How can a check duplication scam like this work?

So, I saw this report titled “” on NY1—a local, reputable news organization in New York City—and find it a bit shocking as well as fascinating; this one paragraph near the end of the piece summarizes it nicelY:     In all, these five people say Remington Biographies solicited personal checks for $14, duplicated the check numbers and took their money without authorization totaling more than $26,000. Though complaints are filed with various local authorities, no criminal charges have been filed.   So essentially, a person is contacted and asked to pay $14 to be in some questionable “” book nobody ever heard of. That’s honestly not that bad of a loss to lose $14 to get your name in a silly book nobody will read.  But the core of the scam seems to be to get a check, get the bank and account routing numbers, create a duplicate check and then cash it.  This make no sense to me since of doing this were so simple anyone who pays for anything by check exposes themselves to potential fraud. Even more odd to me is the duplicated checks that withdrew thousands of dollars clearly don’t look like the original check holder’s check at all.  So how the heck does a scam like this work? How is it even possible?


Roulette Selection in Genetic Algorithms

Can anyone provide some pseudo code for a roulette selection function? How would I implement this:    I don't really understand how to read this math notation. I never took any probability or statistics.


I met some of examples of force in studying classical dynamics, and Lorentz force was represented as  $$ \mathbf{F}=\frac{q}{c} \mathbf{\dot{r}} \times \mathbf{B}  $$ I've searched for meaning of $c$, but I have no idea. Could anyone please explain it for me?


Does copying to clipboard on Android require special permission?

I want to make an Android app that displays latitude and longitude and features a button that copies them both to the clipboard.  Does copying to the clipboard require special permission on Android?


When did British and American English split on "in future" vs. "in the future"?

I'm curious if it's possible to document roughly when the split happened, and also curious whether British or American usage diverged.


Please help me determine the cause.    It is gaining 2gb per hour approximately.    So far,its only happening when I try using the wifi adapter thru usb to rj45 adapter.  The extension chord is badly needed for proper signal.


Only about half of the following tree shows up on my screen, but there is a tonnnnn of white space. Is there any way for me to reduce this and change the length of some of the lines in order for it to fit fully? Thank you! \documentclass[12pt, letterpaper]{article} \usepackage{fullpage}  \usepackage[margin=1in]{geometry}  \usepackage{tikz} \usepackage{tikz-qtree} \usetikzlibrary{shapes.geometric}  \begin{document}  Paragraph paragraph paragraph  \Tree [.Proto-Siouan [.Western [.MissouriValley Crow Hidatsa ] [.*Mandan ] [.OhioValley *Tutelo [ *Ofo *Biloxi ] ] [.MississippiValley [.Dakotan [.Nakota Stoney Assiniboine ] [.``Sioux" Lakhota [ Dakota Nakota ] ] ] [ [.Winnebago-Chiwere [.Hocank ] [.Chiwere [.*Iowa ] [.*Oto ] ] ] [.Dhegiha *Kansa-Osage [ *Quapaw Omaha-Ponca ] ] ] ] ] [.Eastern *Catawba *Woccon ] ]  Paragraph paragraph paragraph  \end{document}


Every Christmas we draw names for gift exchanges in my family.  This usually involves mulitple redraws until no one has pulled their spouse.  So this year I coded up my own name drawing app that takes in a bunch of names, a bunch of disallowed pairings, and sends off an email to everyone with their chosen giftee.  Right now, the algorithm works like this (in pseudocode):  function DrawNames(list allPeople, map disallowedPairs) returns map     // Make a list of potential candidates     foreach person in allPeople         person.potentialGiftees = People         person.potentialGiftees.Remove(person)         foreach pair in disallowedPairs             if pair.first = person                person.Remove(pair.second)      // Loop through everyone and draw names     while allPeople.count > 0         currentPerson = allPeople.findPersonWithLeastPotentialGiftees         giftee = pickRandomPersonFrom(currentPerson.potentialGiftees)         matches[currentPerson] = giftee         allPeople.Remove(currentPerson)         foreach person in allPeople             person.RemoveIfExists(giftee)      return matches   Does anyone who knows more about graph theory know some kind of algorithm that would work better here?  For my purposes, this works, but I'm curious.  EDIT: Since the emails went out a while ago, and I'm just hoping to learn something I'll rephrase this as a graph theory question.  I'm not so interested in the special cases where the exclusions are all pairs (as in spouses not getting each other).  I'm more interested in the cases where there are enough exclusions that finding any solution becomes the hard part.  My algorithm above is just a simple greedy algorithm that I'm not sure would succeed in all cases.  Starting with a complete directed graph and a list of vertex pairs.  For each vertex pair, remove the edge from the first vertex to the second.  The goal is to get a graph where each vertex has one edge coming in, and one edge leaving.


I need to know what all is remains constant in uniform circular motion. The tangential SPEED, angular velocity and centripetal acceleration right? Why is there no tangential acceleration in uniform circular motion? Isn’t the tangential velocity always changing direction? The magnitude of the tangential velocity,I.e,tangential speed is the same at every point but the VELOCITY is not, right? But then why does the formula : acceleration(tangential) = radius*acceleration(angular) tell me that the tangential acceleration is zero?


Which algorithm for controlling cars on a race track?

I think A* is a good place to start, but since cars cannot move in all directions (they move like cars do, trying to move forward and steer), I was wondering if someone could point me at other approaches they've used.  Also, I was wondering about the "Racing Line". Should one just precompute the optimal paths, and then use the A* to select the path that isn't blocked by other cars ?  EDIT: My question is different from  because that question is about approaches.  I am interested in learning about specific tried and trusted algorithms like A*.


Why is blender saying some of my scenes have no user

Blender started "randomly" deleting some of my scenes and when I checked, it was because it said there are no users. I figured out how to add a fake user now (via the "Orphan Data" Outliner) but I'm still unsure why this is necessary.  Why would a scene require a user, and how can I make sure this doesn't happen in the future?  I also haven't found any pattern to which scenes are marked as having no users.


Allow more than one accepted answer, if answers refer to different (sub-) questions

First of all, I do not think this is a duplicate of . This question was about several answers that referred to the same question.    If I ask several questions or a question containing different parts, what should I do if different answers refer to different questions?  Consider a question about a math task that consists of two subtasks. IMHO there is no sense in creating two different posts for each subtask, if they are directly related. So what do I do if person A answers the first, and person B answers the second subtask in a separate question?  Of course I could (and should) upvote both of them, but I really think that awarding only one answer by accepting it isn't fair to the people who spent their time trying to help me.  This is why I would vote for a new feature that allows accepting more than one answer, if the provided answers are equitable.


Application crashes at facebook logout ,NullPointerException

I have a method in my main activity that lets user logout if user is logged in and log in if user logged out. But the application crashes when I call .logout() method of facebook sdk. My code where the error comes Logcat returns NULLPOINTEREXCEPTION Error at fb.logout(MainActivity.this);  public void loginFacebook(View v) {     // TODO Auto-generated method stub     new Thread(new Runnable() {          @Override         public void run() {              // log out if logged in             if (fb.isSessionValid()) {                 try {                     updateButtonImage();                     Log.d("Session Valid", "Session Valid");                     fb.logout(MainActivity.this);                     if (fb.isSessionValid())                         Log.d("Session Valid", "Session Valid");                     else                         Log.d("Session Not Valid", "Session Not Valid");                  } catch (MalformedURLException e) {                     // TODO Auto-generated catch block                     e.printStackTrace();                 } catch (IOException e) {                     // TODO Auto-generated catch block                     e.printStackTrace();                 }             }              else {                 // log in if logged out                 Log.d("Session Not Valid", "Session Not Valid");                 // login                 runOnUiThread(new Runnable() {                     public void run() {                         fb.authorize(MainActivity.this,                                 new DialogListener() {                                      // I have deleted this part as this is not relevant to this question                                 });                      }                 });              }         }      }).start();  }   LOGCAT:      03-08 16:11:22.242: E/AndroidRuntime(11956): FATAL EXCEPTION: Thread-14 03-08 16:11:22.242: E/AndroidRuntime(11956): java.lang.NullPointerException 03-08 16:11:22.242: E/AndroidRuntime(11956):    at android.webkit.CookieSyncManager.createInstance(CookieSyncManager.java:96) 03-08 16:11:22.242: E/AndroidRuntime(11956):    at com.facebook.internal.Utility.clearCookiesForDomain(Utility.java:554) 03-08 16:11:22.242: E/AndroidRuntime(11956):    at com.facebook.internal.Utility.clearFacebookCookies(Utility.java:578) 03-08 16:11:22.242: E/AndroidRuntime(11956):    at com.facebook.Session.closeAndClearTokenInformation(Session.java:798) 03-08 16:11:22.242: E/AndroidRuntime(11956):    at com.facebook.android.Facebook.logoutImpl(Facebook.java:669) 03-08 16:11:22.242: E/AndroidRuntime(11956):    at com.facebook.android.Facebook.logout(Facebook.java:646) 03-08 16:11:22.242: E/AndroidRuntime(11956):    at com.appquest.awaaziitkgp.MainActivity$4.run(MainActivity.java:167) 03-08 16:11:22.242: E/AndroidRuntime(11956):    at java.lang.Thread.run(Thread.java:1019)


What if the P-Value is less than 0.05, but the test statistic is also less than the critical value?

Let's say you let the Null Hypothesis $H_0$ be that the mean volume of water in a bottle is some $\mu$, and the alternate hypothesis $H_1$ be that the mean volume is not $\mu$. Let's assume you pick a 95% confidence interval, so $\alpha = 0.05$. That would give you a critical value (assuming a normal distribution) of 1.96. Let's say the P-Value is less than 0.05, which would mean you reject $H_0$. But what if the test statistic is less than 1.96? In that case you would reject $H_1$, but you already rejected $H_0$ from the P-value. Does one take precedence over the other, or would this never happen?


Where are wireless or internet connection logs?

I want to go into a log file and see what happens when my Wi-fi drops, then take it elsewhere? Where can I find this?


I received UK Visa refusal due to deposits I made in my account just before taking bank statement. Need advice fro applying again

I received UK Visa refusal due to deposits I made in my account just before taking bank statement. Actually first 17 months from April 2018 until September 2019 I received salary in cash, 70125 SAR from which I saved liquid cash 12000 SAR which i deposited in bank. Since September 2019 my salary account was opened by the company, and this is the main refusal point mentioned by ECO. so all my savings which is hardly 10-12% of my net salary I deposited in bank. But I dint mention anything about it.   All my other documents stating my salary slip / traveling itinerary etc were accepted.   For new application : I got the letter from my employer that since when I was receiving my salary in cash.  I also obtained the exit and reentry visa (as its mandatory in KSA for expat) which clearly sates my traveling period and reentry in KSA.  This evidence is enough to prove my case? What should be my cover letter?  Secondly fro example I have submitted 10 documents in my previous application and they raised red flag for two. In new application I will provide same 10 documents with more evidence to prove my case. So is their any chance they raise red flag about some other document from the 10 which I submitted before and now as well.


Downloading Ubuntu, Removing wrecked OS and Windows 10

I downloaded Xubuntu debian OS when I got my Lenovo laptop many years ago by booting from a USB and following a tutorial. Throughout the years I've wrecked my OS from my ignorance in deleting files that programs like ClamTK flagged as viruses and malware. A bunch of little things malfunction like volume controls, I can't send files to the Recycling Bin via the dropdown menus, I can't view files to upload from my desktop, etc...  I'm wondering how I can remove Windows 10 altogether, then USB boot a regular non-debian Ubuntu (which I think is more accessible for my knowledge of computers and interface friendly) without bricking my laptop. Any help/advice is greatly appreciated.


Are configurations written and read directly to/from .yaml files or still to the database?

Background  Drupal 7 and previous versions have attracted criticism for Drupal web site admin configuration being stored in the MySQL database, the criticism being that being in a database means that it cannot be directly managed in git together with the PHP code based development for a Drupal site (custom modules, themes etc.).   Secondly with configuration being in the database along with content, transporting configuration between development, test, staging and live servers as part of development activity is complicated, though Features module (and related) can help.  Reading through:   ...I'm getting the impression that, in Drupal 8, the database is still used to store the config, when for example a site builder creates a new content type, rather than this being written to a .yaml file which is used directly.  So actually it seems that the role of the yaml file(s) is a much more purer (than Features) vehicle for the configuration. Whereas with Features it was PHP code which was harder to read what the configuration was, including if doing diffs between commits where config had been updated resulting in a new version of the Features-based config export. By that I mean not that PHP itself is hard to read, as I'm familiar enough with it, having written custom modules, hooks, themes. What I mean is that to express a configuration in PHP is perhaps not the most legible way to do it. So I can see the rationale of using yaml. The difference is that yaml will be read by a parser to apply a config. The complexity of applying the config is in the parser, which most folks need not concern themselves with most of the time, so the yaml can more cleanly describe the config. whereas in Features, there is no parser / yaml (or other script) separation. The descripton of the config and the means to apply it are necessarily in the same place as PHP code which is executed directly, so it's bound to be a bit harder to read the config, particularly if doing git commit diffs.  So there's the rationale for yaml, a Declarative Programming approach to storing configuration management in Git, contrasted with Features which is an Imperative Programming approach. And next what I need to know is this the case that Drupal 8 does still store config in the database does still and yaml files are the means for transporting config (replacing what Features did in D7 and before)?  (By the way I am a big fan of Drupal and spend most of my time at work, working with it for the sites that my organisation produces and maintained and am also involved in the community. So this question is not a stealth campaign against Drupal in favour of other platforms. It is a genuine question to try to dispel the apparent mystique around Drupal 8 and the new config management system)  Update @Berdir's answer (accepted) is a great definitive summary as to the state of Drupal 8 regarding configuration management.  I recently discovered that using yaml for config in Drupal 8 is a concept that has been developed for Drupal 7 with the  module, also read a  on it which includes comparing features.   Update   Is a definitive answer about making config active from DB storage, which corroborates with @Berdir's answer.


Wrong driver gets installed over and over again

I need to remove the automatically installed driver of a device before I can install the proper/required driver. So far, I used the "Delete the driver software for this device" checkbox and I also used pnputil to remove the driver from the windows driver cache/storage. However, the device magically appears with the allegedly deleted driver again after the required reboot. The driver does also appear again in the driver cache. I am at a loss from where  windows restores that driver. How I can prevent that?    Full story: I did a clean Windows 10 installation on a Lenovo Yoga Book Tablet. Lenovo's driver installation/update tool does not work for some reason on my particular device, so I installed all drivers manually. The driver for the so called "Halo Keyboard" has the following installation instruction:  1. You need to uninstall "Goodix Touch HID" first:     a. Right click on the "Win" button on the left bottom corner of the desktop     b. Click Device Manager --> Expand the "Human Interface Devices" tree     c. Double click on the "Goodix Touch HID" item --> choose "Driver" tab     d. Click "Uninstall" button --> select the "Delete the driver software         for this device" --> click "OK"     e. if need restart, please follow the guide.  2. install KeyboardDriver 2.0.7.msi First.(need restart your computer) 3. install HaloKeyboard 2.0.7.msi Next. 4. install Multi-mode service 1.0.2.7.msi last. 5. restart your computer.   The Goodix Touch HID is the driver that is re-installed regardless of the procedure described above.


I'm tring to write a method the creates an empty rectangle inside which there is another white rectangle surrounded by a pattern of lines (contained in the for loop).  Whenever the method is run I get a null point exception on first line of the loop.  I can't work out what's going on... please help.      public void displayArea () {             Graphics g = chartPanel.getGraphics();             int Xpos = 30;             int Ypos = 50;             int displayWidth = 300;             int displayHeight = 280;             int borderPatternY = 10;             int borderPatternX = 10;               for (int count = 0; borderPatternY <= 300 || borderPatternX <= 280; count++){                 g.drawLine(30, borderPatternY, 330, borderPatternY);                 g.drawLine(borderPatternX, 50, borderPatternX, 320);                  borderPatternX = borderPatternX + 10;                 borderPatternY = borderPatternY + 10;             }              g.setColor(Color.white);             g.fillRect(Xpos + 10, Ypos + 10, displayWidth-10, displayHeight -10);              g.setColor(Color.black);             g.drawLine(Xpos, 60, Xpos + displayWidth, 60);             g.drawLine(Xpos, 120, Xpos + displayWidth, 120);             g.drawLine(Xpos, 180, Xpos + displayWidth, 180);             g.drawLine(Xpos, 240, Xpos + displayWidth, 240);         }


How can fix "Unable to lock the administration directory (/var/lib/dpkg/), are you root?"?

E: Could not open lock file /var/lib/dpkg/lock - open (13: Permission denied) E: Unable to lock the administration directory (/var/lib/dpkg/), are you root?


When passing an array to Twig, words with special characters are disappearing

I can query data from the database use mysqli, output to Twig and create a table, and words with characters with accents(À, Í, etc) are not displayed.  The array can be displayed through a var_dump perfectly. So somewhere in Twig is it going awry.  I have:   A database with data in Spanish PHP Silex/Twig A table schema in utf8, with text being displayed correctly.   I have tried:   mb_convert_encoding before sending it to Twig convert_encoding('iso-8859', 'UTF-8') in Twig   I am at a loss as to what to do next, nor why it is not working. If anyone knows why the entire word disappears, that would be great.  Template Example:  {% if results %}

             {{ "First Name"|trans }}	             {{ "Second Name"|trans }}</T>	             {{ "First Surname"|trans }}	             {{ "Second Surname"|trans }}	             {{ "Number"|trans }}	             {{ "Type"|trans }}	             {{ "District"|trans }}	             {{ "State"|trans }}	             {{ "City"|trans }}

         {% for r in results %}
             {{ r.first_name }}	             {{ r.middle_inital }}	             {{ r.surname }}	             {{ r.second_surname}}	             {{ r.number }}	             {{ r.type }}	             {{ r.district }}	             {{ r.state }}	             {{ r.city|capitalize }}
         {% endfor %}

 {% endif %}   Array is passed from a mysqli query to a variable. Text book example.


Let $G$ be a group. If there exists a positive integer $m$ such that $a^m=1$ for all $a\in G$, then is $G$ finite? That is, all elements should have order that divides the fixed integer $m$. (The set of orders of elements of $G$ is a finite set.)   I have no idea how to prove or disprove this statement. Is there any counterexample for this?


I/O error after suspend when booting from external USB hard drive

I have a computer, it is an ultrabook (fujitsu UH572). This computer doesn't have any problem when installing ubuntu into internal SSD. But when I install the ubuntu 14.04.2 on an external USB 3 HDD (it is a SATA3 to USB3 HDD adapter with ASMedia chipset), and then perform a system suspend, the system suspends successfully. But if I wake up the system, the system wakes up successfully, but dmesg has a lot of I/O errors, and I can't load or save anything into my root partition (/), for example, when I try to save the output of dmesg to my home directory (which resides in my root partition), the command hangs and displays a lot of I/O error.  How do I enable the system to suspend correctly when I boot from the external HDD? Thank you for the asistance in advance.


Showing that the class of all sets of a particular cardinality is not a set.

How to show that the class of all sets of a particular cardinality ,say $h$ is not a set.   My argument:  I assume that I've shown the following lemma.  Lemma: If $X$ is an infinite set of cardinality $h$ , $a\ne x$ for every $x\in X$ then $\{a\}\cup X$ is of cardinality $h$ too i.e. adding new element to an infinite set doesn't change cardinality.  Let $h$ be an infinite cardinal number. Let $T_h=\{x:\text{x is a set of cardinality h}\}$. Suppose $T_h$ is a set.   Let $a$ be any set and consider any $t\in T_h$. Let $R=t\cup \{a\}$. Using the above lemma, $R\in T_h$.   So, $a\in R\subset \bigcup T_h$. As $T_h$ is a set then $\bigcup T_h$ is also a set.  As $a$ was arbitrary set then we have, $a\in\bigcup T_h$ for every set $a$. Hence, the set $\bigcup T_h$ contains all sets which meas that the collection of all sets is a set, contradiction.    If $h$ is non-zero finite cardinal number. Define $T_h$ the same way as above. Let $a$ be any set, Let $A_1=a, A_{n+1}=A_n\times a$. Consider $A=\{A_1,A_2,...,A_h\}$. So, $A\in T_k$. Hence, $a=A_1\in \bigcup T_h=K$. So K is a set containing all sets $a$ since $a$ was arbitary,contradiction.  My main question is, Is there any flaws in my argument? If yes, point it out please.   If the argument is valid, Is there any standard proof to show the same fact?


It doesn't work my tikzcd code in beamer

this code works in a normal latex document but not in beamer. Why?  \section{Project}  \subsection{General scheme} \begin{frame} \frametitle{General scheme} \[ \begin{tikzcd} A \arrow{r}{a} \arrow[bend right]{r}  & B \arrow{r}{b} & C \arrow{r}{c} \arrow{rd}{e} & D \arrow[bend right]{d}\\ & F \arrow{u} \arrow{rr}{f} && E \end{tikzcd} \] \end{frame}


How can I enumerate the open windows (~EnumWindows) of another user session

I have an application that can list the opened windows of the current session. It uses the EnumWindows method from the user32.dll.  I would like to run this code from a windows service, but as the service is not attached to a user session, it returns nothing obviously.  So the question is, how can I enumerate the open windows of another user session (e.g. with a specific logon user)?  Similarly to EnumWindows, I also would like to get the foreground window of the user session as well (like GetForegroundWindow works for the current user).


NullPointerException when trying to recieve image from cache

-edit 2. Tested this on my mobile works as intended. Stupid android avd  I am getting a error and i am not quite sure how to fix it. I could remove the need for caching the image but that would increase the bandwidth needed for the application. My current code should work but it is throwing a NullPointerException here is the error  java.lang.NullPointerException: Attempt to invoke virtual method 'java.io.File android.content.Context.getCacheDir()' on a null object reference                                                                                at android.content.ContextWrapper.getCacheDir(ContextWrapper.java:232)                                                                                at com.program.programmy.application.FileCache.<init>(FileCache.java:18)   and this is the code causing the problem is the one surrounded by **  line 18  public FileCache(Context context) {     // Find the dir to save cached images     if (android.os.Environment.getExternalStorageState().equals(             android.os.Environment.MEDIA_MOUNTED))         cacheDir = new File(                 android.os.Environment.getExternalStorageDirectory(),                 "ParseListViewImgTxt");     else         **cacheDir = context.getCacheDir();**     if (!cacheDir.exists())         cacheDir.mkdirs(); }   if someone could help out with this one little thing my program should work no problem. cheers  -Edit  This is only when i try to leave the list intent to look at a single object. Here is some more code from the area that prompts the error  view.setOnClickListener(new OnClickListener() {             @Override             public void onClick(View v) {                  Intent intent = new Intent(context, SingleItemView.class);                 context.startActivity(intent);             }         });   Also here is a link to something similar that i am doing except no one is having the problem i am


Hotkey to switch input language in Windows 7

I'm using Windows 7 and I'd like to define a custom hotkey to change between different input languages.   I know that I can change them to Ctrl+Shift, Left Alt + Shift or the grave accent, but I don't like either of these. SO is there a way to define something like Ctrl + Space to switch the input language?


Windows is in BIOS mode and dual-boot it with Ubuntu in UEFI mode

I have Windows 7 and I want to dual boot it with Ubuntu 16.04.2. But when I am installing from Bootable USB, it shows a message as follows       This machine's firmware has started the installer in UEFI mode but it looks like there may be some existing operating systems already using "BIOS compatibility mode". If you continue to install Debian in UEFI mode, it might be difficult to reboot the machine into any BIOS-mode operating systems later.      If you wish to install in UEFI mode and don't care about keeping the ability to boot one of the operating systems, you have the option to force that here. If you wish to keep the option to boot an existing operating system, you should choose NOT to force UEFI installation here.     I tried    to change from BIOS to UEFI in Boot Option but after changing no drive is showing from which system can boot.   to make the USB bootable from  and , but in both cases it shows same problem message.   Question   I am getting both /boot and /EFI folder even when my chose partition scheme is MBR partition scheme for BIOS/UEFI. So as some online material suggested choosing the required partition scheme will resolve the problem, my question is how can it be solved if always a /EFI getting generated?? Is this a problem of hardware OR OS conflict(i.e one OS is on BIOS and the other one is on UEFI)? In either case what can be done? Can this be a problem due to ISO image which I am using? Can this be         resolved if I use another ISO image?(If yes then how I can know         which ISO image I should choose?)


Why doesn't the Earth slowly collapse into the Sun?

I understand that the sun exerts a force on the earth and that if that was the only force exerted on the earth then the earth would have already crashed into the sun a long time ago.  The reason the earth is not crashing into the sun but rather spins around it is because there is another force pushing the earth to go straight ahead (or something like that.. :D ). Now the combination of the sun pulling the earth towards it and that other force pushing the earth to keep moving forward results into this centrifugal force that makes the earth go round and round the sun instead.  Much like if I were ice skating and started moving forward really fast and as I was sliding forward I extended my right arm and grabbed hold of a metal pole standing there firmly I would all of a sudden start spinning round the pole. In that case, I am the earth, the pole is the sun, and the force that was pushing me forward and ended up making me go round in circles was generated by me pushing the ice behind me.  My question is, what is this other force in the case of the actual planet earth? Where does it come from and why isn't it fading away to the point where one day the earth will start spinning closer and closer into the sun until it crashes ?  Is it a vector of other forces (which ones) ?  As you can tell I'm just another physics enthusiast (but not a physicist nor a mathematician) asking the same questions over and over again so apologies in advance.


What is the way to get the latest version of LibreOffice?

Should one use the PPA or manually install the .debs from ?  Is there any difference between the two? How long does it take for the ppa to upgrade to the latest version?


I am a bit confused with this sentence.   The team was/were now in the field and about to take their/its place.  Since we are referring to taking positions on the field and as all the players take different positions, I thought we have to use the team as a plural here as the emphasis is on individual units. But my book says otherwise.  Is The team were now in the field and about to take their place, correct? Please clarify.


Sign with one DKIM key for all subdomains

I've set up DKIM key for primary domain as per this tutorial:   Can I use the same key to sign for subdomains as well?  If so, how?


First let me explain what I mean by "transitive" Suppose that the price of product A and the price of product B has a correlation of .5 Suppose also that the price of product B and product C has a correlation of .5  One might thing that if correlation(A,B) = .5 and correlation(B,C) = .5 then correlation(A,C) > 0, but with an intuitive example we can see why this is not the case:  Suppose that A is a fruit salad made of papaya and banana, suppose also that B is a fruit salad made of banana and strawberry and, finally, suppose that C is strawberries and cream. Clearly, when the price of banana goes up, both the price of A and B will go up; when the price of strawberry goes up the price of B and C will go up; but since A and C have no ingredients in common, their price isn't correlated.  My question is which statistical concept captures this intuitive idea. Is it the concept of dimensions?  What do I mean by transitive? Let me define the binary operator X corr? Y as 1 if correlation(X,Y) != 0 and 0 otherwise, so:   A corr? B = 1, B corr? C = 1, but  A corr? C could be = 0   If corr? was transitive, then A corr? C = 1


Can't use beamer package on Windows because 'translator.sty' is missing

I am trying to compile a presentation with beamer on Windows. However, even the most simple example presentation aborts. Instead, I am told:  starting package maintenance... installation directory: C:\Users\admin\AppData\Roaming\MiKTeX\2.9 package repository: http://mirror.physik-pool.tu-berlin.de/tex-archive/systems/win32/miktex/tm/packages/ lightweight database digest: 3a990fd9300abc5d0d8c99b2064abddb going to download 2628706 bytes going to install 346 file(s) (1 package(s)) downloading http://mirror.physik-pool.tu-berlin.de/tex-archive/systems/win32        /miktex/tm/packages/beamer.tar.lzma... 2628706 bytes, 282.04 KB/Sec extracting files from beamer.tar.lzma...  Unfortunately, the package beamer could not be installed.Please check the log file: C:/Users/admin/AppData/Local/MiKTeX/2.9/miktex/log/pdflatex.log ======================================================================   The log file says:  2017-05-24 13:40:57,040+0200 FATAL pdflatex - Info: path="C:\Users\admin\AppData\Roaming\MiKTeX\2.9\tex/latex/beamer/beamer.cls" 2017-05-24 13:40:57,040+0200 FATAL pdflatex - Source: Libraries\MiKTeX\Core\File\win\winFile.cpp 2017-05-24 13:40:57,040+0200 FATAL pdflatex - Line: 286 2017-05-24 13:41:44,697+0200 INFO  pdflatex - installing package beamer triggered by tex\latex\beamer\translator\translator.sty 2017-05-24 13:41:48,400+0200 INFO  pdflatex - mpm: starting package maintenance... 2017-05-24 13:41:48,400+0200 INFO  pdflatex - mpm: installation directory: C:\Users\admin\AppData\Roaming\MiKTeX\2.9 2017-05-24 13:41:48,400+0200 INFO  pdflatex - mpm: package repository: ftp://ftp.tu-chemnitz.de/pub/tex/systems/win32/miktex/tm/packages/ 2017-05-24 13:41:48,633+0200 INFO  pdflatex - mpm: lightweight database digest: 3a990fd9300abc5d0d8c99b2064abddb 2017-05-24 13:41:48,649+0200 INFO  pdflatex - mpm: going to download 2628706 bytes 2017-05-24 13:41:48,649+0200 INFO  pdflatex - mpm: going to install 346 file(s) (1 package(s)) 2017-05-24 13:41:48,655+0200 INFO  pdflatex - mpm: downloading ftp://ftp.tu-chemnitz.de/pub/tex/systems/win32/miktex/tm/packages/beamer.tar.lzma... 2017-05-24 13:41:57,484+0200 INFO  pdflatex - mpm: 2628706 bytes, 290.95 KB/Sec 2017-05-24 13:41:57,504+0200 INFO  pdflatex - mpm: extracting files from beamer.tar.lzma... 2017-05-24 13:41:58,245+0200 FATAL pdflatex - Windows API error 32: The process cannot access the file because it is being used by another process.  2017-05-24 13:41:58,245+0200 FATAL pdflatex - Info: path="C:\Users\admin\AppData\Roaming\MiKTeX\2.9\tex/latex/beamer/beamer.cls" 2017-05-24 13:41:58,245+0200 FATAL pdflatex - Source: Libraries\MiKTeX\Core\File\win\winFile.cpp 2017-05-24 13:41:58,245+0200 FATAL pdflatex - Line: 286   What exactly is happening here and how can I use the beamer package on Windows?


What is the best approch to photographing a mirror or other highly reflective surface?

I have been asked by a client to take some product photographs of some vintage mirrors that they would like to sell and I am struggling with getting good clear shots of the mirrors. As such, what is the best way to approach photographing them such the mirror does not appear to be washed out or contain any unwanted reflections?


PHP: simple mysql query function - cant get it working

i know this must be only a small bug, but i cant find it.  My function:  function del_mysql($table,$id) { $id = $_GET['id']; $exec = mysqli_query($con, "delete from $table where id = '$id'"); return $exec; }   in Code:  if ($_GET['action'] == 'delete') { del_mysql("awsome","$id"); }   if make in function:  $id = $_GET['id']; echo $table; echo $id;   i get right table and id.  Somebody see the bug? I removed already the $exec and return part and leave only mysqli_query command. but dont want to work.


Need help installing Ubuntu16.04.2 desktop

Downloaded 16.04.2 desktop from web. Created disc with Roxio. Searched questions but could not find installation instructions (for desktops) Currently running Vista on a Compac Presario SR2180NX How do I install Ubuntu using the file download OR the disc? ty


After a period of time, would Worf be considered a Dahar Master?

After all that Worf has done, all for the sake of the Empire, would he not deserve the title of Dahar Master?


I own a full service agency within the US and my girlfriend is one of my employees (full time contractor from overseas). She is planning on coming to the US to visit me and my family, I was wondering if there are any rules I should be aware about as she plans to get her B2 visa -- few questions like: 1.) Is she legally allowed to work for me while she is in the US, since she is a full time contractor getting paid in her international country? 2.) If she is coming here, is she expected to take off from work for this time and need a letter from her employer stating she will not be working?


Whenever I run an application in terminal as root (such as sudo gedit  /etc/default/varnish) , subsequently when I open another terminal I get "ls: cannot access .gvfs: Permission denied" error at top line of terminal.   I found a solution on the net     umount /path/to/.gvfs   rm -rf .gvfs   but it only fixes problem temporarily.  It appears that I have two mounted instances of gvfs in my system    $ sudo mount |grep gvfs     gvfsd-fuse on /run/user/1000/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,relatime,user_id=1000,group_id=33)     gvfsd-fuse on /home/****/.gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,relatime,user_id=0,group_id=0)   I don't know if it's related to, a few months ago I had to change permission in my home folder like     sudo chown -R $USER:www-data   Would you please help me fix it?  EDIT: After I unmount /run/user/1000/gvfs I don't get that error.


QWidget: Must construct a QApplication before a QWidget error in pyqt5 and selenium

I want to run another python file when I press the button in the desktop program. However, when I press the button, I get the "QWidget: Must construct a QApplication before a QWidget" error. Other python file is selenium library that works with webdriver. Data is collected in user.py. masaustu.py  import sys , os  from PyQt5 import QtWidgets , QtGui  from PyQt5.QtWidgets import QMainWindow , QApplication , QWidget ,   QPushButton , QAction , QLineEdit , QMessageBox    from subprocess import Popen  class App(QMainWindow):     def on_click(self):         usernameValue = self.username.text()         passwordValue = self.password.text()         nicknameValue = self.nickname.text()         timeValue = self.time.text()               QMessageBox.question(self, 'Message - pythonspot.com', "guduu: " + nicknameValue, QMessageBox.Ok, QMessageBox.Ok)         Popen('python another.py')       if __name__ == '__main__':     app = QApplication(sys.argv)     ex = App()     sys.exit(app.exec_())  user.py import importlib from masaustu import App  App() username = App.usernameValue password = App.passwordValue nickname = App.nicknameValue time = App.timeValue  another.py works perfectly. But I could not connect with the desktop application. How can I do it ?


Some app icons in Ubuntu Dock are black & white

I don't know how to name this issue. So I decide to share a screenshot. Is it something serious? I am freaking out. Can you guys help me resolve the issue?


Should reviewers be accepting edits that make tiny changes and then get around edit limits by adding comments to the post?

For instance, . A non-user (Anonymous) changed the to they while there were , but they added a comment to the bottom, which I have seen before1:  <!--- please remove it, it's for 6chars limit -->   This makes me a little angry, I'll be honest -- either change 6 characters like you're supposed to, or live with nothing changing until a user with edit privileges comes along.  In this case, I would say reviewers should have unanimously rejected with "this edit does not fix critical issues with the post".  Even if there aren't other changes that really need addressing, should reviewers really be accepting edits which make such a tiny change and which make no attempt to hide the fact they're breaking the rules?    1I swear there's an MSE or MSO question complaining about the 6-char limit and this is given as an answer.


Neither you nor I are going to the show, or, Neither you nor I am going to the show


Add a ! or a star to mark an outgoing email as urgent in Gmail

In Hotmail, you can click an exclamation mark "!" for an outgoing email to let the sender know it is important.   How do I do this in Gmail?


Rigging problem with mesh body in pose mode

This is the problem happening while I am rotating the left arm bones in pose mode as you can see in the picture.All the vertex groups are correctly weighted and parent with the bones.Even rotating bones will be transforming the left arm but not exact position with bone position.    Now look the vertex weight paint it is showing correct weight color to move with bones.  Even though left arm is moving not according to bone position.    Please help.Thank you in advanced


Note to moderators: this is not a login item. This is not a LaunchAgent. Please stop marking this as a duplicate. Thank you. Apple has seemingly given 3rd party app developers more control over my OS than me, the user and owner of this computer. Can someone please explain how to disable 'modern login items'? The only work-around I know of currently is to edit the app bundle which did work with one app but I cannot guarantee will work with others, plus Apple will probably get POed that users have control over their Macs and close this loophole.


How to show that the unit sphere is a topological manifold?

Sorry for this basic question, but I´m not sure of something. I want to see one example. The definition of a n-manifold is a Hausdorff space, such that each point has an open neighborhood homeomorphic to the open n-dimensional disc. How can i prove that $$ S^n  = \left\{ {x \in \mathbf{R}^{n + 1} :\left| x \right| = 1} \right\} $$  is an n-manifold


Is there a defined process to communicate with Stack Overflow Inc?

Some time ago I asked  on SO META.   Last week, then put a comment under a response of  asking if he could comment on that. No response.  So, in the end, I accepted that answer on SO META that boils down to "I asked the same thing over a year ago, and nothing happens". (that other question btw saw 100 upvotes and has 5000 views)  In that sense, it feels like: even a SO META question with 150+ votes gets simply ignored by Stackoverflow Inc. And I see similar complaints all over the place: people aren't happy with how their input is treated (ignored) constantly.  Thus:   does SO Inc. have a real "process" to track, assess and prioritize community requests?  or is it a fair statement to say that although the community is providing all the content that attracts users and clicks here has no real way of influencing anything?


Is there a way I can prevent static electricty buildup from shocking me?

I work at a warehouse where we re-pack plastic sheets. Every single day I get shocked when I touch the aluminum foil and even the plastic sheets. What are some useful tips to prevent this from happening?


I have recently purchased two Buffalo AirStation N600 Dualband routers and have set one up to be the main router and the other as a wireless access point.  Both are running open source DD-WRT firmware I was wondering if it was possible to set up all four radios to use the same SSID, and then my devices just roam between them picking up the strongest possible signal.  This is my current setup on one of the routers:   Are these likely to conflict at all?  Any advice on this would be massively appreciated.


Checking if file is checked out through CSOM

Is there a way to check if a file is checked out by another user? I am going trhough a list file by file and would like to avoid the "file is opened by another user" error. Something like this would be nice:  Guid id = new Guid(slideLibrary); // ID of Slide-Library. List list = ctx.Web.Lists.GetById(id); ListItemCollection items = list.GetItems(CamlQuery.CreateAllItemsQuery()); ctx.Load(items); // Loading all the fields System.Security.SecureString pwd = new System.Security.SecureString(); foreach (char c in "pwd".ToCharArray()) pwd.AppendChar(c);  ctx.Credentials = new SharePointOnlineCredentials(login, pwd); ctx.ExecuteQuery();  // Iterating through all the entries. foreach (var item in items) {     String currentID = item["ID"].ToString(); // Getting the ID of the current item.      if (!item.IsCheckedOut()) // This is the part I am looking for.     {        // Do stuff     }     else     {        Console.WriteLine("Item is blocked, skipping it.")     } }   I have yet not been able to find something fitting.


Why do odds ratios from formula and R's fisher.test differ? Which one should one choose?

In the following example  > m = matrix(c(3, 6, 5, 6), nrow=2) > m      [,1] [,2] [1,]    3    5 [2,]    6    6 > (OR = (3/6)/(5/6))    #1 [1] 0.6 > fisher.test(m)        #2      Fisher's Exact Test for Count Data  data:  m  p-value = 0.6699 alternative hypothesis: true odds ratio is not equal to 1  95 percent confidence interval:  0.06390055 5.07793271  sample estimates: odds ratio   0.6155891    I calculated the odds ratio (#1) "manually", 0.600; then (#2) as one of the outputs of the Fisher's exact test, 0.616.  Why didn't I get the same value?  Why do several ways of computing the odds-ratio exist, and how to choose the most appropriate one?


Why does C# limit the set of types that can be declared as const?

Compiler error  indicates that only the basic POD types (as well as strings, enums, and null references) can be declared as const. Does anyone have a theory on the rationale for this limitation? For instance, it would be nice to be able to declare const values of other types, such as IntPtr.  I believe that the concept of const is actually syntactic sugar in C#, and that it just replaces any uses of the name with the literal value. For instance, given the following declaration, any reference to Foo would be replaced with "foo" at compile time.  const string Foo = "foo";   This would rule out any mutable types, so maybe they chose this limitation rather than having to determine at compile time whether a given type is mutable?


I have a few questions on this phrase "Like father, like son".   Is it an idiom or a proverb? Or both? Can it be analysed grammatically? If the answer is "Yes", can you analyse it grammatically for me?


Theoretical explanation for why torque is dependent on the lever arm?

We know that the formula of torque is $\tau=Fl$, where $l$ is the lever arm of the force $F$. I am wondering why is torque dependent on the lever arm? I suspect that it's initially concluded based on experimental data? If so, I am also wondering if there's a theoretical explanation that addresses from the first principle why the value of torque depends on the length of the lever arm?


Was the Wookiee language fully designed or is it just random emotionally-relevant sounds?

We know that some of the other Star Wars languages were fairly well developed by the movie's creators, in terms of vocabulary, grammar, etc.  Was the Wookiee language designed in this level of detail or did they just try to put together sounds that made sense emotionally?


When "dpkg --configure -a" appears to freeze

I'm relatively new to Linux. I tried to install Virtualbox on Lubuntu 18.10. I had never used it before.  During the installation, a prompt told me that I had to alter my Secure Boot. I wasn't anticipating that and tried to discontinue the installation so I could read more about what that meant before moving forward.  I tried to uninstall Virtualbox using the Software application but it would not give me that option. I tried to use the Synaptic Package Manage to uninstall, but it prompted me to run sudo dpkg --configure -a in terminal. That did nothing for an indeterminate amount of time. I had to close out terminal entirely to write another command, and then I uninstalled Virtualbox using sudo apt-get --purge remove virtualbox and dpkg --list seemed to indicate this was successful.  But there still appears to be a residual problem that I can't discontinue.  Synaptic still gives me the same prompt if I try to use it. So does dist-upgrade command when I tried it among other things. If I try sudo dpkg --configure -a now I still get a process that appears to freeze in terminal. I get this:    And then nothing more seems to happen. Task manager seems to indicate nothing is happening. I saw that this was  but those solutions did not seem to work for me in this case.


Java Nullpointer Exception using ArrayList

I have tried to use an ArrayList within my class, but I get Nullpointerexception and I really dont know why, here is my class:  ......      RawVector vector2;      **ArrayList<Long> vectorTime;**         public RawVector CreatingArray(){          try {                   ArrayList<Float> x = new ArrayList<Float>();                 ArrayList<Float> y = new ArrayList<Float>();                 ArrayList<Float> z = new ArrayList<Float>();                 **ArrayList<Long> tm = new ArrayList<Long>();**                 File n = new File("file.csv");                  FileReader fileReader = new FileReader(n);                  BufferedReader reader = new BufferedReader(fileReader);                  for(String zeile = reader.readLine(); zeile != null; zeile = reader.readLine()){                     StringTokenizer data = new StringTokenizer(zeile, " ,");                      **tm.add(Long.parseLong(data.nextToken()));**                     x.add(Float.parseFloat(data.nextToken()));                     y.add(Float.parseFloat(data.nextToken()));                     z.add(Float.parseFloat(data.nextToken()));                     size++;                    }                  vector2 = new RawVector();                 vector2.setX(x);                 vector2.setY(y);                 vector2.setZ(z);                 vector2.setSize(size);                 vector2.setTime(tm);                 reader.close();                 **this.vectorTime = tm;**                               }catch (IOException e) {                  e.printStackTrace();             }          return vector2;     }           public ArrayList<Long> zeitstempel(){          return this.vectorTime;     }   public long getWsize(){          long wsize;         ArrayList<Long> timestamp;         **timestamp = vectorTime;**          **long SumSamp1 = timestamp.get(0);**         long SumSamp2 = timestamp.get(vectorTime.size());         long timespan = SumSamp2 -= SumSamp1;          long timespanInSec = TimeUnit.MILLISECONDS.toSeconds(timespan);           wsize = Zeitfenster*vectorTime.size()/timespanInSec;          return wsize;       }     .....   I have created an ArrayList<Long> tm in the method CreatingArray() and assigned it to the instance variable vectorTime by this.vectorTime = tm. Next, I have used this instance variable in the method getWize() and assigned to ArrayList<Long> timestamp but as soon as I compile this code  you will get an NullPointerException in the code line long SumSamp1 = timestamp.get(0).  What's the problem??? I was pretty sure that the instance variable vectorTime is initialized by this.vectorTime = tm. But according to the exception it doesn't and I don't know why?!  Probably I confuse assginment and initialization...  Im new to Java therefore I think this kind of mistakes are typically for beginners like me. Nevertheless I hope that any of you can help and can give me some useful tips to fix that problem.  Thanks in advance for any help!!!  Best Regards!


Firstly I do not want to round my numbers, I am using base 10 figures so excel should have no bother doing simple add and subtract.  A|  665.110000000000000000000000000000 B|  4.990000000000000000000000000000 C|  =a1+b1 D|  670.790000000000000000000000000000 E|  1,335.890000000000000000000000000000 F|  =e1-(c1+d1)   I should get -5 however F1  returns   -4.999999999999770000000000000000   It is a financial document therefore I want to avoid rounding, more to the point. Why should I need to? I've put cell formatting to Currency with 2 decimal placed and I will get the correct display value but for all calculations I will still get -4.9999...7 which leads to further errors with conditional formatting etc.


How can I manage all of my domains with minimal configuration?

This is a  about DNS server administration.   I have one hundred or so domains. All of these domains need to be configured identically, but it seems like a huge waste of time to have to configure a new zone and/or zonefile for every one of these domains. There has to be a better way to automate this!  I think I'm on to something...if I create a zone called ., or use some other feature in my DNS software to always return a specific IP when an A record is requested, this seems to get me pretty close to my desired end result. My server is responding authoritatively to the requests and it's so much easier to manage!  This was working great until nameserver validation software started checking these domains. I figured out that I can make most of the errors go away by adding NS records, but my software won't let me put more than one SOA record in the same zone file.  How do I work around this multiple SOA record problem?


As our velocity changes shouldn't the span of time taken change

We all know the variation in the velocity of an individual causes different time periods . If we move with the speed of light ,then the time stops for us. Then why does sunlight take time to reach us?


Disable modules per environment / settings.php?

Is there a way to disable certain modules on different environments from settings.php or another means in Drupal 8?  For example, if I am not on prod, I don't want XML Sitemap enabled.


I was taught that ever should be used in questions (Have you ever...?) and never should be used in negations (I have never...). But reading "A wizard of Earthsea" by Ursula K. Le Guin I spotted such a sentence: "Have you never thought how danger must surround power as shadow does light?"   Is that grammatically correct? What does the author want to say by this?


I modeled some logs that together compose a wall. I modeled one and texturized it, then applied an array modifier. Problem is that they all look the same. is there a way to randomize the texture coordinates on each of them? Or am I forced to copy and paste them "manually" and avoid the array modifier?


Is the Canon EF 24-105mm f/4L IS USM lens parfocal or not?

I read a  of the Canon EF 24-105mm f/4L IS USM lens. It said:   Focus shifts while zooming. Zoom before you focus.   Surprised by this (I don't recall ever seeing the focus scale shift while zooming), I took my 24-105mm lens, and manually focused so that the focus scale was at 3 meters distance at the 24mm end. I then zoomed in to 105mm end, and the focus scale was still at 3 meters. So, zooming doesn't affect the focus scale at all (it might affect how autofocus sees things, however).  So, is the lens parfocal or not? If Ken Rockwell is right, this means the focus scale is accurate only at a certain focal length.


While studying the Dirac equation, I came across this enigmatic passage on p. 551 in From Classical to Quantum Mechanics by G. Esposito, G. Marmo, G. Sudarshan regarding the $\gamma$ matrices:     $$\tag{16.1.2} (\gamma^0)^2 = I , (\gamma^j)^2 = -I \ (j=1,2,3) $$    $$\tag{16.1.3}  \gamma^0\gamma^j + \gamma^j \gamma^0 = 0 $$   $$\tag{16.1.4}  \gamma^j \gamma^k + \gamma^k \gamma^j = 0, \ j\neq k$$    In looking for solutions of these equations in terms of matrices, one finds that they must have as order a multiple of 4, and that there exists a solution of order 4.   Obviously the word order here means dimension. In my QM classes the lecturer referenced chapter 5 from Advanced Quantum Mechanics by F. Schwabl, especially as regards the dimension of Dirac $\gamma$ matrices. However there it is stated only that, since the number of positive and negative eigenvalues of $\alpha$ and $\beta^k$ must be equal, $n$ is even. Moreover, $n=2$ is not sufficient, so $n=4$ is the smallest possible dimension in which it is possible to realize the desired algebraic structure.  While I got that the smallest dimension is 4, I fail to find any argument to reject the possibility that $n=6$ could be a solution. I also checked  Phys.SE post, but I didn't find it helpful at all.  Can anyone help me?


Possible Duplicate:          I want to truncate the decimals like below  i.e.   2.22939393 -> 2.229 2.22977777 -> 2.229


I run Ubuntu 16.04 LTS and my cpu is intel i5-7300hq. After updating today I got kernel 4.13.0-26-generic from 4.10.0-42-generic. During the update process I got the following warnings:  update-initramfs: Generating /boot/initrd.img-4.13.0-26-generic W: Possible missing firmware /lib/firmware/i915/kbl_huc_ver02_00_1810.bin for module i915 W: Possible missing firmware /lib/firmware/i915/bxt_huc_ver01_07_1398.bin for module i915 W: Possible missing firmware /lib/firmware/i915/skl_huc_ver01_07_1398.bin for module i915   How do I fix those missing firmware? I think the solution is to get the new linux-firmware package from  but I am not sure which one is appropriate for kernel 4.13. Or is there another way to fix this?  Edit Regarding the  suggested. The answers there suggest downloading some binaries straight from intel. Isn't that though more risky compared to getting the proper linux-firmware package that integrates them more properly with the operating system to make sure weird bugs don't arise?  Here is the information of the current linux-firmware package:  $ apt policy linux-firmware linux-firmware:   Installed: 1.161.1   Candidate: 1.161.1   The newer versions available from  are 1.164, 1.169, 1.170. But I don't know which one corresponds to the 4.13 kernel.


Are numerical variables must for random forest algorithm?

I am trying to find the variable importance on a credit scoring database. I have categorical inputs as well as numerical inputs. My question is does the random forest algorithm works the same way when I   case (1) : give only categorical variables as inputs  case (2): both categorical and numerical variables as inputs.  By this what I am actually asking is only categorical variables are enough or numerical variables should be included along with categorical variables as inputs to the algorithm...???  Thanks in advance...


I want to display the content of a page in the manner as present in the image below:   Are any module present for this?


How to test if the difference between the means of two groups is more than a given value?

The null hypothesis for the t-test is the means between two groups are the same (i.e. the difference between the means of two groups equals 0). However, my null hypothesis is the difference between the means of two groups is less than 5 (alternate hypothesis is > 5). What's the appropriate test/approach in this situation?


How to enable read/write for windows partitions?

With 11.04 I could read and write my partitions that was created in Windows however after upgrading to 11.10 somehow I can only read those partitions. How do I enable this ability in 11.10?


Let $p$ a prime number. Show that the polynomial $X^p-X-1 \in F_{p}[X]$ is irreducible using this hint:            If $a$ is a root of $X^p-X-1$, show that $a^{p^{p}}=a$, who is the extension $F_{p}(a)$?.      Can anyone help me to show this? How I can use this hint?


Can someone explain me the working of this boost converter and the function of individual components. Please. I am unable to understand.  Why are the transistors connected to the MOSFET. What purpose do they serve?   Can someone explain me one cycle of the output current path, please?    The data sheet for IC1 can be found


How should I set up a Linux file server for data sharing with Windows PCs and a PS3?

I have the following pieces of hardware I would like to network mostly for file sharing (media primarily): 1 gaming laptop, 1 i7 (2.3Tb storage) desktop, 1 P4 desktop (500g storage), and 1 250gig PS3.  I am looking to setup a linux host (with a PS3 media server) with the i7 desktop but am concerned about leaving it on all the time. What stripped down, low energy usage distro can I couple with which windows & PS3 friendly software?  Also, how should i reformat my i7 (in terms of partitions, RAID options, whatever)? It has 2 1Tb drives (likely adding a third), and 1 320 gig.


Post Problem Analysis - Rod in a cylindrical time varying magnetic field?

A metal rod of length $l$ is placed (as shown in figure) in a cylindrical time varying magnetic field. Find the potential difference across it.   My answer:  As electric fields as forming circles around the centre with magnitude $$\frac12r\frac{dB}{dt}$$ whose magnitude is same along any chord at a fix distance from centre: $$\Delta V=E.l=\frac12r\frac32at^{\frac12}.l$$ $$\Delta V=\frac34arlt^{\frac12}$$  My question: Is $\Delta V =V_M-V_N$ or $\Delta V=V_N-V_M$ $\bf OR$ equivalently which side is at high potential?  Possible    $(i)$ As Field lines are circular from $M$ to $N$, $M$ must be high potential. $(ii)$ As this field line apply a force on electrons- in the rod- towards left, then $M$ must have excess $e^-$ and $N$ must have deficiency; so $N$ would be high potential as $M$ is $(+)$ and $N$ is $(-)$.


How can one derive Schrödinger equation?

The  is the basis to understanding quantum mechanics, but how can one derive it? I asked my instructor but he told me that it came from the experience of Schrödinger and his experiments. My question is, can one derive the Schrödinger equation mathematically?


I need to install programs in multiple computers but I can't use Internet. There's a way to install programs from USB? (I have only one computer connected)


Is it possible to log phone calls and messages on iOS?

I would like to log and than send to my server following information:  Phone calls   date and time  start of call end of call  contact / phone number   Messages (SMS)   message text receive date and time contact / phone number


Ignoring directories in Git repositories on Windows

How can I ignore directories or folders in Git using msysgit on Windows?


Using variables in matching in javascript

I'm trying to use variables in matching in javascript, but for some reason it's not working. In console, when I tried to alert, it says "ERROR: Execution of script 'test matching' failed! Cannot read property 'length' of null". What am I doing wrong?     // ==UserScript== // @name        test matching // @namespace   John Galt // @description Basic Google Hello // @match       *^https://www.google.com/$* // @version     1 // @require     http://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js // @grant       GM_xmlhttpRequest // @run-at document-end // ==/UserScript==  var temp = "findThis"; var string = "one two findThis three findThis four";  var tempArray = string.match("/"+temp+"/g"); var tempArrayCount = tempArray.length; alert(tempArrayCount);   I need it for matching not replacing.


Change permissions of a folder in Ubuntu

I created a shared folder in Ubuntu which is located in Virtualbox.  When I open that folder I am getting this error line:  You do not have the permissions necessary to view the contents of "sf_ubuntu"


Can "Thanks for your edit!" banner be linkified with the Suggested Edit Link?

When a user without editing privileges suggests an edit to the post, a banner gets displayed until it is reviewed. Can the banner also provide a link to the Suggested edit? For example, I made an edit to a post on Unix&Linux.SE. Can the banner also link to my ?     I know I can access the link through my Profile → Activity → Suggestions. But linking it directly on the face of the post would have immense benefits:  I have been a prolific editor on Ask Ubuntu (my first encounter with Stack Exchange Network) with a lot of Rep derived through Suggestions. I didn't get to know about these suggested edit links until very late (I guess I already had got about 400 edit suggestions approved by the time this came to my knowledge).  This means I didn't know about  when it mattered the most.  I never got to know why my suggestions got rejected because of my ignorance.  This would help reduce the barrier between Reviewers and Editors.  This would also help in case of Anonymous edits. Right now, there is no way an anonymous editor can access it unless the edit gets approved and he comes back to go through the Revision page of that particular post in order to access the Suggested Edit Review link. If the edit gets rejected - it's the end of the road for that anonymous editor. I just made an anonymous edit on one of the SE sites where I don't have an account and already feel like it's the end of the road for me since I just can't access the review link unless it gets approved.    Possibly also expand the banner to mention that they can also access the link to the suggestion via Profile → Activity → Suggestions.


What is the role of NS records at the apex of a DNS domain?

$ORIGIN example.com. ; not necessary, using this to self-document  $TTL 3600 @        IN     SOA   ns1.example.com. admin.example.com. (                       1970010100 7200 1800 1209600 300)  @        IN     NS   ns1.example.com. @        IN     NS   ns2.example.com.  @        IN     A    198.51.100.1 ns1      IN     A    198.51.100.2 ns2      IN     A    198.51.100.3  sub1     IN     NS   ns1.example.edu.  sub2     IN     NS   ns1.sub2 ns1.sub2 IN     A    203.0.113.1 ; inline glue record   The role of a NS record beneath the apex of a domain is well-understood; they exist to delegate authority for a subdomain to another nameserver. Examples of this above would include the NS records for sub1 and sub2. These allow the nameserver to hand out referrals for portions of the domain that it does not consider itself authoritative for.  The purpose of the NS records at the apex of a domain, ns1 and ns2 in this case, seem to be less understood by the internet at large. My understanding (which may not be holistic) is as follows:   They are not used by caching DNS servers in order to determine the authoritative servers for the domain. This is handled by , which is defined at the registrar level. The registrar never uses this information to generate the glue records. They  used to delegate authority for the entire domain to other nameservers. Trying to do so with software such as ISC BIND will not result in the "expected" referral behavior at all, as the nameserver will continue to consider itself authoritative for the zone. They are not used by the nameserver to determine whether it should return authoritative responses (AA flag set) or not; that behavior is defined by whether the software is told to be a master or a slave for the zone. Most nameserver software will quite happily serve apex NS records that disagree with the information contained by the upstream glue records, which will in turn cause well-known DNS validation websites to generate warnings for the domain.   With this being the case, what are we left with? Why are we defining this information if it doesn't appear to be consumed by caching DNS servers on the internet at large?


How do I design this rectangle in Photoshop CC 2017 or Illustrator CC

Just need to know how to give the rectangle this shade kind of effect at the very ending and I also need to know how to cut the bottom line. I need info on exactly how to replicate this amazing rectangle designed by the TypeForm website.  I am not replicating them for a project but for my educational purpose.  Thanks in Advance


sudo apt-get update Hit:1 https://repo.skype.com/deb stable InRelease Ign:2 https://www.dotdeb.org stable InRelease Err:3 https://www.dotdeb.org stable Release   404  Not Found [IP: 195.154.242.153 443] Reading package lists... Done  How can i solve this? I don't need anymore dotdeb


How to find $\lim\limits_{x\to0}\frac{e^x-1-x}{x^2}$ without using l'Hopital's rule nor any series expansion?

Is it possible to determine the limit  $$\lim_{x\to0}\frac{e^x-1-x}{x^2}$$  without using l'Hopital's rule nor any series expansion?  For example, suppose you are a student that has not studied derivative yet (and so not even Taylor formula and Taylor series).


If we have a set of entities which are [metaphorical] children of a given [metaphorical] parent what should we call them?   (Here, 'entity' can refer to anything.)  Are they 'children entities' or 'child entities'?


How to see that this is uniformly distributed on the unit sphere?

Assume  $X_i$ are independent Gaussian $(0,1)$ and  $$ Y:=\left( Y_1 := \frac{X_1}{\sqrt{X_1^2+...+X_n^2}}, ... , Y_n := \frac{X_n}{\sqrt{X_1^2+...+X_n^2}}\right)$$  Then Y is uniformly distributed on the unit sphere. That's what I want to show at least.  Now because $$Y_1^2+...+Y_n^2=1$$ we obviously see that Y is on the unit sphere - but how can I see that it is also uniformly distributed?


I have the next file test.txt with content:  - name: MONGODB_HOST     value: {{MONGODB-HOST}}   I want to replace {{MONGODB-HOST}} with this env variable:  MONGODB_HOST=server.dev.example,server2.dev.example   Command is:  /bin/sed -i 's,{{MONGODB-HOST}},'"$(MONGODB_HOST)"',' "test.txt";   And it fails:  /bin/sed: -e expression #1, char 56: unknown option to `s'   If I leave:   MONGODB_HOST=server.dev.example   it works. Can you help me find the reason why it is failing?


My intention is to remove the whitespaces and semicolons and if one of the resulting string matches "quit"...I'll print "Yikes!"  I am not sure as to why this is not working.        String someString = "abc   ;        def   ;quit";     String[] someArray = someString.split(";");      for(int i = 0; i < someArray.length; i++) {         someArray[i] = someArray[i].trim();         if(someArray[i] == "quit") {             System.out.println("Yikes!");         }     }


Over time I've learned that many (most?) methods used in classical statistics can be interpreted as evaluating a Bayesian model in some plausible way while I find the standard explanations much less intuitive.  So I was wondering whether there are any resources which explain standard stats methods in a Bayesian manner?


Open source java library for HTML to text conversion

Can you recommend an open source Java library (preferably ASL/BSD/LGPL license) that converts HTML to plain text - cleans all the tags, converts entities (&,  , etc.) and handles <br> and tables properly.  More Info  I have the HTML as a string, there's no need to fetch it from the web. Also, what I'm looking is for a method like this:  String convertHtmlToPlainText(String html)


Prove "Infinite Sets Contain Countably Infinite Subsets" without Using Axiom of Choice.

I know how to prove "Infinite Sets Contain Countably Infinite Subsets". But I found that I have to use some kind of AC (at least DC or ACω). I read that in analysis the statement that can be proved by using AC can also be proved without using AC. Is there a way to prove this statement without using AC?  P.S.: Sorry, I didn't pose my complete logic so the "Dedekind" is a mis-input. "Infinite Set" here I mean is the opposite of "Finite Set", so please don't assume the infinite set is defined as Dedekind infinite. My complete logic is to use this fact as the lemma to prove that Dedekind infinite is equivalent to infinite. I appreciate for the nice answer given below, but that's not what I need. Description is edited already.


From Spivak's Calculus:     Prove that $|\sin x - \sin y| < |x - y|$ for all $x \neq y$. Hint: the same statement, with $<$ replaced by $\leq$, is a straightforward consequence of a well-known theorem.   Now, I might even be able to prove this somehow (?), but I can't seem to figure out what "well-known theorem" the author is alluding to here... any hints?


how to get values from hashmap using loop

How can i print all the values from the following hashmap  ServletContext appScope = request.getServletContext();         Map<String, List<String>> onLine = (HashMap<String, List<String>>)appScope.getAttribute("User");         if(onLine != null) {             out.print(onLine.get("1"));         }


Spanish text are not displaying properly in browser

hi Guys i'm working on a website in which some of the text is in Spanish but when i tried to fetch them in browser they look like this    is there any way to solve this with php or html meta tags..i tried using php function and meta tags below here but No diffrence at all  header('Content-Type: text/html; charset=utf-8' ); mysqli_query("SET CHARACTER_SET_CLIENT='utf8'",$connect); mysqli_query("SET CHARACTER_SET_RESULTS='utf8'",$connect); mysqli_query("SET CHARACTER_SET_CONNECTION='utf8'",$connect); ini_set('default_charset', 'utf-8');  htmlspecialchars_decode(); html_entity_decode();  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />   please help!


I would like to install mathtools in Texworks on windows 7. How can I do this task?


Do you know of any tool that could assist me in obfuscating python code?


Problem Summary  I have two network interfaces in the machine, and need them to behave in the following way:   enp3s0: Main network interface for the machine.  Receive over DHCP an IP address (will be in 172.16.0.0/24), a gateway, and a DNS resolver for the office network and the world at large.  Default route is to this received gateway. enp2s0: Local subnet consisting of nothing more than 2 meters away, and nothing that should have access to the main network.  Serve DHCP on this network (192.168.0.0/24, domain is .localnet), and provide the local machine with DNS resolution of .localnet clients.   I had a working solution for all this under 16.04 using /etc/network/ and dnsmasq (no NetworkManager), but I'm just lost in the new era of netplan and systemd-resolved.  Everything just keeps fighting everything else.  So, what's my right, modern solution to make this work right?  Ideally in such a way that I won't have to change it for 20.04.  Additional information  For reference, here is the script that did what I needed under 16.04.  #!/bin/bash # # Configure the PC to use dual network adapters. # # usage: dualnetwork.sh <hinetif> <localnetif> # # This configuration is based around the use of the classic ifupdown # configuration files rather than NetworkManager.  This is substantially # more stable and easier to work with.  It is probably prudent to also # uninstall NetworkManager once this is done: #   sudo apt-get remove network-manager # # Must run as root. # # Rob Gaddi, 29 Jan 2019  GENERATED="Generated by $0 at $(date)" HINET=$1 LOCALNET=$2  abort () {     echo $*     exit 1 }  [[ ! -z "$LOCALNET" ]] || abort Must provide hinet and localnet interfaces. ip -br addr | grep $HINET    || abort Interface $HINET not found ip -br addr | grep $LOCALNET || abort Interface $LOCALNET not found  #################################################################### echo Configuring network interfaces #################################################################### mkdir -p /etc/network/interfaces.d echo source-directory /etc/network/interfaces.d > /etc/network/interfaces cat <<-CONF > /etc/network/interfaces.d/hinet     # $GENERATED     auto $HINET     iface $HINET inet dhcp CONF cat <<-CONF > /etc/network/interfaces.d/localnet      # $GENERATED     allow-hotplug $LOCALNET     iface $LOCALNET inet static         address 192.168.0.20/24      iface $LOCALNET inet static         address 192.168.254.20/24 CONF  #################################################################### echo Installing and configuring dnsmasq #################################################################### apt-get install --reinstall -y dnsmasq mkdir -p /etc/dnsmasq.d cat <<-CONF > /etc/dnsmasq.d/dualnetwork.conf     # $GENERATED     no-negcache     dhcp-range=192.168.0.100,192.168.0.150,4h     interface=$LOCALNET     domain=localnet     dhcp-fqdn     log-dhcp CONF systemctl enable --now dnsmasq.service   Edit  This differs from  in that the problem is not netplanning the machine IP addresses; that part is pretty easy.  The problem is making the system serve DHCP on one network.  When I tried it the obvious way, dnsmasq and systemd-resolved kept stepping on one another's toes.  When I tried just disabling systemd-resolvd and letting dnsmasq do all the work it never got the upstream DNS server when it accepted the main network DHCP.


lim sup inequality $\limsup ( a_n b_n ) \leq \limsup a_n \limsup b_n $

I´m not sure how to start with this proof, how can I do it? $$ \limsup ( a_n b_n ) \leqslant \limsup a_n \limsup b_n  $$ I also have to prove, if $ \lim a_n $ exists then: $$ \limsup ( a_n b_n  ) = \limsup a_n \limsup b_n  $$ Help please, it´s not a homework I want to learn.


Voltage Divider or Step-down transformer for voltage sensing 240V AC

Hello I am trying to measure 240v mains AC as safely as possible. There seems to be 2 ways to do it, which of the two is better and preferred? 1. Voltage divider directly from the mains I have found an schematic that seems to be form a data sheet of an adc where in the mains is directly voltage divided and connected to the adc  Rhi is 300k Ohm and Rlo is 750 ohm . I dont know why the 3 300kOhm are in series though. I do not know how to pick a appropriate varistor though i assume a 375 peak to peak voltage , would  be correct? Also is that earth or ground (adc ground) where neutral is connected because they sometime interchange the two and it becomes confusing in these situations.  Voltage divider After a transformer  This approach seems to be the safer one but not a space saving one using a very small transformer like  that can output 5v and voltage divide from that  Is the ground necessary? I only added it because the other circuit added one. My Thoughts The reason i like number one is because it can be made much more compact than the second, I cannot decide if is it worth the protection of the entire circuit for a compact size. How likely is circuit 1 more to fail than circuit 2?


I have a raster file of 1600 km2 with cell size 2x2 m that I need to polygonize and the script takes a really long time to finish (>25 minutes, but I don't know how long it effectively takes, since I had to kill the task)  How can I make smaller tiles of the large raster in QGIS? Let's say we make 16 tiles, so 4x4 tiles. What is the best method for that in QGIS 3.3+?


I have two variables:  result = 121.0 #  initialized in code, assigned in loop dd = -121.0 #  value returned from result of function   So, when I do  result += dd    result becomes 2.84217094304e-14 (name of this representation of numbers and algorithm of reading is welcome)  But when I assign same values in python console - it returns proper result - 0.0  What is the problem?


Classification of finite subgroups of $\mathrm{GL}_3(\mathbb{R})$

I’m curious about the finite subgroups of $\mathrm{GL}_3(\mathbb{R})$. I’ve looked around, but have only been able to find a classification of the finite subgroups in   ; ; and  ...   ... but not all of $\mathrm{GL}_3(\mathbb{R})$. Is there a complete classification of the finite subgroups in this setting (up to isomorphism)? If so, what is it?    Just for fun context, the reason I ask is because I’m curious about the construction detailed  regarding building a polytope from a faithful group representation. It seems like it would be neat to actually see all the polyhedra you can get in $\mathbb{R}^3$.


Why can't I get my JTable to return a string that is an equal value to another string

I have a JTable that I add rows to by hit of a button after the user fills out the text fields. What I want to do is make sure that they will not have two rows with the same ID. I attempted to do this by using a while statement to compare there entered value to all values in that column of the JTable. The problem is that even if the String is the same value the program says they are not. I will post my code below. If you have any questions feel free to ask and thanks for the help.  addRow.addActionListener(new ActionListener()      {         @Override         public void actionPerformed(ActionEvent e)          {             DefaultTableModel model = (DefaultTableModel) database.getModel();              boolean error = false;             String test = "";             int row = 0;              while(row < rowCount && rowCount > 0)             {                 test = model.getValueAt(row, 2).toString();                 if(test != IDTF.getText().toString())                 {                     row++;                 }                 else                 {                     error = true;                     break;                 }             }              if(priceITF.CheckErrorCode() == false && error == false)             {                 model.addRow(new Object[]{customerTF.getText().toString(),partNumTF.getText().toString(),                         IDTF.getText().toString(),priceITF.getText().toString(),delete});                 System.out.println(model.getValueAt(row, 2).toString());                 rowCount++;             }             else             {                 System.out.println("Error");             }         }     });


I am writing a simple code to reverse a string in C++. However, I am encountering some problems. I am using the string "abcd" as an example because it is simple. When I am printing out the reversed string the result comes out as "dabc" which I'm not sure why. I have tried separating the loops to one for i and the other for j but that did not work as well. #include <iostream>  using namespace std;   int main(){      string s = "abcd";     for (int i = 0, j = s.size() - 1; i < s.size(); i++)     {     char temp = s[i];     s[i] = s[j];     s[j] = temp;     }      cout<<s << endl;          return 0; }


Is it perfectly natural to end sentences with Prepositions?

There are numerous myths relating to grammatical dos and don’ts, many of which were drummed into us at school. The one that stubbornly refuses to budge from my mind is the diktat "never begin a sentence with a conjunction such as and or but" and "never end a sentence with preposition such as about, with, on, etc." but I would like to hear from all if it is perfectly natural to end a sentence with preposition in modern English?


I did try suppose it was a certain arbitrary p/q, but i do not how continue with that proof


How can you detect if text has overflown? For example, the following text is longer than it's div container allows. How can I detect this in javascript?  <div style="max-width: 100px; white-space:nowrap; overflow: hidden;">     Lorem ipsum dolor sit amet, consectetur adipisicing elit </div>


If two real matrices are conjugated over $\mathbb{C}$, are they then also conjugated over $\mathbb{R}$?

As in the title:  If two real (square) matrices are conjugated over $\mathbb{C}$, are they then also conjugated over $\mathbb{R}$?


Solve this: $\frac{1}{n}+\frac{1}{n+1}+\frac{1}{n+2}+...+\frac{1}{2n}>\frac{2}{3}$; without induction

How can I solve this $\frac{1}{n}+\frac{1}{n+1}+\frac{1}{n+2}+...+\frac{1}{2n}>\frac{2}{3}$; using this relation: $AM>HM$?


I am wondering : I work in a hospital or I work in the hospital ? She works on a plane or she works on the plane ? thanks


bash replace part of string based on location

I've looked around for a one line solution ( as bash offers ) to replace part of filename.  Given that a folder has image sequence like   ve2_sq021_sc001_v000.0101.jpg ve2_sq021_sc001_v000.0102.jpg ve2_sq021_sc001_v000.0103.jpg ve2_sq021_sc001_v000.0104.jpg   Need to replace only v000 with v09 ( say ). How is it possible (throughout directory).


Is it true (and under which conditions) that the products of an non-square matrix $A$ and its transpose and vice versa (so the product of the transpose and $A$) share the same eigenvalues (multiplicities omitted)?


Regex for getting parentheses within parentheses infinitely

So I have a String of text lets say "hello world () (foo bar) (foo bar 2 (this looks cozy)) (foo bar 3..." Is there a regex pattern I could use that will get the parentheses and include any parentheses inside them to nth depth. So the matches would be "()", "(foo bar)", "(foo bar 2 (this looks cozy))", ...?


How can I call a custom REST API Method simply?

I've been trying to read through the SalesForce documentation on how to call a custom Method like this via cURL:  @RestResource(urlMapping='/Test/*') global with sharing class RestTest  {     @HttpGet     global static Account getAccount()     {         Account a = [select Id, Name from Account WHERE Name = 'wizzbang' limit 1];         return a;     } }   My gut tells me this should be something as simple as:  $ curl -i -H "Accept: application/json" -H "Content-Type: application/json"  -X GET https://mydomain.salesforce.com/services/apexrest/test/   But I get back that this is unauthenticated. I've gone through the guide and it says I have to setup a "connected app." I've done this...I think. But I'm not sure what my CallbackURL should be? Further, I don't get what I need to make my curl statement look like in order to call the service? Can someone explain what I need to do? This seems horribly overengineered.


How to put MacBook to sleep using only an attached Windows keyboard?

I have a new MacBook Pro that I leave plugged in and closed because I use an external display, keyboard, and mouse. My monitor, keyboard, and mouse are also used by my PC. When I'm finished with work, I'd like to be able to easily sleep the Mac so that my monitor can automatically switch over to my home PC.  say:  Option–Command–Power button* or Option–Command–Media Eject : Put your Mac to sleep  But my Windows keyboard doesn't have a "Media Eject" or "Power" button on it. What are my other options for easily putting my Mac to sleep? I already know I could use the mouse to click Apple > Sleep. And I could open the lid and use the power button. But I'd prefer a keyboard command.


misspelled "chcecked" in the notification mail

I just received an email from Stack Exchange <do-not-reply@stackexchange.com>, which has a misspelled word "chcecked". It should be "checked".     The following items were added to your Stack Exchange global inbox since you last chcecked it on   Screenshot:


Let $A\neq\emptyset$ and bounded above. Let $-A=\{-x\ | \ x\in A\}.$ Prove that $\sup A=-\inf -A.$  We need to show that $-\inf -A$ is the least upper bound of $A.$ Suppose $x \in A.$ Then $-x \in -A,$ and, hence $-x\ge \inf -A. $  This implies that $x \le -\inf -A.$  Thus $-\inf -A$ is an upper bound of $A.$  Let $\beta$ be any upper bound of $A.$  Thus $\beta \ge x$ for every $ x \in A.$  This implies that $-\beta \le -x$ for every $x \in A$ which tells us that $y \ge -\beta$ for all $y \in -A.$  Hence $-\beta$ is a lower bound of $-A.$  Hence $-\beta \le \inf -A,$ $\beta \ge -\inf -A,$ and so $-\inf -A$ is the least upper bound of $A.$


What is tie-breaking procedure in NHL (regular season)?  How are standings for the teams in the NHL table decided. What is used as a secondary criterion, if the teams have the same number of points?    For example, with one match remaining for Detroit and Washington the positions of wild card teams in Eastern Conference are     |            | GP | pts | diff  1 | Columbus   | 82 | 93  | +15  2 | Detroit    | 81 | 91  | -11  3 | Washington | 81 | 89  | -4   (GP = number of games played, pts = number of points, diff = )  I have seen in many sources that at this point the teams qualified for the Stanley Cup playoffs are already decided and that Washington Capitals cannot qualify. But it is still possible that both Washington Capitals and Detroit Red Wings both finish at 91 points. (Capitals would have to win their last game, and Detroit would have to loose in regulation time.) Moreover, Washington would have better goal difference. So I wonder why they cannot qualify.


Apply visa of a country from another county( not your home country)

How can I apply for visa to travel to spain when I am living in Tbilisi. But i am an indian passport holder?


Consider the following MWE:  \documentclass[11pt,a4paper]{book} \usepackage[Conny]{fncychap}  %% I used Conny, but any style gives the same result \usepackage{lipsum} \begin{document} \chapter{Analytical form for ${}^3K_{rs}$ and its trace} \lipsum \end{document}   In the headers the subscripts are automatically changed to capital letters: how do I avoid it?


Scp over a proxy with one command from local machine?

I have my local.machine, the proxy.machine and target.machine. local.machine doesn't have direct contact with target.machine, but needs to go through proxy.machine.   I want to scp a file from target.machine to local.machine. Is this possible to do with just one command from local.machine?


what is the Update from iMac OS X 10.6.8

When I go into my Apple Software Updates on my OS X 10.6.8 computer to update to OS X 10.9, the computer tells me that I do not have any new updates.  How can I upgrade to OS X 10.9 if it does not give me that option?   Operating system of my iMac   Model Name:   iMac   Model Identifier: iMac10,1   Processor Name:   Intel Core 2 Duo   Processor Speed:  3.06 GHz   Number Of Processors: 1   Total Number Of Cores:    2   L2 Cache: 3 MB   Memory:   4 GB   Bus Speed:    1.07 GHz


Is there square matrix $A$ of size $3$ with real entries such that  $$ \operatorname{tr}(A)=0\text{ and }A^2+A^T=I. $$  I have proved that there is not with size $2$ using definition of  "trace", but for size $3$ it becomes complicated.  Here is the sketch of the proof for $2$. $$ a_{11}+a_{22}=0,\\ a_{11}^2+a_{12}a_{21}+a_{11}=1,\\ a_{11}a_{12}+a_{12}a_{22}+a_{21}=0,\\ a_{21}a_{11}+a_{21}a_{22}+a_{12}=0,\\ a_{12}a_{21}+a_{22}^2+a_{22}=1. $$ Putting $a_{11}=-a_{22}$ it is easy to see that above inequalities can't be true together.   Thanks!


Why speed of light is constant with respect to any inertial frame of reference?

Its getting too difficult to think.if we travel at the speed of light then will light will cross us at same speed or travel with us adjacent (special theory of relativity)


Log file is about to be larger than disk, query still executing

I have multiple databases with multiple millions of rows. I am trying to delete millions of those rows but am about to run into a problem.  My log files are getting huge and I am about to run out of disk space.   Database A has an .mdf file that is 10gb, and so far it's log file has grown to be over 100gb. It has been running the query for over 3 hours and I have no idea how much longer it will continue to run or how much larger that log file will grow.   What can I do about this? What happens to my query (that is still running!) if the log file consumes the entire disk?  I have a backup (shy the last 4 hours) of all the databases I am working with.  Any suggestions?


How can I tell if these pipes are gas pipes or water pipes?

I have recently bought a property and am re-doing the kitchen. Whilst stripping the old kitchen the builder has come accross some pipes which I ideally want removed. Have attached images of the pipes. These pipes seem to end up below the staircase and are capped over there. So they dont seem to be going anywhere further. Can someone let me know if these are water or gas pipes and if it safe to tamper with them i.e. cut and cap them at the floor level itself.!  enter image description here


I have seen some videos on how to make Ubuntu into a beautiful and efficient i3 system with all unnecessary apps removed. But rather than having to configuring such a system multiple times, I would prefer to make a flavour of Ubuntu myself. How difficult would it be to do that?


How to inset (or fill in) a complicated mesh?

I have SVG of a tree. I want to make a 3D model of it. Also I want to add a texture on the front face (on the trunk) of this tree, to make it bumpy. But how can I add a 3d texture on it? I extruded the perimeter, but how to fill in the rest?


Is the change in the Lagrangian always a total derivative for symmetry transformations of the action?

Let $\Omega\subset\mathbb R^n$ and consider an arbitrary functional $$ S\colon C^k(\Omega)\to\mathbb R $$ that is local, $$ \phi\overset S\mapsto \int_\Omega L(\phi,D\phi,\dots,D^k\phi) $$ for $L$ some $n$-form taking values in the $k$-jet space $J^k\phi$. We may call $S$ the action functional, and $L$ its associated Lagrangian (although we do not assume that $\delta S[\phi]=0$, i.e., we work off-shell).  There are two notions of a symmetry that are typically discussed:   Lagrangian symmetries, that is, transformations of the form $\phi\to\phi'$ that satisfy $$ L-L'=\mathrm d\Theta $$ for some $(n-1)$-form $\Theta$, and where $L'(J^k\phi)=L(J^k\phi')$. Action symmetries, that is, transformations of the form $\phi\to\phi'$ that satisfy $$ S-S'=0 $$ where $S'[\phi]=S[\phi']$.   If we assume that the boundary conditions are such that $\Theta|_{\partial\Omega}=0$, then it is clear that Lagrangian symmetries are also action symmetries.  If we assume that $\Omega$ is "nice-enough" (e.g. star-shaped) then I believe that any action symmetry is also a Lagrangian symmetry, although I would like to have a more precise statement about this fact. In other words, my question is     Are these two notions of symmetry equivalent? Under what conditions?   Moreover, how much can we weaken the assumptions? For example, can we take $\Omega$ to be simply-connected instead of star-shaped? Can we take $\phi$ to only have weak derivatives instead of strong derivatives?


Tips to extend battery life for laptops and notebooks

This question is present as a matter of historical interest.  While you are encouraged to help maintain its answers, please understand that "big list" questions are not generally allowed on Ask Ubuntu and will be closed per the .   It is possible to greatly extend the usage time of a laptop or netbook running on battery by disabling various services and installing various packages.   What tricks or tips do people have for getting an extra hour or two out of their batteries?


Does an adjective or longer modifier apply to both nouns when they are joined with 'and' [or 'or']?

Can you grab the blue shirts and socks?   Is the above sentence stating that both the shirts and the socks are blue? Or only the shirts?  At this stage, I am leaning towards the earlier (only the shirts) — though writing "Can you grab the blue shirts and blue socks?" seems redundant.


How to find a nether fortress in Minecraft

I need help finding a nether fortress. I'm new to Minecraft and I've searched many times and I always die trying to find one. Any tips?   The seed is 2667099037291472039 if anyone is willing to try find one.


Usage of Windows+Number combination on Windows 7

Windows 7 has built-in keyboard shortcuts of Windows+1, Windows+2 .. Windows+9, Windows+0 which allow to easily switch to the application whose Index in the Taskbar is the one used in the combination. This is very nice for the 1st and 2nd application, and even the 3rd - but what happens when I want to open the Application with Index #7? I actually need to count and see if it is #7 which makes the shortcut less friendly.  I thought of editing the Icon of each application pinned to the Taskbar and add a number to it with its index, but that seems annoying to do and does not support none-pinned applications.  Does Windows 7 support some kind of "highlighting" of the application's index when I hold the Windows key like it does for menus when I hold the Alt key?


Cant connect to mysql using self signed SSL certificate

After creating a self-signed SSL certificate, I have configured my remote MySQL server to use them (and SSL is enabled)  I ssh into my remote server, and try connecting to its own mysqld using SSL (MySQL server is 5.5.25)..  mysql -u <user> -p --ssl=1 --ssl-cert=client.cert --ssl-key=client.key --ssl-ca=ca.cert Enter password:  ERROR 2026 (HY000): SSL connection error: error:00000001:lib(0):func(0):reason(1)   Ok, I remember reading theres some problem with connecting to the same server via SSL. So I download the client keys down to my local box, and test from there...  mysql -h <server> -u <user> -p --ssl=1 --ssl-cert=client.cert --ssl-key=client.key --ssl-ca=ca.cert  Enter password:  ERROR 2026 (HY000): SSL connection error   Its unclear what this "SSL connection error" error refers to, but if I omit the -ssl-ca, then I am able to connect using SSL..  mysql -h <server> -u <user> -p --ssl=1 --ssl-cert=client.cert --ssl-key=client.key  Enter password:  Welcome to the MySQL monitor.  Commands end with ; or \g. Your MySQL connection id is 37 Server version: 5.5.25 MySQL Community Server (GPL)   However, I believe that this is only encrypting the connection, and not actually verifying the validity of the cert (meaning I would be potentially vulnerable to man-in-middle attack)  The SSL certs are valid (albeit self signed), and do not have a passphrase on them. So my question is, what am I doing wrong? How can I connect via SSL, using a self signed certificate?   MySQL Server version is 5.5.25 and the server and clients are CentOS 5.  Thanks for any advice  Edit: Note that in all cases, the command is being issued from the same directory where the ssl keys reside (hence no absolute path)  Edit (in response to mgorven):  ca.cert is the Certificate Authority certificate, which is supposed to tell mysql that my certificate authority is trusted.  The config from my.cnf is   [mysqld] ssl-ca=/etc/ssl/mysql/ca.cert ssl-cert=/etc/ssl/mysql/server.cert ssl-key=/etc/ssl/mysql/server.key   I also tried adding ssl-cipher=DHE-RSA-AES256-SHA but have since removed it as it didn't help.


This morning I selected a routine update to the system following which the system has crashed completely. The best I can achieve now is the grub prompt.  Is there a way to reverse this state of affairs?


Etymological origin of "deosil" and "widdershins"

I've been hearing the words "deosil" used for clockwise and "widdershins" for anticlockwise, but where do they come from?  I'm told that "widdershins" is from a Scottish term meaning , is this correct?  I can't find any evidence of the origin of deosil. Where did it come from? Did it originally mean something else?