i have to test if the cvs file exists and could be downloaded from a webapp, So in the download link element, i see this :  &lt;a class="" target="_blank" download="Myfile(2014-07-01 2014-07-31).csv" href="blob:de3889b8-23d4-4776-bn8f-68f34911fad9"&gt;   it is encoded in Base64 using java.  How can i decode the content of href in order to download the csv file? Thank you
I have an image that is Base64 encoded. What is the best way to decode that in Java? Hopefully using only the libraries included with Sun Java 6.
Handling very large numbers in Python Exercise from Atiyah-Macdonald, Chapter 1, 2.iv) Let $A$ be a ring and let $A[x]$ be the ring of polynomials in an indeterminate $x,$ with coefficients in $A.$ Let $f=a_0 + a_1x+\cdots+a_nx^n \in A[x].$ $f$ is said to be primitive if $(a_0,a_1,\ldots,a_n)=(1).$     Prove that if $f,g\in A[x],$ then $f$ and $g$ are primitive $\Rightarrow$ $fg$ is primitive.   I know Gauss lemma holds true for UFDs, but in this case it isn't required $A$ to be UFD: is it possible to drop the assumption, or is some hypothesis missing here? How to invoke a system call via syscall or sysenter in inline assembly? How to convert milliseconds into human readable form? I need to convert an arbitrary amount of milliseconds into Days, Hours, Minutes Second.  For example: 10 Days, 5 hours, 13 minutes, 1 second. Probability that an integer number having Poisson distribution is even The probability $P(X=n)$ that an event X takes place $n$ times in a fixed period of time follows the Poisson distribution with parameter $\lambda$ i.e.  $$ P(X = n) = e^{-\lambda} \frac{\lambda ^ n}{n!}$$  I have to evaluate the probability that the event $X$ takes place an even number of times. I know that:   $$ P(X \text{ is even} ) = e^{-\lambda} \cdot \sum_{k=0}^{+\infty} \frac{\lambda^{2k}}{(2k)!}$$  but I can't solve the series.  I guess that I have to use the fact that $e^\lambda = \sum_{n = 0}^{+\infty} \lambda^n/n!$, but I got stuck.  How can I evaluate $P(X \text{ is even})$ (alternative solutions appreciated). What are "Community Wiki" posts? Some questions and answers are marked Community Wiki and are owned by a community wiki user:  (In fact, this very question is one of them)  Why have Community Wiki posts? How do Community Wiki posts work? How does a post become a Community Wiki post? How can the Community Wiki status be removed from a post? How can I find Community Wiki posts? Why doesn't Steam start? When I try to start Steam nothing happens. Reinstall doesn't help.  $ steam Running Steam on ubuntu 13.04 64-bit STEAM_RUNTIME is enabled automatically Installing breakpad exception handler for appid(steam)/version(1378500910_client) Installing breakpad exception handler for appid(steam)/version(1378500910_client) Installing breakpad exception handler for appid(steam)/version(1378500910_client) unlinked 0 orphaned pipes removing stale semaphore last operated on by process 7278 with name 0eBlobRegistryMutex_DC7EBB4AEA41D3C6C74E5EFFD6757CEC removing stale semaphore last operated on by process 7278 with name 0eBlobRegistrySignal_DC7EBB4AEA41D3C6C74E5EFFD6757CEC removing stale semaphore last operated on by process 7278 with name 0emSteamEngineInstance removing stale semaphore last operated on by process 7278 with name 0eSteamEngineLock Gtk-Message: Failed to load module "overlay-scrollbar" Installing breakpad exception handler for appid(steam)/version(1378500910_client) [0913/182910:WARNING:proxy_service.cc(958)] PAC support disabled because there is no system implementation   How to fix it? What is this story about 20 y.o. inexperienced "kids" fighting against a stronger foe in space? Years ago (mid 90's) I saw a show on network TV, and I'm trying to figure out what the name of it was. The parts of the plot I remember are:   The crew consisted of 20-year-olds (half were women). They were on some mission when they lose their commander. They must then try to get back home, while being tracked down by a foe in a faster, more powerful ship. One of the main characters turns traitor. He's locked up in the brig pending a decision on his fate. He hangs himself, and his body is incinerated by the crew. One of the main characters plays a video game that basically looks like a visor over his face. While playing the game, he's given an idea on how to outwit their foe by using the laser cannon on their ship to create a holographic projection of a larger ship. In the end, they are about to be destroyed by a torpedo launched from the enemy ship.  The torpedo is destroyed by a laser beam from a friendly capital ship that arrives at the last moment.  I remember there being some sort of romance sub-plot to the show as well between two crew members.    Other non-plot details:   This was live action, not animated. I remember the special effects being quite high-end.   The guns on the ships were manipulated by a person sitting in a gunnery chair. This chair projected a holographic view of the fight in front of him/her. From there the gunner used a joystick and a keypad to control the weapons on the ship.  All the crew wore simple Star-Trek style uniforms throughout the entire program, so no jumpsuits or helmets.    I don't know if this was a movie or a TV show, because I never actually saw the beginning of it. I think I saw at least 45 minutes worth, so it could be either as far as I know.   That's all I remember, other than I think the name of the show was fairly generic (something like "Star Command"). I loved the show as a kid even though I only saw it once. I would like to watch it again and see how lame it really was. Light is clearly affected by gravity, just think about a black hole, but light supposedly has no mass and gravity only affects objects with mass.  On the other hand, if light does have mass then doesn't mass become infinitely larger the closer to the speed of light an object travels. So this would result in light have an infinite mass which is impossible.  Any explanations? I have six upvotes for the one question with no intervening history. They have been summarised into two groups - one with 4 events and one with 2 events. However, when you expand either, both show all 6 events. Minor I know, just letting you know. Does an unbalanced sample matter when doing logistic regression? Okay, so I think I have a decent enough sample, taking into account the 20:1 rule of thumb: a fairly large sample (N=374) for a total of 7 candidate predictor variables.   My problem is the following: whatever set of predictor variables I use, the classifications never get better than a specificity of 100% and a sensitivity of 0%. However unsatisfactory, this could actually be the best possible result, given the set of candidate predictor variables (from which I can't deviate).   But, I couldn't help but think I could do better, so I noticed that the categories of the dependent variable were quite unevenly balanced, almost 4:1. Could a more balanced subsample improve classifications? I am trying to show that $X^n-Y^m$ is irreducible in $\Bbb{C}[X,Y]$ iff $\gcd(n,m)=1$ where $n,m$ are positive integers.    I showed that if $\gcd(n,m)$ is not $1$, then $X^n-Y^m$ is reducible. How to show the other direction. Please help. What are the current travel restrictions on individuals entering the United States from regions affected by Covid-19? Enable 'on the fly' CRS transformation in QGIS 3? How to show that $\sum_{k=1}^n k(n+1-k)=\binom{n+2}3$? I am writing a small KOMA-Script scrartcl document with multiple sections. In the table of contents, LaTeX fills the current line with dots between the end of the section name and the page number. Is there any way to customize this behavior? I would like to reduce the space between the single dots (i.e. use more dots in the same space). NSString question - rangeOfString method So I am asked to find all the isomorphisms between $G = (\mathbb Z_4,+)$ and $H = (U_5,*)$.  I solved it as follows: we will have two isomorphism corresponding to the two generators of $U_5$.  The first isomorphism : $\phi([x]_4)$ = $[2]_5^x$   The second isomorphism is: $\phi([x]_4)$ = $[3]_5^x$   Notice that [2] and [3] are the only generators of $U_5$ one can check it systematically or use the fact that $a^m$ is a generator iff gcd(m,4) = 1.  So I just wanted a verification of my work I showed that they are bijective, well defined, and is a homomorphism. $f$ differentiable except in $1$ point How can you accelerate without moving? I know this question has been asked in other forms, generally regarding the balance of forces.  This time I want to focus on motion.  I've got a laser accelerometer on my desk.  It tells me that I'm accelerating at $9.8~\rm m/s^2$.  For the first experiment I'm travelling in space.  I pick a nearby star and discover that I move about $490$ meters in $10$ seconds from that star.  For the next experiment I'm on the surface of Earth.  I measure the same acceleration with my laser accelerometer.  I pick a spot (the center of the Earth) and discover I don't move at all in $10$ seconds.  How is acceleration without motion possible?