has been, have been , had been
How do the tens­es and as­pects in English cor­re­spond tem­po­ral­ly to one an­oth­er?
A bounce-rate attack to manipulate SEO? This is a question to experienced people that might help us shed some light on the issue.   We noticed a very strange behavior on our site, in Google Analytics. Some dude from Finland, namely, from Kouvola city is hitting one of our pages - only one page on our site, 'bout a hundred times per day, all with an average bounce rate of 90%+...  This is causing our overall bounce rate to go up by 1 to 3% per day... which is very disturbing.. since we're trying to do our best in order to keep it as low as possible. And obviously having it jumped from ~24% to 27%, just because of that crazy dude is not making us happy at all... We tried implementing a geo-targeted script in order to catch this particular visitor and deliver him a juicy message, and it seemed like it helped in the beginning, it has stopped for a day or two, but now he's back...   The geo-targeted script was also logging all IP addresses for page requests originating from Finland in order to find out more details and (in order to block them on the server level, later).. but thing is, it was all mainly cable or DSL connections with various, but not constantly repeating IPs... we are all wondering what is he up to really ?   I think that this page should be kept updated with ideas on how to combat this and perhaps someone could also shed light on what it might be ? What is the reason for doing this "bounce-rate attack", as I call it?  There was a similar question asked on stackoverflow earlier, with no meaningful answer - here - How to evaluate $\int_{0}^{\infty}\exp(-x^2-1/x^2)dx$? Question :  $$\int_{0}^{\infty}\exp(-x^2-1/x^2)dx=?$$  I think the answer is $\sqrt{ \pi/2 \cdot \exp(-2)}$  If I change $-x^2-1/x^2$ to $-(x-1/x)^2-2$ then the above integral becomes    $$\exp(-2)\int_{0}^{\infty} \exp(-(x-1/x)^2)dx$$   integral of $\exp(-x^2)dx$ from $0$ to infinity = square root of $\pi/2$, but then is the   integral of $\exp(-(x-1/x)^2)dx$ from $0$ to infinity=integral of $\exp(-x^2)dx$ from $0$ to infinity ? What word would describe someone who doesn't generally leave much of an impression on people? Duplicate objects transformation applies to both objects I'm facing this frustrating "feature" that I can't seem to remedy; when I duplicate an object (and now, even when I create two completely new objects), their transformations/scaling is synchronized. This is extremely annoying when trying to use any sort of transformation keyboard shortcut.  It should be noted by going to the properties menu (N) and manually setting the properties works just fine.  For instance, here is just the camera selected (trust me, I made sure):   And when I try to transform by clicking+dragging on the X axis OR by hitting G->X, this happens:   They are not grouped (verified by going to the Groups list up in the Scene panel) and they do not have parents (verified by going to Object->Relations).  I have tried the unlink command as well, to no avail.  I have seriously run out of options; what did I change to have my G->X shortcuts transform multiple objects? It seems completely at random, too; certain objects seemed to be "linked" to other random objects, and this "linking" is guaranteed when duplicating even when I do a non-linking duplicate (Shift+D).  What gives? Careers Stack Overflow - Tag "ruby-on-rails" returns jobs that don't contain the tag Why is "high" pronounced "hiy" but is not spelled that way? Using C# .NET 2.0, I have a composite data class that does have the [Serializable] attribute on it.  I am creating an XMLSerializer class and passing that into the constructor:  XmlSerializer serializer = new XmlSerializer(typeof(DataClass));   I am getting an exception saying:      There was an error reflecting type.   Inside the data class there is another composite object.  Does this also need to have the [Serializable] attribute, or by having it on the top object, does it recursively apply it to all objects inside? Can I view a list of my "great comments", perhaps in my profile? I'm a little surprised no one asked this yet, but why isn't it possible to show your comments in descending order of "great comment" votes it has received? You can do this with upvotes on questions and answers, and since I think comments are the third major activity on SO, I'd like to view them. Even if you couldn't order them, it should at least show the number of votes on the activity#comments page of your profile... Deriving the inverse of a 2x2 matrix Reference - What does this error mean in PHP? Set "default" monitor I would like to be able to set my "default" monitor to be my external 25' monitor instead of my laptop one when I have my external monitor connected.  Many applications always open on the laptops monitor instead of the "big" one. Currently, the only way I know to disable this behavior is to disable the laptop monitor, however, as I use a laptop stand to bring it higher, Id like to be able to use my laptop monitor as a "secondary" monitor, without dock (launcher) and without any windows opening on it.  The only way for a window to reach it would be to actually manually grab it and drag it over.  Some known applications that ALWAYS open on the laptop monitor and drive me crazy: Slack, Rocket Chat, Thunderbird, Sky, System Settings, Guake (specially annoying since i cant move it). How to ignore spaces before footnotes how to copy or backup files ignoring dot files I want to back-up all files from my laptop partitions to external HDD.  I ran, for example  cp -a /med*/ravb*/*00   /med*/ravb*/M*L*/7.3GB_CP &amp;&amp; echo "7.3GB BACKED UP PROPERLY" || echo "7.3GB FAILED TO BACK UP"   The issue is that dot files are also getting included which I don't want. What should I do so as to ignore all dot files for backing up. I am not experienced in Number Theory but what I know is that some results of this filed are applicable in other areas, e.g. algebra. For sure FLT made (and makes) people be interested in Number Theory leading to the development of new methods which can be themselves applied not only for the proof of FLT (like financial problems motivated somehow development of stochastic analysis). I am interested - if there are applications or implications of FLT itself?  More precisely: if the fact "for each $n\geq3$ there are no integer solutions of $a^n+b^n=c^n$" leads to solutions of problems which are not in the field of Number Theory?   I would specify that I wonder about some problems which are already formulated: since FLT is known for more then 300 years I am pretty sure that there were formulated hypothesis which follow from FLT directly (if there are such hypothesis not in the field of Number Theory). Best technique to create oldschool (fake 3D) racing game? What would be a good approach to develop the render system for an oldschool type racing game that uses a pseudo 3D scenery, like for example Outrun or Lotus Esprit Turbo Challenge? There's an endless scrolling road and scenery graphics are placed like billboard items, etc. I think you get the idea.    Are these developed in a similar way like  or is there a different technique behind it? Does the technique has a specific name I could search for on the web? I need to develop something like that in Flash. This is a pretty well known quote from the Star Wars movies. But isn't it a bit paradoxical?   It in itself is an absolute, and it was said by a Jedi (Obi-Wan if I recall correctly?). If this holds true, then is he leaning towards the Sith himself? If it isn't true, then both Jedi and Sith can deal in absolutes and the statement is pointless.  Surely it should be phased along the lines of "Jedi's should avoid dealing in absolutes" or something similar? How can I get the page title? Well structured URLs vs. URLs optimized for SEO I have a matrix:  $$ A=\begin{bmatrix}1 &amp; a \\ 0 &amp; 1\end{bmatrix} $$  which satisfies: $A\left( e_{1}\right)=e_{1},A\left( e_{2}\right)=ae_{1}+e_{2}, a\neq 0$  I need compute all powers $A^{n}, n\in \mathbb{Z}$ and find their matrices.  $$ A^n= \begin{bmatrix}1 &amp; na \\ 0 &amp; 1\end{bmatrix} $$  Is it true?  Is there a basis of $V$ (if $V$ is a 2-dimensional real vector space with basis $\left\{e_{1},e_{2}\right\}$) so that the matrix of $A$ is diagonal? Building where clause based upon parameters