdotool seems to be ignored. The pc boots with terminal windows on the screen, not minimized.  Background History:  I'm trying to determine a way to minimize the terminal window with the gnome-terminal command. I need my Ubuntu 14.04LTS remote pc to run several scripts and a C program at startup.  This remote pc is for customer viewing so the monitor needs to be clean. I did not see an option available to minimize: .  The best I could do was to make the terminal windows small, which is acceptable if I don't find a better way.  This is my command entered into Ubuntu's "Startup Applications" program:  gnome-terminal --geometry=60x2 --command "sudo ./My_C_Program"   My programming/Linux skills are mediocre, but growing. I'm looking for a better way to do this.  Based on a comment/feedback tried this:  gnome-terminal -x bash -c  "sudo ./serial_ver2_machine3_free_air_3_95"; wmctrl -r :ACTIVE: -b add,shaded   This works just the way I want when executing in a Terminal window!! The Terminal window is shaded but program is still running and it reappears when I click twice on Ubuntu's Terminal icon.  However when executing within "Startup Applications" the Terminal window is not 'shaded'.  Using 'add,hidden' does not work.  Using 'add,below' works,  except I'm using my desktop background image as part of the customer viewing.


jquery selector doesn't work on added tag

i have problem with new created element using jQuery my little script is here:  $('.view_button').click(function(){      $.ajax({         url: '/devices/view_ajax',         cache: false,         type: 'post',         dataType: 'JSON',         data: {id: $(this).attr('data')},         success: function(data){             var maskHeight = $(window).height();             var maskWidth = $(window).width() - 100;             var body = $('#devices_wrapper');             var div_outside =  $('<div/>', {id:'wrapper'}).appendTo(body);             div_element =  $('<div/>', {id:'popup'}).appendTo(div_outside);             div_element.css({position: 'relative', bottom: 0, 'z-index': 10000});             $.each(data, function(i,v){                 if(v && i){                     div_wrapper =  $('<div/>', {'class': 'part'}).appendTo(div_element);                     div = document.createElement('div');                     span = document.createElement('span');                     $(span).html(i).appendTo(div_wrapper);                     $(div).html(v).appendTo(div_wrapper);                 }             });             close_button = $('<div/>', {'class':'close_popup', text: 'X'}).appendTo(div_wrapper);          },         error: function(data){             alert('error');         }     }) });  $('.close_popup').click(function(){     $('#wrapper').remove(); })   When i click on close_popup nothing is executed, i think the cause of it is that tag > close_popup is not seen by jQuery selector if so how to add it ? Or maybe there is different my mistake


Why is it dangerous to eat meat which has been left out and then cooked?

If cooking meat kills bacteria, and bacteria are responsible for problems with eating meat which has been left out, then why is it dangerous to eat meat which has been left out at room temperature and then thoroughly cooked?   mentions that "Even if the bacteria is dead, toxins can remain if the food was out too long, causing problems".  However, there's no further detail given.  Are these toxins as dangerous as the bacteria themselves?  How long does meat have to be left out to accumulate a dangerous level of toxins and thus be dangerous even if thoroughly cooked?  Are these toxins the reason for the usual guideline of keeping meat unrefrigerated for a maximum of 2 hours?  update  The revelation, courtesy of Aaronut, that e. coli is actually dangerous because of its toxins — which cannot be denatured at temperatures which will leave meat in an edible state — has pretty much answered this question.  And also given me further incentive to stop eating meat altogether :)  Our discussion (see the comments on hobodave's answer) has progressed into the realm of microbiology.  Some highlights from my ongoing research:  .  These seem to be the reason for the importance of keeping meat at a high temperature for a period of time.  .  This also provides fascinating insight into how bacteria evolved immunity to antibiotics.  Fungi.


Removing files matching a numeric range regular expression

I have a folder which has many files. Some of the data files are labelled 1, 2, 3, ..., 300  I want to remove these data files using the terminal. How do I do this?   I want to do something like   rm some-regular-expression-giving-numbers-from-0--300