In these sentences:  "Is he a director of this company?"   "Is he director of this company?"  Why don't we use the article 'a' in this question? Is there any workaround?

I'm reading a book and encountering the phrase "insert name is king" a lot. I'm wondering, what's the difference between them? When and why should I use "He is king" instead of "He is a king"?   Examples:        Tommen is king now   Yet if neither one is king, still, how could it be Lord Renly?   And he is a king, and you’re just a spy   Everyone else is a king or prince these days      Same with other words:        They elected him president.   They called him a thief.


Why is it that when you look in the mirror left and right directions appear flipped, but not the up and down?


Bothe of these phrases seem to express and depict the same meaning.   As I can remember, John was kind-hearted and tolerant; let alone, he was a man of God.  As I can remember, John was Kind-hearted and tolerant; not to mention, he was a man of God.    How to use and differentiate between them?  Dictionary: not to mention: In addition to or as well as what's been discussed; used for adding a comment that emphasizes the main idea of what you have already said.  Let alone: used for saying that something is even less likely to happen than another unlikely thing; used to emphasize that something is more impossible than another thing:

For brevity, I symbolise synonymity with ≈.  So  X ≈ Y  means  X and Y are synonyms.  From : let alone ≈ not to mention  From :  let alone ≈ much less ≈ still less.  Are these all synonyms? What are the similarities and differences between each?


Please resolve an "argument"  Which of the following is correct:  Post an HTML snippet  Post a HTML snippet  I believe it's the first - that the sound/vocalization, not the spelling, is what requires "an" instead of "a"; in other words "HTML" has an "A" sound and is, thus, verbally, a vowel. Am I wrong? The second possibility grates on my ears, and is as dissonant as all get out.

In the following example, is it appropriate to use a or an as the indefinite article, and why?     He ate __ green apple.   I know that in the case of just "apple", it would be "an apple," but I've heard conflicting answers for "green apple," where the noun is separated from the article by an adjective.  Also, which is more appropriate in this case:     He ate  __ enormous Pop-Tart.


Let $ f:[a,b]→\mathbb R$ be a function with  the following property:  For every $y\in f([a,b])$, you have exactly two $ x_1, x_2 $,such as $f(x_1)=f(x_2)=y$.  Prove that f  can not be continuous everywhere.

Suppose $f: \mathbb{R} \rightarrow \mathbb{R}$ is continuous. Is it possible for $f$ to assume each value in its range an even number of times?  To clarify, some values might be taken 0 times, some 2, some 4, etc., but always an even (and therefore finite) number. I don't require that there be a value that is assumed any particular number of times.  For example, the function might be surjective, or never take on any value exactly twice.  This question is possibly the same as . That question may instead have meant, "If $n$ is even, is it possible for $f$ to assume every value in its range exactly $n$ times?"  In any event, it has not been answered.


The Kolmogorov 5/3 law says that in turbulent flow, the energy $E(k)$ contained in a certain wave number k is proportionate to $k^{-\frac{5}{3}}$. How should one interprete this result in physical terms?  One way I considered is this. Energy is proportionate to velocity squared, the velocity of the fluid flow in the mode with wave number $k$ is proportionate to $k^{-\frac{5}{6}}$. Hence I can hope to think of this exponent as a measure of the fractal dimension of the velocity profile for turbulent flow.  Does this interpretation make sense or am I misguided?  Edit: My question is not so much of how one can justify the physical mechanism that results in the law, as the answer to the other question addresses. I am more interested in what it means to design an experiment that verifies this law.

According to Kolmogorov, the energy spectrum function of a turbulent fluid is given as,  $E(k)=C\epsilon^{\frac{2}{3}}k^{\frac{-5}{3}}$  where $\epsilon$ is the energy flux and $k=\frac{2\pi}{r}$ where $r$ is the length scale.   The normal explanation I see in most physics texts and articles is that the -5/3 exponent is found purely through dimensional analysis. Obviously dimensional analysis is very useful, but often times there is a more physical explanation as well. Does anyone have any insights?


What to do if the concatenated + mangled main.js file is just too big? It's now ~2300kB and it's ever growing. Although the dependencies are not too big by themself. We are using jQuery, jQuery UI and jqTouch. jQ is ~90kB minified and others can't be too much bigger.  So the answer "drop some deps" maybe is not feasible enough :/ Have you ever faced with a problem like that? How did you come over the problem?  Thanks  edit: Sorry my bad, I forgot to mention that it's a hybrid mobile project, so this asset will be downloaded to the device, although we have an App in Browser feature which stands for the standard way. So CDN is a good advice for App in Browser but not for the device :/

What are some standard practices for managing a medium-large JavaScript application? My concerns are both speed for browser download and ease and maintainability of development.  Our JavaScript code is roughly "namespaced" as:  var Client = {    var1: '',    var2: '',     accounts: {       /* 100's of functions and variables */    },     orders: {       /* 100's of functions and variables and subsections */    }     /* etc, etc  for a couple hundred kb */ }   At the moment, we have one (unpacked, unstripped, highly readable) JavaScript file to handle all the business logic on the web application. In addition, there is jQuery and several jQuery extensions. The problem we face is that it takes forever to find anything in the JavaScript code and the browser still has a dozen files to download.  Is it common to have a handful of "source" JavaScript files that gets "compiled" into one final, compressed JavaScript file? Any other handy hints or best practices?


protected static Object lock; public void awake(){     synchronized (lock){         if(Thread.currentThread().isAlive()){         Thread.currentThread().notify();         }     } }   I am using this code in a synchronized block so that my main method has a monitor of the thread and doesn't receive a IllegalMonitorStateException.  I don't understand why this is giving me a nullpointer exception. The thread has to be alive to execute the thread.notify command, and the lock is a static object. Nothing can be null. Any ideas?

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


At the time of executing the command sudo apt-get update I get this error in the console. I have done several things to solve it, but I still have this problem. Does anyone know what this is and how to solve it?

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


I have several questions about CDN. Is there a site recommended for this? I know the  site is about network technologies, but the CDN is about an application layer network.

There seems to be more than a few computer science/programming Stack Exchange networks (is that the correct term?). Stack Overflow, being the first, has by far the most users, questions, and answers.  What is the reasoning for creating the others, and are there clear guidelines for which kinds of questions should be posted? I can see a large amount of potential overflow, many cases of people not getting a good answer to their question, because the person who has the answer isn't browsing that particular network at the moment.  I understand that they were probably created for organizational purposes, but wouldn't it almost make more sense to just have them as categories under Stack Overflow, keep them separated but still connected, instead of making people have to create multiple 'account's, one for each network?  I am sure there was a very good reason to break them up, but as someone that is new to SE, it can be somewhat intimidating to decide which one to post in to ensure you get a good answer. For example, if I am a computer science student, my first instinct might to be to post in the computer science network, until I see that it literally has 1% of the users as the Stack Overflow network, which still seems to be for programming/computer science related questions.  So my second instinct would then to be to post it into the Stack Overflow site on the basis that I have a significantly higher chance of my question being seen and getting a good answer. Then I notice that there is also a 'programmers' network, and I don't even begin to know where that fits in. I, and I am assuming most people, will probably just post on Stack Overflow to be safe.  My question is, other than the short little description blurb of each one, is there a clear cut set of guidelines which what each network is intended for, what kinds of questions should go to each one, and is anything being done to encourage people to post in these newer, smaller (more specialized?) networks as opposed to just posting in big daddy Stack Overflow?  Now again, this is for computer science/programming/"why isn't this code doing what I want?" related questions, I am not saying that if I had a question about Linux or WordPress or something I would have the same confusion.


I created a custom pagelayout. I would like to add the sharepoint searchbox inside the pagelayout. I would like to set also the default search scope to "This Site".  UPDATE  This is the solution:  <%@Register TagPrefix="SearchWC" Namespace="Microsoft.Office.Server.Search.WebControls" Assembly="Microsoft.Office.Server.Search, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c"%>                                  <WebPartPages:WebPartZone                                      runat="server"                                      AllowPersonalization="false"                                      FrameType="TitleBarOnly"                                      title="<%$Resources:Microsoft.Office.Server.Search,LayoutPageZone_MainZone%>"                                      id="MainZone" orientation="Vertical"                                      QuickAdd-GroupNames="Search"                                      QuickAdd-ShowListsAndLibraries="false">                                      <ZoneTemplate>                                         <SearchWC:SearchBoxScriptWebPart ID="SearchBoxScriptWebPart1" DefaultDropdownNodeId="1004" UseSiteCollectionSettings="true" EmitStyleReference="false" ShowQuerySuggestions="true" ChromeType="None" UseSharedSettings="true" TryInplaceQuery="false" ServerInitialRender="true" runat="server" _WebPartId="{2243C4B0-F63F-4573-B39E-3A60BA773508}" />                                     </ZoneTemplate>                                 </WebPartPages:WebPartZone>

I am creating a custom page layout using SharePoint Designer. I want to add the search box to this page layout in  one of my div.   How can I achieve this?


I have to parse following xml in C#  <Packages>       <Package>          <PackageName>Create_Staging_Table</PackageName>          <SequenceID>1</SequenceID>          <AlwaysRun>True</AlwaysRun>       </Package>         <Package>          <PackageName>Indigo_Staging_Load</PackageName>          <SequenceID>2</SequenceID>          <AlwaysRun>True</AlwaysRun>       </Package>         <Package>          <PackageName>Indiogo_Load_Package</PackageName>          <SequenceID>3</SequenceID>          <AlwaysRun>True</AlwaysRun>       </Package>    </Packages>   I have tried   XmlDocument doc = new XmlDocument();              doc.Load(filePath);              XmlNode PackagesListNode = doc.SelectSingleNode("/Packages");              XmlNodeList Packages = PackagesListNode.SelectNodes("Package");              foreach (XmlNode node in Packages)              {                  TableLoadInstruction instruction = new TableLoadInstruction();                  instruction.PackageName = node.Attributes.GetNamedItem("PackageName").Value;                  instruction.Sequence = Convert.ToInt16(node.Attributes.GetNamedItem("SequenceID").Value);                  instruction.AlwaysRun = Convert.ToBoolean(node.Attributes.GetNamedItem("AlwaysRun").Value);                  loadInstructions.Add(instruction);              }   I have got error like "Object reference not set to an instance of an object" at node.Attributes.GetNamedItem("PackageName").value since node.Attributes.GetNamedItem("PackageName") is 'null'

Is there a simple method of parsing XML files in C#? If so, what?


I set my displays to sleep with xset dpms force off after locking the screen with kscreenlock. This is great, the displays wake up when the mouse is moved (by me, air, the cat). I'd like to set it in a way that only the keyboards can wake up the screens again.  Is there some way to do this for the KDE screen locker or in general?

I am an avid keyboard user, but I still need the mouse every now and then.  To minimize the hand travel, I have the mouse located below my keyboard.  (On a side note, using the mouse this way feels more natural to my hand.)  I am currently using  to hide the pointer while I don’t use the mouse.  Unfortunately, I am nudging it at times while typing, which causes the pointer to reappear.  Sometimes this will move the pointer over another window, which in turn takes the focus away from my current window.  (I am using sloppy focus, and changing this is not an option.)  I am now searching for a possibility to not only hide the pointer after a certain amount of idle time, but disable the mouse altogether.  Clicking any mouse button or using the mouse wheel should then re-enable the mouse.


A while ago my terminal stopped coming up when I pressed ctrl-alt-T. Then today the terminal stopped coming up when I click on the terminanl app on the dock. I use ubuntu 18.04, a lot of python and jupyter-lab.  The only way that I know of to open terminal anymore is going to Files, and right clicking somewhere and choosing 'open in terminal'. For some reason this still works.  Why is this and how can i recover all the other ways to open terminal?   On a side note, I get an error when trying to do sudo apt-get update.  [sudo] password for user:  Ign:1 http://ppa.launchpad.net/mc3man/trusty-media/ubuntu bionic InRelease      Hit:2 http://security.ubuntu.com/ubuntu bionic-security InRelease               Err:3 http://ppa.launchpad.net/mc3man/trusty-media/ubuntu bionic Release          404  Not Found [IP: 91.189.95.83 80] Hit:4 http://au.archive.ubuntu.com/ubuntu bionic InRelease                      Hit:5 http://au.archive.ubuntu.com/ubuntu bionic-updates InRelease Hit:6 http://au.archive.ubuntu.com/ubuntu bionic-backports InRelease Get:7 http://au.archive.ubuntu.com/ubuntu bionic/main Translation-en_CA [430 kB] Get:8 http://au.archive.ubuntu.com/ubuntu bionic/universe Translation-en_CA [4,118 kB] Reading package lists... Done                                                   E: The repository 'http://ppa.launchpad.net/mc3man/trusty-media/ubuntu bionic Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.   Theres a red error bar on the top right hand side of screen that always says "A problem occurred when checking for the updates".  I don't know if this is related.


Finished an online C++ course and was looking at some code, what does this mean?  DWORD remark(array<String^>^ args);   Specifically this part, I get the rest: array<String^>^ args  I don't have access to the rest of the code, it's compiled, but this is one of the functions I'm able to use.  It's like... converting an array pointer of a string of arrays XOR to an argument or something...

I just came across this code and a few Google searches turn up no explanation of this mysterious (to me) syntax.  Hashtable^ tempHash = gcnew Hashtable(iterators_);  IDictionaryEnumerator^ enumerator = tempHash->GetEnumerator();   What the heck does the caret mean? (The gcnew is also new to me, and I asked about that .)


I was studying  and this is the code .   U1 = np.random.rand(*H1.shape) < p # first dropout mask   Why does it fail when I try to do this?  import numpy numpy.random.rand(*1) < 2    I understand that the rand() function takes in a number which is why I am confused that the code is supposed to work.

Does * have a special meaning in Python as it does in C? I saw a function like this in the Python Cookbook:  def get(self, *a, **kw)   Would you please explain it to me or point out where I can find an answer (Google interprets the * as wild card character and thus I cannot find a satisfactory answer).


I have a . Sometimes randomly, it just disconnects from my router. I check my available connections and they're all there. I try connecting to my main network and it says Can’t Connect To This Network. The only fix that I've found for this is to either Restart, sleep then turn on, or shut down then turn on. I've tried turning the wifi off, then back and try again but that is no use. I've tried other methods such as disabling the network adapter in the control panel and re-enabling it. If I do this it still says cannot connect to this network. This only works on my computer. My phone and laptop is always connected to the internet even when my computer disconnects. If you have any questions, just ask me. Any help is appreciated! My specs:  Windows 10 Pro i5-4590 GTX 1650 12GB DDR3 RAM 1TB HDD PCIe 150 Mbps wireless wifi card

A little background - I have a Lenovo G50 which was running Windows 8.1 up until a few months back. Then came along the free upgrade to Windows 10. Microsoft updated the laptop OS to Windows 10, and all was fine in the first run.  But, as soon as I shut the laptop down, and powered it back up the next time, it just would not connect to the same Wi-Fi hotspot. This situation continues until today. Every time it's the same message - "Can't connect to this network".   The only way I got around this until now, was to manually reboot the Wi-Fi router, and as soon as the router would come back up, Windows 10 would instantly get connected. I have no idea how/why this worked, but while it did work fine up until sometime back, I can't keep doing this anymore. I share my apartment with a few other guys, and having to disrupt their Internet connectivity every single time I turn on my laptop - is not just a minor convenience anymore (not that they haven't voiced their concerns over this, anyway).  I looked at this  question, and tried to check my "advanced adapter options", but it all seemed correct (attaching pictures below).         All other devices [MacBook Air, MacBook Pro, iPhones, iPads, Windows 8.1 (running on a Dell and an HP)] connected to the same Wi-Fi hotspot in this apartment, work just fine.


I am trying to see the concept of tor and prvoxy  import socks import socket def create_connection(address, timeout=None, source_address=None):     sock = socks.socksocket()     sock.connect(address)     return sock  socks.setdefaultproxy(socks.PROXY_TYPE_SOCKS5, "127.0.0.1", 9050)  # patch the socket module socket.socket = socks.socksocket socket.create_connection = create_connection  import urllib2 res = urllib2.urlopen("https://www.google.com")   I started tor and ,  now want to see that in last line, request to google going from which IP. how to look at this?

I can find my IP address using ifconfig or hostname -i command.  But how do I find my Public IP?  (I have a static public IP but I want to find it out using unix command)


running:  ubuntu 14.04 trusty 64bit.  My current version is:  itamar /v/l/a/lists λ git --version git version 1.9.1   I tried: sudo apt-get update; sudo apt-get install git and it didn't work.  I tried: sudo apt-get purge git; sudo apt-get install git and still it installed 1.9.1.  not just that, somehow it uninstalled Atom and Nylas along with git and some other git related packages. I would love to know why it did that also. Below is the output from the purge process.  itamar ~ λ sudo apt-get purge git [sudo] password for itamar:  Reading package lists... Done Building dependency tree        Reading state information... Done The following packages will be REMOVED: atom* git* git-cola* git-core* gitk* nylas* 0 upgraded, 0 newly installed, 6 to remove and 0 not upgraded. After this operation, 543 MB disk space will be freed. Do you want to continue? [Y/n] y (Reading database ... 332614 files and directories currently      installed.) Removing atom (1.8.0) ... dpkg: warning: while removing atom, directory    '/usr/share/atom/resources/app/apm' not empty so not removed Removing nylas (0.4.49) ... Purging configuration files for nylas (0.4.49) ... Removing git-cola (1.9.3-1) ... Purging configuration files for git-cola (1.9.3-1) ... Removing gitk (1:1.9.1-1ubuntu0.3) ... Removing git-core (1:1.9.1-1ubuntu0.3) ... Removing git (1:1.9.1-1ubuntu0.3) ... Purging configuration files for git (1:1.9.1-1ubuntu0.3) ... Processing triggers for gnome-menus (3.10.1-0ubuntu2) ... Processing triggers for desktop-file-utils (0.22-1ubuntu1) ... Processing triggers for bamfdaemon (0.5.1+14.04.20140409-0ubuntu1) ... Rebuilding /usr/share/applications/bamf-2.index... Processing triggers for mime-support (3.54ubuntu1.1) ... Processing triggers for hicolor-icon-theme (0.13-1) ... Processing triggers for man-db (2.6.7.1-1ubuntu1) ...

I read about a security flaw in Git, which was fixed in version 2.2.1. I currently have Git 2.1.0 on my system (Ubuntu 14.10), and tried to reinstall it with apt. However, apt told me that I currently have the latest version.  The Git website does not have prebuilt versions for Linux. They say that you can install it with package managers. Without building from source, how would I install the latest version of Git?


I was getting a certain error for a while. It took long reads and days to fix it. This error could have several causes, and I learned a few of them fixing mine.  So, I was thinking about asking and answering a question to group some causes and fixes in a single thread. However, doing that will cause me to ask a general question, "What are some causes and fixes for this error?", which could be downvoted/closed for being too broad.  Is it fine if I do that? I think that would be helpful for other people.  (Note that my meta question is somewhat similar to , except that that one is about changing a question, not asking a new one.)

As I understand it Q&A style questions are  but a self answered question should be judged independently of the answer. Often after I've solved a problem I would like to share the question and answer on stack overflow (and have on a couple of occasions) but how to show "minimal understanding of the problem" is always challenging. For example I have been looking into the following question  How can I plot a straight line in the JMonkey Engine library I'm trying to plot straight lines between vertices that I specify using the JMonkey Engine 3D graphics library. So for example if I was to try to plot between: (2,0,0) (-1,0,1) (0,1,1) (1,1,1) (1,4,0) Then I would get:   This is something I do (and forget how to do) relatively often and the answer is harder to find than you'd imagine ( provides everything needed to figure it out but its spread out over several posts and isn't a complete solution on its own). Therefore I want to provide a Q&A for it but at present this question feels like it would fail the minimal understanding test  Questions must demonstrate a minimal understanding of the problem being solved. Tell us what you've tried to do, why it didn't work, and how it should work  Should I make up some imaginary problem? (Probably the final source code messed up a bit) Or mention in the question that I’m self answering to assuage some of the normal "This is not a do your work for you site" comments.


Atmospheric pressure is approximately 1 bar, but when I cover my bike pump with my finger and increase the pressure to 1 bar I can feel it pushing my finger away - how come?  I'm guessing that what bike pumps call 1 bar is actually 1 bar above atmospheric pressure - otherwise they it should read 1 bar to begin with, right?  I am disappointed that as a 4th year physicist I can't figure this out...

What are the key differences between Gauge pressure and absolute pressure?  Are there any other forms of pressure?


I'm training a classification model for highly unbalanced data where hits are pairs that have similarity of almost 1 on independent metric. Everything else are non hits. Does it make sense to pick negative samples from pairs which are at least to some extent similar?  Will it make the model more powerful?

We already had multiple questions about unbalanced data when using , , ,  and a number of other similar questions, what makes it a very popular topic! Unfortunately, each of the questions seems to be algorithm-specific and I didn't find any general guidelines for dealing with unbalanced data.  Quoting , dealing with unbalanced data     (...) heavily depends on the learning method. Most general purpose   approaches have one (or several) ways to deal with this.   But when exactly should we worry about unbalanced data? Which algorithms are mostly affected by it and which are able to deal with it? Which algorithms would need us to balance the data? I am aware that discussing each of the algorithms would be impossible on Q&A site like this, I am rather looking for a general guidelines on when it could be a problem.


I have a Google Hangouts icon on my Menu Bar that I'd like to remove.  I cannot find a way to remove it and I'd rather not install a cleaner tool just for this purpose. If a cleaner tool can do it, I should be able to do it too. Where is this stored on the file system? What I've tried so far. command drag and drop onto desktop failed. My understanding is that this indicates that it was installed by a 3rd party tool. Removed it from gmail. Removed the Hangouts Extension from Chrome System Preferences > Users and Groups > Login Items It was not listed

I have a rogue item on my menu bar from a terrible piece of printer/scanner software. I long ago removed the app, but the button for the app remains in the menu bar.   Is there any central way for me to remove an item from the menu bar? Any plist I can hack? command line trick, etc?  It's the one to the left of the Facebook icon:    (I tried holding Command and dragging it away, but it doesn't seem to respect that convention.)


I am struggling to boot the OS after shutting down last night, It is a single boot Ubuntu on a 2011 MacBook Pro, device all working last night and now all I get is this for like 20 minutes before I give up.  I tried both Shift and Escape to boot into recovery and neither seemed to work.  It mentions  [FAILED] Failed to start LSB: Xen daemons   then hangs on a start job is running for...  Any advice?

I've installed ubuntu-desktop on Ubuntu 16.04 Gnome and I picked lightdm and now once I restart, I get this error message when I press CTRL + ALT + F2:  A start job is running for Hold until boot process finishes up (Xmin Xs/no limit)   This goes on for 20 minutes+. What do I do to fix this problem or even troubleshoot?


My bike is an adult mountain bike with different gear shifts and all.   Suddenly my rear tire stopped going but the chain and everything still works - the gear and chain still spins.  What is the easiest way to fix the rear chain/cog if it's not turning the rear wheel?

Yesterday when I was biking my mountain bike on level paved path, I would pedal but get no power to the wheel.  To use a car analogy, it was as if I had the clutch in and was apply gas.  It seemed to happen most often after I coasted and then went back to pedalling.  I would pedal and realize that no power was going to the wheel.  The chain was definitely on the sprockets and moving. I could change gears no problem while I had no power.  Sometimes stopping the bike and starting again would work, or just trying again.  Needless to say, I'm taking it in as I'm not mechanically inclined, but I'm hoping to learn something.  Perhaps a link to a site that explains the problem?  So my questions.   What is going on?  I have heard of something called the "freehub".  I really don't know how bikes work though, so I'm hoping for an explanation of how one can pedal and give power to the wheel and then stop pedalling and the wheel just keeps moving (without the pedals moving).   If you are on a ride, is there any emergency adjustment to make?   For what it's worth, it's an old bike.  Circa 1993 Performance Mtn Bike.  So it's not too surprising that it's falling apart.  I haven't used it a whole lot, and have tried to wash and oil it, but I probably haven't taken the care that a biking aficionado would.  Also, besides losing power after coasting, one time I was pedaling and suddenly the pedals weren't powering the wheel.  I almost went over the handlebars!  So, I definitely want to get it fixed.  I'd just like to know a little bit about what is going on.  Thanks,  Dave.  Bonus question:  If there is enough info to make a diagnosis and you have ideas on costs to fix, perhaps you could comment on whether it's worth fixing.  Like I said, it's circa 1993 and cost about $450 then.  No shocks or anything.  Just 21 speed Mtn. Bike.


I have a simple question :  how to add / import my TTF font into Xcode so that it can be seen on 'Attributes Inspector' custom font list, so that it can be used on any components (text field, button, label, etc).  thank you.

I would like to have an app include a custom font for rendering text, load it, and then use it with standard UIKit elements like UILabel. Is this possible?


I understand that when water flowing at a faster velocity enters an area where it's flowing at a slower velocity, a  occurs. What exactly is responsible for this sudden change? Are there certain variables of the water flow that contribute to the properties of the hydraulic jump such as the jump's height?

I know that a hydraulic jump is formed when a zone of supercritical flow discharges into a zone of subcritical flow, but why exactly is a hydraulic jump formed?  From a mechanical point of view, are the only forces acting in the diagram weight and friction?   If someone could actually label the diagram with forces and explain them to me, I'd really appreciate it.


Why does some questions with no code/effort shown (of the type - "How do i..") gets many up votes, while other questions gets many down votes, for example:  2 up votes.   6 down votes   Notes/Disclaimers: This is just an example - I've saw some more similar cases. I can understand that very complex questions are more likely to get positive feedback even if there is no code or effort shown, but i am talking about question that doesn't consider as most difficult.

Recently, a guideline to demonstrate a "minimal understanding of the problem being solved" was made mandatory on Stack Overflow:  "Questions must demonstrate a minimal understanding of the problem being solved. Tell us what you've tried to do, why it didn't work, and how it should work. See also: Stack Overflow question checklist."  Despite this rule, I've found many popular questions that have remained open, even though they don't demonstrate an attempt to solve a problem before asking for its solution:                   When posting questions, I sometimes follow the example that has been set by these favorably-reviewed (but not well-researched) questions, based on the assumption that it is acceptable to ask questions like these under some circumstances. Is it now forbidden to ask questions similar to these, despite the almost entirely favorable reviews that these questions have earned?


For example, which of the following sentences is correct:  Jack, and his partner Jill, offer a new perspective on child-rearing.  Jack, and his partner Jill, offers a new perspective on child-rearing.  Does the addition of the clause "and his partner Jill" change the tense of the verb "to offer"? Should I just leave out the commas for clarity?

I am having trouble with the following sentence:      "The complexity and diversity of the new platforms is worrying us."   If "complexity" and "diversity" constitute two subjects, then the verb should presumably be "are"; however, the sentence feels more natural with "is". Is this correct? Is there a linguistic term for this occurrence?    The following questions address the general topic of compound subjects, but not specific cases like this:             And the following question seems to have somewhat inconclusive answers:         So this question is not really a duplicate of these three.


I tried "qualifying" through stack overflow and got this:     We had a look at your Stack Overflow activity but it didn’t quite meet our threshold just yet.   No surprise, I guess. I know my SO rep is low, but is there more to it than that? What is the criteria to qualify for the careers site?

What reputation do you need to have on Stack Overflow to receive an invite to Careers?  The site says "Stack Overflow grants new invites to users fitting certain criteria of activity on Stack Exchange sites, including reputation".


What is the purpose of every user's ~/.cache directory?  Under which circumstances can it be deleted, when should one be careful about its contents?

When I use disk usage analyzer and scan my home folder, the .cache folder in my home directory always shows up with a decent bit of things in it.   Would it be okay for me to delete the contents of this folder or would it damage something?


I usually find contractors who do this and I am looking for a word to explain it. They are stating a claim, they know they are terrible at doing in order to get your business.

Is there a word or phrase that describes when a person professes to know about a certain subject, but in fact knows nothing about it?


Let $\lambda$ be a nonzero real constant. Find all functions $f,g: \mathbb R \to \mathbb R$ that satisfy the functional equation $f(x+y)+g(x−y)=\lambda f(x)g(y)$.  I try this : Let $y=0$ in the equation to get $f(x)+g(x)=\lambda f(x)g(0)$ Here we have two cases:  $g(0)=0$ here $f(x)=-g(x)$  $g(0) \neq 0$ here $g(x)=\beta f(x)$ , $\beta = g(0)\lambda-1$   Is this true? And if this true how I can complete the the solution especially in case two?

The D'Alembert functional equation is $f(x+y)+f(x-y)=2f(x)f(y)$. Let $f:\mathbb{R}\rightarrow\mathbb{R}$ satisfy the functional equation for all $x,y\in\mathbb{R}$. It's well known that $f$ is of the form $f(x)=\frac{E(x)+E^∗(x)}{2}$, for some $E:\mathbb{R}\rightarrow\mathbb{C}$. How can I use this functional equation to solve the following problem?     Let $\lambda$ be a nonzero real constant. Find all functions $f,g:\mathbb{R}\rightarrow\mathbb{R}$ that satisfy the functional equation $f(x+y)+g(x-y)=\lambda f(x)g(y)$   for all $x,y\in\mathbb{R}$.


I'm going with an American friend from Belfast to Dublin by bus. Despite the lack of border control at the land border due to the Common Travel Area agreement, non-EU/EFTA nationals are supposed to get processed and stamped into Ireland even when entering from the UK - the Immigration section of the Gardai (Irish Police) has consistently told me this by E-Mail and on the phone  I e-mailed the Gardai asking about entering by bus from Belfast, and they said we should go to the Garda Station in Dundalk for entry processing.  However, Belfast-Dublin buses do not stop in Dundalk, but run non-stop between Newry (UK) and Dublin.  What is the proper procedure in this case?  UPDATE: just found the following on the :     If you arrive via the border with Northern Ireland, you must report to an immigration officer at Burgh Quay Registration Office Dublin or your local Garda Síochána (police) station as soon as possible.   I've noticed a common belief here on Travelstack that, due to the Common Travel Area, you need to do nothing as long as you were admitted to the UK. That is then clearly not the case.

With the Common Travel Area forming a partially open-border zone, what should a non-EU/Schengen citizen travelling within it keep in mind?  For example, do passports get checked, and perhaps stamped, at internal CTA borders?


How to calculate $$\lim_{n \rightarrow \infty} e^{-n} (\frac{1}{n}+1)^{n^2}$$?  The result should be $$\frac{1}{\sqrt{e}}$$  But I have no idea how to get it.  I've been only thinking of rules to multiply the $e^{-n}$ through somehow, but I don't seem to find anything. The different quantities also seem to work in different directions making interpretation difficult, since: $$e^{-n}\rightarrow 0$$  $$(\frac{1}{n}+1) \rightarrow 1$$ $$n^2 \rightarrow \infty$$  So these interactions make it difficult to say anything about this.  Perhaps there's a way to develop inequalities that show which terms will dominate when approaching infinity?

Find the limit $\displaystyle\lim_{n\rightarrow\infty}{(1+1/n)^{n^2}e^{-n}}$?  I found the limit as $e^{-1/2}$ using l'Hospital rule. I guess I made a mistake. Because the limit seems to be 1. Also, can we find the limit without L'Hospital rule?


The annotation on YS253 says that you can't use a Block or Counterspell as a defense action.  But as in Fate Core's , it makes sense that it's always possible to use magic to , rolling Discipline just like any other skill.  In that case, I'm considering the Practitioner will use a simple Evocation (and so, incur mental stress) to define an armor rating instead of weapon rating like how it works for attacks:   if he surpasses the attack roll, he succeeds in deflecting the attack. if he doesn't surpass the attack but still succeeds in the Discipline roll for controlling the spell, he gets hit but still has the armor rating to reduce the stress inflicted by the attack if he fails on the Discipline (control) roll he must deal with backslash or fallout prior to resolving the action.   The caveats on this are:   Rules become too complicated (by adding armor ratings to defense rolls). This would make attack spells less effective (or less dangerous), probably causing a lot of ties during conflicts. A successful defense roll makes the armor rating useless, so it would be just simpler to buy a use Discipline to defend against Magic Stunt or even allow all Practitioners to do that for free.   So, what would be the best option to defend with magic in DFRPG?

Say that Player X is 2nd in the initiative. 1st is the Black Court vampire that is in a rage and taking a swing at Player X. Player X gets a built in defense [Athletics/Fists + 4dF] but can Player X instead use his action this turn to cast his Rote Evocation Shield?  It is not his turn in the initiative order. A Block is an Action that a Player can take on his turn.   Thematically though, it seems to make sense that the char could cast a Rote Evocation Shield in response to an attack ahead of him in the initiative order. At least thematically in the books. Also, the example in YS252, shows him reacting to an attack by Agatha Hagglethorn by bring up his shield.  I am hoping there is some as yet undiscovered dark corner where this concept is covered or squashed.


I applied for my friend to visit me here in the uk. I am fully sponsoring his visit here. We admit we made a stupid mistake and we thought that his "bank statements" were not worth submitting. As you can see, he doesnt make alot of money and he is a full time student, working only part time. His employer stated in his application that he gets paid cash in hand. In his employment position they dont give "payslips". Upon the question of " how much are you going to spend personally on this trip" we wrote 200gbp. At the end of he application i stated that this was actually going to be paid by me (the sponsor) as i am fully funding his trip. All other documents we have, we would like to apply again if we are able to put his cash in hand cash into his bank account each month (so they can see) will this help when we reapply? it might be difficult to obtain pay slips as in his country they don't actually use these in the type of job he does....... ?? below is a copy of refusal letter. any help will be much appreciated. The decision I have refused your application for a visit visa because I am not satisfied that you meet the requirements of paragraph(s) 4.2 of Appendix V because  You state in your application that you wish to visit the UK for 14 days to visit your friend and for tourism purposes. You state that you are an employed student in Morocco with a monthly income of MAD 800 (£65 @£1=MAD12.2578) and monthly outgoings of MAD 600 (£49). You also state that this trip will cost MAD 2500 (£203) to you personally. I acknowledge that you state you will receive financial support from your friend in the UK. While I am satisfied your friend in the UK is able to provide this support, I am not satisfied having considered all the information you have provided that you meet the other requirements set out in Appendix V of the Immigration Rules.  I note that you have submitted numerous documents demonstrating the financial circumstances of your friend in the UK. However, the information provided does not demonstrate your own current financial circumstances, your receipt of your stated monthly income or how you yourself are supported on a day to day basis in Morocco. Furthermore, the information provided does not demonstrate any additional funds in your name from which you will support yourself for the duration of your stay in the UK. As such, I am not satisfied that the information provided gives an accurate portrayal of your current personal and financial circumstances nor satisfied that your intentions to visit the UK are as stated and that you will leave at the end of your visit.  In light of all the above I am not satisfied that you will leave the UK at the end of your visit and are genuinely seeking entry for a purpose that is permitted by the visitor routes. Appendix V4.2 (a) and (c).

Many of the UK visa refusals we see here share a common pattern and the prevailing reasons refer to V 4.2 (a) and (c).    I do understand that, while the applicants may describe very different individual circumstances, there's a consistent pattern and, broadly, fall into specific categories:    Credibility (lifestyle, lack of ties, visit history, lies & omissions) Funding (insufficient funds, provenance of funds, funds parking) Sponsorship (family, friends, employer)   Question: What most commonly triggers a UK visa refusal where V 4.2 (a) and (c) are given as the grounds?  Secondarily: Given that there is a clear pattern, to what extent are these refusals predictable? Does sponsorship make a difference? Is there a set of personal circumstances, however abstract, where a refusal is all but guaranteed? For example, why do those we see here on TSE who sought entry for the PLAB or British Army appear to be refused with a common theme? Is there a uniform shortcoming or is it just discrimination?   PLAB: What is about applications for a visa, for the purpose of sitting the Professional and Linguistic Assessments Board (PLAB) exam, that seem to invite refusals. After all, the test is given so that international medical graduates can show that they qualify to practise medicine in the UK. The first part, PLAB 1, can be taken in centres outside of the UK. However, PLAB 2 can be taken only in the UK. Why can't you can't get a visa just to sit the exam, promising that you'll leave immediately after?    British Army: Since Commonwealth citizens are eligible to apply online to join, even those who don't reside in the UK, why is it so difficult to get a visa just to attend an interview to see whether you are suitable? Even with an invitation from the Army, such visa applications seem to be unsuccessful. Isn't a career in the British Army a valid reason?     Lastly:  After such a refusal, what approaches would increase the chance of a successful application?


I calculated a likelihood ratio on two likelihoods from my research (LhRatio = 2 * (Time Slice Lh – Normal Lh)). I'm testing a model which is a special case of my null meaning my likelihood ratio should be equal to a chi square statistic. I therefore tested my LR with the Chi Square Dist formula on excel (CHISQ.DIST(B7,2, TRUE)). What do my output values tell me? Some example values i've received are 0.3 and 0.9.

After taking a statistics course and then trying to help fellow students, I noticed one subject that inspires much head-desk banging is interpreting the results of statistical hypothesis tests.  It seems that students easily learn how to perform the calculations required by a given test but get hung up on interpreting the results.  Many computerized tools report test results in terms of "p values" or "t values".  How would you explain the following points to college students taking their first course in statistics:   What does a "p-value" mean in relation to the hypothesis being tested?  Are there cases when one should be looking for a high p-value or a low p-value? What is the relationship between a p-value and a t-value?


I am working with population-wide data, including certain patients with a certain disease. N = 10,000. As may be expected, many characteristics of these patients' care may be compared in an article. One idea of p-values is to show statistically significant differences in these characteristics.  E.g. sex distribution, length of hospital stay between the counties etc. It feels overkill to support all these comparisons with p-values. Is there a good strategy where to show p-values?

From what I understand hypothesis testing is done to identify if a finding in the sample population is statistically significant. But if I have a census data, do we really need hypothesis testings? I was thinking may be I should perform multiple random sampling from the census data and see if there is any random behavior.


2.81a here. I am trying to add a "background image" similar to how , so that I see a screen that looks something like this:    However I can't figure out how/where to access this screen in 2.81a as the UI is wildly different. Any ideas?  I am new to Blender so if you can provide a click-by-click list of instructions it would be enormously appreciated!

Cannot find Background Images feature to add in a photo in Blender 2.8  Where is it?


In Star Trek: The Motion Picture, an entity named V'ger shows up wreaking havoc in the Sol System.    Through some inquiry, investigation and risk taking, the Enterprise crew figures out that it is in fact NASA's Voyager space probe, which had met a machine race somewhere in deep space (possibly the Delta Quadrant).  This machine race repaired Voyager to the best of their ability, gave it a ship and sent it home to Earth.  Somewhere along the way, V'ger became self-aware and wanted to know its purpose.   In fact, it was willing and able to destroy anyone it met who couldn't tell it what its purpose was.   Captain Decker allows himself to be merged with V'ger (trying to get some of the Ilia probe chick at the same time), creating a new bio-mechanical entity, which satisfies V'ger's need for purpose.    They then vanish into what Spock assumes is another dimension (but could just as easily be transwarp back to the Delta Quadrant or elsewhere).  My question is this - does this mean that Captain Decker, by virtue of merging his biological distinctiveness with that of V'ger's technology and the technology added to V'ger by the machine race, become the very first Borg?  In essence, the first Borg King to the artificial "Ilia" as the Borg Queen?  And does Decker's ultimate morality cause the Borg Queen to then seek out Picard/Locutus and Data as replacement Borg Kings?  Clearly she was very motivated to find a companion in each mention instance.   If so, then in the prequel series Enterprise, when Archer and his crew are unable to destroy the shuttle modified by the Borg drones found in the arctic (the one presumably stranded in the ice during the events of Star Trek: First Contact)  before they could send their message to an unknown location deep in the Delta Quadrant - was that message ultimately the reason for V'gers return?   Or perhaps the reason for the machine race sending V'ger back?   In essence, did we create the Borg ourselves?

I remember reading somewhere a theory that  (the being that the Voyager probe had become in Star Trek: The Motion Picture) was somehow responsible for the creation of the Borg.  Is this canonical?  Where does the theory come from?  And how exactly did it go down?


I've always seen people using interfaces of collection framework when there is a One-to-many relationship in Entity classes. For Example if Author has written many books then it Looks like this:  @OneToMany(mappedBy = "author") private List<Book> books;   and why not   @OneToMany(mappedBy = "author") private ArrayList<Book> books;   Or  @OneToMany(mappedBy = "author") private Set<Book> books;   and not  @OneToMany(mappedBy = "author") private HashSet<Book> books;   So why to use interfaces and not implementations of collection framework?

I have seen this mentioned a few times and I am not clear on what it means. When and why would you do this?   I know what interfaces do, but the fact I am not clear on this makes me think I am missing out on using them correctly.   Is it just so if you were to do:  IInterface classRef = new ObjectWhatever()   You could use any class that implements IInterface? When would you need to do that? The only thing I can think of is if you have a method and you are unsure of what object will be passed except for it implementing IInterface. I cannot think how often you would need to do that.   Also, how could you write a method that takes in an object that implements an interface? Is that possible?


Trying to create student register which should allow users to input their names. I want an error to prompted when the same name is entered unfortunately as I'm a beginner I'm finding it hard to achieve this. Is it possible to target all the names in the array? function idCheck() {   let names = ['Mark', 'John', 'Tom', 'Dave', 'Jim'];    alert('Welcome to Club 332');    let name = prompt('Please Enter Your Name');      if (names[0] === name) {     console.log('Unfortunately, the following name is taken, Try Again');   } else if (name !== names) {     names[names.length] = name;   }    console.log(names);    let age = prompt('Enter Your age');       if (age < 18) {     console.log(alert('Access Denied Over 18s Only'));     console.log('Access Denied Over 18s Only');   } else if (age >= 18) {     console.log(alert('Access Granted'));     console.log('Access Granted');   } };  idCheck();

What is the most concise and efficient way to find out if a JavaScript array contains a value? This is the only way I know to do it: function contains(a, obj) {     for (var i = 0; i < a.length; i++) {         if (a[i] === obj) {             return true;         }     }     return false; }  Is there a better and more concise way to accomplish this?


I am requesting a string from the user. After the user enters their strings a prompt asks if they want to see strings with no, one or more spaces in their strings, then displays the strings. I am running into issues with counting the spaces in the string. The code provided only counts 1 if there is more than one space in the string. Whole code: import java.util.*; import java.util.Scanner;  public class CountSpacesInStrings {  public static void main(String[] args)  {          Scanner s = new Scanner(System.in);     String[] array = new String[20];     System.out.println("Please enter anything..., or type QUIT to quit.");          for (int i = 0; i < array.length; i++) {         array[i] = s.nextLine();         boolean result = Arrays.stream(array).anyMatch("QUIT"::equals);        if(result)         {            break;        }     }     String str = null;     int len = -1;               System.out.println("Would you like to display strings with No Spaces, One Space or More? Type No, One, More to see the results: ");     String answer = s.nextLine();     if(answer.equals("No")){                  for (int i = 0; i < array.length;i++) {             int count = 0;             if (array[i] != null) {                 if (array[i].charAt(i) != ' ') {                     count++;                     System.out.println(count);                 }             }         }                           }         else if(answer.equals("One"))         {             for (int i = 0; i < array.length;i++) {                 int count = 0;                 if (array[i] != null) {                     if (array[i].charAt(i) != ' ') {                         count++;                         System.out.println(count);                     }                                              //System.out.print(array[i] + " ");                    }              }         }         else             System.out.println("No values to show");      System.out.println(); }     } The section I'm looking at is:         if(answer.equals("No")){                  for (int i = 0; i < array.length;i++) {             int count = 0;             if (array[i] != null) {                 if (array[i].charAt(i) != ' ') {                     count++;                     System.out.println(count);                 }             }         }

I have the string   a.b.c.d   I want to count the occurrences of '.' in an idiomatic way, preferably a one-liner.  (Previously I had expressed this constraint as "without a loop", in case you're wondering why everyone's trying to answer without using a loop).


So, I'm trying to change my theme from a light to a dark version in the evening, and vica versa in the morning. However, Gsettings doesn't work from Cron, and the solutions posted  and  don't seem to work, neither do those posted in the comments below them.  This is the script Cron is executing:  #!/bin/bash  #Export DBUS_SESSION_BUS_ADDRESS environment variable PID=$(pgrep -o gnome-shell) export DBUS_SESSION_BUS_ADDRESS=$(grep -z DBUS_SESSION_BUS_ADDRESS/proc/$PID/environ|cut -d= -f2-)  #Change theme gsettings set org.gnome.desktop.interface gtk-theme 'Arc-Dark' gsettings set org.gnome.shell.extensions.user-theme name 'Arc-Dark'   And this is the error I'm getting in dead.letter (Crons' way of logging errors):  grep: /proc/1098/environ: Permission denied  (process:28536): dconf-WARNING **: failed to commit changes to dconf: The given address is empty   grep: /proc/1098/environ: Permission denied  (process:28811): dconf-WARNING **: failed to commit changes to dconf: The given address is empty   I know I can use sudo -u to run the script, but I'd rather not use the root cron.

I must have a blind spot, but I cannot find what it is.   I made a small python script that removes VLC from the sound menu. It runs perfectly in any way I run it from the terminal or from a launcher or whatever you can think of.   What the script actually does is nothing more than get the get the current settings:  gsettings get com.canonical.indicator.sound interested-media-players   edit the list, and set the changed list by:  gsettings set com.canonical.indicator.sound interested-media-players "['newlist']"   These commands are executed by a python script,. However, when run from a cronjob (crontab -e) only the gsettings - get - part works, but not the gsettings - set - section. That the get section works fine with cron, I checked by making the script write data (the original as well as the edited) to an external file.  Not a python problem  To see if the problem is related to python code, I created a bash script that applies a changed sound menu items list. The story is the same: the bash script runs fine from the command line or a launcher, not from cron, while any other command in the same script would run fine. Also, if I add any command at the end of the script below, it works fine and it looks like the script is satisfied with its own work.  Why is the gsettings set command not working when initiated from cron?  This is the script:  #!/usr/bin/python3 import subprocess  def read_soundmenu():     # read the current launcher contents     get_menuitems = subprocess.Popen([         "gsettings", "get", "com.canonical.indicator.sound", "interested-media-players"         ], stdout=subprocess.PIPE)     return eval((get_menuitems.communicate()[0].decode("utf-8")))  def set_current_menu(current_list): # this takes no effect from cron     # preparing subprocess command string     current_list = str(current_list).replace(", ", ",")     subprocess.Popen([         "gsettings", "set", "com.canonical.indicator.sound", "interested-media-players",         current_list,         ])  current_list = read_soundmenu() for item in current_list:     if item == "vlc.desktop":         current_list.remove(item) set_current_menu(current_list)


I'm looking for a solution for using rsync between 2 remote servers. It seems like its not possible. Does any one know why its not possible? I ask that because I think if I know the reason, maybe I could use another tool to make it possible.  Update: I have a hypervisor on my primary site with n vm's running on. I have another hypervisor on my secondary site which I want to be the backup server for my primary server. For keeping the file synced between these two, the best way I've found is using rsync. The problem is I don't want to run my code (rsync) on the VMs because I want my product to be agent less. In this case I need to add a third computer to do run the code. Now, I need to rsync between my primary and secondary site which I'm stuck with because rsync doesn't work for remote to remote servers.

I have 3 servers.  Call them A, B, and C.  B and C are remote and only have A in their hosts.allow.  What I need to do is log into A, and then rsync over SSH the files from B to C.  I want to use rsync because many of the files are similarly present on both B and C.  I could try to rsync from B -> A and then from A -> C except I don't have nearly enough disk space on A, so I'd have to find some way of "chunking" the files and I don't see an obvious way of grouping them, and even if I did, I'd have to babysit it too much, with deleting files off A's disk, restarting the process with the next chunk etc.  So is it somehow possible for me to rsync between the two servers?  I don't think I will be able to get anyone to change the hosts.allow for me :(


In Captain America: Civil War, Black Widow says "You could at least recognise me" while fighting a 'hypnotised' Bucky. Most people suggest that it's simply a reference to her past encounters with him from The Winter Soldier and prior to that film, and possibly there relationship from the comics.  Natasha Romanoff: I know who killed Fury. Most of the intelligence community doesn't believe he exists. The ones that do call him the Winter Soldier. He's credited over two dozen assassinations in the last 50 years. Steve Rogers: So he's a ghost story. Natasha Romanoff: Five years ago I was escorting a nuclear engineer out of Iran, somebody shot at my tires near Odessa. We lost control, went straight over a cliff, I pulled us out, but the Winter Soldier was there. I was covering my engineer, so he shot him straight through me. -  Black Widow was a former KGB operative before joining SHIELD.  "At a young age[5], Romanoff was recruited by the KGB." -  Bucky Barnes was part of the Winter Soldier Program which was a Soviet/Hydra program. And apparently was given his name because of his work with the KGB.  "The Winter Soldier Program was a top secret Soviet project started by Arnim Zola that involved brainwashing American hero James Buchanan Barnes and turning him into a deadly assassin for HYDRA using a serum similar to the Super Soldier Serum." - "Receiving vast training from HYDRA, Barnes became a formidable fighter and an even more ruthless killer. His experiences with the KGB would earn him the name of the "Winter Soldier." -  My question(s), is it possible that Black Widow saying "You could at least recognise me" had much more significance than just referencing Captain America: The Winter Soldier and her experience in Iran? I understand that it may be a stretch and she hasn't really given any other indication that this may be the case. Being that she is apparently one of the worlds top spies, like Fury, she holds her cards close to her chest. Could they have crossed paths before while she was still with the KGB, but she is yet to explain/admit this? I also understand that similar questions have been asked on here before. However these questions and the answers provided do not take into consideration that the comment was referring to something that is yet to be properly explained. The answers dismiss the comment as simply being sarcastic and/or referencing Captain America: The Winter Soldier. Whereas I'd like input on whether or not the comment was or could be much more significant than this.

In the movie Captain America: Civil War, Black Widow told Bucky: "You could at least recognise me". What does that mean? Did they know each other during WWII?


so I'm fairly new to Java and I've looked up a lot of information on static methods and static fields, and nothing seems to really answer my question so I'm going to ask it here. I'm creating a program that uses an arrayList of Card objects and performs methods on those card objects. For example:  Card chooseNewCard() {     currentCardIndex = num;     return myCards.get(currentCardIndex); }   With the myCards being the name of the array.List I'm not sure if 2 part questions are allowed but my question(s) is should a method like this be static, and if so what does that say about where the objects of the class should be created? To clarify the last part, when you're dealing with static objects, should the objects be created near the instance variables, or in the main method or within another method?  Thank you in advance, again I'm very new to Java so I could be thinking about this the entire wrong way.

To be specific, I was trying this code:  package hello;  public class Hello {      Clock clock = new Clock();      public static void main(String args[]) {         clock.sayTime();     } }   But it gave the error      Cannot access non-static field in static method main   So I changed the declaration of clock to this:  static Clock clock = new Clock();   And it worked. What does it mean to put that keyword before the declaration? What exactly will it do and/or restrict in terms of what can be done to that object?


I'm following  and  example that supposedly is using gnuplot. First, I'm getting results (U15.10, gnuplot 4.6.6, Emacs 24.5, latest Ubuntu texlive) from simply pasting the code into Emacs and hitting "Latex". It produces many files, including a pdf. But upon viewing the pdf I see everything plotted well but the actual plot lines. Not sure what this means or how to correct. Also, how does this involve gnuplot? I don't see it being called.

In my .emacs I have  '(TeX-PDF-mode t)    set. So I'm using PDFLaTeX. I'm not sure why this is not the default these days. I had also set  '(LaTeX-command "latex -shell-escape")   In hindsight this was a bad idea, but I didn't realise it till  I was trying to get SyncTeX to work, but it wouldn't. I belatedly realized that because I had set LaTeX-command manually, I was overwriting the   --synctex=1   option that would normally have been there.  Which brings to my question.   Is LaTeX-command the right command to modify to add the -shell-escape option, and if so What is the right way to add an option to LaTeX-command?   @David Carlisle suggested   (setq LaTeX-command (concat LaTeX-command " -shell-escape"))   which seems to be in the right ballpark, but this gives the error:   Symbol's value as variable is void: LaTeX-command   NOTE: Evaluating LaTeX-command just gives "latex", so this may not be the right thing to append to.


There are a lot of questions concerning how NOT to cache, but no questions on how to cache JavaScript in IE(8).  I tried all 4 options under Browsing History -> Settings, but on each request the same thing happens: IE successfully downloads the newest version of the .js file. I've checked the log at C:\inetpub\logs\LogFiles\ and on every request I make, I can see that jsFile.js is requested:  2013-11-28 13:55:29 10.120.59.9 GET /developmentMachine1/js/jsFile.js - 80 - 10.241.247.58 Mozilla/4.0+(compatible;+MSIE+7.0;+Windows+NT+6.1;+WOW64;+Trident/5.0;+SLCC2;+.NET+CLR+2.0.50727;+.NET+CLR+3.5.30729;+.NET+CLR+3.0.30729;+Media+Center+PC+6.0;+.NET4.0C;+.NET4.0E;+InfoPath.3;+BRI/2) 304 0 0 62  How can I cache that file?   Edit: I'm using ASP to generate the page.  Edit 2: I solved this by adding the web.config file with the following contents in the js folder of my app.  <configuration>    <system.webServer>       <httpProtocol>          <customHeaders>             <add name="Cache-control" value="private" />          </customHeaders>       </httpProtocol>    </system.webServer> </configuration>

Which is the best method to make the browser use cached versions of js files (from the serverside)?


I watched the pilot for a series I thought I would like but now I can't find it, I can't remember what it was called.  It had a young woman with bright red hair(I think) and her eyes were like a cats. She was traveling with a human man who treated her like a daughter but he had 'adopted' her. I remember they went to a settlement and there were different types of aliens there.   At the settlement, the son of the rulers fell for a girl of a different breed.

Someone recently recommended a TV show to me. I remember them saying it starts with aliens coming to Earth, because something happened to their planet and they are in need of help. They agree to be settled or integrated somewhere, and then mysteriously the ship they had come in blows up. It leaves so much debris around the Earth that people/aliens can no longer go into space. I think he also said that the aliens have the ability to terraform.  Does anyone know what show this is/was?


I want to change bullet in itemize to specific char but I can't find solution how to put '^' and ']' char in to this... Any thoughts?  \begin{itemize}[labelindent=1.5em,labelsep=1cm,leftmargin=*] \item[+] A \item[-] B \item[\^] C  \item [ $]$] ] D \end{itemize}

I want to make an enumerated list in the following format:  [1] foo foo [2] foo foo ...    How I can do that using enumerated lists? I have tried the following:  \begin{enumerate}[\left[ 1 \right]]   but it does not work.


I am using a while loop and an if loop to determine a response and action.  For some odd reason it continues to ignore my if statements.              Boolean _exit = false;         while (_exit == false){             System.out.println("\nWould you like another meal?\tYes or No?");             String answer = scan.next().toLowerCase();             if (answer == "yes"){                 System.out.println("Reached1");                 _exit = true;             }             if (answer == "no"){                 System.out.println("Reached1");                 exit = _exit = true;             }   Could someone explain what is happening and why it is failing to check the if statements.  I've tried scan.nextLine as well.  This problem even persisted when I removed of the toLowerCase as it was brought to my attention that it can have an affect on string values, though I did try Locale.English.  Any suggestions?

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


I have an electromagnet and a 12V power supply. I would like to apply +12V to the electromagnet at some times and -12V at other times.  My current thought is to use four transistors (two NPN, two PNP) in a matrix (see diagram). I have two concerns:   When all four transistors are open, the "inside" leads will be floating. Is this a problem? If so, would a pulldown resistor on the "inside" sides mitigate it? Using two transistors (one each side) would be cheaper and take up less space, but I can't figure out a way to do it (even with diodes) that doesn't short out the power supply. Is there an easy way to do this (besides adding a second -12V supply)?   Thanks!

this is one of my first circuit "designs" (quotes on since it's simply switches). I need current to be able to flow in both directions through a certain load, and the direction of travel should be electronicaly commanded. This is what I thought of:         – Schematic created using   Sorry if it's too messy. This way, making pins 1/2 high (but never both at the same time) makes current flow in each direction. Is this a good way or is there a simpler one?


Every time, and it's now getting bloody annoying, an edit is made to this answer I get a blob notification in the "Inbox" notification icon. The answer is Community Wiki, has been forever,  and has taken a life of it's own and I really have no more interest in it:    How can I turn this off? And if not can the devs add a feature to turn this off (at least for CW posts)?

Please could we have a way to disable notifications on CW posts?  If I post a CW answer, (especially on meta) it is almost certainly because I want others to edit content into it. This means me getting 2 notifications a day is redundant and a little annoying.  When we make a CW post, please could we have the option to disable notifications on it?  I'm imagining something like this:    Maybe the notifications checkbox only appears when you tick the CW one, or it could be available for any question.


After a phd and a 1 year boring job in a private company, I finally found a postdoc position than looks very interesting to me. I am very excited to perform research again, but I would like to avoid the mistakes I did during my Ph.D. to be more efficient.  I would say that my main waste of time was that I was too disorganized.  Often I did measurements, forgot to write all the parameters, and had to do it again. I think I will now be ok on this point, with but if you have advices here, I will happily read them.  Then, my main problem and one of the things I felt very inefficient at, was bibliography research. For example, when I wanted to get information on a very precise topic, I searched through google scholar or science direct and found several articles. I tried to picked the most interesting ones, but then I often got lost in the different references cited by the article. I always felt that I had to read every of these references to get things perfectly clear and become confident on the topic. Of course this never worked, because there are usually many references and references in those references (would take ages to read them all) ... So I often ended reading only parts of all the articles cited by the main article, barely remembering what I have read.   Does someone have an efficient method to avoid getting lost in all the articles cited in one article, and all of their references ... and so on?

Often while reading a paper, I will see a citation that that seems more relevant than my current one. I'll switch to the new paper, only to experience a similar feeling. Or maybe I need to look something up on Wikipedia. An hour later, I'll still feel as if I didn't really digest anything. I will have skimmed 2-4 papers' introductions and conclusions, scratched some notes on the side, and generally feel overwhelmed.  Is this a bad habit? An abnormal feeling? How have others dealt with this to become more productive readers?  I'm fairly new to research, if that matters.


$ ls sess.vim -lh               -rw-r--r-- 1 root root 11K Feb 26 18:52 sess.vim   I want this file to be readable for everyone and writable by no one (except by root). Thus I set its permissions to 644 and ownership to root:root.    $ echo "text" >> sess.vim       zsh: permission denied: sess.vim   Seems fine. After some changes in vim I do :w! (force write) and the file is saved successfully. Now:  $ ls sess.vim -lh -rw-r--r-- 1 MY_USERNAME users 11K Feb 26 19:06 sess.vim   Wt.. Why? How?

I understand that it means force to do something.  When doing $ vim -R file I enter in read-only mode, but this works as preventive mode only   -R  Readonly mode.  The 'readonly' option will be set for all the     files being edited.  You can still edit the buffer, but will     be prevented from accidentally overwriting a file.  If you     forgot that you are in View mode and did make some changes,     you can overwrite a file by adding an exclamation mark to     the Ex command, as in ":w!".  The 'readonly' option can be     reset with ":set noro" (see the options chapter, |options|).     Subsequent edits will not be done in readonly mode.  Calling     the executable "view" has the same effect as the -R argument.     The 'updatecount' option will be set to 10000, meaning that     the swap file will not be updated automatically very often.   But what I can't get yet is why it makes the instruction to skip permissions even if the file's owner is root user, besides it also change owner & group.


I would like to to get list of all pairs of numbers between 0 and 100:  [(0,0), (0,1), (0,2),...,(99,99)]   How can I make it in pythonic way? Cause I know, that I can just append needed tuples in two for cycles.  Thank you in advance.

How can I get the Cartesian product (every possible combination of values) from a group of lists?  Input:   somelists = [    [1, 2, 3],    ['a', 'b'],    [4, 5] ]   Desired output:  [(1, 'a', 4), (1, 'a', 5), (1, 'b', 4), (1, 'b', 5), (2, 'a', 4), (2, 'a', 5) ...]


I am trying to get my Bose QC 35 to work with Ubuntu. I have managed to get the headset paired, but the headset doesn't want to connect to the PC for some reason.   Here is a screenshot of what it looks like:    When I turn on the headphones nothing happens. I have also tried going into ControllerMode and changed it from Dual mode to bredr

In System Settings > Bluetooth, the Bose QC 35 is visible when searching for devices but pairing fails.  After multiple attempts and playing with the PIN options I managed to pair it but once selected in System Settings > Sound, it would fail and fall back to Built-in Audio or playback some garbled sound.


It just occurred to me that across the different Star Trek series, there are many instances where the show's main ship or base is destroyed.  For example, in Next Gen, alternate (time looped) Picard ran from his ship while it exploded, or the crew keeps ramming Dr Frasier Crane's ship (presumably because his radio show was drawing attention away from Troi). Which show has the most separate instances of this?  To be clear, anytime a ship was physically replaced (the defiant, for example) would be the end of its run.  The new ship or base would begin as its own string of destructions.  Ships magically becoming two of the same ship,  time travel events, and the ship/base's actual destruction count.  In the situation of exploding over and over again in the same event, count it as one occurance.  As a technicality, if the ship melts instead of explodes, or is somehow destroyed in a non fiery manner, that counts too.  Finally, DS9 and the Defiant qualify as "main" for the purpose of my question.

The question "" made me wonder...  Which starship has been destroyed on screen the most?  Time travel loops count individually, but watching a recording of the same in-universe destruction only count once. For instance, only the actual self-destruct in "The Search for Spock" counts, not any replays in later films.


I've tried doing this with a subdivided plane and shrinkwrapping it to a model, then applying it as a shape-key. Unfortunately, I tend to get a lot of jagged edges and spikes in the plane when the face is extending out - and often, the resemblance to the original model is quite faint.  Does anybody have any tips or suggestions for making this look good? Could really do with the advice, have been hacking at this for some time now. =/  Best regards,  --Rev

I am trying to figure out, how vacuum packed sausages can be done in blender. The one you can buy in every grocery.  The sausages are not the problem, but the plastic packaging outside, which is normally really tight to its content  My first thought was to do it with a cloth simulation, letting a sheet falling down on it so the contours get visible. That will not work, because ... yeah it just looks like what it is... a sheet falling down on a couple of sausages...  The second thought was to use the shrink wrap modifier but that also will not work. If place a square under and over the sausages, the modifier only stretches the sheet also over the little gaps between the sausages. That doesn't look like accurate.  Is there maybe a way to let the content be a force to the surrounding package?  Its a bit complicated. The package behaves not quite like a second skin. You can see the plastic making an arc from one sausage to another but sticks very close to the content ...   Any other ideas?


Prove that if $x,y,z$ are positive real numbers then the following inequality holds $$ \frac {x+y}{x^2+y^2} + \frac {y+z}{y^2+z^2} + \frac {z+x}{z^2+x^2} \leq \frac 1x + \frac 1y + \frac 1z . $$  I tried to put all of them under a common denominator, but that didn't work. I don't know how to find something greater than the LHS and less than the RHS to prove the inequality.

Question: Prove that if $x$, $y$, $z$ are positive real numbers then the following inequality holds: $$\frac{x+y}{x^2+y^2}+\frac{y+z}{y^2+z^2}+\frac{z+x}{z^2+x^2}\leq\frac{1}{x}+\frac{1}{y}+\frac{1}{z}.$$I tried thinking of applying QM-AM, but I didn't know what variables to use. I also thought that this could be related to Cauchy's inequality, but I wasn't sure, again, of what variables to use. Any help would be greatly appreciated, thanks!


It is a homework question which wants us to prove that  $I=(x,2)=\{h(x)=xf(x)+2g(x):f,g\in\mathbb Z[x]\}$ is not a principal ideal.  I thought of trying to make a contradiction but I have no idea where to start with.  Could anyone help me with this please?

Hi I don't know how to show that $\langle 2,x \rangle$ is not principal and the definition of a principal ideal is unclear to me. I need help on this, please.   The ring that I am talking about is $\mathbb{Z}[x]$ so $\langle 2,x \rangle$ refers to $2g(x) + xf(x)$ where $g(x)$, $f(x)$ belongs to $\mathbb{Z}[x]$.


I can't see image previews on Windows 7. Only icon view on all pics. Other computers work fine. I checked the pic views

I am curious if there is a way to see thumbnails for more than the default file types (i.e. GIF, JPG, BMP, PNG) in Windows 7. I tend to use other formats like DNG, CRW, CR2, TIFF, etc., and sadly, Windows does not support thumbnail previews of these images by default.  I used to use a few registry hacks in previous version of windows, however they no longer seem to work for Vista/7. I currently run Windows 7 64bit.


I am parsing a string to an integer and it works fine until certain values. After that the result is not exact. The code will be like below  parseInt(someString);//this string will have any value.   For example when i execute the below code i get result as 18446744073709552000  parseInt(18446744073709551616) //result 18446744073709552000   But I am expecting the result to be 18446744073709551616.  Can any one tell what is wrong? And how do I accomplish what I want.  I need to check if a string exceeds the maximum value or not. So how is that possible?

Is this defined by the language? Is there a defined maximum? Is it different in different browsers?


I am currently learning symmetries/group theory and I learnt that the fundamental representation and the anti-fundamental representation of $SL(2,\mathbb{C})$ are not equivalent. This means that no similarity transformation can map one of them to the other.  My professor gave an explanation (on the 2nd last paragraph on page 75 of the following document ) but I don't see how the difference in the signs in the exponent imply that the representations are inequivalent.  Can anyone please explain the explanation of my professor, or perhaps give another explanation?

I am currently learning group theory and I learnt that the fundamental representation and the anti-fundamental representation of $\text{SL}(2,\mathbb{C})$, $2 \times 2$ matrix with determinant of $1$, are not equivalent.  This means that no similarity transformation can map one of them to the other.  My professor gave an explanation (on the 2nd last paragraph on page 75 of the following document ) but I don't see how the difference in the signs in the exponent imply that the representations are inequivalent.  Can anyone please explain the explanation of my professor, or perhaps give another explanation?


I watched a movie when I was little about a boy who was abducted by an alien (maybe by choice I'm not sure) but while he was abducted, they sent an alien or robot version of himself to take his place so his family did not know. I also remember a part where the brother of the abducted kid saw the robot/alien version of his brother at night and the alien/robot was fixing his wiring inside of his head or something and he told the brother that it was all a dream and to go back to sleep. I think that the alien place that the boy was in was like an all-white building with stars or something outside and I think one of the alien people had red or green hair. I think it is an 80s or 90s movie but not positive.

In the comedic music video  there are many clips of vintage scifi films, some of which I recognize.  This one however, of a large blue floating holographic head talking to some kind of military installation does not look at all familiar.  Does anyone recognize this film?


When I look at the  (as an example) on a beta site where I have a fair amount of reputation, I see my reviews and those of others.     However, if I look at  where I have less reputation (academia.SE), I only see my reviews.     I also see this on  (travel.SE).    and on .    Is there a reputation threshold for seeing reviews by other users in the history tab, or is there another feature/nuance at work that I'm unaware of? If so, where is this defined on the privileges page?

On Stack Overflow, where I am not a 10K user, I can only see my decisions, on review-beta/suggested-edits/history. On sites where I am a 20K user, I can see decisions made from other users.  Is that caused from my reputation, or is Stack Overflow an exception?


I have a shell script that looks something like that:    #!/bin/bash  mysql -udb_user -pdb_password -e "LOAD DATA LOCAL INFILE '/srv/some_file.csv'  INTO TABLE db_name.db_table FIELDS TERMINATED BY ','  LINES TERMINATED BY '\n'   (\`col1\`,\`col2\`,\`col3\`);"   the problem is that when I run this script on my master server the call doesnt get replicated to the slave server (even though /srv/some_file.csv exists on both servers).  any ideas how to make shell command replicate over servers?


Why are the tops of mountains covered with snow, but not at the bottom? There is always snow even on high peaks in very hot areas. It has to be very cold at the top of the mountaintop so that the snow doesn't melt. But why are they so cold?

Why there is always cold at high altitudes. e.g. at peak of mountains. Also as we go high from sea level, temperature starts decreasing. Why is it?


As I read, Jedi learn early on to 'force shield' themselves so that another Jedi cannot turn their Lightsaber off during battle.  Is there a in-universe explanation as to why Obi-wan Kenobi didn't do that in Revenge of the Sith with Grievous Lightsabers?

Lightsabers turn OFF when its wielder drops it or he/she dies. It means there's some kind of pressure button on lightsabers which needs to be always pressed to keep is ON.  In case of lightsaber throw, one uses the Force for that. It means, lightsabers can be turned ON using the Force.  Why doesn't someone try to turn ON enemy's lightsaber to do some lethal damage to someone nearby? Or, has this happened in any canon?


I know that there are several posts about colouring matrices rows and columns, but I was trying to create a diagram to show matrix multiplication, and ended up with the following code, which is a bit empirical and a bit clumsy. I was wondering if there wasn't a more intelligent way to do the same thing. \documentclass{article}  \usepackage{tikz} \usetikzlibrary{matrix,positioning,calc}  \begin{document} \begin{tikzpicture}[     every node/.style={minimum height=14pt,minimum width=1em},     every matrix/.style={matrix of math nodes,         column sep=1mm,         row sep=1mm,         left delimiter=(,         right delimiter=)}] \fill[red!10] (-1,-6pt) rectangle (1,6pt); \fill[red!10] (4.8,0) ++(-7pt,-1) rectangle +(13pt,2); \fill[red!10] (10.3,0) ++(-7pt,-6pt) rectangle +(13pt,15pt); \matrix (A) at (0,0) { \phantom{\bullet}  &        &   \\ \bullet & \cdots    & \bullet \\ \phantom{\bullet}  &        &   \\ }; \matrix (B) at (4.5,0) { \phantom{\bullet} & \phantom{\bullet}  &    \bullet & \phantom{*} \\  &  & |[rotate=90]| \dots &  \\  &  &   \bullet &  \\ }; \matrix (AB) at (10,0) { \phantom{\bullet} & \phantom{\bullet}  &    \phantom{\bullet}   & \phantom{\bullet} \\ \phantom{\bullet} & \phantom{\bullet}  &    \bullet & \phantom{*} \\  &  &  &  \\ \phantom{\bullet} &  &  &  \\ }; \node[left=3mm] at (A.west) {\tikz\draw[semithick,<->] (0,0) -- (0,2) node[midway,anchor=center,fill=white] {$m$};}; \node[above=-1mm] at (A.north) {\tikz\draw[semithick,<->] (0,0) -- (2,0) node[midway,anchor=center,fill=white] {$p$};}; \node[left=3mm] at (B.west) {\tikz\draw[semithick,<->] (0,0) -- (0,2) node[midway,anchor=center,fill=white] {$p$};}; \node[above=-1mm] at (B.north) {\tikz\draw[semithick,<->] (0,0) -- (2.5,0) node[midway,anchor=center,fill=white] {$n$};}; \node[left=3mm] at (AB.west) {\tikz\draw[semithick,<->] (0,0) -- (0,2) node[midway,anchor=center,fill=white] {$m$};}; \node[above=-1mm] at (AB.north) {\tikz\draw[semithick,<->] (0,0) -- (2.5,0) node[midway,anchor=center,fill=white] {$n$};}; \node at ($(A)!0.45!(B)$) {$\times$}; \node at ($(B)!0.45!(AB)$) {$=$}; \node[below] (a) at (A.south) {row $i$}; \node[below] (b) at (B.south) {column $j$}; \node[below] (ab) at (AB.south) {$(i,j)$-cell}; \node at ($(a)!0.45!(b)$) {$\times$}; \node at ($(b)!0.45!(ab)$) {$=$}; \end{tikzpicture}  \end{document}  Thank you for any help to make this a bit better.

I have a matrix shown below. I would like to have the whole row green rather than only the cells.   How can I do that?  \begin{equation}\label{eq:appendrow} \newcommand\x{\times} \newcommand\y{\colorbox{mygreen}{$1$}}   \left(\begin{array}{cccc}     \x  & \x  & \x & \x \\     0   & \x  & \x & \x \\     0   & 0   & \x & \x \\     0   & 0   & 0  & \x \\     \y  & \y  & \y & \y \\   \end{array}\right) \end{equation}   The output is:


I have added the language tag like so --  <!-- language: js -->  But for some reason syntax highlighting still doesn't seem to be working.   Here is the answer I am talking about --

I noticed that sometimes my code gets highlighted in different colors when rendered.   What is syntax highlighting? How does it work? Why isn't my code being highlighted correctly? How do I report a bug or request a new language? How do I use syntax highlighting? What languages are currently available on Stack Exchange?


I'm trying to compute the 2nd order correction to the energy spectrum of a 1D quantum harmonic oscillator when a perturbation of the form $\gamma\,\hat{x}^k$ (with $\gamma\ll1$) is added to the Hamiltonian. This is $$E_n^{(2)}\equiv\langle \psi_n^{(0)} | \,\gamma\hat{x}^k\, | \psi_n^{(1)} \rangle = \sum_{n'\neq n} \frac{{\left|\, \langle \psi_{n'}^{(0)} | \,\gamma\hat{x}^k\, | \psi_n^{(0)} \rangle\,\right|}^{\,2}}{E_n^{(0)}-E_{n'}^{(0)}} = \left(\frac{\hbar}{2m\omega}\right)^k \sum_{n'\neq n} \frac{{ \gamma^2 \left|\, \langle n' | \,(\hat{a}^\dagger+\hat{a})^k\, | n\rangle \,\right|}^{\,2}}{\hbar\omega\,(n-n')}\;.$$ where $\,\hat{x}=\sqrt{\frac{\hbar}{2mw}}\,(\,\hat{a}^\dagger + \hat{a}\,)\;$, $\;E_n^{(0)}=\hbar\omega(n+1/2)\;$ and $\;| \psi_n^{(0)} \rangle\equiv|n\rangle$.  Now, the question is how to compute this term: $$\alpha_{n'n}\equiv \langle n' | \,(\hat{a}^\dagger+\hat{a})^k\, | n\rangle =\left(\frac{\langle \,0\,|\hat{a}^{n'} (\hat{a}^\dagger+\hat{a})^k {\hat{a}^\dagger}^n\, |\,0\, \rangle}{\sqrt{n'\,!\; n!}}\right)\;.$$ I think it can be "easily" obtained uaing Wick's theorem but I'm not sure about how to apply it. I'm struggling with the part of counting all of the possible ways to fully-contract the operators for any $k$. Do you know any shortcut or some hint to help me compute it?. In fact, is it even manageable?.

I'm trying to evaluate $(\hat{a}+\hat{a}^\dagger)^k|n\rangle$ Where $\hat{a}$ and $\hat{a}^\dagger$ are ladder operators and $|n\rangle$ the $n$th Fock state. For this, I separated the problem in three parts: $k<n$, $k=n$ and $k>n$. In this part I'm a bit confused: Is it possible to evaluate such operations? Some tips on how to start would be really great.


Sometimes I want my question to reach a wider range of audience, are there any ways or "hacks" that can be used to achieved that?

I asked a question almost as soon as I got my account. I got a few decent answers, but none of them helped solve my problem. The question has long since become buried by newer questions, and there's still no accepted answer. Unfortunately, because there are quite a few answers with votes, to a casual observer it probably looks like the question was answered and I just neglected to mark an answer as accepted, and the system does not consider it "unanswered".  Or, I asked a question that was a bit more difficult to answer. After waiting for some time, I received no answers, little or no comments, and only a few views. The question does show up in the "unanswered" list, but no one has answered my question.  In either case, what's the protocol for me to try to get this question answered?  I see several options:   Post the question a second time, possibly linking to the original, to get attention for the original question. This is encouraged on sites like Reddit.  However, it's probably not appropriate here, since we're encouraged to check for duplicates and not submit a question that's already been asked by someone else, so this probably falls under that heading. Wait for some kind of wiki-like talk page to be implemented, then post a plea on the talk page for input and hope that activity on the talk page bumps up the question. Edit the question, but do nothing further on the Stack Exchange site. If I edit my post to say that I haven't accepted any of the current answers but am looking for more, then the question might get answered eventually by people browsing through old questions to find something they can answer. Post the question on other sites, but link to my original question on Stack Exchange. People will either answer here, or they'll answer on the other site and I can post the accepted answer here myself.  This might be considered spamming, so it might be better to do this without the link.      For more information, see the "" page in the .


I want to know how I can use the CanPLaceOn tag along with a display name for a lever.  I've tried this:  /give @p lever 1 0 {{CanPlaceOn:[log]},{display:{Name:Jungle Key}}}   This doesn't work and says:   Data tag parsing failed: Invalid tag encountered, expected '{' as first char.   What should I do?

I'm trying to create an item that can break certain blocks, but also has a colored name in 1.13.2   Here's the command I'm using.  /give iAugust minecraft:shears{display:{Name:"[{\"text\":\"Arcane Shears\",\"color\":\"aqua\",\"italic\":false,\"bold\":false}]CanDestroy:[minecraft:iron_bars]"}}   But it only has a colored name, and it can't break specific blocks.


The dark frame is extending from a random section in the camera and the issue only started after opening a blend file I was previously working on with no issues.

When looking at my objects in 3d view I'm seeing a gray cone that seems to be hiding other objects.   Can anyone help me turn this off and explain what it is please.  Screenshots attached.


How to draw a cylinder with height and radius with TikZ. According to the figure:

I am attempting to generate the following diagram in latex:    I've been using the tikz package, which although its capabilities seem to be endless, it does have a rather steep learning curve. I am currently learning how to generate simple diagrams including circles, arrows, squares, and have no idea how to include text yet. I am working through the manual so I will eventually have a good understanding of the tool, but as of yet, the diagram shown is beyond my capabilities. Could someone specify how I should go around generating this diagram? Many thanks for your help.


I just checked my WordPress site () and there is this bar that runs across the top of the page and when you click anywhere on the site it wants to open a spam page. Lucky the functionality of the site does not seem to be too compromised and this does not apply to the mobile version using chrome on an iPhone.   I am aware that many hacks can be different and it is very hard to find them and fix sites but I would appreciate pointers and helpful hints. The only reason I have not upload one of my total backups is because I am trying to fix this in a way that I don't loose orders and customer data off of the site.   Steps that I have taken to try to hunt down this hack are from this post . I have  running a scan and I will report back if I find any script injections.

This is a  about Server Security - Responding to Breach Events (Hacking)   See Also:                  Canonical Version I suspect that one or more of my servers is compromised by a hacker, virus, or other mechanism:   What are my first steps? When I arrive on site should I disconnect the server, preserve "evidence", are there other initial considerations? How do I go about getting services back online? How do I prevent the same thing from happening immediately again? Are there best practices or methodologies for learning from this incident? If I wanted to put a Incident Response Plan together, where would I start? Should this be part of my Disaster Recovery or Business Continuity Planning?   Original Version       2011.01.02 - I'm on my way into work at 9.30 p.m. on a Sunday because our server has been compromised somehow and was resulting in a    attack on our provider. The servers access to the Internet   has been shut down which means over 5-600 of our clients sites are now   down. Now this could be an FTP hack, or some weakness in code   somewhere. I'm not sure till I get there.      How can I track this down quickly? We're in for a whole lot of   litigation if I don't get the server back up ASAP. Any help is   appreciated. We are running Open SUSE 11.0.            2011.01.03 - Thanks to everyone for your help. Luckily I WASN'T the only person responsible for this server, just the nearest. We managed   to resolve this problem, although it may not apply to many others in a   different situation. I'll detail what we did.      We unplugged the server from the net. It was performing (attempting to   perform) a Denial Of Service attack on another server in Indonesia,   and the guilty party was also based there.      We firstly tried to identify where on the server this was coming from,   considering we have over 500 sites on the server, we expected to be   moonlighting for some time. However, with SSH access still, we ran a   command to find all files edited or created in the time the attacks   started. Luckily, the offending file was created over the winter   holidays which meant that not many other files were created on the   server at that time.      We were then able to identify the offending file which was inside the   uploaded images folder within a  website.      After a short cigarette break we concluded that, due to the files   location, it must have been uploaded via a file upload facility that   was inadequetly secured. After some googling, we found that there was   a security vulnerability that allowed files to be uploaded, within the   ZenCart admin panel, for a picture for a record company. (The section   that it never really even used), posting this form just uploaded any   file, it did not check the extension of the file, and didn't even   check to see if the user was logged in.      This meant that any files could be uploaded, including a PHP file for   the attack. We secured the vulnerability with ZenCart on the infected   site, and removed the offending files.      The job was done, and I was home for 2 a.m.            The Moral   - Always apply security patches for ZenCart, or any other CMS system for that matter. As when security updates are released, the whole   world is made aware of the vulnerability.   - Always do backups, and backup your backups.   - Employ or arrange for someone that will be there in times like these. To prevent anyone from relying on a panicy post on Server   Fault.