maybe it was there discussed before but i have never ever found a solution for this and iam trying it for long time, I was trying many ways but it always didnt work.the problem is that my wifi adapter tl-wnb821N  is not working,when i plug other devices like standart usb it works,when i plug wifi adapter it doesnt work even it wont change a adapters color.
I just installed my first Ubuntu Server (12.04) instance and immediately ran into the following problems:   Running apt-get install or update fails (see below) Running ifconfig produces peculiar IP addresses starting with 10.x.x.x and my router does not see the server at all in its "Attached Devices" page (its a consumer grade Netgear)   When I run apt-get I get 50+ of the following errors:  Failed to fetch &lt;some-http-url&gt;. Temporary failure resolving &lt;blah&gt;.ubuntu.com   I read up on this error for 12.04, and found some similar posts on this forum and on server fault that recommended going into /etc/resolv.conf and adding an entry:  nameserver 8.8.8.8   To my surprise, I found that /etc/resolv.conf was a symlink pointing to somewhere else  and I had to delete it first, then create a new one with the entry indicated above.  I restarted the server and tried running apt-get again, same results.  How do I start diagnosing the problem (I'm a relatively new Linux/Ubuntu user)?  Additional details that may help:   This is actually a virtual machine running as a VirtualBox guest OS The physical host that is running this VM is my laptop which has a wireless connection; I'm wondering if (somehow) the laptop is getting the network wirelessly, but perhaps either the VBox VM and/or the Ubuntu server OS isn't configured for wireless and so nothing is "getting through"?   Thanks in advance for any pointers!  Edit:  Here is a snapshot of my VM's Network settings (only Adapter 1 has any information populating its fields, so I assume my VM has only 1 adapter):    Here is the output when I run ifconfig from the terminal:    And here is the output when I run route from the terminal:    Running ping google.com:
I've created a series of DEM files using the  tool from LAStools; however since I don't have a licensed version they have black streaks running across them. Does anyone know a good method for removing these streaks? Is the 5-foot range of the Help action my range to the ally, the enemy, or both? Evaluation Symbol: Consistent Implementation Prove $\sum{\frac{1}{(x+2y)^2}} \geq\frac{1}{xy+yz+zx}$ Can one construct a non-measurable set without Axiom of choice? Is axiom of choice required to show the existence of non-measurable sets? Is there a Lebesgue non-measurable set that can be constructed without axiom of choice?  Related question on MO says it is consistent: I use Lasso logistic regression in order to identify a smaller subset of important variables. I start with N=51 (28/23) and 32 predictors.   So far it looks pretty promising, because I can identify four important predictors in my optimal model.   Now I would like to take those four predictors and examine them along with some control variables in a standard logistic regression.   My question is, does that analysis strategy make sense? Is there a better way to include controls or other variables that might be interesting?  For a better understanding:   Identify important variables via Lasso logistic regression Do further analysis including identified predictors and other control variables using standard logistic regression (using AIC to check model fit) What's the best way of checking if an object property in JavaScript is undefined? My task is to write a precise mathematical statement that "the sequence $(a_n)$ does not converge to a number $\mathscr l$"  So, I have my definition of a convergent sequence: "$\forall\varepsilon&gt;0$ $\exists N\in\Bbb R$ such that $|x_n -\mathscr l|&lt;\varepsilon$ $\forall n \in \Bbb N$ with $n&gt;N$"  Would the correct negation of this be "$\forall\varepsilon&gt;0$ $\exists N\in\Bbb R$ such that $|x_n -\mathscr l|&gt;\varepsilon$ $\forall n \in \Bbb N$ with $n&gt;N$"?  It doesn't seem that this is the answer as the next part of my task is to prove that a sequence is divergent using my formed proof, but it'd be difficult to do since it's a general proof of divergence and not just a proof that $(a_n)$ doesn't converge a specific number $\mathscr l$  Perhaps I should find a prove that $(a_n)$ tends to $\pm\infty$? This is more simple but it does not include monotone sequences such as $x_n:=(-1)^n$.  Can someone assist me with this task? All comments and answers are appreciated. Convert UTC date time to local date time Possible Duplicate:          In a question, I see that each time I refresh the page, the answers were placed in a different order. The question has 3 answers each with zero votes. The users' reputation was something like 6, 1200, and 7300 but these numbers didn't affect the order.  What is the criteria of the sort order of the answers? addplot3[surf] creates lines instead of a surface Connected to wifi successfully, but no internet connection I'm a relatively new macOS user. Let me try to describe the problem I'm facing as succinctly as possible  Just this morning, when I'm unable to get any internet connection even though WiFi is connected (full strength). All my other devices has no issues when connected to the same network (it's my home network)  I've logged into the router, and checked, there are no blacklisted IP/MAC addresses.  Additional information   I'm using a tMBP 15" for over a year I've had no issues with any WiFi connectivity to my home network before today. ping from terminal doesn't work as well. I'm able to connect to my phone's hotspot, and get internet from my MBP.  I have bootcamp set up. When I boot into Windows, I'm able to get internet access through my home WiFi   How can I troubleshoot this to get to the root cause of the problem? $f(x,y)=4x^3y^2$ Dealing with Directional Derivatives and Vectors Let $f(x,y)=4x^3y^2$  How do I find the directional derivative of $f$ at $(2,1)$ in the direction of the vector $3i-4j$? What would be a unit vector in the direction in which $f$ decreases most rapidly from the point $(2,1)$? And, what is the rate of change of $f$ in the direction given in the second question?  My Work (What I have done so far):  For the first question: $\nabla f(x,y)=12x^2y^2$i$+8x^3y$j$\nabla f(2,1)=48$i$+64$j$u=(3/5)$i$-(4/5)$j $\therefore D_u f=\nabla f\bullet u=0$  I'm not entirely sure if this is right? Can someone please verify?  For the second question: $u=(3/5)$i$-(4/5)$j $\therefore -||\nabla f(2,1)||=$? How do I find this? And am I doing this right?  I have no idea what to do for the third question. It would be nice to see what users have recently been active. This is somewhat standard with many forum-style websites, showing how active the site has been in the last n-minutes or so. As a functional advantage, this also serves to let you know when is a good time to get a question in. My lecturer has used some notation that I've never seen before: it is a (matrix) product symbol with a left-to-right arrow over the top. Does anybody know what this means?  Thanks in advance.  Edit: It looks like this: Use hostnames to connect to machines on LAN I have just had my broadband upgraded to  which means my router has had to change. Previously I was using a Thomson TG585v7 ADSL thingy provided by my ISP. One nice thing about that router was that it would act as a local DNS and allow me to find my other machines on the network by using &lt;hostname&gt;.lan instead of IP addresses.  I've now switched to a Linksys WRT320N ethernet router which connects to my fibre modem, and which I've updated to the latest firmware (1.0.04). I have 2 machines on the network which I regularly want to connect to each other; one is running Windows 7 and the other is running OS X Lion.  The problem I'm having is that I'm unable to connect to my Win7 machine from the OS X machine using the Win7 machine's name. However, I'm able to ping the OS X machine from my Win7 machine using the hostname. How can I reduce the ever-increasing time to push a subtree? Increase iPhone call history How to prevent Windows 10 from automatically adding keyboard layouts (i.e. US keyboard) Update: this is a lengthy post, you can     Note: The quick language list refers to the list in the screenshot below, accessible throught the shortcut Win + Space bar  I have two languages for windows spell check in my system, English (United States) and French (Switzerland), but despite both languages being properly configured with "Swiss French" input keyboard, US Keyboard input keeps appearing on this list:    Here's the settings for English (United States) language, you can see the only input is "Swiss French":    Same for Français (Suisse), the only input is "Swiss French":    In the Control Panel, both are also set as Swiss French:    All my settings are set to use "language list":     Here's a few things that I already tried:   I already managed to remove it by some language configuration gymnastics, by adding and removing languages, it always eventually comes back I have already done this:  There's no mention of US Keyboard in my registry settings either:     Please help, I'm desperate, this is my third computer with Windows 10 and they all do the same thing. I'm working through Knuth's Metafont Book as preparation for learning Metapost and I'm running into some problems working through his "experiments".  I've installed the latest TeX Live 2013 distribution on my system but I'm having problems.  Here's the code (contained in file io.mf as recommended by Knuth):  mode_setup;  em#:=10pt#; cap#:=7pt#;  thin#:=1/3pt#; thick#:=5/6pt#;  o#:=1/5pt#; define_pixels(em,cap); define_blacker_pixels(thin,thick); define_corrected_pixels(o);  curve_sidebar=round 1/18em; beginchar("O", 0.8em#, cap#, 0); "The letter O";  penpos1(thick,10); penpos2(.1[thin,thick],90-10);  penpos3(thick,180+10); penpos4(thin,270-10);  x1l=w-x3l=curve_sidebar; x2=x4=.5w;  y1=.49h; y2l=-o; y3=.51h; y4l=h+o;  penstroke z1e{down}..z2e{right}             ..z3e{up}..z4e{left}..cycle;  penlabels(1,2,3,4); endchar;   Now, when running the mf command and loading this file, I get a window that is unfortunately empty.  Supposedly a large letter "O" should appear.  $ mf This is METAFONT, Version 2.718281 (TeX Live 2013) **io (io.mf The letter O [79]) *end Output written on io.2602gf (1 character, 1724 bytes). Transcript written on io.log.  $ gftodvi io.2602gf  gftodvi: fatal: tfm file `gray.tfm' not found.   Then, when trying to use the gftodvi command I get the above error.   Any ideas why my "window" that should display the letter "O" is blank/empty? How do I resolve the gray.tfm error? Are the two related?   Note: I'm using Ubuntu 14.04, but the TeXLive installation is NOT from the Ubuntu repository.  I used the installer from  and created a local "portable" installation.