Have a question about multiple clients connecting a single server. Here is my server side code:  //...     ServerSocket serverSocket = null;         try{             serverSocket = new ServerSocket(port);         }catch(IOException e){             e.printStackTrace();         }         Socket server = null;          while(true){             try{                 server = serverSocket.accept();                 new createdThread(server).start(); //This is a thread class specified somewhere else to handle the socket.              }catch(IOException e){                 e.printStackTrace();             }   createdThread() is a thread that will start to handle the socket, and it takes the Socket server as an argument. Suppose I have a connection and a thread starts, the accepted socket was passed to the thread as an argument. In this case, server should be passed as a reference if I'm not wrong. If before the end of the first thread, serverSocketgets a new connection and create a new socket, which will change the value of server. Will this impact the execution of the first thread since the first thread takes the reference as its argument, meaning the underlying object of that reference is changed?   I tested the program and it seemed working well. Each thread was not impacted by each other, although all of their constructor arguments are references to the same object. This does not make sense to me, and hope someone could clarify. Thanks.


I have to compare geometries anywhere in the world; mainly between 65N and 40S but also in the Arctic latitudes. I need "commercial accuracy" - not military or navigational. For example does a line intersect with a polygon and - if so - so they intersect for 50 km rather than 55 km. I store the lat and lng of  these geometries.   Can anyone please tell me how to select the most suitable cartesian projection (from spatial_ref_sys) to transform the coordinates into before compare any line with any polygon ?  I have tried to use the lng of the centre of the line to select one of the SRIDs between 32601-32660 and 32701-32760. As many of you will know, these are based on the equator every 6 degrees and the 601-660 are for northern hemisphere while the 701-760 are for the southern hemisphere.  To test whether this works, I check whether the ST_Intersects() function detects that a point in Asia at 36.9417, 75.4083 intersects with a polygon of Asia after both are transformed with SRID 32643 whose central_meridian is 75 degrees. Sadly the ST_Intersects() function doesn't detect that the point is right in the middle of Asia, but when I use SRID 32644 whose central_meridian is 81 degrees, ST_Intersects() function detects an intersection between point and polygon.  There are many other examples of my "calculated" SRID being the wrong one. Maybe I'm overcomplicating ? I originally used SRID 4326 anywhere worldwide before testing with ST_Intersects(), and things seem fairly accurate except in high northern latitudes, so I was hoping to minimize inaccuracies by using different cartesian SRIDs at different longitudes.  Perhaps I need to find SRIDs which centre on the latitude of the geometries - not just the longitude ? Maybe I'm overcomplicating ?   Many thanks for your initial welcoming response. I hope that gives good information.


I have a PC running Windows Vista Home Premium with Norton Internet Security 2009. I like to help my father and sister by connecting their PCs over the internet and taking full control. My father has Windows Vista Home Premium and my sister has Windows XP SP3. Both of them are using McAfee Internet Security 2009. One of my friends recommended me to use TeamViewer. I didn't try it yet. Any comments for this work and for any possible adjustments in both security programs and OS?


Variable from concatentation of variables

I think this is a rather simple question but, I cant make this work: I have a whole lists of variables eg:  SP60=OLA SP61=BYE SP62=TRT   I want to create a loop to call them in the specific number of the variable so I thought a short solution could be:  for i in {60..62}; do SP=$"SP$i"; echo $SP.txt; done   I was expecting the outcome to be:  OLA.txt BYE.txt TRT.txt   but I get   SP60.txt...   I would like to know if there is a simple way to get this done.


What are some open problems in classical electrodynamics?

I am about to finish reading 'Introduction to Electrodynamics' by David Griffiths. Throughout the textbook, Griffiths makes frequent references to current literature (mostly articles from American Journal of Physics). So, I concluded that even though the theory of electrodynamics has a well established foundation, there might be some interesting "side problems" which are still open, hence the question.


Is $[0,1] \cap \Bbb Q$ a compact subset of $\Bbb Q$?  I get the feeling it isn't compact, but I can't figure out a way to prove this.  I understand that,  in $\Bbb Q$, any open set $U = \Bbb Q \cap O_i$ such that $O_i \subseteq R$.  But I can't figure out a way to construct a finite set that doesn't contain the intersection set.


Sorry this is a very small segment of code:  var arr = [2,4,6,8]; var obj = {}; for (var i in arr) {     obj[arr[i]] = arr[i] * 2; }   What I expect it to do is output the values of arr in an object, and return those values doubled.  My does that but also includes this:  'function () {\r\n  var result = [];\r\n  for (var property in this)\r\n    result.push(property);\r\n  return result;\r\n}': NaN   Can anyone explain to me why this happens?  Thank you.


I am developing code in python that should compare the date of the files in the folder to the current date. But I Can't get dates of the files can you help me ?


How to align (9) A to right?  \documentclass[12pt,a4paper]{report} \begin{document} \begin{description} \item [Hlavní poloosa] (9) A \\ $a$ může být určena  \end{description} \end{document}


c# write into existing XmlDocument from specflow table or dictionary

I am trying to find a solution to read xml(wsdl) from a soap api so my test will be dynamical (not break if the xml structure has been changed) and add my values to this xml to send it as a request.  from the Speclow tables I could create my dictionary  and I got the service xml as welll per operation  but how can I write my values into the XmlDocument ?  Thanks for the help.  public static XmlDocument GetRequestByData(Table createRequestTable, XmlDocument soapXML)     {         Dictionary<string, string> myDictionary = TableExtensions.ToDictionary(createRequestTable);          XmlDocument requestXML = new XmlDocument();          soapXML[] = myDictionary[];            return requestXML;     }


toggleClass when specific section is on screen

I am making one big scroll page. And my nav is fixed positioned. I want to change the color (from black to white and vice versa) on the nav when it reaches specific sections on my page. It's because some of them are white, and some of them are dark - I want to make a contrast. I already made a class in css that should be toggled. But I am having difficulties using my code. Take a look at it:      $(window).scroll(function (event) {     var scroll = $(window).scrollTop();         $('nav').toggleClass('light-mode',             //add 'light-mode' class when div position match or exceeds else remove the 'light-mode' class.             scroll >= $('.section2').offset().top         );     });      //trigger the scroll     $(window).scroll();//ensure if you're in current position when page is refreshed body {   margin: 0px;   padding: 0px; }  nav {   width: 100%;   position: fixed;   text-align: center;   padding-top: 20px;   padding-bottom: 20px; }  .light-mode {     color: #fff; }  .section1 {    width: 100%;    height: 400px;    background-color: #fff;    color: #000;    padding: 100px; }  .section2 {    width: 100%;    height: 400px;    background-color: #000;    color: #fff;    padding: 100px; }  .section3 {    width: 100%;    height: 400px;    background-color: #fff;    color: #000;    padding: 100px; }
navigation links

     section 1

     section 2

     section 3
     The conclusion:  My navigation by default is dark colored. When I reach the section that is dark I want to tell jQuery to add class .light-mode to . But when user goes off the section, I want it to go back to normal (so delete the class). In my solution it has issues:   It seems to it is not going back to original when user is not on the section. The class is added just when user scrolls from top to bottom page. It looks on .offset().top. I want to make it more professional and universal. I want to add this class when each section is on screen not matter if its from bottom or top.


Proving divisibility of expression using induction

Question:  Part a:  Prove that for any $ b\in \Bbb N,$ if $ 2^{3b -1} + 5 . 3^{b}$ is divisible by $ 11$, then $ 2^{3(b+2) -1} + 5 . 3^{b+2}$ is divisible by $11$.  Part b:  Is statement 1 or statement 2 true? Explain answer.   For any odd number $a\in \Bbb N $, $ 2^{3a -1} + 5 . 3^{a}$ is divisible by $ 11$ For any even number $a\in \Bbb N $, $ 2^{3a -1} + 5 . 3^{a}$ is divisible by $ 11$   My attempt:  Part a:  I am not sure what the base case should be.  Induction hypothesis: Assume $ 2^{3k -1} + 5 . 3^{k}$ is divisible by $ 11$, for some $k$ natural number.   I am not sure how to prove true for $ 2^{3(k+2) -1} + 5 . 3^{k+2}$.  Part b:  Would statement 2 be correct since the expression is divisible by $11$ when $ a=2$


What are the differences between a clustered and a non-clustered index?


how can I force the task to use the first value and not the second value. This is a simpler example of code that has become a problem for me.         static void Main(string[] args)         {                        string testString = "1 value";            Task.Factory.StartNew(() => PrintStr(testString));            testString = "2 value";            Console.ReadLine();         }          static void PrintStr(string str)         {             Console.WriteLine(str);         }  In response I get "2 value" The problem is that I need to pass a string to the task, after which this string will be changed and I cannot guarantee. that the task will receive the correct information. I have a collection of posts, for each post I create a task and I need to pass the html markup in a string variable. For each step of the loop, this variable will change, and therefore I cannot be sure that the task will receive the correct data. Sample code: foreach(var uid in uids) // collection of messages {   message = imapClient.Inbox.GetMessage(uid);   var htmlData = message.HtmlBody.ToString();   tasks.Add(Task.Factory.StartNew(() => someHandle(htmlData));    }  void someHandle(string data) {  //some code to handle the message  }


I installed the MATE GUI on my server so that I could use remote desktop to test some things. It worked fine, but I don't want it it running all the time. It just bothers me to have  running when I don't need them 99.9% of the time (and possibly never will again).  How do I disable MATE without uninstalling it? Preferably keep it disabled until I want it (i.e. not start on system startup).


Does OpenSSH SFTP server use umask or preserve client side permissions after put command (chrooted environment)?

I know this question has been already discussed, but by reading the posts I could not figure the answers, because some said "yes umask can work", and others say "OpenSSH put command always preserve permissions"   Before all just to precise:   I use OpenSSH 5.9 on RHEL 6.2 I have configured a chrooted SFTP server, using internal-sftp subsystem, with -u 0002 for umask I precise I don't use the -p or -P option   From what I have read on one hand: there are many ways to define umask for SFTP transfers:   option -u of internal-sftp (or sftp-server) , since OpenSSH 5.4 create a wrapper to sftp-server (in which we explicitly set the umask - this doesn't fit for chrooted environment btw) add a specific configuration in pam.d/sshd file   On the other hand I have read:     The OpenSSH SFTP client and server do transfer the permissions (as an   extension) and create the remote file with the permissions on the   local side. AFAICT, there is no way to disable this behavior.   So I did the following test:   On my client I created file MYFILE and directory MYDIR with permissions 600 and 700.  Then with sftp commands:  mkdir => the new directory has permissions following the umask (OK) put MYFILE => MYFILE has same permissions as on client (KO) put -r MYDIR => MYDIR has same permissions as on client (KO)   If I change permissions of MYFILE and MYDIR on client side, and upload again, I get the new permissions on server side.  I tried the pam.d solution too, but it changed nothing.  So now I'm confused :  From what I tested and a part of what I read, I would say OpenSSH always preserve permissions. But as there are many posts saying that a umask could be defined, I can imagine I do a wrong thing in my test configurations.  I would appreciate some experienced feedback.  Thank you.


I'm doing a rest GET callout to an external open database. But I'm getting max size limit error. I know this error is due to 12 MB Heap Size limit.  I'm getting the data from "CPSC Recalls Application Program Interface (API)"  I want to know, what should be my approach to handle the error or reduce the size of data returned from the database.


I'm a Ukrainian, so when I try to download update for Ubuntu (for example by Terminal) or some programs via the vanilla store, then connection gets aborted. It happens because the Ukranian goverment has passed a law that blocks the Russian node in Ubuntu CDN. What can I do to avoid it? For example, is there any way of changing my default node?


Picard wants Tea, Earl Grey, Hot! - How does the computer know how hot "hot" is?

On Star Trek: The Next Generation, Captain Jean-Luc Picard wants his tea "!" How does the computer know exactly how hot to make it? For instance, I'm drinking my tea at 50-55c right now, but some people like it at 60 or even 70c which is just too hot for me. How hot is Picard's tea?


"any further doubts" or "any further doubt"

If you were to ask Harry what was in the bottle, he would tell you that it contained perfumed mud. If you expressed doubt or surprise, he would immediately invite you to smell it and then to rub some into your skin. This brief experiment would dispel any further doubts you might have.   Generally, the word after "any" is singular.Such as:     Any large American city is filled with restaurants serving international cooking.   Can anyone tell me why it uses the plural form? Does it mean that both singular or plural form are correct?


If $x_{n}$ is decreasing and $\sum x_{n}$ converges, prove that $\lim nx_{n} = 0$

I need a little hint in a proof on convergence of a sequence. The problem I have is: Suppose $(x_n)$ is a monotone decreasing sequence of real numbers such that $\sum x_n$ converges, prove that:  $$\lim_{n \to \infty} nx_n=0$$  My idea is: proving this fact aims to prove that given $\epsilon >0$ there's some natural $n_0 \in \mathbb{N}$ such that if $n >n_0$ we have $|nx_n|<\epsilon$.  Now, I know that $\sum x_n$ converges, so that given $\epsilon'>0$ there's some $k_0 \in \mathbb{N}$ such that if $k > k_0$ we have:  $$\left|\sum_{i=1}^{k}x_i - S\right|<\epsilon'$$  Where $S = \sum x_n$. Now, since $(x_n)$ is monotone decreasing we know that we must have $x_1 > \cdots > x_k$ so that the sum of all $x_i$ should be less or equal to $k x_k$. So I know that I have:  $$\left|\sum_{i=1}^{k}x_i - S\right|\leq\left|\sum_{i=1}^{k}x_i\right|+|S|\leq|kx_k|+|S|$$  I feel that the proof will come from this, however I'm stuck at this point. Can someone give just a little hint on how to proceed from here?  Thanks very much in advance for your help.


I installed Redhat 6 x86_64. I am using the Network connection screen to set a static IP address like below (I want two PC's in my house to see each other: one Redhat PC and one Mac)   192.168.0.5   255.255.255.0   192.168.0.1     When I run ifconfig it displays only lo and virbr0 information. I don't know what these items are (I don't really know much about network settings).   When I try ifconfig -a it displays eth0, lo, sit0 and virbr0. The information for  eth0 is as follows:   Link encap : Ethernet HWaddr 90:2B:34:74:05:30 BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:192 errors:0 dropped:0 overruns:0 frame:0 TX packets:6 errors:0 dropped:0 overruns:0 frame:0 collisions:0 txqueuelen:1000 RX bytes 53811 (52.5 KiB) TX bytes:468 (468.0 b) Interrupt:29 Base address:0xc000   Could someone help me to point out if anything wrong with my setting or how to resolve this problem?


How small does a land-mass have to be before you live "on" it, rather than "in" it?

I'm sure virtually everyone agrees that people live on the Isle of Wight, but in Ireland.  Apparently the usage depends somewhat on physical size, but that can't be the whole story. How exactly do we decide which form to use? And are there any really glaring 'outliers' that don't fit the normal pattern?  LATER - I must just add that the most uncertain case I've found so far is The Falklands. Most people go for in there, but a substantial minority (about 1 in 3) opt for on.


Everytime I hit a rate limit (doing legitimate things) I am slapped in the face two times:   I have to wait The timer will reset each time I try   I will concede that there must be a reason for timer resets. The team would not have added them without reason.  Feature request: No timer resets for users with >= 1000 rep. Even better, increase all rate limits by dividing the minimum interval by 5 or so. Show the timer ticking down.  The probability that a high rep user is engaging in vandalism is extremely low. Let's stop punching them in the face.


Why can a neutral pion decay into 2 photons but not one?

Hi Sorry if this is a simple question I just can't seen to get my head at what law is being violated due to a neutral pion decaying into a photon (I have an inclining its to do with 4-vector momentum however that further makes the neutral pion decaying into 2 photons less sense to me.) If anyone could help that would be great, thanks!


The injectivity of $f\mapsto f\circ v$ on $\hom(M'',N)$ implies that $v$ is surjective

I'm an undergrad getting familiar with some notions of commutative algebra by reading Atiyah-McDonald. On the exact sequences part, a part of the proof of (2.9) is proving that if $\hom(M'',N)\xrightarrow{\overline{v}}$ is injective for all $N$ (where $\overline{v}(f)=f\circ v)$ then $v$ is surjective.   Any idea on how to prove this? Atiyah makes it seem obvious, I don't see why.


Is "NASDAQ to launch etc.." is a right usage?

I saw this title at a website:     What Crypto Winter? Nasdaq to Launch Bitcoin Futures Market: Report   It seems to me that there is a problem with this sentence. To my point of view, it should be : Nasaq is launching etc..  Is it a different meaning? There is a role for that? Thanks


I bought a new system with 4 GB of RAM. I don't know how do I check how much swap memory  I have allocated. I know that we can increase RAM physically. I want to increase swap memory on windows. How can I increase swap memory?  Is that possible?


How to get a pop alert on browser back button or reload button

I want to apply a alert pop on browser back button or reload button when exiting from current landing page (or switching from current page). ** I am using this code. <script> $(window).on('beforeunload', function() { var c = confirm();  if (c) { return true;  } else  return false;  });  </script>  Result: I am getting an alert popup on the browser back button after clicking on any hyperlinks or buttons on my current landing page. Looking for the result: An alert popup on the browser back button should come without clicking on any hyperlinks or buttons on my current landing page. Scenario ** : After landing on my desired page, if I clicked on the browser back button directly (without any click on the current landing page) then it should give me an alert pop (eg : content has not been saved, do you want to save it). Can someone please help me in that.


How to import a module given its name as string?

I'm writing a Python application that takes as a command as an argument, for example:  $ python myapp.py command1   I want the application to be extensible, that is, to be able to add new modules that implement new commands without having to change the main application source. The tree looks something like:  myapp/     __init__.py     commands/         __init__.py         command1.py         command2.py     foo.py     bar.py   So I want the application to find the available command modules at runtime and execute the appropriate one.  Python defines an __import__ function, which takes a string for a module name:     __import__(name, globals=None, locals=None, fromlist=(), level=0)      The function imports the module name, potentially using the given globals and locals to determine how to interpret the name in a package context. The fromlist gives the names of objects or submodules that should be imported from the module given by name.       Source:    So currently I have something like:  command = sys.argv[1] try:     command_module = __import__("myapp.commands.%s" % command, fromlist=["myapp.commands"]) except ImportError:     # Display error message  command_module.run()   This works just fine, I'm just wondering if there is possibly a more idiomatic way to accomplish what we are doing with this code.  Note that I specifically don't want to get in to using eggs or extension points. This is not an open-source project and I don't expect there to be "plugins". The point is to simplify the main application code and remove the need to modify it each time a new command module is added.


Is the Pauli group for $n$-qubits a basis for $\mathbb{C}^{2^n\times 2^n}$?

The Pauli group for $n$-qubits is defined as $G_n=\{I,X,Y,Z \}^{\otimes n}$, that is as the group containing all the possible tensor products between $n$ Pauli matrices. It is clear that the Pauli matrices form a basis for the $2\times 2$ complex matrix vector spaces, that is $\mathbb{C}^{2\times 2}$. Apart from it, from the definition of the tensor product, it is known that the $n$-qubit Pauli group will form a basis for the tensor product space $(\mathbb{C}^{2\times 2})^{\otimes n}$.  I am wondering if the Pauli group in $n$-qubits forms a basis for the complex vector space where the elements of this tensor product space act, that is $\mathbb{C}^{2^n\times 2^n}$. Summarizing, the question would be, is $(\mathbb{C}^{2\times 2})^{\otimes n}=\mathbb{C}^{2^n\times 2^n}$ true?  I have been trying to prove it using arguments about the dimensions of both spaces, but I have not been able to get anything yet.


What happens if an integer is raised to an imaginary power?

When I raise some integer to some imaginary power I obtain a complex number. E.g., $$2^i = 0.7692 + 0.6390i.$$ Why does this happen? What does it mean to raise an integer to an imaginary power?


Creating Advanced Search with text & Dropdowns

I am working to develop an advanced search option. Where there will be fields:    Text input Field (Post Title) Dropdown (it will be a taxonomy) Dropdown (it will be a taxonomy)   Basically I need this kind of search option. Please take a look at the image to better understand.   I am using the solution found  for searching taxonomies but I need to integrate the text field which will get data from Post Title field..


Dropping a question, and then just logging out and leaving

This is an etiquette and maybe even rules question.   I take the questions I ask seriously over at StackExchange. I form my question in an editor, I check for clarity and make edits, I take care to present my code nicely. I adhere to the idea that doing all that is like talking to the stuffed frog in the corner of the IT office analogy; I often see my own answer in my work while creating a conscientious question. I even wait to post it, and when I'm ready, it's like handing in a formal essay to me, like for grades.  The point is, it's enough of a big deal to me, and a rarity that I even post a question, that (and here's where I get to my point) ... that I stick around for five minutes, at least, me longer ... to see if anyone immediatey engages my question.  So, today ... a first time user, first question from them ever at stackexchange ... drops their fairly advanced question, upon which I engaged almost immediately. I found them an answer on the stack, and posted. I decided to explore the answer myself because I'm working with similar stuff myself, so was interested ... but did from the context of solving their problem.  I find that old answer has not just deprecated parts, but methods that don't even exist in the dependency anymore. So ... and this is now four hours later ... I post that the original answer is not cutting it, take a different path, and post the first time questioner my full code of how I do what they are trying, through a different approach.  Four hours later ... and not once had the asker engaged me. They walked across the office ... asked for help ... and while I engaged their problem, they promptly excused themselves and went for coffee. Just as I sat down and started to help them with their code. My first response was almost immediate. Four hours later, and more engaging ... first time questioner ... and silence. Nothing.  Four hours later ... in a void of silence ... I removed all my posts and code from over the four hours.  It may not be a rule ... but, as a social user, I reserve the right to take note of someone who does that; drops and leaves. I take my questions on stack exchange more seriously than that. So, I removed my answers.  What's the etiquette? What's the rule? (The two may not be the same, rule and etiquette.)


Using a Sony E mount lens on a Nikon body?

I was just wondering if it's possible to use a Sony E mount lens on the Nikon D3200 by using an adaptor? I recently got given a Sony lens for free so I dont want to get rid of it.


tcpdump shows traffic until I use a filter

I have a server that is receiving traffic from a mirror port on a switch. The interface that is connected to this mirror port is in promisc mode. When I use just a plain catch all tcpdump on the interface, like   tcpdump -nn -i eth1   I see a ton of traffic.  I can even grep this for certain things like, say, port 443.  tcpdump -nn -i eth1 | grep 443   obviously this shows anything that has a 443 in it, not just port 443. I have visually inspected it and I do see stuff like this:  15:08:08.112550 IP 12.34.56.78.1430 > 87.65.43.21.443: . ack 35124 win 32768   But I want just port 443 so...  tcpdump -nn -i eth1 port 443 ... 0 packets captured   Weird. I am not seeing any traffic when I use a filter. I have tried "ip port", "dst port", and a few other filters. I have also tried filtering by the IP instead of port. Nothing.  eth1      Link encap:Ethernet  HWaddr 00:24:81:A5:AD:7A             inet6 addr: fe80::224:81ff:fea5:ad7a/64 Scope:Link           UP BROADCAST RUNNING PROMISC MULTICAST  MTU:1500  Metric:1           RX packets:4114781478 errors:0 dropped:1 overruns:0 frame:0           TX packets:17 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:1000            RX bytes:2240970313430 (2.0 TiB)  TX bytes:15155497 (14.4 MiB)           Interrupt:98 Memory:fa000000-fa012800    This interface has seen a ton of traffic. And my filter is valid, right? Why do I not see anything?


How many times can you use a weapon in one round?

So I'm playing a D&D 5e homebrew campaign and while I was in a battle in one round I did this.   Move 15 feet (from basic 35 feet) Put my light crossbow away Drew a longsword with two hands (as a part of the attack) Attacked an orc with that longsword with two hands   I'm not sure how many times I can interact with an object and I searched the player's handbook and it only says that you can draw your sword as a part of the attack? And I'm not sure that you can put your crossbow away too.


Proof that $\lim_{n\to\infty}{\sin{100n}}$ does not exist

How to prove that $$\lim_{n\to\infty}{\sin{100n}}$$ doesn't exist?    Some possible approaches:   It would be enough to find two subsequences $n_{k}$ that converge to two different numbers. But it's not clear how to find $n_k$ so that $\sin 100n_k$ converge.  Show that $\sin (100(n+1))-\sin 100n$ does not approach $0$. This is not obvious, either.


How can I resize an LVM partition? (i.e: physical volume)

I want to shrink my second (LVM) partition, in order to create a new partition in the newly freed space. I am using the Live CD to do so, because I know I can't resize/move this partition while it is in use. When I opened GParted in the Live CD, I realized that I could not resize the partition, because when I right-click it, the option "resize/move" is disabled.  I tried to unmount it, to "lazy" unmount it (umount -l /dev/sda2) but it didn't work.  A screenshot from GParted:


jQuery doesn't respond after change of div content - delegated event handler

In my html document I use

 to import external content of calendar from .js file.  I want check  fields by add class with jQuery. In the ready table I can do this with...    $(window).load(function() {   $("td.available.cur-month").on("click", function() {     $(".current").removeClass("current");     $(this).addClass("current");   });   $("td.unavailable.cur-month, td.available.near-month").off(); });   ...and it goes fine. But when I change the month (by clicking  or ) jQuery method is stopping.  I didn't give up and I added to the JavaScript file...  function($) {   var plugin_name = 'calendar',   data_key = 'plugin_' + plugin_name,   defaults = {     modifier: 'datetimepicker', // wrapper class     day_first: 1,     day_name: ['Nd', 'Pn', 'Wt', 'Śr', 'Cz', 'Pt', 'So'],     month_name: ['Sty', 'Lut', 'Mar', 'Kwi', 'Maj', 'Cze', 'Lip', 'Sie', 'Wrz', 'Paź', 'Lis', 'Gru'],     unavailable: ['*-1-1'],     paging: ['', ''],     adapter: '',     month: null, // month of calendar = month in js + 1, month in js = 0-11     year: null, // year of calendar     num_next_month: 0, // number of next month to show     num_prev_month: 0, // number of prev month to show     num_of_week: 'auto', // number of week need to show on calendar number/auto     onSelectDate: function(date, month, year) {}, // trigger on select   };   ...the same lines of code like above and I get this (last lines of code):  onSelectDate: function(date, month, year) {   $("td.available.cur-month").on("click", function() {     $(".current").removeClass("current");     $(this).addClass("current");   });   $("td.unavailable.cur-month, td.available.near-month").off();   Now jQuery is working, but after the second click. It looks like jQuery doesn't work after change of the month and start when some of  is clicked.  What I have to do to have good working script?   I've used this ) and someone ask about this project here  but it was different case.


Convolutional networks: how to deal with duplicate filters?

I have to train a convolutional network. When I visualize its conv filter matrices from a layer, many filters are quite similar, almost equal.  1) Don't you know a common way to detect couples of similar kernels? Maybe, it is somehow connected with their correlation?  2) Don't you know any good strategies to deal with such duplicate kernels? My only offer is to re-initialize such duplicate with noise and continue the training, but I don't think it is the best idea.


How to make VIM settings computer-dependent in .vimrc?

I share my VIM configuration file between several computers. However, I want some settings to be specific for certain computers.   For example, font sizes on the high-res laptop should be different to the low-res desktop. And more importantly, I want gVIM on Windows to behave more windowsy and MacVim on OSX to behave more maccy and gVIM on Linux to just behave like it always does. (That might be a strange sentiment, but I am very used to switch mental modes when switching OSes)  Is there a way to make a few settings in the .vimrc machine- or OS-dependent?


I want to fit linear and nonlinear regression to my data (linear and logarithmic) in one graph. how can I do this with pgfplots?


I suggest that when a post is migrated from one site to another, that the question vote score get reset to zero (or perhaps only a negative vote score is reset to zero). Often people will downvote a question when the only thing that's "wrong" with it is that it's posted on the incorrect site. After migration, those downvotes hang around as a negative score and may unfairly bias the treatment of the question.


Getting details about a package before installing it?

When I type "mc" on my 14.04 Ubuntu terminal I get a   The program 'mc' is currently not installed. You can install it by typing: sudo apt-get install mc   How can I get details about the program 'mc' before installing it? I want to confirm that that is the file I want, and not some other one.


Rescue inaccessible VM without SSH in Google Cloud Platform

I made a mistake in the script of a service in my linux VM in Google Cloud Platform. Now the VM does not boot properly, and no ssh server starts.   Is there any other way to rescue this instance and its files, like, somehow edit files without starting the instance?  Maybe somehow download a snapshot and use some tool to edit?


Effect of humidity on removing excess charge from objects

The usual answer to the question "why electrostatic discharge happens more often on dry days" is that water - due to its polarity - has the tendency to remove the excess charge.  But I do not understand how exactly does it happen since water is an insulator, not a conductor. Are electrons from charged objects shuffled from one water molecule to another, until they reach the ground? If they could do so, then pure water would conduct electricity - but it does not. Perhaps individual water molecule collect excess electrons and move away from the object, staying in H2O- state? Or is it because ion-containing water (i.e. minerals, salts and other impurities) condenses on the charged, non-conductive objects and creates a thin layer of conductivity? But the answers usually refer to the conductivity of the air, not the objects in question. Maybe the ions present in the air conduct the electricity? If so, then why question (and answers) refer mostly to the polarity of water?


I have a simple table like:  \documentclass[varwidth]{standalone} \usepackage[table]{xcolor} \usepackage[english]{babel} \usepackage{multirow}  \begin{document}     \begin{center}         \renewcommand{\arraystretch}{1.9}         \begin{tabular}{cc}             \cellcolor[rgb]{0.0,0.5,1.0}Unsolvability & \multirow{2}{*}{ \cellcolor[rgb]{0.91,0.91,0.91}Chapter 7}\\             \cellcolor[rgb]{0.0,0.5,1.0}Relaxation & \cellcolor[rgb]{0.91,0.91,0.91}\\         \end{tabular}     \end{center} \end{document}   But the output is not what I exactly wants since the background color covers the cell's text.    How should I fix this?


If $\sum_{n_0}^{\infty} a_n$ diverges prove that $\sum_{n_0}^{\infty} \frac{a_n}{a_1+a_2+...+a_n} = +\infty $

I've tried to use the limit test: $\lim_{n \rightarrow \infty} \frac{a_n}{b_n} = C$ in the series of $a_n$ and $\frac{a_n}{a_1+a_2+...+a_n}$ but it was inconclusive.  The question does not especify the sign of $a_n$ but proving it for positives would already help.  I think the sign can change as long as the partial sums never get to be zero. Like if the series has only negative numbers the result seems to stil hold.


How to Align Multiple Pluses accross Multiple Lines?


Does LaTeX support including a specific part of an \input, like a specific environment and ignoring everything else?

Can LaTeX natively include only specific expressions from an input file (ignoring the rest)? I am not sure how to best word my question. Below is an example of what I'd like to do.  Situation  For example, let's say I have many files with all kinds of code, but each one shares something in common, a summary environment.  I decide to create a document that contains summaries of all of the other documents. For a meaningful document, I need to get the name of the input file and include only the following code from the input:   \begin{summary} A bunch of text. \end{summary}   Here is a sample file structure:  Documents/   JimsAdventures.tex   CrazyGorilla.tex   BrightHorizon.tex   MoonLanding.tex   Summaries.tex <-- includes summaries of all other tex files and their file names   It would be great if Summaries.tex could automatically detect new files in the Documents folder such that it is completely automated (obviously that is a bonus and not really a criterion for the question).  I know this is possible with scripting languages by calling a shell script with the --shell-escape option combined with \immediate\write18 or \include{|myscript.sh}, but is this possible natively in LaTeX?    UPDATE June 30, 2015  Solution based on Werner's suggestion:  LaTeX does support this feature with the catchfilebetweentags package. What it does not support is getting a list of files (e.g. within the same folder) to input automatically (unless the only change between file names is a number: in which case you can use a sequence see ) .   To avoid using --shell-escape and maintain an OS-independent workflow, it is possible to achieve the same thing by creating a separate file (e.g. Documents.txt) that contains the names (or paths depending on whether you want to reconstruct paths with a macro or not) of the documents (stories). To have Summaries.tex automated, you can reference this file (e.g. Documents.txt) instead of having LaTeX generate it with --shell-escape + external script. Of course, 100% automation would require a system that runs a pre-compilation script that collects all of the tex files you want to include and spits them out into Documents.txt beforehand.  see


Why it causes this "Undefined control sequence" after "\lt"

I got this error in using pdflatex:  ! Undefined control sequence. l.6 \(1.5 \lt               x \lt 5.5\) ?  ! Undefined control sequence. l.6 \(1.5 \lt x \lt                     5.5\) ?    The tex-file is:  \documentclass[preview,border=2pt]{standalone} \usepackage{amsmath} \usepackage{tikz}  \begin{document} \(1.5 \lt x \lt 5.5\) \end{document}   The sequence "\lt" should represent "<" symbol. But it causes the error. Should I add some additional packages?


How to make inductive step for a Fibonacci proof

I have to prove $F^2_{n−1} = F^2_n + F^2_{n−1}$ for any $n >=1$ by induction (for the Fibonacci sequence).  For the basis step, I have:  $n = 1; $  $F_{(1)-1} = F^2_{(1)} + F^2_{(1)-1}   ->$  $ 1 = 1^2+ 0$  As the base case holds, we can then assume that $n=k$:  $F_{2(k)-1} = F^2_{(k)} + F^2_{(k)-1} $  Next, this has to be proven for k + 1:  $F_{2(k+1)-1} = F^2_{(k+1)} + F^2_{(k+1)-1} $  I know that you have to somehow used the statement derived on the LHS of the equation in the previous step ( i.e. $F_{2(k)-1}$ ) when proving for $k+1$, but I'm not really sure how to apply the logic here since I've normally seen it used in cases where there is a summation on the LHS.   I currently have worked this out:  $F_{2(k+1) - 1} = F^2_{k + 1} + F^2_{(k+1) -1} ->$  $F_{2k + 1} = F^2_{(k+1)} + F^2_k$  and with some manipulation (I was thinking), you could factor out the $F^2$ from both terms on the RHS resulting in this:  $F^2_{(2k +1)}$, but even after doing this, the term on the LHS is:$F_{2k + 1}$ so even though both sides are similar, they differ by the squared term on the LHS.   Is my logic wrong in the inductive step? If so, how should I go about the proof?


Was the expansion after the big bang faster than the speed of light?

I think it's called Planck time and it's the speed at which matter spread during the big bang. Was the big bang expansion faster than the speed of light?


Want to shape this spiderman lens around the Faceshell so it fits perfectly against the shell

Was wondering if someone can help me. I want ti be able to bend this lens around the spiderman faceshell so that it sits flush with the shell. I have tried shrinkwrap and adding depth after but it looks horrible. Any ideas please?  Thanks


I need to show that if $n=2\phi(n)$, then $n=2^j$, where $n,j\in\mathbb{N}$.  I have a strong feeling that this can only be shown by contradiction. Therefore, I assumed that both $n=2\phi(n)$ and $n\neq2^j$. Then if we let, say, $n=5$, it follows that $5=2\cdot\phi(5)=8$, which is a contradiction. Hence, it must be the case that $n=2^j$.  Is this a valid proof?


Another holographic hot stamping material

Hi, How do I get the holographic hot stamping effect like this?  I've tried few setup but non of them look a like. Please help....


Do children inherit their parents' powers in the X-Men universe?

In the X-men universe, when two mutants have a child, does the child inherit their parents' powers? If this is the case, does the child inherit only one parent's power or both, or do they develop their own separate power?


logged on today and my activity tracker suddenly changed to this:     but....    still about 40 away from even getting awarded the grammar badge.  Don't know what the tracker is thinking.


Carrying television in flight from Germany to India

I have searched on the airline websites, but however have not found a concrete answer to my question which is: if I were to take my 55" TV along with me from Germany to India, will the airlines allow this as a checked luggage? If yes, how much would the cost for such a transport be.  Hope someone can throw some light on this.


I ma having an uneasiness about the use of the preposition of and from. I decided to ask when I saw . So that, am I correct to understand, according to , and , when of is used, we refer to the direct cause such as cancer, heavy headache (if there were such thing). But when from is used, we refer to the (rather) indirect cause, such as poverty, weather condition (which is to me questionable.) Am I correct to understand this in this way?


Convert audio stream to WAV byte array in Java without temp file

Given an InputStream called in which contains audio data in a compressed format (such as MP3 or OGG), I wish to create a byte array containing a WAV conversion of the input data. Unfortunately, if you try to do this, JavaSound hands you the following error:  java.io.IOException: stream length not specified   I managed to get it to work by writing the wav to a temporary file, then reading it back in, as shown below:  AudioInputStream source = AudioSystem.getAudioInputStream(new BufferedInputStream(in, 1024)); AudioInputStream pcm = AudioSystem.getAudioInputStream(AudioFormat.Encoding.PCM_SIGNED, source); AudioInputStream ulaw = AudioSystem.getAudioInputStream(AudioFormat.Encoding.ULAW, pcm); File tempFile = File.createTempFile("wav", "tmp"); AudioSystem.write(ulaw, AudioFileFormat.Type.WAVE, tempFile); // The fileToByteArray() method reads the file // into a byte array; omitted for brevity byte[] bytes = fileToByteArray(tempFile); tempFile.delete(); return bytes;   This is obviously less desirable. Is there a better way?


Formal proof of $\exists x \forall y P(x,y) \implies \forall y \exists x P(x,y)$

Say that the variables $x,y$ of a predicate $P$ are taken from some non-empty set. It is clear that the following statement is true. How should a formal proof look?  $$\exists x \forall y P(x,y) \implies \forall y \exists x P(x,y)$$


Extinction probabilities of binomial tends to Poisson distribution

I am stuck on exercise 11.2 From Grimmett's  probability on graphs. Here is a  to the pdf on his website.     Consider a branching process whose family-sizes have the binomial distribution bin$(n, \frac{\lambda}{n})$. Show that the extinction probability converges to $\eta(\lambda)$ as $n \rightarrow \infty$, where $\eta(\lambda)$ is the extinction probability of a branching process with family-sizes distributed as $\text{Po}(\lambda)$.   To solve this exercise, we use a theorem from his other book, which states that if you have a branching process whose family sizes are $X$ distributed then the extinction probability of this branching process is the smallest non-negative fixed point of the equation $s = G(s)$ where $G$ is the probability generating function $G(s) = \sum_{k = 0}^\infty \mathbb{P}(X = k)s^k$.  My next step was computing these probability generating functions for $\text{bin}(n,\lambda)$, these are $G_n(s) = (1+\frac{\lambda( s -1)}{n})^n$. When the family sizes are Poisson distributed with parameter $\lambda$ we get $G(s) = e^{\lambda(s-1)}$. and so clearly $G_n$ converges pointwise to $G$.  This however is not enough, as we want to show that the extinction probabilities also converge, so we have $s_n$ extinction probabilities of the $n$-th process, i.e. $s_n$ is the smallest non-negative solution to $s = G_n(s)$, and we want to show that this converges the smallest non-negative solution of $s = G(s)$. I hoped I could use some theorem which states that if you have pointwise convergence then the fixed points also converge, but this is false, see this .  During writing this I thought of an attempt to solve this using Hurwitz theorem, namely, show that the smallest non-negative fixed point of $G(s)$ is smaller than 1, then show that the function $G'$ is complex differentiable with non-zero derrivative, use inverse function theorem, get an open neighbourhood of our fixed point, find sequence of fixed points which converge to the smallest non-negative fixed point $\eta(\lambda)$ of $G$. Here I am stuck trying to show that $s_n$ are the smallest non-negative fixed points of $G_n$.     How to proceed?


I killed my first wife once I found out there is a mercenary you can marry who gives you up to 300 gold a day (in Whiterun). The only requirement, of course, being that I had to hire her first. So I hired her, and then I popped the question, to which she replied the usual: tell the priest to arrange the wedding.   When we reached Riften I told her to wait, just outside the bee and barb, and arranged the wedding. I went through the process, and the second it finished she left, I followed but as I left she was nowhere to be seen. I have tried going back to my house, the pub where I hired her and that same spot in Riften about 6 times each now, some during the day, some during the night and cannot find her at all.   Now this isn't to much of a problem because I can re-marry...oh wait, to remarry, my spouse has to die, so I can't claim gold off her and can't remarry, and the autosaves have been used up fast travelling to the places I thought she might've been. My last save is something like 6 levels ago, and I don't want to have to load it.   What should I do about this situation?


Why is v.v accessible if MyTest is not a parent-class of Val?  public class MyTest  {     public static void main (String args [])     {         ValX v = new ValX ();         System.out.println ("A: " + v.v);  // is working, why?     } }   public class ValX extends Val { }   public class Val  {     protected float v = 11; }   EDIT  I learned about the visibility of proteced within the package. Thats the reason. thanks!  Is there a way I can make v only visible to parent-classes without moving it to another package?


Can anyone tell me what make or brand this frame is?

I can't figure out who made this or what brand maker it is. It has the serial number and on top of it it has a different number.  G0Q230-2 Wbdo26l0431p


I know that there's a difference between relativistic and rest mass. Relativistic mass is "acquired" when an object is moving at speeds comparable to the speed of light. Rest mass is the inherent mass that something has regardless of the speed its moving at.  When fusion happens, a certain percentage of the rest mass of two hydrogen atoms is converted into energy. I understand that $E = m_{rest}c^2$.   How does the rest mass of an object turn into energy? Does this involve particle physics? Doesn't this suggest that rest mass can be viewed as some sort of potential energy? It seems to me that it's a sort of locked energy that has to undergo a certain process to expel its energy to surrounding particles.  Also, Why does only a small percentage of rest mass turn into energy? Why not all of it. What dictates how much rest mass gets converted into energy?


How I can run .exe file with monodevelop, without running it through compiler?

So I have monodevelop.  I can run .exe file (in my case PC steam guard authenticator) How I can run it without going to program itself?  Can I somehow 'emulate' it?    I just want to get rid of that 'Run debugging' thing... Thanks for help.


I've used Ubuntu a few years ago and got a error regarding a Password. I never had a password for this computer, but it really said I did and I tried and tried to get it corrected.... I finally gave up I bought the last 64 bit cd-- and when I pulled it out, it had a sractch on it... I don't want to buy another.  I've downloaded the iso file!    I unzipped it and burned it to a DVD  but I can't get it to boot the computer???  what am I doing wrong? This is the third time I've burned it!  I need help aj


6 LEDs in parallel with a single resistor to simplify soldering

I'm trying to wire up 6 RGB LEDs in parallel, all controlled from a single source (well, three sources, one for each colour). The LEDs came supplied with resistors to limit the current of 270 Ohm for a 5v supply.  The problem is, 6 LEDs x 3 colours = 18 resistors, which is a lot, and means I need a much bigger board and a lot more soldering.  So, can I instead wire the LEDs in parallel with each other, with a single resistor protecting all six? (3 resistors in total, one for each colour). How do I calculate the value of that resistor?  More details:  The LEDs are being driven from a  to supply a bit of current, which is in turn controlled by a Netduino providing a PWM signal on the three channels.  . If I've correctly understood the data sheet they want 20mA of current, and forward voltages of 2, 3, 3 volts (for R,G and B respectively?). The supplied resistors were all 270 Ohm, so the channels may not be balanced quite right.  For extra credit: I'm only using 3 of the transistors in my driver chip, which has 8 in total. could I wire the PWM from the netduino to a second trio of transistors, and split the LEDs into two groups of three? Is it worth the effort?  PS I don't have any diagramming tools to hand, but I can provide a diagram (drawn in paint) if it would help clarify my question. (see also )


Complex structure on $\mathbb S^1 \times \mathbb S^3$

Apparently there is a complex structure on $X = \mathbb S^1 \times \mathbb S^3$ but I have no ideas why. Any hints ?


Looking at my dmesg output I see (among others) the following in red:  [   11.880554] kvm: disabled by bios [   11.911578] kvm: disabled by bios   … and a little further down:  [ 4816.264697] [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun [ 4816.266824] [drm:intel_set_pch_fifo_underrun_reporting [i915]] *ERROR* uncleared pch fifo underrun on pch transcoder A [ 4816.266844] [drm:intel_pch_fifo_underrun_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun   Should I be worried / take any action with regards to the above messages? The computer is a refurbished Lenovo T420 I just bought.


I ordered a CD from an online music store. My confirmation email reads "your order has shipped." English is not my first language, and this strikes me as odd. Shouldn't it be a passive-voice sentence, i.e. "your order has been shipped"?


I was evaluating  RabbitVCS as replacement  of RapidSVN to connect to my SVN repository on Ubuntu server.   This what I did on my 12.04   Opened the Ubuntu software centre Searched for RabbitVCS-Core and RabbitVCS-nautilus. They were listed. Installed both of them and they are successfull installed.   Then,    I used the dash home to see if I can find these programs. Opened Home folder and right clicked on certain folders which was checked out using Rapid SVN. I could not find any options to use RabbitVCS in nautilus from here. I restarted my machine and repeated both process again.   So How can I use RabbitVCS?   Am I seeing everything as it is expected or some thing weird?


If an elephant can apply 250N force and a rabbit can apply 25N force , and if they are pulling each other , then elephant will pull with 250N force and according to newtons third law the rabbit should also pull the elephant with 250N force.then from where do the rabbit got the extra 225N i.e.(250-25=225) force??? can anyone please explain.


Chat message duplication filter is over-aggressive

, I wanted to post a link to a question, followed by a relevant YouTube video. Because I wasn’t paying attention, I posted the video first by mistake. No problem. I edited the existing comment to be the question instead, and then posted the video. Except that it wouldn’t post: nothing happened at all when I tried. I think it was the duplicate message filter preventing me from repeating myself, even though the previous message had been edited, I posted a nonsense message, then the YouTube video, then deleted the nonsense. This worked, but should not have been necessary.


"Windows was unable to complete the format" when trying to format HP USB flash drive?

I have a 2 GB HP flash drive, when  I right click and select the format option , I get a warning dialogue that says       Windows was unable to complete the format   How do I format a flash drive?


How to remove the function hooked to action within a class

I want to remove the function listify_single_job_listing_meta which is hooked in action inside the following class  class Listify_WP_Job_Manager_Template extends listify_Integration {      public function __construct() {         $this->includes = array();         $this->integration = 'wp-job-manager';          $this->is_home = false;          parent::__construct();     }       public function setup_actions() {                 add_action( 'listify_single_job_listing_meta', array( $this, 'single_job_listing_meta' ) );     }    public function single_job_listing_meta() {         do_action( 'single_job_listing_meta_start' );          do_action( 'single_job_listing_meta_end' );          }      }   I am using the following code in functions.php  global $myclass; $myclass='Listify_WP_Job_Manager_Template'; remove_action( 'listify_single_job_listing_meta', array( $myclass, 'single_job_listing_meta' ) );   But this is not giving me the desired result . Please help


How can I use ffmpeg to isolate one channel from an audio file? I have a stereo audio file, and I need the output to be the contents of the right channel in a mono audio file.  While I'm sure it's fairly easy to do, I can't figure it out. Thanks for the help!


How do I find additional free repositories for Ubuntu 18.04 LTS?

I'm new to Linux. I'm running Ubuntu 18.04 LTS and I want to find additional open source free software packages available for installation.  I tried to add other software sources to the Ubuntu Software applications but after a lengthy process of updating the available applications by downloading updates, the new software repositories don't show and I have the exact same packages available as I always had. I used a repository list generator website to find the URL for the repositories to add.  Obviously I'm doing something stupid? I don't think I yet fully understand how repositories work despite much reading about it. Is it like having multiple Windows Stores? Or multiple Android Google Plays???  Thanks in advance for any help at all which would be greatly appreciated.  johnnym


How to add Rhythmbox controls to the sound menu?

I recently installed a fresh install of Ubuntu 11.10 64-bit on my notebook.   I personally prefer Rhythmbox over Banshee so I searched for and installed it from the Ubuntu Software Center. (including all plugins that were listed). Unlike previous versions of Ubuntu (11.04, 10.10, etc..) the (previous, play/pause, next) controls have been removed from the sound menu. Rhythmbox is still listed (above "Sound Settings...") but when clicked all it does is open the application. To add insult to injury the Banshee controls are displayed right above it - even though that application isn't running.   I have tried opening Rhythmbox from the Unity dashboard, the Unity launcher, and the sound menu with the same results. I've also verified that I had rhythmbox-plugins installed. I even tried to remove and install the application. Still no controls.    It looks like they were removed and that we are now expected to use Banshee. Why?  Here is a screenshot of what my sound menu looks like when I'm playing a file in Rhythmbox. (Notice that Banshee isn't running but it's controls are displayed) In Ubuntu 10.10 and 11.04 Rhythmbox had controls just like Banshee's controls in the screenshot.


When do we double the consonant before '-ing' affix?

My son is learning how to spell. He is doing a good job listening to sounds and working out spelling that way (which doesn't work for many words, but at least a lot of common ones), but although he's gotten the -ing chunk, he frequently misses doubling letters in these words.  Is there a guideline for when the end consonant is doubled? He's working on these sorts of words:        riding   sitting   skating   writing   getting


I'm trying to update from ubuntu 12.10 lately but I keep getting the "Failed to fetch" error.  W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/quantal-security/Release  Unable to find expected entry 'independent/binary-amd64/Packages' in Release file (Wrong sources.list entry or malformed file)  W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/quantal/Release  Unable to find expected entry 'independent/source/Sources' in Release file (Wrong sources.list entry or malformed file)  W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/quantal-updates/Release  Unable to find expected entry 'independent/binary-amd64/Packages' in Release file (Wrong sources.list entry or malformed file)  W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/quantal-backports/Release  Unable to find expected entry 'independent/binary-amd64/Packages' in Release file (Wrong sources.list entry or malformed file)  E: Some index files failed to download. They have been ignored, or old ones used instead.   I changed the server and deleted the source lists from /var/lib/apt/lists/ like some answers say but still. This is really annoying.


How to disable special history editing on bash command line

The letter g at the end of a path entry in either Terminal or iTerm2 is being captured and processed - I think by bash.  Here is what typing cd /git/ciderg looks like:  Notice the g is not typed.  If I type ESC it does show:  But if I hit g again it looks like some kind of history editing happens: a command from way long ago is posted and replaces the command I was typing It seems that gg is being something like History | Go to beginning .  How do I disable that? I had already removed the ~/.vimrc  and ~/.vim directory.  I do use set -o vi but that had been working for years - and without this strangeness.


I need to create a data transfer object, which I will use for storing the records retrieved from database. In this data transfer object, I need to declare a numeric field. For that which one is better - int or Integer  If I am defining the field as Integer, will there be any performance impact because of 'Integer' type if I am going to retrieve more than 2000 records from DB!?  Thanks in advance.


Manuscript revision deadline: how strict are these [at Scientific Reports]

I am a Ph.D. student and presently dealing with my first paper that I had submitted to Scientific Reports.  I received back the reviewer comments together with a note from the editor asking me (as the first author) to revise and resubmit within 4 weeks (exact wording below*). However, my coauthors and I will likely not be able to finish the revision in time (there are only a few days left), and I am wondering how strictly editors stick to these deadlines, and if they are typically likely to close the submission altogether, or rather happy to accept the revision even sometime later. The editor him/herself would obviously be the best person to ask, however, I am not getting a reply to my request for an extension, and I would need to know soon whether to drop everything and just work crazy hours to get the revision to them in time.      We hope to receive your revised paper within four weeks. If you cannot send it within this time, please let us know so that we can close your file. In this event, we will still be happy to reconsider your paper at a later date as long as you haven’t submitted similar or related work elsewhere in the meantime.


Windows executables are started with archive manager

I have Wine installed and several Windows applications installed there run fine, if I start them using the right mouse menu "Open with Wine program loader". But if I try starting an .exe file by just double clicking instead, the archive manager tries to open the executable.  How do I fix that?  And something like a bonus question as a former Windows user: Can this be done easily for a single file I currently see in the file manager (similar to the "Open with..." context menu in Windows) and for many file types together (like in Windows, using the menu "Folder settings" in the Explorer)?


Have temporary editing bans for rejected edits been removed?

I've done a fair number of reviews this morning, and have repeatedly rejected one particular user's edits as they've been very minor (i.e., changing "i" to "I" and adding newlines). So far, I've rejected at least 10 edits from this user.  My question is, why is this user still able to edit anything?  According to the answers and information from previous (albeit, outdated) questions, including  and , indicate that after a certain number of edits, users are barred from editing, yet after many rejections from myself alone, all in the last couple hours, this user is still editing posts as I write this question. So far, he's almost hit the rep cap today for edits alone, no other contributions (he has received 168 rep so far today), likely from other reviewers accepting his minor edits.  Is there still a limit on the number of rejected edits you get before you're barred from editing? If not, why was it removed, and is there a possibility that it can it be added back in?  Edit: According to Bart in the comments, the edit ban is still active, so I guess a more appropriate question is what is the new limit for bans or how is it calculated?


How to resolve "InnoDB data dictionary has tablespace id N"

I recently messsed up a migration to table-per-file for my dbs. In the end I (thought) I dropped all dbs, deleted any left over files, and then started over from scratch, importing only dbs I needed as I went.  However, today I find loads of these in my log:  InnoDB: Error: table 'db/table' InnoDB: in InnoDB data dictionary has tablespace id 384, InnoDB: but tablespace with that id or name does not exist. Have InnoDB: you deleted or moved .ibd files? InnoDB: This may also be a table created with CREATE TEMPORARY TABLE InnoDB: whose .ibd and .frm files MySQL automatically removed, but the InnoDB: table still exists in the InnoDB internal data dictionary. InnoDB: Please refer to InnoDB: http://dev.mysql.com/doc/refman/5.5/en/innodb-troubleshooting-datadict.html InnoDB: for how to resolve the issue.   Going to the URL, I find near the end.   If this occurs, try the following procedure to resolve the problem:      Create a matching .frm file in some other database directory and copy it to the database directory where the orphan table is located.      Issue DROP TABLE for the original table. That should successfully drop the table and InnoDB should print a warning to the error log that the .ibd file was missing.   What does "Create a matching .frm file" mean? Since it directly speaks of creating a "file", I would assume this is something like touch [file], but then it doesn't make any sense that I should copy it from one directory to another.  I tried it anyway and mysql complained about the table not existing, so that's not it.


Here is what I know/proved so far:  Let $c_0\subset\ell^\infty$ be the collection of all sequences that converge to zero. Prove that the dual space $c_0^*=\ell^1$.  $Proof$: Let $x\in c_0$ and let $y\in\ell^1$. We claim that $f_y(x)=\sum_{k=1}^\infty x_ky_k$ is a bounded linear functional. Clearly $f_y$ is bounded since $$ |f_y(x)|=\left|\sum_{k=1}^\infty x_ky_k\right|\le\sum_{k=1}^\infty |x_k||y_k|\le||x_k||_\infty\sum_{k=1}^\infty |y_k|=||x_k||_\infty||y||_1. $$ We can also easily see that $f_y$ is linear. Let $x,z\in c_0$ and $y\in\ell^1$ then $$ f_y(x+z)=\sum_{k=1}^\infty (x_k+z_k)y_k=\sum_{k=1}^\infty (x_ky_k+z_ky_k)=\sum_{k=1}^\infty x_ky_k+\sum_{k=1}^\infty z_ky_k=f_y(x)+f_y(z) $$ and for $\alpha\in\mathbb{R}$ $$ f_y(\alpha x)=\sum_{k=1}^\infty \alpha x_k=\alpha\sum_{k=1}^\infty x_k=\alpha f_y(x). $$  Let $\varepsilon>0$ and since $y\in\ell^1$, we know that $\sum_{k=1}^\infty |y_k|$ converges. So there exists $N\in\mathbb{N}$ such that whenever $n>N$ we have  $$ \sum_{k=n}^\infty |y_k|<\varepsilon. $$ Now define the following sequence $x=\{x_k\}_{k=1}^\infty$ as $$ x_k=\begin{cases} \operatorname{sgn}(y_k),&\,k\le N\\ 0, & \,k>N \end{cases}. $$ Thus $x\in c_0$ and   $$ \begin{align} \left|f_y(x)-||y||_1\right|&=\left|\sum_{k=1}^\infty x_ky_k-\sum_{k=1}^\infty |y_k|\right|\\ &=\left|\sum_{k=1}^N\operatorname{sgn}(y_k)y_k-\sum_{k=1}^\infty |y_k|\right|=\left|\sum_{k=1}^N |y_k|-\sum_{k=1}^\infty |y_k|\right|=\left|\sum_{k=N+1}^\infty |y_k|\right|<\varepsilon. \end{align} $$  So we conclude that \begin{equation} \ell^1\subseteq c_0^*. \end{equation} Observe that the above argument also establishes that $||f_y||_*=||y||_1$.  Now let $f$ be any linear functional on $c_0$ and let $\{e_k\}$ be the sequence with a 1 in the $k$-th position and zero elsewhere. Then for any $x\in c_0$ we have $$ |f(x)|=\left|f\left(\sum_{k=1}^\infty e_kx_k\right)\right|=\left|\sum_{k=1}^\infty f(e_k)x_k\right|\le\sum_{k=1}^\infty |f(e_k)|\,|x_k|\le||x||_\infty\sum_{k=1}^\infty |f(e_k)|. $$ Since $f$ is a bounded functional, we must have $\sum_{k=1}^\infty |f(e_k)|$ converging, otherwise $f(x)$ would be unbounded. Thus $\{f(e_k)\}_{k=1}^\infty\in c_0$ and we conclude that  \begin{equation} c_0^*\subseteq\ell^1.  \end{equation} Thus (1) and (2) tell us that  $$c_0^*=\ell^1.$$    QUESTIONS: If we take $c$ to be the collection of sequences that converge to some real number and $c^*$ to be it dual space, I know that $c^*=\ell^1$ as well, but I am not sure how to prove it. Is it enough to observe that if $x\in c$ and that $x\to x'$ then $x-x'\in c_0$, therefore they have the same dual space? I am a little fuzzy here, obviously.  Also, can someone clean up my align environment. I can't figure out how to make it compile properly. The code looks fine on my LaTeX implementation, but it doesn't work here.


Prove that $\text{aff}(X) = \text{aff}(\text{closure}(X))$

I am trying to prove that the affine hull of a set $X \subseteq \mathbb{R}^d$ is equal to the affine hull of the clojure of that set: $$ \text{aff}(X) = \text{aff}(\text{cl}(X)). $$  Proving $\text{aff}(X) \subseteq \text{aff}(\text{cl}(X))$ is easy, but containment in the other direction is harder.  I am assuming there is a sequence $\{ x_k \}_{k=1}^\infty \subseteq X$ such that $\lim_{k\to \infty} x_k = x^*$. The point $x^*$ is obviously contained in $\text{aff}(\text{cl}(X))$. But I am not sure how to show it is also in $\text{aff}(X)$, specifically because I am not sure how to show that $x^*$ lies on a line connecting two points in $X$.  Any suggestions on how to surmount this hurdle are welcome.


I just updated to 18.04, and facing a slow boot I ran the following:  $ systemd-analyze blame          14.760s dev-sda5.device          13.228s systemd-journal-flush.service          12.607s dev-loop1.device          12.537s dev-loop0.device          12.486s dev-loop2.device          12.453s dev-loop4.device          12.423s dev-loop3.device          12.375s dev-loop6.device          12.344s dev-loop7.device          12.331s dev-loop5.device          12.299s dev-loop8.device          12.279s dev-loop10.device          12.263s dev-loop9.device          12.223s dev-loop11.device          10.228s apparmor.service           9.953s systemd-udevd.service           9.155s NetworkManager-wait-online.service           7.387s plymouth-quit-wait.service           4.037s udisks2.service           4.001s snapd.service           3.950s NetworkManager.service           2.964s plymouth-start.service           2.906s ModemManager.service           2.809s accounts-daemon.service           2.756s grub-common.service           2.045s networkd-dispatcher.service           1.852s avahi-daemon.service           1.791s thermald.service           1.274s wpa_supplicant.service           1.224s keyboard-setup.service           1.082s fwupd.service   and next  $ lsblk NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT loop0    7:0    0  86.6M  1 loop /snap/core/4486 loop1    7:1    0    21M  1 loop /snap/gnome-logs/25 loop2    7:2    0   140M  1 loop /snap/gnome-3-26-1604/59 loop3    7:3    0 162.9M  1 loop /snap/spotify/16 loop4    7:4    0 124.3M  1 loop /snap/thunderbird/3 loop5    7:5    0   1.6M  1 loop /snap/gnome-calculator/154 loop6    7:6    0   3.3M  1 loop /snap/gnome-system-monitor/36 loop7    7:7    0  12.2M  1 loop /snap/gnome-characters/69 loop8    7:8    0 299.9M  1 loop /snap/pycharm-professional/68 loop9    7:9    0   198M  1 loop /snap/vlc/365 loop10   7:10   0 139.4M  1 loop /snap/chromium/343 loop11   7:11   0   4.9M  1 loop /snap/canonical-livepatch/41 loop12   7:12   0  86.6M  1 loop /snap/core/4650 loop13   7:13   0   3.7M  1 loop /snap/gnome-system-monitor/41 loop14   7:14   0   2.3M  1 loop /snap/gnome-calculator/170 loop15   7:15   0  14.5M  1 loop /snap/gnome-logs/34 loop16   7:16   0    13M  1 loop /snap/gnome-characters/96 loop17   7:17   0 139.5M  1 loop /snap/gnome-3-26-1604/64 sda      8:0    0 465.8G  0 disk  ├─sda1   8:1    0   248G  0 part /media/foo/4afaaee5-473b-41c9-acd0-506a3566fcf5 ├─sda5   8:5    0 201.9G  0 part / └─sda6   8:6    0  15.9G  0 part [SWAP] sr0     11:0    1  1024M  0 rom   It appears that my main device takes 14 seconds (not sure if that's a lot), but then all these loop devices (snaps?) add up a lot of time too. Is that normal behavior? Is there any other way to reduce boot time other than uninstalling them?


How to combine fill and pattern in a pgfplot bar plot?

Is it possible to combine a TikZ pattern with a background of a chosen color?  \addplot[black,fill=yellow,pattern=north east lines] ...   yields bars which have black stripes on white (transparent?) background, whereas  \addplot[black,pattern=north east lines,fill=yellow] ...   yields bars which are plain yellow with not stripes at all. Any chance of getting tiger-like bars (black stripes on yellow) without defining an inherently-colored pattern by hand?


Let $k^p = k$, $K = k(x)$ and $F = k(u)$ for some $u \in K$. Show that $K/F$ is separable $\iff u \not\in K^p$.

Let $K$ be the rational function field $k(x)$ over a perfect field $k$ of   characteristic $p > 0$. Let $F = k(u)$ for some $u\in K$, and write   $u = f(x)/g(x)$ with $f$ and $g$ relatively prime. Show that $K/F$ is   a separable extension if and only if $u\notin K^p$.   There is already a post on this but it has not yet been answered :   The truth is that I am very confused with this problem, I would like someone please help me to understand what happens with this exercise and explain to me how it could be done by giving me a help or something. I already have an approach for the left-to-right implication, but I do not know very well how good it is. Could someone help me with the other implication please? Thank you very much.


Do gods keep their +1/+1 counters if they stop being creatures?

Do counters added to a god with  disappear when the god stops being a creature?  Scenario:  is a creature (due to devotion reaching the required amount) and Gleam of Battle is also on the battlefield. Then Purphoros attacks and gets a +1/+1 counter for attacking. If my devotion to red then drops below 5 and Purphoros is no longer a creature, would the +1/+1 counters stay on him or will he reset to his original power/toughness level?  My thinking is when he becomes an enchantment he loses it due to the fact that he is no longer a creature and that his power and toughness are technically not there and so he gets remade into being a creature only when devotion is high enough.


Does Eldritch Knight grant 2 Cantrips known in addition to a High Elf's knowing 1 to begin with?

Starting as a High Elf lets me know a single wizard cantrip at level 1. By the time I hit level 3 and get my archetype, Eldritch Knight, I am supposed to know 2.   I'm just a bit confused on whether this would mean 2 overall, or 2 in addition to the High Elf starting cantrip, meaning 3 known cantrips at level 3.


Unable to install Ubuntu on motherboard GA-H97M-D3H

As a new member of this Ubuntu forum, I say greetings to you all! I cannot consider myself much of an advanced Linux guy, but I do prefer it over Windows in my work desktop PC. Which is very sad for me to find out that Ubuntu won't install or even run from live USB. Here's a few screenshots of my PC spec and BIOS settings:          What I've tried:   Creating bootable USB from mac with unetbootin, which makes the USB bootable only through UEFI. GRUB shows up upon booting, but choosing install Ubuntu or try live session ends up with blank screen. Creating bootable USB from Windows with rufus, the USB is now bootable through Legacy. Upon booting, an Ubuntu/Gnome splashscreen shows up about 2-3 seconds, then an empty terminal about another 3 seconds before going blank again. Tried with fast boot on and off. Same results. Tried with secure boot on and off. Same results. Tried with 4GB and 8GB flashdisk. Same results. Tried Ubuntu Gnome 14.04 and 16.10. Same results.   At this point, I ran out of solution to make it work. I notice the official  implying that Linux won't work with my motherboard, but I have had successes installing on my other PCs with similar warning. As of now, I have to live with Windows, which I hope will not be for long as I am optimistic about the prospect that Linux users like you guys will always make things work.  Thank you and good day to you all.


I am trying to install prodigal.   I downloaded it and extracted it in a particular location and in terminal I when I used the command:  make Install   After reaching that location it showed error:  install -d -m 0755 /usr/local/bin install -m 0755 prodigal /usr/local/bin install: cannot create regular file '/usr/local/bin/prodigal': Permission denied Makefile:43: recipe for target 'install' failed make: *** [install] Error 1   I also tried to change the INSTALLDIR in the make file and then wrote make install. It made a directory(from home to prodigal) in the prodigal folder itself and again error came like  install -d -m 0755 /usr/local/bin install -m 0755 prodigal /usr/local/bin   Do I need to change something else in make file?


Add packages (application) to my ubuntu based distro

I am creating an ubuntu based distro, and I want to add an ubuntu app to it so it is available for use straight away when the user installs the iso. I was just wondering how to go about this. Any help is greatly appreciated.


will a correlation between a percentage variable and a numerical variable work?

I am trying to conduct a simple correlation analysis between a group of variable, however I have a number of these variables in percentage change (or percentage yield) form and the others in strictly numerical prices. I was wondering whether it is possible to find the correlation coefficients between a percentage variable and a numerical variable?  I have tried with the data as it is as well as with all variables in some percentage return format with varying results, hence my current confusion!  The data I am working with relates to the prices of stocks, gold etc and the percentage yield/change of bonds and CPI %change.  Any help would be greatly appreciated!


find duplicate records based on multiple fields

I have a large amount of duplicate records (25.000) in an even larger table (250.000 records). I've done the detection using the reporting function. The criteria I used to detect the duplicates were 3 fields (unique account identifier, unique user identifier and date). Based on a list of criteria, I would like to either merge or delete these records. I've got a handle on the logic associated with the merging and the deleting but what I'm having trouble with is defining the duplicate detection process.   I'm looking at either creating a custom object to take care of the detection or dumping the records into an SQL database and taking care of it offline. Any thoughts on which one of the two is the best approach?  Edit:  After reading the first comment, I think the more appropriate question would be "How do I approach the problem in SOQL".  The object I'm working with is the Event object and I'm really only looking at the standard fields, AccountId, OwnerId and ActivityDate. From what I've found online, there's no easy way to find records that have the same value for these three fields. I think it could be accomplished by nesting SOQL queries but I'd like to use a different approach if at all possible.


The simple equation that decides whether you get question banned or not is:  (total questions - negative score questions - closed questions)/total questions >= 0.5   And closed questions probably includes deleted questions too. For example, a new user asks a question, and the question gets:   Downvoted, stays at negative score Deleted before 30 days from posting time Closed   The equation above would not work as:  (total questions - negative score questions - closed questions) < 0.5   Which means question ban. But that is way too early to get banned. It seems that the user has to reach a certain number of questions or rep or time for the above equation to be implied towards the user. I have a small grip on the subject myself. So when does the question ban equation get applied?


Why is $C_v$ used in the derivation of the adiabatic equation?

For any adiabatic process $P$,$V$ and $T$ change while $dQ=0$. By first law of thermodynamics,  $$dQ=dU+dW$$  That is, it becomes  $$dU+dW=0$$  At this stage, we set   $$dU=C_v dT$$  Any further calculations are on this basis. If, in an adiabatic process, volume is not constant, then why do we write the above equation?


How to change group for apache user in Fedora

I have directory project in home directory and symlink to it in /var/www/html  And I can't open files because got error 403, I set the Group in httpd.conf to kuba (my main user/group)  run systemctl restart httpd but simple php script like this:  <?php echo exec("id"); ?>   Display:  uid=48(apache) gid=48(apache) groups=48(apache) context=system_u:system_r:httpd_t:s0   I've also tried to add apache to kuba group but with no effect. How can I make apache run as group kuba?  I'm using this in my httpd.conf  <Directory "/var/www/html">     Options Indexes FollowSymLinks Includes ExecCGI     AllowOverride All     Require all granted     Allow from all </Directory>   UPDATE After few reboots, because of installation of VirtualBox, I got this from php script:  uid=48(apache) gid=48(apache) groups=48(apache),1000(kuba)  context=system_u:system_r:httpd_t:s0   but the php script in localhost/projects still return 403 error. I don't see any SELinux errors but just in case I've executed setsebool -P httpd_enable_homedirs 1 as in here


How can I backup everything on an android?

I have a redmi note 5. It has been asking for updates for a while, which I have been postponing. The reason is that my previous phone, a huawei, got locked into bootloop when I did update it, so I have been weary.  But since I'm starting to cave, I was wondering if there was a way to backup absolutely, utterly everything on the phone, to the point of being able to flash it if I have to, load the data again, and end up holding the exact same phone I did before all that.


Can I take a photo with blurred background with Samsung s5 for a subject far by 2 metres of the lens? and what is the specific distance for manual focus for a 16 megapixel mobile phone lens to take a blurred background picture for someone ?


Suddenly the dopesheet acting weird. I click at a certain place, but the yellow straight line isn't at the place I clicked. If I locrot a bone, the keyframe was created not at the yellow stragiht line. I type the end frame of 150, but the playback stop before 150. How to fix this?


Recovering a accidently deleted file in Ubuntu

I'm using ubuntu 9.10 and accidently deleted a specific file within a directory on my system. I checked in the Trash bin and could not locate the file. I deleted it 10mins ago, are there any tools available that I can recovery this file? It's a really important file.  Any help would be highly appreciated  My partition is ext4


How Can I Tell the Day of the Week of a Date?

I'd like to build in some logic based on the weekday (e.g. Monday, Tuesday, Wednesday) of a given date.  How can I identify the date, using either formulas or Apex code?


My past answers being downvoted out of revenge?

I've recently had a stream of downvotes without comment on a number of my answers. I personally feel these answers are of objectively good quality and I fear I am being targeted out of spite.  Could someone please investigate?              I'm not sure who it is but the only person I've gotten into a tif was recenlty on this question, where I felt the answer was misleading and didn't answer the question.


Why is Java disabled in Chrome? Is it some security concern?  From the official :     Chrome no longer supports NPAPI (technology required for Java applets)   The Java plug-in for web browsers relies on the cross platform plugin architecture NPAPI, which has been supported by all major web browsers for over a decade. Google's Chrome version 45 (scheduled for release in September 2015) drops support for NPAPI, impacting plugins for Silverlight, Java, Facebook Video and other similar NPAPI based plugins.   But does anyone know why? How could it be dangerous for Chrome users with the latest version of the Java JRE installed?


My friend's iPhone's sleep/wake button no longer works. Is there any way to turn off the screen besides setting up auto-lock and waiting a few minutes?


Proof of this fairly obscure differentiation trick?

Suppose we're tying to differentiate the function $f(x)=x^x$. Now the textbook method would be to notice that $f(x)=e^{x \log{x}}$ and use the chain rule to find $$f'(x)=(1+\log{x})\ e^{x \log{x}}=(1+\log{x})\ x^x.$$  But suppose that I didn't make this observation and instead tried to apply the following differentiation rules:  $$\frac{d}{dx}x^c=cx^{c-1} \qquad (1)\\ \frac{d}{dx}c^x = \log{c}\ \cdot c^x \quad (2)$$  which are valid for any constant $c$. Obviously neither rules are applicable to the form $x^x$ because in this case neither the base nor the exponent are constant. But if I pretend that the exponent is constant and apply rule $(1)$, I would get $f'(x)\stackrel{?}{=}x\cdot x^{x-1}=x^x.$ Likewise, if I pretend that the base is constant and apply rule $(2)$ I obtain $f'(x)\stackrel{?}{=}\log{x}\cdot x^x$.  It isn't hard to see that neither of the derivatives are correct. But here's where the magic happens: if we sum the two “derivatives” we end up with $$x^x+ \log{x}\cdot x^x=(1+\log{x})\ x^x$$ which is the correct expression for $f'(x)$.  This same trick yields correct results in other contexts as well. In fact, in some cases it turns out to be a more efficient way of taking derivatives. For example, consider $$g(x)=x^2 = \color{blue} x\cdot \color{red} x.$$ If we pretend the blue $\color{blue} x$ is a constant we would get $g'(x)\stackrel{?}{=}\color{blue}x\cdot 1=x$. Now if we pretend the red $\color{red}x$ is constant we get $g'(x)\stackrel{?}{=}1\cdot \color{red} x=x$. Summing both expressions we end up with $2x$ which is of course a correct expression for the derivative.  These observations have led me to the following conjecture:     Let $f(x,y)$ be a differentiable function mapping $\mathbb{R}^2$ to $\mathbb{R}.$ Let $f'_1 (x,y)=\frac{\partial}{\partial x} f(x,y)$ and $f'_2 (x,y)=\frac{\partial}{\partial y} f(x,y)$. Then for any $t$ we have: $$\frac{d}{dt}f(t,t)=f'_1 (t,t) + f'_2 (t,t).$$   (I apologise for the somewhat awkward notation which I could not seem to get around without causing undue ambiguity.)  This formulation also seems to lend itself to following generalisation:     Let $f:\mathbb{R}^N \to \mathbb{R}$ be a function differentiable in each of its variables $x_1,x_2,\ldots,x_N$. For $n=1,2,\ldots,N$ define $f'_n(x_1,x_2,\ldots,x_N)=\frac{\partial}{\partial x_n}f(x_1,x_2,\ldots,x_N)$. Let $t$ be any real number and define the $N$-tuple $T=(t,t,\ldots,t)$. Then one has: $$\frac{d}{dt} f(T)=\sum_n f'_n(T).$$   Thus my question is:   Is this true? How can it be proven? (Specifically in the case $N=2$ but also in the general case.)


How can i track down how is these files created

How can i track down what command or how is all these files being created?  My server is always occupied 100% of its storage. and I've checked my another instances which don't have these files.   52.7 GiB [##########] sys1.sys 23.3 GiB [#### ] sys5.sys 14.9 GiB [## ] sys4.sys 9.2 GiB [# ] sys.sys 8.4 GiB [# ] sys8.sys 8.4 GiB [# ] sys3.sys 8.4 GiB [# ] sys2.sys 3.7 GiB [ ] sys7.sys 1.9 GiB [ ] sys6.sys   I got this from ncpu.  -rw-r--r--   1 root root    9892426060 Apr 28 09:00 sys.sys -rw-r--r--   1 root root   56626016256 Apr 28 09:04 sys1.sys -rw-r--r--   1 root root    9007920576 May  3 06:32 sys2.sys -rw-r--r--   1 root root    9007920576 May  3 06:32 sys3.sys -rw-r--r--   1 root root   16010560576 May  3 06:34 sys4.sys -rw-r--r--   1 root root   25013200576 May  3 06:35 sys5.sys -rw-r--r--   1 root root    2005040576 May  3 06:36 sys6.sys -rw-r--r--   1 root root    4005280576 May  3 14:11 sys7.sys -rw-r--r--   1 root root    9007920576 May  3 14:12 sys8.sys   Is there a way to validate my install of Centos of find out the files not belong to etc?


Can metamagic be acquired at first level?

In D&D 3.5, can I acquire a metamagic feat at lvl 1? I'm wondering this because I am playing a cleric and would like to get Empower spell to increase my healing to my party


I want to install apps on internal sd card but instead all apps get installed on phone storage which is low in memory


How many questions and answers are asked in one day at Stack Overflow?

I was wondering how many question and answers are posted each day at Stack Overflow?  I have gone through , but I didn't get a perfect answer.


OS Update moved external_sd to extsdcard; Apps previously on SD card are now missing/uninstalled.

I just upgraded my Galaxy Note (1st gen) from ICS 4.0.x to JS 4.1.2. I'm using the Samsung ROM supplied by my carrier (with all the bloat in it). After the upgrade, I noticed many of my apps were missing (the ones installed on the SD card), as well as my photos/videos and personal files (previously stored in sdcard/external_sd/DCIM/...).   So I checked various parameters, and using a file explorer, I found out that all the sdcard/ contents moved to storage/sdcard0, and the sdcard/external_sd moved to storage/extSdCard. I found my personal files, and my photos/videos, but the apps previously installed on the sdcard are no longer installed. Also, the gallery app doesn't detects the photos taken before the upgrade.  Can someone enlighten me about why my SD Card apps are missing/uninstalled?


$\lim\limits_{x \to 0} \frac{\tan(mx)}{\tan(nx)} =$?

I've tried by writing it as $\tan(m x) \cot(n x)$, but I couldn't really continue from there.


Achieve manager like view of compressed files in Terminal

If I can, I will avoid using the GUI to get around my system, and recently what I have found very annoying is that I seem unable to view the contents and open the contents of a compressed file without decompressing like the GUI application Achieve manager seems to manage to do, although I suspect that it temporarily decompresses the contents of the compressed file into another location and then allows you to browse the contents of the compressed file without having to decompress the contents first into the directory that you are in.  So what I am wondering is if there is any way that I can in Terminal view the contents of a compressed file without actually having to decompress it into a location myself (so that I can get a Terminal view of what Achieve manager does without having to launch a GUI)?


How to detect network disconnection from client side(JAVA)

I have written java client server socket connection code. In that the server accepts the client connection, then the server sends the data using PrintStream , and client reads the data in readline(). After this, the client will wait for the server in readline. If there is a network disconnection, the client keeps waiting in the readline and never exits from readline. Is there is a way to detect the disconnection from client side itself? Or whether I have to write new heartbeat thread to check network disconnection?


If $X_n$ is a martingales with $sup E|X_n|^p<\infty$ where $p>1$, How can show that $$E^p|X_n|\leq E |X_n|^p$$


What is the difference between Canon "L" lenses and non-L lenses?

The Canon L lenses are much more expensive and presumably much better quality than non-L lenses. What makes an "L" lens? How much better are they over a similar length/speed "ordinary" canon lenses?


If your document use itemize a lot of time, you are likely to get fed up putting \begin{}...\end{}. Is there any better way to do this? Something like a org mode of emacs use or lyx use?


Mail Server problem sending mails to external domains

Recently I have setup a mail server with Postfix, Dovecot and Squirrelmail on Ubuntu cloud server. The server has static ip address with proper MX record(mail.mydomain.net). When I send mail to Google its going to Spam and I should mark as not spam and yahoo is not at all receiving. Is there anything apart from Static ip and MX record to validate my domain name so that all external domains receive mails sent from my mail server without any problem?. Please need help...


Why have all the "Have you considered accepting an answer or starting a bounty for this question?" reminders disappeared in my list of questions?

I remember seeing red messages like these when I look at my list of questions:  Have you considered accepting an answer or starting a bounty for this question?  But I have not seen these (annoying) reminders recently. Did I gain a new privilege that would explain why I no longer see these red reminders when I look at my list of questions?


The question is simple. I'm having problems dealing with signs and square roots in my computations, I guess the problem comes from my reasoning but what's wrong here?  $$i = \sqrt{-1} = \sqrt{\frac{1}{-1}} = \frac{1}{\sqrt{-1}} = \frac{1}{i} = -i.$$  I usually tend to keep all signs in the numerator. Do you think I should keep them together with the quantity they came from? (Numerator or denominator). What do you suggest to avoid discrepancies.  Thanks in advance.


Question regarding having a 21 day long stay in the Netherlands first, then studying in France

I have faced a question regarding application for visa for traveling to Europe in order to study there. I would be grateful to receive guidance on this.  I have been admitted to a European master program. Right now I am in Iran and I should travel to the Netherlands on August to participate in an introduction program and then move to France to take part in the first semester of the program. The second semester is going to be held in Hungary starting in February. My coordinator at the French university has asked me to start the application procedure for a visa for France while I am supposed to first enter the Schengen area in the Netherlands. Is it going to be ok? I've already asked about this from the Netherlands embassy in Iran and have been told that I should apply for a visa for my main destination (France) but they didn't say whether it would ok to enter the Netherlands by flying directly from Iran and without traveling to France first (while I am issued a visa for France).


Inherit the permissions on to the subfolders

I want to create a directory, for instance testing-data on CentOS 6.5 Linux version, and have read,write,execute to all the sub-folders and sub-sub-folders and files within them to everyone(all users), not to any specific group. In fact, whenever a new file is written into any of these sub-folders without using chmod 777 the new file should be able to be accessed by any user.   Is this possible?


Let $f$ be a Riemann-integrable function on a closed interval $[a,b] \subset \mathbb{R}$. Let g be a function on $\mathbb{R}$. What conditions must g satisfy so that $g \circ f$ is also Riemann-integrable ? Thank you!


When a proper noun is converted into a verb, should it be capitalized?

If a proper noun (e.g. Google) is converted into a verb (e.g. Let me (G/g)oogle that for you), should it still be capitalized when used as a verb? I recognize that English has no such concept as a "proper verb," but writing a brand name like Google in lower case seems odd to me.


fiber text in paragraph is printed in pdf as ber in latex "fi ïs eliminated how to fix it.   In paragraph fiber is displayed as ber in pdf, how to fix it.  \documentclass[12pt,a4paper,oneside]{article} \begin{document} \thispagestyle{empty}  \section{Introduction} connectivity, which can be either X-DSL or ﬁber.  \end{document}


My machine can't play encrypted DVDs on a fresh install.  How do I add this capability?  Another useful bit of information would be what programs are best for playing DVDs, once I'm able to do so.  See the .  Will I be able to play DVD movies from ?


Would a caster know whether casting Remove Curse on a lycanthrope born that way was unsuccessful?

I have a player that's a born lycanthrope (weretiger), that was bitten by a known werebear.  one of my other players is planning on casting remove curse on them.  Would the caster know that the spell was unsuccessful, or would it be a "weird feeling", or would it be a "find out at the next full moon" thing?  The reason for the question is that the other players don't know that this character is a born weretiger.  This player is waiting for an exciting moment or something to unveil their weretigerness and would prefer me to not give anything away, however I don't want to possibly change how remove curse works.  If the caster knows it didn't work i can phrase it so they're just confused, until the unveiling of the weretiger, but if they didn't know if it worked then there's nothing to worry about.


What are some good books on group theory?

I want to self-study group theory.  Does anyone have good recommendations for me?


$Y^\varnothing$ has one element; if $X \ne \varnothing$, then $\varnothing^X = \varnothing$

From Section 8 of Halmos' Naive Set Theory.     (i) Show that $Y^\emptyset$ has exactly one element, namely $\emptyset$.   (ii) Show that if $X\neq\emptyset$, then $\emptyset^X=\emptyset$.   I'm not completely sure I understand what this means nor how to prove it.  For (i), we want to show that the set of functions $f:\emptyset\to X$ is exactly $\{\emptyset\}$. To me, this means that there is one "map", the "empty map", which associates nothing to something. I'm not really sure how to show this. We know that $Y^\emptyset\subseteq\mathcal P(\emptyset \times Y)=\{\emptyset\}$. Then we can show that $\{\emptyset\}\subseteq Y^\emptyset$ to obtain the equality. So this is vacuously true?  For (ii), since $X\neq\emptyset$, to me this exercise means that we're showing that there are no maps which associate something to nothing. But how to show that there is no function $X\to\emptyset$? Is this just immediate from the definition of function?


I want to make an all out Mage character in Skyrim... No weapons or armor (except for Mage attire). What class would be best for this way of playing?


Connect monitor of a defective laptop to desktop PC

Possible Duplicate:        Is it possible to connect my laptop's LCD screen to my desktop PC? If so does anyone know of  a good tutorial for this?  I'd like to use my laptop's screen as a secondary monitor on my desktop PC. My laptop is dead and I was hoping to put it's screen to good use rather than throw it out. By dead I mean that it just won't boot at all. I believe that either the motherboard or the chip is fried and I don't have the $$$ or time to replace them.


What order were Lord Voldemort's horcruxes made in?

In what order and when were Voldemort's Horcruxes made? I found a list with . But not creation date.


Find the value of k, (if any), for which the system below has unique, infinite or no solution.

The system of equations are:  $\begin{cases}x+y+kz = 1\\x+ky+z=1\\kx+y+z=1\\ \end{cases}$  I am looking to finding values of $k$, for which this system has either no solutions, infinite many solutions or a unique solution (if any).  I've had a look around the web for some help, and know that this question has been asked, but in a way that I have not yet learnt (something to do with determinants I think).  However, I have only been working with reducing the matrix to REF/RREF and thus I'm trying to find rows, such as $( 0 \ 0 \ 0 \mid 2)$ and $( 0 \ 0 \ 0 \mid 0)$ etc to show if we have no solutions or infinite many solutions, for instance.  So far, I've got the following:  $\left[\begin{array}{ccc|c}1&1&k&1\\1&k&1&1\\k&1&1&1\end{array}\right]$  Then, $R_2$$\mapsto$$R_2-R_1$  $\left[\begin{array}{ccc|c}1&1&k&1\\0&k-1&1-k&0\\k&1&1&1\end{array}\right]$  Then, $R_2$ $\leftrightarrow$ $R_3$   $\left[\begin{array}{ccc|c}1&1&k&1\\k&1&1&1\\0&k-1&1-k&0\end{array}\right]$  This is where I got stuck, and I'm not sure how to continue.  Thank you in advance, and I'm sorry if this question has been asked and solved in the same way as presented above.  Cheers.


Find the integral $\int_0^\infty \mu^x / \Gamma(x + 1) dx$

Basically, I'm looking for advice on how I could find the value of $$\int_0^\infty \frac{\mu^x}{\Gamma(x + 1)}dx $$ where $\mu > 0$ is an arbitrary positive constant. Based on the infinite series, I was initially expecting this to be something close to $e^\mu$ (if not exactly that). However, numerical experiments have convinced me that this is a flawed assumption unless $\mu$ is relatively large. I'm happy to push on the problem myself --- I'm just a bit unsure where to start. P.S. For context, I'm an applied statistician trying to force through an unorthodox probability distribution for data-efficiency reasons. Thanks in advance!


where have all my decorations gone?  I had decorated 12 levels yesterday morning.  When I went back to check my game that afternoon I only had one that was decorated... whats going on?