Running an Arcpy stand alone script on PyScripter I followed everything in  to   As:   Start up the Streets.mxd in ArcMap  Run the mxd=arcpy.mapping.MapDocument("CURRENT") inside the ArcMap (without no error)    3- Add the same mxd=arcpy.mapping.MapDocument("CURRENT") to my code in PyScripter IDE as  import arcpy ####mxd = arcpy.mapping.MapDocument(r"C:\Temp\Street.mxd") mxd=arcpy.mapping.MapDocument("CURRENT") df = arcpy.mapping.ListDataFrames(mxd, "Layers")[0] targetGroupLayer = arcpy.mapping.ListLayers(mxd, "Main", df)[0] addLayer = arcpy.mapping.Layer(r"C:\Data\NetMap.gdb\Streets\OneWay") arcpy.mapping.AddLayerToGroup(df, targetGroupLayer, addLayer, "BOTTOM") arcpy.RefreshActiveView() arcpy.RefreshTOC()   but I am getting this runtime error message:       Traceback (most recent call last):   File   "C:\Users\bhosseini\Documents\ArcPy\Trace With Graphics\module3.py",   line 3, in        mxd=arcpy.mapping.MapDocument("CURRENT")   File "C:\Program Files (x86)\ArcGIS\Desktop10.4\ArcPy\arcpy\arcobjects\mixins.py", line 625,   in init       super(MapDocumentMethods, self).init(mxd)   File "C:\Program Files (x86)\ArcGIS\Desktop10.4\ArcPy\arcpy\arcobjects_base.py", line   47, in init       for arg in args)) RuntimeError: Object: CreateObject cannot open map document

I am attempting to use this code in a tool that I am working on:  mxd = arcpy.mapping.MapDocument("CURRENT") df = arcpy.mapping.ListDataFrames(mxd)[0] XMIN = df.extent.XMin YMIN = df.extent.YMin XMAX = df.extent.XMax YMAX = df.extent.YMax   I then go on to do other calculations with the extent. The code works perfectly in the Python window, but because Toolbox tools are run in separate processes I am unable to use "CURRENT".  I think I could probably add a derived input variable and pass the coordinates through the validation script, but that doesn't work for what I am doing. I need to be able to do this later on in the script and add an additional temporary feature to the current map:  points = arcpy.CreateFeatureclass_management("in_memory", "NewFeature", "POINT") arcpy.AddField_management(points, "NewField", "TEXT", "", "", 20)   I know all of my code works right, because I can paste the entire .py into the  Python window and then call Main() and run through it, but I need to share it with others in an easier way.   I would prefer the solution be compatible with 10.0 and 10.1 if at all possible, because some of the people I work with do not have 10.1 yet. I will accept a 10.1 only solution if I have to though.  What options do I have to do this?    I still can not get this to work, they have not gotten me Python Add-In Wizard yet so I am unable to test that approach. I have again tried the "Run in process" box checked and unchecked. Neither are working.   Checked gives me this: RuntimeError: CreateObject cannot open map document  Handled that exception: Object: CreateObject cannot open map document  From my testing looks like it is having the same error running in process or not.    I will still be attempting to do this within the Add-In Wizard, when they finally give me it.  The winning answer is I wasn't running it in the foreground.


Trying to add the object member to the ArrayList loggedInList when logging into the Website class.  public class Website { // The name of the website. private String name; // The number of hits on the website. public int hits; // The amount of money taken at the checkout. private double salesTotal; //  private ArrayList<Member> loggedInList;   Is the code for my Website class.      public Website(String newName) {     // Intialises the name of the website.     name = newName;     // Intialises the number of hits on the site.     hits = 0;     // Intialises the amount of money taken at the checkout.     salesTotal = 0;     //      loggedInList = new ArrayList<Member>();   }   Is the constructor for the Website class.      public void memberLogin(Member member) {     member.setLoginStatus(true);     member.setWebsite(this);      System.out.println(name + " welcomes member " + member.getMembershipNumber() + "," + " you are now logged in.");      member.setWebsite(this);      hits +=1;      loggedInList.add(member); }   Is the method which SHOULD add the current member into the ArrayList.  The error I get is a NullPointerException on the line:  loggedInList.add(member);   I honestly have no clue why.

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


If so, how? What would be the entry cost?

Can a wealthy investor invest his money in any company before it goes public / IPO? I am referring to a recent Goldman Sachs and Facebook deal worth $450 Million at a valuation of $50 Billion dollars.   I want to know what is the procedure and how are these valuations made prior to the company going public? Is is possible that an investor could raise capital from investment banks, private equity, or commercial banks to re-invest in a pre-IPO deal at some valuation?  Knowing that angel investors don't provide so much money, can they play their role here with a normal investor?


What are the requirements to war in clash of clans?   We have 12 members but every time we war, one of our members can't participate.  We are the only clan this member has been in so why is he ineligible for wars?

I am currently in a clan with three members. When we tried to initiate a clan war it said we had insufficient clan requirements. Does anyone know what the full requirements are? Is there a minimum clan member requirement?


I am trying to prove that $Aut(D_8) \equiv D_8$. It is not hard to see that $\lvert Aut(D_8)\rvert = 8$. Indeed, it is at most $8$ as $r$ (canonical rotation) has order $4$ and $s$ (canonical reflection) has order $2$. On the other hand, $D_8$ is normal in $D_{16}$ which acts by conjugation on $D_8$. So, the order is exactly $8$. However, I am having troubles to show that $Aut(D_8) \equiv D_8$ (I could check all possible solutions and stop once I have 8 different automorphisms but I wonder if there is a simpler solution).

Problem statement: I need to find out if $\mathrm{Aut}(D_4)$ is isomorphic to $D_4$ and explain my answer. I already know that it is isomorphic, so now all I need to do is to prove it.   I assume that first we need to look where it sends $s$ and $t$ and it must send them to elements that satisfy the same relations() And then need to show that those two are conjugation by some element in $D_4$(?)  Any help is appreciated. I was hoping for a duplicate post, but couldn't find it.  Thank you!


Hi I was using previous versions of 2.8 and now version available today, does not show the modifier tab on the right. I might get lost on UI updates?

I'm brand new to Blender, and am attempting to subtract one object from another. Simple, I know, and all I have read says to use the modifier tool, which is a wrench.  However, I can not find this wrench.    attached is a screen shot of my toolbar showing where I thought the wrench should be.  Can anyone please tell me what I am doing wrong?  I thank you kindly, Matt


Studying commutative algebra I've found this statement:     If $M$ and $N$ are finitely generated $R$-modules, with $R$ a commutative ring, and $\mathfrak{p} \subset R $ is a prime ideal, then $M_{\mathfrak{p}} \otimes_{R_{\mathfrak{p}}} N_{\mathfrak{p}} = 0$ implies $M_{\mathfrak{p}} = 0$ or $N_{\mathfrak{p}} = 0$.   Is it true ? Why ?

If $R$ is a local ring and $M$ and $N$ are finitely generated $R$-modules such that $M\otimes N=0$ then how does it follow from Nakayama's lemma that either $M=0$ or $N=0$?    This is an exercise in Atiyah and Macdonald. The part I could not show in the hints is $({M{\otimes}_R N)}_{k}=0$ implies $M_{k}{\otimes }_{k} N_{k}=0$, where $k=R/\mathfrak m$ and $\mathfrak m$ is the maximal ideal of $R$.


About two months ago, I started to see articles appear regarding the potential interactions between ACE inhibitor medications (commonly used to treat high blood pressure) and the severity of Covid-19  The articles centered around the idea that Covid-19 attaches to the ACE2 enzymes and people taking these medication have more of them.  Various studies have been conducted questioning if it would make the people taking these medications more prone to infection, or if the infections would be more severe, etc. Some hypothesis was also made that a higher level of ACE2 could have a protective role if an infection is established.  A quick search returns many links and all of them seem to say that more research is needed. The general conclusion is that people taking these medications should continue to take them for now. Many of these papers are in pre-print, some by people that do claim receiving grants from companies manufacturing these drugs, etc.  Has a consensus been somehow reached? or are things still totally fuzzy in that domain?

Angiotensin-converting enzyme 2 (ACE2) is a membrane-bound aminopeptidase that has a vital role in the cardiovascular and immune systems4. ACE2 is involved in heart function and the development of hypertension and diabetes mellitus. In addition, ACE2 has been identified as a functional receptor for coronaviruses4, including SARS-CoV and SARS-CoV-2. SARS-CoV-2 infection is triggered by binding of the spike protein of the virus to ACE2, which is highly expressed in the heart and lungs4. SARS-CoV-2 mainly invades alveolar epithelial cells, resulting in respiratory symptoms.   ..     SARS-CoV-2 is thought to infect host cells through ACE2 to cause COVID-19, while also causing damage to the myocardium, although the specific mechanisms are uncertain. Patients with underlying CVD and SARS-CoV-2 infection have an adverse prognosis. Therefore, particular attention should be given to cardiovascular protection during treatment for COVID-19.   Although women have higher levels of ACE2 receptors, those taking ACEI anti-hypertensive drugs have higher levels again as a result of the action of these drugs.     Myocardial injury associated with the SARS-CoV-2 occurred in 5 of the first 41 patients diagnosed with COVID-19 in Wuhan   and there are reports that MERS-CoV also caused cardiac injury.  So, is there other data for physicians to assess on whether they should change their patients' anti-hypertensive medications during this pandemic?


I've been trying to make a basic calculator, but the thing is every time I use if else, it either says I have to remove it due to syntax error or the green underline thing shows up and it says dead code. Could someone help me?   import java.util.Scanner;  public class additionCalculator {  public static void main(String[] args) {     int addresult;     int subtractresult;     int divideresult;     int multiplyresult;      String addition = null;     String subtraction = null;     String division = null;     String multiplication = null;      Scanner reader = new Scanner(System.in);     System.out.println("Do you want to do subtraction, division, multiplication, or addition?");     String i = reader.next();      if(i == addition)   {         Scanner additioncalc = new Scanner (System.in);         System.out.println("Enter a number");         int add1 = reader.nextInt();          Scanner additioncalc2 = new Scanner (System.in);         System.out.println("Enter another number");         int add2 = reader.nextInt();          addresult = add1 + add2;          System.out.println("The sum is " +addresult);        }   else if (i == multiplication) {         Scanner multiplicationcalc = new Scanner (System.in);         System.out.println("Enter a number");         int multiply1 = reader.nextInt();          Scanner multiplcationcalc2 = new Scanner (System.in);         System.out.println("Enter another number");         int multiply2 = reader.nextInt();          multiplyresult = multiply1 * multiply2;          System.out.println("The product is " +multiplyresult);      } else if (i == division) {         Scanner divisioncalc = new Scanner (System.in);         System.out.println("Enter a number");         int div1 = reader.nextInt();          Scanner divisioncalc2 = new Scanner (System.in);         System.out.println("Enter another number");         int div2 = reader.nextInt();          divideresult = div1 * div2;         System.out.println("The product is " +divideresult);       } else if (i == subtraction) {         Scanner subtractioncalc = new Scanner (System.in);         System.out.println("Enter a number");         int subtract1 = reader.nextInt();          Scanner subtractioncalc2 = new Scanner (System.in);         System.out.println("Enter another number");         int subtract2 = reader.nextInt();          subtractresult = subtract1 - subtract2;         System.out.println("The difference is " +subtractresult);     } }   // Addition calculator // Scanner reader = new Scanner(System.in); // System.out.println("Please enter a number.");         // int i = reader.nextInt(); // Scanner reader2 = new Scanner(System.in); // System.out.println("Please enter another number."); // int j = reader2.nextInt();  // sum = i + j; // System.out.println("The sum of the two numbers is " +sum);   }

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


Are there any differencies in functionality between those two or any advantages of one over the other? The only thing that comes to mind why someone would use diode-connected transistors over diodes is if, for example, the whole integrated circuit technology is based on transistors and it's easier and more cost-friendly to just configure some of them as diodes when it's needed, other than integrating a diode in the circuit. Or, if transistors are more temperature resistant than diodes? Are there any other differencies?

I faced lots of circuits that has transistors connected as diodes (gate connected to the drain). I know some of these circuits employ such transistor for safety reason but I couldn't figure out the reasons of others.  My question: Is there any reason behind connecting the transistors as diodes other than the one I mentioned? Some of my colleagues suggest that they may be used to realize high resistance but I think connecting the transistor in such configuration (\$V_{g} = V_{d}\$) will force the transistor to work in saturation region, not in linear region. Am I right?


I had to reinstall Ubuntu today and despite having configured proxy for Apt, when trying to add a new PPA, the step that communicates with keyserver.ubuntu.com fails:  $ sudo add-apt-repository ppa:webupd8team/sublime-text-3  Sublime Text 3 Installer: the package in this PPA downloads and installs the latest Sublime Text 3 beta builds.  For more info, see: http://www.webupd8.org/2013/07/sublime-text-3-ubuntu-ppa-now-available.html  More info: https://launchpad.net/~webupd8team/+archive/ubuntu/sublime-text-3 Press [ENTER] to continue or ctrl-c to cancel adding it  gpg: keyring `/tmp/tmp_wo9o6sl/secring.gpg' created gpg: keyring `/tmp/tmp_wo9o6sl/pubring.gpg' created gpg: requesting key EEA14886 from hkp server keyserver.ubuntu.com ?: keyserver.ubuntu.com: Host not found gpgkeys: HTTP fetch error 7: couldn't connect: Success gpg: no valid OpenPGP data found. gpg: Total number processed: 0   I have no trouble installing package via Apt, so as far as I can tell, proxy is setup properly:  $ cat /etc/apt/apt.conf Acquire::http::proxy "http://my-proxy:8080/"; Acquire::ftp::proxy "ftp://my-proxy:8080/"; Acquire::https::proxy "https://my-proxy:8080/"; Acquire::socks::proxy "socks://my-proxy:8080/";  $ env | grep proxy http_proxy=http://my-proxy:8080/ ftp_proxy=ftp://my-proxy:8080/ https_proxy=http://my-proxy:8080/   I can communicate with the keyserver.ubuntu.com as well:  $ curl keyserver.ubuntu.com  <?xml version="1.0"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"     "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml">   <head>     <title>SKS OpenPGP Public Key Server</title>   </head>   ...   I can't remember having done anything different in the past. I only had to configure http/s_proxy environment variable as well as configuring /etc/apt/apt.conf.  Any ideas what am I missing here?

In my office i want to update and download through (wget) and here they are using proxy?  How can i do this by commandline?


I am trying to include image to LaTeX, but I loose quality.  It is a print-screen with image and little bit of text and it looks awful after the conversion to PDF.  I guess that DPI of the image is 90, it was taken in windows 8 with it's snipping tool.  I can convert the image with no visual cost to EPS but not PDF.  ANY suggestions, please ?  EDIT: it almost looks like the image is rescaled to 99.99%  I have tried to use pdflatex, ps2pdf, dvipdfm... nothing helped

I have this picture:  (I have the original in Pixen and could export it to several different formats. I went with PNG though since it's lossless.)  When I open my picture in Preview (OS X) and zoom in, it looks fine. The characters have extremely sharp boarders between them and the background. However, when I put it into my LaTeX document, compile it to a PDF (using TeXShop) and then zoom in, it suddenly have gotten blurry (see screenshot: ).  Minimal working example:  \documentclass[12pt]{article} \usepackage{graphicx} \begin{document} \includegraphics[scale=1]{fig1.png} \end{document}   In the end, I would like to be able to scale the picture freely without there being any blurring at all.


I am on macOS Catalina. On a site they say that, if I am having problems, in order to be able to run the app I need to input (sudo chown -R 755 AppName.app) in the terminal. My question is: is it safe to do so? Is there a way to reverse my actions?

Experiencing a problem with several apps after installing macOS Catalina.  When the app is downloaded from the internet I get the error:     "APP NAME" is damaged and can't be opened. You should move it to the trash.   Any workarounds to bypass macOS gatekeeper for specific apps?


I have created an app with 5 tabs, in my 1st tab I am having a button on click of which I want to go to tab3. This is my code of button event --  moreButton3.setOnClickListener(new View.OnClickListener() {     @Override     public void onClick(View v) {         Intent intent = new Intent(view.getContext(), Tab3_Image.class);         view.getContext().startActivity(intent);     } });   But while clicking the button the app crash, below is the logcat error --  E/AndroidRuntime: FATAL EXCEPTION: main Process: com.s2s.doupnow, PID: 22481 java.lang.NullPointerException     at com.s2s.doupnow.Tab1_Home$6.onClick(Tab1_Home.java:313)     at android.view.View.performClick(View.java:4444)     at android.view.View$PerformClick.run(View.java:18457)     at android.os.Handler.handleCallback(Handler.java:733)     at android.os.Handler.dispatchMessage(Handler.java:95)     at android.os.Looper.loop(Looper.java:136)     at android.app.ActivityThread.main(ActivityThread.java:5113)     at java.lang.reflect.Method.invokeNative(Native Method)     at java.lang.reflect.Method.invoke(Method.java:515)     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:796)     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:612)     at dalvik.system.NativeStart.main(Native Method)

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I am trying to create a send email button for a custom sobject, but I am unsure where to find the rtype id for the particular object. I tried to follow the documentation but I couldn't find anything relevant.

I know of two approaches to get the recordtype id of a particular record type   Use SOQL   RecordType RecType = [Select Id From RecordType  Where SobjectType = 'Account' and DeveloperName = 'Business'];    Benifit here is if the admin changes the name of the record type, the code still works as we can use developer name   Using Describe  Map<String,Schema.RecordTypeInfo> rtMapByName = d.getRecordTypeInfosByName(); Schema.RecordTypeInfo rtByName =  rtMapByName.get('Business');    Saves on SOQL limits but uses a describe call.  What would be your choice and why   EDIT : Usage is for setting up recordtype while inserting records in apex or trigger


For many visa applications, you need a flight reservation that shows you have purchased a round trip to your destination and back. But when you buy a flight there is a change your visa application won't be approved and then you already spent money. Yes, I know you can get cancellation insurance, but you have to do some extra administrative work before you get your money back.  So is it possible to make a flight reservation without paying for it right away and pay for it after you visa application is approved?

I am applying for a complicated visa right now and I was told the chance of refusing visa application is high.   What happens if my visa is refused and I already have my airplane ticket? My flight is in one month, with British Airways. Is there a chance of getting my money back? Will the embassy give some affirmation for the flying company to cancel the ticket?


In my terminal it printed out a seemingly random number 127. I think it is printing some variable's value and to check my suspicion, I defined a new variable v=4. Running echo $? again gave me 0 as output.  I'm confused as I was expecting 4 to be the answer.

I'm having difficulty locating a comprehensive up-to-date list of error codes from Bash.  e.g.:  $ udevadm info /dev/sdx; echo Exit code $? Unknown device, --name=, --path=, or absolute path in /dev/ or /sys expected. Exit code 4   How is one supposed to look up such exit codes?


Is it entirely correct to use the adjective 'whose' when the grammatical subject is not a person but a thing? For instance,     The first poem whose publication he ever sanctioned

Whose is used for people (e.g. "Whose that girl?"), but is it acceptable to use whose for objects too? Is there another word I should use for objects?  To make the question clearer, when I ask "Whose that car?" I am expecting an answer similar to "It's X's car." where X refers to a person. I could say "a man whose opinion I respect." and whose opinion would refer to the opinion of a person. Could I say "the desk whose drawer was broken by my brother"? Should I replace whose with another word?


I am going to Paris. I have a direct flight there (YYZ-CDG) but on the way back it is a 2-stop flight (CDG-BRU-YUL-YYZ). Could I just miss the flight at CDG and drive or take a train to Brussels and start my flight there? The time is much better as I won't have to wake up earlier and I get to go to Brussels.

I'm planning a trip to South-Korea in April. I was looking at flight ticket prices and found that I can go from Brussels to Seoul (and back) for about 600€. It lands in London however. I then tried to find the same flight but from London (I was expecting I could get the price even more down if I'm not doing BRU-LHR), but no search engine found it and the cheapest was at about 700€.  Here you can see what I'm talking about in action:    It's the same date and everything, and it's much cheaper from Brussels although it lands in London.  Question: This seem really strange.  Why does this happen, and is it possible to buy the ticket from Brussels but only get on the plane from London?


The question is show that $$ \int_0^{a} f(x) dx  = \int_0^{a} f(a-x) dx $$          Hence or otherwise, calculate the value of the following integral           $$ \int^{\frac{\pi}{2}}_0 \frac{\sin^n(x)}{\sin^n(x) + \cos^n(x)} $$        What I have done for the first part   $$ \int_0^{a} f(x) dx  = \int_0^{a} f(a-x) dx $$   $$ \left[F(x) \right]^a_0  dx  = \left[-F(a-x) \right]^a_0 $$  $$ F(a) - F(0) =  \left[-F(a-a) - -F(a-0) \right] $$  $$ F(a) - F(0) =F(a) - F(0)   $$  $$ LHS =  RHS $$    Now I am stuck applying this to the integral. I have attempted this:  $$ \int^{\frac{\pi}{2}}_0 \frac{\sin^n(x)}{\sin^n(x) + \cos^n(x)} $$  Because $ \int_0^{a} f(x) dx  = \int_0^{a} f(a-x) dx $ The integral is transformed to   $$ \int^{\frac{\pi}{2}}_0 \frac{\sin^n(\frac{\pi}{2}-x)}{\sin^n(\frac{\pi}{2}-x) + \cos^n(\frac{\pi}{2}-x)} $$  Which then becomes   $$ \int^{\frac{\pi}{2}}_0 \frac{\cos^n(x)}{\cos^n(x) + \sin^n(x)} $$  Now I am stuck...

Calculating with Mathematica, one can have $$\int_0^{\pi/2}\frac{\sin^3 t}{\sin^3 t+\cos^3 t}\,\mathrm dt=\frac{\pi}{4}.$$   How can I get this formula by hand? Is there any simpler idea than using $u = \sin t$?     Is there a simple way to calculate $$ \int_0^{\pi/2}\frac{\sin^n t}{\sin^n t+\cos^n t}\,\mathrm dt $$ for $n>3$? Could anyone come up with a reference for this exercise?


According to Muslims traditions Muhammad said "If a house fly falls in the drink of anyone of you, he should dip it (in the drink), for one of its wings has a disease and the other has the cure for the disease." (Sahih Al-Bukhari: Volume 4, Book 54, Number 537) they claim that , the words of Muhammad is a scientific foreknowledge ... and backup their claim ,by the following studies,articles     now the question: Is it proven scientifically that ,what is Located on the right wing of the fly is the antidote, to the harmful microbes that exist on the left wing of the same fly?

There was  study but the conclusion and it's source's relability seemed a bit off. How come a house flies one wing contain all microbe and the other don't.


Possible Duplicate:          I am required to create a 2x2m design that will be printed. I'm using Adobe Photoshop CS5.  What is the best width, height and resolution? I think it is odd to create a 2x2m document! Do you?

(This question is meant to be a resource to direct others to given that this is a common question.)  Given the task of creating an image that will be printed at a certain size, what pixel dimensions and resolution should I be setting my file at?


Running Kubuntu 17.10.  And wanted to upgrade to Kubuntu 18.04.  But  it says:     Note: Upgrades from 17.10 will not be enabled until a few days after   18.04's release. Upgrades from 16.04 LTS may not be enabled until a few days after the 18.04.1 release expected in late July.   This is pretty vague --- 'until a few days' part.  So, can I upgrade now?

I'm following the , but on launching the upgrade tool I get this response:  Checking for a new ubuntu release No new release found   Am I doing something wrong? Is there a workaround?


WS2812B LED-strips are ran at 5V, and can consume up to 60mA per LED. This can quickly add up to a few amperes.    Would I receive a chock if I'd touch the connections between each LED while the strip is powered up? I'd guess so, since the current flows between the points -- however I've seen videos of people touching the strip while powered up.  Is it safe to touch the connection points while the strip is powered up?

Related:        From what I've heard:   110 V (or 220 V; household voltage pretty much) is dangerous (i.e. can kill you) I think there's consensus on this, no need to try :) 60 V (old telephone lines) is supposedly dangerous (never tried, only heard it once... probably won't try)   From what I know first-hand:   9 V is not dangerous (I've put a 9-V battery on my tongue, nbd... actually it kinda hurt!) 1.5 V can indeed be quite shocking with enough current (fell for one of those "Do you want some gum?" tricks back in high school...), but they sometimes do not use 1.5 V with the low amperage levels, some use a DC motor to vibrate and complete the trick.   So I guess there's two parameters here, voltage and current... but are there rough numbers on how much of each (or in combination, which I guess would be power) would be considered hazardous?  No old telephone lines have always been 48vDC well at least since from 1950s, if your skin is wet you can feel it slightly, like on your forearm.  Now the ring voltage is 90-110vAC with a 2 on 4 sec off cycle (USA).  It will ring your bell but good, should you be touching the wires when someone calls. The ring voltage rides on top of the 48vDC, so its present on the same two conductors that the voice voltage(DC) is on. Luckily it's 4 seconds off will give you a chance to get off the conductors with a scream (of pain).


How to calculate integral $$J_n=\int_{-\pi}^\pi \frac{\sin{(nx)}}{(1+2^n) \sin{x}}\,\mathrm{d}x\:?$$ I tried partial integration but did not succeed in finding a recurrent relation? Also, tried Moivre formula for $I_n+iJ_n$, where $I_n=\int_{-\pi}^\pi \frac{\cos{(nx)}}{(1+2^n) \sin{x}} dx$, but also without success. Any help is welcome. Thanks in advance.

How do I integrate :$\int_{0}^\pi \frac{\sin(n\theta)}{\sin \theta} d\theta $  I did the following: $\int_{0}^\pi \frac{\sin(n \theta)}{\sin \theta}d\theta = \mbox{Im} \int_{0}^{\pi} \frac{e^{i n \theta}}{\sin \theta} d\theta = \mbox{Im} \int_{0}^{\pi} 2i \frac{e^{i n \theta}}{e^{i \theta}-e^{- i \theta}} d\theta$   Put $ z=e^{i \theta}$ then  $ \mbox{Im} \int_{|z|=1} \frac{z^n}{(z^2-1)} dz$  Now I have problem , because the function $f(z)= \frac{z^n}{(z^2-1)}$ is not analytic on the boundary of the unit disk. Now I can not use the Cauchy Residue Theorem.  The answer is $0$ if $n$ is even and $ \pi$ if $n$ is odd.  I stuck:   Any suggestions ?


In the Example 1.1.3 of Stanley's book Enumerative Combinatorics Vol 1 (2nd edition), an explicit formula for the number $f(n)$ of $n\times n$ matrices of $0$'s and $1$'s such that every row and column has three $1$'s is presented:  $$f(n)=6^{-n}n!^2\sum\frac{(-1)^\beta(\beta+3\gamma)!\,2^\alpha\,3^\beta}{\alpha!\,\beta!\,\gamma!^2\,6^\gamma}\;,$$ where the sum ranges over all $(n+2)(n+1)2$ solutions to $\alpha+\beta+\gamma=n$ in nonnegative integers.  But, I would like to know how we can prove it? It seems that inclusion-exclusion principle is used.

Stanley's Enumerative Combinatorics () contains next fact: 1.1.3 Example. Let f(n) be the number of n × n matrices M of $0$’s and $1$’s such that every row and column of M has three 1’s. For example, f(0) = 1, f(1) = f(2) = 0, f(3) = 1. The most explicit formula known at present for f(n) is $$f(n)=6^{-n}{(n!)}^2\sum\frac{(-1)^{\beta}(\beta+3\gamma)!2^\alpha 3^{\beta}}{\alpha!\beta!\gamma!^26^{\gamma}}$$ where the sum ranges over all (n + 2)(n + 1)/2 solutions to α + β + γ = n in nonnegative integers.   I need proof of this fact. (i.e. reference to book or articles that contains proof this fact).


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

I have a hard time formulating proofs.  For this problem, I  can see that if $n$ is equal to $8,$ this statement is true.  $(\mathbb{Z}/8\mathbb{Z})^{\times}$ includes elements:  $1,3,5,7$, and all of these are roots of $1-x^2 \pmod 8.$  And obviously $8$ divides $24.$  But how do I prove this without depending on number calculations and only using theorems?  Help Please?  I need a step by step walk through of how to do this proof and what theorems would be appropriate to use.


The accepted (and highly upvoted) answer to the question in the question   states that the easiest way to find out whether to use who or whom is to try with he/him and see which fits. But that doesn’t seem to fit very well in this case:   Who will it be?  Whom will it be?    If I replace with he/him there, it becomes:   Will it be he?  Will it be him?    – and I don’t know which of these is right, either. Is it really true that you can always associate who with he and whom with him? Or does that not always work? And which out of 3 and 4 is correct?

I can never figure out whether I should use who and whom. Most people use who for both colloquially, but some people say this is not correct.  What’s the rule for using who and whom correctly?


Prove: Each set which consists of 2016 natural numbers contains a non-empty set that has a sum divisible by 2016  My attempt: Use the pigeonhole principle. Let $A$ be a set of 2016 natural numbers. I'll split the answer to two different possibilities:   $A$ contains at least one number which is divisible by 2016. In this case the claim is true. $A$ does not contain numbers that are divisible by 2016. In this case, we'll apply the pigeonhole principle.    Holes: $\{1,2,3,4,...,2016\}$, A set of all possible remainders when dividing a number (which is not divisible by 2016) by 2016. In total there are 2015 holes. Pigeons: 2016 numbers.   Each number will be divided by 2016 and put into the appropriate hole according to the that number's division remainder. By the pigeonhole principle, at least in one hole will be $\lceil \frac{2016}{2015} \rceil$. objects. In this case, the claim is also true.   Is my proof sufficient? Can I prove this not using 2 different possibilities, or maybe not using the pigeonhole principle?  Edit: As stated in the comments and in the answers, my proof is false. The proof shows that there exists at least 2 numbers in the set $A$ with a difference divisible by 2016. It does not prove that there is a non-empty set with a sum divisible by 2016.

Consider a set A of 10 integers, $A= \{a_1,a_2, \ldots ,a_{10}\}$. Prove that there is at least one subset of A whose sum is divisible by 10. Use the pigeon-hole principle. Hint: Consider the 10 sums $s_1 = a_1, s_2 = a_1 + a_2, \ldots ,s_{10} = a_1 + a_2 + \ldots+a_{10}$. If one of these ten sums is divisible by $10$, we are done. So assume that none of these ten sums is divisible by $10$.  I'm pretty sure this is the proof but im not exactly sure what's $b_l$ and $b_k$ stand for?    Let $A=\{a_1,a_2,...,a_{10}\}$ Define set of numbers $b_n=\sum\limits_{i=1}^n a_n$ i.e. the set $$\{a_1, (a_1+a_2),(a_1+a_2+a_3),\ldots ,(a_1+a_2+\ldots +a_{10})\}$$ If any element of the set is divisible by $10$, then we are done.  Hence proving case $1$.  Case 2: Assume that no element of this set is disible by $10$.  Then, by Pigeon hole priciple, there exists some $k<l$, such that, $b_l\equiv b_k$   then $b_l\equiv b_k (mod 10)$ with $l>k>0$   Hence, $\{b_k,b_{k+1}, \ldots,b_l\}$ is a subset of $A$ whose sum is divisble by $10$. Thus proving Case $2$.


date = [2, 5, 2018] text = "%s/%s/%s" % tuple(date) print(text)   It gives result 2/5/2018.How to convert it like 02/05/2018

What is a Pythonic way to pad a numeric string with zeroes to the left, i.e. so the numeric string has a specific length?


I want to purge storage data from SAN which accumulates to 10 TB. The OS is linux. The storage is mounted as mount-points on a system for which it is visible I was recommended by a friend to use winscp But I don't think the tool is efficient to such an extent.   I appreciate if you can be recommended a tool or command which can help me perform this job.

We have an issue with a folder becoming unwieldy with hundreds of thousands of tiny files.  There are so many files that performing rm -rf returns an error and instead what we need to do is something like:  find /path/to/folder -name "filenamestart*" -type f -exec rm -f {} \;  This works but is very slow and constantly fails from running out of memory.  Is there a better way to do this? Ideally I would like to remove the entire directory without caring about the contents inside it.


It's an old story (maybe from the fifties?) about a man stranded on Mars, and about to die. He finds the remains of an ancient Martian civilization, now extinct. But the machines are still working, and provide him with food. But the problem is that the food is made for Martians, so he can't eat it. The story ends with the machines somehow turning him into a Martian, so that he can eat the food and survive.

This is a story that was read on BBC radio about thirty years ago, and this is about as right as I can remember it: The human pilot of a spacecraft is doing some reconnaissance on an alien planet. He crashes but survives. For some reason, no one will know where to look for him. He sees something in the distance that looks like a building of some sort. When he gets there, it seems to be a home. Very much like a human home. There's furniture, but it's strange and uncomfortable . There's food, but it's inedible. There's a faucet but what comes out of it seems more like acid. Everything looks as though it should be right, but it's not. He leaves the house, wanders and after a few days is desperate for water. But there isn't any water anywhere. He's close to death, crawling on the ground and then something happens. There are cracks in the soil and there appears to be water bubbling up from perhaps some underground stream. The water revives him. He goes back to the house and tries the food again. It's delicious and he eats enough to gain back his strength. Then he decides to try the water again. It's pure and wonderful. He takes a shower and the last line of the story is how refreshing the water is on his skin and something about him lifting his tail.


When a user tries to close the browser window a popup box pops up. But the problem with that is, it displays its own popup data. So please let me know how can I customize it content of popup box in "Firefox".    window.onbeforeunload = function() {       return "my text";  };   Here instead of "my text" it is displaying its own data. Note: its working fine in Chrome!   Thank you.

I need to warn users about unsaved changes before they leave a page (a pretty common problem). window.onbeforeunload = handler  This works but it raises a default dialog with an irritating standard message that wraps my own text. I need to either completely replace the standard message, so my text is clear, or (even better) replace the entire dialog with a modal dialog using jQuery. So far I have failed and I haven't found anyone else who seems to have an answer. Is it even possible? Javascript in my page: <script type="text/javascript">        window.onbeforeunload = closeIt; </script>  The closeIt() function: function closeIt() {   if (changes == "true" || files == "true")   {       return "Here you can append a custom message to the default dialog.";   } }  Using jQuery and jqModal I have tried this kind of thing (using a custom confirm dialog): $(window).beforeunload(function () {     confirm('new message: ' + this.href + ' !', this.href);     return false; });  which also doesn't work - I cannot seem to bind to the beforeunload event.


Number of views increases for the question if page refreshes. Is it a design intent? Or increase number of views per question only when the non-current user views at once.

I saw it's not just a page views number, because, if I press F5 several times, it won't increase the number of views.  They could store my IP address in a table, but wouldn't that make it slow? They would need to query a database one more time for each request.


I am new to calculus and currently learning differentiation. I understood that the first derivative indicates the slope of the function and the second derivative indicates the rate at which the slope is increasing or decreasing. I have seen some questions asking to find the 3rd derivative of functions and can't understand what would be its geometrical/physical significance. I would appreciate if someone could explain why 3rd derivatives are important. Thanks in advance :)

(Originally  by AJAY.)  What is the geometric, physical, or other meaning of the third derivative of a function at a point?  If you have interesting things to say about the meaning of the first and second derivatives, please do so.


if photons are emitting graviton while it going near to mass then this graviton should effect the mass the much as the graviton that object with mass emit, and we know light have no mass  so it not have an effect  on gravity. another problem I was thinking about  is that gravity may expends in the speed of light but when object is going through curve of space time and getting way for mass we may say that the gravity force it fill is weaker but if it just follow the space-time curve then it would be effected immediately, and if it result of emitting graviton then the effect would be delayed till the graviton get to the mass which would make the gravity getting weaker in the upside relation as we except because it would be more delayed the much you get a way from gravity

I know a photon has zero rest mass, but it does have plenty of energy. Since energy and mass are equivalent does this mean that a photon (or more practically, a light beam) exerts a gravitational pull on other objects? If so, does it depend on the frequency of the photon?


I have 3  Monitors connected to a NVIDIA Geforce GTX 980 graphics card via display port. The monitors are not chained. So each monitor is connected directly to the graphics card. I'm running the latest NVIDIA drivers (344.48).  When I turn one monitor off. Windows 8.1 helpfully re-arranges my desktop down to two monitors. Then down to one when I turn of all the panels.  Is there anyway to stop windows from doing this? Its especially frustrating to have to re-organize my desktop windows every time I turn my monitors off.

I have 2 monitors connected to a NVIDIA GeForce GTX 660:   Left is 1920x1080 via DVI (Samsung SyncMaster 2443BW) Right is 2560x1440 via DisplayPort and is set to Primary (Samsung SyncMaster SA850)   I often leave my computer running overnight (working on long render job, doing backups, etc) so I only power off my monitors manually. However, if I power off the primary monitor, it is disabled completely as if it were unplugged from the graphics card (i.e. icons are moved, open apps are moved and resized to fit on the new primary monitor). If I switch from DP to a DVI cable, this does not occur. It seems to be an issue when using DisplayPort.  Is there a way to disable the monitor from being disabled completely in Windows when I power it off physically?   I have found no relevant settings in either Windows Display settings, nor the NVIDIA control panel software.  Edit #1: I'm using an .  Edit #2: Here is a screenshot of my NVIDIA Control Panel v7.2.710.0:   Edit #3: Here are screenshots of my Monitor configuration:    Clicking on Advanced settings reveals a Generic PnP monitor running at 59 Hz? 60 Hz is the only other option available.    Here is my secondary monitor which is connected via DVI:    Edit #4: If I open the "Screen Resolution" configuration panel and power the monitor off (via the power switch), this is what is shown:    It looks like I disconnected the monitor from the video card.


To make this more specific, I show a broken procedure for generating random points in a circle and a correct (hopefully) procedure for generating random dates within an interval.   I'd like to be able to precisely explain why one of them is wrong and the other is not, given that they sound very similar. What is so special about polar coordinates, that is not true about the case with dates?  Point in Circle  When placing a random point within a circle, the following is incorrect approach.  Use polar coordinates. First, generate the distance from center of the circle as number in interval [0, r). Then, generate the angle as number in interval [0, 2*pi).  The problem with the method described is that half of such points would lie within distance r/2 from the center, but that is only 1/4 of the surface of the whole circle.  (Anyways, how can one come up with such argument or know for certain there isn't one? It is obvious when it is stated, but I cannot imagine coming up with it myself; I'd just accept the method as correct.)  Random Date  randomdate = startdate + new TimeInterval(     days: random(from: 0 to: (enddate - startdate).days)     hours: random(from: 0 to: 23)     minutes: random(from: 0 to: 59) )   When proving uniform distribution of values, what exactly am I trying to prove (how come that in the circle example I have to think of area density, which is not necessary in the date example) and how do I go about it, in a general case?

Consider the task of generating random points uniformly distributed within a circle of a given radius $r$ that is centered at the origin. Assume that we are given a random number generator $R$ that generates a floating point number uniformly distributed in the range $[0, 1)$.  Consider the following procedure:   Generate a random point $p = (x, y)$ within a square of side $2r$ centered at the origin. This can be easily achieved by:  a. Using the random number generator $R$ to generate two random numbers $x$ and $y$, where $x, y \in [0, 1)$, and then transforming $x$ and $y$ to the range $[0, r)$ (by multiplying each by $r$).  b. Flipping a fair coin to decide whether to reflect $p$ around the $x$-axis.  c. Flipping another fair coin to decide whether to reflect $p$ around the $y$-axis. Now, if $p$ happens to fall outside the given circle, discard $p$ and generate another point. Repeat the procedure until $p$ falls within the circle.   Is the previous procedure correct? That is, are the random points generated by it uniformly distributed within the given circle? How can one formally [dis]prove it?    Background Info  The task was actually given in . If you're interested, you can  in which I've implemented the procedure described above. I would like to know whether the procedure is mathematically correct or not, but I couldn't figure out how to formally [dis]prove it.  Note that the actual task was to generate random points uniformly distributed within a circle of a given radius and position, but I intentionally left that out in the question because the generated points can be easily translated to their correct positions relative to the given center.


I tried to chown a file to root, that I own, But my machine says I'm not permitted. I've googled a bit and found a few topics that say chown is a root only command. But others say that's not true. Am I doing something wrong?  pi@raspberrypi /media/usb1 $ whoami pi pi@raspberrypi /media/usb1 $ ls -laxo total 8 drwxr-x---  2 pi   4096 Jul 30 09:39 . drwxr-xr-x 10 root 4096 Jul 29 12:52 .. -rwxr-x---  1 pi      0 Jul 30 09:29 lol pi@raspberrypi /media/usb1 $ chown root lol chown: changing ownership of `lol': Operation not permitted

Why is the chown command root-only? Why can't non-root users use chown to give away files they own?


On the  for Salesforce Certified Identity and Access Management Designer, it says that you should be able to  Describe the configuration requirements of delegated authentication in Salesforce.  As I've been researching, SSO has been brought up quite a bit. There is obviously an overlap between delegated authentication and SSO. I get the impression the exam guide should say  Describe the configuration requirements of delegated authentication single sign-on (SSO) in Salesforce.  Are delegated authentication and SSO the same thing? Can there ever be an instance when working with delegated authentication that you are not using SSO?

This is a follow up question to this . According to the answer to that question, it is possible to use Federated Authentication and Delegated Authentication in parallel. I'd like to understand how does this work in detail. How does Salesforce know which method to use when authenticating users?  Thanks in advance!


I am trying to run the query shown below to include the results in a report and am getting an Operand should contain 1 column error #1241. I have not been able to figure out the cause of this. If I run this part by itself I do not get any errors: (pct_return_1 * .25) + (pct_return_2 * .25) + (pct_return_3 * .15) + (pct_return_4 * .15) + (pct_return_5 * .2)  Here is the code:   DROP TABLE IF EXISTS temp_5; CREATE TABLE temp_5 (     date_value date default NULL,     pct_return_portfolio double default NULL,     pct_return_benchmark double default NULL);  INSERT INTO temp_5 (date_value, pct_return_portfolio, pct_return_benchmark) SELECT  (date_value,   (pct_return_1 * .25) +   (pct_return_2 * .25) +   (pct_return_3 * .15) +   (pct_return_4 * .15) +   (pct_return_5 * .2)   FROM Temp_4), pct_return_6) FROM temp_4;

I tried running the following statement:  INSERT INTO VOUCHER (VOUCHER_NUMBER, BOOK_ID, DENOMINATION) SELECT (a.number, b.ID, b.DENOMINATION)  FROM temp_cheques a, BOOK b WHERE a.number BETWEEN b.START_NUMBER AND b.START_NUMBER+b.UNITS-1;   which, as I understand it, should insert into VOUCHER each record from temp_cheques with the ID and DENOMINATION fields corresponding to entries in the BOOK table (temp_cheques comes from a database backup, which I'm trying to recreate in a different format). However, when I run it, I get an error:  Error: Operand should contain 1 column(s) SQLState:  21000 ErrorCode: 1241   I'm running this in SQuirrel and have not had issues with any other queries. Is there something wrong with the syntax of my query?  EDIT:  The structure of BOOK is:  ID  int(11) START_NUMBER    int(11) UNITS   int(11) DENOMINATION    double(5,2)   The structure of temp_cheques is:  ID  int(11) number  varchar(20)


I would like to add two extra HTTP headers to all responses that are of filetype (mime type) text/html, but not other files.  The current headers (edited):  curl -I https://www......  HTTP/1.1 200 OK Date: Fri, 23 Feb 2018 20:43:15 GMT Server: Apache Expires: Thu, 19 Nov 1981 08:52:00 GMT Cache-Control: no-store, no-cache Vary: Content-Type,Accept-Encoding X-Frame-Options: SAMEORIGIN Connection: keep-alive Content-Type: text/html; charset=UTF-8 Content-Language: de-DE   The <If> statement I tried is not working (my idea was to check for text/html, and if that is set, then also add two extra headers with Header set.  I have checked multiple sources like , but cannot seem to find the answer.  This is one of the things I've tried that seems most logical to me. Do a check for a current header; if result is true then add extra headers.  <If "%{HTTP:Content-Type} in { 'text/html' }"> Header set Header1 test Header set Header2 test </If>   But I do not know if this ENV is taken from the request or response header.  Does anyone know of a way to achieve this -- add custom HTTP header in the response based on mime type?  Thanks.

I want to set a environment variable when a specific response header has a value.  But when I make this it doesn't set the variable.  Header add X-foo "bar" <If "resp('X-foo') == 'bar'">     Header add X-test-foobar "foobarnew" </If>   It doesn't set the header X-test-foobar.  Maybe I don't have correctly understand how does it should work. I'm not really fluent in apache programming... I think that programming is not sequential in apache environment but I don't know how to set an env variable with the content of the response header.  Thanks for any help,  ZS


How do indexes help in speeding up searching for data based on specific criteria?  If there's a table with 6 columns and none of them are indexed, the program has to check all table rows.  Indexing involves creating another separate table with just two columns, the id and the column you want indexed.  What I don't understand, is how does that help the application do faster searches? It doesn't read the entire 6 column table, but it still has to read the entire 2 column table, right? Which has the same number of rows...

Given that indexing is so important as your data set increases in size, can someone explain how indexing works at a database-agnostic level?  For information on queries to index a field, check out .


If I use for example the command \cite[X.2]{book} with X.2 as optional argument, I get [p. X.2,BOOK] as a result (where BOOK stands for the reference number of the book reference). Because X.2 stands for a chapter, rather then page number, I would of course like to get rid of the "p.". Because I rather rarely refer to pages, I would like to have this behaviour by default. I can probably change it using an optional argument of \usepackage{biblatex}. Which one?  Now I have in my preamble: \usepackage[doi=false,url=false,isbn=false,sorting=none,style=numeric-comp,backref=true]{biblatex}

I'm using \cite[1]{A01}. The result is     Author 2001, p. 1   The desired result is     Author 2001, 1   How do I achieve that? I'm aware of , , and  but they're not exactly my issue.  Minimal example:  \documentclass{scrartcl} \usepackage[backend=biber,style=authoryear-comp]{biblatex}  \usepackage{filecontents} \begin{filecontents}{\jobname.bib} @misc{A01,   author = {Author, A.},   year = {2001},   title = {Alpha}, } \end{filecontents}  \bibliography{\jobname.bib}  \begin{document}  \cite[1]{A01}  \end{document}


I have tried everything and I gave it 256 (yes 256) fish and it still won't tame! It's just running around in my house. If anyone can help me please do so.

I have several raw fish and have been trying to tame an ocelot. However, every time I get it to approach and feed it a fish, it simply wants to breed. I am playing on SMP, and have tried logging in/out to see if maybe the texture just didn't change, but it appears the ocelot is simply un-tamed. The  that this should tame the ocelot.  Is this a bug or a change? How can I tame this ocelot?    Here is a screenshot of my second attempt. This time, unlike last, clicking with the fish caused the ocelot to also flee. I am not sure if this is the same ocelot or not.


I use ubuntu 14.04LTS, when I type in:  sudo apt-get install vlc       I receive this error:  Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:    vlc : Depends: vlc-nox (= 3.0.0~~git20150319+r59816+33~ubuntu14.04.1) but it is not going to be installed    Depends: libavcodec55 (>= 6:9.1-1) but it is not installable or             libavcodec-extra-55 (>= 6:10~~git20131218.b3189af~ubuntu14.04.1) but it is not installable    Depends: libavutil53 (>= 6:9.1-1) but it is not installable    Recommends: vlc-plugin-notify (= 3.0.0~~git20150319+r59816+33~ubuntu14.04.1) but it is not going to be installed    Recommends: vlc-plugin-samba (= 3.0.0~~git20150319+r59816+33~ubuntu14.04.1) but it is not going to be installed E: Unable to correct problems, you have held broken packages.

Occasionally, when I'm installing stuff, I get an error like the following:  Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  package1 : Depends: package2 (>= 1.8) but 1.7.5-1ubuntu1 is to be installed E: Unable to correct problems, you have held broken packages.   How can I resolve this?


So I'm gonna travel to Spain next Monday from Japan and I'm a Philippine passport holder but residence here in Japan. I got my type C schengen visa single entry from the Spanish embassy.  My itinerary has a 5 hour layover in Munich, Germany and I need to pick up my luggage and re check in again, do I still need a visa in germany?

I found many related questions on this site but I am still not sure about the rules. How can I decide if I need a visa to transit? Schengen members as of May 2021 are as follows:  Austria Belgium Czech Republic Denmark (excluding Greenland and the Faroe Islands - but an open border with the Schengen Area is maintained) Estonia Finland France (excluding overseas departments and collectivities) Germany Greece Hungary Iceland Italy Latvia Liechtenstein Lithuania Luxembourg Malta Netherlands (excluding Aruba, Curaçao, Sint Maarten and the Caribbean Netherlands) Norway (excluding Svalbard) Poland Portugal Slovakia Slovenia Spain (except Ceuta and Melilla) Sweden Switzerland


I would like to force default execution to happen from my home directory.  However, regardless of what I try, it seems that the whereis utility finds programs to be in /bin instead of /home/user.  E.g. if I do  export PATH=.:$PATH   I can echo $PATH to see that this is indeed updated correctly.  However, if I now type ls, /bin/ls will still be executed. Indeed, when I look in whereis ls, I see that it finds ls in /bin/ls first, and then in /home/user/ls.  Why is that? How can I force it to use /home/user over /bin?  This is bash 4.4.12 on Debian 9.6.

When I execute a program without specifying the full path to the executable, and Bash must search the directories in $PATH to find the binary, it seems that Bash remembers the path in some sort of cache. For example, I installed a build of Subversion from source to /usr/local, then typed svnsync help at the Bash prompt. Bash located the binary /usr/local/bin/svnsync for "svnsync" and executed it. Then when I deleted the installation of Subversion in /usr/local and re-ran svnsync help, Bash responds:  bash: /usr/local/bin/svnsync: No such file or directory   But, when I start a new instance of Bash, it finds and executes /usr/bin/svnsync.  How do I clear the cache of paths to executables?


How can I prove that $$\|f\|_{L^r}\leq \|f\|_{L^p}^\alpha \|f\|_{L^q}^{1-\alpha }$$ if $\alpha \in[0,1]$, $\frac{1}{r}=\frac{\alpha }{p}+\frac{1-\alpha }{q}$ and $f\in L^p\cap L^q$. It looks to be something with Holder, but I can' conclude.

On , one can see that   $$\|fg\|_r\leq \|f\|_p\|g\|_q,$$ when $$\frac{1}{r} = \frac{1}{p} + \frac{1}{q}, \ p,q\in(0,\infty].$$  I have two questions,   Is the statement true? If so, is it stated in some references? I need it for my thesis.


I would like to drive 144 leds with a battery power supply. I want to drive all the leds all the time. 12 leds in series on each string.  The Led specs are:   PD 100 mW Max.  VR 5 V IAF 25 mA IPF 85 mA VF at 20mA 1.8 Typ, 2.1 Max IR at 5V 100 uA   Where do I start for something with a low cost?

I understand that I can not connect an LED directly to a battery because it will draw too much current. Thus, there must be something else in the circuit to limit the current. What options are there? Are some methods more efficient than others?


I upgraded 12.04 to 14.04 last night. I'm using unity. After upgrade this is what it looks like  .      How to place these menus back in global menubar?   I haven't touched any compiz settings.  Thanks in advance!

I'm fairly excited for Unity, as it looks like a promising new direction for Ubuntu.  However, I do have a concern - will it be possible to use Unity without the global menu?  I have my window manager set to focus-follows-mouse/sloppy focus, and find the productivity gains to be immense. Sloppy focus is incompatible, however, with global menus, as it is possible for the focus to change while you move from window to menu.  Will Unity support an option to use window menus while still using Unity?


Theorem 1.20 (a) If $x\in\mathbb{R}$, $y\in\mathbb{R}$ and $x > 0$, then there is a positive integer $n$ such that  $nx > y$. In the proof, set $A$ is assumed to have a least upper bound in $\mathbb{R}$ that implies set $A$ is bounded above. But I don't known how set $A$ is bounded above, given the constraint, $x$ is a positive real number and $n$ is a natural number. More clarification: $$A = \{nx\in\mathbb{R}_{>0} \mid (n\in\mathbb{N})\wedge(x\in\mathbb{R}_{>0})\}$$ My question is: how this set $A$ have a upper bound? And the whole theorem and proof didn't really make sense to me. I mean, if this theorem were reversed, i.e. $nx < y$, I wouldn't be able to make difference between these two scenario. Potential duplicate post: is referring to possibility of set A being empty. In this post, I’m asking(implicitly) about contradiction statement of theorem and bdd property of set. Non empty set is just one of the condition must satisfy to talk about bddness of sets.

$1.20 (a)$: If $x,y \in \mathbb{R}$ and $x \gt 0$, then there is a positive integer n such that $nx \gt y$.   The proof in the book:     Let $A$ be the set of all $nx$, where $n$ runs through the positive integers. If (a) were false, then $y$ would be an upper bound of $A$. But then $A$ has a least upper bound in $R$. Put $\alpha = \sup A$. Since $x \gt 0$, $\alpha -x \lt \alpha$, and $\alpha -x$ is not an upper bound of $A$. Hence $\alpha -x \lt mx$ for some positive integer $m$. But then $\alpha \lt (m+1)x \in A$, which is impossible, since $\alpha$ is an upper bound of $A$. $\blacksquare$   My question: for $A$ to have an upper bound in $R$ it also has to be non-empty. The author doesn't say that anywhere in the proof. Why? The proof must be incomplete, right?


What is the classic way to say for example that I have 3 friends females in my neighborhood?  If I'll say "I have three girlfriends" it's supposed to sound weird or polygamy. I just want to say that I have 3 friends while the listener will understand that I'm talking about female friends.

When I'm talking about my friend, who is a girl, but not a girlfriend, what word or phrase should I use? If the gender was unimportant, it would not be a problem. But if I want to note that the friend is female, not male, how should I say that, to avoid ambiguity?


EDIT: I dont think it's an obvious duplicate. That Q just asks how a water jet pack works. My Q asks how 2 forces in 2 opposite directions producing 2 opposite-equal reactions can somehow produce a net thrust.  These are some hydro jet packs. There are plenty of youtube videos demonstrating them.      But note the water is pumped out of the sea and runs up a tube to the device. In other words, the mass flow of water has to take a u-turn at the top of the device.  So according to Newton's 3rd Law, there should be an opposite reaction for both directions: one for the initial pumping in an upwards direction, causing a downwards reaction...and one for the later expelling in a downwards direction, causing an upwards reaction. The mass flow of water has to be the same in both cases, so the two reactions should cancel each other out and result in no net thrust.  What am I missing?

So I was cruising around at YouTube and saw this , and as I was watching started to wonder: "How is this possible?".  For a little bit of background, in case you decide to not watch the video, what is happening is an individual can hook out a 'pack' that sucks up water and then shoots the water downward:    This water Jet Levitation (JetLev) causes the rider to be able to fly upward into the air and move about forward, backward, side-to-side and even underwater (you have to watch the video for that).  So my question is:  How exactly is this possible?


In a book on Classical Electrodynamics we meet fonts for r and  r as shown in the image below    Do there exist these math symbols in LaTeX ?

The near-ubiquitous undergraduate reference on electrodynamics, "Introduction to Electrodynamics" by David Griffiths make extensive use of a script-r symbol, defined to be \vector{\scriptr} \equiv \vector{r} - \vector{r}^{\prime} and looks like:    Although the question of how to produce such a symbol in LaTeX is quite a common one I am yet to find a satisfactory solution.  The closest I've found is from the physymb package and uses the Calligra fonts:    Sadly, there is not a bold variant of this character and it is far more cursive than I would like.  I am hence wondering if there are any better facsimiles.


What would be the sum of the following series?  $$\sum_{n=1}^{\infty} \frac{1}{n \cdot 2^n}$$  Thanks

Just encountered a problem in my BC Calculus sequences and series unit that I just can't figure out.   I don't know the latex, but the problem was to find compute  $$ \sum_{n=1}^\infty \frac{1}{2^nn} $$ The handout was just on convergence, so it was easy to see that by ratio test, it does converge, but I think I'm missing some ideas to be able to calculate the sum.   We have done Taylor series, I just don't quite know how to go backwards, although my guess is that you find a way to write the partial sums and find it's value as the limit approaches infinity.  How would you go about solving this?  Thanks!


How to uninstall all the app in the home-brew with out deleting the brew. and I also wants to know how to delete the waste packages or unnecessary packages in my home brew. Can anyone pls help me how to do this.

I am wondering if there is a way to uninstall all "programs" installed by Homebrew? I was using it and installed programs that corresponded to programming or using C/C++ and used the terminal to compile it but will not be using it in a few months.


I asked this question before, but I don't quite understand it.  So the question is   A particle undergoes simple harmonic motion. Initially its displacement is 1 , velocity 1   and acceleration is -12. and find out displacement and acceleration when the velocity is   square root of 8.  Someone says that harmonic equation takes the form y(t)=Acos(Wt+@)    But, I can not solve this equation by taking derivative and putting in the values//  Someone help me plz

Particle undergoes simple harmonic motion.  Initially Its displacement is $1$, velocity $1$ and acceleration is $-12$   Compute displacement and acceleration when the velocity is square root of $8$.  I am not familiar with this kind of application question.  So, its displacement is $1$, does that mean that $y=1$ when $x=0$ ?


Do i need force myself to create 3-4-sided polygons like on 1st picture or i can make faces like on 2nd pic? Does it depend on future use of the model (CNC, animation etc).

Support for N-Gons (polygons consisting of more than 4 vertices) has been in Blender for a while now, but many of us still may not know when to use them, and how to do so effectively.  In what situations do N-Gons really come in handy? When should they be just plain left out? Do they have any place in finished models?


Not sure if this is possible and I just didn't read well enough but a not operator in search might be helpful.  For Example:  [android] studio is:question ![android-studio] To exclude questions with the tag android-studio but with results with studio in the body  [android] android studio is:question ![android-studio] or to find questions about android studio but without the correct tag.

I've tried using the - (not) symbol in searches on Stack Overflow to reduce the number of irrelevant matches in the results, with no effect.    I'm getting really sick of "Whats your favorite programmer joke / cartoon?" appearing in the results for almost every search I perform.  I've read  and there is no mention of how to use a Not operator to exclude the following word.  I've heard about excluding tags using -, but I'm talking about excluding words.  Is this possible?  Has it just not been implemented?  If not, I'd really like to see this added to search.


I am trying to send email using Selenium , but I failed to locate the To field and email body.  This my code:   @Test public  void createEmail(){        WebDriver driver= new FirefoxDriver();       driver.get("http://gmail.com/");        driver.findElement(By.name("Email")).sendKeys("myUsername");;       driver.findElement(By.name("Passwd")).sendKeys("myPassword");;       driver.findElement(By.name("signIn")).click();        driver.manage().timeouts().implicitlyWait(40, TimeUnit.SECONDS);        // create the Email       driver.findElement(By.cssSelector("span.gb_7.gbii")).click();       driver.findElement(By.id("gb_71")).click();          driver.findElement(By.name("to")).sendKeys("test@gmail.com"); }

We have merely just had a kick off meeting for a new project that I am required to automate ASAP. The project is essentially a "mailbox project", if you will, and I have no idea as to where to start my test automation on this type of project as I am fairly new to selenium automation. Emails will however be sent/received via Gmail. I would really appreciate any help or advice on how/where to start my automation with regards to this project... if at all possible :).  The framework I am using is Eclipse, TestNG and of course selenium:). Language - Java


i trying to implement banner ad in my quizz activity by Admob documentation , i m doing every thing according to documentation but dont know why i m getting null pointer exception. in my quizzactiviy i added below codes for banner ads  private AdView mAdView;   MobileAds.initialize(this, new OnInitializationCompleteListener() {         @Override         public void onInitializationComplete(InitializationStatus initializationStatus) {         }     });      mAdView = findViewById(R.id.ads);     AdRequest adRequest = new AdRequest.Builder().build();     mAdView.loadAd(adRequest);  xml code for ad  <com.google.android.gms.ads.AdView     android:id="@+id/ads"     android:layout_width="288dp"     android:layout_height="60dp"     android:layout_alignParentBottom="true"     android:layout_centerHorizontal="true"     android:layout_marginStart="64dp"     android:layout_marginLeft="64dp"     android:layout_marginTop="20dp"     android:layout_marginEnd="59dp"     android:layout_marginRight="59dp"     app:adSize="BANNER"     app:adUnitId="ca-app-pub-3940256099942544/6300978111"     app:layout_constraintEnd_toEndOf="parent"     app:layout_constraintStart_toStartOf="parent"     app:layout_constraintTop_toBottomOf="@+id/quit_btn">  Error i m getting  Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.google.android.gms.ads.AdView.loadAd(com.google.android.gms.ads.AdRequest)' on a null object reference     at com.example.quizztime.QuizActivity.onCreate(QuizActivity.java:73  Dependencies i used implementation 'com.google.android.gms:play-services-ads:20.0.0'

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I'm using IntelliJ in Windows and Ctrl-Alt-M is a shortcut that is very useful but right now it's doing nothing. The shortcuts just don't reach IntelliJ. My suspicion is that some other app registered it as a global shortcut or something like that.  In IntelliJ, it seems correctly set:    and if I add another shortcut to "Method...", such as ctrl-alt-shift-r, I can properly use it in the editor in IntelliJ.  I'm running the latest Windows 10 and the latest IntelliJ.  Any ideas how I can find that out?  I followed the process described here:    using Visual Studio tool Spy++ and apparently the M-key-down event is never triggering.  This is what happens for ctrl-alt-t:    a shortcut that works as expected in IntelliJ. And this is what happens with ctrl-alt-m:    I have two keyboards connected to this computer: a Kinesis Advantage and a Logitech K120. They both behave the same way in regards to ctrl-alt-m.

Given a hotkey, how can I find which program owns it?


FirstI'm trying to display the spinner into a dialog, I'm calling the data from database into ArrayList via getData object and everything is working fine but in the last step I got the above error when I tried to assign the adapter to the spinner and here is my code :      public class ViewDialogCities {     public void showDialog(int layoutID , Activity activity){          final Dialog dialog = new Dialog(activity);         dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);         dialog.setCancelable(false);         dialog.setContentView(layoutID);         Button OkButton =  dialog.findViewById(R.id.btn_dialog_ddl_ok);         Button CloseDialogButton =  dialog.findViewById(R.id.btn_dialog_ddl_cancel);         Spinner spn_ddl_dialog_list = findViewById(R.id.spn_ddl_dialog_list);           //Define data object         final GetData getData = new GetData();         ArrayList<String> getListOf;           //Retrieve data from data object and store it an ArrayList         getListOf = getData.getListOf("R");          //ArrayList to ArrayAdapter         ArrayAdapter<String> arrayAdapter = new ArrayAdapter                 ( HomeActivity.this, android.R.layout.simple_spinner_dropdown_item, getListOf);          arrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);          // Assign ArrayAdapter to spinner         spn_ddl_dialog_list.setAdapter(arrayAdapter);          CloseDialogButton.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View v) {                 dialog.dismiss();             }         });          OkButton.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View v) {              }         });          dialog.show();     } }


I have a sentence like this.     I applied this method to the problem.   I want "the problem" to be the subject of the sentence.  If "this method" were the subject, this might be very easy.     This method was applied to the problem.   However,     The problem was applied this method to.   this sentence looks a bit awkward. Is the last sentence OK?

How can I reliably and accurately identify the passive voice in writing or speech? I'm not interested in advice about whether or not to use it yet... I just want to know for sure what it is, so that I don't look as stupid as .


When trying to display a record's field via lightning:recordViewForm, I am successful when I set the recordId attribute (ProjId) directly by defining a default value.  However, when I assign ProjId in a helper class, it doesn't display.  I am verifying that I am successfully setting ProjId in the helper class because I display it above the recordViewForm.  I don't understand why recordViewForm isn't working when ProjId is set in the helper class and it is working when I hardcode the record id when I define the ProjId attribute. /* when I set the recordId as the default value, the recordViewForm works. */ <aura:attribute name="ProjId" type="String" default="" access="global" />                      {!v.ProjId}                    <lightning:recordViewForm recordId="{!v.ProjId}"                           objectApiName="Project2__c">                           <lightning:outputField variant="label-hidden" fieldName="Abstract__c" />                    </lightning:recordViewForm>  Here is what I am doing in the helper when the recordViewForm doesn't work. component.set('v.ProjId','a003u00000bEWNRAA4');

I have a <lightning:recordViewForm in a custom lightning component.  When I hardcode the recordId attribute it works, but when I pass an attribute in it fails without any error messages in either the console or the debug log.  Component  <aura:handler name="init" value="{!this}" action="{!c.doInit}" /> <aura:attribute name="recordId" type="Id"></aura:attribute>  <lightning:recordViewForm recordId="{! v.recordId }" objectApiName="MyCustomObject__c">      <lightning:outputField fieldName="Name" />  </lightning:recordViewForm>   JavaScript Controller  doInit : function(cmp, event, helper) {      // var recordId = helper.getQueryStringParameter('recordId');      cmp.set("v.recordId", "a0C4E000003YMkmUAG"); }   The above does not work, even if I put the recordId directly into the attribute.  It only works when I set the Id in the recordId attribute of the <lightning:recordViewForm like below:  <lightning:recordViewForm recordId="a0C4E000003YMkmUAG" objectApiName="MyCustomObject__c">      <lightning:outputField fieldName="Name" />  </lightning:recordViewForm>


my old laptop is i3 2370m dual core 2.4ghz. in the laptop windows 7 os became slow.can i download linux on it.will it become fast with linux os. AND I don't know programming .how could i handle the linux operating systam ?

I would like to see a full how-to guide on how to install Ubuntu.


I installed openSUSE Tumbleweed on my HP probook in dual boot with Windows 10. Then, I noticed some bugs in openSUSE and decided to try Ubuntu 18.04. But after I installed Ubuntu the openSUSE didn't show up in the boot options any more.  I searched for help and found out that I should run some sudo grub-something (don't remember what) and the grub.cfg was rebuilt and then openSUSE started appearing in the GRUB menu on boot. But when I choose openSUSE in that menu I get an error saying   cannot find vmlinuz-5.1.4... Need to load kernel first   I tried searching everywhere but have no luck, so I'm here to get a little help. If you need more details, please, let me know.  EDIT:  I don't know if openSUSE is sharing /boot with Ubuntu.  This is the output of lsblk -o name,fstype,size,label,mountpoint  NAME   FSTYPE     SIZE LABEL MOUNTPOINT loop0  squashfs 140,7M       /snap/gnome-3-26-1604/74 loop1  squashfs    13M       /snap/gnome-characters/139 loop2  squashfs  14,5M       /snap/gnome-logs/45 loop3  squashfs   8,4M       /snap/canonical-livepatch/77 loop4  squashfs  34,6M       /snap/gtk-common-themes/818 loop5  squashfs   2,3M       /snap/gnome-calculator/260 loop6  squashfs    91M       /snap/core/6350 loop7  squashfs   3,7M       /snap/gnome-system-monitor/57 sda             298,1G        ├─sda1 ntfs       500M        ├─sda2 ntfs     242,1G        ├─sda3              1K        ├─sda4 btrfs       35G        ├─sda5 swap       3,8G        └─sda6 ext4      16,2G       / sr0              1024M

I installed Windows 7, which ate Ubuntu's boot file. When starting up the computer, it now goes straight to Windows, without giving me the option of booting Ubuntu.   How can I get Ubuntu back?


Why do circuits mostly run on a DC current? I understand that electric motors use AC but things like my laptop operate on DC.  Are there another advantages to AC current that made it the standard besides the big one, that voltage can be more easily changed?   Thanks

I'm pretty sure the answer to this should be obvious - even to me ...  It's been a while I've been reading and attempting to construct simple electronic circuits. The supply almost always is either through a battery/cell, or AC duly rectified to DC.   I have the impression electronic circuits rarely ever work off an AC supply.    Is this impression correct? If yes, why is an electronic circuit rarely (if ever) powered/biased using straight AC?


I've been using my 13" 2015 MacBook Pro with BenQ projector. I'm connecting these with simple HDMI and watching Netflix, that's all, no Apple TV, no fancy stuff.  Right now my projector is connected to 5.1 home theater but I need something more mobile and I've been thinking about a bluetooth soundbar, .  My question is, will watching movies using HDMI cable and streaming audio using bluetooth at the same time work? It will look something like this:  Macbook <===== HDMI CABLE (VIDEO ONLY) =====> Projector Macbook <===== BLUETOOTH (AUDIO ONLY) =====> Soundbar   Has anyone tried it?

Lolo Joe wants earphone jack to plug and use big speakers but at the same time he wants to partner the music coming out the earphone jack and his Bluetooth system and speakers. Is it even possible to use the earplug connection and the Bluetooth system and devices at the same time?


I've used my flareon in the gym a lot, it's been about two weeks of me trying to put it in the gym but when there are free slots open it won't show some of my pokemon, mainly my higher level ones. All alive and with full hp

So I defeated a Team Valor gym earlier today using my highest cp Pidgeot. It turned grey, so I went to claim it with that Pidgeot, except it wouldn't let me. What determines which pokemon you are allowed to place at a gym? Is it just those who have participated in a battle can't? Is there a time period for it? What about training at a friendly gym? Does this impact anything?


despite several attempts at making Google Chrome work as my default browser I simply cannot.  I've read countless threads on the internet, checked mimeapps.list and so on, tried about anything, from simple system configuration by going to settings and change as the default browser there, which, for some odd reason, won't allow me to set a default browser, to more advanced terminal scripting.  This is a clean install of Ubuntu 12.10 x64 bit updated to the latest version including kernels.

How can I set Google Chrome as the default browser? If I set it in the browser settings, nothing happens. The browser says it's default, but in preferred applications in Gnome, there's only Firefox to choose from. Clicking any link i.e in Thunderbird opens a blank Firefox window, not with the link embedded. Can I set the  default browser in dconf2 or any configuration file?


Reading  reminded me of an idea I once had, and I wonder whether it's feasible.  Imagine a hollow ball made of something strong, like steel. Imagine there is nothing inside; only vacuum.  Is there any size of ball and any available material such that, if you made a ball like this, it would float like a helium balloon? In other words, that the mass of the ball itself plus the (0) mass of the vacuum would be less than the mass of the air it displaces, making it bouyant?  I suspect there is no material strong and light enough, but I don't know how to do the calculations.  (It's fun to imagine these being used in fantastical bridges or airships, though I suppose a bridge would be unwise; you wouldn't want it to rise or sink when the weather changes.)

Is it possible to make a solid rigid evacuated "balloon" out of Beryllium or other elements or alloys?  The critical buckling pressure at which an evacuated sphere is given as $$ P_1=\frac{2E\cdot\left(h/R\right)^2}{\sqrt{3\left(1-\nu^2\right)}} $$ where $E$ is , $h$ the shell's thickness, $R$ the radius to the midsurface shell, and $\nu$ is .  Of course this is theoretical and experimental and literature values for submersibles hover around 1/4 of the theoretical pressure.  Beryllium has the following properties:   Density=1.85 g/cm$^3$ Young's Modulus=287*10$^9$ Pa Poisson Ratio=0.032   Calculating the upward force, buoyancy at 101.3 kPa atmospheric pressure and Radius of 10m gives 4.24*10$^8$ N. The weight of this sphere with shell thickness 1mm has 2.32*10$^7$ N downward force of Beryllium material, so it will theoretically float at ground level.   Calculating the critical buckling stress of this beryllium sphere is 331.57 kPa, which is 3.27 times the atmospheric pressure of 101.3 kPa, so theoretically it won't buckle. But in experimentation done in earlier experiments as stated before, due to construction/material non-ideal situations, the critical buckling formula predicts about 4 times stronger than actual, so it would need about 400 kPa, not 331 kPa as Beryllium sphere with this specification would hold. Increasing the strength capability also increases weight and therefore lowers it's ability to float, but Beryllium is the closest element with this situation I have calculated that could work if ideal (I have only been using periodic table elements and household materials)  Is it possible with an alloy of elements? Using the equations for buckling and buoyancy, the following is needed. What alloys/materials come to your mind?  Material considerations:   Material with larger Poisson ratio Material with larger Young's Modulus Less dense material Construction (is it possible)   Material considerations affect on lift   Thickness can be larger, increases strength by the squared. But also increases weight. If a material with lower density with similar structural properties as Beryllium is used, it would help. Radius can be lower for same reason, but also lowers buoyancy (volume)   My other designs (don't worry about these just yet, just if you are curious is a vacuum sphere with a pressurized "outer tube" with spokes in tension (carbon fiber nanotubes maybe) to keep the 2 spheres in position. Another is a spherical truss out of carbon fiber nanotubes with a light membrane around. The truss prevents the outer membrane from collapsing due to the atmospheric pressure  The "point" of this if you ask, as to why not use a traditional balloon is it can be used as a boat by filling the sphere with air, and then used as a aircraft at will by evacuating the sphere. An alternative mode of transportation for sea vessels etc.


The observed red shift of objects is assumed to indicate that those objects are moving away from Earth but is it possible that there could be another explanation for the observed red shift that does not require the expansion of the Universe ?

I'm interested if any of the following explanations have enough predictive capability to explain the observations we see today. The claim is that the Universe is not expanding, and that red-shift of light is caused by:    Though a couple of these are simply ridiculous, I'm still interested. Keep in mind that I am not a creationist, but am looking for reasons to see if any of these are valid or invalid.


I'm developing a program in Qt that will help users to manage (create, edit and delete) their quicklists in Unity launcher.  I got to a point where I created .desktop file and I don't know how to programmatically place that file on Unity launcher.   I found two (bad) ways to do this:   Manually drag and drop created .desktop file to unity launcher Edit favorites key with "gsettings set com.canonical.Unity.Launcher favorites" and force unity to reload with "unity --replace"    So, I'm searching for a function or a system command that is called on first 'drag and drop' method so I can do it in my program without need for user to do it manually.  I don't even know where (or how) to search for my solution so any suggestions will be helpfull.

Although there are several posts on the Internet on the subject, I did not find a solution yet: my goal is to find a command that adds an icon (.desktop file) to the Unity launcher and shows it immediately. when I open dconf-editor (desktop > unity > launcher) and I add an item to the favorites list, it shows at once in the launcher, so my idea is that it must be possible to do the same thing by command. The solutions I found so far on the Internet do not do the job.    I need to do it by command, to use in a quicklist editor I am working on.  You would make someone unbelievably happy if you could help out


If I do the code:  echo "printf 'working'" | sh   the code prints out working  but when I want to change the current directory this way:  echo "cd ../" | sh   the current directory isn't changed.  Do you know the reason behind that behavior? do you know how to echo cd command to sh in a working way?

I'm trying to write a small script to change the current directory to my project directory:  #!/bin/bash cd /home/tree/projects/java   I saved this file as proj, added execute permission with chmod, and copied it to /usr/bin. When I call it by: proj, it does nothing. What am I doing wrong?


I'm having issues with remove buttons on dynamically generated text boxes. The click function does not get called at all, and I'm not sure why. Can someone please point me in the right direction?   Here is the code:  HTML

Additional Authors

         <input id="addAuthorButton" type="button" value="Add Author" class="btn btn-lg btn-default btn-block" />

     JS  $(document).ready(function(){      var counter = 0;      $("#addAuthorButton").click(function () {          if(counter==5){             alert("Only 5 additional authors allowed.");             return false;         }          counter++;          var newTextBoxDiv = $(document.createElement('div'))             .attr("id", 'additionalAuthor' + counter).attr("class", 'additionalAuthor input-group');          newTextBoxDiv.after().html("<input class='form-control' type='text' placeholder='Author Name'>");          newTextBoxDiv.appendTo("#additionalAuthorsTextboxes");      });      $(".removeAdditionalAuthor").click(function () {         $(this).closest('div').remove();     }); });   CSS  @import url('https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap.min.css'); @import url('https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap-theme.min.css');    I also have setup a JSFiddle page:

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


The title says it all. To elaborate, In Sweden Ph.D. is being considered a formal job and students receive a monthly salary and pay taxes. Therefore, the question is specifically about whether applying and pursuing an MBA in parallel with pursuing Ph.D. is legally feasible or a special type of permission is required from the university? Update 1: I'm aware that it's not recommended to pursue these two demanding degrees together. The question is whether in Sweden it's technically possible or not. Update 2: It's a question related to Sweden, only!

The situation: You did your B.Sc. and M.Sc. in CS with focus on subfield X1 and are now pursuing a PhD in subfield X2. There is a Masters program in subfield X2 available where you do your PhD that offers courses that allow you to advance in this subfield (which is pretty new to you).  Does it make sense to get a second M.Sc. while pursuing a PhD if the courses of the Masters program will be beneficial to your PhD work? Subquestion: Do you think it is even feasible to do this based on your experience?  The geographic context is Europe/Germany so a PhD does not include course work. A Masters (at a university of applied sciences) takes 3 semesters full time with the possibility to double that time when doing it part time.


I had a look at the .desktop files on my 12.04 Ubuntu system, and many of them do not have a full path specification for their icon file.  It is rather something like:  Icon=anjuta   or  Icon=vlc   or   Icon=application-x-clementine   Is there a common path where icons can be stored so that this can work ? If not, how does this work ? If I try to do the same thing with my own icons I have to specify the full path.  e.g.  Icon=/usr/local/share/my-icon.png   works fine, but  Icon=my-icon.png   will fail.  Any kind of help is welcome!

On my desktop I have a .desktop file. If I type:  Icon=/home/ianbell/Pictures/myLogo.png   the icon of the .desktop file changes (the expected result).  But, if I type:  Icon=~/Pictures/myLogo.png   it doesn't work.  Isn't ~/ a shortcut for /home/$USER?


How to know which API is calling & which operations are performed in my saleforce org whenever other Application(Java) hitting salesforce Org. I am able to know which application and how many Calls but I am unable to know which operations performed ?

We are using Avaya CTI Adapter Managed Package . There are 4 classes in the package .  Is there a way I can see/access the code in the package ?  I want to see where the call details values are stored temporarily.


Let $G$ be the group of invertible $2\times 2$-matrices over the real numbers. Let $H \subseteq G$ be a group consisting of matrices with determinant equal to 1.  I'm to show that $H$ is a normal subgroup. I tried showing that $ghg^{-1}$ would end up with a determinant equal to 1, but that was just an awful lot of calculating. Then I thought perhaps I should find a group homomorphism $\phi: G \to G$ such that the kernel was the identity matrix. But I couldn't figure out how.  Any tips would be awesome.

Let $N= GL_n(\mathbb{R})$ and $M=SL_n(\mathbb{R})$. Is $M$ normal subgroup in $N$? Why or why not?  I know how to do this with $GL_2(\mathbb{R})$ and $SL_2(\mathbb{R})$ but with $N= GL_n(\mathbb{R})$ and $M=SL_n(\mathbb{R})$ I don't even know all of their elements so I can't check the left and right cosets of $M$ in $N$.


I'm trying to get a figure in my LaTeX document, but I struggle to set the search-path  I use  \addplot[blue] table {invcum.dat};   from the example, however it keeps saying  ! Package pgfplots Error: Could not read table file 'invcum.dat'.   After trying around with various things I looked at the reportings from Process Monitor (Sysinternals) and it shows, that the file is only looked for in the temporary directory.  In LyX I found the TEXINPUT option and it was set to "." I added my working directory to it (where the data file lies) but I keep getting the same behaviour.  I will continue by inserting the data into the documents directly, but I'd really like to see what I missed to get things working.

I have recently discovered the wonderful pgfplots package and I've started coding my Python code to output tabular data of whatever is plotted (at least for simple plots). In my LaTeX source code, I use plot file {../datafiles/data.dat}; and similar commands extensively. All my external figures (yes, I still have some) are in a separate directory that I specify in my preamble using \graphicspath{...}. Is there any equivalent path that TikZ and pgfplots use to search for data files?  I have difficulties searching for an answer to this question, because the word path has such a specific meaning in a TikZ context. I'm using PGF 2.10 and pgfplots 1.5.  I checked in the PGF manual (section 19.4, page 224) and in the pgfplots manual (section 4.2.2, page 25–26) but did not find anything relevant.  MWE:  \documentclass{standalone} \usepackage{tikz} \usepackage{pgfplots} \begin{document} \begin{tikzpicture} \begin{axis} \addplot plot file {somedata.dat}; \end{axis} \end{tikzpicture} \end{document}   where somedata.dat contains:  1 2 3 4 5 6 7 8 9 10   Sorry for not adding a MWE earlier, I figured it wasn't needed because the question was obvious.


I tend to use (floating) listings, as you can observe below in the MWE. To set the width of those listings, xleftmargin and xrightmargin are set to equal values to mimic centering of the listing.  I saw unexpected behaviour using the caption package, in the following condition: Depending on the resulting width of the listing, the listing's caption does not respect the justification and is not centered. Simply removing \usepackage{caption} (and \captionsetup therefore too of course) puts the caption right in the center where it is intended to appear.  So i suspect the caption package is overwriting sth. Can this be corrected in a simple way without hacking with minipage/figure/tabular-environments?      \documentclass[]{scrbook}  \usepackage{xcolor} \usepackage{listings} \usepackage{caption} %removing it centeres the listing's caption again  \captionsetup{     %... some modification     justification = centering, % does not help with the listing's caption }  \begin{document} \begin{lstlisting}[     frame=shadowbox %helper, to see listing's dim     ,captionpos=b     ,float     %center the listing         ,xleftmargin=.20\textwidth         ,xrightmargin=.20\textwidth     ,label=code     ,caption={This caption is not centered at all}     ,language=Delphi] i := 1; \end{lstlisting}  \end{document}

I would like that caption position is at the center of the page, like the one at the top in my example.  Here my code:  \documentclass{article}  \usepackage{color}  \usepackage{listings} \usepackage[justification=centering]{caption}  \lstdefinestyle{SC}{     language=erlang,     xleftmargin=.2\textwidth,     xrightmargin=.2\textwidth }  \lstset{      numbers=left,     numberstyle=\tiny,     basicstyle=\scriptsize,     showstringspaces=false,     showspaces=false,     commentstyle=\color{blue},     keywordstyle=\bfseries\color{purple},     captionpos=t,     frame=lines }  \begin{document}  \begin{lstlisting}[style=SC, caption={test}] % Stop all containers docker stop $(docker ps -a -q) % Delete all containers docker rm $(docker ps -a -q) % Delete all images docker rmi $(docker images -q) \end{lstlisting}  \end{document}   The image shows the problem.    How can I set the caption to be centered? I have not found a solution in the package documentation.


I installed Ubuntu 17.10 but there's a very annoying bug. When I'm watching videos (streaming or YouTube, not only in full-screen) the monitor goes to sleep. Some solution? Thanks you!

In earlier Ubuntu versions like 16.04 and 17.04 while watching YouTube videos in full-screen mode, the screen would not get locked automatically.  In Ubuntu 17.10 while watching videos in browser, system is getting locked. So Ubuntu 17.10 is considering this scenario as user is not doing anything.  Kindly suggest a solution for that.