I suppose you will assume this question as a duplicate and probably will ban it, but believe me I tried almost everything I could find on this forum and beyond but nothing helped. Please help me with this weird problem, laptop is brand new. WiFi signal is very weak, even when I put it next to adapter, it disconnects after logout/sleep and needs reboot to reconnect.  Tried following solutions: lfwinger/rtlwifi_new, rtl8723be.conf in /etc/modprobe.d/...but none of this solutions has any effect.  wlan0 IEEE 802.11bgn ESSID:"one13"  Mode:Managed Frequency:2.467 GHz Access Point: 50:2E:5C:EE:D0:E1  Bit Rate=72.2 Mb/s Tx-Power=20 dBm  Retry short limit:7 RTS thr=2347 B Fragment thr:off Encryption key:off  Power Management:off  Link Quality=40/70 Signal level=-70 dBm  Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0  Tx excessive retries:0 Invalid misc:1088 Missed beacon:0
I have installed Ubuntu 15.04 on my laptop with RTL8723BE Wi-fi card. But it is always disconnecting from network. I have tried echo "options rtl8723be fwlps=N ips=N" | sudo tee /etc/modprobe.d/rtl8723be.conf but that didn't helped. What can I do to prevent the wifi from disconnecting? If I upgrade to kernel 4.X, will it help?  ~$ lspci -knn | grep Net -A2  09:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter [10ec:b723]     Subsystem: Hewlett-Packard Company Device [103c:2231]     Kernel driver in use: rtl8723be   ~$ rfkill list 0: hci0: Bluetooth     Soft blocked: yes     Hard blocked: no 1: phy0: Wireless LAN     Soft blocked: no     Hard blocked: no   ~$ ifconfig &amp;&amp; iwconfig &amp;&amp; route -n &amp;&amp; ping -c 1 google.com eth0      Link encap:Ethernet  HWaddr 38:63:bb:cd:4a:7e             UP BROADCAST MULTICAST  MTU:1500  Metric:1           RX packets:3 errors:0 dropped:0 overruns:0 frame:0           TX packets:53 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:1000            RX bytes:752 (752.0 B)  TX bytes:8445 (8.4 KB)  lo        Link encap:Local Loopback             inet addr:127.0.0.1  Mask:255.0.0.0           inet6 addr: ::1/128 Scope:Host           UP LOOPBACK RUNNING  MTU:65536  Metric:1           RX packets:3870 errors:0 dropped:0 overruns:0 frame:0           TX packets:3870 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0            RX bytes:314613 (314.6 KB)  TX bytes:314613 (314.6 KB)  wlan0     Link encap:Ethernet  HWaddr c0:38:96:6d:c4:83             inet addr:192.168.1.205  Bcast:192.168.1.255  Mask:255.255.255.0           inet6 addr: fe80::c238:96ff:fe6d:c483/64 Scope:Link           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1           RX packets:15240 errors:0 dropped:0 overruns:0 frame:0           TX packets:14627 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:1000            RX bytes:14410285 (14.4 MB)  TX bytes:2192744 (2.1 MB)  eth0      no wireless extensions.  wlan0     IEEE 802.11bgn  ESSID:"DIR-615"             Mode:Managed  Frequency:2.437 GHz  Access Point: 00:90:4C:08:00:0D              Bit Rate=150 Mb/s   Tx-Power=20 dBm              Retry short limit:7   RTS thr=2347 B   Fragment thr:off           Power Management:off           Link Quality=70/70  Signal level=-22 dBm             Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0           Tx excessive retries:0  Invalid misc:186   Missed beacon:0  lo        no wireless extensions.  Kernel IP routing table Destination     Gateway         Genmask         Flags Metric Ref    Use Iface 0.0.0.0         192.168.1.1     0.0.0.0         UG    400    0        0 wlan0 169.254.0.0     0.0.0.0         255.255.0.0     U     1000   0        0 wlan0 192.168.1.0     0.0.0.0         255.255.255.0   U     0      0        0 wlan0 PING google.com.Dlink (172.26.136.19) 56(84) bytes of data. 64 bytes from 19.136.26.172.in-addr.arpa (172.26.136.19): icmp_seq=1 ttl=249 time=102 ms  --- google.com.Dlink ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 102.547/102.547/102.547/0.000 ms
In discussing , I noted that while the statement:     Any vector space has a basis   is equivalent to the axiom of choice, I wondered if the statement that:     Any vector space either has a finite basis or an infinite set of linear independent vectors   was weaker than the axiom of choice. It feels weaker - it feels like you can inductively define a countably infinite set of linearly independent vectors without full choice, but I'm not sure if that is possible with ZF alone, or requires all of the Axiom of Choice, or is weaker but requires some form of choice. Orthogonal projections with $\sum P_i =I$, proving that $i\ne j \Rightarrow  P_{j}P_{i}=0$ Random images appearing in my home directory... Where are they coming from? Here's an odd problem I've had for a while. Every so often, I find that I have several jpeg images sitting in my home directory that I didn't put there. I'm fairly sure this isn't a security breach but rather, there's something writing these files in there that I've forgotten about.  Here's what I'm looking at today:  oli@bert:~$ ls -l *.jpg -rw------- 1 oli oli  8061 2010-11-19 18:30 An-alien-from-Mars-Attack-002.jpg -rw------- 1 oli oli 24362 2010-11-19 18:30 An-alien-from-Mars-Attack-006.jpg -rw------- 1 oli oli  8147 2010-11-05 18:08 Avatar-Film---2009-002.jpg -rw------- 1 oli oli 35602 2010-11-05 18:08 Avatar-Film---2009-006.jpg -rw------- 1 oli oli  6058 2010-12-03 18:42 Britney-Spears-victim-of--002.jpg -rw------- 1 oli oli 28330 2010-12-03 18:42 Britney-Spears-victim-of--006.jpg -rw------- 1 oli oli  8135 2010-11-12 19:19 charlie-brooker-twitter-p-002.jpg -rw------- 1 oli oli 22115 2010-11-12 19:19 charlie-brooker-twitter-p-006.jpg -rw------- 1 oli oli  8059 2010-10-29 18:47 Leonardo-DiCaprio-002.jpg -rw------- 1 oli oli 29988 2010-10-29 18:47 Leonardo-DiCaprio-006.jpg -rw------- 1 oli oli  8064 2010-10-22 16:41 Spot-the-difference-.-.-.-002.jpg -rw------- 1 oli oli 29188 2010-10-22 16:41 Spot-the-difference-.-.-.-006.jpg   They all seem like they're TV or film related... But I honestly don't have a clue what could be writing them. They don't bother me enough to go on a full-scale witch hunt but if anybody knows of something that writes images in the home directory like this, please let me know. In QGIS, I have been learning a few expressions to style my trail maps but still know little and am stumped on what to use to filter my symbol data. I am showing Parking locations on my map. I use a marker symbol as a background element, so I can do callouts. I created a data field and added values to display beside this symbol a number that references a list of parking addresses in the book's text. All good except if the field has no number to display, it is NULL, it does not display my marker symbol. I need to filter this, so it does show even when there is no value in the field. How can I use the instant messenger program Kik - most commonly installed on smartphones and other mobile devices - on a laptop or desktop running Win7Pro, without a phone being involved and without needing any kind of Google account?  The two ways of using Kik from my laptop that I have so far found are both inadequate, or at least I do not how to tweak them to make them meet the requirements.  The first is to install on my laptop the Bluestacks emulator of Google's Android operating system, and then to run Kik on it. Unfortunately to run Kik on Bluestacks requires (or at least I have not found a way to avoid) having a Google Play account.  The second is to run Bluestacks on Manymo, the online emulator of Google's Android OS. Unfortunately, using Kik on Manymo similarly requires a Google Play account.  I realise Kik was made for use on a mobile OS, but it is supposed to be cross-platform where mobile OSes are concerned, and therefore not to be tied into Google's mobile OS - or, as far as I know, into any other software supplied by Google or any procedure prescribed by that company, such as giving it personal information - so I am optimistic that someone will be able to advise on what I am asking for here.  I notice that Microsoft have made a , so there might be a way to get Kik to work on this without dealing with Google. I couldn't find anything online about this, though. Why is the net speed of Stack Overflow so fast? This question is about the net speed.  I'm from China, and I find that opening pages on Stack Overflow is very fast, normally within a range of 1 to 4 seconds. This speed is very good for a website outside China; it's even faster than some native websites.  Not every website outside China has such good speed, so I am wondering why and how Stack Overflow manages to be so quick. As of the November 2018 core book updates, what changes were made in the latest printings of the PHB that aren't noted in the errata document? How to launch the default (native) application for a given file from Java? How do I count the number of occurrences of a char in a String? To which extent is general relativity a gauge theory? Ethernet Without Magnetics? How / can you connect Ethernet devices together without magnetics? How do you wire it up? What sorts of practical limitations are there on doing this?  To clarify, I'm not trying to connect two computers here. I'm thinking specifically of creating a small network of microcontrollers on a single board. Lets say the total length of a network segment is no longer than 6 inches. This would be for 10BaseT or at most 100BaseT. How to ignore spaces before footnotes Is there a quasistatic process that is not reversible? I have seen several questions and good answers on the link between reversible and quasistatic processes, such as  or . However, these questions only adress one side of the problem : a reversible process is necessarily quasistatic.  I am interested in the other side of the equivalence : is there a process that is quasistatic, yet not reversible ? It looks to me that an irreversible process cannot be made perfectly quasistatic.  The  article about quasistatic processes takes as an example the very slow compression of a gas with friction. As the compression occurs very slowly, the transformation is quasistatic, and the friction makes it irreversible. I am not convinced by this example : if you press on the piston with a vanishingly small force you will have to reach the threshold of the Coulomb law for solid friction before moving the piston anyway. It makes the process non-quasi-static, however small the Coulomb threshold might be.  Another example I've heard of is the reaction between a strong acid and a strong base. It is always an irreversible process, and you could make it quasistatic by adding very small drops of base into acid at a time. But by trying to do that, you would inevitably reach a limit to the size of the drop imposed by surface tension.  Even if "reversible" and "quasistatic" mean very different things, is it true to consider that in practice, a reversible process and a quasistatic process is essentially the same thing ? Is there any package or a method to force LaTeX to keep floating environments like table and figure closer to where they are declared? Random piece of plastic convexity proof of a function including ln and sums Using NPN transistor as switch Android: How to draw route directions google maps API V2 from current location to destination Gauss's Law with Moving Charges I want my Qt application to be able to save simple vector graphics to clipboard in a compatible way. On windows I want to be able to paste the graphics into Microsoft Word or Powerpoint. On Linux I want to be compatible with the Open Office.   Which format would you recommend? Can Qt generate EMF in an easy way? Is SVG an option?  Update:  My current plan is to add a piece of native win32 code to render the graphics to emf on windows. This code will not be available on linux.