I have installed Ubuntu 18.04 on my laptop. How do I resolve this? Thanks  $ lspci -knn | grep Net -A3; rfkill list 03:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8821CE 802.11ac PCIe Wireless Network Adapter [10ec:c821]     Subsystem: Hewlett-Packard Company RTL8821CE 802.11ac PCIe Wireless Network Adapter [103c:831a] 04:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Raven Ridge [Radeon Vega Series / Radeon Vega Mobile Series] [1002:15dd] (rev c5)     Subsystem: Hewlett-Packard Company Vega [Radeon Vega 8 Mobile] [103c:84ae]     Kernel driver in use: amdgpu 0: hci0: Bluetooth     Soft blocked: no     Hard blocked: no
I have recently a purchased Lenovo Thinkpad E480 laptop, I have installed Ubuntu 18.04 on it, everything is working fine except am not able to connect to network via WiFi. Please help.  I followed this , but am unable to solve the issue.  Below are the outputs of some commands.  lsb_release -a  No LSB modules are available. Distributor ID: Ubuntu Description:    Ubuntu 18.04.1 LTS Release:    18.04 Codename:   bionic   uname -r  4.15.0-33-generic   rfkill list all  0: tpacpi_bluetooth_sw: Bluetooth     Soft blocked: no     Hard blocked: no 1: hci0: Bluetooth     Soft blocked: no     Hard blocked: no   lspci -nnk | grep 0280 -A3  05:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8821CE 802.11ac PCIe Wireless Network Adapter [10ec:c821]     Subsystem: Lenovo RTL8821CE 802.11ac PCIe Wireless Network Adapter [17aa:c024] 06:00.0 SD Host controller [0805]: O2 Micro, Inc. SD/MMC Card Reader Controller [1217:8621] (rev 01)     Subsystem: Lenovo SD/MMC Card Reader Controller [17aa:5068]   sudo lshw -C network   *-network                         description: Ethernet interface        product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller        vendor: Realtek Semiconductor Co., Ltd.        physical id: 0        bus info: pci@0000:03:00.0        logical name: enp3s0        version: 10        serial: 8c:16:45:a3:d9:f1        size: 100Mbit/s        capacity: 1Gbit/s        width: 64 bits        clock: 33MHz        capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation        configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=full firmware=rtl8168g-3_0.0.1 04/23/13 ip=192.168.2.2 latency=0 link=yes multicast=yes port=MII speed=100Mbit/s        resources: irq:16 ioport:d000(size=256) memory:f1204000-f1204fff memory:f1200000-f1203fff   *-network UNCLAIMED        description: Network controller        product: Realtek Semiconductor Co., Ltd.        vendor: Realtek Semiconductor Co., Ltd.        physical id: 0        bus info: pci@0000:05:00.0        version: 00        width: 64 bits        clock: 33MHz        capabilities: pm msi pciexpress cap_list        configuration: latency=0        resources: ioport:c000(size=256) memory:f1100000-f110ffff   It seems I have to clone, compile and install the required WiFi driver, please guide me which WiFi driver to use and how to install (with steps if possible).  P.S.: Let me know if any further information is needed to solve this issue, I will add the required info (if any) in the question as per the guidance given.
Stack Overflow duplicated layer bug Originally posted on Stack Overflow:   Requirements to reproduce:  Windows 7 x64  Firefox 71.0 x64  Steps to reproduce:   Go to the ask question section Write something to the title field Start scrolling similar questions Change the title field Start scrolling the similar questions again How does a sarlacc gain any energy if it keeps victims alive for a thousand years? When eaten by a sarlacc, according to C-3PO,     In his belly, you will find a new definition of pain and suffering, as you are slowly digested over a thousand years.   I imagine that keeping a victim alive for a thousand years takes much more energy than is available to the sarlacc from the body of the victim.  Thus, keeping victims alive for so long would seem to be a net loss of energy for the sarlacc.  Is there a canon answer to resolve this conundrum?  Did the sarlacc have another energy source (for example, ability to harvest sunlight)? If a batsman hits the ball inside the ground and begins running between the wickets and now the ball is thrown back to the Fielder/Bowler/WK(FBWK)    If the FBWK catches the ball in one hand and hits the stumps with other hand before the batsman gets reached, is this a run out? If the FBWK catches the ball in hands and hits the stumps with leg or any other part of his body before the batsman gets reached, is this a run out?   This scenario can occur, when the ball was thrown far away from stumps. Is $\mathbf{Q}(\sqrt{2}, \sqrt{3}) = \mathbf{Q}(\sqrt{2}+\sqrt{3})$? Why are my Cycles settings missing? so I'm working on a little bathroom scene and wanted to make a clay render. I started looking for the material override which I kinda knew where it was and on the way I switched my render engine accidently to workbench instead of cycles. Switched to cycles all my seetings on the render tab are missing except color management and free style. Hows that? I restarted blender multiple times and tried some other stuff but nothing changed a thing, and I'd rather avoid a new installation Difference between $\sum_{i=1}^{k}{\frac{s_i}{kn_i}}$ and $\frac{\sum_{i=1}^{k}{s_i}}{\sum_{i=1}^{k}{n_i}}$ I am getting confused at how to calculate the average probability.  Suppose we repeat a kind of binary survey $k$ times each of which was done on a completely separate sample group.  For each $i^{th}$ group, $i=1,2,3,...,k$, Let $n_i$ be the number of samples and $s_i$ be the number of positive results. With this we know that the probability $p_i$ of the positive result for the $i^{th}$ group is $s_i/n_i$  With my ignorance, I happened to use two ways to calculate the average probability in my work wrongly assuming that they are the same:  $$\frac{p_1+p_2+p_3+...+p_k}{k}$$ and $$\frac{s_1+s_2+s_3+...+s_k}{n_1+n_2+n_3+...+n_k}$$  I don't know which is the correct way to calculate the average probability. So could you please explain the difference of these two and when to use which? I want to upgrade my Ubuntu 13.04 to Ubuntu 13.10. I'm unable to do via GUI.   [ The reason why I'm unable to do so:  Via software updater, I proceed ahead and click upgrade (for upgrading my OS). I authenticate by providing my password. Then it proceeds and downloads upgrade tool. That time only (while downloading the tool) error message comes "system program problem detected". It then doesn't proceed ahead and I click to report the problem ]  So, I tried via command line but here also I couldn't succeed upgrading my OS.  For the same I ran   $ sudo apt-get update   Then I ran  $ sudo apt-get dist-upgrade   And then:  ravbholua@ravbholua-Aspire-5315:~$ sudo do-release-upgrade Checking for a new Ubuntu release Get:1 Upgrade tool signature [198 B]                                                                                                  Get:2 Upgrade tool [1,135 kB]                                                                                                         Fetched 1,135 kB in 6s (32.9 kB/s)                                                                                                    authenticate 'saucy.tar.gz' against 'saucy.tar.gz.gpg'  gpg exited 2 Debug information:    gpg: Signature made Friday 01 November 2013 10:34:27 AM IST using DSA key ID 437D05B5 gpg: Can't check signature: public key not found  Authentication failed Authenticating the upgrade failed. There may be a problem with the network or with the server.  ravbholua@ravbholua-Aspire-5315:~$    Please suggest how to go ahead and upgrade my OS. check if "it's a number" function in Oracle Formatting datetime2 in LaTex to 4th September, 2016 without the current day? I'm currently using  \usepackage[UKenglish]{babel} \usepackage{datetime}   and I'm getting  Sunday 4th September, 2016  with the commands \today or with \newdate{example}{01}{09}{2016} (outside of \begin{document}) and \displaydate{example} inside the document.  How can I reformat this date to not have the name of the day in it (Best would be with using datetime2)? So like 4th September, 2016. With the "th" as a high letter like this:   Full document example:  \documentclass[a4paper, 12pt, DIV=calc, headings=small]{scrreprt} %Used packages \usepackage[UKenglish]{babel} \usepackage[utf8]{luainputenc} \usepackage{datetime}  %Other definitions \pagenumbering{arabic}  \newdate{sample}{31}{01}{2017}   \begin{document} \displaydate{sample}\\ \today \end{document} "NG NS" on ticket after airport security How to distinguish between American Indians and Indian Indians in native English (language) parlance? How to distinguish between American Indians and Indian Indians in native English (language) parlance?  Can I say Indian Indian to say Indian from Asia compared to the Native Americans? Layers with same coordinate system should align/overlap in ArcMap but do not? I put 4 different layers into my ArcMap document, but only one of them will show up on the map! I should be seeing the other 3 layers as well. When I do a Zoom to layer, I can see one layer, but I cannot figure out how to make the other 3 show up at once on top of each other.  Before I opened ArcMap, I used ArcCatalog where I right-clicked 3/4 of the shapefiles and  clicked Properties &rarr; Coordinate system &rarr; Import and then clicked on my Trees layer, which has the coordinate system I want the other 3 to have. But when I opened ArcMap the 4 layers did not overlap, nor could I move them above or below each other. apt-get autoremove wants to remove linux headers Today I ran apt-get autoremove to remove un-needed packages and it wants to remove linux-headers-3.2.0-37 and linux-headers-3.2.0-37-generic  Reading package lists... Done Building dependency tree        Reading state information... Done The following packages will be REMOVED: libglademm-2.4-1c2a linux-headers-3.2.0-37 linux-headers-3.2.0-37-generic ttf-umefont    ttf-unfonts-core 0 upgraded, 0 newly installed, 5 to remove and 0 not upgraded. After this operation, 67.6 MB disk space will be freed. Do you want to continue [Y/n]?    Is it safe to remove these? My installed kernel is a newer version than the headers that autoremove lists.  uname -r 3.2.0-38-generic What does the plus sign do in '+new Date' CSS Pseudo-classes with inline styles MathJax does not work on question title on Android app Although, the question is displayed correctly with MathJax when opened.   App Version: 1.0.85 Device Manufacturer: Spreadtrum Device Model: Celkon A35K   OS Version: 4.4.2 (eng.root.20140613.225402) This is probably easier to show than tell...   On the recent question , I see the following:    As you can see, the first five links render properly, but after that, they stop converting.  Unfortunately, this isn't obvious to the person writing the post, which I discovered when I went to edit the post to fix the "broken" links. In the edit window, it renders all of the links just fine:    I understand that this behavior is expected based on balpha's answer :        Links to questions on the same site are unlimited.   Links to other sites are limited to             a) 5 linked-to sites and     b) N questions per target site, where N is 200 on meta sites and 10 on non-metas (this is about the site that the post containing the link is posted on, not the site that is being linked to)         So if this rule is still going to stay in effect, please fix the edit view to also not automatically convert more than five linked-to sites to help people writing posts know that they need to manually title the links to the other questions.  That said, I'd prefer that (at least on MSE) this limitation be removed or raised. Even in the answer, balpha says:     The restrictions are currently as follows, but note that they do look a bit contrived, resulting from the fact that they have grown over time (from single site to cross-site, from "there are no subsites" to "facebook.SO", etc.), so it's not unlikely that we'll revisit them.   So, if it's not hurting performance, can we please increase the limit or remove it? How to secure recommendations and apply for PhD after having worked outside of academia for two years? dynamic does not contain a definition for a property from a project reference Permutation module of $S_n$ Let $G=S_n$ and let $V$ be the permutation module of $G$ with basis $\{x_1,\ldots,x_n\}.$  Let $\lambda, \mu \in \mathbb{C}$ to allow one to define a $\mathbb{C}G$-homomorphism $\rho:V \to V$ by $$\rho(x_j):=\lambda x_j+\mu\sum_{i \neq j}x_i.$$  By using the above fact or otherwise, how can we prove that $V$ is the direct sum of two non-isomorphic irreducible $\mathbb{C}G$ -submodules?  I tried to prove this by construction. A familiar irreducible submodule in this case is the $1$-dimensional space $U:=\operatorname{span}\{x_1+\cdots+x_n\}$. I intend to find another $(n-1)$-dimensional submodule $W$  which makes $V=U\oplus W$ hold, but it's hard to do so. Is there a way to use the fact instead of a random construction?