I don't know what is wrong. I use 18.04, every time when I boots into my laptop Ubuntu, I find that Bluetooth is ON. I turn it off and it stays so till I switch off my laptop. But when I boots into Ubuntu again Bluetooth is ON. No matter how many time I turn it off, it comes back with every new session. Is there any way to permanently turn it off ?
How can I deactivate Bluetooth on system startup?
When entering the US on an international flight, and then on to a connecting domestic flight, what is the exact order of the process that will take place? In other words, what happens first, second, third, etc.? How would I import/export Blender's preferences? Why have my email notifications stopped? How to format a USB flash drive? In Windows there is a straightforward "Format" option in a flash drive's right-click pop-up menu. Where's that in Ubuntu? AMD-V is not enabled in VirtualBox on AMD APU I am running on a dual core AMD E450 CPU. When I tried to run a 64-bit OS that requires hardware virtualization using VirtualBox, it showed me an error message that "AMD-V is not enabled".    My AMD processor is supposed provide AMD-V support, but I can find no option for enabling AMD-V in BIOS.    How can I solve this problem? How can I enable AMD-V for my CPU?  Thanks in advance  lscpu :-  Architecture:          x86_64 CPU op-mode(s):        32-bit, 64-bit Byte Order:            Little Endian CPU(s):                2 On-line CPU(s) list:   0,1 Thread(s) per core:    1 Core(s) per socket:    2 Socket(s):             1 NUMA node(s):          1 Vendor ID:             AuthenticAMD CPU family:            20 Model:                 2 Stepping:              0 CPU MHz:               1650.000 BogoMIPS:              3291.72 Virtualization:        AMD-V L1d cache:             32K L1i cache:             32K L2 cache:              512K NUMA node0 CPU(s):     0,1   EDITED:-  Error message from VirtualBox:-  Failed to open a session for the virtual machine XXX.  AMD-V is disabled in the BIOS. (VERR_SVM_DISABLED).  Result Code: NS_ERROR_FAILURE (0x80004005) Component: Console Interface: IConsole {1968b7d3-e3bf-4ceb-99e0-cb7c913317bb} I have written below Wrapper class.  global class BI_VA_AutomationWrapper {      global class BI_VA_AutomationRequest {      webservice String userName;     webservice String emailId;     webservice String buinessUnit;     webservice String orgName;     webservice String country;     webservice String environment;     webservice String myShopNumber;     webservice String BidsId;//for testing     webservice String Type; //for testing  }  global class BI_VA_AutomationResponse {      webservice String responseStatus;     webservice String myShopNumber;     //webservice list&lt;Error&gt; errorMessages;     webservice String  errorMessages;//for testing   } global class BI_VA_Error {      webservice String type;     webservice String message;    }}   And test class is,  @isTest public class BI_VA_AutomationWrapperTestClass  { public static testMethod void unitTest(){      BI_VA_AutomationWrapper.BI_VA_AutomationRequest wrap= new BI_VA_AutomationWrapper.BI_VA_AutomationRequest();        wrap.userName='Test@test.com';     wrap.emailId='Test@test11.com';     wrap.buinessUnit='AH';     wrap.orgName='ORD';     wrap.country='US';     wrap.environment='QA';     wrap.myShopNumber='123456789';     wrap.BidsId='123';     wrap.Type='ResetPassword';              BI_VA_AutomationWrapper.BI_VA_AutomationResponse res= new BI_VA_AutomationWrapper.BI_VA_AutomationResponse();     res.responseStatus = 'Success';     res.myShopNumber = '987654321';     res.errorMessages = 'Test error';      BI_VA_AutomationWrapper.BI_VA_Error error = new BI_VA_AutomationWrapper.BI_VA_Error();     error.type = 'Test';     error.message = 'Test';  }}   Code coverage is 0% only. I noticed that the locked message still references the FAQ. See :  locked by  yesterday This question exists because it has historical significance, but it is not considered a good, on-topic question for this site, so please do not use it as evidence that you can ask similar questions here. This question and its answers are frozen and cannot be changed. More info: .  Since the FAQ has been replaced by the , this message should provide a link there instead. Currently, the link actually takes you to the ; even if it doesn't link to the help center, the text should probably be something like &quot;More info: &quot;. Typo in First Posts queue If you go to the First Posts review queue, and if there's an answer in the queue and if you hover with your mouse over "No Action Needed", then you get a tooltip "this answers seems to be valid":  But it should be "this answer seems to be valid". "Much of it is" or "Much of it are"? I'm writing an college-entrance essay and for me it's imperative that I understand and implement the correct one of these two expressions:     "Much of it is" or "Much of it are"   If you need context:     I'm having trouble with my writing. The reason I'm having trouble is that much of it is about....   Should there be an "is" or an "are"? Connect Tikz nodes via two parallel arrows I am just starting to learn using Tikz and am a little lost within its seemingly infinite amount of options and possibilities.  What I am trying to do is visualize a few Matlab function interaction (which one calls which one, what is the in- and output). Since there are only about six subroutines, I place each one manually as a node. This is an example:  \documentclass{article} \usepackage{tikz} \usetikzlibrary{shapes,positioning}  \begin{document}  \begin{tikzpicture}[auto] \node           [rounded rectangle,draw]        (node1)     {Node 1}; \coordinate [above=of node1]                                (input); \node           [rounded rectangle,draw]    at  (-10:6cm) (node2)       {Node 2}; \draw           [-&gt;,very thick]             ([xshift=0.1cm]  input.south)  --                  node {right}                ([xshift=0.1cm]  node1.north); \draw           [-&gt;,very thick]             ([xshift=-0.1cm] node1.north) --                  node {left}                 ([xshift=-0.1cm] input.south); \draw                                            (node1) -- (node2);  \end{tikzpicture}  \end{document}     Now I would like to apply these double in/out arrows I (probably pretty awkwardly) created using xshift to all node connections, so in this example also for the connection between Node 1 and Node 2. Ideally, the space between these two arrows would be the same, independant of their angle and they would nicely connect to the outer line of the nodes. Any idea how I could achieve this? Similar questions I have found only used rectangle and orthogonal lines. Can I have a common account across the Stack Exchange family of sites? Given a field $F$, can you necessarily construct a field extension $E \supset F$ such that $\operatorname{Gal}(E/F) = S_n\,$? What happens to Bruce Banner when Hulk loses a tooth? In Age Of Ultron we witnessed Hulk lose a tooth.   My question is: Has Bruce Banner lost a tooth as well? Text formatting now allowed in comments (List of proven and disproven abilities) Now that the , I've been seeing tag-only suggested edits from 1500-rep users.  For example, one had the summary of 'burninating [tagThatWasRemoved]'.  It's very tempting to reject these as Too Minor, but I know that these users used to have a Retag privilege (and are obviously trying to participate in a burnination.)  What should we do for tag-only edits from high(er) rep users? How do you rotate a two dimensional array? Inspired by , say you have a 4x4 two dimensional array, write a function that rotates it 90 degrees. Raymond links to a solution in pseudo code, but I'd like to see some real world stuff.  [1][2][3][4] [5][6][7][8] [9][0][1][2] [3][4][5][6]   Becomes:  [3][9][5][1] [4][0][6][2] [5][1][7][3] [6][2][8][4]   Update: Nick's answer is the most straightforward, but is there a way to do it better than n^2? What if the matrix was 10000x10000? Should I capitalise "or" between examples? On this site, there are often many different options as an answer, for example both with and without the Oxford comma.  When giving multiple options, should I capitalize the word "or" between them?  Option 1:     Eggs, butter and milk are dairy products   Or   Eggs, butter, and milk are dairy products     Option 2:     Eggs, butter and milk are dairy products   or   Eggs, butter, and milk are dairy products     Notice in Option 1 the "or" is capitalised. In Option 2 the "or" isn't. Let $a_k:=(-1)^k$ where $k\in\mathbb{N}$. $\mathbb{N}$ is the set of all non-negative integer.  And we define the partial sum $S_n:=\sum \limits_{k=0}^{n}a_k$. Notice that the sequence $\{S_k\}$ diverges which also implies that the infinite series $\sum \limits_{k=0}^{\infty}a_k$ cannot be defined.  If I consider the infinite sum $1-1+1-1+1-1+\cdots$, then this statement is equivalent that I just defined the infinite series $\sum \limits_{k=0}^{\infty}a_k$, which is contradiction.  But, suppose that the sum $1-1+1-1+1-1+\cdots$ exists and let the value of the sum be $S$. Then, we can easily observe that $S=1-S$, therefore $S=1/2$. The supposition of this proposition already proved as false, but if I ignore the definition of infinite series, it holds.  Which one is right? Or are these propositions depends on what we define? Let $L$ and $R$ be $n \times n$ matrices. I am trying to solve the following minimization problem  $$ L^{k+1} := \arg \min_{L} \lambda \|L\|_{\ast} + \frac{1}{2\mu}\|L-R^{k}\|_{F}^{2} $$ $$ \mbox{s.t.}\ L \succeq 0 $$  where $\|\cdot\|_{\ast}$ and $\|\cdot\|_{F}$ denote the nuclear and Frobenius norms, respectively. Also, $k$ expresses the $k$th iteration when solving an optimization problem successively.  I don't know how to solve this problem. Would you tell me the way? After the performance problems we have run into with  we've decided to make a change, we're moving the network on to .  Here's where to get started:   What works:   All search operators should be in Many changes below from the old search behavior   What's different:   The new search is AND, adding a search term will narrow your results, not expand them. The look of search results is now more unified with the following differences between Q&amp;A:   "Q:" or "A:" prefix Answer counts and tags will be present in questions. The answer count will be highlighted in green if it's accepted. (We may index other things later, that's why the results are more generic/google-y now.)  It's faster, about 5-10x faster for almost all searches on large sites like Stack&nbsp;Overflow Quoted phrases are exact matches except for case-sensitivity, for example,  or . If not in a quoted phrase, words will now be stemmed () Snippets for context will now be more relevant Excludes are now explicitly supported (like -term and -"my phrase") We don't roll up to the question anymore, if you searched for something that matched an answer, we'll show you the answer directly in search results The search per minute limit is effectively gone, it'll block a bot, but no one else should hit it... We'll be monitoring performance though infavorites:mine is back, with infavorites:12345 (any user id) added   What needs work:   What you tell us is broken... Do your worst.   Testing, not yet final:   New range support, here are some examples:   answers:1..1 (exactly one answer) answers:10..20 (10 to 20 answers) created:2008..2009 (created between Jan 1st, 2008 and Dec 31, 2009) created:2010-04..2010-05 (created between April 1st, 2010 and May 31st, 2010) created:2011-01-05..2011-01-06 (to be clear: it goes to end-of-day) This range syntax applies to a new advanced operator: lastactive: and the other numerical ranges, views:, and score:  Additionally, the above syntax is a bit more flexible if you forget it exactly (e.g. score:20-30) in an effort to be intuitive as possible, give it a try - tell us what you think.    I'll try and improve the search as much as possible before it becomes default... At the very least we want it equivalent in relevance and functionality before the switch, but ideally much better. We won't switch until then.  Please give it a try, tell us what you think here, and we'll continually improve it over the holidays as time allows. Bear in mind you may get a search offline page during this test if a change we're making for results necessitates a reindex, and even that should only last about two minutes here on Meta&nbsp;Stack&nbsp;Overflow.  Give it your worst, compare results to the old search, tell us what's better and what's not. We look forward to the feedback.  Update The new search is now the default across the network - we'll be monitoring things over the next few days and would appreciate reports of any crazy behavior you see here.