Schengen Visa Free Travel as Tourist (90/180) Immediately Following Long Stay (D Type Visa)

I have been residing in France for a year on a D type visa. Now, by the end of this year the visa will be over, and I would like to take advantage of being a Schengen visa free passport holder (annex II country, like Argentina, Australia or Singapore for example) to spend another 3 months as a tourist in Europe, immediately following my current stay.   Do you think I should exit upon visa's expiry and re-enter the Schengen again, or can I just stay for the extra 3 months without leaving? In case I do exit end re-enter, I thought of doing that through the border in Andorra (it's not Schengen, but not sure if they stamp the passport), or make my way south to cross the border to Gibraltar (also not Schengen - and they do stamp for sure).   What would you advise on the situation?


I'm currently based in Shanghai, China. I have recently updated my system to iOS 9.2, and after this, my SE app on my iPhone doesn't seem to work well.   The problem is, when my cellphone is connected to a wifi whose condition is not very well, Stack Exchange will almost always crash on startup, stuck in the following stage for several seconds then flashing back to main screen:    By "whose condition is not so well" I mean a wifi that is slow when connecting to foreign websites. (Due to some reasons, many wifi connections in Shanghai are in such a condition, sigh) Even when the wifi connection is so good that the app won't crash, it will still take a much longer time to open it. (Before iOS 9.2, it takes about 2 or 3 sec for the screen to stay in the stage shown in the image above, but now it takes about like 7 or 8, which is really an awfully long time.)  Nonetheless, when I turn my wifi off and connect my phone to 3G cellular network, or even when I simply disconnect my phone from Internet (like turn on airplane mode), the app won't crash and will function just as well as before iOS 9.2. (Of course when on the airplane mode I can't refresh to fetch new info but at least the app doesn't crash!) So now every time I want to browse SE I have to switch to cellular network...  I tried deleting and redownloading and reinstalling the app, but the situation doesn't get any better.   I'm sorry I don't quite know how to get the error log on my iPhone, but if you need any more specific information about this problem I can provide that for you on request.   Thanks in advance.


Granting Read access to Replica database (via data guard) but need to restrict the same login in production Database

We use Data Guard to replicate production Oracle database. We have a need to grant read access to replica DB and at the same time need to restrict that same login gaining read access to production.   Since the data guard replicates everything (including user/roles) is there any way we can apply this restriction to the production databases? Should I look into to database server inbound port restrictions? Any thoughts on this are greatly appreciated.


Installing Ubuntu with Windows, which is left and right when allocating space?

I'm installing Ubuntu (or Xubuntu/Lubuntu/Kubuntu) alongside Windows 7/XP. I got to the screen that says, "Allocate drive space by dragging the slider below." On the following screen, I'm not sure whether the right side or the left side is for Ubuntu or for Windows. Which side is which?  Screenshot for Ubuntu: (see  for Lubuntu)


Loss function can not converge during training neural network

In my scenario, I use deep reinforcement learning to fix a problem that is related to transportation. During training, I plot the gradient and loss, I find that the gradient converges and then explodes while the loss can not converge all the time. I wonder what caused such result.  The fist graph indicates one of the output gradient and the second graph indicates the cumulative reward for each sample(red curve), and corresponding loss(blue curve)


What Is The General Term Of These Sequences?

$a_{n,3}$     $$1,0,0,1,0,0,1,0,0,1,0,0,1,0,0,1,0,0,1,0,0,1,0,0,1,0,0,1,0,0,\cdots \cdots $$   $a_{n,5}$     $$1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,\cdots \cdots $$   $a_{n,7}$     $$1,0,0,0,0,0,0,1,0,0,0,0,0,0,1,0,0,0,0,0,0,1,0,0,0,0,0,0,1,0,\cdots \cdots $$   $$\vdots $$  $a_{n,2k+1}$     $$1,\cdots \cdots\cdots \cdots,1,\cdots \cdots\cdots \cdots,\overbrace{1,\cdots \cdots\cdots \cdots}^{2k+1},1,\cdots \cdots\cdots \cdots,1,\cdots \cdots$$   I found  $$a_{n,k}= \left \lfloor \left | \cos\frac{\pi (n-1)}{2k+1} \right | \right \rfloor$$ but this term include abs and floorfucntion.  I mean i want the General Term without abs and floorfucntion.(plus sum)  Any hints will be appreciated, thank you.


How to change a Schengen visa with single entry valid for only 15 days?

As I am traveling Greece from Nepal for the first time to attend a volunteer program of 15 days (including travel days), I have Schengen visa with single entry And also my flight return ticket is fixed already. I have to return after completion of my program.  Can I extend my Schengen visa from Greece? As I want to visit my relatives who lives in Spain and Portugal. What if I stay more than 15 days in my owns. Is not it that the Schengen visa is valid for 90 days?


Prove the implication "if $ac>bc$ and $c>0$, then $a>b$" using the contrapositive

Let $a,b,c\in \mathbb{Z}$. If $ac>bc$ and $c>0$, then $a>b$   I think I would use contrapositive to prove this. But I am not sure proper contrapositive statement.   Is it If $a<b$, then $ac<bc$, and $c<0$.? If so, contrapositive is not a good choice, isn't it?


A continuous surjective function from $(0,1]$ onto $[0,1]$

I'm trying to construct a continuous surjection from $(0,1]$ onto $[0,1]$, but I'm not getting anywhere. I don't immediately see a contradiction which falsifies the existence of such a function, so my intuition tells me one exists. I feel like an absolute value function would work, but I'm not sure how to arrive at it in the proper way. Thanks for any help.


By mistake I misspelled my last name while booking air ticket, It was supposed to be GanGArajuvardhana instead of GanAGrajuvardhana (I've highlighted the mistake in uppercase letters). Will that be a problem at immigration?


ubuntu installation alongside vista to uninstall vista later

if I decide to install ubuntu alongside vista, in order to try it first, can I disintall vista afterwards?


Why did apt-get update fail? What is cdrom in it?


How do I remove a question? I have ask a few questions and I have gotten the answer either on here or an outside source, or the question wasn't understood so I have to rephrase it.  Anyways  I want to delete some of them now. How do I do that?


When doing substitution problems in integration, I've often come across things like $\mathrm{d}x/\mathrm{d}\theta =\cos \theta$ and so $\mathrm{d}x=\cos\theta \mathrm{d}\theta$, which seems like $\mathrm{d}x$ divided by $\mathrm{d}\theta$? I've asked it in a comment, by I got a complicated answer which I can't understand as I am a newbie in calculus. So could anyone give me a simple and step by step answer to explain why is that the case?


The limit I need to calculate is $\lim_{(x,y)\rightarrow (0,0)}\frac{xy^{2}}{x^{4}+y^{2}}$. Using polar coordinates I get: $lim_{r\rightarrow 0}\frac{r\cos(\theta)\sin^{2}(\theta)}{r^{2}\cos^{4}(\theta)+\sin^{2}(\theta)}$. Now if $\sin(\theta)\neq 0$ then the limit is $0$. How do I handle the case where $\theta=0$ or $\theta = \pi$? And is there a better way to approach this limit?


Difference yea/nay and yes/no - four-form system

So, my brother is watching on tv a vote a in the American Congress.  He says that the members are asked to vote with yea/nay (I have heard that from the Chamber of Commons in the UK as well).  Now we are trying to figure our whether there might be an actual difference between yea/nay and yes/no, that might have gone lost with time. In particular, a person on  gave an interesting explanation: "English used to use what’s called a “four-form” system. “Yea” and “nay” were only used to answer positive questions, while “yes” and “no” were only used to answer negative questions." However, I cannot find confirmation of what is said.  On a side note, an aspect of this answer that is intriguing me is that I have never heard of a "four-form" system. As I have studied French and German, I am know of the existence of three-form systems (in German, ja/doch and nein, and in French, oui/si and non), but four??  Can anybody confirm/refute the theory of the "four-form system"?  If you are going to confirm it, could you please provide the source of your information?  (I have looked on stackexchange for answers, but, to the best of my knowledge, questions on yay/nay never wonder about the comparison with yes/no)


Generalized Pauli matrix for spin larger than 1/2

for Spin 1/2, we have Pauli matrix as in . So what's the generalized 3-by-3 Pauli matrix for spin 1 or even larger spin? Is there a generalization method?


Are eggs left in car trunk for 3 days safe to eat?

I had purchased eggs at the supermarket and i forgot them in the trunk of my car for for 3 days are they still okay to eat?


Is the limit $ \lim_{n\to \infty}\left(\sum^{n}_{r=0} \binom{n}{r}\big/{n^{r}(r+3)}\right)$ rational or irrational?

How can I prove that the result of the following limit is rational/irrational?$$ \lim_{n\to \infty}\left(\sum^{n}_{r=0} \frac{\binom{n}{r}}{n^{r}(r+3)}\right)$$  Would solving this limit satisfy? How would I solve this? So, if the result came out to be say $\pi$, can we conclude that it is irrational? Meaning, is it a complete proof?


Can I remove the second 'a' when asking "Is it a peach or a banana?" without changing the meaning?

Is there any difference between asking     Is it a peach or a banana?   vs.      Is it a peach or banana?   The latter sounds to me like a yes/no question, while the prior does not. Is it just me?


I am unable to turn on the labels within my Python script:  import arcpy mxd = arcpy.mapping.MapDocument(r"Mypathhere") #Map document reference layer = arcpy.mapping.ListLayers(mxd, "Layername")[0] #Indexing list for 1st layer if layer.supports("LABELCLASSES"):     for lblclass in layer.labelClasses:         lblclass.showClassLabels = True arcpy.RefreshActiveView() mxd.save() del mxd   If I need to enable labeling in the label manager first, can that be done with ArcPy?  The script does not break. I do not get any errors. The points just do not get labeled.


I would like to show an idea on how to make real numbers infinitely countable. It is quite simple, too simple for me to believe it has been overlooked. So my question is, what have I overlooked?    So the "countable" list would start like this {0.1, 0.2, 1.1, 2.1, 1.2, 0.3, 0.4, 1.3, 2.2, 3.1 ...}, the way Cantor diagonally counted the list of rational numbers and potentially covering every real number there is.  And for the numbers after the decimal point, you go down a column and count normally after the decimal point but reverse the number.


How can I get Google to index all my pages when only 10% are currently indexed?

Google is indexing parts of the site www.findinplumbing.com. If you use site: search, you get 5000 results. BUT: that is by far not enough. The site has around 11000 pages.  In Google search console it says:     11.240 URLs transferred 1.386 indexed URLs   so 10% ONLY.  Well now what? What can I do so Google indexes all 11,000 pages?  I provided a sitemap.xml here  and a page that I triggered in Google search tools to have indexed manually and recursively that contains all pages (). Still, nothing happens.  I provided even a page where ALL pages appear as direct links. Still: not all pages get indexed. What is the problem? Now: this page went live in November 2016. That is 2 months ago now. And only 10% are indexed... very little


I m struggling with RMI. I m totally new at this and tried   All my classes and interface compile well but when I try to run the Server class, I get some Exceptions (listed below) the project is build as follows:  -pakage hello             --interface Hello.java             --class Server.java             --class Client.java   I'v done Somme research and they always suggested to change the security policy file. So I added following policy to java.policy:  grant  {        permission java.security.AllPermission "", "";   };   a secondary "question": I run Linux mint, so i came to understand that i don't need to run the rmiregistry, is that correct or do I need to start it as well and how can I do that.  The listed exceptions:  Server exception: java.rmi.ServerException: RemoteException occurred in server thread; nested exception is:      java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is:      java.lang.ClassNotFoundException: hello.Hello java.rmi.ServerException: RemoteException occurred in server thread; nested exception is:      java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is:      java.lang.ClassNotFoundException: hello.Hello     at sun.rmi.server.UnicastServerRef.oldDispatch(UnicastServerRef.java:419)     at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:267)     at sun.rmi.transport.Transport$1.run(Transport.java:177)     at sun.rmi.transport.Transport$1.run(Transport.java:174)     at java.security.AccessController.doPrivileged(Native Method)     at sun.rmi.transport.Transport.serviceCall(Transport.java:173)     at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:556)     at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:811)     at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:670)     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)     at java.lang.Thread.run(Thread.java:744)     at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:275)     at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:252)     at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:378)     at sun.rmi.registry.RegistryImpl_Stub.bind(Unknown Source)     at hello.Server.main(Server.java:23)   Anybody who can help me?


I have a list of stations in rivers. I want Earth Engine to return me a list of stations whose upstream area overlaps with at least one other country in addition to the country the station is in. This is more or less the code for one station in Brazil using the hydro package by gena. The station should be in the list because its upstream area crosses into Colombia and Venzuela. How can I run a code over all stations and return a list with the property 'GEMS_Stati' for stations with an international upstream area?  var stations = ee.FeatureCollection('users/basins/stations'); var countries = ee.FeatureCollection('USDOS/LSIB_SIMPLE/2017'); var hydro = require('users/gena/packages:hydro');  var filter = ee.Filter.inList('GEMS_Stati', ['BRA00020']); var FilteredStation = stations.filter(filter);  var catchmentsSelected = hydro.getCatchments({outlet: FilteredStation, level: 6})  var union = catchmentsSelected.union(); Map.addLayer(union);  var spatial_filter = ee.Filter.intersects({   leftField: '.geo',   rightField: '.geo',   maxError: 10 });  var saveAllJoin = ee.Join.saveAll({   matchesKey: 'scenes', });  var join_output = saveAllJoin.apply(union, countries, spatial_filter); print(join_output);


Problems with my Ubuntu 14.04 64 bits bootable USB

I'm trying to install Ubuntu 14.04 in my computer by using a bootable USB but I keep getting this error:  SYSLINUX 4.07 EDD 2013-07-25 Copyright (C)... Unkown keyword in configuration file: =J(triangle) No DEFAULT or UI configuration directive found! boot: _


Show Lightning component Modal above Salesforce Global header (Position Issue)

I have added lightning Modal (slds) component A in a another Lightning Component B.  Lightning component B is used to create Lightning Tab.  Now when I show the modal, Position of Modal component A is restricted inside Parent component B. I would like to display modal above global Header (outside Component A) as in attached screenshot. CSS z-index is not much helpful, may be i am wrong. Please help to fix this position issue.  Thanks for your time.`    Followed - Markup From SLDS Page (Summer ’17)


Should I use the datetime or timestamp data type in MySQL?

Would you recommend using a  or a  field, and why (using MySQL)?   I'm working with PHP on the server side.


javafx java.lang.NullPointerException controller class

I have my controller class as:   public class Empty_pageController implements Initializable,Runnable{   Which declares all IDs as:  @FXML  private TextField IDno; @FXML  private TextField branch; ...   Now these is my clear() function to clear the FXML form:  public void clear(ActionEvent Event){     IDno.clear();     branch.clear();     bookname.clear();     ID.clear();     author.clear();     address.clear();     name.clear();     year.clear(); }   Then I have another class (in same package) that calls these clear():  new Empty_pageController().clear(null);   These gives me following error:  Exception in thread "Thread-4" java.lang.NullPointerException at library.Empty_pageController.clear(Empty_pageController.java:147) at library.server.doInBackground(server.java:45) at library.Empty_pageController.run(Empty_pageController.java:84) at java.lang.Thread.run(Thread.java:748)   What I tried after seeing some solutions here: I passed the object of contructor class by following code:  s.doInBackground(this);   and then made changes accordingly in the other class's method:  public void doInBackground(Empty_pageController E) throws InterruptedException {   Then I Called using these statement:  E.clear(null);   I got the same error Don't Know where I'm going wrong....?  EDIT:MY FXML file


Limit of: $\lim\limits_{x\to \infty}\left(\frac{1}{n}\sum_{k=1}^{n} k^{1/x}\right)^{nx}$

Compute the following limit ($n\in \mathbb{N}$) $$\lim_{x\to \infty}\left(\frac{1}{n}\sum_{k=1}^{n} k^{1/x}\right)^{nx}$$  My idea was to use the inequality:  $$\left(\frac{1}{n}\sum_{k=1}^{n} 1^{1/x}\right)^{nx}<\left(\frac{1}{n}\sum_{k=1}^{n} k^{1/x}\right)^{nx}<\left(\frac{1}{n}\sum_{k=1}^{n} n^{1/x}\right)^{nx} \\ \implies1<L<n^n$$  This gives that the required limit $L$ lies between $1$ and $n^n$. But how can we find its value?


Make Windows 10 show password prompt immediately instead of requiring an action first

In Ubuntu, when a computer is locked, you can just type the password immediately followed by enter and it will unlock. This is nifty because I can type the password before the monitors have even turned back on.  I want to achieve this on my Windows 10 machine. The issue is that I seem to need to hit a key to wake Windows up, then another key to make it go from its relatively blank lock screen to the screen that actually shows the password. The time it takes to show the password prompt isn't instantaneous. The end result is that what I often end up doing is spamming spacebar a bit to get to where this prompt should be, then spam backspace in case I ended up typing into the password prompt, then enter my password. It fails a lot, presumably because I started typing my password too soon, anyway.  I want the lock screen to just show my password prompt from the start instead of this relatively blank and useless lock screen it starts off on.


What is the difference between \number and \the ? No.2

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% %% Here is the example tex-file that illustrates use of \number and \the .    %%                                            %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%         \documentclass{article} \usepackage[paperwidth=4in, paperheight=0.8in]{geometry}  \begin{document}  \newcount\a  \newcount\b  \newcount\Sum  \a=1   \b=5  \Sum=0 \advance\Sum by \a  \multiply\Sum by \b \advance\Sum by \a  \multiply\Sum by \b  \noindent The Sum equals \number\Sum  \quad;\quad I used ``number''. \par \vskip 10pt \noindent The Sum equals \the\Sum     \quad;\quad I used ``the''.  \end{document}


How to install Ubuntu alongside Windows 7/8

I have a pre-installed Windows 7/8 and I want to install Ubuntu alongside that. When I try to install I do not have an Install ubuntu alongside windows 7/8 option during the installation (it's missing). How can I have or get back this option?


I'm new to Apex code, got below error Error: Invalid Data.  Review all error messages below to correct your data. Apex trigger PositionTrigger caused an unexpected exception, contact your administrator: PositionTrigger: execution of AfterInsert caused by: System.FinalException: Record is read-only: Trigger.PositionTrigger: line 4, column 1  trigger PositionTrigger on Position__c (after insert) {   Position__c ThePosition = trigger.new[0];   if(ThePosition.Days_Open__c>90){     ThePosition.Educational_Requirements__c='Featured';     update ThePosition;   } }   please let me know the solution.


I've found  how to write author's names in latex bib. However, the first author name is always separated in two with a comma. Here is an example:   @conference{ASoDToED, title = {A Study on Deduplication Techniques over Encrypted Data}, author ={Ganesh,Amal and Sunitha,C. and Akhila,K.}, year = {2016}, booktitle = {procedia Computer Science}, volume = {87}, pages = {38 to 43} }   As output i will have:   Ganesh, Amal, C.Sunita and K.Akhila   And it's the same for ALL my bibliography: the first author name is splitted with a comma. I've tried many other ways, like writing:   Ganesh,A. and... Ganesh Amal and ...    It doesn't change anything.   However, the reference is good. For the example i gave here, the reference is [GSA16], which is the good one. So it didn't consider "Amal" as a name, but it still write it separately with a comma... How can i get rid of this comma? It feels weird that the first name is not written as the other ones.  EDIT: Here is a minimal example. The documentclass wissdoc can be found on GIT.  \documentclass{wissdoc}  \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage[english]{babel} \usepackage{bibgerm} \usepackage[     numbers,     sort&compress ]{natbib} \usepackage[protrusion=true,expansion,babel=true]{microtype}  \usepackage{amsmath} \usepackage{amsthm} \usepackage{amsfonts} \usepackage{dsfont} \usepackage{moreverb} \usepackage{subcaption}  \begin{document}  \graphicspath{{images/}}  \selectlanguage{english} \chapter{first Chapter} let me introduce the chapter ~\cite{ASoDToED} \section{first section of chapter 1} this is my text ~\cite{SDoED} \section{second section of chapter 1} i have a lot of sections   \bibliographystyle{geralpha} \bibliography{textest} \end{document}   The bib file:   @conference{ASoDToED, title = {A Study on Deduplication Techniques over Encrypted Data}, author ={Ganesh,Amal and Sunitha,C. and Akhila,K.}, year = {2016}, booktitle = {Procedia Computer Science}, volume = {87}, pages = {38 to 43} } @article{SDoED, title={Secure Deduplication of Encrypted Data: Refined Model and New Constructions}, author={Jian, Liu and Li, Duan and Yong, Li and N., Asokan}, year={2017}, }


Defining bin sizes for plotting histograms

Perhaps a basic question, but is there a method or definition of how to choose the optimum bin size for some data with the intent to plot as a histogram?  At present the best option I can think of is to fit distribution functions to the histograms and choose the bin size where the fit is best.  Is there a definition based on the data size or some other metric?


Is $\mathbb{Z} \left[ \frac{1+i \sqrt{7}}{2} \right]$ euclidean?

Is the ring $\displaystyle A=\mathbb{Z} \left[ \frac{1+i \sqrt{7}}{2} \right]$ euclidean?  If $N : z \mapsto z \overline{z}$, then for all $z \in \mathbb{C}$ there exists $a \in A$ such that $N(z-a)<1$, except when $z$ has the form $\displaystyle \left(n+\frac{1}{2} \right)+ \left(m+ \frac{1}{2} \right) \frac{1+i \sqrt{7}}{2}$; in this case, you can only find a large inequality. So $A$ is "almost" euclidean, but is it actually euclidean?


Alternative to function overloading in C?

Since function overloading isn't allowed directly in C, how can it be done for these functions?  void MotorDriver_Create(float speedAddress,float frequencyAddress, float db_input); void MotorDriver_Create(float speedAddress, float frequencyAddress, float minDB, float maxDB);


Why do electron and proton have the same but opposite electric charge?

What is the explanation between equality of proton and electron charges (up to a sign)? This is connected to the gauge invariance and renormalization of charge is connected to the renormalization of photon field, but is this explanation enough? Do we have some experimental evidence that quarks have 2/3 and -1/3 charges? By the way I think about bare charge of electron and proton. And I am also wondering if this can be explained by Standard Model.


I'm 26 and a double masters student in transportation planning and engineering. I have received 50k in settlement money; I don’t know what’s the best course of action with this money. Im looking at 56,000 in student loans at 6% APR over 10 years. I graduate in two years, then, upon finding a job, I expect a minimum starting salary of 50k. I earn a small stipend from an internship, about 800 a month. I pay 550 in rent. Should I invest or should I try to reduce the loan? Should I save it all and worry about it when I graduate? Should I buy a condo and rent it to other students?


Does the distance between nodes affect the advance of the Rebel Fleet?

When jumping between nodes in a sector, does the distance to the destination node affect the advance of the rebel fleet, or is it only the number of jumps?  I read , but it did not address distance versus quantity.


Capacitor connected across two isolated sources

Lets say there are two isolated sources of positive charges $q_1$ and $q_2$ $(q_1>q_2)$ located sufficiently far apart. If the two are connected to the two plates of a capacitor, then what is the resulting charge distribution across each capacitor plate?


On giving the command  sudo apt-get update   I am getting the following error:  E: Syntax error /etc/apt/apt.conf.d/01autoremove-kernels:1: Extra junk at end of file.   Also a red circle with negative sign is present on the upper right corner of the desktop and I am unable to access update manager.


Is Dr Quantum's Double Slit Experiment video scientifically accurate?

I'm fascinated by the fundamental questions raised by the Double Slit Experiment at the quantum level. I found this  which seems like a great explanation. But is it scientifically accurate?


In UTF-8 it should be possible to use ä and ö. But actually in my code listing I use the package listings I receive by this example \lstset{language=HTML}  % Set your language (you can change the language for each code-block optionally) \begin{lstlisting}[caption=Socket Connection, frame=single]  % Start your code-block  // einbinden der Library mittels CommonJs var net = require('net');  // Socket Client erstellen var client = new net.Socket();  // mit dem Server verbinden IP Port angeben client.connect(<PORT>, '<IP>', function() {     console.log('Connected');     client.write('Hello, server! Love, Client.'); });  // verschiedene Events Listener // dieser wird ausgelöst s der Server Daten zum Client sendet  client.on('data', function(data) {     console.log('Received: ' + data);     client.destroy(); // kill client after server's response });  client.on('close', function() {     console.log('Connection closed'); });  \end{lstlisting}  the error message ! Package inputenc Error: Invalid UTF-8 byte sequence.  And it is denoting to the line with the 'ö' // dieser wird ausgelöst s der Server Daten zum Client sendet Note: Sure I know it isn't HTML but when I say JavaScript it doesn't work In the preamble I say \usepackage[utf8]{inputenc} % Unicode Text


Tilted rectangle in residuals vs fitted plot

When performing diagnostics on an OLS model, what can make a plot of the predicted responses vs the residuals. Ideally we want a horizontal rectangle shape. But what does it mean when the plot is a tilted rectangle? Some books like Draper and Smith say this indicates an error in the analysis, but they do not elaborate on what this means. Can someone explain what we can infer from this particular case?


Would a Bayesian admit that there is one fixed parameter value?

In Bayesian data analysis, parameters are treated as random variables. This stems from the Bayesian subjective conceptualization of probability. But do Bayesians theoretically acknowledge that there is one true fixed parameter value out in the 'real world?'  It seems like the obvious answer is 'yes', because then trying to estimate the parameter would almost be nonsensical. An academic citation for this answer would be greatly appreciated.


Proof for Dim(V) = Dim(Kernel(T)) + Dim(Image(T)): Is this enough to prove it?

Prove that $dim(V) = dim(Ker(T)) + dim(Im(T))$  Let $dim(Ker(T)) = k$, and let the basis be {$v_1,...,v_k$}  If $k = 0$, $Ker(T) =$ {$0$}, which means that every vector in $V$ is in $Image(T)$  Let $dim(V) = n$  If $k = n$, then every vector in v is in the kernel. Therefore $Im(T) =$ {$0$}  If $n > k$, we can add $n-k$ vectors to the basis of the kernel to create a basis for $V$  Basis $=$ {$v_1,...,v_k,v_{k+1},...,v_n$}  The Image of T is {$T(v_1),...,T(v_k),T(v_{k+1}),...,T(v_n)$}  As $v_1,...,v_k$ are in the kernel, $T(v_1),...,T(v_k) = 0$  Therefore the basis for the Image of T is {$T(v_{k+1}),...,T(v_n)$}  $dim(Ker(T)) = k , dim(V) = n$  $dim(Im(T)) = n-k$  $dim(V) = dim(Ker(T)) + dim(Im(T))$


How can logistic regression have a factorial predictor and no intercept?

I tried a regression in the form ${\rm logit}(Y) = {\rm coefficient}\times X + 0 + e$, where $Y$ is a binomial variable and $X$ is a factor variable with $n$ levels. I noticed that removing the intercept yields higher $p$ values. I'm wondering how to interpret it though.  Since removing the intercept makes it equal to $0$, I believe that the coefficients returned are relative to a $0$ probability of the event $Y$ and that all $X$ factors are in the $0$ state. But I think this is impossible isn't it?  $X$ are mutually exclusive factors, therefore it's impossible to have a case where no factor is $1$, at least in the presented observations. And it cannot be interpreted like the coefficient is relative to hypothetical cases in which really no one of the factors is present, because we have no data like that.  Regarding $Y$ having a $0$ intercept, wouldn't it mean forcing the probability of the event to $0$ when none of the factors is present? Again, this is an impossible case.  Nonetheless this kind of regression would allow me to retrieve pure probability range of the event Y given a factor by transforming the coefficients in the confidence intervals given as $\exp({\rm coefficient})/(1 + \exp({\rm coefficient}))$, and the $p$ values would test whether this probability is not $50\%$. This could also be a valuable result, since it would give independent probabilities for each factor.  Am I wrong?


cleaner script to recursively replace a string in all directories and file names

I want to replace a string with a different string in all directory and file names, recursively.  So if I want to replace foo with bar and have this file:   foo_project/my_app/old_foo/start_foo.sh   I would want it to become   bar_project/my_app/old_bar/start_bar.sh   I have been able to do this, but it's pretty ugly.  Writing it from memory (can't copy paste so forgive typos) the command I have is:  find $PROJECT_DIR -name "*foo*" | tac | xargs -n 1 -I % bash -c "eval mv % \$\( echo % \| sed \''s/\(.*\)foo/\1$PROJECT_NAME/'\' \)"   This works for me, but it's hideous.  Is there a cleaner approach to do what I want?  To give context on above command, the issue I had was that early rename commands would break later mv commands by making the paths differ.  That's why I switched to a tac before an xargs (instead of the -evalcmd argument for find I started with) to ensure that I ran the most deeply nested renames first.  I then had to make my sed only rename the last instance of foo so I could move everything within a folder before renaming the folder.  The ugly part is the need of eval, and thus multiple levels of escaping arguments, because I didn't otherwise know how to pass the contents of xargs to the sed command.  There has to be something cleaner then this though?


Most school books still say that recapitulation is an evidence of evolution but as far as I know it has been proved wrong so why is it being still taught? Has it got any sort of relevance?


Is there any intuition or meaning regarding Cauchy-Riemann equations?

Holomorphic functions are one of the most beautiful objects in mathematics. However, Cauchy-Riemann equations are a little bit of a mystery for me. What does that mean intuitively when a function satisfyes those equations?


Is there a way to HIDE a file/dir from a specific user/group?

I'm setting up ACL permissions in CENTOS.  I'm getting close to the structure that I have in mind however one piece is missing for completing the puzzle.  Is there any way to HIDE a file/directory from a specific user/group?  I'm not talking about not being able to read, change dir to it. I want to completely hide it from the specific user/group (not to show up on ls -la).


I've gone through many article which says the purpose of IDisposable is to close the unmanaged objects like DB connections and Third party reports.But my question is why should I define Dispose method if I can handle the unmanaged objects in my methods without defining Dispose() method? For an example, class Report : IDisposable {     public void GenerateReport()     {         Report rpt=new Report() //unmanaged object created         rpt.Dispose(); // Disposing the unmanaged object     }      private void Dispose()     {         //not sure why this block is needed     } }  Is my understanding correct?


Is it ok to delete the contents of var/log

var/log is huge: 4.6GB+. Is it ok to just delete all this stuff? Will it mess up my computer?


How to find integral's upper limit using optimize function without knowing the interval where it will occur

I'm working on the following to get the upper limit of my integration, as I know I need to have some idea where the point might occur but in real it can be any value between 0 and infinity. May I know is there any improvement can be done so that it can work within 0 and infinity?   findx = function(f, interval, target) {   optimize(function(x) {     abs(integrate(f, 0, x)$value-target)   }, interval)$minimum }  pdf = function(x, a=2, b=0.5, lam=-1.2, del=1.5){   s = besselK(2*sqrt(a*b), lam/del, expon.scaled = FALSE)   pdf = del/2 * (a/b)^(lam/(2*del)) / s * x^(lam-1)*exp(-a*x^del-b*x^(-del))   return(pdf) }   findx(pdf, interval=c(0,Inf), target=runif(1, min = 0, max = 1))   The following is the error I get when I have my interval=c(0, Inf)  > findx(pdf, interval=c(0,Inf), target=runif(1, min = 0, max = 1)) Error in optimize(function(x) { : invalid 'xmax' value   EDIT:  Actually, I'm referring to technique in the link of  but it mentioned that "optimize needs an interval in which to search for a solution so you'll want to have some idea of where the point might occur" but my x is from 0 to infinity in which I wouldn't know where will it occur. While I need to find the minimum upper limit for my integration.


Inhumans vs. Mutants in the Marvel Universe

What's the difference between those two? Aren't Inhumans supposed to be an evolution of the human race "forced" by the Kree? Which is almost the same as Mutants, the natural evolution of the human race...  What exactly am I missing?


"This paper, combined with some glue" — singular or plural?

If I have an item, combined with another item, is it still a singular subject in the sentence? For example:        This paper, combined with some glue, makes for an afternoon of art projects.   This paper, combined with some glue, make for an afternoon of art projects.      All of my experience tells me that it should be the first, but I have multiple people arguing for the second.


How to reduce the white space between the end of the text from a previous chapter and the begin of a new chapter?


Should the logo tag be renamed to logo-language?

On Stack Overflow, the logo tag is used to refer to the  and also to refer to . The latter is also used in Meta Stack Overflow.  Is the latter tag a legitimate one? If so, should we move questions referring to the former to the tag logo-language? How do I move the questions?


I have apply glass material and sun is in the position everything looks good but no lights enter the room. I have added hdr file and a lamp. Whats the reason what im missing to get light enter the room. All black inside the room and just the hdr image is seen from the window. In the red mark there is no light. And in green mark where the edge is coming from as there is no wall. And from the window the background look so artificial.


Box-Cox transformation vs. predictor transformation in multiple linear regression

I first tried to transform my predictors one by one, but I couldn't find a satisfactory transformation. Then I tried Box-Cox which solved a lot of linearity and constant variance issues, but I still had a not-so-great QQ plot   The data set I'm using is , and above is a scatter plot with chlorides as response (after Box-Cox) and alcohol as a predictor. This QQ plot pattern appeared every time that I used Box-Cox on chlorides with one predictor.   Thus, I decided to just Box-Cox the full model, and I think(?) I got a better QQ plot (less left skew I believe):   In my case, should I give up on transforming the predictors and just go with Box-Cox on the full model, or am I missing something? I am still a beginner to linear regression, so I may be making some mistakes here. My end-goal is to find the optimal model to predict chlorides.


CUDA error out of memory in cuCtxSynchronize()

I need your help about an error, this is the screenshot of the problem.


How to find the Wi-Fi Password of a Connected Network on Android mobile

Is it Possible to know that in android devices, what are the supported versions are available, please share your ideas.


How to test your router's data transfer speed?

I've an internet connection of 50Mbps, but on speed test on my laptop over WIFI, it shows variable speed, sometimes 20Mbps or sometimes even less than 1Mbps. So I connected WAN cable directly to my laptop, so then it showing the speed of 50Mbps exactly. So I'm pretty sure it is my router's issue. But I want to check what's my router's max speed not the internet. How can I test this?


Is there a practical way to change the phone number in Uber app when arriving at a country?

I use Uber app heavily to get taxis basically in any country that has Uber, and I also get a local sim card sometimes.   I always have my roaming turned on but the problem is in receiving calls, I don't want the drivers to call me and it will be considered an international call for them, some might cancel because of that.   I have played around the app and tried to edit the account info, it redirects me to the website, and in the website its grayed out, i can't edit the phone number and a note says contact customer service. It seems there is no easy way to change the phone number. I have tried on another uber account as well, same result.  Is there a more practical and easy way to change the phone number when I land in a new country and get a local sim then change it back after leaving without contacting customer service?


Is Robert Oppenheimer's phrase “Now I am become Death, the destroyer of worlds.” grammatical in English?

Is physicist Robert Oppenheimer's phrase “Now I am become Death, the destroyer of worlds.” grammatical in English? Why not "becoming" or "now I become"?


I modified an existing model by removing unwanted vertices, then selecting surrounding vertices and creating faces one triangle at a time (By pressing 'F').  On UV unwrapping the mesh, the faces which were added by me seem to stretch from the very bottom left of the map, shown below.    How do I create a face so it appears on the UV map as expected?


There are any references of who is the actual lord of Storm's End (Season 6 Episode 4, and the end of the last book)? since Tommen is the king an the only heir of the main Baratheon's house.


The Lagrangian density for a single real scalar field theory is \begin{equation}\mathcal{L}=\frac{1}{2}(\partial_{\mu}\phi)^{2}-V(\phi)\end{equation} I have often seen this written \begin{equation}\mathcal{L}=\frac{1}{2}\partial_{\mu}\phi\partial^{\mu}\phi-V(\phi)\end{equation} which appears to differ in the kinetic term.  Specifically \begin{equation}(\partial_{\mu}\phi)^{2}=(\partial_{\mu}\phi)(\partial^{\mu}\phi)\neq\partial_{\mu}\phi\partial^{\mu}\phi=(\partial_{\mu}\phi)(\partial^{\mu}\phi)+\phi\partial_{\mu}\partial^{\mu}\phi\end{equation} where the product rule has been used in the last equality. Is this just sloppy notation (which is acceptable because only first derivatives in the field are considered anyway), or is my maths very bad?


apache/php/oci automatically replaces unicode characters with a question mark - how?

I am migrating between servers and with the same code running the same query against one of my databases I get different results if the result data contains a unicode character. I'm moving from:  Red Hat 4.4.7-23 PHP 5.6.32 Apache/2.2.15 OCI8 Version => 2.0.8 /opt/oracle/product/112020_cl_64 (client)  My new environment has:  Red Hat 4.8.5-39.0.1 (OL7) PHP 5.6.36 (built manually) Apache/2.4.6 (built manually) OCI8 Version => 2.0.12 /usr/lib/oracle/12.2/client64 (client)  The database is:  read only Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production With the Partitioning, Real Application Clusters, Automatic Storage Management, OLAP, Data Mining and Real Application Testing options NLS_CHARACTERSET = WE8ISO8859P15  The query returns a column containing a \00BF character (i.e. asciistr(column) contains \00BF). select description raw, asciistr(description) tidied from aradmin.CHG_INFRASTRUCTURE_CHANGE where asciistr(description) != description and rownum < 2;  Raw: 08:00 ▒ 17:00 Tidied: 08:00 \00BF 17:00  Using sqlplus I get the same result on both servers. Using php/oci my old server automagically replaces the '▒' with a '?' which a subsequent json_encode handles without issues. My new server is currently returning the raw value, which is breaking the subsequent json_encode. How do I get the new server to do automatic replacement too? I'd like to avoid changing individual queries but they all use a common DatabaseConnection class which I can change, if required. New Apache build: sudo ./configure --enable-so --prefix=/usr/local/apache2.4 --with-apr-util=/usr/local/apr/bin/apu-1-config New php build: sudo ./configure --prefix=/usr/local/php5.6 --enable-bcmath --with-bz2=/usr/bin/bzip2 --enable-calendar --with-curl --enable-dba=shared --with-cdb --enable-exif --with-gd --with-gettext --with-gmp  --with-ldap --with-mhash --with-openssl --with-readline --with-snmp --with-xmlrpc --with-xsl --with-zlib --enable-sysvsem --enable-sysvshm --with-libdir=lib64 --enable-dtrace --with-config-file-scan-dir=/usr/local/php5.6/php.d --with-config-file-path=/usr/local/php5.6 --with-unixODBC=/usr --enable-soap --with-jpeg-dir=/usr/lib --with-xpm-dir=/usr/lib64 --with-apxs2=/usr/local/apache2.4/bin/apxs --with-pdo-mysql


Does 'but for' mean:  'If we had X (but we didn't), Y would have been the consequence'?  Or can it also mean; because we had X, as a result Y happened?   Some different examples of but for:  (Case 1)     But for a cup coffee, it was to be a productive day of writing.   Unfortunately, I'd run out, and spent the day craving.    (Case 2)     But for the glass of wine I had dinner, the house work didn't get   done.   (Case 3)     But for the glass of wine I had for dinner, I would have got the   house work done   What is the correct usage of "but for"?


I'm having trouble understanding how to access each individual result returned from a subquery. The picture shows the code which:   takes fields and objects chosen by a user and assigns them to String variables, the string vars are used to query a dynamic query string, the query string is feed into a database.query and the result is stored in an array I can individually access each of the query results from this array (parent object results),  But I have not been able to individually access the subquery results.   If I feed the subquery results into an array...something like:  SObject[] c = p.get(i).getSObjects(childO);   I still can't get to each individual child record per parent. I can only see all child records per each parent. I need to get to each child record per adult, so that I can roll up results.  Can anyone help?  // These strings will be populated dynamically from a VF page String parentO  = 'Account'; String parentF  = 'Products_Purchased__c'; String childO   = 'Opportunity';     if(childO  == 'Opportunity'){ childO = 'Opportunities'; } String childF   = 'Product_Type__c';  // create dynamic SOQL query string String query = 'SELECT id, (select ' +childF+ ' from ' +childO+') FROM ' +parentO;  // query and store 33 results in variable p SObject[] p = Database.query(query);  for(Integer i = 0; i < p.size(); i++){     system.debug('Parent result from SOQL query: ' +p[i]);     if(p.get(i).getSObjects(childO) <> null){         system.debug('Child result(s) from SOQL query: ' +p.get(i).getSObjects(childO));         system.debug('Child field: ' +c.get(i).get(childF));     } }


Prove that if the quadratic form $x^{T}Ax$ is positive definite, so is $x^{T}A^{-1}x$

Is it because the values in the inverse matrix will have the same positive/negative values?


Let $a,b,c$ be $3$ distinct integers, and let $P$ be a polynomial with integer coefficients.Show that in this case the conditions $$P(a)=b,P(b)=c,P(c)=a$$ cannot be satisfied simultaneously.  Any hint would be appreciated.


Cannot browse website from web server local network

I have an web server where I have hosted my domains. Also I am using the same network to my home. But I can not see my domains from the same network. I have to use different internet service to access that. WHat should I do now?


How to Summary a table in Oracle with Dates

I have this table called HISTORY:  CREATE TABLE HISTORY (START_DATE DATE, POSITION  VARCHAR2(80 BYTE));   The table is populated like this:  START_DATE    POSITION 15-jun-1983   SUPPLY ATTENDANT 01-abr-1987   SUPPLY HELPER 01-mar-1990   SUPPLY ASSISTANT 01-mai-1991   TECHNICAL SUPLY ASSISTENT 01-abr-1999   TECHNICAL SUPLY ASSISTENT SR 01-dez-1999   SUPPLY TECHNICIAN 01-mai-2001   SUPERVISOR 01-jul-2002   SUPERVISOR 01-jan-2004   SECTOR MANAGER 01-jul-2005   SECTOR MANAGER 01-fev-2006   SECTOR MANAGER 01-jan-2007   SENIOR SUPPLY TECHNICIAN 01-mai-2007   SECTOR MANAGER 01-fev-2008   SENIOR SUPPLY TECHNICIAN   I want to make a query that summarize it like this way:  START_DATE    POSITION 15-jun-1983   SUPPLY ATTENDANT 01-abr-1987   SUPPLY HELPER 01-mar-1990   SUPPLY ASSISTANT 01-mai-1991   TECHNICAL SUPLY ASSISTENT 01-abr-1999   TECHNICAL SUPLY ASSISTENT SR 01-dez-1999   SUPPLY TECHNICIAN 01-mai-2001   SUPERVISOR 01-jan-2004   SECTOR MANAGER 01-jan-2007   SENIOR SUPPLY TECHNICIAN 01-mai-2007   SECTOR MANAGER 01-fev-2008   SENIOR SUPPLY TECHNICIAN   In a nutshell, I would to like to remove the grouped position repetitions, keeping only the first one.  Does anybody know how?  Thanks in advance


There's an old story, probably from Dozois's yearly anthology (pre-2000), about a human who plays an alien game. IIRC, it plays like Go and the pieces are red and blue. At the end of the story, the human becomes a master from a revelation from gameplay. "Blue is red and red is blue", or something along those lines. Haven't found it, hoping someone might know the tale.  Thank you


What does this mean & what impact does it have: Failed to download repository information

Today out of the clear blue I received the following message when I ran my updater under Ubuntu 13.10 laptop. Failed to download repository information. I see there are a ton of questions regarding this issue but this is not a duplicate because this is just more of an over view that I am looking for. So I did apt-get update and started seeing a bunch of 404 errors. I am far from a Linux pro, so how do I read these errors and how can I tell if these are important? I can tell you I have never manually modified the source list directly. And if these are dead ppa sources how can I remove and what does the letter mean in the below, almost looks like a drive letter but I dont have a W: drive.  W: Failed to fetch http://ppa.launchpad.net/pmcenery/ppa/ubuntu/dists/saucy/main/binary-amd64/Packages  404  Not Found W: Failed to fetch http://ppa.launchpad.net/pmcenery/ppa/ubuntu/dists/saucy/main/binary-i386/Packages  404  Not Found E: Some index files failed to download. They have been ignored, or old ones used instead.


java.lang.NullPointerException when using methods from multiple classes

I'm new to programming java and I'm attempting to find out why my code keeps giving me the error java.lang.NullPointerException. It's supposed to take 6 points, and create 2 triangles.  MAIN CLASS  public class Themain{   public static void main (String[] args){     Point pointone = new Point(1,2);     Point pointtwo = new Point(3,4);     Point pointthree = new Point(0,5);      Point josh = new Point(1,2);     Point abby = new Point(3,4);     Point trevor = new Point(0,6);       Triangle2D triangleone = new Triangle2D();     Triangle2D triangletwo = new Triangle2D();      triangleone.setPoint1(pointone);     triangleone.setPoint2(pointtwo);     triangleone.setPoint3(pointthree);      triangletwo.setPoint1(josh);     triangletwo.setPoint2(abby);     triangletwo.setPoint3(trevor);       } }   TRIANGLE CLASS    public class Triangle2D{    Point p1;   Point p2;   Point p3;   //no args constructor   public Triangle2D(){      }    //set point one    public void setPoint1(Point p){     p1.setXPos(p.getXPos());     p1.setYPos(p.getYPos());   }   //set point two   public void setPoint2(Point p){     p2.setXPos(p.getXPos());     p2.setYPos(p.getYPos());   }  //set point three   public void setPoint3(Point p){     p3.setXPos(p.getXPos());     p3.setYPos(p.getYPos());   }    //get point one    public Point getPoint1(){     return(p1);   }  }   POINT CLASS   public class Point{    int x;   int y;     //args constructor   public Point(int x, int y){     this.x = x;     this.y = y;   }    //get the x-coordiante   public int getXPos(){     return x;   }    //set the x-coordinate   public void setXPos(int x){     this.x = x;   }     //get the y-coordinate   public int getYPos(){     return y;   }    //set the y-coordinate   public void setYPos(int y){     this.y = y;   }    //is equals method    public boolean isEquals(Point t){     return(this.x == t.x && this.y == t.y);   }  }   I'm not sure why it's giving my the null error. The real code is much longer than this but I have take the section that was causing the error and I put it into this file. I'm mostly writing this because stack overflow says there is too much code. If someone could help me understand why this error appears it would be greatly appreciated.


What is correct:      helping one to accomplish the dreams?    OR      helping one accomplish the dreams?    The question I have is about the use of to in the first sentence?


"Try and get some rest" OR "Try to get some rest"?

Which sentence is grammatically correct?      Try and get some rest   (or)   Try to get some rest


I want to install Ubuntu on my dad's computer. The trouble is his computer will not boot from the live cd. I think the trouble has something to do with the bios. It is an Acer,model number 4520 and currently it has Windows Vista on it. How do you find bios on this computer? Here are some more details about the computer:   120 GB harddrive 64x2 dual core processor up to 384 MB NVIDIA GetForce  Thank you all in advance for your kind and generous support.


Regex not correctly replacing expected result python

I have a dictionary of words I want to replace. preprocess_pattern = {r" AND ": r" & ",  r" O\A ": r" O/A ",  r" D\B ": r" O/A ",  r" D/B ": r" O/A "}  def preprocess_rules(text):      for detect_pattern, replace_pattern in preprocess_pattern .items():         text = re.sub(detect_pattern, replace_pattern, str(text))              return text  preprocess_rules('AMAZON O\A MICROSOFT')  It gives me a result of 'AMAZON O\A MICROSOFT'; with two slashes(). The O\A didn't replace to O/A. Was wondering what is causing this issue.


Prove for two symbols a and b, if p(a) >= p(b), then according to Huffman encoding algorithm, the resultant code length L(a) <= L(b).  I did several examples of this and it is true. But how can I prove this?


Low loss and low accuracy. What is the reason?

We have trained two different neural networks for MNIST dataset. Here are the losses and accuracies obtained by these networks for the training data:  net0: loss: 20780.8291187 net1: loss: 209.928699374 net0: TRAIN ACCURACY     0.985890040888 net1: TRAIN ACCURACY     0.835298627336   The used loss function is the cross-entropy. We expect higher accuracies for lower losses, but here, the loss for net1 is about 100 times lower than net0 but its accuracy is lower. What is the reason?


Smoothness is the same as regularity at closed points for a finite type scheme of pure dimension $d$ over an algebraically closed field

This is exercise 12.2.I in Vakil's notes:     Suppose $X$ is a finite type scheme of pure dimension $d$ over an   algebraically closed field $k$. Show that $X$ is regular at its closed points if and   only if it is smooth.   For the forward direction, for a closed point $p$, $\operatorname{dim}\mathcal{O}_{X,p}=d$. From Exercise 12.1.G, one has that the Zasiki cotangent space at a closed point is given by the cokernel of the Jacobian matrix. If $X$ is regular at closed points, then corank of the Jacobian matrix is $d$ at all closed points, hence by Exercise 12.2.H, the Jacobian matrix has corank $d$ at all points. This shows the smoothness. Conversely, smoothness of $X$ implies the Jacobian has corank $d$ at all points, in particular closed points.   Is the result true for $k$ not algebraically closed? I don't see why it's required that $k$ is algebraically closed.


Can I run out of disk space by creating a very large number of empty files?

It is well-known that empty text files have zero bytes:    However, each of them contains , which according to my research, is stored in , and do use space.   Given this, it seems logical to me that it is possible to fill a disk by purely creating empty text files. Is this correct? If so, how many empty text files would I need to fill in a disk of, say, 1GB?    To do some checks, I run df -i but this apparently shows the % of inodes being used(?) rather than how much they weigh.  Filesystem             Inodes  IUsed    IFree IUse% Mounted on udev                   947470    556   946914    1% /dev tmpfs                  952593    805   951788    1% /run /dev/sda2            28786688 667980 28118708    3% / tmpfs                  952593     25   952568    1% /dev/shm tmpfs                  952593      5   952588    1% /run/lock tmpfs                  952593     16   952577    1% /sys/fs/cgroup /dev/sda1                   0      0        0     - /boot/efi tmpfs                  952593     25   952568    1% /run/user/1000 /home/lucho/.Private 28786688 667980 28118708    3% /home/lucho


How would I write the Granger Causality formula in Latex?

I require to write the Granger Causality formula in Latex for a project that I am undertaking. I do not, however, know how to produce the formula in math mode. Please can someone either point me towards a database of symbols and their corresponding Latex symbols or provide the Latex code for the formula itself. The formula, taken from  is as follows:


In the following command I would like to know why $0 was evaluated to the file found by find and not the echo command.  $ find . -type f -perm -u=x -exec bash -c '   /bin/echo $0 is the name of the file' {} \;   I know that if I had used double quotes, $0 would equal -bash and using single quotes delays the expansion, but why doesn't it expand to /bin/echo since that is the called command (which normally would be $0)?


Randomize widgets displayed in my sidebar

I have a sidebar which might have any number of widgets. I can count the number of widgets that exist in the sidebar. How do I display randomly only one of the widgets in my sidebar at each page load?  Use: We have specials which we display as widgets, but we only want to display one widget's content at a time in the footer of the site.  re: the count code  <?php $the_sidebars = wp_get_sidebars_widgets(); echo count( $the_sidebars['center-footer'] ); ?>   re: generating a random widget instance  <?php echo rand(1, count( $the_sidebars['center-footer'] )); ?>


Is there a package containing the squiggly arrow that Artin uses in his Algebra text? It looks like:  I've seen some of the options using tikz on here, but they aren't quite the same.


I had windows & Kali linux (dual boot) then I took off Kali linux Parition so I delete it but I Made a mistake ... and PC won't boot "Rescue grub error" or something ...   but I installed Ubuntu & removed Windows and all .  All is running fine but I just can't open one of my disks , this is the error :   Error mounting /dev/sdb5 at /media/imad/Disque local: Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,dmask=0077,fmask=0177" "/dev/sdb5" "/media/imad/Disque local"' exited with non-zero exit status 14: The disk contains an unclean file system (0, 0). Metadata kept in Windows cache, refused to mount. Failed to mount '/dev/sdb5': Operation not permitted The NTFS partition is in an unsafe state. Please resume and shutdown Windows fully (no hibernation or fast restarting), or mount the volume read-only with the 'ro' mount option.   I asked this question before but no one had an idea , help please .


Why isn't the least squares predictor $\Phi(\Phi^\top\Phi)^{-1}\Phi^\top$ simply the identity matrix?

Given target vector $y$. Want to predict it using linear regression $h(w) = w^Tx$  Let $\Phi$ be the least squares matrix, i.e., $\Phi = \begin{bmatrix} x_1^\top \\ \vdots\\ x_n^\top \end{bmatrix}$   The least squares prediction is,  $$\hat y = \Phi(\Phi^\top\Phi)^{-1}\Phi^\top y$$  But why isn't  $\Phi(\Phi^\top\Phi)^{-1}\Phi^\top$  simply the identity matrix?  Observe,  $\Phi(\Phi^\top\Phi)^{-1}\Phi^\top = \Phi(\Phi^{-1}{\Phi^\top}^{-1})\Phi^\top = I I = I$  Thanks!


(Ubuntu 16.04) Where can I find gthread-2.0?

trying to compile qemu-stm32 I get this error message ERROR: glib-2.12 gthread-2.0 is required to compile QEMU  but sudo apt-get install gthread-2.0 (or just gthread)  resulted in E: Unable to locate package gthread-2.0 / gthread  Any help will be appreciated. M'


How to restore data part by part after dd?

I wiped out data on external HDD (NTFS) by dd. Wanted to write ISO on usb-stick. But I don't have any storage that could embrace volume of those external HDD. So I need to safe part of data here and part there during recovery (Testdisk tells that there not enough space).  Could you recommend software ? And would be nice to have guidance through this.


How to compute varimax-rotated principal components in R?

I ran PCA on 25 variables and selected the top 7 PCs using prcomp.   prc <- prcomp(pollutions, center=T, scale=T, retx=T)   I have then done varimax rotation on those components.  varimax7 <- varimax(prc$rotation[,1:7])   And now I wish to varimax rotate the PCA-rotated data (as it is not part of the varimax object - only the loadings matrix and the rotation matrix). I read that to do this you multiply the transpose of the rotation matrix by the transpose of the data so I would have done this:  newData <- t(varimax7$rotmat) %*% t(prc$x[,1:7])   But that doesn't make sense as the dimensions of the matrix transposes above are $7\times 7$ and $7 \times 16933$ respectively and so I will be left with a matrix of only $7$ rows, rather than $16933$ rows... does anyone know what I am doing wrong here or what my final line should be? Do I just need to transpose back afterwards?


Note: This was posted when I was starting out C#. With 2014 knowledge, I can truly say that auto-properties are among the best things that ever happened to the C# language.  I am used to create my properties in C# using a private and a public field:  private string title; public string Title {     get { return title;  }     set { title = value;  } }   Now, with  3.0, we got auto-properties:  public string Title { get; set; }   I know this is more a philosophical/subjective questions, but is there any reason to use these auto-properties except from saving five lines of code for each field? My personal gripe is that those properties are hiding stuff from me, and I am not a big fan of black magic.  In fact, the hidden private field does not even show up in the debugger, which is OK given the fact that the get/set functions do nothing. But when I want to actually implement some getter/setter logic, I have to use the private/public pair anyway.  I see the benefit that I save a lot of code (one vs six lines) without losing the ability to change the getter/setter logic later, but then again I can already do that by simply declaring a public field "Public string Title" without the need of the { get; set; } block, thus even saving more code.  So, what am I missing here? Why would anyone actually want to use auto-properties?


Using Python script as precondition in ArcGIS ModelBuilder?

I have a model that has two preconditions, in which I need to figure out if there is a way to prioritize one precondition to 'run' prior to the second. Is anyone aware of any built-in ability to do so with Model Builder or that can suggest a work around?  For instance, if I try to 'link' one precondition to another, I get the error "Can only connect a variable to a process", this is because my 'output' has a precondition that a python script needs to be run against it first, and then that output has the second precondition executed (but only once the original output has been altered by the Python script).


I have dozens of vector layers that I want to join together in QGIS.    They have identical fields.    How do I do this?


Why are titles of blocks in beamer not translated with the babel package

Is there a way to change only the title of a build in beamer block? Because the babel package doesn't do it. \documentclass{beamer} \usepackage[dutch]{babel} \begin{document} \begin{frame}{Translate example into voorbeeld} \begin{example} test     \end{example} \end{frame} \end{document}   thanks


Very short phd interview presentation in just 2 slides

I have been invited for a phd interview and I was asked to prepare a 4 minute presentation with a max of 2 slides only on myself and my research interests. The fact that it's extremely restricted in time and number of slides makes me a bit too anxious. I'm not sure what info I'm expected to present in such a short time and in just 2 slides. Any tips?


A Novel that had dragon riding as a normal thing and the main character stole a runt to raise as his own

I read this book when I was very young and I wanted to find it again.  Things I remember:    Male and female humans as main roles Dragons are normal part of the world Riding dragons without proper saddles or doing it in a certain way can lead to major injuries or death Towards the end the whelpling grows up and has its own hatchlings and the two main characters end up taking care of them after the original dragon dies and they have to hide in its belly to survive freezing cold weather. Afterwards they had special eye power things? Like they saw in prism colors or something.


I want to write a query for the , but I'm not sure which language I need to learn in order to do so. At a glance it looks a bit like SQL, but I'm not entirely sure.  What language are SE Data Explorer queries written in?


How to create UEFI-only bootable USB live media?

Having live media that can boot both ways can be a problem when installing Ubuntu onto currently available Windows 8 computers.  In other words the key advantage to creating UEFI-only bootable USB live media is: You know that it definitely booted and installed via UEFI.   Since Valve has already been doing UEFI-only booting USB installers with their Debian-based Steam OS and UNetbootin — the top voted alternative to Ubuntu's Startup Disk Creator — isn't UEFI compatible and therefore misleading, I think we should have a separate topic for creating UEFI-only bootable USB live media.


Weird error when launching VLC from command line

Does anyone know how to solve this error? I tried viewing the content of the files in question, but I can only see weird characters.  cannot load module `/usr/lib/vlc/plugins/gui/libqt4_plugin.so' (/usr/lib/libEGL.so.1: undefined symbol: _mali_clz_lut)


Assume that a variable $x$ is strictly postive. I m looking for resources about polynomials with real degree, i.e: $a_1x^{r_1}+...+a_px^{r_p}$, where $a_i,r_i$ are real numbers. Is there any name for this ? Or better yet for integrals of such, i.e. $\int a(s)x^s ds$ with a(s) being some function


Is there a way to get trig functions without a calculator?

In school, we just started learning about trigonometry, and I was wondering: is there a way to find the sine, cosine, tangent, cosecant, secant, and cotangent of a single angle without using a calculator?  Sometimes I don't feel right when I can't do things out myself and let a machine do it when I can't.  Or, if you could redirect me to a place that explains how to do it, please do so.  My dad said there isn't, but I just had to make sure.  Thanks.


How can I get the value of a property of all the classes that implements an interface?

I have the following architecture:  public interface IStatus {     string StatusName {get;} } public class A: IStatus {     public string StatusName {get {return "A Status";}} }  public class B: IStatus {     public string StatusName {get {return "B Status";}} }  public class C: IStatus {     public string StatusName {get {return "C Status";}} }   I tried the following and I can see in debug all the relevant classes but I am not sure how to get the StatusName property for each one of the classes. I presume, I need to create an instance of each class somehow and ask for the StatusName property.  public class Test {     var type = typeof(IStatus);     var types = AppDomain.CurrentDomain.GetAssemblies()             .SelectMany(s => s.GetTypes())             .Where(p => type.IsAssignableFrom(p));          foreach (Type mytype in types)         {             var i = mytype.GetMember("StatusName");             if (i.Count()!=0)             {                 var n = i.GetValue(0);             }                        } }   The expected result I need is a list of string with values:     "A Status",     "B Status",     "C Status"


Uploading a revised version of published journal article on arXiv

I uploaded a pre-print of an article on arXiv 1 year ago. The article was accepted in SCI journal and currently available online. However, I found a typo mistake in one equation and want to add more discussion related one figure (On researchgate I am receiving a lot of queries regarding that figure). Should i upload a new version of pre-print on arXiv? (How citations will work in this case? as arxiv version is more advanced compare to Journal version) OrI may upload a short document on arXiv as an errata/correction with extra discussion?Or I may address errata and discussion in online page of journal? Actually this journal allows the registered users to comment and start discussion related to published article.


Show that an algebraically closed field must be infinite.    Answer  If F is a finite field with elements $a_1, ... , a_n$ the polynomial $f(X)=1 + \prod_{i=1}^n (X - a_i)$ has no root in F, so F cannot be algebraically closed.  My Question  Could we not use the same argument if F was countably infinite? Couldn't we say that if F was a field with elements $a_1, a_2, ... $ then the polynomial $f(X) = 1 + \prod_{i=1}^{\infty} (X - a_i)$ does not split over F?  Thank you in advance


Sum as an increasing sequence of two or more consecutive integers

In how many ways can $105$ be written as the sum of an increasing sequence of two or more consecutive positive integers?   I got the above question for small numbers. For example I took 15.  Since $15=3\times5$  $15=3+3+3+3+3=(3-2)+(3-1)+(3)+(3+1)+(3+2)=1+2+3+4+5$  $15=5+5+5=(5-1)+(5)+(5+1)=4+5+6$  So there are $2$ ways for $15.$ Can I apply this method to $105.$ How ?


I'm a typical student in a 3rd world country working to pay for college. My monthly tuition is about 300 USD. Internships average pay is 450 USD for 30h/week of work... As I get to end of my bachelor, i'm required to write a dissertation, and when i start looking for articles and references if found this amazing paper: "QODM: A query-oriented data modeling approach for NoSQL databases" which lines 100% with my thesis. But it costs whooping 33 bucks! for a single source that might turn out to be not useful at all...  Are there alternative sources? (besides piracy, which i'm strongly against but is becoming really tempting right now...)


How to get the current column name in Excel?

What is the function to get the current line number and the current column name for a cell in Excel?


If the sum of eigenvectors is an eigenvector, then they all correspond to the same eigenvalue

I believe I am very close to finishing this proof, but I cannot figure out the last part. If anybody could check my work and maybe give me a little hint, it would be greatly appreciated!  Let $V$ be a finite-dimensional vector space and $T \in \mathcal{L}(V)$, and let $\mathbf{u,v} \in V$ be eigenvectors of $T$.  Claim:  If $\mathbf{u} + \mathbf{v}$ is an eigenvector of $T$, then $\mathbf{u}, \mathbf{v}$, and $\mathbf{u+v}$ all correspond to the same eigenvalue.  Proof (So far!): Suppose $T(\mathbf{u}) = \lambda_1 \mathbf{u}$ and $T(\mathbf{v}) = \lambda_2 \mathbf{v}$ with $\mathbf{u}, \mathbf{v} \neq \mathbf{0}$.   Now suppose $T(\mathbf{u+v}) = \lambda_3(\mathbf{u+v})$ with $\mathbf{u+v}\neq \mathbf{0}$.  Then, $$ T(\mathbf{u}) + T(\mathbf{v}) = \lambda_3 \mathbf{u} + \lambda_3 \mathbf{v}\\ \lambda_1\mathbf{u} + \lambda_2\mathbf{v} =  \lambda_3 \mathbf{u} + \lambda_3\mathbf{v}\\ \lambda_1\mathbf{u} + \lambda_2\mathbf{v} - \lambda_3 \mathbf{u} -\lambda_3\mathbf{v} = \mathbf{0}\\ (\lambda_1 - \lambda_3) \mathbf{u} + (\lambda_2 - \lambda_3)\mathbf{v} = \mathbf{0} $$  Now I know in order to show that $\lambda_1 = \lambda_2 = \lambda_3$, I must show that the only solution to the last line is the trivial one. This would imply that $\mathbf{u}$ and $\mathbf{v}$ are linearly independent which I am unconvinced of!  The only information I have to my advantage I haven't used yet is the fact that $\mathbf{u}, \mathbf{v}, \mathbf{u+v} \neq \mathbf{0}$. I really cannot see how this information can help me though.  Perhaps I am going about this wrong, but that's why I want to ask! Thanks for your help.


How to fix Exception in thread "main" java.lang.NullPointerException Error?

I am getting Exception in thread "main" java.lang.NullPointerException error. I am stuck at this code from so long . Can I get some help? Also when I tried running this code in Hackerank(Since it is a hackerank problem) editor, it worked. I am new to Data structures. So can someone help me in getting this error fixed? This is the error I am getting: Exception in thread "main" java.lang.NullPointerException     at java.base/java.io.FileOutputStream.<init>(FileOutputStream.java:225)     at java.base/java.io.FileOutputStream.<init>(FileOutputStream.java:123)     at java.base/java.io.FileWriter.<init>(FileWriter.java:66)     at Test/LinkedLists.Solution.main(Solution.java:79)  This is the code: public class Solution {      static class SinglyLinkedListNode {          public int data;          public SinglyLinkedListNode next;                    public SinglyLinkedListNode(int nodeData) {                 this.data = nodeData;                 this.next = null;             }         }     static class SinglyLinkedList {         public SinglyLinkedListNode head;         public SinglyLinkedListNode tail;          public SinglyLinkedList() {             this.head = null;             this.tail = null;      }         public void insertNode(int nodeData) {             SinglyLinkedListNode node = new SinglyLinkedListNode(nodeData);              if (this.head == null) {                 this.head = node;             } else {                 this.tail.next = node;             }              this.tail = node;         }     }      public static void printSinglyLinkedList(SinglyLinkedListNode node, String sep, BufferedWriter bufferedWriter) throws IOException {         while (node != null) {             bufferedWriter.write(String.valueOf(node.data));              node = node.next;              if (node != null) {                 bufferedWriter.write(sep);             }         }     }       static SinglyLinkedListNode insertNodeAtPosition(SinglyLinkedListNode head, int data, int position) {         if (head == null) return null;         SinglyLinkedListNode temp = new SinglyLinkedListNode(data);         if (position == 0) {             temp.next = head;             return temp;         }         SinglyLinkedListNode p = head;         for (int i = 0; i< position-1; i++) {             p = p.next;         }         SinglyLinkedListNode next = p.next;         p.next = temp;         temp.next = next;         return head;     }    private static final Scanner scanner = new Scanner(System.in);      public static void main(String[] args) throws IOException {     BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));      SinglyLinkedList llist = new SinglyLinkedList();      int llistCount = scanner.nextInt();     scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");      for (int i = 0; i < llistCount; i++) {         int llistItem = scanner.nextInt();         scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");          llist.insertNode(llistItem);     }      int data = scanner.nextInt();     scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");      int position = scanner.nextInt();     scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");      SinglyLinkedListNode llist_head = insertNodeAtPosition(llist.head, data, position);      printSinglyLinkedList(llist_head, " ", bufferedWriter);     bufferedWriter.newLine();      bufferedWriter.close();      scanner.close(); } }


What is the correct capitalization if "3D Printing"?

How should "3D Printing be capitalized? Why?  A) 3D Printing  B) 3D printing  C) 3d Printing  D) 3d printing


How to construct a dictionary from two dictionaries in python?

Let's say I have a dictionary:  x = {"x1":1,"x2":2,"x3":3}   and I have another dictionary:  y = {"y1":1,"y2":2,"y3":3}   Is there any neat way to constract a 3rd dictionary from the previous two:  z = {"y1":1,"x2":2,"x1":1,"y2":2}


I want to allow one more tag in Filter html Allowed HTML tags: <a> <em> <strong> <cite> <code> <ul> <ol> <li> <dl> <dt> <dd> <blockquote>.   I want to add <table> in this list. How can I edit this and in which hook I can modify this.  Anyone can help me?


How to write dihedral group in cycle notation?

Since each symmetry can be thought of as a permutation of the vertices, the elements of $D_n$ can be thought of as elements of $S_n$. So I'm wondering if there's a systematic way that we can always write elements of $D_n$ in disjoint cycle notation?


Why is my code not parsing a given string to xml as here? It is not duplicate as I used help from existing answers too but can't correct it

public static void main(String[] args) throws SAXException, ParserConfigurationException, IOException     {         String fXml="<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>\n" + "<Emp id=\"1\">\n" + "    <name>Pankaj</name>\n" + "    <age>25</age>\n" + "    <role>Developer</role>\n" + "    <gen>Male</gen>\n" + "</Emp>";        DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();     DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();     Document doc = dBuilder.parse(fXml);      doc.getDocumentElement().normalize();      System.out.println("Root element :" + doc.getDocumentElement().getNodeName());     }   I am getting the following errors:  Exception in thread "main" java.net.MalformedURLException: no protocol: <?xml version="1.0" encoding="UTF-8" standalone="yes"?>   How do I make work as intuitive? Yeah the problem lies in the very first line but I am not sure how to correct this.


Expressing the area of the cross section of a cylinder

I was able to solve similar questions where a triangle was involved, but this one has had me looping and pondering on it for the past week.  The Condition: Let $r$ be a positive constant. Consider the cylinder $x^2+y^2\leq r^2$ and let C be  part of the cylinder that satisfies $0\leq z\leq y$.  The questions:  (1) Consider the cross section of $C$ by the plane $x=t(-r\leq t\leq r)$ and express its area in terms of $r,t$  (2) Calculate the volume of $C$, and express it in terms of $r$.  (3) Let $a$ be the length of the arc along the base of the circle $C$ from the point $(r,0,0)$ to the point $(r cos\theta,r sin\theta,0)(0\leq\theta\leq\pi)$. Let $b$ be the length of the line segment from the point $(r cos\theta, r sin\theta, 0)$ to the point $(r cos\theta, r sin\theta, r sin\theta)$. Express $a$ and $b$ interms of $r,\theta$  (4)Calculate the are of the side of $C$ with $x^2+y^2=r^2$, and express it in terms of $r$.  Here are the expected answers(which I keep failing to get to):  (1) $\frac{1}{2}(r^2-t^2)$  (2) $\frac{2}{3}r^3$  (3) $r\theta$ and $r sin\theta$  (4) $2r^2$


I am reviewing for a test and i find the following good exercice. Would you please help me to prove the second part of the question b) here   for question a) i find $|G|=32$ since $G=C_8\ltimes C_2\times C_2$ Thanks for your help in advance.


Reformatted Windows 8 laptop not loading Installed Ubuntu 13.04 x64

I have a new(er) HP Pavillion G6, and I completely wiped the hard drive to install ubuntu primarily, with a small Windows 7 partition. I created a partition for "/", the "/home" directory, a little for swap, and one for the windows section. Finished installing, restarted, it says "boot device not found, please install operating system. What steps should I take to install ubuntu and windows 7? Thank you for any help offered.


I am going to ask a simple question, for sure.  The pressure with respect to the altitude is given by this formula    Where    sea level standard atmospheric pressure p0 = 101325 Pa sea level standard temperature T0 = 288.15 K Earth-surface gravitational acceleration g = 9.80665 m/s2. temperature lapse rate L = 0.0065 K/m universal gas constant R = 8.31447 J/(mol·K) molar mass of dry air M = 0.0289644 kg/mol   ( from  )  In addition to this, we have $L = \frac{g}{C_p}$ where $g = 9.80665\ m/s^2$ and $C_p$ is the constant pressure specific heat $ = 1007\ J/(Kg\ K)$  Understood and thence the above formula can be written in this simple way:  $$\boxed{P = P_0\left(1 - \alpha h\right)^{\beta}}$$  where  $\alpha = \frac{g}{C_p\ T_0} \approx 3.3796\cdot 10^{-5}\ m^{-1}$  $\beta = \frac{C_p\ M}{R} \approx 3.5081971$  On the other side we learnt from the elementary physics that the formula for the pressure is also given by  $$\boxed{P = P_0 + \rho g h}$$  Where $\rho$ is the air density $(1.23\ kg/m^3)$.  The question  First thing first: I assumed that  $$h = h_1 - h_0$$  is that correct? I mean it's the difference between two heights (maybe from a table and the ground, just to say).  Since the two formulae seems quite different, I tried with a numerical example in calculating the pressure in two points, with a difference of height about $0.18$ m and I got a really similar result.  Since the first formula is more technique, I think it's the correct formula but I would like to understand if one could pass from the first to the second or vice versa somehow.  Also I would like to know if there are cases in which I can use only the second formula or only the first formula!


Is there something as simple and easy to use as Paint?

Is there a simple and easy app on Ubuntu to do some quick and dirty blocking of say... a license plate in a picture?    I'm hoping that I don't have to install anything, because it's going to long and painful if I do.


Can't make partition, GParted shows 450 GB unused

I'm using Ubuntu 16.04. I can't create new partition on sda 2, GParted shows 450 GB unused but still I can't do partition. Please let me know what's the problem?


Suppose $u\in W^{1,1}$ and $\partial u$ is $C^1$. I want to prove the following: $\int_{\partial\Omega}|u-\bar u|\leq A\int_{\Omega}|\nabla u|$, where $\bar u=\dfrac{1}{|\Omega|}\int_{\Omega}u$ and $A>0$. Note that unlike Poincare inequality, the left integral is over $\partial\Omega$ and not $\Omega$. How can I do that?


Bijections from $A$ to $B$, where $A$ is the set of subsets of $[n]$ that have even size and $B$ is the set of subsets of $[n]$ that have odd size

Let $A$ be the set of subsets of $[n]$ that have even size, and let $B$ be the set of subsets of $[n]$ that have odd size.  Establish a bijection from $A$ to $B$.  The following bijection is suggested for $n=3$:  $$\matrix{A: & \{1,2\} & \{1,3\} & \{2,3\} & \varnothing\\  B: & \{1,2,3\} & \{1\} & \{2\} & \{3\}}$$  I know that first we have to establish a function that is both surjective and injective so that it is bijective. I don't know where to take a step from here in the right direction. So I need a bit of guidance.   Something suggested is let f be the piecewise function:  $$f(x) = x \setminus \{n\}\text{ if }n \in x\text{ and }f(x) = x\cup\{n\}\text{ if }n \notin x$$


Extending my root partition on windows/ubuntu dual boot

I want to resize /dev/sda5 to take all of the unallocated space (242.25 GiB). How can I accomplish this?  EDIT 1:   swapon output: NAME         TYPE       SIZE USED  PRIO /dev/sda6    partition  14G  0B        -1  sudo blkid | grep swap output /dev/sda6: UUID="d4ae2fb5-2069-4b6d-b86d-e8c94ebf0fd9  grep swap /etc/fstab output: # swap was on /dev/sda6 during reparation UUID=d4ae2fb5-2069-4b6d-b86d-e8c94ebf0fd9 none swap sw 0 0


I get a string from database that contains strange characters, and the characters break the json string.  Here is the json string:  {"id":13,"code":"cflw`2B2[h1s`lNzF@sPC1FtaCiK0VF@","label":"Anonymous lifestyle App cflw`2B2[h1s`lNzF@sPC1FtaCiK0VF@"}   It looks OK, but there are '^A' between i and K (2B2[h1s`lNzF@sPC1FtaCiK0VF@), we can not see it from here, but if you copy it to a text editor, it will show up.  My question is how to make this json string parsable? or how to use Python to remove '^A'?


I want to uninstall Ubuntu that I have partitioned on my hard drive.   I want it uninstalled so that I can install the new version for Windows that allows for dual booting (alongside Windows). How do I get to the area where I can access Ubuntu that was partitioned?  I want to get to in so I can uninstall it before I install Ubuntu for Windows.     I tried creating an ISO image of Ubuntu on my USB drive, but I couldn't access the Welcome page of the program so I could get to the Allocate drive space portion, but it never showed up. Is that the way to go about it?


update-java-alternatives vs update-alternatives --config java

On Ubuntu 12.04 LTS I have installed Sun's JDK7, Eclipse, and the Arduino IDE. I want the Arduino to use OpenJDK 6 and want Eclipse to use Sun's JDK 7.   From my understanding I need to manually choose which Java to use before running each application. This led me to the update-java-alternatives -l command. When I run this I only see the following:   java-1.6.0-openjdk-amd64 1061 /usr/lib/jvm/java-1.6.0-openjdk-amd64   but when I run update-alternatives --config java I see the following:   *0  /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java   auto mode 1  /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java   manual mode 2  /usr/lib/jvm/jdk1.7.0/bin/java                   manual mode 3  /usr/lib/jvm/jre1.7.0/bin/java                   manual mode   I don't understand why the update-java-alternatives doesn't display the same 3 options. I also don't understand how to switch between OpenJDK6 and JDK7. How I can go about using the OpenJDK6 for Arduino development and Sun JDK7 for Eclipse/Android development?


Why can infinite series be summed different ways to get different results?

$$S = 1 - \frac12 + \frac13 - \frac14 + \frac15 - \frac16 + \frac17 - \frac18 + \frac19 - \frac1{10} + \frac1{11} - \frac1{12}\ldots\text{(to infinity)}$$  Rearranged, this series looks like: $$S = \left(1 - \frac12\right) - \left(\frac14\right) + \left(\frac13 - \frac16\right) - \left(\frac18\right) + \left(\frac15 - \frac1{10}\right) - \left(\frac1{12}\right) + \left(\frac17 - \frac1{14}\right) \ldots\text{(to infinity)}\\  S = \left(\frac12\right) - \left(\frac14\right) + \left(\frac16\right) - \left(\frac18\right) + \left(\frac1{10}\right) - \left(\frac1{12}\right) + \left(\frac1{14}\right) \ldots\text{(to infinity)}$$  This rearranged infinite series contains every number that the original infinite series had.  Further,  $$ 2S = 1 - \frac12 + \frac13 - \frac14 + \frac15 - \frac16 + \frac17 - \frac18 + \frac19 - \frac1{10} + \frac1{11} - \frac1{12} \ldots\text{(to infinity)}$$ Thus: $2S = S$ $2 = 1$ Mathematics disproven.  Sorry.  Jokes aside, I know that infinite series can be calculated in different ways to get different results.  My question is: Why?  While it makes sense with Grandi's and similar series, it doesn't make sense to me for a series whose final term is $\frac1\infty = 0$.


How can I dump the memory of a process in Windows 7?

Are there any tools to dump the running application from memory in Windows 7?


How to prevent software updater from crashing in at 8 AM?

Software updater runs itself exactly at the moment I start important work in the morning. It stops proper work of all other processes as the disk starts working violently. It's not unusual that it leads to locking up of certain more sensitive software.  How do I prevent software updater from taking all the resources of the system and halting all other processes which do not have any access to memory resources while "software updater" prepares itself to run?  Is there any solution how to use a computer without restarting it daily?


How do you configure proxy settings in the Ubuntu Server or Minimal (CLI) versions using the terminal?


How to connect device with 5V power to PC via USB without power conflict?

The PC's USB port design to suppply 5V to connected device but what if device already has 5V supply? Considered voltage stabillity/accuracy and data-tranfer abiility, what is the best way to do?  Don't use USB 5V, just use common ground to transfer data. Use USB 5V to power device and disconnect internal 5V supply.


Loop through properties of one Object base type

I have to iterate through property of one object base type that i get from database and i have to check if any property i snull. Here is some code:   req = "select * from Ga_Periodes_Absence";  var resultat = Session.CreateSQLQuery(req).List<object>();  foreach (var elem in resultat)  {      int i = 0;       i++;  }   resultat contains list of objects that I want to check if property of any of them is null. Any help please.


Why voltage regulators instead of voltage dividers for supplying power to loads?

I have to supply 80 Raspberry Pi's with power, so I began looking into it and found a power supply of 12V 20A (might not be enough current to supply 10 Pi's that typically draw 1.5A - 2A though).  This meant that I would need to drop 12V to 5V, which I was originally planning to do using resistors for a voltage divider. However with a bit of brief researching I found you should never use voltage dividers as a power supply to loads due to the power that needs to be dissipated.  So I discovered using a voltage regulator was the way to go, however what I don't understand is, if a schematic of a voltage regulator component shows it is comprised of many resistors and transistors wouldn't this suffer the exact same problems as a voltage divider? Wouldn't the resistors internally burn up due to the power dissipation?  Or is it due to the heat sink attached to the component, which would mean hypothetically if you could attach a heat sink to a resistor it'd be fine to use a voltage divider to supply a load?  The reason I ask is trying to work out the best way to efficiently and safely supply 5V at 1-2A to all 80 Pi's I'm aware a few computers is a smarter option however the project involves 80 Pi's and that'sthe way it must remain


How wide does a wall of ice need to be to stay in place?

Let us say that we have unlimited manpower to construct a huge wall of water ice e.g. 200 m tall (700 feet). -and that the wall is placed in a climate, where the temperature never (for your purpose) goes above freezing point. The wall is to have fairly steep sides, so let us assume a perfect rectangular cross section. A very narrow wall would obviously shatter at the bottom. A very wide wall would approach a natural ice cliff side and thereby be possible.   How wide does the wall need to be? What properties of ice is relevant to calculate that?


Partial transparency in viewport (cycles)?

Is there a way to display partial transparency in the 3d view in cycles while modeling?   Related:   The method above looks like it only works in rendered view in the viewport which isn't very compatible when modeling. Is there another way to have transparency in the 3d view?


What is the intuition behind the fact that: $$ 0.9999999\ldots = 1 $$ My Teacher's Proof: We know that any number which belongs to the interval $[0,1)$ can be uniquely written as decimal expansion: $$ x=0.a_1a_2a_3 \ldots = a_1×10^-1+a_2×10^-2+a_3×10^-3 + \ldots $$ where the digits $a_1,a_2,a_3 \ldots$ satisfy the following: Each digit $a_i$ is an integer in the 10-element set ${0,1,2,....,9}$ So, $$ 0.9999999 \ldots = \frac{9}{10} + \frac{9}{100} + \frac{9}{1000} \ldots = 9 [$\frac{1}{10} + \frac{1}{100} + \frac{1}{1000} \ldots$)] = 9 × \frac{1}{9} = 1 $$ My doubt: Since $$ [\frac{1}{10} + \frac{1}{100} + \frac{1}{1000} \ldots)] ≈ \frac{1}{9} $$ So $0.9999999 \ldots ≈ 1$ not exactly equal to $1$. Am I correct? Suppose some people jump towards the right with velocity $u$ relative to a cart. Let the mass of each person be $m$ and that of cart be $M$. If there are $N$ people then, $Nm=M$ Case 2: All people jump simultaneously. $$ \Rightarrow Nm(u-v_B)=M(v_B) $$ Hence, $v_B=\frac{u}{2}$ Case 1: People jump one after other. After the first man jumps off the velocity $v_1$, acquired by the cart to the left, $$ m(u-v_1)=(M+Nm-m)v_1 $$ Hence, $v_1 = \frac{mu}{M+Nm}$ After the second person jumps off, the velocity $v_2$ acquired by cart to the left, $$ m(u-v_2)+(M+Nm-m)v_1=(M+Nm-2m)v_2 $$ Hence, $v_2=v_1+\frac{mu}{M+Nm-m}$ Similarly, after the $n^{th}$ person jumps off, the velocity $v_n$ acquired by the cart to the left $(2≤n≤N)$. So, $v_n=v_{n-1}+\frac{mu}{M+Nm-nm}$ Therefore the velocity $(v_A)$ after all people have jumped off, $$ v_A=\frac{mu}{M+Nm}+\frac{mu}{M+(N-1)m}+\cdots+\frac{mu}{M+m} $$ How do I proceed from here? Answer:  $$\frac{v_A}{v_B}=2ln2 $$


Proving inequality $4n<2^n$ using induction all natural numbers that's greater than or equal to 5

Using mathematical induction, prove that $n\le5: 4n<2^n$  base case: $4(5) < 2^5$ $20 < 32$ Correct  I need help with the inductive process


Generic Interface takes self as Parameter. Recursive Generic?

Disclaimer: I don't have a whole ton of experience with Java Generics, but my colleagues and I just spent a solid hour trying to decipher an interface that was structured like this:  interface HasAttributes<A extends HasAttributes<A, B>,                          B extends HasAttributesType<B>> extends Identification<B> {   What exactly does it mean when an interface generic takes a type parameter that is itself?  What does this do?


How to get lamp object?  def test():     Lights = bpy.data.lamps     for light in Lights:         light.use_nodes = True;         light.type="POINT";         AdddLightIes(light)   #how to get light.object? and set position?


Which is correct:  She is married to a tall broad-shouldered man, or She is married to a broad-shouldered tall man?  Thanks.


Remove colon in the caption of a figure if the caption is empty

One of my figures should not have a caption, only the normal numbering. To get this, I use this code:  \begin{wrapfigure}{l}{4cm}   \begin{center}     \includegraphics[width=3cm]{graphic.pdf}     \caption[Caption for the list of figures]{}     \label{fig:figureX}   \end{center} \end{wrapfigure}   But now I get "Figure x.y:" as caption of my figure. How can I remove the ":", if the caption is empty? I found some solutions with renewcommand, but this changes the caption style in the whole document. I want to remove the colon only if the caption is empty. In any other case, it is good to have "Figure x.y: My Caption".


Cannot create a new document in /var/www

I'm unable to create a new document in /var/www/  I followed this tutorial :-   and did as suggested, but still I'm unable to make a new document. Any suggestions ?


How does circuit completes when physical ground(earth) is used as neutral?

In my locality there is no neutral wire. Our transmission company runs only 3 wires(all line/phase) and no neutral(4th wire) at all. Out of three, one runs to our houses. I know it sounds incorrect, but this is the case, they are saving the expense on neutral wire.  Here we use earth wire(physicaly connected to earth) in place of neutral . Each house has its own earthing/grounding. So our earth is our neutral. No difference at all. Everything works just fine, no problem at all.  I know that two wires with different potential are required to create a potential difference. I also understand that we can run loads between two phases. But in this case there is only one. Here we are running loads between a phase and a wire physicaly connected to earth.  I know that current flows in closed loop(it goes back to the source). But in this case, there is only one wire coming from sub-station and another is just physicaly grounded, how the circuit even completes?  Where is the closed loop?


How do I narrow my review queue using tags?

A follow-up to   I'm new to review queues, and apparently there's a way to greatly save one's time (please read the linked question, I can't agree more) by subscribing to review only those Q&A which fall into my areas of expertise. ( I suppose we'll be using StackOverflow' tags to do so. )  Can someone please enlighten me on how to do this ?


How to describe the use of 'them' with nouns?

I'm looking for a short and precise word to describe the use of the pronoun them with plurals, i.e. Let's kill them zombies! Them townsfolk sure are full of baloney. I hate them bees. It appears to be a fairly common solecism (?) in some areas/communities. It's also quite common in prose and pop culture. Does this convention have a name?  Inhabitants of the rural mid-west of Foobarland are in the habit of prefixing nouns with the word them, using the combined phrase as the subject or the object of a sentence. Descriptive grammarians refer to this pattern as the/a _______.


Does someone knows how to install Docker with PPA packages to Ubuntu 20.10?


An application of Eisenstein's criterion

So, this is Hungerford problem 9 on page 166. Here's the problem in full:     Let $f(x) = \sum_{i=0}^n a_i x^i \in \mathbb{Z}[x]$. Suppose that for some $k$, $0 < k < n$, and some prime $p$ such that $p \nmid a_n$, $p \nmid a_k$, and $p \mid a_i$ for all $i = 0, \dots, k-1$, but $p^2 \nmid a_0$. Show that $f$ has a factor of degree at least $k$ that is irreducible in $\mathbb{Z}[x]$.   Here's my progress:  If we construct a new polynomial $g$ where $g$ is $\sum_{i=0}^k a_i x^i$ , we know by Eisenstein's criterion that $g$ is irreducible in $\mathbb{Q}[x]$. If we somehow knew that $g$ was irreducible in $\mathbb{Z}[x]$ too (that would follow if $g$ were primitive), then we could say that the smallest thing we could possibly factor out of $f$ that isn't a unit has to be of degree $k$ and that $g$ must be a factor of it. I tried writing $f$ as $C(f) \cdot f_1$ where $C(f)$ is the content of $f$, so that we'd be dealing with a primitive $f_1$ (and of course, the nice things about $g$ don't go away since $p$ doesn't divide every term), but this doesn't necessarily result in $g$ being primitive (right?)!  So, here's where I'm stuck: how can I show I can even factor $f$? How can I show that $g$ is irreducible in $\mathbb{Z}[x]$, whether by showing it's primitive or by some other means?  Thanks so much, everyone!


Similar questions have been asked before on MSE, but this is somewhat different. I have to prove the following fact  The straight line that passes through the point of intersection of the diagonals of a trapezium and through the point of intersection of the non parallel sides, bisects each of the parallel sides.  I tried using congruence and similarity, but could not find any congruent or similar triangle.


How does this numerators and denominators relate with the fraction?

Suppose if we have two fractions $\frac{a}{b}$ and $\frac{c}{d}$ then how are their values related with the fraction $\frac{a+c}{b+d}$ ?  I have observed this inequality: $\frac{a}{b}\le\frac{a+c}{b+d}\le\frac{c}{d}$.   Does this hold true $\forall a,b,c,d \in N$ ? Is there any proof?  I am sorry if this question is too basic, but I want help regarding this.


How to parse a query string into a NameValueCollection in .NET

I would like to parse a string such as p1=6&p2=7&p3=8 into a NameValueCollection.  What is the most elegant way of doing this when you don't have access to the Page.Request object?


Short last names appear with initials with biblatex/biber and authoryear

When I cite a paper of an author with a short last name like \autocite{li2018}, biblatex/biber include initials when rendering it in author-year.   This is my setting in the preamble:  \usepackage[backend=biber,style=authoryear-icomp,citestyle=authoryear-comp,doi=false,url=false,isbn=false,maxcitenames=2,uniquelist=false,date=year]{biblatex}   What would be the right setting to make sure, that only the last name and year are rendered and not the initials?