Wireless not working on Dell XPS 13 with Ubuntu 18.04
Why do I get "Required key not available" when install 3rd party kernel modules or after a kernel upgrade?
The comment with the Flagged Posts that seems to be new as of today states there are posts with flags awaiting my attention but the counter shows zero and when I go into flagged posts there is nothing waiting for me. How can I animate an object fading out? What does the 'B' (or bonus) mean on a basketball scoreboard? Given a Möbius transformation that maps one pair of concentric circles to another pair of concentric circles, why is the ratio of the radii preserved through the map?   I thought about how Möbius transformations are compositions of rotations, scaling, inversion, and translation, and that intuitively, these types of maps shouldn't change the ratio of radii between two circles.   Would it be correct to just say that if $\frac{r_1}{r_2}$ is the ratio of radii between the two circles, then   1) The radii are invariant under translation, $z \mapsto z+a$, so $\frac{r_1}{r_2}$ stays the same  2) Under scaling by a factor $z \mapsto az$, $\frac{ar_1}{ar_2} = \frac{r_1}{r_2}$   3) Under inversion, $z \mapsto \frac{1}{z}$, $\frac{1/r_1}{1/r_2} = \frac{r_2}{r_1}$  Or is there a different/better way to think about this problem? Project Euler - 34 / Find a mathematical approach for upper bound 145 is a curious number, as 1! + 4! + 5! = 1 + 24 + 120 = 145. Find   the sum of all numbers which are equal to the sum of the factorial of   their digits. Note: as 1! = 1 and 2! = 2 are not sums they are not   included.   So I tried a random enough large upper bound (100000) in my program and it worked.  I deleted this part to not spoil the answer  My question is : How to find the closest upper bound using a mathematical approach ? Turn off paragraph indention for a single line How do I use the different shutter speeds my camera offers? In JavaScript:  encodeURIComponent("©√") == "%C2%A9%E2%88%9A"   Is there an equivalent for C# applications? For escaping HTML characters I used:  txtOut.Text = Regex.Replace(txtIn.Text, @"[\u0080-\uFFFF]",     m =&gt; @"&amp;#" + ((int)m.Value[0]).ToString() + ";");   But I'm not sure how to convert the match to the correct hexadecimal format that JS uses. For example this code:  txtOut.Text = Regex.Replace(txtIn.Text, @"[\u0080-\uFFFF]",     m =&gt; @"%" + String.Format("{0:x}", ((int)m.Value[0])));   Returns "%a9%221a" for "©√" instead of "%C2%A9%E2%88%9A". It looks like I need to split the string up into bytes or something.  Edit: This is for a windows app, the only items available in System.Web are: AspNetHostingPermission, AspNetHostingPermissionAttribute, and AspNetHostingPermissionLevel. How do I set a static IP address in Windows? It seems that a List object cannot be stored in a List variable in C#, and can't even be explicitly cast that way.  List&lt;string&gt; sl = new List&lt;string&gt;(); List&lt;object&gt; ol; ol = sl;   results in Cannot implicitly convert type System.Collections.Generic.List&lt;string&gt; to System.Collections.Generic.List&lt;object&gt;  And then...  List&lt;string&gt; sl = new List&lt;string&gt;(); List&lt;object&gt; ol; ol = (List&lt;object&gt;)sl;   results in Cannot convert type System.Collections.Generic.List&lt;string&gt; to System.Collections.Generic.List&lt;object&gt;  Of course, you can do it by pulling everything out of the string list and putting it back in one at a time, but it is a rather convoluted solution. What does ` (backquote/backtick) mean in commands? I came across the following command:  sudo chown `id -u` /somedir   and I wonder: what is the meaning of the ` symbol. I noticed for instance that while the command above works well, the one below does not:  sudo chown 'id -u' /somedir Question Prove that for every integer k≥1, exists a self-complementary graph with 4k vertices half of which are of degree 2k-1 and the other half of degree 2k.  My approach So, I think the easiest way to prove what is asked is by induction. I can prove the base case for k=1, but as far as the inductive step is concerned, I cannot seem to reach a conclusion as to why if the statement holds for n, then it holds for n+1.  Any help would be appreciated. I'm  having some trouble editing the content of a Managed Email Template, I can quite easily modify the content of the Email Template, but when I wish to refer to an unmanaged component, like this:  &lt;messaging:attachment renderAs="PDF" filename="invoice.pdf"&gt;     &lt;c:MyComponent/&gt; &lt;/messaging:attachment&gt;   I get the error message:     Error: Unknown component c:mycomponent   Does anyone know if its possible to embed an unmanaged component in a managed Email Template? I love making our own bread - we rarely buy shop bought, but it tends to go off very quickly. Part of the appeal is that it doesn't have any "junk" in it - artificial preservatives - which I'm sure contributes to the lovely flavor. Is there anything natural I can add to it to stop it going moldy so fast? Function with same name but different signature in derived class I have a function with the same name, but with different signature in a base and derived classes. When I am trying to use the base class's function in another class that inherits from the derived, I receive an error. See the following code:  class A {     public:     void foo(string s){}; };  class B : public A {     public:     int foo(int i){}; };  class C : public B {     public:     void bar()     {         string s;         foo(s);     } };   I receive the following error from the gcc compiler:  In member function `void C::bar()': no matching function for call to `C::foo(std::string&amp;)' candidates are: int B::foo(int)   If I remove int foo(int i){}; from class B, or if I rename it from foo1, everything works fine.   What's the problem with this? Sources for common laboratory Saccharomyces strains? I'm used to working with bacteria - some of the more common laboratory strains sometimes come with an order from some vendors.  What's the most convenient source to order  for lab work? How to escape text for regular expression in Java I'm looking for an algorithm that sorts strings similar to the way files (and folders) are sorted in Windows Explorer. It seems that numeric values in strings are taken into account when sorted which results in something like  name 1, name 2, name 10   instead of  name 1, name 10, name 2   which you get with a regular string comparison.  I was about to start writing this myself but wanted to check if anyone had done this before and was willing to share some code or insights. The way I would approach this would be to add leading zeros to the numeric values in the name before comparing them. This would result in something like  name 00001, name 00010, name 00002   which when sorted with a regular string sort would give me the correct result.  Any ideas? Flows/Processes, Version Control and CI I've started using Processes and Flows and am really excited about these features -- but am still wrapping my mind about how to manage them in Version Control (which I use) and Continuous Integration (which I don't yet... but am trying to work in that direction). The underlying challenge is that each time a process or flow is edited, the metadata file is renamed to reflect its update version, e.g. MyFlow-1.flow, MyFlow-2.flow, etc. The Challenge for Version Control If each version of the flow has its own file name, this makes it more complicated to track changes to flows.  It seems like there could be two strategies here:  Rename the files to remove the version number.  I'd need a script to run through my src folder pre-commit, and remove the number so that my file name is always MyFlow.flow.  This is an annoying extra step, but makes version control simpler.  On the other hand, it probably makes deployment much harder.  Track each file in version control with its original name.  We'd need to be diligent about deleting MyFlow-1 in the commit where we add MyFlow-2 so that git would recognize this as a rename/move and show helpful diffs.  Otherwise, the whole file appears to change with every change, which makes version control rather less useful.   The Challenge for Deployment/Continuous Integration From my experiments so far, once a flow has been activated in a given environment, the metadata file can't be deployed again (either it is currently active, or has been active in the past and superseded). That means that I need to prevent my previous flow versions from being included in a deployment package (either by not tracking them at all, or by using a script to delete earlier versions).  I also need some way to determine whether the current version (in my repo) should be included in the deployment payload for a given environment or not. I could imagine a script that (1) downloads flows from the target environment, and removes *.flow files from the payload if they already exist in the target environment, but that feels complicated.  And it's even harder if I've removed the version numbers from my flow files. Are you using flows in VS or CI?  How are you managing these issues? Note:  I'm not sure whether VC and CI should be one question or two - depends on how integrated the strategy for dealing with these two challenges.  If you think these should be separate questions, comment and I'll re-post. What are the fundamental differences between the mainstream *NIX shells? What are the fundamental differences between the mainstream *NIX shells and what scenarios might prompt you to use one over the other?  I understand that some of it probably comes down to user preference but I've only ever used Bash and I'm interested to hear where another shell might be useful. Also, is there an impact on user-written shell scripts when running under one shell or another or is it simply a matter of changing the shell at the top of the file?  My instinct says it's not that easy.