I have been offered a phd position in Germany at 75% TVL-E13. It seems very difficult to get a precise figure for what this is in Euro. From a Google search I have figures for this position ranging from €21000 right up to €30000 on various websites dating back over the last couple of years.  I have a deadline on my decision so I really need to know what this 75% TVL-E13 rate amounts to in Euro at the moment so I can weigh it up against offers in other countries. Is this a 'good' rate for a PhD? Is anyone on this rate at present or does anyone have a good idea of how much this salary is currently worth in Euro?


Read .py file variables in another python file using the filepath

Considering I have two files - abc.py and xyz.py abc.py contains the following code - li = [1, 2, 3, 4] dt = {'m':1, 'n':4, 'o':9}  I want to read the file abc.py and use the python variables in xyz.py just like how we import using from abc import li, dt. The path to abc.py (say, path/to/abc.py) will be provided and I want to import the contents and use it in xyz.py just like python variables. The following code provides the content in a string format, while I can do some coding and get the job done but I want to generalize and look for a better approach to this. Also note, I find using abc.json a better option but due to some reasons I cannot use it for my purpose. with open(path, "r") as f:     s = f.read()     print(s)


How to list configuration files for a package before installing the package?

I learned how to view the configuration files for a package that's already installed from reading:    Using dnsmasq as an example, I can view the files and configuration files for that package after it's installed using these two commands:  cat /var/lib/dpkg/info/dnsmasq.conffiles dpkg -L dnsmasq   I know I can search for the existence of the package and get relevant meta data about the package using these commands  dpkg --list | grep dnsmasq apt-cache search dnsmasq apt-cache show dnsmasq   But, I'd like to know the configuration files for the package before installing it.  How do I list configuration files for a package before installing the package?


Which is correct? - "Guess, what it is?" or "Guess, what is it?"

I want to know which sentence is correct. If i say     Guess, what it is?   or     Guess, what is it?   which one is correct?


Document library to support/store/upload .doc,.xls files only

I am searching for an OOTB procedure to make Document library support store/upload of a specific type of file (based on extension - for example .doc, .xls).  Can anyone provide specific guidance on how to achieve this?


When I publish content – for instace an article – on a Drupal site, I'd like Drupal to push a status update with a link to the article to a Facebook company page.  I know there are a lot of Drupal modules that offer Facebook integration, but does any of them offer this particular functionality? Or is perhaps the best way to go to generate an RSS feed and use a third-part app like  to push it to Facebook?  The site in question is a Drupal 6 site.


Convert coordinates from picture to textpos

I am trying to convert some code from using the picture environment to textpos for a titlepage but I have run into problems getting the text to align.The coordinates are given in points.  the original text is placed with  \AddToShipoutPicture*{\put(50,583.5){\fontsize{20 pt}{22pt}\tyk \OPGAVE}}   where the t-coordinate is given form the bottom of a (A4) page presumably with the lower left corner at the coordinates.  And the new text:  \begin{textblock}{200}[0,1](50,258.5)      \noindent\fontsize{20 pt}{22 pt} \tyk \OPGAVE  \end{textblock}   where the y coordinates is given from the top of the page. I calculated the new y coordinates by y_new = 842-583.5=258.5, since the vertical dimension of a A4 page is 842 points.    The red text is the original.  Any assistance would be greatly appreciated!


prioritized power path controller for battery backup

I'm searching for a simple solution for a prioritized power path controller to maintain a system supply line through a rechargable battery when the main supply fails.  My goal is to make the cheapest solution. During a long searching on the internet I came accross Ti's design . It uses a voltage window comparator and two couples of back-to-back mosfet for the changeover.  I studied the circuit (Page 8, Figure 4). carefully and I can see a basic problem here. Considering the secondary rail a Li-ion battery 3.7V and the primary rail with a significant greater voltage, for example >5V or >12V. In that case, when the primary rail fails, after the switchover and exactly after the Q1 is fully on (lowest Rds) the battery will see a charged capacitor (C1) with a primary's rail voltage, because when the mosfet is on it does allow the flowing of reverse current. If the load's current is very low, the Capacitor on the load will not discharge enough during the switchover and that remaining amount of voltage may cause damage to the battery.  I found that the problem is solved by ideal diode controllers or ORing controller but I wasn't able to find anything reasonable cheap. In addition, my circuit (load) demands current above 2.5A. Unfortunately, some embedded and cheap TI's chip, are capable to handle maximum 2A.  The TI's schematic above, does not implement any solution for reverse current blocking while the mosfets are on.


Some `BigDecimal` values don't match with `Float`

Some BigDecimal values can be compared with a Float by eq in Rspec3, but some values can't be.  describe "compare BigDecimal with Float" do     it { expect("83.79".to_d).to eq(83.79) } # => fail     it { expect("83.75".to_d).to eq(83.75) } # => succeed end   To avoid error, I'm using expressions like eq("83.79".to_d).  Why does the first test fail while the second succeeds?


Infinite Geometric Series Formula Derivation

We know that the formula for computing a geometric series is:$$\sum_{i=1}^{\infty}{a_0r^{i-1}} = \frac{a_0}{1-r}$$ Out of curiosity, I would like ask: Is there any ways the formula can be derived other than the following two ways?  Method 1 (The way I found on my own): $$\sum_{i=1}^{\infty}{a_0r^{i-1}} \equiv S$$ $$S = a_0r^0+a_0r^1+a_0r^2+\cdots$$ $$S = r\left(a_0r^{-1} + a_0r^{0} + a_0r^1+\cdots\right)$$ $$S = r\left(a_0r^{-1} + S\right)$$ $$S = a_0 + rS$$ $$(1-r)S = a_0$$ $$S = \frac{a_0}{(1-r)}$$ Note that for this to work, you must first confirm this: $$\lim_{n\to\infty} a_n = 0$$ Method 2 (The way I found on the web): $$\sum_{i=1}^{n}{a_0r^{i-1}} \equiv S_n$$ $$S_n = a_0r^0+a_0r^1+a_0r^2+\cdots + a_0 r^{n-2} + a_0 r^{n-1}$$ $$rS_n = r\left(a_0r^0+a_0r^1+a_0r^2+\cdots + a_0 r^{n-2} + a_0 r^{n-1}\right)$$ $$rS_n = a_0r^1 + a_0r^2 + a_0r^3 + \cdots + a_0 r^{n-1} + a_0 r^{n}$$ $$S_n-rS_n = a_0r^0 - a_0r^n$$ $$(1-r)S_n = a_0 - a_0 r^n$$ $$S_n = \frac{a_0(1 - r^n)}{1-r}$$ Given:$$\left|r\right| < 1,$$ $$\lim_{n\to \infty} S_n = \lim_{n\to \infty}\frac{a_0(1 - r^n)}{1-r} = \frac{a_0}{1-r}$$ I personally prefer Method 1 because it is faster and more intuitive, as we don't have to multiply by $r$.  Method 1 for formula of partial sums: $$\sum_{i=1}^{n}{a_0r^{i-1}} \equiv S_n$$ $$S_n = a_0r^0+a_0r^1+a_0r^2+\cdots+a_0r^{n-2}+a_0r^{n-1}$$ $$S_n = r\left(a_0r^{-1} + a_0r^{0} + a_0r^1+\cdots+a_0r^{n-3}+a_0r^{n-2}\right)$$ $$S_n = r\left(a_0r^{-1} + S_n - a_0r^{n-1}\right)$$ $$S_n = a_0 + rS_n - a_0r^{n}$$ $$(1-r)S_n = a_0 - a_0r^n$$ $$S_n = \frac{a_0(1 - r^n)}{(1-r)}$$


Why too many empty sections result in a mess without pagebreak?

When I wrote a template, I found that if there is too many empty sections in a chapter, latex will not produce appropriate page breaks. All these sections will just be listed in a single page. Why does that happen?  \documentclass{report}  \begin{document} \chapter{chp1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \section{sec1} \end{document}


How to create DEM from Lidar point cloud data?

I'm using ArcMap and I want to create DEM(s) over an area to have different outputs depending on which settings/filters I put in. I have access to laser point cloud data as my input files. I've worked with the LAS dataset tools but I'm not really sure if I'm doing everything correct or not. Because the points aren't regular, maybe some interpolation method is needed first? The problem with that is, I don't have any input point features.  This link describes fairly good the steps I've made:


How to count number of distinct values in a range?

I've got a large table that is already organized using filters etc. I'd like to add a summary underneath certain columns that contain the number of distinct values in that column.   There's no function =COUNTDISTINCT(A2:A100) so what can I do instead? (Excel 2003)  I can't exactly use answers to  because I don't want to modify the table or the filtering. I need an addition in the worksheet, not a modification.


I would like to be able to use Console.WriteLine() and Console.ReadLine() in the same line

I am writing a program that will act like a terminal, however, I'm having some issues with it. I would like to be able to prompt the user for a command and have the user be able to type in the command in the same line in the terminal, but I don't know how to do that. Every time I try, the prompt, telling the user to type shows up in one line and my 'ReadLine' is the line under it.  For example, I want it to look like this:  user1> (user types command here)  my code goes like this:      Console.WriteLine("user1>");     string a = Console.ReadLine();   and then I'll of course have more code after that but that's the trouble spot (getting the two on the same line in the console)  But it always compiles as this:  user1> (user types command here)  If someone could come up with an example of what I'm supposed to do in this situation, that would be great help.


VBA List databases on specific SQL Server

I'm trying to create a form with two listboxes. One is for SQL Server names; the other is for the databases on the server selected by the user.  In VBA I can get the server names by calling a stored procedure. However, I don't seem to be able to get a list of databases for a specific server.  Does anyone know how to write such a query?  Thanks.


Is a   select *  from myView   faster than the query itself to create the view (in order to have the same resultSet):  select * from ([query to create same resultSet as myView])   ?  It's not totally clear to me if the view uses some sort of caching making it faster compared to a simple query.


Cartoon with a young unicorn and a demon

In the late 80s or early 90s I remember watching an animated series that followed a young unicorn and a demon.   In one episode the unicorn gave the demon his horn, and the unicorn almost died.   In another episode there was a man who was able to turn people into human shaped building blocks and built a huge tower from them.   Those are the two scenes I remember with any clarity.   Does anyone have any idea?


Why prime avoidance lemma allows only at most 2 non-prime ideals?   The following is the last part of the proof taken from wikipedia:  For the case $n > 2$, choose $z_i \in E \cap (I_i - \cup_{j \ne i} I_j), \, \, 1 \le i \le n$ and then put $z = z_1 \cdots z_{n-1} + z_n.$ Then z is in E but not in any of $I_i$'s. Indeed, if z is in $I_i$ for some $i \le n - 1$, then $z_n$ is in $I_i$, a contradiction. If z is in $I_n$, then $z_1 \dots z_{n-1}$ is in $I_n$ and, since $I_n$ is a prime ideal, $z_i$ is in $I_n$, a contradiction. (Note, after the initial reduction, we only need the fact that $I_n$ is a prime ideal.)  From what I see, as long as one of them is prime, say $I_n$. What am I misunderstanding here? The part on z in $I_i$ does not need $I_i$ to be prime, does it? I think it just need $I_i$ to be ideal.


Term for situation where alternative choice is not really one

What would you call a situation where the current one sucks but you have a 'choice' to an alternative, however the alternative is not really one.  Such as,       "Sure living in an area under a monopoly internet provider sucks, but   you can always live without internet"     Demonstrating an issue where one of the choices isn't really a viable choice or at least comparable alternative.  (There are more dramatic ones)


new search box looks janky when browser width narrow enough for horizontal scrolling

This is not a post about the positives or negatives of the new navbar color at the top of all StackExchange sites, but it does have to do indirectly with the navbar color.  Now that the expandable search box has gone away, an interesting quirk occurs when you have your browser narrow enough to cause horizontal scrolling to kick in.     Exhibit A:  the browser scrollbar has activated because user has reduced the width to a size roughly less than the 980px width of the #content div container.     Exhibit B: the search box looks ok, right?     Exhibit C: well, maybe not...because what is the search box doing there, partly in a black background, and partly in a white background?     To conclude: the top navbar appeareance should persist across the full width of the browser when the browser size is reduced, even if the search box in the right corner makes that more challenging.


I am trying to run some unit tests in a C# Windows Forms application (Visual Studio 2005), and I get the following error:  System.IO.FileLoadException: Could not load file or assembly 'Utility, Version=1.2.0.200, Culture=neutral, PublicKeyToken=764d581291d764f7' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)** at x.Foo.FooGO() at x.Foo.Foo2(String groupName_) in Foo.cs:line 123 at x.Foo.UnitTests.FooTests.TestFoo() in FooTests.cs:line 98** System.IO.FileLoadException: Could not load file or assembly 'Utility, Version=1.2.0.203, Culture=neutral, PublicKeyToken=764d581291d764f7' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)  I look in my references, and I only have a reference to Utility version 1.2.0.203 (the other one is old). Any suggestions on how I figure out what is trying to reference this old version of this DLL file? Besides, I don't think I even have this old assembly on my hard drive. Is there any tool to search for this old versioned assembly?


For what values of $x_1, x_2, x_3, x_4$ is the matrix $A$ is invertible?

For what values of $x_1, x_2, x_3, x_4$ is the matrix $A=\begin{pmatrix} 1 & 1 & 1 &1 \\  x_1 & x_2 & x_3 &x_4 \\   x_1^2& x_2^2 & x_3^2 & x_4^2\\   x_1^3& x_2^3 & x_3^3 &x_4^3  \end{pmatrix}$ is invertible  Do I need to calculate det 2x2, 3x3 and so on or?


Is "the" pronounced as "thuh" or "thee" in this sentence

"the amount of fun"  Is "the" pronounced as "thee" before a schwa?


Is it possible to "re-buffer" river polygon dataset?

I've river polygon data representing the water quality. This polygon data were derived from polyline dataset according to a buffer distance in the attribute table. Unfortunately I don't have this line dataset. So my "possibly naive" question is - is it possible to "re-buffer" the polygon data set to have polyline data again? Maybe there is a way to draw the centerline of each polygon? I prefer to work with qgis 2.6 but also have ArcGIS 2.2 available.


How Do I populate the Last Login Date from User object into a custom object/field?

Aim – Pull the last login date from the user object into my custom object and populate a particular field  Now I am under the impression that LastLoginDate on the user object is not accessible through formulas in custom objects. The only way that LastLoginDate is accessible is through triggers   **Custom Object**  Object Name Mason_Object API Name    Mason_Object__c  **Field I would like to update is on the mason_object**  Field Label : LastLogin Api Name : LastLogin__c Data type: Date/Time  I have written the following trigger (see below) however its not pulling through any values. Any ideas why ?  trigger lastloginDate on Mason_Object__c(before update) {  User u = [SELECT LastLoginDate FROM User WHERE Id =:UserInfo.getUserId()]; trigger.new[0].LastLogin__c = u.LastLoginDate;  }


Are there any Ubuntu tablets that can be purchased?

Is there a tablet that can be purchased with Ubuntu or what tablets are suggested for Ubuntu?


Does there occur any filtering in making merge-to-HDR picture?

I have the interpretation simplistically that you can make this by taking two pictures of high dynamic range picture and low dynamic range picture, and then merging. This way the HDR-picture should be invertible to the original picture.  I am interested in how these two pictures are or can be manipulated before the merge. I have an intuition that there are some linear filters. I want no tonemapping, since it is highly non-linear.  What can these filters be?


Maxing out gear with maxed out smithing, enchanting and alchemy

I have level 100 smithing, enchanting and alchemy. I also have some nice enchanted gear, fortify smithing and alchemy.   How high should I be able to get my fortified equipment?  Currently I'm around 29% for alchemy and smithing.  How high can I get fortify smithing and fortify enchanting potions without using the console (cheating)? And how? Currently I get +147% and +32% respectively.  Is something like this possible without using the console(or photoshop)?


How to hide a trusted domain in the logon screen?

I need to create a bidirectional trust between two Active Directory domains. But management is worried that users will be puzzled out when seeing  another domain name in the drop-down list in the Windows logon screen (many of them use Windows XP), and that help desk calls for failed logins due to having selected the wrong domain will skyrocket. Also, the two domain names are quite similar, adding to the possible user confusion.  Is there any way to hide a trusted domain from the drop-down list in the Windows logon screen?


Suppose $X_1, X_2, \dots, X_n$ are iid Bernoulli(p) random variables. How do you find the restricted maximum likelihood for p where $0<p<0.5$?  My work so far:  Write out the likelihood: $L=p^{\sum x} (1-p)^{n-\sum x}$  Take the log: $\ln(L) = \sum x\ln(p)+(n-\sum x)\ln(1-p)$  Take the derivative and set equal to zero: $\frac{\sum x-np}{p(1-p)}=0$.  Now I'm stuck. I don't know how to incorporate the restrictions for $p$.


How to time how long it takes to insert and sort separatley in a TreeMap

I would like to time how long the program takes to insert in the tree to measure the efficiency of a TreeMap's inserting. I also want to measure how long it takes to sort separately. I am doing this for a report I am writing where I am comparing the inserting time and sorting time for a TreeMap, linkedList and ArrayList. For the linkedList and ArrayList I am just going to insert all and measure first, then call list.sort(comparator) and measure how long it takes to sort. I am not sure how to do this for a TreeMap though.   final long startTime = System.currentTimeMillis();             Comparator<String> secondCharComparator = new Comparator<String>() {                     @Override public int compare(String s1, String s2) {                         return s1.substring(1, 2).compareTo(s2.substring(1, 2));                     }                            };          SortedMap<String,String> map =                 new TreeMap<String,String>(secondCharComparator);             map.put("a", "one");             map.put("a", "two");             map.put("cd", "three");     final long endTime = System.currentTimeMillis();  long totalTime = endTime - startTime;


Errors when using the Corridor Designer tool from Arctoolbox

I am using the corridor Designer ArcToolbox for designing a habitat suitability model and I've got the following errors:  Error 010328: syntax at or near symbol SPACE ERROR 010267; Syntax error in parsing grid expression   I´ve tried moving the files without spaces and number to the default file of ArcGis. Also carefully rewriting the txt.files for the reclass table. And nothing seems to work.


I am a first-year maths student but I occasionally drift away from our taught material. Some years ago I saw the ZFC axioms for the first time, but now that I am in college, and although the stuff I've been taught so far is nowhere near ZFC (in terms of difficulty), it happened to me that we use the axiom of choice all the time in every module, even if we don't know it by name yet.  For example, in the proof that, for every non-negative integers $a, b$, there exist integers $q, r: a = bq + r$ (with the known restrictions on r), and the proof starts like this: $Choose$ the largest integer $q : qb <= a$... blah blah blah.  Is it the axiom of choice that allows us to execute this simple yet so important step?   And a couple more questions: Can you name some other simple proofs, theorems, results etc for which the axiom of choice is essential?  Also, I've read that AOC has long been a topic of dispute for mathematicians, and that even today, some people do not accept it. Are there any alternative axiomatic systems that work equally well without needing AOC? Thanks!


How does gcc implement stack unrolling for C++ exceptions on linux?  In particular, how does it know which destructors to call when unrolling a frame (i.e., what kind of information is stored and where is it stored)?


$|A|=|A\cup B|$, where A infinite and B countable

I know that my direction for this proof is correct, but it feels like my reasoning for few things are off because I am still trying to grasp the Schroder-Bernstein so I would appreciate the guidance! Please note that I am novice on a good day..   Let A be an infinite set and B a countable set.  Prove $|A|=|A\cup B|$  Suppose $B\subset A$, meaning union of A and B are disjoint, this results in $|A\backslash B|=|A|=|A\cup B|$ according to our claim.  This also means that $A\backslash B$ is also infinite, since A is infinite. Let C be a denumerable subset of $A\backslash B$, and since B is countable and C is denumerable their union must also be denumerable. This means that  $|B\cup C|=|C|$ such that there is a bijection $f:B\cup C\rightarrow C$. Now suppose we split A into two pieces, i.e. $A\backslash (B\cup C)$ which is the same as $(A\backslash B)\backslash C$. We already have a bijection $f:B\cup C\rightarrow C$, and we can form another bijection $g:(A\backslash B)\backslash C\rightarrow (A\backslash B)\backslash C$ meaning to itself. Let h be the function that is $f\circ g$, which by definition of composite functions, another bijection such that $h:A\rightarrow A\backslash B.$


How to validate regex pattern to check mimetype?

here i am trying to validate the SVG image mime type. Even I am passing valid content-type also it fails. Can anyone suggest to me what's wrong with this regex?   const mimetypes = /image\/png|image\/jpeg|imagesvg+xml|image\/gif|image\/svg+xml/;  var result = mimetypes.test('image/svg+xml')  console.log(result)


Windows symlink to executable - does not open by double click

On Windows 7 I created a symbolic link to an executable using:  mklink Test.exe C:\Path\to\source.exe   But when I try to run it by double clicking on it, i get the "open with" dialog.  Running it from a command window works. The path is right.   Is there any way a symbolic link will be treated like the file it points to (e.g. executable or batch scripts)?


Why not use the Lagrangian, instead of the Hamiltonian, in nonrelativistic QM?

Undergraduate classical mechanics introduces both Lagrangians and Hamiltonians, while undergrad quantum mechanics seems to only use the Hamiltonian. But particle physics, and more generally quantum field theory seem to only use the Lagrangian, e.g. you hear about the Klein-Gordon Lagrangian, Dirac Lagrangian, Standard Model Lagrangian and so on. Why is there a mismatch here? Why does it seem like only Hamiltonians are used in undergraduate quantum mechanics, but only Lagrangians are used in quantum field theory?


How to convert an input parameter to integer value in a for loop in bash?

in my bash script I try to use a number as an input variable for a for loop I run the script as   ./script.sh InputFolder/ Number_of_iterations   the script should work inside the given folder and run a for loop as many times as the Number_of_iterations variable is set to. But somehow I can't set the variable as an integer.   this is an example of my loop in the script:  for i in {1..$(($2))} do  echo "Welcome $i times" done   I have tried already the double brackets $(($...)) option as well as the double quotations "...", but the output I keep getting is   Welcome {1..5} times   which make me think, this is not an integer.  I would appreciate any help in reading the input parameter as an integer into the script.


Formula obtained by repeated integration by parts.

Tonight I was messing with the integration by parts formula and found the following formula. Starting with the usual $$\int udv = uv - \int vdu$$ and letting $u = f(x)$, $du = f'(x)dx$, $dv =dx$ and $v=x$ we obtain $$\int f(x)dx = xf(x) - \int xf'(x).$$ We then apply the apply the integration by parts formula again to the integral on the RHS to obtain $$\int f(x)dx = xf(x) - \frac{f'(x)x^2}{2} + \frac{1}{2}\int x^2f''(x)dx$$ and again: $$\int f(x)dx = xf(x) - \frac{f'(x)x^2}{2} + \frac{f''(x)x^3}{2\cdot 3} - \frac{1}{2\cdot 3}\int x^3f'''(x)dx$$ So, in general, it seems (at least to me) safe to say that $$\int f(x) dx = xf(x) - \frac{f'(x)x^2}{2} + \frac{f''(x)x^3}{2\cdot 3} - \frac{f'''(x)x^4}{2\cdot 3\cdot 4} + \ldots =\sum_{n=1}^{\infty}\frac{x^nf^{(n)}(x)}{n!}(-1)^{n+1}$$ Next, applying the alternating series estimation theorem, we have that $$|E_N|=\left|\left(\sum_{n=1}^{\infty}\frac{x^nf^{(n)}(x)}{n!}(-1)^{n+1}\right) - \left(\sum_{n=1}^{N}\frac{x^nf^{(n)}(x)}{n!}(-1)^{n+1}\right)\right| \leq \frac{x^{(N+1)}f^{(N+1)}(x)}{(N+1)!}(-1)^{N+1}$$ I then tried to use this estimate to approximate $\int_{a}^{b}f(x)dx$. That is, since we have $$E_N \geq -\frac{x^{(N+1)}f^{(N+1)}(x)}{(N+1)!}(-1)^{N+1}$$ we can conclude that $$\int_{a}^{b}f(x)dx \approx \left(\sum_{n=1}^{N}\frac{x^nf^{(n)}(x)}{n!}(-1)^{n+1}\right)-\frac{x^{(N+1)}f^{(N+1)}(x)}{(N+1)!}(-1)^{N+1}.$$  It then occured to me that to use the alternating series estimation theorem we must have that $$0\leq\frac{x^{n+1}f^{(n+1)}(x)}{(n+1)!}\leq \frac{x^{n}f^{(n)}(x)}{(n)!}$$ and $$\lim_{n \to \infty}\frac{x^nf^{(n)}(x)}{n!} = 0$$ So it seems that the above approximation only works if we choose an $f(x)$ so that the above hypothesis are satisfied. Is there a way to estimate the infinite sum that does not rely on the alternating series test so we do not have to worry about satisfying the above restrictions?  More generally, I am interested if there is a more interesting route to take with this process of repeated integration by parts. The form of the terms in the infinite series remind me of taylor series. Is there a connection?


I'm completely new to Magic the Gathering. I've read the basic rulebook pretty thoroughly and have a pretty good grasp of the basic rules, but it's unclear to me as to when you can tap lands to generate mana.  First off,  mana is supposed to dry up after each phase in a turn. Can I untap my land cards and then tap them again in the next phase if I need more mana to power a spell? Or does a land card remain tapped until my next turn like everything else?  Second, the rules mention that I can play instants and activate abilities during my opponent's turn. Does that then mean that I can tap my land cards during my opponent's turn to power those spells?  Third, does my opponent's untap step for their turn only apply to their cards? Or can I untap mine as well? Not closely related to land cards, but when I can tap and untap my land cards would make a huge difference as to how I play.  Hope these questions aren't painfully obvious, but I've just started playing the game. Thanks for your time!


How to remove Windows 7 if I have installed with Wubi?

So, I just recently installed Ubuntu 12.04 with a windows installer (Wubi) and I want to delete Windows 7 completely leaving Ubuntu alone. Does anyone know how to do that without having to do everything all over again?


Alternative to Ctrl-R reverse search in bash

I am happy and really like the Ctrl-R backward search feature of the bash shell. Some of my colleagues don't like it, since it is sometimes confusing. I understand them. If you enter the wrong characters, the current position in the history is somewhere in the past, and you won't find the recent matches. Is there a more user friendly alternative for seaching backward in the shell history? I want to stick with bash. Suggesting an alternative shell is not an answer to this question. The issue with the "lost position" is explained here: . These solutions work. That's right. But the solution there are not easy and user friendly according to my point of view. These solutions are not simple and straight forward. These are solutions of the past. In the past the human needed to learn the way the computer wanted the input. But today the tools should accept the input in a way which is easy for the user. Maybe someone knows a IDE of jetbrains like PyCharm. If you search for "foobar" you even get the lines which contain "foo_bar". That's great, that's unix :-)


Best way to GetHashCode() for 44-bit number stored as Int64

I have around 5,000,000 objects stored in a Dictionary<MyKey, MyValue>.  MyKey is a struct that packs each component of my key (5 different numbers) in the right-most 44 bits of an Int64 (ulong).  Since the ulong will always start with 20 zero-bits, my gut feeling is that returning the native Int64.GetHashCode() implementation is likely to collide more often, than if the hash code implementation only considers the 44 bits that are actually in use (although mathematically, I wouldn't know where to begin to prove that theory).  This increases the number of calls to .Equals() and makes dictionary lookups slower.  The .NET implementation of Int64.GetHashCode() looks like this:   public override int GetHashCode() {     return (int)this ^ (int)(this >> 32); }   How would I best implement GetHashCode()?


Harry Potter and The Order of Phoenix fanfic with an alternate story line with a love angle between Harry and Hermione

Many years back (more than 10) I came across a PDF for Harry Potter and The Order Of Phoenix. It had a completely different story line. If I remember correctly, in the first chapter Harry was meddling around in the garden thinking about his own physical growth and over the course of the book there was a love angle between him and Hermione. Some portion that I can recollect from the first chapter is about a snake Harry encounters in the garden and the snake is not in a really good shape and Harry takes care of it. Rest of the year in the school was completely different too, Sirius doesn't die as per the story and it's a gradual build up to his and Hermione's relationship. I have never been able to find that PDF again.


If quantum entanglement is not an active link between particles, then how did China transmit data via Earth-to-space quantum entanglement?

So based on this thread :   which was asked 7 years ago, the answer says      "Entanglement is being presented as an "active link" only because most   people - including authors of popular (and sometimes even unpopular,   using the very words of Sidney Coleman) books and articles - don't   understand quantum mechanics"   if so, then how has china developed a technology where they transmitted data via Earth-to-space quantum entanglement?      also some other countries have said that they developed a technology where they transmitted data in a less of a  distance   so am i missing something here?   also not sure how is this the duplicate of my previous question when my previous question is the duplicate of a thread that was posted 7 years ago and now I'm responding to that, basically if someone asks a question even after 7 years no one can ask a question about that thread?


Please suggest some idea to display today date in date picker text box , when i load the page .


What are the differences between these sentences?     1) If I won the lottery, I would buy a house.      2) If I win a lottery, I will buy a house.      3) If I were to win a lottery, I would buy a house.      4) If I had won a lottery, I would have bought a house.


ESXi server under DoS attack, can I use SSH to determine where from?

My VMWare ESXi 4 server appears to be under a Denial of Service attack. I am getting massive packet loss to the server (60+%) and am barely able to load any services on the VMs running on the host.  I have Cacti installed but cannot load it due to the attack. I can SSH in to the VMware host. Are there any commends I can run to either determine where the attack is coming from, or block all IP addresses except mine so that I can load Cacti again to troubleshoot?  I tried esxcli network firewall get but received: Unknown Object firewall in namespace network  All the VMs with network access are directly connected to the internet, that is, there is a virtual switch between the internet-facing VMs and the router.  EDIT: : disable the vswitch that the VMs are on. But I can't get the vSphere console to respond long enough to do this. Can this be done through SSH?


Example of Artinian module that is not Noetherian

I've just learned the definitions of Artinian and Noetherian module and I'm now trying to think of examples. Can you tell me if the following example is correct:  An example of a $\mathbb Z$-module $M$ that is not Noetherian: Let $G_{1/2}$ be the additive subgroup of $\mathbb Q$ generated by $\frac12$. Then $G_{1/2} \subset G_{1/4} \subset G_{1/8} \subset \dotsb$ is a chain with no upper bound  hence $M = G_{1/2}$ as a $\mathbb Z$-module is not Noetherian.  But $M$ is Artinian: $G_{1/2^n}$ are the only subgroups of $G_{1/2}$. So every decreasing chain of submodules $G_i$ is bounded from below by  $G_{1/2^{\min i}}$.  Edit In Atiyah-MacDonald they give the following example:     Let $G$ be the subgroups of $\mathbb{Q}/\mathbb{Z}$ consisting of all elements whose order is a power of $p$, where $p$ is a fixed prime.   Then $G$ has exactly one subgroup $G_n$ of order $p^n$ for each $n \geq 0$, and $G_0 \subset G_1 \subset \dotsb \subset G_n \subset \dotsb$ (strict inclusions) so that $G$ does not satisfy the a.c.c.   On the other hand the only proper subgroups of $G$ are the $G_n$, so that $G$ does satisfy d.c.c.      (Original images  and .)   Does one have to take the quotient $\mathbb{Q}/\mathbb{Z}$?


How to enable bullet points when using the presento beamer theme?

I have the problem that when I use an itemize list and the , there are no bullet points.  Here is a minimal working example (requires the  not available on CTAN to be downloaded first):  \documentclass{beamer} \usepackage{config/presento} \begin{document} \begin{frame} \begin{itemize} \item ... \item ... \item ... \end{itemize} \end{frame} \end{document}     How to fix this problem?


Canonical URL for a home page and trailing slashes

My home page could be potentially linked as:  http://example.com http://example.com/ http://example.com/?ref=1 http://example.com/index.html http://example.com/index.html?ref=2  (the same page is served for all those URLs)   I am thinking about defining a canonical URL to make sure Google doesn't consider those urls to be different pages:  <link rel="canonical" href="/" /> (relative) <link rel="canonical" href="http://example.com/" /> (trailing slash) <link rel="canonical" href="http://example.com" /> (no trailing slash)   Which one should be used? I would just slap / but messing with canonical seems like a scary business so I wanted double check first.  Is it a good idea at all for defining a canonical URL for a home page?


Trying to get over a bad case of something

To me:      'Bad case of (an ailment)'    sounds anything and everything that is either the direct result of an ailment; for example:      I have a bad case of the flu.    would cover other symptoms that might accompany it in a given case (i.e, headache, sore throat, body aches, etc.) Is that right?  Whereas if I said:      I am trying to get over the flu.   means I am doing my best to recover from it. Correct?


How does the gravity well change as space expands? If we assume that the Earth's gravitational field curves flat space to create a gravity well then how does the gravity well change as space expands also is the change in gravity well measurable.


Controlling bandwith while using GPRS on Windows 7

I have an issue with my windows 7 machine using a lot of bandwith while connected to the internet. I'm trying to limit the bandwith by using Opera in Turbo mode, but some other program is sucking down content and emptying my GPRS mobile plan.   Is there some way I can control which applications are allowed to use bandwith while on GPRS? Preferable only Opera should be able to use the network.   Thanks.


Physical intepretation of the absolute value of impedance

If \$\rm{Re}( Z)\$ gives the reactance of a circuit, then what is the physical meaning of \$|Z|\$? How do they differ, and when would one use one over the other? (Where \$Z\$ is the impedance of an arbitrary circuit)


If holding the charge on a touch spell, does getting hit do anything?

If you are  on a touch spell, will getting hit by melee, ranged attack, or spell dissipate the spell you're holding?  If it's a melee attack, does the attacker feel the effects of the spell you are holding?


If $p$ be a prime and r be any integer, $0 < r < p$ then $\frac{(p-1)!}{r!(p-r)!}$ is an integer.

Let $p$ be a prime and $r$ an integer, such that $0 < r < p$. Show that $\frac{(p-1)!}{r!(p-r)!}$ is an integer.     The given number is $ \displaystyle\frac{1}{p}\binom {p} {r}$. after tha how can I show that$p$ divides the given binomial coefficient. can somebody help me please.


why a Triangular Matrix can be not Diagonalizable

we can turn every triangular matrix to a diagonal matrix with elementary Matrices. So; How can it possible to have a matrix which is similar to a triangular matrix but not to a diagonal matrix.    in addition, what is the best trick to know if a matrix is diagonalizable or not?


I broke an LCD tv screen, could it be dangerous?

I accidentally broke my TV(Strange circumstances led to a cracked screen. I've read that it can be dangerous and deadly because there could be something called MBBA inside. It's an LG smart TV (I don't know the model or anything, it's my parents...) but it cracked and there's supposed to be liquid crystal inside. Is it dangerous? Nothing is leaking out yet, but should I get the TV out of the house? It's pretty late, and I'm tired(I've been up all night cleaning bc relatives are coming over soon) and I want to go to bed. Can I leave it in the house overnight? Please answer quickly, I want to go to sleep.


How to both edit and close in the Review queue?

Quite often I come across questions that need both editing and closure.  When this is from the Review Queue as soon as I am done editing (or closing) the queue jumps to the next question, so if I want to do both I either have to find the question again, or I had to have the foresight to open a copy in a new tab so I can complete the review process.  What is standard procedure for both editing and closing a question in the Review Queue?  If there is nothing easier than what I am doing I shall turn this into a feature request.


How to determince convergence and divergence of

How to determine convergence and divergence of $a_n =\sqrt[\Large^n]c$ ?


Does lower resolution result in better signal-to-noise ratio, given the same sensor size?

With the release of the Canon EOS R5/R6, there have been many saying that they prefer the 20MP R6 camera over the 45MP R5 camera, due to its lower price but also because of "better low-light performance." In camera comparison sites, I've also seen the sentiment that bigger pixels (lower resolution) = better low light performance. However, is this a myth? Here is my reasoning for this. Let's say that there are two full-frame sensors, one 20MP sensor and a 80MP sensor. According to many people, the 80MP sensor would be terrible for low-light photography since the pixels are smaller. However, each 2x2 block in the 80MP sensor could be mapped, and in post averaged to a 1x1 pixel, effectively making the image into a 20MP image. This could also be done in-camera as an option. Would this image have just the same amount of usable information as the image from the 20MP sensor? In other terms, since both sensors are 35mm sensors (i.e. equal area), the amount of light falling onto the sensor is the same. So, at the end of the day, there will be no difference between a 20MP image and a 20MP image that has been downsampled from 80MP, right? So their low-light performance would be the same. You even get an advantage from having the option to get 80MP photos if you wanted. Why do people say that a lower-resolution camera has better low-light performance, when it should theoretically be the same as one with higher resolution (all other factors equal)? Note: this question is about sensors with the same size but with different pixel density. Hence, it is different from  asking about different sensor sizes. I am aware that a full-frame camera will have better low-light signal due to its bigger area than an APS-C sensor, but what about the similarly sized sensors?


Should the surname 'de Menezes' be capitalised on beginning a sentence?

(Keir Starmer's entry, the UK Labour Party Leader) has the following :  Within the first few months of his tenure, Starmer upheld the decision not to prosecute the officers who had killed Jean-Charles de Menezes in a High Court appeal lodged by the family.   de Menezes was shot dead by police in 2005 after he was mistaken for a suicide bomber.  I would have expected 'de Menezes' to be capitalised to 'De Menezes' at the beginning of a sentence. Am I wrong ?


Rules for affiliation for student doing unpaid research in his/her free time?

Lets say an undergraduate student does some research in his/her free time and wants to write a paper about the findings. What are the rules regarding affiliation when the student tries to publish?   The student is required to include the university as affiliation, because he/she is enrolled in a program at the university The student is not allowed to include the university as affiliation, because he/she is not officially hired/approved to do research under the name of the university There are no rules, the student can choose ...?   I guess for graduate students / postdocs / professors it is mandatory to include the university as affiliation, as they get paid by the university to do the research they are doing!?


Deep confusion with conventions and signs in geometric optics

This is an equation given in my book.     The question is why have they used a negative sign on the LHS?   Now, if you try to derive the mirror equation with simple geometry, you get  1/v +1/u =1/f . I got that equation without applying any signs there!  So what is the need to apply the signs ‘here'?   If i try to derive this equation ( the one in the photo ) i get the exact answer, but with the positive sign in the LHS. WHY we use the negative sign in the derivation, and then  again we use conventions while solving the questions?


I know it is possible to protect file from printing with Adobe tools, but is this done on latex layer or with pdf tools? And is it also possible to protect created pdf file with password in following situation: I have latex document, that is intended for customer (as pdf) and I am afraid customer will not pay me for this document. What I want is that the customer will be able to open and review file only first time, and then the pdf locks with password I've preset. Is this possible?


Proof by induction that $a_0 = 1, a_1 = 1, a_n=2a_{n-1} + 3a_{n-2}$ satisfies $a_n = \frac12 (3^n) + \frac12 (-1)^n$

The question: The terms of a sequence are given recursively as  \begin{cases} a_0 = 1,\\ a_1 = 1 \\a_n=2a_{n-1} + 3a_{n-2} \quad\text{ for } n \geq 2  \end{cases} prove by mathematical induction $a_n = \frac12(3^n) +\frac12(-1)^n$ for all $n \geq 0$  I've started by proving that the formula works e.g $$a_0= 1\implies a_0 = \frac12(3^0)+\frac12(-1)^0 = 1 \\a_1=1\implies a_1 = \frac12(3^1) + \frac12(-1)^{1} = 1$$  Therefore $p(1)$ and $p(2)$ are true  Now I have to do the hard part.. the inductive step suppose $p(1), p(2),\ldots, p(k)$, that is $a_{k+1} = 2a_{k} + 3a_{k-1}$ Im not sure where to really go from here.


Copied from    The problem  Suppose we have two shapefiles that should border seamlessly. Only, they don't. Is there a way to force them to stick to one another without gaps?      The specific case  I have two shapefiles: one for European regions -- REG, the other for the neighbouring countries -- NEI. Both shapefiles are taken from  and should fit together nicely; but there are small gaps. Also, I need to simplify the polygons, and then the gaps become really notable.       The best I can think of  I've tried several approaches but with no success. The only way to achieve the desired result that I see requires following steps:   create a line sf with just the border between my shapefiles; from this line create a buffer polygon just big enough to cover all gaps; join and dissolve this buffer to the shapefile for neighbours -- NEI; clip off the expanded NEI with the REG shapefile.   Obviously, this is a rather clumsy workaround.    Is there a better way to go?    Reproducible example in     A minimal example  # install dev version of ggplot2 devtools::dev_mode() devtools::install_github("tidyverse/ggplot2")  library(tidyverse) library(sf) library(rmapshaper)  library(ggthemes)   # load data source(file = url("https://gist.githubusercontent.com/ikashnitsky/4b92f6b9f4bcbd8b2190fb0796fd1ec0/raw/1e281b7bb8ec74c9c9989fe50a87b6021ddbad03/minimal-data.R"))  # test how good they fit together ggplot() +          geom_sf(data = REG, color = "black", size = .2, fill = NA) +         geom_sf(data = NEI, color = "red", size = .2, fill = NA)+         coord_sf(datum = NA)+         theme_map()  ggsave("test-1.pdf", width = 12, height = 10)  # simplify REGs <- REG %>% ms_simplify(keep = .5, keep_shapes = TRUE) NEIs <- NEI %>% ms_simplify(keep = .5, keep_shapes = TRUE)   ggplot() +          geom_sf(data = REGs, color = "black", size = .2, fill = NA) +         geom_sf(data = NEIs, color = "red", size = .2, fill = NA)+         coord_sf(datum = NA)+         theme_map()  ggsave("test-2.pdf", width = 12, height = 10)


How do I get out of my problem of not achieving results, feelings of worthlessness, guilt and rejection?

I am currently a PhD student in a biomedical related field. I came a long way. I first did my undergraduate and worked for a few years, though not research related. Later, I identified my research interest before embarking in the PhD with the hope of fulfilling my career dreams. I used to love and enjoy science, but that was long ago. I was happy when I got into the PhD program. Now I'm nearly 2 years into my study, mostly 'wet' lab and basic sciences research.    Unfortunately, my experiments - most of them - fail. Initially, that was due to lack of skills and experience - with time things have improved but I am still lacking good results that can give clear direction in my work. My project has been modified a few times because initially there were problems with the biological samples so I had no choice. Then, I tried to 'reproduce' a piece of result done by a colleague few years ago but the results were always 'off' no matter how many times I did it. Even someone else with better experience in the lab tried but could not replicate the same result. The conclusion was perhaps, change in phenotype of biological samples over time. Then my project changed again, and the technique is now becoming more complicated and 'taxing'. Partly, because my supervisor is not very happy and feels that it is time I should be producing good data and should aim for higher impact. With more complicated experiments, I also need to beef up my basic sciences knowledge but as someone coming from a different background it is taking me extra time to grasp. With my confidence going in a downward spiral.    I am finding more and more difficult to articulate my thoughts clearly to my peers and I feel constant 'rejection' and 'guilt'. Most of my colleagues are actually good people, but harsh words, although not ill-meaning, are slowly eroding my confidence. When I ask questions because there is something that I don't fully understand (without prior knowledge and not something I can read up on), people appear impatient and ask back (e.g. "why are you asking?",  "what do you think?", or just "I can't give an answer to you on this"). It feels more and more difficult for me to ask questions or speak up for myself.    One day, I was blamed for something (from someone outside the lab) that I didn't even do. The accusation was pretty unreasonable - others who witnessed the event felt the same - but to me I felt I was just a bully target. I just broke down and cried because I realized I couldn't take the stress and frustration of rejections and failure. My friend in the same lab gave me some counseling but also at the same time asked me whether working in this lab is truly what I want to do. I don't want to quit my PhD, but then again I don't know how I can get out of this situation.     Should I change project? But my PhD qualifying exam is coming up and I am having a massive problem with writing up a good proposal because of all the frustrations happening.   Should I change to dry lab? I am afraid of talking to my mentor because I don't know whether at my current mental state I'll just suddenly break down again.    In summary, my resentment and contradictory statements that I receive:     Ideology: To do a PhD, perseverance is more important than being smart. Reality: You need to be smart. REALLY SMART.  Ideology: There's not such thing as a stupid question. Ask if you don't understand. Reality: Huh? Why do you even ask?


hashCode and equals relationship with String

String s1 = new String("abc");//it is created at heap area String s2 = "abc";//it is created string constant pool  System.out.println(s1==s2);//false System.out.println(s1.hashCode());same hashCode System.out.println(s2.hashCode());same hashCode   The last two lines give the same hashCode(), but the objects are different.while creating s1 object it create in heap area and s2 object is create in string constant pool.but both are gives same hashCode.i.e my doubt?


How can one decide whether to use the compound form of a word when the one- or two-word versions are acceptable?

This question is an attempt to find an abstract answer to every "one word or two?" discussion.  My problem is exemplified by this scenario: My text editor's spellchecker recently corrected me on my use of "video game" because it felt "videogame" was proper. Searching the Internet, however, led me to feel "video game" was proper, despite there being many credible sources using "videogame". As I'm writing this now, the spellchecker in my browser wants me to use "video game".  Along my search, I found a quote in a forum from a Wired magazine editor saying they always join words whenever possible. That person credited their book, "Wired Style: Principles of English Usage in the Digital Age", for that decision. I thought this was interesting.  It seems it's up to me to decide what form I want to use. How can I make such a decision? What factors should I consider?


How can you prove that the square root of two is irrational?

I have read a few proofs that $\sqrt{2}$ is irrational.  I have never, however, been able to really grasp what they were talking about.  Is there a simplified proof that $\sqrt{2}$ is irrational?


I'm very new to C++. From examples, I find this use of sizeof in order to retrieve the length of an array  int main() { int newdens[10]; // the first line returns 10 which is correct std::cout << "\nLength of array = " << (sizeof(v1)/sizeof(*v1)) << std::endl; std::cout << "\nLength of array = " << (sizeof(v1) << std::endl; //returns 40 std::cout << "\nLength of array = " << (sizeof(*v1)) << std::endl; //returns 4     }   But if i wrote a function like this   #include <iostream>  void myCounter(int v1[])     {     int L, L2, L3;     L = (sizeof(v1)/sizeof(*v1));      L2 = (sizeof(v1));      L3 = (sizeof(*v1));      std::cout << "\nLength of array = " << L << std::endl;     std::cout << "\nLength of array = " << L2 << std::endl;     std::cout << "\nLength of array = " << L3 << std::endl;      }  int main() { int v1[10];  std::cout << "\nLength of array = " << (sizeof(v1)/sizeof(*v1)) << std::endl; std::cout << "\nLength of array = " << (sizeof(v1)) << std::endl; std::cout << "\nLength of array = " << (sizeof(*v1)) << std::endl;  myCounter(v1);     }   the outputs are L=2, L2 = 8, L3 = 4. I can't understand where the problem is.  How to retrieve the correct lenght of v1 inside the function?


How to seal a pipe pass-through in a basement wall

My house is 15 years old, and ground water has suddenly started to leak into the basement around a pipe that passes through the poured concrete foundation.  The method of installation complicates the repair. Situation An iron pipe sleeve (roughly 4"D), is sealed to the wall with spray foam.  A 3" PVC drain pipe passes through the sleeve, with more foam sealing between it and the sleeve. Leakage There aren't signs of leakage between the two pipes, it's all between the sleeve and the wall.  There appear to be small leaks between the foam and the concrete.  However, much of the water enters around the sleeve, between it and the foam. I cut away most of the foam to find the source.  Some pieces cleanly separated from the concrete, indicating that it wasn't bonded.  Around the sleeve, all the foam cleanly pulled off. Embedded in the foam was a layer of black.  It looks like water rusted its way down the sleeve.  The surface of the pipe remained bonded to the foam, and water leaked under that.  There is some powdery residue on the pipe that's a mixture of black and some rust color.  The sleeve otherwise seems virtually intact. Issues  I can try to remove the rust in the exposed area, but the sleeve will rust again, making it hard to do a permanent repair. The foam didn't make a permanent seal with some of the concrete, making me wonder whether it's suitable for this application. Trying to seal with hydraulic cement will require grinding away all traces of foam for it to bond well with the concrete wall.  The area doesn't have great work access, so this would be difficult, messy, and involve risk of damaging surrounding plumbing.  Also, can you even use cement on iron (thinking rebar issues)? My understanding is that the purpose of the sleeve is to facilitate servicing the pipe if needed.  An approach like encapsulating the opening with epoxy would require bonding to the PVC pipe to be permanent. The exterior of the wall is inaccessible; all work must be done on the inside.  Solution? Is there a good, permanent solution?  What I've considered:  I could just clean it up and apply new foam.  Hopefully it would hold for another 10-15 years (and maybe become someone else's problem). I could clean it up and use hydraulic cement to seal it.  That would be a lot more work, and also temporary because of new rust. I could encapsulate the opening in epoxy.  If I ever need to service the pipe, just deal with it then. I could try to seal the hole by injecting Gorilla Glue around the sleeve as far as possible into the hole (syringe with long needle).  That expands as it hardens, after which foam (or cement?) could be added to further seal it.  That might prolong the time until another repair is needed. Wrap the pipe with self-fusing silicone repair tape, and then fill around it with hydraulic cement (no idea whether it would work). I can't think of another material that is waterproof and permanent, cures in the presence of water, stays put while curing under pressure, and bonds with wet surfaces.   Pictures The location is blocked by a utility sink and a water heater, so it's difficult to get at the pipe, to see what you're doing or work on it, and to take pictures.  There are actually two pipes running through the wall in this location.  To the left of the subject pipe is the water line.  Some of the concrete around the two pipes was broken away at construction time; that was all filled with foam before I removed it.  There's still some remaining above each pipe sleeve.  There's also some leakage around the water line sleeve due to gaps in the sealing foam; that one isn't an issue because the sleeve is PVC and sealing that one is straightforward.  This view is the right side of the problem pipe.


I have a server running ubuntu server. It is behind a proxy...I don't know if that makes a difference. But I have found that a couple of processes I've tried, get terminated when I log out of the SSH session. For instance, I have ipython notebook server and a Mongod server processes running on that server. Whenever I logout, both of these processes die even though they are run in the background with &  I have recently discovered the nohud command which works fantastically. However, why is it that I have not encountered this with most servers? Is there some sort of default in unbuntu server that kills all processes by a user when they hangup from SSH? Can I run nohud by default for all processes?  Thank you


How do I get the "accordion" effect for input parameters in a Custom Tool?

I want to get the "Accordion" effect you find in the some tools dialog boxes in my own Python Script tool.  I can't find anything on the ArcGIS Resources website about this.  An example is shown below:    I am referring to the feature shown in "Additional Model Parameters" and the other additional toolsets.


Properties of logs. Why does the log of a power, does the exponent become a coefficient?

I'm having trouble seeing number 3 clearly. Or rather, I'm having trouble seeing a proof. I've tested a series of numbers and it works, but I'm having trouble seeing why. Can anyone clarify?    Here is where I get confused:  I start with this log:  $$ \log_2 4^1 = 2$$  now if I raise both sides to the 2nd power then:  $$ \log_2 4^{1^2} = 2^2$$ $$ = \log_2 4^2 = 4$$ $$ = 2 \cdot \log_2 4 = 4$$  but if I raise both sides to the power of 1.5 then: $$ \log_2 4^{2 \cdot 1.5} \ne 4^{1.5} \ne 8$$


I tried to write my code with and without the syntax "@Override", and both times I receive the same output. Therefore, why should I bother to write the syntax "@Override" before my method in the subclass?  With:   Without:


Python: Is it possible to setup a folder trigger?

I would like to monitor the directory using python. Whenever there is a new file the program will notify the user.  Current I am using a loop, which run os.listdir, to poll the directory regularly. However this is very inefficient. Is there any way that I could setup some software trigger (in Python) to enhance the efficiency?  Thanks in advance


How to solve these $3$ equations for three unknowns $x$,$y$,$z$?

Question:  Solve:  $xy+x+y=23\tag{1}$  $yz+y+z=31\tag{2}$  $zx+z+x=47\tag{3}$  My attempt:  By adding all we get   $$\sum xy +2\sum x =101$$  Multiplying $(1)$ by $z$, $(2)$ by $x$, and $(3)$  by $y$ and adding altogether gives  $$3xyz+ 2\sum xy =31x+47y+23z$$  Then, from above two equations after eliminating $\sum xy$ term we get   $$35x+51y+27z=202+3xyz$$  After that subtracting $(1)\times 3z$ from equation just above (to eliminate $3xyz$ term) gives   $$35x +51y-3z(14+x+y)=202\implies (x+y)[35-3z]+16y-42z=202$$  I tried pairwise subtraction of  $(1),(2)$ and $(3)$ but it also seems to be not working.  Please give me some hint so that I can proceed or provide with the answer.


Panasonic/Leica 15mm 1.7 vs DJI 15mm 1.7

Is the DJI as sharp as the Leica on a OMD E-10 Mark II ?


There is a sentence in my book     It was me that raised the alarm   I am completely  confused with this construction. "I" is used with it but here "me" is placed.   Second confusion is "who" is used for living things but here "that" is used.   Is it grammatically correct? If yes please explain to me.


Why are .deb packages of hplip not sufficient?

I'm using a HP Laserjet Pro M28a with Ubuntu 18.04. Printing is fine, but I couldn't get the scanner portion to work for quite a while. I've installed the Debian packages for HPLIP 3.17.10 (official repo), then 3.19.8 (PPA) and finally 3.19.11 (other PPA).  Scanner still didn't work. Out of desperation, I've run sudo hp-plugin -i as suggested in other SO posts and suddenly the scanner works, too.  Unfortunately, this script has now dumped a bunch of unowned binaries into my filesystem, specifically:  /usr/lib/sane/hpgt2500_ntdcmsdll-x86_64.so /usr/lib/sane/libsane-hp2000S1-x86_64.so.1.0.25 /usr/lib/sane/libsane-hpgt2500-x86_64.so.1.0.27 /usr/lib64/sane/hpgt2500_ntdcmsdll-x86_64.so /usr/lib64/sane/libsane-hp2000S1-x86_64.so.1.0.25 /usr/lib64/sane/libsane-hpgt2500-x86_64.so.1.0.27 /usr/local/lib/libjpeg-x86_64.so.9.2.0 /usr/share/hplip/data/firmware/hp_laserjet_1000.fw.gz /usr/share/hplip/data/firmware/hp_laserjet_1005_series.fw.gz /usr/share/hplip/data/firmware/hp_laserjet_1018.fw.gz /usr/share/hplip/data/firmware/hp_laserjet_1020.fw.gz /usr/share/hplip/data/firmware/hp_laserjet_p1005.fw.gz /usr/share/hplip/data/firmware/hp_laserjet_p1006.fw.gz /usr/share/hplip/data/firmware/hp_laserjet_p1007.fw.gz /usr/share/hplip/data/firmware/hp_laserjet_p1008.fw.gz /usr/share/hplip/data/firmware/hp_laserjet_p1009.fw.gz /usr/share/hplip/data/firmware/hp_laserjet_p1505.fw.gz /usr/share/hplip/data/firmware/hp_laserjet_professional_p1102.fw.gz /usr/share/hplip/data/firmware/hp_laserjet_professional_p1102w.fw.gz /usr/share/hplip/data/firmware/hp_laserjet_professional_p1566.fw.gz /usr/share/hplip/data/plugins/license.txt /usr/share/hplip/fax/plugins/fax_marvell-x86_64.so /usr/share/hplip/plugin.spec /usr/share/hplip/prnt/plugins/hbpl1-x86_64.so /usr/share/hplip/prnt/plugins/lj-x86_64.so /usr/share/hplip/scan/plugins/bb_escl-x86_64.so /usr/share/hplip/scan/plugins/bb_marvell-x86_64.so /usr/share/hplip/scan/plugins/bb_orblite-x86_64.so /usr/share/hplip/scan/plugins/bb_soap-x86_64.so /usr/share/hplip/scan/plugins/bb_soapht-x86_64.so   I assume there is some stupid HP license stuff that prevents these files from being packaged regularly, but is there any dpkg-based way to either install or at least properly manage these files? I'm particularly annoyed by the extra JPEG library in /usr/local/lib, this is a surefire way to mess up some totally unrelated package down the road...  Note: I'm not asking how to install the HP plugins, I've already done that. I'm asking how to avoid a future mess with unowned libraries in the system lib directories.


How can I run original command that aliased with same name?

An alias for ls command in ~/.bashrc file aliased with this one:  alias ls='ls --color=auto'   then, when I run ls command in terminal aliased ls(ls --color=auto) runs. but my question is how can I run original ls only and only ls alone without extra argument and without solving problem with deleting aliased entry? since when I delete this entry I can run it in simple ls.


I am booked to go from Dublin to Hong Kong with Turkish airlines with a stopover in Istanbul.  There is a long layover, and I was wondering if anyone knows if I can leave the airport and head into Istanbul itself, and if so, is 7 hours long enough?


Introduction  Okay, I've almost won my war. The battle, its almost won... However, I must still claim victory in my final battle. The battle against the little enemies, the ones that have fought with my blade of benzoyl peroxide every single day.  Problem  Through spot treatments I have been able to fell every single one of these spots, but only the ones on my face. I've been using a spot treatment with benzoyl peroxide in, which has worked really well for me. However, my issue comes here:     There are spots underneath my skin, I think. The areas where they come through are a bit red.   So, because there is still slightly red skin on my face, and I think this is causing my acne to constantly return. I need to stop this, and end my war once and for all.  What I've tried   Washing my face with a rag and sponge every day, three times a day Changing my pillow case every day Using a benzoyl peroxide spot treatment Minimizing how much I touch my face Not interfering with the spots with my fingers, not picking at them, not playing with them. Just letting spot creams eradicate them.   Conclusion  Seriously, this driving me up the wall. I spot cream in the evening, by the time tomorrow has ended and its time for a shower, they've all come back. Its like they're coming in waves, damn waves! I must put an end to this.  So, how can I prevent acne from coming back within the space of a single school day? How can I get rid of these once and for all? What types of measures could I try? I have no reason to visit my doctor, its only acne, but I have no idea what I can try now.  Is there even a point in me trying? I acknowledge that I am a teenager, but no others that I know seem to have acne/spots like I do.


Request different entry clearance officer

Is it possible for me to request for a different entry clearance officer to review my UK visa application after a prior visa refusal and would that in any way have an adverse effect on the outcome of my application .


Drawing a perpendicular line with the package tkz-euclide

How to draw a perpendicular line from "P" to segment "AB"?    Here is the code:  \documentclass{standalone} \usepackage[utf8]{inputenc} \usepackage{tikz,tkz-euclide,xcolor,graphicx} \usetkzobj{all}  \begin{document} \tikz{ \coordinate(A)at(0,0); \coordinate(B)at(5,0); \coordinate(P)at(3.7896542,3);  \draw[thick](A)--(B);  \tkzDrawPoint[color=red](A)  \tkzLabelPoint[below=2pt](A){$A$} \tkzDrawPoint[color=red](B)  \tkzLabelPoint[below=2pt](B){$B$}   \tkzDrawPoint[fill=yellow](P)  \tkzLabelPoint[above=2pt](P){$P$} }  \end{document}


Finding the most common genre for "eMovies"

Given database of the website "eMovies" that manage data about cinema movies.      Write in SQL query the most common genre (that have the biggest number of movies)   The tables:  Actors      ActorID      PK     Firstname      LastName  Directors      DirectorID   PK     Firstname      LastName  Genres      GenreID      PK     GenreDescr   Movies      MovieID      PK     MovieName      Year  ActorsMovies      MovieID      PK     ActorID      PK   DirectorsMovies      MovieID      PK     DirectorID   PK   GenresMovies      MovieID      PK     GenreID      PK    My attempt:   SELECT GenresDescr  FROM GenresMovies  NATURAL JOIN Genres  WHERE GenresMovies.GenresID=Genres.GenresID  GROUP BY GenreDescr  HAVING  MAX(COUNT(GenresMovies.MovieID));   I'm stuck, my code does not work.       EDIT: attampt number 2 after using @Darwin von Corax hint:     SELECT Genres.GenreDescr,COUNT(GenresMovies.GenreID) AS MCount   FROM GenresMovies,Genres   WHERE GenresMovies.GenreID = Genres.GenreID   GROUP BY GenresMovies.GenreID,Genres.GenreDescr   HAVING MCount=MAX(MCount);      But still the code does not work


Do i have to use the word 'the' in front of ultimate in a sentence?    For instance; You have the power to customize your environment for the ultimate aural enhancement.  Or; You have the power to customize your environment for ultimate aural enhancement.


Wilcox.test for testing count based data in R studio large W

I'm doing a textmining project about a videogame review dataset. I divided de reviews into a positive (reviewgrade > 8) and negative (reviewgrade < 3) and want to draw conclusions based on the frequency of different grading factors mentioned in the text. I now have a dataframe with counts of certain categories mentioned per review.  0    13249 1     1565 2      292 3       65 4       19 5        6 6        4 7        3 8        2 9        1 Name: positive: gameplay, dtype: int64   0    5043 1     348 2      66 3      18 4       8 5       3 Name: negative: gameplay, dtype: int64   For example this are the distributions of the amount of reviews which have a certain amount of mentions of gameplay related words. There are for example 1565 reviews with precisely 1 mention of a word related to the category gameplay. Now I want to use this data to determine if on average gameplay gets mentioned more in negative context than in positive or vice versa. Because the data is not normal distributed, I assumed a t-test is not appropriate, and found online that a Mann–Whitney U test might be suitable.  > wilcox.test(positive$gameplay, negative$gameplay, alternative = "two.sided", conf.int = TRUE)      Wilcoxon rank sum test with continuity correction  data:  positive$gameplay and negative$gameplay W = 43702925, p-value < 2.2e-16 alternative hypothesis: true location shift is not equal to 0 95 percent confidence interval:  2.963844e-05 4.797412e-05 sample estimates: difference in location            4.995671e-05    I do however get a very high W value, which doesn't seem to be correct.  Is this not the appropriate test, or am I interpreting this wrong?


Is Carnot engine the only reversible engine?

Is Carnot engine the only form of reversible engine? Is it possible to have a different form of reversible engine that goes through different processes?  For a standard Otto cycle working with ideal gas, theoretically the two processes involving isochoric pressure change can be reversible processes. Does it mean that the Otto cycle can also have same efficiency as Carnot cycle? Since temperature of the working fluid is changing during isochoric pressure change, does it mean there are infinite number of heat reservoirs being used at different temperatures so that there is no finite temperature difference at every point of the isochoric process?


Create an AutoCompleteTextField with javafx

I'm trying to set up an AutoCompleteTextField. I'm using Callback> versionCollection.  Here is my code :   Callback<AutoCompletionBinding.ISuggestionRequest,Collection<T>> versionCollection = null; for (Object name : this.fixVersionModel.getFixVersions().keySet()) {     versionCollection.add((String) name); } TextFields.bindAutoCompletion(this.autoCompleteTextField, versionCollection)   I get a stupid error while my collection isn't initialized. Is there no better solution to make an AutoCompleteTextField? If no, could someone help me with my code ?  Thank you.


In MTG, what happens when a player loses in multiplayer?

In Magic: The Gathering, the rules for a player losing in a multiplayer game are quite complex, so I'd like to try to understand them by example. I would be happy to ask each of these situations as a separate question if that is preferred, but they all seem related, and I would love to have one place to look up all of these answers.  Let's say I'm playing with two friends, Bob and Chloe, in a simple free for all. Unfortunately, I lose. When I lose, suppose the following:   I controlled an  which has exiled Bob's , does he get his bear back? I have a  on the stack targeting Chloe, does Chloe take the 2 damage still? Earlier in the turn I cast  to prevent damage to one of Bob's . If it later takes 3 damage, will that damage be prevented? Something I controlled gave Bob a 1/1 soldier token. What happens to the token? Something Chloe controlled gave me a 1/1 soldier token. What happens to the token? I had a  enchanting one of Bob's army of . What happens to the bear? I had also played  on Bob's final . What happens to the last bear? Chloe had  my . What happens to the Clone? Are there any other situations specifically addressed by the rules?


I'm getting NullPointerException when trying to access a textbox element which I'm referred from POM file. Please help me to resolve this error

I'm trying to learn the framework structure of Selenium with Page Object model framework. Even though I pass the webdriver instance, I'm getting NullPointerException when trying to access a textbox element which I'm referred from POM file. I'm trying to launch a page and entering text in the textbox.  testBase.java for launching Chrome browser  package TestBase; import org.openqa.selenium.WebDriver; import org.openqa.selenium.chrome.ChromeDriver;  public class testBase {     public static WebDriver driver;     public static WebDriver initDriver()     {         System.setProperty("webdriver.chrome.driver", "C:/Users/edksuresh/Downloads/chromedriver.exe");         driver = new ChromeDriver();         driver.manage().window().maximize();         return driver;     } }   'Object repository file'  package pom; import org.openqa.selenium.WebDriver; import org.openqa.selenium.WebElement; import org.openqa.selenium.support.FindBy;  public class POM_LoginPage {     public WebDriver driver;     @FindBy(xpath="//input[@id='email']")     public WebElement uid;     public POM_LoginPage(WebDriver wd)     {         this.driver = wd;     } }   Registration.java  package generalComponent; import org.openqa.selenium.By; import org.openqa.selenium.WebDriver; import TestBase.testBase; import pom.POM_LoginPage;  public class Registration {     WebDriver driver;     String url;     POM_LoginPage pomLogin;     public Registration(WebDriver wd)     {         this.driver = wd;     }     public void launchPage()     {         driver = testBase.initDriver();         pomLogin = new POM_LoginPage(driver);         url = "http://demo.automationtesting.in/";         driver.get(url);         pomLogin.uid.sendKeys("sss@gg.com");     } }   NullPointerException is thrown at line pomLogin.uid.sendKeys("sss@gm.com").


What is the conventional directory to keep shared scripts that might be used by more than one user?  I've read through  of the standard file system hierarchy, but it doesn't seem to recommend a location for storing shared scripts.  Creating a /opt/scripts directory seems like a reasonable option, but I'd like to know if there is a standard UNIX convention for this.


Error upon booting Ubuntu in Virtualbox - SMBus error

I used to have a different PC, with Ubuntu on it. That PC broke, so I wanted Ubuntu back, but not fully on my laptop. So, I installed Virtualbox, followed all steps. But at boot, I get   The regular VB boot-up.  The purple Ubuntu screen w/ a man at the     bottom next to a keyboard A black screen w/ a blinking cursor Another purple screen with text saying: Ubuntu 14.04, and small dots     under it After about a minute, some text will show saying:     I can't figure out what to do. I've been to many links, also this (which was most suggested):  But the steps aren't clear. I can't get TO the OS, I can only see this at boot-up.  Thanks in advance.  Edit: I found that if I leave it, it eventually gets into the OS. Any steps from there?


Example 80 in Steen-Seebach1 is called Arens Square. It is defined in the book as follows:     Let $S$ be the set of rational lattice points in the interior of the unit square except those whose $x$-coordinate is $\frac12$.    Define $X$ to be $S\cup\{(0,0)\}\cup\{(1,0)\} \cup \{(\frac12,\sqrt2r); r\in\mathbb Q, 0<r\sqrt2<1\}$.   We define a basis for a topology on $X$ by granting to each point of $S$ the local basis of relatively open sets which $S$ inherits from the Euclidean topology on the unit square, and to the other points of $X$ the following local bases:   \begin{align*} U_n(0,0) &= \{(0,0)\} \cup \{(x,y); 0<x<\frac14, 0<y<\frac1n\},\\ U_n(1,0) &= \{(0,0)\} \cup \{(x,y); \frac34<x<1, 0<y<\frac1n\},\\ U_n(\frac12,r\sqrt2) &= \{(x,y); \frac14<x<\frac34, |y-r\sqrt2|<\frac1n\} \end{align*}   The authors claim that:     With this topology $X$ is $T_{2½}$.    This may be seen by direct consideration of cases noting that neither any point of $S$ nor $(0,0)$ nor $(0,1)$ may have the same $y$ coordinate as a point of the form $(\frac12,r\sqrt2)$.   A  or $T_{2½}$-space is a space in which any two distinct points can be separated by closed neighborhoods. (I.e., they have disjoint closed neighborhoods. In Steen-Seebach such spaces are call such spaces completely Hausdorff. As far as I can say, the name Urysohn space is more frequent.)  The problem I see with the above claim is the following: Let us take two points $a=(\frac38,y)$ and $b=(\frac58,y)$, $y\in\mathbb Q$, which have the same $y$-coordinate and belong to the "middle part". If we take any neighborhoods $O_a\ni a$ and $O_b\ni b$ then they contain neighborhoods of the form $B(a,\frac1n)\cap S$, $B(b,\frac1n)\cap S$ for some $n$. Now let $c$ be any point of the form $(\frac12,r\sqrt2)$ with $y-1/n<\sqrt2r<y+1/n$. Then every basic neighborhood of $c$ intersects these two balls and, consequently, it intersects $O_a$ and $O_b$. Which means that $c\in \overline{O_a} \cap \overline{O_b}$. So the points $a$ and $b$ do not have neighborhoods with disjoint closures.  What am I missing here? Or is it a mistake in this book? (In fact, the above problem was found by a colleague of mine. But since I was not able to answer his doubts, I decided to ask here.)  The authors also say that this is a modification of an example given in a paper by Hewitt. I had a look at that paper, but I did not find there exactly the same example as this one.        Hewitt [51] credits Arens with constructing an example of this type; we present a modified version, and then a simplified version.   Arens square is both semiregular and completely Hausdorff but not regular.         [51] Hewitt, E. On two problems of Urysohn. Annals of Math. 47 (1946) 503-509.    It is perhaps also worth mentioning that π-Base list this space as $T_{2½}$-space:   1 Lynn Arthur Steen and J. Arthur Seebach, Jr., . Springer-Verlag, New York, 1978. Reprinted by Dover Publications, New York, 1995.


Is having the same PTR hostname valid for multiple ip addresses?

Currently I have the following setup with two hostnames and two ips:  cheeze1.mydomain.com    IN  A   123.123.123.111 111.123.123.123.in-addr.arpa    IN  PTR cheeze1.mydomain.com  cheeze2.mydomain.com    IN  A   123.123.123.222 222.123.123.123.in-addr.arpa    IN  PTR cheeze2.mydomain.com   I want to change to having a round-robin dns for a single hostname using the two ips. Are the following PTR records valid? Can a host have multiple IPs and with each having valid reverse dns resolution?  cheezeonly.mydomain.com IN  A   123.123.123.111 cheezeonly.mydomain.com IN  A   123.123.123.222 111.123.123.123.in-addr.arpa    IN  PTR cheezeonly.mydomain.com 222.123.123.123.in-addr.arpa    IN  PTR cheezeonly.mydomain.com   EDIT: Please note that this question isn't asking the same as suggested in comments.   I'm going to answer this one myself, you guys are no help marking it as duplicate and not reading the question properly. Hopefully this answer will help others.  ANSWER:::  Yes, it is valid, and yes it will pass a FcRDNS check.  From the "Pro DNS and BIND" book:   An alternate approach is to define multiple A records with the same mail server name: ; zone file fragment         IN  MX  10  mail.example.com. .... mail    IN  A       192.168.0.4         IN  A       192.168.0.5         IN  A       192.168.0.6   In this case the load-balancing effect is under the control of BIND and the rrset-order record. In order to avoid problems if the receiving mail system does reverse look-up as a spam check then the PTR records for 192.168.0.4, 192.168.0.5, 192.168.0.6 above must all define (resolve to) mail.example.com.  And from RFC1912: Common DNS Operational and Configuration Errors   "For every IP address, there should be a matching PTR record in the in-addr.arpa domain. If a host is multi-homed, (more than one IP address) make sure that all IP addresses have a corresponding PTR record (not just the first one). Failure to have matching PTR and A records can cause loss of Internet services similar to not being registered in the DNS at all. " –   Therefor this configuration is valid and passes FcRDNS checks.


Restricting base map on specific extent in ArcGIS API for JavaScript 3?

Currently I am using ArcGIS JS API ver 3.3/3.5 in my application.  I want to restrict the basemap for US only .For example one can use default navigation features like zoom in, zoom out for the US Country only.  Trying following things:   I have set the US extent code in my application but when I zoom out then I can see the whole world map I want to restrict it to certain extent only Going through this question:  Restricting the streets basemap using this question, but unable to restrict the map:  I am using  sample map in my application.


How to change height of line break in math mode

How can I change height of line break in math mode? I need to add more space between each two lines of the equation.  \begin{gather*}     EFF_a = \sum_{j=0}^{2} (\frac{ \sum_{i=1}^{4} (EFF_{{a_j}_i} = {\{ p_i; q_i}\}  \rightarrow p_i \cdot q_i)}{ \sum_{i=1}^{4} q_i } \cdot W_{EFF_{a_j})} =     \\ = \frac{1 \cdot 15 + 2 \cdot 15 + (-1) \cdot 2}{15+15+2} \cdot 0.5 + \frac{1 \cdot 314 + 2 \cdot 101 + (-1) \cdot 33 + (-2) \cdot 4}{314+101+33+4} \cdot 0.4 +     \\ + \frac{1 \cdot 23 + (-1) \cdot 33 }{23+33} \cdot 0.1 = 1.0743718394437423 \end{gather*}   This produces:


Showing that $H_A\simeq H_{A'}$ implies $A\simeq A'$

I'm trying to solve this :    So we are given that for all objects $B$, there is a natural isomorphism $$H_A(B)\simeq H_{A'}(B)$$ Let's write this isomorphism as $f\mapsto \bar f$. The commutativity of the square tells us $$\overline{f\circ\phi}=\bar f\circ\phi$$ where $\phi:B'\to B$ is an arrow in $\mathscr A$. I don't see how to use that. I don't even see how to show that there exists an arrow $A\to A'$ (or $A'\to A$).


How to get a 1000 Mbps network using crossover cable

I am using a crossover cable to connect two computers. Despite having Gigabit LAN, they only provide me with 100 Mbps networking.  My question is whether is it possible to get 1000 Mbps networking using a crossover cable? If so, how?


When will my device get the Android 6.0 update (Marshmallow)?

Android "M" was officially announced on at the Google I/O conference on May 28, 2015 and revealed to be 6.0 Marshmallow on August 17, 2015.  You can review the high-level changes at the  and the announcement on the official .  Of course, not all devices will get this update right away and others won't get it at all. Each manufacturer and carrier often choose to add their custom modifications which tend to delay the official release.  When will each device get Android 6.0, either officially or unofficially, if ever?  See also:


What could/do applicants usually ask professors, and how does this reflect in a statement of purpose?

When applying for PhD programs (or  or ) that require only a statement of purpose and , I was advised to first check if some faculty members (or is one good enough?) in the university have the same research interests as I do. I remember reading or hearing something like, it may be helpful to read up on the research that those faculty members have done and possibly contact some of those faculty members, and then incorporate the reading and contacting in the statement of purpose.   So what could I ask those faculty members? What I think:      Hello Prof/Dr ___ .I'm interested in applying in your univ and am interested in X. Can I ask more about what you research? This is my  (I'm from blah blah blah. I have a master's, but it's in applied not pure math. I've done some self-study blah blah blah). Do you think I am a good fit for the university? Would you consider taking me on as a PhD student? Do you think I am better suited for MS/MPhil than a PhD?    And then how do I incorporate the e-mails in my statement of purpose?


I cannot open jp2-files with gdal:  This works fine (the Sentinel2 metadata):  ~/copernicus/S2A_MSIL2A_20170111T100351_N0204_R122_T33UWP_20170111T100351.SAFE$ gdalinfo MTD_MSIL2A.xml  Driver: SENTINEL2/Sentinel 2 Files: MTD_MSIL2A.xml Size is 512, 512 Coordinate System is `' Metadata:   AOT_RETRIEVAL_ACCURACY=0.0   BARE_SOILS_PERCENTAGE=0.000388   CLOUD_COVERAGE_ASSESSMENT=0.1018   CLOUD_COVERAGE_PERCENTAGE=0.001909   CLOUD_SHADOW_PERCENTAGE=0.389902   DARK_FEATURES_PERCENTAGE=6.691170 [...]   But this not (one of the jp2 files):  ~/copernicus/S2A_MSIL2A_20170111T100351_N0204_R122_T33UWP_20170111T100351.SAFE/GRANULE/L2A_T33UWP_A008127_20170111T100351/IMG_DATA/R10m$ gdalinfo L2A_T33UWP_20170111T100351_B02_10m.jp2 ERROR 4: `L2A_T33UWP_20170111T100351_B02_10m.jp2' not recognized as a supported file format.  gdalinfo failed - unable to open 'L2A_T33UWP_20170111T100351_B02_10m.jp2'.   I am using Anaconda 4.3.11 and created an environment with Python 2.7.13. I want to open jp2-Files which are part of the Sentinel L2A-Product (converted from L1C with sen2cor).   I've installed openjpeg 2.1.0 and gdal 2.1.0 via "conda install":  > conda list  # packages in environment at /home/roland/anaconda2/envs/copernicus: # curl                      7.49.0                        1 gdal                      2.1.0                    py27_0 geos                      3.5.0                         0 geotiff                   1.4.1                         0 hdf4                      4.2.12                        0 hdf5                      1.8.17                        1 jbig                      2.1                           0 jpeg                      8d                            2 kealib                    1.4.6                         0 libgdal                   2.1.0                         0 libnetcdf                 4.4.1                         0 libpng                    1.6.27                        0 libtiff                   4.0.6                         2 mkl                       2017.0.1                      0 numpy                     1.12.0                   py27_0 openjpeg                  2.1.0                         5    sunpy openssl                   1.0.2k                        0 pip                       9.0.1                    py27_1 proj4                     4.9.2                         0 python                    2.7.13                        0 readline                  6.2                           2 setuptools                27.2.0                   py27_0 sqlite                    3.13.0                        0 tk                        8.5.18                        0 wheel                     0.29.0                   py27_0 xerces-c                  3.1.4                         0 xz                        5.2.2                         1 zlib                      1.2.8                         3   The main problem seems to be that I don't manage to install the JPEG2000-driver:  > gdal-config --formats gxf gtiff hfa aigrid aaigrid ceos ceos2 iso8211 xpm sdts raw dted mem jdem envisat elas fit vrt usgsdem l1b nitf bmp airsar rs2 ilwis rmf leveller sgi srtmhgt idrisi gsg ingr ers jaxapalsar dimap gff cosar pds adrg coasp tsx terragen blx msgn til r northwood saga xyz hf2 kmlsuperoverlay ctg e00grid zmap ngsgeoid iris map cals safe sentinel2 mrf wcs wms plmosaic wmts grib bsb netcdf kea hdf5 hdf4 gif jpeg png pcraster pcidsk rik ozi pdf arg   How can I do this?


Stack Exchange reputation graph: unselecting the top site results in y-axis rescaling mess

This is what my  looks like when it first loads:    But if we unselect math.SE, we get a y-axis rescaling mess:    I'm using Firefox. I'm in China, so many things involving Google and Imgur are blocked, and I use  to stop the browser attempting to load unloadable Google objects.  I'm hoping other users can check whether or not this issue is localized to my system, and if it's not just me, here's the bug report.


what kind of TO BE VERBs can we use with nouns such as; police, army, fish, sheep?

If we consider them as plural nouns and sometimes as singular nouns.


class MyPanel extends JPanel implements Observer, MouseMotionListener, MouseListener { private MyModel model; private View view;  private String mode;  private Rectangle rectangle; private Square square;  public MyPanel(MyModel model, View view) {     this.setBackground(Color.black);     this.setPreferredSize(new Dimension(300, 300));     this.addMouseListener(this);     this.addMouseMotionListener(this);     this.model = model;     this.model.addObserver(this);  }  public void paintComponent(Graphics g) {      super.paintComponent(g);     Graphics2D g2d = (Graphics2D) g;      ArrayList<Rectangle> rectangles = this.model.getRectangles();     for (Rectangle r : getRectangles()) {          int width = Math.abs(r.getStartPoint().getX() - r.getEndPoint().getX());         int height = Math.abs(r.getStartPoint().getY() - r.getEndPoint().getY());     }      ArrayList<Square> squares = this.model.getSquares();      for (Square sqr : getSquares()) {          int xPosition = Math.min(sqr.getStartPoint().getX(), sqr.getEndPoint().getX());         int yPosition = Math.min(sqr.getStartPoint().getY(), sqr.getEndPoint().getY());         int width = Math.abs(sqr.getStartPoint().getX() - sqr.getEndPoint().getX());         int height = Math.abs(sqr.getStartPoint().getY() - sqr.getEndPoint().getY());            }      g2d.dispose(); }  public void update(Observable o, Object arg) {     this.repaint(); }  @Override public void mouseDragged(MouseEvent e) {      if (this.mode.equals("Rectangle")) {          this.rectangle.setEndPoint(e.getX(), e.getY());         this.model.addRectangle(this.rectangle);     }      else if (this.mode.equals("Square")) {           // What code should I add here?          this.model.addSquare(this.square);      }  }  // MouseListener below @Override public void mouseClicked(MouseEvent e) {}  @Override public void mousePressed(MouseEvent e) {      if (this.mode.equals("Rectangle")) {         this.rectangle = new Rectangle(e.getX(), e.getY());     }      else if (this.mode.equals("Square")) {         this.square = new Square(e.getX(), e.getY());      } }  @Override public void mouseReleased(MouseEvent e) {      if (this.mode.equals("Rectangle")) {          this.rectangle.setEndPoint(e.getX(), e.getY());         this.model.addRectangle(this.rectangle);         this.rectangle = null;     }      else if (this.mode.equals("Square")) {         this.model.addSquare(this.square);         this.square = null;     }  }  @Override public void mouseEntered(MouseEvent e) {} @Override public void mouseExited(MouseEvent e) {}   }  The user chooses a mode, rectangle or square. Then they can draw a square or a rectangle with their mouse (live feedback is shown). Here is my drawing panel class. I was successfully able to implement the rectangle mode. The user can draw a rectangle and as they move their mouse, the rectangle is shown in mid construction. I want to do the same for the square mode. For some reason, I'm having a hard time doing this. How would I show a perfect square in mid construction when the user is moving their mouse and how would I draw it once released? What code should I add to my paintComponent method, mouseDragged, mousePressed and mouseReleased method to do this? It was easy for a rectangle because there was no constraint but I'm not sure how to do it for a square with my current implementation.


Is it formally right to say that $\Bbb N \subset \Bbb Z$ etc?

I was studying the formal construction of numbers from $\mathrm{ZF}$, assuming the elements of the naturals being $\{\}, \{\{\}\}$, etc. Given the naturals, its ring properties and arithmetic, we can define the integers being a set of equivalence classes on $\Bbb N^2$. This logic is used from the integers to the complex numbers, so the tear always have sets of equivalence classes. My doubt is: since, for example, $\bigcup \Bbb Z = \Bbb N^2$, isn’t it wrong to formally say that $1_{\Bbb N} = 1_{\Bbb Z}$, that is, $1 \in \Bbb Z$? Since that the only thing we can assume is that there is a bijective map $\Bbb N \mapsto \Bbb Z$ (in fact, they’re both countable).


VirtualBox - 64 bit OS on a 32 bit host - Pros and Cons

Is is possible to run a 64 OS in a virtual environment host that is 32 bit. Say for example, I am running Windows XP 32 bit. Would it be possible for me to run a 64bit OS using VirtualBox or VMWare. My processor is a 64bit processor with VT enabled.


Per my understanding, once Arya Stark killed the Waif in  S06E08 ("No One") she came to Jaqen H'ghar and finally admits that,     A girl is Arya Stark of Winterfell. And I'm going home.   So she seems to renounce any ties with the Faceless Men and to have found her real self back again, after a time of confusion about herself and her legacy, to Jaqen's apparent satisfaction.  Then in S06E10 ("The Winds of Winter"), how is she able to still use the faces      when killing Walder Frey?   I thought this magic is only reserved to the Faceless Men who truly became No One. Arya, though, is someone and is done with the Many-Faced God, yet she still can use the faces at her apparent disposal (without even being near the "face storage" in Braavos). Why/how?  This might be based on a lack of understanding from my side about how this "face magic" actually works. Is it just an accquired skill that you can then use however you want (maybe only requiring some "willing" corpse to provide its face)? Or is it tied to other requirements that Arya already fulfills, albeit not belonging to the Many-Faced God anymore? Or does she maybe even still belong to the Faceless Men somehow? Or is she using the faces "illegaly" as she did before?


Passing Parameter Into Schedulable Class

Is there a way to pass a parameter into a schedulable class execute method? We were trying to pass a string from another scheduled class into this scheduled class but it looks like we can't do that?  As quick context we have the scheduled date and time as a record in a custom object so we are trying to pass that info into our scheduled class.  global class MturkVSSchedule implements Schedulable{      global void execute(SchedulableContext SC, **String s**){   Putting String S throws a compile error. Is there a different way that I'm missing?


probability of sum of 5 dice is a certain number

If I throw 5 dice, then the sum of numbers should be integers from 5 to 30.  How can I get the probability that the sum is n? (n = 5,6,...,30)  I used the formula: no of ways to get 8: 5_H_2 = 6_C_2 = 15  But this holds only for small n (n = 5, 6, ...), This is not true for n = 30, 29, 28...


I’m working on an application that has multiple tasks that need to be completed in sequence (e.g. think placing your order with amazon).  We have a progress bar at the top of the web page which shows which step of the process you are in.  My question is with a unique situation we’ve come across.  For the application in question; the number of steps in the process will vary.  At one point; the user is asked to select an option in a drop down.  Depending on their answer;  they may have 2, 3 or 4 remaining steps.  2 of these steps are always the same.  I was wondering if anyone would have a suggestion as to how to handle this.  I think it would look weird and confusing if the number of steps in the task progress bar starts changing based on the users selection.  Thanks!


I am using an HP NoteBook 15-ay503tx. I have been facing this issue since 3 weeks ago.


Drawn rectangles over image are not in right position after image is resized

I have a bunch of images of cars and for each image, I have the top, left, width and height of a box in pixels over the image that is outlining the car.  const rectStyle = {     position: "absolute",     top: rect[0],     left: rect[1],     width: rect[2],     height: rect[3],     border: "3px solid red",     backgroundColor: "transparent",   };    return (     <>

     </>   );  My issue right now is when I try to resize the photos to fit a , the boxes are no longer in the right position. How can I fix this?


Typesetting a pair of slash symbols to indicate parallel lines

To indicate that two lines - or line segments - I want to typeset two slash characters. I used $\overline{AB} \slash\slash \overline{CD}$.  The space between the slash characters is too much, though.  I could use a thin negative space command \!.  I would like to know what is the typical code to do this.


If black hole sucks in all masses, why does it suck in light if it is a form of energy (energy does not have mass)?

I have been searching for a long time for the answer.


Wrap CSV lat/long points around 180 meridian in QGIS

I have a CSV file with lat/long coordinates. I also have a custom CRS to center the map on the Indian Ocean. Is there a way for me to force the points to plot on the blank band of the map where the 180 meridian is?  My proj4 string is +proj=eqc +lon_0=90 +datum=WGS84 +units=m +no_defs +lon_wrap=90. +lon_wrap=90 doesn't appear to have done anything.      As a temporary solution, I first converted my CSV points to a points shapefile, then rasterized my shapefile at the appropriate resolution. In my case my CSV file contained lat/long coordinates every 1/2 degree, so I set my resolution to be 0.5 map units = 1 pixel, because my projection was in degrees lat/long. My raster wraps with no issues:    However, as another user noted, this is only a visual solution and doesn't actually solve my original problem.


Why this code is giving ConcurrentModificationException

import java.util.HashMap; import java.util.Iterator; import java.util.Map; import java.util.concurrent.ConcurrentHashMap;  public class ConcurrentHashMapTest {        public static void main(String[] args) {              Map<String, String> hMap = new HashMap<String, String>();             hMap.put("FIRST", "1");             hMap.put("SECOND", "2");             hMap.put("THIRD", "3");             hMap.put("FOURTH", "4");             hMap.put("FIFTH", "5");             hMap.put("SIXTH", "6");             System.out.println("HashMap before iteration : " + hMap);             Iterator<String> hashMapIterator = hMap.keySet().iterator();              while (hashMapIterator.hasNext()) {                   String key = hashMapIterator.next();                   if (key.equals("FOURTH")){                        hMap.put(key + "-SHIVAM", "I AM NEW KEY IN HMAP");             }             }              System.out.println("HashMap after iteration : " + hMap);       } }    Exception in thread "main" java.util.ConcurrentModificationException   at java.util.HashMap$HashIterator.nextEntry(Unknown Source)   at java.util.HashMap$KeyIterator.next(Unknown Source)   at ConcurrentHashMapTest.main(ConcurrentHashMapTest.java:21)    I am wondering why this exception is coming. The exception is not at all seems to be fair in this case.