im looking  at wiki at the moment as how to use oeap padding and it appears, help  me out if im wrong as G(r) - expands r to the size of the padded message, I am then limited by the size of my hash function as say a SHA-256 hash function would expand to only 256 bits, but what if I had a 2048 bit modulus? I'm unsure if there are any 2000+bit hash functions out there, or could I use a series  of different r values, hash them and use the concatenation of the hash outputs to create a 2000  bit xor?
I can't understand how the "cryptographic functions" are to be selected RSA + OAEP which are used in OAEP. How to choose these "cryptographic functions"(G and H)?
Given  $$ y_n=\left(1+\frac{1}{n}\right)^{n+1}\hspace{-6mm},\qquad n \in \mathbb{N}, \quad n \geq 1. $$ Show that $\lbrace y_n \rbrace$ is a decreasing sequence. Anyone can help ?  I consider the ratio $\frac{y_{n+1}}{y_n}$ but I got stuck. If $\left(1+\sin \phi\right)\cdot \left(1+\cos \phi\right) = \frac{5}{4}\;,$ Then $\left(1-\sin \phi\right)\cdot \left(1-\cos \phi\right)$ If $\displaystyle \left(1+\sin \phi\right)\cdot \left(1+\cos \phi\right) = \frac{5}{4}\;,$ Then $\left(1-\sin \phi\right)\cdot \left(1-\cos \phi\right) = $  $\bf{My\; Try::}$ Given $\displaystyle \left(1+\sin \phi\right)\cdot \left(1+\cos \phi\right) = \frac{5}{4}\Rightarrow 1+\sin \phi\cdot \cos \phi+\sin \phi+\cos \phi = \frac{5}{4}.$  So $\displaystyle \sin \phi+\cos \phi+\sin \phi \cdot \cos \phi = \frac{1}{4}\Rightarrow \left(\sin \phi+\cos \phi\right) = \frac{1}{4}-\sin \phi \cdot \cos \phi.$  Now $\displaystyle \left(1-\sin \phi\right)\cdot \left(1-\cos \phi\right) = 1-\left(\sin \phi+\cos \phi\right)+\sin \phi \cdot \cos \phi =\frac{3}{4}+\sin 2\phi$  Now How can I calculate $\sin 2\phi.$  Help me, Thanks How to get access to USB-storage from an application installed as Snap? How can I port forward with iptables? I want connections coming in on ppp0 on port 8001 to be routed to 192.168.1.200 on eth0 on port 8080.  I've got these two rules  -A PREROUTING  -p tcp -m tcp --dport 8001 -j DNAT --to-destination 192.168.1.200:8080  -A FORWARD -m state -p tcp -d 192.168.1.200 --dport 8080 --state NEW,ESTABLISHED,RELATED -j ACCEPT   and it doesn't work. What am I missing? Checking integrity of my server data How to parse hex values into a uint? uint color;  bool parsedhex = uint.TryParse(TextBox1.Text, out color);  //where Text is of the form 0xFF0000 if(parsedhex)    //...   doesn't work. What am i doing wrong? What are badges? How do users get badges? How can users get tag badges? Can badges be lost/revoked/taken away after they are awarded? If so, how and when? How can I suggest a new badge?   For more information, see &quot;&quot; and the  in the . Installing 3rd party python libraries for QGIS on Windows I'm trying to install , an open-source Microblogging application on my Windows development server using XAMPP as per the . The website cannot find PEAR, and throws the below errors:  Warning: require_once(PEAR.php) [function.require-once]: failed to open stream: No such file or directory in C:\xampplite\htdocs\laconica\lib\common.php on line 31 Fatal error: require_once() [function.require]: Failed opening required 'PEAR.php' (include_path='.;\xampplite\php\pear\PEAR') in C:\xampplite\htdocs\laconica\lib\common.php on line 31   PEAR is located in C:\xampplite\php\pear phpinfo() shows me that the include path is .;\xampplite\php\pear  What am I doing wrong? Why isn't the PEAR folder being included? Obtaining remote host name in bash script Sorry my knowledge of Linux bash commands is pretty basic, I've been searching for a while but I'm not 100% sure what I need to search for.  I was wondering if there's a way to grab the current logged in users remote host name in a Linux bash script? I have a script in which I need to log each time a user runs it. I'm obtaining the date like so:  cdat=`/bin/date +%a' '%d' '%h' '%Y', '%H':'%M`;   I now need to add the users remote host (not the username they logged in with). I'm not 100% sure I'm using the right terminology here either, just to clarify; by 'remote host name' I mean the same output that prints on the screen on most servers I've logged into over ssh, for example:  Last login: Mon Jul 22 16:35:09 2013 from win7-i7-stuart.my.domain.com   I'm looking for the win7-i7-stuart.my.domain.com bit. What is an uninterruptible process? Sometimes whenever I write a program in Linux and it crashes due to a bug of some sort, it will become an uninterruptible process and continue running forever until I restart my computer (even if I log out).  My questions are:   What causes a process to become uninterruptible? How do I stop that from happening? This is probably a dumb question, but is there any way to interrupt it without restarting my computer? How do you prove the set $G = \{(x, f(x)) \mid x \in \mathbb R\}$ is closed? Let $f : \mathbb R \to \mathbb R$ continuous. Prove that graph $G = \{(x, f(x)) \mid x \in \mathbb R\}$ is closed.  I'm a little confused on how to prove $G$ is closed. I get the general strategy is to show that every arbitrary convergent sequence in $G$ converges to a point in $G$.  Here is what I tried so far:   Let $x_k$ be a sequence which converges to $x$. Since $f$ is continuous, this implies that $f(x_k)$ converges to $f(x)$. At this point, can you say every $(x_k, f(x_k))$ converges to a $(x, f(x))$, so $G$ is closed? Not sure if this is a bug or a feature, but I noticed today that if I , it annoyingly one-boxes a link to the room, which is not a link to the info page! That's it. I'm gonna pack up and leave! Such annoyance! But for the time being,  Is this behavior expected? If so, what is the reason for changing the links? If this is really a bug since the responsible bot is not seeing parts of the URLs and ends up one-boxing, and hence linking to the wrong message, could this be fixed please? Worth pointing out that too much exposure to annoying things results in a higher blood pressure. My intent is to show that a composition of bijections is also a bijection by showing the existence of an inverse.  But my approach requires the associativity of function composition.  Let $f:  X \rightarrow Y, g:  Y \rightarrow Z, h:  Z \rightarrow W$ be functions.  $((f \circ g) \circ h)(x) = h((f \circ g)(x)) = h(g(f(x)))$, and $(f \circ (g \circ h))(x) = (g \circ h)(f(x)) = h(g(f(x)))$.  However, I am having problems in justifying that the two compositions, $(f \circ g) \circ h$ and $f \circ (g \circ h)$, have the same domain and range.  When I consulted ProofWiki, whose link is at the bottom, I got even more confused.  Specifically, for $(f \circ g) \circ h = f \circ (g \circ h)$ to be defined, ProofWiki requires that dom$g =$ codom$f$ and dom$h =$ codom$g$.  First of all, I think that it should be dom$g =$ range$f$ ....  Moreover, as you can see in the example below, you actually have to adjust domains and ranges of $f, g, h$ for the requirement to hold true.  Let $f: \mathbb R \rightarrow \mathbb R$ be $f(x) = 2x$, $g: \mathbb R^+ \rightarrow \mathbb R$ be $g(y) = ln(y)$, $h: \mathbb R \rightarrow \mathbb R$ be $h(z) = z - 10$.   Then $((f \circ g) \circ h)(x) = ln(2x) - 10 = (f \circ (g \circ h))(x)$, with dom$((f \circ g) \circ h) = \mathbb R^+$ = dom$(f \circ (g \circ h))$.  As a result, we need to set dom$f = \mathbb R^+$, range$f = \mathbb R^+$; dom$g$, range$g$, dom$h$, and range$h$ remain the same.  Am I allowed to do that?  This adjustment implies that when we say dom$f = X$, $f$ must be defined for all elements in $X$, but $X$ may not be the entire set of elements for which $f$ is defined. This is similar to  but I want the iterate tool to run to collect all the values and only then continue to the merge. Any ideas? Currently it just runs the whole process for each file (which works but takes much longer than if the merge is done only once) or I have to manually break the collect-merge link, run the iterate, reconnect the collect-merge link and then continue running the model which is a pain as it is a lot of towers that need processing and this collect values-finish getting all values and then continue will be required in other models as well.    I tried the "Select Data" tool as well but this doesn't allow for wildcard searches like the Iterate does -my Iterate has the "_Graded*" as the search param as the gdb included many other files related to each tower chunk.  My STOP is set to "True" (tried false as well). I also tried to connect the Stop to the Iterate instead of Collect values but same result.  === SCRIPT ADDED  I just created a python tool for this and it collects all the values but it passes them back to the model as a long list -how can I get it to output in a proper format?      import sys, os, arcpy  GDB=arcpy.GetParameterAsText(0) Search=arcpy.GetParameterAsText(1) Type=arcpy.GetParameterAsText(2)  ##GDB=r'P:\2012\044_DM_Radio_Propogation\Working\Propogation\Propogation_28355.gdb' ##Search='_m' ##Type='Polygon'  path=os.path.dirname(GDB) arcpy.env.workspace = GDB List=[] for item in arcpy.ListFeatureClasses('*'+Search+'*',Type):     List.append(path+"\\"+item)     #arcpy.SetParameterAsText(3, item)  arcpy.SetParameterAsText(3, List) arcpy.AddMessage("List: "+str(List)) How do I change the default application for unknown file types? Ever since installing Bless Hex Editor, all unknown files and text files automatically open with Bless instead of gedit. How do I change it back? I don't want to have to manually associate files with gedit, I just want gedit to be the default if there's no other application set up to open the file.  Solution: modify ~/.local/share/applications/mimeapps.list  [Default Applications]  - text/plain=bless.desktop - application/octet-stream=bless.desktop + application/octet-stream=gedit.desktop I typed up an assignment with a lot of numbers in LaTeX and turned it in to my adviser.  When he returned it to me with some corrections, one of which was a lot of $ around my numbers.  I understand that $ are necessary around some mathematical formulas, but I was just using numbers like -2 and 4.  I did not see any change in the font of the numbers when I added the $ either.  Since my adviser did not want to give me an explanation, what is the rationale? When I open a window to air out the room, how does the smell disperse? Let's say I'm in a room with some kind of noxious stink, possibly of flatulent nature.  The quickest way to right the world that comes to mind is to open a window.  When I open a window, how do the stank particles leave the room? Why do some questions in question lists have a yellow background? On SO, when I'm scrolling through "questions" some have a yellow background.  Is this intuitive to everyone but me?  What is the yellow background trying to tell me about this particular question? It's driving me nuts! I just want to transfer one simple file from laptop to server.  I'm using ubuntu on both machines.  So I have:  -rwxr-xr-x 1 sandro    414622 2011-10-14 23:42 sandrophoto-html.tar.gz   And I'm sending it using:  sudo scp -P XXXX sandrophoto-html.tar.gz usern@server.local:/media/xx/xx/xx   And I get: scp: /media/xx/xx/xx/sandrophoto-html.tar.gz: Permission denied  p.s. I might be doing this other way around - I want to send file tar.gz that is located on my desktop, to remote server into the folder /media/yadayda