I am a German citizen visiting my girlfriend in the US for 2 x 50 days a year under the Visa Waiver Programme (VWP). I already read that some immigration officers might make problems here due to the duration, if there are not at least 6 months between those 2 visits. But I believe 6 months should be feasible.   Now: Can I work remotely (telecommuting) for my German employer under the Visa Waiver Programme? I have an indefinite work contract with my German employer and would work via email and skype, mostly. The employer is ok with this. I have absolutely no intention to settle on US soil, my life centre is in Germany. But how to prove that?  Additionally, if I earn money in the US for more than 30 days, I need to pay US taxes, as far as I understand. That means I need to disclose that I am working to border officers, or do I not? I d be afraid I else might become a tax criminal and tax crimes are major offenses with jail time and all.  If I work for more than 30 days telecommuting, do I need to pay taxes in Germany and the US? That would be a heavy tax burden.
I would like to travel in the USA for a period of 3 - 6 months. But I want to spend some time working for my employer (remote work) and getting paid by the employer. Is this possible under a tourist visa (B1/B2)?  I hope this is OK since I will not be getting paid by a US employer. I am in the IT trade so all that I will be needing is my own laptop and a connection to the internet. The money I earn would actually help me pay for the expenses I get during the holiday.
What are the rules and limits of Accio spell? We know that Accio spell (aka ) has some limits:   It can be blocked (e.g. Harry couldn't Accio the Diadem in RoR in Deathly Hallows). Many more failures are listed on Wikia.   But what are the exact full rules and limitations governing the spell in Harry Potter world?   Distance?  Line-of-sight?  Knowing exact or approximate location?  Specificity of item (e.g. "Accio Broom" seemed to work for Weasleys in OotP to bring their locked-up brooms - why not just a random broom?) Types of Accio-able stuff? Can you Accio water? Lump of earth? Gases/liquids/etc...? Can you Accio based on jQuery selector (or an SQL where clause), for lack of a better description? E.g. "Accio the book that has the word 'Flammel'"? "Accio biggest green ball from this room"? Can you Accio ALL items of a kind? (the reason I thought of this whole question was seeing "Accio all guns" comment in ). Can you Accio vague stuff? ("Accio meal"). Other rules that can be inferred.   NOTE: While Wikia article has some of the info, it is clearly very lacking in details on specific rules based on specific instances in canon. I'm looking for a fully comprehensive, organized ruleset for the charm, not merely 1-2 tidbits in Wikia article. Create JSON using apex I am trying to change the page size in the QGIS 3.0 Composer but I am not able to see the Composition tab.  I have right clicked an empty space in the toolbar but did not see anything about composition.  I am using Windows 7.  I tried looking at the QGIS docs but they are still in testing. Creating Ellipse in WGS84, but with metric parameters I have the function  --Ellipse(x,y,rx,ry,rotation,#of segments in 1/4 of ellipse) SELECT ST_Translate( ST_Rotate( ST_Scale( ST_Buffer(ST_Point(0,0), 0.5, $6), $3, $4), $5), $1, $2)   I have points in WGS84 (x,y), radiuses in meters (rx, ry), rotation angle in degrees. And I need a new WGS84 geometry as a result.  As you can see I can't call this function without conversions between WGS84 and some metric SRID. But my points aren't in a definite region. So a SRID which is optimal for one point, throws an error for another point during conversion.  Is there a common way to get an optimal metric projection (SRID) for a WGS84 point? Or at least to use some rough, but world-wide universal metric projection? Or maybe there's a trick for this case? Product of all monic irreducibles with degree dividing $n$ in $\mathbb{F}_{q}$? English version of Ubuntu with Italian keyboard I want to install Ubuntu in ENGLISH (UK) but I have an ITALIAN keyboard, which has a different layout to the English keyboard. How can I install Ubuntu in English but select an Italian layout for the keyboard. I tried, but it would only allow me to select an English keyboard. Thanks I have Ubuntu 12.04 installed on my PC, recently I have edited /etc/passwd  and changed  user1:x:00:00:user1,,,:/home/user1:/bin/bash   to give root permission to user1 and the system always need to login as root, for running some custom software.  Now it seems the sound is not working, the volume icon is disabled. I understand that the pulseaudio demon can't be run as root that's why the audio is not working. How can I resolve it, like set the permission of pulseaudio to run as root.   When I type the command    /usr/bin/pulseaudio --start   Giving me the output  W: [pulseaudio] main.c: This program is not intended to be run as root (unless --system is specified). E: [autospawn] core-util.c: Home directory /home/user1 not ours. W: [autospawn] lock-autospawn.c: Cannot access autospawn lock. E: [pulseaudio] main.c: Failed to acquire autospawn lock   Edit   Solution for problem:  I have fixed the problem by disable root checking for pulseaudio equalizer  sed -i 's/exit 1/#exit1/g' /usr/bin/pulseaudio-equalizer Generalized Euler sum $\sum_{n=1}^\infty \frac{H_n}{n^q}$ I found the following formula   $$\sum_{n=1}^\infty \frac{H_n}{n^q}= \left(1+\frac{q}{2} \right)\zeta(q+1)-\frac{1}{2}\sum_{k=1}^{q-2}\zeta(k+1)\zeta(q-k)$$  and it is cited that Euler proved the formula above , but how ?  Do there exist other proofs ?  Can we have a general formula for the alternating form   $$\sum_{n=1}^\infty (-1)^{n+1}\frac{H_n}{n^q}$$ Is it possible to install Ubuntu on my Windows 8 computer without any CD or USB drive? Single Variable Calculus Reference Recommendations I am very new to being able to use LaTeX to type up mathematical papers, and I just got my "system" set up. Currently I have installed TexWorks, and MikTex, and I have put together a 'hello world' article which seems to run well.   I have also used the syntax "\usepackage{amsmath}" and "\usepackage{amssymb}" in the beginning of my .tex file to write math symbols, only because some online tutorial said so.   My question is, firstly, are those the only packages I need to use for writing math, and secondly, I remember reading about some shortcuts(?) that can be used for writing math symbols, and/or user defined shortcuts that can be 'set' in the beginning so as to reduce the amount of LaTeX code needed to write mathematical symbols. However, I do not know if this is true, and if it is, how to go about 'installing' such a thing.   Does such a thing exist? Am I able to make my own shortcuts?  Thanks! I've been asked to show that:  $n(n+1)(2n+1) \equiv 0 \pmod 6$  I found in a previous question that:  $n(n+1)$ was divisible by $2$ and resulted in an even number e.g  $n(n+1) \equiv 0 \pmod 2$  so I figured I needed to find:  $(2n+1) \equiv 0 \pmod 3$ in order to complete  $n(n+1)(2n+1) \equiv 0 \pmod 6$  but I am unsure on how to find $(2n+1) \equiv 0 \pmod 3$  Is this the right way to find the mod 6 and if so could you tell me how I could find  $(2n+1) \equiv 0 \pmod 3?$ Including Interaction Terms in Random Forest Suppose we have a response Y and predictors X1,....,Xn. If we were to try to fit Y via a linear model of X1,....,Xn, and it just so happened that the true relationship between Y and X1,...,Xn wasn't linear, we might be able to fix the model by transforming the X's somehow and then fitting the model. Moreover, if it just so happened that the X1,...,XN didn't affect y independent of the other features, we also might be able to improve the model by including interaction terms, x1*x3 or x1*x4*x7 or something of the like. So in the linear case, interaction terms might bring value by fixing non-linearity or independence violations between the response and the features.  However, Random Forests don't really make these assumptions. Is including interaction terms important when fitting a Random Forest? Or will just including the individual terms and choosing appropriate parameters allow Random Forests to capture these relationships? How can I put the computer to sleep from Command Prompt/Run menu? I know that almost everything on Windows, like opening any sort of application, can be done from the command prompt or from the Run menu.  How can I put my computer to sleep or shut it down? What is the command for that? Based  I'm trying to setup Tomcat Server, I have successfully installed it and tested it. Then I stopped it as recommended in the tutorial. I'm setting up "New Server Runtime Environment" as you can see under Tomcat Installation Directory is a windows directory, anyone knows the Ubuntu directory equivalent for this? Thanks. The statement is:     In a commutative ring with 1, every proper ideal is contained in a maximal ideal.   and we prove it using Zorn's lemma, that is, $I$ is an ideal, $P=\{I\subset  A\mid A\text{ is an ideal}\} $, then by set inclusion, every totally ordered subset has a bound, then $P$ has a maximal element $M$.  My question is why $M$ must contain $I$? Did I derive a new form of the gamma function? Why do hard links exist? When is R squared negative? My understanding is that $R^2$ cannot be negative as it is the square of R. However I ran a simple linear regression in SPSS with a single independent variable and a dependent variable. My SPSS output give me a negative value for $R^2$. If I was to calculate this by hand from R then $R^2$ would be  positive. What has SPSS done to calculate this as negative?   R=-.395 R squared =-.156 B (un-standardized)=-1261.611   Code I've used:  DATASET ACTIVATE DataSet1.  REGRESSION /MISSING LISTWISE /STATISTICS COEFF OUTS R ANOVA             /CRITERIA=PIN(.05) POUT(.10) /NOORIGIN             /DEPENDENT valueP /METHOD=ENTER ageP   I get a negative value. Can anyone explain what this means? I came across the :    Which states:     $\pi$ Pi      Pi is an infinite, nonrepeating $($sic$)$ decimal - meaning that   every possible number combination exists somewhere in pi.  Converted   into ASCII text, somewhere in that infinite string of digits is the   name of every person you will ever love, the date, time and manner    of your death, and the answers to all the great questions of    the universe.   Is this true? Does it make any sense ?