I was thinking about black holes. For a simple black hole the event horizon is given by a distance of 2 times mass (energy) of the black hole. (2m).  But according to quantum mechanics, if you try to calculate the energy of a black hole during a very short time frame the energy becomes uncertain. Only over a long time frame can you get a precise energy.   Therefore from that reasoning, does it mean that the event horizon distance is actually fluctuating? And so the black hole is kind of vibrating?  For a black hole when viewed at the scale of the plank time would the horizon be fluctuating on the scale of twice the Planck length?   Does this mean particles can escape from a black hole?  Is that correct?

What are the consequences of applying the uncertainty principle to black holes?  Does the uncertainty principle need to be modified in the context of a black hole and if so what are the implications of these modifications?


I have finished my site on localhost and it displays fine, on all browsers.  When launching to server it shows fine in firefox, chrome, etc.  In Internet Explorer 11 however there are render issues. it just shows it all down one side.( left hand side).  I have tried the compatability method as described for the 7xcore and Microsoft. IE: I have added the site to the compatability list. Cleared all the history and the drupal cache but it has made no difference.  Site still shows as if no CSS is being invoked.  Many thanks Allen

Before you ask ... I have looked everywhere for a solution, even drupal.org but nothing so far seems to work.  I developed a Drupal site (custom child theme for Zen) and on the development server everything looks fine in all browsers.  I did a test migration to another server before the launch. This move went well and everything looks fine in all browsers.  Then I moved the site to its live server where everything looks fine in all browsers except Internet Explorer which is not loading the stylesheets.  I know Drupal is known for generating many stylesheets and Internet Explorer will not load them if there are more than 31 (I believe) of them, but I did set the "Aggregate and compress CSS files" feature and clear the cache. This did not seem to help.  Could the answer be in one of the two following things?   The development site and backup site are both with one hosting provider. The live site is with a different hosting provider. The development site and backup site are in subfolders of two different portfolio sites ... ie www.portfoliosite.com/Newsite. The live site is a subdomain of the parent site ... ie www.newsite.parentsite.com.   I have run out of ideas so if anyone has a possible solution or direction to look, please let me know. Thanks


I typed /kill @e into a repeating, always active command block.   Now whenever I respawn, I am immediately killed.  I've tried to use world edit but was unable to correct the situation.

I set a command block to /tp. It was supposed to activate only if you had 0 time left, and to activate the command block with a hopper clock to keep giving it power.   But it is not checking if you have 0 time left, so it keeps teleporting me. I can't get close enough to the command block to break it, so I'm stuck in a neverending teleport loop.  Any ideas?


I installed python3.5.2 from my home directory from a tar. (I remember using an atlinstall command) Then, I installed django using pip3, by doing sudo -H pip3 install django, and the installation was successful. I also installed numpy, scipy, some other modules. All these modules are accessible when I am using python3.5 as the command from the command line, but I am not able to import these modules when I call python3. And, all the third party software is also using this python3, as a result I am not able to use any GUI to import any of the modules mentioned. My question is, how I can get the other python3 to point to the same thing as python3.5 which has all the modules installed. salman@Skynet ~]$ python3 Python 3.5.2 (default, Nov 17 2016, 17:05:23)  [GCC 5.4.0 20160609] on linux Type "help", "copyright", "credits" or "license" for more information. >>> import django Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: No module named 'django' >>> exit() [salman@Skynet ~]$ python3.5 Python 3.5.2 (default, Nov 30 2016, 11:30:08)    [GCC 5.4.0 20160609] on linux Type "help", "copyright", "credits" or "license" for more information. >>> import django >>>   It works when python3.5 is used. Edit: Requested outputs which python3 python3.5: /usr/bin/python3 /usr/local/bin/python3.5  env | grep -i python; for p in $(ls /usr{,/local}/bin/python3*); do  echo -- $(ls -l $p); $p -c "import sys; print(sys.path)"; done -- lrwxrwxrwx 1 root root 9 Mar 23 2016 /usr/bin/python3 -> python3.5     ['', '/usr/lib/python35.zip', '/usr/lib/python3.5',  '/usr/lib/python3.5/plat-x86_64-linux-gnu', '/usr/lib/python3.5/lib-  dynload', '/usr/local/lib/python3.5/dist-packages',  '/usr/lib/python3/dist-packages'] -- -rwxr-xr-x 2 root root 4460336 Nov 18 01:23 /usr/bin/python3.5     ['', '/usr/lib/python35.zip', '/usr/lib/python3.5',  '/usr/lib/python3.5/plat-x86_64-linux-gnu', '/usr/lib/python3.5/lib- dynload', '/usr/local/lib/python3.5/dist-packages',   '/usr/lib/python3/dist-packages'] -- -rwxr-xr-x 2 root root 4460336 Nov 18 01:23 /usr/bin/python3.5m     ['', '/usr/lib/python35.zip', '/usr/lib/python3.5',  '/usr/lib/python3.5/plat-x86_64-linux-gnu', '/usr/lib/python3.5/lib- dynload', '/usr/local/lib/python3.5/dist-packages',   '/usr/lib/python3/dist-packages'] -- lrwxrwxrwx 1 root root 10 Mar 23 2016 /usr/bin/python3m ->  python3.5m     ['', '/usr/lib/python35.zip', '/usr/lib/python3.5',  '/usr/lib/python3.5/plat-x86_64-linux-gnu', '/usr/lib/python3.5/lib- dynload', '/usr/local/lib/python3.5/dist-packages',  '/usr/lib/python3/dist-packages'] -- -rwxr-xr-x 2 root root 12170760 Nov 30 11:30   /usr/local/bin/python3.5     ['', '/usr/local/lib/python35.zip', '/usr/local/lib/python3.5',  '/usr/local/lib/python3.5/plat-linux', '/usr/local/lib/python3.5/lib- dynload', '/usr/local/lib/python3.5/site-packages'] -- -rwxr-xr-x 2 root root 12170760 Nov 30 11:30  /usr/local/bin/python3.5m     ['', '/usr/local/lib/python35.zip', '/usr/local/lib/python3.5',  '/usr/local/lib/python3.5/plat-linux', '/usr/local/lib/python3.5/lib- dynload', '/usr/local/lib/python3.5/site-packages'] -- -rwxr-xr-x 1 root root 3080 Nov 30 11:31  /usr/local/bin/python3.5m-config Usage: /usr/local/bin/python3.5m-config --prefix|--exec-prefix|--  includes|--libs|--cflags|--ldflags|--extension-suffix|--help|--abiflags|--    configdir  Also, how can I delete the python3.5 from the /usr/local/bin without harming the  python3 in /usr/bin? Thank you everyone for reading the question and answering.

Python virtual environments are used to create isolated python environments to avoid dependency and version conflicts, and also indirectly take care of permission issues. But what is the easiest way to set it up, and use it, in Ubuntu?


I have tried setting a bounty on a question:    Originally set to 400.  Unfortunately I was not able to award it before it exprired.  I understand that I can't get the reputation back, which is not an issue.  The thing is that I can only award bounty that is higher then the one I tried awarding before, so the only bounty I can offer after the previous one expired, so the only bounty I can award now is 500 rep points.  This seems a little odd to me since I might just re-award the same rep amount or possibly less depending on the quality of the answers but the system doesn't allow me to.  Can someone clarify this point?

It's possible to offer and award bounties of reputation on questions.   What is a bounty? How can I find questions that have a bounty attached? How do I start a bounty? When can I start a bounty? Why is the system requiring me to choose a bounty amount that's higher than the minimum? Can I use Markdown formatting in the bounty remarks? Can I edit the remark? How long is the bounty period? How do I award a bounty? Can I award a bounty to my own answer? Can I award a bounty to an old answer? If I offer a bounty on someone else's question, can I award the bounty to their answer? After awarding the bounty, can I remove it or move it to another answer at a later time? What happens if there's no answer after the bounty period? What happens if I feel my question is still unanswered? What is automatic awarding? Are bounty awards exempt from the 200 points/day reputation limit? How does Community Wiki mode affect bounties? How does user deletion or post dissociation affect bounties? Can I award a bounty to an answer from a deleted user or one where the author was dissociated? Can I offer a second bounty after the first one has expired? Can I raise my bounty? What happens if a bounty question is closed or deleted? Why can't I vote to close or migrate a bounty question? What happens if I delete my account while I have an active bounty? Do I keep an awarded bounty when I delete my answer? What happens if a question where I awarded a bounty later gets deleted or migrated? Can I cancel my bounty? Can I affect / divide / share part of my bounty to two (or more) users? How many outstanding bounties can a single user have?      See also:  in the Help Center


Is   $$S=\sum_{n=2}^{\infty} \frac{1}{(\log n)^{\log n}}$$ convergent  or divergent?   My attempt :  $(\log n)^{\log n} = \exp((\log \log n)^2) \le \exp(((\log n)^{1/2})^2) = n$ for $n \ge N_0$, so $$\sum_{n=2}^\infty \frac 1 {(\log n)^{ \log n}} \ge C + \sum_{n=N_0}^\infty \frac 1 n = \infty$$  so it  is divergent   Is its true ?

As the title suggests, I'd like to prove that the sum $$ \sum_{n=2}^\infty (\ln n)^{- \ln n} $$ is finite.  The root and ratio test both fail here, but  suggests that there is a comparison that can be used to show convergence.  The only thought I have is that it may help to write the terms as $e^{-\ln(n)\ln(\ln(n))}$, but this has not led me to any particular insight.  Any ideas are appreciated.


I am a beginner with LED lights, but would like to use a 5mm 365nm UV LED diode to make a pendant with a small fluorescent crystal. I would like to create a very simple, very compact circuit with a coin cell (watch battery), and an on/off switch. What would be the easiest way to do this? I had asked a similar question earlier, but have a brief additional inquiry to make. How would the circuit change if I wanted to use an LED chip instead? Or if I added other diodes for extra brightness?

I am a beginner with LED lights, but would like to use a 5mm UV LED to make a pendant with a small fluorescent crystal. (This is what I purchased ()). I would like to create a very simple, very compact circuit with a coin cell (watch battery), and an on/off switch. What would be the easiest way to do this? Also, would using 2 batteries fix the voltage issue?


I have a data set of 8 rows out of which seven rows are predicted and I need to predict the 8th-row data input. I am not getting where my logic is getting wrong, please let me know where I am getting wrong.{what ever predicted label present before i am getting wrong labels for that too)  flag=0 while flag==0:     cost=0     for i in range(rows):         if lDict.get(i)!=None:             dp=dotproduct(w,x[i])             #print("dotproduct",dp)             sig=sigmoid(dp)             #print("sigmoid",sig)             deviation[i]=lDict.get(i)-sig             #print("deviation",deviation)             step1=lDict.get(i)*sig             #print("step1",step1)             step2=(1-lDict.get(i))*(1-sig)             #print("step2",step2)             cost=cost+(-step1-step2)             print("cost",cost)     for i in range(cols):         for j in range(rows):             if lDict.get(j)!=None:                 delf[i]=delf[i]+(deviation[j]*x[j][i])                 #w[i]=w[i]-(eta*delf[i])                 #print("new_w",w)                 print("delf[i]",delf[i])                 #delw[i]=delw[i]+eta*delf[i]                 #print("delw",delw)     for i in range(cols):         w[i]=w[i]-(eta*delf[i])     print("updated w is ",w)   newcost=0 #print("newcost",newcost) for i in range(rows):     if lDict.get(i)!=None:         #print("w",w)         dp=dotproduct(w,x[i])         #print("newdot",dp)         sig=sigmoid(dp)         #print("newsig",sig)         step1=lDict.get(i)*sig         #print("newstep",step1)         step2=(1-lDict.get(i))*(1-sig)         #print("newstep2",step2)         cost=newcost         newcost=newcost+(-step1-step2)      print("new cost is",newcost)     print("old cost",cost)     if newcost-cost<stop:         flag=1         print("flag",flag)   for i in range(rows):     if lDict.get(i)!=None:         dp=sigmoid(dotproduct(w,x[i]))         print("dp",dp)         print("weights",w)         #sig=sigmoid(dp)         #print("sig",sig)         if sig<0.5:             print(0,"",i)         else:             print(1,"",i)`

I am running an analysis on the probability of loan default using logistic regression and random forests.    When I use logistic regression, the prediction is always all '1' (which means good loan).  I have never seen this before, and do not know where to start in terms of trying to sort out the issue.  There are 22 columns with 600K rows.  When I decrease the # of columns I get the same result with logistic regression.   Why could the logistic regression be so wrong?  **Actual from the data**  0 :   41932  1 :   573426  **Logistic regression output**   prediction for 1 when actually 0: 41932 prediction for 1 when actually 1:573426  A**s you can see, it always predicts a 1**   **Random forests does better:**  actual 0, pred 0 : 38800  actual 1, pred 0 : 27  actual 0, pred 1 : 3132 actual 1, pred 1 : 573399


I came across this in homework but I'm interested in the general example, say $ax+bx^{-1}+c.$

Is there a method to find which numbers to use when simplifying quadratics?   For example $x^2 + 5x + 6$ is easy enough to find, but what if I have bigger numbers, or I have this quadratic expression: $x^2 + 7x – 6$, then it gets very hard to think of a valid simplification.  EDIT: Here's an example: $(x^2 + 5x + 6)/(x + 2)$. When simplifying the first half we get $(x + 2)(x + 3)/(x + 2)$, then we can cancel out $(x + 2)$ and the answer would be $(x + 3)$. The question is: How to always find the right numbers which to put in? (in this example they where 2 and 3)


Does it matter which way I declare the main function in a C++ (or C) program?

What is the correct (most efficient) way to define the main() function in C and C++ — int main() or void main() — and why? And how about the arguments? If int main() then return 1 or return 0?  There are numerous duplicates of this question, including:       — For C++, with a very good answer indeed.     Related:


Since a sudo apt-get update, wine is no longer recognized by Ubuntu (as if I removed the package).  I decided to clean it completely and tried to install Wine again without success. OS : Ubuntu 13.10 64 bits  Output of sudo apt-get install wine  The following information may help to resolve the situation:     The following packages have unmet dependencies:      wine : Depends: wine1.6 but it is not going to be installed or                      wine1.7 but it is not going to be installed   Output of : sudo apt-get install wine1.6  The following information may help to resolve the situation:  The following packages have unmet dependencies:  wine1.6 : Depends: wine1.6-i386 (= 1:1.6.1-0ubuntu1~ppa1) E: Unable to correct problems, you have held broken packages   . I found many different potential solutions on AskUbuntu, but no one works :(  Thanks in advance  EDIT : output of sudo apt-cache policy wine  wine:   Installed: (none)   Candidate: 1:1.7.18-0ubuntu1~saucy1   Version table:      1:1.7.18-0ubuntu1~saucy1 0         500 http://ppa.launchpad.net/ubuntu-wine/ppa/ubuntu/ saucy/main amd64 Packages      1.4.1-0ubuntu7 0         500 http://archive.ubuntu.com/ubuntu/ saucy/universe amd64 Packages

After upgrading from 10.04 to 12.04 I am trying to install different packages.  For instance ia32-libs and skype (4.0).  When trying to install these, I am getting the 'Unable to correct problems, you have held broken packages' error message.   Output of commands:  sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.   After running this:  sudo dpkg --configure -a foo@foo:~$ sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.


My wife with an infant is arriving at Dubai airport at 07:50am on an Emirates, then travelling further to Faisalabad on FlyDubai from terminal 2 at 11.40am. Will her luggage be transferred automatically to that flight? And where will she get her boarding card from for FlyDubai? Somebody please reply thank you.

I have flight where I need to move from airplane to another. Do I need to check out my luggage and then check it in again, or will it be automatically transferred to another plane?


My Acer Aspire E5 Windows 10 computer is broken right now.  I can only boot into Ubuntu Live from this USB, and I fried my BIOS and I cannot boot from any other USB except this Linpus Lite bootable USB of Ubuntu 18.04.  I want to use Ubuntu Live to create another USB that has a custom Ubuntu Live with LaTeX (tex-live) and .tex editor (Tex Studio).  I don't know how to do that.  What are the steps?

I would like to customize Ubuntu live CD by installing some additional packages. I have followed   but it doesn't seems to work. Can anyone provide clear instructions?   Note: I do not prefer Remastersys, manual way will be appreciated.  Customization  Packages that I want to install:   Thunderbird    Samba    SSH       Changes that I need:   Remove Games menu from the Application menu Firefox shortcut on Desktop Radiance as the default Theme Different default Ubuntu Wallpaper   Configuration file changes   I want the panel to be placed at the bottom I want to paste my Samba configuration file instead of default Samba configuration I have few Firefox shortcuts and folders I would like to show that in Desktop Also it will be nice if you say me how to change the icon sets   Recent Updates   I have customized Ubuntu 10.10 with Firefox shortcuts and few folders on desktops. Everything went smooth. But the installer gets crashes after choosing the timezone. How do i fix this issue? Also setting wallpaper affects the login screen. The wallpaper which i set is displayed on the login screen also. I just want the default one for the login screen.


This is the following code. I have to make the array null for a purpose, then when I initialize the array components to 1, it shows null pointer exception. How to handle this?  public static void main(String[] args) {     double[] a;     a=null;     if(a==null)         for(int i=0;i<12;i++)             a[i]=1;         }

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


I have two systems - Ubuntu and Windows, a each of them shows different time. I set "auto internet sync" on both, and it's not working properly. There is a 2h difference for some reason. So when I set on ubuntu 10:48 after restart I will get 8:48 on Windows. When I set on Windows 10:48, after restart on ubuntu I will get 12:48. Anyone had something similar ? Why auto internet sync is not working ?

Dual boot system Windows XP Pro and Ubuntu 12.04.  I have the bios set for the correct time and Ubuntu set for US Eastern time.  Ubuntu will boot up and the time will be off by -4 hours.  If I correct the time in Ubuntu then when I boot up in Windows XP the time will be off by + 4 hours.  This is a fresh install of 12.04. I did not have this problem before reinstalling Ubuntu.


I'm confused on a scenario.  If we roll a ball on a horizontal surface and it rolls without slipping it should eventually stop due to friction.  However rolling without slipping means the velocity at the point of contact is always 0.  Since kinetic friction always opposes movement and the point of contact has v=0 there's no kinetic friction and static friction only arises when there is some force.  Thus there is no friction?  Can anyone clarify what is happening, and point to where I'm confused.

Will a disc or cylinder (rigid body) executing pure rolling on a rough surface stop, neglecting air drag and other heat losses and rolling friction but not static and kinetic friction? If yes, due to which friction it will stop, static or kinetic and how? Assume surface has no rolling friction.


How can I fix permissions for files in the /var/folders/zz?  There are a lot of file under /var/folders/zz that seem to be application caches or some sort.   I am interested in this because, it appears that if the permissions of these folders get set incorrectly (and there is a lot of "help" out there that suggests changing these at one time or another) it can easily break the applications that use them, like Apple Software Update, Apple Setup Assistant, Adobe Flash Installer, and many others.  Note: This asks a different (although similar) question to the one found in , and provides a correct & concise answer to this specific question. It is also not about clearing space, but about fixing permissions on these files, which when incorrect WILL break applications.

I have this folder /private/var/folders/bf/ with 3GB of what seems temporary files. Can I delete this folder?


If I have a record type with picklist fields inside, how can I extract the enabled and non-enabled values from them through a soql query?

How check if a picklist value is available or not for a specified record type ( through SOQL)? Thanks in advance


Next block of code compiles pretty successfully:  #include <map>  template<typename KEY> using umap = std::map<KEY, std::wstring>;  int main() {   umap<int> m;   umap<double> m2; }   Meanwhile, adding an iterator template the same way as the map makes the compiler swear and complain about error C2061: syntax error. So the next block won't compile:  template<typename KEY> using umap = std::map<KEY, std::wstring>;  template<typename KEY> using iter = std::map<KEY, std::wstring>::iterator;  int main() {   umap<int> m;   umap<double> m2; }   Can't we using alias declarations with iterators? Why? And would be a workaround?

In templates, where and why do I have to put typename and template on dependent names? What exactly are dependent names anyway?    I have the following code:  template <typename T, typename Tail> // Tail will be a UnionNode too. struct UnionNode : public Tail {     // ...     template<typename U> struct inUnion {         // Q: where to add typename/template here?         typedef Tail::inUnion<U> dummy;      };     template< > struct inUnion<T> {     }; }; template <typename T> // For the last node Tn. struct UnionNode<T, void> {     // ...     template<typename U> struct inUnion {         char fail[ -2 + (sizeof(U)%2) ]; // Cannot be instantiated for any U     };     template< > struct inUnion<T> {     }; };   The problem I have is in the typedef Tail::inUnion<U> dummy line. I'm fairly certain that inUnion is a dependent name, and VC++ is quite right in choking on it. I also know that I should be able to add template somewhere to tell the compiler that inUnion is a template-id. But where exactly? And should it then assume that inUnion is a class template, i.e. inUnion<U> names a type and not a function?


Like I said, basic....  I have a series of simple illustrations and graphs on physical paper.  Now I need those graphs/ images made to look professional digitally for worksheets, books, online, etc.  Who do I take the physical sheets of paper to and how do I get a hold of such people?  I have some pressing deadlines.  Thanks!

I am developing the backend for a website. I always had the trouble of making an attractive design for my websites and have never hired any graphic designer yet. I have no logo nor web template.  What are the steps to hire a graphic designer? What information should I read about before hiring one in order to make most out of our time? Where should I find him? What questions should I ask him? How much do they charge and what qualifications should I look out for? Should I disclose my business ideas to the designer or could that be risky?


I have applied in Munich, Germany to have a tourist visa to visit UK. Usually, from experience, how long does it take to have the decision made? I have tracked my visa through TLS. Thanks in advance!

On May 9, I applied from Rome using the UK visa center. Two months have passed, and I have not been given any decision on my application. I submitted my visa request on the basis of my husband's Italian passport. It's been 70 days without any response. Is there any way to know when I will receive my visa?  Here's what the status screen shows:


I have a binary string and I want to split it into 31 bits array  1101000011010010010000001101101011110010010000001101110011000010110110101100101001000000110100101110011001000000110000101101110011001110110000101110100  That is just an example of a binary string but I need it to work for any binary string keeping the integrity of the binary string if I want to rejoin the array. Once the array is made append 0's to the front making sure the length of everything is 31.  Thanks

I have a list of arbitrary length, and I need to split it up into equal size chunks and operate on it. There are some obvious ways to do this, like keeping a counter and two lists, and when the second list fills up, add it to the first list and empty the second list for the next round of data, but this is potentially extremely expensive.  I was wondering if anyone had a good solution to this for lists of any length, e.g. using generators.  I was looking for something useful in itertools but I couldn't find anything obviously useful. Might've missed it, though.  Related question:


On trying to install Ubuntu 12.10 Desktop amd64 to a desktop pc using a ga a75 ud4h motherboard (which is using an AMD 3870k APU with a new 1TB HDD) following the advice in the  and  have now got to grub option screen for EFI install. Booting live dvd in EFI mode gives "Secure Boot is not enabled" just before grub kernel option list shows.  If the option to "Install Ubuntu" or "Try Ubuntu without installing" is selected gives "can not read cd/0" and "the kernel must be loaded first" errors. Using DVD or USB installation media gives same results and there has never been at any point an UEFI entry in bios/firmware settings or boot device list/s. It might be helpful to say that have had an alternative non-linux OS installing EFI mode on this hardware giving a GPT installation automagically using USB installation media when the hdd space was completely unallocated space. The USB device was listed under hard drives in bios/firmware one time boot list and did not have an UEFI entry. i.e. it installed EFI although no EFI or UEFI entry was assigned to the device like what is shown in many tutorials regarding UEFI installs. The only constructive information regarding this question is found at  and  but can not work out the answer. Checking md5sum and sha256 checksums on downloaded .iso and used "Check disk for defects" to check burned .iso when booting DVD in BIOS mode. No errors found. "Check disk for defects" will not run (or any other options) when DVD booted in EFI mode. Due to trying different distributions as well as older and newer flavours of Ubuntu all giving similar results in that no options from grub option screen in EFI mode are bootable (if getting that far) as well as spending time searching Ubuntu Forums have come to conclusion the firmware on this system is hardcoded to handle Microsoft EFI files only. After installing Windows EFI mode here is a  and here is a link to a thread i started at  which may be helpful to others building a dual boot system. Installing BIOS mode and using Boot-Repair to install grub-efi is not a complete solution due to the inability of using installation media EFI mode for recovery and maintenance due to the "you need to load kernel first" and "can not read cd/files" errors as described when trying to boot installation media using EFI. Secure Boot is not an issue. Using msinfo32 from windows confirms Secure Boot is not supported on this hardware. How to edit kernel or load kernel for EFI install? = How to EFI install Ubuntu? PLEASE CONSIDER: This is not a dupe!  The linked question that is indicated to having a working answer does not have a working answer to "###How to edit kernel or load kernel for EFI install? = How to EFI install Ubuntu?" therefor the workaround of installing using BIOS then manually install grub-efi without renaming bootloaders which works to get Ubuntu booting using EFI or using boot-repair to do this (and many unnecessary "fixes" if recommended repair is not changed in advanced settings) also works.  This goes some way to confirming hardcoding of firmware is not stopping grub the boot manager seeing the vmlinuz.efi files in /casper on DVD.  I would like an answer to this so would like this question to be reopened.

I installed Ubuntu 11.10 on a newly bought Lenovo ThinkCentre Edge 71 (model: 1577-G3G) with EFI boot enabled. I opted for the Use Entire Disk option. Even though the installation process went without any problems/errors, when rebooting it now just gives me:     No bootable operating system. Insert bootable disk and press any key...   I figure this is because of EFI.   Regression:   I have checked the System Setup (F1 during POST) to find a BIOS option to disable EFI/UEFI boot, however, there is no such option for this machine. This might be caused by a "Secure Boot" feature in the BIOS. The hardware vendor does not know of any such "secure boot" setting in the BIOS that would prevent Linux from booting. Lenovo support did not know anything about a BIOS setting called secure boot. They also did not know of any limitations that would prevent Linux from booting. The  does not mention EFI, UEFI nor secure boot.   How do I install Ubuntu on a machine with EFI? - Or, since Ubuntu is probably already installed: how do I make it boot Ubuntu?


Consider the series $$\sum_1^\infty{(-1)^n\frac{x^2+n}{n^2}}$$ Pick out the true statements: (a) The series converges for all real values of $x$. (b) The series converges uniformly on $\mathbb{R}$. (c) The series does not converge absolutely for any real value of $x$.        (a) is true by alternating series test. (c) is not true as $\sum_1^\infty{\frac{x^2+n}{n^2}} \ge \sum_1^\infty{\frac{1}{n}}$. (b) I have no idea. seek your help for (b)

Consider the series $ \sum_{n=1}^\infty x^2+ n/n^2$  . Pick out the true statements: (a) The series converges for all real values of $x$. (b) The series converges uniformly on $\mathbb{R}$. (c) The series does not converge absolutely for any real value of $x$.        stuck on this problem totally. please help me to solve this problem.thanks .


The configuration of my system(Desktop) is the following:     Processor: Dual core E2140, 1.60 GHz   OS: 64 bit Windows 7   Motherboard: Mercury PVM890M   I am looking for 4 GB DDR2 RAM. But, will the dual core processor will utilize the RAM fully or not? Also, I want to know, can I use DDR3 RAM. Currently my PC has 1 GB DDR2 RAM

If I want to add more RAM to my computer, how can I buy something compatible? What kinds are there? How do I determine which kind my computer will accept and how much I can add?


I have a polygon  that contains all the neighbourhoods in the Netherlands.  My aim is to export the neighbourhoods and coordinates to CSV file (KWT).  Without success I tried (with QGIS) these 'solutions':       It got me to the point where I have all the attributes (from my vector layer) in a CSV file. The problem lies in that I can't seem to find any geodata (coordinates) in them.  Where can I find the polygon coordinates to finally export them with the neighbourhoods out my shapefile to CSV?

Is there a way to choose the field delimiter when exporting a CSV with geometry as wkt in QGIS?  I have a shapefile with donut holes and I'd like to export it as a CSV. It's for a partner whose DB doesn't support spatial data.  I followed  to add a WKT field to my exported file (when exporting to csv, add GEOMETRY=AS_WKT in the "Layer" field, but the exported field delimiter is a comma:   The problem is that each coordinate pairs of my polygons (and I suspect it will be the same for lines) are separated by a comma too so I can't import the data back into QGIS  With point shapefile, it works like a charm.  Does anyone know if I can choose my field delimited when exporting to CSV? Choose a semicolon for instance?  I search on the web and QGIS's documentation but didn't find anything.


I need to align container in the centre as well as in the middle of the body. If I add margin-top it adds a white space above the container div and shifts the background image downwards too. I would prefer everything in percentage.  body {   margin: 0px;   height: 100%;   background-image: url("../Images/LogIn/Background.jpg");   background-size: 100% 100%; }  html {   height: 100%; }  .Container {   margin: auto;   width: 60%;   height: 80%;   background-color: white;   border-radius: 20px; }   <div class="Container"> </div>

I want to center a div vertically with CSS. I don't want tables or JavaScript, but only pure CSS. I found some solutions, but all of them are missing Internet Explorer 6 support.
Div to be aligned vertically
   How can I center a div vertically in all major browsers, including Internet Explorer 6?


Prove for two symbols a and b, if p(a) >= p(b), then according to Huffman encoding algorithm, the resultant code length L(a) <= L(b).  I did several examples of this and it is true. But how can I prove this?

If the frequency of symbol i is strictly larger than the frequency of symbol j, then the length of the codeword for symbol i is less than or equal to the length of the codeword for symbol j.  I attempted to solve this by using Induction.  Basis Step: When we have two symbols, A with prob 0.6, B with prob 0.4, then we can assign A with encoding 0 and B with the encoding 1. This is clear.  Induction Step: Assume that it works correctly for k symbols.  How to show it works for k+1?  Is using induction the right thing to do here?


I had someone design a logo for me and I told him it needed to be in a format that I can resize without losing quality and transparent.  He sent me a transparent PNG file.   If I use a site like pixlr or canva to resize it then I lose the transparency. If I use the file he sent me then the transparency works but the size is wrong.   How do I use the file he sent me and be able to resize it without losing transparency so I can use it on my website? Thank you for your help.

What files should i put in a logo pack to give to clients? Should I put small, medium and large version of my logo as well as the vector file.


I want to make a list of mathematical symbols in a book. I know that using the command \index{}, we can make a list of symbols.  Is there any such easy way to make list of mathematical symbols?

How can I make a list of symbols when I am using \documentclass[a4paper,11pt]{memoir} with input-files?  Here is my main file:  \documentclass[a4paper,11pt]{memoir}  % Include all settings \input{setup} \begin{document}  %\input{titlePage} %\input{hip} %\frontmatter   %\input{abstract} %\input{resume} %\input{preface} %\input{Acknowledgments} %\printnomenclature  %\cleardoublepage %\tableofcontents* %\cleardoublepage %\listoffigures* %\cleardoublepage %\listoftables* \makenomenclature \printnomenclature[6em] \input{Symb}  %\mainmatter    %\input{chapter01} \input{chapter02} %\input{chapter03} %\input{chapter04} %\input{chapter05} %\input{chapter06}  %\input{thebib}  %\appendix %\appendixpage   %\input{appendix01} %\input{appendix02} %\input{appendix03} %\input{appendix04} %\input{appendix05}   %\backmatter %\bibliography{mybib} %\bibliographystyle{unsrt}  \end{document}   And the List of symbols file:  \chapter*{List of Symbols and Abbreviations}  $a$ $N$ $A$ $\sigma$ $m$  \nomenclature{$a$}{The number of angels per unit area}% \nomenclature{$N$}{The number of angels per needle point}% \nomenclature{$A$}{The area of the needle point}% \nomenclature{$\sigma$}{The total mass of angels per unit area}% \nomenclature{$m$}{The mass of one angel}   and here is the setups:  \usepackage[T1]{fontenc} \usepackage[ansinew]{inputenc} \usepackage[danish, english]{babel} \usepackage{graphicx} \usepackage{microtype} \usepackage{lmodern} \usepackage{lipsum} \usepackage[intoc]{nomencl} % Nomenclature package \usepackage{color} \usepackage{times} \usepackage{textcomp} \usepackage{hyperref} \usepackage{textpos} \usepackage{tikz} \usepackage{pgfplots} \usepackage{ifthen} %\usepackage{mathtools} \usepackage{ragged2e,array,booktabs} \usepackage{nomencl} \makeheadrule{headings}{\textwidth}{1pt}   Do you know what I should do?


Can the Puzzle Ring (2.0 version) drop from Kadala? Is there even a slight chance of this.

Reaper of Soul has introduced with  a system of gambling. I know that you can get legendaries from her but I don't know if every legendary in the game can be obtained by gambling.   How do I know if a legendary can be gained through gambling or not ?


I am making a translator that takes english and translates it into a made up language called Talhamr. To do this I take user input and make it into an array. Then I test it against a word bank array that contains english words with the corresponding Talhamr word next to it. If the english word works I want to replace it with the corresponding Talhamr word. Can any one help me code this? bellow is the code I have so far.  Main class:  import java.util.Scanner;  public class Translator {     public static String userInput = "";      public static String[] wordBank = {"a/an","Ai","about","circa" /*...*/};      public static void main(String[] args) {         /**          * getting input          */         Scanner scanner = new Scanner(System.in);         System.out.print("Write something to be translated into ancient language: ");         /**          * formatting input          */         userInput.toLowerCase();         userInput = scanner.nextLine();         String[] wordArray = userInput.split(" ");         /**          * Creating a, and preforming english to talhammir, translation          */         EtoT e2t = new EtoT();         e2t.translateToTalhamr(wordArray, wordBank);         System.out.println(wordArray[0]);         /**          * This is how I formatted the word bank. After I went to quizlet and changed all the spaces between rows and columns to "-"          * String makeNice = ...;          * System.out.println("\""+ makeNice.replace("-", "\",\""));          */      }//end of main method    }//end of Translator class   Second class containing translation method:  public class EtoT {     /**      * establishing word bank to loop through and translate      */     public String[] wordBank = {"a/an","Ai","about","circa" /*...*/};      public EtoT() {     }      public String translateToTalhamr(String[] wordArray, String[] wordBank) {         for (int i=0; i < wordArray.length; i++) {             System.out.print("'");             for (int j = 0; j < wordBank.length; j++) {                 System.out.print(".");                 if (wordBank[j] == wordArray[i]) {                     System.out.print(",");                     wordArray[i] = wordBank[j + 1];                 } else {                     wordArray[i] = wordArray[i] + "!";                 }             }//end of inner word bank         }//end of outer for loop         System.out.println("\n" + wordArray.toString());         return wordArray.toString();     }//end of translateToTalhamr      public static void main(String[] args) {     }//end of main method }//end of EtoT

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


In my unity game I try to give player instruction how to play but it only in first level and first time when game install so how i can do this?

I want to know how to make something happen only once like a tutorial in a game which appears only when you first start your game and then when your game got saved to a further point it never appears again even when you close your game and start again.  I want to give players some amount of gold when they first got their hands on my game ... but I do not want to give them that again and again whenever they restart the game ...  So I want to know how to make something happen only once in a game application..  I hope you get my point ... thanks ..


I already had some courses in statistics and probability.   I would like to learn about statistical modeling. I was looking for resources for a beginner to start with and show me some examples how to use probability and statistical concepts step by step using statistics tools.  Would you please share your experience with me and introduce some resources to start with?

I work in the field of data mining and have had very little formal schooling in statistics. Lately I have been reading a lot of work  that focuses on Bayesian paradigms for learning and mining, which I find very interesting.   My question is (in several parts), given a problem is there a general framework by which it is possible to construct a statistical model? What are the first things you do when given a dataset of which you'd like to model the underlying process? Are there good books/tutorials out there that explain this process or is it a matter of experience? Is inference in the forefront of your mind when constructing your model or do you first aim to describe the data before you worry about how to use it to compute?  Any insight would be greatly appreciated! Thanks.


I tried this:  print(type(list(soup.children)[0]))   but the output I get includes the word 'class' Output: [<class 'bs4.element.Tag'>]  I'd like it to only show me 'bs4.element.Tag', just like if I wrote in the command line:  type(list(soup.children)[0])   Output: bs4.element.Tag

How do I find out a name of class that created an instance of an object in Python if the function I am doing this from is the base class of which the class of the instance has been derived?  Was thinking maybe  might have helped me out here, but it doesn't seem to give me what I want. And short of parsing the __class__ member, I'm not sure how to get at this information.


Is there any way you can find out which devices were previously logged in to your iCloud account even if they are no longer active? If they were removed directly in macOS’ iCloud app, would there be a way to find that information in syslog? Or does Apple provide that information?

Is it possible to determine the exact date and time (if possible) of creation of an Apple ID?   Is there any official or unofficial way to establish this if you don't have the initial sign up information recorded?


I have tried using the formula rt- s^2 but its value is 0 . now how do I search for the points at itsmaximum and minimum.

Q.How do we find out the sum of absolute maximum and absolute minimum values of $f(x,y)=(x+y)^2-(x+y)+1$ on a unit square $\{(x,y):0<x<1,0<y<1\}$?  Using the method of $rt-s^2$ its value is zero. So now how do I search for the Max and main value?


I want to get userid from url like:  http://space.bilibili.com/1950746/#!/channel/detail?cid=1757&order=&page=1   and it should be like 1950746.  And here is the code:  url='http://space.bilibili.com/1950746/#!/channel/detail?cid=1757&order=&page=1' b=userid=re.match(r'\d{7}', url) print(b)   The result is None.

What is the difference between the search() and match() functions in the ?  I've read the  (), but I never seem to remember it.  I keep having to look it up and re-learn it.  I'm hoping that someone will answer it clearly with examples so that (perhaps) it will stick in my head.  Or at least I'll have a better place to return with my question and it will take less time to re-learn it.


coach /koʊtʃ/      umbrella /ʌmˈbrelə/   But how to pronounce "coach's umbrella"   said "The rules for the pronunciation of a noun with ’s are the same as the rules for pronunciation of plural forms of nouns."  So, Is /koʊtʃɪzʌmˈbrelə/ correct?  If it is correct, then "coach's umbrella" & "coaches' umbrella" sound the same.

I know that the "s" becomes "z" when it comes after a voiced sound. And it is pronounced as "s" when it comes after a voiceless sound. I also know rules about possessives but I don't know how natives pronounce a word when it ends in S and "apostrophe S" is added to it. For example: "Stannis's army". Do you add another syllable to it? Like Stannisiz? or just Stannis and ignore the possessive S? I really have difficulty in pronouncing words that end in S and possessive S is attached to it.


Sometimes I find interesting  which has . However, I think that such feature should be implemented and it's possible that other community members also think that. How to handle that case?  I could upvote such question, but then, it wouldn't be clear which upvotes were made before declining the feature, and which after.   I could create new question with similar feature request, but it would be probably closed as duplicate.  I could post a comment that I don't agree with that decline and hope the folks thinking the same would upvote it.  What is the etiquete for showing disagreement with ?

How can one request reconsideration of a   after a certain period of time, let us say after one year?


int random(){     double x = ((double) rand() / (RAND_MAX)); // this i tried but only 0     return x; }    how I generate either 0 or 1 randomly for a tic tac toe player to play

I need to generate random numbers within a specified interval, [max;min].  Also, the random numbers should be uniformly distributed over the interval, not located to a particular point.  Currenly I am generating as:  for(int i=0; i<6; i++) {     DWORD random = rand()%(max-min+1) + min; }   From my tests, random numbers are generated around one point only.  Example min = 3604607; max = 7654607;   Random numbers generated:  3631594 3609293 3630000 3628441 3636376 3621404   From answers below: OK, RAND_MAX is 32767. I am on C++ Windows platform. Is there any other method to generate random numbers with a uniform distribution?


Assume a random vector $X = [x_1, x_2, ..., x_n]$ where the random variables are independent and Gaussian distributed. At the same time, they are not identically distributed; they can have arbitrary means and variances.   What is the probability that $x_k > x_i \forall i \neq k$? In other words, what is the probability that a realization of the random vector will yield $x_k$ as the maximum value in the vector? I'm looking for a closed form solution if one exists.   Here's as far as I got addressing this problem. Assume $k=1$ without loss of generality.  $P\left(x_1 > x_i \forall_{i > 1}\right) = \int_{-\infty}^\infty p(x_1)P\left(x_1 > x_i \forall_{i>1}|x_1\right)dx_1$   $P\left(x_1 > x_i \forall_{i > 1}\right) = \int_{-\infty}^\infty p(x_1)\prod_{i=2}^n P\left(x_1 > x_i|x_1\right)dx_1$  $P\left(x_1 > x_i \forall_{i > 1}\right) = \int_{-\infty}^\infty p(x_1)\prod_{i=2}^nF_i(x_1)dx_1$  where $F_i(x)$ is the cumulative distribution function for $x_i$.   I'm honestly not sure where to go from here. Any suggestions on whether there is a way forward or whether there is a better approach? Numerical integration is an option to move forward but I'd prefer a closed form solution if possible as it would open up other options for investigation in a larger problem I'm attacking.  Thanks!  UPDATE: The previous question-answer pair marked as providing an answer to this question is not for two reasons. (1) The question is seeking the probability that $x_k$ is the minimum, not the maximum and (2) no closed form solution is offered. If a closed form solution was derived, there might have been a similar approach in the answer that could have been leveraged here. But that is simply not present.   UPDATE-2: There is now a  proposed to the related problem for the minimum that provides the basis for solving the question posed here.

I have a set of mutually independent normal distributions $X_1$ to $X_5$ (with means and standard deviations) which represent finishing times for swimmers over a certain distance. The actual data is as follows:  $$X_1(60, 3.0)$$ $$X_2(61, 1.0)$$ $$X_3(58, 2.3)$$ $$X_4(63, 2.4)$$ $$X_5(61, 1.7)$$ So swimmer 1 ($X_1$) has a mean finishing time of 60 seconds with a standard deviation of 3.0 seconds.  Question 1: What is the probability of an event where $X_i$ finishes first. e.g.  $$P(X_1 \lt X_i, i=2,\ldots,n)$$  Question 2: If I calculate this for all swimmers, can I simply order the results to determine the most probable finishing order?  This is not homework.  Based on the answers to this , I have tried to solve this problem based on the first answer. i.e.  $$\Pr(X_1 \le X_i, i=2,\ldots,n) = \int_{-\infty}^{\infty} \phi_1(t) [1 - \Phi_2(t)]\cdots[1 - \Phi_n(t)]dt$$  Where  $\phi_i$ is the PDF of $X_i$ and $\Phi_i$ is its CDF.  Based on this formula, the results I obtained were:  $$\Pr(X_1 \le X_i, i=2\ldots5) = 0.259653$$ $$\Pr(X_2 \le X_i, i=1,3\ldots5) = 0.214375$$ $$\Pr(X_3 \le X_i, i=1\ldots2, 4\ldots5) = 0.611999$$ $$\Pr(X_4 \le X_i, i=1\ldots3, 5) = 0.0263479$$ $$\Pr(X_5 \le X_i, i=1\ldots4) = 0.0697597$$ However, the probabilities add to 1.182135 when they should add to 1.0. I’m not sure if the formula is incorrect or my implementation of the integral (I used Excel and the trapezoidal method).  I also attempted to solve the problem using Dillip’s method (from the above mentioned question) as follows:  \begin{align*} P(X_1 < \max X_i) &=  P\{(X_1 < X_2) \cup \cdots \cup (X_1 < X_n)\\ &\leq \sum_{i=2}^n P(X_1 < X_i)\\ &= \sum_{i=2}^n Q\left(\frac{\mu_1 - \mu_i}{\sqrt{\sigma_1^2 + \sigma_i^2}}\right) \end{align*}  However, the probability results were much greater than 1 in most cases so abandoned this approach. By the way, what exactly does $\max X_i$ mean?  Any assistance in calculating the probability would be appreciated.


I am trying to find quite a simple limit i.e.  for $x_n = \sqrt{2+x_{n-1}}$ and $x_1 = \sqrt{2}$, find:     $$\lim_{n \to \infty}{x_n}$$   So in order to use recurrence relations to find the limit, I must first prove that this limit exists. So i thought I would prove that this sequence is monotone sequence and bounded from above.   By solving $x_{n+1} > x_n$ I got that this holds for $-1 < x_n <2$ . So i thought immediately that by proving $x_n <2$ proves the existence of this limit.   This part seems to be causing me problems. Proving:     $$\sqrt{2+\sqrt{2+\sqrt{2+...}}} <2$$   Now this is intuitive and very simple but I need a formal proof. I did this: $$\sqrt{2} < 2 $$ Adding 2 to both sides gives: $$2+\sqrt{2} < 4$$ Square rooting : $$\sqrt{2+\sqrt{2}} < 2$$ Repeating the process $n$ times: $$\sqrt{2+\sqrt{2+\sqrt{2}...}} < 2$$  But i am not sure of this proof is formal enough or if it is a valid proof. I believe this problem has been solved before but i couldn't find it on math.stackexchange.com .  Of course, calculating the limit gives: $$\lim_{n \to \infty } {x_n} = 2$$  Summary: Is the proof provided above formal enough, and if there are other proofs, I would like to see them?

I need to show that $\sqrt{2}$, $\sqrt{2+\sqrt{2}}$, $\sqrt{2+\sqrt{2+\sqrt{2}}},\ldots$ converges and find the limit.   I started by defining the sequence by $x_1=\sqrt{2}$ and then $x_{n+1}=\sqrt{2+x_n}$. Then I proved by induction that the sequence is increasing and that it is bounded. Then I use the Monotone Convergence Theorem to prove that it converges.  Now, I claim that the limit of the sequence is $2$. So I need to show that for all $\epsilon>0$, there exists $N$ such that for all $n\geq N$ we have $|x_n-2| < \epsilon$. This is kind of where I'm stuck. I don't know how to proceed to prove the convergence to $2$.


I can't import arcpy into 64 bit Python. It works just fine in the python install from arcGIS, though. When I try to import it elsewhere, I get this error:  Traceback (most recent call last):   File "<stdin>", line 1, in <module>   File "C:\Program Files (x86)\ArcGIS\Desktop10.2\arcpy\arcpy\__init__.py", line 21, in <module> from arcpy.geoprocessing import gp   File "C:\Program Files (x86)\ArcGIS\Desktop10.2\arcpy\arcpy\geoprocessing\__init__.py", line 14, in <module> from _base import *   File "C:\Program Files (x86)\ArcGIS\Desktop10.2\arcpy\arcpy\geoprocessing\_base.py", line 14, in <module> import arcgisscripting ImportError: DLL load failed: %1 is not a valid Win32 application.   I've been looking for a solution, but what I'm finding seems to be "too bad, doesn't work in 64-bit." Is this the case?  Edit: working with ArcGIS 10.2.2, Python 2.7.8  Edit: I believe the problem is that I only have the trial version of ArcMap, which apparently doesn't support the 64-bit background geoprocessing installation

I am trying to have Python 64-bit with ArcGIS so that I can use my entire RAM when doing data analysis. Apparently ArcGIS 10.2.2 Desktop comes just with 'Python 32-bit'.   Should I install a fresh Python 64-bit and import arcpy from there?   Is that going to work?   I need to use arcpy and scipy libraries for my data analysis and I need to call both of these libraries in my Python code.   Is there a better way to run 'Python 64-bit' with ArcGIS?


I'm getting real tired of noticing new answers or comments to my questions hours after they were posted because I minimize StackOverflow and resumed working. According to 's answers you're never going to implement instant email notifications, so could you at least give me a sound notification or desktop notification when new inbox items appear? You can even make it optional! Everybody wins.  This would literally just take a few minutes of coding to implement. You already have the events in place, and you've already set up desktop notifications for chat. Come to think of it, I could probably write a Tampermonkey script for this.  My point still stands though. Please consider this.

I noticed that chat supports desktop notifications to notify you when someone pings you, which made me think that maybe the main site has this functionality as well, and I'd really like to use it in that case. But I couldn't find an option to turn them on anywhere.  Chrome notifications look like this:


StackOverflow, ServerFault, and Superuser have ads. (I only see them when I'm not on my own computer where firefox and chrome AdBlock extension is not installed). The new SE 2.0 websites do not seem to have ads. Will this continue for the next couple of years?  I would like to know because ads could be a factor in decisions on whether to migrate existing SE 1.0 communities to SE 2.0 or to use an alternative Q&A platform. There are free-software clones of Stack Exchange (Shapado, possibly others...). I know 1 community (Cheminformatics) that uses a clone and 1 (Bioinformatics) that is considering switching to a free platform. The clones have all the essential features but Stack Exchange software quality and quantity is in the lead.

Some time ago, we announced that . This has gone well and we're extremely thankful to everyone for their support and feedback. Because it has been successful so far, we're going to be extending the program to the majority of our graduated sites. Well, we've pretty much already done that, but there are quite a few sites that have ads enabled, yet still display nothing. The thing is, we don't really have an abundance of clients offering products that a  would find relevant, but Amazon has stand mixers, a selection of super fine chinois, deliciously sharp cutlery and enough cast iron to fill the Gulf Of Mexico with . Beginning as early as this week (week of 5 February 2018), our ad team is going to be hand selecting affiliate ads to be displayed on select sites. The use of inventory will of course depend on the availability of relevant ads to display which means:  Some sites might see very few, if any ads. Some topics simply don't come remotely close to orbiting anything worth advertising. Furthermore, while graduated, some sites simply don't have enough activity for ads to make sense.  Since these are hand-selected, it could take a while for ads to appear initially.  These would of course yield to inventory from clients if clients had products that were relevant to any given topic.   Nothing changes when it comes to the . If you're used to occasionally seeing a community promotion ad, you'll just notice that you'll also occasionally see an ad for something that is likely to be of interest to someone interested in the topic that your site covers. In fact, to be clear, this is simply a continuation of the announcement we made in November of 2016. We just wanted folks to know that we're going to be continuing the program where there's good potential to show relevant advertisements, even if we don't have clients lined up with a demand for it. Where can I give feedback about a certain ad on [site]? Open a meta post on your per-site meta and let us know. Please remember, the bulk of advertisements are an effort to get something small back from folks that hit the sites through search engines and are extremely unlikely to ever become contributors. Their soufflé stopped falling, and we'll probably never see them again. Maybe we can get a few bucks once they realized that copper ions help egg whites stiffen properly and buy a bowl or a proper bloom whisk. However, you're the experts on these topics and we're very likely going to listen to you. What sites, specifically? Are any sites exempt? If you're a former Stack Exchange 1.0 site and / or subsequently joined the network under a special charter, nothing changes - don't panic :) For the rest, we're just extending what we're currently doing with ads on graduated sites to also include those where there's an opportunity to make sensible use of affiliate ads. If a site has less than 15k (average) daily visits, or fewer than roughly 50k combined total posts - it might not yet be time to invest in selecting ads to be shown there. But, part of this exercise is also seeing what works best. I don't really have feedback, just some suggestions Ads aren't just an opportunity to sell stuff, they're an opportunity to really show people that we understand a given topic. That, of course, makes suggestions from people that do that stuff every day quite valuable. Post on your per-site meta and our community / ad critters will take a look. Questions? Comments? Kvetches? Let us know in an answer or comment below. If anything about the plan changes, we'll update this post to let folks know.


Let $V$ be a finite-dimensional vector space. If $\Delta = \{(\textbf{v},\textbf{v})| \textbf{v} \in V\}$ is the diagonal subspace of $V\times V$, show that dim$\Delta$ = dim$V$.   I know this following theorem: Let $W$ be a subspace of a finite-dimensional vector space $V$. Then dim$W$ = dim $V$ if and only if $W=V$.   Then according to this theorem, doesn't it necessarily follow that if I can assume that dim$\Delta$ = dim$V$ is true, then $\Delta = V$ is true since it can be shown that $\Delta$ is a subspace of $V$ (or is that not true?)? But how can $\Delta = V$ if $\Delta$ is made up of tuples of vectors in $V$? For example, if vector $\textbf{v} = (1,1) \in V$, then $(\textbf{v},\textbf{v}) = ( (1,1), (1,1) ) \in \Delta$, but $( (1,1), (1,1) ) \notin V$. Can someone clarify this for me?

Let $V$ be a finite-dimensional vector space. If $\Delta = \{(\textbf{v},\textbf{v})| \textbf{v} \in V\}$ is the diagonal subspace of $V\times V$, show that dim$\Delta$ = dim$V$.   I'm not really sure how to approach this problem at all. Can someone push me in the right direction please?


I have SSMS 2012 installed on my laptop, and SQL Server 2012 on my hosting, but when i try to schedule a sql job i didn't find "SQL Server Agent" in the left side list!!?

I am using SQL Server 2008 Express. I don't have SQL Server Agent option in it. How can I enable it?  I have searched on internet, but couldn't find anything. Do I need to install anything?


Hey I'm new to LTSpice XVII, I couldn't find TL072 or potentiometers in the component library...Could someone kindly guide me on how I could get these two components

I have just started using LTSpice. I need to simulate a circuit with op amps, where the parasitic elements of the op amp may effect performance. So I need to try different 'real' op amps to see which on is best.  Is there a source of commonly available op amp models like TL074 or LM324


I have a generic class I'd like to convert from C# to Java.  The class starts off this way:     public class StackImplementationUsingDynamicArray<T>     {         private T[] _array = new T[10];     }   I can't seem to get the equivalent Java code for the declaration.  This code at least compiles (with a warning) but throws a runtime exception:     public class StackImplementationUsingDynamicArray<T>     {         private T[] _array = (T[])Array.newInstance (StackImplementationUsingDynamicArray.class, 10);     }   Is it possible to do this in Java?  What should the code be?  Thanks in advance for any pointers.

Due to the implementation of Java generics, you can't have code like this:   public class GenSet<E> {     private E a[];      public GenSet() {         a = new E[INITIAL_ARRAY_LENGTH]; // error: generic array creation     } }   How can I implement this while maintaining type safety?  I saw a solution on the Java forums that goes like this:  import java.lang.reflect.Array;  class Stack<T> {     public Stack(Class<T> clazz, int capacity) {         array = (T[])Array.newInstance(clazz, capacity);     }      private final T[] array; }   But I really don't get what's going on.


Shadow Blend from Lords of Madness pg 168 says:     In any conditions other than full   daylight, a shadow creature can disappear into the shadows, giving it total concealment    states that     Total cover or total concealment usually (but not always; see Special, below) obviates the need for a Hide check, since nothing can see you anyway.   Since when you are hidden from an enemy he is flat-footed against your attacks  Rules Compendium pg 92     If you're successfully hidden with respect to another creature, that creature is flat-footed with respect to you. That creature treats you as if you were invisible.   Does shadow blending make my opponent flat-footed?

Can a rogue use cover or concealment in order to Hide, and thereafter make sneak attacks against enemies he is hidden from?  For example:   A rogue sneak attacks an ogre in melee, then runs behind a wall and hides. Having successfully hidden, the rogue runs out the next round and attacks the ogre again. Can he make Sneak Attack? The party is walking through the woods when one is hit by a rogue sniper, who remains hidden. The sniper deals sneak attack damage. The party is now aware of the sniper, but all fail their Spot checks and can't see him. Do the rogue's subsequent attacks deal sneak attack damage?   Rules-as-written, does hiding due to concealment, total concealment or cover explicitly allow you to make sneak attacks? Invisibility or a blinded opponent specifically do, but is there a rule somewhere that you lose Dexterity to AC against opponents who are merely hidden?


This questions has been asked all over the net (here included) but I can't find a satisfactory answer or discussion. Some say it does not radiate if the acceleration is caused by a uniform gravity field. Some even say that it radiates in linear accelerators because of our imperfect technology. All this comes from university member (at least they claim to be). My head is spinning. I always thought (from CED) that any kind of acceleration causes the charge to radiate and loose energy, not that I say that this is the case, but the equivalence principle of relativity never crossed my mind while thinking about this puzzle. Today it did.   Can someone here give some good, kind of fresh, references (no ArXiV please!) or alternatively, try to explain better than what others have done?

The  gives the recoil force, $\mathbf{F_{rad}}$, back on a charged particle $q$ when it emits electromagnetic radiation. It is given by:  $$\mathbf{F_{rad}} = \frac{q^2}{6\pi \epsilon_0 c^3}\mathbf{\dot{a}},$$  where $\mathbf{\dot{a}}$ is the rate of change of acceleration.  If a particle has a constant acceleration, $\mathbf{\dot{a}}=0$, then there is no reaction force acting on it. Therefore the particle does not lose energy.   Does this mean that a constantly accelerating charged particle does not emit electromagnetic radiation?


If I create a Minecraft world (not server) on my computer, will a friend that isn't where I am be able to play in that world?   I am talking about Minecraft for PC. Note that I am only asking about a normal world, not a server. Also, this is without Minecraft realms.

I would like to create a minecraft server for me and and my boyfriend to play on.  How do I set it up? Do I need any additional software? Do you have some links to walkthroughs or tutorials?  I have tried to set this up a few times but have failed every time.


I installed Skype 4.0 following . However my little Skype icon in the unity status bar (in the top right corner with clock, volume, etc.) is gone. How do I get it back?

I have many applications with tray icons like davmail, hardware monitor. I miss this feature on Ubuntu 14.04. Does anyone have a solution?  There are some tools like Skype indicator, but I need a general solution for this problem so that I can add application icons to the system tray.


I have the following schema defined as mentioned  While executing the query   SELECT stn.id      FROM station stn      JOIN station_location_mpng stnloc      ON stn.oid = stnloc.station_oid      WHERE stnloc.location_oid = ?;  Am getting the following exception  ORA-01775: looping chain of synonyms 01775. 00000 -  "looping chain of synonyms"   This is occurring in one of my DB instance. Am a java developer not DBA could anyone point out why am getting exception as above.

I'm familiar with the issue behind ORA-01775: looping chain of synonyms, but is there any trick to debugging it, or do I just have to "create or replace" my way out of it?    Is there a way to query the schema or whatever to find out what the current definition of a public synonym is?    Even more awesome would be a graphical tool, but at this point, anything would be helpful.


Assume a client app that allows OAUTH login (client flow), such that upon login I can access REST, Tooling, Metadata APIs (etc.)  I can get simple org info (id, urls) via an identity call, and I can get the org name by querying the Organization sObject.  There are some Tooling API objects (SandboxInfo, SandboxProcess) related to sandbox creation, but the exist only in the prod org.  How can I get the sandbox name, assuming I'm logged in and can call any API?  I've seen a number of questions about getting the Sandbox name via Apex (and none with simple answers), but I'm wondering if any of the APIs provide better options.  I do not want to rely on hacks such as parsing user names.  Note: As noted above, I am not constrained by running in Apex.  I am looking for an API based solution.  This is not a duplicate of any of the several 'how do I get sandbox name in Apex' questions on the site.

Now after all mere subscribers has per default a lot of sandboxes available, I need a way to programmatically (dynamically) get the sandbox-name of the sandbox org where the actual code is executed.   Just for clarification: I'm not looking for the name of the org, but the name of the sandbox, which are two different things.  One example purpose for this requirement is to tag notification emails, so that it's clear which sandbox-org has created it. For sure I don't want to hardcode it. Also I don't want to use a custom setting.  If found a few unclean approaches like   UserInfo.getUserName().substringAfterLast('.'); ==> this is not reliable, username might have been changed or a system-user might act. But this comes closest to what I need.  use of Organization.IsSandbox ==> not good enough, does not tell me which of the 25+ possible sandboxes it is. Only that's not production. I need more use of Organization.Name ==> all the same for all sandboxes use of Organization.InstanceName ==> provides the server name like CS83, very nice, but not good enough   I think there is no officially supported way to get it... but I'm not 100% sure...  Is there any approach to "hack" that sandbox name out of the guts of the platform? I need no sample code, just an idea or a concept is good enough for me.


I didn't even know this existed. What is it? How do you use it?

According to the Wikipedia page for the , "Use of the comma is consistent with conventional practice" and "Use of the comma is inconsistent with conventional practice." Did the Oxford Comma come before its omission, or was the Oxford Comma traditionally omitted?  It makes logical sense that every item in a list would be separated in the same way: by a comma. If the Oxford Comma is conventionally correct, when and why did people begin to omit it?


I already have Watir-Ruby scripts running on a macintosh which uses Firefox as the browser to run the automation.  I have been given a linux server where the Jenkins build is going on. I got to put my scripts in that server and the automation needs to kick off once the build is done. Will Jenkins on linux be able to trigger UI Automation on a macintosh or will the UI Automation run on the linux machine?

Did anyone succeed deploying Watir test cases to a continuous integration system such as Team City or Hudson?     I'm trying to find a way to have the test scripts executed and have the results generated in a report format? Any experiences using the Ruby plugin for Hudson plus the ci_reporter?


I'm running Dragon Heist for my players, and I've come to a bit of a roadblock so to speak. In chapter 2, the PCs are meant to open and run their own tavern, however it costs 1000gp+ to even open it, let alone pay to operate it. They're only level 2, and seeing as it's the middle of Waterdeep there aren't exactly dragons' hoards or goblin outposts to plunder. How are they meant to make the money in this situation? The book doesn't really offer any specific ways, and I'd rather not run a session based entirely around crafting and performance rolls.

I'm currently running the Waterdeep: Dragon Heist adventure, and want to stay in the book's materials.  There's an opportunity for      the party to renovate Trollskull Manor as an inn, for the cost of 1250gp   How can the party fund this relatively enormous expense, as a party of freshly minted level 2 adventurers? Can they get a loan from a bank? A patron? Ask a faction? Get a (gasp) job?  Are they expected to get this money before continuing in the adventure, or is this something that is expected to be an ongoing project for the rest of the adventure?


After i've used "zonal statistics as table" on some buffers, some values got lost (which seems to be a common problem when buffers overlap as mine does). Now, i would like to replace these Null values by using the "Field calculator". I would like the cells with null values to take on the last value that was not a null value - eg. in the picture attached to this question, i would like the first set of Null values to get the value that preceeded them (in this case 0,655745625495911). I am aware i can do it manually but as the table consists of 330000 rows i would rather not. So, can anyone help me with a pythoncode to change these null values to the value that preceeds them?

I am using QGIS. I have an attributetable with several columns. I want to change the values of column1 if they are NULL with the values of the same row in column5. case WHEN column1 is NULL THEN  END  How do I say "use the value from the same row"?


I have a Bachelor of Business Administration in Information Systems (3rd Class Honors) form a UK University. My Transcript states as follows.  Course Name    Marks    Cats BUS            40       12   How do I convert these to the German Grading System?      I have gone through the above but can't figure out how to calculate the UK (40 Marks and 12 Cats) to the German Grades (scale of 1 to 5) and also how to figure out the ECTS (European Credit Transfer and Accumulation System).

I'm trying to figure out the equivalence between grade schemes in different countries.  According to some Google results:   If you are a U.S. citizen, you need a GPA of 3.2+ (it varies, some say 3.2 and some others say 3.6, etc) to apply for a position in the UK (job or university) where the prerequisite is to have a minimum grade of 2:1. In UK 2:1 is earned if you have a 60-69% of the points. I've read that 2:1 is the same as 67%. In Spain we use a grading scheme of 10 points. So according to (2), for have a UK 2:1 you need to have 6-6.9 points. If you are Spanish and have 6.7, when converting it to GPA the result is 1.5.   However, if you take the above points and treat them as a math equation, the final result will be GPA 1.5 = GPA 3.2, which doesn't make any sense.  GPA 3.2 = UK 2:1 UK 2:1 = Spain 6.7 Spain 6.7 = GPA 1.5   Replacing now...  UK 2:1 = GPA 1.5     GPA 3.2 = GPA 1.5   My question is if someone has a better explanation on converting grades obtained in different countries.


I have a file root.ext2 in a iso file. How can I  open and see content of ext2 file in Ubuntu?

How do I create a file of size 10M, format it with ext3 filesystem and then mount it in /media/fuse?  I tried with  mkfs -t ext3 file   then to mount it  mount -t ext3 file /media/fuse   It didn't work because it said that file wasn't a block device. Can anybody help me?


I have just encountered the following exercise which has me quite stumped:     Let $ f $ be analytic on the closed unit disk, and we assume that $ | f(z) | \leq 1 $ for all $ z $'s in this set. We also have $ f(\frac{1}{2}) = f(\frac{i}{2}) = 0 $. We need to prove that $ |f(0)| \leq \frac{1}{4} $.   I thought about using Schwarz's lemma to modify the function, but in Schwarz's lemma we assume only one zero at the origin, how does one use the two zeroes here to modify the function and obtain the bound?  Any help would be appreciated.

I need some help with this problem:     Let $f\colon D \to D$ analytic and $f(z_1)=0, f(z_2)=0, \ldots, f(z_n)=0$ where $z_1, z_2, \ldots, z_n \in D= \{z:|z|<1\}$. I want to show that $$|f(z)|  \leq \prod_{k=1}^n \left| \frac{z-z_k}{1-\overline{z_k}\, z} \right|$$ for all $z \in  D$.   It seems that I need to use Schwarz-Pick Lemma but it seems that the problem doesn't satisfy the conditions. Another lemma that I can use is that of Lindelöf saying: Let $f:D \to D$ analytic, then $$|f(z)|\leq \frac{|f(0)|+|z|}{1+|f(0)| \cdot |z|}$$ for all $  z \in D$.  It seems to be an easy problem but I couldn't succeed in solving it.


For years I've worked with inset to make many shapes and objects, most notably guns and other game asset-type things. However recently inset has stopped working as I need it to, when using it on vertical faces. On horizontal faces however it works fine.  Refer to the attached images.

I seem to have screwed up something that allows you to inset evenly, I think I have tried every combination of settings in inset and pivot center and even is far from even.  I tried uninstalling and re installing blender 2.71 and get the same result.  The image attached is a simple default cube that I tried to inset evenly.  I have also attached the blend file link  help??


var source = new List<string> { "A1", "A2", "B1", "B2" }; var filtered = source.Where(s => s.StartsWith("A"));  foreach (var s in filtered)     Console.WriteLine(s);    // outputs first A1 and then A2   It seems like  keeps the original order of elements when used on an ordered IEnumerable (such as a List<T> or T[]). Is this always the case? If yes, where is this documented?

I use LINQ to Objects instructions on an ordered array.  Which operations shouldn't I do to be sure the order of the array is not changed?


I am trying to determine what time format is this string "2019-03-31T08:29:00" so I can convert it to datetime object but I can't find the answer to this.  Can somebody help please?

I need to parse  strings like "2008-09-03T20:56:35.450686Z" into Python's datetime type.  I have found  in the Python standard library, but it is not very convenient.  What is the best way to do this?


This is my dd command which I need to modify:  dd if=/tmp/nfs/image.dd of=/dev/sda bs=16k   Now I would like to use pv to limit the speed of copying from NFS server. How can I achieve that? I know that --rate-limit does the job, but I am not sure how to construct pipes.

I am copying huge file from NFS mount using dd:  dd if=/mnt/nfs/image.img of=/dev/sda   I need to limit the speed of reading from NFS. How can I achieve it? The only precondition is to use some easy compilable utility in order to put into my custom ram-only live linux distro.


Basically, I'm looking for advice on how I could find the value of $$\int_0^\infty \frac{\mu^x}{\Gamma(x + 1)}dx $$ where $\mu > 0$ is an arbitrary positive constant. Based on the infinite series, I was initially expecting this to be something close to $e^\mu$ (if not exactly that). However, numerical experiments have convinced me that this is a flawed assumption unless $\mu$ is relatively large. I'm happy to push on the problem myself --- I'm just a bit unsure where to start. P.S. For context, I'm an applied statistician trying to force through an unorthodox probability distribution for data-efficiency reasons. Thanks in advance!

Now since the sum $$ \sum_{n=0}^\infty \frac{x^n}{n!},\quad x\in\Bbb R, $$ does have some relatively nice properties, is the same true for its analogues integral? If we take the gamma function to be a generalisation of the factorial with $\Gamma(n+1) = n!$, an obvious analogues integral formula would be $$ \int_0^\infty \frac{x^t}{\Gamma(t+1)}\text dt,\quad x\ge 0. $$ Does this integral have any similar, nice properties?


1. -->     String s1 = "Rishi";  String s2 = "Ri" + "shi"; System.out.println(s1==s2);  // true  String s3 = "Ri".concat("shi"); System.out.println(s1==s3);  // false   Why while using '+' operator its coming as true but not in case of concatenation?  2. -->     String s1 = "Rishi";  String s2 = "Ri" + "shi"; System.out.println(s1==s2);  // true  String s3 = "Ri"; String s4 = s3 + "shi"; System.out.println(s1==s4);  // false     Why the output varies even if using the same literal value?

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


Can I see or be informed of deletion request reason(s)?  On sites where I have deletion request privileges, for someone else's post, I can click on the "delete (n)" link and see what's been suggested (and then cancel if I was only looking).  I have one deletion request for an answer on a site where I don't have deletion request privileges. In this specific case I don't care much about the answer -- it also has a current score of -1 (and no comments) -- but I noticed I can't find out what the reason for the deletion request is.  For questions, close reasons are reported to the OP so they may attempt to fix the problem. I believe that same opportunity should be offered to answerers.

I'm aware that this only affects high rep users and mods, but nevertheless it would be nice if the following selection would appear when a user casts a delete vote on an answer.    If I am not mistaken, this only appears when casting delete votes from the review queues. I don't see a reason why this shouldn't also appear when casting a vote directly to the answer, instead of the (java script) alert with "Delete this post?".  Or in other words, the selection should always appear when a user does some kind of 'delete answer' action.


Note: Please read the whole thing before you wrongly mark it as a duplicate.  So I'm not sure if this is write and I can't find an easy chart to answer it: -Is it true that if you have a PUBLIC, PROTECTED, OR PACKAGE PRIVATE method or field in the superclass and the subclass is in the SAME PACKAGE, then a class OUTSIDE OR WITHIN the package can access those methods or fields via a new subclass object and if the field or method is PRIVATE, then it CANNOT? -Is it true that if you have a PUBLIC, OR PROTECTED method or field in the superclass and the subclass is in a DIFFERENT PACKAGE, then a class OUTSIDE OR WITHIN the package can access those methods or fields via a new subclass object and if the field or method is PACKAGE PRIVATE, OR PRIVATE then it cannot?  In other words, all the access combinations (32 combinations) of: public, protected, package private, and private for methods, fields, for subclasses in same, or different package, access by a class creating the subclass object in a class in the same or different package. Note the main difference between this question and the "duplicates" is that I am wondering about access with NON-SUBCLASSES within/outside the package. NOT JUST THE STUFF INSIDE THE SUBCLASS. The duplicates are not specific enough because there are tiny rules that are not as simple as a 4 x 2 table. Example, for protected, a subclass outside of the package cannot run a super class method on a superclass object, only the subclass object. Little things like that are not answered in the "duplicates".  And can y'all read the whole dang thing before you mark it as a duplicate. I explained why it wasn't but lazies don't read the whole thing nor answer the question.

In Java, are there clear rules on when to use each of access modifiers, namely the default (package private), public, protected and private, while making class and interface and dealing with inheritance?


I am trying to solve the following problem:  Let $a,b,c>0$ with $\frac{1}{a}+\frac{1}{b}+\frac{1}{c} = 1$. Prove that: $$(a+1)(b+1)(c+1)\geq 64$$  So far, I have gotten that by AM-GM, $(a+1)\geq 2\sqrt{a}$, $(b+1)\geq 2\sqrt{b}$ and $(c+1)\geq 2\sqrt{c}$ so: $$(a+1)(b+1)(c+1)\geq 8\sqrt{abc} \tag{1}$$ Then using AM-GM on $\frac{1}{a}+\frac{1}{b}+\frac{1}{c}$, we get that: \begin{align} \frac{1}{a}+\frac{1}{b}+\frac{1}{c} & \geq 3\times \frac{1}{\sqrt[3]{abc}} \\ 1 & \geq 3\times \frac{1}{\sqrt[3]{abc}} \\ \frac{1}{3} & \geq \frac{1}{\sqrt[3]{abc}} \\ \frac{1}{27} & \geq \frac{1}{abc} \\ abc & > 27 \end{align} Substituting this into $(1)$, we get: $$(a+1)(b+1)(c+1)\geq 8\sqrt{27}$$ So I clearly went wrong somewhere, though I'm not sure why. It would be best if you could provide a solution using AM-GM or Muirhead's Inequality. The question seems so simple, where equality happens at $a=b=c=3$, though I can't prove this. Thank you in advance for your solutions and hints!

Given that $\frac{1}{a}+\frac{1}{b}+\frac{1}{c}=1$ show that:$$(a+1)(b+1)(c+1)\ge 64$$ My attempt: First I tried expanding the LHS getting that$$abc+ab+bc+ca+a+b+c \ge 63$$ I applied Cauchy-Schwarz on $(a+b+c)(\frac{1}{a}+\frac{1}{b}+\frac{1}{c})$ getting that $a+b+c\ge9$.  Then I also tried to manipulate the first condition and got $abc=ab+bc+ca$, then I applied AM-GM on $a+b+c$ getting the following$$a+b+c\ge3\sqrt[3]{abc}$$ Finally I substituted $ab+bc+ca=abc$ in my initial expression, getting:$$2abc+(a+b+c)\ge63$$The last thing I tought about was that I have both $a+b+c\ge9$ and $a+b+c\ge3\sqrt[3]{abc}$ so if I somehow related them I would have $\sqrt[3]{abc} \ge 3 \rightarrow abc\ge27$ and with this conditions the problem would follow by summing, but the direction of the inequality is not allowing me to do as intended...  I'm stuck here, have tried lot of other things but nothing really worked, also partial help is appreciated!


I'm trying to understand the derivation of the transfer function for the following electrical system:     Where \$k\$ is some forward gain element and \$G_{s}\$ is the transfer function of some plant. According to an instruction video, the transfer function for this whole system is $$T(s) = \frac{Y}{R} = \frac{k G_{s} }{1+kG_{s}} .$$  I am wondering how this expression for \$T(s)\$ can be derived. It probably has something to do with the control mechanism, but I am not an electrical engineer so I'm not sure how to derive this expression. I do have a background in mathematics though, so maybe you can take that into account in your answer.

Below is a block diagram of the system. I thought the circle symbol with the plus and minus sign was an op-amp but I'm not sure whether that's the case. I want to find the closed loop transfer function. If there was no feedback (open loop), then I think I could find the output as Y(s) = Vin*G. This would mean that the transfer function is Y(s)/Vin = G.  Any ideas for how to find the closed loop transfer function and what the circle means?


I would like to create computed index on a table if sql server is 2008 or newer and a simple index if sql server is 2005 or older:  -- check for sql server version if (select cast(left(cast(serverproperty('productversion') as varchar), 4) as decimal(5, 3))) >= 10          CREATE unique nonclustered index ix1_table             ON table (column1, column2)             WHERE column1 is not null and column2 is not null         ELSE             CREATE nonclustered index ix1_table                 ON table (column1, column2)   problem is that the whole statement is evaluated and on sql server 2005 this throws an error      Incorrect syntax near the keyword 'WHERE'.   Is it possible to somehow create different index based on sql server version?  Thanks  Dragan

I would like to create computed index on a table if SQL Server is 2008 or newer and a simple index if SQL Server is 2005 or older:  -- check for sql server version if (select cast(left(cast(serverproperty('productversion') as varchar), 4) as decimal(5, 3))) >= 10          CREATE unique nonclustered index ix1_table             ON table (column1, column2)             WHERE column1 is not null and column2 is not null         ELSE             CREATE nonclustered index ix1_table                 ON table (column1, column2)   The problem is that the whole statement is evaluated and on SQL Server 2005 this throws an error:     Incorrect syntax near the keyword 'WHERE'.   Is it possible to somehow create different index based on SQL Server version?


How to write the following symbol in LaTeX      that's used for Banach algebras.

I know what my symbol or character looks like, but I don't know what the command is or which math alphabet it came from. How do I go about finding this out?


I want to test non-retina/non-HiDPI mode on macOS Mojave on the built-in display of a MacBook Pro (15-inch, 2017). I found articles that suggest enabling the option sudo defaults write /Library/Preferences/com.apple.windowserver.plist DisplayResolutionEnabled -bool true, restarting the computer, opening System Preferences, selecting Displays, and holding down the option ⌥ key when selecting Scaled should show a list of all available resolutions, including non-HiDPI resolutions; however, I just see the following:

A question I've had in my head since I first saw screenshots of the display preference pane on the new Retina MBP is this: Can it be made to run with what you could call a 1.0 UI scaling factor (same amount of pixels for the same widget as you'd get on a regular MBP or say, an iMac)?  To clarify, the preference pane appears to allow you to select between several predefined scaling factors from "Like 1920x1200" (UI scaling factor = 1.5) through "Like 1440x900" (UI scaling factor = 2.0) to "Like 1024x640" (UI scaling factor = 2.8125) and there is also a radio button for "Best for Retina display".  Does this radio button for "Best for Retina display" set the UI scaling to 1.0 or does it simply set the scaling to the "default" 2.0?  If the latter, has anyone checked if there's some defaults write com.apple.[...] 1.0 setting available which forces the scaling of the UI to 1.0?  It might not always be a useful mode to run things in but I can see several use cases where it would be very useful for me to be able to set the UI scaling to 1.0 rather than somewhere between 1.5 and 2.8125...


I recently bought a bq smartphone ubuntu edition, and I was surprised to see so many pre installed apps that I don't want to use. Some of them are apparently easy to remove, by going to the ubuntu store.  But there is something that I don't manage to do. I'm in the Apps scope, and slide the screen upwards. Then, I see a screen with a list of the active scopes named "Home", and a second list named "Also Installed". In this list I see many apps that I don't manage to find in the ubuntu store, and therefore I cannot uninstall. For instance, 7 digital, Amazon, cnet, ebay... many of them.   But I'm not sure that the procedure of uninstalling them from the ubuntu store is really working: If I go to Settings->About this phone->Storage, I see a detailed list of the apps that are using memory in my phone. In this list there are some apps that I previously uninstalled using the ubuntu store procedure. For instance, BBC, BBC sport, facebook,facebook photos, Gmail... and many more are still using memory in my phone.  My question is: How can I really get rid of these apps that I don't want to have? I would like not to dedicate a single bit of space to those apps

Currently, my Ubuntu Phone Aquaris E4.5, wants me to update a bunch of preinstalled apps like engadget, cnet, bbc, euronews, bbc sport.  How can i uninstall those apps?


I cannot find any example of function $f:\mathbb{N}\rightarrow\mathbb{N}$ of which we can say that  $$ f(\mathbb{N})=\emptyset $$ Does there exists any?

Let $A$ to be a nonempty set and $B= \emptyset$; then $ A \times B$ is a set. And let $F$ be a function $A \to B$. Then $F \subseteq A \times B$. By the axiom of specification, $F$ must exists (if I didn't mess up something).   But the book I'm reading, Elements of Set Theory by Enderton, says that no function could have a nonempty domain and an empty range, and no more detail is given.  So my confusion arises. His statement against my proof. The only axiom as far as I know to prove such a set does not exist is the axiom of regularity. But I can't give such a proof. So I need help. I hope someone could clearly explain why such a function doesn't exist, and why this doesn't contradict the axiom of specification.    Let me explain my confusion in more detail:  First of all, I know that $A \times \emptyset$ is empty. But $ \emptyset \times A$ is also an empty set, yet there is no problem with functions with an empty domain.  The book I'm reading defines a function as:      "A function is a relation such that for each $x$ in $\operatorname{dom} F$ there is only one $y$ such that $x \mathop F y$."   and a relation as:     "A relation is a set of ordered pairs."   Now, let me define the function $F$ as: $$F =  \{\langle x,y \rangle \mid x \in A \text{ and } y \in B \text{ and ... other conditions} \}$$  so it's equal to: $$F = \{ \langle x,y \rangle \in A \times B \mid \text{... other conditions} \}.$$  Doesn't that mean that $F$ meets the conditions of the axiom of specification, and therefore exists?    What I would specifically like to ask is:   How do you define a function $F$ (as precisely as possible)? Why does the argument above not imply that a function $F: A \to B$ always exists? Does $F \subseteq A \times B$ still hold when $B = \emptyset$?   (The answer to #2 cannot simply be that $A \times B = \emptyset$, because $ B \times A = \emptyset$ as well, but a function $B \to A$ does exist.)


I want to create a list like toc, lof, lot. Is should be called listofsongs or similar. The question is: Is there any package which allows me to create similar lists or do I have to do this all by myself?  Is there a list of already used file extensions in LaTeX? i.e. I shouldnt use MyDocument.toc because this would cause conflicts with tableofcontents.  In the end, I should be able to write \listofsongs like I write \tableofcontents and it should behave similar.

Is it possible to introduce an own table of contents in LaTeX? I would like to introduce an own tag, to define some terms in my document. At the end of the document I would like to automatically generate a list of defined terms, with links to the page, where the term was defined.


I have recently switched my hosting server to AWS. and in initial all was working fine but recently I am facing issues with my server that its get down several time.  I have monitor it closely and get to know that CPU utilization goes to 100% several times and every-time I need to restart my instance.  So I have checked access log and error logs and seems some hacking activities going on my server. Please have a look below logs of my error log file:  [Wed Sep 23 14:25:56.081268 2015] [:error] [pid 18791] [client 193.0.***.***:59940] script '/var/www/html/includes/custom.php' not found or unable to stat, referer: -1' OR 2+20-20-1=0+0+0+1 or 'Q2fRfUkq'='  [Wed Sep 23 14:25:56.122526 2015] [:error] [pid 18780] [client 193.0.***.***:59939] script '/var/www/html/includes/custom.php' not found or unable to stat, referer: @@EKtcl  [Wed Sep 23 14:25:56.365583 2015] [:error] [pid 18788] [client 193.0.***.***:59930] script '/var/www/html/includes/custom.php' not found or unable to stat, referer: -1" OR 2+392-392-1=0+0+0+1 --  [Wed Sep 23 14:25:56.663520 2015] [:error] [pid 18786] [client 193.0.***.***:59908] script '/var/www/html/includes/custom.php' not found or unable to stat, referer: if(now()=sysdate(),sleep(9),0)/*'XOR(if(now()=sysdate(),sleep(9),0))OR'"XOR(if(now()=sysdate(),sleep(9),0))OR"*/   [Wed Sep 23 14:25:56.994941 2015] [:error] [pid 18791] [client 193.0.***.***:59940] script '/var/www/html/includes/custom.php' not found or unable to stat, referer: (select(0)from(select(sleep(9)))v)/*'+(select(0)from(select(sleep(9)))v)+'"+(select(0)from(select(sleep(9)))v)+"*/   Now here I can see that its trying to access non existing file and adding sql injections, and unbelievable things is its working, its using my CPU utilization to 100% and mysql service uses 90% here.  So how to prevent this, please help me on the same.  Its taking mysql access here so that happening ? As we can see there is no any custom.php available then how they are running mysql queries on the server ?  And most important thing is hacker hacking through curl or post script but not using my machine atall

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