Higgs Boson detected at LHC is massive. It has high relativistic mass means it has non-zero rest mass.  Higgs Boson gives other things rest mass. But, how does it get rest mass by itself?


I have a string with 100 characters and I want to make a code that separates and stores substrings every 10.  def windows(srt):     i = 0     n = 10     str1 = ''     for x in range(i, n):         str1 += srt[i:n]         i += n         n += n        return str1  string = 'ashusdasddsasdsdaisdauihdsuaudhsuiahcnkjacnlskndjkasdhklahcjkchaljkchskjlchaksjchjkahcsjkchalkjhscjklhaskljchlaksjhckjalshcjkaschsjklchajklhcsjkhcakljchkacjs' x = windows(string) print(x)


I am trying to import an Excel table with around 10,000 XY points into ArcMap 10.2. I am using State Plane NAD 1983 Alabama West (US Feet) as the Coordinate System in my map data frame. I then add the excel table to my Table of Contents in the map then select Display XY Data. Next, I choose the same coordinate system as my data frame then select OK. Once it creates the Events layer for my points they are not in the correct location.   Should I switch everything in my map to WGS84 or is there a solution for my points to be added onto my current map with the state plane coordinate system?


Let $ f $ be a continuous function defined on $ [0,\pi] $. Suppose that      $$ \int_{0}^{\pi}f(x)\sin {x} dx=0,   \int_{0}^{\pi}f(x)\cos {x} dx=0 $$   Prove that $ f(x) $ has at least two real roots in $ (0,\pi) $


I have a sequence: $ a_{n}=\sqrt{3+ \sqrt{3 + ... \sqrt { 3} } } $ , it repeats $n$-times.  and i have to prove that it is a Cauchy's sequence.  So i did this: As one theorem says that every convergent sequence is also Cauchy, so i proved that it's bounded between $ \sqrt{3}$  and $ 3 $ (with this one i am not sure, please check if i am right with this one.)And also i proved tat this sequence is monotonic. (with induction i proved this: $ a_{n} \leq a_{n+1} $  so if it's bounded and monotonic, therefore it is convergent and Cauchy. I am just wondering if this already proved it or not? And also if the upper boundary - supremum if you wish - is chosen correctly.  I appreciate all the help i get.


A condition of abelian groups related to an automorphism

Let $G$ be a group. If for any $a, b\in G\backslash\{1\}$ there exists an automorphism $\sigma$ of $G$ such that $\sigma (a)=b$ then $G$ is abelian.  I am not the best of the algebra and I have a problem with the proof of the fact above although I guess it must be very simple.. I will be grateful for hint.


How to store 32 hex decimal digits in 16 bytes array?

I am using Triple DES algorithm for encryption.While doing that i need to pass in a hex decimal(32 characters) key.When i convert that to byte array it's gets stored in 32 bytes.But the input key to the algorithm should of 16 bytes only.So my question is how to store 32 hex decimal digits in 16 byte array?


I created a t shirt and I applied normal maps and displacements to make it look more like a cotton but what i wanna do now is i wanna add a logo on the chest. How can I do it? Thank you alot for any response. Pictures below:


Having Trouble Removing Duplicates From A List

I have a list of like 3000 items, and I think there are a ton of duplicates. So to make my program run faster, I want to delete them. This is the code along with my function, which when I run the program the text file is empty.  List<string> allCombos = new List<string>();         string here = RemoveTheSame(allCombos, allCombos);         System.IO.File.WriteAllText(@"C:\Hodag Image Storage Folder\creo.txt", here);   //////////////////////////////          private string RemoveTheSame(List<String> lista, List<String> listb)     {         List<String> newList = lista;          newList.AddRange(lista);         for(int i = 0; i < lista.Count; i++)         {             int a = 0;             for(int ii = 0; ii < listb.Count; ii++)             {                 if(lista[i] == listb[ii])                 {                     a += 1;                     if(a >= 2)                     {                         newList.RemoveAt(ii);                         a = 0;                     }                 }             }         }          string wat = "";         for(int i = 0; i < newList.Count; i++)         {             wat += newList[i] + " ";         }           return wat;     }


How can I install programs for all users in Windows 10?

I want to set up my PC with a new Windows 10 installation and have a couple of standard accounts and an admin account. I would like to install my programs (not Windows Store apps, which I don't use) so that they can be used from any account. I could install separate copies of each program on each account but that duplication of space is what I want to avoid. I want to end up with the situation where I nearly always use my PC from a standard account for security and have the ability to run most applications from that account, the other standard account and the admin account. Some examples of the applications I mean are LibreOffice, any browser, a VPN client, Visual Studio, EverNote, Ccleaner, WhatsApp desktop. But also whatever programs I install in future, in general. I know questions like this have been asked before but I haven't found a solution yet.


How to disable WP emoji UTF8 by img replacement?

I use some UTF-8 emojis like 😋 Problem: WP changes that automtaically into img ex:  How can I disabled that ? I need my UFT8 chars and not svg img ? Regards


I'm wondering, in which case would you use C#'s 'as' keyword, as opposed to casting and checking for an exception? Consider this example:  Parent obj = new Child();  // Method 1: try {     Child result1 = (Child)obj; } catch (InvalidCastException) {     // Handle failed cast }  // Method 2: if(obj is Child) {     Child result2 = obj as Child; } else {     // Handle failed cast }   Both Method 1 and Method 2 produce, as far as I'm aware, the exact same result. I know that, when they fail, the as keyword will produce null, while a cast will throw a ClassCastException, but to me, that doesn't seem like enough of a reason to have two nearly identical ways to cast an object. So I'm wondering, why did the C# language designers go trough the trouble of adding the 'as' keyword?


Should PCA be fit on test set or only on training set

I am new to PCA and couldn't find an answer online to this. To predict classes for the test set, should I fit PCA on the training set and call the transform function on the test set, or should I fit on the test set for predicting classes for test set?


Is "I’m writing to request the username ‘log’ be released." correct?

This sentence left me thinking:     I'm writing to request the username "log" be released.   Is this sentence grammatically correct, or is it missing something?


How can a user with less than 2000 rep accept or reject suggested edits?

Here is a screenshot of my "select your next badge" window.    As you can see in the screenshot, my rep was 1905 but I have 1/100 for proofreader badge. I took that screenshot recently, but I have been seeing that 1/100 for quite a long time now. I know that a user with less than 2000 rep doesn't have  Moderation Privilege. So, how was it possible for me to get that 1/100 for proofreader?  I have a suspicion though. I think that 1/100 came from  of mine. I get this suspicion because, as far as I remember I once edited that question without logging in. Also, you can see that the question was edited my .    I am tagging this question with "bug" tag, because I had to choose one from "discussion" and "bug", and the latter seemed right to me, though I want to think that this is not a bug!


Whenever I visit a store page for an M-rated game, I am prompted with a warning asking my date-of-birth, to prove I'm old enough for the game.  I understand this.  What I don't understand is why it partially forgets my birthdate.  It seems to remember the day and the year correctly, but not the month.  What's going on here? I am aware of  which seems similar at first glance, but is not.  I understand why steam has to ask me my birthdate every time, but I don't understand why it only partially remembers my birthdate.  It gets the day and year correct, but the month always defaults to January.


As on the image, I want to close his back and front but I don't want to look like a cube or plane. I want how to it's details like belly,nose,mouth,eye and so on. However I try, I can't add the vertices/lines so I can create details. I just want to make a low poly orc, if you can help me out I would appreciate it a lot. Thanks in advance and hope you respond. :)  (Sorry if I posted wrongly or something else since this is my first question)


I'm trying to make a minigame where you have different kits. You step on a pressure plate and get all your armor and effects added. That's all working fine. I'm trying to make it so it places a sign above the pressure plate saying "TAKEN" "BY" "[PLAYERWHOHASTHATKIT]" In bold dark red Is this possible? I've tried /blockdata ~ ~-1 ~ {"Text3":"@p"}with all the other text I want. Is this possible?


Suggestions for workflow for organizing light room library

I'm trying to come up with a workflow to organize my library in a sensible way and I wanted suggestions about it. I'm pretty new to light room so here's what I've come up with:  First of I usually take between 150 to 400 shots per session, which means I can't always go through all of them on the same day. So I'm selecting my photos to be:  Tags.   Picked (meaning the photo has been developed or in the process of being developed) Unpicked (not yet developed) Discarded ... to delete. Red: Uncertain photos. I'm not sure about this photo so I want to take a second look and either select or delete. Yellow: Keep. This is a photo I'm sure I want to develop and save. Green: Final. This photo is final and I'm satisfied with the final result. Blue: Family / Moments. This photo isn't worth anything from a photography point of view but it involves something I want to remember (family, trip, etc). Purple: JPG + Delete. This photo is to be converted to JPG and deleted (no need to keep the RAW file). Stars: basic 1 to 5 to determine how worth the image is to me.   Smart collections:   Unprocessed to review. Not picked + No color Doubtful. Red. Important unprocessed. Yellow + Not picked Important in progress. Yellow + Picked Final. Green Family + Moments. Blue Family Processed. Blue + Picked. Export & Delete. Purple.   Do you have any input on that process? Any suggestions?


SOQL Querry Error for ContentDocumentLink

Error: Implementation restriction: Implementation restriction:   ContentDocumentLink requires a filter by a single Id on   ContentDocumentId or LinkedEntityId using the equals operator or   multiple Id's using the IN operator.requires a filter by a single Id   on ContentDocumentId or LinkedEntityId using the equals operator or   multiple Id's using the IN operator.   Code:  public static List<AttachWrapper> getAttachment(Id parentId){          //attachmentList = [SELECT Id, Name, Description, CreatedDate, LastModifiedDate, ParentID FROM Attachment WHERE ParentID =:parentId];          ConDocLnk= [SELECT ContentDocumentId FROM ContentDocumentLink WHERE LinkedEntityId =: parentId ];}   I've faced error while fetching ContentDocumentLink records with setting filter as its parent id


Fonts and Template File for Journal "Mathematical Notes" by Springer

Dear Friends: Like most of you, I care for the aesthetics of the font and presentation of my work in Tex.   I am interested in the Tex template file for Journal called "Mathematical Notes" which is published by Springer. Unfortunately, I am unable to find a template that matches their publication.   If you some one can find me the template or even identify the fonts used in the layout, it would make me happy! The fonts look like a variant of the family: Obyknovennaya Novaya  I am attaching a screen shot.


I often see people on the Internet using a comma before and in many cases (not adversative cases). Is it ok? In my language it is stricly prohibited to use a comma before an and except for adversative cases or when an apposition is in the front of that and. Examples (which I consider not ok):  He is a great player, and he prefers to play Counter-Strike. John joined the Army, and George joined the Marines.  What I consider exceptions:  Yes, and what is the problem? I called John, my brother, and now I’m speaking with him.


I have been using classes for only a short while and when I write a method, I make all variables reference self, e.g. self.foo.  However, I'm looking through the wxPython in Action book and notice that "self" isn't used all the time. For example:   import wx  class TextFrame(wx.Frame):     def __init__(self):         wx.Frame.__init__(self, None, -1, 'Text Entry Example',             size=(300, 100))         panel = wx.Panel(self, -1)         basicLabel = wx.StaticText(panel, -1, "Basic Control:")         basicText = wx.TextCtrl(panel, -1, "I've entered some text!",             size=(175, -1))         basicText.SetInsertionPoint(0)         pwdLabel = wx.StaticText(panel, -1, "Password:")         pwdText = wx.TextCtrl(panel, -1, "password", size=(175, -1),             style=wx.TE_PASSWORD)         sizer = wx.FlexGridSizer(cols=2, hgap=6, vgap=6)         sizer.AddMany([basicLabel, basicText, pwdLabel, pwdText])         panel.SetSizer(sizer)   The one below does use "self".  import wx class ButtonFrame(wx.Frame):     def __init__(self):         wx.Frame.__init__(self, None, -1, 'Button Example',             size=(300, 100))         panel = wx.Panel(self, -1)         self.button = wx.Button(panel, -1, "Hello", pos=(50, 20))         self.Bind(wx.EVT_BUTTON, self.OnClick, self.button)         self.button.SetDefault()     def OnClick(self, event):         self.button.SetLabel("Clicked")   If I remember correctly, "self" is reference to a particular instance of the class, so when is it not necessary? Is there a general rule of thumb?


Why didn't the Dornish prince go with Jaime Lannister on the boat to King's Landing?

The prince was promised a seat on the small council. At the end of season 5, I thought he was on the boat with them. But in season 6, it turns out he stayed in Dorne. Why did he stay in Dorne when his fiancé was on the boat and he was given a seat on the small council?


Let $f(z)=\sum\limits_{n=0}^{\infty}{a_nz^n}$ is an univalent analytic function on the open disk $\Delta(0,1)=\{z:|z|<1\}$, such that $G= f(\Delta(0,1))$. If $A$ is the area of the region $G$, prove that:  $$A=\pi\sum\limits_{n=0}^{\infty}{n|a_n|^2}$$  I found this question from the book "Fundamentals of Complex Analysis", written by Liao Liangwen. I have no idea about this. So I want to get some help.  Thanks.


Today I wanted to propose to students a very short and stupid code as follows  # include <iostream>  int main()   {    int a[] {10, 20, 30, 40};     for(int k=0; k != 4; ++k) std::cout << ++a[k] << ' ';     std::cout << std::endl;     }   in order to show how the ++ prefix operator acts in an expression.  I inadvertently mistyped the code, ending up with the following line, in place of the one shown above:  for(int k=0; k != 4; ++k) std::cout << ++k[a] << ' ';   shortly: swapping k and a in the operand of ++.  Well... not only this is compiled, but it gives also the correct results. How this could be understood? Is the index of the loop interpreted as an iterator over the array a? Or what else?


ART makes Facebook app non installable (Error: -24)

I have an Android 4.4.2 phone and I enabled ART instead of Dalvik.  When I go to the Google Play Store and try to install Facebook, it can't install the app.  I get two errors, sometimes I get     Invalid installation package   and sometimes     Error -24   Is there a way to know what's going on?


On which topological spaces, can we give a group structure to make it a topological group?

Let $X$ be a non-empty set. It is known that we can give a group structure on $X$. Now let $X$ be a non-empty topological space. Then can we give a group structure on $X$ so that it becomes a topological group w.r.t. its original topology ?


Firefox Quantum installed but doesn't see internal or external storage drives

I recently installed Ubuntu 18.04 on my home desktop and went to upgrade my copy of Firefox to the new Quantum version.  My computer is set up with two internal hard drives; and SSD for the OS and a 1tb WD hard drive for storage. The 'old' version of Firefox could see or navigate to the internal storage drive... the Quantum version can't see/find that drive OR any external drives attached to my computer. Google Chrome has no issues with the internal drive, and I don't think the drive is at fault since Chrome can find and save to it, and the old version of Firefox (now re-installed) can find and save to the internal drive... so what's going on with Firefox Quantum?  Mount at system startup is checked Show in use interface is checked Require additional authorization is NOT checked NO Display Name NO Icon Name NO Symbolic Icon Name unamed field has these properties: nosuid,nodev,nofail,x-gvfs-show Mount Point = /mnt/Storage_Disc_01 Identify As = /dev/disk/by-label/Storage_Disc_01 Fiesystem Type = auto  What am I doing wrong, or can Firefox Quantum only see the drive it's installed on?


Let $W$ be a submodule of $V$. Prove that if $V/W$ and $W$ are finitely generated then so is $V$.

I have a rough idea of how this works intuitively, $V/W$ and $W$ being finitely generated means that they both have a finitely generating subset, we put $\{a_1, \dots, a_n\}$ to be $W$'s basis, and $\{b_1, \dots, b_m\}$ to be $V/W$'s. Any element $c \in V/W$ can be written as a linear combination of $\{b_1, \dots, b_m\}$ and as $a + b$ such that $a \in W$ and $b \in V$, $a$ is written as a linear combination of $\{a_1, \dots, a_n\}$. $b = c - a$ with $c$ and $a$ being linear combinations of finitely generated elements, this forces $b$ to be finitely generated?


Today I earned only 170 rep from upvotes:    But still I got an upvote on one of my questions that did not count. How come?


The tallest building I have ever seen was in New York. Is the use of 'was' acceptable here?

A student has written  The tallest building I have ever seen was in New York.  I know the expected formation is  The tallest building I have ever seen is in New York.  But is the first sentence grammatically acceptable too? There are other sentences like:  The hottest place I have ever been to was Florida. The longest journey I have ever taken was when I went to Los Angeles.


iwlwifi: Could not load the [0] uCode section; Failed to run INIT ucode: -5

I'm getting this error occasionally when my device wakes up from suspend,  iwlwifi: Log capacity -1515870811 is bogus, limit to 1 entries iwlwifi: Log write index -1515870811 is bogus, limit to 1 iwlwifi: Start IWL Event Log Dump: display last 1 entries wlp3s0: HW problem - can not stop rx aggregation for 9c:1c:12:24:0e:18 tid 0 iwlwifi: Command REPLY_ADD_STA failed: FW Error wlp3s0: HW problem - can not stop rx aggregation for 9c:1c:12:24:0e:18 tid 1 p3s0: CTRL-EVENT-DISCONNECTED bssid=9c:1c:12:24:0e:18 reason=4 locally_generated=1 arn>  [1530059866.2378] sup-iface[0x5575dbb13da0,wlp3s0]: connection disconnected (reason -4) ieee80211 phy0: Hardware restart was requested  ... lots of stuff and a stack track  iwlwifi  iwl_trans_wait_tx_queues_empty bad state = 0 iwlwifi: Radio type=0x1-0x2-0x0 iwlwifi: Could not load the [0] uCode section iwlwifi: Failed to run INIT ucode: -5 iwlwifi: Unable to initialize device.  ... another stack trace,   I'm using this Wifi Card in a Lenovo x230 (from lspci, and syslog)  Network controller: Intel Corporation Centrino Advanced-N 6205 [Taylor Peak] (rev 34) iwlwifi: Detected Intel(R) Centrino(R) Advanced-N 6205 AGN, REV=0xB0   I see a lot of errors pertaining to this card, but not with a failure to load uCode (microcode?) When things work, I see this in my syslog,  iwlwifi: can't disable ASPM; OS doesn't have ASPM control iwlwifi: loaded firmware version 18.168.6.1 op_mode iwldvm   According to the , I am running the latest version (18.168.6.1).  From all syslog messages PCI Address (0000:03:00.0) and timestamps cut out.


According to Oxford Learner's Dictonaries, the -'s suffix can have these two meanings: (added to nouns) 1 belonging to  the woman's hat Peter's desk children's clothes  2 used to refer to somebody's home or, in British English, a particular shop  Shall we go to David's (= David's house) tonight? (British English) I'll call in at the chemist's on my way home  So except for the last example, it looks like it's always used for people but not for things. Is it really like that? Song lyrics or Song's lyrics?


Prove that if $\sum_nU_n$ is convergent. Then $\sum_n U_n^2$ is convergent

I know that $\sum_n U_n$ is cgt therefore $\underset{n}{\lim} U_n = 0$ and by definition of limit $0- \varepsilon < U_n < 0+\varepsilon$ for all $\varepsilon > 0$ but I don't know how to get to $\sum_nU_n^2.$  P. S.  Here $\sum_nU_n$ is series of positive terms.


Return type out-of-line definition differs from that in the declaration

First time asking so be gentle.  I am having a problem with a returning a custom type for a function. To be more specific, I have a linked list, and I am writing a function that traverses to the end of the list and returns a pointer to that node. Unfortunately, I am getting a pesky error:  "Return type out-of-line definition of mySpace::CDAL::tailNode differs from that in the declaration"  The header file contains within the "mySpace" namespace and the template class CDAL  private:  struct Node {....};   the function header   Node* tailNode();   and in the .cpp  template <typename T> struct Node* mySpace::CDAL<T>::tailNode() {...}   I tried using struct because someone had mentioned for non-typedef declarations you sometimes would need it, and I no longer received the unknown type error, but received this instead.  Thanks in advance for any help.


Citation warnings - Citation 'bibtexkey' on page '_' undefined

Hey I am still having issues with my citations.  It is the very last thing I need to do before my thesis is complete, but I have to turn in in by Thursday!  I am getting multiple warnings for a number of my citations saying: Citation `Bibtexkey' on page '6' undefined. Some of my citations are fine while others will not work and show up as ( ?) in the pdf. There is nothing wrong with my bibtex file within JabRef that I can see, so I do not no what is causing this to happen.  I am using TeXStudio. Here is a MWE. nuthesis is a class designed for my universities graduate students. I don't believe it has anything to do with the issue as I know many many people who have used this document class successfully. I've tried using different styles as well but no luck. I have a lot of other packages involved, but not sure if they may be affecting the bib. I've seen people talk about how you compile matters, i.e. latex bibtex latex latex, which I believe I am doing correctly but I still get errors.      \documentclass[print,double]{nuthesis}     \usepackage{amssymb}     \usepackage{natbib}     \usepackage[       unicode=true,       urlcolor = blue,       colorlinks = true,       citecolor = blue,       linkcolor = blue]{hyperref}      \begin{document}      \citep{MeroLiu}      \citep{Bonse}     \citep{Keldysh}      \bibliography{Thesis_BIB}     \bibliographystyle{aipnum4-1}  \end{document}   MeroLiu and Bonse are examples of two citations that give warnings.  Keldysh is my most cited reference and cites correctly throughout my entire thesis.  Here are the bibtex sources:  @ARTICLE{Keldysh,   author = {L. V. Keldysh},   title = {Ionization in the field of a strong electromagnetic wave},   journal = {Soviet Physics Jetp},   year = {1965},   volume = {20},   pages = {1307-1314},   owner = {Chris Ferris},   timestamp = {2014.02.18} } @ARTICLE{MeroLiu,   author = {M. Mero and J. Liu and W. Rudolph and D. Ristau and K. Starke},   title = {Scaling laws of femtosecond laser pulse induced breakdown in oxide     films},   journal = {Physical Review B},   year = {2005},   volume = {71},   pages = {1-7},   owner = {Chris Ferris},   timestamp = {2014.02.18} } @ARTICLE{Bonse,   author = {J. Bonse and J. M. Wrobel and J. Kruger and W. Kautek},   title = {Ultrashort-pulse laser ablation of indium phosphide in air},   journal = {Applied Physics A},   year = {2001},   volume = {72},   pages = {89-94},   owner = {Chris Ferris},   timestamp = {2014.04.07} }   Any and all help is greatly appreciated! Thank you!


How to make Excel's "Auto Fit Row Height" feature actually auto fit the row height?

For every generation of Excel I can remember (including 2010, which I'm using now), Excel's "Auto Size Row" features sometimes fails to actually auto size a row when the cell contains wrapped text. When it works properly, all the text is revealed and there is no additional space below the last line of text. When it fails, it adds extra space below the text. To make matters worse, what you see is not always what you get, i.e., text that appeared okay on screen gets cut off when it's printed. You also get different sizing depending on whether you are zoomed in/out or at actual size.  Simple test case:  Why is there a one-line gap after the text in cell A1 but not in A2?  (To reproduce: set width of column A to 17.14 (125 pixels), text wrap on, and cell alignment top.)  (I double-checked that I applied Auto Fit Row Height to both rows. Zoom level is 100%.)    Is there any known remedy for this without resorting to manually adjusting the row heights (which is not practical for more than a handful of rows)?


The normal definition of Work, as far as I have read, is: Energy is transferred through work. But I just heard an educationist state this example, where there is a weightlifter who keeps up a huge mass above his head (stationary), and he (the educationist) says that there is no work done, as the force exerted on the mass does not move the mass. But isn't the weightlifter doing work to keep the mass above his head? Or should I assume that there is no work done if a force exerted on an object does not move the object?   Please explain.......


ImageMagick installation fail on Linux Mint

I am trying to install ImageMagick on Linux Mint.  This is the source for installing that I am using   sudo apt-get build-dep imagemagick  Reading package lists... Done Building dependency tree        Reading state information... Done E: Unable to find a source package for imagemagick   Is it becuase I am using Mint that it is not working or is it some other reason?


I am using Oracle 12c Standard Edition.  I accidentally drop the table and try to recover it, but the table does not appear in Recyclebin.  I think the tablespace is due to SYSTEM.  Create table test(  aaa varchar2(20)  .... )  TABLESPACE SYSTEM  STORAGE (   NEXT 1024K  ) /   thank!


How do I wire a GFCI receptacle using two black wires and two white wires?

I recently purchased an older home and wanted to install GFCI outlets in the kitchen.  When I opened up the outlet, there were four wires (two black and two white) in addition to the ground.  I watched a few videos online about installing GFCI outlets, but they only gave guidance about doing it when there's one black, one white and the ground. Currently, the two-prong outlets have all four wires attached - the two black wrapped around screws on one side and the two white wrapped around screws on the other side. What do I do with these "extra" black and white wires on the GFCI outlets?  Attach them somehow or tie them off?


Does finishing normal mode on the Cayo Perico Heist give you hard mode?

I missed the chance to get the hard mode on the Cayo Perico heist on GTA Online, so if I complete the normal one again can I get the hard mode again?


Is everyone able to learn philosophy?  If not, what kind of person is able to learn philosophy?    Does learning philosophy require a certain intelligence or talent? If I start at the age of 18, is it too late?   I am a student of vocational high school, majoring in informatics engineering. I rarely read books other than textbooks, and just recently read a non-textbook book titled Sophie's World. That is what led me to this question.


Split By Attributes creates no Shapefiles?

I want to create for each polygon of a shapefile a separate shapefile with the  tool. Input is a polygon shapefile and as split field I choose the ID. This tool works fine but in the results I cant find any shapefile, only .dbf , .dbf.xml and .cpg. But why is there no .shp?  As output I tried a workspace and a geodatabase, both didn't worked.


I'm trying to get things like bool instead of Boolean and int instead of Int32. Is there any way out of the box that reflection gives that option when querying for the type name of a certain property or do I have to do my own mapping? To get the name I'm using myPropertyInfo.PropertyType.Name  Thanks!


In Google Drive how do I find everything I shared with other people?

I accidentally shared some photos on Google Drive with the wrong recipient (Google account). Since not all the shared documents were in the same folder, what's the easiest way to go through them and remove sharing privileges?


The panel that appears as shown in the image below, cannot be re-opened. It only appears, on the left-hand-side of the screen when I create a new object. How do I get it back as shown in the image?     My "Data" tab, looks different.


A Stack Overflow question is copied directly from textbook, does it matter?

I just stumbled across a simple one-sentence computer security question on Stack Overflow that is copied directly from the textbook. No further explanation, nothing done to show any understanding or effort on the part of the asker.  What is typically done in this situation? I was tempted to immediately call him/her out in a comment, but I don't actually know if there is a policy against this or not. Is there? What should my response be?


When a vehicle makes a turn, the two front wheels trace out two arcs as shown in the figure below. The wheel facing towards the inside of the turn has a steering angle that is greater than that of the outer wheel. This is necessary to ensure that both front wheels smoothly trace out two arcs, which have the same center, otherwise the front wheels will skid on the ground during the turn.   During a turn, do the rear wheels necessarily trace out the same arcs as the front wheels?


Why is my photo corrupt in Camera RAW when it shows fine in-camera and in Photoshop?

Here is how I see it in the back of the camera and also in photoshop preview:    But when I double click on it to open it in Camera RAW, here is how it is:    What is going on? What has happened?


How do you hang something on sheetrock if you have metal wall studs? The item is a very heavy shelf, so anchors aren't going to cut it.


Android App sometimes loses answer drafts

Often when I am writing an answer in the Android app I need to refer back to the question to confirm a point I have read, so I click the "back to question" button at top right.  When I go back to the question a button "edit your answer draft" appears at the bottom of screen as expected.   Clicking this button often takes me to an empty answer form with my draft work lost. A further "back" click takes me back to the question with no "edit answer draft" button.  Am I doing something wrong or is this a bug in the Android app?  Equipment: Samsung Galaxy S5 phone, Android 5.0


Any stats data advocating integrated social logins over traditional user / password login?

Is there any published, statistical data that shows social logins (such as OpenID, Facebook, etc.) are preferable over traditional username / password login with regards to registration rates?  For example, for the same amount of user visits (of the same profile such as age, gender, education, etc.), which would gain more registrations / sign-ups? The social logins or in-house username / password login?  If no such data are present, anyone care to provide some insights from your own website analytics for comparison? I ask this is because I personally asked a few of my users and neither was more favored over the other given in-house registration is simple to complete.


How to report that a question should be migrated to another site?

How do I report that a question should be moved to a different site (from stackoverflow.com to superuser.com, in example)?


I need to limit the amount of memory being used when running a Python script in NiFi, and I found  answer in Stack Overflow. I follow the logic of how the code works, but I'm a bit stumped as to how to actually implement it in a Python script.   For example, if I have a script  import sys import json  flowFile = sys.stdin.read() try:      j = json.loads(flowFile)     sys.stdout.write(j) except:     sys.stdout.write(flowFile)   would I then implement the memory limit as   import sys import json  def memory_limit():     soft, hard = resource.getrlimit(resource.RLIMIT_AS)     resource.setrlimit(resource.RLIMIT_AS, (get_memory() * 1024 / 2, hard))  def get_memory():     with open('/proc/meminfo', 'r') as mem:         free_memory = 0         for i in mem:             sline = i.split()             if str(sline[0]) in ('MemFree:', 'Buffers:', 'Cached:'):                 free_memory += int(sline[1])     return free_memory  if __name__ == '__main__':     memory_limit() # Limitates maximun memory usage to half     try:         main()     except MemoryError:         sys.stderr.write('\n\nERROR: Memory Exception\n')         sys.exit(1)  flowFile = sys.stdin.read() try:      j = json.loads(flowFile)     sys.stdout.write(j) except:     sys.stdout.write(flowFile)   or something else entirely?


I have the following question:          Find the value of:     $$ \frac {1} {\sqrt {4} + \sqrt {5}} +  \frac {1} {\sqrt {5} + \sqrt {6}} + ... +  \frac {1} {\sqrt {80} + \sqrt {81}}$$      The book already provide the answer for this question but it didn't include the ways. Hint or anything that will help is appreciated


Using graphicx with invoice results in strange PDF output

I try to create an invoice with a logo in the background. But I get a strange result when I use graphicx and invoice in the same document. Here is my minimal example:  \documentclass{scrlttr2}  \usepackage[utf8]{inputenc} \usepackage[ngerman]{babel} \usepackage{graphicx} \usepackage{invoice}  \begin{document} % foobar \end{document}   It builds fine with pdflatex, but the resulting PDF file has this on it's first page:     [2007/09/09] [2010/03/01] [2010/12/02] [2010/09/13] [2007/11/11]   [2007/09/09] [2007/09/09] [2010/03/01] [2010/03/01] [2010/12/02]   [2007/09/09] [2007/09/09][2010/03/01] [2010/01/28] [2007/09/29]   [2007/10/02] [2007/11/11] [2009/07/12]   After this, a page break happens and the expected output begins. The footer is also on the first page (where the dates are) and the second page (the first with actual content) has no footer. Starting with the third page, everything seems fine.  Is this a bug in either invoice or graphicx?  Update: This only happens with pdflatex, the DVI output does not show the dates.


How to select within a distance using QGIS

With QGIS 2.12.3, I have two projected EPSG:2927 point shapefiles, A and B.  I would like to create a selection of A points that are within 100 meters of any B point.  This is easy in Arc, using the Select by Location tool with the search distance option.    I am aware of two Select by Location tools in QGIS (Vector -> Research Tools -> Select by Location and the Spatial Query plugin).  However, neither has a search distance option.  In summary, how to do a QGIS Select by Location with a search distance?


Connect points from two SpatialPointsDataFrames in R, considering the closest distance

I have two SpatialPointsDataFrames. In SpatialPointsDataFrame one (dat1) I have three points (A, B and C). In SpatialPointsDataFrame two (dat2), I have eight points with temperature measurements. I must connect each of those eight points to the closest point from dat1 and then calculate the average temperature for each point. How can I do that in R?  library(sp) library(tmap)  # SpatialPointsDataFrame 1 dat_orig <- read.table(text=" point   lat   lng A   15.6  80.9 B   20.9  10.9 C   1.2   81.8", header=TRUE, stringsAsFactors=FALSE)  dat1 <- dat_orig coordinates(dat1) <- ~lng+lat  # SpatialPointsDataFrame 2 dat2_orig <- read.table(text =  "temp   lat   lng 18   15.6  81.9 18.5   19.9  10.9 12.3   11.2   81.8 14.2   15.6  85.9 13.1   1.2  60.9 18.5   20.8  40.9 17   14.6  10.9 18.1   14.6  11.9", header=TRUE, stringsAsFactors=FALSE)  dat2 <- dat2_orig coordinates(dat2) <- ~lng+lat  # tmap plot tm_shape(dat1, ylim = c(-10, 35), xlim = c(-10,100)) + tm_dots(col = "red", size = 0.2) + tm_text("point") +   tm_shape(dat2) + tm_dots(size = 0.1)


Java - Why is this code repeating? NoSuchElementException?

I'm learning Java by trying to make a simple Rock-Paper-Scissors game in Eclipse:  package com;   import java.util.Random; import java.util.Scanner;   public class Game {      public static void main(String[] args) {         Game game = new Game();         game.playerChoice();         game.aiChoice();         game.playGame();     }  public void playGame() {      if (playerChoice() == "Rock") {         if (aiChoice() == "Rock") {                 System.out.println("Tie!");             } else if (aiChoice() == "Paper") {                 System.out.println("AI wins!");                 } else {                 System.out.println("You win!");                 }          } else if (playerChoice() == "Paper") {             if (aiChoice() == "Rock") {                 System.out.println("You win!");             } else if (aiChoice() == "Paper") {                 System.out.println("Tie!");             } else {                 System.out.println("AI wins!");             }          } else {             if (aiChoice() == "Rock") {                 System.out.println("AI wins!");             } else if (aiChoice() == "Paper") {                 System.out.println("You win!");             } else {                 System.out.println("Tie!");             }         }     }      public String playerChoice() {          Scanner scanner = new Scanner(System.in);         String word = null;          try {             System.out.println("Type Rock, Paper, or Scissors");             word = scanner.next();             System.out.println(word + " is saved as your choice");         } finally {             scanner.close();         }         return word;     }      public String aiChoice() {          String[] wordlist = {"Rock", "Paper", "Scissors"};         String word = wordlist [new Random().nextInt(wordlist.length)];         System.out.println("AI has randomly picked " + word);         return word;     } }   When I input "Rock", "Paper", or "Scissors" in the scanner input I get the following in the console:  Type Rock, Paper, or Scissors Rock <--- This is what I input into the console Rock is saved as your choice AI has randomly picked Scissors Type Rock, Paper, or Scissors <--- This unintentionally repeats Exception in thread "main" java.util.NoSuchElementException     at java.base/java.util.Scanner.throwFor(Unknown Source)     at java.base/java.util.Scanner.next(Unknown Source)     at com.Game.playerChoice(Game.java:53)     at com.Game.playGame(Game.java:17)     at com.Game.main(Game.java:12)   What am I doing wrong that causes this exception and why does the System.out.println("Type Rock, Paper, or Scissors"); repeat itself? Thank you.


Can I use ADB without connecting over USB?

Is there a way to use adb directly via bluetooth instead of always via usb?  --  Thanks for the adb wireless solutions below, but I am looking for something that works well on hotel or public wifi. Bluetooth short-range might be the only way to go about it.


Can you create tags in the Stack Exchange iOS app?

I seem to be able to search for tags, but not to create. I double-checked that I do have the create tags privilege.


What do you call someone who has extensive knowledge but won't share it?

What do you call a person that has a lot knowledge/information but decides to not share it?  Is it really the classic know-it-all or enlightened?


How to check if the system console is displayed?

It there any way to check if the system console is displayed on (Windowse Os)?  I would make a custom task progress.


Is it the case that every quotient ring ${F[x]}/{(p(x))}$ is a PID?

Let $F$ be a field and $F[x]$ the univariate polynomial ring over $F$. Is it the case that every quotient ring ${F[x]}/{(p(x))}$, where $p(x) \in F[x]$, is a PID (principal ideal domain)?    This is just a minor issue that's been bothering me for the last couple of hours. I'm aware that when the ideal $(p(x))$ is prime (i.e. $p(x)$ irreducible) then ${F[x]}/{(p(x))}$ is a PID.


Is spin really just "rest angular momentum"?

Spin is the intrinsic angular momentum of a particle. The particle itself is elementary and is not spinning on its axis, and has this momentum even at rest. The absolute magnitude of this momentum cannot increase or decrease without changing the particle. The particle may have angular momentum in addition to its spin, increasing its total angular momentum linearly.   Rest mass is the intrinsic confined energy of a particle. The particle itself is elementary and does not physically contain internal energy (binding energy, elastic potential, vibrational, etc), and has this energy even at rest. The absolute magnitude of this energy cannot increase or decrease without changing the particle. The particle may have energy in addition to its rest mass, increasing its total energy linearly.   Would it therefore be correct to call spin "Rest angular momentum", in the same sense mass is "Rest energy". In what ways does this analogy break down?


I have a Mac Mini, which died due to motherboard and power supply failure. I'd like to know if it is safe to take out the RAM module and check it in another computer too see if it is working. If the RAM module is bad, do I risk breaking the computer I want to test it in?


I don't think there will be a canonical answer for this question. I'm just wondering if this is how it works.  It's said that when you kill someone, you split your soul. I believe that means you split it in half.  So, I came up with this graph:      The splitted part of the soul couldn't be exactly 1/7 every time because he didn't know how many he would make, perhaps he would make more in the future.  He asked Slughorn about making 7, that's why I'm using this number here.  Perhaps it's just a random percentage of the soul... I don't know.  But, as I said, considering that the soul is split in half.  When he splits it again, I don't think a soul already "horcruxed" would be a part of this division, since it is intact inside another object that could be anywhere in the world.  So, this means that the first Horcrux he made would have half his soul. Then, the second would have 1/4 of it, just as himself.  Does that means that Voldemort fought against Harry in the last book with only 0,78% of his soul in his body?  Is my math insane?


Why is $\displaystyle\sum\limits_{k=0}^{n}(-1)^k\binom{n}{k}^2=(-1)^{n/2}\binom{n}{n/2}$ if $n$ is even ?   The case if $n$ is odd, is clear, since $\displaystyle(-1)^k\binom{n}{k}+(-1)^{n-k}\binom{n}{n-k}=0$ (we have $(n+1)/2$ such pairs.)  but if $n$ is even we have no symmetry, I tried to consider the odd and even terms separately but with no success.   Do you have an idea ? Thanks in advance.


In regression analysis it could happen that some samples are more relevant than others (i.e. they are more important in understanding the underlying model). Is there any technique to train a regressor by weighting training samples according to their relevance? A trivial example could be giving 0 weight to outliers.


how to get image name and image size from base64 string image

I am working on mobile app development. I am uploading image in base64 string format. i want image name and image size from base64 image string.  $("body").append("<img id='hiddenImage' src='" + "data:image/jpeg;base64," + imageData + "' />"); var file_size = $('#hiddenImage').size(); alert(file_size); var width = $('#hiddenImage').width(); var height = $('#hiddenImage').height(); $('#hiddenImage').remove(); alert("width:" + width + " height:" + height);


Let $M$, $L$, $N$ be $A$-modules and $M=N\oplus L$. If $M$ and $N$ are free, is $L$ necessarily free?


If N is a nilpotent subgroup of a group G and G' is a commutator of G then show that [N,G']=1

I try this but unable to find a relation between nilpotent subgroup and commutator  Sinc N is nilpotent so Ni is a subgroup of zi (G) then no idia how to proceed further


Advice with How to Return the # of Files found within a folder

Create a script to ask a user for the name of a folder and have the script return the number of files found within the folder. If folder doesn't exist, display error message to the screen  I've gotten the first part of this question completed, and I'm aware that a variable will need to be created to store the num of files found in the folder.  I'm just stuck on how to return the number of files found. Any advice on how I would go about doing this? I know the ls command will be used.  clear echo -e "Option #11: Acquire the number of files within a particular folder\n\n" echo -e "Enter in the Folder Name below\n" read foldername answer=$(grep $foldername) if [ "$answer" = "" ] then clear echo -e "\n No Such Folder Exists" else


Workaround needed: Buying an application for someone else in the Android Market

Reading around I can see that Android Market doesn't yet support Gift tokens or similar, and while Amazon's Android market does, its only available in the USA. So the question is, what sort of workarounds are there for this?   For example, could I log in to android market from the recipients phone with my google credentials, buy and then download the application, then logout again? Would the application still work? Can I pay with my credit card with the other persons Google wallet? Is this consistent with the usage policy of the Android market? What other options might I have?


Having trouble with ' character being entered into a MYSQL database

I am having issues whenever I put a ' in text on a page that updates the database,  $query = "UPDATE news SET news1_title='$news1_title', news1_info='$news1_info', news1_body='$news1_body', news2_title='$news1_title', news2_info='$news2_info', news2_body='$news2_body' WHERE id=1";   As it cuts off and ends up throwing the text into the code.  Is there a way that I can add things like this safely, I know I can use ' but then when it shows it back in the page it returns as ' and I have to update them every time to ' otherwise it errors.  Thanks.


showing error in update in ubntu 16.04.2

W: The repository 'http://extras.ubuntu.com/ubuntu xenial Release' does not have a Release file. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details. E: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/xenial/main/source/Sources  404  Not Found [IP: 91.189.92.152 80] E: Some index files failed to download. They have been ignored, or old ones used instead.   how do i solve it


Coverting String to char Array throwing an error - Exception in thread "main" java.lang.NullPointerException

I am Beginner in java ,I am just trying out to convert string into char array,though it is running fine on my System but on a competitive coding website it is throwing an error.Here is the link of that Exception in thread "main" java.lang.NullPointerException    Here is my piece of code I have used BufferedReader to take input:-                  String s1;                 s1= inp.readLine();                 String s2;                 s2=s1;                 char ch1[] = s1.toCharArray();                 char ch2[] = s2.toCharArray();   Please help!


Let $f: \mathbb{R}\to\mathbb{R}$ be a bounded function and suppose that $g(x)=\sup \left(f(t)\right)$ for $t>x$. Show that $\lim_{x\to a^+} g(x) = g(a)$ for all real $a$.  I'm not sure how to start this. Do we want to show that $\limsup f(t) = g(a)$? If so, is it possible to say that since we are evaluating a right sided limit, we then want to find a $\sup f(a^+)$ since $a^+>a$ which is then $g(a)$ since $g(x)=\sup \left(f(t)\right)$? How can I write this more concretely?


Show that if the edges of $K_n$ are colored with $n$ different colors, then there must be a triangle where all three edges have distinct colors.  So, I want to use induction on $n$ where $n$ is the number of vertices in the graph then the base case would be $n=3$ ($K_3$ graph) because you must have a triangle with three distinct edge colors. Then, I know if I draw it with $n=4$ and so on so forth it is true, but I'm having trouble putting it more eloquently.


How many entries in $3\times 3$ matrix with integer entries and determinant equal to $1$ can be even?

Let $A$ be a $3\times 3$ matrix with integer entries such that $\det(A)=1$. At most how many entries of $A$ can be even?  I get a possible solution as $6$ by considering the $3 \times 3$ identity matrix. But I am not sure about that is it possible to have more than $6$ even entries. Please help me enumerate this problem to prove my answer.


Prove that ::     If $A$ is an $n\times n$ matrix such that $AB = BA$ for any $n\times n$ matrix $B$, then $A=\lambda I_n$


A word for "intimate friends" without any kind of romance?

I'm looking for a word to describe that a particular situation where two people (a man and a woman) are probably the best of friends but have no romantic inclinations towards each other. They may invade each others thoughts periodically but aren't really in a relationship per se. What would be a good word to describe this?  I'm aware of "platonic" but am wondering if there is another word?


find-new/posts&recent=1 as homepage: what about SEO?

I can't change the URL of my website with .htaccess, because the query does not work anymore if I make it a pretty URL, so I am desparate to know what impact this will have on SEO. I mean, I have to use this one, because my community wants to see this page as the homepage, which I can understand, but I don't know what effect this will have on my pageranking.  The funny part is that this page has no canonical URL and it has noindex on it, so that is not good at all, but I am asking you for the URL in the address bar specifically. Can someone explain to me what will happen?


Current source with unlimited cap drive op-amp oscillating

I've been trying to make a current source, and have finally gotten my hands on some  which should be an 'unlimited cap drive' op-amp. The problem is, it is still oscillating. This is the schematic and PCB layout:   I have tried to route the ground inside the loop area, close to the 5V connection for the opamp, so I could place the bypass capacitors as close as possible. Although the bigger 10uF cap has one of its legs at the groundplane (forgot to include this cap in the schematic picture.) This is what it looks like when I probe the gate of the MOSFET:  It's all over the place. I tried adding a 10uF capacitor across the DUT, so from VDD to ground. This removed a lot of the wierd noise and made it look almost like a sinewave:  I've tried with and without the gate resistor R1, it didn't seem to make any difference. What is going on? Any clues on why this just doesn't work? EDIT: Solved it! With the help from @Andyaka below, I used his solution of inserting a BJT emitter follower in between the op-amp and the MOSFET, together with an integrator and got some great results! Final circuit:  The simulations can be seen here:  The gain/phase bode plots I made on the PCB:  Bandwidth of approximately 350kHz! Very pleased.


Consider $D_4$ generated by the "reflection" element, $\sigma$, and the "rotation" element $\rho$.  $D_4 = \{\mathbb{1}, \rho , \rho^2 , \rho^3 , \sigma, \sigma \rho ,  \sigma \rho^2 , \sigma \rho^3\}$ Now consider the (cyclic) group of order $2$,  $\mathbb{Z}_2[\sigma] = \{\mathbb{1} ,  \sigma \}$ Then $D_4 / \mathbb{Z}_2[\sigma] = \{ \{ \mathbb{1},\sigma\} , \{ \rho ,\sigma\rho\} , \{ \rho^2,\sigma\rho^2\} , \{\rho^3,\sigma\rho^3 \} \} = \{\{ \mathbb{1},\sigma\} , \rho\{ \mathbb{1},\sigma\} , \rho^2\{ \mathbb{1},\sigma\}, \rho^3\{ \mathbb{1},\sigma\} \}  $ Which is surely cyclic? But I have been told that it is not. Could anyone clear something up for me Thanks :)


.'Failed to load document' error after PDF save.?

I am opening a pop up VF page as 'render as pdf'.I have created a button Save and on click on save i am closing the pop window and saving PDf to opportunity.  Issue  When i am saving the code when calling the savePdf method without rerender and oncomplete.Its saving the attachment and i am able to open the attachment in opportunity without issue.When i am using either using rerender or oncomplete i am able to save the attachment but it says ".'Failed to load document'"  Its been a week i am stuck please help.  <apex:form>   function myClose(){      self.close();     window.opener.location.href="/{!$CurrentPage.parameters.Id}";      //you could also use self.close();         }  <apex:pageBlock mode="maindetail" id="thePb">          <apex:pageBlockButtons >         <apex:commandButton value="Save to Opportunity" action="{!savePdf}" oncomplete="myClose();"  />        </apex:pageBlockButtons>       <apex:pageMessages />       <iframe height="600px" id="Page" name="InvoicePDF" src="/apex/GenerateQuotePDF?id={!parentId}" width="100%"></iframe>      </apex:pageBlock>    </apex:form>   Class  public void savePdf() {      PageReference pdf = Page.GenerateQuotePDF;     pdf.getParameters().put('id',parentId);      pdf.setRedirect(true);     // create the new attachment   Attachment attach = new Attachment();      // the contents of the attachment from the pdf     Blob body;          body = pdf.getContent();      attach.Body = body;     // add the user entered name     attach.Name = 'Opportunity'+ '.pdf';       attach.IsPrivate = false;     // attach the pdf to the account     attach.ParentId = parentId;     attach.ContentType = 'application/pdf';     insert attach;     }


How do I solve this probability question?   let's say there are 3 totally independent weather forecast websites. They use totally different ways to predict the weahter.  Website 1 says: there's a 55% chance it's gonna rain, Website 2 says: there's a 60% chance it's gonna rain, Website 3 says: there's a 65% chance it's gonna rain.  What would be a correct estimate of the total probability it will rain? You could argue it's 60% because that's the average, but intuitively that sounds wrong to me. Because for example if 1000 websites claim there's a 60% chance it's gonna rain, isn't that prediction more valuable than if 1 website would claim that? What am I missing here?


Unable to open app from unidentified developer

I'm trying to install  on my MacBook. My operating system is macOS Mojave 10.14.5. When I try to install the software, I receive the following unidentified developer message:    But when I go to the System Preferences, I can't find any options to overrule it.    I was wondering why is this the case and how to fix it.


I have been proposed this enigma, but can't solve it. So here it is:  $$\begin{align} e^{2 \pi i n} &= 1 \quad \forall n \in \mathbb{N} && (\times e) \tag{0} \\ e^{2 \pi i n + 1} &= e &&(^{1 + 2 \pi i n})\ \text{(raising both sides to the $2\pi in+1$ power)} \tag{1} \\ e^{(2 \pi i n + 1)(2 \pi i n + 1)} &= e^{(2 \pi i n + 1)} = e &&(\text{because of (1)}) \tag{2} \\ e^{1 + 4 \pi i n - 4 \pi^2 n^2} &= e && (\div e) \tag{3} \\ e^{4 \pi i n - 4 \pi^2 n^2} &= 1 &&(n \rightarrow +\infty) \tag{4} \\ 0 &= 1 &&(?) \tag{5} \end{align}$$  So the question is: where is the error?


When a solid is dissolved in a liquid, is it still a solid, what about individual atoms or molecules in a vacuum?

I am trying to gain a better understanding about states of matter, the last paragraph is the most important one to be answered.  It is my understanding that when a solid is dissolved into a liquid, at least some of it is individual molecules or atoms are are not attached to other molecules and atoms of the same type, instead they are completely separate, not part of any solid structure. In that situation, are those molecules or atoms a solid, a liquid or something else?  Additionally, if I have an individual atom or molecule in a vacuum, which at that temperature and pressure would normally be solid, is it still considered a solid? What if that single atom or molecule would be a liquid at that temperature and pressure, is it still considered a liquid?  Is there something fundamental about the state of an atom or molecule that, independently of other atoms or molecules of the same type, determines if it is in a solid, liquid or gas state (plasma I understand)? Are there observations, tests or measurements (other than temperature) that could be applied to an individual atom or molecule in a vacuum that could be used to test its state (perhaps how it reacts chemically with other substances, perhaps how it interacts mechanically with other substances, how it moves, perhaps how it responds to radiation)?


Why does dark energy seem to push things apart?

Ordinary matter acts to slow down the expansion of the universe. That makes intuitive sense, because the matter is exerting a gravitational force, acting to pull things together.  Moreover,  has “negative pressure” and negative pressure corresponds to a pull. Then why are galaxies being pushed apart?


I was trying to install 14.04 on my computer (dual boot).   I am new to Linux and I really don't want to loose my windows OS. Any advise would be appreciated.  I got this error message "no root file system is defined"


In Destiny, the Stargate vents and flashes when it closes. I don't think I've seen this happen to any other gates. Are there any reasons why this is the case?


Appending to one nested list appends to all nested lists

example code:  my_list = [[]] * 4 my_list[2].append(3) print my_list   expected: [[], [], [3], []]  actual: [[3], [3], [3], [3]]  My inference is that the nested lists are copies of one another. Is there a way to achieve the expected?


What test do I use for two variables that are ordinal and seem to have a non monotonic relationship?

I'm trying to find the right test for association for two likert scale, ordinal variables from a questionnaire I did:    "How often do you recycle" - (1) Almost Daily, (2)2-3 times a week, (3)Once a week, (4) Less than once a week, (5)I don't recycle "Recycling can conserve the environment" - Ranges from (1)Strongly agree to (5)Strongly disagree, with (3)Neutral in the middle and a (6)I don't know option.   After graphing the data from my two variables together, it seems to that they don't have a monotonic relationship. From what I've searched, Kendall's tau c might suit my situation but I'm not sure if its a good idea since they don't have a monotonic relationship.    Edit: I'm aware that this seems like a duplicate from another similar question found , but as I said in the below comments, Glen_b, who answered the question in the other post, mentioned that when one is looking for some general measure of non-monotonic association, you can look at nominal-nominal (such as Cramer's V), and nominal-ordinal association and he gave a reference to an article about that. But I want to know how does looking at nominal-nominal or nominal-ordinal association help me since I'm trying to do ordinal-ordinal association testing?


What is the dimension of $R[[X]]$ where $R$ is a Noetherian ring?

If $R$ is a Noetherian ring then we know that the Krull dimension of the polynomial ring $R[X]$ is $\rm dim(R)+1.$ Is there any formula for the Krull dimension of the power series ring $R[[X]] $ When $R$ is a Noetherian ring ?


Can 's be used as a contraction of was?  For example, can "maybe she's born that way" mean "maybe she was born that way"?


The Thinkpad T480 boasts 30 hours of battery life, I'm getting 6

What gives? How come Ubuntu chews through both of my two batteries so fast?  Using 18.04.1 by the way.


Apex Cast sObject list dynamically to a specific sObject Type

The upsert() DML operation requires a specific List based on a specific sObject type, for instance:List<Account> lstAccount = new List<Account>();   However, we are trying to generate a generic method which allows us to pass by an sObject list containing all data records to be upserted for a specific sObject. An insert() operation allows us to use a List<sObject> to be inserted but the upsert() function is rejecting it:  List<sObject> listWRecords = new List<sObject>(); listWRecords.add(new Foo__c(Name="Record1")); listWRecords.add(new Foo__c(Name="Record2"));  upsert(listWRecords, 'ExternalIdFieldFrom_Foo__c', false);   Which will result in an error saying that the upsert must be performed on a concrete entity type.   Dynamically casting an sObject list is also not possible; I've seen solutions to 'hard code' or create Wrapper classes for each sObject on your org. But we would like to create a generic option here.  Another possibility would be to create some logic mimicking an upsert by splitting it into an update() and an insert() operation. Keeping in mind Salesforce limits, I do not see an option to go this way.


Convert from a textplain reference to bibtex

I have the following list of publications in a text plain file:  [1] Heikki Ailisto, Petteri Alahuhta, Ville Haataja, Vesa Kyllönen, and Mikko Lindholm. Structuring context aware applications: Five-layer model and example case. In Proceedings of the Workshop on Concepts and Models for Ubiquitous Computing, pages 1–5, Goteborg, Sweden, 2002.  [2] Chris Allan, Pavel Avgustinov, Aske Simon Christensen, Laurie Hendren, Sascha Kuzins, Ondrej Lhoták, Oege de Moor, Damien Sereni, Ganesh Sittampalam, and Julian Tibble. Adding trace matching with free variables to AspectJ. In Proceedings of the 20th ACM SIGPLAN Conference on Object-Oriented Programming Systems, Languages and Applications (OOPSLA 2005), pages 345–364, San Diego, California, USA, October 2005. ACM Press. ACM SIGPLAN Notices, 40(11).  [3] Malte Appeltauer, Robert Hirschfeld, Michael Haupt, and Hidehiko Masuhara. ContextJ: Context-oriented programming with Java. Information and Media Technologies, 6(2):399–419, 2011.   and I need to generate a bib file (or any other kind of reference database).  To sum up, I need to generate a reference database from a text plain file. Is it possible?  Best,


Command for including all .tex files from a folder into the current file

What command can I write in main.tex as shorthand for "include all .tex files from a given folder". So I don't have to write a lot of \include{} commands for each file like \include{sections/introduction.tex} \include{sections/section2.tex} // And so on...  EDIT: MY SOLUTION \begin{document}  \foreach \folder in {sections, images} {%         \foreach \i in {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ..., 19} {%         \edef\FileName{\folder/\i}%     The % here are necessary to eliminate any         \IfFileExists{\FileName}{%      spurious spaces that may get inserted            \input{\FileName}%           at these points         }     } }  \end{document}  Reference:


Proper to add tense to acronyms, abbreviations and initialisms

asked about pluralising acronyms, abbreviations and initialisms, but is there a standard way to add verb endings e.g. -ing and -ed (what are these called?), at least in informal English?  For example, which of these is/are best?   I'm SMSing her. I'm SMS-ing her. I'm SMS'ing her.   I know I can rephrase it to "I'm sending her an SMS." but I wish to use SMS as a verb.  Similarly,   He FUBARed. He FUBAR-ed. He FUBAR'ed. He FUBAR-d. He FUBAR'd.   In the latter set, as the verb is actually the F ("foul", or something more explicit) — the expanded sentence being "He fouled up beyond all recognition." — should it even be "He FedUBAR." or similar?


Not getting notifications on new badge being rewarded

I was recently awarded a new badge but didn't receive notification for that in inbox. I observed that in the two recent badges that I was awarded.  Is this the default behavior on Meta or something is not working?


How to create data driven effects/abilities for collectable card game

I'm trying to create cards for a ccg/tcg that are completely "data-driven" from an xml/json/external file. I've read multiple articles on this issue already, even here on stack exchange, but i can't figure out how to actually code this. I have a simple example:  My two cards have the following abilities   1) "Increase the value of all adjacent red cards by 1"  2) "Increase the value of this card by the amount of all adjacent red cards"  In my code i have the following functions (pseudo) that i need to accomplish these effects:  Increase(targetCards, byValue) // increases a card's value by another value FindCards(filter=adjacent) // returns all adjacent cards FilterCardsBy(filter=isRed) // returns only red cards Count(targetCards) // counts the number of cards   To create effect 1 i would use the functions like this:  Increase(FilterCards(FindCards(adjacent), isRed), 1);   and to create effect 2 i would use:  Increase(this, Count(FilterCards(FindCards(adjacent), isRed)));   So here's the problem: I have no clue how i can describe these functions in my external file and also i have no clue how i actually tell my functions to work in this combination to achieve the desired effects.  Maybe i'm misunderstanding the concept here but as far as i understood and described  i can create some pseudo script/code in my external file that then my code can interpret and execute on. But i feel i somehow missing the middle part where i write code to interpret these commands i'm defining in the external file.  Anyone with experience here that can give me some super simple starter ideas on how to takle this. Especially the part where i can combine several functions into one.


Do you need a search button with a search box?

On websites with a search box, should you add a button they can click on, or will users understand a search box like on this site?  The target group is not very technical, such as women aged 40-60.


My contact list and chatbox has suddenly disappeared from the left hand side of Googlemail. It has disappeared on both my desktop and laptop computers.  Chat is on, browser is good, black box at bottom checked...still nothing.


What could be using an HTTP request method of "-"

Got an apache log entry that looks like this, actually I have a bunch of them spread out over time.  XXX.XXX.XXX.XXX - - [27/Apr/2012:14:39:52 -0500] "-" 408 - "-" "-"   It wasn't a GET or POST, the method was "-".   Anyone else seen requests like this?  It wasn't from the penetration tester, but I have it from LOTS of other IPs from Apr of 2012 up until and including today.  We failed it with a 408, just wondering what someone might be trying and googling for minus sign does NOT work.


Does one need to adjust for multiple comparisons when using MANOVA?

There are 10 dependent variables and 2 groups. When I wanted to compare 10 dependent variables between two groups, I performed MANOVA.  I wonder if there is a multiple comparison problem in that case. Should I have performed Bonferroni correction because of 10 dependent variables? Or is Bonferroni useless because MANOVA just does analysis once?


What happened to Charles Xavier after X-Men 3?

I remember watching X-Men 3 and seeing Charles Xavier get disintegrated by Phoenix, however the post-credits scene and his appearance in later movies indicate that he actually survived. How is that possible?


I've put a brand new SSD into my work computer and my IT department wants me to use BitLocker. I  on standard harddrives, but I was wondering - what's the performance impact of BitLocker like on a Solid State Drive?   Will it noticeably impact the speed with which I open my archive files in Outlook or open projects in Visual Studio?


Why does a program with fork() sometimes print its output multiple times?

In Program 1 Hello world gets printed just once, but when I remove  \n and run it (Program 2), the output gets printed 8 times. Can someone please explain me the significance of \n here and how it affects the fork()?  Program 1   #include <sys/types.h> #include <unistd.h> #include <stdio.h> #include <stdlib.h>  int main() {     printf("hello world...\n");     fork();     fork();     fork(); }   Output 1:  hello world...    Program  2  #include <sys/types.h> #include <unistd.h> #include <stdio.h> #include <stdlib.h>  int main() {     printf("hello world...");     fork();     fork();     fork(); }   Output 2:  hello world... hello world...hello world...hello world...hello world...hello world...hello world...hello world...


I'm reading John Stillwell's "Naive Lie Theory" and it was mentioned there (without giving a proper definition of what a Lie group is) that the only Lie groups among the unit n-spheres are $S^1$ and $S^3$. Is there a simple or naive explanation of what makes $S^2$ so different from $S^1$ and $S^3$?


Java skips a line of System.out.println();

I need help with my Java code. For some reason it skips the System.out.println("Username does not exist");. I'm almost sure i messed up with the {} somewhere. Help would be appreciated.  Updated:  import java.util.Scanner;  class Bot { public static void main(String[] args) {     Scanner input = new Scanner(System.in);     System.out.println("Do you want to start the bot?");     String startup = input.next();     if (startup.equalsIgnoreCase("yes") || startup.equalsIgnoreCase("y")) {         System.out.println("Okay, starting...");         System.out.println("Please type your username");         String user = input.next();         if (user.equalsIgnoreCase("admin")) {             System.out.println("Valid username. Please type your password.");             String pass = input.next();             if (pass.equalsIgnoreCase("admin") || pass.equalsIgnoreCase("root")) {                 System.out.println("Logging in...");             } else if (!(pass.equalsIgnoreCase("admin") || pass.equalsIgnoreCase("root"))) {                 System.out.println("Wrong password.");             } else {                 System.out.println("Username does not exist");             }             ;         }     } else if (startup.equalsIgnoreCase("no") || startup.equalsIgnoreCase("n")) {         System.out.println("Okay, shutting down...");     } else {         System.out.println("Please answer with 'yes', 'y', 'no' or 'n', not '" + startup + "'.");     } } };   Original:  class Bot {     public static void main(String[] args) {         Scanner input = new Scanner(System.in);         System.out.println("Do you want to start the bot?");         String startup = input.next();         if (startup.equalsIgnoreCase("yes") || startup.equalsIgnoreCase("y")) {             System.out.println("Okay, starting...");             System.out.println("Please type your username");             String user = input.next();             if (user.equalsIgnoreCase("admin")) {                 System.out.println("Valid username. Please type your password.");                 String pass = input.next();                 if (pass.equalsIgnoreCase("admin") || pass.equalsIgnoreCase("root")) {                     System.out.println("Logging in...");                 } else if (!(pass == "admin")) {                     System.out.println("Wrong password.");                 } else if (!(user == "admin")) {                     System.out.println("Username does not exist");                 }                 ;             }         } else if (startup.equalsIgnoreCase("no") || startup.equalsIgnoreCase("n")) {             System.out.println("Okay, shutting down...");         } else {             System.out.println("Please answer with 'yes', 'y', 'no' or 'n', not '" + startup + "'.");         }     }     };


What should we understand from the definition of orthogonality in inner product spaces other than $\mathbb R^n$?

In the beginning of linear algebra courses, there are vectors in $\mathbb R^n$ and the dot product is introduced. We learn that if the dot product of two vectors is zero, then these vectors are called orthogonal and there is a right angle between them. Therefore, we understand perpendicularity from the definition of orthogonality.   In the last chapters, all previous notions are generalized as vector spaces and inner products are introduced. Then we learn vectors $\vec u$ and $\vec v$ are orthogonal if $\langle \vec u, \vec v \rangle=0$ in inner product spaces. Our previous knowledge guides us to seek a right angle between them.   Let $P$ be the vector space of first degree polynomials. Let $p(x)=ax+b$ and $q(x)=cx+d$. Define $\langle p(x), q(x) \rangle$ as  $$\langle p(x), q(x) \rangle=ac+bd$$  Then if we consider $p(x)=x-2$ and $q(x)=4x+2$, we find that $\langle p(x), q(x) \rangle=0$. But if we draw them, we see that there is $30.96$ degrees between them. So orthogonality in inner product spaces does not necessarily mean perpendicularity. If not perpendicularity, what should we understand from orthogonality in inner product spaces?


Can I install xscreensaver on Ubuntu MATE 64-bit?

I rather like xscreensaver. It allows me configure its gltext module as a clock, which also displays a current date.   I wondered If I could install it onto Ubuntu MATE 64-bit without breaking anything in my system. When I tried to uninstall my default screensaver I got a message stating that mate-desktop would be removed as well.


Insertion and retrieving from MySQL returns ?????????????? sign for Arabic text

I have this insertion PHP code :  <?PHP  require("config.inc.php"); if (!empty($_POST)) {        $query = "INSERT INTO projects ( project_author, project_title, project_spec, project_links, project_desc,created_at ) VALUES ( :user, :title, :spec, :links, :desc, NOW() ) ";     $query_params = array(         ':user' => $_POST['author'],         ':title' => $_POST['title'],         ':spec' => $_POST['spec'],         ':links' => $_POST['links'],         ':desc' => $_POST['desc'],     );     try {         $stmt   = $db->prepare($query);         $result = $stmt->execute($query_params);     }     catch (PDOException $ex) {         $response["success"] = 0;         $response["message"] = "Database Error. Couldn't add post!";         die(json_encode($ex));     }      $response["success"] = 1;     $response["message"] = "Post Successfully Added!";     echo json_encode($response);  }else{ echo 'omar almrsomi'; } ?>    The retrieving PHP code from MySQL is:  <?php $mysql_db_hostname = "com"; $mysql_db_user = "xxxxx"; $mysql_db_password = "xxxxxxxxxx"; $mysql_db_database = "xxxxxxxxx";  $con = @mysqli_connect($mysql_db_hostname, $mysql_db_user, $mysql_db_password,  $mysql_db_database);  if (!$con) {  trigger_error('Could not connect to MySQL: ' . mysqli_connect_error()); } $var = array(); $sql = "SELECT * FROM projects"; $result = mysqli_query($con, $sql);  while($obj = mysqli_fetch_object($result)) { $var[] = $obj; } echo '{"projects":'.json_encode($var).'}'; ?>     Problem:  The insertion and retrieving from MySQL gave ????????????? sign.  Note:  Inserted text in Arabic.  Question:  How to insert Arabic (Unicode) to MySQL?  Thanks in advance


Show rigorously that the sum of integrals of $f$ and of its inverse is $bf(b)-af(a)$

Suppose $f$ is a continuous, strictly increasing function defined on a closed interval $[a,b]$ such that $f^{-1}$ is the inverse function of $f$. Prove that,   $$\int_{a}^bf(x)dx+\int_{f(a)}^{f(b)}f^{-1}(x)dx=bf(b)-af(a)$$   A high school student or a Calculus first year student will simply, possibly, apply change of variable technique, then integration by parts and he/she will arrive at the answer without giving much thought into the process. A smarter student would probably compare the integrals with areas and conclude that the equality is immediate.  However, I am an undergrad student of Analysis and I would want to solve the problem "carefully". That is, I wouldn't want to forget my definitions, and the conditions of each technique. For example, while applying change of variables technique, I cannot apply it blindly; I must be prudent enough to realize that the criterion to apply it includes continuous differentiability of a function. Simply with $f$ continuous, I cannot apply change of variables technique.  Is there any method to solve this problem rigorously? One may apply the techniques of integration (by parts, change of variables, etc.) only after proper justification.  The reason I am not adding any work of mine is simply that I could not proceed even one line since I am not given $f$ is differentiable. However, this seems to hold for non-differentiable functions also.  I would really want some help. Pictorial proofs and/or area arguments are invalid.


Can you organize imports for an entire project in eclipse with a keystroke?

Wouldn't it be nice to just do a keystroke and have eclipse organize all imports in all java classes instead of just the one you are looking at? Is this possible? Is there a keystroke for it?


How to generate uniformly distributed points on the surface of the 3-d unit sphere?

I am wondering how to generate uniformly distributed points on the surface of the 3-d unit sphere? Also after generating those points, what is the best way to visualize and check whether they are truly uniform on the surface $x^2+y^2+z^2=1$?


I'm new to Ubuntu and I'm not sure which version to install.  Which offers better performance? Which would you recomend? Thanks in advance.


When there are X New Questions, the views don't update untill you refresh the page

First, you see the banner:    Then you click it and the 5 new questions appear:    But all of them have 0 votes, 0 answers and 1 view. You have to refresh to see the real numbers:


Surface Area of Cone (And Solid of Revolution in General)

From my understanding, a cone/frustum is a stack of circles with radius $r(h)$, $r$ being a linear function, and h the height.   Cone:  The surface area of a circle with radius $r$ (slice), by my understanding, should be $2πr$ $dh$.  Therefore, adding up this surface area should give us $2π\int_{H_1}^{H_2}r(h)$ $dh$, where $H_1$ and $H_2$ are the lower and upper heights (for a cone the lower bound is 0, for a frustum, >0 because the cone is truncated by a similar cone).  Apparently in the formula for the cone and general solids of revolution, the slant height is involved. How does this work?


Images in meta T-shirt questions seem to have become spam?

I was looking at the , which leads to  about T-shirts, and then from there, . However, as you can see in  and in the latter question, it seems that some of the T-shirt images have become plugs for free iTunes gift cards (once you download a certain app)! It seems as if the images are hosted on imageshack.com, but I'm not sure if that's the problem. What do we do with these images?  Also, I have a secondary question, which is: what happened to the boat-programming answer in the "Help design our T-shirts" question? I can't find it, even though it's linked to from multiple boat-programming meme explanations...


Prove that if $b\mid c$ then $\gcd(a,b)=\gcd(a+c,b)$.

My solution is as follows: Let $d_1= (a,b) > 0$. Then by Bezout's identity, there exists integers $x_1$and $y_1$ such that, $d_1=ax_1+by_1$. Similarly let $d_2 = (a+c,b) > 0$ then there exists integers $x_2$ and $y_2$ such that, $d_2=(a+c)x_2+by_2$. Then since $b\mid c$ there exists integer $k$ such that $c=bk$ for some $k$. Note that, $d_2=(a+c)x_2+by_2$. Since $c = bk$ then, $d_2=(a+bk)x_2+by_2$ $\Rightarrow$ $d_2 = ax_2+b(kx_2+y_2)$, which is a linear combination in $a$ and $b$. Since $d_1 = (a,b)$, it divides any linear combination in $a$ and $b$. Thus $d_1\mid d_2$. Similarly, $d_1=ax_1+by_1$ $\Rightarrow$ $d_1=ax_1+by_1+cx_1-cx_1$. Since, $c=bk$ $\Rightarrow$ $d_1=(a+c)x_1+b(y_1-kx_1)$. Which is a linear combination in $a+c$ and $b$. Thus $d_2\mid d_1$. Since $d_1$ and $d_2$ are $\gcd$ of two integers, and $d_1\mid d_2$ and $d_2\mid d_1$, we conclude that $d_1=d_2$ as desired. Thank you for reading upto here. If there is any errors feel free to comment.


Biblatex, authoryear, and first name abbreviations in citations

Here is an MWE:  \documentclass{article} % \usepackage[backend=biber,style=authoryear]{biblatex} %  \usepackage{filecontents} \begin{filecontents}{\jobname.bib}   @Book{pollis-schwab79a,     editor =       {Pollis, Adamantia and Peter Schwab},     title =        {Human Rights: Cultural and Ideological Perspectives},     publisher =    {Praeger},     year =         {1979}   }         @Article{schwab-meijaard13,     author =       {Schwab, Arend L. and Jaap P. Meijaard},     title =        {A Review on Bicycle Dynamics and Rider Control},     journal =      {Vehicle System Dynamics},     year =         {2013},     volume =       {51},     pages =        {1059--1090}   } \end{filecontents}  \addbibresource{\jobname.bib}  \begin{document}  % \textcite{pollis-schwab79a}  \textcite{schwab-meijaard13}  \end{document}   The citation appears as      Schwab and Meijaard (2013)   This is fine.  But uncomment now the line with % \textcite{pollis-schwab79a}.  This is what appears:     Pollis and P. Schwab (1979)      A. L. Schwab and Meijaard (2013)   Biblatex puts first name abbreviations into the citation for the duplicate name (Schwab).  I do not want this for several reasons.  How can I tell it not to do this?


Explicit definition of sequence of partial sums of 1/n!

is there an explicit definition of the following sequence? $$s(n)=\sum_{i=0}^n \frac1{i!}$$ Sincerely


I need to prove one thing: $$ n \ge 1: \sqrt{n} \le \sqrt[n]{n!} \le \frac{n + 1}{2} $$  The second part: $$ \sqrt[n]{n!} \le \frac{n + 1}{2} $$ is easy to proof.But the first is more complicated. Help please.


What is the purpose of indenting "StackOverflow" under "Meta Stack Overflow" in the new Top-Bar's Stack Exchange selector?

In this screenshot:    I see: 1. The current site I am on 2. My top 5 sites 3. A search bar to locate other sites.  All of this is really good - but I'm not sure I fully understand the impact of the "Stack Overflow" indented under Meta Stack Overflow.  Obviously, the relationship between a meta and main site is logical - but how is this intended to operate when looking at a non-meta site?  Will the order still exist and simply be reversed, will it be empty, or is there a set of business rules to define what will be there?


I had Windows 7 and Ubuntu installed on the same partition   Some time later, decided to uninstall Ubuntu.So I booted Ubuntu,Changed the hd related to it to NTFS,I did NOT extended my main drive   restarted-> GRUB rescue>. No surprise since I had just wiped out the whole GRUB directory staff   Now I just want to boot into my windows.Move my necessary files to an external memory and reinstall the windows seven     What I have in my hands: Ubuntu live CD, A copy of win7 DVD I tried to make use of the win7 DVD(I had lost my DVD) to fix the mbr but the problem is when I choose repair, It says that this version of Windows is incompatible with yours What should I do?


I'm a Chinese living in NYC. How do Americans call these things? Are they all named "trash can"?  And If I want to drop something, like an empty bottle, what is the right way to say that? "drop garbage"? "litter" ? "throw away garbage" or else?  Thanks!


Show Applications - Change icon size and/or grid

I have a 4x6 grid when click on the Show Applications icon in Ubuntu 18.04.  The resulting icons look MASSIVE on my desktop.  Is there a way to either alter their size or, ideally, alter the grid dimensions so that more icons fit on each page (thereby reducing the icon size)?


Dealing with "difficult" usernames in targeted comments

Once in a while you wish to address a comment to someone in particular, so you type @ and then you pause ... because the username is  or .  Short of using copy-paste to get their username right (which is even more cumbersome on a mobile device), is there another way around this? In a few cases I've noticed that the system will attempt to "promote" a comment to a reply, but I'm not sure if that's very reliable.  Should user names at least start with a normal letter?  Update  The auto-complete feature seems to normalize Zalgo'ish usernames, so typing the letter L will trigger the suggestions as expected; this is of course knowing that the name actually spells "lawrence", which may not always be obvious.  Knowing the way of the symbol ninja would surely help to type Ω using only the elbows as well, but not everyone is blessed with the same keyboard layout.  Suggestion  It would be nice to have a reply feature like this:        When ↳ reply is clicked, it will automatically populate the comment box with @username pre-filled in.   Additional notes  To clarify, I'm not suggesting to put the "reply" on all comments, as proposed , because in most cases the owner of a post is already notified of a new comment; this would strictly be to effect cross-commenter communication.


How to remove the Mail icon indicator applet?

I'm wondering how it's possible to remove the little mail indicator applet in the global menu. I've uninstalled all the programs that use it, like Thunderbird, Empathy, and Gwibber, since I don't use any of them, but the icon is still there.  Any ideas?


I don't understand how we could bruteforce a symmetric cipher. Let's take AES with a key size of $128$ as an example. It means that there are $2^{128}$ possible keys, and as many ways to decrypt a ciphertext $c$. Given that there are so many different keys, it is theorically possible to decrypt $c$ into multiple plausible messages (e.g. message that read like english). So while we are bruteforcing $c$, if at some point we obtain a plausible message we can't tell for sure that we found the good key because there are plenty of other plausible messages that we haven't found yet. It's not like with hash functions or asymmetric ciphers, where we have a way to make sure that we found the good antecedent/private key. So I don't understand what they mean in this article:  For example:  For instance, Triple DES was designed to have a $168$ bit key, but an attack of complexity $2^{112}$ is now known (i.e. Triple DES now only has $112$ bits of security, and of the $168$ bits in the key the attack has rendered $56$ 'ineffective' towards security).  Even if Triple DES only had 50 bits of security, we would still be able to decrypt multiple plausible messages that are not the original message, let alone the case where the original message is gibberish and not necessarily natural language. I feel like the notion of "security level" is not the same for hash functions/asymmetric ciphers and symmetric ciphers. For both, it refers to the subset of the antecedent/key space that we know the good antecedent/key is in, but for the latter, we can never be sure that we have found the good secret key, and thus that we bruteforced successfully. Could you explain it to me please? Thank you for your help.


Proof that absolute value of supremum equals suprememum of absolute value

Can someone prove that |sup(A)|=sup|A| ? Please and thanks.


I want to select all records form database using WHERE IN, using values form an array that I have. Is there a way to actually pass the array to the query?  I tried SELECT id FROM tag WHERE name IN "+myArray.toString()+". But, of course, it is destined to fail) I could use preparedStatement, but number of values is always different and quite large - 5000 or so. Or maybe I should take a different approach?


Run a cronjob on every month 2nd thursday

I want to generate a report by executing a python script. This script has to run on every 2nd thursday of a month, 3.30am . How to achieve this.  Below code might work, if the dates are fall under 8-14.  30 3 6-12 * 4 <script>   However sometimes, the days are not falling as expected and it leads to error.


Given a linear functional on $X$, Royden's book define the norm of a linear functional $T$ as $$\{ \|T\| = \inf \{ M \geq 0 \mid |T(f)| \leq M \|f\| \forall f \in X \}, $$ How is this definition equivalent to the sup definition, where $$ \|T\| = \sup \{ T(f) \mid f \in X, \|f\| \leq 1 \} $$


Is there a simple setting to allow a MacBook to continue running with the lid shut?  All signs that I found pointed to no supposedly due to concerns about overheating, but when docked, a MBP is able to be used if the monitor and keyboard are plugged in.   My use case would be running a terminal command that takes awhile, leaving my desk, locking my account, and closing the lid to keep nosy people out.


Cofactor reflection maps greatest proper divisor to least (prime) proper divisor

Suppose that $y$ is a positive integer, and $z$ is the largest factor of $y$ such that $z<y$, then let $x=y/z$. Prove that $x$ must be a prime number.  Is there a simple way to solve this? It should be obvious but it's stumping me :/


Olympiad Inequality $\sum\limits_{cyc} \frac{x^4}{8x^3+5y^3} \geqslant \frac{x+y+z}{13}$

$x,y,z >0$, prove   $$\frac{x^4}{8x^3+5y^3}+\frac{y^4}{8y^3+5z^3}+\frac{z^4}{8z^3+5x^3} \geqslant \frac{x+y+z}{13}$$   Note: Often Stack Exchange asked to show some work before answering the question. This inequality was used as a proposal problem for National TST of an Asian country a few years back. However, upon receiving the official solution, the committee decided to drop this problem immediately. They don't believe that any students can solve this problem in 3 hour time frame.   Update 1: In this forum, somebody said  that BW is the only solution for this problem, which to the best of my knowledge is wrong. This problem is listed as "coffin problems" in my country. The official solution is very elementary and elegant.   Update 2: Although there are some solutions (or partial solution) based on numerical method, I am more interested in the approach with "pencil and papers." I think the approach by  in  may help.    Update 3: Michael has tried to apply Peter Scholze's method but not found the solution yet.  Update 4: Symbolic expanding with computer is employed and verify the inequality. However, detail solution that not involved computer has not been found. Whoever can solve this inequality using high school math knowledge will be considered as the "King of Inequality".


To demonize an app, I used to use upstart. I know it is discarded from debian packages, but I still need it as I can not make my app run using systemd.   Currently, when I try to install it I get:  # apt install upstart Reading package lists... Done Building dependency tree        Reading state information... Done Package upstart is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source However the following packages replace it:   systemd-sysv sysvinit-core  E: Package 'upstart' has no installation candidate   So appreciate your hints to install upstart.


Generalization of Banach's fixed point theorem

I wanted to show that if $f:X\to X$ is a function from a complete metric space to itself and if $f^k$ is a contraction, then $f$ has a unique fixed point (say $p$) and for any $x$ in $X$ $f^n(x)\longrightarrow p$.  What I did is use what I know from Banach as follows: Take $x$ arbitrary in $X$. Then consider the sequence $f^n(x)$, which I denote by $x_n$. Let $x^{(i)}$ be the sequence $x_i, x_{i+k}, x_{i+2k}...$ for $i$ between 0 and $k - 1$. As $f^k$ is a contraction, we can apply Banach and so it has a fixed point (say $l$) and all the $x^{(i)}$ are convergent to $l$.  Then $x_n$ is convergent to $l$ (for any $\epsilon$ exists $N$ such that $d_X(x_n, l) < \epsilon$, this $N$ being the maximum of the corresponding N's obtained from each of the $x^{(i)}$).  Since $x$ was arbitrary and $l$ is unique, this means that $p=l$ and the proof is completed.  Am I doing something wrong or missing anything?  I just want to ensure I understand this properly, this is not a homework or something similar.  Thank you!


Need to know which day-of-week is represented by the DateTime object

I'm using the DateTime object in my apex code.  In the documentation of the DateTime class I saw there are methods to return day-of-month, day-of-year but there is no method to return day-of-week what I need.  I need to know which day-of-week is represented by this object?


How to read up on what's on topic in-app?

When I join a new site I don't want my first question to be closed as off-topic. On the web I can navigate the help labyrinth to arrive at an answer, but I can't find that info in-app, nor a link to the help.   I think it's natural to have this close at hand when writing one's first question on a new site.   Unless it's already in here somewhere, I'd like to request it


How would you prove the following using induction. n is a non negative integer  $$1+\sum_{i=1}^n i i!=(n+1)!$$  This be what I did  base case let $n=3$  $$1+1+4+18=(3+1)!$$  $24=24$  Hypothesis step let $n=k$  $$1+\sum_{i=1}^k i (i!)=(k+1)!$$  Induction step let $n=k+1$  $$1+\sum_{i=1}^{k+1} i (i!)=(k+1+1)!$$  so start on the left hand side and get  $$1+\sum_{i=1}^k i (i!)+(k+1(k+1)!)=(k+1)!+(k+1(k+1)!$$  and I am stuck.


Using a hypothetical photo from a hypothetical telescope, we were able to determine that the farthest galaxy present in the photo is 1 billion light years away. Because we are awesome we were able to also tell which direction all the galaxies in the pic are moving. We are also capable to estimate the mass of the galaxies.  In possession of these information aren't we capable to locate their "source", aka the local of the big bang? In another words, can we, in possession of objects current position, mass and relative speed tell where they were?


What is this Sci-Fi time-travel Movie/TV Movie from the 1970's (I think) called?

Does anybody know the title of a film that features robots or androids I think they were called and the humans, I think being chased by these androids, jumping through a time travel machine that speeds up and replays almost the whole film 2 or 3 times becoming faster each time.  It is a bit fuzzy as I was a child when it was shown on TV and this is all I can recall.


Precisely how does CBC mode use the initialization vector?

As I understand it, AES in CBC mode does an XOR of the 128-bit initialization vector and the first 128 bits of plain text. Is this correct?  I am using the PHP 5.3 openssl extension in aes-256-cbc mode. I'm experimenting with a round trip, that is, encrypting and then decrypting to make sure I get back the original string.  I find that if I encrypt with one initialization vector and decrypt with another initialization vector, using the same secret key, the first 128 decrypted bits are corrupt (as expected) and the rest is the correct plain text.  I find that if I encrypt with one initialization vector, and decrypt with a barely-different initialization vector, the decryption shows barely-different plain text. That is, when I change the third byte of the initialization vector, the decrypted plain text shows the third byte corrupt and everything else correct.  This does seem to show how the initialization vector affects AES cipher-block chaining. Is the initialization vector simply XOR'd with with the first 128 bits of plain text, and that's it?


How to use a public class Reports (for logging purpose) with public static methods across other classes of the same project

Here's an excerpt of my prorgam:  package something.util; public class Reports {     public static void logStatus(LogStatus testStatus, String testDetails) {         test.log(testStatus, testDetails);     } }  package something.pages; public class MainPage {     public void someMethod(){         Reports.logStatus(LogStatus.INFO, "Clicked A/B Testing link");     } }   When I execute the code above, I keep getting NullPointerException and I am not sure why. At least a pointer to the mistake I'm making will help.


I downloaded a shell executable and man pages from a source I trust. Where should I put them?

I downloaded a binary file for a shell executable, and the corresponding man pages, from a source I trust. Unpacking the archive returns a binary file and some man pages. There's no installer. Which is the "canonical" location to put this kind of stuff? I guess it should be somewhere on my PATH. echo $PATH returns: $ echo $PATH /Users/.../google-cloud-sdk/bin:/anaconda3/bin:/anaconda3/condabin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Library/.../bin:/opt/X11/bin  Of these, I seem to recall that tampering with /usr/local/ is considered bad practice. Logically, Users/.../google-cloud-sdk/bin:/anaconda3/bin:/anaconda3/condabin also don't seem appropriate. This leaves me with /usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin. Which one should  I use? Or am I going about this the wrong way? Also, do the binary file and the man pages go into the same folder? Or do they go to different folder? PS I really wonder how much effort would have been to add a damn installer....


Close Menu With a Click on body with event listener & parentnode

I want to close the re-sized menu when one clicks anywhere on the page. I've searched various stack overflow answers but haven't found one that does not interfere with the menu code itself, my menu...    jQuery(document).ready(function($) {   //open-close submenu on mobile   $('.cd-main-nav').on('click', function(event) {     if ($(event.target).is('.cd-main-nav'))       $(this).children('ul').toggleClass('is-visible0');   });   //i have tried adding this but hasn't worked   $('html').click(function() {     if ($('.cd-main-nav').children('ul').hasClass('is-visible0')) $(this).children('ul').toggleClass('is-visible0');    }); });


Generic array in ArrayList implementation

How to make following code completely generic?  Why I'm not allowed to write:  private E[]store = new E[length];  import java.util.Arrays; public class MyArrayList<E> {     private int size = 0;     private int length = 10;      private Object [] store = new Object[length];         public E get(int index){         return (E)store[index];     }      public void add(E item){         if(size >= store.length -5){             increment(store);         }         store[size++] = item;     }      private <T> void increment(T[] store2) {         store = Arrays.copyOf(store2, store2.length * 2);     }      public int size(){         return size;     } }


What exactly is the singleton class in ruby?

Is the singleton class in Ruby a class in and of itself? Is it the reason why all objects belong to "class?" The concept is fuzzy, but I believe it has something to do with why I can define a class method at all (class foo; def foo.bar ...).  What is the singleton class in Ruby?