Can we use non-adaptive zero-knowledge proof in group signatures

Group Signature schemes are used to provide anonymity of the signers. During signature generation, signers provide a NIZK proof to prove that they are certified group members. Verifiers check whether the proof is valid during verification of signature. Can we use non-adaptive NIZK proof to prove signer is a certified group member?


How I can turn off the Two-Step verification, it's driving me crazy.  here is ICLOUD security settings from my MacBook Pro-2015   As you can see from the below pictures I don't have the option to turn off the two-Factor authentication.    Another screenshot of my ICLOUD's security


"Why didn't (or did not) somebody do something?" or "Why did somebody not do something?"

I was wondering which one is grammatically correct between "Why didn't (or did not) somebody do something?" and "Why did somebody not do something?"


I installed Ubuntu 12.10 on my computer and decided to go to Windows XP. I inserted the reinstall CD and it just says:     BOOTMGR Missing, click CTRL+ALT+DEL to restart.   The same thing happens with Windows 7. I'm assuming that the BOOTMGR needs to be restored/repaired but I don't know how to do that in Ubuntu. I've read many articles that say to insert the install CD and use the command prompt but seeing as I can't even load the CD that is a problem. So basically my question is, how do I replace/reinstall the BOOTMGR through Ubuntu?


Let's say we have a hydrogen atom in electric field. If the field is strong enough, electron will be separated from nucleus. How to determine the value of $E$ at which it happens?  To my understanding, field pulls electron with force $eE$ in one direction and proton with the same force to another. But how to determine the force holding them together?  EDIT: I am asking specifically how to calculate the value $E$ of external electric field which is "just enough" to ionize the atom.


How to print a float number without extra zero digits in C

When I print a float number with "%f", it prints a float with 6 digits, but I don't want to print extra zeros. I can to use for example "%.3f" to print just 3 digits, but I want to print a float with number of random digits ,and using "%.{number}f" is not my answer. for example in: #include <stdio.h> int main() {     float a, b;     printf("Please enter a number: ");     scanf("%f", &a);     printf("Please enter another number: ");     scanf("%f", &b);     printf("%f", a / b);     return 0; }  a/b can have even decimal digits. Of course, my question also applies to double and long double too.


How to add the layout.template_node_view into a Toolshelf Panel

I saw this toolshelf creation, and tried to figured out how he done that without copy all the code? Without succeed!    Is there an easy way to do this?   layout.template_node_view(ntree, node, input)  layout.template_node_view(???)  Maybe someone could help?


My jquery selector is not working when I used innerHTML in my page? can some tell what I have to do?

When I click on a link it works but when I click that link which is loaded with the help of of innerHTML then it works normally my jquery selector is not working at that time and link redirected to that link as usual some can tell what I should use?   $(document).ready(function() {  }); document.writeln("script load");``  $("a").click(function(e) {   //To prevent refresh   e.preventDefault();   console.log(e.isDefaultPrevented);   // Get the link in clicked anchor tag.   var link = $(this).attr("href");   console.log(link);   // Get that file in via ajax.   $.ajax({     type: "GET",     url: link,     success: function(data, status, xhr) {       history.pushState(data, document.title, link); //for pushing that page into history       document.querySelector("html").innerHTML = data; //change the page       }   }); });  // History handler window.addEventListener('popstate', function(event) {   console.log('popstate fired!');   updateContent(event.state); });  function updateContent(data) {   if (data == null)     return;   var full = document.querySelector("html");   full.innerHTML = event.state; } // very first page pushed into history. var soon = $("html").html(); history.replaceState(soon, document.title, document.location.href);


Configuring ArcGIS Desktop to use already installed Python instead of own installation?

Whenever ArcGIS Desktop is installed, it installs its own installation of Python 2.7 plus Numpy. Yet, I already have many different versions of Python installed in my machine and do not want to have ArcGIS' redundant new version of Python installed (nonetheless, in as a high-level folder as `C:\Python27').   How could I configure ArcGIS to use a Python installation that is already present in the computer somewhere else and then uninstall the one that comes with ArcGIS?


How to (safely) remove Ubuntu from Windows 7?

In case anyone is still reading this, I finally figured it out.  Install . Scroll down to the box that says "Noncommercial" and click register. You can enter your email, or use one at . After you've installed it, click the "BCD Backup/Repair" tab. Click the second option, Re-create/repair boot files, and hit Perform Action. Screenshot: i.imgur.com/9Bb3awL.png. It'll load for a few seconds and then disappear.  Restart your computer, and the GRUB screen should be gone. Boot back into Windows   Now you'll need to get rid of the extra partition space. Click the start button (Windows button in bottom left-hand corner) and right click the 'Computer' option on the right side panel. Select 'Manage' under the drop down menu. Computer Management should open up. Several partitions will be listed.  Two of these will be from Linux and the third will be Windows'. The two Linux ones will be white with no title. Right click both and select 'Delete' on the drop down menu. A popup will appear saying that the partition is used by another operating system and that it will be effected. Click Okay. Once you do this there will be a green square that says "X GB Free space". Right click it and select "Delete partition" on the drop down menu. Now the box is unallocated space. You'll need to extend the Windows partition to utilize this space. This time right click the Windows OS partition (not the unallocated space) and select "Extend Volume". A screen will be brought up; just click yes and skip through the menus and the Finish button.  Now the box should change to reflect that this space is now apart of Windows. You can double check by going to the start menu and clicking 'Computer' on the right. Your C: should now include that space.  Hopefully this helps someone out there. Credit goes to Jeremy Matthews' "How To: Remove Ubuntu from a Dual Boot Computer" video.  Note: This won't affect anything (files, etc.) currently on your Windows system. Backup anything of importance on Linux, though.  This method also doesn't require an installation CD, since I was getting continually frustrated that everything was saying that I needed one to fix it (I don't even own one).


How to compute effect sizes (cohen's d) for lmers in R?

I need to calculate effect size from linear mixed model coefficients. I am not entirely sure how to do this and some of the readings I've found are not helping me understand this. Can anyone shed some light on this process? Below is the code for my linear mixed model. Thanks for any help!  p1 <- lmer(dv ~ IV1 * IV2 +           (1 + IV1 | subj),        data,        control = lmerControl(optimizer = "bobyqa"))


I create some models for 3D-printing, and as are several cm large I use scaling 0.01 (1 cm). Then I convert the result to .stl and pass it to Slic3r to create .gcode. What I expect is scaling back by *100 will give me the correct result. However, in that case I get models 10 times smaller, and scaling by *1000 does the job. I wonder if I don't understand smth or it's a bug of either Blender or Slic3r. So, it this a bug? How to check if it's because of Blender of Slic3r?


I was going through fluid dynamics and I came upon this section on the shape of a liquid surface in a rotating cylindrical vessel. The working in the book is something like this:   It considers a mass $m$ of water on the surface of the rotating liquid at a distance $x$ from its axis of rotation .It takes into account a pseudo force ($m \cdot x \cdot \omega^2$) radially outwards and its weight force ($mg$).It then proceeds to calculate the net force and the angle it makes with the vertical.From there through basic integration it gets the equation of the surface of liquid  i.e. $y= \dfrac{(x^2 \cdot \omega^2)}{2g}$ .  I get this working.  But if I were to view the same rotation through an inertial frame,how would I proceed? I mean, there wouldn't be any pseudo force, rather a centripetal acceleration of same magnitude radially inwards.This is where I am facing certain doubts.  The forces on the liquid would be  the centripetal force inwards and the weight force downwards.The net force would therefore be in a different direction,and consequently the slope of the surface at that point would be in a different direction.How is it possible for the same surface to have two different shapes in two different frames?   I would be obliged if someone could help me out by pointing out the flaw in my understanding.


I was caught cheating in my exam, how should I deal with it?

Since High School, I have cheated a lot in exams. But in college it became a habit and I developed successful ways of doing it, without getting caught throughout first and second year. But I eventually got caught, and I feel horrible about it, it was the most humiliating thing ever, but I guess karma comes to us all.  A lot of the other students know that I've cheated a lot throughout the course and lost respect for me, so they'll be happy now. This time, I cheated in the same way that has worked a lot for me in the past. I recorded full essays on my phone, put it in my pocket with earphones hidden up my jumper and sleeves, and I rested my head on my hand with the earbud in my ear, listening to the recorded material. I knew early on that this invigilator was more wary of my body language than any others have been before, she was a lot younger than any others and probably more alert about technology. I became a bit unsettled, and she noticed that as well. When the first essay finished, I put my arm down and she immediately came over to me and investigated me. My major mistake this time was that, instead of putting my phone in my pocket and covering the wire with my jumper, I had it between my legs with the wire sticking down the middle of my trousers. She saw the wire, bent down and pointed at it asking 'what's this?' then rolled up my sleeve and found the ear socket inside. I was busted, so I gave her my phone and earphones, then she took my paper of me and gave me a new one to restart. It wasn't subtle, the whole class knew about it and I saw a lot of them turning around to look at me. She then phoned her invigilator boss and told her about it to make sure she handled it correctly, and she said clearly 'I just caught a student cheating' in front of everyone. I just sat there for the rest of the time, not knowing anything because I didn't study for it, and wrote a letter to the marker about it. At the end, everyone left the room staring at me while she took a photo of the evidence.  I burst into tears when I was left with the invigilator on my own, and she told me to speak to my tutor. He told me that I'd fail the module, and I emailed the programme leader about it, who said he would wait for the invigilator's report. I think I'm going to have to go through a disciplinary hearing, but I have to protect myself. I can't admit that I've cheated in just about every exam in the three years I've been there, I'll have to say that this was a one off thing because of personal problems and lack of preparation.  But it's not a good feeling having a conscience guilty of such dishonesty, and more lies to tell. I can't get expelled from the course, because I want to get my degree, but I'll deal with failing the module and having a disciplinary record.  Am I just an evil person by nature? I know I don't deserve to be on the course having not been caught so many times, yet I'm doing everything I can to stay. A lot of people say honesty is the best policy, but I don't believe that is true within the business of living and getting success.  Also, how will a disciplinary record affect my future? Will employers/other education institutions know of it after I leave?


Why are atoms so different from one an another?

An atom is composed of a positively charge nucleus, with a cloud of electron(s) around it. But I can seem to understand the huge differences between 2 components that seem so close in terms of what they are made of.   I don't understand why adding one or 2 electrons, neutrons or protons, to get an other element, completely changes the behavior of said component.


Using Unity/Unreal as graphic engine while programming the game externally

My favorite language is C++ and I feel most comfortable to stick to it.  I made a game in C++ primarily using the console output as a graphical interface: somewhat like that of dwarf fortress.   However I wish to connect my game to either Unity or Unreal so that I can take advantage of their graphic rendering.  Is it possible? Running a game on other program while separately running an application on Unreal or Unity for rendering purpose? Or should I just make a game from ground up on Unreal or Unity?


I heard an advice once to level up your gear before dismantling to produce more parts and materials. From my subjective experience this seems to work more or less with rare items, though I can't say for sure.  As I care most for Ascendant Shards and other top-level materials, the question is mainly about legendary gear. So basically what I'm asking is this: is there a difference in material output between these options:   Dismantle item right away; Level up item before dismantling, but without actually upgrading it; Level up item and upgrade (buy) it's skills before dismantling;   I can't seem to find any concrete info on this, and don't have enough legendaries to experiment yet (the ones from Queen don't produce Shards).


A group that needs to be proven by definition?

Let X be a set and let $P(X)$ denote the set of all subsets of X, that is $P(X)=   \{A|A\subseteq X\}$. given $A,B\in P(X),$ define $A \triangle B:=(A\setminus B)\cup(B\setminus A)$.      Prove that $(P(X), \triangle)$ is a group.    Using the definition of a group I assume I have to show that there exist an associativity, identity, and inverse.


Preventing NullPointerException error on empty result set returned in JDBC

I need advice on how I can avoid java.lang.NullPointerException when dealing with JDBC result set which I put on Swing components such as JTable  I have written a method which gets the result set encapsulated in an object from a DAO Implementation which I populate inside a DefaultTableModel.  The problems is, the object returned by the dao implementation service may or may not have data/result set if the database table has no record yet.  This results to a NullPointerException  public DefaultTableModel getMiscellaneous(int gradeLevelId){         DefaultTableModel defaultTableModel = new DefaultTableModel();         String[] columns = {"Name","Amount"};         MiscellaneousFees miscellaneousFees =  schoolFeesDaoImpl.getMiscellaneous(gradeLevelId);         List<Fee> feeList = miscellaneousFees.getFees();         for(Fee fee: feeList){             Object[] rowData = {fee.getName(),fee.getAmount()};             defaultTableModel.addRow(rowData);         }         defaultTableModel.setColumnIdentifiers(columns);         return defaultTableModel;     }  public MiscellaneousFees getMiscellaneous(int gradeLevelId) {         MiscellaneousFees miscellaneousFees = new MiscellaneousFees();         List<Fee> feeList = new ArrayList<>();          String SQL = "{CALL getMiscellaneousFeesByGradeLevelId(?)}";         try (Connection con = DBUtil.getConnection(DBType.MYSQL);                 CallableStatement cs = con.prepareCall(SQL);){             cs.setInt(1, gradeLevelId);             try(ResultSet rs = cs.executeQuery();){                 while(rs.next()){                     SchoolYear schoolYear = new SchoolYear();                     schoolYear.setSchoolYearId(rs.getInt("schoolyear_id"));                     schoolYear.setYearFrom(rs.getInt("yearFrom"));                     schoolYear.setYearTo(rs.getInt("yearTo"));                     schoolYear.setIsActive(rs.getBoolean("isActive"));                     schoolYear.setStart_date(rs.getDate("start_date"));                     schoolYear.setEnd_date(rs.getDate("end_date"));                     schoolYear.setIsCurrentSchoolYear(rs.getBoolean("isCurrentSchoolYear"));                      GradeLevel gradeLevel = new GradeLevel();                     gradeLevel.setId(rs.getInt("gradelevel_id"));                     gradeLevel.setLevel(rs.getInt("grade_level"));                     gradeLevel.setIsActive(rs.getBoolean("isActive"));                      FeeCategory feeCategory = new FeeCategory();                     feeCategory.setCategory(rs.getString("fee_category"));                     feeCategory.setId(rs.getInt("fee_category_id"));                      Fee fee = new Fee();                     fee.setId(rs.getInt("fee_id"));                     fee.setName(rs.getString("fee_name"));                     fee.setDescription(rs.getString("fee_description"));                     fee.setAmount(rs.getDouble("fee_amount"));                     fee.setFeeCategory(feeCategory);                     fee.setGradeLevel(gradeLevel);                     fee.setSchoolYear(schoolYear);                     feeList.add(fee);                 }                 miscellaneousFees.setFees(feeList);             }         } catch (SQLException e) {             JOptionPane.showMessageDialog(null,e.getMessage());         }         return miscellaneousFees;     }   Any suggestion or advice of how I can prevent the NullPointerException when result set contained in the miscellaneous object is empty?  I get the NullPointerException error in this line of code   MiscellaneousFees miscellaneousFees =  schoolFeesDaoImpl.getMiscellaneous(gradeLevelId);   Thank you.


What is the "gratitude" at the end of the letter or post called?

What is the "gratitude" at the end of a letter or post called in English?  For example:  Hi everyone,      <--- salutation  bla bla bla       <--- body  Thanks in advance <--- what is that called?


Showing $\prod\limits_{i<j} \frac{x_i-x_j}{i-j}$ is an integer

Let $x_1,...,x_n$ be distinct integers. Prove that  $$\prod_{i<j} \frac{x_i-x_j}{i-j}\in \mathbb Z$$   I know there is a solution using determinant of a matrix, but I can't remember it now. Any help will be appreciated.


how to recover from a freeze without rebooting?

What alternatives are there to REISUB for  system problems?  The windows task manager has its good points in this regard.  Or, key combination to logout.  It's not always possible to get to a virtual console.  Some combination to just logout would be my preference.  Or kill the window system and revert to CLI.   but a reboot.  But how do you then recover?


Mutual Independence Definition Clarification

Let $Y_1, Y_2, ..., Y_n$ be iid random variables and $B_1, B_2, ..., B_n$ be Borel sets. It follows that  $P(\bigcap_{i=1}^{n} (Y_i \in B_i)) = \Pi_{i=1}^{n} P(Y_i \in B_i)$...I think?  If so, does the converse hold true? My Stochastic Calculus professor says it does (or maybe misinterpreted him somehow?),  I was  the  that independence of the n random variables was equivalent to saying for any indices $i_1, i_2, ..., i_k$ $P(\bigcap_{j=i_1}^{i_k} (Y_j \in B_j)) = \Pi_{j=i_1}^{i_k} P(Y_j \in B_j)$.  So, if the RVs are independent, then we can choose $i_j=j$ and k=n to get $P(\bigcap_{i=1}^{n} (Y_i \in B_i)) = \Pi_{i=1}^{n} P(Y_i \in B_i)$, but given $P(\bigcap_{i=1}^{n} (Y_i \in B_i)) = \Pi_{i=1}^{n} P(Y_i \in B_i)$, I don't know how to conclude that for any indices $i_1, i_2, ..., i_n$ $P(\bigcap_{j=i_1}^{i_k} (Y_j \in B_j)) = \Pi_{j=i_1}^{i_k} P(Y_j \in B_j)$, if that's even the right definition.  p.17  seems to suggest otherwise. idk  Help please?  Also this:    or    So, this answer is to use the Omega part to establish pairwise independence and ultimately conclude independence. Without that assumption, we cannot conclude independence. Is that right? Why does that not contradict the definition of independence: $P(\bigcap_{i=1}^{n} (Y_i \in B_i)) = \Pi_{i=1}^{n} P(Y_i \in B_i)$ ?


What is the meaning of "Put together 'f****ing sh*t' ~" in the following sentence?

What is the meaning of "Put together 'f****ing sh*t' is ~" in the following sentence?      Put together 'f****ing sh*t' is stuff that really bothers, angers, or disgusts you.   (Source: )   Does it mean "That we put together 'f****ing sh*t' is stuff that really bothers, angers, or disgusts you"?   There is another verb (->is) after the sentence that starts with the verb(->Put).   2. Is it grammatically correct?


Why is it disproportionately difficult to delete an account but easy to create one?

I have used this site for many years and personally have had my Stack Overflow account deleted twice. During the times I did/do not have an account, I'm more of a lurker. However one of the things that has irked me is just how easy it is to rack up accounts on the Stack Exchange network. While I understand that ease of registration and network integration is one of the goals of the website, the amount of time it takes to create an account (maybe a few clicks) is disproportionately less than the amount of time it takes to delete an account.  The question  seems to suggest the only way to delete all of the accounts is to go to each site, fill out the request form, and follow the procedure. This is (IMO) simply ridiculous as I don't want to follow the steps (which IIRC waiting for support to contact you, doing an activity to confirm your identity, and e-mailing them back) for every account.  The fact that I may continue to "use" the site (visit, lurk whatever) does not imply I want an account or want it to be easy to make an account, because then I'm back to square one. I'm not going to lie when I say this site is addicting and I find it depressing how high the barrier is to kick the addiction.  I am not criticizing the individual deletion procedure, but merely asking why there's a lack of a network-wide procedure. It smells like [citation needed] to me. Is there an official explanation for this or a compelling argument for why this is a good idea?


Understanding the "$\pi$" of a rotating disk

Let us say you are in an inertial reference frame with a circular planar disk. If you take your meter measuring rods (or perhaps tape measure) you can find the diameter and circumference of the disk. If you divide the circumference by the diameter, you will get exactly $\pi$. Now you start rotating the disk. A book I have claims that now the ratio will be different (lets call it $\pi_\circ$ to avoid ambiguity.) This has caused to reevaluate my understanding of special relativity (this is a set up to general relativity, but the problem itself only requires the special theory.) My problem is that, sure, the measuring rods (or tape) would contract on the circumference, but wouldn't the circumference contract a similar amount, therefore giving a measurement of $\pi$ in every reference frame according to your own measuring rods. Of course, this reasoning goes on to make me question how I understood all of special relativity up this point.


how to insert the name of the file in the text?

I´m making bigwork-096.tex  The source of that file is  \begin{document}   This source is very big.\\   The name of this file is **????????** \end{document}   What I must type instead ??????  to obtain the PDF with this result  This source is very big.\ The name of this file is bigwork-096.tex


Some windows don't fit on 1024x600, what can I do?

I read on  that the netbook edition of Ubuntu was discontinued and that it is now integrated into the main distribution (as of 11.04).  I tried 11.04 on my new Samsung NC110-A06AU with 10.1" 1024x600 display. Most things worked out of the box, but some (like backlight power control) needed some  before they began to co-operate.  One thing that seems to be an ongoing problem is the resolution.  At 1024x600, most of the dialogue boxes run off the bottom of the screen, including the update manager. I have tried 11.10 beta 1 and it has the same problem.  Is there any way to fix this, or at least make it more usable? (I suspect not). Given the recent rise in popularity of netbooks, do you think Ubuntu will include a low-resolution-friendly version in the near future?  How well does KDE deal with these low resolutions? I noticed KDE Plasma has a netbook interface. Is it worth switching for that?


Applying for a B2 visa after previous overstay as a child?

Background:  So I was brought into the US under the visa waiver program as an 11 year old child in January 2000. I voluntarily left the country on Sept. 2009 when I was  20 years, 9 months, and 3 days old.  I visited America twice since I left in 2009 under the ESTA VWP -  Once in June 2012 and another time in July 2014 via the Visa Waiver (ESTA) program with no problem. On Oct 2nd 2014 I came to visit my brother for his birthday and I was refused entry because of my previous overstay as a CHILD but given Parole to Depart for the duration of my holiday (so I still got to go on vacation.)  The guy told me that I could apply for a B2 visa when I get back to London but I would have to also apply to get my overstay waived. He said I would need to get my overstay waived at the same time as I apply for my visa. My older brother who is a US citizen (by birth) has put a petition for me to become a citizen a few years ago.  My Question:  I've filled in the B2 Visa application. I've disclosed the details above as it would definitely come up in the interview. My question is - is there a specific application that I would fill out to ask to get my overstay waived? Or is that something that is at the discretion of whoever I am talking to?  I'm asking this before I book my interview - thanks a lot.


Please, I have used rm * in a script shell, it deleted all my files? (a typo)  Is there a solution to recover these files ?


Limit point of the set $G= \{1/n: n \in \mathbb N\}$?

In $\mathbb{R}$ , what is the limit point of the set $G= \{1/n: n \in \mathbb N\}$?  Definition:  A point $p \in X$ is a limit of of E if every neighborhood of $p $ contains a point $q \in E$ $q\neq p$  I do understand $0$ is a limit point but shouldn't it be the case that all the points in [0,1] are limit points by the definition?


It hasn't explicitly been taught to me what the rules are after speech, especially regarding capitalisation.   "Hello?" called June to the yellow figure. "Hello?" Called June to the yellow figure.   I'm pretty sure #1 is correct, but should the second one be corrected?


I think we should be able to retract NAA and VLQ flags.  makes a good case for that: the original post should've been a comment (when I raised the NAA flag), but it was later edited to be a real answer. Since I raised the flag, I think I should be able to retract it the same way I can a close vote.   It can help shorten the queues It helps users maintain a good flagging record   Like retracting a close vote, or after raising a NAA or VLQ flag now, a user could not raise the same type of flag again for the same post -- only spam, offensive, and custom-reason flags would be permitted.  EDIT:  I've also had cases where I'd like to retract a custom-reason flag. This may be even more valuable queue-shortening-wise.


If $\frac{X+Y}{\sqrt{2}}\stackrel{d}{=}X\stackrel{d}{=}Y$, use the CLT to show that $X,Y\in N(0,1)$

(a) Suppose that $X$ and $Y$ are i.i.d. $N(0,1)$. Show $\frac{X+Y}{\sqrt{2}}\stackrel{d}{=}X\stackrel{d}{=}Y$.   (b) Conversely: Suppose $X$ and $Y$ are i.i.d. with mean $0$ and variance $1$, and suppose further that \begin{equation*} \frac{X+Y}{\sqrt{2}}\stackrel{d}{=}X\stackrel{d}{=}Y \end{equation*} Show that both $X$ and $Y$ have a $N(0,1)$ distribution. (Use the Central Limit Theorem)  I have solved part (a) as follows: (a) Since $X,Y\in N(0,1)$, we have that: $\phi_X=\phi_Y=\exp\big(\frac{-t^2}{2}\big)$, thus: \begin{align*} \phi_{\frac{X+Y}{\sqrt{2}}}&=\phi_{\frac{X}{\sqrt{2}}+\frac{Y}{\sqrt{2}}}\\ &=\phi_{\frac{X}{\sqrt{2}}}\phi_{\frac{Y}{\sqrt{2}}} \quad\text{by independence}\\ &=\phi_X\big(\frac{t}{\sqrt{2}}\big)\phi_Y\big(\frac{t}{\sqrt{2}}\big)\\ &=\exp\big(\frac{-(t/\sqrt{2})^2}{2}\big)\exp\big(\frac{-(t/\sqrt{2})^2}{2}\big)\\ &=\exp\big(\frac{-t^2}{4}+\frac{-t^2}{4}\big)\\ &=\exp\big(\frac{-t^2}{2}\big)\\ &=\phi_X=\phi_Y\\ &\iff \frac{X+Y}{\sqrt{2}}\stackrel{d}{=}X\stackrel{d}{=}Y \end{align*} but I am stuck on part (b). In particular, I am not sure how to bring the CLT into it, any help would be greatly appreciated.


How to restore TF2 item server connection?

Occasionally I will get a message from TF2 about being unable to connect to the item server, and I will be stuck with a pure stock loadout.  What is strange is everyone else on the same server will have all of their items.  How can I restore the item server connection?  It must be a problem on my end - if the item server were down, everyone else should be using stock loadouts with no hats as well.  Note: I know about the heartbeat console command.  That is for servers, not clients and does nothing for me.


How can I make a button in a panel that runs a custom script that I have already written

I have written a few scripts, some are over 8000+ lines. How would I put these in a tab and link a button to those scripts. All I could find on the internet was how to run basic stuff like put down cubes but not how to make a button run an already written script.


How to use chapter number in algorithm numbering in Latex

I am using the algorithmic and algorithm2e package to write the algorithm. I want to use the chapter number in algorithm number. for example for chapter number 3 the first algorithm should be 3.1 and so on.  This can be achieved in algorithm package as  \usepackage[chapter]{algorithm}   How to do this for algorithmic and algorithm2e package.


How can I resolve the error “cannot execute binary file”?

I'm trying to test my installation for  on my Mac for the first time  and when I put in: pk2cmd -?v I get:  -bash: /usr/local/bin/pk2cmd: cannot execute binary file   How do I resolve this problem?


"Before" the Big Bang was the Universe really compressed into a mathematical point?

A couple of weeks ago a teacher of mine (I'm taking mathematics) was giving a final inspiring lecture about how fundamental Math is to every possible universe. During the lecture though, he said that what the current physics theories tell us is that the Universe originated from a point. Not a really small point, but an actual mathematical point, one with 0 dimensions. I've heard the concept of a singularity before, but even in theory, can it happen in Nature?  EDIT: My question is not the same as . I'm not interested in how the Universe expanded, I want to know if the Universe was compressed into an actual point.


How choreographed/scripted is wrestling?

Let me start by saying that I know nothing about the big wresting leagues I see on American TV, I've seen them on a couple of times. A couple of things strike me:   Some of the "moves" they do are potentially very dangerous, this implies that the wrestlers have at least some understanding of the moves which are coming and how they can avoid becoming seriously injured. There is certainly amateur wrestling around which is a serious competitive sport therefore there must be some improvisation/competition.   When we watch a big wrestling match on the television with the top wrestlers how choreographed is the fight (for safety and entertainment reasons) and how much is genuine competition (like boxing)?


Images within nested lists can overflow outside of the post cell

This was originally noticed  but some quick checks show that this is not an issue exclusive to GD.SE. It occurs in both questions and .  Here's a Demonstration:   List             Image credit


How do I completely download a web page, while preserving its functionality?

I've been trying to save  webpage using all of the methods that I know, but none of them have worked so far. The website itself has some great functionality. It is able to render MathJax in realtime, without any noticeable lag. I want to be able to use it offline, so I wanted to save it. I haven't been very successful. I'm on MacOS. Here is what I have tried so far:   Save as on Safari as a Web Archive (.webarchive) – doesn't preserve the page's functionality Save as on Safari as Page Source (.html) – Completely messes the page up HTTrack – doesn't preserve the webpage's functionality Save as on Chrome as Webpage, Complete (.html) – messes up layout and functionality WebDumper – gives me a "Forbidden" error itsucks – messes webpage up SiteSucker – messes webpage up ScrapBook (firefox) – messes up A couple of other things that I can't remember anymore.   I just want to save the website and be able to use it offline. I noticed something interesting, however. When I'm in Safari and I go offline, the webpage performs fine. This undoubtedly means that the webpage can run offline with no problem – I just need a way to save it properly. I suppose I could create a virtual machine, load up the site on it and then save it as a snapshot and use it whenever I want to offline, but that seems like quite a disproportionate solution for such a seemingly simple problem.  On a side note: would it be possible to save a webpage like  (iPhone 6S page) with all of the scrolling animations, embedded pictures and videos and all the rest? I've only tried creating a Web Archive using Safari, but it only saved the nice scrolling animation – not the embedded pictures and such.


Here is what it looks like (two regular png images which previews were working fine before I upgraded to Mojave). Third one is a folder with custom picture and it was like that on High Sierra too. About the filenames, I like using spaces but using anything else don't change anything.    Here is what I've tried:   Right click on Desktop, then "View options" -> "Show icon preview" (disabling/enabling it doesn't change anything) Restart computer Restart Finder I don't see anything in system.log I couldn't find much in "Console" in general I also tried to mess with the IconServiceAgent (, )   Thanks for the duplicate suggestion, I found this is Console when starting iconserviceagent manually (either root or not):  iconservicesagent[20837]: assertion failed: 18A391: libxpc.dylib + 39253   Finder[870]: objc[870]: Class FIFinderSyncExtensionHost is implemented in both /System/Library/CoreServices/Finder.app/Contents/MacOS/Finder (0x10a018b80) and /System/Library/PrivateFrameworks/FileProvider.framework/OverrideBundles/FinderSyncCollaborationFileProviderOverride.bundle/Contents/MacOS/FinderSyncCollaborationFileProviderOverride (0x10e74ddc8). One of the two will be used. Which one is undefined.


How to install google chrome to watch netflix in ubuntu?

I tried to install google chrome for ubuntu users from my Firefox web browser, but that did'nt work


I'm not sure if this is a duplicate question (I can't find anything like it), but I've tested using the == operator on 2 separate strings with the same value in 2 different IDEs and both have worked? I'm especially confused with this snippet of code:       public static void main(String args[]) {         String s1 = new String("aaab");         String s2 = new String("aaa");         System.out.println(Integer.toHexString(s1.hashCode()));         System.out.println(Integer.toHexString(s2.hashCode()));          s2 += "b";         System.out.println(Integer.toHexString(s1.hashCode()));         System.out.println(Integer.toHexString(s2.hashCode()));          Boolean b = s1==s2;         System.out.println(s1==s2);         System.out.println(b);         if (s1.equals(s2)){             System.out.println("this works");         }     }   (sorry if my formatting kinda sucks) For me, the console output is  2d9041 17841 2d9041 2d9041 false false this works   (I know the memory addresses might be different for different people, the point is the similarity between the two) This output doesn't make sense to me? Shouldn't s1==s2 return true because the memory addresses are the same? Is this an OS/Windows thing? Or an IDE thing? Sorry for the long question and thank you for any answers


How to solve $\left(1+\frac{1}{n+2}\right)^{n+2}\geq \left(1+\frac{1}{n+1}\right)^{n+1}$ for all $n\in \mathbb{N}$

any impulses, suggestions? I have been trying for a while but it doesn't get me anywhere...  Kind regards


Let $X(t) = \left[\begin{matrix}a(t) & b(t) \\c(t) & d(t)\end{matrix}\right]$ and let $U$ be a nonsingular matrix. How do you solve $$\frac{d}{dt} X(t)=UX(t)$$ I presume there is some general method to solve these kinds of ODEs but I cannot find anything about it, online.   BTW: -----------------  I know that you can get 4 ODE equations for the four unknown functions of $t$. The problem is that each ODE equation includes other functions as so $$\frac{d a}{d t}=u_{11}a+u_{12}c$$


I just baked a batch of chocolate chip cookies (). I felt like they were just a tad bit on the sweet side, so wanted to know if there would be any negative consequences from reducing the sugar? (like 1/2-3/4 of the sugar in the recipe) Would the cookie not bake as desired or something like that?


Travelling in Schengen area while waiting for permit of stay renewal in Italy

I am a non-European living in Italy. Currently, my permesso di soggiorno has expired and I have applied for a new one. However, I need to go to another Schengen country for a job meeting before I get my permesso di soggiorno. Do you think if it is possible for me to get a temporary permit to travel in Schengen area from the Questura office in my city if I supply my claim with proper documentation?  Thanks for the help.


Precision problems with realistically scaled planets/terrains

Recently I've been working on a realistically scaled planet engine. I found several interesting links about how to do it, what problems will come up after, and how to solve them. The approach I took was the one I found on many articles: Use 6 quadtrees, one for each faces, then transform the cube into a sphere.  My quadtree logic seems to be working, I tried it on a flat terrain and on a sphere ( with reasonable distances ), and it worked great, then I tried with bigger distances.  The first problem was z-fighting, fixed using a logarithmic depth buffer (  ). The second was floating point precision on big numbers.  I read two main approaches to fix it. The first one is to use doubles instead of floats for operations, and give the gpu every positions relative to camera space. The second was to use different spaces in different units ( object space in meters, planets space in kilometers, solar system space in AU, etc... ). While the second was encouraged by many people, I took the first one because it seemed easier to do. I plan to try the second in the future anyway.  The first approach worked on flat terrains because it was easy to compute the position relative to the camera ( centerOfNode - cameraPos ). One bug I still have with it is about height. I use 3D simplex noise on the gpu, which works in float and needs a vec3 input. With relatively small distances, the worldspace position works great. With huge distances, the worldspace position doesn't work when far from the origin, the pattern is very odd because of missing precision. And of course, it won't work with cameraspace position as input. I haven't find anything about that. Something I will try tomorrow is the second approach above. That is, define several spaces with different units, transform the position in each of the spaces, and use each of them as input for the simplex noise function, which will give me several textures I will be able to use for scale. I don't know how I will do in details, but I think it won't work since transform from the lower to the high space might result in floating points errors right? I could dynamically create vertices in the CPU using simplex noise with double precision but it doesn't sound right... I'd like to use the GPU as much as possible, unless I have no other choices.  Second problem I have is with spherical terrains this time. So my steps to get the planet are:  1) From the quadtree nodes, scale, rotate and translate an unit quad to his position in the current plane of the 6 quadtrees  2) normalize it to get the normal  3) multiply the radius to get a sphere at sea level  4) add the height  Since the first step is related to the origin of the planet, even in view space it will require operations with huge numbers ( the radius ), so I am not sure how I can avoid precision problems here... Again, I could create them on the CPU and send them to the GPU, but this sounds exhausting and I don't want to do it unless I have no other reasonable choices. I would gladly use the second solution ( several spaces ) if I had an idea of how to fix it with it, but I'm not sure how to do it...


Transit through Stockholm (Schengen) from Beijing to Ukraine?

I have residence ID in Ukraine (out of Schengen) and I want to travel from Beijing airport.    My flight has 6 hours connection in Stockholm.  Do I need a (transit) visa?


What does different focal length offer me?

I have a beginner photographer and I have spent a lot of time learning the basics (exposures, lenses, focal lengths, crop factor etc). It's all good except I'm not so sure when I need to buy lenses of different focal lengths.   With a short focal length (a lens like ), I can still use it to take landscape. It doesn't mean I can't take photo of things that are far away from me. So unless I need magnification why would I need any other lens?   Also, I read that for portrait lens I really want focal length of 80-85mm but again wouldn't I be perfectly fine to take portraits with the lens above?


Prove that if $\gcd(a,c)=1$ and $\gcd(b,c)=1$ then $\gcd(ab,c)=1$. My attempt is let $\gcd(ab,c)=d$. Since $d \mid ab$ and $d \mid c$ , $d \mid (abt+cs)$ for some integers $s$ and $t$. Then by definition of divisibility, we have $$abt+cs=dk$$ for some integers $k$. Then I got stuck here.


How to know if someone is downloading torrents in my wifi network

My internet connection is very slow. I suspect someone in the network is using a BitTorrent client which takes huge amount of bandwidth.  Is there a way to detect who is using my bandwidth (network sniffing tools etc)?  I should have pointed out that I have no access to the router, what I am looking for is a way of detecting someone's MAC/IP if she uses Bittorrent.


HTTP -> HTTPS script didn't change everything

In 2017 the network decided to implement the HTTPS protocol, as was announced in . Although that post isn't completely marked as  I think most, if not all, of that came through. During that process there was a script that converted all links in posts from HTTP:// to HTTPS://, as you can see in the screenshot below (freehand circle mine).  Was this intended behaviour? EDIT: I wrote a  to have the community user change these links as an answer to the original announcement.


After an English class on the subjunctives, I am now confused about the usage of "would".  The definition provided for "would":     (expressing the conditional mood) indicating the consequence of an imagined event or situation.   Before the class, I would typically say something like "I'm sure that would happen."  But come to think about it now, how could you be sure if the consequence is imaginary?  My questions are, instead of saying "that would happen" in the sentence, should I use "that will happen"? And is the original sentence grammatical?  Edit: I'm not asking about the general usage of "will" and "would". I guess my question is more about the combination of word "sure" and "would" since the definition confused me in the first place. So I really don't think my question is a duplicate.


Why are there exceptions for the i before e except after c rule?

The exceptions such as"foreign" and "weird" seem abnormal to me because most of the rest of the ie or ei words follow the i before e rule.  They don't have a "c". Why does that happen?


Is it wrong to use the "==" operator when comparing to an empty list?

PyCharm (4.0.6) complains when I do a comparison to an empty list using the == operator, but it doesn't when I use the is operator:    I guess this is something related to PEP 8, but the problem is that when I use the is operator, as PyCharm suggests, I have a false negative. Here is a simple example in iPython shell to show that in this case the == operator seems more appropriate, since the is operator returns a false negative:  In[2]: actions = [] In[3]: actions == [] Out[3]: True In[4]: actions is [] Out[4]: False   Could someone please explain why PyCharm complains about the == operator when comparing to an empty lists? Am I doing something wrong according to PEP 8?


I thought the universe was finite, but then I read this:    And they seem to assume it is infinite. So which is it?


Can you set a file's ctime to min(ctime, mtime)

We know that the mtime of a file can be earlier than the ctime when you make copies of files (or, in my case, move files between file systems without successfully retaining timestamps).  I see many web search results on how to copy the ctime to the mtime (using touch), but not vice versa.  In the below example, I want the file WXBR.m4b to show it as created in 2014, not 2019. Can this be done?  $  stat WXBR.m4b   File: 'WXBR.m4b'   Size: 370988549       Blocks: 724592     IO Block: 4096   regular file Device: 851h/2129d      Inode: 13          Links: 1 Access: (0755/-rwxr-xr-x)  Uid: ( 1000/sarnobat)   Gid: ( 1000/sarnobat) Access: 2019-08-07 20:40:00.300216369 -0700 Modify: 2015-07-05 19:07:38.752375000 -0700 Change: 2019-08-08 15:37:05.511788978 -0700  Birth: -


I'm having trouble finishing a problem on an old national competition.  As the title states, the question says asks:  Given $a,b,c \neq 0,a+b=c$ such that $\frac{1}{a}+\frac{1}{b}+\frac{1}{c}=\frac{1}{a+b+c}$,  Find all integers $n$ such that $\frac{1}{a^n}+\frac{1}{b^n}+\frac{1}{c^n}=\frac{1}{a^n+b^n+c^n}$.  I know that if it is true for $n$, it is also true for $-n$ since $(a^n+b^n+c^n)(\frac{1}{a^n+b^n+c^n})=1$ and $(a^n+b^n+c^n)(\frac{1}{a^n}+\frac{1}{b^n}+\frac{1}{c^n})=1$ and the statment follows for $-n$ given that we can make the substitution for $n$. Thus I found out that $n=-1$ satisfies the equality.  I also know that it fails for all even $n$. If $n$ were even, $(a^n,b^n,c^n)$ would all be positive, and Titu's Lemma asserts that $\frac{1}{a^n}+\frac{1}{b^n}+\frac{1}{c^n}\geq \frac{9}{a^n+b^n+c^n}$. Thus $n$ must be odd.  I also observed that $(2,-1,1)$ was a solution, and from here noted that this particular solution satisfies all odd $n$.  I have been trying to prove that all other solutions satisfy all odd $n$ with no success.  Any help would be greatly appreciated. Thanks!


How can I sign in after upgrading to a 'Mojang' account?

I was playing Minecraft and then I changed my skin. It said that I can migrate my old Minecraft account into a Mojang account, so I did.   However I cannot log in anymore. Then after 5 tries of the same thing I got in but couldn't play multiplayer because it says I wasn't authorized. Is it because Microsoft bought Mojang? Because I fully bought Minecraft a while ago.


Exception in thread main with no errors in Netbeans

This error started randomly after making a change in my program. There are no errors being diplayed by Netbeans.   I've encountered random errors in Netbeans 8.2 before that were usually resolved by deleting the cache but I have deleted the cache, restarted Netbeans and still get the same error.   I performed a clean and build to no avail.    The program ran. I can still compile it and run it on a separate machine, but Netbeans keeps giving me this error:  Exception in thread "main" java.lang.NullPointerException at rss.RSSFeedParser.main(RSSFeedParser.java:157) ....\NetBeans\Cache\8.2\executor-snippets  \run.xml:53: Java returned: 1 BUILD FAILED (total time: 3 seconds)   run.xml line 53  <java classpath="${classpath-translated}" classname="${classname}" dir="${work.dir}" jvm="${platform.java}" fork="true" failonerror="${java.failonerror}">   Update: I was catching a "NumberFormatException" on my try catch. Netbeans threw no errors on this previously until all of a sudden. I changed it to "Exception". The program Runs fine, but I have a suggestion from Netbeans to change it back to "NumberFormatException". What gives here? I thought that as long as the required exceptions were caught, there would not be a problem.   Please see attached screen shots.


Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'float java.lang.Float.floatValue()' on a null object reference

When I launch my app this problem shows. This is my Java code:  protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(layout.activity_main);     ImageView imageView = new ImageView(this);      imageView.setBackgroundColor(Color.WHITE);      SVG svg = SVGParser.getSVGFromResource(getResources(), raw.canel);`       imageView.setImageDrawable(svg.createPictureDrawable());    setContentView(imageView); }


Turn off retina internal display while connected to external monitor in Sierra

How do you turn off the MacBook retina internal display with the lid open while using an external monitor on Mac OS X 10.12.6 Sierra? All the previous method doesn't work! 1.Turning down the brightness is not the same as turning off the display as the GPU still sends a signal to the internal display and the external monitor. 2.These were the terminal commands to achieve this on Mavericks: Enable sudo nvram boot-args="iog=0x0" Disable sudo nvram -d boot-args 3.sudo nvram boot-args=niog=1 4.sudo pmset -a lidwake 0.  So, how can i do it without use the third party app? Thank you


Why did Voldemort stop employing Occlumency against Harry in Deathly Hallows?

During Order of the Phoenix Harry gets regular insights into Voldemort's thoughts and feelings. He gets snapshots of where Voldemort is and what he's doing. These visions stopped during Half-Blood Prince because Voldemort was practising Occlumency.     "So tell me, Harry," said Dumbledore. "Your scar...has it been hurting at all?"   Harry raised a hand unconsciously to his forehead and rubbed the lightning-shaped mark.   "No," he said, "and I've been wondering about that. I thought it would be burning all the time now Voldemort's getting so powerful again."   He glanced up at Dumbledore and saw that he was wearing a satisfied expression.   "I, on the other hand, thought otherwise," said Dumbledore. "Lord Voldemort has finally realised the dangerous access to his thoughts and feelings you have been enjoying. It appears he is now employing Occlumency against you."   (Half-Blood Prince, Chapter 4, Horace Slughorn).   It seems that at this point Voldemort realises that giving his archenemy intimate access into his mind and his plans isn't such a good idea. Which makes it all the stranger when those visions start up again in Deathly Hallows. Why would he make himself vulnerable in this way?  In Order of the Phoenix, he uses his connection with Harry as a weapon, to trick Harry into going to the Department of Mysteries to retrieve the prophecy. Even though he also gives Harry unintended insights into his plans as well (such as when he interviews Rookwood) he is basically a step ahead of Harry. The connection serves a purpose.  In Deathly Hallows it surely serves no such purpose. It only makes Voldemort vulnerable. Because of the connection Harry is able to keep track of Voldemort's movements and plans, which hindered Voldemort on several occasions. Through the connection Harry was forewarned that Voldemort was on his way to Godric's Hollow and to Malfoy Manor. Through the connection Harry realised that Voldemort was obsessed with the Elder Wand, meaning that Harry could potentially have worked out its location and taken it before Voldemort got there. Through the connection Voldemort showed Harry that he was worried about his Horcruxes being discovered, and in the process revealed to Harry that the last Horcrux was hidden in Hogwarts. And through the connection Harry knew Voldemort was in the Shrieking Shack during the Battle of Hogwarts, allowing Harry to get Snape's last memory. Time after time, Voldemort exposed himself in a way he didn't during the previous book.  Was stopping Occlumency a conscious decision on Voldemort's part? What purpose did it serve?


The problem with reputation: does high reputation attract too many upvotes?

It's not that I feel bitter when somebody else's answer is upvoted above my own, but it's when a user with a high rep answers a question and their answer seems to attract an immediate barrage of upvotes.  Now I'm not saying that these votes are always unwarranted, but by simply observing this behavior, I think the system seems flawed.    The concept of reputation (or at least one of the concepts) is to give users a sense of trust in the reputed user's answers.  But this should be trust, not blind faith.  I know that this problem doesn't exist for every question asked on SO, but it's definitely present.  I'm sure this is a contentious question, as it might seem overly critical, but does anybody else agree with me and, if so, does anybody have any thoughts on how this problem could be alleviated? It's a great shame when a new or less active user's answer is stifled by the reputation-rich user's answer.


Do spells that change power/toughness of all creatures until end of turn affect creatures played afterwards?

If I play  or , THEN play a creature after the prior spell resolves, is that creature affected? I assume so, but is this ever not true?


Good day! So, I need to present my disertation code to my thesis advisors, but I'm quite unsure how to actually do it in a proper way. I found  showing some ideas.  Is there a way of making the slides 48-67 in beamer without using tikz? Any ideas to implement the whole ideas the author propose?  Thanks in advance.


In the Star Wars the Old Republic MMO, can two new subscribers "refer" each other so they both get the referral rewards?


Given an X sided die, and Y throws, what is the probability that the sum of the throws is at least Z

Given an X sided die, and Y throws, what is the probability that the sum of the throws is greater than or equal to Z? For example, given a 6 sided die and 5 throws, what's the probability that the sum is at least 10? I tried to do this by trying to figure out the probability of of each individual possible value, but I couldn't get it to work out. What is the approach to this? Is there an easy programmatic way of figuring this out?


Rules for over-riding while using Collections

Why java wont allow this over-riding? Is there something that I am missing?  class Abc {     public void add (List<String> li)     {      }  } public class Test extends Abc {     public static void main(String args[])     {      }      @Override     public void add (List<Object> li)     {      }   While it does allow the method to override if I remove the  <Object>    and just write List li in the over riding method which is actually the same as   List<Object>   Also to add, it allows over-riding if both the List in over-ridden and over-riding method have same type.  List<String> - over-ridden method List<String> - over-riding method


What is the difference between phase difference and path difference?

The  is the difference between the distances travelled by two waves meeting at a point. Given the path difference, how does one calculate the phase difference?


I know $\pi$ is 3.141592653589793...... We all learn this at school.  But I haven't learned why pi is irrational number.  How can prove that pi is irrational number?  I would be grateful if you can explain it easily.  :)  Maybe I didn't understand it, but  didn't help me anyway.


Java Interfaces/Implementation naming convention

How do you name different classes / interfaces you create? Sometimes I don't have implementation information to add to the implementation name - like interface FileHandler and class SqlFileHandler.  When this happens I usually name the interface in the "normal" name, like Truck and name the actual class TruckClass.   How do you name interfaces and classes in this regard?


Is it possible to activate iMessages without phone number on iPhone?

I have iPhone with a SIM card and a phone number. I would like to activate iMessages, but only for my Apple ID's e-mail address, and not phone numbebr. Is it possible to do this?


Hard puzzle about people walking in the street.

We have a 1 dimensional street (straight) where people can either walk left or right. They all walk with the same speed. If two people meet they instantly change their direction (without loss of speed). It takes 10 minutes to walk the entire street with this speed. The people can start at anny point on the street. How long will it take until they are all out of the street?  It seems that the answer depends on the starting configuration, but the question implies there is a universal answer. Annyone an idea?


Override Default Constructor of Partial Class with Another Partial Class

I don't think this is possible, but if is then I need it :)  I have a auto-generated proxy file from the wsdl.exe command line tool by Visual Studio 2008.  The proxy output is partial classes. I want to override the default constructor that is generated. I would rather not modify the code since it is auto-generated.  I tried making another partial class and redefining the default constructor, but that doesn't work. I then tried using the override and new keywords, but that doesn't work.  I know I could inherit from the partial class, but that would mean I'd have to change all of our source code to point to the new parent class. I would rather not have to do this.  Any ideas, work arounds, or hacks?   //Auto-generated class namespace MyNamespace {    public partial class MyWebService : System.Web.Services.Protocols.SoapHttpClientProtocol {       public MyWebService() {          string myString = "auto-generated constructor";          //other code...       }    } }  //Manually created class in order to override the default constructor namespace MyNamespace {    public partial class MyWebService : System.Web.Services.Protocols.SoapHttpClientProtocol {       public override MyWebService() { //this doesn't work          string myString = "overridden constructor";          //other code...       }    } }


Plot the longitude and latitudes on map using geotools

I am new to geotools and i find bit difficult to plot a point using the latitude and longitude values. can any one help me out to solve my problem. I tried the following code but not helpful.By quickstart i can able to pass a shapefile and getting the map but unable to plot the lat long values on it.     SimpleFeatureTypeBuilder b = new SimpleFeatureTypeBuilder();           b.setName( "MyFeatureType" );           b.setCRS( DefaultGeographicCRS.WGS84 );           b.add( "location", Point.class );            //building  the type           final SimpleFeatureType TYPE = b.buildFeatureType();          SimpleFeatureBuilder featureBuilder = new SimpleFeatureBuilder(TYPE);         GeometryFactory geometryFactory = JTSFactoryFinder.getGeometryFactory();          Point point = geometryFactory.createPoint(new Coordinate(longitude, latitude));           featureBuilder.add(point);           SimpleFeature feature = featureBuilder.buildFeature( "fid.1" );           DefaultFeatureCollection featureCollection = new DefaultFeatureCollection("internal",TYPE);           featureCollection.add(feature);   Adding to map:    List a=new ArrayList(); a.add(-155.2792); a.add(67.3623);  double longitude=(Double) a.get(0); double latitude=(Double)a.get(0);  File file = JFileDataStoreChooser.showOpenFile("shp", null);  if (file == null) { return; }  FileDataStore store = FileDataStoreFinder.getDataStore(file);  SimpleFeatureSource featureSource = store.getFeatureSource();  MapContext map = new DefaultMapContext();  map.setTitle("Show Map");      Layer layer = new FeatureLayer(featureSource, null);         map.addLayer(layer);     map.addLayer(featureSource, null);      JMapFrame.showMap(map);


Header space is different on pages after first

When I build the document the output is perfect, however, all other pages but the first have a consistent and significant amount of vertical spacing after the header that the first page does not have. Additionally, I get some Missing number, treated as zero and Illegal unit of measure errors (coincidentally, one for each \newpage), but I don't know if that's related.  \documentclass[12pt]{article}  \usepackage{amsmath,amsthm,amssymb,fancyhdr}  \addtolength{\textheight}{1.5truein} \addtolength{\topmargin}{-.75truein}  %\setlength{\textheight}{9.5truein} %\addtolength{\topmargin}{-.75truein}  \setlength{\oddsidemargin}{0.3truein} \setlength{\evensidemargin}{0.3truein} \setlength{\textwidth}{5.9truein}  \addtolength{\oddsidemargin}{-0.5truein} \addtolength{\evensidemargin}{-0.5truein} \addtolength{\textwidth}{1.0truein}  \newcommand{\argmin}{\mathop{\rm argmin}}  \newcommand{\real}{\ensuremath{\mathbb{R}}}  \newcommand{\comment}[1]{} \newcommand{\vsph}{\vspace{.40cm}} \newcommand{\vsp}{\vspace{.80cm}} \newcommand{\vecc}[1]{\mbox{\boldmath $#1$}} \newcommand{\utilde}[1]{\underset{\widetilde{}}{#1}} \newcommand{\G}{\,|\,}  \def\EE{ {\rm I} \kern-.15em {\rm E} }  \newcounter{qnum} \newcounter{pnum}[qnum]   \newcommand{\topic}[1]{\vsph \hrule \vsph \mbox{} \hfill { \it #1}   \hfill \mbox{} }  % \newcommand{\QQ}{\vsph \hrule \vsph \stepcounter{qnum} {\noindent \bf %     Problem \theqnum.} \hspace{.2cm} } \newcommand{\QQ}{\vsp \stepcounter{qnum}                 {\noindent \bf Problem \theqnum.} \hspace{.2cm} }  %\newcommand{\QQ}[1]{ %\pagebreak[2] %\vsph \hrule \vsph \stepcounter{qnum} {\noindent \bf %    Problem \theqnum.}\hspace{.05cm} (#1) \hspace{.15cm} }   \newcommand{\PP}{\stepcounter{pnum} \item[{\bf (\alph{pnum})}]\, }   \newenvironment{parts}{   \begin{list}{}{\setlength{\topsep}{2.0ex}\setlength{\itemsep}{1.5ex}       \setlength{\leftmargin}{2.3em}\setlength{\labelsep}{0.8em}}   }{\end{list}}  \def\god{{\buildrel {\cal D} \over \longrightarrow}} \def\goas{{\buildrel {\rm a.s.} \over \longrightarrow}}  \def\r{\rightarrow} \def\p{\stackrel{p}{\r}} \def\d{\stackrel{d}{\r}} \def\argmax{\mathop{\rm argmax}}  \newcommand{\var}{\mbox{Var}}   \usepackage{amsfonts}  \newcommand{\RR}{\mathbb {R}}  \newcommand{\eps}{\varepsilon}   \newenvironment{clist} {%\vspace{-1cm} \begin{list}{$\bullet$} { %\setlength{\topsep}{0.0cm} %\setlength{\itemsep}{0.0cm} %\setlength{\parsep}{0.0cm}} \setlength{\topsep}{.1cm} \setlength{\itemsep}{.1cm} \setlength{\parsep}{.1cm}} }{\end{list}}  \setlength{\headheight}{70pt} % make header taller  % \fancypagestyle{plain}{} % Change default page style \pagestyle{fancy} \fancyhf{} % clear all header and footer fields \fancyhead[C]{       \vspace{0.1in}       \bf {\large Ph.\ D.\ Qualifying Exam\\                   Tuesday, January 3, 2012\\}       \vspace{.2in}       Put your solution to each problem on a separate sheet of paper.       \vspace{.4in} }  \renewcommand{\headrulewidth}{} % make line under header disappear  \begin{document}  \QQ     Applied Statistics (STA5166) \hspace{0.2in} \newline ({\bf Note: Need a Chi-Square table for this problem.})  \vspace{0.1in}    A study was conducted to determine whether the age of customers is related to the type   of movie he or she watches. A sample is shown in the following table.  \vspace{0.1in}  \begin{tabular}{cccc} \hline Age            &  Documentary & Comedy  &  Mystery\\ \hline 12-20          & 24 & 19 & 18 \\ 21-40          & 35 & 46 & 58 \\ 41 and over    & 23 & 60 & 49 \\ \hline \end{tabular}  \begin{parts} \PP  Given that the total sample size $n=332$ is fixed, what is the distribution of the nine categories?  What are the mean value and variance of each cell frequency? Run a chi-square test of independence and draw your conclusion. Use $\alpha=0.05$.  % \vspace{0.05in}  \PP  Run a chi-square test of  "Comedy" verse "Mystery".  Use $\alpha=0.05$.   \end{parts}  \newpage  \QQ    Applied Statistics  (STA5166)  etc...


Why don't Starfleet vessels have intelligent on-board computers?

Computers on board Starfleet vessels are quite primitive compared to on board computers such as . At their best, they can decipher requests such as "Computer, delete that last sentence" and utter things such as "That crewman is no longer on board this vessel". Even real life computers will be capable of this within a decade or so (by some estimates). Even computers such as HAL 9000 are likely to be available within a few decades.  So, in a genre where intelligent computers are abound, why this strange absence? Did the Federation run into some Battlestar-Galactica-like problem with AI in the past and decide to keep on board computers decentralized?  But if that is the case, how can one explain Data and highly intelligent holographic characters? The technology and programming constructs clearly exist, yet Starfleet vessels continue to be manned by hundreds of people standing in front of consoles.


An adjective for a person who is new to a certain field/activity

I am looking for an adjective, a compound adjective or adjective phrase that would fill in the blanks below     He is a [...] stamp collector.   = He recently became a stamp collector.      She is a [...] mailwoman.   = She recently became a mailwoman.   The meaning I am looking for is that of a person being new to an activity, which is now performed by them regularly, in a positive sense.


So my local dollar store doesn't sell rubbing alcohol, but does sell acetone.  Can I use acetone instead of rubbing alcohol on electronics?  I know acetone does attack some plastics but rubbing alcohol doesn't.


Altium de-highlighting nets after using 'Find Similar Objects...' command

I can't work out why Altium is doing this, or how to undo it, or how to make it stop doing it.  It happens when I use the 'Find Similar Objects... ' option; all of objects that it hasn't found are faded out and I can no longer select them.  Anyone know how to fix this?  Additionally, if anyone knows how to change, en masse, the components' footprint library to 'Any' through the SCH inspector, that'd be really helpful too.


Is he actually bad throughout the films ? Does he turn to good in the end?


I have a model named Student. This is a Java RMI program. I declared the Student Serialized Object in client side. I got following error.      SEVERE: null java.rmi.UnmarshalException: error unmarshalling return; nested exception is:      java.io.InvalidClassException: com.simulator.model.Student; local class incompatible: stream classdesc serialVersionUID = -6650366980271983195, local class serialVersionUID = 6359019065551364622     at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:173)     at java.rmi.server.RemoteObjectInvocationHandler.invokeRemoteMethod(RemoteObjectInvocationHandler.java:178)     at java.rmi.server.RemoteObjectInvocationHandler.invoke(RemoteObjectInvocationHandler.java:132)     at $Proxy2.performList(Unknown Source)     at com.simulator.ui.student.AddNewStudent.<init>(AddNewStudent.java:90)     at com.simulator.ui.main.Home$3.actionPerformed(Home.java:109)     at org.pushingpixels.flamingo.api.common.AbstractCommandButton.fireActionPerformed(AbstractCommandButton.java:614)     at org.pushingpixels.flamingo.api.common.AbstractCommandButton$ActionHandler.actionPerformed(AbstractCommandButton.java:566)     at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)     at org.pushingpixels.flamingo.api.common.model.ActionRepeatableButtonModel.setPressed(ActionRepeatableButtonModel.java:123)     at org.pushingpixels.flamingo.internal.ui.common.BasicCommandButtonListener.mouseReleased(BasicCommandButtonListener.java:147)     at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:272)     at java.awt.Component.processMouseEvent(Component.java:6263)     at javax.swing.JComponent.processMouseEvent(JComponent.java:3255)     at java.awt.Component.processEvent(Component.java:6028)     at java.awt.Container.processEvent(Container.java:2041)     at java.awt.Component.dispatchEventImpl(Component.java:4630)     at java.awt.Container.dispatchEventImpl(Container.java:2099)     at java.awt.Component.dispatchEvent(Component.java:4460)     at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4574)     at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)     at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)     at java.awt.Container.dispatchEventImpl(Container.java:2085)     at java.awt.Window.dispatchEventImpl(Window.java:2475)     at java.awt.Component.dispatchEvent(Component.java:4460)     at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)     at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)     at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)     at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)     at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)   My Student Class is  public class Student implements Model, Serializable {     public static final long serialVersionUID = 456544542L;     String id;     String name; }   Declaration..  List<Student> performListStd = stdController.performList();         for (Student student : performListStd) {             mpUsers.put(student.getUserName(), student.getStdPass());         }   stdController has MYSQL query for searching.  Thanks in Advance


Prove: The weak closure of the unit sphere is the unit ball.

I want to prove that in an infinite dimensional normed space $X$, the weak closure of the unit sphere $S=\{ x\in X : \| x \| = 1 \}$ is the unit ball $B=\{ x\in X : \| x \| \leq 1 \}$.  $\\$  Here is my attempt with what I know:  I know that the weak closure of $S$ is a subset of $B$ because $B$ is norm closed and convex, so it is weakly closed, and $B$ contains $S$.  But I need to show that $B$ is a subset of the weak closure of $S$.  $\\$  for small $\epsilon > 0$, and some $x^*_1,...,x^*_n \in X^*$, I let $U=\{ x : \langle x, x^*_i \rangle < \epsilon , i = 1,...,n \} $  then $U$ is a weak neighbourhood of $0$  What I think I need to show now is that $U$ intersects $S$, but I don't know how.


Deep NNs, backpropagation and error calculation

I was following the backpropagation tutorial by Michael Nielsen on , one of the very few places where the backprop algorithm is nicely explained both in theory and practice with an actual implementation in python.  Now, something is not clear when he explains how to calculate the error on a specific layer in terms of error in the next layer (I will provide a screenshot because I don't want to mess with notation):    Here, delta^l is the error in layer l, the circled dot is the elementwise product betweeen vectors, w is a weight matrix, and sigma primed indicates the derivative of an activation function.  Now, observe he points out that by applying the transpose operator to the next-layer-error vector (which is the previous layer during backprop), one is "sending back" the error across the network, and then, multiplying by the derivative of sigma, one applies the chain rule which completes the backprop step.  I have troubles understanding what does he really mean by saying that the traspose operator "sends back".  Perhaps he wants to apply the inverse trasformation? But unless the matrix happens to be orthogonal, which is not the case AFAIK, the transpose does NOT equal the inverse..  In any case, I would have thought of applying some kind of differential operator to matrix w, and not the transpose one.  Opinions?  NOTE: Please let me know whether this post is correctly suited for stackoverflow, or should it be posted on stats or math stackexchange.


Can singularities be ever formed from an outsiders perspective?

As far as I know, as an object gets closer to an event horizon, gravitation time dilation makes it move slower from an outside perspective, so that it looks like it take an infinite amount of time for the object to reach the event horizon. It seems like a similar process should slow the formation of the black hole itself: As the star collapses, its gravitational time dilation makes itself collapse more slowly. This makes me wonder: from a perspective of an outside observer, can a singularity ever form? E.g. someone on earth observers a massive star collapse, forming a black hole. From his perspective, the mass gets closer and closer, but does it ever form a singularity before the black hole evaporates? Furthermore, if from the perspective of a mass collapsing into a black hole, its time slows down and the outside universe "speeds up", could this mean that the black hole evaporates before me, the mass, can become singularity? UPDATE: Let me show you my reasoning and correct me when I'm wrong (I assume I will be at some point): From a far away observer the black hole forms. Over a very long period it evaporates. In the end, it evaporates down to nothing. , the black hole cease to exist, the potential singularity is no more. Now, from a perspective of a massive star: I begin to collapse. All the mass gravitates towards my center. Meanwhile, due to gravitational time dilation from GR, my time ticks slower relative to the rest of the universe. My size crosses the Schwarzschild radius, an Event Horizon is now present. However, now I start to lose mass due to Hawking Radiation. From an outsiders point of view, this is very slow, but from my point of view this is getting faster and faster. Could the singularity form before Black Hole's mass is evaporated?


"Undefined control sequence \includegraphics" after TeXstudio update

I know there are a gazillion of threads addressing the error  Undefined control sequence \includegraphics   but I couldn't find the answer to my problem in any of them. So here it goes.  I am trying to use the command \includegraphics, like I have always done so for the past years, but somehow it doesn't work anymore. I am using TeXstudio 2.12.16. Below is a MWE:  \documentclass[12pt]{article} \usepackage[pdftex]{graphics,graphicx}  \begin{document}     \includegraphics[width=\linewidth]{photo.png} \end{document}    When I try to compile, it returns the error  Undefined control sequence. \includegraphics[width=\linewidth]{photo} Undefined control sequence. \includegraphics[width=\linewidth]{photo} Undefined control sequence. \includegraphics[width=\linewidth]{photo} Undefined control sequence. \includegraphics[width=\linewidth]{photo} Undefined control sequence. \includegraphics[width=\linewidth]{photo} File `photo' not found. \includegraphics[width=\linewidth]{photo}   I have made sure that the file photo is in the same directory.  This started happening after I updated TeXstudio, and it happens both in my laptop and desktop. I have reinstalled MiKTeX and TeXstudio countless times in both, but to no avail. I think TeXstudio is unable to detect the graphicx package somehow? The reason why I think it's because of TeXstudio is when I upload this project to Overleaf, there are no issues with it.


Converting Firewire to USB 3 - is it theoretically possible?

I am in the process of buying a new laptop for video capture / editing, and it's proving difficult to find one at a decent price / spec that includes Expresscard for Firewire connectivity (which I really need).  It does seem like Expresscard is on the way out based on what I've seen recently.  Since the assumption seems to be that USB 3.0 is the heir apparent to Expresscard I was wondering what people's thoughts were on whether it should be possible to convert a Firewire input to USB 3.0.  There don't seem to be any devices around at the moment that do this but is this because USB 3.0 is still in its infancy or because it's not practical / possible?


Projecting a point onto a convex set decreases its distance from each point of that set

For a convex set $K$, $x\in \mathbb{R}^d$ and $y=\Pi_K(x) $ (the projection of $x$ onto $K$), we want to show that for any $z\in K$ it holds that: $\|x-z\| \ge \|y-z\|$.  $$ $$  I'm not sure if the following proof is valid:  $$ y=\Pi_K(x) = \arg \min_{y\in K} ||y-x||  \Rightarrow \forall z\in K \langle y-x,y-z\rangle =0 $$ $$ ||y-x||^2_2+||y-z||^2_2=||x-z||^2_2  \quad (Pythagoras)$$  $$ \Rightarrow ||y-z||^2_2 \le ||x-z||^2_2 $$ $$ \Rightarrow||y-z|| \le ||x-z|| $$


Ubuntu Additional Drivers won't install flgrx

I installed Ubuntu 14.04.2, a fresh install. Additional Drivers won't install the AMD flgrx proprietary drivers. I clicked on the radio button, pressed apply changes, and then the button just goes back to open source Xorg driver.   It works on 14.10, but on that version it will not let me enter my encrypted password (works in 14.04). If I type password on 14.10 it does not populate the field. It just shows up at the top in plain text.   Any ideas how to get flgrx in 14.04 or get encryption working in 14.10?


US entry with tourist visa but past alcohol arrest

I’m a UK Citizen, and have a B1/2 Tourist Visa.  I applied for the visa as per the embassy guidelines as I was once arrested for Drunk and Disorderly. No conviction was ever made.   I attended the embassy interview and underwent a US Medical exam to prove I’m not an alcohol abuser and am in good health. This all came back positive and my visa was approved.  I have my visa now. But from what I’ve read, a Visa doesn’t guarantee entry. What are the chances of me now being denied entry by an agent at the border?


Do you consider the subject in the following to be compound, justifying a singular verb?  "His impact and influence is undeniable."  On the one hand, the nouns do not form a common phrase; on the other hand, they have a similar meaning so might be considered a unit. What are you views? And do you know if usage is shifting?


Is there any difference between writing the following two? The code is for C#  String S1 = "The " + Item.Name + " is made of " + Item.Property + " and is at " + Item.Durability + "% durability."   against  String S2 = "The {0} is made of {1} and is at {2} % durability.", Item.Name, Item.Property, Item.Durability   ? Assuming that item is populated with, for instance, name of Axe, property of Steel, and durability of 50 as a string.


Printing text before reading input not working [Clojure]

As this is my first question on SO, I brought a question that's been bugging me for a couple hours. I began "playing" with Clojure some days ago, and have crossed with a rather interesting behaviour when dealing with text printing.  I wrote a small program to take a number as input and print either "ok" or "not ok" when it'd be a multiple of 3 or not. I also added a line of code to print text asking for the user to input a number before reading a line from stdin. The thing is, this print instruction is before the read-line instruction, still it doesn't print to the screen. I mean, not before actually reading from stdin.  What exactly could the problem be? I don't come from the Lisp world (in fact, CLojure is my first Lisp-like language), so I don't really get why that's happening. Any help will be much appreciated.  The code:  (defn ok [n]   (if (= (mod n 3) 0)     "ok"     "not ok"))  (defn main []   (print "Type a number: ") ; This actually prints *after* the read-line instruction   (flush) ; EDIT: The flush function is the missing part of the code. It's all ok now.   (let [n (Integer/parseInt (read-line))]     (println (ok n)))   (recur)) ; it is supposed to run until Ctrl-C is signalized  (main)   And an image of the output:   Thanks in advance!


What will happen if I just take out the hard disk with Windows 10 and replace it with Windows 7

My laptop hard disk is running with Windows 10 and my old laptop hard disk is running with Windows 7, Can i just take them out and put it on my new laptop?


I'm pretty new to coding, and I understand how to do a do while for a yes or no answer in C++. But java is giving me a hard time. This code doesn't give me any errors until I run it. When it asks for the yes or no answer it will say:  Exception in thread "main" java.util.NoSuchElementException     at java.util.Scanner.throwFor(Unknown Source)     at java.util.Scanner.next(Unknown Source)     at midterm.main(midterm.java:40)   Line 40 is the:  ans = s.next();   Maybe I'm doing something wrong with String, I've tried char but had no luck either. Here is my code:   public class midterm  {     public static void main(String[] args)     {      Scanner s = new Scanner(System.in);      String ans;     do     {      System.out.println("Welcome to the Menu!\nA)Guessing Game\nB)Calculator\n"             + "\nEnter Letter: ");     String letter = s.next();     s.nextLine();      if ((letter.equals("A")) || (letter.equals("a")))     {         guessingGame();     }      else      {         calcDecide();     }      System.out.println("\nWould you like to go back to the menu or exit?\n"             + "Press 'Y' yes or 'E' for exit: ");     ans = s.next();     s.nextLine();      }while (ans == "y" || ans == "y");      s.close();  }   Not sure why this was marked as a duplicate. I feel that people don't read the entire thing and like to assume this. This WAS NOT a simple String mess-up(That's part of the mistake,) but there's a bigger issue here, which I believe to be the scanner


Allow a user to read some other users' home directories

I am new to system administration and I have a permission related query. I have a group called administration. Inside the administration group, I have the users user1, user2, user3, superuser. All the users are in the administration group. Now, I need to give permissions to the user superuser to be able to view the /home directory of the other users. However, I do not want user1, user2, user3 to see the home of any other user other than himself. (That is, user1 should be able to see only user1's home and so on).   I have created the users and groups and assigned all the users to the group. How should I specify the permissions for the superuser now?   In other words, I'm thinking of having two groups (say NormalUsers and Superuser). The NormalUsers group will have the users user1, user2 and user3. The Superuser group will only have the user Superuser. Now, I need the Superuser to have full access on the files of users in the group NormalUsers. Is this possible in Linux?


Is there a separable and metrisable topological space $X$ so that $\operatorname{card}(x) > {2}^{\aleph_{0} }$?

Is there a separable and metrisable topological space $X$ so that $ \operatorname{card}(X) > {2}^{\aleph_{0} }$?  I can't think of an example.


How to make the footnote starting from \dag?

The default sequence of symbol footnote is *,\dag,\ddag,... How can I make the footnote starting from \dag, i.e., the sequence \dag,\ddag,...? Thanks in advance. (I have the package \usepackage[perpage,symbol]{footmisc}). My question is answered in the link:


I'm trying to understand imaginary quadratic fields and the ideal class group seems to be really important, yet I cannot find a simple explanation of it and why it's important. I understand that it is related to unique factorization, yet I don't know why. If someone could give a simple explanation of it and maybe a simple example of it I'd really appreciate it.


Which is correct to use in the following example, simple past or past perfect?        We were completely in the dark after the wind blew the candle out.   We were completely in the dark after the wind had blown the candle out.


Why is light absorbed by black holes while it is massless as theory of gravitation works only for masses?


Proof for the completeness of eigenfunctions of a self-adjoint operator

I always heard the eigenfunctions of a  form a complete basis. Where can I find a proof in infinite dimension space? Presumably readable for physicists.


I have an iMac12,2 with Mac OS X 10.6.8. I want to upgrade to the newest possible Mac OS. If I click the Software update button it says "Software Update doesn't have any new software for your computer at this time.". If I want to download High Sierra from the App Store it says "This update requires macOS version 10.8 or later."   What should I do? How can I upgrade my mac?


Database, Table and Column Naming Conventions?

Whenever I design a database, I always wonder if there is a best way of naming an item in my database. Quite often I ask myself the following questions:   Should table names be plural? Should column names be singular? Should I prefix tables or columns? Should I use any case in naming items?   Are there any recommended guidelines out there for naming items in a database?


Is there an in-universe explanation for why so many alien planets have names from human mythology?

Romulus, Vulcan, Kronos, Orion,... and many other examples in the Star Trek universe. Is there a reason why they all have names from Roman and Greek mythology?  is there a reason for that ? Are they just using Federation (human) designations when in fact they have different names in their respective culture's native languages?


Why would there be water in the Death Star's trash compactor?

Water can't be compressed. Even with 150 times the normal atmospheric pressure (such as at the bottom of oceans), it gets compressed by less than 1%.  This would affect the mechanism of trash compactor, for sure. Totally submerged trash wouldn't get compacted at all.  Why was there water in the trash compactor of the Death Star? And, why did they turn on the compactor without filtering out water from the trash (they could certainly drain water using a small hose)?


I'm writing a CMS application in PHP and one of the requirements is that it must be able to interface with the customer's Exchange server.  I've written up this functionality a few times before and have always used  to do it, but now I'm leaning away from that. I will be running the site on IIS OR Apache (no preference) on Windows server 2008.  A few things I would need to do include adding contacts to a given user's address book, sending emails as a given user and running reports on contacts for a user. All of this is pretty easy to do with WebDAV, but if there is a better way that doesn't require any functionality that is likely to be deprecated any time soon. Any ideas? Update: Justin, I love the idea of using com objects, I just worry about maintaining a 3rd product to make everything work... John, I can write a web service in C# to interface with for these functions and access it with my PHP app, but it's also a little bit out of the way. So far, I'm not 100% convinced that either of these is better than WebDAV... Can anyone show me where I'm being silly?


Prove the sequence is Cauchy and therefore Convergent

Let $(x_n)_{n\in\mathbb{N}}$ be a sequence in $\mathbb{R}$. Let $r\in (0,1)$ and suppose that $|x_{n+1}-x_n|<r^n \forall n\in \mathbb{N}$. Show that $(x_n)_{n\in\mathbb{N}}$ converges.  I know that it is sufficient to show that the sequence is Cauchy. So, this is very similar to this past question () but I don't completely understand the answers given so I'm hoping someone can help me out.


I'm trying to solve this integral by using complex analysis, but don't know clearly what to do next. Here is my approach:  $$\int_{0}^{2\pi}\frac{\cos(x)}{2+\cos(x)}dx = \int_{0}^{2\pi}\frac{\cos(z)}{2+\cos(z)}dz = \int_{0}^{2\pi}\frac{\cos(e^{ix})}{2+\cos(e^{ix})}dx$$


How to disable Windows 10 memory compression?

my former wrong assumption: it drains my notebook battery and I've no shortage of RAM. In Task manager you see ntoskrnl.exe is eating more CPU time than any other process. this feature does not appear to be optional and came 2 days ago with the 1st Win10 Update (Win10Pro in my case).  Edit:  I want to disable it, at least to exclude it as a culprit for my (unproven) assumptions. That process never came to my attention in the last 2 months and in task manager's long name it's called "system memory and compressed memory".


Tag descriptions on meta not showing even though they're present

On the , some of the tag descriptions don't show up within their frames even though they are present:  As you can see, the  tag has a description, but it's not showing up directly on the page. In this screenshot the same applies to , ,  and . I assume this has to do with these descriptions being the 'vanilla' SE ones, and the ones that do show up have been edited. Can anyone shed any light on this behaviour?


Opening PDF in Illustrator breaks up text objects

I recently had to convert some PDF files to SVG, and did this by opening the PDF in Illustrator, and saving out to SVG.    The issue was that when Illustrator opened the pdf, many (but not all) text objects would be broken up into different text objects.  For instance, the word "policy" wouldn't be one text object, but rather several text objects, "po", "l", "icy".  There didn't seem to be any rhyme or reason to it.    How can I prevent this from happening?


Linear independence of $\sin(x)$, $\sin(2x)$, $\sin(3x)$ in Map($\mathbb{R},\mathbb{R}$)

It seems rather obvious to me that $\sin(x)$, $\sin(2x)$, $\sin(3x)$ are linearly independent in $\operatorname{Map}(\mathbb{R},\mathbb{R})$, but I'm not sure how to prove it (or disprove it if I'm wrong?). I know that for linear independence it must $$ a\sin(x)+b\sin(2x)+c\sin(3x)=0 $$ $$ \implies a=b=c=0$$ but how can I show this is true for any $x \in \mathbb{R}$?


Can I check if the C# compiler inlined a method call?

I'm writing an XNA game where I do per-pixel collision checks. The loop which checks this does so by shifting an int and bitwise ORing and is generally difficult to read and understand.  I would like to add private methods such as private bool IsTransparent(int pixelColorValue) to make the loop more readable, but I don't want the overhead of method calls since this is very performance sensitive code.  Is there a way to force the compiler to inline this call or will I do I just hope that the compiler will do this optimization?   If there isn't a way to force this, is there a way to check if the method was inlined, short of reading the disassembly? Will the method show up in reflection if it was inlined and no other callers exist?  Edit: I can't force it, so can I detect it?


Is it possible to get fund if I have a poor cgpa?

Many university in North America or in Europe offer fundings for masters program . But it only for those students who have a good CGPA in undergraduate examination .I have completed my bachelor degree in Economics . I have a very poor cgpa . It's 2.84 out of 4.00. Is there any possibility that I can get myself admitted in those institution for masters program with fundings . I don't have any publication. I was champion in two Business case solving competition as extra curriculum. Will good GRE score ( like 320) help me to get fund? Can I get funding if I have a good GRE score with this poor profile?  Thank you.


Turned the television on or turned on the television?

I think turned the television on sounds better. I usually hear 'turned the television on' but I see 'turned on the television' in other references. Which is correct?


Setting custom shortcut for applications not working

I'm a new Macbook user and still struggling with iOS. I've installed iterm2 and would like to setup a shortcut for it (preferably control+command+T  I went to System Preferences -> Keyboard -> Shortcuts -> App Shortcuts and added a shortcut for iterm2 there     However, when actually pressing the shortcut nothing happens...


Why can't I add an object to this array?

public class GroceryList {     //variables     private int count;     private Item list[];     public final int MAX = 30;      //default     public GroceryList(){         Item placeholder1 = new Item();         Item placeholder2 = new Item();         list[0] = placeholder1;         this.count = 0;     } }  I want to assign the Object placeholder1 to list[0] but I get a NullPointerException.


How to set C# application to accept Command Line Parameters?

I have created a C# command line application that creates a few reports automatically for my client.  However, even though they use 95% of the same code I would like to split them in to different processes. I am using Windows task scheduler to run them.  How do I set up the C# application to accept Command line parameters upon runtime?  I cannot find any explanation of this on the internet.


Let $f,g:[a,b] \rightarrow \mathbb{R}$ continuous functions and differentiable in $(a,b)$ , show that $\exists c \in (a,b)$ such $[f(b)-f(a)]g'(c) = [g(b)-g(a)]f'(c)$  I tried using the mean value theorem, but I can not relate the two functions with the same c.  any help is appreciated


Proof by induction; $a^n$ divides $b^n$ implies $a$ divides $b$

I want to prove by induction that $a^n \mid b^n$ implies that $a \mid b$ holds for all integers $n\geq 1$.  Clearly for $n=1$ this is true, since if $a \mid b$, then $a \mid b$.  Suppose this is true for some $n = k$. Then $a^k \mid b^k$, so $a|b$.  $a^k \mid b^k$ means there exists some integer $m$ such that $b^k = ma^k$, and $a \mid b$ means there exists an integer $r$ such that $b=ra$.  Then we can multiply both sides of the above equality by any constant, namely $b$.   Then $b \cdot b^k = bma^k$  so $b^{k+1} = (ra)ma^k = rma^{k+1}$  which means that $a^{k+1} \mid b^{k+1}$ completing the induction step, and thus proving that for all integers $n \geq1$ the original statement holds.  Are there any logical holes in the proof?


What can be said about $\prod_{s=2}^{\infty} \zeta(s) $?


Why RMSE over MAE for matrix factorisation?

I have been trying to compare several matrix factorization algorithms and I've noticed that all the papers and libraries I've seen measure the Root Mean Square Error(RMSE) when intuitively I would have expected a good metric would be the Mean Absolute Error (MAE).  Is there any reason why there appears to be a preference to use RMSE?


How do I install different (upgrade or downgrade) PHP version in still supported Ubuntu release?

I am trying to update to install PHP 5.5, 5.6 or 7.0 in Ubuntu 12.04/14.04/16.04 LTS, and I can only get PHP 5.3.10 for Ubuntu 12.04, PHP 5.5.9 for Ubuntu 14.04 or PHP 7.0.4 for Ubuntu 16.04 using official repositories (using apt-get).  I'm not really sure how to do a manual update – as I need:   to play around with the new(est) PHP features to install older PHP version due support in the software


spelling change from verb form to noun form

Is there a reason why the verb is ABSORB but in the noun form the B becomes a P---ABSORPTION?


How to benifit from CRTP in a real example?

According to my understanding CRTP(Curiously Recurring Template Pattern) is used when a class is derived from a specialization of a templated-base class. So the base class can access the functionality of derived class then delegate to derived class after casting the Parameter to a derived class. Here is an example:  #include <iostream> using namespace std;   template< class T>  class Shape2D{     public:         Shape2D(double, double);         virtual ~Shape2D();          void SetDims(double dim1, double dim2) {             static_cast<T*>(this)->SetDims(dim1, dim2);         }          double GetDim1() const;         double GetDim2() const;         double GetSurface()const;         double GetPerim()const; };  template<class T> Shape2D<T>::Shape2D(double dim1, double dim2) {     static_cast<T*>(this)->SetDims(dim1, dim2); }  template<class T> Shape2D<T>::~Shape2D() {  }   template<class T> double Shape2D<T>::GetSurface()const {     return static_cast<const T*>(this)->GetSurface(); }  template<class T> double Shape2D<T>::GetDim1()const {     return static_cast<const T*>(this)->GetDim1(); }  template<class T> double Shape2D<T>::GetDim2()const {     return static_cast<const T*>(this)->GetDim2(); }  template<class T> double Shape2D<T>::GetPerim()const {     return static_cast<const T*>(this)->GetPerim(); }  class Rectangle : public Shape2D<class Rectangle> {     public:         Rectangle(double, double);          void SetDims(double, double);          double GetDim1() const;         double GetDim2() const;         double GetSurface()const;         double GetPerim()const;          private:             double itsLength, itsWidth; };  Rectangle::Rectangle(double len, double wid) :     itsLength(len), itsWidth(wid), Shape2D<Rectangle>(len, wid) {  }  void Rectangle::SetDims(double len, double wid) {     itsLength = len;     itsWidth = wid; }  double Rectangle::GetDim1()const{     return itsLength; }  double Rectangle::GetDim2()const {     return itsWidth; }  double Rectangle::GetSurface()const {     return itsLength * itsWidth; }  double Rectangle::GetPerim()const {     return ((itsLength * 2) + (itsWidth * 2)); }  int main() {      class Rectangle rct(7, 5);     cout << rct.GetSurface() << endl;     cout << rct.GetPerim() << endl;      cout << endl;      Shape2D<class Rectangle>* pSh2DRect =          new Shape2D<class Rectangle>(7, 5);     cout << "Surface: " << pSh2DRect->GetSurface() << endl;     cout << "Perimeter: " << pSh2DRect->GetPerim() << endl;      delete pSh2DRect;       cout << endl;     std::cin.get(); }    I can't see any benefit above because I can achieve it without CRTP. I want a helpful example to clear my doubts about Static Polymorphism. What if a derived class doesn't inherit from a specialization where this derived class is not the parameter of the template base class?? eg:  class Parallelogram : public Shape2D<Rectangle>{      public:         //... };    As you can see Parallelogram normally inherit from Shape2D<Parallelogram> not Rectangle. Is it a Undefined Behavior?