Is there a way to restart the desktop manager like windows when Ubuntu freezes? Recently I have been facing multiple system freezes where I could move the cursor, but nothing would respond. I couldn't click on anything.  I could, however, switch between open apps using Alt+Tab, but still could not interact with them using the mouse.  I could open new terminals using Ctrl+Alt+T, yet mouse would not work!  In Windows, when a similar event happened, I could easily restart explorer.exe and everything would go back to normal. Is there anything like that in Ubuntu?  I'm asking this because rebooting is not always an option, neither is logging-out, since I may have running scripts/apps doing their chores. Also killing the app(s) that consume a lot of CPU is not an option always since I rarely face such occasions and more often than not, the cause of system freezing is not CPU usage.
How to properly restart unity? I keep on experiencing weird bugs. These usually start after a few hours of use. Sometimes the dash starts opening under every open window (becomes only visible on desktop, but I still can search and open anything with the enter key while it's not visible). Also, there are other minor annoyances, such as random places (especially maximized Chrome, tabs area) after navigating between programs with alt+tab can't be clicked with the mouse. Switching back and forth fixes this.  I cannot use  compiz --replace   since after that, all of the app indicator icons are gone (only teamviewer stays). Skype, network, languages, sound (also keyboard sound up/down stops working) and date are gone. Restarting unity-panel-service does not help.  Any thoughts on how to resolve these?
Exercise $7$, page 51 from Hungerford's book Algebra.     Show that $N=\{(1),(12)(34), (13)(24),(14)(23)\}$ is a normal subgroup   of $S_{4}$ contained in $A_{4}$ such that $S_{4}/N\cong S_{3}$ and   $A_{4}/N\cong \mathbb{Z}_{3}$.   I solved the question after many calculations. I would like to know if is possible to define an epimorphism $\varphi$ from $S_{4}$ to $S_{3}$ such that $N=\ker(\varphi)$.  Thanks for your kindly help. How can I pad an integer with zeros on the left? How can I render an object with an hdr background? I have an object with an hdr for the background. What do I do in Cycles to render the background with my object?  How is this different from an ordinary render in Cycles?  The hdr is a big one, 350MB. Don't include SE site in SE search filter? I couldn't find this question here, but I would like to be able to search all sites in the SE network except some sites. In my case, I want to remove the thousands of results from SO on a popular project for devs so I can see the handful of results on other sites from admins and users.  The current form only allows all sites or listed sites.  The answer linked does not tell me how to use the information in the answer. It is a poor answer for an average user.  As @Laurel describes in the comment below, the answer at  no longer works. How do I uninstall Pandoc in Ubuntu 19.10 (and install most recent version) I have an old version of Pandoc installed, but I'd like to install the latest version of Pandoc.   To begin I've run the following to get rid of the old version:  sudo apt-get autoremove --purge pandoc  But when I check that everything is uninstalled by running: pandoc --version Then pandoc 2.2.3.2 pops up.  I can't seem to get rid of this old version of pandoc so that I can install a new one.  Could you advise me on how I can get rid of the old version and install the new one please. I have county data in which the &quot;FIP&quot;s (actually State &quot;FIP&quot;s and County &quot;FIP&quot;s combined). I have data imported as CSV with the sames &quot;FIP&quot;s data titled 'STCounty'. However, the shapefile &quot;FIP&quot;s is listed as a Real and the CSV came in as an Integer and the Join function does not seem to work.  The drop boxes are greyed out/empty. So the bigger questions is how do you change the attribute type in a table? I tried to create a new column in the shapefile (county data) and set it to an integer and then multiply the &quot;FIP&quot;s*1, but got a column full of NULL. I am new to QGIS and have a lot of experience in MapInfo, so the join concept is not new to me, just the syntax in QGIS. Use of "Or", inclusive or exclusive? My wife and I are playing a game where you roll dice and move so many spaces in a grid "vertically or horizontally".   In the use of English it is very common to say, this or the other when it comes to making a choice  (exclusive or). Now I know that "or" can also be inclusive, for example "she couldn't read or write", or can be clearly used as an xor "you either come or not" making the statement true for only one of the options but not both.   My issue is where it is not clear whether it is an inclusive/exclusive or, the best example being our game.   I argue that you can move in either direction (inclusive) and the normal use of this conjunction in English should be inclusive unless specified otherwise.   Is this right? Behave as if it was or it were You can place the script in the head or body as you like. The   script will behave as if it was located exactly where you put the   script tag in the document.   The sentences above are taken from  (at the very bottom). I think they made a grammatical mistake here: it should be behave as if it were rather than it was. I'm not 100% sure, so want to confirm it. Is it possible to set start-up applications to initialize in certain workspaces? I'd like to not have to manually distribute my start-up applications across my numerous workspaces every time I boot up my machine. I'm running Ubuntu 12.04 .  Any Help ? Can "cattle" be singular? I've grown up on a farm, and my dad and his dad, apparently, always used "cattle" to refer to both the singular and plural forms of the domestic bovine. I've always assumed it's how the word "deer" is.  However, I've heard people say that this is incorrect and the singular is just "cow", but this has always offended us as a cow is a mother cattle, and is incorrect if you're referring to a steer, a bull, or a heifer.  So, is cattle singular as well as plural? If not, is there some general, non-gender-specific word that should be used instead? How do I pass this array of c strings correctly? How to correctly do a division using a slash? What's the correct way to do division using a backslash? If I write $a/bc + d$, will that be equal to $(a/(bc))+d$?   Basically, if I place a slash, will I divide by what's directly behind the slash $(b)$, the term that's behind the slash $(bc)$, or everything after the slash $(bc+d)$? In Thor: The Dark World, Odin and Loki are discussing Loki's actions during The Avengers.  Loki argues that he would have ruled Earth as &quot;a benevolent god&quot;, and Odin replies:  Odin: We are not gods! We are born, we live, we die, just as humans do.  Now that's pretty definitive.  And Loki's snarky reply (&quot;Give or take five thousand years...&quot;) would seem to confirm that Asgardians have a limited lifespan, and will eventually die of old age.1  And we know that Asgardians can die in battle, because we've seen it happen over and over with supporting characters and Asgardian soldiers. Now, I've always been more of a fan of Thor stories (like Jason Aaron's Thor: God of Thunder arc) in which Thor and the Asgardians are gods.  Straight-up, genuine, higher-level-of-existence gods, not von-Däniken-esque wannabes playing on the tired old notion of magic just being super-advanced science.  BUT, despite my preferences, this exchange would seem to confirm once and for all that in the MCU, the Asgardians are not gods, but rather were mistaken for gods because of their ram-horns full of awesome-sauce and their magnificent bulging pecks. But wait!  Watch that movie for about 30 seconds longer and we come across this exchange:  Thor: She is ill. Odin: She is mortal. Illness is their defining trait.  Wait, what?  I thought Asgardians weren't immortal?  They can die in battle, and they naturally die of old age.  In my book, that makes them long-lived, but entirely &quot;mortal&quot;.  Surely Odin isn't splitting a hair so fine as to say that resistance to disease alone makes one &quot;immortal&quot;? So, if the Asgardians of the MCU aren't actually gods (grumblegrumblegrumble...), and they can't live forever (or even particularly long in a cosmic sense), and they can be killed in battle, in what sense are they &quot;immortal&quot; at all?  1 Fun fact: adjusted for a roughly 5,000 year lifespan, 1,048-year-old Loki is currently in the tail-end of his rebellious teenage phase. What is the word for when someone is overly nice and actually isn't nice at all because of the unnecessary added information/comments? For example, they will say things like "Your hair looks so good that wayyyy omg you should do it that way ALL the time! Looks way better than how you usually do it." And the word I'm looking for is not passive aggressive and it is not sarcasm. There is a word for these types of people. What is it? These people think they're being kind but actually blunt and rude. Another example would be for someone to say "hey you're beautiful, but maybe if you didn't wear harsh makeup you would look better" and they intend to sound like they're being nice when you know they don't like you and are saying in out of spite. How to recover a deleted NTFS partition with data I am investigating the vulnerability to  and I think I understand how and why this sort of attack works.  What I don't understand is why Lighttpd and NginX are not affected (according to the same article as linked above). What do they make so different? Idempotent linear operators are projections I have two independent groups: from one I have drawn a sample of size less than 30 due to its small population, while the second group has sample size 100.  Is it appropriate to use an independent samples t-test in this case? Anyone seen this one yet? Vote too old to be changed, unless post is edited My vote was only a few hours old. Then I realized the answer was wrong. Updated my question and went to remove the vote. Even after updating question I still have the issue. Small issue, but frustrating.  See also: Error "Power::infy: Infinite expression 1/0 encountered". Why do I get this?