I want to add an alias for nedit editor   alias ne='nedit'  or  alias ne='nedit $1'   works fine   but i want to add & at its end:  alias ne='nedit $1 &'   so that if i do   ne filename  It should open filename in nedit and run it in background  but I get an error  filename : command not found  How can I pass an argument and send the process to the background using aliases?

I want to make an alias in my .bashrc or .bashrc_aliases file (probably the latter).  Specifically, I want to call the clang command for my *.c file I'm writing. What I'm looking for is best summed up if I provide an example:  I have program1.c written I want to be able to type (in the terminal) compile program1, and something like the following should be actually run:  clang -ggdb -std=c99 -Wall -Werror   program1.c -lcrypt -lcs50 -lm -o program1   For those who have taken Harvard's CS50 class, you will recognize this as their make command. So if the above is impossible, and you know another way to make this happen, I'm all ears. I'm trying to avoid using their VM, as my netbook isn't really up to par to handle a VM.


Please look at the figure above. The contents in the List of Figures are crossing the border and they are not appearing fully.  This is the code that I found in the source latex file.   \newpage  \makeatletter  \let \asas \ps@plain  \let \ps@plain \ps@empty  \makeatother \large  \tableofcontents  %\makeatletter  %\let \ps@plain \asas  %\let\asas\relax  %\makeatother  %\thispagestyle{empty}  \listoffigures  %\thispagestyle{empty}  \listoftables   %\thispagestyle{empty}   What can be done ?

When I use \listoftables and \listoffigures I get in the list long captions that appear next to the tables/figures.  I would like to use short captions for this list which summarize these captions. Is that common to do? If so, what is one way to do it?


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

When searching on a site with  enabled (), I saw some  rendering issues: (and currently it's also in the )        Even though the LaTeX rendering is fine when opening the :        The LaTeX code is:  $f(n) = \begin{cases} 0,  & \text{$ \omega<0, \omega=1, \omega>3 $} \\[2ex] -\omega + 1,  & \text{$ 0\le\omega<1 $} \\[2ex] \omega^2 - 1,  & \text{$ 1< \omega \le 2 $} \\[2ex] 3 \omega,  & \text{$2 < \omega \le 3 $} \end{cases}$


C++ allows the programer to use either stack allocated memory or dynamic memory on the heap. I am fairly clear on how the stack operates (I have created stacks as exercises in C++)  but am still curious about how and where "the stack" is defined.   Is "The Stack" a feature of the language, a feature of the OS or a feature of the hardware? I have a vague idea that each stack is something relating to each of the many active thread processes from the perspective of the operating system. This suggest to me that it's implemented on the software level and not a hardwired feature of the CPU or motherboard.  I imagine, in the case of a C++, the compiler might have inserted an implementation of a stack into each binary. Or maybe the  OS applies it's own stack implementation into each running process? How and were is this defined?  I found a similar question  but I don't see it answered and my hope is to re-state the question more directly.

Programming language books explain that value types are created on the stack, and reference types are created on the heap, without explaining what these two things are. I haven't read a clear explanation of this.  I understand what a stack is. But,    Where and what are they (physically in a real computer's memory)? To what extent are they controlled by the OS or language run-time? What is their scope? What determines the size of each of them? What makes one faster?


I would like to have some explanation about a fact which is written in the first chapter of Milnor's book "topology, from the differentiable viewpoint". The fact is the following: Suppose $M,N$ be two differentiable manifolds of the same dimension. Let $f: M \rightarrow N$ be a differentiable map with $M$ compact and let $y \in N$ be a regular value. We define #$f^{-1}(y)$ to be the number of points in $f^{-1}(y)$, thus $f^{-1}(y)$ does not contain any critical point. And now the part which I do not understand: the book says that an observation that can be made about #$f^{-1}(y)$ is that is locally constant as a function of $y$ (where $y$ ranges only through regular values). I don't understand how to figure out this fact, I tough considering #$f^{-1}: f^{-1}(y) \rightarrow \mathbb{N}$, but still remains unclear to me why it should be a locally constant function. Could someone please can explain to me this fact maybe also (if I am not asking too much) giving a simple example.

This is a doubt from Milnor's "Topology from a Differentiable Viewpoint".     For a smooth $f:M\to N$, with $M$ compact, and a regular value $y\in N$, we define $n(f^{-1}(y))$ to be the number of points in $f^{-1}(y)$. It is easy to see that $n(f^{-1}(y))$ is finite. It can also be seen that $n(f^{-1}(y))$ is locally constant; i.e. there is a neighbourhood of $y$ such that for every point $y'$ in that neighbourhood, $n(f^{-1}(y'))=n(f^{-1}(y))$.   The proof for the statement in bold is the following:     Let $x_1,x_2,\dots,x_n$ be the points of $f^{-1}(y)$, and choose disjoint neighbourhoods $U_1,U_2,\dots,U_n$ of these points, which are mapped diffeomorphically into neighbourhoods $V_1,V_2,\dots,V_n$ of $y$. The required neighbourhood is $(V_1\cap V_2\cap\dots V_n)-f(M-U_1-U_2-\dots U_n)$.   I don't understand how $(V_1\cap V_2\cap\dots V_n)-f(M-U_1-U_2-\dots U_n)$ is open. I know that $(V_1\cap V_2\cap\dots V_n)$ is open. However, how can one prove that $f(M-U_1-U_2-\dots U_n)$ is closed? I can see this working if $f$ is surjective, but not otherwise.


I've come back from vacation, and I have an unknown large number of e-mail alerts piled up. Hitting the x in notification center only cleared some of them - I'm assuming it was the last 5 since that's what I have it configured to show.  It seems the only way I can clear them is by hitting "close" on each individual message, but that is ridiculously tedious and I have no idea how long it's going to take. In notification center, only new mails that come in are being shown and dismissable with the general x button.     I've tried switching off mail alerts, removing mail from notification center completely, closing Mail.app and restarting, and nothing clears the old alerts.  Is there a way?  EDIT: this has been happening since Yosemite at least, and is still happening in El Capitan.

I have notifications in the OSX Notification Center, as for most of my apps I am using the setting, "Show in Notification Centre: 10 Recent Items" This is a good setting but rather than have a very full Notification Center, I would still like to clear it from time to time with 1 click.  I am using Yosemite 10.10.3


Is there any way to load a postgresql style for a vector layer using python? There is a function: loadNamedStyleFromDb (const QString &db, const QString &theURI, QString &qml).Does it support loading of postgresql styles?

I would like to write a python macro that upon opening my QGIS project file will reload the default style for each layer from the postgres 'layer_style' table. I have had a look at the  and can only work out how this is done from a sqlite db or .qml file.   Any pointers would be appreciated.


My script is something like this:  #!/bin/bash sudo teamviewer --daemon enable teamviewer sudo teamviewer --daemon disable   It works fine on its own, and it requests my password with a terminal window. So, now I want to make a launcher for it. I have this in my .desktop file:  [Desktop Entry] Version=1.0 Encoding=UTF-8 Type=Application Categories=Network; Name=TeamViewer 12 Comment=Remote control and meeting solution. Exec=gksu /path/here/Start.sh Icon=teamviewer   That way it requests my password with a pop-up instead of a terminal window, but doing this runs the whole script with sudo, which is a problem, because TeamViewer refuses to start with sudo. How can I solve this?

To do a patch manually I must type this command   sudo ./playback_delete_data_patch.sh 09_delete_old_data_p.sql     There is a space just before the 09:   sudo ./playback_delete_data_patch.sh [space] 09_delete_old_data_p.sql   How can I run this inside a script?  There are also several other commands but this one is giving trouble.


Prove or disprove that if f is continuous on a bounded set S. Then f is bounded function on S.

If $f\colon A\to\mathbb R$ is continuous and $A$ is a bounded set, does it necessarily follow that $f$ is bounded?


How do I prove this?  The problem contains the following "hint": Prove that X/Y contains a denumerable family of pairwise disjoint denumerable subsets.   I am not sure how that proves cardinal equivalence. My first instinct was to try to show that a bijection exists between X and X\Y, but that may be extremely difficult which would be why the hint was given.   Any help would be appreciate, and also carefully describe how the solution was found.  Thank you.

I am going over my professors answer to the following problem and to be honest I am quite confused :/ Help would be greatly appreciated!     Let $A$ be any uncountable set, and let $B$ be a countable subset of $A$. Prove that $|A| = |A - B|$    The answer key that I am reading right now follows this idea:  It says that $A-B$ is infinite and proceeds to define a new denumerable subset $A-B$ as $C$. Of course since $C$ is countably infinite then we can write $C$ as ${c1,c2,c3...}$   Once we have a set $C$, we know that the union of $C$ and $B$ must be denumerable (from another proof) since $B$ is countable and $C$ is denumerable.  This is where I start to have trouble. The rest of the solution goes like this...  Since the union of $C$ and $B$ is denumerable, there is a bijective function $f$ that maps the union of $C$ and $B$ to $C$ again. The solution then proceeds to define another function $h$ that maps $A$ to $A-B$.   I am just so lost. The thing is I don't even understand the point of constructing a new subset $C$ or defining functions like $f$ or $h$.  So I suppose my question is in general, how would one approach this problem? I am not mathematically inclined unfortunately, and a lot of the steps in almost all of these problems seems arbitrary and random. Help would be really appreciated on this problem and some general ideas on how to solve problems like these!!!  Thank you so very much!


I'm having trouble finding a way to express this fraction with the amsmath package.    The result I'm getting isn't quite nice. Are there alternative ways to write this fraction?     \documentclass[10pt,norsk, fleqn]{extarticle}  \usepackage[a4paper, margin=1.2cm,includeheadfoot]{geometry}  \usepackage{amsmath}   \begin{document}   $\displaystyle\frac{a}{\displaystyle\frac{b}{\displaystyle\frac{c}{\displaystyle\frac{d}{e}}}}\to\left(\displaystyle\frac{\left(\displaystyle\frac{\left(\displaystyle\frac{\left(\displaystyle\frac{a}{b}\right)}{c}\right)}{d}\right)}{e}\right)$   \end{document}

The following code:  $\dfrac{\left( \dfrac{\left( \dfrac{1}{2}\right) }{2}\right) }{2}$   gives a nasty output:   It seems that the $\left( \right)$ command doesn't do the job.  Any idea how to solve this in general?


When referring to a committee that has been working hard, which of the following would you say?   The committee which has been working hard. The committee who have been working hard.   The committee is made up of people I know, it is not a group of unknown people so I feel strange referring to them as which, but my husband insists that is the correct usage.

What is the correct relative pronoun for "government"? Which of the following phrases is correct? I am writing for an American [English] audience.     The Queensland Government, who licenses several casinos, ...   or     The Queensland Government, which licenses several casinos, ...


I have a geodatabase that contains a table, a point feature class, and a polygon feature class.   Each record in the table has both a related point and a related polygon, so all one-to-one relationships. The geodatabase is currently set up with composite one-to-one relationships. My issue with this is that we sometimes need to replace the polygons with better data. If a user deletes the old polygon before adding the new one, the corresponding table record is also automatically deleted.  It is important that there is referential integrity in this dataset, but I'm wondering if it might make more sense to maintain the relationship classes as simple, and then explicitly test for referential integrity during the QAQC process. We will eventually be allowing partners to edit replicas of this database, and my concern is that this will cause some problems with users.   Is there an efficient way to replace a polygon within a composite relationshp without deleting the tabular record?

I have a polygon shapefile and I want replace every irregular polygon with a circle.  I think I can do it with the Replace Geometry tool. But once the Replace Geometry tool is selected, draw a polygon mode is immediately entered. If I select the circle tool in the Draw tool window, the Replace Geometry tool becomes inactive.  Is there any way to use the Replace Geometry tool to draw a circle polygon?


Why StringBuffer is thread safe and why StringBuilder is not. Why the StringBuffer is working best in multi-threading and StringBuilder is in single-threading.   I saw there are methods which are common for both StringBuilder and StringBuffer, then why they are varied in their functions.

What is the main difference between StringBuffer and StringBuilder? Is there any performance issues when deciding on any one of these?


Does there exist an infinite set of cardinality such that it can never be reached by taking power sets of a set with cardinality aleph-null. Please prove your answer, or include a link to a proof. I apologize for any excessively loose terminology, I am new to this subject of different infinities.

Can someone explain to me how there can be different kinds of infinities?  I was reading "" by  and came across the concept of countable and uncountable infinities, but they're only words to me.  Any help would be appreciated.


I found a couple of questions where, for example, they ask you to calculate the number of digits in $18^{200}$ and only the value of $\log 18$ is given. Can anyone tell me a way?

I read recently that you can find the number of digits in a number through the formula $\lfloor \log_{10} n \rfloor +1$ What's the logic behind this rather what's the proof?


For the past few days there have been news about scientists solving the old problem of bending a piece of spaghetti and breaking it into exactly two halves. Earlier it was already determined that the spaghetti breaks into several pieces because when it breaks at one spot, mechanical waves travel along the piece. Initially one would believe that such vibrations would dampen without breaking the piece, but opposite was found to be true. In reality, the waves cause heavy bends at several spots that are sufficient to cause further fractures.  I'm wondering how is it possible? If we first beld the piece we "store" potential energy in the bent piece. When we release it, how can it again bend FURTHER at some other spot? Would this require more potential energy than we initially put in the bend?

You can try it with your own uncooked spaghetti if you want; it almost always breaks into three when you snap it. I am asking for a good physical theory on why this is along with evidence to back it up. Or, a reference to a good study previously done on this would also be satisfactory. The math behind everything would be a great bonus if it exists.  My hypothesis is that a strand of dry spaghetti has two main pressure areas being put on it due to how brittle and how high the length to thickness ratio is, and that they snap at almost the same time due to the manufacturing process of the strand causing it to have a very consistent breaking point. Also that vibrations from a first break could influence the causing of another. I'm not sure how this could be tested, though.


I wanted to style every second post inside of a query post and I found a solution which nearly works.   the thing is: it outputs just two posts (older ones will be igrnored) but i want to output ALL posts but with every second one with a sepcific class.  Here's what i did so far…  <?php $paged = (get_query_var('paged')) ?   get_query_var('paged') : 1; $wp_query = new WP_Query(); $wp_query->query('posts_per_page='.get_option('posts_per_page').'&paged=' . $paged);                  global $wp_query;                         query_posts(array_merge($wp_query->query, array(                             'paged'          => get_query_var('paged'),                             'posts_per_page' => 9999999                         )));                 ?> <?php if ($wp_query->have_posts()) : ?> <?php $count = 0; ?> <?php while ($wp_query->have_posts()) : $wp_query->the_post(); ?> <?php $count++; ?>  <?php if ($count == 1) : ?>

   <?php elseif ($count == 2) : ?>

   <?php endif; ?> <?php endwhile; ?> <?php endif; ?>

I'm working on a WordPress site for my band and I'd like to mark every 3rd post on our blog page to have a special class applied to it, anybody have any pointers on how to achieve this? Any help is very very appreciated, thanks! rock n roll.


I'm having trouble with this problem from an old analysis qual:  Find a function $f$ such that for $p\in (1,\infty)$, $f$ is in $L^p(\mathbb{R})$ only when $p=4$.

I'm wondering if it's possible for a function to be an $L^p$ space for only one value of $p \in [1,\infty)$ (on either a bounded domain or an unbounded domain).  One can use interpolation to show that if a function is in two $L^p$ spaces, (e.g. $p_1$ and $p_2$,with $p_1 \leq p_2$ then it is in all $p_1\leq p \leq p_2$).   Moreover, if we're on a bounded domain, we also have the relatively standard result that if $f \in L^{p_1}$ for some $p_1 \in [1,\infty)$, then it is in $L^p$ for every $p\leq p_1$ (which can be shown using Hölder's inequality).  Thus, I think that the question can be reduced to unbounded domains if we consider the question for any $p>1$.   Intuitively, a function on an unbounded domain is inside an $L^p$ space if it decrease quickly enough toward infinity. This makes it seem like we might be able to multiply the function by a slightly larger exponent. At the same time, doing this might cause the function to blow up near zero. That's not precise/rigorous at all though.     So I'm wondering if it is possible to either construct an example or prove that this can't be true.


The decision:      you have submitted an invitation from the British army which state you   have been invitated you for an interview and assessment. I note that   the letter provided does not guarantee your enlistment. You have   provided no explaination for your apparent new interest in joining the   British army and you have nothing to indicate that you have ever   sought to join the military of your home     My question is that could there be that maybe someone removed my visa application letter? Because to my understanding it's like I only provided the invitation letter? And the bank balance from my business account show I have enough money that there is no resonable reason for me to go and do the assessment which am not sure of being enlisted. The the bank balance is 8000pounds and my budget was to use 4500 because I don't know what's out therefore I needed to be financial stable yet they have used it as I have money and I cant go to UK for just an assessment and spend that amount forgetting there is air ticket, hotel bookings, logistics plus pocket money.   And there decision I can not apeal why?

Many of the UK visa refusals we see here share a common pattern and the prevailing reasons refer to V 4.2 (a) and (c).    I do understand that, while the applicants may describe very different individual circumstances, there's a consistent pattern and, broadly, fall into specific categories:    Credibility (lifestyle, lack of ties, visit history, lies & omissions) Funding (insufficient funds, provenance of funds, funds parking) Sponsorship (family, friends, employer)   Question: What most commonly triggers a UK visa refusal where V 4.2 (a) and (c) are given as the grounds?  Secondarily: Given that there is a clear pattern, to what extent are these refusals predictable? Does sponsorship make a difference? Is there a set of personal circumstances, however abstract, where a refusal is all but guaranteed? For example, why do those we see here on TSE who sought entry for the PLAB or British Army appear to be refused with a common theme? Is there a uniform shortcoming or is it just discrimination?   PLAB: What is about applications for a visa, for the purpose of sitting the Professional and Linguistic Assessments Board (PLAB) exam, that seem to invite refusals. After all, the test is given so that international medical graduates can show that they qualify to practise medicine in the UK. The first part, PLAB 1, can be taken in centres outside of the UK. However, PLAB 2 can be taken only in the UK. Why can't you can't get a visa just to sit the exam, promising that you'll leave immediately after?    British Army: Since Commonwealth citizens are eligible to apply online to join, even those who don't reside in the UK, why is it so difficult to get a visa just to attend an interview to see whether you are suitable? Even with an invitation from the Army, such visa applications seem to be unsuccessful. Isn't a career in the British Army a valid reason?     Lastly:  After such a refusal, what approaches would increase the chance of a successful application?


There are some web applications which are running on my server. Most of them use their own small server, which are bound to localhost. So for access them, I am using NGINX which runs as a proxy.  Now, there is a web app which has a hard coded HTML-TITLE. So the problem is that I cannot change it to the name of my site.  My idea: If NGINX is running as a proxy, all data has to pass NGINX so I am able to change this TITLE befor the server sends the data to the client. Because this web application only use on site, the traffic will not be huge so it can take time to change the TITLE.  Does anyone has an idea how to modify this? I only know how to chnage HEADER settings...

Is it possible to use any of the following HTTP servers: Apache, Nginx or Lighttpd as a proxy to make the following:   Disallow certain HTTP bodies (web pages) based on their content (e. g., words) Substitute certain content with another (e. g., by regular expression)   Not only core functionality but also modules may be used. Also, I may consider writing my own module, so the question would be then if it's easy to write such a module for any of these servers.  I know that Squid + DansGuardian/SquidGard allow this but I am interested in mentioned software.


I have a function, unique(a) that takes a list, a, of numbers and returns only one of each value. At the same time, it maintains the order of the list. I also have a function, big_list(n) that generates a list of len(n).  The reason to why I reverse the direction of the list is so that when removing values, It removes them from the back of the original list, just to make the modified list more clean and readable when comparing it to the original list.   The function works when I have a relatively small length of the list I'm creating, but when I get to larger lengths, such as 1,000,000 for ex, the execution time takes FOREVER.  If anyone can help me by making my function a lot faster, that would be great!  FYI : I need to use a set somewhere in the function for the assignment I am working on. I still need to remove list items from the back as well.  Thanks in advance!  def big_list(n) :     # Create a list of n 'random' values in the range [-n/2,n/2]     return [ randrange(-n//2, n//2) for i in range(n) ]  def unique(a) :     a = a[::-1]     b = set(a)     for i in b :         while a.count(i) != 1 :             a.remove(i)             a.count(i)     a = a[::-1]     return a

Is there a built-in that removes duplicates from list in Python, whilst preserving order? I know that I can use a set to remove duplicates, but that destroys the original order. I also know that I can roll my own like this:  def uniq(input):   output = []   for x in input:     if x not in output:       output.append(x)   return output   (Thanks to  for that .)  But I'd like to avail myself of a built-in or a more Pythonic idiom if possible.  Related question:


I wanted to see if anyone can confirm the following sentence reads correct, with proper agreement: "Now remember, your sales and marketing teams are the life force that keeps business flowing to you." I believe this is correct because the nearest noun to the verb "keeps" is singular, but I wanted to make sure. I also believe it is okay to say "sales and marketing teams are the life force," turning these two groups into a singular noun, but again, I wanted to be absolutely sure. Combining singular and plural always seems a little uncertain to me. Thank you all in advance!

My fish's native habitat is rice fields. My fish's native habitat are rice fields.   Which one is correct? I'm pretty sure it's the first, since 'is' modifies 'habitat,' but it still sounds weird...


I'm about to switch my OS from Windows XP to Ubuntu on an HP laptop, primarily for internet use. Is there an "idiot's guide" anywhere here that I can print up before I try it? The plan is to put the OS on a separate USB hard drive so, if I really mess up, I won't lose everything on the laptop HD.  I have some technical programs on the laptop that won't run on anything but Windows so I will still need XP on occasion. Thanks.

I need my pre-installed version of Windows 7 (or any other version of Windows), how could I install Ubuntu without erasing it?


In my survey data I have two variables: One is an ordinal variable with 5-scale scoring from Agree to Disagree. My second variable is an nominal variable where the participants had to choose from 7 different options. I now want to test if people who showed strong agreement to the ordinal variable are more likely to choose one specific option of the nominal variable. Is there any method to use for this situation? Sorry, if this has been asked many times already.

I've already read all the pages in this site trying to find the answer to my problem but no one seems to be the right one form me...  First I explain you the kind of data I'm working with...  Let's say that I have an array vector with several names of city, one for each of 300 users. I also have another array vector with scores response to a survey of each user or a continuous value for each user.  I would like to know if exist a correlation coefficient that compute the correlation between these two variables so, between a nominal and a numeric/continuous or ordinal variables.  I've searched on the Internet and in some pages they suggest to use the contingency coefficient or Cramer's V or Lambda coefficient or Eta . For each of this measure the just say that they could be applied for such data in which we have a nominal variable and interval or numerical variable. The thing is that searching and searching, trying to understand every one of them, sometime is written or watching the examples that they are reasonable to use them if you have dichotomous nominal variable, except for Cramer's V, other time is not written any requirement for the type of data. A lot of other pages say that is right to apply regression instead, that is right, but I would just simply like to know if there is a coefficient like pearson/spearman for this kind of data.  I also think that is no so properly to use Spearman Correlation coeff since the cities are not sortable.  I have also built the function of Cramer'sV and Eta by myself (I'm working with Matlab) but for Eta they don't talk about any p-value to see if the coefficient is statistically significant...  In the matlabWorks site there is also a nice toolbox that says to compute eta^2 but the kind of input it needs is not understandable.  Is here someone that have done a test like mine? If you need more detail to understand the kind of data I'm using just ask me and I'll try to explain you better.


I have a couple of questions about reputation. In order to receive the +100 site association rep, does one need to earn the reputation entirely on one website, or can it be earned accross multiple(For example, 50 on Meta, 100 on StackOverflow, and 50 on Code Review)?   When one does accrue 200 reputation, is the site bonus awarded to accounts on exchanges which had already existed before earning the reputation?

I was just awarded +100 reputation on all of my Stack Exchange accounts.  What is this bonus for? It simply says "Association Bonus" on my reputation overview.  Also:   What privileges does the association bonus grant users? Can I lose the association bonus? Does it make my reputation 101 everywhere? Can I earn the association bonus on sites I haven't joined yet? Does it matter which site I earn the 200 reputation on? Will I get an association bonus every time my reputation on a site crosses 200 points? Does the association bonus allow me to answer protected questions? Does the association bonus count towards the reputation cap? Can I get the association bonus if I only have a profile on one site? What else is there to know about the association bonus?


I wish to travel to Canada, and stop over in Europe for 3 months on my way there. I'm Indian, so I require both a Schengen visa and a Canadian visa.  Logically it should be Schengen first and then Canada but would the Schengen guys ask for a valid Canadian visa for them to grant me a Schengen visa? I fly out of Brussels to Montreal. Can't find information about this online.

I intend to apply for a tourist visa to Canada and a tourist Schengen visa. My itinerary will be from Manila to Paris, France to Rome, Italy then Canada where I plan to visit/stay for 2-3 months with an invitation letter from my daughter who is a permanent card holder. I understand I have to buy a return  ticket from Canada to Manila where I reside. Is this a feasible itinerary?  Will this affect my chance of getting a Schengen or even a visa to Canada as this is my first time to apply for a tourist visa to these countries although I have been to several countries in Asia like Japan, Korea, Hongkong, Macau, Singapore, Thailand, Malaysia, Indonesia, Vietnam, Cambodia to name a few. Will the consul in the France Embassy here in Manila look for a return flight from a member country to Manila?


I am having trouble removing a file which cannot be removed manually via the File manager. Here is the code I tried putting into the Terminal:  rory@rory-laptop:~$ rm /var/www/html/index.html rm: remove write-protected regular file '/var/www/html/index.html'? y rm: cannot remove '/var/www/html/index.html': Permission denied   So as you can see, I am unable to remove the file. Does anyone have any ideas on what I should do to remove the file?

I made a directory called "shadi" and set this permission for it  sinoosh@ubuntu:/home$ ls -ld shadi drwxr-xrwx 2 root root 4096 Jul  1 01:58 shadi   In this situation I have "others" permissions, but why can I not delete it?  sinoosh@ubuntu:/home$ rm -r shadi/ rm: cannot remove ‘shadi/’: Permission denied


I want some symbols/text in math mode to be Arial? This cannot ve done by changing the settings for various kinds of text in math mode like the default italic text or the default bold text. Put another way, I want something like \arial{text} the same there is stuff like \mathbb{text} and \mathcal{text}. How do I do this?

For creating the graphics for my thesis (function graphs, flow charts, line art sketches) I've chosen to use the sans serif font by  \renewcommand\familydefault{\sfdefault}    However when I use mathematical symbols like $p_{s}$, they are still typeset in roman font and that looks weird:    So I wonder:   how could I force mathematical expressions also be typeset in \sfdefault if I do, are there any negative sideeffects to expect (with greek signs or other special symbols?) OR should I typeset all "mathematical" graphs (axis labels etc.) in roman font, and only make the other graphics like flow charts and sketches with sans serif font?


Is it possible to delete an array from an object?  For example, lets say i have an object called response and within it and array called items:  var response = { success: false, items:[] };   How do i delete 'items' from the response object?  thanks

Say I create an object as follows: let myObject = {   "ircEvent": "PRIVMSG",   "method": "newURI",   "regex": "^http://.*" };  How should I remove the property regex to end up with new myObject as follows? let myObject = {   "ircEvent": "PRIVMSG",   "method": "newURI" };


Let's say we are given a closed race track with a given and constant width. I am to implement an algorithm which finds both shortest path trajectory and minimum curvature trajectory for the car.   I have found a paper  which explains both the shortest path trajectory and the  minimum curvature trajectory.  I understood the shortest path equations except (8) but couldn't understand any equations in the minimum curvature path trajectory. Could someone please explain those equations?

Let's say we are given a race track, which may be described as a closed curve of given width (it may differ along the curve). My task is to implement an algorithm which finds two kinds of trajectories for the car. The first one is the shortest path, i.e. such closed curve contained in the race track that enables the car to drive the shortest distance per lap, the speed is irrelevant. The second one is minimum curvature path where the car can achieve higher speeds in the corners, the length is irrelevant.  The following picture shows the two kinds of paths for an example race track:   I found a paper () that describes the two problems in such way that they can be presented as quadratic programming problems. The problem is that I don't have sufficient knowledge to convert the input data to the appropriate matrices, needed in the quadratic equation. I can only understand the transformations up to some moment.  Here are the descriptions of the algorithms, found in the mentioned paper:   Could someone please help me and explain the transformations done in the equation (6) and (7) for the SP problem and virtually all equations for the MCP problem? The format of representation of all the coordinates, depicted in Fig. 2 in the document, is perfectly clear for me. I realize that some equations are just the intermediate steps to achieve the goal, so maybe there's an easy, algorithmic way to explain a newbie like me how I should transform the given coordinates to get the matrices for the quadratic programming solver.


I am trying to install caffe by partitioning my PC hard drive. I am going to use the following codes for this purpose :  cd ~  mkdir deep-learning  cd deep-learning sudo apt-get install libprotobuf-dev libleveldb-dev libsnappy-dev libopencv-dev libhdf5-serial-dev protobuf-compiler  sudo apt-get install --no-install-recommends libboost-all-dev   sudo apt-get install libatlas-base-dev  sudo apt-get install the python-dev  sudo apt-get install libgflags-dev libgoogle-glog-dev liblmdb-dev cd ~/deep-learning  git clone http://github.com/BVLC/caffe.git cd caffe  cp Makefile.config.example Makefile.config #change to only cpu # CPU_ONLY := 1  make all make test make runtest  cd ~/deep-learning/caffe  make pycaffe  echo export PYTHONPATH=~/deep-learning/caffe/python:$PYTHONPATH >> ~/.bashrc    But after executing   sudo apt-get install libboost-all-dev   terminal is showing me error saying   E: Unable to correct problems, you have held broken packages. What can I do to solve this problem?

After upgrading from 10.04 to 12.04 I am trying to install different packages.  For instance ia32-libs and skype (4.0).  When trying to install these, I am getting the 'Unable to correct problems, you have held broken packages' error message.   Output of commands:  sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.   After running this:  sudo dpkg --configure -a foo@foo:~$ sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.


Consider:   Please check that the username and password is correct. Please check that the username and password are correct.   If I had to break the statement into its parts:   Please check that the username is correct. Please check that the password is correct.   I feel that username and password can be seen as a single noun and therefore the correct form is is. Based on  answer, I'm confused: the number of the verb is determined by the number of the verb's subject. Is username the subject or object?  Can someone please advise?    This question was marked as a duplicate but the duplicate tagged isn't quite related. Rather, based on @user2370114 response, this  is a better match. Furthermore, it doesn't address my concern about the subject vs object distinction (as answered by @RegDwigнt♦).  To summarize:   If you are speaking of multiple things, and even if both were singular, the copula (verb of being) would still be plural. Both username and password are the subject. Interestingly, in my use here, are felt more natural :)     So can I rather ask: is there ever a time when items can be seen as a single subject and therefore take the singular form of the verb?

Can anyone tell me if I should use inspire or inspires in this phrase?     An extraordinary leader whose vision, values, integrity and boundless curiosity inspires all who follow in his footsteps.


I could show in calculus where $0<θ<\frac{\pi}{2}$ like this   $$\frac{d(θ)}{dθ}=1<\frac{1}{2}(\cosθ+\sec^2θ)$$  But I curioused about would it could prove by geometric way likewise trigonometric identities. I try to show with the area of circular sector but I failed...  So this is question:   How to show $$\frac{\sinθ +\tanθ}{2}>\theta$$ where $0<\theta<\frac{\pi}{2}$ in geometric way?

Suppose $x \in (0,\frac{\pi}{2})$ and we want to prove $$x<\frac{\sin x +\tan x}{2}$$I tried to prove it by taking $f(x)=\sin x+ \tan x -2x$ and show $f(x) >0 ,when\space  x \in (0,\frac{\pi}{2})$ take f'$$f'=\cos x +1+\tan ^2 x-2\\=\tan^2 x-(1-\cos x)\\=\tan ^2 x-2sin^2(\frac x2)$$ I get stuck here ,because the last line need to be proved $\tan ^2 x>2sin^2(\frac x2) ,when\space  x \in (0,\frac{\pi}{2})$ $\bf{Question}:$ Is there a geometrical method to prove the first inequality ? (or other idea)  Thanks in advance.    $\bf{Remark}: $I can see the function is increasing $when\space  x \in (0,\frac{\pi}{2})$ like below :


As said in the title. Specifically, I want to loose nothing, neither Systemd services, cron jobs, files in my \home folder, config... If upgrading means risking loosing one of these, then I won't upgrade. So is it possible, and if so, how?

I am currently using Ubuntu 10.04. I know there is a 10.10 release, but can I upgrade directly to 11.04? Could you walk me through the steps please?


Let $a, b, c, d, e, f$ be nonnegative real numbers such that $a^2 + b^2 + c^2 + d^2 + e^2 + f^2 = 6$ and $ab + cd + ef = 3$. What is the maximum value of $a+b+c+d+e+f$?   I need help proving that $a+b+c+d+e+f \leq 6$

Let $a, b, c, d, e, f$ be nonnegative real numbers such that   $a^2 + b^2 + c^2 + d^2 + e^2 + f^2 = 6$. $ab + cd + ef = 3$. What is the maximum value of $a+b+c+d+e+f$ ?.   I was thinking about somehow manipulating the numbers to get $\left(a + b + c + d + e + f\right)^{2}$, but I don't really know what to do.


Update:  The user is now suspended network wide again.    Looking at  who is suspended on a few sites, but not most‡, I see he has a reputation of 1 although the graph says different:        The .  (He is currently suspended on some other sites and was suspended network-wide until a couple of days ago.)  Adding up the numbers from 2 pages of  with code like:  var reps = $(".rep-cell").map ( (J, node) => {     return parseInt (node.textContent.trim(), 10); } ).get ();  ttlRep = reps.reduce ( (total, num) => total + num, 0);   yields 61 on the first page and 40 on on the second page for a total of 101.  So,    Is this user suspended on that site (still) and I just can't see it due to low rep or a bug? Did the rep recalc script crash/miss that one user and site combo? (But not the other 174 accounts that the user has.) Something else?       ‡ Note that all of his network accounts are hidden to the casual user.

Recently digging on the data SE I've found an interesting phenomena. Namely, .  He has a question and an answer, both with 4 vote count (if it matters: his question has +5/-1, his answer +4/0).  He is not in cage.  On these data, I think his reputation should be 1+5*5-2+4*10 = 66.  Despite that, his reputation is only 1.  His  seems to show the correct values, although his reputation graph shows a third value (rep 81, with a small decrease around early Januar to 79):  Why is it so? What could affect his reputation out of these?  (P.s. I don't know anything from him, I found his page by some data SE digging.)


I just lost 2TB data when i reinstalled ubuntu 13.04 on already installed ubuntu 13.10. Can anyone help me how to extract or recover whole partition, I am sure hard disk is formatted because its now showing only 30gb used data out of 2TB.  So is there any way to recover whole partition. I am trying test disk for now which is recovering very slowly but at least recovering.

Are there any tools, methods, incantations to recover recently deleted files on Ubuntu?  If it makes any difference, I want to recover a  2.x database file. But would be better to have a method/tool that works on any kind of file.


As the title says, is it possible to have a dynamic IP from an ISP and make it renew when the lease is up to the same IP? I ask because I would like to run a Home-Page and a VPN + FTP service on the IP.

How can a computer with dynamic IP work as a WebServer?


I'm trying to printf the following number:  Float val = 500.5080;  printf("%f",val);   Why the printed value i'm getting is 500.507996 ? I will be glad for a detailed explanation.

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


How would I show this? I tried letting $k=2n+1$ for some $n\in\mathbb{Z}$, then   $$(k-1)k(k+1) = 4n(2n + 1)(n+1).$$    I have shown that $4n(n+1)$ is divisible by $8$... but am unsure of how to get the $3$ factor there.

At our college, a professor told us to prove by a semi-formal demonstration (without complete induction):   For every odd natural: $24\mid(u^3-u)$   He said that that example was taken from a high school book - maybe I din't get something, but I really have no idea to prove that without using complete induction.  Any idea of smart demonstration?  Thanks for your help. (Excuse my bad English.)


Hi I am writing for a book. Header screen should be as follows.    \documentclass[12pt]{book}  \usepackage[top=25mm,bottom=25mm,left=25mm,right=25mm]{geometry}  \usepackage[all]{background} \usepackage{amsthm} \usepackage{afterpage} \usepackage{xcolor} \definecolor{myaqua}{rgb}{1,1,1} \definecolor{myaqua1}{rgb}{0,0.5,0.45} \usepackage{fancyhdr} \usepackage{ptext,xcolor} \usepackage{showframe}  \usepackage{tikz} \usetikzlibrary{calc}   \usepackage{changepage} \strictpagecheck   \usepackage{fancyhdr} \fancyhf{} \fancyhead[LO,RE]{\thepage} \fancyhead[LE]{عنوان کتاب} \fancyhead[RO]{\leftmark} \renewcommand{\headrulewidth}{0pt} \pagestyle{fancy}   \usepackage{xepersian} \settextfont[Scale=1.2]{Yas}  \linespread{1.5}  \newcommand*{\vsp}{2cm} \newcommand*{\hsp}{2.5cm}  \newcommand{\MyTikzLogo}{%  \begin{tikzpicture}[remember picture,overlay] \checkoddpage \ifoddpage     \draw  [color=magenta,line width=2mm] ($(\paperwidth+\hsp,-\vsp)$) --($(\hsp,-\vsp)$); \else     \draw  [color=cyan,line width=1mm] ($(0,-\vsp)$) --($(\paperwidth-\hsp,-\vsp)$); \fi  \end{tikzpicture} }  \SetBgContents{\MyTikzLogo} \SetBgPosition{current page.north west} \SetBgOpacity{1.0} \SetBgAngle{0.0} \SetBgScale{1.0} \makeatletter %\renewcommand \thechapter {\@tartibi\c@chapter} \def\@makechapterhead#1{%     \vspace*{250\p@}%     {\parindent \z@ \if@RTL\raggedleft\else\raggedright\fi \normalfont         \ifnum \c@secnumdepth >\m@ne         \if@mainmatter         \huge\bfseries \@chapapp\space \thechapter         \par\nobreak         \vskip100\p@         \fi         \fi             \interlinepenalty\@M         \Huge \bfseries #1\par\nobreak         \vskip 10\p@ }} \makeatother \begin{document}  \chapter{عنوان فصل} %\pagecolor{myaqua1}\afterpage{\nopagecolor} \pagecolor{myaqua1}\afterpage{\nopagecolor} \newpage \pagecolor{myaqua}\afterpage{\nopagecolor} \section{عنوان بخش}  %\ptext[1-40] \begin{tikzpicture}[remember picture,overlay] \checkoddpage \ifoddpage \draw  [color=magenta,line width=2mm] ($(\paperwidth+\hsp,-\vsp)$) --($(\hsp,-\vsp)$); \else \draw  [color=cyan,line width=1mm] ($(0,-\vsp)$) --($(\paperwidth-\hsp,-\vsp)$);  \fi \end{tikzpicture}   \end{document}

How can I draw  this is  figure?      \documentclass[12pt]{book}  \usepackage[top=25mm,bottom=25mm,left=25mm,right=25mm]{geometry}  \usepackage[all]{background}  \usepackage{ptext,xcolor} %\usepackage{showframe}  \usepackage{tikz} \usetikzlibrary{calc}   \usepackage{changepage} \strictpagecheck   \usepackage{fancyhdr} \fancyhf{} \fancyhead[LO,RE]{\thepage} \fancyhead[LE]{عنوان کتاب} \fancyhead[RO]{\leftmark} \renewcommand{\headrulewidth}{0pt} \pagestyle{fancy}   \usepackage{xepersian} \settextfont[Scale=1.2]{Yas}  \linespread{1.5}  \newcommand*{\vsp}{2cm} \newcommand*{\hsp}{2.5cm}  \newcommand{\MyTikzLogo}{%  \begin{tikzpicture}[remember picture,overlay] \checkoddpage \ifoddpage     \draw  [color=magenta,line width=1mm] ($(\paperwidth+\hsp,-\vsp)$) --($(\hsp,-\vsp)$); \else     \draw  [color=cyan,line width=1mm] ($(0,-\vsp)$) --($(\paperwidth-\hsp,-\vsp)$); \fi  \end{tikzpicture} }  \SetBgContents{\MyTikzLogo} \SetBgPosition{current page.north west} \SetBgOpacity{1.0} \SetBgAngle{0.0} \SetBgScale{1.0}  \begin{document}  \chapter{titel}  \section{sec }  \ptext[1-40]   \end{document}


Does ZF (without choice) prove the following? $\forall \ ordinal \ \alpha \ \exists f( f:\alpha \times \alpha \hookrightarrow \alpha)$ where: $ \alpha\times \alpha $ is the cartesian product of $\alpha$ by itself; and $\hookrightarrow$ signifies injection.

I have a few questions about Godel's pairing function and proving that c = c * c for aleph cardinals.  Mostly, though, I'm concerned that most of the proofs I've seen are erroneous, and this concerns me. (And I've searched many times for a good proof.)  So we order the class On x On lexicographically, and this is a proper well-ordering, so that On x On is order-isomorphic to On by a unique mapping P: On x On -> On.  This makes perfect sense. But in every "proof" of c = c * c that I've seen, there's been some glaring mistake.   For example, one "proof" relies on the "proposition" that "If $\gamma$ = max($\alpha$,$\beta$) and at least one of $\alpha$,$\beta$ is infinite, then P($\alpha$,$\beta$) <= card($\gamma$) x card($\gamma$)."  But it seems to me this is false, and here's why: so it seems clear that (0,$\omega$) is the first limit ordinal in On x On under the lexicographical ordering, and of course $\omega$ is the first limit ordinal in On--consequently, we must have P(0,$\omega$) = $\omega$; but then P(1,$\omega$) = $\omega$ + 1, which contradicts the "proposition" (since P(1,ω) = ω + 1 is not <= $\omega$, which is card($\gamma$) x card($\gamma$), as $\gamma$ = $\omega$). Am I wrong here?  I guess what I'm asking for is some kind of real explanation as to how Godel's pairing function is used to prove that c = c * c for all aleph cardinals c. Even if this just involves pointing me toward a decent source, that would be awesome.


After yesterday Windows Update,Epson printers cannot be used start from this morning. All the PC in Windows 7 and Windows 10 cannot detect these Epson printers. Any solution for this?

I have Windows 10 Pro x32 and an Epson LX-310 printer that was working. Yesterday, Windows 10 automatically updated with 2017-11 Cumulative Update for Windows 10.   Today, I cannot print. The printer status is on. When I click "Print a test page", it quickly says the test page has been sent but the printer does not print it.   My printer is connected to a USB port. What wrong with my Windows 10?


When I create a long beamer frame which is automatically splitted into slides by using allowframebreaks option, it has a little bigger vertical margin for the first slide. I would like to make it more consistent with the rest of the frame. I cannot find the reason of this behavior and a way to fix it.  \documentclass{beamer}  \begin{document}  \begin{frame}[t,allowframebreaks]     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\     A\\ \end{frame}  \end{document}

When you use the allowframebreaks option in beamer then you get additional frames if the content is too high for one frame. The vertical spacing gets disturbed when you use a list (itemize, enumerate, description), for example, see the following animation. I used the t option (for top alignment) for the frame.     \documentclass[aspectratio=169]{beamer}   \begin{document}  \begin{frame}[t,allowframebreaks] \frametitle{Frame Title} \setlength{\mylength}{\baselineskip} \begin{itemize} \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \end{itemize}  \end{frame}  \begin{frame}[t,allowframebreaks] \frametitle{Frame Title}  Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\ Text\\  \end{frame}  \end{document}    I thought of a solution, when I read  question where they explain the different length in lists. The main idea is to check if the current frame is not the first frame of a frame continuation and add the needed vertical space. I thought that \topsep is the needed length but apparently, it is not quite right. It ist almost perfect but it still "dances" a little bit. Which additional length do I need? Here's the animation and the used code.     \documentclass[aspectratio=169]{beamer}  \setbeamertemplate{frametitle continuation}{%     (\insertcontinuationcount)%     \ifnum\insertcontinuationcount>1%     \vspace*{\topsep}%     \else%     %     \fi% }  \begin{document}  \begin{frame}[t,allowframebreaks] \frametitle{Frame Title}  \begin{itemize} \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \item Test \end{itemize}  \end{frame}  \end{document}   Related        Definition of \itemize in beamer  In beamerbaselocalstructure.sty I found  \renewcommand{\itemize}[1][]{%   \beamer@ifempty{#1}{}{\def\beamer@defaultospec{#1}}%   \ifnum \@itemdepth >2\relax\@toodeep\else     \advance\@itemdepth\@ne     \beamer@computepref\@itemdepth% sets \beameritemnestingprefix     \usebeamerfont{itemize/enumerate \beameritemnestingprefix body}%     \usebeamercolor[fg]{itemize/enumerate \beameritemnestingprefix body}%     \usebeamertemplate{itemize/enumerate \beameritemnestingprefix body begin}%     \list       {\usebeamertemplate{itemize \beameritemnestingprefix item}}       {\def\makelabel##1{%           {%             \hss\llap{{%                 \usebeamerfont*{itemize \beameritemnestingprefix item}%                 \usebeamercolor[fg]{itemize \beameritemnestingprefix item}##1}}%           }%         }%       }   \fi%   \beamer@cramped%   \raggedright%   \beamer@firstlineitemizeunskip% }   But I do not understand where the different kinds of spaces are defined that cause the "dancing".  "Evil" Stuff in beamer  Motivated by the comment of @cfr I searched the beamer documentation for "evil" stuff -- this is what I have found (beamer guide version 3.41):   Do not use subsubsections, they are evil. Never ever use the evil option shrink.  Using this [again shrink] option is very evil. The use of this [allowframebreaks] option is evil.


I have a naive question about the option to opt-out of cookies consent. An example is a user has been given consent to place google analytics cookie in their browser. Is it possible to provide a functionality in our website for the user to press "reject cookies" and then the google analytics cookie is deleted from their browser? If not, what is the reason?

How do you delete all the cookies for the current domain using JavaScript?


I'm creating a div with a span on the spot using jquery, like so  $("[data-modal]").click(function(event) {     event.preventDefault();      var container = $("

").addClass("modal m-form").appendTo(document.body);     var close = $("").addClass("modal-close").appendTo(container); }   so far so good...  Then, i'm binding an event to the selector modal-close, like so  $(".modal-close").click(function(event) {     alert("close the dialog"); });   That one doesn't work, so i've tried this one, with no success:  $(".modal-close").on("click", function(event) {              alert('close the dialog'); });   What am i doing wrong?

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


It has been mentioned that the first Death Star had a class 4 Hyperdrive and a class 20 backup, so it could move from system to system (so it could destroy targets.) As the weapons system of the First Order's Starkiller base is partly based off of the Death Star weapons system, does Starkiller base have a hyperdrive to move?

In Star Wars: The Force Awakens, once the Starkiller Base has depleted the star it is drawing power from, is it supposed to travel to another star where it can draw more power? Or is it non-mobile and supposed to fire a few, limited shots only? Or can it somehow reuse the star it is drawing power from, even after it has been depleted?  Its name suggests that it will "kill" or completely deplete the star it is drawing power from, but I haven't noticed an indication in the film that the Starkiller Base can travel to other stars.


I want to show the fundamental group of a topological group is abelian. In fact, the question says the topological group is path connected. I do not know where I should use path-connectedness. I think, it is still true if we do not suppose path-connectedness. Right?  I do not know homotopy. I have just learned the fundamental group.

Hypothesis: Let $G$ be a topological group with identity element $e$.  Let $\mu$ denote the multiplication mapping in $G$.  Goal: Show that $\pi_1(G,e) = \pi(G)$ is an abelian group via the hint below.  Hint: There are two products on $\pi(G)$.  The usual product $\circ$ defined for the fundamental group and the product $\ast$ induced by  $$ \ast: \pi(G) \times \pi(G) \cong \pi(G \times G) \overset{\pi(\mu)}{\rightarrow} \pi(G). $$  Show that there is a common two sided unit, $u \in \pi(G)$ for both products and there is a distributive law  $$ (f \ast g) \circ (a \ast b) = (f \circ a) \ast (g \circ b) $$  Attempt:   Suppose the distributive law in the hint holds.  Suppose further that $1$ -- the identity element in $\pi(G)$ with respect to $\circ$ -- serves also as the identity element in $\pi(G)$ with respect to $\ast$. Then for $a,b \in \pi(G)$, we would have the following relationship:  $$ (1 \ast a) \circ (b \ast 1) = (1 \circ b) \ast (a \circ 1) $$  so that  $$ a \circ b = b \ast a $$ Then if we can show that for all $f,g \in \pi(G)$ that $f \ast g \iff f \circ g$, we could complete the above relation to  $$ a \circ b = b \ast a = b \circ a $$  so that $\pi(G)$ is abelian as desired.   Question: Am I on the right track?


My kid has a battery-operated toy, it runs on three AAA batteries. Once, the toy suddenly stopped working, but all batteries were good. I decided to disassemble the toy and look for internal damage or some loose wire. Found nothing and reasembled it. The next day, on a last attempt before dumping it, I placed the batteries back on just to confirm, but it just started working again. Have no idea what changed. Humidity maybe? Now the issue. Since then, the toy is killing one of the batteries in the pack, in a week or so. It stops working, I check the batteries, the one on the left is completely dead with 0 volts, the other ones are ok. I replace the dead battery, it gets back working ok. Another week or so, the toy stops working again, and the newly replaced battery is dead. It's always on the same deck position. Never seen this happening and it didn't seem possible when using similar batteries, except if one was defective. But this isn't the case. The toy will always kill the battery on the left. Any thoughts on this? (Edit) I thought the above was self-explanatory, sorry if not. The three batteries sit side by side, but in serial on the circuit. One of the batteries depletes really fast. "Battery on the left" is only a visual reference, in practical means, it only represents that the battery that suffers the issue is always the one sitting on that specific slot. I'll try to add some photos, maybe later today if I have the chance. @Frog I thought that a short in one battery would affect them all. But maybe not, now I see. After examining the plates and springs, it doesn't seem possible to have o short here as they seem to be very far from each other. A short makes sense, but it should burn out the battery in less than a day. And I've re-examined the toy inside and can't seem any clue of a short. @Kyle B I've replaced one single cell, because this one was 0 volt and and the other two looked ok. So, by replacing only this dead one by a new one, leaving the other two, and after a week, the new battery was dead and the other two not, it was the proof that the fault was not on the battery. I've disassembled it again and I just can't find any clues on any damaged wire, pinched stuff, short anywhere, any damage on the board, anything. Thank you for the help.

My kid has a battery-operated toy, it runs on three AAA batteries, connected in serial. Once, the toy suddenly stopped working, but all batteries were good. I decided to disassemble the toy and look for internal damage or some loose wire. Found nothing and reassembled it. The next day, on a last attempt before dumping it, I placed the batteries back on, just to confirm, and it just started working again. Have no idea what changed. Humidity maybe? Now the issue. Since then, the toy is killing one of the batteries in the pack, in a week or so. It stops working, I check the batteries, the one on the left is completely dead with 0 volts, the other ones are ok. I replace the dead battery, it gets back working ok. Another week or so, the toy stops working again, and the newly replaced battery is dead. It's always on the same deck position. Seems a short, like @Frog stated, but the plates and springs seem to be far apart. Could be damage to the wires, a pinch, or something like @Kyle B stated. But by looking inside I can't spot anything suspicious. Can't be faulty battery, because replacing just the damaged one by a new one, and the new one gets dead as well, proves the issue cannot be on this battery, I think. Every time this happens, I now remove the dead battery, place one of the others on this place, and place the new one elsewhere. I have now placed photos. Can anyone help? (this is a re-post as the other one got closed. This time I tried to be more clear, and added photos)


I have installed Ubuntu on a 128GB drive, but I ran out of space. Got a few warnings in form of notifications of out of space, me knowing that I used probably 20GB max or even less than that.   Decided to dig in and saw that for some reason /var/log is huge, more precisely kern.log and kern.log.1. In my case:  /var/log$ sudo ls -laSh | grep "kern" -rw-r-----   1 syslog            adm              47G iul  6 23:42 kern.log.1 -rw-r-----   1 syslog            adm              63K iul 11 14:42 kern.log   How can this be? How can a log file, even kernel related can get this big this fast? And more importantly how can I stop it, Permanently? Sure I can remove it but it will grow again fast and chubby.  Also why does Ubuntu behave like this?

( deals with a similar issue, but it talks about a rotated log file.)  Today I got a system message regarding very low /var space.   As usual I executed the commands in the line of sudo apt-get clean which improved the scenario only slightly. Then I deleted the rotated log files which again provided very little improvement.  Upon examination I find that some log files in the /var/log has grown up to be very huge ones. To be specific, ls -lSh /var/log gives,   total 28G -rw-r----- 1 syslog            adm      14G Aug 23 21:56 kern.log -rw-r----- 1 syslog            adm      14G Aug 23 21:56 syslog -rw-rw-r-- 1 root              utmp    390K Aug 23 21:47 wtmp -rw-r--r-- 1 root              root    287K Aug 23 21:42 dpkg.log -rw-rw-r-- 1 root              utmp    287K Aug 23 20:43 lastlog    As we can see, the first two are the offending ones. I am mildly surprised why such large files have not been rotated.  So, what should I do? Simply delete these files and then reboot? Or go for some more prudent steps?  I am using Ubuntu 14.04.  UPDATE 1  To begin with, the system is only several months old. I had to install the system from scratch couple of months back after a hard disk crash.  Now, as advised in ,  I first checked the offending log files using tail, no surprise there. Then, for deeper inspection, I executed this script from the .  for log in /var/log/{syslog,kern.log}; do    echo "${log} :"   sed -e 's/\[[^]]\+\]//' -e 's/.*[0-9]\{2\}:[0-9]\{2\}:[0-9]\{2\}//' ${log} \   | sort | uniq -c | sort -hr | head -10 done   The process took several hours.  The output was in the line of,   /var/log/syslog : 71209229  Rafid-Hamiz-Dell kernel:  sda3: rw=1, want=7638104968240336200, limit=1681522688 53929977  Rafid-Hamiz-Dell kernel:  attempt to access beyond end of device 17280298  Rafid-Hamiz-Dell kernel:  attempt to access beyond end of device    1639  Rafid-Hamiz-Dell kernel:  EXT4-fs warning (device sda3): ext4_end_bio:317: I/O error -5 writing to inode 6819258 (offset 0 size 4096 starting block 54763121030042024)        <snipped>  /var/log/kern.log.1 : 71210257  Rafid-Hamiz-Dell kernel:  attempt to access beyond end of device 71209212  Rafid-Hamiz-Dell kernel:  sda3: rw=1, want=7638104968240336200, limit=1681522688    1639  Rafid-Hamiz-Dell kernel:  EXT4-fs warning (device sda3): ext4_end_bio:317: I/O error -5 writing to inode 6819258 (offset 0 size 4096 starting block 954763121030042024)    (/dev/sda3 is  my home directory. As we can find,   lsblk /dev/sda NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT sda      8:0    0 931.5G  0 disk  ├─sda1   8:1    0 122.1G  0 part / ├─sda2   8:2    0   7.6G  0 part [SWAP] └─sda3   8:3    0 801.8G  0 part /home    Why a process will want to write beyond the limit is actually outside the scope of my comprehension. Perhaps I will want to ask a different question in this forum if this continues even after a system update.)  Then, from  (you may want to check  for a deeper understanding), I executed,   sudo su - > kern.log > syslog   Now, these files have zero sizes. The system is running fine before and after a reboot.   I will watch these files (along with others) in the next few days and report back should they behave out-of-line.  As a final note, both  the offending files (kern.log and syslog), are set to be rotated, as inspection of the files (grep helped) inside  /etc/logrotate.d/ shows.  UPDATE 2  The log files are actually rotated. Looks like the large sizes were attained on a single day.


Can a Windows10 Guru help automate this?  I have failed at automating Lord Neckbeard's solution in the following post:    Ideally, I should either run the batch file on an entire directory of videos, or at least drop the video onto a batch file in file explorer.  EXAMPLE FILE (temporarily available):   Failures: I fell back on Powershell as a last resort, but that leads to code signing issues. I tried extracting the unique changes using a batch file, but I couldn't get the variables to retain their values inside loops or subroutines. One of many attempts:  SETLOCAL ENABLEDELAYEDEXPANSION SET lastres=none FOR /F "eol=; tokens=1,2,3 delims=, " %%i in (allkeyframes.txt) do (    if %j == %lastres% (echo "ignore") ELSE (         set lastres=%%j         echo %%j %%i %%k          echo !lastres!     )  )    I tried extracting the contents of resolutionchanges.txt using SET /P segs=<resolutionchanges.txt but all I got were special characters and 0's.  SET /P segs=<resolutionchanges.txt set filenam=%1 echo %segs% echo %filenam% echo S:\_sys\ffmpeg\bin\ffmpeg -i %1 -map 0 -c copy -segment_times %segs% -reset_timestamps 1 -f segment %filenam%_%%03d.flv ) pause   Here is the currently working "manual" process:    drag video onto a batch file that contains:     ffprobe -v error -show_entries frame=pkt_pts_time,width,height -select_streams v -of csv=p=0 %1 > allkeyframes.txt    (allkeyframes.txt sample...)  13.652000,640,480 13.755000,640,480 13.597000,480,360 13.652000,480,360   paste this text in POWERSHELL:  $o="" $n=0 foreach($line in (Get-Content allkeyframes.txt)){   $nline = $line.Split(",")   $nline2=($nline[1]+$nline[2])   if ($nline2 -ne $preventry) {     $n0=$nline[0]     $o="$o,$n0"     $n=$n0 }   $preventry = $nline2 } if ($o.length -gt 1){ echo $o.Remove(0,1) > resolutionchanges.txt } else { Write-Host "No resolution changes found" -ForegroundColor Red }   (resolutionchanges.txt:)  13.597000,25.618000,33.628000,45.598000   enter the following in the command window, after pasting contents of resolutionchanges.txt and changing "input.flv" to the video name (Win10 refused my attempts at batching this):     ffmpeg -i input.flv -map 0 -c copy -segment_times 13.597000,25.618000,33.628000,45.598000 -reset_timestamps 1 -f segment output_%03d.flv

I have many video files (flv/mp4) that change resolution mid-stream (720p/1080p/640).    I would like to use something like ffmpeg to automatically detect the change in resolution and split the videos into their individual scenes, keeping their existing encoding quality: segment without re-encoding (Video1-scene1.flv, Video1-scene2.flv, etc).  I have found various methods to split upon silence, upon scene change, upon black scenes, but nothing as simple as a change in resolution width.   These files often cause video editors/trimmers to crash, and manually identifying and removing low resolution scenes is very time consuming if I simply convert the entire video to 1080p.  The algorithm is probably as simple as comparing the current frame to the previous frame, and if they are different resolutions, split the video and start a new segment.  Can anyone help please?  EXAMPLE FILE (temporarily available):   Below are a few related answers:          Additional Resources: Using Lord Neckbeard's solution, I am attaching the (unfortunately very manual) process that I eventually got to work on Windows10. Perhaps it can spawn other ideas around ffmpeg. (I posted a separate question for anyone who is GURU enough to: )  drag video onto a batch file that contains:     ffprobe -v error -show_entries frame=pkt_pts_time,width,height -select_streams v -of csv=p=0 %1 > allkeyframes.txt    (allkeyframes.txt sample...)  13.652000,640,480 13.755000,640,480 13.597000,480,360 13.652000,480,360   paste this text in POWERSHELL:  $o="" $n=0 foreach($line in (Get-Content allkeyframes.txt)){   $nline = $line.Split(",")   $nline2=($nline[1]+$nline[2])   if ($nline2 -ne $preventry) {     $n0=$nline[0]     $o="$o,$n0"     $n=$n0 }   $preventry = $nline2 } if ($o.length -gt 1){ echo $o.Remove(0,1) > resolutionchanges.txt } else { Write-Host "No resolution changes found" -ForegroundColor Red }   (resolutionchanges.txt:)  13.597000,25.618000,33.628000,45.598000   enter the following in the command window, after pasting contents of resolutionchanges.txt and changing "input.flv" to the video name (Win10 refused my attempts at batching this):     ffmpeg -i input.flv -map 0 -c copy -segment_times 13.597000,25.618000,33.628000,45.598000 -reset_timestamps 1 -f segment output_%03d.flv


Passing DOM elements to WebWorkers gets tricky since all references to the DOM are 'lost'. I need to check objects that are passed before the WebWorker's message is sent.  What is the fastest way to check if an instance of an object is a DOM-element OR/AND part of the DOM tree, OR has 'children' that contain any references to the DOM tree?  piece of the usage:  var a = new SharedWorker("bigdatahandler.js");    a.postMessage(s);  s //<--should not be a DOM object

I'm trying to get:  document.createElement('div')  //=> true {tagName: 'foobar something'}  //=> false   In my own scripts, I used to just use this since I never needed tagName as a property:  if (!object.tagName) throw ...;   So for the second object, I came up with the following as a quick solution -- which mostly works. ;)  The problem is, it depends on browsers enforcing read-only properties, which not all do.  function isDOM(obj) {   var tag = obj.tagName;   try {     obj.tagName = '';  // Read-only for DOM, should throw exception     obj.tagName = tag; // Restore for normal objects     return false;   } catch (e) {     return true;   } }   Is there a good substitute?


Are there any restrictions to energy that must be consumed to make calculations? Can calculations theoretically be done without consuming it?

As far as I know, today most of the computers are made from semiconductor devices, so the energy consumed all turns into the heat emitted into space.  But I wonder, is it necessary to consume energy to perform computation?   If so, is there a theoretical numerical lower bound of the energy usage ? (I even have no idea about how to measure the amount of "computation") If not, is there a physically-practical Turing-complete model that needs no energy?     edit: Thank @Nathaniel for rapidly answering the question and pointing out it's actually . Also thank @horchler for referring to the  and the related . There are lots of useful information in the comments; thank every one! This whole stuff is really interesting!


I found this question:   It says:   take all the candidates in our system (which only includes people who have at least a total score of 5 in that tag.) sort by their total score in the tag figure out where you fall   I am looking at  where I active answered. Based on Top Answerers, there are at least 20 people with score 7+. So, it should show something like top 20% for me. However, it doesn't.  Am I missing something?

In the Careers CV, there is a zone with one or more "top x% for [tag]".    What are the conditions / rules for a tag to appears in this zone? While I answer quite a lot in the abap and sap tags in SO, I gave only a few answers in java. However, only the java tag appears (and I'm pretty sure that I would be better placed in the top % of abap than in java).  I could not find the rules, or how I can find the same info on my profile. I also checked that I did not ask the top% not to be displayed for these tags. This is not the case. The tag simply doesn't appear.


Let’s say I have an outdoor weatherproof electrical box on the front of my house. Can I use a regular ‘ol outlet instead it, or are there special ones intended for external use?

If I use a regular GFCI in a Weather Proof In-Use box does the GFCI have to be the Weather Resistant kind?


I've cloned an element in jQuery and now want to remove this when I click on the 'x' of the cloned element.    There is a codepen here:     I can't work out if the reason it isn't working is because I need to return the variable $myClone outside the function (which i've tried), or if I need everything to happen inside the main function with a nested function?  For some reason jQuery isn't recognising either the cloned element when I click on the prepended 'x' to remove it, or the prepended 'x' itself.    $(document).ready(function() {    $('.holder').click(function() {     var $myClone = $(this).clone()       .appendTo(this)       .addClass('cloned')       .css({         position: 'absolute',         background: 'blue',         top: 0,         'z-index': 10,         left: 0       });      $($myClone).prepend('
X
');      $('.closeX').click(function() {       $($myClone).remove();     });    });  }); .wrapper {   width: 100%;   height: 100%; }  .holder {   width: 20vw;   height: 100px;   background: red;   position: relative;   margin-bottom: 5px;   display: inline-block;   transition: all .25s ease-out;   z-index: 0;   transform-origin: top left; }   /*CSS for the prepended 'x' that shows on cloned element*/  .closeX {   position: absolute;   background: yellow;   top: 5px;   right: 5px;   width: 25px;   height: 25px;   line-height: 25px;   text-align: center;   cursor: pointer; }

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I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


What would happen in Planetside 2 if one of the three forces were to be completely 100% invaded and all of their territories taken over?

As enemy bases are captured, they just seem to respawn right in the middle of friendly captured territory. This is looking like a perpetual cycle, and none of the three teams ever gets closer than to the very edge of winning the whole continent, only to lose lots of territory again.  So is this by design? Is Planetside 2 eternally to be at war, with no winner ever? I was hoping it would be more like a 'match'. I admit that both are almost the same thing, but there is at least the closure of winning/losing sides this way.


When I enter a multiplication sign, I can either use \times or use the unicode character × (U+00D7) directly. Which one should I use? How about less common things like ∞ (infinity, U+221E)? I really like entering the math symbol directly as it is more readable, but some text editors don't support unicode characters well.

Is there any pros and cons for using of Unicode (and vice versa) in LaTeX equations?  Consider two examples:  \lim_{h→0}∫_{x_0}^{x_0 + h}\frac{f(t)}{h} = f(x_0)  x_0 ⇔ ∀ 𝜀 > 0, ∃ 𝛿 > 0,(|x-x_0| < 𝛿 ⇒ |f(x)-f(x_0)| < 𝜀)   And without Unicode:  \lim\limits_{h \to 0}\int\limits_{x_0}^{x_0+h}\frac{f(t)}{h}=f(x_0)  x_0 \Leftrightarrow \forall\epsilon > 0, \exists\delta>0,(|x-x_0|<\delta \Rightarrow |f(x)-f(x_0)|<\epsilon)   With latest XeLaTeX the result is the same, so!, what's better?


EDIT: Future visitors - the cited duplicate is not a duplicate. Ignore Ramhound's (and other's) claims. This is not a question about removing Get Windows 10 malware because it keeps returning. Instead, its a question about installing the security updates after  Get Windows 10 malware hijacks the update process.    Patch Tuesday was yesterday. My Windows 7 machine took about 10 or 15 security updates. I attempted to install the updates on my mother's Windows 7 machine, but it appears GWX.exe has returned. The malware has gotten more aggressive, and it has hijacked the Windows Update process. (I've already removed it completely twice).    I visited Show all available updates and selected all the updates. But when I clicked Ok and returned to install screen, the malware was still controlling the screen, and there was no Install updates like I am used to seeing.  I also clicked the Get Started button (with an immediate exit) hoping I could dismiss the malware, but it did not return control of the update process to me.  How do I install the outstanding Windows Updates?

I cancelled the Microsoft Windows 10 Reservation and uninstalled KB3035583, but Windows 10 is still trying to install.   After I uninstalled KB3035583 and restarted my laptop as instructed, I could not find KB3035583 to hide it.   Now Windows 10 is sitting in my Windows Update saying that it will install when I restart my computer.


Model: MacBook Pro (13-inch, 2018, Four Thunderbolt 3 Ports)  Cmd-Tab to an application does not keep focus on the app. I have to click on the application for it to get focussed on.   Can someone help me fix this?

On some occasions, when I use cmd+tab to switch to a window, the window itself doesnt show- though the menu bar of that window does show. If I want to show the window, I have to the doc and click the icon- and then the window will show.  I thought it has to do with the desktop space of that window, but it isnt- I just can't seem to make the window show on cmd+tab, I have to click it from the doc.  Am I missing something? is there a way to show the window when using cmd+tab?


I am doing my 1st year Master's degree in Biotechnology. I got selected for the Khorana Program for Scholars conducted by Indo-U.S. Science and technology forum, to do a 3 months internship at a U.S. University.   I have enough reasons to come back to India as I have to complete my Master's degree after returning so that I can apply for higher studies. There was a personal fund mentioned in my DS-2019 that is to be provided by my U.S. mentor as scholarship. I explained this in the interview. I didn't get any questions or asked for any documents to show my tie to my home country, although I brought everything with me.   What should I do next time to avoid visa rejection? Should I have provided them all the documents even if they didn't ask for it?

I went for B1 U.S. Visa at the U.S. Embassy in Delhi.   Interviewer: *Good Morning*. Me: *Good Morning* Interviewer: *What is your designation?* Me: *I am a Software Engineer.* Interviewer: *What is the name of your company?* Me: *It is XXX (I replied).* Interviewer: *What is the name of your client?* Me: *It is YYY (I replied).* Interviewer: *Have you ever been to U.S. before?* Me: *NO* Interviewer: *Have you ever been abroad before?* Me: *NO*   At this point he rejected my Visa with letter mentioning 214 (b) as the reason. I don't know why he actually rejected it.  But, I have decent 2+ years of experience with my company. And, I was going on a business meeting with the client. I would have come back after 2 weeks.  I don't know if re applying will help.


I'm trying to get a grasp on the A* pathfinding algorithm. Using the image I attached.    If the green square represents the start, and red represents the end. wouldn't the algorithm bring me up towards the top of the grid, and then circle me back around, because of the wall?   It would seem the algorithm would never start by moving downward first because the F cost would initially appear more expensive?  Is this a problem with the basic manhattan heuristic? Or am I just missing something?

I would like to understand on a fundamental level the way in which A* pathfinding works. Any code or psuedo-code implementations as well as visualizations would be helpful.


In The Hobbit and The Lord of the Rings, we are introduced to Mithril, a metal described as being stronger than steel but much lighter in weight.  It is also shown to have a silver sheen and the crafting of it is implied to require greater skill than steel.  Tolkien's works are often written in such a way as to create a real world mythological connection; Middle Earth is just our world in the distant past.  In modern times,  and its alloys are used for many industrial purposes due to its light weight -- at 35 to 45% less weight than steel, when built to the same standards, it is considered much stronger per unit weight. It also has a nice silverish gleam when polished and was in use for over a century by the time of Tolkien's writings.  So, to the point: is there any counter proof to the theory that mithril may be the substance currently known as aluminum? I do not require a Word of God answer, but if there is one that would be great.

While reading descriptions of mithril in The Lord of the Rings, it struck me that its properties might well correspond to a real material, possibly as an alloy with other metals. Is there such a real-world substance?


I have installed Ubuntu for Windows 10 Subsystem (WSL2) following all the steps in the official information page. When I click Ubuntu from the start menu of Windows 10, it outputs this: Welcome to Ubuntu 20.04 LTS (GNU/Linux 4.19.104-microsoft-standard x86_64)   * Documentation:  https://help.ubuntu.com  * Management:     https://landscape.canonical.com  * Support:        https://ubuntu.com/advantage    System information as of Sat Aug  8 17:13:27 CEST 2020    System load:  0.35               Processes:             8   Usage of /:   0.5% of 250.98GB   Users logged in:       0   Memory usage: 1%                 IPv4 address for eth0: 172.25.240.158   Swap usage:   0%     0 updates can be installed immediately. 0 of these updates are security updates.    The list of available updates is more than a week old. To check for new updates run: sudo apt update  This message is shown once once a day. To disable it please create the /home/iskandar/.hushlogin file. iskandar@iskandarbasal-dell-2019:~$  My question is: How can I proceed to get the home interface of Ubuntu and use it from a graphical interface? Where can I create the file which is indicated in the above message?

I searched around, and currently there are two methods suggested; installing an enhancement for Windows Subsystem for Linux and installing an XServer.  I want to know which method is the most hassle-free (easy to install AND to use), and which one is less memory-heavy.  I just want Synaptic and CMake. Why couldn't that be a builtin feature?


User Disenfranchisement  When a user notices a featured Meta.SE topic in their own site's sidebar that impacts them, and they click through to Meta.SE, a significant number of them, regardless of their expertise in their subject and site, cannot show their disagreement with the change by downvoting because they have not already participated in Meta.SE enough to downvote.  Evidence  The results of this user disenfranchisement are clear.  You have announcements with an upvote/downvote record of 594/124 while the highest voted response is negative towards the proposal, and has 629/26 votes.  It is then trivial to assume that because the main post's votes are largely positive, there must be significant support for the proposal, when the reality is that there is significant unhappiness about the proposal, but we've disenfranchised users so they are unable to express it appropriately. Further, we cannot simply assume that the 629 negative cancel out the 594 positive and assume half the people don't like the proposal because it's possible to vote positively for the proposal, then after reading the later discussion changing one's mind and being unable to change their vote on the proposal until someone edits it (they certainly can't edit it!).  Work-arounds  While there are some work-arounds, such as hosting discussions on individual metas and trying to bring those responses to the table, as well as upvoting the negative responses in the hopes that people they trust pay attention, this is inadequate.  In such cases people still assert that there is more positive support for such a proposal than negative disapproval.  Meta is murder different  Meta is actually another Stack Exchange site for experts about Stack Exchange, and so it makes sense to have some bars for participation in terms of how new users can contribute and gain reputation.  As you notice, though, there are things discussed here that have significant, direct impact on other sites.  Further, downvotes on Meta are often used to indicate disagreement - in the same way we originally used Uservoice to prioritize features and express agreement and disagrement. To some degree it's a priority queue, but it's terribly unbalanced if the vast majority of our users can only put positive pressure on change proposals.  Conclusion and recommendation  Down-voting should not be tied to the high level of reputation currently required -  you don't need Meta.SE expertise to evaluate the usefulness of an idea to you or your site. On a regular site you vote according to truthiness, but here you vote according to usefulness given your perspective/experience.  Meta.SE should lower the bar for downvoting, making it equivalent to upvoting.  Because there is still a 2 rep cost associated with downvoting, this will still be self-limiting, and prevent significant abuse.  Once a person downvotes significantly, they will have to also participate in other ways to continue to downvote.

To make your opinion known on MSE you need both up and downvotes. Given at the moment you need 125 rep to downvote on this site, the voting patterns will be skewed positive because not everyone is active on the site.   This is to be expected for regular Stack Exchange sites as you are expected to be involved in the community before you are deemed knowledgeable enough to be part of the community voice. However, MSE is different because you are voting for the entirety of the Stack Exchange network and you shouldn't need to be active on MSE itself to have a voice on changes to the entire network.  This is especially important for questions like  because it will effect every network to do with coding at all. This was brought up in .  I would suggest reducing the rep required to downvote on MSE down to 100 (or 101) rep. This is the amount you get for the site association bonus. This is given once you achieve 200 rep on any network site and shows that you are active in at least one community. I think this would be the perfect use of the association bonus in showing that you are a member of the Stack Exchange community.


I'm currently trying to use Freestyle with Cycles to render a toon shaded image of a robot. The robot is holding a sword, which uses a separate material, and since it glows, I don't want freestyle to draw edges on its blade. However, I can't figure out how to make freestyle ignore specific edges. The sword does have a separate material and is a separate object, so perhaps I can disable freestyle just for that sword's material/object?  Ideally I'd love to know how to disable freestyle for edges, materials and objects.

Is it possible to deselect freestyle edges?  For example, I enabled Material Boundary in Render layers → Freestyle Line Set → Edge Types to draw lines on all edges between faces with different materials:      Is it possible to explicitly exclude an edge from freestyle drawing so I can have all material boundary edges drawn except for ones I specify?  e.g:


I want to save output of command to a file that my current user do not have access to. But my user can have root access using sudo. I'm running for example:  sudo crontab -l > /var/BackUp/crontab -bash: sudo: Permission denied   But I can run just sudo crontab -l So I think sudo relevant only to crontab command and as user do not have access to /var/BackUp/crontab it gives such error.  Is it possible to write output to a file that requires root access under current user?

I have a small question regarding using sudo with output redirect >. To enable IP forwrding, someone can use the command:  echo 1 > /proc/sys/net/ipv4/ip_forward   Executing this command will give permission denied as it requires root privileges. However, executing the same command with sudo gives also permission denied error! It seems that output redirect > does not inherit the permissions of the preceding command echo. Is this right?  As a workaround I do:  echo 1 | sudo tee /proc/sys/net/ipv4/ip_forward   Is this the best way to do it? Am I missing something?  Please, note that this is an example and it applies to all commands that use output redirect.


If $X$ and $Y$ are independent. How about $X^2$ and $Y$? And how about $f(X)$ and $g(Y)$? I always have confusion about it. I feel ... yeah of course $f(X)$ and $g(Y)$ are independent, because $X$ and $Y$ are. But .. is it right?? Then how can I prove it?

If X and Y are independent random variables both with the same mean (0) and variance, how about $X^2$ and $Y^2$? I tried calculating E($X^2Y^2$)-E($X^2$)E($Y^2$) but haven't been able to get anywhere.


If the quality of the camera (i.e. the megapixels) (assume to be $x$) of the camera is known and an object is kept a known distance from the camera (assume to be $d$), can the actual width and length of the object be determined?

Can I calculate the size of a real object by just looking at the picture taken by a Camera? (I think people  do that) i dont understand how? (from physics point of view)


I use software to produce kitchen visuals that use dwg files, does anyone know how I can get this file into Blender, is there a free converter or any other way so I can try to use Blender to render?  I look forward to any feedback

I'm trying to figure out how to import an engineering drawing from AutoCAD into Blender while retaining all layers and fills... is this possible? I also use Carrara and it opens files from CAD in this way... I want to switch fully to Blender but, if this feature doesn't exist, I just cannot make the leap.  Any info would be fantastic.


I've read a lot of questions from people who have the same problem as me however there results didn't work for me. So I've already manually partitioned but it doesn't even see that either. It sees my SSD partitions but can't see my HDD. I'd like to try other ways to install Ubuntu like partition it from the USB. But I have 2 built in HDDs The new partition I've made on my HDD isn't formatted either so I can't really see what's wrong here.  Thanks in advanced for the help  EDIT: After reading some other answers I have found that I should disable Intel Smart Response Technology, I am going to do that now.  EDIT2: Ok I'm currently in the live session and I found that Ubuntu CAN see the partitions just fine but in the installer it won't, any ideas?

I'm having a problem installing Ubuntu, and Kali as well. I downloaded the iso from the official site & tried installing using USB. I also tried desktop installation, but the problem is same.  It shows a single drive i.e. my total Hard Disk and if I select it, it asks me to create a new partition & shows total space as FREE.  It's with all Ubuntu I downloaded, 11.10 Server, 12.10 and 13.04. I also tried to install BackTrack's new version Kali Linux but again I got the same problem.  I hope I meet thier system requirements. Here's my system details for your ease:   OS: Windows 7 Ultimate Processor: Intel P4 2.80 GHz RAM: 3GB Hard Disk: 320GB No of Local Drives: 4 (1 Primary, 3 Logical) Free Space: 195GB (about) Motherboard: G31 Cache: 1MB Help me, please.


I am styling point markers in a layer that I imported using "Add Delimited Text Layer". I want the style markers based on the color marker. So each color relates to a different species (I have two different species).

I want to give multiple colors to different features within a shapefile based on attribute values , is this possible in QGIS ?  If yes what is the procedure ?  Is there a way to provide color by means of hexadecimal codes ?


Please consider the following MWE:  \documentclass{minimal}  \usepackage[backend=biber,bibstyle=ieee-alphabetic]{biblatex} \usepackage{hyperref}  \begin{filecontents}{bibliography.bib}   @book{tst,         author = {Smith, John},         title = {\(\pm\) On the run},         year = {2010}   } \end{filecontents}  \addbibresource{bibliography.bib} \nocite{*} \begin{document} \printbibliography \end{document}   I'm having trouble compiling the previous source. The Error messages state something about missing { while this is clearly not the case.  However, if I remove the bibstyle setting I can compile without any problems. Since I need to use this particular style this is not an options. Does someone know how to fix the math related issue?

In a comment to my , Peter Grill said that he read that the minimal class should not be used for a Minimal Working Example. I wonder why, and which class should I use instead?  BTW: Is it preferable to use article or scrartcl, i.e. the standard classes or the ones form the KOMA-Script bundle?


I am reading David Fraleigh, A first course in Abstract Algebra, and they mention in one of the questions about $<R^*,•>$ my questions is, what does $R^*$ denote?  Edit: some context The question is to show $<U,•>$ is not isomorphic to either $<R,+>$ or $<R^*,•>$ where they are all groups. I am not asking for how to do it, I'm just not sure what the notation means

What does $\Bbb Z^\ast$ mean? I would think some subset of the integers but I cannot find a definition. Thank you.


To prove that if $(S, d)$ is a metric space, $p \in S$ and $X_n$ are random variables on a probability space $(\Omega, A, P)$ such that the law of $X_n$ converges weakly to $δ_p$, then $X_n \to p$ in probability.  Here $\delta_p(S) = \begin{cases} 1 & \text{if } p \in S \\ 0 & \text{otherwise} \end{cases}$.  Require some hints to proceed with the problem.

This is question 10.3.1 from Rosenthal's First Look at Rigorous Probability.  Suppose $\mathcal{L}(X_n) \Rightarrow \delta_c$ for some $c \in \mathbb{R}$. Prove that $\{X_n\}$ converges to $c$ in probability.  Here $\mathcal{L}(X_n)$ refers to the distribution of $X_n$.  Is the following proof correct?  Is a simpler proof available?  Is there a simple proof using Skorohod's theorem?  I attempted to prove the contrapositive. Suppose $X_n \not \to c$ in probability.  This means that there is an $\varepsilon > 0$ so that for all $N$, there exists an $m > N$ such that  \begin{equation}   P(|X_m - c| \geq \varepsilon) > \eta, \text{ for some $\eta > 0$}. \end{equation}  Consider  \begin{equation}   B := \{x \in \mathbb{R} : |x - c| \leq \varepsilon\} \in \mathcal{B} \text{ the Borel sets on $\mathbb{R}$}. \end{equation}  Then $B^c \in \mathcal{B}$ and denoting the distribution of $X_n$ as $\mu_n$ we have  \begin{equation}   \mu_n(B^c) = P(X_n \in B^c) = P(|X_n - c| \geq \varepsilon) > \eta. \end{equation}  For all $N$, there exists an $m > N$ such that the cumulative distribution function of $X_m$ is not the same as the cumulative distribution function of $\delta_c$; in particular it's mass changes somewhere at least $\varepsilon$ distance from $c$. Finally because $\delta_c(\{x\}) = 0$ for all $x \neq c$ this completes the proof.


For functions $f$ satisfying appropriate (good) conditions, the following property is called to be isometric.     $$ E\left[\left|\int_{a}^{b}f(t,\omega)dB_{t}(\omega)\right|^{2}\right]=E\left[\int_{a}^{b}|f(t,\omega)|^{2}dt\right] $$   Here $B_{t}(\omega)$ is the Brownian motion.  Why is this called to be isometric?  If one defines the $L^{2}$-norm by $$ \|f\|_{L^{2}(P)}=(E[|f|^{2}])^{1/2}, $$ then the above equality is rewritten as $$ \left\|\int_{a}^{b}f_{t} dB_{t}\right\|_{L^{2}(P)}^{2}=\int_{a}^{b}\|f\|_{L^{2}(P)}^{2}(t)dt $$ provided that Fubini theorem is valid. However I don't look isometry as in functional analysis in Hilbert space, i.e., $\|Tf\|_{H_{1}}=\|f\|_{H_{2}}$ for some operator $T$. What I don't connect between Ito integral and Riemann integral is also a reason that I don't know why it's called to be isometric.  I'm glad if you tell me a reason.

Itō isometry from :     Let $W : [0, T] \times \Omega \to \mathbb{R}$ denote the canonical   real-valued Wiener process defined up to time $T > 0$, and let $X :  [0, T] \times \Omega \to \mathbb{R}$ be a stochastic process that is   adapted to the natural filtration $\mathcal{F}_{*}^{W}$ of the Wiener   process. Then $$      \mathbb{E} \left[ \left( \int_{0}^{T} X_{t} \, \mathrm{d} W_{t} \right)^{2} \right] = \mathbb{E} \left[ \int_{0}^{T} X_{t}^{2} \,  \mathrm{d} t \right], $$ where $\mathbb{E}$ denotes expectation with   respect to  $\gamma$. In other words, the Itō   stochastic integral, as a function, is an isometry of normed vector   spaces with respect to the norms induced by the inner products $$      ( X, Y )_{L^{2} (W)} := \mathbb{E} \left( \int_{0}^{T} X_{t} \, \mathrm{d} W_{t} \int_{0}^{T} Y_{t} \, \mathrm{d} W_{t} \right) =  \int_{\Omega} \left( \int_{0}^{T} X_{t} \, \mathrm{d} W_{t}  \int_{0}^{T} Y_{t} \, \mathrm{d} W_{t} \right) \, \mathrm{d} \gamma  (\omega) $$ and $$      ( A, B )_{L^{2} (\Omega)} := \mathbb{E} ( A B ) = \int_{\Omega} A(\omega) B(\omega) \, \mathrm{d} \gamma (\omega). $$   I was wondering what the two normed spaces are and what their norms are, so that the two normed spaces are isometric wrt their norms?  Thanks and regards!