Booting from usb just goes back to bios menu

I have gone through the process of installing the boot for usb drive. The drive had no problems when I went through the process. The problem is when I try to boot from the drive it just goes to the windows boot up.   So I tried disabling the windows drive and only allowing the usb and then what happen was it just keeps going back to the bios menu like there is nothing there.   I am using windows 10 Home 32-bit installed by manufacture, on an asus netbook model X205TA. I tried installing ubuntu 17.04 through the set up that ubuntu provides to put on a usb drive.


I think I have a system compromise, with sudden perl process starting at the background with the same user as apache (daemon). I found today ZMUIE, which was script to do some sort of bruteforce attack. Anyway this is what I have now (any ideas?):  this is my top output  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND                                      16603 root      20   0  2496 1080  804 R 12.8  0.0   0:00.23 top                                          11474 daemon    20   0 80568  57m  35m R  7.9  1.7   0:08.58 httpd                                        14716 daemon    20   0  6364 2924 1328 S  5.0  0.1   1:04.41 perl       I have concerns about the process with PID 14716:   ps -aufx gives me this:  daemon   14716 21.4  0.0   6364  2924 ?        S    21:51   0:46 /usr/sbin/ap   at the same time:  [root@saritasa chkrootkit-0.49]# ls -l /usr/sbin/ap ls: cannot access /usr/sbin/ap: No such file or directory [root@saritasa chkrootkit-0.49]# ls -l /proc/14716/exe lrwxrwxrwx 1 daemon daemon 0 2013-11-05 21:52 /proc/14716/exe -> /usr/bin/perl [root@saritasa chkrootkit-0.49]# ls -l /proc/14716/cwd lrwxrwxrwx 1 daemon daemon 0 2013-11-05 21:52 /proc/14716/cwd -> / [root@saritasa chkrootkit-0.49]# cat /proc/14716/cmdline  /usr/sbin/ap   lsof:  [root@saritasa chkrootkit-0.49]# lsof -p 14716 COMMAND   PID   USER   FD   TYPE  DEVICE     SIZE    NODE NAME perl    14716 daemon  cwd    DIR   253,0     4096       2 / perl    14716 daemon  rtd    DIR   253,0     4096       2 / perl    14716 daemon  txt    REG   253,0     8128 3753892 /usr/bin/perl perl    14716 daemon  mem    REG   253,0    22284  721480 /usr/lib/perl5/5.10.0/i386-           linux-thread-multi/auto/IO/IO.so perl    14716 daemon  mem    REG   253,0    24260 4039105 /usr/lib/perl5/5.10.0/i386-linux-thread-multi/auto/Socket/Socket.so perl    14716 daemon  mem    REG   253,0    84804   18333 /lib/libresolv-2.8.so perl    14716 daemon  mem    REG   253,0    15060   18340 /lib/libutil-2.8.so perl    14716 daemon  mem    REG   253,0   137348   17865 /lib/ld-2.8.so perl    14716 daemon  mem    REG   253,0  1758448   18259 /lib/libc-2.8.so perl    14716 daemon  mem    REG   253,0   210212   18278 /lib/libm-2.8.so perl    14716 daemon  mem    REG   253,0    20460   18266 /lib/libdl-2.8.so perl    14716 daemon  mem    REG   253,0   131332   18331 /lib/libpthread-2.8.so perl    14716 daemon  mem    REG   253,0  2549860  721535 /usr/lib/perl5/5.10.0/i386-linux-thread-multi/CORE/libperl.so perl    14716 daemon  mem    REG   253,0   113600   18310 /lib/libnsl-2.8.so perl    14716 daemon  mem    REG   253,0    49368   18262 /lib/libcrypt-2.8.so perl    14716 daemon    0r  FIFO     0,6          1169171 pipe perl    14716 daemon    1w  FIFO     0,6          1169180 pipe perl    14716 daemon    2w  FIFO     0,6          1169173 pipe perl    14716 daemon    3r   REG   253,0 22465197  542969 /usr/local/php532/bin/php-cgi perl    14716 daemon    4u  IPv4 1347582              TCP linux1.domain.com:53815-    >146.185.162.85:opsession-clnt (SYN_SENT) perl    14716 daemon  201r  FIFO     0,6           909408 pipe perl    14716 daemon  202w  FIFO     0,6           909408 pipe perl    14716 daemon  203r  FIFO     0,6           909409 pipe perl    14716 daemon  204w  FIFO     0,6           909409 pipe perl    14716 daemon  211r  FIFO     0,6          1169173 pipe


How to reduce log size of database in SQL Server 2008 r2?

I have a database with mydb.mdf file size in 4GB and mydb.ldf is 400GB, how to reduce this log .ldf file?


I have a pdf file that is 1.1MB of size but I need upload 400kb of that file. Please tell me how to resize the file to get an output of 400kb.


How does one update the default printer settings to use Duplex with macOS Big Sur? To clarify, I would like to change the default settings, not create an additional set of settings with a different name.  Changing the default settings will impact all of my apps. Creating a new collection of settings will require me to tell every app to use this new set of settings. I see instructions that tell me to “System Preferences” > “Print and Fax” > Click on the “Printer” > “Options and Supplies {Settings}” > “Driver Tab”. My Big Sur has "Printers and Scanners" instead of "Print and Fax" and the "Options and Supplies" button does not reveal a Driver tab. Based on these instructions, it used to be possible, in older versions of macOS. I found a way to change the defaults, but it is clearly not The Apple Way.  One can:  cupsctl WebInterface=yes http://localhost:631/admin Manage Printers Select a printer Administration Set Default Options Two-sided Printing = Long-Edge Binding Press "Set Default Options" Give it your macOS user/password when it prompts  Is this the only way to change the Default settings for all apps in one place?


Prove that $\frac1{a^3(b+c)}+\frac1{b^3(a+c)}+\frac1{c^3(a+b)} \geq \frac32$

Let $a,b,c$ be positive real numbers with $abc = 1$. Prove that $$\dfrac{1}{a^3(b+c)}+\dfrac{1}{b^3(a+c)}+\dfrac{1}{c^3(a+b)} \geq \dfrac{3}{2}.$$   Attempt  We can rewrite it as $\dfrac{bc}{a^2(b+c)}+\dfrac{ac}{b^2(a+c)}+\dfrac{ab}{c^2(a+b)}$. Then, using AM-GM we have $$\dfrac{bc}{2a^2\sqrt{bc}}+\dfrac{ac}{2b^2\sqrt{ac}} \dfrac{ab}{2c^2\sqrt{ab}} \geq  \dfrac{bc}{a^2(b+c)}+\dfrac{ac}{b^2(a+c)}+\dfrac{ab}{c^2(a+b)}.$$ I get stuck here.


How can I tell which of several solutions to a LaTeX problem is the fastest/most efficient?

Consider  I posted yesterday. I asked for a way to create a particular macro with a somewhat idiosyncratic calling pattern, which is not trivial to code. After waking up and coming back to the site, I found that seemingly viable solutions had been suggested by users , ,  and  (links go to the answers).  Now it is worth noting that the efficiency (however you define this) of a particular approach to the problem is not the only thing that is of importance in deciding which solution to use. There are other things that might be considered: how versatile an approach is, how fragile/easy to break with unforeseen use-cases it is (I am using "fragile" in the generic sense, not in the TeX macro sense), how helpful its errors are when it is used incorrectly, how easily deciphered (and potentially repurposed) the TeX code is. For example, A.Ellett notes that their answer "is not fail-safe!"; I'm not sure what he means, but I assume he is warning that his version of the macro might break if used in the wrong way. For another example, egreg's approach mandates that one of the arguments must be in a TeX group ({...}), which is not a problem as such but is a potential "gotcha" given that a typical LaTeX command does not mandate this.  But it would still be interesting to know which approach performs best (in that it allows a document that uses the macro many times to be compiled fastest). In the Python programming language,  is provided that allows one to time alternative approaches to a problem to see which is most efficient, by running through each approach a certain number of times and seeing which one gives the least total time. In LaTeX, presumably the natural way to do it would be to create a document that does the same sort of thing - repeating each solution a large number of times - and which contains in the finished document a summary of the total time taken by each approach.  Is there a way of doing this? It could look something like:  \documentclass[a4paper]{amsart}  \usepackage{tikz, xparse}  \begin{document} \thispagestyle{empty}  \foreach \file in {file1.tex, file2.tex, file3.tex}{     \input{\file} % file should use \def to define \mymacro     % Here we start a timer     \foreach \x in {1, ..., 1000}{         \mymacro{with}{some}{arguments}     }     % Here we stop the timer and place the time taken in the macro \executiontime.     The time taken for the approach in \file was: \executiontime. }  \end{document}   NB. This is something approaching pseudocode, and won't compile if simply copy-pasted into a file!


I had Windows running on my single 1TB hard drive. The disk was divided like this:   200GB [OS] partition C: 500GB [Data] partition D: 60GB - Fedora Instalation   Then, I booted Ubuntu on LiveCD and chose to install it. On the setup screen, it said "Replace Fedora and install Ubuntu over it", which was exactly what I was trying to accomplish. When setup ended and PC restarted, grub didn't show up. So I rebooted on liveUSB and saw a single 980GB ext4 partition with 4GB used, so I can't access any of my files.  I tried testdisk with no success... I had a lot of important data on that partitions that I can't afford to lose. Do you have any idea?


Reproducible LaTeX builds - compile to a file which always hashes to the same value

I am interested in using LaTeX in a way such that when I compile twice, I get the very same resulting file.  My test.tex:  \documentclass{article} \begin{document} Hello, World! \end{document}   Compiling yields different hashes:  8493b40b225993d01d46ed7479725d8b4e9f6efbfddcc8d6d657f00084d41cdb  test.pdf 05f2a3cd3780df33470a4363da18b008595e42acd9a085d76c83b6c83dc71c41  test.pdf   and so on.  (This also applies when compiling to DVI at least a minute apart.)  My guess is that this is, at least, due to the Created and Modified metadata of the PDF. I followed  for fixing those, but I still get different hashes.  I found out that when compiling with faketime '2008-12-24 08:15:42' pdflatex test the file will be reproducible. I conclude that there is no random data involved, but it's only dependent on the time.  My question is thus, can I influence that time for pdflatex from within my TeX document?


I would like to paint the cover and door of my flush mount load center to match the wall color more closely. The manufacturer does offer a white in addition to the standard grey cover, but it is hard to find and ridiculously overprice.   Only the outside would be painted, so all labels on the inside would not get any overspray or anything else on them and would remain intact. I would also of course first remove the hinges and locking mechanism to ensure their operation wouldn't be affected.   Is this OK to do per NEC 2017 and with typical load center UL listings? Let me know if specifics are needed to answer.


How does pressure cooker increase cooking speed?

My teacher mentioned something about pressure cookers making cooking faster and I was wondering what exactly is the reason behind this?


74190 up/down decade counter starts from 5

I've been connected pins input A and C into VCC so the logical number is 1 and input B and input D with 0. The counter starts with 5, but it doesn't clock or change from number 5 into 0 (5,4,3,2,1,0,5,4,3,2,1,0) as I need.  What should I do for this 74190 so it will count down from 5 into 0 and so on?


How to create .gpkg file using PyQgis with one layer (or more) named different from file name?

I want to create geopackage file using PyQGIS (for example database.gpkg) with one layer (named "myLayer"). I've tried this writer=QgsVectorFileWriter(fileName,'UTF-8',layerFields,QgsWkbTypes.Unknown,QgsProject.instance().crs(),'GPKG',newLayer='myLayer')  but got an error ('newLayer' is an unknown keyword argument). I can't use writeAsVectorFormatV2 because I need to create file first and than add it to QGIS.


$(a,n)=1\Rightarrow \exists [b]\in J_n $ such that $[a][b]=1$

I'm stuck on the following exercise from Herstein's "Topics in Algebra":  "Show that if $(a,n)=1$ then you can find $[b]\in J_n$ such that $[a][b]=1$"  (note: $[a]$ is the congruence class (mod $n$) of $a$, and $J_n$ is the set of congruence classes mod $n$)  I've been thinking about using the property $(a,n)=1\Rightarrow \exists h,k\in\mathbb{Z}$ such that $ha+kn=1$ and also the Euclidean algorithm by writing $a=qn+b$ $0\leq b<a$ (since $J_n=\{[0],...[n-1]\})$ but I haven't been able to come up with a proof.  So, I would appreciate any comment/hint about how to prove this fact.  Best regards,  lorenzo


Construction of multiplicative group of complex numbers

Groups are rarely mentioned during the first semester, but they appear in linear algebra exams. This is an example and my idea which undoubtedly lacks formal language: If possible, find numbers $a,b \in \mathbb R, z\in \mathbb C$ so that the set $$\{a-bi,a+bi,z\},$$ consisting of different complex numbers forms a multiplicative group. Justify the existence or non-existence of such numbers. This my attempt, please, correct me. As a student, I have to be mathematically literate.  Closure under multiplication, the existence of identity and inverse element imply one of the three elements is 1 an the other two are inverse. $$a\pm bi\notin\mathbb C\setminus \mathbb R$$ because there would be two equal elements, therefore, $z=\pm1$ and $$a\pm bi=\frac{1}{a\mp bi}$$ $$\implies a^2+b^2=1,$$ so the set looks like this: $$\left\{a-\sqrt{1-a^2}i,a+\sqrt{1-a^2}i,1\right\}$$ Every critic is helpful.


Package lipsum, babel (french) and active characters

In the following document, the two paragraphs should be composed in the same way. But the spacing before 'high punctuation' characters (;) is not correct in the paragraph created by the \lipsum macro.  \documentclass{article} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage{lmodern} \usepackage[french]{babel}  \usepackage{filecontents} \begin{filecontents}{lipsum-babel-test.ltd.tex} \ProvidesFile{test.ltd.tex}  \NewLipsumPar{Pour moi, je n'ai jamais présumé que mon esprit fût en   rien plus parfait que ceux du commun; même j'ai souvent souhaité   d'avoir la pensée aussi prompte, ou l'imagination aussi nette et   distincte ou la mémoire aussi ample ou aussi présente, que quelques   autres. Et je ne sache point de qualités que celles-ci qui servent à   la perfection de l'esprit; car pour la raison, ou le sens, d'autant   qu'elle est la seule chose qui nous rend hommes et nous distingue des   bêtes, je veux croire qu'elle est tout entière en un chacun; et suivre   en ceci l'opinion commune des philosophes, qui disent qu'il n'y a du   plus et du moins qu'entre les accidents, et non point entre les formes   ou natures des individus d'une même espèce.} \end{filecontents}  \usepackage{lipsum} \SetLipsumText{lipsum-babel-test}  \begin{document}  \lipsum[1]  Pour moi, je n'ai jamais présumé que mon esprit fût en rien plus parfait que ceux du commun; même j'ai souvent souhaité d'avoir la pensée aussi prompte, ou l'imagination aussi nette et distincte ou la mémoire aussi ample ou aussi présente, que quelques autres. Et je ne sache point de qualités que celles-ci qui servent à la perfection de l'esprit; car pour la raison, ou le sens, d'autant qu'elle est la seule chose qui nous rend hommes et nous distingue des bêtes, je veux croire qu'elle est tout entière en un chacun; et suivre en ceci l'opinion commune des philosophes, qui disent qu'il n'y a du plus et du moins qu'entre les accidents, et non point entre les formes ou natures des individus d'une même espèce. \end{document}   Result:    Where is the problem and how to fix it?


How to align a button to the center of the screen html

I am trying to make a button that goes in the centre of the screen I have tried lots of solutions which havent worked html:       <button align="center" type="button" onclick="location.href='https://discord.gg/AsA7P9B5Mv'" class="button">       <span align="center" class="button__test"> Join Server </span>       </button>  css:   .button {   text-align: center;   align: center;   justify-content: center;     align-items: center;     height: 10vw;   width: 25vw;   margin: 0;   padding: 0;   background: #10e321;   border: none;   outline: none;   border-radius: 1vw;   overflow: hidden;   font-size: 4vw;   cursor: pointer; } .button:hover{   background: #11d120; } .button:active{   background: #0eb31b; }  Help would be greatly appreciated :)


Algebraic closed field has infinite many elements

Show that an algebraic closed field must have infinite many elements.  Let's suppose that an algebraic closed field $K$ has finite many elements.  But how could I get a contradiction??


I am considering getting a tablet to use on the go. But I also would like to use it in conjunction with my Laptop and Desktop PC, both running Ubuntu. Specifically, I am imagining using it as an input device for graphics programmes, virtual blackboards and the like. After a cursory search, this seems to be feasible in principle, but is there anything I should be aware before buying any tablet? Are different operating systems on the tablet better suited for this? Thanks in advance for any answers!


How to approach an equation of the form $f(x)=y$ where $f$ is recursively defined?

This is a homework problem so I am not looking for someone to solve it for me. I would like to know how I should approach this problem, or in what direction I should research to figure it out myself.  For $y \in \mathbb N$, $y > 1$, find $x$ for which $f(x) = y$. Given:    $f(0)=1$ $f(1)=1$ $f(2)=2$ $f(2x)=f(x)+f(x+1)+x$ $f(2x+1)=f(x)+f(x−1)+1$


Why is google not indexing (or ignoring) those 200,000+ pages ?

I was wonrdering why on google search console, 200,000+ of my pages are not indexed (it's not because of robots.txt or volontary excluding them):  +------------------------------------+---------+ | Exclusion reason                   | Number  | +------------------------------------+---------+ | Discovered - currently not indexed | 119,000 | +------------------------------------+---------+ | Crawled - currently not indexed    | 101,000 | +------------------------------------+---------+     This  says :     Crawled - currently not indexed: The page was crawled by Google, but   not indexed. It may or may not be indexed in the future; no need to   resubmit this URL for crawling.      Discovered - currently not indexed: The page was found by Google, but   not crawled yet. Typically, Google tried to crawl the URL but the site   was overloaded; therefore Google had to reschedule the crawl. This is   why the last crawl date is empty on the report.   Some examples of URL's:  Discovered - currently not indexed:        Crawled - currently not indexed:        --   Those page I gave are all user generated and exist in multiple language (the user content is not translated, but the website interface is)   Is it because of my canonical markup ? All website exist in 2 languages, and each page has a canonical tag to itself (ex: /fr/example points to /fr/example, and /en/example points to /en/example. Could it be because of some technical reason ? (bad use of canonical ? bas use of hreflang ?


I am trying to solve this problem, the answer should be 15/20 = 75%.  However, I am not sure how this was calculated and want to understand the underlying concept.  A program core consists of five conditional branches. The program core will be executed thousands of times. Below are the outcomes of each branch for one execution of the program core (T = taken, N = Not taken).   Branch 1: T-T  Branch 2: N-N-N  Branch 3: T-N-T-N-T  Branch 4: T-T-T-N  Branch 5: T-T-N-T-T-T   This behavior remains the same. For dynamic schemes, assume each branch has its own prediction buffer and each buffer initialized to the same state before execution.   What is the prediction accuracy for the 2-bit predictor, initialized to weakly predict taken? (Answer is at the beginning but I'd like to understand the concept of the calculation.)


“I hope he visit us more often” Why is this wrong?

I desire he visit us more often.     This is correct, right?     I hope he visit us more often.     Why is this incorrect? Why should I use “visits” instead?


Is it true that the number $$\frac{b^3+1}{ab-1}$$ is never an integer for positive integers $a$ and $b$ such that $a\geq 6$ and $a\geq b$?


Is there any (known) way to have Arxiv waive the endorsement requirement?

I’m trying to submit a preprint of my paper to the Arxiv as an independent researcher. My academic background is in theoretical physics; I have a PhD in physics, did a postdoc, published several papers in Physical Review and PRL before taking a job in industry. I’ve been working in industry ever since, so I do not currently have an affiliation (i.e. an .edu email). I’ve spent the past few years working on my research project independently, and I’d like to submit to the Arxiv and have the community review my results.  I’m currently stuck at the “not endorsed” step. I’ve reached out to qualified endorsers in my subject per the Arxiv’s endorsement process but got no replies. I then contacted the moderation to appeal, but they rejected with what seems like a template reply (“We insist submitters be affiliated...”)  Given my situation, I am wondering if there is any known way to make the Arxiv waive the requirement of endorsement? For example, does the Arxiv make an exception for former academic researchers who have previous publications in peer-reviewed journals?


Error on boot : dev/sda6 UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY

fsck from util-linux 2.31.1 /dev/sda6 contains a file system with errors, check forced. /dev/sda6: Inodes that were part of a corrupted orphan linked list found.  /dev/sda6: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.         (i.e., without -a or -p options) fsck exited with status code 4 The root filesystem on /dev/sda6 requires a manual fsck  Busybox v1.27.2(Ubuntu 1:1.27.2-2ubuntu3) built in shell (ash) Enter 'help' for a list of built-in commands.  (initramfs) _   I installed Ubuntu 18.04. I earlier faced this problem which I solved by simply writing fsck /dev/sdax. Later on I faced unable to mount boot with something error (0,0), so I reinstalled Ubuntu again, but unluckily I updated and again I ended up with this.  This time when I run fsck /dev/sda7 it shows   fsck: error2 (no such file or directory) while executing fsck.ext2 for /dev/sda7   How to fix this? Please help


Recurrence relation for number of relations with length $n$ from symbols $0,1$ and $2$

i have a problem with recurrence relations problem.. I need to find a recurrence relation for a number of strings with length $n$ ranging from symbols $0,1$ and $2$ that do not contain two consecutive $0\,$s. Thanks in advance!


How do you pluralize the first letter of acronym?

How does one pluarlize an acronym (or initialism) when the first letter of the acronym is the one to be pluarlized? What acronym is to be used for "ways of reasoning" if WoR is "way of reasoning"?


Are other human spirits reincarnated in the world of Avatar: The Last Airbender?

Obviously, human spirits can reincarnate, as the Avatar is constantly reincarnated into another body.  Through Avatar: The Last Airbender and Avatar: The Legend of Korra, we see and hear about spirits of people which are trapped in the spirit world. Do any human spirits other than the Avatar ever get reincarnated into a new body?


I want to know that can we have the following inequality for $x>0$, $y>0$?  $$\log(1+x/y) \leq x/y$$


how can i aggregate text from different sources for example   char * a , * b,* c, *d; a = argv[1] ; b = "something"; c = "another text"; d=b&a&c; //this what i want to know printf("%s",d);   output :  somethingTESTanother text


Trying to find story of Earthman given power to create planets.

An Earthman who completed a course of study on an alien planet was given the ability to make worlds, which involved going through a ritual and being assigned a god of their pantheon.  The ability to create worlds is dependent on his connection to this god.    When the book starts, he has been residing on his own planet for a while, either taking a break from or retired from worldmaking.  [Creating custom planets pays very well.]  He receives a notice from the aliens who gave him the ability to create worlds.  Someone of his race -- he is the only Earthman to receive the gift of world creation -- has illegally gone through the ritual that gave him his power.  The god this person was given is the sworn adversary of his god.  Think of this as a god's version of a Holmes-Moriarty competition.  To protect the worlds he has created, he reluctantly leaves his planet and searches for his god's adversary who, as it turns out, is also his Earthly rival.  My memory insists the author was Roger Zelazny but I am not certain of that.


I'm travelling from Madrid to Brisbane, but I have a 9 hours layover at Dubai Airport. I do not plan to leave the airport, and the connection is with the same airline (Emirates). I'm from El Salvador.    Do I need a transit visa?


I just got my first Ubuntu server but it's so hard to work with terminal only.  How can I install a good GUI for Ubuntu Server? How can I connect it with my Ubuntu desktop ?


I have been rejected by a particular university for MS two times now. I really want to get into it to work with a professor. I am thinking of emailing him to ask him what I can do to improve myself to become acceptable. I am trying to improve myself on various fronts that I can think of, so I would like ask him if I am on right path. I am a first generation student and I have no guide to ask, so he is that only one I can think of, to ask these questions. What would be the proper subject line for this? Right now I have "Help needed to improve myself" as subject. In the body, I will explain my situation and ask him if he could give me some of his time. What would be the proper way to proceed in asking for his help?


I've researched this a little bit on meta and there are some good ideas on how to handle FAQs, but I come across event delegation in jQuery every single visit I've ever had to Stack Overflow and it always results in the same comments/answer.  Instead of marking these questions as "duplicates", because some of the questions can be phrased very differently and they are very rarely marked as duplicates, can we have some functionality to flag a question as a "Frequently Asked Question"?  The user could then select one of the  questions from the relevant tag to link to. The OP gets their answer and it's quick for those who know what the answer is to flag the question as an FAQ.  edit: This illustrates my point quite well. Say I want to flag  as a duplicate of an event delegation question:  Step 1: Try "event delegation"  Even though the question is tagged only jQuery, it pulls back results for C#  Step 2: Try "jquery event delegation"  Only 4 votes? Surely has to be something more popular than that?  Step 3: Try "jquery .on()"  Not even close.  Step 4: Give up  If I clicked on "Duplicate of a Frequently Asked Question", had the choice of the top 20 questions in the jQuery tag, it would be so much easier.


Why remove the vegetables from vegetable stock?

Most meat stock is based on boiling bones, so it's not hard to imagine why you'd want to remove the bones before using the stock. Vegetable stock, on the other hand, is broadly similar to the mirepoix that's used as the basis for a huge number of savoury dishes: onion, carrot and celery. When you cook something based on a mirepoix or soffritto, you leave those ingredients in. Yet most stock recipes suggest you filter them off and throw them away. So why not do the same for a stock? I'm specifically thinking of ways to try and add flavour to the broth of vegan noodle dishes, and I'm struggling to see a reason why I wouldn't just grate the onion, carrot and celery and leave it in the stock for texture and better nutritional value.


If $X \sim F$ where the support of $X$ is $\mathbb{R}^p$. So, $X = (X_1, X_2, \dots, X_p)$. Then say I assume $X$ has $k$ finite moments. When $p = 1$, I know that that means  $$\int_{\mathbb{R}} x^k\, f(x)\, dx < \infty, $$ where $f(x)$ is the associated density of $F$. What the mathematical equivalent of assuming $X$ has $k$ finite moments when $p > 1$?    In  link, on page 2, the authors define the $k$th moment as $$E\|X\|^k = \int \|X\|^k f(x) \, dx, $$ where $\| \cdot\|$ is the Euclidean norm.  Glen_b's answer  suggests that the $k$th moment would be $$\int x_1^kx_2^k \dots x_p^k \, f(x) dx. $$  Does assuming one to be finite imply the other is finite?


Why is this argument for the reals being countable wrong?

After watching a proof of the set of computer programs being countable, I thought of the following argument: Consider the sets of real numbers (of the form $0.xxx...$) with $0$, $1$, $2$, $3$, $...$ significant decimal places. Each of these sets is finite as it has $0$, $10^{1}$, $10^{2}$, $10^{3}$, $...$ elements respectively.  Now, there are countably many of these sets, as I can list them using the number of significant decimals as index.  Finally, I have seen a proof (using a zig-zag argument) that the countable union of at most countable sets is countable. But, we just showed (seemingly) that the reals can be written as such an union, so they must be countable!? What may have I done wrong?


Selecting large numbers of items from a large list

Selecting an item from a large number of items is a very well-solved problem. However, there doesn't appear to be a good solution for selecting large numbers of items, ie. when the user needs to select 100+ items from a list of thousands. Note that there's no real way to reduce the number of selectable items - all those items need to be available to select at once.  My best approach solution so far is a list of checkboxes with a search field and "select all" and "un-select all" buttons. It seems like it'd work, but it feels clumsy and I'd love to know if anyone's got a better solution.         – Wireframes created with


I 'm trying to solve an axler text book question (6B 14) which is   Suppose $e_1,\dots,e_n$ is an orthonomral basis of $V$ and $v_1,\dots,v_n$ are vectors in $V$ such that  $\|e_j - v_j\| < \frac{1}{\sqrt{n}}$ for each $j$. Prove that $v_1,\dots,v_n$ is a basis of $V$.  Here is a solution. But the mistake I have in this is that I've used Cauchy Shwartz for something which does not have the absolute value. (I've highlighted where in my proof below)   Suppose $dim V=n$, then any list of $n$ linearly independent vectors form a basis for $V$. Now suppose $v_1..., v_n$ is a list of linearly dependant vectors such that for some $a_1..., a_n \in \mathbb{F}$ for atleast one $a_i \neq 0$, we have  $$\sum^n_{i=1}a_i v_i =0$$ We can have two possibilities. One is  $$||\sum^n_{i=1}a_i(e_i - v_i)||^2= ||\sum^n_{i=1}a_i e_i||^2 = \sum^n_{i=1}|a_i|^2$$ Cross products cancel and it may be a basis. Another possibility is  $$||\sum^n_{i=1}a_i(e_i - v_i)||^2=\langle\sum^n_{i=1}a_i(e_i - v_i), \sum^n_{i=1}a_i(e_i - v_i)\rangle$$ $$=\sum^n_{i=1} \sum^n_{j=1}\langle a_i(e_i - v_i), a_j(e_j - v_j)\rangle$$ $$\leq \sum^n_{i=1} \sum^n_{j=1} ||a_i(e_i - v_i)|| ||a_j(e_j - v_j)||$$ ^^^Here is where the mistake is used Cauchy Schwartz without absolute value.. $$=\leq \sum^n_{i=1} \sum^n_{j=1} |a_i| |a_j| ||a_i(e_i - v_i)|| ||a_i(e_j - v_j)||$$ $$< =\leq \sum^n_{i=1} \sum^n_{j=1} \frac{1}{n} |a_i| |a_j|$$ $$\frac{1}{n} (\sum^n_{i=1} |a_i|)^2$$ $$\leq \sum^n_{i=1} |a_i|^2$$ But then this means that  $$\sum^n_{i=1} |a_i|^2 < \sum^n_{i=1} |a_i|^2$$ Which is not possible. This is a contradiction.  So $v_1..., v_n$ is a linearly independent list of vectors of size $n$ and thus is a basis of $V$.   Would really appreciate help on this!


If an object A exerts a force on another object B, an equal and opposite force will be applied on object A by object B, so that means for a force to be applied on object B by object A, a force must have been applied on object A itself, so when object B exerts a reaction force on object A, the net force on object A will be "0" and object A will not move but object B will. If this is so then how will walking be possible? Because when we push the ground, it pushes back to cancel the force we are already applying on the ground.


How does natural selection explain how organisms that are poisonous evolved?

Natural selection makes perfect sense when describing the evolution of say camouflage. For example 2 bugs of the same species live on a tree. One is mutated to look slightly more like a tree, so the bird misses it and eats the one that sticks out more.   This logic seems to fail for poisonous animals though. For example, two bugs are equally visible but one has developed a mutation to be poisonous. Since they are both easy to spot they both get eaten. Now the poisonous mutation has died out. How does natural selection explain the poison mutation overcoming the initial hurdle?


Is it possible to merge rows like we can merge columns in Latex. I want a table like following.


WiFi hotspot during another WiFi connection

I saw it in Windows 10. Notebook is connected to WiFi network via WPA2 Enterprise, let's call it "work network". I can't connect to this network from my smartphone but I can make WiFi hotspot in Windows and connect to it with smartphone. Windows is automatically share "work network" to hotspot WiFi and I can use this network to connecting to internet. Is it possible to achieve on Ubuntu?


Stack Exchange sites use CloudFlare in a way that can break CSS and images

Stack Exchange sites use CloudFlare. When an IP address is used quite a lot to access Stack Exchange sites, CloudFlare will present a CAPTCHA to be solved. After it's solved, the site is supposed to be normally usable.  The problem is that solving the CAPTCHA for a Stack Exchange site doesn't remove the need to solve a separate CAPTCHA for Stack Exchange's CDN servers. This leads to people solving the CAPTCHA for the site they're trying to access and receiving pages with no CSS or images. This is something a lot of users aren't going to know how to correct.


Left aligned text in equations bound by right curly brace

I wish to have the following. There are several solutions on the platform, dealing with either left aligned text or rightly placed curly brace to the numbered set of equations. But, I am not able to produce both simultaneously.


i have a php script that has to compare some words in a csv file to a mysql table element. The problem is that apparently the csv file is'nt created in the correct codification.  The first error is this: SQLSTATE[HY000]: General error: 1267 Illegal mix of collations (latin1_general_ci,IMPLICIT) and (utf8_general_ci,COERCIBLE) for operation 'like'  Now when i use utf_encode on the variable, the error goes away but it didnt find my variable int the mysql database.  To be clear, i have several accented words in my csv file, and i can´t change thhis.  i'm using latin1 charset and latin1_general_ci collation in my DB.  Another observation is that i'm using thw following code to get information in the file:  if (($handle = @fopen("../arquivos/atualização/$name", "r")) !== FALSE) { while (($data = fgetcsv($handle, 1000, ";")) !== FALSE) {   Can i somehow convert my csv file in php without losing the accents? or convert my db tables?   Note: in notepad++ my CSV file is in ANSI codification, and when i convert it to utf the accents turn into strange characters.


Fantasy series with a warrior elf who had magic tattoos

I remember reading a series of fantasy novels around early 2000. I think the name was the Cartographers Map, the other title was Hunters Moon (Something Moon?) but I've searched of these titles and not found any suitable results.    I remember there was a warrior elf with magic tattoos that glowed blue. I also remember the main villain was an ice queen from the north lands named Chytrine(?).  There were dinosaur-like birds on the evil army's side. There were many different states / countries around a vast lake. There were many different armies and magical groups. It was a very violent series.


I have managed to work out the answer in some dirty brute force manner and was wondering if there was an easier way.  The question is, find the locus of points of $z$ such that:  $$ (z-2+i)^2+(z-2-i)^2+2zz^*+6=0$$  I substituted $z=x+iy$ and just worked out a relation and got a parabola.  Is there an easier way?  Thank you


Old young adult sci fi book about wars fought with robots remotely, allusions to chess

This is a science fiction book I read about the year 2000.  The main premise that I vaguely remember was that humans were now fighting wars with robots by proxy BUT there were still normal humans in the war zones trying to survive.  I don't have much more to go on I'm sorry - but the main scene/piece that sticks out to me, was there were these "burrowing" robots that were the "hunter-killers" for the non-robot humans - I think the characters referred to these robots as Ferrets, Stoats or Weasels. I think at the end they made it to the control room or something, and realised it was all some big game of real life chess so to speak that they were caught in the middle of.  English book, unsure if series. Possible female main character but unsure.


Does the following inequality hold $||a|^p-|b|^p|\le C|a-b|^p$?

Let $a$ and $b$ be some real numbers. Are there some constants $C>0$ and $p>0$ (where $C$ does not depend on $a$ or $b$) such that the following inequality holds? $$||a|^p-|b|^p|\le C|a-b|^p$$ I can show $|a|^p \le C |b|^p + C|a-b|^p$ but not exactly this one ?


Review Audit shows an answer that's duplicate

I just had a review audit which showed a highly voted answer to the original question but showed it with 0 votes. I thought some user just copied the original answer and was spamming the system so I flagged it. And apparently I've failed the audit. What's the purpose of this ridiculous audit which was obviously misleading?


How to subtract two days from a date in Java?

String dateSample = "2016-09-30 21:59:22.2500000";      String oldFormat = "yyyy-MM-dd HH:mm:ss";     String newFormat = "MM-dd-yyyy";      SimpleDateFormat sdf1 = new SimpleDateFormat(oldFormat);     SimpleDateFormat sdf2 = new SimpleDateFormat(newFormat);      sdf2.format(sdf1.parse(dateSample));   From this, I got 09-30-2016 But, I want the result 09-28-2016 How to do it?


Anyone knows the commands to install Adobe Flash player and the packages needed for ubuntu 18.10?


How many combinations are possible between a note-event and a silence-event (i.e. a played note and a pause) over 16 consecutive beats? In other words, if one musical bar is divided into 16 parts (16th notes) of equal duration, filled with either a sound or a silence, how many combinations of the two are possible within the given structure of 16 events?   I hope this is clear enough...sorry, musician here, therefore almost completely unprepared to approach the question. I am not even sure if I am asking about combinations or permutations.   An example: (1= sound 0= pause) .  1000 0010 0011 0011  1111 0000 0111 1010


Visitor requesting a cash advance to purchase airfare in-country. Legitimate or scam?

Woman planning to visit me from Ukraine to the US applied for a visa and such, claims to have paid for the visa but needs 500 dollars more for the airfare from Ukraine to the US. She says strict rules apply that the airfare cannot be purchased by US person, and must be purchased in Ukraine by person applying for the visa because of terrorist issues, etc..   Is there truth to such?


I teach ELL students and have found conflicting information with respect to "Who"  vs "What"  Please help determine if one or both of these statements are correct:  A)  Who are they? They're musicians. B)  What are they? They're musicians.


What should I do to save myself from legal trouble when I'm using iPod in my domain name

I had registered a domain with "iPod" in it something similar like ipod-to-pc.com in January 2013. At that time I was unaware that using someone's trademark is not okay. I sell some desktop programs that transfer files between iPod and PC via this website. I get around 1000 visitors per day and earn 400-500 USD per month from this website. Now it's not practically possible to shut down this website and start a new one from scratch. Will I likely to get legal notice from Apple asking me to shut down this site? What would you do if you were in my position?  P.S. In a footer I have text that says "iPod®, iPhone®, iPad®, iTunes® and Mac® are trademarks of Apple Inc., registered in the U.S. and other countries. This website is not developed by or affiliated with Apple Inc."  The person in the duplicate question is asking if it's okay to register a domain with trademark in it whereas I want to know what I do if I'm already running a website with a trademark in it's domain name.


How to make a ISO file out of a folder containing Windows setup files

I copied the Windows 8 CD to my HDD. I want to convert that folder to an ISO and use that to create a bootable USB.  Please tell me how I can make an ISO image out of that folder containing files.  This is my folder which I want to convert to a ISO file:


Exchange of Limit and Integral with Nets

In topology, we have seen that there are examples of nets so that monotone and dominated convergence do not hold anymore.   In particular, we worked with the net $\mathfrak{F}$ containing finite subsets of $[0,1]$ ordered by inclusion. We used the Lebesgue-measure $\lambda$ restricted to $[0,1]$.  The net $(\chi_F)_{F \in \mathfrak{F}}$ is monotonically increasing and is dominated by $\chi_{[0,1]}$. $(\chi_F)_{F \in \mathfrak{F}}$ converges pointwise to $\chi_{[0,1]}$ as well.  But $\lim_{F \in \mathfrak{F}} \int \chi_F d\lambda ≠ \int \chi_{[0,1]} d\lambda$.  Are there properties/constraints of the net itself (except the ones elaborated by David C. Ullrich below) or of the measure that expand the exchangeability of limit and integral to nets?     Some of my thoughts on monotone convergence: The problem is that we cannot sort the functions we have in order to make it monotonous as one is used to when dealing with natural numbers as an index. But we do have a directed set at least. Do you have any ideas how to constrain the functions in the net in order to get a behavior that is similar to monotonicity? I have the impression it is, because monotonous functions only have countable points of discontinuity calling them $(a_n)_{n \in \mathbb{N}}$, at least in $\mathbb{R}$, which might be used for collecting some functions of the net.   Defining a set: $\{]a_i, \infty[;$$a_i$ point of discontinouity$\}$ and taking a look at its $\sigma$-Algebra, introducing an ordering there via inverse inclusion ($ A ≤ B \Leftrightarrow A   \supseteq B$). Adding ${\infty}$ to this set, we might find a directed set. (just some thoughts... to be continued)


I have a document containing a table which is slightly too wide for the page. But instead of growing to the right side only, I would like to have it centered on the page.  I have tried to use the center environment but this doesn't seem to help.


How do I use SQL's GETDATE() and DATEADD() in a Linq to SQL expression?

If I have a Linq to SQL expression like this:    from subscription in dbContext.Subscriptions  where subscription.Expires > DateTime.Now select subscription   I want this to to use the SQL Servers GETDATE() function instead of the time of the machine running the C# program.  The next question would be how to translate this:  DateTime.Now.AddDays(2)   to this:  DATEADD(dd, 2, GETDATE())


Does anyone know how to draw a simple process flow diagram like this?


Unity unable to login (can login with xubuntu)

Any and all help would be appreciated...  Ok so. My laptop is Ubuntu 14.04, and the other day I restarted it and then was no longer able to login. So what happens? I attempt to login (lightdm) and then it goes to wallpaper only (not the user wallpaper), waits a while then goes back to the login screen.  So why do I need your help - Isn't there lots of threads talking about this already? Yes there is however I can not find any which solve it for me.  This is what I have tried:   Removed .Xauthority 777 pem .Xauthority Reinstall gnome-session, ubuntu-desktop, unity Update everything Reconfigure lightdm Reinstall Xorg I may have done more. But will update as appropriate.   I am able to login with both terminal (Ctrl + Alt + F1) and also with xubuntu-desktop (but not gnome-shell!)  Upon trying to view some crash logs (/usr/crash/_usr_gnome_session..._) It is due to signal 11?  Some additional information. I am unable to use gdm as my screen goes black and nothing happens. I am also unable to log into the guest account. Also I do not have enough linux knowledge to see all the packages which changed which might have affected this.


Converting Degree Minutes to decimal degrees using Excel formula?

I have location points collected from a garmin device stored in an excel sheet in Degree Minutes format --- W00208.172,N1046.977.  I am looking for an Excel formula to convert either to Decimal Degrees or Degrees Minutes seconds Format ?


I am trying to install DROPBOX in Ubuntu 17.10 using   cd ~ && wget -O - "https://www.dropbox.com/download?plat=lnx.x86" | tar xzf - ~/.dropbox-dist/dropboxd   All goes well until I reach      (dropbox:2190): LIBDBUSMENU-GLBI-WARNING **: About to Show called on   an item without submenus.  We are ignot. Initializing nautilus-dropbox   1. 6. 0   Is there a specific installation package for Ubuntu 17.10?


There is a webserver which has example.com, www.example.com, my.example.com, shop.example.com, static.example.com.  All sites except www.example.com is on https.  My problem is when I type randomstring.example.com -> shop.example.com gets served. But I want nothing to be served.  For example mail.google.com is a valid subdomain.  if you type johndoe.google.com you see "This webpage is not available". How to achieve this via Vhost/.htaccess file.


Null Pointer Exception when accessing database

I'm working on my first database project for school. I thought I was going along nicely, but ran into a null pointer exception and I'm not sure how to fix it in the situation I'm in. The assignment is to open and read an access database, and pull information from it to find the customer with the smallest balance.  package dbproject;  import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement;  public class MyFirstDB {   public static void main(String[] args) {     ResultSet resultSet = null;     double totalPref = 0.0;     double lowestBalPref = 1000000;     String lowestBalCust = null;      double highestBalPref = 0.0;     String highestBalCust = null;     double totalBalance = 0.0;     ResultSet rs = null;     String convertTo = "";     double result = 0.0;     long lngCN = 0;     String query = null;      String url = "jdbc:ucanaccess://c:/cps/ms121.accdb";      try{         Class.forName("net.ucanaccess.jdbc.UcanaccessDriver");          Connection con = DriverManager.getConnection(url);          if(con!=null){             System.out.println("Connecton Successful!");          }         else{             System.out.println("Connection Unsuccesful!");             System.exit(0);         }            Statement statement = con.createStatement();         if(statement != null)             System.out.println("Statement is not null");          resultSet = statement.executeQuery("SELECT * FROM CUSTOMER where preferred = 'y'");          while(resultSet.next()){ //                System.out.println(resultSet.getString("CustomerName"));             totalPref = totalPref + 1;             if(rs.getDouble("Balance") < lowestBalPref){                 lowestBalCust = rs.getString("CustomerName"); //                System.out.println(resultSet.getDouble("Balance"));             }         }         System.out.println("Total Preferred Customers is " + totalPref);         System.out.println("The Customer with the lowest balance is " + lowestBalCust);          if (con != null)             con.close();      }catch (Exception e)     {         e.printStackTrace();     } } }   These lines in particular seem to be causing the error:                  if(rs.getDouble("Balance") < lowestBalPref){                 lowestBalCust = rs.getString("CustomerName");


Let $A$ be a local unital algebra, that is, it contains a unique maximal left ideal $J$ ($J \neq A$). I want to show that $J$ is also a right ideal. For that, I want to use the fact that an element $y \in A$ is left invertible if and only if $y \not \in J$. So, let $x \in J$ and $a \in A$, and we want to show that $xa \in J$. If this is not the case, then $xa$ is left invertible: there exists $b \in A$ such that $b(xa) = 1$. How do I conclude?


Garbage collection of a instances with circular reference

I know that when an object has no references, the garbage collector frees the memory. But I have a doubt.  I have a class that is represented by a tree:  class MyNode {     string Name;     List<MyNode> Descendants;     MyNode Parent; }   When I create a node that has descendants, I have the reference to the node and also the son has a reference to the node in the Parent property. Also, the node has a reference to the descendant in the list of descendants.  So an example.  Node myNode = new Node(); Node myDescendant = new Node(); myNode.Descendants.Add(myDescendant); myDescendant.Parent = myNode;   I can delete the reference to myNode setting it to null. However, the object is still referenced because myDescendant references to it in the Parent property. The myDescendant object is not recollected because is referenced in the descendants list of the node object.  So it seems that there are a cycle that avoid the node recollection. Is this true? Perhaps I need to set to null all the properties in the node and in the descendants and clear the list of descendants?  Thanks so much.


Hi i'm making a simple Android APP, which only displays data from Database depending on current time. There are a lot of tutorials how to fill DB through inputs in emulator, but how can i fill the DB before building the APP in Android studio?  Thanks!


Extract image src from a post and send it to an external form

I have created a  to upload photos to facebook from image url with help of some tutorials. It needs an image url and description. I want to put a button "Upload to Facebook" below every "Image" type posts in wordpress.   App Main Part to upload images -   <?php if(isset($_POST["source"])) { try {     $access_token=$facebook->getAccessToken();     $graph_url= "https://graph.facebook.com/me/photos?"   . "url=" . urlencode($_POST["source"])   . "&message=" . urlencode($_POST['message'])   . "&method=POST"   . "&access_token=" .$access_token;     $response=file_get_contents($graph_url);     $json=json_decode($response);   }   catch (FacebookApiException $e) {     error_log('Could not post image to Facebook.');   } } ?>                           <form enctype="multipart/form-data" action=" " method="POST">         Paste an image URL here:         <input name="source" type="text">

         Say something about this photo:         <input name="message"                type="text" value="">

         <input type="submit" value="Upload" class="btn btn-primary"/>
     </form>   How can i extract image src dynamically from a custom post type(Image), and set src as source in form automatically. (There is only one image in every image type post)


How do I pre-generate a Minecraft world?

I want to create a new world on our Minecraft server, but exploring a new map and generating terrain causes massive lag.  Is there a way to pre generate the chunks (with the default map generator) in a specific radius around the spawn?  I'm looking for a Bukkit plugin or tool I can use on our Linux machine. An offline tool I can run on my local machine is ok, too.


Why does linear regression use a cost function based on the vertical distance between the hypothesis and the input data point?

Let’s say we have the input (predictor) and output (response) data points A, B, C, D, E and we want to fit a line through the points. This is a simple problem to illustrate the question, but can be extended to higher dimensions as well.  Problem Statement    The current best fit or hypothesis is represented by the black line above. The blue arrow ($\color{blue}\rightarrow$) represents the vertical distance between the data point and the current best fit, by drawing a vertical line from the point till it intersects the line.   The green arrow ($\color{green}\rightarrow$) is drawn such that it is perpendicular to the current hypothesis at the point of intersection, and thus represents the least distance between the data point and the current hypothesis.  For points A and B, a line drawn such that it is vertical to the current best guess and is similar to a line which is vertical to the x axis. For these two points, the blue and the green lines overlap, but they don’t for points C, D and E.  The least squares principle defines the cost function for linear regression by drawing a vertical line through the data points (A, B, C, D or E) to the estimated hypothesis ($\color{blue}\rightarrow$), at any given training cycle, and is represented by   $Cost Function = \sum_{i=1}^N(y_i-h_\theta(x_i))^2$  Here $(x_i, y_i)$ represents the data points, and $h_\theta(x_i)$ represents the best fit.   The minimum distance between a point (A, B, C, D or E) is represented by a perpendicular line drawn from that point on to the current best guess (green arrows).   The goal of least square function is to the define an objective function which when minimized would give rise to the least distance between the hypothesis and all the points combined, but won’t necessarily minimize the distance between the hypothesis and a single input point.   **Question**  Why don’t we define the Cost Function for linear regression as the least distance between the input data point and the hypothesis (defined by a line perpendicular to the hypothesis) passing through the input datapoin, as given by ($\color{green}\rightarrow$)?


How to transfer buildings and objects from one Minecraft world to another?

I was playing mine craft on a friends account. I liked it so much I bought my own account. But now I want to transfer all the cool stuff I made from the random world on their account to my account.   How do I do this?


Strange Characters in Calculator UBUNTU 18.04

I think the issue is in someway related with GTK, any Ideas ?


How does SQL Server's optimizer estimate the number of rows in a joined table?

I am running this query in the  database:   SELECT      s.SalesOrderID,     d.CarrierTrackingNumber,     d.ProductID,     d.OrderQty FROM Sales.SalesOrderHeader s  JOIN Sales.SalesOrderDetail d      ON s.SalesOrderID = d.SalesOrderID WHERE s.CustomerID = 11077   If I look at the estimated execution plan, I see the following:     The initial index seek (top right) is using the IX_SalesOrderHeader_CustomerID index and searching on the literal 11077. It has an estimate of 2.6192 rows.     If I use DBCC SHOW_STATISTICS ('Sales.SalesOrderHeader', 'IX_SalesOrderHeader_CustomerID') WITH HISTOGRAM, it shows that the value 11077 is between the two sampled keys 11019 and 11091.     The average number of distinct rows between 11019 and 11091 is 2.619718, or rounded to 2.61972 which is the value of estimated rows shown for the index seek.  The part I don't understand is the estimated number of rows for the clustered index seek against the SalesOrderDetail table.     If I run DBCC SHOW_STATISTICS ('Sales.SalesOrderDetail', 'PK_SalesOrderDetail_SalesOrderID_SalesOrderDetailID'):    So the density of the SalesOrderID (which I am joining on) is 3.178134E-05. That means that 1/3.178134E-05 (31465) equals the number of unique SalesOrderID values in the SalesOrderDetail table.  If there are 31465 unique SalesOrderID's in the SalesOrderDetail, then with an even distribution, the average number of rows per SalesOrderID is 121317 (total number of rows) divided by 31465. The average is 3.85561  So if the estimated number of rows to be loop through is 2.61972, and the average to be returned in 3.85561, the I would think the estimated number of rows would be 2.61972 * 3.85561 = 10.10062.  But the estimated number of rows is 11.4867.  I think my understanding of the second estimate is incorrect and the differing numbers seems to indicate that. What am I missing?


Did spacetime curve infinitely about 13.7 billion years ago?

GR/Big Bang Model implies that there was a singularity about 13 billion years ago, in which all the matter and energy along with the observable universe (or perhaps, the entire universe) was contained. This small point yielded an infinite density, coupled with infinite temperature and infinite energy. Also that it was infinitely small. Would it be safe to presume that spacetime curved infinitely during the era of this bewildering singularity? And if spacetime curves, it gives rise to gravity as stated by GR. Since there was infinite spacetime curvature, would there have been infinite gravity?


Is "rumored" a verb or an adjective (a participle adjective)?

According to a dictionary, rumor can function as a noun or a verb.  I can see rumor being a noun, but am having difficulty accepting it as a verb.   The dictionary gives the example sentence, John is rumored to be next in line for a promotion.   In this sentence I would argue that rumored is functioning as an adjective, not a verb as the dictionary suggests.    Are there any clear examples of using rumor as a verb?   The only example I came across was For years people have been rumoring the CEO's imminent retirement.


Suggestions for settings.php - Local dev, Development server, Live server

Basically, one of the greatest questions of all time: What are some ways you're using settings.php in your development/staging workflow?  Right now, I have my settings.php file set up like the following, and I base my development on the server's $HOST directive—meaning I can work on dev.example.com for the development (shared) server, local.example.com for my local computer (and other dev's local code checkouts), and www.example.com (or just example.com) for the live site.  (This code is in the 'Database settings' section of settings.php):       $host = $_SERVER['HTTP_HOST']; $base_url = 'http://'.$host; $cookie_domain = $host;  switch($host) {   case 'example.com': # Production server     $db_url = 'mysqli://prod_sql_user:password@127.0.0.1/prod_db';     $update_free_access = FALSE;     $conf = array (       // Set production config options here...       'example_setting' => 0,     );     break;    case 'dev.example.com': # Development server     $db_url = 'mysqli://dev_sql_user:password@127.0.0.1/dev_db';     $update_free_access = FALSE;     $conf = array (       // Set production config options here...       'example_setting' => 0,     );     break;    case 'local.example.com': # Local server     $db_url = 'mysqli://local_sql_user:password@127.0.0.1/local_db';     $update_free_access = FALSE;     $conf = array (       // Set production config options here...       'example_setting' => 0,       // Turn off most core caching.       'cache_inc' => 'includes/cache.inc',       'cache' => CACHE_DISABLED,     );     break;  } ?>   This works pretty well for most purposes, but it means we have a lot of extraneous code sitting around in our shared settings.php file... is there a better way?


What's the protocol for requesting a tag warning?

On a particular site, RPG Stack Exchange, we've decided on our meta on a couple of tags that should have tag warnings, and on what those tag warnings should say. I am  on the site in question.  What should we do to get the tag warnings implemented? Do we do any/all of the following?:   start a [feature-request] on our meta for the tag warnings? raise a CM escalation? contact staff via the contact form? ping a staff member in the Teacher's Lounge? anything else?


Is union of two subspace a subspace too?

Assume that $W$ and $V$ are two subspace of $X$. Is their union a subspace of $X$ too? I think it is not true unless under certain conditions but I do not know what conditions...


is $y = \sqrt{x^2 + 1}− x$ a injective (one-to-one) function?

I have a function  $y = \sqrt{x^2 + 1}− x$ and I need to prove if it's a Injective function (one-to-one).  The function f is injective if and only if for all a and b in A, if f(a) = f(b), then a = b  $\sqrt{a^2 + 1} − a = \sqrt{b^2 + 1} − b$  $\sqrt{a^2 + 1} + b = \sqrt{b^2 + 1} + a$  $(\sqrt{a^2 + 1} + b)^2 = (\sqrt{b^2 + 1} + a)^2$  $a^2 + 1 + b^2 + 2b\sqrt{a^2 + 1} = b^2 + 1 + a^2 + 2a\sqrt{b^2 + 1}$  $2b\sqrt{a^2 + 1} = 2a\sqrt{b^2 + 1}$  $b\sqrt{a^2 + 1} = a\sqrt{b^2 + 1}$  $(b\sqrt{a^2 + 1})^2 = (a\sqrt{b^2 + 1})^2$  $b^2(a^2 + 1) = a^2(b^2 + 1)$  $b^2a^2 + b^2 = a^2b^2 + a^2$  $b^2 = a^2$  $\sqrt{b^2} = \sqrt{a^2}$  $b = \pm a$  then the function is not injective because $b$ in not equal to $a$, but using online  the function is injective.


Decrypting WiFi packets on a public hotspot

To decrypt 802.11 header in Wireshark, you must know the WPA password.  Now, for example, there is a network which when clicked takes you to a login page where every user on the network has a username and a password. So, it's an open network but redirects you to a page with a login screen.  If I decrypt the 802.11 packets with wireshark with my username and password, can I see all the other packets, like other people that are browsing without knowing their username and password? Like, instead of seeing "protocol:802.11", can I see "http,tcp"? Even though it's all on the same network but everyone has their own password? If, what i am saying is wrong, is there a way to decrypt 802.11 headers without knowing the WPA password?  I am not sure how much sense it made but if some part does'nt make sense, please ask.


Let $H$ be the subgroup of the group $G$ of all $2 \times 2$ non-singular matrices whose entries are integers modulo a given prime $p$ consisting of those and only those matrices in $G$ whose determinant is $1$.   What is the order of $H$? And how to find it?   I've already managed to find the order of $G$. It is $p^4 - p^3 - p^2 + p$.   Last but not least, I would also like to be able to compute the order of $G$ and that of $H$ in the general case corresponding to the  $n \times n$ matrices for an arbitrary integer $n > 2$.


Is it acceptable to vote to close a question without leaving a comment?

Although  is obviously an exceptionally poor question, it still amazes me that 5 people can vote to close and yet not one of them leave a comment to help explain how the poster can improve their question.  I see loads of similar examples where questions from new users are closed and heavily voted down without anyone taking any effort to explain why - not a pleasant experience for new users.  Is there anything that can be done to encourage users to leave comments when voting to close?


In , why is ElementByElement highlighted as a method, but ElementByElement2 isn't?  EDIT: To submit a new issue to Prettify, I'd like to know what version Stack Overflow uses. 21-May-2009? Some other?


Word for people who like to spend money?

Is there a specific word for people who like to purchase lots of things? For instance, let's say someone has an Iphone 7, but as soon as the Iphone 8 is released, he buys it, even if he doesn't need it at all. In fact, I am looking for a word with a financial perspective, like people who really enjoy spending money.  In my native language, which is Portuguese, we have a specific word for that, which is "consumista", but when I translated it into English, I got "consumerist". However, when I checked this word on Cambridge dictionary, I saw it is mostly used to describe societies, but I am not sure about specific individuals.  Thanks in advance.


Valid commands in /etc/crontab not executing (FreeBSD)

My /etc/crontab contains the following lines: 0      *       *       *       *       root    /usr/bin/touch /root/IT_WORKED 1      *       *       *       *       root    /bin/sh -c '/sbin/zfs snap -r zpool@snapped_$(/bin/date '+%Y.%m.%d-%H.%M.%S-%Z-A') ' 2      *       *       *       *       root    /bin/sh -c "/sbin/zfs snap -r zpool@snapped_`/bin/date '+%Y.%m.%d-%H.%M.%S-%Z_B'` "  When it's left to run, I see that the touched file is updated, so cron is clearly picking up the file on the hour. But the zfs snapshots aren't created. I've tested the 2nd and 3rd lines in shell and they both work fine as CLI commands, and snapshots are created. So why aren't they running from cron?


Attempt to invoke virtual method 'java.lang.Object java.util.HashMap.put(java.lang.Object, java.lang.Object)' on a null object reference

I am getting this above error when the json response values are null  { "restaurant_area_min_order":null, "restaurant_id":null }.   The above error is appearing inside try catch block. When there is values inside restaurant_area_min_order and restaurant_id, The function is working fine without error. How can I check if the response data are null and continue the function without any error?  Here is my code.   private void getAreaMinOrders() {     for(int i = 0; i < Utils.cart_restaurants.size(); i++)     {         RestaurantModel restaurant = Utils.cart_restaurants.get(i);         String restaurant_id = restaurant.getId();          String url = LinksConstants.BASE_URL + LinksConstants.CHECK_MINIMUM_ORDER;          RequestParams params = new RequestParams();         params.put("restaurant_id", restaurant_id);         params.put("area_id", city_id);          NetworkRestClient.post(url, params, new JsonHttpResponseHandler()         {             @Override             public void onStart()             {                 super.onStart();                 progressActivity.showLoading();             }              @Override             public void onSuccess(int statusCode, Header[] headers, JSONObject response)             {                 super.onSuccess(statusCode, headers, response);                 try                 {                     if (response != null)                     {                         String restaurant_id = response.getString("restaurant_id");                          String rest_area_min_order = null;                          if(rest_area_min_order != null)                         {                             rest_area_min_order = response.getString("restaurant_area_min_order");                         }                         HashMap<String, Object> items_hash = (HashMap<String, Object>) rest_cart_hash.get(restaurant_id);                         items_hash.put("rest_area_min_order", rest_area_min_order);                     }                     progressActivity.showContent();                 }                 catch (Exception ex)                 {                     GSLogger.e(ex);                     showError();                 }             }               @Override             public void onFailure(int statusCode, Header[] headers, String errorResponse, Throwable throwable)             {                 super.onFailure(statusCode, headers, errorResponse, throwable);                 showError();                 if (AppConstants.DEBUG_MODE)                     showToast(errorResponse);             }           }); //end of NetworkRestClient.post     } //end of for }


I enters in a chat room every day . But last Saturday I did not come here . But a user having the same name  as mine user name was in the room . some people was chatting with that user . But as I was not in the room , I should not get the notifications for chat messages for that room. Today I received a mail from stack-overflow as notifications for those chat messages . I checked it out but that was not for me . These were for the user having same user name . Is it bug??


My terminal used to read   username@computername:~$   but after navigating to some directories, it now says  username@computername:/$   and I can't get back to my Home directory.


I'm new to scripting in Blender 2.91.0 and I'm trying to modify nodes via code. According to the API I should be able to access my current node selection via the . My material is using nodes and I can access them like this: bpy.data.materials[0].node_tree.nodes["Image Texture"]  However, for some reason, I am not able to access the node context at all. Neither bpy.context.selected_nodes nor bpy.context.active_node seem to exist, so I can't get the current node selection. Contradicting the documentation my Python console autocompletion doesn't show them as valid options (see image).  Note: Executing bpy.context.active_node anyway returns the error 'Context' object has no attribute 'active_node' Does anyone have an idea what I am missing? Any help is appreciated.


Ubuntu 12.04 on VMWare doesn't accept password

I install Ubuntu 12.04 on VMWare. It works about month. But now it doesn't accept password. Password correct 100%. What should i do?


How can one estimate drag for a bicycle?

I am curious how to estimate drag for a bicycle. This has two different framings:   Find the amount of power required to ride at a certain speed. That is, when one is traveling at a constant speed, the power added to the system (with my effort and/or coasting on a descent) equals the power subtracted by aerodynamic drag, rolling resistance, ascending, deflecting objects thrown by spectators, etc. Find the amount of pushing force required to maintain a given speed (again, the pushing forward equals the pushing backward at constant speed). The most obvious example is aerodynamic drag, which one can feel “pushing” back when one is riding at speed.   Online calculators and formulas exist, but they assume coefficients of rolling resistance or aerodynamic drag, or assume that I can provide these coefficients. How do they make these assumptions, and/or how can I make those estimates myself?  (Credit goes to  for urging me to ask, in the commentary of .)


How to build ubuntu touch for unofficial cyanogenmod device

I own a Samsung galaxy scl i9003 and I would like to port Ubuntu touch on this device. We don't have an official cyanogenmod, but we have an unofficial version of it. I did the built of the unofficial cyanogenmod 10.1 but now I don't know how to proceed, and from where start following the porting guide to create a Ubuntu touch build flashable to my device.  Please, I hope someone could help me  Thanks in advance


Let $a = \sqrt{2+i}$ and $K$ is the splitting field of minimal polynomial of $a$ over $\mathbb{Q}$. Prove that $Gal(K/\mathbb{Q})$ is $D_4$.   I find the minimal polynomial of $a$ is $p(x)=x^4-4x^2+5$ and its   roots are $\sqrt{2+i},-\sqrt{2+i},\sqrt{2-i},-\sqrt{2-i}$. Let $b=\sqrt{2-i}$. So the splitting field of $p$ is $K=\mathbb{Q}(a,b)$. Also by rational root theorem, $p$ is irreducible over $\mathbb{Q}$. Thus $[\mathbb{Q}(a):\mathbb{Q}]=4$. Also $b\not\in\mathbb{Q}(a)$, and minimal polynomial of $b$ over $\mathbb{Q}(a)$ is $x^2-2+i$. Thus $[\mathbb{Q}(a,b):\mathbb{Q}]=[\mathbb{Q}(a,b):\mathbb{Q}(a)]\cdot[\mathbb{Q}(a):\mathbb{Q}]=2\cdot 4=8.$ Now since $K$ is the splitting field over $\mathbb{Q}$ of a separable polynomial, $K/\mathbb{Q}$ is Galois. Hence $|Gal(K/\mathbb{Q})|=8$. Hence the 8 automorphisms are $$a\to \begin{cases}a\\-a\\b\\-b\end{cases}\quad\text{and}\quad b \to \begin{cases}b\\-b\end{cases}.$$ From this how to conclude $Gal(K/\mathbb{Q})$ is isomorphic to $D_4$?  Thanks


How to create secure autologin with session and cookies

I have small question. A want to create a login system, which will remember logged user. But there are lots of security problems and I dont know how to do it correctly. So the target is, when user logs in, browser save something into cookies and when user open page again, it will select his data from db according to cookies and save it into session? But what to save to cookies and why? Thank you very much.


How many writes do I have on my 250GB SSD hard drive on my Macbook Pro High Sierra

I would like to know how many writes I have on my Mac's SSD hard drive?  I would also like to know if there is a terminal command I can run to find out this information and how many writes I have left so I can check the status of it?


I want to build an Ender pearl dispenser that gives me a specific amount of pearls if i step on a pressure plate.   How do I do that?


I think that I don't quite understand combining templating with derived classes.  I suspect I am not using typename where I am supposed to.  With the following class that I've made:  template <typename T> struct NumericStruct {   public:     NumericStruct():       value(0),       index(0) {}      T value     unsigned int index; };   template <typename T, template <typename, typename = std::allocator<NumericStruct<T> > > class Container> class SuperBuffer {   public:     enum Category     {       THIS = 0,       THAT     };      SuperBuffer(const Category cat):       category(cat),       buffer() {}      void push_back( T number, unsigned int index );     T calculate() const;    protected:      Category category;     Container<NumericStruct<T> > buffer; };   When I make a derived class such as the following, it compiles okay.  //THIS IS OKAY class SuperCircularBuffer : public SuperBuffer<double, boost::circular_buffer> {   public:     SuperCircularBuffer(SuperBuffer<double, boost::circular_buffer>::Category type = SuperBuffer<double, boost::circular_buffer>::THIS):       SuperBuffer<double, boost::circular_buffer>(type)     {};      bool full() const     {       return buffer.full();     }     };   However, when I do the following, it doesn't compile:  //COMPILER COMPLAINS ABOUT THIS template <typename T = double> class SuperCircularBuffer : public SuperBuffer<T, boost::circular_buffer> {   public:     SuperCircularBuffer(SuperBuffer<T, boost::circular_buffer>::Category type = SuperBuffer<T, boost::circular_buffer>::THIS):       SuperBuffer<T, boost::circular_buffer>(type)     {};      bool full() const     {       return buffer.full();     } };   I've been trying different things but at this point I think I am just guessing.  Any help would be appreciated!


How can I make nice, professional looking corporate portraits?

I have been asked to shoot a couple of portraits at work for a conference brochure. I am a keen amateur but never really shot corporate portraits.  I will use a Nikon D40 and the 50mm 1.4G.   I am planning on using natural light from a terraced roof we have. Would you have any tips to help me getting nice pro looking shots?


Do I need to get out of International Zone at Charles de Gaulle airport when changing terminals from 1 to 2e?   I'm flying ULN-Beijing-Paris-Manchester. ULN-Paris is Air China then Paris-MCR is Flybe. I have 3.40 hours between the connecting flight at Charles De Gaulle airport. my problem is that Air China won't check my baggage to my final destination. I have to pick it up then re-check again. If I don't have to leave the international zone of the airport, then I won't need a transit visa. Do I have to leave the international zone and go through passport control to collect my bag and re-check it in again to board Flybe to Manchester? Also is 3:40 hours enough to do all of this when solo traveling with a 3-year-old child? If I decide to travel baggage free and with carry-on only, I don't need to leave transit zone to change terminals?   Than you very much for any advice!


Humanity stumbles across ancient booby trap

I probably read this before 2000 in an anthology work.  I frequently read books like "Best SF of yyyy".  The style of the writing is like that of the SF Golden Age.  Humanity developed interstellar FTL drives and is out exploring the Universe.  The Human ship discovers a inhabitable world with ancient ruins.  The Human ship lands and the crew begin exploring the ruins.  One member of the crew stumbles into an ancient trap that eviscerates and kills him.  It replaces his innards with machine controlled (I don't recall whether it's biological or mechanical) fake.  It also infects at least this crewman and maybe the entire crew with a plague designed to kill the entire Human species.  As the Human ship departs the planet, the machine expresses satisfaction with finally getting revenge on Humanity, the species that eliminated its master's species.  Apparently short-sighted Humanity has completely forgotten the ancient conflict.


If $\sum u_n^2$ is convergent the prove that $\sum(u_n/n)$ is convergent

If $\sum u_n^2$ is convergent then prove that $$\sum \frac{u_n}{n}$$ is convergent


How do I uninstall XFCE and other GUI in Ubuntu 12.04 server?

I'm very new to Linux. I thought having a GUI would be nice, but it is using too much RAM so I'd like to just use the regular terminal for now. I have Ubuntu 12.04 server with XFCE installed.  How can I uninstall all GUI related packages and everything that came with them?


I'm trying to start an exe from the command line  shell> wampmanager   When I do that, a User Account Control popup pops up and prompts me for permission. I press "yes" to run and it runs. But is it possible to grant permission via the command line? This is because I am writing a batch file that runs this program on its own, and I won't be around to press the "yes" button when it does. Thank you.


VBox on 14.04, Kernel driver not installed (rc=-1908)

On Installing Virtual box on Ubuntu 14.04, I got following message:     Kernel driver not installed (rc=-1908)      The VirtualBox Linux kernel driver (vboxdrv) is either not loaded or there is a >permission problem with /dev/vboxdrv. Please reinstall the kernel module by executing      '/etc/init.d/vboxdrv setup'      as root. If it is available in your distribution, you should install the DKMS package >first. This package keeps track of Linux kernel changes and recompiles the vboxdrv >kernel module if necessary.   Then on following the   I entered these commands:  sudo apt-get install linux-headers-generic build-essential dkms sudo apt-get remove --purge virtualbox-dkms sudo apt-get install virtualbox-dkms   On Running the last command   sudo apt-get install virtualbox-dkms   I get an error:  Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable  distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies: virtualbox-dkms : Depends: virtualbox (>= 4.3.10-dfsg-1) E: Unable to correct problems, you have held broken packages.   Just for reference, I checked the version of the Virtual Box, I got 4.3.16 r95972  It worked using the solution  sudo apt-get install build-essential module-assistant sudo m-a prepare   Second as mentioned in the error reinstall kernal module.  sudo /etc/init.d/vboxdrv setup   More Details are from


Isn't LIGO basically measuring the luminiferous aether?

I am bit confused about this one. I am not very acknowledgeable about gravitational waves and LIGO. But if it is basically a Michelson interferometer and can detect shifts in vacuum, doesn't this means that we detected the luminiferous aether and if not, why? Is there an analogy or direct correlation between gravitational waves and aether?


Cannot log into iMessage or FaceTime from mac

I have two macs, and at some point one of them stopped being able to log into Messages ( just the apple account ) and FaceTime.  The other mac worked fine, but was not using iCloud keychain ( at the time I did not realize this was the issue ).  Later, I activated iCloud keychain on the working mac and FaceTime stopped working there as well so I think this is related. De-activating iCloud keychain does not fix it.  Making a new account does, but this is a pain.  This started I think on Mavericks, and upgrading to Yosemite Beta hasn't fixed it.  My hunch is there is some keychain confusion going on, but I erasing any keychains related to apple hasn't helped either.  This apple discussion shows I'm not the only one, but nobody has a solution.    Any ideas?  Thanks!


Unable to remove red circle with white line

I recently tried to update Ubuntu 12.04 on my computer, but I am unable to do this because a red circle with a white line at the top of my screen. When I run the update in the terminal, I get this error message:  E: Type '<!DOCTYPE' is not known on line 1 in source list /etc/apt/sources.list.d/playonlinux.list E: The list of sources could not be read.   What to do?


My Windows 8.1/Ubuntu 12.04 dual boot won't boot windows after updating to v 8.1

I've searched the internet for similar problems, but I couldn't find an answer. Thus, my question is:  After upgrading my windows 8 to 8.1, I am no longer able to boot windows from the GRUB menu. Ubuntu still functions fine. Whenever I select the option to boot windows, the screen goes to black.


I asked my teacher what is the real meaning of $\cfrac{0}{0}$, and the answer I got was "nobody knows". I can't leave this subject "as is". I need a decent explanation, at least an explanation to why "nobody knows". I'm sure you'll come up with a few good answers.


Is it possible to define a command \MyCommand which does not swallow the next space (standard) but inserts a real space after itself only if the next symbol followed by it is a real space-symbol or CR? The command is supposed to have no arguments.


New Force.com IDE (Eclipse) - not auto-deploying?

I'm trying out the new Force.com IDE plugin (31.0.0.201406301722), under Eclipse Kepler (SR2, build 20140224-0627).  When I now save an Apex class, the class does not get automatically deployed to the server (as it used to in the older plugin). Instead, I get the "File only saved locally, not to server" marker, and have to manually right-click and select Force.com > Save to Server. This is much worse than before, not only because of the extra clicks, but I now get a popup window which blocks my UI until the deployment is over. Saving a single class also appears no faster, and maybe even slower, than it was in the old IDEE.  Under the "Project" menu, I do have "Build Automatically" checked. I also have checked all the Force.com and Project Preferences and can't find any other setting that would control this.  Is this a change in functionality, or is there some shortcut or setting I'm missing?


Broken dependencies while installing redmine using apt on fresh 14.04

On vanilla 14.04:   run aptitude chose package redmine see broken conflicting package problem (something with ruby-rack)   How can I deal with it?


"How to edit" side gadget fell down below

Here's a screenshot of the editing page as can be seen from far away:        As you can barely see, the side gadget called "How to edit" with formatting tips and such is below the "Save edits" button. This just happened to me right after I posted a question and without refreshing the page pressed "edit".  ()


Why do non-hydrogen atomic orbitals have the same degeneracy structure as hydrogen orbitals?

The solutions of the Schrödinger equation for hydrogen are the "electronic orbitals", shown in this picture:  ()  They have the following degeneracy structure:  ()  It is often said that atoms in other elements simply have more electrons "filling up" the orbitals in increasing order of energy, as required by the Pauli exclusion principle.  This is somewhat confirmed via xray spectroscopy:  ()  But why would non-hydrogen atoms have the same orbital degeneracy structure as hydrogen, if the actual Hamiltonian is different from one atom to another?


I have implemented a method getUsers(), which basically construct a List<ShoppingCart>, then create a List<User>:  public List<User> getUsers() {    // construct a liste of List<ShoppingCart>    ....    // update     ... }   The construction of List<ShoppingCart> contains a lot of logic, so I decided to move those code out and create a private method:  public List<User> getUsers() {    // construct a liste of List<ShoppingCart>    List<ShoppingCart> shoppingList = getShoppingList();    // update     ... }  private List<ShoppingCart> getShoppingList() {   ... }   Now I need to unit test getUsers(). But I realized that I have difficulty to get the List<ShoppingCart> because it's a private method.  And I don't want to make getShoppingList() public because I don't need it anywhere else.  I think there is a design problem in my code, what is the best way to unit test these kinds of methods containing returned value of private methods ?  Thanks.  UPDATE  No it's not the same question as , my question is not if it's necessary to test private method, but what should be a better design


Ubuntu 14.04.2 LTS stopped working on New Years Day!

I was using my computer today (1st January 2017). Everything was working fine. I restarted my computer. I have two accounts, user account and guest account. I clicked on my user account and entered my password, but all I get now is a purple blank screen (no side tool bar is showing either, no access to the terminal). Why did this happen on the new years day, this has never happened before, and I've had Ubuntu for years. Has this version expired or something? Anyways, I have some very important files on my hard drive, and I need to access them before I install the latest Ubuntu version.   I tried accessing my hard drive via LIVE UBUNTU CD by clicking devices/hard-drive/home/user-account but I get the following message: "This location could not be displayed. You do not have the permissions necessary to view the contents of this account".  I'm not reinstalling Ubuntu because I don't want to risk losing any of my files. Does anyone know how to access the hard drive via live CD, recovery mode, or any other way? The easiest and quickest way of course. I don't know any terminal or command lines, please share these with me if these are required to access my hard drive. Thanks  UPDATE:  The system is not frozen, the desktop is just blank purple screen with no side tool bar. I can move the mouse cursor around but there is nothing there to click on. I tried CTRL+ALT+F1 and I can access the black screened terminal. The terminal asked for my login and password. I entered it and I got the following message.  "Current version 14:04:3. New release 16.04.1 is available. Run do-release-upgrade"  Then the sudo:$ appears, but what command do I type to access all the files on my hard drive, desktop, documents, downloads, firefox bookmarks, etc? I will not upgrade to the new release because that involves a risk losing all my files.  Thanks for all your comments and support. Happy New Year!


Radial Schrodinger equation with inverse power law potential

Recently I read a  about solving radial Schrodinger equation with inverse power law potential.  Consider the radial Schrodinger equation(simply set $\mu=\hbar=1$):  $$\left(-\frac{1}{2}\Delta+V(\mathbf{r})\right)\psi(\mathbf{r})=E\psi(\mathbf{r}).$$  A  gives a one-dimension equation:  $$-\frac{1}{2}D^2\phi(r)+\left(V(r)+\frac{1}{2}\frac{l(l+1)}{r^2}\right)\phi(r)=E\phi(r),$$  where $D=\dfrac{d}{dr}$, and $l$ is the azimuthal quantum number.  If we only consider the ground state, then $l=0$, so  $$-\frac{1}{2}D^2 \phi(r)+V(r)\phi(r)=E\phi(r).$$  We want to find eigenvalue $E$ such that $\phi(0)=\phi(+\infty)=0$.  The central potential discussed in the paper is of this form:  $$V(r)=\alpha r^{-\beta}.$$  It states (see page 4) that if $\beta>2$ then the potential is repulsive (i.e. $\alpha>0$).  My questions are:    Is this conclusion (i.e. If $\beta>2$ then we must have $\alpha>0$) generally valid in physics? What would happen if $\alpha<0$ and $\beta>2$? Is there 'ground state' in this condition? What about the condition $\alpha>0$ and $\beta=1,2$? I have tried to solve the equation numerically with $\alpha=1,\beta=1,2$, and the ground state energy in this two conditions seem to be $0$, is my result correct?   P.S. When I try to find ground state when  $\alpha=-1,\beta=2$, the energy seem to be $-\infty$, which is qualitatively different from $\alpha=-1,\beta=1$.


If t is a quadratic residue mod p, how can I efficiently solve the equation $x^2=t \pmod {p}$?

I know that if $({t\over p})=1$, then $t$ is a quadratic residue, which means that $x^2 \equiv t$ mod p has solutions. So is there any skills or methods that I can use to solve the equation given a prime $p$ and $({t\over p})=1$? Thanks a lot!


stop apache from asking for SSL password each restart

Using  but varying them just a little i created a CA using -newca, i copied cacert.pem to my comp and imported as trusted issuer in IE. I then did -newreq and -sign (note: i do /full/path/CA.sh -cmd and not sh CA.sh -cmd) and moved the cert and key to apache.  I visited the site in IE and using .NET code and it appears trusted, great (unless i write www. in front which is expected). But every time i restart apache i need to type in my password for the site(s?).  How can i make it so i DO NOT need to type in the password?


If MSE is     $$ \mathrm{MSE}(\hat Y) = \mathrm{Var}(\hat Y) + \mathrm{Bias}^2(\hat Y) $$   and the Bias-Variance decomposition is given by     $$ \mathrm{Err}(\hat Y\,|\,X=x_0) = \mathrm{Var}(\hat Y) + \mathrm{Bias}^2(\hat Y) + \sigma^2 $$   so it looks like they're related, the second one being for a single event, while the first one is a mean. But it's not clear how to get from one to the other. So what is the relation?  (I have copied the equations from different sources, and there are slight notational differences, e.g. $\mathrm{Bias}(\hat Y)$ vs $\mathrm{Bias}(\hat Y, Y)$, and it's not clear to me if these are equivalent or not, so please point out/correct any misuse of notation.)


What does %~d0 mean in a Windows batch file?

I'm looking at a batch file which defines the following variables:  set _SCRIPT_DRIVE=%~d0 set _SCRIPT_PATH=%~p0    What do %~d0 or %~p0 actually mean? Is there a set of well-known values for things like current directory, drive, parameters to a script? Are there any other similar shortcuts I could use?


Explain the "@" symbol in this permissions example

I have a file on my Darwin system and the permissions are:  -rwxr-xr-x@   User: read, write, execute Group: read, execute Other: read, execute  What is the 11th notation the @ mean?  In addition to this, I was led to believe that files/directories only had 10 places for their permissions? This, including the missing d from the front, would make 11.


Limit of $S_n=\sqrt[n(n+1)]{\prod _{k=0}^{n}\binom{n}{k}}$

could anyone help me with the limit of the following sequence : $S_n=\sqrt[n(n+1)]{\prod _{k=0}^{n}\binom{n}{k}}$ Using the GM-AM inequality, we can prove that : $S_n\le \frac{2}{(n+1)^{\frac{1}{n}}}\rightarrow2$  and I've been trying to find a sequence $u\le S$ that converges to $2$ (eventhough I have no reason to believe such a sequence exists !) but I can't find any. Thank you in advance for your help !


When I installed Ubuntu Studio 19.10, I didn't add password for login. Now anytime I try to do something with the terminal it asks for my sudo password but of course I have no way of finding out what that is, since:  a) GRUB does not appear for me at all when I boot system b) I cannot open etc/sudoers  Totally new user...have installed Ubuntu in light of world events, covid and love for open source community.  THANK YOU!


Difference between electric and magnetic force

I watched the video which says that electric and magnetic forces are one and the same thing it is just that when electric Field when viewed from different frame of reference becomes electric field the link for the video is given below .     My confusion is that if the two forces are same and differ only in frame of reference will there magnitude ne always same and what is the need to segregate the forces then.is there something related to newtonian mechanics which alks about forces in inertial and non inertial frame of reference


Can a matrix have a null space that is equal to its column space?

I had a question in a recent assignment that asked if a $3\times 3$ matrix could have a null space equal to its column space... clearly no, by the rank+nullity theorem... but I have a hard time wrapping my head around the concept of such a matrix, no matter what size, even existing. How could this be possible, and does anybody have an example of such a $m\times n$ matrix?


What are some of the prerequisites for studying quantum field theory?

What are the mathematical and physics prerequisites for studying quantum field theory?


How to install gnome-terminal 3.18.3 (from Ubuntu 16.04) in Ubuntu 14.04?

I am trying to install the gnome-terminal 3.18.3 in Ubuntu 14.04.  The reason is want to have the username@computer name colored:    Ubuntu 14.04 has gnome-terminal 3.6.2 by default. This is what I have tried so far:  Runned:  sudo apt-get upgrade -f gnome-terminal   But it says gnome-terminal is already in the newest version.  I found the 3.18.3 package  but I do not know how to install it. Once extracted the gnome-terminal_3.18.3-1ubuntu1.debian.tar.xz file there is a python script gnome-terminal-wrap, I guessed it was the installer, but didn't worked.  Does someone know how to install it?  If this is not possible, is there a way to color the username@computer text?  PD: Or installing gnome 3.18....  Thanks a lot.


I booked an American Airlines ticket Newark --> Philadelphia --> Pittsburgh since it was cheaper than direct Philadephia --> Pittsburgh. I would like to simply get on at Philadelphia (I am traveling from central Jersey), but I assume my ticket will be voided if I don't show up in Newark. Is it possible to get the airline to divide my ticket onto two bookings so I can cancel one?


How to install ooVoo on ubuntu 12.04 64 bit

kindly help to install ooVoo in Ubuntu 12.04 64 bit.


ElasticSearch doesn't start after installing 5.6.4

I just installed ElasticSearch 5.6.4 from  via DEB (I use Debian 9) package using these commands:  wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-5.6.4.deb dpkg -i elasticsearch-5.6.4.deb apt-get install openjdk-8-jre-headless update-rc.d elasticsearch defaults 95 10 service elasticsearch start   But ElasticSearch won't start, this is log:  ● elasticsearch.service - Elasticsearch Loaded: loaded (/usr/lib/systemd/system/elasticsearch.service; disabled; vendor preset: enabled) Active: failed (Result: exit-code) since Mon 2017-11-13 16:59:24 UTC; 13min ago Docs: http://www.elastic.co Process: 16503 ExecStart=/usr/share/elasticsearch/bin/elasticsearch -p ${PID_DIR}/elasticsearch.pid --quiet -Edefault.path.logs=${LOG_DIR} -Edefault.path.data=${DATA_DIR} -Edefault.path.conf=${CONF_DIR} (code=exited, statu Process: 16500 ExecStartPre=/usr/share/elasticsearch/bin/elasticsearch-systemd-pre-exec (code=exited, status=0/SUCCESS) Main PID: 16503 (code=exited, status=1/FAILURE)  Nov 13 16:59:12 Mysite systemd[1]: Starting Elasticsearch... Nov 13 16:59:12 Mysite systemd[1]: Started Elasticsearch. Nov 13 16:59:24 Mysite systemd[1]: elasticsearch.service: Main process exited, code=exited, status=1/FAILURE Nov 13 16:59:24 Mysite systemd[1]: elasticsearch.service: Unit entered failed state. Nov 13 16:59:24 Mysite systemd[1]: elasticsearch.service: Failed with result 'exit-code'.   But it doesn't say anything useful.  In config file I just changed this:  network.host: 51.15.212.76 http.port: 9200 cluster.name: elasticsearch node.name: "db-master" node.master: true node.data: true   UPDATE:  I just used default settings and it works, problem is here:  Caused by: java.net.BindException: Cannot assign requested address   Why? I am using my IP adress (I copied it). I don't want to bind it to localhost, because I want to be able to connect it from different machine.  Result from ifconfig -a  eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500         inet 10.5.85.149  netmask 255.255.255.254  broadcast 10.5.85.149         inet6 fe80::207:cbff:fe0b:4d8c  prefixlen 64  scopeid 0x20<link>         ether 00:07:cb:0b:4d:8c  txqueuelen 1000  (Ethernet)         RX packets 18975397  bytes 14313412446 (13.3 GiB)         RX errors 0  dropped 0  overruns 0  frame 0         TX packets 61630671  bytes 85441277828 (79.5 GiB)         TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0         device memory 0x80000000-8001ffff  ip6_vti0: flags=128<NOARP>  mtu 1500         unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 1  (UNSPEC)         RX packets 0  bytes 0 (0.0 B)         RX errors 0  dropped 0  overruns 0  frame 0         TX packets 0  bytes 0 (0.0 B)         TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0  ip6tnl0: flags=128<NOARP>  mtu 1452         unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 1  (UNSPEC)         RX packets 0  bytes 0 (0.0 B)         RX errors 0  dropped 0  overruns 0  frame 0         TX packets 0  bytes 0 (0.0 B)         TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0  lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536         inet 127.0.0.1  netmask 255.0.0.0         inet6 ::1  prefixlen 128  scopeid 0x10<host>         loop  txqueuelen 1  (Local Loopback)         RX packets 26883466  bytes 4169327225 (3.8 GiB)         RX errors 0  dropped 0  overruns 0  frame 0         TX packets 26883466  bytes 4169327225 (3.8 GiB)         TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0  sit0: flags=128<NOARP>  mtu 1480         sit  txqueuelen 1  (IPv6-in-IPv4)         RX packets 0  bytes 0 (0.0 B)         RX errors 0  dropped 0  overruns 0  frame 0         TX packets 0  bytes 0 (0.0 B)         TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0


Can one prove the existence of tensor product without explicitly constructing it?

R is  a ring with 1.  We construct tensor product $M \otimes N$ of right R-module $M$ and left R-module $N$ to basically be able to state its universal property that any R-bilinear map from $M\times N$ to R-module P factors through an R-linear map from $M \otimes N$  to P. Atiyah and McDonald even mention that one can forget the construction if one wants to, we only need the universal property.  Given all this, can one do away with the process of constructing $M \otimes N$ and rather just prove the existence of one.