I'm trying to pass multiple argument to a function, but one of them is consist of two words and I want shell function to deal with it as one arg:  args=("$@") function(){  echo ${args[0]}  echo ${args[1]}  echo ${args[2]} }   when I call this command sh shell hi hello guys bye  I get this  hi  hello  guys   But what I really want is:  hi  hello guys bye

Or, an introductory guide to robust filename handling and other string passing in shell scripts.  I wrote a shell script which works well most of the time. But it chokes on some inputs (e.g. on some file names).  I encountered a problem such as the following:   I have a file name containing a space hello world, and it was treated as two separate files hello and world. I have an input line with two consecutive spaces and they shrank to one in the input. Leading and trailing whitespace disappears from input lines. Sometimes, when the input contains one of the characters \[*?, they are replaced by some text which is is actually the name of files. There is an apostrophe ' (or a double quote ") in the input and things got weird after that point. There is a backslash in the input (or: I am using Cygwin and some of my file names have Windows-style \ separators).   What is going on and how do I fix it?


I used to have access to two different app store accounts. My own, personal one and another that belonged to a client I worked with. I had to use that client's account a lot and AFAIK you can't configure an iOS device to remember multiple logins, so I would often install apps I already owned from their account.  I no longer work with that client and, at some point, they changed their password. Now, when I try and update those apps, it challenges me for a password. I could understand this if these were apps I don't have on my own account, but I do.  Deleting and re-installing these apps fixes the problem. But there are some apps I'd prefer not to delete because I want to keep local content.  I'm presuming I might be able to get round this by hooking up my iOS devices to my PC and backing them up with iTunes. Then deleting and reinstalling the apps. However, I'm not sure this will work. I also hate iTunes with a vengeance and would prefer not to use it if at all possible.  Will this work if I try it? Or is there any other way I can get my apps to update?

My daughter was using my Apple ID with her Ipad mini. I want her to use her own Apple ID now that she is old enough. How can we transfer the content of her ipad mini, ( music, photos, apps) particularly game apps WITH THEIR DATA onto her new account? She doesn't want to start from scratch with all her games.


I am struggling to find an explicit bijection $\mathbb{N} \times \mathbb{N} \to \mathbb{N}$ when $\mathbb{N}$, by definition, includes $0$. If $\mathbb{N}$ were to exclude $0$, I could note that any positive integer can be written uniquely in the form $2^{a-1} (2b - 1)$ and then map $(a,b) \to n$. Including $0$, I have to change $a - 1$ to $a$ and $2b - 1$ to $2b + 1$, but I still run into the issue of what to map to $0$. I can't map $(0,0)$ to $0$, for example, because $2^{0} (2(0) - 1) = 1$ is the unique element of the form $2^{a-1} (2b - 1)$ mapping to $1$. Does anyone have any tips for how to repair this bijection?

Towards the end of , how do I get  $$ \frac{\sqrt{8z + 1} - 1}{2} < w + 1 $$  Here $w = x + y \geq 0, t = (w^2 + w)/2 , z = t + w, x,y \in \mathbb N_{\geq 0}$.  Thanks.


I am trying to to override a binding in a child injector that was already configured in a base injector.  like that :   public class PersistenceModule extends Abstract{      @Override     protected void configure() {         bind(IProductPersistenceHelper.class).to(ProductPersistenceHelper.class);     } }   then :   Injector injector = Guice.createInjector(new PersistenceModule()); injector.createChildInjector(new AbstractModule(){         @Override         protected void configure() {             bind(IProductPersistenceHelper.class).to(MockProductPersistenceHelper.class);         }  })   Guice is complaining that it has already a binding for that. Are there any patterns or best practices for that problem ?

I've just started playing with Guice, and a use-case I can think of is that in a test I just want to override a single binding.  I think I'd like to use the rest of the production level bindings to ensure everything is setup correctly and to avoid duplication.  So imagine I have the following Module  public class ProductionModule implements Module {     public void configure(Binder binder) {         binder.bind(InterfaceA.class).to(ConcreteA.class);         binder.bind(InterfaceB.class).to(ConcreteB.class);         binder.bind(InterfaceC.class).to(ConcreteC.class);     } }   And in my test I only want to override InterfaceC, while keeping InterfaceA and InterfaceB in tact, so I'd want something like:  Module testModule = new Module() {     public void configure(Binder binder) {         binder.bind(InterfaceC.class).to(MockC.class);     } }; Guice.createInjector(new ProductionModule(), testModule);   I've also tried the following, with no luck:  Module testModule = new ProductionModule() {     public void configure(Binder binder) {         super.configure(binder);         binder.bind(InterfaceC.class).to(MockC.class);     } }; Guice.createInjector(testModule);   Does anyone know if it's possible to do what I want or am I completely barking up the wrong tree??  --- Follow up: It would seem I can achieve what I want if I make use of the @ImplementedBy tag on the interface and then just provide a binding in the test case, which works nicely when there is a 1-1 mapping between the interface and implementation.  Also, after discussing this with a colleague it would seem we'd head down the road of overriding an entire module and ensuring we have our modules defined correctly.  This seems like it might cause a problem though where a binding is misplaced in a module and needs to be moved, thus possibly breaking a load of tests as bindings may no longer be available to be overriden.


Are there 15pin VGA cables that don't have a screw connection on one end?  What are they called?

I guess I could imagine that there was a time when accidentally disconnecting the monitor would have been catastrophic, though I don't see that being the case today.  Is it just a legacy holdover that they are still secured with screws?  Also, why is it that the video connection is really the only one that is still secured this way?  It seems like the power cable would be a better candidate to be secured with screws.  That really could be catastrophic.  In the end, the reason this question occurred to me is that I've never had a video cable come out when not screwed in, so why the significant security?


If I draw a line as follows:  \documentclass[article]{standalone} \usepackage{tikz} \usetikzlibrary{decorations.pathmorphing,calc,shapes,arrows,snakes,shapes.geometric,patterns,fadings} \begin{document} \begin{tikzpicture} \draw[very thick](0,0)--(1,0);   How can I draw the line so that the line starts as red but then fades into blue, I have tried  \documentclass[article]{standalone} \usepackage{tikz} \usetikzlibrary{decorations.pathmorphing,calc,shapes,arrows,snakes,shapes.geometric,patterns,fadings} \begin{document} \begin{tikzpicture} \draw[very thick,top color=red,bottom color=blue](0,0)--(1,0);   but it does not seem to do anything, any advice?

I want to draw arrow with two colors, the resulted arrow should be filled by one color at the top and by other color at the bottom, like the following code do to a rectangle:  \draw[top color=blue,bottom color=green] (0,0) rectangle (2,1);   What should I do?


How can you put text on top of a <picture> tag? so lets say you have:  <picture>   <source media="(min-width: 650px)" srcset="someotherimage.jpg">   <img class=" w-100 " src="someimage.j" alt="The Advocates   </picture>  So basically its a width 100% image that is supposed to work as a background image, but you want to add some text on top of it, kind of like floating on top of it. How can you do that? Lets say I do something like this:  <picture>   <source media="(min-width: 650px)" srcset="someotherimage.jpg">

Hello I am the text over the image

  </picture>  I know the code above wouldn't, but what would be the right way to do it?

I want to overlay one image with another using CSS. An example of this is the first image (the background if you like) will be a thumbnail link of a product, with the link opening a lightbox / popup showing a larger version of the image.   On top of this linked image I would like an image of a magnifying glass, to show people that the image can be clicked to enlarge it (apparently this isn't obvious without the magnifying glass).


I have   T1: USER_ID OSX        1     Y        2     Y    T2: USER_ID ANDROID        1     Y        3     Y     I want to join the tables as follows but i don't know how  T3: USER_ID ANDROID  OSX        1     Y        Y        2     null     Y        3     Y        null

Also how do LEFT JOIN, RIGHT JOIN and FULL JOIN fit in?


I work as a software engineer, and we have many uses for converters.  I saw here that "convertEr" is used, and did not find any reference to "convertOr". However, at work I've encountered this word many times.  Questions:   Specifically,when is it acceptable to use "convertor"? Generally, when and where to use "xxxxxxOr" / "xxxxxxEr" ? Is there any rule as to when I should use this and not that?

What’s the rule to decide whether you add -er or whether you add -or when creating an agent noun from a verb?    Sometimes it’s -er:      read > reader hate > hater hit > hitter   But other times it’s -or:    meditate > meditator collect > collector


In order to type non-english characters like ł, ó, or ź I need to use the right alt key but in Gnome the default action is to drag the current window so I'm looking for a way to disable this behavior.

On my Ubuntu 16.04 laptop installation, Alt-Gr does not work. So I cannot type characters like {, }, ~, | etc. (doing this on my PC where everything works). I tried various suggestions from multiple Ubuntu wikis, forums, Ubuntu support site: Nothing works.  Most solutions are for older Ubuntu versions, a lot seems to be different on Ubuntu 16.04: There is no System Preferences (you can install the app manually, but there are no keyboard settings there), I don't find Keyboard Layout anywhere...  This is not a duplicate of , Ubuntu 16.04 is different!  Edit: Found the keyboard layout display, and it matches the keyboard (now). But Alt-Gr combinations don't work.


When writing a C/C++ program, specifically with latest compilers, why do we need to return an integer from the main() method? Like int main() and we return "return 0" from it. So what is the exact reason behind this?

What is the correct (most efficient) way to define the main() function in C and C++ — int main() or void main() — and why? And how about the arguments? If int main() then return 1 or return 0?  There are numerous duplicates of this question, including:       — For C++, with a very good answer indeed.     Related:


According to Benjamin Franklin, current flow from +ve to -ve terminal. But after Joseph Thomson's discovery it was conceived that although current flows from +ve to -ve electrons flow from -ve to +ve terminal.  Now w.r.t. Alternating Current neutral provides return path, so why touching metal of neutral doesn't give a shock?

If the neutral wire carries current, why do many people believe that it's safe? I've heard "You can touch the neutral wire/bar in the breaker box and not get shocked. Only the hot can hurt you." If the circuit is complete and current is flowing, can't you receive a shock?


First off, apologies if this is not the right place for this specific question, but new to both the site and the OS in question.  -System Details- OS: Xubuntu 14.04 (xfce)  Question: I have manually added a new program to my Applications List, by creating a new file with the following script:  [Desktop Entry] Version=1.0 Type=Application Terminal=false Icon[en_AU]=/home/username/programdir/programexe.gif Icon=/home/username/programdir/programexe.gif Exec=/home/username/programdir/programexe Name[en_AU]=ProgramName Comment[en_AU]=Program Name Name=ProgramName Comment=Program Name   This file is than placed in /usr/share/applications  This program requires SUDO access to launch correctly, which I was able to accomplish by editing the following lines:  Terminal=true Exec=sudo /home/username/programdir/programexe   This causes a Terminal window to open where I can enter the SUDO pass, and allow the program to launch fully.  Issue: Once the Terminal window opens, it remains open and will only close when the program is shutdown.  I have tried setting the line "Terminal:true" to "Terminal:false", but this effectively stops the program as the Terminal window will not launch during startup for the SUDO pass entry.  Is there a way for me to get the Terminal window to close once the pass has been entered, so that it is not constantly present?  Thanks in advance.  Best Regards, TH

Mainly I am looking for a way to pin an application to the Unity launch bar, and run it as root.  Currently, even if I start the application with sudo, and pin it after it starts, it will start as current user next time.  Sad, but there is no context menu option "run as ...".  Update: I switched to gnome3 and now I'm happy, I'm missing only the search.


My current directory is ~/Dropbox/RECENT and I want to copy a file input.txt from my current directory to ~/Dropbox/RECENT/SORT without deleting the original. And I want to copy input.txt with another name in my current directory.

I have read about copying files with terminal but these examples will help me a lot. So here is what I want to do:  Examples:   I have a file in /home/levan/kdenlive untitelds.mpg and I want to copy this file to /media/sda3/SkyDrive and do not want to delete any thing in SkyDrive directory. I have a file in /media/sda3/SkyDrive untitelds.mpg and I want to copy this file to /home/levan/kdenlive  and do not want to delete any thing in kdenlive directory  I want to copy a folder from home directory to sda3 and do not want to delete any thing on sda3 directory and opposite I want to cut a folder/file and copy to other place without deleting files in that directory I cut it into.


I want to consider the geometric meaning of Im$\frac{z-z_1}{z-z_2}=0$ and Re$\frac{z-z_1}{z-z_2}=0$. I know that subtracting by $z_1$ will be some sort of vertical or horizontal shift.  Then, dividing by $z-z_2$ will result in a stretch or shirnk of $z-z_1$, as long as $z-z_2$ is real-valued, and if $z-z_2$ is complex-valued then we will also have a rotation of $z-z_1$.  So, if the imaginary part is equal to $0$, then we know that these transformations has transformed $z$ to the real axis, and if the real part is equal to $0$, then these transofrmations has transformed $z$ to the imaginary axis.   I am wondering if this is a good way of thinking about these things, if anyone has anything to add, or if my thought process is incorrect in some way.  Thank you!

$$S_1=\left\{z:Im\left(\frac{z-z_1}{z-z_2}\right)=0, z_1,z_2 \in \Bbb C\right\}$$  $$S_2=\left\{z:Re\left(\frac{z-z_1}{z-z_2}\right)=0, z_1,z_2 \in \Bbb C\right\}$$  Can someone help me with the geometric description of the above two sets. I have no clue as to where I should start. Thank You!


It would be nice to have an easy way to link to user profiles from answers. It is common to give credit to helpful comments within answers.  Although it's possible to embed links to comments, that's not really useful because comments are meant to be ephemeral, and by making them part of the answer, they have fulfilled their purpose and could be deleted.  Simply mentioning the author of the comment, as in @HelpfulJoe, is not good enough, because if a reader wants to check out the profile of the user for more words of wisdom, he would have to search by name, which is tedious, error-prone, and may not even work, for example if the user has changed his display name in the meantime.  To make this really easy, it would be great to implement this with similar auto-completion as it works in comments. The auto-completion candidates should be limited to users who commented on the answer, and authors of other answers.  This feature-request is different from these similar previous questions:    -- that question is asking for magic links like [opa] and [opq] and with a more limited scope. I'm asking for auto-completion + linking by typing usernames prefixed with @, as it works in comments.  -- that question is asking for linking to other answers. That would be nice too, but I'm asking for linking to user profiles, as it works in comments.   My current workaround is to manually add the @username with a link to the profile. With minimal typing and mouse clicks:   Right-click on user link, copy URL Click in the answer's text area where you want to insert the username reference, and press Controll to bring up the Insert Hyperlink pop-up Press Controlv to paste the copied URL, and before closing the pop-up, press Right to jump to the end of the pasted URL, ControlShiftLeft to select the last word, hopefully the entire username, if not then adjust the selection, press Controlc to copy the username, and press Enter to close the pop-up Type @ and press Controlv to paste the username

Sometimes I want to refer to a specific user in an answer.  Something along the lines of      "From the answers of UserA and UserB I have crafted this super useful solution..."   Is there a shortcode creating a link to a user profile using the user name? Similar to the @ we have in the comments, but in an answer.


We are working with current version of Apache 2.4. 6 available in a Centos 7 repos. Installed with yum.  and we are dealing with the PCI compliance and the report says:  IP Address: x Host: x Path:   THREAT REFERENCE  Summary:  vulnerable Apache version: 2.4.6  Risk: High (3) Port: 443/tcp Protocol: tcp Threat ID: web_server_apache_version  Details: Apache HTTP Server mod_proxy_fcgi Response Handling Vulnerability 11/21/14 CVE 2014-3583 Apache HTTP Server before 2.4.11 is prone to a vulnerability, which can be exploited to cause a DoS (Denial of Service). The vulnerability exists due to an overflow condition in mod_proxy_fcgi. when handling responses from FastCGI servers. The vulnerability can be exploited by sending a crafted response from a malicious FastCGI server, which could lead to a  crash when reading past the end of a heap memory.  Apache HTTP Server NULL Pointer Dereference Vulnerability 10/08/14 CVE 2014-3581 Apache HTTP Server 2.4.10 and earlier is prone to a vulnerability, which can be exploited to cause a DoS (Denial of Service). The vulnerability exists because the application contains flaw in the cache_merge_headers_out() function which is  triggered when handling an empty 'Content-Type' header value.  Multiple Vulnerabilities Fixed in Apache HTTP Server 2.4.10 07/24/14 CVE 2014-0117 CVE 2014-0118 CVE 2014-0226 CVE 2014-0231 CVE 2014-3523 Apache HTTP Server before 2.4.10 is prone to multiple vulnerabilities, which can be exploited to cause a DoS (Denial of Service). The vulnerabilities exist because the application contains flaw in  mod_proxy, mod_deflate, mod_status, and mod_cgid modules and in the winnt_accept function of WinNT MPM.  Note: the WinNT MPM denial of service vulnerability can only be exploited when the default AcceptFilter is used. Apache HTTP Server Two Denial of Service Vulnerabilities 03/19/14 CVE 2013-6438 CVE 2014-0098 Apache HTTP Server before 2.4.9 is prone to two vulnerabilities, which can be exploited to cause a DoS (Denial of Service). The first vulnerability exists due to an error in the mod_log_config module when logging  with truncated cookies. The second vulnerability is due to a boundary error in the mod_dav  module when removing leading spaces. HTTP-Basic Authentication Bypass Vulnerability 08/14/09 Apache 2.2.2 and prior are prone to an authentication-bypass vulnerability  because it fails to properly enforce access restrictions on certain requests to a site that requires authentication. An attacker can exploit this issue to gain access to protected resources,  which may allow the attacker to obtain sensitive information or launch further attacks. Apache HTTP Server OS Fingerprinting Unspecified Security Vulnerability 11/03/08 Apache 2.2.9 and prior is prone an unspecified security vulnerability.  Information From Target: Service: https Received: Server: Apache/2.4.6 (CentOS) OpenSSL/1.0.1e-fips PHP/5.6.13   We update the server once a week "yum update"  but when i do:  rpm -q --changelog httpd | grep CVE i can see this:   core: fix chunk header parsing defect (CVE-2015-3183) and ap_force_authn hook (CVE-2015-3185) core: fix bypassing of mod_headers rules via chunked requests (CVE-2013-5704) mod_cache: fix NULL pointer dereference on empty Content-Type (CVE-2014-3581) mod_cgid: add security fix for CVE-2014-0231 (#1120608) mod_proxy: add security fix for CVE-2014-0117 (#1120608) mod_deflate: add security fix for CVE-2014-0118 (#1120608) mod_status: add security fix for CVE-2014-0226 (#1120608) mod_cache: add secutiry fix for CVE-2013-4352 (#1120608) mod_dav: add security fix for CVE-2013-6438 (#1077907) mod_log_config: add security fix for CVE-2014-0098 (#1077907)   How can i apply the patches that the security scan is asking for? i cannot find rpms to do it.  thanks in advance.  Regards.

We run Ubuntu Lucid 10.0.4 as the foundation of our LAMP environment. We are trying to become PCI compliant so that we can pass CC info through our server. We have run some third-party scans on our servers to begin the certification process and have run into errors regarding PHP 5 versions and Apache versions. The latest PHP version hosted in our official lucid repository is about 10 versions lower than what PCI compliance requires.   How do we upgrade to stay current with PCI compliance requirements?   We need to get from php 5.3.2 to php 5.3.15  As well as up to apache 2.2.23  I've searched far and wide for an answer and haven't come up with a realistic answer. Some recommend compiling manually - which sounds like a nightmare, and others recommend a PPA - which sounds insecure. What should we do?


Light from a source passes by a Kerr black hole on two sides at the equator and converges at the observer. The axis of rotation of the black hole is perpendicular to the direction of light. Two rays of light pass through the spacetime regions of a significant frame dragging, on one side along and on the other side against the direction of light.  Would frame dragging cause a red shift of one ray and a blue shift of the other? Or would both rays come to the observer with the same frequency?

Imagine 2 photons traveling along the equator in opposite directions, of course I'm not suggesting light goes into orbit I'm just wandering if these photons will be blue and red shifted ever so slightly as massive body such as Earth spins in general relativity?


Leuenberger's inequality states that the sum of the medians of a triangle is at most the sum of its exradii. I understand how to prove this when the triangle is acute. However, the proof I've seen in Bottema et. al., or even here:  is wrong (look at it carefully, it doesn't work for an obtuse triangle since one of the cosines is negative, so $p_a+p_b+p_c$ is greater than $R+r$ in this case. In fact, if $C$ is the obtuse angle then $p_a+p_b-p_c=R+r$). How to fix the proof for obtuse triangles? and, is there a simple unified proof for all triangles?

Let $m_a, m_b, m_c - $ are median of triangle $ABC$.   Prove that:   $$ m_a + m_b + m_c \le 4R + r $$   I used   $$m_a^2=\frac{2b^2+2c^2-a^2}{4}$$ $$R=\frac{abc}{4R}$$ $$r=\frac{2S}{a+b+c}$$ and $R \ge 2r$


I added an Image Sequence texture to an object. I also added a rotation animation. In 3D Viewport, the Image Sequence texture animates, and the object rotates. Yet, when I export to a glb file, the object only rotates, and the Image Sequence texture will not animate. Does anyone know how to solve this?

I used node textures in a mesh I exported to .FBX.  I then imported it into Unreal Engine 4 and it didn't import any textures; I clicked the Upload Textures option in Unreal Engine.  Is there something I'm doing wrong or is it Blender?


I installed a fresh Ubuntu 17.10 and tested my Bluetooth settings. I have two Logitech X100 Bluetooth speakers. hciconfig -a returns this when I turned on my bluetooth:  hci0:   Type: Primary  Bus: USB         BD Address: E4:A7:A0:56:DC:A8  ACL MTU: 1021:4  SCO MTU: 96:6         UP RUNNING PSCAN ISCAN          RX bytes:15707 acl:0 sco:0 events:2449 errors:0         TX bytes:601048 acl:0 sco:0 commands:2441 errors:0         Features: 0xbf 0xfe 0x0f 0xfe 0xdb 0xff 0x7b 0x87         Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3          Link policy: RSWITCH SNIFF          Link mode: SLAVE ACCEPT          Name: 'Bluemoon Universal Bluetooth Host Controller'         Class: 0x000000         Service Classes: Unspecified         Device Class: Miscellaneous,          HCI Version: 4.2 (0x8)  Revision: 0x100         LMP Version: 4.2 (0x8)  Subversion: 0x100         Manufacturer: Intel Corp. (2)   Now the first issue was, that when I connect to the speakers, it disconnects after a few seconds and it disappears in the audio settings. More strange, the Bluetooth speakers and Ubuntu are still paired (the LED is still on (not blinking) and Ubuntu shows me its connected). In Ubuntu I cannot disconnect the speakers anymore, because I got a timeout for this action (seen in the sys-logs).  So I tried installing Blueman, and it didn't help, so I uninstalled it again. Now I cannot find the first Bluetooth box anymore (it never appears in the scan-list) and I cannot connect to the second speakers (at least, Ubuntu bluetooth can find them). More strange, Ubuntu thinks it connects and pairs with the 2nd speakers, but the speaker itself shows me, nothing happened.  And again, disconnect won't work because Ubuntu receives a timeout.  Any ideas?

My Logitech bluetooth mouse worked in 17.04 until I did a fresh install of 17.10 on my Dell Inspiron, now it doesn't see it. Bluetooth is on and sees my iPhone.


Suppose a vibrating tuning fork compresses air molecules.And for this it has to do work.As compression occurs,its temperature increases.Does the energy spent by the fork go as the increased internal energy of the molecules?If so,then which energy goes as sound energy?As the process is adiabatic,does this given energy always remain inside the air particles even when it is expanded or is it used to compress another layer to make forward the disturbance-energy to our ear as sound?  In a word,the main query is what happens to the energy given out by the vibrating fork:does it become sound or the heat of the compressed layer or both?

Suppose a vibrating fork exerts force to the air particles to compress which leads to the increase of internal energy (heat).This heat or energy given by the fork is given to the next layer of air and in this way, this energy makes sound. But if it was so, it will be isothermal. And Laplace told it was adiabatic. How can it be? I am confused. The heat energy infact is the energy given by the fork. If it is adiabatic, how can the air pass this energy ?


I have a Xerox Versalinkc600 network printer and Xerox Debian package printer driver installer, which I have downloaded. How do I (step by step) install the printer driver?

How do I install a .deb file via the command line?


Premiss: I'm a java newbie and this is my first question on stack, I looked over the internet but I can't find any answer.  I started working on a dynamic web project on a windows pc, on eclipse, connected to a mysql database and it was working just fine.  I came home and I wanted to work on it on a mac but I have this problem with the server I guess..     Description: "The server encountered an unexpected condition that   prevented it from fulfilling the request."      Exception: java.lang.NullPointerException   I already changed the jdbc and everything but I'm having the same error. Do you have any idea or suggestion to help me solve this problem?  Thank you  Edit 1  Full Stack     mar 30, 2018 2:09:45 AM org.apache.catalina.core.StandardWrapperValve   invoke GRAVE: Servlet.service() for servlet [webUI.PersonaServlet] in   context with path [/WebSalari] threw exception   java.lang.NullPointerException    at   database.DbAccessore.eseguiSelect(DbAccessore.java:73)    at   database.FilmDbAccess.caricaTutteLePersone(FilmDbAccess.java:14)  at   contenitori.ContenitoreFilm.caricaDati(ContenitoreFilm.java:24)   at   webUI.PersonaServlet.processRequest(PersonaServlet.java:83)   at   webUI.PersonaServlet.doPost(PersonaServlet.java:49)   at   javax.servlet.http.HttpServlet.service(HttpServlet.java:661)  at   javax.servlet.http.HttpServlet.service(HttpServlet.java:742)  at   org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)     at   org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)     at   org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)     at   org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)     at   org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)     at   org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)     at   org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)     at   org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:504)     at   org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)     at   org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)     at   org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:650)     at   org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)     at   org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)     at   org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)     at   org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)     at   org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790)     at   org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459)     at   org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)     at   java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)     at   java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)     at   org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)     at java.lang.Thread.run(Thread.java:748)   I'm also getting this ClassNotFoundException when trying to connect to the database  Edit 2  Here's my DBAccessore.eseguiSelect method  Connection conn;      public ResultSet eseguiSelect(String p_sql) {         ResultSet rs = null;          try {             Statement comando = conn.createStatement(); // Line 73             rs = comando.executeQuery(p_sql);         } catch (SQLException sqle) {             LogManager.scriviLog("Errore nella esecuzione della              query! Dettagli:");         LogManager.scriviLog(sqle.getMessage());         }          return rs;     } // end method

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


How accurate is it to say I might would, if I could? Just reading on the intricacies of can and may and it got me curious.

I have a friend from the southern U.S. who uses the phrase “might could” quite often. He’ll say, for example:     I might could do that this weekend.    When I first heard him say this, it made me do a double-take. I wasn’t sure whether it’s incorrect, or correct but just not idiomatic outside the southern U.S.


As the title suggests I want to start off with Arabic section counting and continue with alphabetic for the source codes. It should look somewhat like the following.  Currently, I achieve this by renewing the section command as follows: \renewcommand\thesection{\Alph{section}} \setcounter{section}{0}  But this results in a problem with the hyperlinks. If I no click on A Source Code: Gridworld Environment, it navigates to the Introduction. Somehow the hyperlinks are messed up, and I don't know how to fix it.

I need some help with creating an appendix for my thesis. I have about 10 figures which need to be in the appendix. I have a good appendix with the following code:   \appendix  \addcontentsline{toc}{chapter}{APPENDICES}  \chapter{XXXX}   I have a main thesis.tex file where I call this appendix.tex file after the last chapter. Problems are:   The appendix starts without any notice that it is the appendix except for the chapter number being A, but I want to have either a separate page which says "Appendix" prior to the start of the appendix or on top of the first appendix page to explicitly say "Appendix". Now I use the \chapter{} command to have the title of the appendix but I think I will have only one chapter in the appendix. Is there some command which can make the title insited of chapter?


I would like to build an authorization system to handle role-based permission within the database itself.  Basically, I want my application user to have different access. The problem of basing this on Postgresql users is that if my application has millions of users, then I must have million of Postgresql users with potentially different connection parameters every time, making unable to use any kind of connection pooling (stop me if I am wrong).  So instead I thought I should base this on roles, but since roles don't have much effect on row security (which is my primary purpose here), I can just go on and create a session variable containing the user identification upon querying. Meaning if I want to do a select on some table. My application (actually a REST API) would do the following:  SET SESSION app.user = 'my user' SELECT * from table   It would add the SET SESSION for every request to the database. If table has the proper row security, this would get the rows from table that belongs to 'my user'  I want to know if this solution makes sense and if I understood the concept of SQL session properly, any big performance impact to expect?  Edit: The question  describes the details implementation on how to go about implementing a full authorization system. I want to know if I can use a session variable, to identify my user and reuse it somewhere later in my query, instead of just using role to identify a specific user. I changed the title to make this clearer.

I want to store user id in custom session variable and use it (read) in trigger procedures to authorize user actions. I found something like this:  set session "myapp.user" = '12345'; ... SELECT current_setting('myapp.user');   and it seems to work - I thought that "myapp.user" should be declared in .conf file but it seems that I can create session variables on the fly (I didn't change .conf file at all).  Is there any disadvantage of doing like this?


I would like to convert a String into an Array. My string looks like this:      First-Second-Third-Fourth-Fifth-Sixth   and my Array should look like this:     ["First", "Second", "Third", "Fourth", "Fifth", "Sixth"]   Is there any way to do that?

I have this string  'john smith~123 Street~Apt 4~New York~NY~12345'   Using JavaScript, what is the fastest way to parse this into  var name = "john smith"; var street= "123 Street"; //etc...


I want display my beamer slides on dual-screen during my presentation in Windows 10. which PDF viewer should I use?  And, is there a portable version of this software, like SumatraPDF ?

Most of the time when presenting a talk people connect their laptop to a video projector. So they effectively have an extra screen at their disposal. Because of that many Software options for presentations use the extra screen of the laptop to display notes, time left for the talk, a preview of the next slide and such information to the presenter.  I'm using LaTeX-Beamer which outputs a pdf. I'd like to have notes, a preview of the next slide and the time I have left for my talk displayed to me on the laptop screen, while the projector shows the regular presentation slides.  Ideally this program should work under Linux (Ubuntu 12.04). Does such a program exist?


I am trying to statically link a C++ library to a C project but can't seem to figure a way out. I read multiple posts but nothing helped. Below is the snippet of my Makefile:   CFLAGS += -I../path/to/headers  LIBS += ../path/to/lib.a   I get the below linking error:  "undefined reference to ... collect2: ld returned 1 exit status"   I checked this post for ordering but I don't that is an issue here:   I wanted to know if it is even possible. If so, what flags I would need to add into my C project Makefile.

I have a C++ library that provides various classes for managing data.  I have the source code for the library.  I want to extend the C++ API to support C function calls so that the library can be used with C code and C++ code at the same time.  I'm using GNU tool chain (gcc, glibc, etc), so language and architecture support are not an issue.  Are there any reasons why this is technically not possible?  Are there any gotcha's that I need to watch out for?  Are there resources, example code and/or documentation available regarding this?    Some other things that I have found out:   Use the following to wrap your C++ headers that need to be used by C code.     #ifdef __cplusplus extern "C" {   #endif   //   // Code goes here ...   //   #ifdef __cplusplus   } // extern "C"   #endif    Keep "real" C++ interfaces in separate header files that are not included by C.  Think  here.  Using #ifndef __cplusplus #error stuff helps here to detect any craziness. Careful of C++ identifiers as names in C code Enums varying in size between C and C++ compilers.  Probably not an issue if you're using GNU tool chain, but still, be careful. For structs follow the following form so that C does not get confused.  typedef struct X { ... } X  Then use pointers for passing around C++ objects, they just have to be declared in C as struct X where X is the C++ object.   All of this is courtesy of a friend who's a wizard at C++.


I'm new to this, so wondering if someone could please advise why isNaN() is undefined? package nan;  public class nan {      public static void main(String[] args) {                 {            if (isNaN(1))            {System.out.println("true");}             };      } }  thanks

What's the difference between JavaScript and Java?


I’m new to MacOS world.  By accident I deleted the admin partition (Directory). Every time when I want to install a programme, the system ask me for the admin login. I enter the login but it is not accepted.  I tried yesterday to reinstall a new OS via recovery to get everything new. The reinstallation was successful (it took more than 2 hours ), but as started the system I found that all my data is still there and I still have the same admin login problem and the same username.  I have tried resetpassword via Recovery but I get a window which says there is user account available   my question is:  How can i fix this problem quickly?  Any advice will be apreciated

On my mac I have 2 accounts and the both are normal account. So in this moment I don't have a Administrator account, only one that was in the past a administrator, but now is not.  How I can have again a Administrator account?


The Earth carries a negative electric charge of roughly 500 thousand Coulombs. Does that mean the Earth is negatively charged?

This question arose in a seminar today about the solar wind... This is my vagueish understanding of the problem - please correct if you see errors! The 'classical' picture of atmospheric electricity is that the Earth as a whole is neutral, but that thunderstorms maintain a voltage of around +300kV at the electrosphere with respect to the Earth's surface, with a current of around 1 kA slowly discharging around 500 kC of total charge separation. The solar wind is supposed to neutralise any net charge that might be there between the Earth as a whole and the solar wind. However, positive and negative charges in the solar wind are differently trapped in the van Allen belts, from which they can then descend to the Earth's atmosphere, which implies that a net charge can be developed due to this differential leakage. This begs the question of whether there are any estimates of the total net charge. I've hunted in the literature but have found little useful material other than Dolezalek's 1988 paper:  Can anyone offer an explanation, or point me to some more relevant papers?


I really hate Arial, which happens to be the default for Google Docs.  Does anyone know if there is a way to change the default font and font size in Google Docs?  Thanks.

For a Document (Word-like) in Google Docs, I want to be able to change the font size, family and spacings for the built-in in styles. How can I do that?


Let us define Hermite polynomials as $H_n(x)=(-1)^n e^{x^2/2}\frac{d^n}{dx^n} e^{-x^2/2}.$ One can prove that $e^{\theta x-\frac{1}{2} \theta^2}=\sum_{n=0}^{\infty} \frac{1}{n!}H_n(x)\theta^n \quad (*).$  Now denote $H_n(t,x):=t^{n/2}H_n(x/\sqrt t)$.  We want to prove that $H_n(t,B(t))$ is a martingale. Now, I've thought to use the identity $H_{n+2}(t,x)=xH_{n+1}(t,x)-(n+1)tH_{n}(t,x)$, so $$\mathbb E(H_{n+2}(t,B(t))|\mathcal F_s)=\mathbb E(B(t)H_{n+1}(t,B(t))|\mathcal F_s)-(n+1)t \mathbb E(H_{n}(t,B(t))|\mathcal F_s),$$ but that seems not to be the right way to solve the exercise. So I guess one shall use $(*)$, but I don't know how to do it. Can someone help me?  If it is possible, I'de like to prove it without using the fact that $dH_{n+1}(t,B(t))= H_{n}(t,B(t))$, because the exercise I proposed here is from a sheet that contains also the exercise $e^{\theta x-\frac{1}{2} \theta^2}=\sum_{n=0}^{\infty} \frac{1}{n!}H_n(x)\theta^n$, and I think that I should use that fact, but I'm not sure.

I am asked to prove the following :  Let $B_t$ be a standard brownian motion.   The $n$th Hermite polynomial is $\displaystyle H_n(t,x)=\frac{(−t)^n}{n!} e^{x^2/(2t)} \frac{d^n}{dx^n}e^{-x^2/(2t)}$.   Show that the $H_n$ play the role that the monomials $\dfrac{x_n}{n!}$ play in ordinary calculus.   In other words show : $dH_{n+1}(t, B_t) = H_n(t, B_t)$  Now my guess is that we can take the integral of both sides and use ito integration ? But I am not sure how to proceed from there.


I have a file in which the data is like below,  01,0000000,xxxxxxx/                         02,xxxxxxxx,yyyyyy/                                     03,test1,41203016,,/       01,0000000,xxxxxxx/                         02,xxxxxxxx,yyyyyy/                                     03,test2,41203017,,/      01,0000000,xxxxxxx/                         02,xxxxxxxx,yyyyyy/                                     03,test3,41203018,,/       I will not be knowing what values will be there In the file for test1,test2 and test3. I know that it will be in the line starting with 03 and also I have to dynamically derive the replace strings based on test string.  Is there a way to do this in unix? Is yes, please provide the command.

Replacing strings in files based on certain search criteria is a very common task. How can I    replace string foo with bar in all files in the current directory? do the same recursively for sub directories? replace only if the file name matches another string? replace only if the string is found in a certain context? replace if the string is on a certain line number? replace multiple strings with the same replacement replace multiple strings with different replacements


I have enjoyed studying Feynman's book "QED". I have sufficient mathematical maturity to go beyond his analogies. I am hoping someone has provided notes on the book enumerating the mathematical basis for his analogies and images.

I am currently in the process of teaching myself QFT.  It is not an easy task.  I have armed myself with many of the standard textbooks.  However, I am slow learner.   I get stuck on a thousand different terms which I don't understand, and a style of 'mathematics speak'  which loses me 95% of the time.   There are so many gaps in my knowledge that if I were a ship I would be at the bottom of the ocean.  What I really need is a book called 'QFT for Morons'. That's a bit harsh but 'QFT for dummies' doesn't quite express it clearly enough and besides there isn't such a book as far as I can find.  Any suggestions of resources or books that might help?   What I am really looking for is the one that explains QFT like you were talking to a five year old.  Perhaps I am asking the impossible.  I will add a bit more of a specific question here.    I have learnt that there are groups and non-abelian Lie groups like SU(2) etc., and then there a lagrangians, as well as a few other things like operators and states.   So a really dumb question is how are the lagrangians derived?  Are they determined by the group?  I am also confused because I understand some of the groups like SU(3) are used for different things in QFT.   I feel compelled to appologize for my ignorance but I am determined to make so more progress with this.   The problem when one is teaching oneself is you don't know which is the most fruitful path to follow.


I am using C++11 and have a general question. I have a counter to count number of messages received so it's just a simple "count = count + 1" but my co-worker said I should put a mutex around it. I would think this simple operation only takes a few assembly instructions and it's impossible to be preempted by another thread. I'd like to hear input from experts. Thanks.

Inspired by this question:   Take the following psuedo code:  class test {    int _counter;    void Increment()    {      _counter++;    }  }   Would this be considered thread safe on an x86 architechure? Further more are the Inc / Dec assembly instructions thread safe?


Running OSX 10.10.3  The office LAN is wired, the guest LAN is WiFi. I need to be on both at the same time.  I want to be able to accept connections from the office LAN, but I want to limit access to many of those services from the WiFi network. The clickable System Preferences for the firewall don't give me anything more powerful than "Allow Incoming Connections" which allows connections over all interfaces.  Where do I go to get more control over the firewall? Any tips for getting this config right?  This is not an issue of getting WiFi and Ethernet to work at the same time. They already work like I want them to. It's about firewalling-off services from certain interfaces, something that is not available in the standard System Preferences control panel.

Brief Description:  I need my Ethernet card (en0) to see all traffic under 192.168.2.xxx.  However I also need to use WiFi card (en1) for all other traffic.  OS: OS X Lion    I am using a separate network location to deal with this specific use (since this is a for a robotics project that communicates via Ethernet). Ethernet (en0) had to be set up as a static IP (192.168.2.10) per the requirements for the device I am connecting to. All connections on the Ethernet card (en0) should be 192.168.2.xxx as specified above. WiFi (en1) is set up as DHCP to a router since their is no point in assigning it as a static for general purpose traffic. Ethernet (en0) is set up as priority over WiFi (en1).  I would also like to keep this under the network location preferences if at all possible since I do not require this feature to be on all the time.  I would really appreciate your help on this. No one I have talked to knows how to solve this.


I was working on an assignment on finite fields, and I think it boiled down to prove the following, for every prime $p>2$: $p^{2} \overset{8}{\equiv} 1$ I checked it directly for small primes, and it seems to hold. Is this statement true? If it is, I'd appreciate help in reaching a general proof.  Many Thanks!

How can we prove that every odd perfect square is congruent to $1$ modulo $8$?


The package ncview requires X development headers and headers.  On Ubuntu 12.04 I tried the following command sudo apt-get install xorg-dev and I got the below error message.  This looks like a very long list of packages. Is there something I am missing ?   Reading package lists... Building dependency tree... Reading state information... Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  xorg-dev : Depends: libdmx-dev but it is not going to be installed             Depends: libfs-dev but it is not going to be installed             Depends: libx11-dev but it is not going to be installed             Depends: libxaw7-dev but it is not going to be installed             Depends: libxcomposite-dev but it is not going to be installed             Depends: libxcursor-dev but it is not going to be installed             Depends: libxdamage-dev but it is not going to be installed             Depends: libxext-dev but it is not going to be installed             Depends: libxfixes-dev but it is not going to be installed             Depends: libxfont-dev but it is not going to be installed             Depends: libxft-dev but it is not going to be installed             Depends: libxi-dev but it is not going to be installed             Depends: libxinerama-dev but it is not going to be installed             Depends: libxkbfile-dev but it is not going to be installed             Depends: libxmu-dev but it is not going to be installed             Depends: libxmuu-dev but it is not going to be installed             Depends: libxpm-dev but it is not going to be installed             Depends: libxrandr-dev but it is not going to be installed             Depends: libxrender-dev but it is not going to be installed             Depends: libxres-dev but it is not going to be installed             Depends: libxss-dev but it is not going to be installed             Depends: libxt-dev but it is not going to be installed             Depends: libxtst-dev but it is not going to be installed             Depends: libxv-dev but it is not going to be installed             Depends: libxvmc-dev but it is not going to be installed             Depends: libxxf86dga-dev but it is not going to be installed             Depends: libxxf86vm-dev but it is not going to be installed             Depends: xserver-xorg-dev but it is not going to be installed

Occasionally, when I'm installing stuff, I get an error like the following:  Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  package1 : Depends: package2 (>= 1.8) but 1.7.5-1ubuntu1 is to be installed E: Unable to correct problems, you have held broken packages.   How can I resolve this?


I found this example:   $('#addScnt').live('click', function () {     $('
<input type="text" id="p_scnt" size="20" name="p_scnt_' + i +'" value="" placeholder="Input Value" /> Remove
').appendTo(scntDiv);     i++;     return false; });  $('#remScnt').live('click', function () {     if (i > 2) {         $(this).parents('p').remove();         i--;     }     return false; });   , and when I'm trying to replicate the result and try the created  are not selected by jQuery   My Fiddle:   $(".addItem").on("click", function () {     var newInput = $('
<input type="text" class="item" placeholder="item"></input>remove
');     $(this).closest(".category").append(newInput); });  $(".removeItem").on("click", function () {     $(this).closest("p").remove(); });

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


Say an electron outside a wire is moving with the same velocity as the electrons inside, then due to Lorentz contraction, an electric field would be generated in the outside electron's frame of reference and hence the electron will move towards the wire, and the positive charges moving in this frame of reference with the same velocity of the electrons but in the opposite direction will create a magnetic field that wouldn't affect the electron that is not moving in this frame of reference. Now, if a grounded shield is placed around this wire, the electric field would not penetrate it and therefore there should be no attraction but then why is the electron attracted to the wire in spite of this shield?

Suppose an electron outside a wire is moving with the same velocity as the electrons inside, then due to length contraction, there would be excess positive charges per unit area causing attraction of the election towards the wire, and the positive charges moving in this frame of reference with the same velocity of the electrons but in the opposite direction will create a magnetic field that wouldn't affect the electron that is not moving in this frame of reference. Now, if a grounded shield is placed around this wire, the electric field would not penetrate it and therefore there should be no attraction but then why is the electron attracted to the wire in spite of this shield?


Let $S$ be a finite set with $n$ elements and let $f \in A(S)$ the set of all bijective functions onto $S$ (this is a group with the composition). Suppose that the order of $f$ is $p$, with $p$ prime, and $p$ does not divide $n$. Prove that there is an element $s \in S$ such that $f(s)=s$. So, the things I know is that $p$ is the least positive integer such that $f^p(s) = id(s) = s$ for all $s$; $n = qp+r$ for some $q,r$ with $0\leq r<p$. I also established that $s^n = e$ for all $s$ where $e$ is the identity of $S$, but then I realized that $S$ is not necessarily a group. My first approach was to compute $f^r(s) = f^{n-qp}(s) = f^n \circ((f^p)^{-1})^q(s) = f^n(s)$ since $f^p$ is the identity and so is the inverse, and so is after take $q$ compositions. What I'd like is to find that $f^r(s) = id(s)$ and since $p$ is the order of $f$, necessarily $r=0$ but then $p$ divides $n$ and derive a contradiction. Then I though about the set $H = \{s \in S:f(s)=s\}$ and show that is not empty, but didn't help. I couldn't came up with the assumtion that $f(s) \neq s$ for all $s$ because I didn't know how to use it. Now, since $f:S \rightarrow S$ is bijective and $S$ is finite, $f$ is just a permutation, so the cardinality of $A(S)$ is $n!$, and $p$ divides $n!$ but doesn't divide $n$, so $p$ has to divide some number from $1,2,3,\dots,n-1$. But didn't help either. Any hint, please. Thanks

Let $M$ be a finite set and $\varphi$ a permutation of this set with prime order $q$. How do I show that $\varphi$ has a fixed point if $q$ is not a divisor of $|M|$?


The way I am thinking about this is thinking of a bomb floating in the middle of a room until it is set off. Once it explodes, the room doesn't expand. Instead the contents of the bomb does.  Is that what universal expansion is? The matter, particles, energy, etc simply moving away from the starting point in all directions. Or can the universe be thought of as a bubble that contains all those things, but is itself expanding and taking along its contents with it?

TV documentaries invariably show the Big Bang as an exploding ball of fire expanding outwards. Did the Big Bang really explode outwards from a point like this? If not, what did happen?


evaluate $\int_{0}^{1}\frac{x-1}{\ln x}dx$,where x is real.   Approach:  The suggestion is to differentiate $H(m)=\int_{0}^{1}\frac{x^{m}-1}{\ln x}dx$. This leads to  $$H(m)'=m\int_{0}^{1}\frac{x^{m-1}}{\ln x}dx, $$  $$H(m)''=\int_{0}^{1}\frac{x^{m-1}}{\ln x}dx+m(m-1)\int_{0}^{1} \frac{x^{m-2}}{\ln x}dx$$  ...

I would like to show that   $$ \int_{0}^{1} \frac{x-1}{\ln(x)} \mathrm dx=\ln2 $$  What annoys me is that $ x-1 $ is the numerator so the geometric power series is useless.  Any idea?


Let us suppose that we have received a rejection of our paper form a journal, but this rejection contains a really very valuable and detailed review, so some ideas of this review after some consideration and rethinking will be included into the new version of the paper.  And I here have two questions. No doubts: the new version of paper will contain acknowledgements to the anonymous reviewer. But:   Is it a good manner to answer editor's rejection letter and ask him to pass our deep appreciation to the anonymous reviewer? Is it somehow possible to ask the editor to pass our desire to invite this reviewer to be a co-author of our paper?

I recently submitted an article to a math journal and got a response from a reviewer, with an attachment. In it, I have found some good  advice that could improve my article tremendously.  I am a bit suspicious of its accuracy since it could resolve what I have been working with for some months in a few  sentences.   But anyway, it was enough for me to ask the reviewer for coauthoring with me.   My question would be, does it often happen that an author asks a referee for coauthoring during the review process? Or could it even be possible?  I was given a month to revise my article, but the chance that I could revise successfully by myself seems to be fat.  I would be looking forward to any advice.  Thanks in advance.


I am currently in an live environment and I am trying to clear some disk space. I noticed that a SQL Server database transaction log file is kinda big (12GB).  The recovery model of that database is set to simple. How can I decrease its size without killing any data or wrecking havoc on the server?

This one seems to be a common question in most forums and all over the web, it is asked here in many formats that typically sound like this:  In SQL Server -  What are some reasons the transaction log grows so large? Why is my log file so big? What are some ways to prevent this problem from occurring? What do I do when I get myself on track with the underlying cause and want to put my transaction log file to a healthy size?


I am trying to assign variables dynamically to a class: Example: class P:     def __init__(self, field):        for key, value in self.func(field):            self.key = value  field = {'a' : 1, 'b' : 2}  obj = P(field) print(obj.a) print(obj.b)  Here I want to assign attributes dynamically to a object, basically keys of field dict as attribute. but I think it will assign 'key' as attribute to that object. How can we do this?

Suppose I have a python object x and a string s, how do I set the attribute s on x? So:  >>> x = SomeObject() >>> attr = 'myAttr' >>> # magic goes here >>> x.myAttr 'magic'   What's the magic? The goal of this, incidentally, is to cache calls to x.__getattr__().


I have class  function Foo(a) {   this.a = a;   this.bar = function () {     console.log(this.a);   };   this.buz = function () {     this.a();     console.log('bzz');   }; }   and I'll have quite many instances of this class. Should I move methods to prototype?  function Foo(a) {   this.a = a; } Foo.prototype = {   bar: function () {     console.log(this.a);   },   buz: function () {     this.a();     console.log('bzz');   } }

What's the difference between  var A = function () {     this.x = function () {         //do something     }; };   and  var A = function () { }; A.prototype.x = function () {     //do something };


Say you have a creature A that gives your creatures a +1/+1 counter, and a creature B you control with that counter on it. If that counter on B is removed, does A restore the counter on the following turn?  For example,  (creature A) is on the battlefield (giving all non-humans +1/+1 and Undying), and  (creature B) enters the battlefield (with 5 +1/+1 counters) and gets the counter from Mikaeus. When a spell is played, a counter is removed from Noosegraf and I put a 2/2 zombie onto the battlefield. In my following turn, is the counter from Mikaeus put back onto Noosegraf Mob?

Is a +1/+1 counter I get from, say Unleash or Undying different than +1/+1 from something like  or ?


Before starting with my problem description, I would like to say that this is my very first time using Ubuntu or anything related to Linux!  Now my question!  I have installed the very last distribution of Ubuntu in my laptop (MSI FX620DX).  After a few updates I tried to install new applications such like Gparted or Synaptic... but it has been impossible to even get the package installed.   The same happens with any other application that I would like to install.  After launching the installation I get each time the same message:  *Package operation failed The installation or removal of a software package failed. installArchives() failed: (Reading database ...  (Reading database ... 5% (Reading database ... 10% (Reading database ... 15% (Reading database ... 20% (Reading database ... 25% (Reading database ... 30% (Reading database ... 35% (Reading database ... 40% (Reading database ... 45% (Reading database ... 50% (Reading database ... 55% (Reading database ... 60% (Reading database ... 65% (Reading database ... 70% (Reading database ... 75% (Reading database ... 80% (Reading database ... 85% (Reading database ... 90% (Reading database ... 95% (Reading database ... 100% (Reading database ... 158448 files and directories currently installed.) Removing xserver-common-lts-raring ... Removing 'diversion of /usr/lib/xorg/protocol.txt to /usr/lib/xorg/protocol-precise.txt by xserver-common-lts-raring' dpkg-divert: error: rename involves overwriting `/usr/lib/xorg/protocol.txt' with   different file `/usr/lib/xorg/protocol-precise.txt', not allowed dpkg: error processing xserver-common-lts-raring (--remove):  subprocess installed post-removal script returned error exit status 2 Errors were encountered while processing:  xserver-common-lts-raring*   I have tried several things that I found in different forums, but I could not find a solution for this.  Any idea or suggestion please?  Update: When I run the software updater,it says that only a partial upgrade is possible.   Then I get the following msg:      Could not install 'xserver-common-lts-raring'     subprocess installed post-removal script returned error exit status 2      Could not install the upgrades      The upgrade has aborted. Your system could be in an unusable state. A recovery will run now (dpkg --configure -a).     Any clue??        Update:      rs@rs-GE620-GE620DX-FX620DX-FX623:~$ sudo uname -a     [sudo] password for rs:      Linux rs-GE620-GE620DX-FX620DX-FX623 3.8.0-32-generic #47-Ubuntu SMP Tue Oct 1         22:35:23 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux     rs@rs-GE620-GE620DX-FX620DX-FX623:~$ sudo lsb_release -a     No LSB modules are available.     Distributor ID: Ubuntu     Description:    Ubuntu 13.04     Release:    13.04     Codename:   raring      rs@rs-GE620-GE620DX-FX620DX-FX623:~$ sudo dpkg -l | grep xserver-xorg-video-intel     ii  xserver-xorg-video-intel                  2:2.21.6-0ubuntu4.3                      amd64        X.Org X server -- Intel i8xx, i9xx    display driver     rc  xserver-xorg-video-intel-lts-raring        2:2.21.6-0ubuntu4.1~precise1            amd64        X.Org X server -- Intel i8xx, i9xx display driver

I just installed Ubuntu (12.04.4) and I upgraded to 13.10  I have no idea how to fix this :/  $ sudo apt-get install -f  Reading package lists... Done Building dependency tree        Reading state information... Done The following packages will be REMOVED:   xserver-common-lts-saucy 0 upgraded, 0 newly installed, 1 to remove and 2 not upgraded. 1 not fully installed or removed. After this operation, 1,718 kB disk space will be freed. Do you want to continue [Y/n]? y (Reading database ... 175174 files and directories currently installed.) Removing xserver-common-lts-saucy ... Removing 'diversion of /usr/lib/xorg/protocol.txt to /usr/lib/xorg/protocol-precise.txt by xserver-common-lts-saucy' dpkg-divert: error: rename involves overwriting `/usr/lib/xorg/protocol.txt' with   different file `/usr/lib/xorg/protocol-precise.txt', not allowed dpkg: error processing xserver-common-lts-saucy (--remove):  subprocess installed post-removal script returned error exit status 2 Errors were encountered while processing:  xserver-common-lts-saucy E: Sub-process /usr/bin/dpkg returned an error code (1)


I have downloaded Ubuntu 13.10 desktop. Now I can't open it to install it. Keep getting a request for which program to use to open it. How do I install it?

I would like to see a full how-to guide on how to install Ubuntu.


As I know, the word "there" has been used as an adverb a lot.   But it's also a noun. Not only can you say "What are you doing there?" but "What are you doing in there?" also works. But what about "at there"?  I was checking some homework from a few kids in my work. There was this question: What did he get at the supermarket?  Nearly all the kids wrote "He got some apples at there."  I've never heard people say that, but I'm not quite sure if it's grammatically correct but people just don't say it, or it's just ungrammatical.

I just read the discussed topic "look here vs. look at here":  It's got me wondering.  What is the reason for not using the preposition at before here?  Is it because here is an adverb and it is wrong to use a preposition before an adverb?  What if we use here with its nominal meaning, as in "get away from here", or "It's really hot in here", and then say "Look at here" meaning "Look at this place"?    If it is wrong and there is some other reason why at here is incorrect but in here and from here are correct, what is it?


With regards to the four quadrants of a town or city, which is correct?     The north side of town, or The North side of town?   He lives in the west side of town, or  He lives in the West side of town?   They live in the south side, or They live in the South side?

I am trying to capitalize Western Canada or western Canada properly and am wanting a definition for when the "ern" is added as a suffix to a locational distinction of a proper noun.  I believe the capitalization is related to the suffix and am grouping two questions.  After researching on the internet I have found a trend that areas of discrete area become capitalized along with their proper noun   East New York West Hollywood East London (Britain) East Los Angeles   Some locations have "ern" added to their locational modifier.    Web Examples (from government sites):   eastern Canada ( Western Canada ()   All the examples listed contain discrete areas.  The "ern" suffix is used for larger areas, but I am unable to determine when an area becomes large enough.


I am trying to print out a simple picture (below) that is composed of sections of the following RGB colors:  255,0,0  255,0,255  0,255,0  0,255,255  0,0,0  I am using this image for color sensing (with a sensor that measures intensity of red, green, and blue light) and need these values to be accurate.    The problem is, when I convert this image to CMYK for printing using an online tool, the equivalent RGB values are not accurate.   I was wondering if there's any way to convert an image like this to CMYK for printing while maintaining the RGB values.

I designed a poster in CorelDraw X5 for printing purposes. I was told by the Printshop guy to use colors only in CMYK. For the most part I did, I don't know why I missed it but I used one color in RGB. I liked this color so much that I've used it at many places. So, current situation is that some colors are in RGB and some are in CMYK. So, I want to convert all RGB to CMYK and thought the problem would be solved. But now I'm actually facing a lot of trouble. The colors are not at all same. I hate the colors that it is showing me.  This is the color I used in RGB:    When I changed the "Model" to CMYK, the color it shows is really different. As you can see in the picture below, it's too dull:    The RGB values of both colors are not the same. What can I do to get the same color in CMYK? I did a little bit of reading here and there. They say, that you can't get same. In that case, what is the closest color that I can get?


Acer w/ AMD Athlon 64 x2 dual core 3800+ 2.00 GHz, 4 gig RAM, 32 bit Windows 7, originally built for Windows Vista. Added an NVIDIA graphics card.    1 TB barracuda hard drive partitioned into 3, 1 partition [201GB] set aside for Ubuntu,  Win 7 on one and files on the third.   I want to put Ubuntu 12.04 LTS on the empty partition to work alongside Windows. Am also concerned, as I read that Ubuntu 64bit may not see the existing Windows installation – especially if it is a 32 bit program.   Can anyone tell me the safest and most effective means of installation ?

I need my pre-installed version of Windows 7 (or any other version of Windows), how could I install Ubuntu without erasing it?


Consider the square of an $8 \times 8 $ chessboard filled with the number $1$ to $64$ as in given figure .If we choose $8$ squares with the property that is exactly one from each row and exactly one from each column , and add up the numbers in the chosen squares , show that sum obtained is always $260$ .   My work   I can just observer that it is happening but I don't know how to prove it . $$1+10+29+28+37+46+55+64$$ $$2+11+20+29+38+47+56+57$$ I know many pair like are existing but how I will show this ?

Consider the squares of an $8 \times 8$ chessboard filled with the numbers $1,2,3,4 \ldots ,64$ in sequential order.   If we choose $8$ squares with the property that there is exactly $1$ from each row and exactly $1$ from each column, and add up the numbers in the chosen squares, show that the sum obtained is always $260$.  Please provide full solution and explanation.


I am trying to populate a 2d list with lists (making it a 3d list). My code is of the form:  a=[[],[],[]] toydata1 = [1,2,3] toydata2 = [4,5,6] a[0].append(toydata1) a[1].append(toydata2)   after this, the value of a is   [[[1, 2, 3]], [[4, 5, 6]], []]   as expected. However if I use  a=[[]]*3 toydata1 = [1,2,3] toydata2 = [4,5,6] a[0].append(toydata1) a[1].append(toydata2)   the value of a is   [[[1, 2, 3], [4, 5, 6]], [[1, 2, 3], [4, 5, 6]], [[1, 2, 3], [4,5,6]]]   Can someone explain why append behaves differently based on how I initialize a? Also, why is it appending to all list elements in the second case?     [[]]*3 == [[],[],[]]  returns True, so I am guessing they have the same value.  I am running Python 3.7.4 on Ubuntu 18.04 if that helps.

I needed to create a list of lists in Python, so I typed the following: my_list = [[1] * 4] * 3  The list looked like this: [[1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]]    Then I changed one of the innermost values: my_list[0][0] = 5  Now my list looks like this: [[5, 1, 1, 1], [5, 1, 1, 1], [5, 1, 1, 1]]    which is not what I wanted or expected. Can someone please explain what's going on, and how to get around it?


I have a new rear wheel (Shimano Ultegra WH-6800) and the freehub has about 1mm-2mm of play in it. When the cassette is installed and the wheel is on the bike I'm getting a lot of wobble which is noisy and affects shifting. The cassette is installed correctly. All the spacers are in place as per the Shimano manual and the lock ring is tight. The wobble is so bad that the chain moves laterally while pedaling which is causing all the noise and slippage.  My old wheel had no play in the freehub at all. I've canvased my friends and one guy who's always had problems with shifting said his freehub had play but everyone else said their freehubs have no play. I've taken the wheel to the LBS and one mechanic said that there shouldn't be any play but another said that there is always some play and it seemed OK to him. There is also conflicting information about this on the wider Internet.  Is it common for a freehub to have 1mm-2mm of play?

I have a brand new Shimano Ultegra WH-6800 rear wheel. The freehub has about 2mm of play in it. I can feel the play without the cassette installed by grabbing the freehub body and moving it. It moves side to side and a little less in and out.   I installed a cassette (brand new Shimano Ultegra CS-6700 10spd) and put the wheel on the bike (only in a stand) but it makes some awful noises when pedaling and shifting is a mess. If I look at the cassette from the back it is wobbling all over the place.  Should I return the wheel or is this something that can be fixed by disassembling the hub?


Ran across this interesting question about the Fibonacci numbers but quite unsure how to go about it, any ideas ?

So I'm being asked to find a formula for the nth fibonacci number.    I know the answer is $$x_{n}=\frac{(1+5^{1/2})^{n} -(1-5^{1/2})^n}{\sqrt{5}2^n}$$  However I don't really know how to get there.  It seems so complicated and I need some help.


I work in Ubuntu 16.04 LTS and I have Unreal Engine installed. As you know, UE is only for MacOS and Windows, so I had to use the source code from Github. I installed it, but if I move the UE folder from Desktop to Downloads and try to run the shortcut, it says that it couldn't(even if I modify the UE's folder's location from Properties). Because I hate putting too much shortcuts/files on Desktop, I want to hide the file for UE. Do you think if I hide the folder,the shortcut will work? If yes, can you tell me how to hide it?  The UE's folder is on the Desktop. If I move it anywhere on the PC and change the path in the shortcut:    OR    So, what should I do?  P.S. : This  shows you how does the UE responds to the modify.  Thanks, Matthew

The OCD in me wants directories I do not like the name of to be hidden since I do not interact with them directly.  How can I hide directories without using the dot notation?


Just noticed this on :    The diamond being outside the blue owner-highlighting looks really weird. Pretty sure it used to be inside the highlighting. Could it be moved back?

In comments, moderators have their diamonds in the OP rectangle:        And in the review (suggested edits), mods have their diamonds outside the blue OP background highlight rectangle:        Of course, it Doesn't Really Matter At All, but it is a small discrepancy (I am not saying that in the review, OP rectangles have a bigger padding).


Can you increase the amount of time in a day?  Minecraft has the same amount of time each day, but what if you want to have longer days and shorter nights so zombies wont have as much time to kill you.  Is there a command out there so I can extend the time of day in vanilla Minecraft for my world?

While there is a command that you can use to set the time, the problem with it is that one would have to remember to use it when it's getting late to set it back.  I'm looking for a way to slow down the day/night cycle to add a little more danger to the game when I get caught out at night without a shelter and a bed, and also so that when I'm building I have more daylight to not have to worry about Creepers blowing crap up and more nighttime to see if I have enough lights around.


I have someone how changed the view that the Attributes are displayed when right clicking on a layer > "Open Attribute Table".  I don't see the individual cells but instead see a view that appears to be the structure of the table. How to I change it back?

When I open the attribute table in QGIS 2.14 it looks like this:    In 2.18 the attribute table for the same project looks like this:    How do I make the attribute table of 2.18 look like the attribute table of 2.14?  How can I get the 2.18 attribute table to display the rows and columns that I see in 2.14?


I have installed Ubuntu Server on an old desktop, and I'm new to this.  I had set it up and was trying to connect through Putty but that was not working.  When I tried ifconfig there was no eth0 IP address, and logging onto the router showed the only device connected by ethernet is the printer.  However, the ethernet cable is plugged into the server and is showing the green light by it.  I tried opening /etc/networking/interfaces but this shows the following:  source /etc/network/interfaces.d/*  # The loopback network interface auto lo iface lo inet loopback   I tried adding 'auto eth0' after this and saving but made no difference, and have tried sudo ifconfig eth0 up which didn't do anything either.  sudo lshw -C network says that the network is DISABLED.  Any ideas to help get this up and running?  EDIT: Running command lspci -knn | grep Eth -A3 results in the following:  02:05.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL-8110SC/8169SC Gigabit Ethernet [10ec:8167] (rev 10)          Subsytem: Gigabyte Technology Co., Ltd GA-MA69G-S3H Motherboard [1458:e000]          Kernel driver in use: r8169          Kernel modules: r8169

My wired connection does not work in Ubuntu. I don't have a WiFi card so I need to fix this. I have run some commands to provide some more information(editing this post with results in a few minutes).   I have tried reading through similar questions and answers and nothing I have tried works.   Results:  $ ifconfig -a enp3s0    Link encap:Ethernet  HWaddr 94:de:80:78:2f:de             UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1           RX packets:10562 errors:0 dropped:2 overruns:0 frame:0           TX packets:15 errors:0 dropped:730 overruns:0 carrier:0           collisions:0 txqueuelen:1000            RX bytes:644547 (644.5 KB)  TX bytes:2382 (2.3 KB)  lo        Link encap:Local Loopback             inet addr:127.0.0.1  Mask:255.0.0.0           inet6 addr: ::1/128 Scope:Host           UP LOOPBACK RUNNING  MTU:65536  Metric:1           RX packets:8708 errors:0 dropped:0 overruns:0 frame:0           TX packets:8708 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:1            RX bytes:654867 (654.8 KB)  TX bytes:654867 (654.8 KB)  $ lspci -nn | grep Ethernet     03:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev 06)  $ cat /etc/network/interfaces     # interfaces(5) file used by ifup(8) and ifdown(8)     auto lo     iface lo inet loopback


I am translating from italian, and a question suddenly struck me:  Can I say:      The items’ content in the Navigation Drawer.   or     This is a class handling the cards’ layout.

I know that to mark possession of an item you can use 's like in the following example:     The user's password shall not be blank.   However, is it correct to use the following:     The car's antenna is embedded in the windshield.   I seem to remember that possession must only be used for people but I'm not certain really.


I recently watched a video by Cut on YouTube called "Guess my Zodiac Sign." It's at the following link:  So, at the end, two of the people got $4/12$ correct and it got me wondering what the expected value is. They were saying they did well, but I'm not convinced that they did better than average. I will rephrase this question. Say that I have $12$ distinct cards and $12$ pots; each card corresponds to exactly one pot. Assuming we place the cards randomly in the pots, what is the expected value of correct guesses? I have attempted this question, but, I must admit, my probability skills are very rusty. There are $12!$ ways one can place the cards in the pots. I started by trying to count the number of ways one could get 0 correct. Going to the first pot, there are $11$ incorrect choices, but then with the second pot it branches. It's possible that we put pot 2's card in pot 1, so there are again $11$ choices. It's also possible that we did not do that, so there are 10 choices. I can see how we would calculate the total number of ways to get 0 correct from there, but it seems it will be very tedious. Is there are a faster/more clever way? I feel like I'm overthinking this. It would be interesting to see this done in general as well with $n$ pots and $n$ cards, however I would be completely satisfied with the case $n=12$. Thank you!

I just watched  where someone assigns a zodiac sign to twelve different individuals. There is one of each sign.  My question, Guessing at random, (this was not quite at random), what number of people are you expected to guess correctly? And with what probability are you expected to guess a given number of people correctly?  i.e. What are the odds of getting 1, 2, 3, 4, etc. correct.


I'm a developer of self hosted web application. which creates the error log but others can access it rather than only admin of that application. is there any way to protect it from page other people like hackers?

There is a file in my public_html folder called error.log which is viewable by anyone if they just enter the URL in their browser, like: example.com/error.log  I'm running Apache. My question is, how can I hide or perhaps move this error.log so that it isn't visible to regular users?  ErrorDocument 401 default ErrorDocument 403 default ErrorDocument 404 default ErrorDocument 500 default  <IfModule mod_rewrite.c> RewriteEngine On  #   If you are having problems with the rewrite rules, remove the "#" from the #   line that begins "RewriteBase" below. You will also have to change the path #   of the rewrite to reflect the path to your XenForo installation. #RewriteBase /xenforo  #   This line may be needed to enable WebDAV editing with PHP as a CGI. #RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]  RewriteCond %{REQUEST_FILENAME} -f [OR] RewriteCond %{REQUEST_FILENAME} -l [OR] RewriteCond %{REQUEST_FILENAME} -d RewriteRule ^error\.log$ - [F] RewriteRule ^.*$ - [NC,L] RewriteRule ^(data/|js/|styles/|install/|favicon\.ico|crossdomain\.xml|robots\.txt) - [NC,L] RewriteRule ^.*$ index.php [NC,L]


I have somewhat idea of the difference between these but would like to understand it with an example.  Few questions  Nikon D7000 Vs equivalent Full frame camera  1) Portraits : Would there be any difference if rest of the kit is same, like external flash, strobes etc? Would I be able to produce equally good results professionally.  2) Low Light Photography : Is low light photography where the real power of full-frame professional cameras come into play?  3) Landscapes etc : Is full-frame required more for landscape, long distance,  Gigs etc  4) Can I use D7000 for professional wedding photography. If not then where does it lack.  Where is the real potential of full-frame come along. I think what I am trying to understand is what I can & can't do(By way of example)  with crop frames professionally.  Many Thanks

I'm trying to decide on a higher-end digital SLR, and I'm down to choosing between an APS-C model and a full-frame model.  I understand that the sensors are of different sizes, and as such have an effect on the perceived magnification of the lens, with the smaller APS-C sensor having an effective focal length greater than what it otherwise would be with a full frame sensor. But why does this matter?     What things should drive my choice between one or the other?   In which situations is one better than the other, and why?


So I was starting my VM, booted up Ubuntu, but the problem is, it didn't start the GUI. It just shows a command-line. Can you please tell me how to install LXDE or any other desktop environment?

After installing Ubuntu server how do I install the desktop environment?


Should I use dd or similar before I use testdisk? I reformatted an ntfs partition and would like to recover some of the data. I am using live ubuntu. Also is testdisk good for this type of job? Thank you in advance.  My question is different from  because that doesn't say if you should clone the drive before using testdisk.

I have a Toshiba satellite A-200 laptop with a Vista OS on it with 4 NTFS partitions  (C:) Vista  (D:) Entertainment  (E:) Work  (F:) Sources   and I wanted to start using Ubuntu instead. So I tried it first from the live CD and everything was OK and all the partitions were shown and working and so I decided to install Ubuntu to replace Vista on the (C:) drive. After I did that I can no longer find my folders and files on the (D:), (E:), (F:) partitions and the only file system that is shown is one 198 GB although my HDD is 320 GB.  I can't access the lost data on the remaining 120 GB which I hope is still there and not totally lost  I am now working from the live CD but I am unable to install testdisk. Can I recover the Vista partitions by the product recovery CD to get my laptop back to the factory settings? Can I recover the NTFS partitions using a recovery program for Windows or will that make the problem worse?   I need these data badly as I don't have a backup for them.


What really is ? Is it just the reemission of EMR? I asked my teacher, he said in quantum sense, it is true. But when I read something about emissivity in Stefan Boltzmann's equation, it states that if an object reflects most light, then it absorbs and reemits less. So what it said means reflection and absorption and reemission are different concepts.

How does quantum electrodynamics actually explain HOW reflection occurs on a microscopic scale?   Note that Feynman's QED lecture series/book is not sufficient, as he only assumes that light DOES reflect ('turn around and go back') in order to expound his path integral theory. My question is why does light have the propensity to turn around in the first place.  Is it just the absorption and re-emission of photons, and if so, why does it happen so uniformly (i.e. on a shiny thing, entire scenes are reflected near-perfectly). In essence, why are flat things shiny? Are all the molecules arranged at exactly the same angle?


If you are saying that somebody wishes that they could have been somebody else, which would be more correct:  E from the eels wishes he was Elliott Smith  or  E from the eels wishes he were Elliott Smith?

If I was... If I were...   When is it correct to use "If I was" vs. "If I were" in standard English?


I am trying to prove that the topologist sine curve is not path connected. I think I have a  proof but my proof relies on Intermediate Value Theorem. So, I was wondering if there is a way  to prove it without using Intermediate Value Theorem.  Thank You.

Is there a (preferably elementary) proof that the graph of the (discontinuous) function $y$ defined on $[0,1)$ by $$ y(x) =\begin{cases} \sin\left(\dfrac{1}{x}\right) & \mbox{if $0\lt x \lt 1$,}\\\ 0 & \mbox{if $x=0$,}\end{cases}$$ is not path connected?


I havent worked with Pivot. Not sure if pivot is the right thing to use. Is it possible to show this data:  ------------------- | Name     | Code | ------------------- |Test A    | 1    | |Test B    | 2    | |Test C    | 3    | -------------------   In this format:  ------------------------------ | Customer | Fleet | Account | ------------------------------ |Test A    |Test B |Test C   | ------------------------------   If Code is 1 it is Customer.  If Code is 2 it is Fleet.  If Code is 3 it is Account.

My table is like this:  Sitecode    Month  Amount --------    -----  ------ XX          Jan     1000 XX          Jan     3000 XX          Apr     3000 XX          Apr     1000   What I want is, to show the result something like this:  Sitecode    MonthJAN   MonthAPR --------    --------   -------- XX          4000       4000


Currently, when we vote to close a question as being a duplicate it provides a comment with a link to the duplicate question. The OP then has the option to follow that link to review the question.  As it stands, a question requires 5 votes to close (though I assume admins/mods can close as duplicate immediately?). The problem with requiring 5 votes is that a question might not always get all 5 votes.  Now, this is good from the point of view that we want multiple reputable people to agree it should be closed. But there are likely some instances (I would assume quite a few) where a question has been voted as duplicate, but not enough times to close. However, the OP may have already reviewed the possible duplicate, found it to be a match (and therefore solved their problem), but we are still stuck with an open, unanswered duplicate that the OP doesn't care about anymore.  So my proposition is to have a feature that allows the OP to say "I confirm this is a duplicate, my problem has been solved, this question can be closed". This could be an option that only becomes available once a duplicate vote has been logged. If multiple questions are identified as duplicates, then the OP should select which one was the one that solved their problem so the closed question can be correctly linked.

Since the  to the close as duplicate mechanism it is a lot more visible to the OP that there is/might be a duplicate to their question. Empirically, I've noticed a lot more people agreeing, in the comments under their question, that their question is a dupe.   For instance, :        I'm aware that allowing  is  (back in the stone age) but now Stack Exchange is so much larger, and Stack Overflow is groaning under the weight of questions, I think this should be partially revisited.  Based on the principle that the simplest way to keep a site clean is to have as many people as possible nibbling away, I propose that the OP gets granted a binding close-as-duplicate vote.  It should simply be an additional line in the banner, which is . It might be something like this:     This question may already have an answer here:     "" 3 answers     Does this fully answer your question?  Yes / No   I'm not wedded to the Yes / No thing I just can't think of a better way at the moment.  Clicking on Yes would take the OP to the close as duplicate dialogue with that question highlighted. If there are multiple duplicate questions you'd need to ask the OP multiple times. A No could be used to track the relative success of the project, i.e.   Whether the question subsequently gets closed. Whether the question gets reopened again. How many times the OP actually clicks. How many times the OP disagrees with the analysis of the community.   Potentially, a No could be used to open a comment dialogue asking the OP to explain why they think their question is not a duplicate thereby stopping them simply putting "this is not a duplicate" in the question and formalising this process somewhat. Not sure about this idea...  I do not think this should be restricted by reputation, anyone should be able to close their own question as a duplicate. It gives people with lower reputation a more positive experience of the closing process and emphasises the importance of duplicate finding.  Most importantly, self-closes should not, initially, count towards the question ban. We can help new users learn how to use a lot more of the site than they might otherwise see and encourage them to search for duplicates more thoroughly. If the OP then goes on to do the same thing 10 times in a row then you can start using it toward the ban as they're obviously using the users as a personalised search service but at least the first 3-4 times this should not have any effect.  This question is, deliberately, only requesting 20% of the linked question (from 2009) and then only based on the new UI. The linked question asks for binding migration votes etc, which I do not want to see and I am not requesting a binding close-as-duplicate for the OP until someone else has already voted to close (though I think if the OP has 3k rep this might be allowable). This, I hope, addresses the concern's raised in the linked question and explains why this is not a duplicate of that question.


Err:10 http://ppa.launchpad.net/aims/sagemath/ubuntu focal Release   404  Not Found [IP: 2001:67c:1560:8008::19 80] Err:11 http://ppa.launchpad.net/morphis/anbox-support/ubuntu focal Release   404  Not Found [IP: 2001:67c:1560:8008::19 80] Err:12 http://ppa.launchpad.net/ubuntu-wine/ppa/ubuntu focal Release   404  Not Found [IP: 2001:67c:1560:8008::19 80] Reading package lists... Done E: The repository 'http://ppa.launchpad.net/aims/sagemath/ubuntu focal Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'http://ppa.launchpad.net/morphis/anbox-support/ubuntu focal Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'http://ppa.launchpad.net/ubuntu-wine/ppa/ubuntu focal Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.

When updating, I get the following error message:   W: The repository 'http://ppa.launchpad.net/mc3man/trusty-media/ubuntu xenial Release' does not have a Release file.   Here, I find another statement on this error:   This recommends removing certain PPAs; and, I'm not sure if I should do that since it might mean not getting the updates that I need.    Is this what I should do?


Just finishing up my thesis which I've created in TexShop in osx. I'd like to allow others to edit my document. I've got a desktop that's got Windows and Ubuntu installed that they could do this on (they'll be latex newbies).  My main concern is that TexShop has the feature of having a master document, with sub documents able to be compiled with a special comment line (that directs the compiler back to the main document). Are there any other editors that also support this feature?  Main question: what editor do you suggest?

What editors/IDEs are available for easing the process of writing TeX/LaTeX documents? Please state some useful features like code completion, spell checking, building final DVI or PDF files, etc.  This question is undergoing a systematic refurbishment, see  on Meta. If you’d like to see another editor feature covered here or to take care of an editor that’s not covered yet, share your ideas in that meta question.  List of editors Links to answers.


Is there any benefit for the following JavaScript module defenition:   var module = (function(){   var PublicFnc = function(){ // variable declaration       alert('hi');  }   return {    f : PublicFnc  }  })();   module.f();   Over the following:   var module = (function(){   function PublicFnc(){ // function declaration       alert('hi');  }   return {    f : PublicFnc  }  })();   module.f();   Although the second example is more convenient since it is more similar to Java/C# the anonymous methods are used more often and I'm wondering what is the benefit?  @Alexander, thanks for marking the question as duplicate but I tend to leave it open since I'm asking for the benefits within the context of module patterns and not generally

I've recently started maintaining someone else's JavaScript code. I'm fixing bugs, adding features and also trying to tidy up the code and make it more consistent.  The previous developer used two ways of declaring functions and I can't work out if there is a reason behind it or not.  The two ways are:  var functionOne = function() {     // Some code };     function functionTwo() {     // Some code }   What are the reasons for using these two different methods and what are the pros and cons of each? Is there anything that can be done with one method that can't be done with the other?


Recently my battery of Pokemon Ruby died and I was thinking if I am going to replace the battery will my save be deleted too? I was looking into this but could not find any anwsers, I found one for the pre gameboy advance games but what is the best option with GBA games?.  Thanks for the help in advance

Do Game Boy Advance cartridge batteries run dry after some amount of time, like GBC/GB games do? I got ton of games, the only save files I would miss are the ones from RPG games, and maybe some platformers. Would this happen after some time?


Telegram-desktop can't attach any file: can't see any file in attach dialog, nor open any drag-n-dropped file.  Telegram installed correctly, I'm not asking how to install it.  I installed Telegram Desktop via snap.  sudo apt install snapd sudo snap install telegram-desktop   When I open file browser, it shows empty folders. When I drag files into app window, it shows a popup can't attach empty file <filename>.  In htop, application Telegram has my own user. Everything seems to work correctly except for attachments. Here's what it prints to stdout/stderr in shell:  Qt: Session management error: None of the authentication protocols specified are supported Gtk-Message: Failed to load module "appmenu-gtk-module" Gtk-Message: Failed to load module "canberra-gtk-module" propsReply "An AppArmor policy prevents this sender from sending this message to this recipient; type=\"method_call\", sender=\":1.663\" (uid=1000 pid=23067 comm=\"Telegram \" label=\"snap.telegram-desktop.telegram-desktop (enforce)\") interface=\"org.freedesktop.DBus.Properties\" member=\"GetAll\" error name=\"(unset)\" requested_reply=\"0\" destination=\"org.freedesktop.NetworkManager\" (uid=0 pid=889 comm=\"/usr/sbin/NetworkManager --no-daemon \" label=\"unconfined\")" nmReply "An AppArmor policy prevents this sender from sending this message to this recipient; type=\"method_call\", sender=\":1.663\" (uid=1000 pid=23067 comm=\"Telegram \" label=\"snap.telegram-desktop.telegram-desktop (enforce)\") interface=\"org.freedesktop.NetworkManager\" member=\"GetDevices\" error name=\"(unset)\" requested_reply=\"0\" destination=\"org.freedesktop.NetworkManager\" (uid=0 pid=889 comm=\"/usr/sbin/NetworkManager --no-daemon \" label=\"unconfined\")" "Object path cannot be empty"   How can this be fixed?

I want to work on a small app that will use Telegram from within Ubuntu but wanted to first know if there was already a work in progress for this since I noticed that, for example, pidgin has support for WhatsApp. With this in mind, is there a messenger app that has support (even basic support) for Telegram from within Ubuntu.