First Complete Lockup Hard Reset of New PC
Blender render crash when using subsurf modifiers.
How many fixed points in a permutation I am taking a probability course and we have been of course learning the classic problems of men with hats or variations of that in some other form. The problems being of the type if $n$ men have $n$ hats and mix them all together, whats the probability $0, 1, 2,$ or $k$ men choose their hat.   But from what I can gather is that they are all problems of the same type, for any given random permutation of $k$ objects how many fixed points are there. My professor taught us to solve this using conditional probabilities (conditioning on whether the first person matched and then generating a system of equations) and using the inclusion-exclusion principle. But is there any other way to reason this? MariaDB won't start on Ubuntu: Can't lock aria control file jQuery :first vs. .first() When I created my account, I used Facebook Connect as my only login type and I can only log in to my account using it.  I wish to create a Stack Exchange login to be able to log in with instead of Facebook Connect, but I can't find how to do this. It seems that the option for creating a Stack Exchange login is only present when creating a new account? Mixed DML operation error I am facing Mixed DML error in the following case:  static testmethod void method1() {     User u1 = DataFactory.createUser('testUser','test@user.com','permissionSetAPIname');        Obj1 rec1 = DataFactory.createrec1('Record1');     insert rec1;      Obj2 rec2 = DataFactory.createrec2('Rec2',rec1,system.today()-10, system.today()+10 );     insert rec2;       Obj3 rec3 = DataFactory.createrec3(rec2,'Tester',u1,'US');     insert Role;      test.starttest();         //testing code      test.stoptest();  }   However the following is working fine  static testmethod void method1() {      User u1 = new User(Alias = 'testRole',                   Email             = 'role@test.com',                   EmailEncodingKey  = 'UTF-8',                   LastName          = 'user',                   FirstName         = 'test',                   LanguageLocaleKey = 'en_US',                   LocaleSidKey      = 'en_US',                   ProfileId         = [select Id from Profile where Name = 'Basic User' limit 1].Id,                   TimeZoneSidKey    = 'America/Chicago',                   Username          = 'stakeholder@test' + Math.round(Math.random() * 10000) + '.com',                   UserRoleId        = null,                   Country           = 'Great Britain');     insert u1;         Obj1 rec1 = DataFactory.createrec1('Record1');     insert rec1;      Obj2 rec2 = DataFactory.createrec2('Rec2',rec1,system.today()-10, system.today()+10 );     insert rec2;       Obj3 rec3 = DataFactory.createrec3(rec2,'Tester',u1,'US');     insert Role;      test.starttest();         //testing code      test.stoptest();  }   Please explain the difference. As my understanding is that transaction remains the same in both the cases. I was wondering if there were any two integers $a$ and $b$ where $a^3=b^2$. What permissions should my website files/folders have on a Linux webserver? This is a  about File Permissions on a Linux web server.   I have a Linux web server running Apache2 that hosts several websites. Each website has its own folder in /var/www/.  /var/www/contoso.com/ /var/www/contoso.net/ /var/www/fabrikam.com/   The base directory /var/www/ is owned by root:root. Apache is running as www-data:www-data. The Fabrikam website is maintained by two developers, Alice and Bob. Both Contoso websites are maintained by one developer, Eve. All websites allow users to upload images. If a website is compromised, the impact should be as limited as possible.  I want to know the best way to set up permissions so that Apache can serve the content, the website is secure from attacks, and the developers can still make changes. One of the websites is structured like this:  /var/www/fabrikam.com     /cache     /modules     /styles     /uploads     /index.php   How should the permissions be set on these directories and files? I read somewhere that you should never use 777 permissions on a website, but I don't understand what problems that could cause. During busy periods, the website automatically caches some pages and stores the results in the cache folder. All of the content submitted by website visitors is saved to the uploads folder. Best way to restrict access by IP address? For an ASP.NET C# application, we will need to restrict access based on IP address. What is the best way to accomplish this? What's the fastest connection speed / shortest elapsed time using Migration Assistant? Is there any difference between "color" and "colour"? What is the difference between color and colour? Changing Unsubscribe reason through SSJS I noticed that you can unsubscribe a user , is it possible to use SSJS to change the unsubscribe reason?  I notice that doing it through ? why is that?  Thanks Requirements for a clan war? I am currently in a clan with three members. When we tried to initiate a clan war it said we had insufficient clan requirements. Does anyone know what the full requirements are? Is there a minimum clan member requirement? Multiple Damage Resistance Similar questions to this have been asked, but I wasn't able to find one that answers this specifically.  Say that you have resistance to slashing damage as well as resistance to fire damage (no caveats to nonmagical damage or not).  You are fighting someone who has a flaming greataxe (just an enchanted item) that deals 1d12+STR slashing damage, plus 1d6 fire damage on hit and they hit you.    How do you calculate the damage?   (1d12+1d6+STR)/2 (1d12/2) + (1d6/2) + STR (1d12+STR/2) + (1d6/2) something else? There is this famous example about the order difference between gravitational force and EM force. All the gravitational force of Earth is just countered by the electromagnetic force between the electrons on the surface of my feet and the ground.  But also wave-function of electrons(fermions) do not overlap each other due to Pauli exclusion principle.  So which one is the true reason of me not flopping inside the earth forever? Is it only one of them(my guess is Pauli exclusion) or is it both? What does one second after big bang mean? Consider the following statement:     Hadron Epoch, from $10^{-6}$ seconds to $1$ second: The temperature of the   universe cools to about a trillion degrees, cool enough to allow   quarks to combine to form hadrons (like protons and neutrons).   What does it mean to say "from $10^{-6}$ seconds to $1$ second"?   How is time being measured?  One particle might feel just $10^{-20}\ \mathrm s$ having passed and another could feel $10^{-10}\ \mathrm s$ having passed.   Is saying "1 second after the big bang" a meaningful statement? I find in many places mentions of pre-amplifiers being used to boost audio signals prior to feeding to a power amplifier.  Wikipedia's article on  gives some hints at their usage, but it doesn't really explain why it would be necessary to have two amplifiers in series rather than a single one with greater gain.  If a pre-amp is just a power amp with a smaller gain, what's the point, and why the distinction between the two kinds? Is the distinction in function, or simply purpose? Fibonacci Recurrence Relations Solve the recurrence relation $f(n) = f(n − 1) + f(n − 2)$ with initial conditions $f(0)=1$, $f(1)=2.$   So I understand that it grows exponentially so $f(n) = r^n$ for some fixed $r$.  This means substituting this $r^n = r^n-1 + r^n-2$ which gives the characteristic equation of $r ^ 2 - r - 1 = 0$. I'm not 100% sure where to move on from here. I just installed Lyx 2.1 on my computer for the first time. I wanted to create my first trial pdf but switching to viewing mode is for some reason not working with the Acrobat Reader DC. I tried many options found on the web but I am afraid my little knowledge is not sufficing to make it work.  I would really appreciate a detailed answer :)   Thanks. Is a function defined at a single point continuous? Is a function defined at a single point continuous?  For example $f:\{0\}\to\{0\}$ defined by $f(x)=\sqrt{x}+\sqrt{-x}$ is a sum of two continuous functions and is therefore continuous, however for $f$ to be continuous, it has to have the limit $\lim\limits_{x_0\to x}f(x_0)=f(x)$ but it dosen't seem to have that limit. Gauge fields and strings: Loop equations