How to prove that there exists exactly two self- complementary graph with five vertices. I am having difficutly to prove this. I only know the definition of self- complementary graph.But I am unable to use it. Any help would be appreciated. Thanks in advance.

I know that the two complements should have an equal number of edges, namely $\binom{5}{2}/2=5$. Since there are 10 possible edges, there are at least $\binom{10}{5}/2=126$ possible pairs of graph-complement pairs.  But after making drawings for the same problem with four vertices, I know many of them are isomorphic and can be obtained from by rotations and reflections.  How should I proceed in eliminating these isomorphic graphs?  In the first place, am I taking the right approach, or is their a more effective solution?


We have Ubuntu 14.04 LTS as client in virtual manager. I have to join it in a network with a system running Windows server 2008.   How can I join a Windows Active Directory?

We have a "mix-mode" Lab. and we want to migrate to Ubuntu, from Windows.  In this process, how do we add Ubuntu workstations to a Windows Domain / Active Directory ('AD') setup?


I read this statement in an English book and I wonder if this statement is correct:  She told me that she still remembers how scared everyone was.  I have learned that in indirect speech statements the present-tense verbs must be converted to past-tense verbs. Rendering the statement thus:  She told me that she still remembered how scared everyone was.  Is either incorrect?

I received an email saying that the documents are/were being processed.   Which is correct? Are or were?


Does $\pi = re$ for some rational $r$? I assume the answer is no but cannot prove so.

Is there an argument for why $\large \frac {\pi}{e}$ is rational, irrational, or trandescendal? Can the quotient of any two transcendental numbers (which are not rational multiples of each other) be rational, or at least irrational? Thanks.


Toilet paper, paper towels or cardboard are all relatively strong when dry but as soon as they are wet it is much easier to tear them. Why is this?

My four-year-old daughter asked me why paper tends to fall apart when wet, and I wasn't sure.  I speculated that the water lubricates the paper fibers so that they can untangle and separate more easily, but I really wasn't sure.


I'm using Ubuntu 14.04.  I have purchased an additional partition in my hosting environment hta tis supposedly 100 GB.  However, when I check the space of that partition, I see something odd  myuser@myproject:~$ df -h /mnt/volume-nyc1-01/ Filesystem      Size  Used Avail Use% Mounted on /dev/sda         99G   93G  730M 100% /mnt/volume-nyc1-01   Shouldn't the Used + Avail equal the total size?  If not, how do I figure out where the rest of the space is getting used?

As the output of df -h shows here, something is eating up 5GB of free space. So, it's not available to use.   I'm also noticing sometimes that the hard disk gets filled up to 100% sometimes. So, I had to restart the machine or delete some unncessary files. Only noticed these in /home partition. Don't know whether these two are related, but appreciate if anyone can put some insight into this.  $ df -h Filesystem            Size  Used Avail Use% Mounted on /dev/sda8             100G   92G  2.7G  98% /home


Prove ${{n+1} \choose {m+1}} = \sum_{k=m}^{n}{k \choose m}$ using a   purely combinatorial argument.   I don't think I understand how to do a combinatorial proof. I know the left side expands to:  $${{n+1} \choose {m+1}} = \frac{(n+1)!}{(m+1)!(n+1-m-1)!} = \frac{(n+1)!}{(m+1)!(n-m)!}$$  For the right side:  $$\sum_{k=m}^{n}{k \choose m} = {{k+1} \choose {m+1}} = \frac{(k+1)!}{(m+1)!(k+1-m-1)!} = \frac{(k+1)!}{(m+1)!(k-m)!}$$  Which is similar to what I got on the top.  Where do I go from here?

After reading , the most popular answer use the identity $$\sum_{t=0}^n \binom{t}{k} = \binom{n+1}{k+1}.$$  What's the name of this identity? Is it the identity of the  modified.  How can we prove it? I tried by induction, but without success. Can we also prove it algebraically?  Thanks for your help.    EDIT 01 : This identity is known as the  because, on Pascal's triangle, when the addends represented in the summation and the sum itself are highlighted, a hockey-stick shape is revealed.


I have ZERO experience at this. The laptop is 10 years old, running Windows 10 Home, and it is slowwwwwwww. I've done all the hdd cleanupa and defrag, but nothing changes.   My question is, if my Grandkids (ages 9 and less) still want to run it for games, am I doomed? Or is there a version of Linux I can install on USb stick that they can play Minecraft and Roblox from?  I'm just barely pc savvy, and know nothing about tech acronyms, so please don't assume I get everything you type unless its somewhat explained.   Thank you

I'm thinking about installing Ubuntu Desktop, but I don't know what flavor is the best for my system. What are the minimum and recommended hardware requirements? What kind of CPU? How much memory? Should I have Hardware Acceleration? What flavor should I use?  This is an attempt of a canonical answer. My answers have the "official  requirements", the recommended are a mix of official sources and opinion based (along with the answer it's told the source). You can comment or edit if you feel that the information is obsolete or incomplete. It is a good rule of thumb that any system capable of running Windows Vista, 7, 8, x86 (Intel) OS X will almost always be a lot faster with any Ubuntu flavor even if they are lower-spec than described below.


What is the interpretation of the number that is the output of the logistic regression function?   The logistic function   $$f(\vec{x}) = \frac{1}{1+e^{-g(\vec{x})}}$$  (where $g$ is a linear function) is supposed to map a continuous variable (or more generally a whole bunch of totally ordered variables) to between 0 and 1.  I've always assumed it is the probability of inclusion in one set or the other. The range is $[0,1]$ (well, maybe not 0 and 1), which is what a probability is. And frankly anything between 0 and 1, what else could it be other than a probability.   But looking at the curve, I started to doubt. I wondered if it is necessarily to be interpreted as a probability. It looks like a probability but is it really? Just because they share the same range doesn't mean they are the same. If $f(\vec{x}) = .75$, does that really mean that $75\%$ of $f$ is less than $f(\vec{x})$?  This could go in two directions:   Suppose it is a probability, or more exactly the probability of a 'true', '1', or 'positive' classification of a point in the domain. How is this justified? Suppose not. Then what is it exactly and why? How far a way is it from a probability (numerically and conceptually)?   Another way to say this is what is so special about $1/(1+e^{-g(x)})$? Why not any monotonically increasing odd (about $y=1/2$) function with the same range, like  $$f(x) = \frac{\tan^{-1}(g(x))+\pi/2}{\pi}$$ or $$f(x) = {\rm erf}(g(x)) = \frac{2}{\sqrt{\pi}} \int_{-\infty}^x e^{-t^2} \ {\rm d}t$$ (very close but not equal to the logistic function)     or frankly  $$f(x) =  \begin{array}{ll} 0,& {\rm if\  } g(x) < 0\\ 1,& {\rm if\  } g(x) >= 0 \end{array}$$ ?

What is the difference between  and ?  I'm more interested here in knowing when to use logistic regression, and when to use Probit.  If there is any literature which defines it using , that would be helpful as well.


My question is:      How to prove that $(a+b)$ is the factor of $a^n+b^n$ if and only if $n$ is an odd natural number?   I tried this using mathematical induction but failed.   I don't have any other idea to prove it. I am a 12 grade student. thank you

I read somewhere that     $(a^n - b^n)$         It is always divisible by $a-b$.   When $n$ is even it is also divisible by $a+b$.   When $n$ is odd it is not divisible by $a+b$.      and     $(a^n + b^n)$         It is never divisible by $a-b$.   When $n$ is odd it is divisible by $a+b$.   When $n$ is even it is not divisible by $a+b$.      I wonder what's the proof for this.  First postulate is clear. $(a-b)$ would or would not be a factor. Any light on others?


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

Is there a website or some other way to find out if I need a transit visa for a short stop in the UK on my way somewhere else? Ideally this should give me the answer for all nationalities, and take into account any other visas I may have.


Would running a book through the universal translator make an accurate translation? The universal translator is able to translate languages never heard by the federation practically instantly,(with little to nothing lost in meaning or intent) would it be reasonable to assume, any given modern book could be simply and accurately translated from English to French with no translation issues or lost meaning?   EDIT- the suggested answer is about visually translating a language, this is not what im asking about, as in Enterprise we have at least 1 instance in which Hoshi is communicating with another species through the UT by text, not speech, which shows that the UT can accept input and translate it. This is different then the crew being able to read something on another ship, as the UT does not have optical receptors to input what they are seeing, since it runs audibly off of the ship.

In the series 7 episode of Star Trek: Voyager, "Nightingale", Ensign Kim repairs and takes control of a Kraylor ship.   I'm curious at the ease at which Kim fixes the warp matrix using the control panel. Does the UT also translate the control panels and displays? The  suggests that it does, but doesn't out and out say it.  Is there a canonical statement of the UT's ability to also handle visual languages, not just aural?


If an exception is happened in a Subfunction, I would like to have this exception also in the parent method. For example:  In my main Class I have such functions:  public static void ParentFunction(TraceWriter log) {    logger = log;                   subFunction1(logger);      }   static int subFunction1(TraceWriter log) {    try    {      SubFunction2(int param1,int param2)      //Some Code here    }    catch( exception e)    {     //Some Code here    } }   In another c# class I have the definition for SubFunction2:   public static void SubFunction2(int param1, int param2)  {    //Constructor     SubFunction2();  } //if some exception in this function is happened, I would like to have also an exception in ParentFunction private static void subFunction2() {    try    {      //Some Code here    }    catch( exception e)    {     //some code    } }   if some exception in subFunction2() is happened, I would like to have also an exception in ParentFunction. Ho should I change my code to achieve this aim?

I have a question for you that stems from my partner doing things a different way than I do.  Is it better to do this :  try {     ... } catch (Exception ex) {     ...     throw; }   or this:  try {     ... } catch (Exception ex) {     ...     throw ex; }   Do they do the same thing? Is one better than the other?


I am using a rig made by someone as a prop in my scene, but it has these borders / seams on the texture. I think it may be because the model is divided a lot, or it could be something else. Picture:   I googled this, but I didn't find anything about this problem. Can someone tell me how to fix this or show me a tutorial? Also, I am a beginner so excuse me if this is a dumb question.  Project file to recreate problem:

I am kind of new to the whole animation aspect and in fact still in high school.  I am trying to make a Minecraft character rig and I want to make some 3D hair. I did not know how to quite make it so I kind of when just did something pretty simple. It isn't the greatest in any means, but any how the point is every time I render it white lines show up between objects or joined objects. I don't know how to fix this and would like help (a picture is posted below of the problem).


What should be the approach to draw the graph of the above inequality with modulus? Should I need to begin like this? $$|y| = 1 - |x|$$

Can anybody explain as how to plot a graph of $|x| + |y| = 1$. Here $|x|$ and $|y|$ are absolute values.


Given the matrix:      $$ A =      \begin{pmatrix}     0 & 0 & 1 \\     0 & 1 & 0 \\     1 & 0 & 0 \\     \end{pmatrix}  $$      Find the number of solutions (in $M_3(\mathbb{R})$) of the equation $X^2 = A$.    I tried writing $X$ as:  $$ X =      \begin{pmatrix}     a & b & c \\     d & e & f \\     g & h & i \\     \end{pmatrix} $$  And then I multiplied $X$ by itself and created a system with the terms of $X^2 = A$, but $X^2$ is very messy and I got stuck. I couldn't solve this problem. Is there another (and possibly better) approach to this?

$A=\begin{pmatrix}0&0&1\\ 0&1&0\\ 1&0&0\end{pmatrix}$  How do I show that there are no solutions for $X^2=A$ in $M_3(R)$?  I tried $X^2=\begin{pmatrix}a_{11}&a_{12}&a_{13}\\ a_{21}&a_{22}&a_{23}\\ a_{31}&a_{32}&a_{33}\end{pmatrix}^2=A$, but I couldn't seem to find anything that shows there are no solutions. How should I approach this?


Let $a_n$ be a sequence of real positive numbers. Show $$\liminf_{n\to  \infty} \frac{a_{n+1}}{a_n} \leq \liminf_{n\to \infty}\,(a_n)^{1/n}  \leq \limsup_{n\to \infty} \, (a_n)^{1/n} \leq \limsup_{n\to \infty}  \frac{a_{n+1}}{a_n}.$$   Here's the proof I had in mind, and I'm interested to know if anyone knows a simpler one, or if anyone can find a gap in my logic.  Suppose $\liminf_{n\to \infty}(a_n)^{1/n}=L_1$. Then we have a subsequence $a_{n_k}$ such that $(a_{n_k})^{1/n_k}\to L_1$. Now   $$(a_n)^{1/n}=\left( \frac{a_n}{a_{n-1}} \frac{a_{n-1}}{a_{n-2}} \dotsb \frac{a_2}{a_1} a_1 \right)^{1/n}\\ \log\left( \sqrt[n]{a_n} \right)=\frac{\log\left(\frac{a_n}{a_{n-1}}\right) +\dotsb +  \log\left(\frac{a_2}{a_1}\right) + \log(a_1)}{n}.$$  If $\log(\sqrt[n_k]{a_{n_k})}\to \log(L_1)$, then we can show by contradiction that $\forall \epsilon$ there are arbitrarily high $n_l$ such that $$\frac{a_{n_l}}{a_{n_l -1}} < L_1 + \epsilon $$  If not, then eventually the averages on the right-hand side would be too large.

This may have been asked before, however I was unable to find any duplicate. This comes from  of "Mathematical Analysis: An Introduction" by Browder. Problem 14:     If $(a_n)$ is a sequence in $\mathbb R$ and $a_n > 0$ for every $n$. Then show:   $$ \liminf(a_{n+1}/a_n) \le \liminf((a_n)^{(1/n)}) \le \limsup((a_n)^{(1/n)}) \le \limsup(a_{n+1}/a_n)$$   The middle inequality is clear. However I am having a hard time showing the ones on the left and right. (It seems like the approach should be similar for each). This is homework, so it'd be great if someone could give me a hint to get started on at least one of the inequalities.  Thanks.


I'm thinking something on the site, similar to the way you can star questions. You should be able to star tags or groups of tags and when something new happens in that set (an edit to a question or answer, a new answer to an existing question, or a new question), you get notified on the site.  Yes, you can use an RSS feed, but if I were to do that, my RSS feeds would probably triple. I would like to be notified on-site of events such as these.

Update:   Once upon a time there was a feature called . Its goal was to help our most active users find the questions they can answer. "New nav" never made it out of beta and that beta only ever made it to Stack Overflow users. Several months ago we gave new nav a sad, but overdue burial. As we promised, we've been working on a replacement for new nav, and now it's time for us to start rolling it out. We're calling it custom question lists and we are really excited about its potential to help all users get at the questions that are most interesting to them. While we hope what we've built hits the mark for many of you who have requested a feature like this (e.g., , , , , , ), we know how difficult it is to make something complex simple. So, we are rolling this out in beta to gather feedback from you and iterate on it. (Don't worry, we promise to actually release it this time.) When it's live later you'll be able to opt-in to the beta by turning on a new account preference. This will enable the feature for Stack Overflow, Meta Stack Overflow, and Meta Stack Exchange. It will be available for all network sites when the beta period is over. Schedule for future improvements This feature will roll out in four phases:  Phase I: Filter and sort controls to let you modify a question list view (Julyish) Phase II: Saved custom lists (In progress, ETA November 2018) Phase III: Notifications on custom lists (December 2018) Phase IV: Final fixes and official release (January 2019)  Sneak peak Phase I: Filter and sorts We'll add filter and sort controls to question lists. This does two things:  Clarifies the definition of built-in views - Naming is hard and short names can't always describe what a view is showing you. By exposing the filter and sort controls it is more obvious. Introduces the ability to create new custom views - This won't be super useful until we add the ability to save the views to the UI (phase II). Until then you can bookmark the URL and get back to your views.  Question list with new controls   Views drop down   Filter   Sort   Phase II: Saved custom question lists In this phase we will add the ability to save your custom questions lists. Create custom list In our current design, a dialog will be pre-populated based on the filters and sorts you're currently using. Give it a name, confirm your options, and click save.  Accessing your saved lists When you save your custom lists they will show up in the "More" drop down for question list views. Additionally, you can add them to the left navigation bar for easy access (see image below).  Phase III: Notifications For phase III we'll enable indicators for when new items are available in a custom question list. When you pin a question list to the left nav you can see a dot on any list with new items.  Feedback welcome As usual, we're interested in your constructive feedback. This is a work in progress and, as mentioned, will be rolled out in phases. You can provide feedback on the concepts now based on the information in this post and provide feedback based on the working elements as they are released.


In LaTeX the symbol for material implication is produced by $\to$, but for  ?

I know what my symbol or character looks like, but I don't know what the command is or which math alphabet it came from. How do I go about finding this out?


Express $i^{i^i}$ in the form $a+bi$ where $a,b$ are real.   From euler's formula, I get $\ln i=i\pi/2$, which leads to $i^i=e^{-\pi/2}$.  Therefore, $\ln i^{i^i}=i^i\ln i=i\pi e^{-\pi/2}/2,i^{i^i}=e^{i\pi e^{-\pi/2}/2}$, but I don't know how to deal with this.  Please help. Thanks.

Is $\large i^{i^i}$ real ? How to find it?   Thank You!


I am trying to determine the use of "that" or "who" in this sentence: Workers ____ were sent did not speak English.

Which of the following is correct?        There were 10 people that went to the store.   There were 10 people who went to the store.      Edit:  Which of the following is correct?        There were 10 people that had brown hair.   There were 10 people who had brown hair.


Which would be advised as the first line in a bash script:  #! /usr/bin/env bash   or   #! /bin/bash

In scripts, first line should specify the path to interpreter. But on different servers Linux, Unix, or BSD this path could be different.  What is more preferable?  #!/usr/bin/env bash    or  #!/bin/bash


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

With a macro such as:  \def\naive{na\"{\i}ve}   I find that the space which I would hope to follow it, is absent. So, with  the \naive approach   I get     the naïveapproach   in the output. How do I bring back the space?


I'm using phpmailer to sending emails to users,but the email account which i send with to users,it wasn't created on the same hosting,it created on Office 365, I used SMTP authentication,when i sent emails to users they considered as spams_for example hotmail say :This sender failed our fraud detection checks and may not be who they appear to be .  when i google the problem i found the following issues:  1) Email failed in SPF and DKIM checks: but on cpanel in email authorization,i make SPF and DKIM enabled, so as my hosting company mentioned "that help reduce the amount of spam." . Do i need to setup SPF and DKIM records manually at zone file?   2) My Hosting company advise to setup reverse DNS:but does this important for my problem?   Sending code :   $mail = new PHPMailer(true);  $mail->Host = "smtp.office365.com";  $mail->Port       = 587;  $mail->SMTPSecure = '';  $mail->SMTPAuth   = true;  $mail->Username = "xxxxxx";  $mail->Password = "xxxx";  $mail->SetFrom($from, 'Name');   $mail->addReplyTo($from);  $mail->SMTPDebug  = 2;  $mail->SingleTo = true ;  $mail->clearAllRecipients();   for($i = 0 ; $i < count($to) ; $i++)  {       $mail->addAddress($to[$i]);   }     if(!is_null($cc))   {       foreach ($cc as $email)       {           $mail->addCC($email);       }   }    $mail->Subject = $subject;  $mail->IsHTML(true);  $mail->MsgHTML($body);    if(!$mail->send()) {      //echo 'Message could not be sent.';      echo 'Mailer Error: ' . $mail->ErrorInfo;      //  return false ;  } else {       return true ;  }   So what do you advise me?

This is a tricky one and I've always relied on techniques, such as permission-based emails (i.e. only sending to people you have permission to send to) and not using blatantly spamish terminology.  Of late, some of the emails I send out programmatically have started being shuffled into people's spam folder automatically and I'm wondering what I can do about it.  This is despite the fact that these particular emails are not ones that humans would mark as spam, specifically, they are emails that contain license keys that people have paid good money for, so I don't think they're going to consider them spam  I figure this is a big topic in which I am essentially an ignorant simpleton.


I am trying to get images in table and when we click on that image,it should get download.I am using apex:outputLink but image is not downloading.  <apex:column >    <apex:facet name="header">File</apex:facet>    <!-- apex:outputlink styleClass="{!IF(AttachVar.ViewingStatus == 'Not Viewed' && (runningUser.Profile.Name == 'Profile1' || runningUser.Profile.Name == 'Profile2'),'actionLink disableLink','actionLink')}"target="_BLANK" value="/servlet/servlet.FileDownload?file={!AttachVar.attachmentID}" >{!AttachVar.attachmentName}         <apex:actionSupport  event="onclick" action="{!updateHistory1}" >             <apex:param value="{!AttachVar.attachmentID}" name="updateHistory1" assignTo="{!SelectedId1}"/>         </apex:actionSupport>     </apex:outputlink --> </apex:column>   I used commandLink as well but it is also not opening the image.

I want image to get download or disply after clicking on link.  Visualforce page :-      <apex:pageBlockTable value="{!DORESAttachmentsWrapperList}" var="AttachVar" border="3px" width="98.5%">     <apex:column >     <apex:facet name="header">File</apex:facet>     <apex:commandLink action="{!DORESupdateHistory1}" styleClass="{!IF(AttachVar.DoresViewingStatus == 'Not Viewed' && (runningUser.Profile.Name == 'Profile1' || runningUser.Profile.Name =='Profile2'),'actionLink disableLink','actionLink')}"     value="{!AttachVar.attachmentName}" >   <apex:param value="{!AttachVar.attachmentID}" name="DORESupdateHistory1" assignTo="{!DORESSelectedId1}"/>   </apex:commandLink >   </apex:column>     Controller - DORESupdateHistory1 will update the timing and name of the person in a table who clicks on the new attached image.     public String DORESSelectedId1{get;set;}         public PageReference DORESupdateHistory1(){            system.debug('--DORESSelectedId1---' + DORESSelectedId1);            List<Profile> Profile= [Select Name from Profile where Id =:UserInfo.getProfileId() LIMIT 1];              list<attachment> relatedPaadAttachment = [select ID,parentID,name from attachment where ID=:DORESSelectedId1 limit 1];            system.debug('--DORESSelectedId1---' + DORESSelectedId1);              List<PAAD_Application_Attachment__c> ClickedAttachList1 = [Select id,Name,Type__c,CreatedDate,Dores_Viewer_Name__c,Dores_Viewed_Time__c,Dores_Viewing_Status__c from PAAD_Application_Attachment__c where id = :relatedPaadAttachment[0].parentID]; //To get the clicked attachment Id    if(ClickedAttachList1[0].Dores_Viewing_Status__c == 'Not Viewed' && Profile[0].Name == 'Profile1' || Profile[0].Name == 'Profile2'){    ClickedAttachList1[0].Dores_Viewing_Status__c = 'Viewed';    ClickedAttachList1[0].Dores_Viewed_Time__c = system.now();    ClickedAttachList1[0].Dores_Viewer_Name__c = UserInfo.getName();    update ClickedAttachList1;    List<PAAD_Application_Attachment__c> viewedattach1= [SELECT Id,Dores_Viewing_Status__c FROM PAAD_Application_Attachment__c where Dores_Viewing_Status__c != 'Viewed' and PAAD_Applicant__c=:app.ID];   List<PAAD_Application_Attachment__c> attach1 = [SELECT Id FROM PAAD_Application_Attachment__c where PAAD_Applicant__c=:app.ID];     if(viewedattach1.size() == attach1.size()){    List<PAAD_Applicant__c> attachcheck1= [SELECT Id,New_Dores_Attachment_Checker__c FROM PAAD_Applicant__c where ID=:app.ID];                   if(attachcheck1[0].New_Dores_Attachment_Checker__c == 'Y') {                       attachcheck1[0].New_Dores_Attachment_Checker__c = '';                       update attachcheck1;                   }                  }       List<AttachmentWrapper>  dummyWrapperList = new List<AttachmentWrapper>();                for(AttachmentWrapper wrap : DORESAttachmentsWrapperList){                   if(DORESSelectedId1 !=  wrap.attachmentID){                       dummyWrapperList.add(wrap);                   }else{                       dummyWrapperList.add(new AttachmentWrapper(ClickedAttachList1[0].Type__c,ClickedAttachList1[0].Member__c, ClickedAttachList1[0].Description_Final__c, relatedPaadAttachment[0].ID,relatedPaadAttachment[0].name, ClickedAttachList1[0].CreatedDate,'Attached', ClickedAttachList1[0].Dores_Viewed_Time__c, ClickedAttachList1[0].Dores_Viewer_Name__c, ClickedAttachList1[0].Dores_Viewing_Status__c));                     }               }               DORESAttachmentsWrapperList.clear();               DORESAttachmentsWrapperList.addAll(dummyWrapperList);            }              return null;        }


I have been having issues trying to get my dual boot to work. Specifically, windows won't boot to GRUB. Even after the first restart my computer didn't boot into GRUB In addition, I have tried to boot ubuntu using the normal boot manager. I go "Boot From EFI File" -> a very long set of characters -> EFI -> ubuntu and the error reads "No valid file selected in the selected file system". I am running Windows 10 on an HP Specter and trying to boot into Ubuntu 20.04. I have tried many things like changing the boot order, however there is no windows or Ubuntu option to choose from. I have disabled secure boot. I have redownloaded Ubuntu several times. I just ran the boot repair and it gave this url:  and was told to post it on the forums for help. Thank you for any help, I have been struggling with this for weeks.

Ok, so I'm such a newbie to Ubuntu and I bought a Windows 8 pre-installed laptop last month.  I updated to Windows 8.1 and then I thought about installing Ubuntu as a dual boot so I could mess around and learn more about it.   So I followed a Youtube tutorial (  ) and I got my stuff working fine.   The first few times I booted I got the GRUB menu instead of my default HP Boot OS Manager, and I was able to select my OS.   So I went to sleep and the next day I turned on my computer and the GRUB menu did not show up. I tried several times and it didn't automatically show up.  In order for me to see the GRUB menu I had to turn on my PC and on start had to press ESC to pause startup and press F9 to get boot options. Then from there I had to pick from OS Boot, Ubuntu, Ubuntu (Yes there were two Ubuntus available) and a default EFI file thingy.   When I click the first Ubuntu I get the GRUB Menu (I was too scared to try the second in case I screwed my laptop up) and I can safely load Ubuntu from there and use it (although I do have to increase my brightness every time I load Ubuntu because it somehow reduces my brightness to complete darkness on boot)  So my problem here is why isn't my GRUB showing on boot, after it worked on the first day?   My laptop is a HP TouchSmart j-078CA.  EDIT 1: FYI I just switched to Ubuntu LiveCD to check my Installation and found out that one of my partition is flagged as msftres. Here is a screenshot of my GParted on a LiveCD:


I'm using H2 Database and when double and float values inserted into my H2 DB, the loss of precision is occurred and, for example, 1.7999999523162842 displayed instead of 1.8.

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


I have recently installed Windows 7 in my virtual box and my main OS is ubuntu 14.04 LTS.  I have gallium 0.4 on AMD RS-780.  Can I get a stepwise manual to install graphic card accelerators required to enable high quality gaming in virtual box? This is the status of my computer.

I recently bought a new laptop with following configuration   CPU: Intel i5 2450 RAM: 8 GB DDR3 GPU: NVIDIA GeForce GTX 520 1GB   I've setup a virtual machine using VirtualBox with Windows 7 as guest. I want to use my (host's) graphics card in it but the virtual machine is only showing 128 MB of video memory.  I am using Bumblebee and start the virtual machine using   $ optirun VBoxManage startvm "Windows 7"   Please suggest me how should I use my graphics card for 3D acceleration in virtual machine.


I am trying to build a feature within a ROM, the build completes without any isseu and the feature is working, however when i want to open it's settings it force closes.   I have made a logcat:  E/AndroidRuntime( 3440): Caused by: java.lang.NullPointerException E/AndroidRuntime( 3440):    at com.android.settings.mahdi.aokp.ProgressBar.onCreate(ProgressBar.java:86)   And this is the corresponding lines in ProgressBar.java:      mprogressbar_speed = (SeekBarPreference) findPreference(PROGRESSBAR_SPEED);     mprogressbar_speed.setValue(Settings.System.getInt(getContentResolver(), <---- this is line 86                                 Settings.System.PROGRESSBAR_SPEED, 4));     mprogressbar_speed.setOnPreferenceChangeListener(this);   I dont know how to resolve this isseu and i can use some help...  Thanks in advance...

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I would like to use \paragraph{} as a subsubsubsection. It's working fine but I want to change the number to a letter.   For example instead of having 1.1.1.1 I would like to have 1.1.1.a.  How can I do that ?   Thx !

I'm using pandoc and in my template.tex exists this code to make the paragraphs and subparagraphs to behave like sections.  % Redefines (sub)paragraphs to behave more like sections \ifx\paragraph\undefined\else \let\oldparagraph\paragraph \renewcommand{\paragraph}[1]{\oldparagraph{#1}\mbox{}} \fi \ifx\subparagraph\undefined\else \let\oldsubparagraph\subparagraph \renewcommand{\subparagraph}[1]{\oldsubparagraph{#1}\mbox{}} \fi   This code generate number like this:  1. chapter  1.1 section  1.1.1 subsection  1.1.1.1 subsubsection  1.1.1.1.1 paragraph  1.1.1.1.1.1 subparagraph   How to change this code to enumerate with letter like this:  1. chapter  1.1 section  1.1.1 subsection  1.1.1.1 subsubsection  1.1.1.1.a paragraph  1.1.1.1.a.a subparagraph


In Clan Wars your opponent is determined by your clan's average base value, would a player's offense affect what clan you go up against?

In the clan wars matchmaking, what criteria is used to determine the clan that you are fighting against? Is it based on Clan Total Points (i.e. trophies), or something else?  If you win many wars in a row, does this mean you will get harder opponents?


I only have 2 (-1) downvoted questions and 2 closed questions.  Is this enough for Stack Overflow to not accept questions anymore? Because I tried to post a question and it wouldn't let me.  Also, do downvotes on deleted questions still count towards this? Or is it over written into just a deleted question where the downvotes no longer matter?

If you are reading this, you may have been affected by one of our post quality bans. If so, it is important that you  to understand what has happened and how to regain the permissions that you lost. While trying to ask a question, one could see:  We are no longer accepting questions from this account. See  to learn more.  Likewise, for answers:  We are no longer accepting answers from this account. See  to learn more.   Why am I getting this message? Are deleted posts taken into account too? Is a question/answer ban the same as a suspension? How do I avoid getting a question ban? How long do I have to wait before I can post again? What can I do to release the ban? How can I reactivate my account? Can I simply create a new account? I'll just ask somewhere else on the SE network, and they'll migrate my question to the correct site! Will a ban on one Stack Exchange site affect my standing on other sites in the network? Does this apply to meta sites too? My account is in good standing. Why am I still blocked?


Using this example  \documentclass[a4paper,12pt]{lettre} \usepackage{fontspec} \usepackage[frenchb]{babel} \usepackage{lipsum}  \begin{document} \begin{letter}{Service des réclamations} \nofax \opening{Madame, Monsieur,} \lipsum[3] \end{letter} \end{document}   Built with  latexmk -pdf -xelatex   I get a pdf with is not A4, but letter perhaps. However I mentionned a4paper on the \documentclass option.   What did I miss ?  EDIT  It seems I can get the correct pdf size with the following. So what should I include these two lines in addition to a4paper?  \pdfpagewidth=\paperwidth \pdfpageheight=\paperheight

I am attempting to finish my LaTeX project, and I can't seem to get the PDF to compile to the right size no matter what I do.  In my .cls file I have this set:  \paperheight 11in \paperwidth 8.5in   But no matter what I change it to, it compiles to about 8.25x11.7".  I can post my .cls files or anything else for that matter if someone knows hat I am doing  Here is my .cls file:  - I am using BakomaTex Word for my editor.  When I compile my PDF, I am still getting strange dimensions.  I really appreciate this, thank you.


Consider RL circuit consisting of a battery , resistance , inductor , and switch .all components are in series .  If we close the switch at time t =0 the current will build up until reaching a maximum .now i want to put the differential equation that discribes the circuit while the current is building up and i know from walter lewin lectures that i have to use Faraday's law not kirchhoff's loop rule because we have nonconservative electricfield .  Walter lewin derives the differential equation as follows  Closed loop integral of (E.dl)=-Ldi/dt  IR - v = -Ldi/dt  What baffles me is what kind of electric field do we mean in the above formula ?do we mean the nonconservative electricfield only or do we mean the superposition of conservative and nonconservative electricfield ?

I am self-studying electromagnetism right now (by reading University Physics 13th edition) and for some reason I always want to understand things in a crystalclear way and in depth. Now look at this simple RL-circuit:    I am assuming the wire is superconducting and suppose at $t=0$ the switch is turned on. My problem is that I want to come up with this differential equation for this circuit: $V-I\cdot R=-L\cdot \frac{dI}{dt}$. I know that I can't use Kirchoff's voltage law $(\oint  \vec{E}\cdot d\vec{l}=0)$, because there is a non-conservative electric field near the inductor. Therefore I use Farayday's law of induction: \begin{equation} \mathcal{E}=\oint_{\Gamma}  \vec{E}\cdot d\vec{l}=-\frac{d}{dt} \int_{S} \vec{B} \cdot \hat{n}\,dA \end{equation}  where $\Gamma$ is a closed loop and $S$ is the open surface attached to the loop. Now, my textbook says:     In general, the total field $\vec{E}$ at a point in space can be the   superposition of an electrostatic field $\vec{E_c}$ caused by a distribution of charges at rest and a magnetically induced, nonelectrostatic field $\vec{E_n}$. That is $\vec{E}=\vec{E_c}+\vec{E_n}$.   Inserting this in Faraday's law I get:  $$\oint_{\Gamma}  \vec{E}\cdot d\vec{l}=\oint_{\Gamma}  \vec{E_c}\cdot d\vec{l}+\oint_{\Gamma}  \vec{E_n}\cdot d\vec{l}=-L\cdot \frac{dI}{dt}$$ Now by definition: $\oint_{\Gamma}  \vec{E_c}\cdot d\vec{l}=0$ since $\vec{E_c}$ is conservative. This gives: $\oint_{\Gamma}  \vec{E_n}\cdot d\vec{l}=-L\cdot \frac{dI}{dt}$, which is perfectly fine and consistent with my textbook. However it also gives (going counterclockwise in circuit): $\oint_{\Gamma}  \vec{E_c}\cdot d\vec{l}=-V+I\cdot R=0$ which it shouldn't. I think my flaw is here, but I've tried to think about this this whole day with no succes.  I have my inspiration from Walter Lewin's video:  but I still can't get the equation by Faraday's law.  Any help is greatly appreciated.


I was able to run my application on using Legend earlier but now I want to update my Legend when scrolling on the map. So I tried to used this code GetLegendGraphic and getLegendUrl function filter by extent . And I got the gist of how he is able to do that but when I am trying the same I keeping getting the error. var graphicUrl = wmsSource.getLegendUrl(resolution);  This is mainly due to the getLegendUrl is not getting declare. I have tried to initialize the same using different ways but it seems getLegendUrl is not getting declare correctly. This is my JS var wmsSource = new ol.source.TileWMS({     url: 'http://localhost:8089/geoserver/India/wms',     params: {'LAYERS': 'India:India', 'TILED': true,'TRANSPARENT':true},     ratio: 1,     serverType: 'geoserver',     transition: 0, })   var getExtent = function () {     return map.getView().calculateExtent(); } var getProjectionCode = function () {     return map.getView().getProjection().getCode(); }  var updateLegend = function(resolution) {     console.log(wmsSource);     console.log(wmsSource.getLegendUrl(resolution));     var graphicUrl = wmsSource.getLegendUrl(resolution);        const crs = `&CRS=${getProjectionCode()}`;     const bbox = `&BBOX=${getExtent().join(',')}`;     const height = getHeight(getExtent());     const width = getWidth(getExtent());     const heightAndWidth = `&srcwidth=${height}&srcheight=${width}` ;     const legenOptions = "&legend_options=countMatched:true;fontAntiAliasing:true;hideEmptyRules:true;forceLabels:on" ;        var img = document.getElementById('legend');     img.src = `${graphicUrl}${crs}${bbox}${heightAndWidth}${legenOptions}`; };  var map = new ol.Map({       target : 'mymap',       view: myview,       layers: [         new ol.layer.Tile({             source : new ol.source.OSM({                 attributions: 'Surveyor Allpication'             })         }),         new ol.layer.Tile({             source : wmsSource         })       ] })  var resolution = map.getView().getResolution(); updateLegend(resolution);  This is my HTML

         Legend:

  Any idea how can I make this work? I keep getting the error of: wmsSource.getLegendUrl is not a function at updateLegend

I was able to run my application on using Legend earlier but now I want to update my Legend when scrolling on the map. So I tried to used this code  . And I got the gist of how he is able to do that but when I am trying the same I keeping getting the error var graphicUrl = wmsSource.getLegendUrl(currentResolution);  I think this is mainly due to the wmsSource not declare. But I tried to initialize  seems wmsSource in TileWMS but does not seems to work. var getExtent = function () {     return map.getView().calculateExtent(); } var getProjectionCode = function () {     return map.getView().getProjection().getCode(); }  var updateLegend = function() {     var currentResolution = map.getView().getResolution();     var graphicUrl = wmsSource.getLegendUrl(currentResolution);        const crs = `&CRS=${getProjectionCode()}`;     const bbox = `&BBOX=${getExtent().join(',')}`;     const height = getHeight(getExtent());     const width = getWidth(getExtent());     const heightAndWidth = `&srcwidth=${height}&srcheight=${width}` ;     const legenOptions = "&legend_options=countMatched:true;fontAntiAliasing:true;hideEmptyRules:true;forceLabels:on" ;        var img = document.getElementById('legend');     img.src = `${graphicUrl}${crs}${bbox}${heightAndWidth}${legenOptions}`; }; //Updated Legend End   //View var myview = new ol.View({     center : [8717490.201868,2788422.791843],     zoom : 4 })  var firstSel = document.getElementById("City"); var secSel = document.getElementById("Sector");  //var LayerArray = [baseLayer, firstLayer]  //Map var map = new ol.Map({       target : 'mymap',       view: myview,       layers: [         new ol.layer.Tile({             source : new ol.source.OSM({                 attributions: 'Surveyor Allpication'             })         }),         new ol.layer.Tile({             source : new ol.source.TileWMS({                url: 'http://localhost:8089/geoserver/India/wms',                params: {'LAYERS': 'India:India', 'TILED': true,'TRANSPARENT':true},                ratio: 1,                serverType: 'geoserver',                transition: 0,             })         })       ] }) updateLegend();   This here is my JS

         Legend:

  This is my HTML. How do I make this work?


Suppose I have a polynomial ring $k[x_0,\cdots,x_n]$ and let $k[x_0,\cdots,x_n]_m$ denote the homogeneous part with degree $m$. How can I see that this $k[x_0,\cdots,x_n]_m$ has dimension $\binom{m+n}{m}$? Or more exactly, why does this give the Krull dimension?

says that the number of different monomials of degree $M$ in $N$ variables is $$\frac{(M+N-1)!}{M!(N-1)!}\; .$$ Can anyone explain why this is true?


I have triple boot with : Windows XP, Windows 7, and Ubuntu Server. I have a GRUB and a Windows 7 Bootloader. I want to remove Ubuntu Server and GRUB. How to remove GRUB? And can Ubuntu Server is uninstalled with just deleting the partition?

I have absolutely no experience with Linux, and I desperately need to get my computer back up and running again with Windows.  How do I remove Ubuntu and reinstall Windows?    Editor's note: many of the answers are about removing Ubuntu from dual-boot but keeping Windows (which is a bit complicated), while other answers are about removing Ubuntu from single-boot (which is easy: basically just format the disk while installing Windows). The question as written is ambiguous between dual-boot or single-boot.


I have two words separate by space in each line I can have a tabular environment with two cell but I'm wondering if is there (in latex) a command like the tabin every word processor.  TIA  Renato

I have a problem adding tabs and I can't use a tabular environments (like tabular or tabbing) because I can't mix it with enumerate environments.  Is there a way to add a simgle tab like in any text editor? I use MathType to make equations writing much easier and there you can insert tabs, so when you export the code you see MathType uses & for that, but when you compile that code, LaTeX complains with:  Misplaced alignment tab character &.   So somehow LaTeX knows that I'm trying to add a tab and it's driving me crazy.  I thought to create my own "tab" macro or command: the idea is to tell LaTeX to go back to the left (or right) margin with \hspace and the move to the "tab" with another \hspace, something like:  Hi everybody. \hspace{-len_to_left_margin} \hspace{tab_value} My name is Agustin.   Is that posible?


Although I understand that both "Perry and he" and "He and Perry" mean the same thing, which is more grammatically correct and why?

It's convention and polite to always list yourself last in a list. I say "John and I went to the store" and not "I and John went to the store."  So does that mean that I should always list myself last, even in the case when the pronoun that represents me is first person, plural (i.e. "us" or "we")? In my case, I'm writing a recommendation letter about my experience on a team with "John," who is the highlight of the letter. I hit a point where I was about to write something similar to:     John and we got a lot of experience working on the project.   or     That project's experience really benefited John and us.   Clearly, he is mentally separated from the others of us who were on the team, at least in this context, so I was just wondering if there were some grammatical conventions to govern this situation.


I have a request like this.  "SELECT *  FROM st_items WHERE item_id < " . $_POST['id'] . " AND item_board=" . $_POST['board'] . " ORDER BY item_id DESC LIMIT {$itemLoad_limit}"   WHERE item_id < " . $_POST['id'] . " It works as it should.  But when I add AND item_board=" . $_POST['board'] . "  I have a Fatal error.     Uncaught exception 'PDOException' with message 'SQLSTATE[42S22]:   Column not found: 1054 Unknown column '' in 'where clause''   Can you help me figure out what the problem might be?

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?


I have the following in a .fs file:  namespace fsHoldem  module holdemPlayer  type Player()=   ... etc...   and I'm trying to reference the type Player in another file.  I've tried using open:  namespace fsHoldem  module BetStrategies  open fsHoldem.holdemPlayer          but I'm getting the error "Namespace or module 'fsHoldem' is not defined."  Note that both .fs files share the same namespace, and both exist in the same project.

This will hopefully be an easy one.  I have an F# project (latest F# CTP) with two files (Program.fs, Stack.fs).  In Stack.fs I have a simple namespace and type definition  Stack.fs  namespace Col  type Stack=   ...   Now I try to include the namespace in Program.fs by declaring  open Col   This doesn't work and gives me the error "The namespace or module Col is not defined."  Yet it's defined within the same project.  I've got to be missing something obvious


I am getting this error message whenever I try to use the Openlayers plugin. I can not read or write Python particularly well at the moment, though I am trying to learn, so I am struggling to identify the problem. I have tried un-installing and reinstalling openlayers plus using it on previous versions of QGIS with no success. Basic attempts but really haven't got the time to delve deeper into more complex procedures with out really knowing what I'm doing.  "An error has occurred while executing Python code:  Traceback (most recent call last):   File "C:/Users/*****/.qgis2/python/plugins\openlayers_plugin\weblayers\weblayer.py", line 97, in addLayer     self._addLayerCallback(self)   File "C:/Users/*****/.qgis2/python/plugins\openlayers_plugin\openlayers_plugin.py", line 130, in addLayer     layer = OpenlayersLayer(self.iface, self._olLayerTypeRegistry)   File "C:/Users/*****/.qgis2/python/plugins\openlayers_plugin\openlayers_layer.py", line 330, in __init__     self.olWebPage = OLWebPage(self)   File "C:/Users/*****/.qgis2/python/plugins\openlayers_plugin\openlayers_layer.py", line 48, in __init__     proxy = getProxy()   File "C:/Users/*****/.qgis2/python/plugins\openlayers_plugin\tools_network.py", line 42, in getProxy     proxy.setPort(settings.value("/proxyPort", 10, type=int)) TypeError: unable to convert a QVariant of type 10 to a QMetaType of type 2  Python version: 2.7.5 (default, May 15 2013, 22:44:16) [MSC v.1500 64 bit (AMD64)] QGIS version: 2.10.1-Pisa Pisa, d20c5b7 Python path: ['C:/PROGRA~1/QGISPI~1/apps/qgis/./python/plugins\\processing', 'C:/PROGRA~1/QGISPI~1/apps/qgis/./python', u'C:/Users/*****/.qgis2/python', u'C:/Users/*****/.qgis2/python/plugins', 'C:/PROGRA~1/QGISPI~1/apps/qgis/./python/plugins', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\matplotlib-1.3.1-py2.7-win-amd64.egg', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\nose-1.3.3-py2.7.egg', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\tornado-4.0.1-py2.7-win-amd64.egg', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\backports.ssl_match_hostname-3.4.0.2-py2.7.egg', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\certifi-14.05.14-py2.7.egg', 'C:\\PROGRA~1\\QGISPI~1\\bin\\python27.zip', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\DLLs', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\plat-win', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\lib-tk', 'C:\\PROGRA~1\\QGISPI~1\\bin', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\PIL', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\jinja2-2.7.2-py2.7.egg', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\markupsafe-0.23-py2.7-win-amd64.egg', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\pytz-2012j-py2.7.egg', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\win32', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\win32\\lib', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\Pythonwin', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\Shapely-1.2.18-py2.7-win-amd64.egg', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\six-1.3.0-py2.7.egg', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\wx-2.8-msw-unicode', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\xlrd-0.9.2-py2.7.egg', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\xlwt-0.7.5-py2.7.egg', u'C:/Users/*****/.qgis2//python', 'C:\\PROGRA~1\\QGISPI~1\\apps\\qgis\\python\\plugins\\fTools\\tools', 'C:/Users/*****/Documents/*****/*****']

I've been using QGIS for a while but since using QGIS 2 the OpenLayers plugin doesn't work for me on my home PC. However, I have installed the same version at my workplace with success. I have looked through other posts, and tried setting the CRS and allowing on the fly but it doesn't work for me.  Can anyone offer any other guidance?   I have also tried uninstall/ re-install.  Error code below:     An error has occurred while executing Python code:      Traceback (most recent call last):     File "C:\Users\Lee/.qgis2/python/plugins\openlayers_plugin\openlayers_plugin.py", line 48, in addLayer       self.plugin.addLayer(self)     File "C:\Users\Lee/.qgis2/python/plugins\openlayers_plugin\openlayers_plugin.py", line 194, in addLayer       layer = OpenlayersLayer(self.iface, self.__coordRSGoogle, self.olLayerTypeRegistry)     File "C:\Users\Lee/.qgis2/python/plugins\openlayers_plugin\openlayers_layer.py", line 64, in __init       self.page = OLWebPage()     File "C:\Users\Lee/.qgis2/python/plugins\openlayers_plugin\openlayers_layer.py", line 38, in init       proxy = getProxy()     File "C:\Users\Lee/.qgis2/python/plugins\openlayers_plugin\tools_network.py", line 42, in getProxy       proxy.setPort(settings.value("/proxyPort", 10, type=int))   TypeError: unable to convert a QVariant of type 10 to a QMetaType of type 2      Python version:   2.7.5 (default, May 15 2013, 22:44:16) [MSC v.1500 64 bit (AMD64)]      QGIS version:   2.0.1-Dufour Dufour, d94c044      Python path: ['C:/PROGRA~1/QGISDU~1/apps/qgis/./python/plugins\processing', 'C:\Users\Lee\.qgis2\python\plugins\GeoCoding', 'C:/PROGRA~1/QGISDU~1/apps/qgis/./python', 'C:\Users\Lee/.qgis2/python', 'C:\Users\Lee/.qgis2/python/plugins', 'C:/PROGRA~1/QGISDU~1/apps/qgis/./python/plugins', 'C:\PROGRA~1\QGISDU~1\bin\python27.zip', 'C:\PROGRA~1\QGISDU~1\apps\Python27\DLLs', 'C:\PROGRA~1\QGISDU~1\apps\Python27\lib', 'C:\PROGRA~1\QGISDU~1\apps\Python27\lib\plat-win', 'C:\PROGRA~1\QGISDU~1\apps\Python27\lib\lib-tk', 'C:\PROGRA~1\QGISDU~1\bin', 'C:\PROGRA~1\QGISDU~1\apps\Python27', 'C:\PROGRA~1\QGISDU~1\apps\Python27\lib\site-packages', 'C:\PROGRA~1\QGISDU~1\apps\Python27\lib\site-packages\PIL', 'C:\PROGRA~1\QGISDU~1\apps\Python27\lib\site-packages\win32', 'C:\PROGRA~1\QGISDU~1\apps\Python27\lib\site-packages\win32\lib', 'C:\PROGRA~1\QGISDU~1\apps\Python27\lib\site-packages\Pythonwin', 'C:\PROGRA~1\QGISDU~1\apps\Python27\lib\site-packages\Shapely-1.2.18-py2.7-win-amd64.egg', 'C:\PROGRA~1\QGISDU~1\apps\Python27\lib\site-packages\six-1.3.0-py2.7.egg', 'C:\PROGRA~1\QGISDU~1\apps\Python27\lib\site-packages\wx-2.8-msw-unicode', 'C:\PROGRA~1\QGISDU~1\apps\Python27\lib\site-packages\xlrd-0.9.2-py2.7.egg', 'C:\PROGRA~1\QGISDU~1\apps\Python27\lib\site-packages\xlwt-0.7.5-py2.7.egg', 'C:\Users\Lee\.qgis2\python\plugins\mmqgis/forms', 'C:\PROGRA~1\QGISDU~1\apps\qgis\python\plugins\fTools\tools']


Original Question:  Let $G$ be a group and $N \trianglelefteq G$. $N$ is abelian. If $\gcd(|G/N|,|\text{Aut}(G)|)=1$, then prove that $N \subseteq Z(G)$.  All I could find is that Inner Automorphisms of $N$ is trivial and the automorphism group is of the form $|N|k, k\in \mathbb{N}.$ I am feeling kind of lost and just wanted a push in the right direction. Thank you in advance.

I was trying to prove that a normal, abelian subgroup of $G$, $N$ is in the center of $G$ given that $|\operatorname{Aut}(N)|$ and $|G/N|$ are relatively prime.   The official question:     Let $N$ be an abelian normal subgroup of a finite group $G$. Assume  that the orders $|G/N|$ and $|\operatorname{Aut}(N)|$ are relatively prime. Prove that $N$ is contained in the center of $G$.   My approach:  I considered the homomorphism: $f:G \to \operatorname{Aut}(N)$ such that $f(g)(n) = gng^{-1}$. This was given as a hint on the problem. So naturally, the first this I did was compute the kernel, and found the kernel to be $N$ since any element in $N$ maps to the identity automorphism since $N$ is abelian.   But I don't know how to use the fact that $\gcd(|G/N|, |\operatorname{Aut}(N)|) = 1$ since it is not necessarily true that $G/N$ and $\operatorname{Aut}(N)$ each have prime order.   Am I missing some trivial property about the kernel of this homomorphism that would enable me to say something about $N$ and or its relationship with $Z(G)$?  Any help would be thoroughly appreciated.


I have ubuntu20.04 lts iso file downloaded from ubuntu website. Can you please guide to convert the iso file into qcow2 file. For instance I need the file ubuntu.qcow2 to be made from ubuntu.iso

Hi all :) I want to create a KVM image from an existing iso file (for glance on OpenStack), but I didn't find how to do it. Can you help me please?


I'm trying to print data from a table that contains a special character such as é. I've used the function htmlentities() hoping it solves the problem, but instead of solving the problem, the data wouldn't appear at all.  For example:  I'm supposed to print this:      "Lightroom 3 pour les Phototographes du Numérique"   However, the character é appears as �. Thus using the fuction htmlentities() should logically solve the problem. Yet whilst using it with a string that contains the character é nothing prints but an empty space. Using the function on a string that contains no special character works fine.     "Lightroom 3 pour les Phototographes du Numerique"   prints as it is, while      "Lightroom 3 pour les Phototographes du Numérique"   prints as     " "   My databse and all the tables are UTF-8 encoded, as well as my html document.

I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1.  Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur?  This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2.


Given a perfect field of prime characteristic $p$, is it necessarily finite? I believe there must be some counterexample. However, the only infinite field of characteristic $p$ that I know of is $\mathbb{Z}_p(t),$ which is not perfect. Any hints?

Motivation for the question: in Neukirch - Algebraic Number Theory (Chapter II - Section 6 - Henselian Fields) the author discusses the context of a nonarchimedean valued field $K$ and its completion $\widehat{K}$, and considers the separable closure $K_v$ of $K$ in $\widehat{K}$, so that $K \subseteq K_v \subseteq \widehat{K}$.  Then he writes the following:     When $K_v$ is algebraically closed in $\widehat K$ - hence in particular $\text{char}(K) = 0$ - this is immediately obvious [...]   (emphasis mine).  My question is about the implicit claim that if $K_v$ is algebraically closed,  then $\text{char}(K) = 0$.  Now we know that $K_v$ is algebraically closed if and only if $K$ is perfect (since every $K_v$ will be the algebraic closure of $K$ and so every algebraic extension of $K$ is separable).  So we're asking whether it is true that if $K$ is perfect, then it must have characteristic $0$.  I know that all fields of characteristic $0$ are perfect. I also know that we have the example of finite fields which are also perfect fields but have prime characteristic. This does not contradict the claim above because the finite fields have only the trivial valuation.  So is there something about having a nonarchimedean valuation on a perfect field that forces its characteristic to be zero?


I am trying to align my words with icon. I tried the methods from this site:     My code:

<%= link_to item.title, item , id: "font-colour" %>

<%=  if item.description.length > 70                     item.description[0..70].gsub(/\s\w+\s*$/, '...')                 else                      item.description                 end         %>

           <%= link_to complete_item_path(item), id: "font-colour", method: :patch do %>              <% end %>
         <%= link_to item_path(item), id: "font-colour", method: :delete do %>                      <%end%>

I have a div with two images and an h1. All of them need to be vertically aligned within the div, next to each other. One of the images needs to be absolute positioned within the div. What is the CSS needed for this to work on all common browsers?

testing...


I was considering how a kayak travels through water, and the thought processes I came up with drove me to this question. Here's what went through my head (keep in mind, what went through my head about how a kayak works could be totally wrong, but nonetheless it's what I thought):   A person with  two oars in his/her kayak can be considered as one collective mass. Since this is a collective mass, if the person turned the boat with his left oar, there is a restoring force pushing the system in the exact opposite direction of the oar's force vector, which is towards the person, so that the water's restoring force vector is away the person. Since the system is a collective mass, this causes a torque on the mass, causing it to rotate in the positive direction. This makes sense, since the boat turns to the right if you drive the left oar.    This made sense to me, since the farther you drive the oar from you, the easier you rotate (which should make sense since torque is directly proportional to the length of the radial vector).  However, this, in my view, shouldn't drive the boat forward, but merely cause it to rotate. Even when you use the left and right oar one after the other like one would do to go forwards, in my mind this would merely make it turn left, then right all in place, each time an oar is driven.   In my view, only a force that is placed on the object's center of mass can cause it to move linearly instead of causing a torque and rotate it. However, this seems to not be true in reality. How should I expand my view of this, and my knowledge of torques, to explain how applying a torque can accelerate an object linearly (albeit not with as much force as it would if it were applied at the center of mass, I'd assume)?  Oh, and just as an aside, when I say "drive the oar" it's just a for-lack-of-a-better-term of using the oar to push the boat forward. I guess "row" is synonymous.

If I push or hit an object in space (vacuum and no gravitation) in direction what is not going trough its centroid, will it rotate or move along in straight line?   I expect that on earth it will depend on what is less difficult for the object (rotation or linear movement). So the object will do some kind of combination of both movements (rotating and also moving along the direction of impulse or force).  But how could an object "decide" what to do in space, where is not resistance?


Hi I am trying to make a home page for my school project and I am trying to put a text box over my image. I have been playing around with position:absolute/relative but the image just covers my navigation bar every time I make it absolute, and the div won't go on top. I don't know if I explained it well but this is what I have:    .navbar {   list-style-type: none;   margin: 0;   float: right;   width: 100%;   position: relative;   clear: none; }  .navbarlist {   float: right;   padding: 2%;   clear: none;   padding: 40px; }  .image1 {   width: 100%; }  .cover {   width: 100%;   height: 500px;   position: relative;   background-color: royalblue;  }  .covercontainer {   position: relative; }

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I want to overlay one image with another using CSS. An example of this is the first image (the background if you like) will be a thumbnail link of a product, with the link opening a lightbox / popup showing a larger version of the image.   On top of this linked image I would like an image of a magnifying glass, to show people that the image can be clicked to enlarge it (apparently this isn't obvious without the magnifying glass).


This sentence extracted from . I wonder whether 'ensure' has been used correctly here? Or as I guess it should be either 'ensuring' or 'to ensure'?     What promises do is ensure that callbacks are always handled in the same predictable manner, eliminating some of the nasty surprises and hard-to-find bugs you can get with callbacks alone.

I was speaking to an English learner and said, “All you have to do is read a lot.” And they thought that sentence wasn’t grammatically correct because I dropped the word to between is and read.  They thought it should be “All you have to do is to read a lot.” That sounds weird to me.   How do I explain to them the reason you drop the to? Or am I incorrect and it really should have a to?


I am running an Ubuntu guest on a Mac host using Virtualbox.  I ran out of space so I doubled the size of the disk from 8G to 16G using VBoxManage modifyhd /path/to/my.vdi --resize 16384  and extended the partition using a GParted live CD.  As you can see, the partition is now 16GB.  $ sudo parted /dev/sda p Model: ATA VBOX HARDDISK (scsi) Disk /dev/sda: 17.2GB Sector size (logical/physical): 512B/512B Partition Table: msdos Disk Flags:   Number  Start   End     Size    Type      File system  Flags  1      1049kB  512MB   511MB   primary   ext2         boot  2      513MB   17.2GB  16.7GB  extended  5      513MB   17.2GB  16.7GB  logical   However, the extended space is not automatically being recognized by /dev/mapper/nanu64--vg-root:  $ df -h Filesystem                   Size  Used Avail Use% Mounted on udev                         477M     0  477M   0% /dev tmpfs                        100M  3.2M   97M   4% /run /dev/mapper/nanu64--vg-root  6.3G  3.9G  2.1G  66% / tmpfs                        497M  4.0K  497M   1% /dev/shm tmpfs                        5.0M     0  5.0M   0% /run/lock tmpfs                        497M     0  497M   0% /sys/fs/cgroup /dev/sda1                    472M  105M  343M  24% /boot tmpfs                        100M     0  100M   0% /run/user/501 /home/stephen/.Private       6.3G  3.9G  2.1G  66% /home/stephen   I tried to extend the volume but it is unaware of this extra space:  $ sudo lvextend -L +8G /dev/mapper/nanu64--vg-root   Insufficient free space: 2048 extents needed, but only 0 available   I also tried the lvresize command with similar results:  $ sudo lvresize -L +8G /dev/mapper/nanu64--vg-root    Insufficient free space: 2048 extents needed, but only 0 available $ sudo lvresize -l +100%PVS /dev/mapper/nanu64--vg-root   Insufficient free space: 1924 extents needed, but only 0 available   I need more room in my home directory.  Is there a way to add extents to /dev/mapper/nanu64--vg-root?  Is there another way to use the extended partition size to increase the free space in /home?  Running resize2fs seems unnecessary:  $ sudo resize2fs /dev/mapper/nanu64--vg-root  resize2fs 1.42.13 (17-May-2015) The filesystem is already 1708032 (4k) blocks long.  Nothing to do!   Running pvdisplay gives the following:  $ sudo pvdisplay   --- Physical volume ---   PV Name               /dev/mapper/sda5_crypt   VG Name               nanu64-vg   PV Size               7.52 GiB / not usable 4.00 MiB   Allocatable           yes (but full)   PE Size               4.00 MiB   Total PE              1924   Free PE               0   Allocated PE          1924   PV UUID               EiMXHd-Kwql-bpFF-Wafc-Beit-o72B-nU8M23

I want to shrink my second (LVM) partition, in order to create a new partition in the newly freed space. I am using the Live CD to do so, because I know I can't resize/move this partition while it is in use. When I opened GParted in the Live CD, I realized that I could not resize the partition, because when I right-click it, the option "resize/move" is disabled.  I tried to unmount it, to "lazy" unmount it (umount -l /dev/sda2) but it didn't work.  A screenshot from GParted:


I want to setblock a command block to setblock a command block with a command inside. For example: /setblock ~ ~ ~ command_block{Command:"say hi"}  works, but: /setblock ~ ~ ~ command_block{Command:"setblock ~ ~1 ~ command_block{Command:"say hi"}"}  does not work (it says its missing a bracket). Is it possible to make this work?

I need help with a specific command that I am using in a new game that I am creating inside of Minecraft. The command is:  /give @p sign 1 0 {BlockEntityTag:{Text1:"{"text":" [MF2]","color":"gold","clickEvent": {"action":"run_command","value":"tellraw @a [""{"text":"[MF2]  ","color":"gold"},{"selector":"@p","color":"dark_aqua"},{"text":" is now an admin of the server!","color":"white"}]"}}",Text3:"{"text":"Click to join Admin","color":"dark_aqua","clickEvent": {"action":"run_command","value":"scoreboard teams join admin @p"}}"},display: {Name:"Custom Sign"}}   If I take out the /tellraw command then the command works fine, but I need the command in there to announce to the game that a new admin has joined.  With the tellraw command, the error message is the following:  Data tag parsing failed: Unexpected token 't' at: text":" [MF2]","color":"gold","clickEvent":{"action":"run_command","value":"tellraw @a [""{"text":"[MF2] ","color":"gold"}, {"selector":"@p","color":"dark_aqua"},{"text":" is now an admin  of the server!","color":"white"}]"}}",Text3:"{"text":"Click to join Admin","color":"dark_aqua","clickEvent": {"action":"run_command","value":"scoreboard teams join admin @p"}}"   If anyone knows how to fix this, please let me know.


How to deserialize this kind of XML document :   <?xml version="1.0" encoding="utf-8"?> <ModelInformation Version="0.9"> <Model> <Block BlockType="SubSysteme" Name="subSysteme1">
xx

xx
    <System>
xx
       <Block BlockType="Entree" Name="Entree_1">          <p Name="coordonne"
       </Block>        <Block BlockType="Entree" Name="Entree_2">
xx
       </Block>       <Block BlockType="Entree" Name="Sortie_3">
xx
       </Block>       <Block BlockType="SubSysteme" Name="SubSysteme1.01">
xx

xx
          <System>
xx
             <Block BlockType="Entree" Name="XXX">                <p Name="coordonne"
              </Block>             <Block BlockType="Sortie" Name="XXX">
xx
             </Block>          </System>       </Block>    </System> </Block </Model> </ModelInformation>   There can be have several systems,subsystems,blocks...  I need to retrieve their attributes names.  First I tried this :   public class Block {     public Block() { }      /*[XmlAttribute("BlockType")]     public String BlockType { get; set; }*/      [XmlAttribute("Name")]     public String Name { get; set; }      [XmlArrayItem("Block")]     public List<BlockType> BlockTypes = new List<BlockType>(); }   and the main :   Block block = null;             using (var stream = new StreamReader(@"C:\Users\U503124\Desktop\BstSP_v41_01460_14_01420_v41_0\simulink\blockdiagram.xml"))             {                 var serialiser = new XmlSerializer(typeof(Block));                 subsystem = (Block)serialiser.Deserialize(stream);                 Console.WriteLine(block.Name);              }   block.Name is null, I don't know why.  There are the same tag HTLM inside tag HTLM. How to process?

How do I Deserialize this XML document:  <?xml version="1.0" encoding="utf-8"?> <Cars>   <Car>     <StockNumber>1020</StockNumber>     <Make>Nissan</Make>     <Model>Sentra</Model>   </Car>   <Car>     <StockNumber>1010</StockNumber>     <Make>Toyota</Make>     <Model>Corolla</Model>   </Car>   <Car>     <StockNumber>1111</StockNumber>     <Make>Honda</Make>     <Model>Accord</Model>   </Car> </Cars>   I have this:  [Serializable()] public class Car {     [System.Xml.Serialization.XmlElementAttribute("StockNumber")]     public string StockNumber{ get; set; }      [System.Xml.Serialization.XmlElementAttribute("Make")]     public string Make{ get; set; }      [System.Xml.Serialization.XmlElementAttribute("Model")]     public string Model{ get; set; } }   .  [System.Xml.Serialization.XmlRootAttribute("Cars", Namespace = "", IsNullable = false)] public class Cars {     [XmlArrayItem(typeof(Car))]     public Car[] Car { get; set; }  }   .  public class CarSerializer {     public Cars Deserialize()     {         Cars[] cars = null;         string path = HttpContext.Current.ApplicationInstance.Server.MapPath("~/App_Data/") + "cars.xml";          XmlSerializer serializer = new XmlSerializer(typeof(Cars[]));          StreamReader reader = new StreamReader(path);         reader.ReadToEnd();         cars = (Cars[])serializer.Deserialize(reader);         reader.Close();          return cars;     } }   that don't seem to work :-(


I would like to edit the metadata of several mp3s at once (say Album, Artists etc.). What is a quick and easy way to do that? I have Windows, OS X and Ubuntu available, so I don't mind using any of these OSes, as long as it's easy and quick.

What software do you recommend for editing MP3 ID3 tags?  (The OS is Windows XP.)


Is there miscegenation in the Star Wars universe? Not only between humans, but also between humans and aliens?

The title is pretty self explanatory, although to expand on the question further I am looking for any examples of inter-species breeding in the Star Wars universe, not just inter-species (ahem) "relations".


I've just installed Kali linux 2.0 and when I tried to install software center by typing apt-get install software-center it didn't work so I did some googleing. And the only answer I found is to update and upgrade by apt-get update apt-get upgrade apt-get dist-upgrade it shows me this:    any help

It shows this error  oot@kali:~# apt-get install software-center Reading package lists... Done Building dependency tree        Reading state information... Done Package software-center is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  E: Package 'software-center' has no installation candidate


I think I read this in the early 90's. In this story, technology was divided up and zealously guarded by the cultures that use it. Different groups held different tech. One group held the secret of internal combustion. The protagonist was from off world and knowledgable. He had to travel from place to place and used his wits to assist/escape from those he encountered along the way.

I listened to this on audiobook and it was great.  The premise was a human ends up travelling to an alien planet. The aliens have a perimeter to their 'base' that is under constant attack from the planet's animals. It is revealed towards the end that there is some sort of signal being transmitted that is making all the animals and plant life attack a certain point on the planet (where the aliens are).   Other major plot points I remember: The human traveller falls in love with an alien. The aliens have a sort of virtual training environment that simulates life outside the perimeter, where plants attack you etc. There is a secondary alien group that the human ends up with, and although they are rivals to other group, they have a trade set up.   Any help much appreciated! Thanks.


I am trying to add glow to windows on a spaceship design. however, I cannot find anywhere half of the nodes I am seeing online, such as glare or glow. I have textures on my model but turning to cycle render turns it into a particle mess, and I have no idea what 'cycle renders means'. my question: can I find the right nodes in standard Blender Render mode? if not, how do I retain my previous model render look in Cycles Render?

I have been following  tutorial until I started adding nodes. The problem is that he has completely different nodes than I have. Even nodes that are created at start are different (I have Material and Output and he has Render Layers and Composite). Have I missed something or should I use different nodes than he?


I installed ubuntu server as VM in VirtualBox and then installed Docker in it to run some containers.  Installed Portainer in it (so it means the VM is connected to the internet).  Now I typed ifconfig to see my IP address and I saw this:  br-70e261a4f7c8: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500     inet 172.18.0.1  netmask 255.255.0.0  broadcast 172.18.255.255     inet6 fe80::42:66ff:fe9b:a3f7  prefixlen 64  scopeid 0x20<link>     ether 02:42:66:9b:a3:f7  txqueuelen 0  (Ethernet)     RX packets 211  bytes 3306540 (3.3 MB)     RX errors 0  dropped 0  overruns 0  frame 0     TX packets 228  bytes 33889 (33.8 KB)     TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0  docker0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500     inet 172.17.0.1  netmask 255.255.0.0  broadcast 172.17.255.255     ether 02:42:41:c6:88:8c  txqueuelen 0  (Ethernet)     RX packets 0  bytes 0 (0.0 B)     RX errors 0  dropped 0  overruns 0  frame 0     TX packets 0  bytes 0 (0.0 B)     TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0  enp0s3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500     inet 10.0.2.15  netmask 255.255.255.0  broadcast 10.0.2.255     inet6 fe80::a00:27ff:feab:bbc0  prefixlen 64  scopeid 0x20<link>     ether 08:00:27:ab:bb:c0  txqueuelen 1000  (Ethernet)     RX packets 89848  bytes 118364599 (118.3 MB)     RX errors 0  dropped 0  overruns 0  frame 0     TX packets 39603  bytes 2588176 (2.5 MB)     TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0  lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536     inet 127.0.0.1  netmask 255.0.0.0     inet6 ::1  prefixlen 128  scopeid 0x10<host>     loop  txqueuelen 1000  (Local Loopback)     RX packets 836  bytes 3376136 (3.3 MB)     RX errors 0  dropped 0  overruns 0  frame 0     TX packets 836  bytes 3376136 (3.3 MB)     TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0  vethfaa59c1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500     inet6 fe80::c4fd:4aff:fe13:a309  prefixlen 64  scopeid 0x20<link>     ether c6:fd:4a:13:a3:09  txqueuelen 0  (Ethernet)     RX packets 211  bytes 3309494 (3.3 MB)     RX errors 0  dropped 0  overruns 0  frame 0     TX packets 215  bytes 32719 (32.7 KB)     TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0   This is what I get when using traceroute 8.8.8.8:    The host OS is Windows 7.  This made me really confused.  I have to say I am really new to Linux, have been using Linux Unity for only around the last 6 months.   At first, I thought 10.0.2.15 is my IP address but I can’t SSH into the VM through PuTTY using it.  The only way I can SSH is through port forwarding in the VM and then using 127.0.0.1 through that port from PuTTY but the internet does not work through this process and as expected it will work only on the host os, not outside.  To open Portainer I have to enter https://serverip:port, but what is my server IP?  And why can’t I ssh into my VM?  P.S. If I use 10.0.2.15 in putty then it says connection refused and the other "inet's" give connection timed out. I even went as far as to install Openbox and Firefox to check Portainer and localhost:port worked flawlessly... but only inside the VM.   EDIT: This is what I want my server to do (if possible)   I open my computer, run my server VM, open PuTTY and SSH into VM from Windows host but internet connection should be there Take out my laptop running Windows and then SSH into the VM on my PC from PuTTY Open browser on my host OS and type https://serverip:port, where port is the port no. of Portainer in my VM server Take out my laptop and open browser and do step 3 to open Portainer Take my laptop and go 10 km away from home and do step 2 and 4   The last step will come later but right now none of them are working. Any suggestions?

I installed Apache on an Ubuntu VM. When I go into the guest and load up Firefox I can see that Apache is working fine when I browse to localhost.  I would like to access this same page through the host. I've tried using the IP address of the guest but nothing comes up. Ideally I would love to set up my Windows 7 (host) to request http://guestserver.com of the Apache server on the guest. How can I do this?


Domain exemple-domain.com has two DNS server: dns1.exemple.com (master) and dns2.exemple.com (slave).  questions: If dns1.exemple.com temporarily disabled and dns2.exemple.com works, is it possible that some attempts to define ip addresses fails?  I try it many times in succession  dig @8.8.8.8 exemple-domain.com | awk '/^;; ANSWER SECTION:$/ { getline ; print $5 }'   and part of the query does not receive a reply  Could there be a part of that traffic would be lost if dns1.exemple.com not working and dns2.exemple.com work?

This is a  about DNS geo-redundancy.   It's extremely common knowledge that geo-redundant DNS servers located at separate physical locations are highly desirable when providing resilient web services. This is covered in-depth by document , but some of the most frequently mentioned reasons include:   Protection against datacenter disasters. Earthquakes happen. Fires happen in racks and take out nearby servers and network equipment. Multiple DNS servers won't do you much good if physical problems at the datacenter knock out both DNS servers at once, even if they're not in the same row. Protection against upstream peer problems. Multiple DNS servers won't prevent problems if a shared upstream network peer takes a dirt nap. Whether the upstream problem completely takes you offline, or simply isolates all of your DNS servers from a fraction of your userbase, the end result is that people can't access your domain even if the services themselves are located in a completely different datacenter.   That's all well and good, but are redundant DNS servers really necessary if I'm running all of my services off of the same IP address? I can't see how having a second DNS server would provide me any benefit if no one can get to anything provided by my domain anyway.  I understand that this is considered a best practice, but this really seems pointless!


I've seen two external drives die without any "notice", lack of speed, performance, nothing, out of the blue, in the past 2 years.  For the current ext. usb drive I have, what would be the most secure and reliable way to check the drive health?

I tried a few utils and none of them worked. Either USB wasnt supported or the drive was 'recognized'. I am trying to figure out if i should dump the drive or not. Its only a year old but the warranty is only a year which is a pity.


Hey guys Im following up a tutorial from Blender Guru making this anvil. However when i add my sub modifier i get these gray spots. The more i zoom in they get bigger, it doesnt matter how many subdivisions i add in the modifier it stays there, only when i turn sub mod off it dissapears. Its probly a noob problem, i tried googling gray spots but didnt come across anything.

TLDNR: Are the circled thingies in the picture normal with a subdivision modifier while in edit mode? (note: subdivision set display modifier in edit mode)  I've been trying to create a character that I might like to use for a game in the future. I'm pretty new to blender and these "artifacts" (unsure if that's what they are) are slowing me down.    This problem doesn't show itself when in object mode, only in edit.  I'm using the mirror modifier and the subdiv modifier.  I've applied the mirror mod before the sub mod, due to some strange separation of vertices at the origin of my character.  However, I went back and forth to check, and with the subdiv mod before the mirror mod, these odd "artifacts" don't seem to show. I can't use that arrangement thought, because of the weird tearing problem D:  Any experienced blenderers out there that think they might have the solution to my problem?  PS/Side question: Should I just go ahead and continue making the model of my character, no matter the mistakes/ngons there might be, and then just go over it afterwards with some nice retopology afterwards?


Let $$F(a)=\int_{-\infty}^\infty \frac{e^{-x^2}}{x^2+a^2}\ dx, \quad a>0.$$ Is it possible to relate $F(a)$ to some known (special) functions?

I would like to evaluate the following integral $(a>0)$      $$\int_{-\infty}^{\infty}\frac{\exp\left(-a x^2\right)}{x^2+b^2}dx.$$   I've have tried integration by parts, putting $e^{-ax^2}=u$, but I come across with this integral  $$\int_{-\infty}^{\infty}\exp\left(-a x^2\right)\arctan\left(\frac{x}{b}\right),$$  and I don't know how to do it. Could you help me?


I am citizen of Poland and I will fly to Canada through US. So, do I need a US visa for my transit journey?

In Europe usually you don't need to go through immigration to change planes (unless you are entering/exiting Schengen). Is it the case in the US as well? May I catch a connecting flight on one of the US airports if I don't have US visa?


Prove that for all positive integers $n, 1^3+2^3+\ldots+n^3=(1+2+\ldots+n)^2$

I tried to prove the following statement using complete induction but I couldn't manage to solve it because I got a complex notation eventually. The statement is the following:  $$\sum_{k=1}^nk^3 = \left(\sum_{k=1}^n k\right)^2$$  I hope someone can help me out!


Currently, hovering the mouse over a Hot Network Question title does nothing (but show the URL in the bottom of the browser, if supported). Sometimes the title of the question alone doesn't make it clear what the question is about, like what programming language, or what fictional universe/work it regards. Clicking is the only way to know for sure.  Can hovering on the title of a question show the current tags of the question?

When browsing Stack Exchange sites, I often notice questions that may interest me in the Hot Questions column, however they sometimes have titles that don't exactly tell what product/game/software/technology they are about (very frequent for Arqade's questions) and the only way to know that is to open the question - not very efficient in my opinion.  This is my feature request - display all the question's tags in a tooltip for a quick look without needing to open the question :


I am trying to do some pretty jewelry photography and I am wondering what type of lens I would need to create a shot like this? Also what is the lighting environment required to take this shot?

I've been looking to upgrade the camera I use at my job. Thinking of getting the Sony a6000. We list things on ebay to sell, and quite frankly I just don't like the lightbox, nor the camera we currently have.  We're using a Nikon D3100, and I forgot the name of the Macro Lens.  Basically, I want to have my own personal camera, that's better than the D3100, but one I can use at the job as well for when we photograph our jewelry.  I do mainly macro photography in the lightbox, and I'm working on my own setup with better lighting and other things to improve our photos. I just ordered an external flash for the D3100 so I can over expose the background to get a nice white one with the pics when I finish my own setup as well, but I digress lol.  I need suggestions for what I should look for in a good macro lens to use when I photograph jewelry. I mainly work with rings, but I also do pictures of pendants/charms, necklaces, bracelets, watches, and other related items too.  Right now I'm considering the SEL30M35. But I haven't bought anything yet (Including the new camera)  To get a better idea of the type of photos that I'm producing with the Nikon, you can check these out: (I don't have the stats for the Aperture, Shutter Speed, ISO, etc)       You can see that when you're 100% zoomed in, things aren't that detailed. Don't get me wrong I've had some nice shots. But that ugly grey background usually says otherwise. I use different backdrops in the cases when the background looks too ugly. I take all my pics handheld, Manual Mode, the focusing is Auto Manual (focuses when I hold the shutter release halfway) and when I'm at the lightbox the rings are only about 5 - 8 inches away, unless I bring them closer to get detailed diamond shots. (Which, I might add, aren't too good.)  I want to get some photos as close to these as possible:       I'm still an amateur, and I'm still learning, but I really want to take better photos. I'd love for them to be sharp and really detailed on most parts of the subject. That and seeing the photos on an LCD screen with the a6000 before actually snapping them to have a look would save me a lot of time.  Merging some of the macro shots to get everything in focus (I think its called focus stacking), and to use focus peaking on the new camera would probably help me a lot more as well. That and a lot better lighting than the lightbox gives off.  Heck, maybe these photos are actually good and I'm just too picky lol, idk.  Anyway, what do you guys think? Would the SEL30M35 macro lens be a good lens for my needs with the jewelry photography I'm trying to do? I understand some lenses aren't compatible with the auto focus or something like that on the a6000 (maybe the E-mount?). How can I be sure they're compatible? Or if I need an adapter, can you suggest one as well?


How can I disable automatic updates in Windows 10? I would prefer to install updates as and when I choose. This was an option in Windows 7 but looks to be missing in Windows 10.  Needless to say 'unplug the internet' isn't a satisfactory solution.

We've upgraded some machines to Windows 10 and realized there were some updates which updated as required. However, I realized there was no option available to stop the download similar to that on Windows 7 and 8.1. The only way I could stop the download was to stop the Windows Update service.  My question is does anyone know of a way to stop auto updates or is stopping the service is the only solution?


I have to prove that there is no natural numbers a,b and c such that a^a + b^b = c^c.  I assumed that a $\geq b $\ Thus a+1 $\ge b $\ and (a+1)^(a+1) $\ $\ge b^b  But I have no idea if I’m thinking correctly.

I was wondering about a problem which i could reduce to asking the following   Does there exist a set $a,b,c$ of prime numbers such that $$a^a+b^b=c^c$$  Is it really a tough problem or do you think it can be solved with some amount of work .  Thank you for your ideas and help .


I want to make my user's input (in Python) case insensitive. Like if user type admin, Admin ADMIN or even he or she types like aDMIN. This should be insensitive so i can get exact input

How can I do case insensitive string comparison in Python?  I would like to encapsulate comparison of a regular strings to a repository string using in a very simple and Pythonic way. I also would like to have ability to look up values in a dict hashed by strings using regular python strings.


there was a nice write up somewhere on here about...  not using kill-9 all the time which is SIGKILL and explained the reasons for doing so, and then went on to explain an order in which one should proceed from least aggressive SIGTERM ending up eventually at SIGKILL or rebooting.  can someone post a link to that for me?  i cannot find it  using kill -l to do a listing I receive as output on the terminal  this is kill dash lowecase L, and NOT dash numeral one  HUP   INT    QUIT     ILL      TRAP     ABRT     BUS      FPE      KILL   USR1 SEGV  USR2   PIPE     ALRM     TERM     STKFLT   CHLD     CONT     STOP   TSTP TTIN  TTOU   URG      XCPU     XFSZ     VTALRM   PROF     WINCH    POLL   PWR SYS   RTMIN  RTMIN+1  RTMIN+2  RTMIN+3  RTMAX-3  RTMAX-2  RTMAX-1  RTMAX   I spaced out the above for readability.  This is from SLES 11.4 x86-64  Am I correct in assuming the order of which these signal names are printed from kill -l correspond to the number you provide the kill command, such that if I wanted the bad KILL I would do kill -9 and if I wanted the better choice of TERM that would be kill -15 ?   Is this the only way to find out these numbers on a given system? Is there a better more universal way of verifying what signals are available on a given linux system {RHEL, SuSE, debian, ... some stripped down version of linux from i don't know where used on some piece of hardware}? If I write code, where & how should one check something system level like this before assuming a signal is: first available, and then that kill -number corresponds to a specific signal? is there a good source for learning about all these types of signals, and what should be expected to always be available, for a typical Linux operating sytem?

I am always very hesitant to run kill -9, but I see other admins do it almost routinely.  I figure there is probably a sensible middle ground, so:   When and why should kill -9 be used? When and why not? What should be tried before doing it? What kind of debugging a "hung" process could cause further problems?


I just , and rejected it for "no improvement whatsoever."  When I hit the "reject" button, I noticed that the text box for entering a custom reject reason is wider than the whole reject box:    This was seen today in Chrome 40.0.2214.93 (and thank you for making me check the version, I'm currently updating my browser)  I believe this is a .

The custom reject reason box goes outside the popup in suggested edit review. See here.    Can we fix this? Please.


I saw many other old posts which states that we won't get our reputation back but I would like to know whether stackoverflow has added an option for it or not? If there is no feature till now please consider adding that feature.

It's possible to offer and award bounties of reputation on questions.   What is a bounty? How can I find questions that have a bounty attached? How do I start a bounty? When can I start a bounty? Why is the system requiring me to choose a bounty amount that's higher than the minimum? Can I use Markdown formatting in the bounty remarks? Can I edit the remark? How long is the bounty period? How do I award a bounty? Can I award a bounty to my own answer? Can I award a bounty to an old answer? If I offer a bounty on someone else's question, can I award the bounty to their answer? After awarding the bounty, can I remove it or move it to another answer at a later time? What happens if there's no answer after the bounty period? What happens if I feel my question is still unanswered? What is automatic awarding? Are bounty awards exempt from the 200 points/day reputation limit? How does Community Wiki mode affect bounties? How does user deletion or post dissociation affect bounties? Can I award a bounty to an answer from a deleted user or one where the author was dissociated? Can I offer a second bounty after the first one has expired? Can I raise my bounty? What happens if a bounty question is closed or deleted? Why can't I vote to close or migrate a bounty question? What happens if I delete my account while I have an active bounty? Do I keep an awarded bounty when I delete my answer? What happens if a question where I awarded a bounty later gets deleted or migrated? Can I cancel my bounty? Can I affect / divide / share part of my bounty to two (or more) users? How many outstanding bounties can a single user have?      See also:  in the Help Center


Okay I am wondering if there is a solution I can use that incorporates itself into the Windows log off, shutdown, restart, etc... menu.   I am looking for this solution to add in the lock screen option. Not lock screen as in log off but lock screen as in lock the screen and have a password prompt on the screen but you can still see what everything is doing in the background (Useful when scanning the computer).  This would be especially useful on my shared computer because then my family can see my screen when I am scanning but not snoop through my account. Obviously, this solution would need to have an option to also switch users in-case the other user really needs to use the computer and the screen is locked but they don't want to shut it off/restart it.  Is there a solution someone can point me to that can do just this???  Oh yeah btw I would like it to be free (Not a trial)...

I am looking for a transparent screensaver. Or a way for there to be no screen saver, but instead of locking, it disables the mouse and most of the keyboard, until I hit an unlock key.


I'm trying to find an example of a ring without identity that does not contain any maximal ideal.    Help me some hints.

As a brief overview of the below, I am asking for:   An example of a ring with no maximal ideals that is not a zero ring. A proof (or counterexample) that $R:=C_0(\mathbb{R})/C_c(\mathbb{R})$ is a ring with no maximal ideals.    A homework question in my algebra class earlier this year asked to exhibit a ring (necessarily without identity) without any maximal (proper) ideals. For solutions to this, it suffices to exhibit an abelian group $(G,+)$ without maximal (proper) subgroups. For, given such a group, define multiplication to be constantly zero. In this case, $G$ becomes a zero ring without maximal ideals (because ideals correspond to subgroups).   It is not particularly difficult to construct examples of the above. For example, consider $(\mathbb{Q},+)$. Another interesting example is $P=\{z\in\mathbb{C}\mid \exists n\in\mathbb{N}, z^{p^n}=1\}$ with standard complex number multiplication as "addition" (that is, as the abelian group operation).   However, any example constructed in this manner is a zero ring, and as such seems "artificial," which I admit, is not a rigorous term. I would like to find a somewhat less artificial example of a ring without maximal ideals. For a definition of "less artificial," let us start with "not a zero ring."   I have a candidate in mind, but I am having trouble explicitly proving that it has no maximal ideals. Let $C_0(\mathbb{R})$ denote the ring of continuous real-valued function on $\mathbb{R}$ vanishing at infinity. Let $C_c(\mathbb{R})$ denote the (two-sided) ideal of compactly supported functions. I believe that the ring $R:=C_0(\mathbb{R})/C_c(\mathbb{R})$ contains no maximal ideals, but I am having trouble showing it.   My intuition for this problem is as follows. Given a function $f\in C_0(\mathbb{R})$, $f(x)$ approaches zero at some "rate" as $x\to\pm\infty$ (possibly different based on $\pm$). Furthermore, for any given rate, we can find a function with a larger rate, in the sense that we can find a $g\in C_0(\mathbb{R})$ such that $f(x)=o(g(x))$ ($f$ is little-$o$ of $g$). Now, even if $f$ is non-vanishing, there is no $h\in C_0(\mathbb{R})$ such that $fh=g$, for any $h$ could not vanish at infinity. Thus the principal ideal generated by $f$ does not contain $g$. By iterating this process we could construct a strictly ascending chain of principal ideals.   Now, the idea is that the ring $R$ consists of these "rates" as described above. I know that this is not precise, or necessarily even correct. But it's my intuition. The previous paragraph shows that we can find an ascending chain of "rates," but a lot of work still needs to be done. If anyone can clean this up, it would be much appreciated.


Suppose we are to colour edges of a regular n-gon with k-colours. How do we count the number of such distinct coloured n-gons?  I know that one way to count these is to use burnside's lemma, but im not able to apply it.

By using Burnside's lemma, I want to find the number of different coloring of vertices of a regular n-gon, with X colors.  By "different" I mean : up to rigid motions.  I've seen some partial results, but I'm not sure about the genralized version.


I was curious if anyone would be able to help me or give me some direction. I have a worksheet with the following sort of data.    +---+----------------+--------+-----+----------------+ |   |       A        |   B    |  C  |       D        | +---+----------------+--------+-----+----------------+ | 1 | Customer Names | Gender | DOB | Customer Names | +---+----------------+--------+-----+----------------+  Etc.   So I wanted to know whether there's a way of being able to search Column A with a predefined list of customer names in Column D, then return the unused names in another column?   I tried the following code but it seems to be repeating the names that don't match. Can anyone see where I am going wrong?  =IFERROR(INDEX($A$3:$A$1999,MATCH(0,IFERROR(MATCH($A$3:$A$1999,$F$3:$F$399,0),COUNTIF($G$1:$G1,$A$3:$A$1999)),0)),"")

I have two columns in Excel, and I want to find (preferably highlight) the items that are in column B but not in column A.   What's the quickest way to do this?