Several times I have met young visiting faculty members who got "bought out" of teaching. This means that some senior professor opened their grant treasure chest and pays money so their younger co-worker needs to teach one course per semester less than usual.   How does that actually work? On the department side, they probably need manpower to offer courses to their students. Does somebody else do the job then (for the money) or what is the background with those buy-outs? Can people buy out themselves? Who can do such things and what are the official and unofficial issues with such a procedure?


I need a Iterator<Character> from a String object. Is there any available function in Java that provides me this or do I have to code my own?


In Python:  s = "Gwen Stefani" a = s[:0] b = s[0]  print type(a) # str print type(b) # str print len(a)  # 0 print len(b)  # 1   I understand that s[:0] is empty, but it also means from the start of the string so I would have thought that:   s[:0] is the same as s[0]


Register and enqueue conditional (browser-specific) javascript files?

The WP.SE community has always advised the use of wp_register_script and wp_enqueue_script for adding scripts in a theme/template (and likewise, wp_register_style and wp_enqueue_style for stylesheets).    This is how I register and enqueue my scripts...  First, I add something like this in functions.php  add_action('init','wpse54189_register_script'); function wpse54189_register_script(){      //Register scripts     wp_enqueue_script( 'jquery' );     wp_register_script( 'aahan_bootstrap_transition', get_template_directory_uri().'/js/bootstrap-transition.js');     wp_register_script( 'aahan_bootstrap_carousel', get_template_directory_uri().'/js/bootstrap-carousel.js', array('aahan_bootstrap_transition'));         wp_register_script( 'wpse54189_ajax_comment', get_template_directory_uri().'/js/no-reload-comments.js'); }   then call it in a template file (say, header.php) like this  <?php wp_enqueue_script( 'aahan_bootstrap_carousel' ); ?> <?php wp_enqueue_script( 'wpse54189_ajax_comment' ); ?>     Now, coming to the point, how do I register and enqueue "conditional JavaScript files" that are there to be recognized by specific browsers? For example:  <!--[if lt IE 9]> <script src="<?php echo get_template_directory_uri(); ?>/js/html5.js" type="text/javascript"></script> <![endif]-->   How do I register and enqueue this properly?  PS: I use the , developed by the theme wranglers at Automattic. And the theme's header.php directly uses the just aforementioned code -- i.e. it's not enqueued. So, does that mean, it's the only way to do it?


Unable to upgrade/update iPad 2 from iOS 5.1.1 (to iOS to 9.3)

I have an iPad 2 (MC769LL/A) that is running iOS 5.1.1. I need to update the OS. The device is telling me there's an update for 9.3, but I'm getting an error saying unable to verify the update because I'm no longer connected to the internet.  Before you even suggest it, I did all these things mentioned here (and everywhere else): . Is this iPad in un-update-able hell? Is there some way I can manually update it to a lower version than 9 as a stepping stone?


I wanted to make a bash script that takes a random picture from a folder and sets it as the desktop background. I figured out the algorithm (it's not hard) but I can't find a command that would change the background picture if you give it the path to the picture.   I found gconftool for bash 2.~ and gsettings for bash 3.~, but i have GNU bash, version 4.3.42(1)-release on Ubuntu 16.04 LTS and these don't work.


Does MISSINGNO. actually destroy saved game files?

The effects of the MISSINGNO. glitch in Pokemon Red and Blue have    sources. Encountering MISSINGNO. corrupts Hall of Fame data, causes temporary graphics glitches, and sets the most-significant bit of the 6th item in the player's inventory.  That said, there are also a lot of rumors about MISSINGNO. and its origins. There are many sites online that claim that MISSINGNO. can delete saved game files, but I've yet to find any actual verifiable claims that support this.  Are there any verifiable reports of MISSINGNO. actually deleting saved game files or otherwise rendering an existing save file unusable? Or is this just another urban legend?  Thanks!


How do you indent code in the post editor?

Possible Duplicate:          When writing code in SO, I always press Tab to indent my code. It doesn't work. Instead, I lose focus on the question text area.  To actually indent, I use Spacebar, but doing this to many lines of code is annoying.  What is the right way to indent code?


What equation would give me a graph like this?

Is there some equation that will give me a line/curve that will pass through two points (say, the origin and (1,1)), and allow me to adjust the bend of the curve between these two points, by manipulating some variable in that equation?  Here's an image to show what I mean:   Sorry if this is a poorly asked question - I'm not too sure how else to ask.  Thanks


closure of a convex set in a normed linear space is convex ?

Is it true that if $A$ is a convex set in a normed linear space $V$ , then the closure of $A$ is also convex ? (I know that the interior is convex )


Putting questions On-Hold from the moderator queue does not clear mod flags

While handling flags over the past few days, I've noticed something odd. It seems that when closing a question from the queue using the queue's "Close Question" button, the flag is not marked as handled.  I have noticed this in a couple circumstances. First, by questions I have put on-hold myself; when reloading the queue, or refreshing the question's page, I still see the flags there. Also, I have seen flags requesting closing, and seen that another mod has viewed and closed the question, yet the flag remains.  The only other automatic-handling situation was for deleting posts; this seems still to mark the flag(s) as handled as before; it seems only to be Closing which has this trouble.    Per the comments and further information, it seems this only applies when the post has had a Custom flag on it. That makes sense, and I'll be testing it (for example, on one with only a close flag).  In the meantime, I'll note that if intended, the UI could use some improvement there, as the way is works now once we close the question, it's not apparent that the flag(s) are still present.    Just confirmed with a Low Quality flag that when closing from the Mod Queue, the flag is indeed cleared.


I see a lot of website down in the footer from the Stack Exchange group. Where can I get a brief description of each of them rather than going on each website and look what it talks about.


How can I print a length of hsize (Horizontal size) in mm (millimeter)?

I am new to VTEX. How can i solve this??  \documentclass{article} \begin{document} \the\hsize \end{document}   Output: 345.0 pt  but i have to write a macro to calculate hsize in mm example: \printdimen[mm]\hsize  and if i take hsize 6.5in then what will be output in mm?


I'm making a 2d rpg game with libgdx and java, and I'm wondering how I would organize different attack systems - magic, melee, etc. (it's not a turn-based rpg). I have a PlayerClass enum, a Player2D class(2d representation), and a Player class (for storing player data). Would I make an Attack class, with MagicAttack and MeleeAttack? Then have a method in Player2D like attack(Attack attack)? I've considered a few options, but I want to be sure. Thanks!


Why do I get a black rectangle instead of my external picture?

I write some of my network notes in TeX. I wanted to make a table, and inside it insert an image:   .   I wrote a document:  \documentclass{article} \usepackage[demo]{graphicx} \usepackage{booktabs} \usepackage{array}  \begin{document} \begin{tabular}{m{3cm}m{3cm}m{5cm}} \toprule Configuration for ... & Commands & Topology\\ \midrule PPP: CHAP, PAP & \#sh int se 0/0/0  & \includegraphics[width=4cm, height=4cm]{chappap.png}\\  & & \\ \bottomrule \end{tabular} \end{document}   But instead of my network topology image, I see only this: .   I don't know what is wrong, cause my image is 100% in the same dir, as my *.tex file.  EDIT:  Changed my code as @Jubobs suggested, now everything is as I wanted:  \documentclass{article}     \usepackage{graphicx}     \usepackage{booktabs}     \usepackage{array}      \begin{document}     \begin{tabular}{m{3cm}m{3cm}m{5cm}}     \toprule     Configuration for ... & Commands & Topology\\     \midrule     PPP: CHAP, PAP & \#sh int se 0/0/0  & \includegraphics[width=4cm, height=4cm]{chappap.png}\\      & & \\     \bottomrule     \end{tabular}     \end{document}


Is there any reason to have an SSL certificate on a forward-only domain?

Our company acquired a new domain name a few years ago and have been forwarding (a significant amount of) traffic from our old domain, which no longer hosts content. Is there any reason to continue paying for an SSL certificate installed at the old domain?


I am having 2 textboxes and applied timepickers. Here I am leaving textboxes to null i.e not giving any date and sending to db as a fromdate and todate parameters. in msql storedprocedure if Fromdate and todate are empty, one action is performed.inorder to do that task I have taken 2 variables  DateTime fromdate; DateTime todate;   and declared as a Datetime in codebehind.  fromdate = Convert.ToDateTime(txtfromdate.Text); todate = Convert.ToDateTime(txttodate.Text);   When I am sending to db  fromdate = Convert.ToDateTime(txtfromdate.Text); todate = Convert.ToDateTime(txttodate.Text);   it is getting error.formate exception. Is it possible to apply null to datetime variables?


I'm writing an article on  and some people pointed out that this is completely useless.  My idea is to amend my article with some theories that seemed useless when they are created but found use after some time.  I came with some ideas like the Turing machine but I think I'm not grasping the right examples.  Can someone point me some theories that seemed like the Lychrel numbers and then become 'useful'?


Is "Linear Algebra Done Right 3rd edition" good for a beginner?

Amazon book reviews say it takes unorthodox approach and is for a second exposure to linear algebra. I didn't have a first exposure to linear algebra.  Is this book going to be bad for me, then? Or, should I read another linear algebra book after reading it? I want to avoid reading two linear algebra books because reading such a textbook consumes a lot of time.


Windows 8 install problems on a desktop PC

I'm trying to install Windows 8 on a brand new drive and have encountered a few problems.  My error message (as shown in the photo) is: "We couldn't install windows in the location you chose. Please check your media drive. Here's more info about what happened 0x8007045d".    I have two other similar posts - I figured it may be less daunting to tackle if I split the large problem into individual units.


There's target object and cutter object, boolean modifier can work for one frame, but how can I use animation node to cut the target with cutter object and keep the all history cutting. I have tried almost all nodes, can't find the solution.     Expected result:    You may think why not using a invisible full size object to cut it. A case is CNC simulation, engraving a human face like a coin.


Methods for meta-analysis: z-transform (Stouffer's approach) vs. Fisher's method vs.... infinite others?

Fisher's method and Stouffer's approach (z-transform) for meta-analysis roughly follow the same scheme:   take the p-values from some different experiments on the same hypotheses apply to them some monotonic transformation sum the transformed values together check the result against some well-known distribution.   Now, my question is: what is the rationale for step 2? P-values are (under the null hypothesis) uniformly distributed over [0,1]. The sum of $n$ p-values hence already tends to a normal distribution (and the approximation is fairly good already for small values of $n$).  This is not just a theoretical curiosity. The p-values I am working with come from Mann-Whitney tests (but many other examples could be made). There is a strictly positive probability (under the null, but also under my H1) that the (one-tailed) p-value for a given test is 1. If this happens, the aggregated p-value according to the Z-transform method is also 1 (unless there was some test which yielded a p-value of 0 - let us assume this is not the case), simply because the normal distribution has $cdf(c)=1$ for $x \to + \infty$. And this is true whatever the number of p-values we are aggregating! To make an extreme example, if one p-value is 1, the other 100 are 0.1% and I know that a p-value of 1 has a 10% of probability to arise by chance, my intuition is that the null hypothesis should be rejected - instead the aggregated p-value is 1.  What is wrong with just summing up the p-values, and then comparing them to the appropriate normal (or Irwin–Hall, or even a discrete version of it, if it's a matter of accuracy) distribution?!  Even in cases in which the above problem does not arise, I fail to see why extreme p-values should be given higher importance: and if there is a reason, then how much importance should be given to them (i.e. how the specific transformations used at step 2 can be justified).


My problem is that I would like to write something like in LaTeX:   But I can't seem to do it wihtout reading like:   Which is pretty anoying to do all the time, in the middle of writting. Is there a code to do it for a whole paragraph without written \hspace*{1,5 cm} in middle of a sentence


Protecting AVR flash from reading through ISP?

I'm trying to protect whole flash from reading through ISP. It has bootloader, able to self program application section.   Setting lock byte to:   LB1/LB2 will not let user to use bootloader to upload new firmware.   BLB12/BLB11 and BLB01&BLB02 will not prevent reading flash through ISP, if I am not mistaken.   So there is no way to let user update firmware by custom bootloader and protect flash from reading at the same time?


Keyboard shortcut to unhide or unminimize a window in OS X

I know how to Hide (Cmd+H) or Minimize (Cmd+M) a focused window in OS X, but I can't find a keyboard shortcut or even a menu item to restore, unhide, unminimize, or otherwise show a window that I've hidden or minimized.  Anyone have a suggestion?


What are CNRS research units and how are they staffed

The  is the major funding body in France. With nearly 32,000 staff members it is bigger than the  and  combined, yet only has a 1/10 of the budget.  Both CNRS and NIH have multiple institutes (although the NIH institutes are all health related and CNRS covers a range of science). The  then has 952 mixed research units, 32 proper research units, 135 service units, as well as 36 international units while the NIH has a large number of intramural labs.  What are these different research units and how are they staffed (full time researchers or academics with other teaching duties)? Is it at all like NIH intramural labs or MRC centres?


Hey all i am trying to find the section within the edit.php page where it populates the table with all my current pages. What i want to do is add another colum to the table in order to launch a side page for changing a picture.    Could anyone point me to the code that populates the table?  Thanks!  David


Switching between windows with scroll wheel on Ubuntu Dock

I would like to switch between windows using the scroll wheel of the mouse over each app icon in Ubuntu dock, as we could do in Unity, but apparently this doesn't work in Ubuntu 17.10. Is there a way to enable it?   Related:


Help identifing a book about people exiled to the distant past

This book (pre-1980s?) is about people who are exiled to the distant past for serious crimes. However, men and women are exiled to different time periods. So all men are sent to a certain time, but are separated from the women (who are sent to another period).


JQuery is not getting fired when  is constructed programmatically

Please have a look at my JavaScript     Now the associated HTML

text

   What happens is that when the above JavaScript code gets called, it adds
 elements to li_list. As you can see, I have already hard coded one
 element there as well.  Now when the
 element is called, the below Jquery code needs to be executed.        Now the thing is, the above Jquery code gets called only for the hard coded
. It never gets called for the
 element I added via the JavaScript.  How can I fix this?


How to open the "File Browse" dialog from PyQGIS plugin code?

I am in the process of developing a plugin for QGIS using Python. Note that this is my first plugin, so the query could be quite basic...   I have used  to create the basic plugin, and (quite surprisingly found it easy) created the plugin files.   I am stuck at a very basic concept. Previously, while using Python IDLE, using   QtCore.QObject.connect(self.Input, QtCore.SIGNAL("clicked()"), self.OpenBrowse)   to signal a click and writing a function OpenBrowse      def OpenBrowse(self):         self.Input_TB.setText(filename1)   I was able to open the Windows File Browse window on click and set the File location to an adjoining text box.   How do I do this while developing the plugin in the Python file that is created by Plugin Builder.? I am very confused about where should the code be written? Because if I place the 'clicked()' actions, etc. in the Python file generated from the UI file, it is not recognizing the variables as they are not global (obviously).   I am using QGIS 2.4, on a Windows 32-bit system.


We have put build breakers in our CI process for failing the build for insufficient junit coverage. The problem is with how to increase the code coverage because earlier we had broken down the methods in to smaller private methods due to sonar complexity issue.Now we need to work our way to add more junits to test each of the methods.  what are the best options?  1) Change the access modifier to protected or default? I have already seen the question of how to test private method. 2) Use reflection? 3) how best to work towards increasing branch coverage?  Example:      Class A {      public Object complexLogicMethodA(){        //1.Call private method B         methodB();      //2.Call private method C         methodC();      //3.Call private method D         methodD();      //Based on      }      private methodD(){      if(){      //some code here      }else{      //Some code here      }   } }


Does anyone know of a relationship between the number of zeros (complex and real) and the degree of a polynomial?  Specifically, if a polynomial has a double root, is it compensated with complex zeros?


Suppose that $(U,V)$ has the following joint pdf: $$f_{U,V}(u,v)=\exp(-\theta u-\theta^{-1}v)$$ , where $u\geq0$, $v\geq0$, $\theta>0$. Define $X=UV$ and $Y=U/V$. Find the marginal pdf of $X$ and $Y$.  With transformation, I got $U=\sqrt{XY}$ and $V=\sqrt{X/Y}$ and the absolute value of Jacob is $1/2Y$. Then, the joint pdf of $(X,Y)$ is  $$f_{X,Y}(x,y)=\exp(-\theta \sqrt{XY}-\theta^{-1}\sqrt{X/Y})1/2Y, X,Y>0.$$  But I am not sure how to get the marginal pdf?  Thank you!


How to back up MySQL databases to SQL files?

I'm having significant server issues at the moment, and am worried the server will go at any moment. I need to backup my SQL databases immediately.   Could I please get a command just to dump all my databases (different domains) into their own sql backup files?  I'd like to work with this cron syntax, since it already works fine for backing up individual SQL files.   mysqldump -uadmin2 -p$(cat /etc/psa/psa.my/.psa.myshadow) MyActualDB > /var/www2/backup/mybackup1.sql   The above syntax is just for one SQL file. But I need to add:  all-databases   syntax in there somewhere. Also, for each backup, to backup to their own SQL file (preferably using their already established database name).


In an Inn, while trying to speak with someone I accidentally picked up an item, stealing it. The Inn's owner and wife immediately began attacking and chased me out of town. Every time I go back into the Inn, the two immediately recognize me and chase me out of town again.  Is there anything I can do to get forgiveness in the Inn?


Correct numbering and reference for appendix

In my paper, I tried to create an appendix and refer to it from the main text.  I tried to post it a very easy example. It does not depend on the journal class thus I don't know what's wrong with this simple syntax.    \documentclass[a4paper,10pt,draft]{article} \usepackage{pslatex,graphicx}  %opening \title{bla bla} \author{a, b, c} % \begin{document} % \maketitle % \begin{abstract} ipse dixit  \end{abstract} % \section{ introduction} % In Figs.~\ref{figA1}, \ref{figB1}, \ref{figC1} % Should be: In Figs. 1, 2, 3 \section*{Appendix} % \appendix % \begin{figure*}  \centerline{\includegraphics[width=0.2\textwidth]{figureB1.png}}  \label{figA1} \caption{Ipse dixit...}  \end{figure*}  \begin{figure*}  \centerline{\includegraphics[width=0.2\textwidth]{figureA1.png}}  \label{figB1} \caption{See Fig.~\ref{figA1}.} %Should be "See Fig. 1"  \end{figure*}  \begin{figure*}  \centerline{\includegraphics[width=0.2\textwidth]{figureC4.png}}  \label{figC1} \caption{See Fig.~\ref{figB1}.}  %Should be "See Fig. 2" \end{figure*}  \end{document}   I add two explicative images here:     shows the numbering in the main part of the text. Which should be "1, 2, 3" not "1, 1, 1" and the      shows the reference calling in the  appendix itself which, again, is wrong.  Many thanks in advice for your help.


There is a minor bug in the display of deleted comments (visible to ♦ moderators and SE staff only) that is, well, bugging me. Background , which is very handy when we're trying to evaluate certain flags and evaluating whether or not a user is being abusive in some way. Unfortunately, the view for deleted comments seems to have a bug. Ordinarily user display names in certain on-screen elements—flair below a post, comments, edits in a post's revision history and certain "deleted by" blurbs—get a special background if the action was by OP, like these examples:   On SO Main, the highlighting happens to be blue, but it varies by site. Other users—that is, anyone other than OP for a given question—aren't highlighted. The Problem When comments by OP get deleted by someone other than OP, the deleting user is given this OP-specific highlighting nonetheless. In other words, on each of OP's comments, the deletion user's display name has the highlighting, but on each comment by any other user, the deletion user does not have the highlighting. This seems to happen regardless of whether the deletion was by a ♦ moderator or because of flags on particularly bad comments. I'd include a screenshot, but it's basically impossible without redacting it for privacy reasons to the point that the highlighting is hidden, anyway. This is clearly not a major, site-breaking bug, but it is making life a little harder on moderators, or at least this one. Proposal Please fix this! It seems like it's just an incorrect condition causing a class attribute to be given an incorrect value.


get reference to the script as HTML DOM element from itself

How can one refer to the script itself as an element of HTML DOM from inside the script using pure javascript?  The purpose of this is to manipulate other elements of HTML DOM relatively to script.  Something like <script>this.previousSibling ... this.nextSibling ... </script> .


As a non native English speaker I've always found the following form strange:  Said Hamlet, "To be, or not to be".   I would more naturally say:  "To be, or not to be", said Hamlet.   Is there a stylistic difference between the two?


Why do we need to repeat the verb "to be" in this kind of statements?:   She is being kind to me.   It is supposed that the second "be" takes a meaning of the verb "behave".


How to model the curly cable part of the phone

Hello. I am a beginner in Blender. I started modeling this phone and when I got to the curly cable part it was a real challenge. Could someone guide me on this.


I'm from Pakistan and live in Turkey.  I have one year residence permit of Turkey.  Can I apply for schengen visa from Turkey and what will be required documents for it


Rendering a cube as png file using Blender's Python API

I am new to Blender. I create a cube and want to render it. Since, we are later going to do this for large number of shapes, we are working with Blender's Python API. I want to save this rendering as a png.  I have the following code:   image = bpy.ops.mesh.primitive_cube_add(radius=1, location = (0,0,0)) image.save_render("/Users/tarun/Work/check.png")   But it gives an error :      AttributeError: 'set' object has no attribute 'save_render'   Although when I do only bpy.ops.mesh.primitive_cube_add(radius=1, location = (0,0,0)), it shows the cube in the scene.   How can I create and save a shape like cube from the Python console in Blender?


MathJax website is Shutting Down? From where we now getting support?

SE network mandates a programing language called MathJax, to format chemistry or math equations.   The left click on MathJax processed text shows the following icons:   . Fig 1. MathJax processed text from Puzzling SE .   Now, a further click on "about MathJax" and "MathJax Help"; leads to following flashcard:     Fig.2:  MathJax Help   The help box refers the website.   . (Certainly it is the official website of MathJax?)  Now shockingly; the website tells; they are closing their service!    Also it is not very clear to me from their  link that whether they are completely closing their service or it is a temporary pause. They also telling to download local copies.   .......................................................  Now, how the SE questions and answers will survive if MathJax provider official website shuts down? what alternatives are being thought? Is there any chance of existing Mathjax and mixed-formatted portions of Q/A could break-down?


Developing Unit Tests While Refactoring Legacy Code?

I have a big code library that I need to refactor in order for it to fit more nicely together (one big problem is there aren't clear enough boundaries between each component).  Since there will be some regression testing necessary to validate any refactoring, would it make sense to:   Create a unit test for a particular piece of code Run the unit test and make sure it passes Refactor the code and check that the unit test still passes   This seems like a good idea to start using a TDD approach to this refactoring process, although my biggest concern is that I'm writing unit tests after the existing code (instead of writing the code after the unit tests).    Since I'm writing unit tests AFTER the code, should I first refactor, do my own regression tests, then continue using the TDD steps (write failing test, write passing code, refactor, repeat)?


Why are Stack Exchange websites so strict?

I'd love to just ask a simple question and not have to worry about spending a large amount of time to make it perfect. Why is Stack Exchange so strict on question format and content?


Using local MySQL Database in JPA driven Java Application

I'm trying to create a Java application that will run on a hypothetical client machine, where members of staff can both view or add customer details from a local MySQL database. I'm trying to use JPA to do so, with query methods being in this form:  public class DataManagerImpl implements DataManager{ @PersistenceContext  private EntityManager em;   public List<Customer> AllCustomers(){     TypedQuery<Customer> query = em.createNamedQuery("Customer.findAll", Customer.class);     return query.getResultList(); } }   I've got a DBConnection class:   public class MyDBConn implements DBConnectivity { @Resource(mappedName="jdbc:mysql://localhost:3306/solsoft_DB") DataSource dataSource;     Connection myConn = null;      public Connection open_Connection() {      String user = "root";      String pass = "password";       try {         Class.forName("com.mysql.jdbc.Driver");         myConn = dataSource.getConnection(user, pass);         return myConn;     } catch (Exception exc) {         exc.printStackTrace();         return myConn;     }   }}   And then in my main method:  DataManagerImpl dm = new DataManagerImpl();     List<Customer> allCustomers = dm.AllCustomers();      for(Customer c : allCustomers){        String cust = "" + c.getForename() + " " + c.getSurname();         System.out.println(cust);     }   I'd really appreciate if anyone could point my in the right direction on how to actually go about getting some information from the DB using JPA in this way.


What is the status of the LaTeX3 Project?

I was just downloading a new copy of LaTeX for my Mac and I noticed this comment on the www.latex-project.org website:  The LaTeX3 Project  LaTeX3 Project  The LaTeX3 project is a long-term research project to develop the next version of the LaTeX typesetting system.  So I looked at  and it refers to the .  So it's been 20 years since the Mittlebach and Rowley article came out. That's certainly long-term. Did LaTeX3 ever happen?


Civilization 5 - Science victory vs. conquering the capital

So, an AI civ was on the verge of a science victory when I managed to conquer its capital. My question is: what happens now? Have I prevented a science victory for that Civ unless it takes back its capital? Does it just have to bring the one remaining part to its new capital? Or does it have to rebuild all the parts and bring them to its new capital?  What few hints I've found in Googling suggest things may have changed at some point, so just to be sure, this is with both G&K and BNW.


Continuous Lorentz Transformation for time-like and space-like points

On the page 28 of the book "An Introduction to Quantum Field Theory" by Michael E. Peskin and Daniel V. Schroeder in the last paragraph it says: "When $(x−y)^2<0$ we can perform a Lorentz transformation taking $(x−y)→−(x−y)$. Note that if $(x−y)^2>0$ there is no continuous Lorentz transformation that takes $(x−y)→−(x−y)$."  Is the fact that there is no continuous transformation due to the necessity of having to cross over the null surface of the light cone (see fig. 2.4 in the book) to get from say, $t$ to $–t$, and therefore the transformation cannot be continuous? If so, if this could be explained I would appreciate it.


Let $\Bbb{Z}^+$be the set of all non-negative integers where $n$ and $k$ are given natural numbers. We consider the following non-decreasing function,  $$f:\Bbb{Z}^+ \to \Bbb{Z}^+$$ such that   \begin{align} f\left(\sum_{i=1}^{n} a_{i}^{n}\right)  =\frac{1}{k}\sum_{i=1}^{n} \left(f(a_{i})\right)^{n}\\ \end{align}  Found all functions for $n=2014$ and $k=2014^{2013}$  Found, how many functions and which satisfy the condition of the problem depending on the values of parameters $n$ and $k$.  PS. I've tried to make some operations with this function and found $f(0) $, but I can't imagine what can I do with it


When I'm reading Computer Systems: A Programmer's Perspective, I met the sum of binary numbers and failed to prove it:  $$ 2^0 + 2^1 + 2^2 + 2^3 + \cdots + 2^n = 2^{n+1} - 1 $$  This might be preliminary knowledge, I'm not good at mathematics, any body could give me a hint?


Get network utilization from command line

In the Windows task manager there is a handy network tab which shows the link speed and network utilization (in percentage of available bandwidth) for connected network adapters:  Is there a way to get this information through the command line?


What is the 10.7.2.15 entry in the history log of my SE Open ID account?

I'm asking this question on behalf of my second account:   KennyBOT uses a Stack Exchange account and therefore logs in with the Stack Exchange Open ID provider which enables users to see their login and authentication history on .  The page contains the following entries in the history table:  Authenticated To    Authenticated to stackexchange.com          80.*.*.*    1 min ago Login               Logged In                                   80.*.*.*    1 min ago Authenticated To    Authenticated to data.stackexchange.com     80.*.*.*    2 days ago Login               Logged In                                   80.*.*.*    2 days ago Login               Logged In                                   10.7.2.15   Mar 19 at 11:27 Authenticated To    Authenticated to data.stackexchange.com     80.*.*.*    Mar 15 at 22:25 Login               Logged In                                   80.*.*.*    Mar 15 at 22:25 Authenticated To    Authenticated to stackoverflow.com          80.*.*.*    Mar 15 at 22:25 Login               Logged In                                   80.*.*.*    Mar 15 at 22:25 Authenticated To    Authenticated to data.stackexchange.com     80.*.*.*    Mar 15 at 21:58 Login               Logged In                                   80.*.*.*    Mar 15 at 21:58 Authenticated To    Authenticated to stackoverflow.com          80.*.*.*    Mar 15 at 21:57 Login               Logged In                                   80.*.*.*    Mar 15 at 21:57   The 80.* IP addresses are clear to me because that is my own IP address. But why and how did it manage to login from  which is an internal-ip address within the SE-network server farm?  I  over the weekend to rule out that the account was somehow compromised and in the response (ticket:Other - 201503211033317703) I learned that the account was not used on the sites from the 10.* address, only from my own 80.* address. They also directed me to check  and if questions remained to ask them here, so here we are:  Who or what logged in with the account  from 10.7.2.15 and why did it do so?  I use that account from a separate browser to prevent any mishaps with my normal account or from a .Net WebClient programmatically. On that particular day I didn't have any test-session going and I don't recall having used the other browser to login.


Is it correct to use that/which in the relative clause when it is referring to the place as an object pronoun?

I was teaching an ESL class and came across this sentence which confused me a lot:  "The Queen Alice is the place that I go to the most" "Isn't that the place which kids under 12 can't enter?"  Are these 2 sentences correct? Shouldn't "where" be used for both sentences when it's referring to the place and replacing the object?


Minimizing SSD read/write with USB storage

I'm purchasing an ultrabook with an SSD (I've used only HDDs hitherto), and am slightly worried by the drive's read-write longevity. Should I store frequently read/written directories (e.g. downloads, cookies, documents) on a flash drive (easily replaceable after protracted use) to minimize wear and tear on the SSD itself? Would there ultimately be a noticeable positive effect, or should I not bother? If yes, then what should I store on the flash-drive (caches, etc.)?


Can't get admin rights in newly bought laptop

I had bought a new laptop(Windows 10) and set it up by making a new microsoft account. However, I forgot the password to the account. Thus, I went to settings and logged in using local account. Then I made a new microsoft account, logged in and set it up as the admin. I had then deleted the original (The first account I set up after buying the laptop) from the laptop and from services like outlook, MS office etc. However, I faced a new difficulty. I couldn't sync my settings in the control panel (Which is referred as "settings" In win 10). It showed up, "couldn't sync. Ask your administrator". What should I do now? Do I have to somehow log into the original account and set it up? Or is there any other way?


My husband and I will be catering our daughters wedding. It's a very simple ceremony with about 120 to 130 people. An afternoon wedding with the reception right after. My question is how do you figure how much meat per person. We will be having chicken (fried), ham and turkey. Potato salad, green salad, and a fruit salad. Would love any input anyone can give me!!! Thanks!!


Ubuntu 16.04 full disk encryption after installation

I know this was asked for previous releases. Has anything changed for 16.04? The official documentation hasn't been updated for a while.   If FDE after installation is not possible, what about encrypt /home (for all users, not just one). Any outstanding bug preventing it from working properly? I have hit so many bugs in 16.04.


If $A-B = B-A$ what can we conclude about A and B?

If $A$ and $B$ satisfy $A-B = B-A$. What can we conclude about A and B?   To satisfy $A\setminus B = B\setminus A$ we know that $A \setminus B \subseteq B \setminus A$ and $B \setminus A \subseteq A \setminus B$. Not sure what to conclude for this information.


How to draw and annotate a spherical coordinate system

For some lecture script I am preparing I would need some descriptive images showing how to work with spherical coordinates as often seen in textbooks, i.e. a globe and some descriptive arrows annotating \Phi, \Theta, etc.  Can someone tell me if, and how, this can be done in latex (I am a fairly familiar with LaTeX for typesetting text but a novice when it comes to PSTricks and co.)!


extra thermostat, electric dampers and 1 furnace

I have a problem similar to others that have posted: balancing heating/cooling throughout the house. I have already played with adjusting the vent's air flow as well as the manual dampers in the basement runs.... nothing seems to work sufficiently.   So I am trying to figure out how to add both an extra thermostat for the bedrooms and electric dampers to control the air flow to just the bed rooms when needed. My thought is to install electric dampers on the main level HVAC branches off the main run.   The trick is I need something to help with the very simple logic:    When both thermostats on are, all vents are open.  When The Main is on but bedroom off, all vents remain open.  But when just the bedroom thermostat calls for heat and the main doesn't, the dampers close to redirect the heat to those rooms only.   I have 7 vents in the main house and 5 in the bedrooms. I figure I can install a mechanical damper to control overpressurization if that becomes a problem. The real trick is something to control the logic. The electric dampers will run me around $400 for the 7 that need controlling so even another few hundred would be worth it for comfortable rooms. Any ideas?  EDIT: I have been thinking about this a lot the last few days and have bounced it off some especially handy family members. I think I may have some solutions...  I was thinking about it backwards. I would install dampers that are usually closed vs open. When power is applied, they would open. So when the main house calls for heat, the dampers open and heat goes all over the house (although mainly on the first floor). When the second thermostat in the bedroom calls for heat and the main doesn't the dampers would be closed and heat would pump towards the bedrooms.  It turns out wiring two thermostats in parallel isn't such a big deal as long as they are both set to heat or cool and if I install a backflow damper, I can ensure I don't do damage to the hvac system.  So I just need to wire the main thermostat to not only the furnace but also to a power panel that opens up the dampers  No computer controller needed, right? What am I missing?


If $f$ divides $g$ in $S[x]$, show that $f$ divides $g$ in $R[x]$ for $R$ a sub-ring of $S$.

Let $R$ be a sub-ring of a ring $S$. Let $f,g$ be non-zero polynomials in $R[x]$ and assume that the leading coefficient of $f$ is a unit in $R$. If $f$ divides $g$ in $S[x]$, show that $f$ divides $g$ in $R[x]$.   Thoughts: If $f$ divides $g$ in $S[x]$, then  $g(x) = f(x)q(x)$ for some $q(x)$ in $S[x]$. From here I'm not sure what the question is asking. Do I have to show that $q(x)$ is an element of $R[x]$ ? Insights appreciated.


Find the value of $\textrm{cosec}^2\left(\frac\pi7\right) +\textrm{cosec}^2\left(\frac{2\pi}7\right)+\textrm{cosec}^2\left(\frac{4\pi}7\right)$

What is the value of $$\textrm{cosec}^2\left(\frac\pi7\right) +\textrm{cosec}^2\left(\frac{2\pi}7\right)+\textrm{cosec}^2\left(\frac{4\pi}7\right) \qquad\qquad ? $$  I tried to write $\textrm{cosec}^2\left(\frac{4\pi}7\right)$ as $\textrm{cosec}^2\left(\frac{3\pi}7\right)$. Then converted in $\sin$... But in vain.. Is there any other approach?


how would I create up to 15-20 random numbers between 100-200 in java?  I have this atm but it creates any random numbers but I want the numbers to be between 100 and 200 but I don't know how I would go about adding this to the code below. please can someone help.  Random rand = new Random();     int Randnum;     for(int i = 0; i <=20; i++) {         System.out.println(Randnum + " ");          }     }


What licence is subscriber content provided under 4.0, 3.0 or them all?

In the footer it says:     site design / logo © 2018 Stack Exchange Inc; user contributions licensed under  with . rev 2018.8.7.31273   However, in the footer under Company > Legal > '6. Content Permissions, Restrictions, and Creative Commons Licensing' it instead doesn't specify which CC BY-SA licence we're releasing our content under. It also links to the CC BY-SA 4.0 license:     The CC-BY-SA Creative Commons license terms are explained in further detail by , but you should be aware that all Public Content you contribute is available for public copy and redistribution, and all such Public Content must have appropriate attribution.   Since  if subscriber content is only provided under 4.0, where the footer says 3.0 it can cause users to break the licences.  The footer under Area 51 also mentions that content is licensed under CC BY-SA 2.5.  Since it's not defined which version of the license the content is provided under, I also interpret it to potentially mean all the versions.    What license is subscriber content licensed under?


can someone help me to exclude below the error.  Thanks in advance  Can't locate XML/Writer.pm in @INC (@INC contains: /home/svceln/usr/lib/perl5/site_perl/5.16.2/x86_64-linux /home/svceln/usr/lib/perl5/site_perl/5.16.2 /home/svceln/usr/lib/perl5/5.16.2/x86_64-linux /home/svceln/usr/lib/perl5/5.16.2 .) at /opt/apps/tomcat_scripts/allocate_ports.pl line 7. BEGIN failed--compilation aborted at /opt/apps/tomcat_scripts/allocate_ports.pl line 7. Error in allocating ports, server.xml cannot run`  The script i am using  #!/home/svceln/usr/bin/perl -w # allocate_ports.pl  # allocate ports, create port_config.xml and write to stdout  use strict; use XML::Writer; use IO::File;enter code here use File::Basename;  my ($increment) = 0; my ($execDir) = dirname($0);  $#ARGV eq 0 or die "Usage: allocate_ports.pl server_name\n";  my ($port_read) = new IO::File ("$execDir/port_increment.txt"); if (defined $port_read) {   while (<$port_read>) {     chomp;     $increment = $_;   }   $port_read->close() or die "Can't close port_increment.txt: $!"; } else {   $increment = 0; }


Are there any methods for listing all current keyboard shortcuts a system recognizes?

I've been spending some time with tools like BetterTouchTool, Hammerspoon, Alfred, etc. and I've found different uses for each. However I'm having a hard time keeping everything straight, particularly tracking conflicting keyboard shortcuts between default app settings, system level commands, etc.  Is there a way to generate a complete, system-wide list of key commands that would indicate any conflicts and/or where a particular command is set?   Xcode for instance will show conflicts with system settings - is there a way to do this globally?


How to use .mouseenter and .mouseleave(function() in ajax loaded content?

I have a jquery code in my articles, and this works fine on my first pages, but I use ajax pagination, and in the ajax loaded articles I get blank  <script></script> ...  I find that, the solution for this, I need use the .on() function (also would work the .live() with jQuery 1.4.3- or the .delegate() with jQuery 1.7-), but I very beginner in javascript, and I dont know, how can use correctly the .on() in my code. I try multifarious combinations, but my script absolute not firing or also not firing after the ajax calls...  Here is my full jquery code (I use jQuery 2.1.0 in this code, but I can use also 3.3.1 with .noConflict(true)):   var $hidedcontent = $("#hided-content");   $("#activator-field, #hided-content").mouseleave(function(){       $hidedcontent.hide( "slow", function() {       });  });   var timer;  $( "#activator-field" ).mouseenter(function() {       var that = this;   timer = setTimeout(function(){       $hidedcontent.show( "slow", function() {       });  }, 500);   }).mouseleave(function() {       clearTimeout(timer);  });   How can I put to this code the .on() function?  The linked question dont solution for my problem.  I in vain I use it .on(), not working after ajax calls... Here this simple test code, also not working!:   jQuery(document).ready(function() {          jQuery('#activator-field').on('click', function() {            alert('test');          });  });   If these codes are in ajax loaded content, I get blank <script></script> ... Maybe better solution for me, if I include my ajax pagination that, calls scripts? How can I do this?


Why it is necessary to put two 120 ohm termination resistors at each end of CAN transmission line respectively? Does it make an equivalent resistance of 60 ohm? (parallel resistors). Is it OK to put only a single resistor at any end or in middle of this transmission line?


What is the best downloadable US-English word list? Similar to a dictionary without the definitions.  I've found  which is the source list for he English dictionary used by many open-source projects, however it doesn't attempt to be a complete list (they avoid adding less common words since it can confuse auto-suggestions).


as the title says "Mesh mirror itself without a mirror modifier". I had a mirror modifier on but not anymore but the mesh keeps mirror itself and i don't know what is causing it, in my modifiers tab i only have and armature and subdivision modifier. Any idea what is causing it? I have applied the mirror but the problem is that any new change i make it mirror it    My english is not that good sorry


How to buy a cellphone SIM card in Paris?

How do I buy a SIM card for my cellphone in Paris? Also, is there anything I should keep an eye out? (things like fees, cellphone-compatibility in europe...) and do they have pre-paid plans (in Brazil we have those, I don't know how it's called in other parts of the world, but its simply a plan wich you pay before using, and once your credit is over you cannot make any more calls before recharging the SIM card).  If you know any, please post some buying places near the Arc de triomphe.


Show the series $ \sum_{j=1}^{\infty} \frac{(2^j)+ j}{(3^j) - j} $ converges

Show the following series converges     $$ \sum_{j=1}^{\infty} \frac{(2^j)+ j}{(3^j) - j} . $$   I tried to use the comparison test and tried to compare it with the series of $\dfrac{2^j}{3^j}$ because this is the geometric series. However, $\dfrac {2^j}{3^j}$ is smaller than $\dfrac{2^j+j}{3^j-j}$, so by comparison test, the series $\sum_{j=1}^{\infty}\dfrac{2^j}{3^j}$ converges does NOT indicate that the series $\sum_{j=1}^{\infty}\dfrac{2^j+j}{3^j-j}$ converges... Thus I'm confused. Thanks!  Thanks!


Possible to "snap" top/bottom instead of just left/right in Windows 7?

In Windows 7, I know you can do Windows + Left to put a window in the left half of the screen.  Is there a feature that will do top and bottom?


Shapefile PRJ to PostGIS SRID lookup table?

I was wondering if there is such a thing as an shapefile PRJ to PostGIS SRID lookup table?  Something that can translate the most standard shapefile PRJ definitions into the likely SRID.  When using PostGIS and pgAdminIII, if you use the postgisgui to import your shapefiles, the SRID is left as "-1".  It seems like the tool should be able to parse the Esri PRJ and determine the correct (or at least a couple of options) that are the likely SRID, rather than just leave the default.  Or does the importer have the capability to reproject on the fly if you choose another SRID?  It may seem lazy on my part, but to me it seems curious that this function hasn't already been put in place.  Does anyone know if this concept is in the works, or good reason's why it has been left out?


Is using "fruits" as the plural of "fruit" acceptable?

I've always understood the plural of fruit to be fruit, not fruits.  I was looking at some marketing material and they used the word "fruits" in the following context:      A unique infusion made with ... strawberry, raspberry and cranberry fruits    In discussion with someone about this sentence, he described that the  is not necessarily always people, and could be persons. Therefore it's possible that fruits could be a legitimate plural form.  Is fruits used correctly in this context, or could it be used correctly in ANY context?


Should you use "a" or "an" with foreign words that start with "hi"?

For example, the word hikikomori (recluse in Japan).  Some sources use "an hikikomori," like this  in IMDb.  And this article in the  uses "a hikikomori."  Are both usages acceptable? Or only one is correct?


Pipe output to a command while still writing to stdout

I have a command that writes to stdout, let's say it's ls. I want to pipe its output to a program foo, while still writing that output to stdout.  I looked into tee, but I couldn't figure out how to get it to pipe to a program instead of writing to a file.


My friend has been using ubuntu 10.10 on vmware player for many days now. But today, it has a problem booting, so we started the ubuntu live cd to try and fix it.  Running sudo fsck /dev/sda1 (got from ) says that the device or resouce busy. So, I'm guessing the partition was not unmounted correctly on the last shutdown for some reason.  Any help on how to fix the problem would be appreciated. If you need any further information, please provide the command to get it, as we have little knowledge of that.  Thanks.


Bash script did not change the directory as written

Here is my script to change the directory  [user@linux ~]$ cat script.sh echo Before: $(pwd) cd "$1" echo After : $(pwd) [user@linux ~]$   When I tested it, it did not really change the directory as shown in the last pwd command.  Manual pwd command  [user@linux ~]$ pwd /home/user [user@linux ~]$   Test 1  [user@linux ~]$ script.sh dir01/ Before: /home/user After : /home/user/dir01 [user@linux ~]$   Test 2  [user@linux ~]$ script.sh /home/user/dir01 Before: /home/user After : /home/user/dir01 [user@linux ~]$   Manual pwd command again after that  [user@linux ~]$ pwd /home/user [user@linux ~]$   What's wrong with my code?


The question asks how to prove this statement.  I have been unable to prove by contradiction and by induction for the same $k$.


javascript "destroy" timer without using undefined

I have a function that starts a timer:  startTimer() {     this.timer = setInterval(() => {         let newCount = this.state.count -1;         this.setState({             count: newCount >= 0 ? newCount : 0         });         if(newCount === 0) {             this.setState({countdownStatus: 'stopped'});         }     }, 1000) }   Now when my React component unmounts, I want to remove the timer from memory. So what I am currently doing is this:  componentWillUnmount() {     clearInterval(this.timer);     this.timer = undefined; }   Is there a way to get rid of the timer altogether, without setting it to undefined?


D&D3.5e -- Damage Reduction -- DR/Unholy vs DR/Evil

We've got a party with a Celestial Mystic (Book of Exalted Deeds), and I was reading about his level 9 ability, which grants him DR 10/Unholy. Would this be different from DR/evil, as in it would only be breached by unholy weapons, and not attacks from evil outsiders?   I'm asking this because I haven't seen any monsters or anything that have things like DR/Unholy, Holy, Axiomatic, etc... it's usually just Good/Evil/Lawful/Chaotic. Has anyone seen any material throughout the books like this? My intuition tells me it's a typo and should be DR 10/evil, but the errata doesn't say anything about this.  Thanks!


Maximum switching current of this relay at 250 V is 10 A.  Why is the maximum switching current at 30 V also 10 A?  I wonder why it can tolerate 10 A at 250 V but not 80 A in 30 V because the power is the same?  P1 = P2 = 250 V x 10 A = 30 V x 83 A


BIOS doesn't find UBuntu iso after Fedora installation

Created a bootable USB from an iso-file with  sudo dd if=./ubuntu-18.04.3-desktop-amd64.iso of=/dev/sda1 bs=8M    using  BIOS does not see this USB. Did Fedora 31 mess up my BIOS and what can I do?


Nullpointerexception using array variable

I'm answering a practice problem in java and I've created some code. However, when I run it I get an error and I'm not sure what the error means   I've tried re-reading the code, but I still don't know what the error is:    Exception in thread "main" java.lang.NullPointerException   at SugarSmashPlayer.setHighestScore(SugarSmashPlayer.java:42)   at Main.main(Main.java:7) Process finished with exit code 1    public class Main {      public static void main(String[] args) {         SugarSmashPlayer Jacob = new SugarSmashPlayer();         Jacob.setHighestScore(40,1);         System.out.println(Jacob.getHighestScore(1));     }  }   public class SugarSmashPlayer {     private int IDnumber;     public String screenName;     public int[] highestScore;     public int level;       public int getIDnumber() {         return IDnumber;     }      public void setIDnumber(int IDnumber) {         this.IDnumber = IDnumber;     }      public String getScreenName() {         return screenName;     }      public void setScreenName(String screenName) {         this.screenName = screenName;     }      public int getHighestScore(int level) {         if(level > 10 || level < 1) {             System.out.println("Invalid level");             return 0;         } else {             return highestScore[level-1];          }     }      public void setHighestScore(int highestScore, int level) {         if(level > 10 || level < 1) {             System.out.println("Invalid level");         } else {             if(level > 2 && this.highestScore[level-2] > 99) {                 this.highestScore[level - 1] = highestScore;             } else {                 if (level == 1) {                     this.highestScore[level - 1] = highestScore;                 } else {                     System.out.println("You have not achieved a score of 100 or greater in the previous level");                 }             }         }     } }   I expected the highscore for level 1 to be set to 40 and when I gethighscore I expected it to display 40


How to use Differentials to find the area of a ring?

A ring of a planet has an inner radius of approximately 51,400 km (measured from the center of the planet) and a radial width of 17 km. Use differentials to estimate the area of the ring. (Round your answer to the nearest thousand.)


Reduce vertical blank space between centered mathematical phrases and normal text

When I use $$$$ for mathematical text, there is too much vertical blank space between the mathematical text and the main text. How can I solve this problem?


What is the excel keyboard shortcut alternative for ALT+SHIFT+ARROWS

ALT+SHIFT+ARROWS in Word or Powerpoint, helps in moving a particular paragraph or line up or down. What is the corresponding shortcut in excel.  I am not looking at cut, copy, paste or mouse drag or macro solutions. Is there a shortcut, as simple as that.


What does it mean by waiting on object monitor

I know what wait() and notify() does. But I am slightly confused by a part of definition of notify() method that I find most at the places.  Here is definition given for notify() method:     For all threads waiting on this object's monitor (by using any one   of the wait() method), the method notify() notifies any one of them to   wake up arbitrarily.   I was confused with the part waiting on this object's monitor.  Question : When we call obj.wait() method. Current thread releases the monitor lock.  So my current thread is now not waiting on object's monitor. It is just in waiting state. As I know what does it mean by waiting state, It acknowledges Operating system to put the thread into sleep state and It keeps information of such threads into somewhere with Object(I am not sure where It stores information) So don't you think,      It is just in waiting state. not waiting on object's monitor.   I appreciate if you can help me with my understanding.


What is the type of this kind of declaration?

I am trying to learn Android. I have some Java experience but have never seen a code block like this one:         addNumsButton.setOnClickListener(new View.OnClickListener()     {         @Override         public void onClick(View v)         {             EditText firstNumEditText = (EditText) findViewById(R.id.firstNumEditText);             EditText secNumEditText = (EditText) findViewById(R.id.secNumEditText);             TextView resultTextView = (TextView) findViewById(R.id.resultTextView);             resultTextView.setText((Integer.parseInt(firstNumEditText.getText().toString()) + Integer.parseInt(secNumEditText.getText().toString())) + "");         }     });  What is getting declared after the View.OnClickListener()? I checked that View.OnClickListener() returns type Interface. What does the code after that method is used for?


One-dimensional Schrödinger equation: reproducing a given set of energy values

Given a set of $N$ increasing real numbers $\{E_1, E_n, \cdots, E_N \}$, is it always possible to find a potential $V(x)$ such that the set of $\{E_j\}$ are the lowest eigenvalues of the corresponding one-dimensional Schrödinger equation for given mass?


Explanation behind Second Derivative of a Parametric Equation Formula

I am looking to find out how the second derivative formula works.  I can blindly apply it but I don't have a grasp of what is going on or why. The first derivitive has the formula $\frac{dy}{dx} = \frac{\frac{dy}{dt}}{\frac{dx}{dt}}$. I told this was because if you divide them you cancel out the dts and get dy/dx. The second derivative has the formula $\frac{d^2y}{dx^2} = \frac{d}{dx} \left(\frac{dy}{dx}\right) = \frac{ \frac{d}{dt}\left(\frac{dy}{dx}\right) }{\frac{dx}{dt}}$. Is this something that can be explained with only a knowledge of calculus or is this something I would have to take on faith until I learn more. Any help would be greatly appreciated.


How to add a guest account without a password?

Sometimes I have friends in my house that want use my computer. How can they use a guest account without typing a password?


I posted a question that had a white filter over it. Basically, it still appears on the "newest" questions, and is still clickable, but has a white filter over it, such that it's barely visible. Can anyone explain this phenomenon?  The question, btw, is NOT on hold, and rather has 2 up-votes as of now. I don't know if anyone else can see it as faded too. I would post an image, but my rep is too low. Remember, this is happening on the newest questions category only, not the question itself.


What should be in the sources.list for Kali Rolling Linux?

This is exact content from my sources.list:  #  # deb cdrom:[Debian GNU/Linux 2016.1 _Kali-rolling_ - Official Snapshot amd64 LIVE/INSTALL Binary 20160830-11:29]/ kali-rolling contrib main non-free #deb cdrom:[Debian GNU/Linux 2016.1 _Kali-rolling_ - Official Snapshot amd64 LIVE/INSTALL Binary 20160830-11:29]/ kali-rolling contrib main non-free   I couldn't install the Synaptic package manager and was told to modify sources.list.  I googled a lot and added some repos into it and ran update and upgrade command only to see Kali crash... I had to recover it.  Please mention the exact content that should be there to ensure that Kali Linux works.


Why is my Bash script returning a syntax error?

I am writing a script which loops into recent files in a folder and executes a command...   #!/bin/bash cd /home/Downloads recent_files = ($(ls -t | head -20)) for file in "${recent_files[@]}" do     ./cmd $file done   I get the following syntax error:  line 3: syntax error near unexpected token `(' line 3: `recent_files = ($(\ls -t | head -20))'


How to generate XML file dynamically using PHP?

I have to generate a xml file dynamically at runtime. Please help me in generating the below XML file dynamically using PHP.  <?xml version="1.0" encoding="UTF-8"?> <xml>  <track>      <path>song1.mp3</path>      <title>Track 1 - Track Title</title>  </track>  <track>      <path>song2.mp3</path>      <title>Track 2 - Track Title</title>  </track>  <track>      <path>song3.mp3</path>      <title>Track 3 - Track Title</title>  </track>  <track>      <path>song4.mp3</path>      <title>Track 4 - Track Title</title>  </track>  <track>      <path>song5.mp3</path>      <title>Track 5 - Track Title</title>  </track>  <track>      <path>song6.mp3</path>      <title>Track 6 - Track Title</title>  </track>  <track>      <path>song7.mp3</path>      <title>Track 7 - Track Title</title>  </track>  <track>      <path>song8.mp3</path>      <title>Track 8 - Track Title</title>  </track>


Move Minecraft world from one PS4 to another

I've got a nice Minecraft world on my friend's PS4, but I want to continue with the same world on my own system. Am I able to copy it and if so, how do I do that?


New line in pgfplots/tikz not displaying in TeX

I have a multiple-line legend entry to preserve the width of my figure. I can use  \newline in Matlab and the legend entry is split between two lines. When I produce a .tikz of the figure however, I can't figure out how to get a new line... It appears there was a similar issue or the same issue  but when I use this syntax the same issue arises where Matlab shows the multi-line legend entry but LaTeX doesn't. Am I missing a package or writing the syntax wrong ?   LaTeX code generated by matlab2tikz to display the multiline legend (\newline works in matlab, tried "\n" and tried removing all of the \text{}'s which didn't help - the \newline command is just ignored by LaTeX):   \addlegendentry{$\text{R}_{\text{Darcy,pwr}}\text{ = [1.26x10}^{\text{10}}\text{, 3.76x10}^{\text{9}}\text{] (1/m)**\newline** MAE=1.14x10}^{\text{-2}}\text{(g/min)}$};  Unfortunately I can't post images because I don't have 10 repuation... sorry about the  links:  Matlab output:    LaTeX output:


Prove that $\lim_{n\rightarrow \infty} (x_1+x_2+...+x_n)/n= \infty$

I need help with this exercise: Consider the sequence $\{x_n\}$ that verifies $$\lim_{n\rightarrow \infty} x_n = +\infty$$ Now prove that $$\lim_{n\rightarrow\infty} \frac{x_1+x_2+...+x_n}n= +\infty$$  Also I need to find an example that the converse does not apply.  Thank you for all your answers.


An unproven proposition in my book states that if the series of $a_{n}z^n$ has radius of convergence $R_1$ and the series of $b_{n}z^n$ has radius $R_2$. Then the radius of convergence of $(a_{n}+b_{n})z^n$ is either $min(R_{1},R_{2})$ or (if $R_1=R_2$) greater or equal to $R_1$


I plan to invest a portion of my savings in cryptocurrencies that I understand on a technical level (e.g. Bitcoin and Ethereum). However, otherwise prudent financial advice articles on the internet invariably claim that my decision is unwise. Cryptocurrencies are not commonly seen as a proper investment; they are seen as "risky", "speculative", or even "gambling". I don't understand why cryptocurrency is not considered a proper investment in the same class as real estate, stocks, bonds, and foreign currency. The Bitcoin-USD price volatility probably contributed to the "speculation" and "gambling" labels, but stock market volatility doesn't stop stocks from being considered investment-grade! To reduce risk from individual cryptocurrencies, I could simply hold a large basket of cryptocurrencies instead of just one or two (similar to diversified index funds for stocks).  Why are cryptocurrencies not considered proper investments? Can I make my cryptocurrency holdings "investment-grade" by holding a basket of cryptocurrencies instead of just one or two?


Oracle VARCHAR2(20 BYTE) vs VARCHAR2(20 CHAR)

If I want to pass values such as Sylvie Doré to a column in Oracle will I need to configure my columns as VARCHAR2(20 CHAR) as special characters such as é take up more than one byte?


Identifying a story about a boy who travels to a mirrored universe with ketchup that makes you intoxicated

There was a novel I read back in the day about a boy who travels back and forth between a mirror-image of our universe.  I am afraid I cannot recall much about the plot, except that mirrored food is inedible and when mirrored ketchup packets were brought back from the other universe they taste like chocolate and mess you up.  Could someone help me identify this book?  After going through organic chemistry back in college, I think it should be required reading for any writer who has a story where the characters land on alien planets and find everything to be edible.


In the elements of statistical learning book the lasso is written like this:  $\hat{\beta}^{lasso}=\operatorname{argmin}\left \{ \frac{1}{2}\sum_{i=1}^{N}(y_i-\beta_0-\sum_{j=1}^{p}x_{ij}\beta_j)^2 +\lambda \sum_{j=1}^{p}|\beta_j| \right \}$  Note that before the sum 1/2 is used. In some cases I see it as 1/(2N). Like e.g. this equation:  $\hat{\beta}^{lasso}=\operatorname{argmin}\left \{ \frac{1}{2N}\sum_{i=1}^{N}(y_i-\sum_{j=1}^{p}x_{ij}\beta_j)^2 +\lambda \sum_{j=1}^{p}|\beta_j| \right \}$  I don't understand what this would represent if I divide with the number of observations? I would very much appreciate any clarification.


Why are certain commands before \include executed afterwards?

I'm experiencing some weird behavior using \include instead of \input. I create a custom table of contents with all frames which I fill by creation of the frametitle on every slide and with creation of every section automatically. In the minimal example I do that fully manual to keep the example simple.  Usually I have one .tex file per frame (maximum 2 or 3), so I can interchange frames between presentations easily. So in my main file you can find just the \sections and \include.  However the line  \addcontentsline{lbf}{section}{First Section\par}   seems to be executed after \include as you can see here:  with \include    In comparison \input works as desired and expected.  with \input    I can't see any logical reason for this behavior. What's wrong?   I'd like too keep using \include, mainly because of the \excludeonly functionality. Are there alternatives to switching to input?  \RequirePackage{filecontents} \RequirePackage{excludeonly}  \documentclass{beamer}  \begin{filecontents}{frames.tex} \begin{frame} \frametitle{Test Frame One} \addcontentsline{lbf}{subsection}{First Frame\par}% test \end{frame}  \begin{frame} \frametitle{Test Frame Two} \addcontentsline{lbf}{subsection}{Second Frame\par}% test \end{frame}  \begin{frame} \frametitle{List of Frames} \listofframes \end{frame} \end{filecontents}  \begin{filecontents}{exframes.tex} \begin{frame} \frametitle{Excluded Test Frame} \addcontentsline{lbf}{subsection}{Excluded Frame\par}% test \end{frame} \end{filecontents}  \makeatletter \newcommand\listofframes{\@starttoc{lbf}} \makeatother  \excludeonly{exframes}  \begin{document}  \section{Test section one} \addcontentsline{lbf}{section}{First Section\par}%  %\input{frames.tex}\input{exframes.tex} \include{frames}\include{exframes}  \end{document}   Further remarks   Using or modifying the original ToC provided by beamer (which would work) is no option as I want to keep its complete functionality as it is. Of course I could put the  \addcontentsline inside the include command, but that wouldn't work for my workflow using interchangeable frames, so it's no option neither In the worst case I'd use \input, so if you think that's the only way it would be nice to have an explanation   Thank you!    The answer of the duplicate question, which did the job, is .


Trouble downloading Adobe Reader in Xubuntu 14.04

I been trying to install adobe reader from Synaptic Package Manager but I keep getting a error message. Are any of you experiencing the same error or bug? I even tried downloading it from the Terminal but no dice! What do you guys think it could be? The website is no help since Linux is not listed as one of the OS to download, what's up with that?


I was trying to update Skype and it gave me this message    I went to Programs and Features to uninstall it, but I couldn't find 'Skype' in the list. I deleted the Skype directory manually in Program Files and also Program Data and tried to install again. It gave me the same message. I really want to use Skype so that I am communicate with my friends. Btw, Java is missing from the list too.


No fancy parentheses {} in align-environment

In the following code lines, the fancy parantheses F{x} do not appear:   \documentclass[11pt, a4paper]{article} \usepackage{amsmath} \usepackage{amsfonts}  \begin{document}  \begin{align}\label{Hilbert} \operatorname{F}{\hat{x}(t)} = \hat{X}(j\omega) &= \operatorname{Im}\left\{X(j\omega)\right\} \operatorname{sgn(\omega)} -j\operatorname{Re}\left\{X(j\omega)\right\} \operatorname{sgn(\omega)}\\ \end{align}  \end{document}   I assume it is because I am using the align-environment. But I need it.


css flexbox div to fill the available viewport height

My markup has the following structure:
Left Panel

Main Content
     Do not bother about . It is a React component that lies at the top of the page and has a certain height (not fixed). What I want is div one to take the entire height of the available viewport; that means 100vh minus the height of the header that we do not know. How is that possible?


change UID and GID file attributes on read only file system with mount

I have some file image of filesystem, and I want mount it with parameter changing files and directories UID and GID. I cannot change its parameters, because it is read-only filesystem.  I found some idea, using some overlayfs and by find command walk through all files on mount points and rewrite attributes. But it needs some additional filesystem. I don't want use this method. I don't need write anything to this filesystem.  Then is there some idea to change UID/GID on the fly by mount options? Is there some cover like filesystem to use on this situation?


Suppose we have a prime number $p$ as well as a positive integer $n$. Consider a group $G$ with $p^n$ elements. I want to prove that $G$ has a normal subgroup with $p^{n-1}$ elements. I found this in the book I am reading. When I think about it, it makes sense, but I was a little iffy on how to prove it.


Why does "defenestrate" mean "throw someone out a window" and not "remove a window"?

When I fenestrate something I put a window into it.  But when I defenestrate I throw someone out of a window.  Why does defenestrate not mean "remove a window"?    As examples - when someone has a detox they remove toxins.  When someone de-clutters they remove clutter.


A vessel is filled with liquid,3 parts of which are water and 5 parts syrup.How much of the mixture must be drawn off and replaced with water so that the mixture may be half water and half syrup?  What is the best possible way to solve this question?


Assume that a given postdoctoral position does not require teaching/laboratory.     Are there postdoc positions for someone who wishes to stay in his/her country and just be in touch with the post-doc advisor by e-mail or/and Skype?   Perhaps communicating only by e-mail may be slightly annoying for some people, so I also suggested Skype.  In my opinion (but correct me if I am wrong), there should be no difference between live meetings and Skype meetings.   Remark: Truly, I am asking about a post-doc position in mathematics, but I guess that my question is also relevant for other fields.  Edit: I wish to thank all the people answering (or commenting on) my question.


I have a double 2D array:  a[0,0]=1.1      a[0,1]=0.1      a[0,2]=2.9      a[0,3]=1.6  a[1,0]=-2.2     a[1,1]=-1.7     a[1,2]=0.3      a[1,3]=-0.4  a[2,0]=2.0      a[2,1]=-0.1     a[2,2]=-1.8     a[2,3]=-3.1   1) I want to sort it in descending order AND save the 2 indexes (in order to know which array indexes has the absolute higher/lower values):  a[2,3]=-3.1 a[0,2]=2.9 a[1,0]=-2.2 a[2,0]=2.0 a[2,2]=-1.8 a[1,1]=-1.7 a[0,3]=1.6 a[0,0]=1.1 a[1,3]=-0.4 a[1,2]=0.3 a[0,1]=0.1 a[2,1]=-0.1   2) I also need a different sort: on the first index and save the 2nd index:  a[0,2]=2.9 a[0,3]=1.6 a[0,0]=1.1 a[0,1]=0.1  a[1,0]=-2.2 a[1,1]=-1.7 a[1,3]=-0.4 a[1,2]=0.3  a[2,3]=-3.1 a[2,0]=2.0 a[2,2]=-1.8 a[2,1]=-0.1   I don't know if I'm a moron of not :-) but I've unsuccessfully tried to understand the Microsoft "Array.Sort()" function variations to solve these problems.  Is it possible with "Array.Sort()" ?  I'm a beginner, some help will be greatly appreciated!  Thank you very much!


Calculate mean and autocovariance function to check stationarity

Hey I need some help with this exercise:  Assume $z_{ t }$ be a sequence of independent normal random variables, each with mean 0 and time independent variance $\sigma^{ 2 }$, and let c be a constant. Is the following process for a time series stationary? If it is stationary specify the mean and the autocovariance function:  $$ x_{ t }=z_{ 1 }*cos\left( ct \right)+z_{ 2 }*sin\left( ct \right) $$  So for a weak stationarity time series the mean and covariance function should be independent of time. I'm not sure how to calculate them by hand without R.  Thanks for help.


$\lim_{n\rightarrow +\infty} \frac{a_{n}}{a_{n+1}} = z_{0}$ with $z_{0}$ pole

This is an exercise from Stein-Shakarchi.  Suppose that $f$ is holomorphic in an open set containing the closed unit disc, except for a pole at $z_{0}$ on the unit circle. Show that if $f(z) = \sum_{0}^{\infty}a_{n}z^{n}$ in the open unit disc then$$\lim_{n\rightarrow +\infty} \frac{a_{n}}{a_{n+1}} = z_{0}$$  Any hint ?


Cross-validation: Which classifier to use in the end?

This might sound like a very simple question, but I haven't been able to find an answer to it, yet:  Assuming I am working on a binary classification task and I am using k-fold cross-validation to train classifiers on a train/test split of my data: After running CV I would end up with k trained classifiers. Which one of these would I actually use to classify new data? Would I simply meassure F1 etc. and use the best one? Or should I use some kind of ensemble method and use all k in some kind of voting?


Finding center and radius of circumscribed triangle

Let $u=(6,7), v=(-2, 3), w=(7,0)$. Find the center and the radius of the circumscribed circle of triangle $[u,v,w]$.  My approach would look like this:  (1) Determine the angles of the triangle $[u,v,w]$ via dot products.  (2) If we draw three lines from the the center $o$ of the circle to the three vertices, the triangle $[u,v,w]$ will be made of three equilateral triangles. We can then easily find from (1) all the nine angles of the three triangles.  (3) Determine the heights of the three inscribed triangles, which will be the same for all of the three, and which will be the radius $r$ of the inscribed circle.  (4) Then we can drop a perpendicular line from $o$ to, say, $[v,w]$ in order to find the coordinates of $o$.  But is there a much less tedious way to solve this problem? And do you think my approach is correct?


How can I install one language by command-line

I'm trying to have everything ready to install a new desktop with a few command line instructions. Unfortunately, to install the language packages, I couldn't find how to do it.  I can run  gnome-language-selector   But it doesn't seems to be usable in command line directly. I need to go on with clicks...  An other thing that could be done is that I do those clicks and find out which packages have been installed and read the changes in /etc/environment and /etc/default/locale (and other /etc/... file?) but the list of packages is probably different depending on the packages installed (Firefox, Thunderbird, LibreOffice, Gnome, ...)  Is there a tool for that? Like let's say :  gnome-language-selector --install fr   or a package that has all necessary dependencies :  sudo apt-get install super-language-pack-fr   Thanks,


I want to find the following integral: $$\int_{0}^{\infty} \frac{e^{3x}-e^x}{x(e^{3x}+1)(e^x+1)} dx$$ I have been trying to apply simple substitutions like $u=e^x$, to simplify the integral without any luck. I simplified it to  $$\int_{0}^{\infty} \frac{1}{x(e^x+1)}-\frac{1}{x(e^{3x}+1)}dx$$  which seems to have increased my problems.  Wolfram Alpha gives the answer to be 0.5493... and the graph looks like a Gaussian distribution.  Somehow, I feel that this integral is very non-trivial due to the 'troublesome' $x$ in the denominator.


Prove that $\lim_{n\to\infty}\frac{1}{a_n}=\frac{1}{g}$ if $\lim_{n\to\infty}a_n=g$

Prove that if the sequence $(a_n)$ of numbers different from zero converges to the boundary $g$ different from zero, then  $\lim_{n\to\infty}\frac{1}{a_n}=\frac{1}{g}.$  I should show that  for every $\epsilon>0$ there exists $n_0 \in N$ such that forr all $n>n_0$ we have  $$|\frac{1}{a_n}-\frac{1}{g}|<\epsilon.$$  Now,  $$|\frac{1}{a_n}-\frac{1}{g}|=|\frac{g}{ga_n}-\frac{a_n}{ga_n}|=|\frac{g-a_n}{ga_n}|$$  I do not know what to do next. I would be grateful for any hints.


Let us consider an ellipsoid in $\mathbb{R}^n$ of the form $\{x \in \mathbb{R}^n | x'Cx \le 1\}$, where $C$ is a symmetric positive definite matrix.  What is the smallest box $\prod_{i=1}^n [-a_i,a_i]$ the ellipsoid is a subset of?


How to create a Gant-Chart in LaTeX-Beamer

I am trying to create a Gant-Chart in Beamer. I found the following example:   \documentclass{beamer}  \usepackage[utf8]{inputenc} \usepackage{pgfgantt}  \title{Sample title} \author{Anonymous} \institute{Overleaf} \date{2019}   \begin{document}  \frame{\titlepage} \begin{frame}{Gant-Chart}     \begin{ganttchart}[vgrid, hgrid,                         bar/.append style={fill=blue!80},                        milestone/.append style={fill=green}]{1}{15}         \gantttitle{2019}{15} \\         \gantttitlelist{1,...,15}{1} \\         \ganttbar{Task 1}{1}{2} \\         \ganttmilestone{Milestone}{7} \ganttnewline         \ganttbar{Final Task}{8}{12}     \end{ganttchart} \end{frame}    \end{document}   Now, I want to change it slightly. The first row shows the year. I want the second row to show months. And then the third row shows the number of weeks that I have planned for the task. Also, I don't want to see any arrows, but just have the rectangles. Is there a way to add a grid? Basically I want everything to just look as in an Excel-Table: Grids and then color the rectangles during which I am working.   Here is an example of what I would like to have:   Can somebody show me how to do this?   Here is another example that seems to get pretty close to what I want. Only in the week-row now it is always written "week 1", "week 2" and so on. I just want the number.   \begin{frame} \begin{figure}[h!bt]     \begin{center}         \begin{ganttchart}[             vgrid={*{6}{draw=none}, dotted},             x unit=.08cm,             y unit title=.6cm,             y unit chart=.6cm,             time slot format=isodate,             time slot format/start date=2019-02-01]{2019-02-01}{2019-07-31}             \ganttset{bar height=.6}             \gantttitlecalendar{year, month=name, week} \\             \ganttbar[bar/.append style={fill=blue}]{Task 1}{2019-02-11}{2019-02-17}\\         \end{ganttchart}     \end{center}     \caption{Time Plan} \end{figure} \end{frame}


How is Angular Momentum Conserved when Mass is Released?

I am not a physicist (math/comp-sci) but I understand that Angular Momentum is supposed to be conserved.  I find this confusing because there seems to be many simple, common cases where a restrained, revolving body, when released seems to lose it's angular momentum.  For example, let's say that a hammer thrower is revolving a 10kg hammer around herself at a 1 meter distance from their combined center of mass every second.  Taking the hammer as a point-mass, then before release, the hammer and the thrower each have an angular momentum of      $l\omega = (mr^2)*(2\Pi) = (10*1*1)*(2*3.14..) =~ 62.8 kg\text{-}m^2/s$   Now, after the hammer is released, the thrower still has her same angular momentum (also 62.8), but the hammer no longer seems to have any.  Yes, I know that the hammer is still rotating (spinning) as it did when it was revolving around the thrower, so that angular momentum seems to be conserved, but the angular momentum from revolution (orbiting) seems to be gone.  AFAIK, it's not transferred to it's spin angular momentum (observation seems to bear this out).  Nor is it transferred to the thrower.  Besides having no mechanism for this (she let go of it), if it did, we would have noticed hammer throwers being knocked over by having their angular momentum suddenly doubled.  So where does it go?  Or is it not actually conserved in this case?


Would like to update answer, but it has 9 edits already

I would like to update  to add some new information. (I realized that when "walking the clustered index" of a table that has a multi-column clustered index, in most cases a great simplification can be achieved by using WITH TIES in the update statement to enable working only with the first column of the clustered index. I'd also like to change a couple of other minor things.)  However, if I make this update, I'll hit 10 updates, and the answer will get converted to community wiki. I hate asking moderators to remove community wiki status--it seems like a waste of their time. At the same time, it bugs me that my answer is not as good as it could be! And yes, it bugs me to lose the reputation if it goes community wiki.  Note that I am doing my best to make more substantial edits and fewer trivial ones, so I don't run into this limit as often. But it does happen sometimes. You can look at the answer history to see if you think that my 8 edits were excessive or not.  Should I:   Avoid making the edit, Make the edit in pursuit of having the best answer and just take my lumps so I don't inconvenience moderators, Or make the edit and flag for a moderator as it's not that big a deal for them?


How Exactly Current Flow Through a Capacitor?

Capacitors behaving as an open circuits, How can we understand the concept of the Electrons flowing through a capacitors.


I am graduated in computational physics and from south asian country. i got  F and D- grades for elective physics courses in my first and second year. but i didn't retake those classes. another D+ grade for non major course. Will that grades keep me from going to a  grad school in USA ?


Quadratic Rings which are UFDs but not PIDs

D=-1,-2,-3,-7 and-11 are the only five negative square free integers for which the corresponding quadratic Rings are Euclidean domains. Also D=-19,-41,-43 and-167 are the only four square free negative integers for which the  corresponding quadratic rings are PIDs but not EDs. Are there any negative square free integers <-167 for which the corresponding quadratic rings are UFDs but not PIDs? Thank you in advance for your valuable time.


Why is it problematic to regard the Lorentz group as ${\rm SO}(4, \mathbb{C})$?

If the four-vector $x^\mu$ is defined as $x^\mu\equiv(ict,{\bf x})$, instead of $x^\mu\equiv (ct,{\bf x})$, the Lorentz group will be the compact(?) ${\rm SO}(4, \mathbb{C})$ group. But the Lorentz group is regarded as the noncompact group ${\rm SO}(3,1)$. But I could never figure out what is the real problem of using $ict$ instead of $ct$? In short, what will go wrong if I choose to work with $ict$? Does it pose a problem from the point of view of representation theory? I am only interested in flat spacetime.


I have fibonacci numbers defined as such:  $$  f(n) = f(n-1) + f(n-2)$$with$$    f(0) = 0 $$$$f(1) = 1$$  I have to prove that $$ F(n) \geq 1.5^{n-1}, n \geq 6$$  Base Case:  $$ f(6) = 8 \geq (1.5)^5 = 7.6 $$  Base holds  Inductive hypothesis $$  k \geq 6 $$$$ f(k) \geq (1.5)^{k-1} $$  Inductive Step  Here is how I have started, any hints or pointers on how to continue are appreciated  $$ f(k-1) \geq (1.5)^{k+1-1}$$ $$ f(k) + f(k-1) = (1.5)^{k-1} + (1.5)^{k-2}$$ now I think where I want to go from here is to expand the right side of this equation out, but I am unsure how to do this.


jQuery ISBN no validate: How to validated ISBN number formats?

I am using the jQuery validation plugin. How to validate ISBN number formats in jQuery rule or pattern or Regular Expressions? Is there any Regular Expressions to achieve this? Please share your idea.  jQuery.validator.addMethod("isbnNo", function(value, element) {     return isValidISBN(value); }, "Please enter valid ISBN number");  // ISBN Number validationValidation function isValidISBN(isbn) {       isbn = isbn.replace(/[^\dX]/gi, '');       if(isbn.length < 10 || isbn.length > 13){         return false;       }       var chars = isbn.split('');       if(chars[9].toUpperCase() == 'X'){         chars[9] = 10;       }       var sum = 0;       for (var i = 0; i < chars.length; i++) {         sum += ((10-i) * parseInt(chars[i]));       };       return ((sum % 11) == 0);      }


apache: how to redirect one HTTPS TLD to another HTTPS TLD of the same domain

I have 3 domains: domain.com, domain.org, and domain.net I have an SSL cert for .org, but not .com and .net. I would rather not have to purchase SSL certs for all 3 TLDs. How do I redirect the .com and .net domains to .org ? Normal HTTP apache redirection methods don't seem to be working.    Thanks in advance.


At present, any votes that are to close have priority. Normally thing would be that if someone wants the thread closed that a single vote should be registered. Then if someone wants to keep the thread open that that vote should be annulled. At present, close votes are preferences until the thread is closed. But by then the thread loses momentum and is is basically cast aside.   Logic would say that if someone choices to close and some chooses to keep open that the count should be zero.   Why the biased system towards closing threads, is that the policy of stack? Why can't a vote to keep the thread open negate the close vote, before the thread is actually closed?  Simple really, 3 votes to close, 3 votes to keep open. This should mean zero on the close votes .


There is a problem in the book 101 Problems in Algebra which is:  Evaluate this $$C_{2}^{2000}+C_{5}^{2000}+C_{8}^{2000}+\cdots+C_{2000}^{2000}$$  I cannot understand the solution (shown below) to this problem. How can the statement is equal to the next line in the green marked box? Can anyone make me understand?


How do I start completely over with the latest version of Ubuntu?

I have an outdated and unsupported version. I have been racking my brain trying to figure out how to download the latest version, I have run into one brick wall after another. Please help a non-tech savy ubuntu fan.


How to make a process invisible to other users?

How could you launch a process and make it invisible to the top command? The process is started by a normal user (not root), and should not be visible to other normal users.


Is there a holomorphic and bijective function of the unit disc onto the complex plane?

Is there a holomorphic and bijective function between the open unit ball of $\mathbb{C}$ and $\mathbb{C}$?  The usual homeomorphisms $\psi(z):=\frac{z}{1+|z|}$ and his composition with the conjugate map are not holomorphic on $\mathbb{C}$.


How did German universities outperform the US's and the UK's, before the 1930s?

I narrowed the outperformed in this question to the US and UK, but please feel free to include other First World nations' universities (eg: Canada, France).    The top American universities didn't really compare to the best in Germany, France, or the UK before then.   inducted this post.


Can we have a sticky "Add Answer" button on the iOS app?

It often occurs that there are many answers on a single post and thus makes it time-consuming to scroll down and click "Add Answer" on the iOS app, a perfect example is the , with a whopping 1360 answers. Can we get a sticky "Add Answer" button so I don't have to scroll down?


Why is scanf taking the wrong input for large float numbers?

#include <stdio.h>  int main() {  float k;     scanf("%f", &k);     printf("%f", k); }    In this simple program when I enter a number containing at most 8 digits then it is displayed correctly.  But if I exceed 8 digits i.e. for the input 123456789 the output is 123456792.   Why this is happening? Well the fun fact is that if I enter any number between 123456789 and 123456796 then it always shows 123456792.  Is it something related to the 8 decimal precision of floating numbers?


Help me prove that $\frac{(2n)!}{n!^2}$ is a natural number by induction.

When $n$ is a natural number, prove that $\frac{(2n)!}{n!^2}$ is a natural number.  If possible, I would like you to prove this by induction.  I tried to prove this by induction, but I can’t because $k+1$ is left in the denominator when I substitute $k+1$ to $n$.  Help me to solve this.


Does having a minimum length in space violate Lorentz invariance?

I’m trying to understand different approaches to quantum gravity. One involves quantising space and time themselves, which i believe can result in there being a minimum possible length and time interval. My question is, does making space discrete like this violate lorentz invariance? From special relativity we know that length contraction is a thing, so would having a minimum length cause a problem?


I am using PostgreSQL. Can I change the order of columns?

I know that the order is meaningless.  But I want to adjust the order for readability.  Can not change the order of columns in the postgresql?  I am using postico for mac. Thanks.


On the limits, prove that and find its limit

Can any one tell me how to prove that: The sequence $x_{1}=\sqrt{2}$ , $x_{2}=\sqrt{2+\sqrt{2}}$, $\cdots$, $x_{n}=\underbrace{\sqrt{2+\sqrt{2+\cdots+\sqrt{2}}}}_{n \text{ times}}$ converges and compute its limit.  Thanks


Can someone please give me a total recap on One Piece

I'm a Naruto fan, not really a One Piece fan. I want to start watching it, but I don't have any time to do a marathon.  Just a little summary would be nice.


How come I can't give more than 500 rep?

Why can't I give more than 500 reputation as a bounty at a time? The system won't let me choose an option more than 500.  Also, how were some users able to do so? On  the OP has given a single bounty worth 550 rep, but at the moment I have 844 rep and I can't give any more than 500 rep on a bounty.  Can you please tell us if this is a bug or not?


Given four nodes forming a quadrilateral, how do I find the node at the intersection of the diagonals

I'm trying to find and name a node at the intersection of the diagonals of a quadrilateral formed by four other nodes.  However, I'm not drawing a path.  All I can seem to find in the tikz manual are examples involving drawing paths.  Is there a way to do this without drawing anything?  For example,  \documentclass{article} \usepackage{tikz} \pagestyle{empty} \begin{document}  \begin{tikzpicture}   \node (A) at (0,0) {1};   \node (B) at (1,0) {2};   \node (C) at (5,3) {3};   \node (D) at (-2,7) {4}; \end{tikzpicture}  \end{document}   How do I find and label the node at the intersection of the diagonals AC and BD?  Actually, most of the quadrilaterals I'm working with are rectangles with sides parallel to the axes.  So, I'd be interested in solution that might only work for rectangles too.


Javascript adding onclick to a dynamically created element

I'm trying to create a script to help sort list items, and in doing so I need to dynamically create buttons to select what tags to look for. The problem I am having is that every button element runs the checktags() script with the same parameter, despite using a changing value when creating the element.   One thing I noticed is that when I go into chrome developer tools and look at the buttons, there is no "onclick" attribute despite it still having some functionality.                 function checktags(tagnum){         var res = document.getElementById("itemlist").innerHTML.split(/\n/);         for (var i in res) {             var list = document.getElementById(i).getElementsByTagName("input");             var itemnum = + i + 1;             var categorynum = + tagnum + 1;             if(list[tagnum].checked) alert("List item " + itemnum + ", checkbox " + categorynum + " has been selected");             else alert("List item " + itemnum + ", checkbox " + categorynum + " is UNchecked");          }     }       function myFunction() {         var res = document.getElementById("itemlist").innerHTML.split(/\n/);         res = res.filter(function(str) {return /\S/.test(str);}); // remove empty lines         var taglist = ["Tag 1", "Tag 2", "Tag 3", "Tag 4", "Tag 5"]           for (var i in taglist){             var buttonElement = document.createElement('button');             buttonElement.onclick = function() {checktags(i);};             var tagnum = + i + 1;             alert("Creating button " + tagnum);             buttonElement.innerHTML = taglist[i];             document.body.appendChild(buttonElement);         }           for (var c in res) {             var newElement = document.createElement('div');             newElement.id = c;              newElement.innerHTML = + c + 1 + ") " + res[c];              for( var j in taglist){                 newElement.innerHTML += "<input type='checkbox' value='" + taglist[j] + "'>";             }             document.body.appendChild(newElement);         }      }   </script>       <div id="itemlist" style="display:none">      List Item 1     List item 2      List item 3     List item 4     List item 5  </div>


How to setup a domain that doesn't use www prefix on Azure/EC2

Suppose I have a domain, foo.com where I have a series of pages like foo.com/123 and foo.com/456 etc.  I want to use the domain and provide links without a www prefix.  These pages also will have links to other pages (and each other) without the www prefix.  I'm using Azure to host our site which is the same as EC2 in that the domain cannot have an A record because the server environment is virtualized. So both Microsoft and Amazon tell you to use CNAME records to point your domain to an A record they manage.  In the case of Azure, my CNAME record points to a cloudapp.net record (which microsoft manages):  foo.com  CNAME  foo.cloudapp.net   where foo.cloudapp.net is my domain I've setup on Azure.  I'm encountering all sorts of problems with various things like email delivery and various people not being able to load the site.  2 different nameserver providers and my hoster tells me that it violates the RFC to have a root domain be a CNAME entry which is why my problems are sporadic.  I'm surprised to hear this as you see so many sites these days hosted on EC2 or Azure, and do not use a www prefix.  How are these sites setup so that they can use just foo.com (without www prefix)?  Update: While I asked the question about EC2 or Azure, I'm specifically looking for info on Azure.


Transfer world from multiplayer to singleplayer and continue with the right progress

Not long ago I started a minecraft world on a new 1.9 snapshot and friends wanted to join so I took my world file and dropped it in a server. Now a little later they are losing intrest in it already but I'm still having my fun. I tried copying the world file back in the saves folder but then I ran into a little problem. I started with the progress I was in before I put it on a server. I was in the same location with the same health, hunger, items, armor, ... This wasn't all a problem when I transfered it to a server. So how do I end up with the progress I was at when I last played on the server?


How to cut unwanted area (polygon) using ArcGIS for Desktop?

I am using ArcGIS 10.2 for Desktop with a Basic level license.  There are two overlapping polygon. Polygon A (with line stripes) and Polygon B (in beige color). Polygon A and Polygon B is a separate feature class. Both feature class contains similar attribute column details.  Is it possible to remove all area in A and get the remaining area B?   I've been trying to use Union but it does not works.


How can I manually download the Play Store APK from Google?

I have a Xiaomi Mi Note that doesn't come installed with Play Store. I'd like to install an APK for it manually, but all resources I've found on the web require me to install a binary from untrusted sources (e.g., a Mediafile upload).  How can I download the Play Store APK directly from Google?


I'm getting an error on latex and don't understand why ... The purpose was to create some tables on latex, but it is getting me some error which i don't really understand ... Any hint for me please ? Thank you :)  error:  ! LaTeX Error: Illegal character in array arg.  See the LaTeX manual or LaTeX Companion for explanation. Type  H <return>  for immediate help.  ...                                                l.5 \begin{tabular}{ | 1 | p{5cm} |}   code:  \documentclass[12pt,a4paper]{article} \usepackage[portuguese]{babel} \usepackage[applemac]{inputenc} \begin{document} \begin{tabular}{ | 1 | p{5cm} |} \hline Nome & Manuel da Silva  \\ \line  Data de nascimento & 1977 \\ \line  Data de falecimento & 2011 \\ \line  \end{tabular} \begin{tabular}{ | 1 | p{5cm} |} \hline Nome & Ana da Silva  \\ \line  Data de nascimento & 2006 \\ \line  \end{tabular} \begin{tabular}{ | 1 | p{5cm} |} \hline Nome & Maria Felisbina  \\ \line  Data de nascimento & 1980 \\ \line  \end{tabular} \end{document}


Prove that if $G$ has no subgroups of index $2$, then every subgroup of index $3$ is normal

This is my question : Let G be a group without subgroups with index 2 (i.ee. there is no subgroup M s.t $[G:M]=2$).prove that every group $H<G$ s.t $[G:H]=3$ is normal in G.  What I thought to do: Let N be a subgroup s.t $[G:H]=3$ so $G/H={N,xN,yN}$ so every $g \in G$ is of the form : $g=n,g=xn,g=yn$ when $n \in \mathbb N$. I tried to prove that for every $g \in G$ : $gNg^{-1} =N$  but without a success.


dropping number of levels in nominal features

I do not have a good theoretical background in machine learning, therefore will ask a maybe naive question, nonetheless, it's important for implementing my learning algorithm.   I'm having a question about dropping levels in machine learning classifiers. As I'm having about 20 nominal varaibles as my features, and each feature having 20 levels. Right now the learning speed of the gradient boosting machine with these features are pretty slow and the classification accuracy is also not as good as I want it to be.   My question is, does dropping levels in each of the nominal variable based on MCA may help with the learning speed and classification accuracy.