ANN resulted in less than 0.4 R-squared value. Is my methodology correct?

I am using ANN for solving Regression problem. But it turns out that ANN is performing badly. I have a daily data (2000 - 2018) which contains 6400 rows and 5 variables (including 2 target). This is how my data looks like:    Rain Discharge  Level Discharge0 Level0 1  9.27     0.226 791.12    65.4600   1.08 2 17.62     0.433 791.18   209.6000   1.98 3 10.01     0.791 791.25   129.3000   1.50 4  4.61     0.988 791.28    60.3000   1.07 5 10.37     0.822 791.25    42.7400   0.98 6 46.25     9.564 791.78   173.0624   1.67  Here, I am trying to predict Discharge0 and Level0, one day ahead (in future). This is what I have tried: data <- data.frame(Rain, Discharge, Level, Discharge0, Level0) data1 <- data  # slide function can be used to take leads (for predicting one day ahead)  data1 <- slide(data1, Var = "df2.Discharge", slideBy = 1) data1 <- slide(data1, Var = "df2.Level", slideBy = 1)  # Last value of both variables is now NA (as one day lead is taken), it can be removed     data1 <- na.omit(data1) data1 <- data1[-c(4, 5)] # removing Discharhe0 and Level0.  I have taken lead of one day for both Discharge and Level. This is how final data looks like on which model is applied:    Rain Dischrge  Level   Level1 Discharge1 1  9.27    0.226 791.12 209.6000       1.98 2 17.62    0.433 791.18 129.3000       1.50 3 10.01    0.791 791.25  60.3000       1.07 4  4.61    0.988 791.28  42.7400       0.98 5 10.37    0.822 791.25 173.0624       1.67 6 46.25    9.564 791.78 352.5326       2.55  Now, the targets are Discharge1 and Level1 (they have one day lead). # 1:5844 contains data from 1st june, 2000 to 31st May, 2016  index <- 1:5844 datatrain = data1[index, ] datatest = data1[-index, ]  # Scaling data between 0 and 1.  max = apply(data1 , 2 , max) min = apply(data1, 2 , min) scaled = as.data.frame(scale(data1, center = min, scale = max - min))  # Splitting into training and testing  train = scaled[index , ] test = scaled[-index , ]  # Applying neuralnet function  NN = neuralnet(Discharge1 + Level1 ~ rain + Discharge + Level, train, hidden = c(16, 8, 4), threshold = 0.05) plot(NN)  predict_test = neuralnet::compute(NN, test[, c(1, 2, 3)]) # Unscaling: converting back to original range  predict_test1 = (predict_test$net.result[, 1] * (max(data1$Discharge1) - min(data1$Discharge1))) + min(data1$Discharge1) predict_test2 = (predict_test$net.result[, 2] * (max(data1$Level1) - min(data1$Level1))) + min(data1$df2.Level1)  # Plotting acutal observations v/s real predictions  plot(datatest$Discharge1, predict_test1, col='blue', pch=16, ylab = "Predicted Discharge", xlab = "Real Discharge") title("Predicted Discharge v/s Real Discharge"); abline(0, 1, col = "black")   plot(datatest$Level1, predict_test2, col='blue', pch=16, ylab = "Predicted Level", xlab = "Real Level") title("Predicted Level v/s Real Level"); abline(0, 1, col = "black")  The model performs badly. Here are evaluation parameters: For Discharge: R-Squared -> 0.36 NSE       -> 0.30 RMSE      -> 121.96  For Level: R-Squared -> 0.39 NSE       -> 0.29 RMSE      -> 0.43  I am not able to understand what I am doing wrong. It would be great if someone can help me.


Does a comma have to be used before a quotation?

If before the quote the word "saying" or "said" is used, does a comma always have to be used before it? When does a comma not have to be used?


My files keep getting encrypted with the Rakhni Ransomware

I used the RakhniDecryptor to decrypt my files, but they keep getting encrypted.  I used multiple scanners to search for the RakhniEncryptor on my PC:  Malwarebytes/SuperantiSpyware/NOD32/Kaspersky Malware Scanner.   But, no luck. I used RakhniDecryptor to decrypt, but don't want to keep doing that.   Any suggestions?  Usefull links:


How to open QGIS using a customisation file?

I have a customisation file which can provide a much simplified QGIS interface for beginner users. We have QGIS available on a shared machine. I'd like to provide a shortcut which would open QGIS with the simplified interface already active (and another which opens it without customisation). It seems that on Linux this can be done with command line options. Is there some equivalent SIMPLE arrangement for Windows (I'm not a programmer, and I don't have admin permissions on any machines).


I changed my email in my "Email Settings", and I'm not completely sure what happened

On my "DUO" account, I changed my email address in "Email settings" to my email address for my "Quote Dave" account. However, when I pressed "save", it changed my profile picture and name to those in my "Quote Dave" account. My questions are still the same, so I'm not completely sure what happened. EDIT: Great, now I can't sign into the "Winter Bash 2020" site :(


How do I tell my brother that he needs to wake up early tomorrow?     Tomorrow we are having breakfast together.   Or     Tomorrow we are going to have breakfast together.


Is a 2-hour layover at Muscat enough to change flights?

I am travelling from Toronto to Delhi. My route is Toronto to London (Air Canada) >> London to Muscat (Oman Air) >> Muscat to Delhi (Oman Air).  I have a 2-hour layover at Muscat before the next flight to Delhi. I'm not sure if this is enough time.  Can someone with experience in this matter share, please?


When can an autonomous system be written using a Hamiltonian?

If I have an autonomous series of differential equations $$\tag{1} \frac{dx_i}{dt} ~=~ A_i(x_1,...,x_n)$$ with the condition that $$\tag{2} \sum_{i=1}^n\frac{\partial A_i}{\partial x_i}~=~0$$ in all regions of phase space, can this be written as a Hamiltonian system in terms of some generalized position and momentum coordinates?


Show that if $n^2$ is even then $n$ is even, for $n$ an integer.

I know that this is a common question, but I want to see your take on this. The way I approached this was by contraposition (i'm still new with the proofs but any help would be appreciated, even if it's by contradiction.)  Assume $n$ is odd, thus $n^2$ is odd as well.   Since $n$ is odd then $n=2k+1$ for some integer $k$.  Then $n^2= (2k+1)^2 = 4k^2+4x+1 \rightarrow 2(2k^2+2k)+1.$ Which clearly shows that $n^2$ is odd.


Why ZSH ends a line with a highlighted percent symbol?

I've noticed this on occasion with a variety of applications. I've often thought it was because the output was cancelled early (ctrl+c, for example) or something similar, and zsh is filling in a new line character. But now curiosity has gotten the best of me, since it doesn't seem to do this in bash.   zsh    bash    The Sequence program is something I pulled from a book while reading on Java certifications and just wanted to see if it would compile and run. I did notice that it does not use the println() method from the System.out package/class. Instead it uses plain old print().  Is the lack of a new line character the reason I get this symbol?


The use of negative with indefinite pronouns

Is it correct to say: Everything doesn't go easy in life. Or should one say : Not everything goes easy in life.


Finding sum of sequence $\sum\limits_{k=2}^n \frac{1}{k^2-1}$

Here is a problem I need to solve:  $$ \sum_{k=2}^n  \frac{1}{k^2-1} $$  It came with another one alreay done in the same task:  $$ \sum_{k=1}^n  \frac{1}{k(k+1)} = \sum_{k=1}^n  \frac{(k+1)-k}{k(k+1)} = \sum_{k=1}^n  \frac{1}{k} - \sum_{k=1}^n  \frac{1}{k+1} = \sum_{k=1}^n  \frac{1}{k} - \sum_{k=2}^{n+1}  \frac{1}{k} = 1 - \frac{1}{n+1} $$  So, the problem have to have similar solution. I can't find a proper change for the numerator. I think the numeratore could be find using factorised dominator:  $$ \sum_{k=2}^n  \frac{1}{(k-1)(k+1)} $$


Is it possible to remove WYSIWYG for a certain Custom Post Type?

I dont want to use the WYSIWYG at the top of my Custom Post Type. I want to use a custom field textarea that i can place at bottom of my list of custom fields instead.  Is this possible?


I am trying to compile a PDF Output with an R Markdown file and build my bibliography with the biblatex package and using R Studio.  Here are my code/files  in index.Rmd  --- title: |    Hello World!  author: |   Juan Pérez  bibliography: refs.bib ---   # Intro  Lorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsumLorem ipsum.  [@Somoza1968]   In a separate file I have _output.yml file:  bookdown::pdf_document2:   latex_engine: lualatex   includes:      in_header: preamble.tex   keep_tex: yes   citation_package: biblatex   In a separate file I have Refs.bib:  @Book{Somoza1968,   title         = {Argentina, la mortalidad según tablas de vida de 1914, 1946-1948 y 1959-1961},   publisher     = {CELADE},   year          = {1968},   author        = {Somoza, Jorge L.},   address       = {Santiago},   timestamp     = {2018-07-03},   type          = {Book}, }   And preamble.tex  \usepackage[]{biblatex}   Without any other options, it works, but every time that I want to add an option to biblatex (for example style=alphabetic) I get this error message:   tlmgr search --file --global '/biblatex-dm.cfg' ! LaTeX Error: Option clash for package biblatex.  Error: Failed to compile index.tex. See index.log for more info. In addition: Warning message: In parse_packages(logfile, quiet = c(TRUE, FALSE, FALSE)) :   Failed to find a package that contains biblatex-dm.cfg Execution halted   Any ideas what could be the problem? Do I need a specific configuration for R Studio? Any suggestion of which one could be the best practice to build a customized bibliography using R Markdown, is welcome.


I am trying to stop a stacktrace which doesn't seem to be listening to my null check.            if(amountEntered != null){                     amntEntered = Double.parseDouble(amountEntered);                    }              else if(amountEntered != ""){                  amntEntered = Double.parseDouble(amountEntered);             }              else if((amountEntered == null || amountEntered == "")){              System.out.print("");                 }   With this code, it should stop the stacktrace which executes when I try and cancel out of the JOptionPane (amountEntered is the variable in which the JOptionPane is assigned to) -- amntEntered is the double equivelent.


Proof by contradiction, Assume $2^{1/n}$ is rational so:  $$2^{1/n} = \frac ab $$ where a,b have no common factors.  $$2 = \frac{a^n}{b^n}$$  $2$ divides LHS, therefore $2$ divides RHS so $2$ divides $a^n$ or $2$ divides $b^n$ which implies $2$ divides $a$ or $2$ divides $b$.   Stuck on what to do next.


Book about a town that is transported by an explosion into a freezing desert

It starts with a town that was hit by a mysterious explosion which transports that town into a desert. The weather is cold and people burn coal but they soon run out and send out an expedition to look for signs of life - they navigate the desert for a couple of days and come across a glass dome covering a city. Apparently they have been transported far in the future.  And that's where I stopped reading and want to resume now. Don't remember the title or the author and it's at least 20 years old.


(pyqgis) How to get temp object created by the processing tool "qgis:saveselectedfeatures"

Usually when I try to get object:  buffering = processing.runalg('qgis:fixeddistancebuffer', in_layer, 100, 10, False, None) buf_layer = processing.getObject(buffering['OUTPUT']) QgsMapLayerRegistry.instance().addMapLayer(buf_layer)   But when I do the following it does not work:  saving = processing.runalg('qgis:saveselectedfeatures', in_layer, None) output_layer = processing.getObject(saving['OUTPUT']) QgsMapLayerRegistry.instance().addMapLayer(output_layer)   The error is   KeyError: 'OUTPUT'   Anyone knows how to get this object?


How can I enable adaptive subdivision in Blender 2.8? I have a noise texture plugged into the displacement output for a material, with the displacement method set to Displacement Only. There is no "adaptive" option for my subdivision surface modifier, however, when I increase the subdivision levels manually, the mesh is displaced in the rendered view.  I am rendering with cycles with the 2.8 beta version downloaded today.


Show that $E(Z^p) = p \int_0^\infty (1-F_Z(x))x^{p-1} \, dx$ for every $p>0$ and nonnegative random variable $Z$

Given a continuous positive r.v. (I think this means $Z \geq 0$), with pdf $f_Z$ and CDF $F_Z$, how would I show that the following expression $$\mathbb{E}(Z^p) = p \int_0^\infty (1-F_Z(x))x^{p-1} \, dx\text{?}$$ I don't know where to start, I tried maybe changing it to a by-parts question or something using $px^{p-1} = \frac{d}{dx}(x^p)$ but that's all I can think of.


Is it possible to delete from own table without tmp table

I am trying to do the following query:  DELETE FROM main_history WHERE id NOT IN (   SELECT max(id) FROM main_history GROUP BY instance_id, xpath, new_value )   However, I get the following error:  You can't specify target table 'main_history' for update in FROM clause   Is there a way to do this directly in mysql in a single query? I'm currently creating a tmp table like so:  INSERT INTO main_history_new (     SELECT id, instance_id, territory_id, xpath, field, old_value, new_value, max(date)     FROM main_history     GROUP BY instance_id, xpath, new_value )


Can Sour/Acidic Food reduce libido in men?

I live in Asia which means I am surrounded by a lot of myths and superstitions. I have heard in here that if a man eats food that women eat while they have cravings during pregnancy (Sour/Acidic Food), the man can get himself something that is called ED or Erectile Dysfunction. Is it true by any means? is it even near to the truth? I like to eat sour food such as Tamarind, Pani Puri etc, so it would be very helpful for a person like me to get the answer to this questions.


I have a USB Stick that seems to be write-protected. I already searched and tried a lot of solutions, but they don't work for me. E.g. I tried:  hdparm -r0 /dev/sdb     but that does not change anything.   badblocks –v   did not show any errors on the disk. Also gparted or the disk-utiliy tool could not make the usb stick work again. In gparted it says I have to create a partition table first, but when I do it it gives me an input/output error and tells me it is an unkown partition table.  I also tried it with Windows, but that was also not successful. Does anyone have other ideas how to make the USB stick writeable again?


Simple Random Samples from a Sql database

How do I take an efficient simple random sample in SQL? The database in question is running MySQL; my table is at least 200,000 rows, and I want a simple random sample of about 10,000. The "obvious" answer is to: SELECT * FROM table ORDER BY RAND() LIMIT 10000  For large tables, that's too slow: it calls RAND() for every row (which already puts it at O(n)), and sorts them, making it O(n lg n) at best. Is there a way to do this faster than O(n)? Note: As Andrew Mao points out in the comments, If you're using this approach on SQL Server, you should use the T-SQL function NEWID(), because RAND() . EDIT: 5 YEARS LATER I ran into this problem again with a bigger table, and ended up using a version of @ignorant's solution, with two tweaks:  Sample the rows to 2-5x my desired sample size, to cheaply ORDER BY RAND() Save the result of RAND() to an indexed column on every insert/update. (If your data set isn't very update-heavy, you may need to find another way to keep this column fresh.)  To take a 1000-item sample of a table, I count the rows and sample the result down to, on average, 10,000 rows with the the frozen_rand column: SELECT COUNT(*) FROM table; -- Use this to determine rand_low and rand_high    SELECT *     FROM table    WHERE frozen_rand BETWEEN %(rand_low)s AND %(rand_high)s ORDER BY RAND() LIMIT 1000  (My actual implementation involves more work to make sure I don't undersample, and to manually wrap rand_high around, but the basic idea is "randomly cut your N down to a few thousand.") While this makes some sacrifices, it allows me to sample the database down using an index scan, until it's small enough to ORDER BY RAND() again.


Truncate (not round) decimal places in SQL Server

I'm trying to determine the best way to truncate or drop extra decimal places in SQL without rounding.  For example:  declare @value decimal(18,2)  set @value = 123.456   This will automatically round @value to be 123.46, which is good in most cases.  However, for this project, I don't need that.  Is there a simple way to truncate the decimals I don't need?  I know I can use the left() function and convert back to a decimal.  Are there any other ways?


Let $H$ be a subgroup of $G$. Let $K = \{x \in G: xax^{-1} \in H \iff a \in H\}$. Prove that $K$ is a subgroup of $G$.

Closure under multiplication:  $\to$  Let $a, x, y \in H.$  Since $H$ is closed under inverses and multiplication, $xax^{-1} \in H$ and $yay^{-1} \in H.$ Since $H$ is closed under multiplication, $xyax^{-1}y^{-1} \in H.$   $\leftarrow$  Suppose $xyax^{-1}y^{-1} \in H$, then $a \in H$ since $H$ is closed under multiplication. So, $xy \in K.$  Closure under inverses:  Since $H$ is closed under multiplication and inverses, if $a \in H,$ then $x^{-1}ax \in H.$ If $x^{-1}ax \in H,$ then $a \in H$ because $H$ is a group. So, $x^{-1} \in K.$  Identity:  Suppose $a \in H.$ Then $a = eae^{-1} \in H.$ So, $e \in H.$  I'd like to see how I can fix/improve this proof.


Aggregate data from several polygons into one in QGIS

I am using QGIS 3.10.1, and I am trying to aggregate Census data (polygons) according to another set of polygons (neighbourhood areas that I have drawn). While I am able to clip the Census data to each neighbourhood, the census data polygon boundaries still show within the neighbourhood polygons, and is still separate data. Does anyone know how I can take all the census polygon data within a neighbourhood boundary and combine it in to one dataset showing averages / sum etc?


Trying to find old uk scifi children’s tv show about children making a ship out of hollowed asteroid

I remember a live action show - late 70's early 80's - about children who use a hollowed out asteroid to make a ship. I think they were in a future school and running away to maybe looking for parents. I remember they had a computer they rigged up to fly the asteroid. It’s definitely a UK show. The set I remember was cave looking with a flat floor and the computer in the middle on the floor with wires leading off.  It was very low budget. I've googled every variation I can think of and gone through the various wiki lists to no avail. I did not find anything close in searches.


Does restricting the number of links for new users do any good?

:     What are the new user restrictions?      New users cannot:         post images   post more than two hyperlinks at a time, either in a post or their user profile   contribute answers to protected questions   ask or answer questions too rapidly         Why are restrictions placed on new users?      Because we allow participation from anonymous internet users, we must   take some precautions to ensure that the rare malicious or spammy   anonymous user doesn't ruin the experience for everyone else.   I understand the reasoning for disallowing images, protecting questions and for rate-limiting new users. I don't understand how restricting the number of links for new users does anything useful. The privileges page suggests that it is meant to limit the damage malicious users or spammers can do.  For spammers, I don't see the difference whether they link one time to their site, or a dozen times. The spam post will be deleted shortly in any case, I can't really see any advantage to restricting the number of links.   For malicious users you don't really need more than one link to a NSFW site to cause trouble, I also fail to see how the restriction should help there.  I , I'd like to understand how this restriction is supposed to help SE sites. It's a significant annoyance for new users, especially on sites like Skeptics, and I'm doubting whether this restriction is useful at all.  I'm thinking about requesting to remove this restriction everywhere on the SE network, but I'd like to understand the reasons behind it and it's effectiveness better before I do that. My perception of the usefulness of this restriction seems to me vastly different to what the SE team thinks of it.  Update:  The link restriction has been removed on Skeptics for a while now, and I haven't seen any increase in spam.


Why does a dielectric slab move inside the capacitor?

The electric field is in Y direction.Therefore shouldn't force be also in the vertical direction.Also if electric field is y direction then what's the force that is pulling the slab inside the capacitor? I am not asking to calculate the force.I am just asking what's the origin of this force


Is a generic method that works on int and uint not possible in dot net?

In C# is a generic method that works on int and uint not possible because the generic type must be a class and not a primitive or is this only on constraints?  public decimal shift<T>(T input, byte b) where T : int, uint {    ///.... }   Is there anyway to make this work without the constraints?  public decimal shift<T>(T input, byte b)   {    ///.... }   When I do the latter, I get further but still error out on a bit shift operation on the int or uint. It's as though, it doesn't know what type it is at run time.


I haven't noticed this before, so I don't know if this have always been like this or not. But at a new question () which are currently unanswered, there is some text at the bottom that reads Know someone who can answer? Share a link to this question via email, , , or . . I guess this is showing on new unanswered questions. At least I cant find it on any of my other questions.  It is a tiny problem, but the , , , or . part doesn't look good.


Can I say I'm undecided yet in my statement of purpose ? (PhD in math)

I just started my 2nd year of master and it's already time to apply for a PhD in math, deadlines are in ~1+ month.  In most samples, students had a clear idea of what they would like to study. They write that they have studied this and that, and that they would like to be under Prof. X's supervision because they worked on his papers.  As for me, I liked most math topics that I have studied, with very few exceptions. In short, I'm undecided, exactly when I buy an ice cream and  I'm facing 20 good flavours.   Most universities, on their application page, offer "undecided" among the options (algebra, number theory, ...). Although they may say "it's totally fine" (because everything is nowadays), what is the truth behind the appearances?  Stories from people who are on admissions committees or from [un]successful applicants who wrote that in their SOP are most welcome.  EDIT: I successfully got admitted to some really good US universities with "undecided" in my SOP


Where do I get the key for the first house?

I've 'completed' the game, but didn't find the key for the first house. (I got the one for the arcade machine house). Where can I find it?


Solving for $x$ in $A=B\cdot \cos(x)+C\cdot \sin(x)$

I´m working on a little paper, and I want to know if it´s possible in any way to solve this:  $$A=B\cdot \cos(x)+C\cdot \sin(x)$$  $A$, $B$ and $C$ are known. I need a way to get the $x$ without using a computer. If not, how do I make it to work on excel? I've tried SOLVER, but it doesn't work...  Thanks in advance


Sending data and image file through form using JQUERY and PHP

Hello I want to send form data and the image file which users upload, to my e-mail (that I defined email address previously in send.php), using JQUERY.  With my current codes, it just sends data and not uploaded image. But when I remove JQUERY, it sends both by going to another page first and returning back to main page.  My JQUERY should responds with a message on the same place after sending the form successfully or even if we get error.  Then I have not problem in my PHP code I think because it works.  "I want my form shows successful message on same place after it sends data and image to my e-mail."   Here is JQUERY code:  $(document).ready(function() { $(".validate").validate(); $(document).on('submit', '.contact-form', function() { $.ajax({   url : 'send.php',   type : 'post',   data : $(this).serialize(),   success : function(data) { $('.form-respond').html("

SENT SUCCESSFULLY

");   },   error : function(xhr, err) {     $('.form-respond').html("

ERROR. PLEASE  TRY AGAIN

");   } }); return false; }); });   and here is my html form:
 <form class="contact-form col-md-6 fade-down validate" id="form1" method="post" action="send.php" enctype="multipart/form-data">

 BUY
   <input type="name" name="Name" id="name" class="" placeholder="name" required>   <input type="email" name="Email" id="email" class="" placeholder="email" required>   <input type="file" name="attachment" size="40" class="eses" id="attachment">   <input type="hidden" name="Price1" id="Price1" value="">   <input type="text" name="Message" id="Price" value="" readonly>

      <button id="submit" type="submit" class="btn-submit"> Submit </button>

   </form>
   Also at the end of my send.php I defined blow code for form responding. That it does not do anything when the JQUERY code is available. Then when my JQUERY code is available in .js file, it responds there on same page with message. But does not send file. It only sends name and email of contact form.  if(!$mail->Send()) { echo '
'.$error.'
' . $mail->ErrorInfo; echo ("<meta http-equiv='refresh' content='1; url=http://example.com'> "); } else { echo '
'.$accept.'
'; echo ("<meta http-equiv='refresh' content='1; url=http://example.com'> "); } ?>


How can I stick something to the bottom, but not overlapping other elements

I want the footer to stick to the bottom, but not being in front of other elements.  I've tried with position and bottom, but fixed is above the elements and absolute isnt' even at the bottom, it's only at the bottom of what you can see, but if you scroll down it stays there.      Copyright Duarte Arribas © 2019    footer{     display: block;     position: absolute; /*tried fixed also*/     background: #262626;     width: 100%;     height: 15%;     bottom:0;     color: #fff;     text-align: center; }


If $a$ and $b$ are positive real numbers, then $a + b \geq 2 \sqrt{ab}$.   I know how to do the direct proof, but in this case, I want to try proving it by contradiction. I have tried manipulating the inequality $a + b < 2 \sqrt{ab}$ after making the assumption that $a,b >0$ to get a contadiction $a,b \leq 0$.  $\begin{align} a + b &< 2 \sqrt{ab} \\a^2-2ab+b^2 &< 0 \\(a-b)^2 &< 0\end{align}$  How do I show that $a,b \leq 0$?


How to check if a point is inside a square (2D Plane)?

There is a point $(x,y)$, and a rectangle $a(x_1,y_1),b(x_2,y_2),c(x_3,y_3),d(x_4,y_4)$, how can one check if the point inside the rectangle?  $M$ of coordinates $(x,y)$ is inside the rectangle iff  $$(0<\textbf{AM}\cdot \textbf{AB}<\textbf{AB}\cdot \textbf{AB}) \land (0<\textbf{AM}\cdot \textbf{AD}<\textbf{AD}\cdot \textbf{AD})$$ (scalar product of vectors)  I found this formula but I don't understand how I have to calculate it. I haven't done much math in a long time.  I don't understand why this is considered a duplicate when I'm asking how to solve the equation provided by the answer of that question.


Multiple addresses in JSON-LD Schema.org

I have a site I am creating for a non-profit organization. Their organization has a United States Mailing Address and a Canada Mailing Address. I want to add both addresses with Schema.org (using JSON-LD), but I cannot figure out how. I originally tried this:   "address": {     "@type": "PostalAddress",     "addressCountry": "United States",     "addressLocality": "City",     "addressRegion": "State",     "postalCode": "12345",     "postOfficeBoxNumber": "1234" }, "address": {     "@type": "PostalAddress",     "addressCountry": "Canada",     "addressLocality": "City",     "addressRegion": "Province ",     "postalCode": "Zip",     "streetAddress": "Box 123 12345 - 123 Street NW" },   When I run a test on this schema it uses only the last address.   I tried wrapping the addresses using "location": {} but that threw an error.   How would I add both addresses in the Schema.org markup using JSON-LD?


Prove the following: $$\frac{1}{1+k}=\frac{\frac{1}{k}}{1+\frac{1}{k}}\leq \ln(1+\frac{1}{k})\leq\frac{1}{k}$$  I know I can prove it with induction if the values were naturals. However, the "problem" for me is that they're real.


Selecting multiple values with Select by Attributes in ArcGIS Desktop?

Can anyone help me with selecting multiple values from the attribute table?   I tried "Classes"='14'AND'07' but it doesn't work.


If Voldemort made all the Horcruxes so he can return with the help of those, and Harry is a horcrux made by accident, even though they destroyed all of the Horcruxes, Harry is still alive, so, while Harry lives, isn't there another chanse for Voldemort to come back?


How would you prove this question about tuples

Let $n$ be a positive integer. Using induction, prove that there are $2^{(n−1)}$ tuples $(m_1, \ldots , m_k)$ of positive integers with the property that $m_1 + \cdots + m_k = n$.


I heard that  does not really exist; that it is made as opposite substance to . Is it true? Could someone define for me what centrifugal force is in terms of vectors and common sense?


$3X^3+4Y^3+5Z^3$ has no rational solutions?

How to show $3X^3+4Y^3+5Z^3$ has no rational solutions ?  I managed to bring it down to the elliptic curve $Y^2=X^3-2^43^360^2$ but now I'm stuck to show group of rational points of this curve is trivial. Please help anyone. Or could any one suggest me some different proof without using elliptic curves ?


From bull to bear - what can be done to decrease the mass of close votes?

Sure enough a lot of work is done on the , which steadily approaches a total of a first million all-time reviews. But unfortunately, the queue still seems to grow at a rate of approximately 1k additional close votes every four days (crude average over the last week, but ). Sure enough there are mechanisms to assist reviewers to more or less efficiently crawl that queue, e.g. by filtering tags, but apparently this is not enough, so     What further measures can be taken to decrease the close votes queue without compromising it?   Is reviewing still too tedious and improvements in the queue could help? Or do we need more reviewers? How many of those who can do actually review the close votes queue regularly? (And how is a virtual badge supposed to motivate them into spending their precious time?)


Ran out of primary partitions, want to install another system

I have a Fedora 18 system installed on my hard disk, but upon installation I created 4 partitions for boot, swap, root and home, and now I want to install Windows on some unallocated space (I need it, don't judge me :D) but I'm limited to 4 primary partitions. Is there anyway I can change one of them do logical, or something else to empty one partition?  I can free up to 300 GB, which can hold all 4 partitions easily, in the extended partition that holds only home, if it is possible moving.  fdisk -l /dev/sda  Disk /dev/sda: 500.1 GB, 500107862016 bytes, 976773168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000668e4  Device    Boot      Start     End       Blocks   Id  System /dev/sda1 *         133120    1026047   446464    83 Linux /dev/sda2           1157120   8202239   3522560   82 Linux swap / Solaris /dev/sda3           8333312   113059839 52363264  83 Linux /dev/sda4           113190912 894853119 390831104 5  Estendida /dev/sda5           113324032 894722047 390699008 83 Linux   Of course, without excluding existing partitions/files.


Do I need to buy all the released updates to begin playing WoW?

If I want to begin to play World of Warcraft, do I need to buy every update released from the beginning?


What happens when additional costs can't ultimately be paid, but the spell is on the stack?

I have a question that bothers me after reading a part of the big book of rules :).  It's about the rule 717, illegal actions.     717.1. If a player realizes that he or she can’t legally take an action after starting to do so, the entire action is reversed and any payments already made are canceled. No abilities trigger and no effects apply as a result of an undone action. If the action was casting a spell, the spell returns to the zone it came from. The player may also reverse any legal mana abilities activated while making the illegal play, unless mana from them or from any triggered mana abilities they triggered was spent on another mana ability that wasn’t reversed. Players may not reverse actions that moved cards to a library, moved cards from a library to any zone other than the stack, or caused a library to be shuffled.   For example, player A plays a .     As an additional cost to cast Goblin Grenade, sacrifice a Goblin.   Goblin Grenade deals 5 damage to target creature or player.   It goes on the stack. Player B gains priority and casts a  on the only goblin of Player A.     Destroy target nonartifact, nonblack creature. It can't be regenerated.   The terror goes on the stack. Then both players agree to resolve the stack. The terror kills the last goblin standing and then the Goblin Grenade can't be cast because of the additional cost which can't be paid. So in my opinion that leaves two possibilities:   The Goblin Grenade returns to the zone it was previously from (the hand of Player A) The Goblin Grenade becomes illegal and gets countered, so it goes to the graveyard   Based on rule 717 I think it goes back to the hand but I'm not quite sure. :)


Unexpected result of product of 2 double variables

double price = 4.35;  double quantity = 100;  double total = price * quantity;   // Should be 100 * 4.35 = 435.00  System.out.println(total); // Prints 434.99999999999999   Why does this happen?


Create individual feature classes for every record in a single feature class

I have arc desktop 10.3.  I have a feature class (nycd) with 59 records in it.  I'm trying to create a simple map with an inset that shows where each community district is located in that borough. I'd like to create an individual feature class for every record (with every field included) and put them in a file geodatabase (Comm_Snap) and am looking for different ways to do this. I'm not very familiar with arcpy but want to start utilizing it. I was initially thinking a simple script with a Search Cursor and a data management tool would work. Any suggestions?


Is my MAC address public when browsing the Internet?

Possible Duplicate:          Can anybody see my MAC address when I'm on the Internet?   Also, where can I check my MAC address?


Bold Chapter bookmark entries in PDF-Reader except LOF

I would like to highlight all chapters except the appendix, table of figures and table of tables. I'm using the bookmark-package and I tried to set all entries at the level = 0 to bold and just to turn bold off for the LoF etc. but it seems it has no effect to turn bold off.     \documentclass[listof=totoc]{scrreprt}  \usepackage{bookmark} \bookmarksetup{     open,     addtohook={%         \ifnum\bookmarkget{level}=0 %         \bookmarksetup{bold}%         \fi     }, }   \usepackage{graphicx} \usepackage{lipsum} \usepackage{mwe}  \begin{document} \pdfbookmark[0]{Content}{toc} \tableofcontents  \bookmarksetupnext{bold=false} \listoffigures   \newpage  \chapter{Chapter 1} \lipsum[1] \begin{figure}[h] \includegraphics[width=\textwidth]{example-image-a} \caption{I am a figure\label{fig:one}} \end{figure} \section{Section 1} \lipsum[1] \begin{figure}[h] \includegraphics[width=\textwidth]{example-image-a} \caption{I am a figure\label{fig:one}} \end{figure}  \bookmarksetupnext{bold=false} \appendix \addtocontents{toc}{\protect\contentsline {chapter}{Appendix}{}{}} \chapter{App 1} \lipsum[1] \end{document}


How did Jane start suffocating after smoking heroin?

In Breaking Bad S02E12 I couldn't understand the last scene when Walter came back to Jesse and, while trying to wake him up, Jane just starts vomiting and suffocating. Was it because of heroin? If so then why did the same not happen to Jessie?  Please explain the whole thing.


Database design - passenger, driver, wallet. How to handle multiple foreign keys with Id and type fields?

I have to design a database schema for new project. I will use PostgreSQL for the implementation of the schema.  Right now I'm stuck in a scenario where I need to handle foreign keys based on type and id. Here are the tables:  Passenger:  PassengerID FirstName Email DOB Address   Driver:  DriverID CNIC Vehicle License Status   Wallet:  WalledID Amount UserId UserType   Problem: I want that every wallet row should have UserId as DriverId or PassengerID and in the type field the name of the table.  How can I achieve this with PostgreSQL? I have heard that it is possible from polymorphic association but don't know how to implement it.


How to show that any biholomorphism between $\mathbb C$ and itself is linear?

In complex analysis textbooks $\mathrm{Aut}\,(\mathbb C)$  frequently serves as an example of conformal automorphism groups, which is said to consist of all linear functions $az+b$ with $a\neq0$. Equivalently it means that any biholomorphism $\mathbb C\to\mathbb C$ is of the form $az+b$ where $a\neq0$.   However, all textbooks that I have say this fact is obvious but I cannot see it, so I want to ask how to prove it?


Unknown Indentation Error in the following code

this is the code: 3nd line is giving error.  class RawMassegeForm(forms.Form):     subject = forms.CharField(widget= forms.TextInput(attrs={'placeholder':'Enter your Subject'}))     name = forms.CharField(widget= forms.TextInput(attrs={'placeholder':'Enter your Name'}))     email = forms.EmailField(widget= forms.EmailInput(attrs={'placeholder':'Enter your email'}))     message = forms.TextField(widget= forms.Textarea(attrs={'placeholder':'Enter Your Message      here...'}))


How i make this script execute every minute without cron?

I have this:  #!/bin/bash  wlan=`/sbin/ifconfig wlan0 | grep inet\ addr | wc -l` if [ $wlan -eq 0 ]; then echo wlan0 not connected, connecting... echo sudo ifup wlan0 logger wlan0 reconnected. echo echo wlan0 reconnected. else echo echo wlan0 connected. Nothing to do. fi       Maybe with sleep command i can make this wait a minute, but i've been reading that there is no "goto" command in shell scripting so i don't know how to jump from the end to the start of scripts so it can repeat the steps forever..


Apple Configurator 2 - How to edit an installed Configuration Profile?

I wish to modify an existing Configuration Profile installed on an iPhone, but I do not have a disk copy of it, nor can I download it again from the source (no longer available).  Using Apple Configurator 2 there appears to be no way to export to disk, or modify, the full contents of an already existing and installed Configuration Profile.  Nor indeed to inspect its contents (which would provide a tedious but manual way to re-create a new profile by inspecting the contents of an existing one)  Is there a way of extracting an installed Configuration Profile from an iDevice to disk so that I can then open it and modify it using Configurator?  Thanks.


I'm new and need help. When I try to render an animation or image, this screen is all I get. I've followed a bunch of other posts on how to fix it and nothing, I'm using Cycles Render. I don't know what other info to add, I've never done this and it's as simple as my animations won't render and pause like that in the picture every time. That's all I know, this is my first animation ever and I don't know what I did.


Let $A$ be a commutative ring and $\mathfrak{p}$ be a prime ideal of $A$. Under which assumptions for $A$ and $\mathfrak{p}$ does localization by $\mathfrak{p}$ and completion with respect to $\mathfrak{p}$ commute? To be more precise,      when is $\widehat{A}_\widehat{\mathfrak{p}}$ (completion w.r.t. $\mathfrak{p}$) isomorphic to $\widehat{A_\mathfrak{p}}$ (completion w.r.t. $\mathfrak{p} A_\mathfrak{p}$)?   For example, is it true under the assumptions $A$ noetherian and $\mathfrak{p}$ a maximal ideal?  It seems to me that one important ingredient for a possible proof (under the right assumptions) is that localisation and building factor rings commutes. So a side question: Is it always true that $A_\mathfrak{p}/(\mathfrak{p}A_\mathfrak{p})^k \cong (A/\mathfrak{p}^k)_{\overline{\mathfrak{p}}}$?  Thanks


Security problems if ECDH and ECDSA use the same key

Hy! I want to use an EC key for ECDH and ECDSA too. Using the same key does compromise the security of the key in a cryptographic / mathematical sense? I read a lot in this theme, but I found nothing exact. I know that the usage of the same key for encryption and for signing is not recommended (because of encryption keys must be escrowed, and signing keys must not be escrowed), but is there any mathematical/cryptographic reason to use different keys? (Only in Elliptic curve cryptography of course). Is there an RFC or something formal paper about this? (A haven't found any) I want to generate an EC key on a HSM, but I can't enable SIGN, and DERIVE at the same time. (I think that's because the HSM generates an ECDSA key in the precending case, and an ECDH key in the latter case, and don't know what to do if they are enabled in the same time). But I can generate an EC key with openssl without so much as to know if I want to use it for ECDH, or ECDSA purposes. Is there any workaround for that? Can I generate a general EC key on the HSM?


How a faster air flow creates a lower air pressure on an airplane wing?

An airplane wing creates a faster air flow on the upper side and slower air flow on the lower side. Pressure of a gas and the speed of the gas molecules are directly related. If the speed of molecules increases, pressure will also increase.   Are these assumptions correct? If not can you correct it? If they are not wrong: can you please help me understand how an higher speed of air flow creates a lower air pressure? A higher speed of airflow does not mean a higher average molecule speed as well?  Another question, that might be related with this: Suppose we have a sealed room that no molecules and heat can escape or enter. We started to run a fan which has a motor that do not produce any heat. So the air start to flow inside the room.  Will the room temperature and pressure increase?  I hope these questions are not too stupid. I don't have Physics or Math education (but I have a great admire on them), and its really hard for me to understand the equations. Explanations that would help me visualize how things are happening is very appreciated.  Edit: My question was set as "duplicate" to a question to which I cannot see-understand how it is same with my question. My aim is just to understand, please help. Thank you.  Edit2: My actual question here is not to understand how a wing creates a lift, but to understand how this is possible:


Steam doesn't launch... trying to run it from the icon doesn't do anything, no errors, nothing.   Trying to launch from the terminal and I get this:   Running Steam on ubuntu 15.04 64-bit STEAM_RUNTIME is enabled automatically Installing breakpad exception handler for appid(steam)/version(1437790054) libGL error: unable to load driver: r600_dri.so libGL error: driver pointer missing libGL error: failed to load driver: r600 libGL error: unable to load driver: swrast_dri.so libGL error: failed to load driver: swrast   Any help would be great.


Responsive Web Design - what should happen when the mobile device is rotated?

Currently, the standard behaviour for viewing web pages on a mobile is that:   If viewed in portrait the text is smaller because the width of the device is small and the whole page width needs to fit into view. If viewed in landscape the view 'zooms in' as the width is now wider so that the text is larger and more readable, but with less content on screen as a result.   So, this brings a dilemma. When creating a responsive website what should happen on device rotation? (Not on initial page load, I am referring to what should happen once the site is loaded and you decide to then rotate the screen)   When rotated from portrait to landscape should you:   a) Re-detect the device widths and map the contents according to the new dimensions (thereby retaining the same font / images sizes as when viewing portrait). b) Keep the same dimensions and on rotation just bring the content to fit the window (thereby zooming in the content to make it more readable for viewers if the portrait orientation text is too small).          – Wireframes created with   Bear in mind that with a traditional web-page viewed in the mobile you have the option of pinch-to-zoom the text, so if it's too small you can zoom in. With a responsive site this isn't an option because the site will fit the dimensions so there is nothing to zoom into.  (I guess there is a third option too - use responsive fonts so that the font sizes change according to the screen width. But that's probably a different question altogether).


Syntax highlighting hints not working for in-line code

It appears that  aren't working properly for in-line code samples.  If I specify the language for my question using <!-- language-all: lang-java -->, the language highlighting displays properly in code blocks, but inline code displays as regular un-highlighted text.    Inline  public static final String CONST_NAME = "Name";  Code Block  public static final String CONST_NAME = "Name";


I tried to remove Chess.app from my Mac:    Moving to Trash: “Chess.app” can’t be modified or deleted because it’s required by macOS. Trying to change permissions for everyone in Get Info: The operation can’t be completed because you don’t have the necessary permission. chmod 755 Chess.app/ in Terminal works, but then doing sudo rm -rf Chess.app/: long list including rm: Chess.app/: Operation not permitted   So how can I remove it?


Question on the coefficients of $(1+x+x^2+x^3+x^4)^{496}$

Consider the expansion $$(1+x+x^2+x^3+x^4)^{496} = a_0+a_1x+\cdots+a_{1984}x^{1984}.$$   $\quad$ (a) Determine the greatest common divisor of the coefficients $a_3,a_8,a_{13},\ldots,a_{1983}$.      $\quad$ (b) Prove that $10^{340} < a_{992} < 10^{347}$.   Is there an easier way to solve this and is there a formula for the multisection for just the sum of the coefficients and not including $x^k$?  I thought of using the Multisection formula to prove (a). That is, $$\sum_{k \equiv r \pmod{m}}a_kx^k = \dfrac{1}{m} \sum_{s=0}^{m-1} \epsilon^{-rs} f(\epsilon^s x)$$ where $\epsilon$ is a primitive $m$th root of unity and $\displaystyle f(x) = (1+x+x^2+x^3+x^4)^{496}$.  Thus we have $r = 3, m = 5$ and so \begin{align*}\sum_{k \equiv 3 \pmod{5}}a_kx^k &= \frac{1}{5} \sum_{s=0}^{4} w^{-3s} (1+w^s x+(w^{s}x)^2+(w^{s} x)^3+(w^{s}x)^4)^{496}\\&=\dfrac{1}{5}\sum_{s=0}^4 w^{-3s}\left(\dfrac{(w^s x)^{5}-1}{w^s x-1}\right)^{496}\\&= \dfrac{1}{5}\sum_{s=0}^4 w^{-3s} \left(\dfrac{x^{5}-1}{w^s x-1}\right)^{496}.\end{align*}


Protecting game assets through archiving

I'm writing a game in C++ (with OpenGL) and am getting quite far into development. Currently I'm loading the data directly from different directories.  (E.G. I load textures from a /Data/Textures/...png)  This is fine, but not preferable. Ideally I would like to protect these assets without too much of a performance hit. I looked at other games that I own, both Indie and AAA and found that the majority of them archive the data. However, I am unable to access these archives with programs like Winrar Archiver which implies that they have some level of protection.  I'm not particularly knowledgeable in the field of encryption and data storage, so I may be overlooking something obvious but I would like to know how exactly I could achieve something similar.  (I am aware that competent individuals are able to use the GPU to gain access to the data but that's not preventable)


Composition of absolutely continuous function on $\mathbb{R}$

Is it true that the composition of two absolutely continuous functions on the real line is absolutely continuous?    I feel like this should be a resounding no, however, I'm unsure of any quick counterexamples to this claim.  Can anyone think of one?


Android pop-up wording if confirming is canceling an action

Running into a case where I need the user to confirm the canceling of an action. Not sure what the correct text here is for the button. 'Yes' and 'No' make the most sense to me but the Material Design guide  discourages that. Maybe I can change the main text? Anyway, what I have below is somewhat confusing. Any suggestions?


Show that $a^2 + b^2 = c^3 $ has infinitely many solutions in $ \{ (a,b,c) \in \Bbb Z ^3 | (a,b)=1, (a,c)=1, (b,c)=1 \}$ . Describe all these solutions.    I don't know how to approach this question. I'm thinking about something like $a^2+b^2=(a-bi)(a+bi)$, so we get $xy=c^3$ where $x,y \in \Bbb Z [i]$. I'm not sure it's the right way to do this.


Globally disable "include online search results"

We have started replacing some Windows desktops with Ubuntu for some users in the organization I work. Because of our policies we need to globally disable the following features:   The Include online search results from the Search tab of Security & Privacy The Amazon launcher icon from the launcher   I noticed that when I manually un-click  the "Include online search results" it changes the ~/.config/dconf/user. But this file in in some GVariant binary format so I cannot tweak it with a text editor or a script.  I also tried this command I found on another post, but it does not appear to have an effect and suggestions still work:  $ gsettings set com.canonical.Unity.Lenses disabled-scopes "['more_suggestions-amazon.scope', 'more_suggestions-u1ms.scope', 'more_suggestions-populartracks.scope', 'music-musicstore.scope', 'more_suggestions-ebay.scope', 'more_suggestions-ubuntushop.scope', 'more_suggestions-skimlinks.scope']"   Is there a way to disable these features to comply with the my organization's policy? We are using 14.042 LTS but it would be ideal if the solution works for later versions as well.


Pass argument and function as argument in python

This code given is a part of my program. Here I want to reduce the 3 functions to just 1 as they are exactly similar except 1 line. I read about passing function(let this function be Bar) and its arguments as arguments in another function(let this function be called Foo ).   But in this scenario, I can't change the function Foo. Here my Foo function is .clicked.connect() and addXMin is my function Bar. I want to pass Bar and its argument num into Foo, where I can't change whats going on in Foo. Is there a way I can reduce the 3 functions into 1 and pass 15, 10 and 5 as arguments to that single function?  self.add15m.clicked.connect(self.add15Min) self.add10m.clicked.connect(self.add10Min) self.add5m.clicked.connect(self.add5Min)  def add15Min(self):     global mins, secs, time     time = self.lineEdit.text()     mins = int((time.split(':'))[0])     mins+=15         #The only different line     secs = int((time.split(':'))[1])     time = str(mins).zfill(2) + ":" + str(secs).zfill(2)     self.lineEdit.setText(time)  def add10Min(self):     global mins, secs, time     time = self.lineEdit.text()     mins = int((time.split(':'))[0])     mins+=10         #The only different line     secs = int((time.split(':'))[1])     time = str(mins).zfill(2) + ":" + str(secs).zfill(2)     self.lineEdit.setText(time)  def add5Min(self):     global mins, secs, time     time = self.lineEdit.text()     mins = int((time.split(':'))[0])     secs = int((time.split(':'))[1])     mins+=5         #The only different line     time = str(mins).zfill(2) + ":" + str(secs).zfill(2)     self.lineEdit.setText(time)


Can I board a UK train I am booked on half way with a mobile, advanced ticket?

I have a ticket from Southampton to Manchester in the next month or so. Its a non-refundable Single Advance ticket but due to circumstances out of my control, I won't be in Southhampton on the date - but rather Birmingham.  Considering that Birmingham is on the train route anyway, can I join at Birmingham and resume my travel to Manchester?  I have seen similar questions to this posted, but most of the advice is upon the assumption that a ticket inspector will mark your ticket to prove you have been on the train from the start of its journey. Considering that I will have an E-ticket on my phone, would an inspector know?  Any advice welcome, as the original price of the ticket is pretty high and I'd rather not waste it.


So I'm trying to make a villager that would sell items to a player in a server. I was doing well until I messed up my brackets, and now I don't know what to do.  This is the command:  /summon Villager ~1 ~ ~ {Profession:2,CustomName:"Apollos",CustomNameVisible:1,Career:1,CareerLevel:42,CanPickUpLoot:0,PersistenceRequired:1,NoAI:1,Invulnerable:1,Attributes:[{Name:"generic.knockbackResistance",Base:"1f"},{Name:"generic.movementSpeed",Base:"0f"},{Name:"generic.maxHealth",Base:99999}],Offers:{Recipes:[{buy:{id:"diamond_block",Count:12},buyB:{id:"diamond",Count:5},maxUses:9999999999,sell:{id:"dragon_egg",Count:1,tag:{display:{Name:"&c&lDragon Egg",Lore:["Used in shops","It is a currency"]},rewardExp:false},{buy:{id:"dragon_egg",Count:1,tag:{display:{Name:"&c&lDragon Egg",Lore:["Used in shops","It is a currency"]},maxUses:9999999999,sell:{id:"diamond_block",Count:8},rewardExp:false},{buy:{id:"nether_star",Count:4},maxUses:9999999999,sell:{id:"dragon_egg",Count:1,tag:{display:{Name:"&c&lDragon Egg",Lore:["Used in shops","It is a currency"]},rewardExp:false},{buy:{id:"obsidian",Count:64},maxUses:9999999999,sell:{id:"nether_star",Count:1},rewardExp:false},{buy:{id:"obsidian",Count:64},buyB:{id:"obsidian",Count:64},maxUses:9999999999,sell:{id:"fire_charge",Count:1,tag:{display:{Name:"&c&lEmber",Lore:["Used in shops","It is a currency"]},rewardExp:false},{buy:{id:"fire_charge",Count:2,tag:{display:{Name:"&c&lEmber",Lore:["Used in shops","It is a currency"]},maxUses:9999999999,sell:{id:"dragon_egg",Count:1,tag:{display:{Name:"&c&lDragon Egg",Lore:["Used in shops","It is a currency"]},rewardExp:false},{buy:{id:"dragon_egg",Count:1,tag:{display:{Name:"&c&lDragon Egg",Lore:["Used in shops","It is a currency"]},maxUses:9999999999,sell:{id:"fire_charge",Count:2,tag:{display:{Name:"&c&lEmber",Lore:["Used in shops","It is a currency"]},rewardExp:false}]}}   The error that I'm getting is:     Data tag parsing failed: Expected non-empty key at: ... is a currency"]},rewardExp:false},<--[HERE]]


Let $\omega$ be a complex number such that $\omega^5 = 1$ and $\omega\neq 1$, find ...

Let $\omega$ be a complex number such that $\omega^5 = 1$ and $\omega \neq 1$. Find $$\frac{\omega}{1 - \omega^2} + \frac{\omega^2}{1 - \omega^4} + \frac{\omega^3}{1 - \omega} + \frac{\omega^4}{1 - \omega^3}$$  I've been having trouble with this unit, need help  on solving this problem.


What is the definition and purpose of a pre-amplifier?

I find in many places mentions of pre-amplifiers being used to boost audio signals prior to feeding to a power amplifier.  Wikipedia's article on  gives some hints at their usage, but it doesn't really explain why it would be necessary to have two amplifiers in series rather than a single one with greater gain.  If a pre-amp is just a power amp with a smaller gain, what's the point, and why the distinction between the two kinds? Is the distinction in function, or simply purpose?


What is and what isn't a "closed form solution"

I had a friendly discussion with someone about closed form solutions. They contended that the backpropagation algorithm used in calculating the gradients of deep neural networks can't be called a closed form expression in itself, though it is computing a closed form and can be easily converted to one. I pointed them to the  which says -      "In mathematics, a closed-form expression is a mathematical expression that can be evaluated in a finite number of operations. It may contain constants, variables, certain "well-known" operations (e.g., + − × ÷), and functions (e.g., nth root, exponent, logarithm, trigonometric functions, and inverse hyperbolic functions), but usually no limit."   On the one hand, backpropagation can be completed in a finite number of steps. But the next question becomes, is it a "Mathematical expression".   From the , it isn't clear if function composition should be an operation that qualifies.   For me, backpropagation should certainly be qualified as a "closed form solution" but I can't come up with a water-tight argument for why.  Also, other examples came up in the discussion. Let's say I have an algorithm for finding the smallest prime number larger than some integer. This involves checking each number greater than that integer and stopping when I find a prime. This algorithm can be completed in a finite number of steps and calculates the solution exactly. But can we say there is "no Mathematical expression" here and hence no closed form?     EDIT: My question is different from the linked question since it focuses on these two cases in particular. The first one being backpropagation for deep neural networks. This basically involves the following:  In general we get a loss function that looks like - $L = f(g(h(x)))$ and then we take the derivative and get - $L' = f'(g(h(x))g'(h(x))h'(x)$. The argument being that because we calculate $h(x)$ separately and then substitute it, this is not a closed form.  The second example being the algorithm for finding the smallest prime number larger than an integer.


The product of $\phi$ is a Schwartz function with $m \in L^\infty$.

If $\phi$ is a Schwartz function and $m \in L^\infty$, if the product $m\cdot\phi$ a Schwartz function? The Hilbert transform is given by a multiplication with the $L^\infty$ function $m(\xi) = -i\,\text{sgn}(\xi)$, ie $$Hf(x) = (\hat{f}(\xi)m(\xi))^\vee(x), \forall \; f \in \mathcal{S}(\mathbb{R})$$ Is it true that $Hf \in \mathcal{S}(\mathbb{R})$??


How to change the kernel max PID number?

The default PID max number is 32768. To get this information type:  cat /proc/sys/kernel/pid_max  32768   or   sysctl kernel.pid_max kernel.pid_max = 32768   Now, I want to change this number... but I can't. Well, actually I can change it to a lower value or the same. For example:  linux-6eea:~ # sysctl -w  kernel.pid_max=32768 kernel.pid_max = 32768   But I can't do it for a greater value than 32768. For example:  linux-6eea:~ # sysctl -w  kernel.pid_max=32769 error: "Invalid argument" setting key "kernel.pid_max"   Any ideas ?  PS: My kernel is Linux linux-6eea 3.0.101-0.35-pae #1 SMP Wed Jul 9 11:43:04 UTC 2014 (c36987d) i686 i686 i386 GNU/Linux


Which factors should I look at to make the reflection as neat as that of the reference image? Some of the thigs I've tried:  Increasing roughness, but still have too many distorted reflections and also I can't see the yellow sphere in the cube clearly like the reference image.  Changing variables on Ray visibility, but nothing seemed to work. Material of the cube is set to default material with : Specular 0.5 / Roughness 0 / Transmission 1 level   Reference  My Cube  – Bottom and left sides has way too many distortions.


In Drupal 7, we can quickly change the base URL of the website. How can I do this, in Drupal 8?


Possible Duplicate:          I obtained a question asking for how to solve $\large x^y = y^x$. The given restraints was that $x$ and $y$ were both positive integers. By a bit of error an trial we quickly see that $x=2$ and $y=4$ is one solution.   My question is: How do one show that $(2\,,\,4)$ is the only non trivial, positive solution to the equation?   Now my initial approach was as follows: We have   $$\large x^y = y^x$$  The trivial solution is obviously when $y=x$, so let us focus on when $y \neq x$.  Let us make a more general statement. Firstly I take the log of both sides  $$\large y \log x = x \log y $$  Let us divide by x and \log x (We now assume $x\neq 0$ and $x\neq 1$ since 0 is not a positive number, and 1 gives us a trivial solution)  $$\large \frac{y}{x} = \frac{\log y }{\log x}$$  For these sides to be equal, we must remove the logarithms on the right hand side, this is achived if $y$ is on the form $x^a$. Now This gives  $$\large \frac{x^a}{x} = \frac{\log \left(x^a\right) }{\log(x)}$$  $$\large x^{a-1} = a$$  So finaly we obtain that $ \displaystyle \large x=\sqrt[ a-1]{a}$ and $\displaystyle \large y = \sqrt[a-1]{a^a}$  Now setting $a=2$ gives us $x = 2$ and $y=4$ as desired.  My question is, how do we prove that $x=2$ and $y=4$ is the only integer solutions? My thought was to show that $ \displaystyle \large \sqrt[ a-1]{a}$ and $\displaystyle \large \sqrt[a-1]{a^a}$ are both irrational when a>2, but I have not been able to show this.   Any help is greatly appreciated, cheers =)


Let $a,b,c\in \Bbb R^+$ such that $(1+a+b+c)(1+\frac{1}{a}+\frac{1}{b}+\frac{1}{c})=16$.  Find $(a+b+c)$.  I computed the whole product ;If  $(a+b+c)=x\implies (1+x)(1+\frac{bc+ca+ab}{abc})=16$. Unable to view how to proceed further.  Please help.


Self-study book for dynamical systems theory?

What textbook would you recommend for a bachelor in theoretical physics to study ? I don't want to focus too much on chaos, just having a broad view of every interesting characteristic is enough. Physical meaning behinds equations should be explained.  Some related resources:   , but obviously those are math-y.  While there are some overlaps, the evolution of a simple oscillator can evoke interesting dynamics characteristics. , but I'm not sure if studying only fluid dynamics is too narrow for me.


Consider a sentence that ends with a dotted abbreviation, like inc..   , the sentence should end with a single dot, but I did not find a more formal reference to that rule.  Should the sentence be ended with one dot or two?


How to find all hard links to a given file?

How can we find all hard links to a given file? I.e., find all other hard links to the same file, given a hard link?  Does filesystem keep track of the hard links to a file?  The inode of a file only stores the number of hard links to the file, but not the hard links, right?


converting image file into byte array using bitmap

I want to convert the image file into byte[] array format. I used this code     Bitmap bm = getBitmapFromLocalPath(file1.getPath(),1);    ByteArrayOutputStream baos = new ByteArrayOutputStream();    bm.compress(Bitmap.CompressFormat.JPEG, 100, baos); //bm is the bitmap object    bm.recycle();    byte[] image = baos.toByteArray();   //method  public static Bitmap getBitmapFromLocalPath(String path, int sampleSize)     {         try         {             BitmapFactory.Options options = new BitmapFactory.Options();             options.inSampleSize = sampleSize;             return BitmapFactory.decodeFile(path, options);         }         catch(Exception e)         {             //  Logger.e(e.toString());         }          return null;     }   It showing error like  E/BitmapFactory: Unable to decode stream: java.io.FileNotFoundException: /storage/emulated/0/DCIM/Camera/IMG_20200324_121621.jpg (Permission denied) E/AndroidRuntime: FATAL EXCEPTION: Thread-2     Process: com.example.multiupload, PID: 5477     java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.graphics.Bitmap.compress(android.graphics.Bitmap$CompressFormat, int, java.io.OutputStream)' on a null object reference


Science Fiction - Boy recieves powers from elephant at the zoo

I read a book about maybe 8-12 years ago. The book was brown and there was a black haired boy running away from two men in suits.   The book was about a boy who gets given powers at a zoo by the elephants. The powers include talking to animals and being able to mimic the abilities of anyone he thinks of (ie. he thinks bruce lee and then can fight like bruce lee) but only for a limited time.   I don't remember much about the plot but I do remember some snapshots; during the book he has to get away from the people chasing him so he plays the piano at a store well enough that he gets a crowd.  At the beginning of the book when he gets the powers the hippos object to the elephant giving them to him so the elephant kills them. (something about a gas leak the next day? maybe?)  If any of this rings a bell I would be really greatful. Its been on my mind for forever!


Probability of getting 2 tails on 3 coin tosses?

I just learned in class that if you toss 3 coins (a quarter, a dime and a nickel), the probability of getting 2 tails only is $\frac14$ and I don't really understand why.  My first intuition is that:  0 heads => 1 tail  1 head => 2 tails  2 heads => 1 tail  3 heads => 0 tails  Therefore, it should be $\frac14$. I understand that the number of permutations is 8, thus:  HHH THT  HHT THH  HTT TTH  TTT HTH  And if you take those with 2 tails, it's $\frac38$. But where is the flaw in my first reasoning? Why do I care about which coin gets Tails when I only want to know the probability of getting 2 tails?  Thanks for your help.


Visual glitch in HTML: dropdown menu and next privilege tracker

The progress bar in the reputation tab overlaps with the site selection dropdown (see screenshots). Browser: Firefox 52.3.0.


Laptop touchpad right-click problem Ubuntu 16.04 [Dell Vostro 3568]

I have installed Ubuntu 16.04 LTS in my new Laptop (Dell Vostro 3568) about a week ago. My right-click is working same as the left click.  I am attaching a screenshot of the settings.  I tried various options, but no result.


Where can we translate Format settings label?

I am just wondering that where we can translate the Format setting labels which is configured in Manage display of content type. I checked in configuration translation, user interface translation but i didn't find the label which i am searching for.Can anyone help me in this regard. please find below screenshot for reference:


Prove that $a^{2n} -b^{2n}$ is divisible by $a+b$

Prove that for all $n\in\Bbb{Z}$, $a^{2n}-b^{2n}$ is divisible by $a+b$ using induction.     I know that if $a$ is divisible by $b$, then $a=kb$, where $k\in\Bbb{Z}$. Here we have that $a^{2n}-b^{2n}=(a+b)k$, with $k\in\Bbb{Z}$.  For the base case I set $n=1$, so $a^2-b^2=(a+b)(a-b)=(a+b)k$, where $k=a-b\in\Bbb{Z}$.  Now the inductive step (where I have doubts): $$a^{2n}-b^{2n}=(a+b)k\implies a^{2(n+1)}-b^{2(n+1)}=(a+b)m,\;k,m\in\Bbb{Z}.$$ We start from $a^{2(n+1)}-b^{2(n+1)}$. Then $$a^{2n+2}-b^{2n+2}=(a+b)\color{red}{(a^{2n+1}-a^{2n}b+a^{2n-1}b^2-\dots-a^2b^{2n-1}-ab^{2n}+b^{2n+1})},$$ so $a^{2(n+1)}-b^{2(n+1)}=(a+b)m$, where $m=a^{2n+1}-a^{2n}b+a^{2n-1}b^2-\dots-a^2b^{2n-1}-ab^{2n}+b^{2n+1}\in\Bbb{Z}.\qquad\square$    I have two questions:   Is the math in $\color{red}{\text{red}}$ a correct descomposition of $a^{2(n+1)}-b^{2(n+1)}$? We have not used the inductive hypothesis. Could we use it?


Is there any chance to change the vertical spacing in theorems when using beamer? The space I am talking about is between the word "Theorem" or "Definition" and the first line in the theorem.  And also, how to force text to continue right after the word "Theorem" without making the newline?


In math mode, when I type   \dot{x}, \ddot{x}, \dddot{x}   the third expression doesn't look like the two previous ones. The three dots are widely spaced and higher above the symbol. Is there a way to have three dots above a symbol so that it looks more regular compare to one dot and two dots?


Feature request not well received, risk of being blocked?

Related questions:      However I would like to address a specific case: feature requests. I  that was not well received. Feature requests questions . Now, if you get a ban, the  says:     All questions are expected to be useful to future visitors, too, so   put effort into writing with proper grammar and spelling, formatting   your post so it can be read easily, and providing as much detail as   possible about your problem and what you have already tried. Reading   your question out loud to yourself can help you understand what it   sounds like to others.   However, the automatic algorithm does not know about the quality of a post, it knows about votes, and for feature requests the votes can be very low even if the quality is ok. That puts in danger low rating users (but maybe experienced from other Stack websites) who want to propose an idea, and contribute to the website.  Is this is a relevant problem? How could be this situation prevented/mitigated?   Note: I know one "bad" question alone is not sufficient to get the warning. But since I got another question closed, I got a warning and for example now I am at risk even by posting this very question. Where I think I did my homework, but God knows who I can find out there in this dark night... :)  Edit: (This was the status of this question when justcool393 updated his answer)  Now I read about  However, why is the warning still so scarying?     Stack Exchange has automatic filters in place to ban questions from   accounts that have contributed many low-quality questions in the past   (Note: I am still readying details, but I urged to edit here to save this question from being closed)  (Then the question got closed so I moved to a new, more specific question)


Book about RPG players who get pulled into their game

I read a book as a teenager and I am searching for it. (from around the 90's)  Things I remember:   I remember that one of the players was in a wheelchair and he played a dwarf, Also remember when the wizard woke up in the game world, he set off a lightning bolt and exploded most of their gear.    I wish I could give you more, I read it and it inspired me to start playing D&D. Want to revisit it.


Does (or did) "a trouser" or "a scissor" have a meaning?

We say (a pair of) trousers, (a pair of) scissors. For these two particular words, is/was there something like "a trouser" or "a scissor"? Did it use to mean anything?   E.g. in Czech, the word for scissors is also plural but is derived from "knives". So I was wondering if the pair-words like these are derived from some (now forgotten) words with a meaning in singular. Similarly, the Slovak word for trousers is a plural of a Czech word meaning "a single trouser leg". (Czech and Slovak are very close.)


Add a class to the html element using angular js dynamically on the basis of If condition

I am implementing some default styles for a div for a "condition id" as (id="default")
 /* if(id == "default") */   I need to set some other styles (class="changeStyle"), if the "condition id" is changed i.e. (id != "default")
 /*if(id != "default") */   which should be added dynamically, if it's finding the (id != "default").   Any suggesstion/example would be highly appreciated.


In 2011, could a UK visa holder go to France without a French visa?

In 2011, could a Bangladeshi citizen, with a Bangladeshi passport and a valid UK visa, enter France without needing an additional French visa?


In GnuPG, what's the difference between --s2k-cipher-algo and --cipher-algo?

I want to change some encryption options while using GnuPG to encrypt a file symmetrically.  1) However, for choosing the cipher algorithm, GnuPG has two commands and I don't know which one to use.  Between these two, which one should I use?     --s2k-cipher-algo AES256      --cipher-algo AES256   2) Also for choosing the digest algorithm, there are two options,  Between these two, which one should I use?     --s2k-digest-algo SHA512      --digest-algo SHA512   3) Is there anything wrong with this encryption?     gpg -symmetric --cipher-algo AES256 --digest-algo SHA512 --s2k-mode 3   --s2k-count 65011712 PlainText   Edit: This is not a duplicate question, I can't find any post here on Stackexchange or any where in the net that specify the difference between --s2k-cipher-algo and --cipher-algo.


what is the torque required by stepper motor to hold an object of 400 grams

What is the torque required by a stepper motor to hold and fully rotate an object of about 400 grams ? I will be using an arduino uno along with the motor. The object will be mounted on a circular platform below which the motor and arduino will be placed.


I was reading a book, "" which, I think, was published in the middle of 1856, and I see "S" was replaced by the "ʃ" symbol (in small letter s, it looks more like "f'). Or perhaps it is not ʃ.  Very curious about the reason behinds it, but can't find any info from google search.


I know there is a public bus from the Denver International Airport to the Market street. I tried to figure out the schedule, but was not able to find it. Does anyone know where I can find it?  Is this a good (decent) option for getting to the city of Denver from the airport?


Given x points that must be on the surface of a sphere, how should they be placed so they are a maximum distance from each other?

Given x points that must be on the surface of a sphere, how should I place them so they are the maximum distance from each other? I'm attempting to create a script that will place any given number of objects on the surface of a sphere. I think the simplest way to represent the position of each point would be two degrees, the first representing horizontal position and the second the vertical. (0, 0) would the highest point, (90, 90) would the leftmost point, (270, 90) the rightmost point, etc. (x, y) would be like:  Is there a way to get the positions for each point on the sphere given the number of total points? For example, if I had 2 points, the furthest they could be is (0, 0) and (180, 180). 6 would have a point on each of the furthest points (top, bottom, front, back, left and right) 2 points example:  Is this possible? Also is there a better way to do the coordinate system?


Term for verb+adverb with distinct meaning

There are verbs that, when paired with certain adverbs, can have a distinctly different meaning.  For example,     I looked up the word in the dictionary.   The phrase looked up functions as a verb with a distinct meaning than looked in a sentence like     I looked ridiculous.   In all of these two-word verb examples I can think of, they become a single word when used as a noun or adjective:     The software performs millions of lookups per second.   Is there a term for these verb+adverb pairs, and, if so, what is it?  Additional examples:  back up, run off, hang out  Once upon a time, I though these were called verbals, but that was wrong.  The term verb phrase is not quite right either; a verb phrase generally encompasses additional modifiers, objects, etc.


The United States is afflicted by a cold- or flu-like disease that has the epidemiologists floored because its distribution is so spotty. In one town practically every adult person comes down with it, but not the children. Children aren't immune, however. Postal employees seem immune to the disease. Fortunately it's not fatal, and it's not obviously contagious, but it keeps spreading. Eventually someone deduces that it is caused by licking postage stamps. The town where the adults all got it had just had a big meeting where they all agreed to write their congressman. And postal employees used a sponge instead of their tongues to moisten stamps. The problem was traced to a single barrel of glue that had gone bad.   Obviously, this story was published long before "lickless" self-adhesive stamps were developed, becoming standard I think in the 1990s. I probably read the story in the 1960s or 70s in an English-language anthology.


Further customize color of hyperref links

I have tried to find a way to customize how internal links are colored, but I don't yet have the expertise in finding and redefining commands. In the LaTeX example below, I describe how I would like to change the colors of various links. Any ideas or examples are much appreciated.  \documentclass{article}  \usepackage[backref=true]{biblatex} \begin{filecontents}{refs.bib} @book{cit1, title = {The backreferences should be yellow}, author = {Last, First} } \end{filecontents} \bibliography{refs.bib}  \usepackage{color} \usepackage[usenames,dvipsnames,svgnames,table]{xcolor} \usepackage[colorlinks=true,             linkcolor=red,             urlcolor=blue,             citecolor=gray]{hyperref}  \begin{document}  \title{Title} \maketitle \tableofcontents \listoffigures  \section{Table of content's links should be green} \label{s1} All text, captions, and section headers after the list of figures should be black. The citation links should be gray.\autocite{cit1} \subsection{Table of content's subsections links should be orange} Internal links like this section link \ref{s1}  or this figure link \ref{f1} should be blue.  \begin{figure}[h] \caption{List of figures links red} \label{f1} \end{figure}  \printbibliography  \end{document}


Windows 8.1 fresh install with Windows 8 licence

I purchased Windows 8 online from Microsoft a while ago. Today Windows 8.1 was released as a free update to Windows 8 users over the Windows Store.  I was planning to do a fresh install of Windows 8.1 to have a clean system again and UEFI support because I got new hardware since the Windows 8 installation.  So my questions are:   Where do I get the ISO installation medium for Windows 8.1 64-bit? I tried  where I initially got my Windows 8 ISO from, but when entering my Windows 8 key in the Windows 8.1 installer, it says the key is wrong. Even if I get the ISO, will my old key work? I'm concerned because it didn't work in their installer (see previous point)   Do they seriously want me to reinstall Windows 8 and after that upgrade to Windows 8.1 through their Store?!


PostGIS Geometry Query returns "Error: Operation on mixed SRID geometries" only for certain values

I have PostGIS table with two geometry columns, both defined with SRID 4326. I can insert into the table without problem, using the following INSERT statement (where lng and lat are values passed in programmatically):  INSERT INTO pad_meta (     uuid, created, updated, name, origin, radius, area, expiry, creator ) VALUES (     $1, now(), now(), $2, ST_GeomFromText('POINT(lng, lat)', 4326), $3,      ST_Buffer(ST_GeomFromText('POINT(lng, lat)', 4326), $4), $5, $6 )   But when i query for an intersection using ST_Intersects, depending on the value of the point I get ERROR: Operation on mixed SRID geometries.   For example, this query works:  SELECT * FROM pad_meta where ST_Intersects(     'POINT(-122.334172173172 46.602634395263560)'::geometry, area::geometry  ) ORDER BY created DESC;   And this errors out:  SELECT * FROM pad_meta where ST_Intersects(     'POINT(-122.334172173172 47.602634395263560)'::geometry, area::geometry  ) ORDER BY created DESC;   Note, they are identical queries except the value of the longitude. I have experimented with different values, but not identified a clear transition point between the queries that work and don't.   I think I am fundamentally misunderstanding something. For the moment, I have solved/corrected/worked around the problem by re-formatting the query to use ST_GeomFromText and explicitly specifying the SRID:  SELECT * FROM pad_meta where ST_Intersects(     ST_GeomFromText('POINT(-122.334172173172 47.602634395263560)', 4326), area ) ORDER BY created DESC;   But I honestly don't really understand what the difference is, or if this truly "the" solution.    Why am I getting an error only for specific values, and what is the proper way to format this query?  Here is my table definition for reference:  CREATE TABLE IF NOT EXISTS pad_meta (   uuid CHAR(32),   created TIMESTAMP,   updated TIMESTAMP,   name VARCHAR(128),   origin GEOMETRY(Point, 4326),   radius INTEGER,   area GEOMETRY(Polygon, 4326),   expiry TIMESTAMP,   creator CHAR(32),   PRIMARY KEY (uuid) );   I have also verified that there is only one type of SRID in the geometry_columns:   SELECT f_table_name, f_geometry_column, srid FROM geometry_columns; f_table_name | f_geometry_column | srid --------------+-------------------+------  pad_meta     | origin            | 4326  pad_meta     | area              | 4326   I have also seen , but since I am already explicitly defining my geometry SRIDs when inserting into the table, it seems like that is not what is happening.


$\mathbb{Q}[X,Y]/(Y^2-X^3)$ is not a UFD

I'm trying to show that $R = \mathbb{Q}[X,Y]/(Y^2-X^3)$ is not a UFD, but I got stuck.  To prove this, I could try to find two "different" factorisations for one element, but I am not familiar with this, so I tried to use a lemma and one of the previous exercises. If my syllabus is right, in every UFD counts $$ x \ \text{is irreducible} \quad \iff \quad x \ \text{is prime}$$ My syllabus also states that the elements $\bar{X}, \bar{Y} \in R$ are irreducible. So I tried to show that at least one of the elements $\bar{X}, \bar{Y} \in R$ does not generate a prime ideal.  This would mean that I should find two polynomials $f,g \in \mathbb{Q}[X,Y]$, such that  $$\exists p \in \mathbb{Q}[X,Y], \quad fg - pX \in (Y^2-X^3)$$ and $$\forall q \in \mathbb{Q}[X,Y], \quad f-qX \notin (Y^2-X^3) \ \wedge \ g-qX \notin(Y^2-X^3)$$ or the same thing but then for $Y$.  I hope that you can tell me if this approach is correct, and provide me a hint. I'd appreciate it if you told me the solution, but please start your answer with a hint, clearly separated from the rest.


After finishing the main quests, is Dishonored an open-world game?

I want to buy Dishonored, but can I play open-world after finishing the main quest? I mean playing free-roam, killing anyone like in Assassin's Creed.


Is it actually safe for battery health to keep power adapter plugged if MacBook is charged (Mac OS10.15.5 )?

Sometimes I do small gaming on my MacBook Pro and it discharges quite quickly while running games. I understand that this is normal for every laptop. But in the latest update 10.15.5, there is a "Battery Health management feature" but there is no description of what exactly it does.   So, my question is Is it safe to keep MacBook plugged while it is charged?  This question in my case is applicable for gaming and other heavy programs (Video editing, etc).


DualShock 4 wireless controller not working

I bought a PS4 and a DualShock 4 controller, and when I turned on the power button it told me to press the PS button. When I do, the controller, connected using the USB cable, just blinks blue and goes back to power off. I tried resetting the controller, but nothing happened.  What is going on, and what can I do to fix the issue?


Hyperlinking a Record in Lightning:datatable

Having an issue with just one small part of   my question is what is the second ID (the one with key value of "Id" in the picture) in the object that is being passed to V.data? the "show_record_c" appears to be the standard 15 digit record ID used in hyperlinks so im not sure what that 18 digit id might be / if it is needed.     The object being passed to v.data is a URL (specifically Hyperlink to a record) linking to a record. I know i can create an object with record ID and a Name, just don't want to get too far down the road and discover that the 18 digit id is something essential


Why does the ordering of the following sentences matter?

Recently I was been posted with this question: Why is  1. I don't know who is he. (grammatically incorrect) 2. I don't know who he is. (grammatically correct) Even as a native English speaker, I could not give the person asking this question a definite answer or explanation. Please enlighten me on this. Thanks!


Prove that if an average of a thousand numbers is less than 7, then at least one of the numbers being averaged is less than 7

I tried proving this by contraposition, by saying, "If every number that is being averaged is greater than 7, then the average of a thousand numbers is less than 7."  This seems easier to prove, but I don't know where to go from there.


Prove GCD statement with multiple variables

For positive integers $a_{1}, a_{2}\cdots, a_{k},$ define $\gcd(a_{1}, a_{2}\cdots, a_{k})$ to be the largest positive integer $d$ such that $d$ divides every $a_{i}$ and any positive integer $c$ that divides every $a_{i}$ also has to divide $d.$ Is it true that there are integers $m_{i},$ not necessarily positive, such that $d= \sum_{i= 1}^{k}m_{i}a_{i},$ right ? How can i prove this ? I was thinking maybe one could use mathematical induction but i'm not quite sure.


Inequality. $(n+1)\left(a^{n+1}+b^{n+1}\right) \geq (a+b)\left(a^n+a^{n-1}b+\ldots+b^{n}\right). $

Let $a$ and $b$ be positive numbers, and $n \in \mathbb{N}$. Prove that (using Rearrangement Inequality) $$(n+1)\left(a^{n+1}+b^{n+1}\right) \geq (a+b)\left(a^n+a^{n-1}b+\ldots+b^{n}\right). $$  Thanks :)


Is an array of length 1 the same size as a single variable of the same type?

Fairly basic question, imagine  int a = 5; int[] b = new int[1]; b[0] = 5;   Do both a and b take up the same space in memory? I assume b is larger than a as it has to store the length of itself somewhere, so I thought it would be IntPtr.Size larger, but I am not sure.   I am trying to write code where the length of the array is determined at runtime, and can be 1 or larger (<10). I didn't know if I should just make an array if the length is set to one, or to have a special case in the code and just use the underlying type for length == 1.  I know that a is a value type while b is a reference type.


is it good to install ubuntu and windows on lenovo g510?

i recently bought lenovo g510(i5,8GB RAM) how to install windows and ubuntu on this without having any crash of os.


How tall should I build my minecraft mob farm?

My first attempt at a mob farm seems to have been too close to the ground. I wasn't getting very many mobs. When I killed mobs at ground level, more mobs would spawn in the mob farm. How tall should I build the next one so that it isn't affected by mobs on ground level?


EU copyright laws (2018-2019). Any risk for Stack Exchange?

The European Parliament JURI committee will be voting on 20th June 2018 on  (). According to a Creative Commons article titled :     The final copyright directive will have deep and lasting effects on the ability to create and share, to access and use education and research [...]   The author also argues that Article 13 would limit freedom of expression since copyright-filters would have a hard time distinguishing fair use from unauthorized copyright use.     [...] it puts into jeopardy the sharing of video remixes, memes, parody, and code, even works that include openly licensed content   FSFE's Openforum wrote , supported by GitHub, Debian, LibreOffice, SUSE, KDE and others, which states:     The proposed Article 13 of the EU Copyright Directive targets every online service that allows its users to upload and share content with each other, including code hosting platforms.      Under this proposal code hosting platforms will be compelled to prevent any possible copyright infringement by developing fundamentally flawed filtering technologies. These filtering algorithms will ultimately decide what material software developers should be allowed to share.      [...] This restricts the freedom of developers to use specific software components and tools that in return leads to less competition and less innovation.   (emphasis mine)  Update June 2018:   The EU committee has approved the new copyright rules. It will be voted on by the European Parliament on July. Creative Commons twitted:      @EP_Legal has adopted both Article 11 (#linktax) and Article 13 (#CensorshipMachines). It’s a dark day for the open web, but the fight will continue in the upcoming plenary vote in the European Parliament. #SaveYourInternet #SaveTheLink #FixCopyright      — Creative Commons (@creativecommons) June 20, 2018   against the law.   Update 6 March 2019:  According to :     The Group of the European People’s Party [...] is trying to push the final vote on the copyright reform to 12 March. This sound like an attempt to vote before the major Article 13 action day that’s planned for 23 March. On Thursday 7 March at 10 AM CET, the European Parliament’s (EP) Conference of Presidents (CoP) will vote on this request from the EPP.   Update 26 March 2019  :     all 750 Members of the European Parliament (MEPs) adopted an EU copyright reform that forces upload filters onto the Internet, as Article 17 (ex Art. 13) was not deleted. The next step is the final approval of the Council (= EU Member States) at the Ministerial level, which is expected in April. [...]      THIS IS OUR LAST CHANCE TO OVERTURN THE EU COPYRIGHT REFORM   Update     Article 17 (ex Art. 13) of the adopted text will force upload filters onto the Internet. The EU Member States will now have 2 years’ time to implement the Directive into their own national legislation. The fight continues, but now at national level. This copyright legislation is a Directive, which means that the EU Member States have some margin for manoeuvre at the national level with regards to how they ensure that the legislation will work in practice. Therefore, it will be important to convince national policymakers to ensure that they implement Article 17 (ex Art. 13) in the least harmful way, by ensuring the best possible protection of citizens’ fundamental rights.     Do these copyright proposals represent a risk for Stack Exchange?


Why does the Sun's emission spectrum have missing lines?

I know it is because the electrons in hydrogen and helium absorb them however, they also drop back to ground state immediately and emit the previously absorbed photon. So there should be no net difference as absorbed photon gets emitted. Therefore the emission spectrum should not have missing lines. But they do. What am I missing?


unable to install mongodb properly on ubuntu 17.04

I'm getting errors in my terminal every time I try to apt-get install something or update. I guess it has something to do with installing mongodb.  I'm new to Linux, and I followed this guide exactly on how to install it. I couldn't find a guide for 17.04 version so I did the 16.10, and now every time I try to apt-get something I get this error:  Reading package lists... Done W: GPG error: http://repo.mongodb.org/apt/debian wheezy/mongodb-org/3.0 Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 9ECBEC467F0CEB10 W: The repository 'http://repo.mongodb.org/apt/debian wheezy/mongodb-org/3.0 Release' is not signed. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details.   Plus I have an alert in my top bar:     an error occured please run package manager from the right-click menu or apt-get in a terminal to see what is wrong   the error message was :  Error brokenCount > 0. this usually means that your installed packages have unmet dependencies.


How to create a folder in HOME Folder with ModelBuilder in ArcGis 10?

I am just getting started with ModelBuilder and I would like to create a folder in the same folder where the respective mxd is located. The tool have to be usable in different projects, so setting Current Workspace to a specific folder doesn't do the trick.  Is there any chance to get access to a path of the Home folder which would be the same in any given project?


Quoting backslashes in Python string literals

I have a string that contains both double-quotes and backslashes that I want to set to a variable in Python. However, whenever I try to set it, the quotes or slashes are either removed or escaped. Here's an example:  >>> foo = 'baz "\"' >>> foo 'baz ""'   So instead of baz "\" like I want I'm getting baz "". If I then try to escape the backslash, it doesn't help either:  >>> foo = 'baz "\\"' >>> foo 'baz "\\"'   Which now matches what I put in but wasn't what I originally wanted. How do you get around this problem?


Show that $ \{\lnot,\leftrightarrow\} $ is not functional complete

I have to prove that this set of logical operators is not functional complete -  $$ \{\lnot,\leftrightarrow\} $$  i've tried implement this set by $ \{\rightarrow,\lor\} $ which is not functional complete too, but didn't success.. thanks !


Why is the use of the F-Statistic / p-value as a criteria in Stepwise Model Selection outdated?

I am coming from the field of psychology and in most publications Model Selection (OLS, Regression) is done via Forward/Backward Selection using the F-Static/p-value of the regression coefficients to decide which coefficient to include/exclude in the next step.  Now i read in the statistical learning literature (for example in ESL) that this strategie is outdatet because "it doesn't account for multiple testing issues correctly".  Unluckily there is no further explanation on those problems.  Does anybody can explain me, what exactly is the problem of this approach and why using other criteria (Cp, AIC) is better?  Thanks a lot in advance!


Is LibreOffice Writer able to read properly Ms Office Word docx Files?  I think it can't and users should be aware of it!  I tried to open many documents .docx created with Ms Office 2007 and appeared modified/transformed when I tried to open them with LibreOffice.  Can I do anything about it?


Checking to see if a word is in a Text File

I'm trying to make a program that checks to see if a string of letters is a text file, for a dictionary type program, but I can't get it to work. My code is:  package main;  import java.io.*; import java.util.Scanner;  public class Test { public static void main(String [] args) {     Scanner Enter = new Scanner(System.in);       System.out.println("Please Enter your word");     String Guess = Enter.next();      // The name of the file to open.     String fileName = "../Dictionary/Resources/wordsA.txt";      // This will reference one line at a time     String line = null;      int i = 0;     int numWords = 0;      String[] wordArray;     wordArray = new String[15000];       try {         // FileReader reads text files in the default encoding.         FileReader fileReader =              new FileReader(fileName);          // Always wrap FileReader in BufferedReader.         BufferedReader bufferedReader =              new BufferedReader(fileReader);          while((line = bufferedReader.readLine()) != null) {             numWords++;              wordArray[numWords] = line;         }          // Always close files.         bufferedReader.close();              }     catch(FileNotFoundException ex) {         System.out.println(             "Unable to open file '" +              fileName + "'");                     }     catch(IOException ex) {         System.out.println(             "Error reading file '"              + fileName + "'");                           // Or we could just do this:          // ex.printStackTrace();     }     for(i = 0; i < 10; i++){         System.out.println(wordArray[i]);         if(Guess == wordArray[i]){             System.out.println("In dictionary");         }         else{             System.out.println("Not in Dictionary");         }     } } }   It runs through my text file and prints the first 10 words in the file and displays whether or not my word given is in the text file dictionary or not. What I don't get is as you can see from my output below, I enter a word like "AA" and it still says not in the dictionary but it should say it is? I can't figure out why.  Example Output:   Please Enter your word AA null Not in Dictionary AA Not in Dictionary AAH Not in Dictionary AAHED Not in Dictionary AAHING Not in Dictionary AAHS Not in Dictionary AAL Not in Dictionary AALII Not in Dictionary AALIIS Not in Dictionary AALS Not in Dictionary


Why is the Ruby Math.log function returning the wrong values?

Given 3^5 (3**5 or 3*3*3*3*3) = 243.  Why/how does Ruby do the following:  n = 243 Math.log(n,3) returns:  4.999999999999999  Math.log(243)/Math.log(3) returns:  4.999999999999999  3**Math.log(n,3) returns: 242.99999999999977   That last one really gets me. Something is going wrong here? I'm missing something? Both?  Thanks!


A question on the "sum" of an uncountable "number" of positive quantities

In the answer to  Ittay Weiss wrote that, "...a sum of infinitely many positive elements can be bounded only if there are countably many elements." Though I asked about a rigorous proof of this fact and a reply was given, as can be easily seen, I still have some doubts which I need to clarify. I also didn't understand how Weiss's comment gives a proof of my question and so I am asking it here again.   It seems from the phrasing of the quote that there are other types of sum of positive elements for which the number of elements isn't countably infinite. What are some examples of sums of this type? To be precise, if sum of positive elements for which the number of elements isn't countably infinite then should it be necessarily uncountable?  If so, then how do we define a "sum" of uncountable number of positive quantities?  What is meant when we say that the "sum" is unbounded?  Why is a sum of infinitely many positive elements can be bounded only if there are countably many elements?    Any help will be appreciated.


How do you determine what technology a website is built on?

Quite often I come across a nice looking or functional website, and wonder what technology was used to create it. What techniques are available to figure out what a particular website was built with?  Few frameworks seem to include any kind of generator meta tag like web editors do. Are there any tell-tale signs of particular languages and/or frameworks?    Summary of answers  Site URLs may betray the framework and/or programming language but cannot be relied upon (e.g. file extensions such as .asp). HTTP response headers, cookies, stylesheets and source comments may also give clues.  Some nice tools for querying site details (no doubt there are many more):          Firefox addons:    - CMS, frameworks/libraries, e-commerce, message boards etc.  - IP, country and webserver details  - Javascript libraries in use   Chrome Extensions:        Bookmarklets:    - shows Javascript framework in use


I'm playing on xbox and I sold a few of my masks to Niranye. Usually when I sell important items to her, she keeps them even after restocking. Except she didn't keep those. Is there any way I can get them back? Please help if you can!


How can I install modules of python in Ubuntu?

I have python3 installed in Ubuntu 18.04 and I want to use different modules of python. Can anyone tell me how to install them?