I would like to create a template for a publication list that can then be used by several people. The idea is that there is one bib-file which contains all of the publications. Peer-reviewed entries are marked with the keyword = pr. Then there is the master-file of the type scriptreport in which everyone can integrate their chapter-file in order to merge the publication lists of everybody into one file. The chapter file is the core of everything and should be reusable. It should filter out the entries for the respective author from the bib file and print them out in two lists (peer-reviewed and non-peer-reviewed). My problem is that I don't really know how to filter by author in this case. Here are the rough codes of the two files: Master: \documentclass[a4paper]{scrreprt}  \usepackage{biblatex}  \title{Publication list}  \addbibresource{sample.bib}  \begin{document}     \maketitle          \tableofcontents     \newpage          \include{Researcher}     \newpage \end{document}  chapter: \chapter*{Researcher} \addcontentsline{toc}{chapter}{Researcher}          \nocite{*}     \printbibliography[keyword={pr}, title={Peer-reviewed}]          \nocite{*}     \printbibliography[notkeyword={pr}, title={Non-peer-reviewed}]


I just installed Ubuntu 18.04 and the System Monitor app shows transparent and I have to put it on a dark background to actually see the info. ALso the window does not have borders.     What can it be? I installed the communitytheme but it seems like that is not the problem.


I want to find the unit digit of $ 1^1+2^2+3^3+...+2018^{2018} $ . I have find out the unit digit of $ 2^2,3^3,4^4,....259^{259},....2018^{2018}$ . But I cant find out the unit digit of sum of all of this term .   Is there any way to find out the digit of sum of all of this term ? Please help me .


How do you kill a java.lang.Thread in Java?


If $A \in M(n,\mathbb R)$ , and rank of $A$ is $m$ , then what is the rank of the adjugate of $A$?

Let $A \in M_5(\mathbb R)$ ; if what is rank $adj(A)$ when rank of $A$ is $3$ or $5$ respectively ? In general , if $A \in M(n,\mathbb R)$ , and rank of $A$ is $m(<n)$ , then what is the rank of the adjugate of $A$ ?  I think that if  rank $A=n$ , then det $A \ne 0$  , then det $(adjA)=(det A)^{n-1} \ne 0$ , then $adj A$  should also have rank $n$ ; but I can't figure out what if rank$A$ is less than $n$ . Please help. Thanks in advance


Simple question on connectedness in a subspace

For some reason I am having some trouble on this basic point set topology question:  Suppose $X$ is connected, and $A$ is a connected subset of $X$, and that $B$ is a clopen set in $X-A$ (not in $X$, obviously. Clopen in the subspace topology on $X-A$).   Show $A \cup B$ is connected.   I'm getting a little confused on the correct way to approach this...i.e. which definition or notion of connectedness I should use to approach it.


Disable the guest user completely in El Capitan without having to disable 'Find My Mac'

I know it should be straight forward but unfortunately, it  isn't.  I did disable the guest user in the System Preferences by unchecking the checkbox for Allow guests to login in to this computer, but it still shows up on the login screen.  I have heard that disabling 'Find My Mac' would fix it for OS X Lion, but I want to keep it.  Is there a way to do this?


Preview Breaks with Invalid Tag Name [tag:+]

In the formatted preview for Questions & Answers, typing a tag link with an invalid tag name "crashes" the preview. As soon as you type the following the preview stops updating and an error can be observed in the Javascript console.   [tag:+]   Observed in Safari 7 and Chrome 31.   seems related to the business rule of not allowing certain characters in tags, but it sounds like a different bug.


Enable fingerprint reader login in 18.04 w/ Unity

I have a Dell laptop with fingerprint reader built in. I just ran  with  the following result:  Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 006: ID 138a:00a6 Validity Sensors, Inc. Bus 001 Device 005: ID 0cf3:e009 Atheros Communications, Inc. Bus 001 Device 004: ID 0bda:0129 Realtek Semiconductor Corp. RTS5129 Card Reader Controller Bus 001 Device 003: ID 0bda:5689 Realtek Semiconductor Corp. Bus 001 Device 002: ID 04ca:00ac Lite-On Technology Corp. Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub  Is it possible to use fingerprint scanning instead of traditional login with 18.04 and Unity ?


Exponential generating function with Stirling numbers

I want to prove in particular this result- $$ \newcommand{\gkpSII}[2]{{\genfrac{\lbrace}{\rbrace}{0pt}{}{#1}{#2}}} \sum_{k \geq 0} \gkpSII{2k}{j} \frac{\log(q)^k}{k!} =       \frac{1}{\sqrt{2\pi}} \int_0^\infty \left[       \sum_{b = \pm 1} \frac{1}{j!} \left(e^{\sqrt{2 \log(q)} t}-1\right)^j       \right] e^{-t^2 / 2} dt $$ Hence to start my attempt I found this result that- $$\sum_{k \geq 0} \gkpSII{2k}{j} \frac{z^{2k}}{(2k)!} =       \frac{1}{2 j!}\left[(e^z - 1)^j + (e^{-z} - 1)^j\right]$$ But I couldn't find its proof anywhere. So I need hints/answers to prove the latter result. I found this formula mentioned in a  with this  But I cannot understand anything in that


When I try to delete an write protected file, I get an UnauthorizedAccessException. Permissions are fine, I can delete the file, if I remove the write-protection-box in Explorer->File properties.  How can I delete the file anyway?


df -h reports the '/' partition to be 100% full. While running du -hs * on each directory of this partition shows there is still lot of space.  tune2efs which reports just one block to be free. Ran fsck as well, which also shows all blocks being used.  ionode use is  14% on the '/' partition.  Please note that /var, /usr, /dev, /tmp, /home are mounted on different partitions and have space available in them.  Can you please let me know the possible causes for all blocks to be occupied and disk reporting to be full even tough there is a lot of space.


Does SPSS Homoscedasticity Residual scatterplot have meaning for Likert Data?

I'd think using plots to test the assumptions of multiple linear regression requires some experience anyway, but in this case all my independent variables, and my dependent variable,  are 5-level Likert rather than continuous variables.  I understand applying non-ordinal regression to this kind of data is somewhat controversial, but is often done.   The plot consists of 5 linear arrays of points at 45 degrees. Is that interpretable at all?  If not, what should be substituted?


Single drop down with data from separate columns

I have a spreadsheet that I need to add new data to but the previous user made it so that I can't add data in a new row without moving down a lot of data which would mess with all the calculations.  What I am trying to do is to make it so I can add the new data to the side instead and still have the same drop down access the two separate columns. I attached a screen cap of an example of what I want below.  I have tried everything I can think of and all my searches come back with putting multiple columns in a drop down instead of just the data from them.  As you can see below the example has data in D1 to D5 and F1 to F5. If I wanted the dropdown to have the data from those columns how would I do it?  EDIT: Just to clarify there is data between the columns in the actual page which is why I can't just highlight all of it.


Does "Download and Keep Original" require manual sync of each photo?

Following the update to iOS 10.3.1, my phone warned me (unnecessarily as it turned out) that I had too little space to store all my photos at full resolution, and suggested that I switch to "optimized" storage (which for those unfamiliar with the feature stores a uselessly blurry simulacrum of the original only), which I foolishly did.    I immediately realized my mistake, and restored the "Download and Keep Originals" setting. But this appears to have had no effect. I still see only the placeholders, until I click on an individual photo and wait for it to download.  So the question is: what does "Download" mean? Does it mean   download all photos automatically (e.g., in the background over time) or  download a photo only when it is viewed?   If the answer is 2, is there a way to force all my photos to sync at full resolution to my iPhone without clicking on each individual photo (which would take about a month of continuous clicking, with no breaks for sleeping)?


Return the [DefaultValue] if property is not initialized in c#

I'm wondering what is the cleanest way to make a property return the value specified in its  if not initialized.  For example, I would like the getter of this property to return 42 if not initialized:  [DefaultValue(42)] public int MyProperty { get; set; }   Any solution / refactored code welcomed. Target is .Net 4 (if greater, please indicate a fallback)  Ultimately, the aim is to avoid "hardcoding" the default value twice in order to facilitate maintenance. Also note that in a real scenario, there would be several such properties in one class. So ideally, I would prefer to avoid a solution that manually lists and initializes each properties to its default value.


Boolean functions built from $\wedge$ and $\vee$

Prove that not every Boolean function is equal to a Boolean function constructed by only $\wedge$ and $\vee$. Please can you help me giving some hint.


I am at 3 days, I just fed, and I ran down to the Shrine of Talos and pressed it, but it still says I'm a vampire. How do I cure this?


How to get 'n' no of rows and columns in a table using visuaforce pages or html or javascript

Can any one help me out how to get this achieved in the below screen shot.I tried using Visual force pages but unable to do it.I shall appreciate your help.Is this the correct way im doing Code  Written is :                                                       -->                                                   -->                                      -->     <apex:pageBlockTable value="{!Opportunitylineitem}" var="oli" columns="2"  >         <!--<apex:column value="{!oli.Product2}"  />-->          <apex:column value="{!oli.UnitPrice}" />         <apex:column value="{!oli.Quantity}" />        <!-- <apex:column value="{!oli.listprice}" />-->         <!-- Header Generated automatically -->     </apex:pageBlockTable>                -->                                        -->                                            -->                                        -->                                            -->                                        -->                                            -->                                        -->                                            -->                                        -->                                            -->                                        -->                                            -->                                        -->                                            -->                                        -->                              </apex:pageBlock>


Does anyone know how to get Japanese or other double-byte character sets to appear correctly in email?  I'm sending Japanese in email. While I can see the characters, people in Japan have been telling me that they cannot see the characters. That's kind of makes my emails useless @_@  I've tried setting all kinds of character sets in the web.config and in the CDO config, but haven't found out how to get the characters to display properly.


get element as selector in jquery which is loaded after page load

I had made one function for making pagination ,sorting and  listing all in one and that function I call on load of page of body like  <body onload='MYFUNCTION(parm1,param2,param3)'>   Now i want to apply some jquery on the button which shows all document in fancybox which come by that onload but when i try to do on  $(function(){     $(#container).on('click','#button',function(){         //code here for load fancybox and getting all image stuff by ajax      }); });   than i not get that element because it cant find it on page load so what can i do  inshort - how to select element in jquery which is load after page load Thank you..


How do I disable the drum beat sound on the login screen?

I would have expected System ▸ Administration ▸ Login Screen ▸ Play login sound to control this, but unchecking it does not prevent the drum beat sound from playing.


What signal does being prepared to stay overnight on a Saturday give to the airlines?

What signal will "a trip with an overnight stay on Saturday" give to the airlines and how would they possibly react?


I am trying to match a numeric value that is purely numbers to another value in my database that is the same numbers but has symbols etc (it's phone numbers).  How can I get MySQL to only match the regexp of the mainNumber column (which has symbols etc in it) to my value (just numbers)?  Below is my code:  $SQL = "SELECT entities.name         FROM entities_main_numbers            LEFT JOIN entities ON entities.id = entities_main_numbers.entityId         WHERE mainNumber = ?         LIMIT 1";     E.g. +44 (0)800 123 123 to match against 440800123123


How can I display all Multisite blogs where this user is administrator?

Given the user ID, how can I display all the blogs where this user is administrator?  I tried:  <?php $user_id = 2; $user_blogs = get_blogs_of_user( $user_id ); echo '
'; foreach ($user_blogs AS $user_blog) {     echo '
'.$user_blog->blogname.'
'; } echo '
'; ?>   However, it will return all the blogs where user has access to regardless if it is an administrator or just a subscriber. But all I want to display is those blogs where this user is administrator.  Is this possible? If yes, How?


What is the rationale for restricting vote split views to 1000 rep?

When I join a new site, one of my biggest pet peeves is that I cannot see the vote split on a question and/or answer.  This feature is a great education - a +5 / -4 answer tells me a lot more about the consensus of "on-topic" is then a simple +1.  And yet, the feature waits until you have 1000 rep, which is a fairly significant hurdle.  So, why did this feature get put so high on the cookie shelf anyway?


I am using Apache 2.4, on Debian 9.  I can access all my subdomains from my mobile phone.  However on my local network, from separate clients (windows 8,  Debian (not the server), and Mac OS 10.10), from different browsers (Firefox, Chrome, Brave), I get mixed results. One subdomain doesn't load at all (nextcloud), but I guess that is specific to nextcloud.  Just perlpexes me, that I can reach all of them from my phone, and weird behavior on local network.  Anyone able to offer a tip on how I can resolve this??  UPDATED: Thanks for the immediate replies.  I have to admit, a "hairpin NAT" is outside of my scope of knowledge. I am not using a NAT. I do have a local DNS server running (Pihole), but that doesn't seem to be a factor, since it affects machines with it (and those without Pihole configured to be used as it's dns server). So, I do not think that is a factor.  Also, don't think it's a browser, OS issue, because I just failed on two configurations (Windows/Mac), jumped on my VPN (outside location), and everything worked (was served) as expected.  I am starting to narrow down that one of my virtualHosts is figured incorrectly. I have one setup to work as a ReverseProxy, per a tutorial (so I can run gitlab from apache, instead of nginx--nginx is disabled). From what I read about ReverseProxy's, I don't know exactly why we would need one? But, ok. Here is virtualHost file.


Here is my code:  \documentclass[a4paper,twoside]{book}  \usepackage[utf8]{inputenc}  \usepackage[titletoc]{appendix} \usepackage[english]{babel}  \usepackage{csquotes} \usepackage{lmodern}  \usepackage{comment} \usepackage{makeidx}  \usepackage{bm}  \usepackage[usenames,dvipsnames]{xcolor} \usepackage[protrusion=true,expansion=true]{microtype}  \usepackage{graphicx}  \DeclareGraphicsExtensions{.pdf} \usepackage[font=small,labelfont=bf]{caption}  \usepackage{wrapfig}  \usepackage{float}  \usepackage[bottom]{footmisc}  \usepackage{multirow} \usepackage[multidot]{grffile} \usepackage{subcaption}  \usepackage{geometry} \geometry{a4paper,top=2.5cm,bottom=2.5cm,left=2.5cm,right=2.5cm}  \usepackage{lipsum}  \usepackage[24hr]{datetime}  \usepackage{titlesec,titletoc} \usepackage{hyperref} \usepackage{amsmath}  \usepackage{amsfonts}   \graphicspath{{graphs_folder/}}  \usepackage[      backend=biber,       natbib=true,      style=numeric,      sorting=none  ]{biblatex}  \addbibresource{biblio.bib}   \begin{document}  Hello.I want to cite \cite{braitenberg2013anatomy} and   \cite{hebb2005organization}   \backmatter  \cleardoublepage   \printbibliography   \end{document}   I'm on Ubuntu 14.04, I'm using TexMaker 4.1 and I did what suggested   However:  when I try to run the compiler with PDFLaTeX option, I obtain  line 50: Empty bibliography line 1: There were undefined references line 1: Please (re)run Biber on the file:(biblatex) and rerun LaTeX afterwards    I think is important to tell you that when I run quick build it should go through the whole process and showing me the pdf. Instead, it ends with  Error:could not start the command   and doesn't show anything. The same message appears if I use the BibTeX option of the compiler.   If I open the pdf manually, I can't find the bibliography and the citations are like     [braitenberg2013anatomy] and [hebb2005organization]    while what I need is      [1] and [2]    (note that I need them to be sorted as they appear).  What is wrong with my code?  Thanks in advance.


Suppose that $\displaystyle\frac{1}{a}+\frac{1}{b}+\frac{1}{c}=\frac{1}{a+b+c}$ . Then , prove that $\displaystyle\frac{1}{a^5}+\frac{1}{b^5}+\frac{1}{c^5}=\frac{1}{a^5+b^5+c^5}.$  Attempt :  From the given relation , $\displaystyle \frac{a}{b}+\frac{b}{a}+\frac{b}{c}+\frac{c}{b}+\frac{a}{c}+\frac{c}{a}=-2$.........(1)  Now I want to calculate , $\displaystyle \frac{a^5}{b^5}+\frac{b^5}{a^5}+\frac{b^5}{c^5}+\frac{c^5}{b^5}+\frac{a^5}{c^5}+\frac{c^5}{a^5}$. I tried by expanding pair of terms and putting the value of (1), but it can't help...


Most efficient way to convert an HTMLCollection to an Array

Is there a more efficient way to convert an HTMLCollection to an Array, other than iterating through the contents of said collection and manually pushing each item into an array?


How inflation explains the missing monopole?

I read that Alan Guth used phase transition model of early universe to dilute the monopole so that nowadays we don't get to see any of them? I know there is no monopole in nature but I am interested to know how the inflation upset the grand symmetry?


How can one redefine the spacing that the \and command puts between authors in \author within the standard article class?  I have a document with three authors whose names are just too long to fit on one line with the standard spacing.  I feel like this should probably be doable with a \setlength command, but I have no idea what length to set.  For the record, I'm aware of packages like  (which I may ultimately use for my purposes), but am more interested in how to modify this spacing directly.


Can a meta site be used to formulate a question? If so, how do I do it?

According to a comment on the question , it's okay to formulate a question on a Meta site. I asked the question  but it got a score of -9. Somebody asked the question  except that it was about whether an already existing question should remain. I also once saw a question on Mathematics Educators Stack Exchange that was moved from its Meta site, that I can no longer find.  It seems that some people can find a way of formulating a question on a Meta site that gets accepted by other people. How can I learn how to do that? I'm not an expert in anything. I'm wondering if I just don't have enough of the right knowledge and experience to have any hope of that. According to kcrisman's answer to my question at , sometimes a question is not well accepted because there aren't enough users who have the skills to answer it. Do you think that maybe the same goes for some of the questions for formulating a question?  I know it appears to be promoting my own questions but what am I supposed to do? Of all the questions about a question that there are, it's so much easier for me to track down the ones that were either asked by me or were about one I asked. Other people don't seem to be having a problem with my question  even though it seems to be promoting my own questions.  I know that if I didn't believe the question  or the question  were worthy of asking, it would work better not to ask them even though I would have less information from which I could make this question more useful. Maybe I made a mistake asking the one at  but now that I asked it, I might as well refer to it. If I had a real good point to make in this question, I probably could have made it some other way by asking a totally different question. Maybe I wouldn't have thought of it but maybe after enough time of trying things and making mistakes, I will become so much better at thinking of things.


Java. How to convert random line of characters to a string?

I'm new to java. I have started about 3 days ago. I want to make a line of random characters and to put them into a string. Thank you.       import java.util.Random;       public class test{       public static void main (String[]args){  final String alphabet = "abcdefghigklmnopqrstuvwxyz"; final int N = alphabet.length(); Random r = new Random();  for (int i = 0; i < 50; i++) {     String s = alphabet.charAt(r.nextInt(N));     // System.out.println(alphabet.charAt(r.nextInt(N))); }}}


What does this black visa rejection stamp from Israel mean?

I had applied for B2 visit visa for Israel. They rejected and marked my passport with the following black stamp:    What does the black stamp mean and what are its restrictions? Can I reapply and if yes, when should I apply? I plan on reapplying next month. Will that be fine?


In some languages, such as Italian, when addressing someone who is senior to you or at a higher level with respect to some social hierarchy, it is customary not to use the second-person singular pronoun but some other form to indicate deference. In Italian for example, the second-person plural feminine is used (e.g. "How are you" becomes "How is she"). The closest phenomenon in English that comes to my mind is the use of "sir" or "madam" but of course this does not work in the same way grammatically.  My question is: what is the technical English term for this grammatical construction?


Inequality with condition $x^2+y^2+z^2=1$.

let $x,y,z>0$ such that $x^2+y^2+z^2=1$. Find the minimum of $$\frac{1}{x}+\frac{1}{y}+\frac{1}{z}.$$  Is the answer $3\sqrt{3}$ by any chance?


I'm using OpenLayers to show my map with some layers. I've a field where I can add some filters with CQL code. I can successfully add a new filter to my map, and only the right points appear in my map but when I try to remove the filters it's deleting my Layer instead of my previous CQL_Filter result, so is deleting ALL the points from the map.   //My var map is previously declared var layerFromMap = map.getLayersByName(input.name)[0]; //If my input is empty then I should delete the filters, like resetting the search if (input.value.length > 0) {     layerFromMap.mergeNewParams({ 'CQL_FILTER': input.value });     layerFromMap.redraw(); } else {     delete layerFromMap.params.CQL_FILTER;     layerFromMap.redraw(); }   When input is empty layerFromMapparams.CQL_FILTER is deleting my layer from the map, so all the points are deleted. Why is this happening? How can I only remove the filter so all the points appear again?


Under the tag description are two buttons, watch/unwatch and ignore/unignore.  What   are those buttons supposed to do?  I didn't  see any effects from using them.


Hyperref link placement: alignment to left page border and top of page

(a) Is is possible to have certain hyperref-hyperlinks (such as those to sections and also (when using memoir) to the table of contents, lists of figures and tables, and bibliography) point to the very left border of the page, not to the interior? Note that I have already tried the hypcap package, which positions figure and table links to the left edge of the text (just where the left margin ends) but not to the left page border. (For reading text, it is good if the text starts not exactly at the edge of one's viewing window but a tad into the window's border.) Also, hypcap doesn't deal with the table of contents, the lists of figures/tables, and the bibliography.  (b) If, in addition, one could make hyperlinks point not only to the left page border but also to the top left corner of the respective page, that would be a useful option. Is that possible?  If people would like starter code for this, here is some I've slightly adapted for :  \documentclass{memoir}   % using the memoir class here is necessary   % for all the desired hyperlinks to be created \usepackage{hyperref} \usepackage[all]{hypcap} % hypcap doesn't help here  \begin{document}  \tableofcontents  \section{A section} This is the only section.  \listoftables \listoffigures  \begin{thebibliography}{9} \end{thebibliography}  \end{document}   Note: I am aware of the hypcap package but not sure whether/how it can be used to address this.


I can't install WINE. When I go to the terminal and type sudo apt-get install wine1.7, I get  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:  wine1.7 : Depends: wine1.7-i386 (= 1:1.7.12-0ubuntu1~saucy1)            Recommends: winbind E: Unable to correct problems, you have held broken packages.   I've looked around here on AskUbuntu, and haven't found a solution to the problem. I tried going into Synaptic and going to Edit --> Fix Broken Packages, but this doesn't fix the problem. I've tried sudo apt-get autoremove and sudo apt-get update, but those do not solve the issue either. I've tried adding the WINE PPA, but that doesn't work either.  This issue started after trying to install netflix-desktop from the ppa:ehoover/compholio PPA. After I installed this, an icon appeared in my panel telling me of a problem involving wine1.7:i386 not being in the cache. I had this problem once before, so I uninstalled WINE and removed the PPA, but now WINE won't install at all.  Any ideas?


batch to repair local area connection Windows XP

I have a sporadic internet connection that shows high ping and low bandwidth. I can manually fix it with LAN repair but it happens again in a short while. I'm looking for a batch that can repair it automatically on timed intervals. On Windows XP. I don't know what it is that the LAN repair is doing so i can't even start the batch. thanks.


I am under the impression that Einstein never explains in his General Theory of Relativity, why matter curves spacetime; could explanations please be given?


How to stop "NTFS new version", or any notification for that matter?

I used paragon NTFS for a while and then deleted it from applications folder. I also removed the dmg file(I know it would not stop notifications).   But I keep getting notifications like this everyday.  .  Clicking on it is useless. Safari would open(if not already) but no new window, no webpage, nothing.  I searched the Library folder for NTFS and paragon and deleted files and folders for e.g. from application support, from caches. One folder in its name had "notification". I deleted that too. Unhid hidden files by CMD + Shift + . For a temporary fix, I turned off notification from System Preferences. But I need a permanent fix.


Due to large number of reviews waiting do be done - at the time about 46,000 - did you consider - maybe temporary increase daily close votes limit from 40 to higher number ?  I know there is limit daily 50 question that we can vote to close, however review limit could be higher - not every review need to be closed.


Let $W_1 ,W_2 ,W_3 $ be three distinct subspaces of $\mathbb R^{10}$such that each has dimension 9. $W=W_1\cap W_2\cap W_3 $.What will be dimension of W? I think dimension of $W$ will be 7 since $W_1 ,W_2 ,W_3 $ are distinct.But answer is dimension of $W$ could be 8 as well.  According to my reasoning Let $\{a_1, a_2 ,...,a_{10}\}$ be elements of basis of $\mathbb R^{10}$ .Now we can choose basis for $W_1$ any nine elements, say  $\{a_1, a_2 ,...,a_{9}\}$.Now,for $W_2$ we choose $\{a_2 ,...,a_{10}\}$ as basis. To make $W$ of dimension 8 we $\{a_2 ,...,a_8,a_{9}\}$ must be in the basis of $W_3$.Now to complete $W_3$,only one dimension is needed for which we have two choices either $a_1$ or $a_{10}$.Choosing any of them will make $W_3$ either equal to $W_1$ or $W_2$. I could not find any any case where dimension of $W$ is 8. I don't understand what went wrong. Please help.


Is it bad for SEO to use a subdomain other than www as main domain?

Somebody told me recently "Subdomain generally ranks lower than domain", this is not the only one to say to avoid use subdomain.  Can a subdomain rank as a root domain? Will it hurt ranking or SEO to use a subdomain as main domain?   I'd redirect 301 the root domain to the subdomain.  I'd have lastname.example and www.lastname.example each 301 redirect to firstname.lastname.example,


Is there any Good comprehensive reference for tensor calculus?

I am currently reading this  blog, where it talks about Backprop through time. I am struggling to derive it and don't understand how to go about such derivations in general.  Stuff like this ends up being a pain point in most literature related to ML/DL/AI. Is there any resource that explains derivatives of different objects of higher dimensions in detail with proper examples.


Uninstall Apache2 from terminal on Ubuntu14.04

How can I uninstall Apache2 on Ubuntu 14.04, from the terminal? I don't know the commands.


Get text value of selected option in Jquery

I have some custom Jquery which grabs the id's from a select list, and populates a secondary select list with those that are selected.    I have this working well, however I need the secondary select list needs to display the text value of the selected option.  Currently I just get the actual id.    Can anybody assist please?  JQUERY  $('#myselect').change(function() {         var row = $(".chosen-select").val();         $('#secondSelect').html('');         jQuery.each(row, function(i, val) {             $('#secondSelect').append('<option value=' + val + '>' + val) + '</option>';         }); });   HTML  First select list  <select data-placeholder="Choose cars..." class="chosen-select" name="myselect[]" id="myselect" multiple>    <option value="1">Vauxhall</option>                                                                                <option value="2">Volvo</option> etc... </select>   Second select list  <select name="secondSelect" id="secondSelect">     <option value="">Select Model</option>     should be populated here.. </select>


What is the "Rule of 600" in astrophotography?

mentions the "Rule of 600" for avoiding star-trails in astrophotography.   What is this rule? How was it derived? How should it be applied?


Can a non-EU citizen with an EU residence permit cross the border in the EU citizen channel?

This is the question I am really eager to know. If I already have an EU residence permit from Poland, when I enter into the EU zone, can I line up in the same channel as EU citizens? Or is there any special channel for residence holders?


Preempting inadequate answers and the ‘XY problem problem’

A number of times I have asked a certain kind of ‘attractive nuisance’ question – that is, one in which I anticipate a certain kind of answer would be given that I already know I am going to find insufficient or entirely inadequate. Some examples:      A more abstract example would be asking ‘is it possible to do this 100% correctly’, where people itch to come up with hacks, workarounds and half-baked solutions of various degrees of robustness – while the point of the question is obtaining a fully correct and reliable solution.0 I try to be very explicit in the question body about what kinds of answers I am not interested in. And yet, every time I ask such a question, someone gives such an answer anyway, or an outright XY-type, i.e. frame-challenge answer – where in fact the framing of the question is exactly how I want it, and I don’t want it challenged. Since I have already said in the question body that such an answer would be inaqeduate, when I get one, I downvote it. I believe it’s only appropriate, but it tends not to be received very well – I get insulting comments and downvotes in retaliation. I realise that a proper answer would be much harder to come up with than an ‘obvious’ inadequate answer. I suspect that often a real answer should be negative: ‘there is no way to do that’ or ‘there is no way to answer that for sure’. Nevertheless, if that is the right answer, this is the one I want posted – I don’t want the Internet polluted with more tumbleweed of what is already well-known (and may even be subtly wrong), and I don’t want to give ‘A for effort’ upvotes. What is the most appropriate way to act in such a situation?  0 I am also reminded of when Gary Bernhardt  while trying to avoid reflexive ‘don’t use eval’ replies. Of course, expecting nuance from Twitter of all places is silly, but that’s beside the point.


At what level are spells duplicated by the Wish spell cast?

Wish is a 9th level spell, one of the uses written into it is:     The basic use of this spell is to duplicate any other spell of 8th level or lower. You don’t need to meet any requirements in that spell, including costly components. The spell simply takes effect.   The question is what level is that copy of the spell cast at? I can see three possibilities here:   Wish was cast from a 9th level spell slot, so the copied spell is cast at 9th level. Wish can cast up to an 8th level spell as a copy, so the copy cast is cast as if it were using an 8th level slot. The spell being copied is of Nth level, so the copy is cast as if it were using an Nth level slot.   There are good reasons to cast low level spells at higher levels, the extra die per level of healing for cure wounds, the extra missile per level for magic missile, etc, so using a 9th level slot to cast a low level spell copy at the low level would generally be undesirable, but the wish spell isn't clear.  The first two possibilities both make some sense and are useful, in the 9th level example you just get the spell as if you had cast it normally in the slot, in the 8th level example you're sacrificing one level of casting bonuses for the ability to cast possibly unknown, unprepared or cross-class spells (no restriction against copying say cleric spells as a wizard with wish) - and that utility seems like a fair trade off.  But which is 'officially' correct?


From  by Richard Brualdi  We have a chess master. He has 11 weeks to prepare for a competition so he decides that he will practice everyday by playing at least 1 game a day. To make sure that he's able to take a couple of breaks, he also decides that he wont play more than 12 games per week.  My question is, how do you prove/dis-prove that there will be a succession of (consecutive) days in which he will play k games, $k \geq  22$?  Specifically, I don't quite understand the use of the pigeonhole principle here.  Thanks in advance! :D  EDIT  I'll try to clarify what I'm asking:  The goal is to prove that for every possible practice schedule that the chess master makes, there will always be a consecutive sequence of days such that he plays exactly k games.  So for example, if k = 22, how do you prove that no matter what his schedule is like, he will always play exactly k games in r days, $1 \leq r\leq  77$.  My main question is: what is the general method for proving different values of k? Are there values of k (from 1 to 132 inclusive) that are impossible to obtain?  Note that he does not necessarily have to play 132 games within 77 days! Also, keep in mind the bounds of k.


Estimate the size of a set from which a sample has been equiprobably drawn?

Here is the problem I'm trying to solve:  In order to send spam, a spammer generates fake nicknames, by picking random girl names (and appending a random number to it). I suppose it randomly and fairly picks names from a fixed list, and I get to observe the outcome. Over time, names eventually start repeating.  From the distribution of the repetition count of every distinct name, is there a way to estimate the size of the fixed list ?  Intuitively, if there was no repetition among the names I have observed, I would have no information about the size of the list, but the minimum bound given by the actual distinct names observed.  On the other hand, if the distribution of the repeat counts is far away from zero, I can be reasonably confident that the sample size is much larger than the word list, and that I probably have observed the full list already.  The problem lies in the middle zone. So far the distribution of repeat counts looks like this:  $$ \begin{matrix}       n & k \\    114 & 1  \\     66 & 2 \\     30 & 3 \\      4 & 4 \\      2 & 5 \\      1 & 6 \end{matrix} $$  Here $n$ is the count of distinct names appearing $k$ times in the sample.  Is there a simple estimator for the size of the list?


How to display the combination of some values in array?

For example, I have an array ["Sam", "Mary", "John"]. I would like to display the combination of choose 2 out of 3. The results should be:    [Sam, Mary] [Sam, John] [Mary, John]    I have researched a lot but still dun know how to do it. Of course, this example only contain 3 people. In fact, the number of total people will be larger, e.g. 15    Here is what I found:     Some of them is only display the value of nCr, but not giving out the combination.


I want to run a bash script in a directory /media/aliakbar/New Volume(internal drive)/further/path/to/file . The problem is: with chmod +x the file's permission is not changed (proof: I couldn't execute script from terminal):  -rw------- 1 aliakbar aliakbar    561 Jun  8 14:05 buildscript_0.10.0.sh   I moved the file to /home/<user>/Downloads/, did chmod +x which worked, and moved file back to /media/aliakbar/New Volume(internal drive)/further/path/to/file, replaced non-executable file but still with ls -l there's no change!?  NOTE: I'm on Ubuntu LTS 14.04 (dualboot) with df -T run in file directory returning:  /dev/sda3   fuseblk   277228568   168883892   108344676   61%   /media/aliakbar/New Volume    New Volume is on an internal drive unfortunately I don't know how it's mounted, I have only an empty /etc/fstab.d/ folder   What am I doing wrong?


Changing the color of one line/stroke of a shape (Illustrator)

I'm new to illustrator. When I try to shape certain objects for a 2D cartoon character like the nose, for example, I want it to make the outer part of a nose one color while the color of the inner part of the nose matches the skin. Or if I make a triangle and color two sides of a triangle blue while making the remaining one side yellow. How do I that?


Function returned from another function gets closures Closures is a permanent memory Variables and functions that never referenced from the parent function inside the inner function don't go into the inner function's closures.  For example, here's the code: function parentFunc(){   let x = 10;   let anotherX = 10;    function childFunc(){     console.log(x);   }        return childFunc; }      let generatedFunc = parentFunc();      generatedFunc();  Only x will go into the inner function (which ends up being generatedFunc) and not anotherX because it was never referenced from the childFunc. Could anyone please tell me if I'm missing out on something here?


Need to check via if condition that variable named "var" contains the contents of variable "value" and "var" must have more than 113,469 characters

Check via if condition that variable named "var" contains the contents of variable "value" and "var" must have more than 113,469 characters above described conditions are met, the script must then print last 20 characters of the variable "var".  I am stuck at this question from a HTB Academy tutorial and tried out by different ways but still no luck with solution. Any help?  #!/bin/bash var="8dm7KsjU28B7v621Jls" value="ERmFRMVZ0U2paTlJYTkxDZz09Cg" for i in {1..40} do         var=$(echo $var | base64)                  #<---- Need to frame an if condition here: done


Fallacious Induction Proof that All Integers are Equal

We're currently learning about induction in my real analysis course. I came up with the following proof that is obviously false but cannot quite figure out why it fails. Here it is...  "Any set $S$ of $n \in \mathbb{N}$ integers are equal."  Proof: For $n = 1$, we only have a single integer in $S$, and thus it is equal to itself. Assume our statement is true for $n$ integers. Now consider any set of $n + 1$ integers. Without loss of generality they are integers $\left\{ 1, 2, \dots, n, n + 1\right\}$. Consider the sets $\left\{ 1, 2, \dots, n \right\}$ and $\left\{ 2, 3, \dots, n + 1\right\}$. Each of these two sets have only $n$ integers, so they are all equal. But this means $1 = 2 = 3 = \cdots = n = n + 1$, so all integers are equal.


When saying goodbye and thank you after hosting something, it is common to say something like "I have been your host" or "I, person X, have been your host" BUT, would it also be correct to simply say "I have been person X" Even though one does in fact continue to be person X after the event has ended?  I have seen examples of this  (Stephen Fry to be more precise), but is it a correct use of grammar?  The wording was: "You have been watching QI, I have been Stephen Fry. Thank you and good night!"


Animated TV show of unique cars that fought robots

I remember watching an animated show during my childhood(I was born 2004 so must've been around 2008-2014). The main premise of the show was about a group of friends that each owned a unique cool car. And the show was sci-fi. With their cars they would fight against robots in different contests which used their cars. I remember there was a 'restaurant' type place in the middle of a desert and one of the characters from the main group of friends was always there eating pizza. I also remember one of the peoples' car had a front half that could flip/rotate (I think his car was red) around him while he stayed upright.


I was studying about alternating current, and I stumbled upon RMS. I clearly cannot understand what it means, the only thing my textbook says is: RMS current $I$ is related to the peak current $i_m$ by $ I=0.707 i_m$  Why are we multiplying AC current by $0.707$?  Are there any sort of things I've missed learning?


I already read this question:  and this one   and I know this isn't standardized but still I believe it's a legit question.  Why is the size of this struct 16 on a x64 system?  struct foo { char* b; char a;};   The effective size would be 8 + 1 = 9, but I know there's padding involved. Anyway I thought a would only be padded to reach the size of an int, i.e. with other 3 bytes giving a total of 12 bytes.  Is there any reason why the specific compiler (gcc) thought it should have 16 bytes as a size?  Wild guess: is it possible that the biggest type (e.g. double or in this case x64 pointer) will dictate the padding to use?


I have calculated NDVI and SAVI for landsat-8 image. But I am getting higher value of NDVI than SAVI Can you tell me reason for this NDVI=0.46 SAVI=0.34 Specific band pixel values are toa b4- 0.130 toa b5- 0.365 L= 0.5 taken


$f$ continuous, $f^N$ analytic on a domain D implies $f$ analytic on D

Working on a problem in Gamelin's book.  "Show that if $f(z)$ is a continuous function on a domain $D$ such that $f(z)^N$ is analytic on $D$ for some integer $N$, then $f(z)$ is analytic on $D$."  He starts a hint with the statement "Show that the zeros of $f(z)$ are isolated." This makes me think. I know that if $f$ is analytic and nonconstant, then the zeros are isolated. Is there some sort of converse to this theorem? I.e., for example, if continuous and zeros are isolated then analytic?  His next hint is: "At a zero of $f(z)$, write $f(z)^N=(z-z_0)^mh(z)$ where $h(z_0)\ne 0$ and show that $N$ divides $m$." However, the book has covered nothing on winding numbers thus far. Also, how will the fact that $N$ divides $m$ help to show that $f(z)$ is analytic?


Is there a way to tell make to apply a rule to every file that matches a pattern?

I am working on a project that has a directory structure that looks a bit like this:  inputs/    a.txt    b.txt    c.txt  outputs/    a.out    b.out    c.out  makefile   The files in the outputs folder are generated from the files in the inputs folder and I want to automatically update them whenever one of the input files changes.  I tried to do this by creating a makefile with a pattern rule. (To keep this question simple, I'm just copying the input file instead of transforming it)  outputs/%.txt: inputs/%.out     cp $< $@   However, this makefile didn't quite do what I want. If I run make outputs/a.txt it will apply the rule that I wrote and regenerate the output file if it is outdated but if I just run make then nothing happens:  make: *** No targets.  Stop.   Is there a way to tell make that by default I want to generate an output file for every file in the inputs folder?  edit: made the output files have a different file suffix than the input files.


/dev/disk1 (synthesized):    #:                       TYPE NAME                    SIZE       IDENTIFIER    0:      APFS Container Scheme -                      +250.8 GB   disk1                                  Physical Store disk0s2    1:                APFS Volume Macintosh HD - Data     149.4 GB   disk1s1    2:                APFS Volume Preboot                 79.1 MB    disk1s2    3:                APFS Volume Recovery                527.0 MB   disk1s3      $ mkdir /tmp/recv      $ sudo mount -t apfs /dev/disk1s3 /tmp/recv/      $ ll BaseSystem.dmg     -rw-r--r--@ 1 root  wheel  496664671 Jun 18 15:09 BaseSystem.dmg      $ hdiutil mount BaseSystem.dmg     Checksumming Protective Master Boot Record (MBR : 0)… Protective Master Boot Record (MBR :: verified CRC32 $D80226F2 Checksumming GPT Header (Primary GPT Header : 1)…  GPT Header (Primary GPT Header : 1): verified CRC32 $3488C747 Checksumming GPT Partition Data (Primary GPT Table : 2)… GPT Partition Data (Primary GPT Tabl: verified CRC32 $FB2C82B9 Checksumming  (Apple_Free : 3)…                     (Apple_Free : 3): verified CRC32 $00000000 Checksumming disk image (Apple_HFS : 4)… .............................................................................................................................................           disk image (Apple_HFS : 4): verified CRC32 $E3D25767 Checksumming  (Apple_Free : 5)… ......................................................................................................................................................                     (Apple_Free : 5): verified CRC32 $00000000 Checksumming GPT Partition Data (Backup GPT Table : 6)… GPT Partition Data (Backup GPT Table: verified CRC32 $FB2C82B9 Checksumming GPT Header (Backup GPT Header : 7)…   GPT Header (Backup GPT Header : 7): verified CRC32 $B193AD93 verified CRC32 $C286C93C /dev/disk2              GUID_partition_scheme            /dev/disk2s1            Apple_HFS                       /Volumes/macOS Base System      $ cd /Volumes/macOS\ Base\ System/      $ cd Install\ macOS\ Catalina\ Beta.app/Contents/Resources/      $ sudo ./createinstallmedia --volume /Volumes/test/    /Volumes/macOS Base System/Install macOS Catalina Beta.app does not appear to be a valid OS installer application.   Do I have to download full pack again, even when I just want BaseSystem to boot up?


Why did it seem like only Voldemort and Snape could fly?

In the seven books, flying is an ability we only see from Voldemort and Snape. Why is that so? and How do they do that?  Moreover, why couldn't anyone in the Order of Phoenix fly?


How to calculate the focal length for old lenses (m42 or m39) mounted on Sony Nex?

As far as I know, it is necessary to multiply the focal length by the crop factor. My Sony Nex 5 has a crop factor = 1.5 For lens Helios 77M-4 1.8/50 focal length will 50 * 1.5 = 75  Is this true for Sony Nex?  And also for M39 lenses?


For Riemann sums involving square roots, why do we let $c_{i} = \frac{i^{2}}{ n^{2}}$?

My Calculus book asks us to evaluate the limit:  $$ \lim_{n \to \infty} \sum_{i=1}^{n} f(c_{i}) \Delta x_{i}  $$  of f(x) = $\sqrt{x}$ within [0,3]  Why is the right endpoint given as $3\frac{i^2}{n^2}$?  Similarly, $c_{i}$ becomes $\frac{i^3}{n^3}$ for $\sqrt[3]{x}$ within [0,1].  I apologize if my LaTeX is bad, my first attempt.  It doesn't explain it very well in the book.  Thanks!


Do we feel the full force of the earths gravity even though the earth is spinning

As far as I know, since the earth is spinning, centrifugal force should be throwing you off the earth. However, gravity counteracts that by being a stronger force. So if you stood an object with the exact mass and size of earth, but it wasn't spinning, would you perceive gravity to be stronger?  If this is true, wouldn't an object outside of the atmosphere not in orbit of the earth have greater acceleration than an object in orbit?


Add browser tab/desktop notification when user gets notification

I would like to suggest a Stack Exchange (and all its sub websites) modification. When the user gets a notification, it should show it on the tab of the browser. (.) And even better, would be to get a desktop notification.  In my opinion, it is kind of annoying to just stay at the same page while you could be doing other things.


Error Occured in the deployment step 'Add Solution': error cannot find this file specified in the manifest file

I created one more SharePoint Project in my solution which has a module with pages. But this solution keeps on deploying the solution in a folder at ..../14/TEMPLATE/FEATURES/ProjectName_FeatureName, I want it to be just /ProjectName so I updated the package file accordingly.    Now I am getting this error saying it is not getting feature manifest file but I see Feature.xml file the packaged wsp file.  What am I missing here, please help?  Thanks.


Why doesn't CD .. throw an error but other incorrect commands do? How to have it give me an error?

From my understanding, bash is case sensitive. So cd .. would work and CD .. wouldn't.  However, inputting CD .. doesn't throw any errors (it doesn't do anything). Why is that? If I type an incorrect command such as ls-a instead of ls -a the terminal throws an error immediately, but for CD .. nothing is displayed. In fact, I thought it actually worked until I took a closer look at my directory.  Also, if the error is being suppressed by default, is there a way to have it throw an error?   My biggest concern is that no errors are being thrown, and I am under the false impression my commands are actually working making it harder to debug.


Show that if $n > 2$, then $(n!)^2 > n^n$.  I cannot find any way out to these.Please help.  I tried break $n!$ and then argue but failed.


SQL Server Restore a SINGLE table from a backup

on SQL Server 2005, we do a weekly full backup with nightly incremental backups.   I want to know if it is possible to restore a single table from a backup, either to the source database or a different one.   I can not find any clear answer online.   Thanks in advance.


How can I disable the notification sounds while playing music?

I don't like the notification sounds overlaying my music playback, but I can't find any setting to disable notification sounds while playing music.  I also don't like the way the sound overlay works. The IPhone handles this much better.  Is there any way to set this up to behave more like the Iphone or turn off the notifications while playing music at all?


Python 2.7.9 (default, Jun 29 2016, 13:08:31) IPython 5.6.0 -- An enhanced Interactive Python. In [1]: import numpy as np  In [2]: np.__version__ Out[2]: '1.14.3'  In [3]: np.arange(1.1, 1.12, 0.01) Out[3]: array([1.1 , 1.11, 1.12])  In [4]: np.arange(1.1, 1.13, 0.01) Out[4]: array([1.1 , 1.11, 1.12])   In both cases, the array gets to 1.12... how would you explain that?


Writing and saving user input to text file on the desktop

I am new to learning C#, and i'm attempting to create a simple console application that asks the user a set of questions, and then saves the answers into a .txt file on the desktop. However, my below code doesn't seem to work.  static void Main(string[] args)         {             Console.WriteLine("Enter your first name.");             string firstName = Console.ReadLine();             Console.WriteLine("Enter your last name.");             string lastName = Console.ReadLine();             Console.WriteLine("Enter your job title.");             string jobTitle = Console.ReadLine();             Console.WriteLine("What came first, the chicken or the egg?");             string chickenEgg = Console.ReadLine();              string path = @"C:\Users\njones\Desktop\NiallJones.txt";              File.WriteAllText(path, firstName, lastName, jobTitle, chickenEgg);              Console.WriteLine("Your information has been recorded. A copy can be found on your desktop.");         }   I believe the problem lies around the File.WriteAllText part. Please could someone help point me in the right direction as to why this doesn't work, and what I can do in order to improve on this?  Thanks!


I use the term database loosely here -- it can be an actual database, or a spreadsheet (in any format including CSV) or can be package-dependent.   Is there a way to create mail-merged documents similar to what can be done in word processing packages? I found the  which sort of works but it puts all the mail-merged data into one document.   Is there a package or way to generate new, individual documents for each part of the database? In other words, if I have a firstName value in whatever storage system, can I get LaTeX to generate a file called <firstName>.dvi for each of the names in the database? Or do I need to resort to a scripting language driver to pull that off?  EDIT  So to further explain what I am trying to do (and will now set it up based on the answer to  ) :  I'm trying to create a "welcome to the company" sort of document that has a cover page, table of contents, welcome letter, then various sections of information. I've never tried this in anything other than a word processor where it's easy to set "master pages" or "template pages" for individual pages in the document. So I could use a letterhead template page for the welcome letter part and a standard article-type template for the rest and still have the letter numbered/referenced in the ToC.   If I use the approach on the answer there, how can I tell \pdfpages which page to include? Ultimately I would like to have many files like Bob.pdf, Sue.pdf, John.pdf etc. where each file is the same document with a custom letter embedded within.


Is it legal to copy Stack Overflow questions and answers?

I just found http://programmingfaq.w3ec.com/faq/4761/whats-the-hi-lo-algorithm which has an exact copy of this Stack Overflow question, , with all its answers and no difference in a single character. There is no reference to Stack Overflow.  Is this legal, or at least tolerated? Is this impertinent theft of information? I just can't see any sense in copying whole pages, particularly when not referencing the source.


Minimax problem for optimization $\inf \sup \frac{x f(x)}{\int_0^1 f(t) dt}$

Consider $\bar{C} = C_{d}^0[0,1] $ is the space of continuous decreasing functions, s.a. $f(1) = 0$. We want to determine $\displaystyle \inf_{f \in \bar{C}} \sup_{x\in [0,1]} \frac{x f(x)}{\int_0^1 f(t) dt}$.   I thought about $\displaystyle xf(x) = xf(x) + 1\cdot f(1) = \int^x_1 f(t)dt - \int_1^x tf'(t)dt$. Actually I even don't know whether derivate exists or not.  Now we should consider $\dfrac{\int^1_x \left[tf'(t) + f(t)\right] dt}{\int_0^1 f(t)}$.  Then I thought about Poincare inequality, but fails there. Any hints ?


How do we know that the idea of entropy is true?

How do we know that the idea of Entropy is True?   What I mean is,  Do we really know "Scientifically" that Entropy of Universe is Bound to increase?  Or We know it "Statistically" that Entropy of Universe "Increases"?   Do we know it "Inductively", from the past experiences and our understanding of the universe till now, that Entropy of the universe tends to increase?   Or   There is some "Deductive" proof that the Entropy of the Universe is bound to "Increase"?  In summary, the question is, the idea of Entropy is assumed to be true, Scientifically or Statistically?  I would be very happy if somebody can also provide me some resources which throw light on the history of the development of idea of Entropy.   PS: I do not say that "Statistics" is non-science, just considering the difference of ways of working in two disciplines - "Science" and "Statistics".


What place do prime numbers have in cryptography?

My understanding of hashing and encryption is rather limited. I certainly do not understand the mathematical formulas at play in these algorithms. With that said, what part do prime numbers play in cryptography?  When I was in college, one of my professors told me that the fact that there is no formula to predict a prime number (other than just trying them) is what makes many encryption schemes (like PGP) so secure, since it's not possible to guess the number used for the public/private key in any reasonable amount of time. Is that correct?


First Post suggests an answer from a "new user" who is 3+ years old with 1800 rep

NB: I'm not sure if this is actually a bug, or if I just don't know enough about what constitutes a new user. It just seems off to me.  The first post in question:   :   In the context of reviews, is a new user just someone who has never posted an answer no matter their age or rep?  Also: How is it possible for a user to have -1 other answers? Could this be related?


RunDLL Error... Module could not be found

I keep getting this error on my computer and I can't find any way to get rid of it.  I've looked all over the internet. Can anyone help?  Operating System: Windows 7 When it occurs: Randomly, 3 of them just pop-up.


Object passing through a small hole how to make it blender

How do I make something like the picture above.


I have data frame which has a column full of date-time of format yyyy-mm-ddTHH:MM:SSS.000Z For example, 2019-06-17T19:17:45.000Z. I want to convert this to long type (unix epoch time) in python. How to do that? Thanks! (How do I parse an ISO 8601-formatted date? This question is abut parsing the string. I want to do a conversion and hence it is different)


There  exists  a connected topological  space  such  that the  permutations  group $S_3$ acting without  fixed  points?  I  try  to  consider  matrice spaces.


f, g continuous for all rationals follow by continuous on all reals?

Possible Duplicate:          Let $f, g:\Bbb{R}\to\Bbb{R}$ to be continuous functions such that $f(x)=g(x)\text{ for all rational numbers}\,x\in\Bbb{Q}$. Does it follow that $f(x)=g(x)$ for all real numbers $x$?  Here is what I think:  f continuous when $\lim\limits_{x\to x_0}f(x)=f(x_0)$ and $\lim\limits_{x\to x_0}g(x)=g(x_0)$  So it does not neccesarily mean that $f(x)=g(x)$ when x is irrational. So I can pick a function f so that   $f(x) = \begin{cases} g(x)  & \text{if $x\in\Bbb{Q}$} \\ x & \text{if $x\in\Bbb{R}\setminus \Bbb{Q}$}  \\ \end{cases}   $


Is it possible take take part in a research project if I'm not a part of a university?

I graduated with a Masters of Engineering, concentrating in digital signal processing, in particular medical and audio, almost two years ago. I've always been interested in research, but due to personal circumstances I could never commit a lot of time to working on a research project with a professor, and obviously didn't get a chance to publish anything. Now that I'm more settled and have much more time on my hands, I started getting involved in some open source projects and reading some technical literature (engineering, mathematics) that I couldn't get to before. However, I'd still like to find someone to to collaborate with on a research project who is already established in the field and publishes papers. Part of the reason I want to do that is to be able to eventually apply for a Ph.D. program in a good school, and having publications would be a great thing on my resume.  What I'm trying to find out is how I can work on a research project similar to those graduate students work on as a part of their studies if I'm not a student anymore? Should I contact my old professors from the university? Is it possible to find some "open research" team that accepts collaborators from outside? Do I have to do it on my own (quite frankly I'm not sure I can give myself a good enough quick-start)? In short, I'm willing to volunteer my time in exchange for a possibility of publication in the future. Can I do it, and if yes then how?


How to migrate from test environment to production environment?

The migration is from the local environment to the production environment. The production environment has run some time and created a lot of articles.   In order to add new things to my site, I added a custom theme and installed CCK, Views and other modules in my local test environment. Now that the local test environment is finished, how do I migrate it to the production environment, without destroying the content of its database?


What's the most concise way to check for an integer or float in JavaScript?

I want a concise expression to tell me if a given value is an integer or float. When provided the input value NaN or Infinity, I want the output value to be false, so this rules out simply checking whether typeof(val) == 'number'  Desired input / output:   1 => true -42 => true 3.14 => true NaN => false Infinity => false null => false undefined => false   isFinite() is almost perfect, but there's one gotcha: isFinite(null) returns true, when I actually want it to return false.  Short of always checking if ((val != nul) && isFinite(val)), is there another more concise technique?


Fatal error LNK1120 when separating code into .h and .cpp files

I'm trying to code Matrices in C++, and weirdly enough, although everything was compiling fine; the moment i added a new constructor that takes a 2D array by ref, my build started always failing with this error: 1>Main.obj : error LNK2019: unresolved external symbol "public: __thiscall Matrix::Matrix<4,2>(double (&)[4][2])" (??$?0$03$01@Matrix@@QAE@AAY131N@Z) referenced in function _main 1>C:\Redacted\For\Privacy\Reasons\Matrix.exe : fatal error LNK1120: 1 unresolved externals  I tried compiling the code in a single file and it works fine :  The only code i have right now is in 3 different files, Main.cpp, Matrix.cpp and Matrix.h which are as follows: // Main.cpp #include "Matrix.h"  int main(char* args) {     double data[4][2] = {         {1,2},         {3,4},         {5,6},         {7,8}     };     Matrix* matrix = new Matrix(data);     std::cout << matrix->toString() << std::endl;     delete matrix; }  // Matrix.cpp #include "Matrix.h"  template<int r, int c> Matrix::Matrix(double (&matrix)[r][c]) : ROW_DIM(r), COL_DIM(c), ELEMENTS_COUNT(r * c) {     data = new double[ROW_DIM * COL_DIM];     for (int x = 0; x < ROW_DIM; x++)         for (int y = 0; y < COL_DIM; y++)             data[x * COL_DIM + y] = matrix[x][y]; }  std::string Matrix::toString() {     std::string result = "";     for (int i = 0; i < ELEMENTS_COUNT; i++)         result.append(std::to_string(*(data + i)))             .append((i+1) % COL_DIM == 0 ? "\n" : " ");     return result; }  #ifndef MATRIX_H #define MATRIX_H  #include <iostream> #include <string>  class Matrix { public:     template<int r, int c>     Matrix(double (&data)[r][c]);      std::string toString(); private:     const int ROW_DIM, COL_DIM, ELEMENTS_COUNT;     double* data; };  #endif  I've been banging my head at this for 4h and I googled fatal error LNK1120 but all were unrelated to my specific case. Any ideas or help is greatly appreciated


How to handle UNABLE_LOCK_ROW errors when this is caused by a batch APEX job

we are facing a serious issue. We have a batch APEX job running daily which makes updates on records fulfilling certain conditions. There is another job running parallel to this, in some cases updating or accessing to the same records than the batch job and hence, causing the error:     Update failed. First exception on row 400 with id XXX; first error:    UNABLE_TO_LOCK_ROW, unable to obtain exclusive access to this record or 200    records:   So, I had then read that in order to fix this kind of error you should use FOR_UPDATE in your select statement (records that have to be updated). The problem is, that you can not use FOR UPDATE for batch jobs. We tested this and effectively, we get the error:     System.QueryException: Locking is implied for each batch execution and   therefore FOR UPDATE should not be specified      It will however lock the records within each execution of execute. See   QueryLocator.getQuery()usage:      You cannot use the FOR UPDATE keywords with a getQueryLocator query to   lock  a set of records. The start method automatically locks the set   of records in  the batch.   Could you find a solution to this?. We would like to handle this in the code itself, because we don't have the permission to schedule the batch job for another time as the another job.


Is there any way to keep the alignment of the previous align environment?

Basically, I want to break up an align environment with a line or two of comments and then continue with a new align, but I want to keep the alignment (aka the positioning of the & character) in the same horizontal space as the previous align. Is there any way to do that? Alternatively, is there any way to break out of the align environment for a comment in text mode and then break back in?


Acer Aspire Z5101 Realtek Network Card Not connecting after resuming from suspend mode

I have a problem with my realtek network card not connecting after resuming from suspend mode.   Ubuntu 13.10 Realtek network card using the r8712u driver on an Acer Aspire all in one z5101, any help appreciated.  This is the fix for this Machine Here is a technique that sometimes works:  gksudo gedit /etc/pm/config.d/config Add a single line:  SUSPEND_MODULES="r8712u" Proofread, save and close gedit. Reboot, suspend and let us have your report.  for me the driver is r8712u. You find the driver by sudo lshw -C network  the line driver = 'the driver', the driver is what you use in that line  SUSPEND_MODULES="the driver"


Moving layers in QGIS Table of Contents via PyQGIS?

I have loaded two layers in canvas and would like to move the layers using the following code in TOC, but it is not moving the layers to the position based on the index given.   from PyQt4.QtCore import * from PyQt4.QtGui import *  from qgis.core import * from qgis.gui import * import qgis.utils  canvas = qgis.utils.iface.mapCanvas() layers = canvas.layers()  for i in layers:   if i.name() == "Layer2":     alayer = i   elif i.name() == "Layer1":     blayer = i  qgis.utils.iface.legendInterface().moveLayer(alayer, 0) qgis.utils.iface.legendInterface().moveLayer(blayer, 1) canvas.refresh()   How can I do that?


Off-center propulsion of space ship : Does it travel in a straight line or rotate?

I'm designing a space ship for a comic I'm writing. I was just finishing up the first sketch when I thought whether such a design would actually be possible. Hence my question:  A spaceship is located in deep space. A propulsion system (let's make it a rocket) is attached to the side, and thus not in one line with the ship's center. Would this spaceship travel in a straight line, or rotate?


Proper submodules of Noetherian modules are intersections of indecomposable modules

If $M$ is Noetherian, any submodule $N \neq M$ can be written as a finite intersection of intersection-indecomposable ones.   I just don't know how to begin with the proof of this proposition.   Very kind of you for reading or answering.


The application manager doesn't find the update

I can't find trusty tar. This update seems somewhat half-baked.


If entropy decreases for cold systems, isn't the heat death of the universe a state of low entropy?

Entropy is a consequence of heat. The heat death of the universe results in an approach to absolute zero temperature. Does this mean the end of the universe is low entropy?


I'm having 2 problems with  references  in my thesis.  First when a last name starts with letter W, it always comes at the top. Before A. But if I change the authors lastname from Wolf to Solf it works. W isn't a special character in this context... or is it?  Second problem is when I have two names like 'Ivan and Me', in the references list I get 'Ivan, A and B Me' not 'Ivan, A and Me, B'. Does anyone have any suggestions? Thanks in advance.  My mwe is:  \documentclass[12pt,a4paper,swedish]{report} \usepackage[latin1]{inputenc} \usepackage[swedish]{babel} \usepackage[style=authoryear,natbib=true,backend=biber,sorting=nyt]{biblatex}  \addbibresource{incl/tgene.bib}  \begin{document} Foo \parencite{ivan} bar \parencite{wolf}. \printbibliography[heading=bibintoc] \end{document}   And my .bib looks like:   @book{ivan,     author = {Ivan, A and Me, B},     title = {Title A},   }   @book{wolf,   author={Wolf, Ceasar},   title={Title B},   }


Pin or hold? What's the proper way to tell apt-get dist-upgrade that I want to keep a particular package over another?

At the moment, when I do apt-get dist-upgrade on my Raspbian it prompts me to throw out upstart again and install sysvinit. I don't get the same with apt-get upgrade.  However, I find the behavior of dist-upgrade more desirable in general, just not in this specific case.  I use apt-get most of the time and dpkg every once in a while. I don't use aptitude or any of the other front-ends.  What would be the proper method to tell apt-get that I want to keep any version of upstart over any version of sysvinit? Will this work, or will it screw up something else in the process?:  Package: sysvinit Pin: version * Pin-Priority: -1   Is pinning (apt_preferences(5)) the way to go - and if so how - or do I have to tell one of the many package management tools to "hold" the package some other way? This is somewhat related to the as of yet unanswered (at least not in a meaningful way) question .    The following will at least shut up apt-get dist-upgrade, but will it perhaps mess up something in future? There are numerous explicit warnings in apt_preferences(5) about how much things can be messed up by pinning.   Create a file /etc/apt/preferences.d/prefer-upstart-over-sysvinit.pref. Fill in the contents produced below this list. Run apt-get update && apt-get dist-upgrade.   File contents:  Package: sysvinit Pin: version * Pin-Priority: -1  Package: upstart Pin: version * Pin-Priority: 1001   According to the man page this should yield the desired result.     P >= 1000        causes a version to be installed even if this constitutes a        downgrade of the package     990 <= P < 1000        causes a version to be installed even if it does not come        from the target release, unless the installed version is        more recent     500 <= P < 990        causes a version to be installed unless there is a version        available belonging to the target release or the installed        version is more recent     100 <= P < 500        causes a version to be installed unless there is a version        available belonging to some other distribution or the        installed version is more recent     0 < P < 100        causes a version to be installed only if there is no        installed version of the package     P < 0        prevents the version from being installed   The confusing part is whether this is the proper method and why the entry only for sysvinit (with priority -1) didn't work out.    # apt-cache policy sysvinit upstart sysvinit:   Installed: (none)   Candidate: 2.88dsf-41+deb7u1   Version table:      2.88dsf-41+deb7u1 0         500 http://mirrordirector.raspbian.org/raspbian/ wheezy/main armhf Packages upstart:   Installed: 1.6.1-1   Candidate: 1.6.1-1   Version table:  *** 1.6.1-1 0         500 http://mirrordirector.raspbian.org/raspbian/ wheezy/main armhf Packages         100 /var/lib/dpkg/status  # apt-get install sysvinit Reading package lists... Done Building dependency tree Reading state information... Done The following package was automatically installed and is no longer required:   libjson0 Use 'apt-get autoremove' to remove it. The following packages will be REMOVED:   upstart The following NEW packages will be installed:   sysvinit 0 upgraded, 1 newly installed, 1 to remove and 0 not upgraded. Need to get 129 kB of archives. After this operation, 940 kB disk space will be freed. Do you want to continue [Y/n]?


If space of bounded operators L(V,W) is Banach, V nonzero, then W is Banach (note direction of implication)

Let $V,W$ be normed vector spaces, and $L(V,W)$ be the space of bounded linear operators. Usually I would only see the statement "If $W$ is Banach, then $L(V,W)$ is Banach.". But  writes that there is a converse: "If $L(V,W)$ is Banach, and if $V$ is non-trivial, then $W$ is Banach". This is pretty interesting since I never seen a converse before. I was wondering if anyone has a nice proof.  I tried reversing the proof for the usual direction, but the inequalities can't be reversed. I also tried to start with a Cauchy sequence in $W$, and construct linear operators (using Hahn-Banach to control the operator norms), but alas I cannot say much about the distance between these operators (much less say that it is Cauchy)


the least possible value for :$ \lfloor \frac{a+b}{c}\rfloor +\lfloor \frac{b+c}{a} \rfloor+\lfloor \frac{c+a}{b} \rfloor $

If we know that for every $a,b,c>0$ ,how we can find  the least possible value for :  $$ \lfloor \frac{a+b}{c}\rfloor +\lfloor \frac{b+c}{a} \rfloor+\lfloor \frac{c+a}{b} \rfloor $$


(English is not my native language.) Is the sentence 'only then did she realised the sun was setting.' correct? Or should I write 'only then did she realise the sun was setting.'? Is 'did' even correct at all in this sentence?


How to properly escape whitespaces in filenames for ffprobe with bash

I am trying to extract parameters from video files with ffprobe and process depding on these results. However i am not able to pass the files properly to ffprobe if they contain whitespaces. echo $1  inputfile=$(printf '%q' "$1") #inputfile=${1@Q}  echo $inputfile  ffprobeout= ffprobe -v error -select_streams v:0 -show_entries stream=width,height,bit_rate -of csv=s=x:p=0 $inputfile  when i now call a smaple file  with files2reenc.sh "test file with spaces.mp4" it results test file with spaces.mp4 test\ file\ with\ spaces.mp4  Argument 'file' provided as input filename, but 'test' was already specified.  So ffprobe sees every part of the name as seperate file and does not recognize it as one parameter. I'm not sure how to pass/escape my input so it would work as expected. I'm not sure if the problem is already when invoking my bash script or with the way i try to handle input paramter. I also tried using echo $inputfile | xargs -0 ffprobe ... with no success.


Is it wise to purchase a new car when faced with big repairs?

So you are frugal, and understand that driving to work is not an exercise in style. Therefore you hope for your car to get to 250,000 miles. However, parts start to break down at 150,000 miles and you are hit with a couple of repairs within the last two years of $2,000 and $5,000 respectively for a car you bought for $25,000 in 2010.  Now there is a new repair bill coming in, and if you make the calculus of investing the difference between $25,000 you would be spending in a new car minus the cost of the expected repairs in a 5-year period you expect to keep the current car if you repair it (for example $8,000, and assuming it is paid upfront today) at a 6 percent yield (say, stock market): the present value of the investment will be -$17,000 and the future value of that investment will be ~$23,000 in 5 years, for a gain of $6,000.   If this way of thinking is sound, there is no question that keeping the car, and repairing is the right choice. Further, if you buy a new car now, as opposed to in 5 years, that new car will start siphoning savings in repairs 5 years earlier also.  The counterargument is that I should already be factoring in the $7,000 spent in recent repairs, and although this is money already spent, I could make the same argument every day, even if I was hit with a similar repair every day in the next few months. So there has to be a different way to calculate the difference.  I could just calculate the future value of $25,000 invested in stocks at an expected return of 6 percent (conservative or not - I don't know - but there is no bank interest anymore, so just humor me) for 5 years as $33,000, and say that the break-even figure is $8,000, but of course, this is future money - not present.     So what is the right way to calculate whether to dump the car or repair it?


Is it possible to see my favorite posts on Android app?

I haven't found the place to see my "favorite" posts from the Stack Exchange android app. Can anyone help me confirm is there such a feature?


As you might be able to see, i am a complete newbie to java. but i'm trying to make a rock-paper-scissor game. But when i pass the input to the method, it doesn't return true, while the input is "rock". i checked.  What should happen, is that as the input is rock, true gets returned. now it just returns false.  thanks in advance!  import java.util.Scanner;  public class Game{      static Boolean validInput(String input){         if("rock" == input){             return true;         }         else{             return false;         }     }      public static void main(String[] args){         Scanner input = new Scanner(System.in);          String choice;         choice = input.nextLine();          if(validInput(choice)){             System.out.println(choice + " is valid input");         }else{             System.out.println(choice + " is not valid...");         }      }  }


Transforming from SRID 900913 to 4326 with PostGis

I have two Postgres tables with different SRIDs: 4326 and 900913. I want to convert the latter to 4326. I first changed the SRID using:   Select UpdateGeometrySRID('table', 'geomcolumn', 4326).     I then transformed the reference data using:   update table set geomcolumn = ST_Transform (geomcolumn, 4326).    This seemed to work. But when I changed the SRS setting of the relevant layer in TileMill to WGS84, I get this error:      Detected out of bounds geographic extent.     Presumably the transformation didn't work but it's not clear why.


Prove $ \forall c \in \mathbb{R}^{+}, \forall B \in \mathbb{N}, \exists n \in \mathbb{N}, (n \geq B) \wedge (\sqrt{2n} > c \ln(n+2)) $

So far I've proved the following:   $2n \geq \ln(2n) > \ln(n+2)$   for $n \geq 3 $  The proof must be without the use of calculus but I have no idea on how to proceed.


Finite groups and Normal subgroups - $G$ is a finite group such that $|G|=n$. Let $p$ be the smallest prime such that $p|n$.

$G$ is a finite group such that $|G|=n$. Let $p$ be the smallest prime such that $p|n$. If $H\triangleleft G$ such that $|H|=p$, then prove that $H\subset Z(G)$.  My Work:  Since $|H|$ is a prime $H\cong \mathbb{Z}/(p)$. Hence $H$ is cyclic and abelian. I was stuck afterwards. Can anyone please give me a hint?


Prove that $\operatorname{dist}(x,M)=\frac {|f(x)|}{\| f \|}$

Let $f\in E'$ (dual space of $E$), $f\neq 0$, $M=\{f=0\}$. Prove that $\operatorname{dist}(x,M)=\dfrac {|f(x)|}{\|f\|}$.    My idea: $\operatorname{dist}(x,M)=\inf\limits_{v\in M}\|x-v\|$, $|f(x-v)|=|f(x)|\leq \|f\|\cdot\|x-v\|\implies \|x-v\|\geq\dfrac {|f(x)|}{\|f\|}$. But I can't prove the opposite inequality. Can anyone help me? Thank you.


How do you prove that $\frac{1}{n+1}\le\int_{n}^{n+1}\frac{1}{x}dx\le\frac{1}{n}$?

I tried to simplify things to see what I could do:  $\frac{1}{n+1}\le\int_{n}^{n+1}\frac{1}{x}dx\le\frac{1}{n}$ $\implies\frac{1}{n+1}\le ln(n+1)-ln(n)\le\frac{1}{n}$  However, after this, I'm in a bit of a rut.  I then tried to say that  $\frac{1}{n+1}\le ln(n+1)-ln(n)$    and    $ln(n+1)-ln(n)\le\frac{1}{n}$  But that didn't really help either. I'm assuming I'm going the wrong direction; how should I go about this problem? Thanks!  edit: I should add that this is to be proved only for $n \ge 1$.


How to divide a face into a square grid?

I need to do this for displacement mapping, subdivision gives a bad result and makes triangles distinguishable.    Related to:   But I get the error "No other selected object found to use for projection".


I have some data that has been mapped in ArcGIS Desktop.  I would like to develop something like if I add/change some parameters a new map can be derived so that it can be used for predicting as well.  All this need be done online.  I need this because mine is a health based project and I want it to be made available for public use.   At least I would like to know how it can be published online.


There is a sign outside a shop near us which says 'Parking for loading vehicles only from 7 to 12pm'. Does that mean between 7pm and midnight, or between 7am and noon?   For me 12.00 is neither post-meridian nor ante-meridian, it is either noon or midnight.  Equally when someone says from midnight on the 3rd, do they mean midnight which precedes the 3rd or midnight which ends the 3rd. The precise moment of midnight belongs neither to one day nor the other.  These are crucially important matters as regards flight timetables, and insurance policies. If the policy expires at midnight on the 15th, when exactly is that? It is why many insurance companies now speak of 12.01am on the 22nd or 11.59pm on the 21st.   Should it be insisted that all references to 12.00 state either noon or midnight and how can we express midnight with clarity?


What is the best US bank account to use for extended world travel

I will be traveling the world over the next 1.5 years: mostly Europe, but some Middle East, South America, Africa and Asia.  I am looking to switch to a US based bank that can provide me with a debit card that has:   No international ATM fees/reimbursement Mobile check deposit No monthly fee Pin & chip? I am seeing references of this, unsure of what it is, but seems important?


Why does Guillotine have of 45 degreed blade rather than the one parallel to the ground?

What is the point of having 45 degreed blade in Guillotine? After all, the pressure-Force over Area-blade imposes to the neck is the same either way.


What does it mean when a private VM page is none of `rwx`?

UPDATE:  It's a padding: every such non-rwx area is preceded with a readable and/or writable area and together they constitute a 64Mb segment (for 64bit architecture).  A relevant question on SO:   I have discovered there are plenty of VM segments that don't have any of rwx flags, just p:  7f7e98033000-7f7e9c000000 ---p 00000000 00:00 0 Size:              65332 kB Rss:                   0 kB Pss:                   0 kB Shared_Clean:          0 kB Shared_Dirty:          0 kB Private_Clean:         0 kB Private_Dirty:         0 kB Referenced:            0 kB Anonymous:             0 kB AnonHugePages:         0 kB Swap:                  0 kB KernelPageSize:        4 kB MMUPageSize:           4 kB   Any reference on what it means?  Unlike what's described in , it's not a mapping from a shared library since it does not have a corresponding fd attached. It's a custom long running C++ daemon, but I found some other processes have similar usage patterns: eg erlang (which also has plenty of them). In contrast long running php-fpm and python processes have literally 0 of such segments. "What other mappings does it have?" --- everything else is kind of expected and usual: just normal r/w private segments and shared libraries.


Measurement current consumption of low power circuit

I have a circuit which has uC, Bluetooth module and some other ICs. Current consumption of it varies between 100uA and 20mA. I want to see current waveform using oscilloscope. I worked before high current measurement(above 1Ampere) using low-side sensing technique but not so small this. How to setup a small circuit to see current values of each phase(sleep, active, transmission) separately?       Note: The circuit is powered by battery


What is the difference between model prediction and model estimation?

Could you please explain for me what's the difference between model prediction and model estimation ?  What is the difference between a prediction interval and an estimation interval?


Let $a$ and $b$ be non-zero integers, and $c$ be an integer. Let $d = \gcd(a, b)$. Prove that if $a|c$ and $b|c$ then $ab|cd$.

Let $a$ and $b$ be non-zero integers, and $c$ be an integer. Let $d = hcf(a, b)$. Prove that if $a|c$ and $b|c$ then $ab|cd$.   We know that if $a|c$ and $b|c$ then $a\cdot b\cdot s=c$ (for some positive integer $s$). $(ab|c)$  Then doesn't $ab|dc$ since $ab|c$?  I feel like I'm misunderstanding my givens.    Can we say $\operatorname{lcm}(a,b)=c$,  $\operatorname{hcf}(a,b)=d$, and $\operatorname{lcd}(a,b) \operatorname{hcf}(a*b)=a*b$? Thus, $ab|dc$  as $dc = ab$.


How to get system information on the Desktop?

I am really interested to have something exactly like this on my Desktop :


How does langid field in biblatex differ from language field?

Could someone summarise the differences in the use of the langid field from language field in biblatex? Documentation to Gost package for bibtex says that langid is a synonym of language but has priority over it.


In Java, how do I dynamically determine the type of an array?

Object o = new Long[0] System.out.println( o.getClass().isArray() ) System.out.println( o.getClass().getName() ) Class ofArray = ???   Running the first 3 lines emits;  true [Ljava.lang.Long;   How do I get ??? to be type long?   I could parse the string and do a Class.forname(), but thats grotty.   What's the easy way?


How to open file with default application from command line?

In Nautilus, when you double click a file, it will open it with the default application associated with the file's extension. For instance, .html files will open in a web browser and .pdf will be opened with Document Viewer. Is there a way to reproduce the same behavior from within the command line (i.e. open path/filename)? I'm asking because I like to browse my file-system from the command line but sometimes don't remember which app. opens what.


How can I force Windows to display the seconds in the date modified/created column of Explorer?

This is primarily for Windows 7, but I work in multiple versions and would happy to be able to do it in as many of them as possible.  Currently, when I open Explorer and look at a list of files, the date modified column shows something like:  09/18/2013 10:03  I would like it to display:  09/18/2013 10:03:42  I've tried changing the region and language settings for the short time format from HH:mm to HH:mm:ss, but it says it ignores seconds for that.  Does that mean I'm just out of luck?  And again, I'd like to be able to do this in any other  previous versions of Windows too.  It's useful for me as a developer to be able to see the seconds in a lot of situations.  Minor clarification: I did find , which helped me to improve the file properties display, but I wanted to be able to view the full timestamp for all the files in a folder at once, instead of individually.


Denied Schengen Visa twice, what should I do?

I hold a Nigerian Passport and I was invited to Netherlands for a final set of interviews. I have completed 4 stages of interview already but I was refused with the first time with this reason "Justifications for the purpose and conditions of the intended stay was not provided".   After the first denial, the company called the embassy to ask why and they were advised to provide a cover letter to the embassy detailing the purpose of my visit. This was provided together with the company's registration document for my second application. So I submitted the following to justify my case:  -Invitation from the company to me  -Cover letter to the embassy  -The company's registration document  After a week, I also got an email from the visa office asking for an introduction from my current company which I sent back the same day. But I was surprised to be denied a second time for the same reason "Justifications for the purpose and conditions of the intended stay was not provided".  Please advise, what can I do next? Will an appeal affect my chances if I do?


Proving $ \frac{(a-b)^2}{8a}\leqslant\frac{a+b}{2} - \sqrt{ab} \leqslant\frac{(a-b)^2}{8b}$ when $ 0<b\le a$

I'd like to prove that $$\frac{(a-b)^2}{8a}\leqslant\frac{a+b}{2} - \sqrt{ab}\leqslant\frac{(a-b)^2}{8b}$$ when $ 0<b\leqslant a\,$. I have been brushing up on inequalities and I cannot figure this one out. I have searched this site, and found this  , but haven't seen how to apply it. I have tried to find a factor that I can multiply the entire inequality with that will allow me to simplify the middle term. So far no luck there. I have also tried assuming that $b > a$ and looked for a contradiction to either of the terms individually. Does anyone have any hints that can get me somewhere?


Maximum power transferred by the source to the load

I am in the middle of doing this question however have reached an issue. To find maximum power transfer I understand the equation is P=I^2RL However the answer I get is 2.4w the answer should be 50W  The Answer i get for R2 is 15 ohms. Any help would be appreciated


Sci-fi short story about an idealist and a realist

I'm looking to find a science fiction short story (I think it was by Asimov but I could be wrong). The story is about 2 characters, one who is an idealist who is opposed to military buildup, and a realist who sees it as necessary. Initially, the idealist is seen as naive and is ignored and the military is expanded. Eventually the military ends up collapsing in some way, and the realist is seen as a villain and the idealist is seen as a hero. However it turns out that the realist was also opposed to the military, but became its head so that he could lead it to collapse intentionally. This is never made public though, so he remains forever a villain in the eyes of history.


A woman experiencing the perfect life & family is abruptly awakened to find herself in a chamber

I've been racking my brain on this one! It aired in the 80s as what could have been an Outer Limits or Twilight Zone episode?   The woman had the perfect family when suddenly, the program shuts down and she finds herself in a VR pod or chamber. There are technicians discussing a malfunction in her pod and the camera zooms out to show hundreds of other chambers. I know; it sounds like 50 other movies or tv shows that do exactly the same thing.


Distribution for $Y = \sqrt{X_1^2 + X_2^2}$, when $X_1, X_2$ are dependent and normally distributed with different variance?

Is there a closed form distribution for the transformation given by $Y = \sqrt{X_1^2 + X_2^2}$, when $X_1, X_2$ are jointly normal but dependent random variables with different variance?  OBS: I know, when $X_1$ and $X_2$ are independent and have the same variance, the resultant distribution is $Y \sim {\rm Rice}(\sqrt{\mu_1^2 + \mu_2^2},\sigma)$, but in this case $X_1$ and $X_2$ are linear transformations of the same original distributions, so, they will be dependent and have different variance.


What is the difference between a multi-label and a multi-class classification?

What is the difference between multi-label classification and multiclass classfication.  Speficially, what is the difference between a label and a class? Please provide a clear example.  "Multiclass classification should not be confused with multi-label classification, where multiple labels are to be predicted for each instance." -wikipedia  ... was not very helpful.


table too wide for twocolumn-mode document

I have a table which comes outside the text column width into the margin of the paper. How do I make the text in the table align to left ?   \documentclass[a4paper,10pt]{article}  \usepackage[utf8]{inputenc}   \title{} \author{}  \begin{document}  \maketitle   \begin{abstract}  abc \end{abstract}  \section{table} \begin{table}[h!] \caption{Top 5 movies recommended by content-based CF algorithm} %title of the table \centering % centering table \begin{tabular}{c r} % creating eight columns \hline\hline %inserting double-line Movies&\multicolumn{1}{c}{Genre} \\ [0.5ex] \hline % inserts single-line The Flintstones(1994) & Children's,Comedy\\ % Entering row contents Son in Law(1974) & Comedy, Horror\\ The Princess Bride(1987) & Action, Adventure, Comedy, Romance\\ Star Wars(1977) & Action, Adventure, Romance, Sci-Fi, War\\ Toy Story(1995) & Animated, Animated Children's, Comedy\\[1ex] % [1ex] adds vertical space \hline % inserts single-line \end{tabular} \label{tab:hresult} \end{table}  \end{document}    This is how it looks :


How do I query on a self-defined variable? Example:  SELECT *, MID(dateandtime, 12, 2) as 'xxx' FROM xyz WHERE year = '18-19' AND xxx > 18   Is there a way to use xxx in the query like in the last line of the example?


Moderator actions on items in the review queues don't count towards the review totals

When I'm checking the review queues as a moderator - particularly the Low Quality Posts queue - I'm presented with an extra link beside the question mod. This gives me access to the moderator tools which include the "convert to comment option".  A valid option for some low quality answers is the option to convert them to a comment on the question. However, selecting the mod tools and that option    Doesn't count towards my review total.   Now I know it's not much in the scheme of things, but I have reviewed that question. The only workaround I have is to   Open the page in a new tab Use the delete button to increment the review count. Switch to the other tab Undelete the answer Use the mod tools to convert it to a comment.   Needless to say I'm not doing this as life's just too short, but it does annoy me that I'm not getting any closer to the Reviewer or Steward badge in that queue.


Polynomial division: an obvious trick? [reducing mod $\textit{simpler}$ multiples]

The following question was asked on a high school test, where the students were given a few minutes per question, at most:     Given that,   $$P(x)=x^{104}+x^{93}+x^{82}+x^{71}+1$$   and,   $$Q(x)=x^4+x^3+x^2+x+1$$   what is the remainder of $P(x)$ divided by $Q(x)$?     The given answer was:     Let $Q(x)=0$. Multiplying both sides by $x-1$:   $$(x-1)(x^4+x^3+x^2+x+1)=0 \implies x^5 - 1=0 \implies x^5 = 1$$   Substituting $x^5=1$ in $P(x)$ gives $x^4+x^3+x^2+x+1$. Thus,   $$P(x)\equiv\mathbf0\pmod{Q(x)}$$     Obviously, a student is required to come up with a “trick” rather than doing brute force polynomial division. How is the student supposed to think of the suggested method? Is it obvious? How else could one approach the problem?


A question concerning cyclic property of a group

For which $n$ is the group $U_n$ (group of all positive integers less than $n$ that are coprime to $n$) a cyclic group?


Android View nullPointerException cause by setVisibility() method

I'm have an issue with changing the visibility of my buttons.  Whenever I use the setVisibility() method I get a nullPointerException.  Here is the error I get:   04-08 15:59:02.529: E/AndroidRuntime(2807): FATAL EXCEPTION: main 04-08 15:59:02.529: E/AndroidRuntime(2807): java.lang.NullPointerException 04-08 15:59:02.529: E/AndroidRuntime(2807):     at com.android.Rides.RideTracking.onClick(RideTracking.java:307) 04-08 15:59:02.529: E/AndroidRuntime(2807):     at android.view.View.performClick(View.java:4204) 04-08 15:59:02.529: E/AndroidRuntime(2807):     at android.view.View$PerformClick.run(View.java:17355) 04-08 15:59:02.529: E/AndroidRuntime(2807):     at android.os.Handler.handleCallback(Handler.java:725) 04-08 15:59:02.529: E/AndroidRuntime(2807):     at android.os.Handler.dispatchMessage(Handler.java:92) 04-08 15:59:02.529: E/AndroidRuntime(2807):     at android.os.Looper.loop(Looper.java:137) 04-08 15:59:02.529: E/AndroidRuntime(2807):     at android.app.ActivityThread.main(ActivityThread.java:5041) 04-08 15:59:02.529: E/AndroidRuntime(2807):     at java.lang.reflect.Method.invokeNative(Native Method) 04-08 15:59:02.529: E/AndroidRuntime(2807):     at java.lang.reflect.Method.invoke(Method.java:511) 04-08 15:59:02.529: E/AndroidRuntime(2807):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) 04-08 15:59:02.529: E/AndroidRuntime(2807):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560) 04-08 15:59:02.529: E/AndroidRuntime(2807):     at dalvik.system.NativeStart.main(Native Method)   Here is the code:          public View btnStart = null;         public View btnPause = null;         public View btnResume = null;          case R.id.btnPauseRide:             mLoggerServiceManager.pauseGPSLogging();              setResult( RESULT_OK, intent );             btnPause.setVisibility(View.GONE);             btnResume.setVisibility(View.VISIBLE);             break;          case R.id.btnResumeRide:              mLoggerServiceManager.resumeGPSLogging();             setResult(RESULT_OK, intent);              btnResume.setVisibility(View.GONE);             btnPause.setVisibility(View.VISIBLE);         default:                             break;   Any help would be greatly appreciated.


understanding $\frac{\partial x}{\partial y}\frac{\partial y}{\partial z}\frac{\partial z}{\partial x}=-1$

In particular, when $x=y=z$ isn't the above expression equal to 1 and not -1?


Wireframe become x-ray alike in edit mode

I don't know what i've clickin, but somehow this happening. when i enter edit mode, the wireframe in the backside keeps showing on, and i can't choose the proper faces which i want, pls help me :D