I needed some basic advice about impedance matching. I have an RF amplifier with 50 ohm output impedance, capable of generating 400W output power at 500kHz. I am trying to deliver this to a 12 ohm load.  I looked online and figured out that I need to match the impedance of the amplifier to the load. What is the best way to achieve this? Would it be possible to simply use a capacitor and inductor and put an L section to the output of the amplifier? I saw that online stores have very cheap capacitor and inductors that are rated for very high voltages.  If that is not going to work, is it possible to buy any transformers that would do that? For instance I saw that there are many cheap 220V-110V voltage converters, which should have 2:1 coil ratio. So in theory that should convert 50 ohm to 12.5 ohm and matches to my load. Will these work at 500 kHz as required for my application? Or are there other type of transformers that I can use for this purpose (there are many many types of transformers and I got confused which ones are suitable for impedance matching)?


Let $p$ be an odd prime, $a\in\mathbb{Z}$. Try to prove $$\sum_{y=0}^{p-1}\Big(\frac{y^2+a}{p}\Big)\equiv-1\pmod{p}\tag{1}$$ I find that when $p|a$ it obviously holds, since $$\sum_{y=0}^{p-1}\Big(\frac{y^2}{p}\Big)=p-1$$ Then for $p\!\!\!\not|a$ case, I checked many examples and I guess the LHS may exacatlly equal to $-1$. Then I make it equivalent to consider giving a proof for the following $$\Big(\frac{a}{p}\Big)+2\sum_{y=1}^{\frac{p-1}{2}}\Big(\frac{y^2+a}{p}\Big)=-1\tag{2}$$ which means that we add a same number to modular $p$'s all quadratic residue. I'm really not sure about my guess $(2)$, does the quadratic residue have such translation-like property? And I do not know how to prove $(1)$, can you give me some ideas?


power pin to ground impedance- Short(0.3 Ohm)

I am designing a board and the problem I am facing on the board hardware is that the core power supply and ground has very low impedance of around 0.3 Ohm. This is leading to a conclusion of two nets as if these are shorted together. Although the current drawn for that particular assembly for core power supply is 9A the impedance would be low(may be around 4-5 Ohm).But is 0.2 Ohm a correct value. We have done the x-ray analysis of BGA, and no solder bridging is observed. Can anyone suggest what could be the issue?


moving object on game background after scaling it based on screen size

I am creating a game using Corona SDK, I have a map with a ball and another other object that moves on the map.  I use the the ultimate  file for scaling background based on device screen resolution.  My problem is that I want to arrange some objects on this map.  I have created specific assets for a specific device resolution, but on devices with aspect ratio lower than 1.72 the map is stretched horizontally so that appears wider than other assets.  Also when I want to arrange an object to a specific location on top of the map the result is that things don't line up right because of the scaling issue.  For example, when i set myobject.y=100 on a device with aspect ration more than 1.72 it set on the right place but when I do the same thing on device with aspect ratio less than 1.72 my object is off the map.  I tried to convert my pixels to inches using device DPI but it's still the same.


What is the address at Le Port where I pick up Bus 100 to ride to Monaco from Nice?  Wife is slightly handicapped so I don't want to have to walk a lot to find the bus stop.


I'm going to Los Angeles in the summer and the flight is 11 hours long. I can't bear such a long flight so I thought of taking a sleeping aid with me that has worked in the past.  Even though codeine is available here OTC, I've read that it is scheduled as a narcotic in the States and thus I would require a prescription. The thing is however some of my friends have brought codeine based medicines with them before and they weren't stopped.  Will it be an issue?


Derive $\sum i^2$ without knowing the answer first

Standard proof that $\sum_1^n i^2=\frac{n(n+1)(2n+1)}{6}$ is given by induction. It is of course a valid method. However, I find that it requires me to memorize the answer. Is there any way I can sit in an exam and just derive the result from scratch without memorization?  This question is apparently more general and different than  and I have seen quite a few great answers other than the "Gaussian method" in the post


How can I create light trails without a blurry subject?

I would like to achieve this effect using my Nikon P510:      Are there any suggestions or tips that would help me do that?


I am a very new user to Ubuntu so excuse me if this is a silly thing to ask. Im using Ubuntu for Windows 10 and I have downloaded a file from AWS S3 to my windows 10 machine. Can someone tell me how I can cd to this in Ubuntu? I can see /home/username/Downloads but how can I put the S3 file in there? Thanks


This is the first time that I have worked with geospatial data and QGIS, so please be kind.  I was given a shape file that contains house districts for the state of FL.   (for ArcMap users) to import the house districts into Tableau, which is my goal.  I was able to generate a file that contains the district, and coordinates, but I need the order column, and am not sure how to do this using QGIS (assumedly using an add-in).   "shapeid","x","y" "0","-87.634896","30.866261" "0","-87.634871","30.866344" "0","-87.634851","30.866536"   The format that I am looking for is ...  "shapeid","x","y","order" "0","-87.634896","30.866261","1" "0","-87.634871","30.866344","2" "0","-87.634851","30.866536","3"


Is passing of Objects in Java memory-consuming

When I pass an Object to another Class in Java - is this memory consuming or not? Does the object function as some kind of pointer, such as c-language?  Or when passing it to another class's constructor - I am making a copy of the object?  for instance in Android   Context context   Class Foo = new Foo(this.context);


When AC electricity is generated, how does the current flow?

I have read multiple different versions of how AC current flows in our power lines.   How does the current flow?   Is the energy just photonics waves passing through electrons that vibrate or are electrons flowing in the direction of usage.   How would they flow if the current oscillates both forward and backwards?  I have read that energized electrons flow at almost light speed toward usage, but I have also read that they don’t flow, they oscillate and transfer the electromagnetic wave energy generated from the power generator or storage.


Is there a consensus about the trueness of the randomness in QM?

I personally believe that there is a very strong case in favor of true randomness in QM but not being a physicist I would like to know from experts if there is a consensus about this.  @John Rennie: this question is different because it specifically asks about the consensus of the true randomness, not about the true randomness itself.


Where does the extra power come from in Compounding?

I understand the basics of Allomancy and Feruchemy, but I'm unsure of how exactly the powers support each other so well. Namely: where does the EXTRA investiture come from when Compounding? How is it provided? And why do you get so much extra investiture?  Note: the question  is focused on the mechanics - what do you have to do to "compound" your ability. While it notes that the end result is that the compounder winds up with more power than what they put into the system, it doesn't really address where that power comes from.


"!Missing $ inserted" error using amsmath environments

I am trying to compile a document with equations but whenever I use \begin{eqnarray}..\end{eqnarray} or \begin{align}...\end{align} or anything like this I get the error msg !Missing $ inserted.<inserted text>$. However if I type those equations without using \begin{eqnarray}...\end{eqnarray} or similar things I do not get any error msg and my document runs perfectly.  Even this simple thing does't work....Please help...  \documentclass[a4paper,12pt]{article} \usepackage{amsmath} \usepackage{amssymb}  \begin{document}  \begin{align} $=$  \end{align} \end{document}


I am trying to make sense of this logic diagram for an ON Semiconductor 7-segment display driver. What is this logic symbol? I have never seen it before, and I have not seen it anywhere online after looking for about an hour.    Here it is in the larger logic diagram:


I'm using the alpha version of the android app on the first generation nexus 7 tablet.  The font size is a little bit small for my liking and I'm not able to pinch zoom to increase the font size.  Is this a feature that is planned in the release?


I found a cool trick in the  which allows the square root sign to be altered such that it "closes" over its contents. Here's an example:  ("closed" root on the left, normal one on the right) The way they do this is as follows: % New definition of square root: % it renames \sqrt as \oldsqrt \let\oldsqrt\sqrt % it defines the new \sqrt in terms of the old one \def\sqrt{\mathpalette\DHLhksqrt} \def\DHLhksqrt#1#2{% \setbox0=\hbox{$#1\oldsqrt{#2\,}$}\dimen0=\ht0 \advance\dimen0-0.2\ht0 \setbox2=\hbox{\vrule height\ht0 depth -\dimen0}% {\box0\lower0.4pt\box2}} The cool thing is that (as far as I've tested it) this works regardless of the math font and with pdftex as well as xetex. However what is not possible is mulitple roots, such as \sqrt[3]{a}. Those produce incorrect output when this "trick" is being used. So my question is, is somebody able to tweak this code so that it works for multiple roots as well?


When I check for updates on Windows 10, the system starts to install automatically all the updates found. Is there any way to choose before installing updates like in previous windows versions?


In Python How do i loop a time series list by steps and keep all the values?


S04E08 (Hermanos): Why is Gus allowed to live?

I was rewatching the Breaking Bad episode S04E08 (Hermanos) and I didn't quite understand why exactly Don Eladio killed Gus's partner, but he let Gus live. He says:     The only reason you're alive and he's not, is because I know who you are.   But I still have yet to fully understand.


I am trying to create the FMT file by using the latex.ltx for the following procedures.   Copy latex.ltx file from the base directory to my local working directory. Rename this file. I Load my orginal source files for the following commands before the \dump command.  \input xmltex.tex \input Sample.cfg \input Sample.xmt \LoadClass{article} \dump \endinput   I am compailing the ltx file for the following command like latex -ini filename.ltx  First i am getting the following error.  ! LaTeX requires e-TeX. l.98     {LaTeX requires e-TeX}  ?   So i comment the those lines from the ltx file and try to run the ltx file.  %   \errmessage %     {LaTeX requires e-TeX} %   \expandafter\endinput   After comment those lines from the ltx file, i will run the ltx file once again. But i am getting the below mentioned errors.   So, i will change my compilation command etex -ini filename.ltx. But the same errors are repeated.   The .ltx show the plenty of errors during the compilation process  \utfthreeuniglyph ... \expandafter {\the \numexpr                                                   4096*(#1-224)+64*(  ! Extra \else. \unicodechar ...nichar@\number #1\endcsname \else                                                   \errmessage {Unicode   I am unable to fix this error. I place my MWE for your reference.  %%Sample.tex%% \def\xmlfile{sample.xml} \input xmltex  %%Sample.xml <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE article SYSTEM "JATS-journalpublishing1.dtd">
 <front>
 <title-group>
The sample title
 </title-group>
 </front>  <sec id="j_nanoph-2018-0214_s_001"> <title>Introduction</title>
The <bold>Sample.cfg, Sample.xmt, Sample-entity.sty</bold> files needs to be converted into unreadable format &#x00C1; &#x00E1;.

  %%Sample.xmt%%  \XMLentity{TeX}{\TeX} \XMLentity{LaTeX}{\LaTeX}  %%%%Main Root Tag%%%% \XMLelement{article}%     {}%     {\documentclass{article}%     \begin{document}}%     {\end{document}}% %%%%  \XMLelement{bold}{}{\xmlgrab}{\textbf{#1}}   %%%%Front Matter Tags%%%% \XMLelement{front}{}{}{%   \date{}   \maketitle% }% %%%%  \XMLelement{article-title}{}{\xmlgrab}{\title{#1}}  \XMLelement{title}{}{\xmlgrab}{\section*{#1}}  \XMLelement{p}{}{}{\par}%   Could you please advice how to clear those errors and getting the successful FMT creation for the following source files.


Ubuntu freezes in the Ubuntu logo (initialization) when I try to install from USB (dual boot)

I'm trying to install the Ubuntu 14.04 alongside windows, but it isn't working. I am trying to install using a USB (I already tried with 3 USBs).  The Ubuntu logo (initialization) just freezes and my machine stops.  The computer is new, its specifications are:  NVIDIA GeForce GTX 1060 GPU (6GB dedicated) CPU: Intel® Core™ i7 Skylake - 6700HQ 2.6 GHz, 6MB Cache (3.50 GHz com Max Turbo) MEMORY: 32GB Memória DDR4 (2133 MHZ) HARD DISK (HDD), SSD OU SSHD: SSHD 1 TB com 8GB SSD SATAE M.2: SATAe M.2 - 480GB SATA III - 6Gb/s TELA (LCD): 15.6" FullHD (1920 x 1080p) 16:9 LED-Backlit - (Matte)   I already tried to install 16.*


Remove space between left bracket and square root

Sorry for my bad English.   I have a problem with removing the space between left bracket and multiple root square.  I use code   \documentclass{article}  \usepackage{amsmath}  \usepackage{letltxmacro}  \LetLtxMacro{\oldsqrt}{\sqrt}  \renewcommand{\sqrt}[2][]{\oldsqrt[#1]{#2}}   \begin{document}  $\left(\sqrt{3} \right)$ $\left(\sqrt[3]{4}\right)$    \end{document}   But only space in the left one got removed.


I'm looking to see if there is a way to catch an assertion exception in apex and handle it gracefully. For instance, I have some number fields with a default value as 0. However, I'm hoping to use an assertion exception to ensure those values will never be null. I've done some searches so far and one post suggests creating a custom exception to handle this, but 'm not quite sure how this would resolve the issue. Is this even possible?


Searching my own questions & answers over all Stack Exchange sites

Today I came across a situation where I knew that I'd answered another similar question some time ago, but couldn't remember on which Stack Exchange site it was. I ended up doing multiple searches on several different Stack Exchange sites before giving up and just doing the research again - answering the question from scratch.  As such, I wonder if it would be possible to implement  on the  mechanism.  If this had already been implemented then it would have given me a single place to try out the different sets of keywords that I thought might help me find my answer.  Note, this question goes one step further than  and I can see that there might be implementation issues with it due to issues raised , but couldn't the OpenID for the Stack Exchange account be used to filter the questions and answers from other Stack Exchange sites?


If $G_1$ and $G_2$ are finite group and $H\leq G_1\times G_2$ then $H=P_1\times P_2$ with $P_i\leq G_i$?

Suppose $G_1$ and $G_2$ are two finite groups and let $H\leq G_1\times G_2$.  Is it true that $H=P_1\times P_2$ with $P_i\leq G_i$?  I think so for since $H\subseteq G_1\times G_2$ we must have $H=P_1\times P_2$ with $P_i\subseteq G_i$. We have $P_i\neq \phi$, otherwise $H=\phi$. Indeed, $(1_{G_1}, 1_{G_2})\in H$ for $H\leq G_1\times G_2$.  Now, if $a, b\in P_1$ then $$(ab, 1_{G_2})=(a, 1_{G_2})\cdot (b, 1_{G_2})\in H=P_1\times P_2$$ so that $ab\in P_1$. A similar reason would work for the inverse.  I read somewhere this was not true, but I can't see what is wrong in the above argument.   Obs: The group structure on $G_1\times G_2$ is given pointwise.


Why the Jacobson radical of a finite generated Z-algebra is 0

Assume that $R$ is a f.g. $\mathbb{Z}$-algebra which is an integral domain. I want to show that the intersection of all the maximal ideals of $R$ is $0$.  I know that by the generalized version of Nullstellensatz that the f.g. algebra $S$ over Jacobson ring $R$ is Jacobson, but the proof of the theorem is quite non-trivial and long. Does someone have a shorter answer of this special case over $\mathbb{Z}$? The previous question of this problem is to show the residue field at each maximal ideal $\mathfrak{m}$ of $R$ is a finite field, that may helps.


Is there a way to install Ubuntu completely on a portable external HDD and boot into it on any computer/laptop?

I found  but ended up with an unbootable Ubuntu which loads into GNU GRUB command prompt and cannot proceed further.  Is there a reliable way to do this?


Assuming that the Cosmological Principle is correct, does this imply that the universe possess an empirically privileged reference frame?

OK...before everyone blasts this with references to the relativistic invariance of the physical laws, time dilation, etc let me add some context. Also, I am an amateur with an interest in physics, so I don't know the details of the physics. However, I have read enough about the cosmological principle and cosmic time to develop this "confusion" .  Based on evidence gathered to-date, it appears that the universe is both , as evidenced by observations and the . This principle, when combined with the FLRW metric, allows space-time to be divided into non-intersecting slices and therefore establish a "cosmic time."   Now, the existance of such a time in no way suggests that it is the "right" time or a true "now", hence violating relativity -- although some presentist philosophers (e.g., W.L. Craig) have tried to make this argument, but it is not generally accepted in philosophical circles.  However, this leaves me confused about an apparent disconnect between relativity and the cosmological principle:  Isotropy only holds if we are at rest relative to the cosmic microwave background radiation (universal rest frame), o/w anisotropy is present - yet each reference frame is supposed to allow equally valid observations. How can these two be reconciled when most reference frames would lead us to conclude that the universe is NOT isotropic?  It seems that only by appealing to the idea of being at rest relative to "universal rest frame" can we explain away any discrepancies from isotropy as due to "peculiar motion". However, doesn't this give this "universal rest frame" and its associated time an empirically privileged status, even though physical laws work just fine in every reference frame?   For example (pardon any abuse of astronomy): if look off in some part of space and see only quasars, and then in another part of space and see only brown dwarfs, but I measure both as apparently the same distance from me, then can I conclude that we are in motion, since otherwise we would have an empirical contradiction (kind of like finding dinosaur and human remains in the same strata)?  Any help on where I am going wrong would be helpful. Intuitively, I don't think there should be a way to establish absolute ordering between space-like separated events, but the above reasoning suggests otherwise.


Answer draft is blank everytime go for edit it

Specifications  App version 1.0.71  Android 4.1.2  Steps to reproduce   Go to a question and click Add answer Write whatever you want in the answer body Go back to the question with back arrow of the StackExchange app Now you will see the Edit draft answer bottom, click it   Again in the write answer page, the content is blank, the text you wrote was ereased. There is nothing to edit, really an annoying bug for android app jeje  Note I never go out the app, just navigate from draft to the question and back  Note2 this works fine in the previous app version that I was using, sorry I don't know the number but I installed more than 2 month ago.  Update with version snapshot   Edit Jan 2016: This wasn't a duplicate question and it is not answered in the , please read .  To clarify, the question  was published in September and for the Stack Exchange version 1.0.73. Is a different context.  Don't confuse the people or edit to remove relevant information. Someone could be going through the same!


Attempt to invoke virtual method 'void com.basicprofileapp.dataholder.setUsername(java.lang.String)'on a null object refrence

I was creating a basic application that takes input and stores it in a firebase database with auto incrementing but it crashes everytime giving a nullpointer exception. I think there is some problem in my dataholder java file but I can't fix it. I've tried changing arguments in dataholder file.i have checked my android manifest file for firebase services. Here's my dataholder java file public class dataholder {      String username,password1;      public dataholder(String username, String password1) {         this.username = username;         this.password1 = password1;     }      public String getUsername() {         return username;     }      public void setUsername(String username) {         this.username = username;     }      public String getPassword1() {         return password1;     }      public void setPassword1(String password1) {         this.password1 = password1;     } }  and MainActivity import androidx.annotation.NonNull; import androidx.appcompat.app.AppCompatActivity;  import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.Toast;  import com.google.firebase.database.DataSnapshot; import com.google.firebase.database.DatabaseError; import com.google.firebase.database.DatabaseReference; import com.google.firebase.database.FirebaseDatabase; import com.google.firebase.database.ValueEventListener;  public class MainActivity extends AppCompatActivity {      EditText name;     EditText password;     Button login;       DatabaseReference reff;     dataholder obj;      long maxid = 0;      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);         name = (EditText) findViewById(R.id.etusername);         password = (EditText) findViewById(R.id.etpassword);         login = (Button) findViewById(R.id.Login);          reff = FirebaseDatabase.getInstance().getReference().child("dataholder");         reff.addValueEventListener(new ValueEventListener() {             @Override             public void onDataChange(@NonNull DataSnapshot dataSnapshot) {                 if (dataSnapshot.exists())                     maxid = (dataSnapshot.getChildrenCount());             }              @Override             public void onCancelled(@NonNull DatabaseError databaseError) {              }         });          login.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View v) {                   obj.setUsername(name.getText().toString().trim());                 obj.setPassword1(password.getText().toString().trim());                  reff.child(String.valueOf(maxid + 1)).setValue("obj");                 Toast.makeText(getApplicationContext(), "Data inserted ", Toast.LENGTH_SHORT).show();              }         });     }  }


What work of scifi broke the mold of zombies being undead voodoo minions and depicted them as mindless maneaters?

In the beginning, IIRC, zombies were undead creatures created and controlled by voodoo priests or priestesses. What work of scifi was the first to break that tradition by depicting zombies as uncontrolled, reanimated dead humans that craved live flesh?


Season 1, episode 15: Leonard tries to talk to Sheldon to persuade him that he is a suitable mate for Sheldon's sister. The scene is taken in Sheldon's room.     What is that object on the wall over Sheldon's right shoulder? It looks like it moves and there could be some sort of connector? Is it mechanical or electric perhaps?


Error using auto for return type of specialised template function

consider the following code snippet (simplified from a more complex code): #include <typeinfo> #include <iostream>  struct A{     template<int S>     void print(){ std::cout << S << std::endl; } };  struct B{};  template <class T> A foo(int);  template<> A foo<B>(int){ return A{}; }  template<class T> int bar(int){   auto res = foo<T>(0);   std::cout << typeid(res).name() << std::endl;   res.print<5>();       // This line gives an error   return 0; }  int main() {   bar<B>(0);   return 0; }   If I try to compile it (either with gcc or clang) it results in the following error: main.cpp:21:16: error: expected primary-expression before ')' token    21 |   res.print<5>();  and I have to either:  explicitly declare res as a A_int object call the method print() using the template keyword (res.template print<5>();)  in order to make this code compile. I'm not really good in interpreting the Standard language, but as far as I understood the template keyword in a function call is needed when invoking a template member function on an object which type explicitly depends on a template parameter (see for instance ). In this case, I didn't expect the keyword template to be needed since res should be an object of type A, which is not explicitly dependent on a template parameter (even if it's the result of a template function call). Could someone help me understanding where I'm wrong, and when the template keyword is actually needed? Thanks in advance, and apologise if this is a duplicate question, but I could not find anything specific for similar issues.


What determines the max CP and which methods are there to predict them?

Yesterday I started leveling my first pokemon what worked quite different as I expected.  I caught a Raticate and when I made power it up, I noticed it hit a CP cap when the bar was full. I challanged a arena with it (If this is related for the next part) and my whole time died. Today I noted the same Raticate's CP value remained the same to yesterday, but the cap raised, what led me to my question:  What determines the CP cap, and what may effect this cap(up to whcih final cap)?  And how I can determine early what the cap for a pokemon will in its final stage be so I don't have to waste stardust on them.  Also are there cases where evolving makes the pokemon worse? I had a rattata with XL in size and weight which came to a relative high CP and HP value. So I thought "Ok, this is gonna be extrem if you evolve it!". I evolved it and both stats turned into XS and while still beeing at CPcap, the Raticate had almost the same stats as rattata. So all this is pretty confusing to me, and I don't dare to raise addtional mosnters in fear of wasting resources, but staying low to jsut don't make errors is mindering the fun and therfor I'm lookign here for help. And how can I de


In oracle, how can i give grant to 'A' user to access 'B' schema?  Also, Is it possible to give, 'SELECT, EXECUTE AND VIEW' grant to A user on B schema?


What do the 2 asterisks do or mean when added in front of a parameter to a pandas function

I'm trying to fully understand this answer:   The responder provided this as an answer: df1.assign(**df2)  When I adapt this to my scenario it works but df1.assign(df2) does not work.  Can anyone explain the function of ** here?  Thanks!


Why does Round produce a different result than Application.Round

I am finding that the VBA Round function returns the wrong result. I found a working alternative which is to use the Application.Round instead.  Why doesn't the VBA Round function work as expected?  Sub roundingResults()     Range("A1") = 123456.705     Debug.Print "Approach #1 " & Round(Range("A1").Value, 2)     Debug.Print "Approach #2 " & Application.Round(Range("A1").Value, 2)     End Sub   Output  Approach #1 123456.7 Approach #2 123456.71


What is exactly the difference between "all" and "any"?

I have problems understanding this two sentences:   There are no entailment relations for any of an omnipotent, omniscient being‘s allowances of evils E1…En between his allowances of those evils and greater (possible) goods. There are not entailment relations for all of an omnipotent, omniscient being‘s allowances of evils E1…En between his allowances of those evils and greater (possible) goods.


Finding MLE for $\frac{\theta}{1-\theta}$

Let $Z_1, Z_2,... Z_n \sim Ber(\theta)$  Let $X$ be the number of trials before the 1st success. So $X \sim NB(1,\theta)$  First, I was asked to find an MLE of $\theta$ based on $X$. I did this by going through the MLE procedure for a single rv $X$ which yielded my estimator $\frac{1}{x}$.  Next, I was asked to find the MLE for $f(\theta)=\frac{\theta}{1-\theta}$. For this, I used the invariance property of MLEs so since $\frac{1}{x}$ estimates $\theta$, the estimator for $f(\theta)=\frac{1}{x-1}$. My problem with this estimator is that it is undefined when $x=1$.  Where did I go wrong? Thanks.


How do I make my desktop computer wireless?

I want to make my desktop computer wireless, how exactly can I do this? Do I have to install a  wireless card in my PC? Is there another way?  I've read I can use a usb wireless adaptor. Are these difficult to install?


Get the collection of All User Profiles with REST API

I want to fetch all user profiles with Rest API,  If I did this with the SSOM - it takes a lot of time because the users are near about 7000 or more and I have to show them on search.  E.g =>If I have searched with A then result should show all the users whose Last Name start with letter A.  I got some references, , But this not worked for me!


I know how Booster Packs drop, but I am wondering just how often they drop. Is it random? Do they drop when you get achievements in games? Do they drop when you buy a game?


Why can't I select transmission to download torrents?

I've been using transmission for quite a while now for my torrents and up until recently everything has been fine. Now when I click a torrent download link, transmission, or any other torrent program for that matter, will not take the download or even indicate that I selected it at all from the choose program menu.  How do I fix this?  Btw, I'm a complete noob here lol but I love using Ubuntu.


How to display a Japanese Characters in phpMyAdmin database?

on my database I've properly set up the Collation to utf8_general_ci in the case for the Japanese Characters may insert into the table. but when I tried to insert a Japanese character and viewing the table data in my phpMyAdmin database, It posted like this characters--> ãƒ™ãƒƒãƒ‰ãƒ¡ã‚¤ã‚¯(å®¢å®¤æ¸…æŽƒ)ã®ãŠä»•äº‹   How can I setup the phpMyAdmin to display the right Japanese characters?  on my HTML page I set up like this <meta charset="utf-8">  em I wrong?


Backend menu sidebar collapsed by default every time?

I would like the backend left menu sidebar be collapsed by default.  Yes, I can click the "Collapse menu" button every time but is there a way to have WP open up every time with it collapsed by default?  I tried this solution but it didn't work for me:   I'm also trying to apply this to a multisite website, not sure if that's why the code from the link didn't work.  Any ideas on how to achieve this?


Biblatex: Cannot switch from Chicaco to APA style - undefined control sequence 'mkbibdateapalongextra'

On the request of a publisher, I am trying to change from Chicago style bibliography to APA style. I had this working fine:  \usepackage[backend=biber,authordate]{biblatex-chicago}   I have tried this:  \usepackage[backend=biber,authordate,style=apa]{biblatex}   It fails with   ! Package xkeyval Error: `authordate' undefined in families `blx@opt@pre'.   I remove authordate:  \usepackage[backend=biber,style=apa]{biblatex}   It compiles first, but then after I ran Biber, it fails with  ! Undefined control sequence. <argument> \mkbibdateapalongextra                                 {year}{month}{day}\iffieldundef {endyear}{...   Example:  \documentclass[11pt,a4paper]{article} \usepackage{color} \usepackage{graphicx} \usepackage[hidelinks]{hyperref} \usepackage[UKenglish]{babel} \usepackage[lf]{venturis} \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc} % \usepackage[backend=biber,authordate]{biblatex-chicago} % works \usepackage[backend=biber,style=apa]{biblatex} % doesn't work  \begin{filecontents*}{foo.bib}  @article{denning2010computation,     AUTHOR      = {Denning, Peter J.},     TITLE       = {What is Computation?},     JOURNAL     = {Ubiquity},     YEAR        = {2010},     DOI         = {10.1145/1880066.1880067} } \end{filecontents*} \addbibresource{foo.bib}  \usepackage{csquotes} \usepackage{tabularx} \usepackage{epigraph} \usepackage[shrink=10, babel=true]{microtype}     \begin{document} foo \autocite{denning2010computation} \printbibliography \end{document}


I'm new to java and new to stackoverflow. Here is a code from my textbook:  public static void main(String[] args) {     Circle circle1 = new Circle(1);     Circle circle2 = new Circle(2);      swap1(circle1, circle2);     System.out.println("After swap1: circle1 = " +      circle1.radius + " circle2 = " + circle2.radius);      swap2(circle1, circle2);     System.out.println("After swap2: circle1 = " +      circle1.radius + " circle2 = " + circle2.radius); }   public static void swap1(Circle x, Circle y) {     Circle temp = x;     x = y;     y = temp; }  public static void swap2(Circle x, Circle y) {     double temp = x.radius;     x.radius = y.radius;     y.radius = temp; }   class Circle {     double radius;      Circle(double newRadius) {         radius = newRadius;     } }   The output reads as "After swap1: circle1 = 1.0 circle2 = 2.0" "After swap2: circle1 = 2.0 circle2 = 1.0" My question is how does this work? Why isn't the first print statement the same as the second? Are you not allowed to swap two different objects? Thanks in advance.


round to 2 decimal point using string.format .places java

my homework exercise gave skeleton of attendaces and my job was to name weeks so it maches values in arrays and get avarage attendance for each week and get output  and the code is:  public class AttendanceTest {      public static void main(String[] args) {         final Integer CLASS_SIZE = 15;         Integer[] attendances = {10, 14, 12, 9, 11, 15, 12, 13, 8, 14};         final Integer ACADEMIC_WEEKS = 10;         final String[] weeks = {"1", "2", "3", "4", "5", "6", "7", "8", "9", "10"};         Double totalAvg;          for (Integer week = 0; week < ACADEMIC_WEEKS; week++) {             totalAvg = (double)(attendances[week]*100)/CLASS_SIZE;             System.out.println(weeks[week] + "    " +totalAvg);         }     } }   and gives output of:   1    66.66666666666667 2    93.33333333333333 3    80.0 4    60.0 5    73.33333333333333 6    100.0 7    80.0 8    86.66666666666667 9    53.333333333333336 10    93.33333333333333    how can i round the output to 2 decimal point using String.format and/or .places?  so the output will be:   1   66.67 2   93.33 3   80.00 4   60.00 5   73.33 6  100.00 7   80.00 8   86.67 9   53.33 10  93.33


How to SSH into Android which is a hotspot?

I am using Wi-Fi hotspot on Android. Can I SSH into it from my laptop which is connected to hotspot? How would I do this?


In Eclipse, what can cause Package Explorer "red-x" error-icon when all Java sources compile without errors?

I'm using Eclipse for Java development. All my sources compile fine and the resulting application compiles fine. However, I keep getting an "red-x" error notification in the Package Explorer.  All my sources in this source directory (too long for the snapshot) compile fine, none of the show the "red-x" error icon.  Any suggestions on how to fix the problem would be highly appreciated.


I want to draw the region bounded by y=x^2 and y=x. Any ideas? I was hoping this would be somewhat simple. I've tried used a similar, with \begin{axis}..\end{axis}, but it doesn't like that. Did I not declare a package or something?   Also, if I wanted to show the solid this region creates by rotating it about the x-axis, is there a way to did this in latex? (If you had cal 2, think volume of a solid rotated about ...).


Sampling from unknown probability distribution

I'm reading about Monte Carlo methods. Suppose that $X_1,...,X_n$ are i.i.d $p(x_i|\theta)$, where $\theta$ is an unknown parameter of interest. My textbook states: Suppose we could sample some number $S$ of independent, random $\theta$-values from the posterior $p(\theta|x)$. Then the empirical distribution of the sample $(\theta_1,...,\theta_S)$ would approximate the posterior $p(\theta|x)$.   What does it mean to sample from a probability distribution that is unknown? How is this possible? I would greatly appreciate a simple example.


I have the following question on Lie theory:   Prove that $U(n)$ has no nontrivial normal subgroup except $Z(U(n))$.   I know from Schreier's theorem that since $U(n)$ is path-connected, if it does have a discrete normal subgroup then it is contained in the centre of $U(n)$, this being $\left\{ \omega I: |\omega| = 1 \right\}$ (i.e. has to be the nth roots of unity). I also know the centre is the largest discrete normal subgroup. However, these don't appear to help much.   I have proved there is a 1-dimensional ideal of $\mathfrak{u}(n)$, the space spanned by $iI$, where $I$ is the $n \times n$ identity matrix. This is the tangent space of $Z(U(n))$. So I'm guessing the problem is reduced to showing that this is the only nontrivial ideal of $\mathfrak u(n)$, which I just can't seem to figure out how to do.   This is substantially different from the $SU(n)$ case (which is dealt with here: ), since in that case $\mathfrak g$ is simple, thus has no nontrivial ideals. In this case, we have a nontrivial ideal, and the goal (I'm guessing) is to show it is the only one.   If anyone has any hints on how to do this, or some other way of approaching the problem, I'd be very thankful.


Suppose $X_1,\ldots,X_n$ are a random sample of $U(-\theta,\theta)$ with $\theta>0$. How can find $$ E\left(|X_1|\ \big|\max |X_i| \right) $$ that $1\leq i\leq n$?


So, this bit of information confused me lately. Before, I figured galaxies were no longer visible by us because their luminosity decreased in an inverse square manner. However, while watching a movie I stumbled upon the concept of how galaxies disappeared from our sight because the space which both galaxies occupy is moving away from each other faster than the speed of light.  I understand nothing can move faster than the speed of light, but the argument here, I guess, is that space itself can move, as a consequence of the Big Bang, faster than the speed of light. Is this correct? If not, how do galaxies disappear?


A word for a person who always needs there to be a problem?

I spoke to a woman who had several issues dealing with a common process we go through at work. I gave her several solutions to her issues and even explained that one of her main issues was not really even an issue, just something she wasn't understanding fully and actually had the power to manage and maintain. She fought me throughout our conversation and kept repeating that she was having these issues, even as I tried to reinforce that these were solvable and manageable problems. After it was completely clear that everything had been explained and taken care of, she was obviously hesitant to accept that things were actually okay and seemed to want to not be okay with everything, just sighing and repeating, "Well... okay. But.... okay."  It was like she just wanted to be mad, perhaps because she was just foul-tempered, but also like she did not want to let go of the problem. I talk to these people every now and then who just seem unable to let go of that pessimistic mindset and want there to be a problem. Is there a word for this kind of person or a suitable adjective? The words I've come up with that touch on what I'm thinking of are argumentative, irrational, disagreeable, and dramatic, but none of these fully encapsulate that certain quality of just seeming to NEED there to be a problem.


Does a force have to be maintained during a distance to do work?

Suppose I kick a ball horizontally with force $F$ and the distance traveled during impact is $d$. The ball then travels distance $d' = d + 10 \mathrm{m}$ before stopping.   Is the work done $W = Fd$ or $Fd'$? Is there no work done during the distance $10 \mathrm{m}$ after the ball leaves my foot?


Which one is correct: "The friend who I met is cute" or "The friend whom I met is cute"?

Or maybe both are correct?  I would be inclined to think that 'whom' is correct, because its case is in sync with the verb 'met'. I know that in the languages with developed cases (like Russian), only the equivalent of 'whom' would be correct. But what about in English?


If $0 < r < 1$ show that $r^n$ goes to $0$ as $n \to  ∞$.  If $|r| < 1$ then  $r^2  < r$  similarly $r^4 < r^3 < r^2 < r$  so $r^n$ as $n \to +\infty$ will be equal to $∞$  Let $r=\frac1m , m>1 \to$ you need to show $$lim_{n\to +\infty} r^n = ∞$$ Since $0<r<1$ $$lim_{n\to +\infty} r^n = lim_{n\to +\infty} \left(\frac1m\right)^n=lim_{n\to +\infty}\frac{1}{m^n} = \frac{1}{+\infty} = ∞$$


Order of muliplication with or without times sign

Is 6:2(2+1)=1 or is 6:2(2+1)=9 ? I can't find any information regarding the order of multiplication without a sign. I'm sure that 6:2*(2+1) is 9, but I'm not sure about this.


I try to split a string with multiple delimiters (spaces and parenthesis), but all I managed to do is a split with one delimiter thanks to getline(...).  Here's an example of what I try to do:  hello world(12)   And I would like to get theses as strings:  hello world ( 12 )   Any help?


What informal and formal letter/e-mail closings are used the most?

I often struggle with doubts about the correctness of the closings which I use. I'm not a native speaker and I'm worried that I'll make a mistake in the last part of the letter/e-mail.  Some examples:  Formal:  I look forward to hearing from you soon. If you need any more information, please let me know   Informal:  I hope to hear from you soon. If you need any more info, just drop me a line.   Could you let me know which closings are used the most?


Why do the up-votes after reaching daily rep cap not contribute to compensate the subsequent down-votes?

Let's just assume that I've hit the rep cap and got the Mortarboard. None of mine have extra scores (i.e) from accepted answers, bounties, etc. All are up-voted posts. I've got some 300 points but the engine stops at 200. Now, we've to count the down-vote. I got down-votes up to some -6. Now, my rep.cap decreases to 194.  My question is, Why doesn't the engine normalize the rep cap again to 200 from the remaining posts? Now, my graph indicates simple 194 and not 200. Why is that?  Is it because - "Once we attain the rep. cap, no other ups count except the downs..?"  P.S: I think it's related to many questions like


Show $\bigg(\frac{\partial x}{\partial y}\bigg) \bigg(\frac{\partial y}{\partial z}\bigg)\bigg(\frac{\partial z}{\partial x}\bigg) = - 1,$

Question statement: Let $F(x,y,z)$ is a continuously differentiable function with nonvanishing partials at $(0,0,0).$  Define $x = x(y,z), \; y = y(x,z), \; z = z(x,y)$ as the solutions of the equation $F(x,y,z) = F(0,0,0)$ in the neighborhood of $(0,0)$ in the corresponding variables.  Prove that  $$\bigg(\frac{\partial x}{\partial y}\bigg) \bigg(\frac{\partial y}{\partial z}\bigg)\bigg(\frac{\partial z}{\partial x}\bigg) = - 1,$$ where  the  three partial  derivatives  are  taken at  point $(0,0)$  in  the corresponding pair of variables.    I know I have seen a couple weak proofs of this, one in thermodynamics where my professor referred to this as "The -1 Rule", and another in the back of a long lost textbook of mine.  However, I am interested in a detailed, unshakable proof of this explicitly using the implicit function theorem.  I've tried several times now and I have been unable to produce one.  Any helpful comments/answers would be appreciated!


Prove that $\int \limits _{0}^{\infty}\frac{e^{-2x}-e^{-ax}}{x}\text{d}x$ converges for any $a>0$

I'm doing this exercise:     Prove that $F(a)=\displaystyle\int \limits _{0}^{\infty}\frac{e^{-2x}-e^{-ax}}{x}\text{d}x$ converges for every $a>0$. Calculate $F'(a)$ and deduce $F(a)$.   I've separated the integral in  $$F(a)=\displaystyle\int \limits _{0}^{\infty}\frac{e^{-2x}-e^{-ax}}{x}\text{d}x=\displaystyle\int \limits _{0}^{\infty}\frac{e^{-2x}}{x}\text{d}x-\displaystyle\int \limits _{0}^{\infty}\frac{e^{-ax}}{x}\text{d}x$$ and I've tried to identify them with the gamma function, but $\Gamma(0)$ does not exist.  Edit: To decide whether it's convergent or not, can I use Dirichlet's test?  Any hint would be really appreciated. Thanks.


Java if statements only displaying the else statement

Hey im coding a simple program for java and im having problems with my if and else statements.  Scanner coffee = new Scanner(System.in);     String z = coffee.nextLine();     if (z == "y")         System.out.println("Great! Let's get started.");     else if (z == "n")         System.out.println("Come back next time, " + x + "." );     else          System.out.println("Error please try again");   Where it only comes up with the else statement.


can i use my C1 visa transitting to japan

Im holding a philippine passport whith c1 visa (issued by US embassy) a transit visa that can transit to any airport in USA , can i use my C1 visa to transit to Japan or do i still need to get a transit visa to pass through their airport in japan? my last destination will be in Manila,Philipines. Thanks in advance.


allow permission to apache html to both www-data and user

I am using mkdir function in php and I use sudo chown -R www-data:www-data /var/www/html/ than I am able to mkdir folder. But than I am not able to edit any file in /var/www/html/ . So I tried both below method :   sudo chown -R www-data:username /var/www/html/ and   sudo chown -R username:www-data /var/www/html/  But In that mkdir stops working giving permission denied error.  How to give permission to both www-data and myself both.


I have seen some people using them while others not. Should I still use a suspended hyphen in the following snippet?     I have used upper- and lowercase in my script.


How to connect and access Mapd Database by GeoServer

In my project requirement to access table data from Mapd Database on GeoServer  Mapd(GPU Based database) Database documentation link:   But in GeoServer provided some extension to connect and access particular database  GeoServer Extension link:    How can I connect MapD databse with geoserver is there any plugin.


How do I produce the output >> in a LaTeX Beamer presentation?  When I write >> or \textgreater\textgreater, I get this symbol, which I believe to be the guillemet(»):    I do not want this symbol. I want literally two greater-than symbols, in the context of     Use >> to append to a file, as in date >> dates


Can Bear Hug force a player to destroy an Incorporeal minion?

The wording on Bear Hug states:     Each other player destroys his or her minion with the least power   (owner chooses in case of ties).   The wording on Incorporeal states:     Play on one of your minions.  Ongoing: This minion is not affected by   other players' cards.   Can Bear Hug force a player to destroy a minion that has Incorporeal played on it if it is the lowest power minion?  I ask because my game group came up with two separate interpretations of the rule.  The first interpretation was that Bear Hug doesn't affect the minion because Bear Hug is a card and has no effect against the Incorporeal minion due to the wording of "other players' cards."  The other interpretation is that Bear Hug does force the player to destroy the Incorporeal minion since Bear Hug is played on the player and not the minion directly.  Is there something in the rules that can clarify this or at least a general consensus from some official forums?


Argue that $n!$ dominates any polynomial function of $n$, i.e., $n^x = O(n!)$ for any real $x$.

I'm really not sure how to go about proving this. The only way I can think of is by showing how $n^x$ & $O(n!)$ changes when $n = 1, 2, 3,\ldots$.  Any help would be appreciated. Thank you!


C++ map access discards qualifiers (const)

The following code says that passing the map as const into the operator[] method discards qualifiers: #include <iostream> #include <map> #include <string>  using namespace std;  class MapWrapper { public:     const int &get_value(const int &key) const {         return _map[key];     }  private:     map<int, int> _map; };  int main() {     MapWrapper mw;     cout << mw.get_value(42) << endl;     return 0; }  Is this because of the possible allocation that occurs on the map access? Can no functions with map accesses be declared const? MapWrapper.cpp:10: error: passing const std::map<int, int, std::less<int>, std::allocator<std::pair<const int, int> > > as this argument of  _Tp& std::map<_Key, _Tp, _Compare, _Alloc>::operator[](const _Key&)  [with _Key = int, _Tp = int, _Compare = std::less<int>,  _Alloc = std::allocator<std::pair<const int, int> >] discards qualifiers


How to calculate the number of subgroups of a group whose order is $19$? Normally, I'd resolve this problem with the Lagrange's Theorem, but I don't know how to do it with this one because I only know the order. So this is not the best approach. What's the answer to this problem? Thanks.


Merged characters hand to the arm and got a weird choppy result


Harry Potter Portrait's life - an act of creation?

The portraits in the Harry Potter world - they talk, they act. Are they reflections of the person whom they portray, or are they, at least potentially, independent? Do they have free will? Do they, therefore have a soul?  We know that the Fat Lady could be afraid (3rd book) and Sir Cadogan could show courage, we know that Phineas Nigellus could like or dislike people, spy and whatnot. All of this seems to imply a measure of self-awareness.  What I'm curious about is, do artist in the HP universe perform an act of true creation, when painting a portrait? I am given to understand that Christianity only allows God to give things souls (Tolkien struggled with orcs, Morgoth's creations, possessing Free Will, and eventually made their origin to be tortured elves, making the Free Will thus come from Ilúvatar). Considering Rowling is also quite devout and , I find this element curious.


Recommended to use Readonly against Interfaces?

Does it make sense to make an Interface readonly?  While using Resharper 8.0, i got the following suggestion and I was not sure how this will help me.    What I've found from researching (still not clear how it works against an Interface):   It's simply a check to ensure that once the object is fully constructed, that field cannot be pointed to a new value. The real advantage of this keyword is to generate immutable data structures. Immutable data structures by definition cannot be changed once constructed The readonly keyword is used to declare a member variable a constant, but allows the value to be calculated at runtime. Use readonly if you don't want to have to recompile external DLLs that reference the constant (since it gets replaced at compile time)   Cited:


Which of the following to use, especially in the context of programming:   hashtag well number pound sign


Solutions to $a+b+c=12$, $a, b, c \in \mathbb{N}_0$

Let $a, b, c \in \mathbb{N}_0$. If $a+b+c=12$, how many solutions $(a,b,c)$ satisfy the equation?   Is the answer:      $729$


I am running Ubuntu 14.04 server with ISPConfig installed and etc.  Latest I saw a suspicious home directory named ub. It has some encrypted files in it. Also I found /run/shm/ecryptfs-ub-Private is owned by this user.   I changed password of the user and ssh login to the account. Just saw encrypted files. Later on I deleted the user ub and group ub. But I am not sure if I have done the right thing.   Does it might be a auto generated user and group by some services? Or is it really suspicious?   I did not see any processes run by this user by top command.


Let $X,Y$ be two firms. An MBA applies for the job in $X$ and $Y$. The probability he being selected in firm $X$ is $0.7$ and being rejected at $Y$ is $0.5$. Probability of at least one of his applications being rejected is $0.6$. What is the probability that he will be selected in one of the firms?  i.e.,  $P(X)=0.7$, $P(\bar{Y})=0.5$, $1-P(X\cap Y)=0.6$  So, my doubt is,  $P$(he  will  be  selected  in  one  of  the  firms)  =$P(X\cap \bar{Y})+P(\bar{X}\cap Y)$  or  =$P(X\cup Y)$ {but this means atleast one firm, am i correct}  So, what does the question actually mean.


Which style for buttons in a wizard and a simple form?

I am wondering which style I should use for my "cancel" button. As you can see, on the wizard, the "cancel" button doesn't have border. But in a form which has only two buttons, should I use a "cancel" button with borders or not? What is the best practice? Thank you guys! Peace out!


Difference between "classical" and "classic"

What's the difference between classical and classic? Should we say classic content in textbooks or classical content in textbooks?


Why are detectives/investigators referred to as "gumshoe"s?

Why are detectives/inspectors colloquially referred to as Gumshoes?  Is it anything other that they would travel a lot in investigations and, presumably, wore hard-wearing shoes?


Removal of serial voting actions does not remove any badges awarded as a result of the upvoting

I was a victim of some serial upvoting, see the post, , on SE Raspberry Pi. Nothing particularly new or amazing in that, granted. However, during, and as a cause of, the serial upvoting, I was awarded the "Nice Question" bronze badge. The votes have, rightly, been removed by the system, but I still have the badge in my collection.  Here is a screen shot of my reputation changes, showing that the votes have been removed.        Here is a screenshot of the badge being awarded due to one of the serial upvotes.        Here you can see that I still have the badge awarded.    Shouldn't I be stripped of the badge, in the same way that I was stripped of the reputation, if it was awarded as a by product of someone's thoughtless upvoting?


How does one detect when the currently visible workspace is switched?

I'm using Ubuntu 14.10 and would like to be able to have different screen resolutions on different workspaces. I was thinking of writing a script/daemon that calls xrandr whenever it detects a switch – the question is, how does one detect a change?


Scenario: I see a dubious question A on basketweaving.SE, and I want to discuss its appropriateness. So I open a question B on meta.basketweaving.se. Of course question B will contain a link to question A.  I believe that SE should display somewhere inside A a link to B, so that when other users browse question A they can know that there is an ongoing discussion in Meta about it. For instance, before the "linked questions" on the right sidebar, or maybe even in a more prominent position.   I have seen in multiple occasions users posting a comment there is a meta discussion (link) about this question, but this is only a workaround for something that (in my opinion) should be done automatically.  Unless one visits Meta regularly, it is difficult to find out about a new discussion. Currently Meta doesn't get much visibility on the main site; the only place where a link appears is the "hot meta posts". This suggestion would partially fix this problem.


Extra RAM memory on disk in VMWare Workstation

Can you add RAM momory to a virtual machine by adding a (say 4 GByte) disc to the system such that this disc is added to the existing memory. What is the procedure for doing this.  Of course you have RAM discs, but this is (kinda) the other way around (i.e. using a disc as memory, instead of using memory as disc),


Making $x+\frac1y$, $y+\frac1z$, and $z+\frac1x$ all integer.

Let $x,y,z\in\Bbb R$, and at least one is be a postive integer, and such that  $$x+\frac{1}{y},\;y+\frac{1}{z},\;z+\frac{1}{x}\in\Bbb Z$$ Find the value of $x,y,z$.  My try:  $$\left(x+\dfrac{1}{y}\right)\left(y+\dfrac{1}{z}\right)\left(z+\dfrac{1}{x}\right)=\dfrac{(xy+1)(yz+1)(xz+1)}{xyz}\in Z$$  Then I can't. Thank you.  I konw $(x,y,z)=(1,1,1),(-1,-1,1),(2,0.5,1)$ is such condition,But How prove it?


Recently I had a question to find the electric field at a distance $R$ from the origin, where the space is filled with charge of density $\rho$. I did this by assuming a Gaussian surface of radius $R$. Now outside won't affect the field so I calculated the field as:  $$\left|\,\vec E\,\right| = \frac{\rho R}{3\varepsilon} \tag{1}$$  I was satisfied with my solution, until a thought struck me: as the space is infinite, for an infinitesimal charge producing a field $\vec {E_1}$ there will be another charge producing $-\vec {E_1}$ thus the resultant field should be zero. Thus bringing me to my first question, is Gauss' law always valid, or does it have some limitation?


Is there a way to auto-run a script when entering a directory in powershell?

I have multiple folders containing different python projects. Each project has its own virtual environment that I activate before working on it. I activate the virtual environment by running in the project directory:    .\venv\Scripts\activate.bat     Is there a way to automatically run this command once I cd into a directory?


Multivariate normal distribution, show distribution and independence

I noticed that this problem was already posted on this page twice. But one was marked as a duplicate and the other was removed, so I hope this isn't breaking any rules.  I wish to solve the following problem:  The random variables $X_1$ and $X_2$ are independent and $\mathrm{N}(0,1)$-distributed. Set $$Y_1 = \frac{X_1^2-X_2^2}{\sqrt{X_1^2+X_2^2}}, \hspace{2mm} Y_2 = \frac{2X_1X_2}{\sqrt{X_1^2+X_2^2}}. $$ Show that $Y_1$ and $Y_2$ are independent, $\mathrm{N}(0,1)$-distributed random variables.  My current plan is to use the transformation theorem. Since I have $$f_{X_1,X_2}(x_1,x_2) = \frac{1}{2\pi}\mathrm{exp}\{-\frac{1}{2}(x_1^2+x_2^2) \},$$ I thought I might be able to find $f_{Y_1,Y_2}(y_1,y_2)$ by computing $$f_{Y_1,Y_2}(y_1,y_2) = f_{X_1,X_2}(x_1(y_1,y_2),x_2(y_1,y_2))|\mathrm{J}|, $$  (where $x_1(y_1,y_2)$ means $x_1$ in terms of $y_1,y_2$).  The issue I have is finding the inverses, i.e. for example $x_1$ in terms of $y_1,y_2$. So that is my main reason for posting. I'm also not completely sure if this is the right approach. There is a later chapter in by book on something called quadratic forms but this problem isn't a part of that chapter. But any other alternative ideas for approaching this would be much appreciated.


Shell Script does not send email from Cron job

I have a shell script which sends email when the disk is more than 80% full; when I run the script as sh -x script.sh or ./script.sh I get an email but when I keep the script in cronjob I do not get any email.  The script has execute permissions (755).   When I type mail I can see the cronjob has ran at that time, but there is no email sent.


Ubuntu 20.04 background -- is there a way to make the screensaver rotate/change every five minutes?

I would like to rotate/change screen saver on my background on Ubuntu 20.04. Is there a way to have it change/rotate every five minutes? Thanks


Setting GPU fan speed using free ATI driver?

Is it possible to set the GPU fan speed using the default free ati driver?  My card (X1900) was deprecated in the fglrx drivers a while back.  The free drivers seem to work with 3D, Compiz and such, but running graphics intensive programs makes my GPU heat up and produce artifacts, while the GPU fan never seems to increase. (When set to 100% in Windows it makes a massively louder noise.)


Want two instances (Windows) of Notepad++

I am not a programmer, just a user who finds Notepad++ very useful.  I want to open Notepad++ twice for separate projects. Each would open with different shortcut (icons). I've read about opening separate instances of Notepad++ using -multiInst and/or -nosession and have not figured this out. I either open the original instance or a blank instance (with no obvious way to open the first, much less the second).  Someone had suggested loading Notepad++ twice, but all that happens is an over-write. I tried creating a sub-directory in Notepad++ with the same results as above.  I am using Windows XP and Notepad++ 5.9.6.2  What am I doing wrong?


Traversal through a string with a loop in Python

My code below is not generalized; it handles each line of output as a special case.  How I could get the same output using a while or for statement?  string = "Apple" i = 0  one = string[0:i+1] two = string[0:i+2] three = string[0:i+3] four = string[0:i+4] five = string[0:i+5]  print(one) print(two) print(three) print(four) print(five)   I have the following result:  A Ap App Appl Apple


Word for a person who just talks but would not do what he/she says

I'm looking for a word which describes a person who just talks but would not do or practice what he/she says - like somebody who doesn't practice what he/she preaches.


separate appendix file with cross-referencing

I have a tex file with appendices. The publisher wants separate source files for the body of the document and the appendices. However, I have used many cross-referencing in the appendices that refer to equations and theorems in the document body.  Is there any way that I can provide a separate tex file for the appendices without replacing all cross-references by hard typed numbers?


What's the cardinality of the infinity introduced in Riemann sphere model?

In the Riemann sphere model, people extend the complex plane with a point at infinity: $\mathbb {C} \cup \{\infty \}$ and claim this expression: $\frac{1}{0}=\infty$. I'm confused with what is this $\infty$. Is it a member of $\{\aleph_n\}$ numbers? When we study infinities, we usually discuss cardinality. Does this $\infty$ corresponds to something's cardinality?


If $E$ has eigenvalues $\lambda_1, \ldots, \lambda_n$, then $B \mapsto [E,B] = EB - BE$ has eigenvalues $\lambda_i - \lambda_j$.

Let $E \in M_n(C)$ be an $n \times n$ matrix with entries in a(n algebraically closed, characteristic 0) field $C$, with eigenvalues $\lambda_1, \ldots, \lambda_n$. Show that the commutator map $M_n(C) \to M_n(C)$ given by $B \mapsto [E,B] = EB - BE$ has eigenvalues $\lambda_i - \lambda_j$.  This is an ingredient a proof of the fact that any regular singular equation $y' = Ay$ over $C((z))$  is equivalent to $v' = Dz^{-1}v$ with $D$ a constant matrix. See exercise (7) (a) (i) of  by Marius van der Put (page 6 of the PDF).  This is homework, so hints rather than full answers would be appreciated.  Things I have found that may or may not be useful:   $EB - BE = (\lambda_i - \lambda_j)B$ can be written $(E-\lambda_i)B = B(E- \lambda_j)$. $EB$ and $BE$ .


Below a part of subtitles from the Angry Birds movie.     77 00:04:25,400 --> 00:04:26,435 Get outta here!      78 00:04:26,520 --> 00:04:28,440 Already? But you're the only one   that's had cake.      79 00:04:28,480 --> 00:04:29,480 What...      80 00:04:29,640 --> 00:04:30,640 Mmm.      81 00:04:31,040 --> 00:04:32,268 Oh, that's good stuff.   Can you please tell me what "-'s" is in the bold sentence above? Does "-'s" represent "has", "is" or anything else?


Can I do a release update on Ubuntu 7.10?

I have an older server that still has Ubuntu 7.10, is there a way that I could update this since it is no longer supported?  lsb_release -a gives:  Distributor ID: Ubuntu Description:    Ubuntu 7.10 Release:        7.10 Codename:       gutsy   I did the following instructions from here and they don't work for me:  :  sudo sed -i -e 's/archive.ubuntu.com\|security.ubuntu.com/old-releases.ubuntu.com/g' /etc/apt/sources.list   then updated with  sudo apt-get update && sudo apt-get dist-upgrade   and then:  do-release-upgrade   and i get this error:  Checking for a new ubuntu release Failed Upgrade tool signature Failed Upgrade tool Done downloading extracting '/tmp/tmp8S5pl1/hardy.tar.gz' Failed to extract Extracting the upgrade failed. There may be a problem with the network or with the server.


How to calculate the binomial sum $S=\mathop{\sum}\limits_{i=0}^{\lfloor \frac{n}{4}\rfloor}\binom{n}{4i}$?

How to calculate the sum $S=\mathop{\sum}\limits_{i=0}^{\lfloor \frac{n}{4}\rfloor}\binom{n}{4i}$ ? Or how to get a good upper bound on $S$ in terms of $n$?


Structuring game narrative. Handling NPC, Quest, General Dialogue. Is Json/XML the right way to go? Or any other solutions?

Hello guys I'm try to make some games that have more to it than just simple high score scrolling shooters etc.  I'm trying to design my own systm of handling narrative. I want to be able to place NPC's in the game world, with scripts attached to them. Some of the NPC's would just have n random greetings. Others will be mission givers and will offer you a quest of sorts. (The quest could be go speak to Bob in the pub, or it might be bring me the Holy Grail and Crown Jewels, or something in between).  I've wracked my brain for a long while over this but sadly keep slipping back to the only way I know how, which is to manually code all the strings that people can say and have a horrible web of if statements and other such insanity to give me a rudimental dialogue system. Its not good enough even with just a few characters, but if I had dozens/hundreds of characters it would be even worse.  I've read lots about it already but I'm still very confused when I start trying on my own project. I've read that Json/XML might be the way to go and that I can add custom markups in the Json text to call methods in my code, but I dont even know if this is right and if so how I can do it.  The back of my brain is screaming at me that there is a simpler way to do it, but I've sat here for a very long time without managing to think of ideas.  Here is a diagram I drew which pretty much shows the flow of how I want my NPC to behave. If anyone can see this and then tell me how they might do something like this that would be fantastic!! (note: if Json is the correct advise, please give me a exact example of how exactly to format the Json in order to check the bools I mention in my flowchart - thanks!):    note: The circles denote an output from the data as Text for the dialogue system. The bools will need to be checked against by the data file to see which output to give (hope that makes sense and is possible)


What Is the Difference Between Wizard and Warlock in Potterverse?

One of Dumbledore's titles is "Chief Warlock of the Wizengamot".   What is the difference between a Wizard and a Warlock in Potterverse? As we don't see the term Warlock used often in the books, my impression is that a Warlock is somehow officially different from a Wizard.  Please no Wikipedia, HP Wikia, or dictionary.com answers. I'm looking for a canon-based¹ explanation.  ¹Any of the ten HP books or a quote from JKR


Ending a for cycle after an if construct has been executed ONCE

I'm new to the community, I hope I'm not doing anything wrong. So, I'm trying to develop a Turing machine simulator. I want to exit a for construct after the if construct (which is inside the for) is executed ONCE. Is there an easy way to do it or I do have to redo all the coding?


Is there a way to restore ubuntu 18.04 as fresh install?

I am wondering if I can restore Ubuntu 18.04 as fresh installation. As new copy


Is there a unix-like system that doesn't come with Perl?

As far as I know, every desktop/server distribution of Linux has Perl (and core modules) installed by default, AIX and Solaris (IIRC) also do.   By "by default" I mean that even the most lightweight variant has it.  I haven't worked on BSD or similar ones, do they come with Perl?  Motivation: I'm trying to figure out if encouraging people in my team to use Perl instead of awk/sed/other text utils would make sense.   Note:  does't answer my question. Portability it's not my main concern here, availability out of the box is. Even if all unix-like systems have awk/sed I would still prefer Perl.  Note: also, by Perl I mean Perl 5.8+


I just booted up and it was like this, everything is zoomed in, but only in Chrome. Even the menu's in chrome are huge. Is this normal? How can I bring this back to normal?  Here is a picture.


I have a good amount of files I have to rename. My files are called sample_1.wav sample_2.wav ...  I need to rename each one of them with a smaller number in the name, sample_1.wav has to become sample_0.wav and so on.  I have tried this script, but it does not maintain the order:  #!/bin/bash  count=0  for file in *.wav do     new=$(printf "sample_%d.wav" "$count")     mv -- "$file" "$new"     (( count++ )) done   Thank you for the help


Determine the SQL Server version and edition from the available set up, before actually installing it?

We are going through a downgrade process from SQL Server 2008 R2 Enterprise to Standard edition.  To kick off the above activity, we were looking for available Standard Edition of SQL Server. We found one, but got confused on below points:   The setup files (saved by an earlier team member) are in a folder that says it is SQL Server 2008 R2, but just to cross check before we start installing, we went through the default.ini file, which says:   SQLSERVER2008 Configuration File [SQLSERVER2008]    This created a doubt if this is the correct version of SQL Server required. So is there any other way, in case above mentioned method is incorrect to determine the version, before we actually go ahead and try installing? Can we also check the edition of that available SQL Server, because on the set up, we can hardly figure out if it is really Standard Edition?   We cannot simply download new media, per our security policies. Also, we have no rights to download.


Disjoint compact subsets of Haurdorff space has a separation

Let $A$ and $B$ be disjoint compact subsets of a Hausdorff space $(X,τ)$. Prove that there exist disjoint open sets $G$ and $H$ such that $A⊆G$ and $B⊆H$.  This one was getting a bit messy for me, but my idea is to first fix a point $x$ in $B$ and then apply Hausdorff property on points of $A$ so for all points an in $A$ with $x$ in $B$ we can find disjoint open sets containing them. We can say $U_a$ and $V_a$ be the set of all open sets we just created such that $U_a$ and $V_a$ are disjoint. We note that $U_a$ is an open cover for $A$ and we can pick out a finite subcover. Then we select another point in $B$ and repeat the same process and do this for every single point in $B$. Then we have a family of finite subcovers each corresponding to each point in $B$. We can take the intersection and call it $W$ and let that be the open set that contains $A$. Then the next step would be to repeat everything above by fixing a point in $A$ and cycling through points in $B$ then fixing another point in $A$ and create a family of open subcovers to cover $B$ and intersect them all and call that $G$. Now I believe $A$ is contained in $W$ and $B$ is in $G$ and $W$ and $G$ are disjoint. A concern I have is that while each subcover is finite, the family of subcover may be uncountable and the intersection of uncountable open sets are not always open.


Recursive (online) regularised least squares algorithm

Can anyone point me in the direction of an online (recursive) algorithm for Tikhonov Regularisation (regularised least squares)?  In an offline setting, I would calculate $\hat\beta=(X^TX+λI)^{−1}X^TY$ using my original data set where $λ$ is found using n-fold cross validation. A new $y$ value can be predicted for a given $x$ using $y=x^T\hat\beta$.  In an online setting I continually draw new data points. How can I update $\hat\beta$ when I draw new additional data samples without doing a full recalculation on the whole data set (original + new)?


Is there an equation to determine the Ability Modifier?  I'm not talking about the chart that lists   1 = −5 2-3 = −4 4-5 = −3 6-7 = −2 etc.   I mean a legit equation that, if I somehow misplaced this information, I could determine what the modifier is based on the score?


What book has human colonies at war against a (possibly bat-like) alien race?

The story takes place in the future; humans have colonized our galaxy but they encounter an alien race with which peace is impossible. Colonies start the war but Earth doesn't help them and decides to block the solar system entirely with space mines so nobody can enter. Decades pass and humans from the colonies are losing the battle against the aliens because they lack battleships, and the only way to win against the aliens is to fight the same way but with more battleships than them.  Finally, one day Earth sends a ship with a very small crew. All the crew member have developed special powers, like tactical genius, telepathy, and telekinesis. This ship goes to the planet of origin of the aliens and thanks to their power manages to convince the alien leader to attack Earth massively.      Half of the alien army goes to Earth. Too late they realize it’s a trap: the sun or Earth (not sure which) explodes, half of the alien army is wiped out, and then the human colonies can win the war. Earth has been sacrificed for the fate of the human race.   I think the alien race look like giant bats.  I think the author is American and the book was released from 1990 to 2005.  What book is this?


How do we encourage edits to obsolete/out of date answers?

As the network ages and we have answers that are , we run into situations where changes in technology, etc. result in a once great answer becoming out-of-date, obsolete, or somewhat problematic.  We don’t want to , due to legacy applications that still need the code but we need to figure out the right way to handle them. This has been brought up and discussed , ,  times over the years, and the community seems to suggest the following steps to update these answers:  Comment to the OP suggesting that their answer is out-of date and needs to be updated Post a new answer with the updated information Edit or suggest an edit (if you don’t have privileges) to correct the answer  There are pros and cons to each one of these, and I’m going to outline a few of them here: Adding a Comment: What if the user is no longer active on the site? They won’t get the notification to update and then it’s up to someone else to potentially edit the answer. What if the user gets notification and disagrees that the answer is wrong, so they don’t edit it.  Now we have a conflict between the original author and another user on the validity of an answer, how do we proceed? Posting a New Answer: This is a great solution to the above problem when the original author doesn’t want to edit their obsolete answer, but we run into the “sorting problem” where the highly-upvoted, accepted answer appears above an up-to-date answer.  The hope is that eventually this new answer will gain enough upvotes to move up the list and will be easily visible to people with the same question. Editing or Suggesting an Edit This is where we have the biggest issue when it comes to improving out-of-date or obsolete answers.  Editing posts is  and it’s even a  that is earned. The help center explicitly states  When should I edit posts? .... to correct minor mistakes or add addendums / updates as the post ages  Users are advised to make these edits, yet this seems to be a stumbling block. Why, you ask, do I see it as a stumbling block? Several reasons... First, when a user doesn’t have full edit privileges it goes to the review queue where . If the edit is substantial enough, there is even a rejection reason provided:  This edit deviates from the original intent of the post. Even edits that must make drastic changes should strive to preserve the goals of the post's owner.  With the rejection we lose the proposed fix and are back at the start, with an answer that needs a bit of tending to. If a user has full edit privileges, they can make a sizable edit without review to bring it up-to-date but if there are  As you see, we have a disconnect. Users are told to edit and we have posts that need to be edited. But no one wants or is able to edit them, because they might alter code which is a big no-no when the answer is not a community-wiki. What do we do? What can we do to fix this? We’re taking a good hard look at how we should handle answers that were once great but need some gardening to keep them that way.  Lots of things have been suggested over the years, but so far nothing has been implemented:           Before we do anything we want some feedback and a discussion from the community on how we can encourage these edits to these answers (we ). Would you be more likely to edit them into something no longer obsolete, if they were made community wikis?  Should we add a post notice that it’s obsolete or out-of-date?  Figure out some way to give rep to the user who makes a substantial edit?  Something else that we haven’t thought of?


Model selection in binary logistic regression

I have 3 possible "final" models in binary logistic regression (N=176, Number of events = 36).  Now I am trying to decide which one to select. It´s clear,"All models are wrong, but some are useful", but I have to decide.  My goal is prediction and so parsimony over complexity.  Which criterion to use? Corrected AIC in combination with adjusted Pseudo-R2? And then AUC with calibration curve for each model in order to compare them?


In the , lasers - in the context of true electromagnetic beams - are mentioned to be archaic, suggesting they existed in Star Wars military history. The , however, are in the context of being interchangeable terminology with blasters, and so do not refer to true lasers.  What records of true laser weaponry are there?  Legends answer preferred, since the article that contains the references are from Legends.


Problem:     $f(x)$ is a continuous function, and it is periodic with period $T$. For any $a<b$, prove that   $$\lim_{n\to\infty}\int_a^bf(nx)dx=\frac{b-a}{T}\int_0^Tf(x)dx$$   I tried substituting $nx=t$, but it gave me $\frac{1}{n}\int_{na}^{nb}f(t)dt$, and I don't know what to do. Can anyone give me hints to solve this? Or is there another way to solve this problem?


Logged in to 20.04 and a screen appeared 'distribution update' which I clicked (I'm only on LTS updates so not sure why this came up). I was on 20.04 and still on 20.04 so I presume this might be a point update to 20.04. When I tried to update after it said could not load repository information. Upon looking it said 'The repository 'http://archive.canonical.com/ubuntu wily Release' no longer has a Release file.' As such I deleted this update path. I left the remaining ones in below and tried to remove anything from Wily/Bionic. My question is - the update paths in the image, are these all the ones I need or should I add (or remove) anything else for 20.04? Thanks


As some of you may know, there is a common problem in some old notebooks, between battery and adapter, which is when charger plugged in, computer restarts itself, and this is a real pain in the neck.  There are one or two different solutions for this problem, for example, the one can disable the second CPU via Device Manager in Windows' safe mode and by this way restarting would be prevented. But you know, things work different in Ubuntu, there isn't any chance to disable the second CPU via "Device Manager" since there is not any "Device Manager". So I was looking for a appropriate solution and I found one. There is a terminal code that let me disable the second CPU, which is:   echo 0 | sudo tee /sys/devices/system/cpu/cpu1/online   When I enter this command, it works like a charm and there is no problem, but the problem is, after shutting down the computer and reopening it, CPU enables itself automatically.  So that's the problem. Sometimes I forget to enter this command and thus my laptop repeats itself and my whole work goes into trouble.  Is there any way to make this command "permanent" ? Or is there any other way to disable the second CPU?


Difference between Object and variable Object

I'm trying to get the length of seznam2 by using int postle in Stanovanje. However, the variable getPostle() does not pass and I  get Exception in thread "main" java.lang.NullPointerException error for this line:      private String[] seznam2 = new String[getStanovanje().getPostle()].    I would also like to know when to use:  Stanovanje stanovanje = new Stanovanje();    or  private Stanovanje stanovanje1;    Here is my code:  Potovanje.java  public class Potovanje {      Stanovanje stanovanje = new Stanovanje();     private Stanovanje stanovanje1;      private String datumOdhoda;     private int trajanje;      private Popotnik[] popotnik;     private ArrayList<Popotnik> seznam = new ArrayList<>();     private String[] seznam2 = new String[getStanovanje().getPostle()];       public Potovanje(String datumOdhoda, int trajanje){         this.datumOdhoda = datumOdhoda;         this.trajanje = trajanje;     }      public void setStanovanje(Stanovanje stanovanje1){         this.stanovanje1 = stanovanje1;     }      public Stanovanje getStanovanje(){         return stanovanje1;     }      public void setPopotnik(Popotnik[] popotnik){         this.popotnik = popotnik;     }      public Popotnik[] getPopotnik(){         return popotnik;     }      public ArrayList<Popotnik> getSeznam(){         return seznam;     }      public void setSeznam2(String[] seznam2){         this.seznam2 = seznam2;     }      public String[] getSeznam2(){         return seznam2;     }       public void dodajPotnika(Popotnik[] popotnik){         //System.out.println("postle: " + stanovanje.getPostle());         for(int i=0; i<getSeznam2().length; i++){             //System.out.println("wadap");             setPopotnik(popotnik);             seznam.add(getPopotnik()[i]);         }      }      public String toString(){         return "datumOdhoda: " + datumOdhoda + "\n" + "trajanje: " + trajanje + "\n" + "popotnik: " + getPopotnik();     } }   Stanovanje.java  public class Stanovanje {      private int postle;      public Stanovanje(){      }      public Stanovanje(int postle){         this.postle = postle;     }      public void setPostle(int postle){         this.postle = postle;     }      public int getPostle(){         return postle;     }      public String toString(){         return "postle: " + postle;     } }


Resultant capacitance of a capacitor having a combination of dielectrics between parallel plates

In few questions, I am having some confusion on how to take the resultant capacitance of a parallel plate capacitor with a combination of dielectric in between parallel plates. Here is a an example  (From JEE Advanced 2000) $k_1, k_2, k_3$ represent the dielectric constants of the dielectric slabs. A is the plate area, d is the distance between the plates. I know that we could split it into equivalent capacitors and from there it is easy to find the resultant capacitance. But I am confused on how to split them. I have 2 possible approaches (i) (ii) ($k_1, k_2, k_3$ represent the dielectric constants of the dielectric slabs. A is the plate area, d the distance between the plates) The 2nd part makes more sense to me and it also turn out to be the right method. However I cannot understand why the 1st part shouldn't work out. Here is another example:  (From JEE Advanced 2015) Even here I could split it in 2 ways- (i) (ii) Here (i) is the correct way but (ii) isn't. I do not understand how either could be wrong or right. It Would really help if someone could point out what I am missing out. (Please Note: The spaces I have left between the dielectrics in my solution are just to illustrate how I split the system. They do not indicate real spaces.)


Predicting Clothing Size Ratios when different products have different size methodologies

For context, when a retailer buys in a clothing item they have to stock it in various sizes. The ratio of stock for each size is referred to as the "size ratio" of the product. E.g. S=0.2, M=0.5, L=0.3 I am looking to build a model that predicts the size curve ratio of sales at the end of the season based on data available at the start of the season e.g. historic sales data, product attributes. The data is structured so that on each line I have a product, product size, and the actual size ratio that sales accounted for in that size. The issue is that the data uses different size methodology depending on the product e.g. jeans might be in numerical sizes, but tops might be in S,M,L etc.  So essentially the model is predicting the size ratio for each line. I was thinking that I could take each product, look at the range of sizes, count them, then align them in the centre?  For example, product 1 has sizes S,M, L and product 2 has sizes 1,2,3,4,5.  I could align the M and 3.  However, I am unsure of how to get this to work.   Questions: How can I standardise the sizes?


Why does Vader think that Obi-Wan can "no longer help" Luke?

In Episode V, what did Vader mean when he told the Emperor:      Obi-Wan can no longer help him?    Help him in what way? Obi-Wan's Force ghost 'had been' helping Luke since the Battle of Yavin which happend 3 years earlier. Were Vader and Palpatine just ignorant of the fact that living Force-sensitives could commune with the dead?


Question about series rearrangement in Baby Rudin (theorem 3.54).

I have trouble following the following theorem in Rudin:  Let $\sum a_n$ be a series of real numbers which converges, but not absolutely. Suppose $$-\infty \leq \alpha \leq \beta \leq +\infty.$$ Then there exists a rearrangement $\sum a_n^\prime$ with partial sums $s_n^\prime$ such that $$\lim_{n\to\infty}\inf s_n^\prime = \alpha, \ \ \ \mbox{ and } \ \ \ \lim_{n\to\infty}\sup s_n^\prime = \beta. \tag{24}$$  Here's the proof:  Let $$p_n = \frac{|a_n| + a_n}{2}, \ q_n = \frac{|a_n| - a_n}{2} \ (n = 1, 2, 3, \ldots). $$ Then $p_n - q_n = a_n$, $p_n + q_n = |a_n|$, $p_n \geq 0$, $q_n \geq 0$. The series $\sum p_n$, $\sum q_n$ must both diverge.   For if both were convergent, then $$\sum \left( p_n + q_n \right) = \sum |a_n|$$ would converge, contrary to hypothesis. Since $$ \sum_{n=1}^N a_n = \sum_{n=1}^N \left( p_n - q_n \right) = \sum_{n=1}^N p_n - \sum_{n=1}^N q_n,$$ divergence of $\sum p_n$ and convergence of $\sum q_n$ (or vice versa) implies divergence of $\sum a_n$, again contrary to hypothesis.   Now let $P_1, P_2, P_3, \ldots$ denote the non-negative terms of $\sum a_n$, in the order in which they occur, and let $Q_1, Q_2, Q_3, \ldots$ be the absolute values of the negative terms of $\sum a_n$, also in their original order.   The series $\sum P_n$, $\sum Q_n$ differ from $\sum p_n$, $\sum q_n$ only by zero terms, and are therefore divergent.   We shall construct sequences $\{m_n \}$, $\{k_n\}$, such that the series $$ P_1 + \cdots + P_{m_1} - Q_1 - \cdots - Q_{k_1} + P_{m_1 + 1} + \cdots + P_{m_2} - Q_{k_1 + 1} - \cdots - Q_{k_2} + \cdots \tag{25}, $$ which clearly is a rearrangement of $\sum a_n$, satisfies (24).   Choose real-valued sequences $\{ \alpha_n \}$, $\{ \beta_n \}$ such that $\alpha_n \rightarrow \alpha$, $\beta_n \rightarrow \beta$, $\alpha_n < \beta_n$, $\beta_1 > 0$.   Let $m_1$, $k_1$ be the smallest integers such that $$P_1 + \cdots + P_{m_1} > \beta_1,$$ $$P_1 + \cdots + P_{m_1} - Q_1 - \cdots - Q_{k_1} < \alpha_1;$$  let $m_2$, $k_2$ be the smallest integers such that $$P_1 + \cdots + P_{m_1} - Q_1 - \cdots - Q_{k_1} + P_{m_1 + 1} + \cdots + P_{m_2} > \beta_2,$$ $$P_1 + \cdots + P_{m_1} - Q_1 - \cdots - Q_{k_1} + P_{m_1 + 1} + \cdots + P_{m_2} - Q_{k_1 + 1} - \cdots - Q_{k_2} < \alpha_2;$$ and continue in this way. This is possible since $\sum P_n$, $\sum Q_n$ diverge.   If $x_n$, $y_n$ denote the partial sums of (25) whose last terms are $P_{m_n}$, $-Q_{k_n}$, then $$ | x_n - \beta_n | \leq P_{m_n}, \ \ \ |y_n - \alpha_n | \leq Q_{k_n}. $$ Since $P_n \rightarrow 0$, $Q_n \rightarrow 0$ as $n \rightarrow \infty$, we see that $x_n \rightarrow \beta$, $y_n \rightarrow \alpha$.   Finally, it is clear that no number less than $\alpha$ or greater than $\beta$ can be a subsequential limit of the partial sums of (25).  I don't understand the last two lines of the proof (put in bold). I'm aware that this question was already asked on this forum, but I didn't understand the answers provided in this question, so that's why I'm writing my own question. Thanks in advance.


I can't figure out how to create shortcuts that don't care where they are mounted.  For example, on my flash drive, I want to run CCleaner or Notepad++ in my college classroom.  The problem is, a shortcut (at least with default settings) doesn't work reliably because it is tied to the same drive it was created on.  Is there a way to do something like in HTML?    Example:  Here is where the actual program is:  Root\Portable Applications\Program Data\CCleaner\ccleaner.exe   Here is where I want the shortcut to be:  Root\Portable Applications\CCleaner.lnk   U3/Portable Apps/etc is not the solution I am looking for  Edit: The Versions of Windows will be XP 32 bit, Vista 64 bit, and Vista 32 bit


Should I stir fry all my vegetables at the same time or do them one at time?

I want to stir fry broccolis, onions, mushrooms, and carrots. Should I do them all at the same time or separately because they might have different cooking time?


Expected value of x in a normal distribution, GIVEN that it is below a certain value

Just wondering if it is possible to find the Expected value of x if it is normally distributed, given that  is below a certain value (for example, below the mean value).


What's the process to propose a new tag? I see lots of Amazon related tags referring to specific products, and found that the CloudWatch tag is missing (and couldn't add it due to lack of reputation).


How can I share a directory with an another user?

I don't want the shared folder to be accessible by anyone on the system, I want it to be accessible just to a restricted set of users.  How to I do that?


Is there a way to use a previous TikZ picture?

Let's say I spend some time drawing this picture:    And after a few paragraphs I want to draw the same picture plus some "spices".  Of course I could just copy-and-paste the code, then edit the few things I want to change. But this turn the LaTeX code messy, as my figure repeats over and over!  Question  How could I use the previous code of a tikzpicture without copying it over and over?  NOTE: There is no caption!


How do I find out the kernel version I am running?

The path to previous driver is usually /lib/modules/<kernel-version>/kernel/net/wireless  I need this info so I can finish updating my STA Broadcom wireless. However, I'm a noob at Ubuntu and I'm not sure how to find the kernel version or kernel. I checked /lib/modules/ and found this: 2.6.27-10-generic  2.6.32-30-generic  2.6.32-34-generic  2.6.32-38-generic 2.6.27-7-generic   2.6.32-31-generic  2.6.32-35-generic  3.2.0-54-generic 2.6.28-19-generic  2.6.32-32-generic  2.6.32-36-generic  3.2.0-54-generic-pae 2.6.31-23-generic  2.6.32-33-generic  2.6.32-37-generic  Which one is the running kernel? Another question. Is there a snippet so I don't have to cut and paste? Thanks for your time! :)


Once I click to run minecraft a small window appears saying "Downloading runtime", then three other folders appear onto my desktop: Game, Native Log, and Runtime. This really annoys me, as I have to keep deleting them after I am done with a session of minecraft. Why is this? It never use to happen before.


Using refreshApex on button click in LWCs?

I have a save and a cancel, both triggered by a button click:  saveCriteria(){     let criteriaToSave = [];     //reassemble drill up/down fields on the criteria     for(let i = 0; i < this.tableData.length; i++){         criteriaToSave.push(parseObjectFieldsForDrillDown(this.tableData[i]));     }     //pass tableData to apex to save.     saveCriteriaUpdates({criteriaJSON: JSON.stringify(criteriaToSave), criteriaApiName: this.objectName})         .then(result => {             console.log(result);             return refreshApex(this.wiredResults);             //Show toast on success/error         }).catch(error => {             console.log(JSON.stringify(error));             //Show toast on error         }); }  cancelUpdates(){     return refreshApex(this.wiredResults); }   The refreshApex() works in the then callback of the apex method call on save. I see my debugs from my wire function after saving again.  But when I just click cancel, I want to refresh my data to its original state from the server to wipe out all changes, so want to do a refreshApex(). But in the cancel, the refreshApex does nothing. I don't see my debugs from my wire function. No debugs from the error part of the wire function... my table does not refresh back to its original state... nothing.   Is there some trick to refreshApex I am missing? It seems to work in an asynchronous callback, but not a direct call like my cancel button...  PS: My wire function and extra property for refresh looks like this:  wiredResults;  @wire(getSObjectsForTable, {stepId: '$stepId', objectApiName: '$objectName'}) getSObjectsForTable(result){     this.wiredResults = result;     if(result.data){         console.log(result.data);         this.tableData = getTableData(result.data);         this.tableColumns = getColumns(this.tableData, allColumns);     } else if(result.error){         console.log(result.error);         let toastEvent = new ShowToastEvent({             title: 'Error',             message: 'Error retrieving records: ' + result.error,             variant: 'error'         });         this.dispatchEvent(toastEvent);     }     this.tableLoaded = true; }


How to design capacitance value for a given full wave rectifier

I have been searching for design equations for 5v regulated power supply but unable to figure it out. Please check the below circuit diagram   Could anyone explain me why 470uf ? why not 2uf? how can we find out the capacitance value? when only Vrms is known? and also help me to understand the need for 0.01uf on both sides of 7805? Actually I want to connect this 5v output to 8051 micro controller. Any help is greatly appreciated.


Possible Duplicate:          I wonder which of the following is more polite:        Can you please change my email address?   Could you please change my email address?      The second one sounds to me as if the request is more urgent. So I would choose the first. But I heard that "could", "should", etc. forms are more polite forms of "can", "shall", etc. Is this true at all and if so, what is the underlying reason?


When we define trigonometric ratios using a right triangle then it denotes the ratio of its side but what does a trigonometric function of angle greater than 90° denotes in a unit circle ?


What's the purpose of 'taxonomies' parameter in register_post_type()?

As mentioned in :     taxonomies   () (optional) An array of registered taxonomies like category or post_tag that will be used with this post type. This can be used in lieu of calling  directly. Custom taxonomies still need to be registered with .   Default: no taxonomies   In my Custom Post Type (product) I'm also assigning two Custom Taxonomies with register_taxonomy() apart from the register_post_type(), and they are working fine. But there's a parameter in register_post_type() called 'taxonomies' where it's said to mention all the taxonomies in an array, but even without this I'm achieving what it's meant to:  'taxonomies' => array( 'product_categories', 'product_tags' ),   So, I wonder what's the purpose of this?


I want to make a combintronic proof for this. So far, I have we want to form a committee of k members with a president from n amount of people. Thus on the left side we can select the k members from the n amount of people and then select a president from there. How would I go about doing the Right side though?


Do you know how can I remove this unwanted software? Status line says copyright Acresso Software and or InstallShield. From the folder in ProgramData I understand it is version 11.


Show that $a_n=\sin(n)$ does not converge     My idea:  Take two subsequences: $a_{n_k}=\sin(\frac {\pi k} 2)$ , $a_{n_l}=\sin(\frac {2\pi l} 3)$  So: $\forall n$ : $\lim_{n\to\infty} a_{n_k}=1$, $\lim_{n\to\infty} a_{n_l}=-1$  So two inifinite subsequence converge to different limits thus the sequence $a_n$ doesn't converge.   Is that correct ?  Edit:   The contrapositive of the defintion of a limit of a sequence:   $\exists\epsilon>0 : \forall n\in N : \exists n>N \Rightarrow |x_n-L|>\epsilon$  Take $\epsilon =1$ and we know that $\sin(n)$ is bounded so lets take it's supermum: 1  $|1-1|>\epsilon=1\Rightarrow 0>1 \Rightarrow$ Contradiction.


Changing email address for the whole network

I'm able to change the email for Stack Overflow, but for login, it still asks for my old mail. Checking Network Profile > My Logins, the old email still appears. How do I fix this?  Furthermore, on the bottom of the question page, the email field for "Send me new responses to my posts via email" had a very old email.


How do you use the CSS content property to add HTML entities?  Using something like this just prints &nbsp; to the screen instead of the non-breaking space:  .breadcrumbs a:before {     content: '&nbsp;'; }