I have reviewed  as well as the answers by  and . There are two critical weaknesses in Nominatim, using Malaysia as a case study: 1) The polygons include water (left = Nominatim, right = Google Maps)  Above are searches for 'Selangor'. I am aware that the boundary over water is the true administrative boundary, but for most visualisation exercises, this would make it look quite weird. 2) Postcode-level data is very coarse, at least for Msia (left = Nominatim, right = Google Maps)  Above are searches for '11900, Penang'. Nominatim just doesn't have it.  So, you can see why I really need to extract the JSON from Google Maps. Does anyone know how to do this, preferably programatically so I can iterate over 2000 postcodes? However, if it requires manual effort, I'm willing to do it.


Is there a standard way to Determine Sample Size when doing Bayesian Inference?

I am currently doing Bayesian Inference by using the BayesAB R library. I've observed that that sample size has a big impact on the posterior distribution.  When doing Frequentist Hypothesis Testing it seems that everyone agrees on how to determine the minimum sample size required to observe a certain effect based on the power of the experiment.  However, is this a valid approach when using Bayesian Inference? If not, is there something equivalent for Bayesian Hypothesis testing?


I got a new laptop and gave my dad my old one but he never changed the user so now he logs in using my password on my user. The problem is any changes I make to my laptop reflect on to his. I'd just like to peacefully change my wallpaper. Both laptops run windows 10. Thank you in advance for your help.


What is the purpose of using super in class initializer?

I was reading some Python code in a private repository on GitHub and found a class resembling the one below:  class Point(object):     '''Models a point in 2D space. '''      def __init__(self, x, y):         super(Point, self).__init__()         self.x = x         self.y = y      # some methods      def __repr__(self):         return 'Point({}, {})'.format(self.x, self.y)   I do understand the importance and advantages of using the keyword super while initialising classes. Personally, I find the first statement in the __init__ to be redundant as all the Python classes inherit from object. So, I want to know what are the advantages(if any) of initializing a Point object using super when inheriting from the base object class in Python ?


With two lists of different sizes:  numbers=[1,2,3,4,5] cities=['LA','NY','SF']   I need to get this:  result={1:'LA', 2:'NY', 3:'SF'}   I thought of doing it with:  result={number:cities[numbers.index(number)] for number in numbers if numbers.index(number)<len(cities)}   But this one-liner gets kind of long. I wonder if there is an alternative way of achieving the same goal.  EDITED LATER:  There were multiple suggestions made to use zip:  dict(zip(cities, numbers))   While it is a definitely a simpler syntax than list comprehension I've used I wonder which would be faster to execute?


Changing units in QGIS: degrees to meters

I have a global map with CRS WGS84-EPSG:4326 and I want to calculate the area of my polygons. From what I read, to change the unit from degrees to meters I need to change my CRS. However, there is no global system for this. Is there any solution to change the unit from degrees to meters for a global map?


I am starting out programming micro controllers and I was reading some documentation and textbooks. I am a little confused as to what the difference is between a Micro-controller and a System on chip?   Some documentation use these two terms inter changeably. However most textbooks point out that using the two terms inter changeably is NOT correct, thus there must be some notable difference...  Thanks!


How the time lag is non-integer in ACF plot?

I'm plotting the ACF of a time series. # Import data Y = scan('https://raw.githubusercontent.com/leanhdung1994/Time-Series/main/trafic.dat') Y = ts(Y, start = 1963, frequency = 12)  # Remove the data about the last year X = window(Y, end = 1979 + 11/12) acf(X)   Could you please explain why the number on lag axis is non-integer?


Do I need proof of onward travel when flying from Malaysia to Vietnam?

I am Lithuanian (EU citizen), on a single entry 3-month visa. I have crossed from  do I need one when coming into Vietnam from Malaysia by air?


Possible Duplicates:             I shut down my laptop every night, and I used to unplug the AC power as well when I shut down. Is there any harm to leaving the power brick plugged in while the laptop is off? Am I wasting energy? Am I causing harm to the battery (which I pretty much leave in all the time)?


I know that in speech we say "the bigger the better", but is this ok in written English as there is no verb....


The following while loop within the program I'm writing is not being entered into, even though the condition within parentheses would evaluate as true (as far as I can tell). Here is the loop with the assignment before it:  String choose = "y";   while(choose=="y");  {      System.out.println("Enter 4-digit time: (0000 - 2359)");      String time_ = s.nextLine();      System.out.println("Angle between hour hand and minute hand is: " + timeToAngle(time_) + " degrees");      System.out.println("Would you like to calculate the angle for another time? (y/n)");      choose = s.next();   }   Please could somebody give me a pointer in the right direction? This is driving me crazy


For $a,b,c>0$ prove that $abc(a+b+c) \le a^3 b + b^3 c + c^3 a$

if $a,b,c > 0$ then prove that $abc(a+b+c) \le a^3 b + b^3 c + c^3 a$  My attempt The hint given for this question was to use the Cauchy-schwarz inequality. But if you look at the expression given, the L.H.S is symmetric but the R.H.S is not. If I understand the inequality(Cauchy-Schwarz)  correctly, both the sides of the inequality should be symmetric. So can we use the Cauchy-Schwarz to prove this? I also tried applying AM > GM but got stuck. Any help would be appreciated.


Error reading undefined reference to std::__cxx11 cannot fix

Receiving undefined reference error in program code #ifndef Property_H #define Property_H  #include <iostream> #include <iomanip> using namespace std; #include <string> #include"Record.h" #include<vector>   template<class T> class Property { public:    Property();  ~Property();   Record* operator[](int);   void operator+=(Record*);   T getname();   void setname(T);  private:   T name;   //Record* elements[MAX_ARR] ;   vector<Record*> elements;   int size;     };   #endif  #include "Property.h"  template <class T> Property<T>::Property() {   size = 0; } template <class T> Property<T>::~Property(){}  template <class T> Record* Property<T>::operator[](int s) {   if (s<0 || s >= size) {     cerr<<"Overflow"<<endl;     return NULL;   }   return elements[s]; }  template <class T> void Property<T>::operator+=(Record* element) {   elements.push_back(element); }  template <class T> T Property<T>::getname(){return name;}  template <class T> void Property<T>::setname(T x){ name=x;}  This is the error g++ -o F main.o ReportGenerator.o Record.o  Property.o /usr/bin/ld: main.o: in function `main': main.cc:(.text+0x2c): undefined reference to `Property<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::Property()' /usr/bin/ld: main.cc:(.text+0x68): undefined reference to `Property<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::setname(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >)' /usr/bin/ld: main.cc:(.text+0x8f): undefined reference to `Property<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::~Property()' /usr/bin/ld: main.cc:(.text+0xdc): undefined reference to `Property<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::~Property()' collect2: error: ld returned 1 exit status  It occurs when I test out the creation of my object in my main.cc Property<string>foo; foo.setname("j");  From what I've learned in so far and even looking at online examples of template objects my code should be working fine. It seems to be an error at compilation but I'm not sure what this means. I also receive an error when I call foo after initializing with brackets(). Been at it all night kind of want to cry in anger at this point. Property<string>foo; foo.setname("j");


Ubuntu 20.04 LTS Desktop install not loading ks.cfg file on an usb key

I search for an Ubuntu 20.04 LTS DESKTOP automatic installation ? i boot on a USB KEY with ubuntu 20.04 lts desktop iso on this , i wan't install on a ssd pc with a automatic script (not the live install) I found on internet an good example (& working ) in grub.cfg file : linux /casper/vmlinuz  file=/cdrom/ks.preseed auto=true priority=critical debian-installer/locale=fr_FR keyboard-configuration/layoutcode=fr ubiquity/reboot=true languagechooser/language-name=French countrychooser/shortlist=FR localechooser/supported-locales=fr_FR.UTF-8 boot=casper automatic-ubiquity initrd=/casper/initrd.lz quiet splash noprompt noshell --- but in my case i wan't scripted a script for create partition, create user, crypted disk with luks (cryptsetup) and install package software, i test with this : `linux  /casper/vmlinuz  file=/cdrom/preseed/ks.seed initrd=/install/initrd.gz boot=casper automatic-ubiquity ks=hd:sda1:/ks.cfg quiet splash noprompt noshell ---`  it's ok boot but not load the ks.cfg , i test with hd:sda1:, cdrom:, ... and http no loading, and all no working :( Have you see this problem ? and how can resolve it ? because i'm loss Thanks you very much for a solution !!!


Minimum size group with an element that is its own inverse

I Believe I saw a proof to the effect that groups of a minimum order were guaranteed to have at least one non-identity element that is its own inverse. I believe that the order was 24, but I cannot find said paper any more. Is this in fact true and can you provide a proof of this fact or refer me to a proof of this fact?


I would like to know how to add dash lines in Matrix (see figuge)  Cheers  S.L.    \documentclass{article} \usepackage{amsmath}  \begin{document} \begin{equation} \begin{bmatrix} N & B_i \\ B_i^T & 0 \end{bmatrix} \begin{bmatrix} x_i\\ k \end{bmatrix} =\begin{bmatrix} n\\ 0 \end{bmatrix} \text{ with } n = A^TPl \end{equation} \end{document}


Why would Charlie Weasley give up his old wand and give it to Ron?

In Harry Potter and the Philosopher's Stone, Chapter 6, Ron says:     You never get anything new either, with five brothers. I've got Bill's old robes, Charlie's old wand and Percy's old rat.   What I don't understand is why Charlie would give up his wand to get a new one. Since the wand chooses its owner, his original wand was already an excellent fit for him, and I seem to recall that a wand grows in power the longer it is in the possession of its owner.  The most common reason we see for wizards getting a new wand is that the old one is broken. But the wand was perfectly intact when Ron had it (before the Whomping Willow incident anyway). And as far as I can tell, there was nothing else deficient about the wand.  So if Charlie had a perfectly good wand that was already in tune with him and would become better as he continued to use it, why would he give it up and give a different wand?


In the MWE below, the logo top left is making some trouble as of it is size I assume. Due to the small margins top and bottom "20mm" its pushing the page number too low. Is there a way this can be done avoiding that or due to the size of the image it is hard?  \documentclass[twoside,a4paper,11pt]{report} \usepackage[top=20mm,right=19mm,bottom=20mm,left=38mm]{geometry} \usepackage{geometry} \usepackage{array,float,graphicx,epic,eepic} \usepackage{fancyhdr}  \pagestyle{fancy}  \fancyhf{} \fancyhead[RE,RO]{Omar Sammour} \fancyfoot[C]{\thepage} \fancyhead[LE,LO]{\includegraphics[scale=0.3]{soton.png}} %\rhead{Omar Sammour}  \begin{document}  \textbf{Headers and Footers}  \newpage \textbf{Headers and Footers 2}  \newpage \textbf{Headers and Footers 2}  \end{document}


The Error is that: String which doesn't == withdraw, whatever i put, it will just say, deposit. i want to be able to use both (withdraw) & (Deposit).  import java.util.Scanner;  public class BasicClasses {     public static void main(String[] args) {         System.out.println("Welcome to First National Bank (FNB)");         Scanner Key = new Scanner(System.in);         String Question = Key.nextLine();         BasicClasses flix = new BasicClasses();          System.out.print(" | Withdraw | or | Deposit | [ ");         Scanner Key1 = new Scanner(System.in);         String Which = Key.nextLine();          if(Which == "withdraw") {             System.out.println("|Withdraw| - | How much do you Want to Withdraw?");          } else {             System.out.println("|Deposit| - | How much will you be Depositing?");     }   }   }


What does multiplying two real-world values represent?

I totally get what division means in the real world.  "dollars / hour", well, that's the number of dollars you will make in one hour.  "kilometers / gallon" is the distance you can go with a gallon of gas.  Division means that given a certain amount of one thing, you'll get a certain amount of another thing.  I'm so good with division that you could give me a ratio I've never seen before and I can tell you what it means.  "Burgers / McDonalds"?  It's the average number of burgers a McDonalds will produce.  "Dolphin / Miles"?  Every mile you drive, you get this amount of dolphins.  Multiplication on the other hand makes no sense at all.  What the heck is a foot-pound?  And I don't really mean the definition.  I mean, what does multiplication actually do for these two values?  What does multiplying two values say about their relationship?  What if I were to say kilometer-hours? Or dollar-kilograms? Or dolphin-miles?  What would those things mean?    Bonus points go to explaining this in a very simple, clear manner.


Signal the end of option arguments: double dashes `--` vs single dash `-`?

I notice in , that single dash - is used to signal the end of option arguments.   Is it correct that double dashes -- can also signal the end of option arguments?  What are their differences then? When to use which? Are they both GNU conventions? Thanks.


How to use poof on all meepos with a single command?

In original dota it was not possible. Is it possible to use poof on all meepos with a single command now? I've tried ctrl-W with unified attack order ON but it doesn't work. (or maybe it was considered as OP)


Can a black hole be explained by Newtonian gravity?

In the simple explanation that a black hole appears when a big star collapses under missing internal pressure and huge gravity, I can't see  any need to invoke relativity. Is this correct?


Unable to login to 14.04 after successful installation

After a successful upgrade to 14.04, now when I am trying to login using administrator id, It loops back to login page and doesn't load my session. Even guest is not working. When I enter wrong password for administrator, it shows invalid password label.  File name ~/.xsession-errors show below error  Xlib:  extension "GLX" missing on display ":0". Script for ibus started at run_im. init: at-spi2-registryd main process ended, respawning init: at-spi2-registryd main process ended, respawning init: at-spi2-registryd main process ended, respawning init: at-spi2-registryd main process ended, respawning init: at-spi2-registryd main process ended, respawning init: at-spi2-registryd main process ended, respawning init: at-spi2-registryd main process ended, respawning init: at-spi2-registryd main process ended, respawning init: at-spi2-registryd main process ended, respawning init: at-spi2-registryd main process ended, respawning init: at-spi2-registryd respawning too fast, stopped   Please let me know what should I do.


How to estimate critical value for F-test for df=91?

I'm trying to do F-test (ratio of the variances) for two samples with 92 data points each. I look at several links for the critical value for degrees of freedom equal to 91 but most of them are skipping values in between. For example, from the link below, the df for the numerator skipped: 40,60,120 and the same as the denominator.    Is there a way to estimate the critical value for an F-test(the easiest way possible)?  I am comparing daily temperatures from 1979-1993 and 1994-2008. I got "daily variance" for both epochs for July-August-September. So I now have 92 values for each epoch.I want to do F-test from this.   I'll appreciate any help.


What is the correct way of standardizing data when there are training, validation and test set

When standardizing data before training a neural network, say by subtracting the mean and then dividing by the standard deviation for each variable, there are several ways one could go about that and I am not clear which one is correct/the best:   Get mean and sd of training, validation and test set separately and apply to the respective sets Get m and sd for combination of train and val set and apply it to both train and val set. Standardize test set separately with its mean and sd Get m and sd for combination of train and val set and apply it to all three sets   Clearly, one cannot get the mean and sd for the combination of all three sets because there should be no information leak from the test set into the training procedure. What is the right way to go about this and why?  Also, in a regression problem, should the targets be standardized too?


Nonsingular projective variety of degree $d$

For each $d>0$ and $p=0$ or $p$ prime find a nonsingular curve in $\mathbb{P}^{2}$ of degree $d$.    I'm very close just stuck on one small case. If $p\nmid d$ then $x^{d}+y^{d}+z^{d}$ works. If $p\mid d$ then I have chosen the curve $zx^{d-1}+xy^{d-1}+yz^{d-1}$. After some work using the Jacobian criterion for nonsingularity I arrive at $3z=0$. As long as $p\neq 3$ this curve is nonsingular. But I haven't been able to deal with the $p=3$ case. Any ideas? Thanks in advance.


Compute $\lim_{n\rightarrow\infty} H_n-H_{\frac{n}{2}}$ where $H_n=\sum_{i=1}^n\frac{1}{i}$.   Alternatively, we can rewrite $H_n-H_{\frac{n}{2}}$ as $\sum_{i=\frac{n}{2}+1}^n\frac{1}{i}$ if this form is easier to manipulate.  I really have no idea where to begin with this problem. Any help/hints would be greatly appreciated!


Why does 'if not ' check empty string in python

Hi I have a quick question regarding 'if not ..' in py.  This is a function that should take a list of strings and return a string.   I wondered what does the first line(if not strs) do? I guess it checks if the input list strs is empty or not? How does it work? Doesn't 'if not' check if it is opposite of expected value, like 'if not None'? Thank you!  def longestPrefix(strs):          # Empty list         if not strs: return ""          ....


Wine - Security risks - Dofus warns it's being run by administrator

Not having the ability to install a game (which I appreciate a lot) in a classic way (normal Linux installation), I decided to use Wine (wine-stable).  First I heard that Wine is not a security risk because it's a virtualization, or something like that, I did not know much about how Wine works.  But are there really no risks? (I doubt that risk 0 does not exist) For example with an elevation of permissions or something like that?  What makes me slightly afraid is this message, I use Wine without using sudo (wine dofus.exe), but here is the message, Wine uses sudo by default? Should I be afraid of this message? I do not intend to install other games or suspicious programs with Wine, but only the one that I think does not have a virus, it is Dofus, despite all this message makes me ask questions and given that I do not know Wine, I would like to have your opinion    Thank you in advance.


Is "What can I help with?" proper English?

"What can I help with?"   Part of our team is claiming it is not proper english and another part is claiming its the correct way for us to say it.    For context this is in reference to working on a chat bot that will be helping customers so we are trying to keep it concise and at a simple level to be approachable to all users.


What exactly is we-ve-just-wanted-to-be-sure-you-are-paying-attention test?

So today one of my answers was edited and the edit itself was quite tricky - it was looking legit though actually was invalidating my answer, so I've declined it.  Then I've got this message:   My question is following - what this testing is about (how massive it is, what exactly are you trying to achieve, who is in the test group etc.)?


mysqli_real_escape_string converts the string but not saved to database properly

i have a php script having some inputs and applied mysqli_real_escape_string() function to filter ..which are shown below       $owner      = mysqli_real_escape_string($conn,$_POST['owner']);     $purpose     = mysqli_real_escape_string($conn,$_POST['purpose']);     $type        = mysqli_real_escape_string($conn,$_POST['type']);     $city        = mysqli_real_escape_string($conn,$_POST['city']);     $location    = mysqli_real_escape_string($conn,$_POST['location']);     $description = mysqli_real_escape_string($conn,$_POST['description']);     $price       = floatval($_POST['price']);     $land_area   = floatval($_POST['area']);     $bedrooms    = intval($_POST['bedrooms']);     $bathrooms   = intval($_POST['bathrooms']);     $expire      = mysqli_real_escape_string($conn,$_POST['expire']);   and below is the insert query  $query = "INSERT INTO add_property SET owner='".$owner."',purpose='".$purpose."', property_type='".$type."',city='".$city."',location='".$location."',description='".$description."',price='".$price."',land_area='".$land_area."',bedrooms='".$bedrooms."',bathrooms='".$bathrooms."',property_expire='".$expire."',image_url='".$targetfile."'"; $result = mysqli_query($conn,$query) or die(mysqli_error());   Problem it converts the string and add a slach if (  ' )etc if found like for 'abc it converts it to \'abc but not saved to database ... it saved to DB as is like ..'abc


Switching between high voltage power sources

I need to get an LED to switch on once the voltage across a capacitor goes above 40V. It must then remain on from 40V to the maximum voltage reached by the capacitor which is currently 1200V. The circuit has to be independent from any other power source so the circuits must be powered off of the capacitor.   I thought about using a comparitor but that would require an outside power source to power the chip and create a reference voltage.   I am currently working with the idea of using two dc to dc converters as I can't find one that will cover the full range. The first converter has a range of 40 to 180V and the second one has a range of 200V onwards.   I need to build a circuit to switch from one dc to dc converter to the other when the first ones maximum voltage is exceeded. I also need to switch over to another power source when in between the two converters ranges so that the led is constantly lit.   I think this can be done using a relay but I have never worked with one before and I'm not sure how to power it when the max voltage is reached and where to power it from.   If someone could shed some light on a possible solution or point me in the right direction it would be greatly appreciated. Thank you!


Is there a way to remove the full file path from the title in Notepad++?  Let's say I only wanted the file name to be displayed there. How can this be done?


limit $\lim\limits_{n\to\infty}\left(\sum\limits_{i=1}^{n}\frac{1}{\sqrt{i}} - 2\sqrt{n}\right)$

Calculate below limit $$\lim_{n\to\infty}\left(\sum_{i=1}^{n}\frac{1}{\sqrt{i}} - 2\sqrt{n}\right)$$


I want to separate two objects along an axis, but without scaling them. I already tried S X in local mode, but it didn't work.


Why is the Moon's Centre of gravity different to its centre of mass?

All the places that I've seen an answer to this question simply state that it's because there is a stronger gravitational pull on the near side of the moon, facing the earth. But I'm wondering how this gravitational pull actually manages to shift the centre of gravity of the moon, and how does it tie into the idea that the centre of gravity is where a body's weight is evenly distributed?


I have a few folders each containing large filenames that downloaded in a strange naming format and obscures the file extension and I want to convert to something very simple.  Here's an example of what I want to do. Let's say these four files are located in one of the folders:  HTTP_services.cgi?FILENAME=%2Fdata%2FMERRA2%2FM2I6NPANA.5.12.4%2F1992%2F08%2FMERRA2_200.inst6_3d_ana_Np.19920818.nc4&FORMAT=bmM0Lw&BBOX=-90%2C-180%2C90%2C180&LABEL=MERRA2_200.inst6_3d_ana_Np.19920818.SUB.nc4&SHORTNAME=M2I6NPANA&SERVICE= HTTP_services.cgi?FILENAME=%2Fdata%2FMERRA2%2FM2I6NPANA.5.12.4%2F1992%2F08%2FMERRA2_200.inst6_3d_ana_Np.19920819.nc4&FORMAT=bmM0Lw&BBOX=-90%2C-180%2C90%2C180&LABEL=MERRA2_200.inst6_3d_ana_Np.19920819.SUB.nc4&SHORTNAME=M2I6NPANA&SERVICE= HTTP_services.cgi?FILENAME=%2Fdata%2FMERRA2%2FM2I6NPANA.5.12.4%2F1992%2F08%2FMERRA2_200.inst6_3d_ana_Np.19920820.nc4&FORMAT=bmM0Lw&BBOX=-90%2C-180%2C90%2C180&LABEL=MERRA2_200.inst6_3d_ana_Np.19920820.SUB.nc4&SHORTNAME=M2I6NPANA&SERVICE= HTTP_services.cgi?FILENAME=%2Fdata%2FMERRA2%2FM2I6NPANA.5.12.4%2F1992%2F08%2FMERRA2_200.inst6_3d_ana_Np.19920821.nc4&FORMAT=bmM0Lw&BBOX=-90%2C-180%2C90%2C180&LABEL=MERRA2_200.inst6_3d_ana_Np.19920821.SUB.nc4&SHORTNAME=M2I6NPANA&SERVICE=   I would like these to just be renamed something very basic like  1.nc4 2.nc4 3.nc4 4.nc4   The new numbers have no relation to the original filenames. I just want to be able to iterate through them easily with another program I have.  I've attempted to use batch renaming programs like pyrenamer and metamorphose but they seem to be good at replacing patterns in names with other patterns, not just overwriting the name with a pattern.


How to get rid of lots of natbib warning?

Again when I run my main.tex file, LateX prompts up with number of lines which has following pattern:  Package natbib Warning: Citation `piaget1973understand` on page 47 undefined on input line 44.  Underfull \hbox (badness 1000) in paragraph at lines 44--45  and at the end:  Appendix A (./mainchapters/appendix.tex) (./main.bbl [49] ./main.bbl:43:Missing  $ inserted. <inserted text> $ l.43 ...s?id=com.google.android.apps.seekh\&hl=en_us. ?   main.tex  documentclass[12pt]{report}  \usepackage{hyperref} \usepackage{natbib} \usepackage{enumitem} \usepackage[utf8]{inputenc} \usepackage{csquotes} \usepackage{graphicx} \graphicspath{ {images/} } \usepackage{caption} \usepackage{subcaption} \usepackage[a4paper, width=150mm, top=25mm, bottom=25mm, bindingoffset=6mm]{geometry} \usepackage{ragged2e}   \date{02 March 2020}  \begin{document}  \input{titlepage}   \chapter*{Dedication}  To my parents.  \chapter*{Declaration} I declare that...  \chapter*{Acknowledgement} I want to thank...  \tableofcontents  \listoffigures  \chapter*{Abstract} \input{chapters/abstract_v2}  \chapter*{Introduction} \input{chapters/introduction_v2}  \chapter{Children Computers and Constructionism} \input{chapters/chapter1_v1}  \chapter{Design methodologies for children's technology} \input{chapters/chapter2_v1}  \chapter{Toys of 21st Century} \input{chapters/chapter3_v1}  \chapter{Child Computer Interaction in Developing countries} \input{chapters/chapter4_v1}  \chapter{Current scenario} \input{chapters/chapter5_v1}  \appendix \chapter{Appendix Title} \input{mainchapters/appendix}  \bibliographystyle{apa} \bibliography{/Users/pythonbuddha/Documents/Thesis/References.bib} \end{document}


Show that $$\sum_{k=0}^n(-1)^k\binom nk=0$$ So for odd $n$ we have an even number of terms. So $\binom nk=\binom n{n-k}$ which have opposite signs. Thus the sum is 0.  For even $n$ we have that $$\sum_{k=0}^n(-1)^k\binom nk= \binom n0+\sum_{k=1}^{n-1}(-1)^k\binom nk+\binom nn$$ Now $$\sum_{k=1}^{n-1}(-1)^k\binom nk= \sum_{k=1}^{n-1}(-1)^k\left[\binom{n-1}k+\binom{n-1}{k-1}\right]$$ What would that sum be in the square brackets?


Sort WP_Query by one meta key and post_date

I want to order by post to check for the existence of a meta key ('featured') and include those posts first and as a secondary option I want to sort by post_date, similar to 'sticky' posts on a discussion forum.  I first tried this straightforward method ...  $args = array(   'store'         => 'walmart',   'post_type'     => 'post',   'showposts'     => '-1',   'orderby'       => 'featured date',   'order'         => 'desc',   'meta_key'      => 'featured' );   It almost worked but instead of having the 'featured' posts at the top of the order it had them at the bottom, and no simple toggling could get it to work.  I then researched some more and came across this method , but I can't get this to work for the life of me. I would prefer to use this filter as I have one other customization that this might help with, can anybody show me what I'm doing wrong.   Here's what I have now ...  add_filter('posts_orderby','customorderby'); $args = array(     'store'         => 'walmart',     'post_type'     => 'post',     'showposts'     => '-1',     'meta_key'      => 'featured',     'meta_query'    => array(         array(             'key' => 'featured'         )     ) );  $query = new WP_Query($args); remove_filter('posts_orderby','customorderby');   and in my functions.php  add_filter('posts_orderby','customorderby'); function customorderby($arg) {     global $wpdb;      $arg = 'mt1.meta_value DESC, post_date+0 DESC';     return $arg; }


How to prove that a congruence system with $n$ equations can be solved if and only if all the equations can be solved two by two?  \begin{cases} x \equiv a_1 \phantom ((mod\phantom mm_1) \\ x \equiv a_2 \phantom ((mod\phantom mm_2) \\ ... \\ x \equiv a_n \phantom ((mod\phantom mm_n) \end{cases}  I know that if $n=2$, the system can be solved if and only if $\gcd(m_1,m_2)\mid a_1-a_2$.  The thesis is: the system is solvable $\Longleftrightarrow$ $\gcd(m_i,m_j)|\mid a_i-a_j$ for all $i\neq j$.


Given an ellipse:  $ax^2 + 2xy + by^2 = 1$  how can I calculate the length of the shorter and longer axis?


Can start, but not join, a chat when <20 rep points

I am receiving some excellent feedback on a recent post in Workplace, which has spawned a bit of a dialogue in comments. No surprise, I was urged to start a chat, which I did -- but then I couldn't sign into the chat!  My Workplace user account is rather new (as is this one on Meta) so I don't have the rep to join a chat.  It seems like a bug to allow me to start one, though. I don't know what the other user saw, whether or not he got "spammed" with an unfruitful chat session.


Understanding the relationship between differentiation and integration

I am trying to understand the relationship between differentiation and integration.  Differentiation has been introduced to me by this diagram:    Which displays that the derivative of a point $x$ on a continuous function $f(x)$ is the gradient of a line which is a tangent to that particular point, as shown in the diagram.  This can be written as  $$\lim_{h \to 0} \left(\frac{f\left(x+h\right)-f\left(x\right)}{h}\right)=f'\left(x\right)$$  and this gives the gradient of the point $(x, f(x))$.  Next examine this diagram:     The area under the continuous function from $f(x)$ from $a$ to $x$ is $A(x)$, shaded pink.  The area of $A(a)$ is $0$ and the area from $a$ to $b$ is $A(b)$.  Following this convention the area of $x$ to $x+h$ is  $$A\left(x+h\right)-A\left(x\right)$$  This section has with $h$ and the area is close to that of a rectangle so it can be said that   $$A\left(x+h\right)-A\left(x\right)\approx hf(x)$$  If you divide this through by $h$ you get an equation which shows that the derivative of $f(x)$ is $A'(x)$.    $$\lim_{h \to 0} \left(\frac{A\left(x+h\right)-A\left(x\right)}{h}\right)=f\left(x\right)$$  and hence   $$A'(x)=f(x)$$  This is where I have a problem, earlier it was stated that the derivative is the gradient of a line which is a tangent to a point on a continuous function.  Here however, we have an area, which encloses many points, which are not a line which is a tangent to a continuous function.  So I do not see how you can find the derivative of an area because it is not a point that you can find the gradient of a line which is a tangent to it.?  (Images taken from course texts provided by the Open University, Chapters C1 & C2 of the course MST121).


How can the speed of light change in the medium when we know that it is always equal to $c$?

How can the  change in the medium when we know that it is always equal to $c$? If we say the speed of light is changing in the medium, it will contradict the Einstein's law of special relativity.


Policy routing with 2 NICs on the same network seems to not do anything

As noted by dirkt, I'm missing information: This is the continuation of  question, but to summarize, I'm trying to receive a lot of multicast traffic, more than one interface can handle, so in order to receive it all, I want to use multiple interfaces and join streams on each of them separately.  I have three NICs, 1 (let's call it webIf) connected to the internet, and the 2 others (let's call them lanIf1 and lanIf2) connected to a LAN (same one for both). I'm trying to receive multicast traffic on both of them, but only one interface reports when receiving IGMP queries, and only for the stream that it joined. Therefore, after the timeout period, the switch stops sending the  stream that the other interface joined.  To solve that issue, I'm attempting to use policy routing: create a routing table for each lanIf, add a route on each to go to the same gateway, and create two rules to use the two new routing tables before using the main routing table  So if my addresses are:  lanIf1: 25.25.43.88 lanIf2: 25.25.43.84 default gateway of the lan switch: 25.25.43.5 igmp querier: 25.25.43.1   I'd first add the tables to /etc/iproute2/rt_tables , such as  cat /etc/iproute2/rt_tables would show:  # # reserved values # 255 local 254 main 253 default 0   unspec # # local # #1  inr.ruhep 2 lanIf1Table 3 lanIf2Table    Then I'd run this script as root:  ip route add 25.25.43.0/24 dev lanIf1 src 25.25.43.88 table lanIf1Table ip route add default via 25.25.43.5 dev lanIf1 table lanIf1Table  ip route add 25.25.43.0/24 dev lanIf2 src 25.25.43.84 table lanIf2Table ip route add default via 25.25.43.5 dev lanIf2 table lanIf2Table   ip rule add from 25.25.43.88 table lanIf1Table prio 1000 ip rule add from 25.25.43.84 table lanIf2Table prio 1001   But then nothing happens, the IGMP queries keep only being answered by one of the interfaces.  The only way I can get anything to work is to change one of the rules: ip rule add from 0.0.0.0 table lanIf1Table prio 1000. Then, the IGMP reports are done on lanIf1. But then I lose all internet access, of course, because all traffic goes through lanIf1Table.  What am I doing wrong? I've been following these tutorials:


How come sizeof(array)/sizeof(int) does not give me proper length of the array?

int *merge (int *array1, int *array2){     int iL = sizeof(array1)/sizeof(int);     int jL = sizeof(array2)/sizeof(int);     printf ("%d, %d\n", iL,jL);     int *mergeList = (int*)malloc((iL + jL) *sizeof(int));     int i=0,j=0,k=0;     while (i < iL && j < jL){         if (array1[i]<array2[j]){             mergeList[k++] = array1[i++];         }         else{             mergeList[k++] = array2[j++];         }     }     while (i < iL){         mergeList[k++] = array1[i++];     }     while (j<jL){         mergeList[k++] = array2[j++];     }     return mergeList; }   so the two lists entering the method is   list1 [6] = {2,-1,0,3,1,6}; list2 [2] = {-6,-10};   but for some reason, when they method prints out the length of each input arrays,  the output: 2,2. I have been stuck with this for 2 hours...


Can I convert binocular zoom to equivalent lens focal length?

I read  that shows how focal lengths can be converted to optical magnification, but it isn't clear to me how it would work the other way around. My binoculars are adjustable from x10 to x30 times zoom, but what would that be in an equivalent lens focal length? Working with the equation you have some reference focal lengths to work off of, but working with magnification it is not clear to me what information to use. Would I use the focal length of the human eye as the minimum focal length, the optical zoom as the magnification number, and the maximum focal length would be what I'm solve for?


When playing Civilization the Gandhi AI seems very aggressive in its use of nuclear weapons.   Real live Gandhi has a reputation of not being aggressive at all, is there a reason why the creators of Civilization made him so aggressive in the game?   Although the answer  explains that Gandhi has a high probability of nuking people, it does not explain why the developers made this choice.


How to slow down internet for some apps?

I want to slow down internet connection for some apps, so that other apps can have more MB/s. Is there any way to control the flow of internet between apps?  Thanks for response!


Result Source Query do not include allitems dispform editform

I am creating a result source and in the query I want to add something so it removes all of the sites like DispForm, Editform, allitems. How can I do this in the query?


I want to define the point X dynamically. Now I have defined the point at -90° but I want to make it changeable depending on the place of O. (I know there are similar questions, but I don't find the answer on my problem.)     \documentclass{article}  \usepackage{pgfplots}  \usepackage{tkz-euclide}  \usetkzobj{all}  \begin{document}  \begin{center} \begin{tikzpicture} \coordinate (M) at (0,0) ; \coordinate (O) at (canvas polar cs:angle=90,radius=3cm) ; \coordinate (A) at (canvas polar cs:angle=-130,radius=3cm); \coordinate (B) at (canvas polar cs:angle=-30,radius=3cm) ; \coordinate (X) at (canvas polar cs:angle=-90,radius=3cm); \draw (M) circle (3cm); \draw (A) -- (M) -- (B); \draw (A) -- (O) -- (B); \tkzDrawLine[dashed, add= 0.2 and 1.3,color=black](O,M) \tkzDrawPoints(O,A,B,M,X); \tkzLabelPoints[left](A,M); \tkzLabelPoints[below right](X); \tkzLabelPoints[above left](O); \tkzLabelPoints(B); \tkzMarkAngle[fill= red,size=1.5cm, opacity=.4](A,M,B); \tkzMarkAngle[fill= red,size=1.5cm, opacity=.4](A,O,B); \tkzLabelAngle[pos = 1.2](A,O,M){$2$};   \tkzLabelAngle[pos = 1.2](M,O,B){$1$};  \tkzLabelAngle[pos = 1.1](A,M,X){$2$};   \tkzLabelAngle[pos = 1.1](X,M,B){$1$};   \end{tikzpicture} \end{center} \end{document}


Not able to attach event handler to dynamically added input fields using jquery

I'm trying to dynamically add input fields based on an input field value. After adding fields, I want to add events on these dynamically added input fields, and this's what I did, but I'm not getting the result I want. Here's what I tried using jquery.  html file :  <input class='cls1' id='num' />

   script file  function add() {     var num = $("#num").val()     data = ""     for (i = 0; i<num; i++) {         var id_name = "input_" + i         data += "<input class='cls2' id='" + id_name + "' />
"     }     $("#samp").show().html(data) }  $(".cls1").on("change keyup paste", function (event) {     console.log("chng1")     // this's logging     add() // this adds input fields })  $(".cls2").on("change keyup paste", function (event) {     console.log("chng2") // not logging })  $("input[id^='input_']").on("change keyup paste", function (event) {   console.log("chng2") // not logging })   Any help would be appreciated.


I recently saw this picture posted on  which shows a so-called  rising from an ice cube tray.    I have read the Wikipedia page, but it doesn't mean much to me. My instinct was that it is caused by vibrations from the freezer setting up a resonant frequency on the surface of the water, and the spike has gradually "built up" as the water freezes. But I'm not a physicist, so I don't know if this makes sense.  I'm ideally looking for a layman's explanation of why this happens.


I'm trying to solve this problem from my group theory course:  Let $H$ be a subgroup of a simple nonabelian group $G$ of index $m\geq  5$. Prove that $G$ is isomorphic to a subgroup of $A_m$ ($G\lesssim  A_m$, being $A_m$ the alternate group of degree $m$).  The things I've noticed so far are:  $|G|=|G:H|\cdot |H|=m|H|$ From Cayley's Theorem I then get that $G\lesssim S_{m|H|}$  I don't know if these are useful things in this problem. I know the simplicity of $G$ is required, since $A_m$ is simple for $m\geq 5$, but I don't know how to follow. How can I solve this? Any help will be appreciated, thanks in advance.


How do I install Ubuntu 14.04 over a current Linux distrobution?

I recently wanted to try out Linux, and I selected Linux Mint.  Wrong choice.  Now, my hard drive partition wise is a mess, and Linux Mint 17.2 is SO glitchy for me, I just wanted Ubuntu.  Can anyone help me?  My laptop is a TOSHIBA Satellite C55-B B5200.


How do I use multiple superscripts (super, super-super, super-super-super, etc) with them all smaller than each other?

I wonder how to make every superscript level smaller than each other.  Like, 2^{2^{2^{2^{2^{2^{2}}}}}} makes the first superscript smaller, but the rest of the superscripts the same size as the first one.  I have done this first on  but of course it doesn't go like I want it to go like.


Basically, it's what it says in the title, could someone solve step by step this induction? It would be even better with an expanation for said steps, but it's not all that needed, I want to read the solution mostly to decipher how to solve it, since I have a few questions regarding Inductive Base, demonstration through hipothesis, and thesis... Esentially everything. Here's the problem: 0+2+4+...+2n = n(n+1), whereas n is a Natural.


When do we still need the table and figure environments when we don't want the enclosed objects to float?

The LaTeX Wikibook :     Please understand: you do not have to use floating tables. It only   looks more professional. If you want to place your tables where they   lie in your source code, do not use table at all! This is a very   common misunderstanding among newcomers.   LaTeX works with an intricate , but I often prefer immediate placement with the H placement specifier (enabled by the float package).  My understanding is that captions and table/figure numbering require the table/figure environments. Is this really so, or are there ways around that? What other reasons are there for using table/figure if we know that we don't want a particular object to float?


Cure for burns from hot peppers / capsicum oil?

So, I foolishly ignored advice about wearing gloves while handling hot peppers. I thought since they were "just" anaheim peppers I'd be fine... I was wrong, and I repent.   Does anyone know of a way to stop the burning? I have washed my hands repeatedly with soap in hot water and tried OTC burn spray.  I'm really worried about getting it off b/c I have a little baby & I don't want to get it on her, too. Can the oil transfer to someone else still?


I understand when we lift an object (a mass), its potential energy increases. Also we know $E=mc^2$, does it mean when we lift an object in the gravitational field (like on earth),  its mass increases?


Ubuntu Server - After reboot key always refused, until login

I installed Ubuntu Server and also configured the ssh server. I tried the "key system", so I have a public key in ~/.ssh/authorized_keys, and also configured this file in /etc/ssh/sshd_config.    When I manually (locally, via the keyboard connected to the server) login on the server PC I can remotely connect via ssh with the private key to the server. However if I reboot the server, and I do not login locally first, and I try to connect via ssh I always get the error:   Server refused our key   However if I then again login locally login, I can again connect via ssh using the keys.   What might I be doing wrong?   (BTW I rebooted using sudo reboot)


I'm quite new to electronics and am doing it as a hobby. I recently bought a 16x2 LCD display online to use it with an Arduino. When I received it, it noticed that there were a few components missing on the back. Is the display still functional or do i need to buy new components? If i do, which components do I need?  The back of the display looks like the display on the top in this photo.


Overlapping Text on Stack Overflow comments

I was just reading through some comments on  and noticed the comments overlap the right-sidebar links slightly.


What is the difference between ~/.profile and ~/.bash_profile?


I really need someone's help. I don't know what else to do, I've read all forums trying all sort of manipulations without managing to solve my problem.   After my login my desktop is empty. I don't know exactly what happend, everything was working well but I think it was after an upate. I cannot access the terminal with Alt+Ctrl+T only with Alt+Ctrl+Fx.   I'm running under Ubuntu 14.04 LTS with Virtual Box (Windows 8 host).   I've tried (among others) :  unity --replace   and I have the following error :  compiz (core) - Error: Plugin 'opengl' not loaded   I'm not an expert with Linux but I can do some basic stuff. :)


I have found a Delphi source code from the net that I am going to use but I see that there are comments like procedure sortList; // sorry for O(n^2) but a log(n) is impossible. gl. Not going to post the code here, but it sorts stuff in a TList with some for loops.  I have read Marco Cantu and Nick Hodges books but I have never seen the O(x) thing. I have googled it and I have seen that indicates how much a procedure is fast. Is it correct?  Does delphi support this feature as well? Sorry but I have seen a lot of maths and I haven't understood very well.


How do I always show (or autohide) menu items in Unity?

Is there any way to have the menu items on window menus always visible? I hate the whole hide and seek thing and have searched Google and here but I'm unable to find anything on how to make them stay visible all the time.  Thanks


Which is correct vs which one is correct?

When using the word "which" is it necessary to still use "one" after asking a question or do "which" and "which one" have the same meaning? Where do you draw the line on the difference between "which" and "which one" when asking a question that involves more than one answer?  Example:  How much is 1 + 1?     Which (one) is the right answer?:      A. 2      B. 11


I'd like some hints for the problem:  Show that the following set is not algebraic: $$ \{ (\cos(t),\sin(t),t) \in \mathbb{A}^3 : t \in \mathbb{R} \} $$  Thanks.


The question is-  Prove that there is a branch for the function $\sqrt{z-a}\sqrt{z-b}$ where $a,b$ are complex numbers, in $C\backslash [a,b]$.  Generally,I have no idea how to prove that there is a branch for a function... Any idea?


Difference between \LoadClass and \LoadClassWithOptions

Can anyone tell me the difference between those two commands?  Edit: Thanks for the answers, but I didn't get the clue yet. Here's an example:  test.tex  \documentclass[a4paper,oneside]{mytestclass} ...   mytestclass.cls  \NeedsTeXFormat{LaTeX2e}  \ProvidesClass{testclass}[2011/01/30 v0.1 testclass] \LoadClass{book}   or  \NeedsTeXFormat{LaTeX2e}  \ProvidesClass{testclass}[2011/01/30 v0.1 testclass] \LoadClassWithOptions{book}   In both examples the options a4paper and oneside are passed to book. So, I don't see any difference in the result.


Initial state: dual boot laptop to either Windows 7 or Ubuntu.  What I tried to do: change my partition of Ubuntu to Ubuntu-Mate.  First problem: first booting for the installation worked fine, but I didn't create a partition with the free space obtained from the previous one.   What I tried to solve it: I restarted the computer and unplugged the usb in order to create the partition in Windows.  What really happened, and final problem: grub rescue is displayed, no matter what boot source used. (Edit 3: I wanted to gain access to my Windows partition, so that I could rearrange my partitions)  Thank you very much for any suggestion.  Edit: I've tried using a bootable Ubuntu usb to get the Boot-info, but it keeps giving an error: "unknown filesystem".  Edit2: I've tried via Boot-Repair-Disk, but even so it doesn't work, to   check whether the iso is correctly burned, I'll try it in another computer.


What is the real meaning of Planck's constant?

My teacher told that  is $h$ and nothing more. So please explain what actually plancks constant is?


Is it a coincidence that quarks have exactly -1/3 or 2/3 the electron's charge?

I have read these questions:                My question is different. We live in a world, where quarks can have a real fraction of the elementary charge (-1/3 or 2/3). I do understand that the experimental data fit the models and that Baryons are made up of three quarks, and that those quarks can have -1/3 or 2/3 the elementary charge. This way, the quarks can combine so that the Baryon will have an integer of the elementary charge. This way, the nucleus and the electron can be in a stable atomic state, where their electric charges cancel (attract) exactly. Any other way, the atom would not be stable.  So electron says: hey quarks, let's team up, let's make an atom.   Quarks: Hey, great idea, how much electric charge do you have? Let's call it e. OK so we will team up of three of us, so we will just take each of us -1/3 or 2/3 of your charge.   Electron says: Great!, I feel it, this way we can have a stable atom.  Quarks: Great!  I mean come on! I do understand the respect that the experimental data tells us that electrons and quarks are both elementary particles.   It seems that the quarks teamed up exactly so three of them in Baryons so they can cancel out (attract) exactly the electron's electric charge. Now I do understand that there could be Baryons made up of four quarks, and they could have then -1/4 and 3/4 charge of the electron's elementary charge. This would work too, and the neutron and proton would have the same way an integer of the electron's charge. So the atom would be stable.   We could do this with any integer number of quarks. But, come on, my question is, what if the quarks' charge could only be -1/sqrt(3) and 2/sqrt(3)? How many quarks would we then need to make up the nucleus - to make it match the electron's charge? Is it mathematically possible to have any kind of electric charge for the quark? We could simply put as many valence quarks in a Baryon to make a stable atom?  Question:   Is it a coincidence that quarks have -1/3 and 2/3 the electron's charge and there are three quarks in a Baryon? Could we have quarks with any kind of electric charge, like Sqrt(3)*elementary charge? Could we make a stable atom this way too? How many quarks would we put in this case into a Baryon to make atoms stable? I accept and respect that currently, electrons are elementary particles. Is it impossible as of today's view that both electrons and quarks are made up of the same something smaller (strings)?


Relation between energy-time uncertainty principle and virtual particles

The energy-time uncertainty principle, given by, $$\Delta E\Delta t\geq\frac{\hbar}{2},$$  can be used to explain the existence of virtual particles which violate the law of conservation of energy. That is, the smaller the uncertainty in time, $\Delta t$, the greater $\Delta E$ that is needed to ensure that this relation holds. My question however is this: What is stopping both the uncertainty in time and the uncertainty in energy being large simultaneously?   From what I can tell, a simultaneously large $\Delta t$ and $\Delta E$ would not violate this relation, so why do virtual particles have such short lifetimes?


Glossaries: Make a glossary entry recognizable in printing

How do you make it visible to the reader that the printed word/term is an entry in the glossary? In my PDF on the computer, I just see it because I use the hyperref package and there's a red box around it. But when printing it, there's just nothing that makes it visible to the user.  Is there a typographically good and common way of doing this?


I want to try old versions of UNIX for fun, but I don't know where to get them. Is there a way to download them?


TypeError: coercing to Unicode: need string or buffer, NoneType found in ArcGIS labeling?

I have found out how to label using multiple attributes via an expression and python. What I have is as follows:  [ID] + '\n' + [Notes]   An ID example is "MH108" and a notes example is "buried, no access". I have used similar code successfully in the past, but in the current situation I get the following error and cannot figure out what I am missing.  The expression contains and error. Modify the expression and try again.  Error 0 on line 0 Error running expressions: Esri_FindLabel(ESRIExpressionArg0,ESRIExpressionARG1) Traceback (most recent call last): Files “<expression>”, line 1, in <module> File “<string>”, line 2, in esri_FindLabel TypeError: coercing to Unicode: need string or buffer, NoneType found


Do hotels send out wifi signals that place you there?

I need some clear cut answers to a question that gave birth to a divorce after 15 years of marriage. My ex husband's phone( Samsung Galaxy 6) would show him at many questionable places that he says he was not while he was supposed to be "at work". For example it showed him at hotels and he told me he didn't know why it would show that. Then gave me the reply that if you drive by a hotel they send out wifi signals that place you there just by driving by there. Now I have driven by a lot of hotels in our area and they never pinged me at any of them and we had the same GPS location feature. Mine always lined up where I went that day and his would be at all kinds of places.I asked around and no one has ever heard of this and I really want to know is this true???


How can I make Chrome stop caching redirects?

I am working on a web application that is using redirects (for pretty URLs).  I am trying to debug logic in the way the redirects are working. However Google Chrome keeps remembering the redirects and even after I change the code, redirecting the same way.  This is making it very hard to troubleshoot.  For example if I redirect /this to /that, then change my code to NOT redirect /this anymore. Google Chrome is still redirecting to /that. Like the redirect is cached or something. Is there a way to turn this off?


It looks like Google's index has been taken over by a man in the middle proxy scheme.  Search Google using google.com/search?q=usinfonow.com and google.com/search?q=stackexchange+usinfonow.com to see some examples.    Programming related queries on Google that would normally show stackoverflow.com pages in the top list of results are now being replaced by the proxy site stackoverflow.usinfonow.com.    How do we prevent this in the future? Any ideas?


I'm looking to download a macOS-Catalina-10.15 but can't find it anywhere on the web nor the apple website. Could anyone help find a safe site, preferably apple to download? Thanks. I have a Macbook-Pro


Why does $\det(A) = 0$ imply linear dependence?

Consider a system, $A$, of homogeneous linear equations given by a $3\times3$ matrix where the columns of the matrix are some given vectors in $\mathbb{R}^3$. s.t. $Ax = 0$. The claim is that if $\det(A) = 0$, then the given vectors are linearly dependent. Why is this the case?


The script below ignores all the -x exclude arguments when run from bash, but it works fine from command line:  #!/bin/sh TIMESTAMP=$(date +%u) ulimit -s 65536  WEEK=`date +"%V"` if [ $(($WEEK%2)) -eq 0 ]; then     echo "even";     BACKUP_DIR="/mnt/backup/2_$TIMESTAMP"     mkdir -p "$BACKUP_DIR/www" else     echo "odd";     BACKUP_DIR="/mnt/backup/1_$TIMESTAMP"     mkdir -p "$BACKUP_DIR/www"   fi  if [ $(date +%u) -gt 6 ]; then     /usr/bin/zip -r -y $BACKUP_DIR/www/web.zip /var/www/ -x '*/.opcache/*' -x '*/phpThumb/cache/*' else     /usr/bin/zip -r -y $BACKUP_DIR/www/web.zip /var/www/ -x '*/mycompany/files/*' -x '*/.opcache/*' -x '*/xml_extras/*' -x '*/files_admin/extras/*' -x '*/chatFiles/*' -x '*/phpThumb/cache/*' -x '*/backup-guard/*' -x '*/mailer/*' -x '*/mycompany/attachments/*' fi  exit 0   Its a 14 day backup solution and I want the weekdays to ignore the bigger folders like images. Any reason the -x arguments gets ignored?


She is a karate coach. She is not very powerful, but she is very quick/fast/rapid.   Can I use all three words quick, fast or rapid in the sentence?  Could you tell me the different meanings between them, if they are fine here?


EFI: Problem loading in-kernel X.509 certificate(-65)

I got this error message after installing Ubuntu off of a USB flash drive, I have turned off secure boot but it just appeared with a black screen and nothing happened after that I am booting from a 64 bit OS and I do have the right format USB and product of Ubuntu, can anyone help me out?


Are There Baggage Lockers at the San Francisco International Airport?

My plane from SFO back to Germany leaves at 10 p.m. tonight, I thought I'd take an Uber from my Hotel in San Jose to the airport early, lock up my baggage there and then go downtown to explore the city.  Are there baggage lockers available at the San Francisco International Airport?  If yes, where are they located?  My flight leaves at the International Terminal G.


Best way to return multiple values from a function?

The canonical way to return multiple values in languages that support it is often . Option: Using a tuple Consider this trivial example: def f(x):   y0 = x + 1   y1 = x * 3   y2 = y0 ** y3   return (y0, y1, y2)  However, this quickly gets problematic as the number of values returned increases. What if you want to return four or five values? Sure, you could keep tupling them, but it gets easy to forget which value is where. It's also rather ugly to unpack them wherever you want to receive them. Option: Using a dictionary The next logical step seems to be to introduce some sort of 'record notation'. In Python, the obvious way to do this is by means of a dict. Consider the following: def g(x):   y0 = x + 1   y1 = x * 3   y2 = y0 ** y3   return {'y0': y0, 'y1': y1 ,'y2': y2}  (Just to be clear, y0, y1, and y2 are just meant as abstract identifiers. As pointed out, in practice you'd use meaningful identifiers.) Now, we have a mechanism whereby we can project out a particular member of the returned object. For example, result['y0']  Option: Using a class However, there is another option. We could instead return a specialized structure. I've framed this in the context of Python, but I'm sure it applies to other languages as well. Indeed, if you were working in C this might very well be your only option. Here goes: class ReturnValue:   def __init__(self, y0, y1, y2):      self.y0 = y0      self.y1 = y1      self.y2 = y2  def g(x):   y0 = x + 1   y1 = x * 3   y2 = y0 ** y3   return ReturnValue(y0, y1, y2)  In Python the previous two are perhaps very similar in terms of plumbing - after all { y0, y1, y2 } just end up being entries in the internal __dict__ of the ReturnValue. There is one additional feature provided by Python though for tiny objects, the __slots__ attribute. The class could be expressed as: class ReturnValue(object):   __slots__ = ["y0", "y1", "y2"]   def __init__(self, y0, y1, y2):      self.y0 = y0      self.y1 = y1      self.y2 = y2  From the :  The __slots__ declaration takes a sequence of instance variables and reserves just enough space in each instance to hold a value for each variable. Space is saved because __dict__ is not created for each instance.  Option: Using a  (Python 3.7+) Using Python 3.7's new dataclasses, return a class with automatically added special methods, typing and other useful tools: @dataclass class Returnvalue:     y0: int     y1: float     y3: int  def total_cost(x):     y0 = x + 1     y1 = x * 3     y2 = y0 ** y3     return ReturnValue(y0, y1, y2)  Option: Using a list Another suggestion which I'd overlooked comes from Bill the Lizard: def h(x):   result = [x + 1]   result.append(x * 3)   result.append(y0 ** y3)   return result  This is my least favorite method though. I suppose I'm tainted by exposure to Haskell, but the idea of mixed-type lists has always felt uncomfortable to me. In this particular example the list is -not- mixed type, but it conceivably could be. A list used in this way really doesn't gain anything with respect to the tuple as far as I can tell. The only real difference between lists and tuples in Python is that lists are , whereas tuples are not. I personally tend to carry over the conventions from functional programming: use lists for any number of elements of the same type, and tuples for a fixed number of elements of predetermined types. Question After the lengthy preamble, comes the inevitable question. Which method (do you think) is best?


Algorithms on Programmers.SE or Stack Overflow?

This seems to come up a bit on Programmers.SE but which site is the canonical site for general (i.e. not research oriented) algorithms questions? If we look at the Stack Overflow FAQ we are told the following:     We feel the best Stack Overflow questions have a bit of source code in   them, but if your question generally covers …         a specific programming problem   a software algorithm   software tools commonly used by programmers   matters that are unique to the programming profession         … then you’re in the right place to ask your question!   Likewise, if we look at the Programmers.SE FAQ we are told the following:     This can include topics such as:         Software engineering   Developer testing   Algorithm and data structure concepts   Design patterns   Architecture   Development methodologies   Quality assurance   Software licensing   Freelancing and business concerns         If your question is about programming tools, please ask on Stack   Overflow instead.   So it looks like there is a bit of overlap in the FAQs that need to be resolved, perhaps we can updated them to indicate a finer-grained example (for example Stack Overflow could have "a specific software algorithm implementation") of which to use on which or just remove it from one to leave the other site as the appropriate location?


I have home station with debian on it. Today while being at office i had to make some changes in debian config, and i had to do it very urgent. I thought there will be no problem, because home station has static ip and ssh on, but after i've downloaded PuTTY 0.63 on my windows workstation i was unable to connect with "connection timed out" error. Here, at my office all machines are behind proxy, but i need some of the blocked sites so admins just added me to exception list and i don't use proxy anymore. Browsing internet pages works fine. SSH daemon on my home machine works. I can connect it via android ssh client from my phone(that's how i've managed to do the work).  RDP on virtual windows machine which is also at my home has the same issue(can't connect from work, but everything works fine with mobile RDP client)  What can be the issue of this? Probably corporate firewall? May be i can find out what ports are free and use them for outcoming connection?


Prove this function cannot be continuous

Let $f:[0,1] \to \Bbb R$ such that for every $y$ either there is no $x$ such that $f(x)=y$ or there are exactly two such $x$. We are required to show that $f$ cannot be continuous. I have no idea how to prove this. Also is there a function which satisfies this?


I'm having trouble installing MySQL Server. Everytime I try to connect to local server with MySQL Workbench I get this message:  "Your connection attempt failed for user 'root' from your host to server at localhost:3306: Access denied for user 'root'@'localhost' Please: 1 Check that mysql is running on server localhost 2 Check that mysql is running on port 3306 (note: 3306 is the default, but this can be changed) 3 Check the root has rights to connect to localhost from your address (mysql rights define what clients can connect to the server and from which machines) 4 Make sure you are both providing a password if needed and using the correct password for localhost connecting from the host address you're connecting from"  I'm running a freshly installied Ubuntu 18.04. These are the packeges I have installed on my system: libmysqlclient20:amd64 libmysqlcppconn7v5:amd64 mysql-client mysql-client-5.7 mysql-client-core-5.7 mysql-common mysql-server mysql-server-5.7 mysql-server-core-5.7 mysql-utilities mysql-workbench mysql-workbench-data    python-mysql.connector               I've tried this: mysql -u root -p Then I'm prompted to enter a password, but during installation I was never asked to create one to begin with. And then I get the error no matter what pass I give: ERROR 1698 (28000): Access denied for user 'root'@'localhost'


Tint and Opacity on swatch do not yield same color on white

On two identical rectangles I use a swatch as fill color. The swatch is C=100, M=0, Y=0, K=0. On one rectangle I've set the Tint for the swatch to 10%, on the Other I've set the opacity to 10%. The result is not the same color on a white background. I'm not sure why this is.  I do understand one makes the rectangle transparent and the other does not, but on a white background I had not expected the difference because the Tint itself would also be calculated based on 0% being whit.


How can I simplify this relation? $$\sum_{i = 1}^m(X_i-\mu)^2=\sum_{i = 1}^m(X_i-\bar{X}_m)^2+m(\bar{X}_m-\mu)^2$$ I know how to set up: $$\sum_{i = 1}^m(X_i-\mu)^2=\sum_{i = 1}^m[(X_i-\bar{X}_m)+(\bar{X}_m-\mu)]^2$$ but when I open the bracket, how do I handle the mixed term? $$2\sum_{i = 1}^m(X_i-\bar{X}_m)(\bar{X}_m-\mu)$$  Thank you!


Is there a way to point many domain names to the same IP without repeating the IP

I own about 100 domain names. Most of them are unused, but I have them all set up to point to the same server so that I can serve a redirect to my main domain name.  Right now, I'm using A records for each domain to point to my server. I'm about to change servers, which means I'll need to change IPs. Using Google Cloud DNS (or any DNS provider), is there a way to use some sort of root CNAME or variable so that I don't have to change the IP 100 times?  I'd love to be able to update a single domain's A record, and then see the rest update automatically, but I don't see a way to make a CNAME record on a non-subdomain, only an A record.


Direct Irrationality Proof for $\sqrt{3}$ and $\sqrt{6}$

I am having trouble with proving this directly. I am currently learning about greatest common divisors and know that this has a role in the proof. However, I can only prove the two through contradiction and not directly.


Getting parameters from the command line to the template

I would like to create a simple script (probably Python 3) to generate invoices based on *.tex template. Is there any way to change some data in this template from the command line? I mean, for example, such a simple situation that I want to run the script and give the amount for the invoice that would be inserted into it: "python generate_invoice.py --value 300$" and that 300$ will appear in a specific field in the resulting pdf file. I couldn't find anywhere else to do that.


Replicate the Invisible Black Background on Photoshop

There is a technique in photography, called Invisible Black Background. You can find details about it in this blog post   An example image is this one:    I have just started using Photoshop, so I am not aware of design techniques and terms. But is there any way (or tutorial better) to replicate this effect in a portrait image with a non-black background?


Windows 7 desktop does not automatically refresh

I am using Windows 7.  If I delete something from the desktop, then the icon remains there.  I have to hit F5 or right-click->Refresh to make the desktop refresh.  After the refresh, the icon disappears.  Any suggestions?


public static boolean checkPallindrone(Node<Integer> head,Node<Integer> last){      //# check if the given linked list is a palindrome      boolean check = true;     if(head==null || head.next==null){         return true;     }      if(head.data != last.data){         return false;     }      Node<Integer>temp = head;     while(temp.next.next !=null){         temp= temp.next;     }     last = temp;     last.next=null;     check = checkPallindrone(head.next, last);      if(check == false){         return false;     }      else return true; }   This is a code snippet to find palindrome. In this code the object head and last are send to the function. In java all the objects are references as I had read somewhere. So here head and last are reference which would point or refer to a linked list in the heap of applications memory structure.  So why when I print the linked list in the main function, do I not get an empty linked list, Since last would make all the elements NULL one by one in the process of checking if its a palindrome?


How to display special German characters "ÄÜÖß" in a map?

I have a shapefile with names for Regions. These don't seem to contain special characters "Ä", "Ü", "Ö", "ß" but ugly hieroglyphs.  What can I do to display them correctly. If I import the shape as UTF-8 it doesn't work.  The names are in a dbase table. So is it possible to save a dbase table in UTF-8 or is there a different way of dealing with it?


I'm looking for a way to swap Esc and Caps Lock on Linux virtual console.  In X11, I can do this with setxkbmap -option caps:swapescape, but I don't know an equivalent in text mode. So, what can I do?


How to cut a mesh by specifying the angle

I wanna cut a mesh by specifying the angle, but knife mode only cut 45° with C key.  I want to cut by the angle around specifying the vertex.


no of non negative solutions of equation a+b+c+...n variables=N where a<=b<=c<=d<=....

I need to find the number of non negative solutions of equation  $\underbrace{a+b+c+ \dotsb }_{n \text{ variables}}=N$ where $a\le b \le c \le d \le \dotsb $.  What I have tried is:     Suppose $S(n)$ gives us the required solution.      For $n=1$, only one solution $(a=N)$, $S(1)=1$      for $n=2$, $a+b=N$. $a$ can take either $0$ or non zero.        if a takes 0 then total solutions = $S(1)=1$;        otherwise, a can take values from 1 to N/2 so total floor(N/2) possible solutions.        Hence $S(2)=S(1)+N/2 = 1 + N/2$      for $n=3, a+b+c=N$, a can take either 0 or non zero        if a takes 0 then total solutions = $S(2)$        otherwise , a can take values from 1 to N/3 so total floor(N/3) possible solutions.        Hence $S(3)= S(2) + N/3 = 1 + N/2 + N/3$      Similarly for $n=n$,        $S(n)=1+ N/2 + N/3 + N/4 + ....... + N/n$   Can anyone tell whether the above formula is right or wrong?


Prove: For $m,n,a \in \mathbb{Z+}$, if $m \gt n$, then $a^{2^n} +1 \mid a^{2^m} -1$

Trying out a few examples, let (i) $a=3, n=1, m=2, 3^2+1=10, 3^4-1=80, 10\mid 80$, (ii) $a=3, n=2, m=3, 3^4+1=82, 3^8-1=6560, \frac{6560}{82}= 80$.  To derive a proof, should derive $a^{2^n} +1$ as a factor of $a^{2^m} -1$, & as $m\gt n$, so $a^{2^m}=a^{2^n}.a^{2^{(n-m)}}$, so  $a^{2^m}-1=a^{2^n}.a^{2^{(n-m)}}-1$.  It is possible to state the next step, based on something like $a^2-1=(a-1)(a+1)$, but lack familiarity with such type of polynomial (if chosen the correct word) division.  Also, would request a generalized answer, for different bases for powers of $n,m$.


What's up. I wanna ask about the sentence:      'I don't think I will know no one at the party'   Which means that I will actually know someone. The question is, is this correct? I know I should not use 'no' or 'not' twice in simple sentences. But what about the complex, like the one above, or compound sentences? I really appreciate any help you can provide.  P.S I agree that I could've made a mistake in terms of complex and compound. If it so, please let me know.


Difference between WinMain,main and DllMain in C++

What is the difference between the three functions and when to use them??


I have two equations which need to be broken into multiple lines. One of the equations has a coeficiente factored out, so that it is of the form X = A(...very long...). The other does not.  The equations were written as  $\!\begin{aligned}      y &= \frac{1}{A}\left(\frac{b_1\cdot{}t_{f1}^2}{2}+h_w\cdot{}t_w\left(t_{f1}+\frac{h_w}{2}\right)+\right.\\     &\phantom{=}\left.+b_2\cdot{}t_{f2}\left(t_{f1}+h_w+\frac{t_{f2}}{2}\right)\right)\\     I_y &= \dfrac{1}{12}\left(b_1\cdot{}t_{f1}^3+t_w\cdot{}h_w^3+b_2\cdot{}t_{f2}^3\right)+\\     &\phantom{=}+b_1\cdot{}t_{f1}\left(y-\dfrac{t_{f1}}{2}\right)^2+\\ \end{aligned}$   The use of $\!\begin{aligned} instead of a standard align environment is because this is contained within a table. This results in the following output:   This is fine and is as expected. However, the global parentheses in the first equation required the use of \right. and \left. at the end of the first line and beginning of the second line, which seems to eat the space between the + and b, as becomes clear when you compare the space between them in the first and second equations.  This is a purely aesthetic issue, but I'm curious to know if it is (preferably trivially) solved.


Install Windows 7 on external drive and boot it from a Mac

I want to install Windows 7 on an external hard drive, and boot from it when needed.   Is this possible on a Mac? I have heard from some sources that it is not possible to boot Windows from external drives, at least on the new Macs. I found this quite surprising.   Any idea if this is true?


How to bypass FRP on Google Pixel(1st Gen)?

First, It's not a duplicate post. I have already tried the methods written for different phones like  but it's for LG and Samsung phones.  Also, I have watched  but "Maps" is not shown as an option along with cut and copy.  Please help me get this phone to work.


Which requires he "be" injected with gamma globulin

He has rare autoimmune disease which requires he be injected with gamma globulin once every 21 days.   Why do we use "be" in the sentence above? What does it mean?


Prove that $\mathbb Z_{m}\times\mathbb Z_{n} \cong \mathbb Z_{mn}$ implies $\gcd(m,n)=1$.  This is the converse of the Chinese remainder theorem in abstract algebra. Any help would be appreciated.  Thanks!


Find all possible functions, $F(r)$, harmonic in $2$ and $3$ dimensions,

Sources: this is an old advanced calculus exam question, which I think is asking for harmonic functions.  The problem statement is:     Suppose $F(r)$ is a smooth function of $r$ for $r>0$ . Define $\Phi(x) = F(|x|)$ with $x = (x_1, ...,x_d) \in \mathbb{R}^d$ and $|x| = (\large \sum_i^dx_i^2)^{\frac{1}{2}}$.For $d=2$ and $d=3$, find all possible functions $F(r)$ so that   $$\sum_{i=1}^d (\frac {\partial}{\partial x_i})^2\Phi(x) = 0.$$   Any hints or comments are welcome.  So, it appears that this problem statement is just a tricky way  of asking to find all functions $\Phi$ such that   $$\Phi_{x_1x_1} + \Phi_{x_2x_2} = 0 $$  and   $$\Phi_{x_1x_1} + \Phi_{x_2x_2} + \Phi_{x_3x_3} = 0$$  I.e., we are looking for all functions that are harmonic.  But what is weird about this question is that it doesn't really specify a domain in which we are to find these harmonic functions.  Unless the domain is simply understood to be for all $| x| \ne 0$.  Thanks,


How to change Web Address for document library in SharePoint 2010

I want to change the web address (URL) for document library.  Is there a way to achieve this? How?


Is there an easy way to have my whole document with a space between paragraphs rather than indentation?

I would like to have my whole document showing a blank line (or space) between paragraphs and no indentation. I know how to do it line by line, but is there a way to change that with just one or a few lines at the beginning of the document? Like a package you can install, or a new command?


$\lim\limits_{n \to{+}\infty}{\sqrt[n]{n!}}$ is infinite

How do I prove that $ \displaystyle\lim_{n \to{+}\infty}{\sqrt[n]{n!}}$ is infinite?


Show that the limit exists and find it's value?

The Fibonacci series defined recursively by $x(1) = 1, x(2) = 2$ and  $x(n+1) = x(n) + x(n-1)$  Find$$\lim_{n\rightarrow\infty}\frac{x(n+1)}{x(n)}$$


I may soon get enough reputation on Stack Overflow to see deleted posts. However, I don't want to see them! They probably were deleted for a good reason, and having them visible (e.g. while browsing through the answers for a question) is annoying. I got that feeling from another site where I have enough reputation to see deleted answers.  The pain is mostly (only?) about deleted answers; I don't remember seeing an annoying deleted question. But maybe these are annoying too (people with enough reputation will know).  Some users even try  to ease that pain for everyone.  Would it be good to not show the deleted posts by default, and provide some way for the users to "unhide" each post they want to see? Like show a small "unhide" button instead of the full answer.  (I am not making this into a [feature-request] because I don't have the details of the presentation that I want to suggest, just a general idea).


Knowing every odd circuit in a graph is a triangle, prove $\chi(G) \le 4$  My approach: an odd circuit requires 3 colors, and an even circuit requires 2. But then I'm stuck. Can you give me a hint on how to proceed? No complete solution please.


It has been suggested that this question is a duplicate of others. Sorry, but it is not. I am merely addressing the issue of:   "flag the post right away as well as editing it, hoping for moderators to see and take notice of the edit in due time and finally delete the post altogether".  In the example given (see attached screenshot), it took 10+ hours for the issue to be addressed. This is the issue.  10+ hours is an eternity in Internet time. So. How does one handle that? Any and all suggestions welcomed.  I had a long and fruitful discussion on the matter with . Still. How could/should one handle SEO spam situations like this?  My approach was to flag the post right away as well as editing it, hoping for moderators to see and take notice of  in due time and finally delete the post altogether. Instead of having it hanging around for 10+ hours (which is just what the spammer wished for in the first place), since it was registered in both Google and  as well. (You can probably still find it there.) I do believe that should be edited to a non-interest link till deleted. Could this be the right way to handle SEO spam? If not, what are your thoughts? I believe the nature of such questions are quite debatable. This is not an easy call. It still needs to be addressed.


Getting all Users and their Custom Permissions

tl;dr  Want to make a SOQL to return all Users and there (custom) permissions    Hi there  I've just started using SF, so bare with me if this is very basic.  One of the usages of salesforce we're trying to do is to manage the permissions and policies of what some departments can do in our internal BO (backoffice).  So I manage to find that we can do that by making the PermissionSet with CustomPermissions, and it is going forward kindly of ok. But now from our BO we need to query SF for users and their permissions.  So, for those who know SQL, this was kind of what I wanted to do:  SELECT    User.Id,   User.Email,   User.Username,   PermissionSet.Id,   CustomPermission.* FROM User   JOIN PermissionSetAssignment      ON PermissionSetAssignment.AssigneeId = User.Id   JOIN PermissionSet     ON PermissionSet.Id = PermissionSetAssignment.PermissionSetId   JOIN CustomPermission      ON CustomPermission ON CustomPermission.??? = PermissionSet.Id   But on SF they use SOQL, which already understood that it takes an object way of querying. Already did a couple of tests, and  helped to understand the properties of each object, but failed of explaining how do the objects interact and which alias they have when interacting. I mean from the POV of PermissionSetAssignments, users are called Assignee. Where can I find these alias? Where can I find the object relations map?  But going back to the topic, I've manage to go till here:  SELECT Id, Email,   (SELECT     PermissionSet.Id     PermissionSet.Label   FROM PermissionSetAssignments) FROM User   Which I already have Users, PermissionSetAssignments and PermissionSet, I was able to find this by some examples and the  (end of the page)  But I'm completely lost in going from there to CustomPermissions. Any idea?    edit  With the help of @adrian-larson so far I've manage to get the users, their permission sets, and the SetupEntityAccessItems SetupEntityId and ParentId, however I still miss the DeveloperName from CustomPermissions that would need to be attached to  SetupEntityAccess. The @adrian-larson answer would be correct if I wanted to do a query (in that case 3) per each user.  The idea is to map the CustomPermissions DeveloperName into our application specific policy, so I intend to from time to time to fetch that Users > PermissionSet > CustomPermissions and update all users permissions on our application.  what I have so far:   get all users and their permission sets  SELECT Id, Email,    (     SELECT PermissionSet.Id, PermissionSet.Label      FROM PermissionSetAssignments   )  FROM User   get all setup entity access items that are custom and the parent id (permission set)  SELECT Label, Name, (   SELECT      Parent.Name,     SetupEntityId,      SetupEntityType   FROM SetupEntityAccessItems   WHERE      SetupEntityType = 'CustomPermission' ) FROM PermissionSet  [STILL MISSING] a way to map setup entity access to the custom permission name     edit  Solution found. On the  doesn't mention an ID, but noticed that @adrian-larson made a match through the ID, so with the simple:       SELECT Id, DeveloperName     FROM CustomPermission   It was possible to get the missing data part. Ideally 1 query would be the best, but this will work also. Thanks @adrian-larson


Perfect vertical icon centering next to the text

I want to make a link with a picture symbolizing play next to the text. What is the best way to do this? I wrote this code, but I don't think it's perfectly centered vertically. How can I center it perfectly?    a:after {   content: '';   display: inline-block;   vertical-align: middle;   width: 20px;   height: 20px;   background: url(https://img.icons8.com/material-sharp/24/000000/circled-play.png) center / cover no-repeat;   margin-left: 5px; } Watch video


I want to know an idiom for something like if the thing is good it will have some negative also. OR something like with good comes bad.    Let's say for a sentence "As they say ...................., nuclear energy has some negative aspects as well."    I know there are a few expressions like "curator's egg" and "double edged sword" but they don't fit in perfectly.


Is there a way to bulk add URLs to a certain YouTube playlist?

Say I have a list of URLs (videos), and I would like to add them to a certain playlist on my YouTube channel. Is there a way to do that?


Story about consumerisms and indebting the son

I'm searching for a short story I read probably around 20 years ago in a school anthology. It was set in a futuristic setting, where consumerism was rampant. The two protagonists were a door-to-door salesman and its customer.   In this futuristic setting a person could buy things with credit not only by indebting himself but also by indebting the first X years of his son's salary (this even when the son was a child... So you could buy a new TV by exchanging it with the first year of the future salary of your son, to make an example).   The customer was already quite heavily indebted (and clearly already had his house full of things he hadn't ever used, like a pool), and the salesman was trying to persuade the customer to indebt a little of his son's future salaries. If I remember correctly, the customer hadn't still indebted his son, and he was reluctant to do so, but he had already nearly tapped out all of his personal future salary. The salesman used at least two ways to persuade the customer:   he told him that anything he bought would then be used by his son, and a day would become his son's property (at the death of the customer), so it was OK to use the son's future salaries. AND, big "secret", he told him that his neighbour had already indebted his yet-to-be-born niece. He told the customer that his company would have to invent new things to sell to this neighbour :-)


Determining the favored penny on a chessboard

Let's suppose there is a chessboard (with 64 squares), and there is a penny on each square. Each of the pennies has a side (head or tails) facing up, chosen at random.  I look at the board and choose my favorite penny. I then tell my two mathemetician friends that I will reveal which penny is my favorite to one of them, who then must flip over exactly one of the pennies on the chessboard, while the other is in another room not looking. Once the coin is flipped over, the uninformed mathematician is summoned into the room and must deduce which penny is my favorite only by examining the coins on the chessboard.  What strategy can the two mathematicians devise to ensure that my favorite penny can always be deduced?


Orthogonal idempotents from disjoint union in $\text{Spec}(A)$

Let $A$ be a commutative ring with unity.  Suppose that $X=\text{Spec}(A)$ is a disjoint union $X_1\cup X_2$ of topological spaces.  Show that $A$ has a pair of orthogonal idempotents $e_1,e_2$ (i.e. $e_1+e_2=1$ and $e_1e_2=0$) such that $X_1=\operatorname{Spec}(e_1A)$ and $X_2=\operatorname{Spec}(e_2A)$.   I think it should be easy but I don't know how to proceed with unspecified topology on $\text{Spec}(A)$.  Do I use a mapping somehow from $A$ to $X$?    I see this post  but don't think is an "exact duplicate." At least, the wording is different enough so I had found it before and did not see it was a duplicate. (And I still don't think so.)


how to write css for inner html of iframe

have one question, i trapped in a prob..The problem is like that --->I have to manipulate the css of inner html of iframe but the content of this iframe is not coming from same domain so how can it makes possible live eg.-u can take ("tweets feed in our website ,it comes from another domain tweeter.com/bla....blaa but render on our web page encapsulate with iframe,so how can i style tweet section in our website") i have tried by jQuery but its not working can u plz help me out in that ? Thanks in advance Smile | :)


Why Didn't Severus Disapparate In the Shrieking Shack?

I do believe that Severus knew he was in danger in the Shrieking Shack. Harry even wondered if he sensed danger. Voldemort said to him,     I have thought long and hard, Severus… do you know why I have called you back from the battle?   If you put two and two together, Snape must have known that he was in danger. He must have known that the fight was almost over, because Dumbledore told him to tell Harry (indirectly) that he was a horcrux. He had orders, so why couldn’t he just disapparate into the castle?


Has Black Panther been injected with Super Soldier Serum allowing him to run that fast?

In Captain America: Civil War, in the fight scene between Captain America, Bucky Barnes and the Black Panther, there is a part where the Black Panther is running, chasing after Bucky Barnes:                                  You can clearly seeing he is running as fast as Bucky and is running past moving cars. This all points to him having super human strength, as a normal human can not run that fast.   So how did the Black Panther run that fast? Did he have Super Soldier Serum?  Edit: I am not asking if the suit is responsible for the Black Panthers speed.


How to add missing options (control panel in start menu & date format) in Windows 10 Creators update?

I recently updated to the Windows 10 creators update and noticed that the option to access the control panel was removed from the start menu and an option for the date time format as well.  Is there any way to get them back? See the below screenshots for more detail.


Do cosmologically redshifted photons violate energy conservation?

I understand that, due to the Doppler effect, different frames of reference moving at different velocities relative to each other will measure different photon frequencies and hence energy.  The amount of energy measured in a frame of reference is specific and unique to that frame.  That was answered in .  However, photons that undergo a redshift due only to the metric expansion of space seem like they lose energy but not because the photon source and observer are in different frames of reference, but because space itself is expanding.  See .  As I understand the expansion of the universe, if a photon was reflected back to its source the source would not measure the same frequency for the photon as when it was emitted due to the elongating of the photon's wavelength by the intermittent metric expansion of space.  How are we to interpret this?  Is the source no longer in the same frame of reference as when the photon was first emitted (thus reducing to the simple Doppler effect)?  Is energy conservation being violated?  Or is the missing photon energy being somehow transmitted into space itself?


Which site answers questions on Google services?

Which SE site should I ask questions about Google services, especially Gmail?


In bash instead of creating new line changing the already made line

Ok hard to explain in few words so  I was wondering how instead of creating a new line......like lets say I want to:  while true; do echo "hello"; sleep 1; done   then I want it to count the number of times it goes through, but instead of it repeating on the next line it just changes it  Would that need some drawing scripting like x11  while true; do echo "hello $(date +%S)"; sleep 1; done


Do file descriptors optimise writing to files?

Is it equivalent to have commands print to a file directly, as opposed to writing to a file descriptor?  Illustration  Writing to file directly:  for i in {1..1000}; do >>x echo "$i"; done   Using an fd:  exec 3>&1 1>x for i in {1..1000}; do echo "$i"; done exec 1>&3 3>&-     Is the latter one more efficient?


I want to make a scoreboard on my server that broadcasts a message to players who join the server for the first time, but I don't know what the scoreboard is. If you don't know what I'm talking about here's an example /scoreboard objectives add join [MY PROBLEM]


How to use reflection in order to execute a generic constructor

Let's say I have String type = "Integer" for example, and I have on the other side a public class MyType<T> with a constructor public MyType(){}  How can I use the java reflection newInstance method in order to be able to do something along the lines:  public static MyType<?> create(String type){      return /*new MyType<Integer>() if type was "Integer", etc*/;  }


Identifying Value of Burnt 5-Band Resistor

I've been having trouble identifying the value of this resistor (see picture below) as the color codes in position does not make sense. It looks like a 5 band coded resistor. The 3rd band seems to be my cause of confusion as I can't make out the color. It looked like silver, or is it a gray?   But still, regardless of the reading direction (which I thought I got it wrong originally) and whether the 3rd band is silver or gray, the value produced is not in any of the standard/preferred resistor values.   Or maybe there's a band visibly missing (blackened or discolored or whatever)?   Or somehow I got it wrong, and it might not be a resistor but an inductor or others?   If possible could you let me know:   What is the value of this resistor?  What is this if its not a resistor?  Is the 3rd band is a silver or gray?    I can't depend on my multimeter readings as its just a cheap one but is the only one I have at the moment.


Sequence of sets $f_n$ that converge almost everywhere to $f$ but not almost uniformly to $f$?

I've been trying to think of a simple example of a sequence of sets $f_n$ that converge almost everywhere to $f$ but not almost uniformly to $f$. Suppose $f$ is the zero function for the sake of simplicity.  The problem I'm having is that almost everywhere means that the set of values where $f_n$ does not converge to $0$ has measure $0$. But this just seems like a special case of almost uniform convergence which means that we can remove a set of arbitrary small measure from the domain and we will have uniform convergence on the remainder.  So is there some simple example that illustrates the difference between these two modes of convergence?


How to show that $(W^\bot)^\bot=W$ (in a finite dimensional vector space)

I need to prove that if $V$ is a finite dimensional vector space over a field K with a non-degenerate inner-product and $W\subset V$ is a subspace of V, then: $$ (W^\bot)^\bot=W $$ Here is my approach:  If $\langle\cdot,\cdot\rangle$ is the non-degenerate inner product of $V$ and $B={w_1, ... , w_n}$ is a base of $V$ where ${w_1, ... , w_r}$ is a base of $W$ then I showed that  $$ \langle u,v\rangle=[u]^T_BA[v]_B $$ for a symmetric, invertible matrix $A\in\mathbb{R}^{n\times n}$. Then $W^\bot$ is the solution space of $A_rx=0$ where $A_r\in\mathbb{R}^{r\times n}$ is the matrix of the first $r$ lines of $A$. Is all this true?  I tried to exploit this but wasn't able to do so. How to proceed further?


How can a computer/OS tell what kind of RAM is in the machine?

How can Mac OS X tell what kind of RAM is in the machine? For example I was working on one that had DDR3 RAM @ 1600MHz and I thought it wasn't possible to know the RAM without physically opening the case and looking at it.How can this be done on other systems?


No reason for anyone to see pending close votes, except OP (and maybe people who already voted)

I don't see why users (even those with high rep) should be able to see the number of close-votes for any questions they did not post. I've observed that the mere presence of a close vote can trigger more, and -- quite often -- this biases things in favor of the person who cast the first vote, which makes all the difference in edge cases.  Mind you, it affects me just as much as anybody -- there have definitely been some cases where I would not have voted had I not seen that others were closing a question. I try my best, of course, but we're all human...  The only exception, in my opinion, is when closing as a duplicate. But even then, it doesn't matter how many votes there are -- instead, the site can simply put the top-suggested votes at the top of the list, without mentioning which ones were chosen by people and which ones weren't.  So really, I don't see why the number of close votes should be visible to anyone other than the OP -- and so I'm proposing we remove the display of pending close votes for anyone who doesn't need to see it.


Flex-box with the central element that fills all the free space

I am trying to design the web page with the following document tree (as to avoid the appearance of the scroll as much as possible):  html    head   body     div (flex-box - height 100%)       header (flex-child - fixed height)       main (flex-child - consumes all the remainig space/height)       footer (flex-child - fixed height)   Apparently, flex-box is the best solution, but I am reading this nice guide  and it appears that there are only limited options how to distribute the space (how to distribute the height of elements) - there are some "growth" properties but nothing else. How can I make the structure I am aiming to achieve? I have no code because I don't see the necessary CSS properties for making even a starter example.


Why do these 2 circuits produce differen output signals (something has to do with charging/discharging capacitor)? Please explain in detail and how does the envelope detector work based on this


How do I find a research topic without the guidance of a professor?

I have been out of uni for quite some time now, but I would like to apply for UK (!) PhDs (so not the MA including US-PhDs). I am in the Humanities and I know the general topic within my field which I would like to focus on.   However, I am not sure what would make a good research question and even less sure how to find one. Any advice? How will I know? I am worried I will propose something ridiculous that will make me look immature, but I don't want to squander my chances with potential supervisors by looking so clueless.


Do 'learn by heart' & 'learn by rote' mean the same?

Here in India, both the phrases learning by heart and learning by rote are taken to have the same meaning, i.e., blind memorisation without true understanding.    However, some sources say that to learn something by heart implies that one knows something so well that it has been thoroughly internalised and imbibed.    So is it wrong to conflate the two?


Can you distinguish the permission to do something from the license, an official document?

According to the dictionary, licence/license refers to an official document which proves you are permitted to do something. What, then, is the word for the permission itself? I'm from Korea, and in Korean the document and the permission are two different things; that is, the formal permission by the authorities is called 면허, and the document is called 면허증.


How to create UINavigationController animation top to bottom

Hey, just wondering how/if possible to get a UITableView to animate from top to bottom.  The standard way of doing a transition animated the page bottom to top, bu I have an undo button on the page that I navigate to that I want to allow the user to click if they decide to go back...  This is my code for the current animation that goes bottom to top.. if you could help me to change it that would be awesome.    - (void)viewDidLoad {       //Title     self.title = @"Advanced Search";     [super viewDidLoad];          //undo button takes you back to main search options     UIBarButtonItem *undoButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemUndo target:self action:@selector(undoButton:)];     self.navigationItem.leftBarButtonItem = undoButton; }  - (void)undoButton:sender {     RootViewController *rootViewController = [[RootViewController alloc] init];     UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:rootViewController];     [[self navigationController] presentModalViewController:navigationController animated:YES];     [navigationController release];  }