Cannot use WiFi on Linux, Alienware 14 laptop I recently got an alienware 14 laptop, and want to use Linux on it. I installed Ubuntu 14.04. However, I found that the wireless adapter does not work - Killer Wireless-n/a/ac 1525 Wireless Network Adapter.  So I purchased usb wifi adapter. Now I can connect to Wifi, but extremely unstable. After I have been connected for about 5 minutes, it still says connected, but cannot use internet. I tried to ping a random address, there is simply no echo, rather than no response - nothing echoes in my terminal. If I disable wifi and enable again, sometimes it will connect for another 5 minutes, sometimes just fails to connect.  I thought it was a problem of the usb wifi adapter, so bought another one for raspberry pi, but exactly the same problem.  I thought it was a problem of my Linux distribution, so I tried Ubuntu 12.04, Linux Mint, Fedora 23. All have the same problem.  Still cannot use WiFi on Linux, on my ALienware 14 laptop. Feeling frustrated. Anyone could help? Thanks.  Results of lspci -knn | grep Net -A2:      03:00.0 Network controller [0280]: Qualcomm Atheros Device [168c:003e] (rev 20)     Subsystem: Bigfoot Networks, Inc. Device [1a56:1525]     04:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS5227 PCI Express Card Reader [10ec:5227] (rev 01)     Subsystem: Dell Device [1028:0685]
Ubuntu 14.04 Wireless not working: no network interface. Atheros [168c:003e] device I just installed Ubuntu 14.04.3 LTS after installing windows 10 in my new VN7-571G and the wireless is not working. It never had: even during the installation it was not recognized. I run a script to gather the data , which is . lspci -knn | grep Net -A2 output 03:00.0 Network controller [0280]: Qualcomm Atheros Device [168c:003e] (rev 20)         Subsystem: Lite-On Communications Inc Device [11ad:0804]  The OS behaves like it has no wifi card. I do not see wifi settings in network settings I'm not a linux power user, so I do not know what to do to solve the issue. What should I do to make it work?
I've always had this question about the pronunciation of Sean.  Is Sean a word from another language? Is it actually not pronounced Shawn and instead it's some sound between Shawn and Seen? Also, why isn't it pronounced as Sawn instead of Shawn, when the word Sean doesn't even have the letter 'h' in it to get that -sh sound?  Bottom line is, why is Sean pronounced Shawn instead of Seen? On exactly what criteria is the Electorate badge awarded? There is a badge named Electorate which is going to be awarded on "Voted on 600 questions and 25% or more of total votes are on questions". Can somebody explain this to me?  Voted on 600 Question and 25% are on Question? is this  means   Voted on 600 Posts and 25% are on Question  Can't SO place some easy text or Definitions for average users? How do I determine if a number is prime?  I'm writing a program where a user inputs any integer and from that the program determines whether the number is prime, but how do I go about that? How to search for list of papers citing both papers A and B? For given papers A and B, I would like to search for all papers that cite both A and B. I guess one can generalize to papers {A,B,C,...} and find all papers that cite all of them.   A quick Google Scholar and Web of Science search revealed nothing. Google Scholar has a "cite=..." thing in the URL, which I messed with a bit to no avail. Ways to obtain new portrait photography clients? I'd like to increase my portrait business. I've had good experiences with family, pet portraits and High School seniors.  My local newspaper is quite expensive. I've had okay luck with Craigslist, although Craiglist shoppers are far from my ideal client that is willing to pay for quality images, fast turn around and a great experience.  I have a flyer on my community message board, but not enough traffic walks by it. I was thinking about posting at my local churches. I get a few of referrals from friends and family of clients.   What are good ways to reach my local base and increase sales? Letter class alternatives with support for figures, tables, and labels Can I get a postdoc in China more than 3 years after having received my PhD? I found Minecraft's marvelous large worlds extremely slow to navigate, even with a quad core and meaty graphics card.  I assume Minecraft's slowness comes from:   Java, as spatial partitioning and memory management are faster in native C++. Weak world partitioning.   I could be wrong on both assumptions. However, this got me thinking about the best way to manage large voxel worlds. As it is a true 3D world, where a block can exist in any part of the world, it is basically a big 3D array [x][y][z], where each block in the world has a type (i.e BlockType.Empty = 0, BlockType.Dirt = 1, etc.)  I assume that to make this sort of world perform well, you would need to:   Use a tree of some variety (//) to split all the cubes out; it seems like an oct/kd would be the better option, as you can just partition on a per cube level not a per triangle level. Use some algorithm to work out which blocks can currently be seen, as blocks closer to the user could obfuscate the blocks behind, making it pointless to render them. Keep the block object themselves lightweight, so it is quick to add and remove them from the trees.   I guess there is no right answer to this, but I would be interested to see peoples' opinions on the subject.  How would you improve performance in a large voxel-based world? The moderator agreement is visible at the following URL:       I acknowledge and agree that as a moderator for Stack Exchange Inc.      I will abide by the then-current Terms of Service of Meta Stack   Exchange, and other moderator policies made available to me,      I acknowledge that I may have access to potentially   personally-identifying information about Meta Stack Exchange users and   that in connection with such access      I will use such information solely in accordance with the then-current   Privacy Policy of Meta Stack Exchange,      I will not disclose this information to anyone,      I will not store or copy this information and      I will only use such information in connection with performance as a   Meta Stack Exchange moderator for the benefit of Meta Stack Exchange.      I acknowledge and agree that I am an independent volunteer moderator   to Meta Stack Exchange and I am not an employee, agent or   representative of Stack Exchange Inc., and I have no authority to bind   Stack Exchange Inc. in any manner. Stack Exchange Inc. reserves the   right to terminate my privileges as a moderator at any time without   warning.   It hasn't been updated with the new company name and still refers to Stack Exchange Inc. instead of Stack Overflow (Inc.?). The following is an real analysis qualifying exam problem that I cannot solve:  Suppose $X$ is a Banach space and that $(x_n)$ converges weakly to $x$. Show that $\liminf ||x_n|| \geq ||x||$.  Using the Uniform Boundedness Principle I can show that $\sup_{n \in \mathbb{N}} ||x_n -x||$ is finite. Using Alaoglu's Theorem I can show that some subset of $(x_n)$ converges in norm to $x$. I feel like I am close with this but cannot seem to finish the problem. CPU Die temperatures reaches 90° C, is that normal? Fingerprint activation in Dell Vostro 14 in Ubuntu 18.04 I have Dell Vostro 14 with OS Ubuntu 18.04.  I tried   sudo apt install -y fprintd libpam-fprintd   but not able to use fingerprint reader of my laptop. Let $f$ be defined on $\mathbb{R}$ by $f(x) = e^{-1/x^2}$ for $x$ not equal to $0$. and $f(0)= 0$. Prove that $f^{(n)}(0)=0$ for all $n = 1, 2,3$ ...  Do I need to use Taylor expansion from calculus class?  Any hint would be appreciated. I understand when we say current, we mean charge (protons/electrons) passing past a point per second. And the charges have energy due to the e.m.f. of the power supply.  Now tell me, if a lamp has resistance and you hook it in the circuit, how will the current stay the same? The charges obviously lose energy in the lamp and so become SLOWER, which should mean current decreases, right?  [Edit] All answers explained a bit of everything, so it was hard to choose one. If YOU are looking for an answer, please check the others too, in case the accepted one doesn't answer your question. fsck error on boot: /dev/sda6: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY I've installed ubuntu 17.04 and I want to upgrade it to 18.04. When I tried to do:   sudo do-release-upgrade   I got a message saying An upgrade from 'zesty' to 'bionic' is not supported with this tool. Need inputs to proceed on this.  sudo do-release-upgrade Checking for a new Ubuntu release Your Ubuntu release is not supported anymore. For upgrade information, please visit: http://www.ubuntu.com/releaseendoflife  Get:1 Upgrade tool signature [819 B]                                            Get:2 Upgrade tool [1,257 kB]                                                   Fetched 1,258 kB in 0s (0 B/s)                                                  authenticate 'bionic.tar.gz' against 'bionic.tar.gz.gpg'  extracting 'bionic.tar.gz'  Reading cache  Checking package manager  Can not upgrade   An upgrade from 'zesty' to 'bionic' is not supported with this tool. How to create a filter in Gmail to identify messages forwarded from Zimbra? Do reactions interrupt their triggers or not? In the Player's Handbook, it is pretty clear that reactions normally interrupt the thing that they are reacting to.    Xanathar's Guide to Everything, however, has explicitly changed all reactions to occurring after their triggers have finished resolving unless the ability specifies otherwise, and is reliant on that implicit assumption for several reaction abilities already.  This leads to contradictory interpretations of reactions that take implicit timing. How should this be resolved?   I'm particularly interested in how to resolve this in Adventurers League games, where players show up with perfectly legal characters reasonably expecting their abilities to work either way on account of owning or not owning XGE. I understand that when I press and release the power button on the top of my iPhone or iPad, it stays on but turns off the screen.  Whereas if I press and hold the power button, a "slide to turn off" control appears on the screen.  Sliding this, as I was told, does turn the unit off, but it does so by suspending the RAM to disk (flash memory, actually.) So, when turning on the iPhone or iPad, it isn't so much rebooting the OS as it is resuming it from flash storage.  How to force the OS to completely reboot on these devices? I know what my symbol or character looks like, but I don't know what the command is or which math alphabet it came from. How do I go about finding this out?