Why does TIA/EIA 568A and TIA/EIA 568B use pins 1, 2, 3 and 6 to send and receive, instead of 1, 2, 3 and 4? Is there a significant reason for this?
Is there a reason why the pin diagram of an RJ-45 looks like this?    I understand that the orange pair is used for Tx and the green pair for Rx. Why is it that the orange pair are kept together while the green pair are separated?  What are the consequences of messing around with this order as long as it is the same at both the ends?
Find out which application listens to specific key bindings? Is there an application to know which key is bound by which process and therefore not usable in another application? How can I repair a buried 120v cable splice to make it meet code? I have an electrical question. I have a cable feeding an outdoor yard light. It was cut, I spliced it, soldered it and wrapped it with tape. Is there a way to splice and bury it safely to code? If not, I'll need to dig a 30 foot trench to replace the whole length.  Was about 8 inches below ground, surfaced over the years and probably hit with the weed trimmer.   It is outdoor cable inside copper tubing. Years ago when I bought the wire I knew outdoor was gray. The box said outdoor but it is white like indoor wire.   It was spliced about 20 years ago but am fixing up house and like to hide the ugly splice. How to reset the Xorg / xserver? Xserver keeps crashing on my general user account both in Unity 3D and 2D. It doesn't do it on the guest account.  That's why I want to reset / rollback everything xserver related, hoping this is going to fix it.  Most answers on this involve sudo dpkg-reconfigure xserver-xorg. However, this does nothing for me (generates no output) and I read in other forums, that it's deprecated.  So, what's the current way to reset all xserver / xorg options; what's the alternative to sudo dpkg-reconfigure xserver-xorg? X crashes during work, not before login or so. And the effect of a crash is, that I get thrown out of the session, not a freeze or machine crash. How to download all OpenStreetMap highways in a large area? I need to download all highways as line features from OpenStreetMap in a large area (about 10.000km²). Therefore I wanted to use overpass-turbo with the following statement in the wizard:   highway=*   in my chosen bounding box.  Unfortunately it looks like my bounding box is too big, because I get the error:   runtime error: Query run out of memory using about 2048 MB of RAM.   Do I have to change my overpass turbo query or is it not possible to download large datasets in overpass turbo? Which alternative method could I use to download all highways as line features in a larger region. I need to have all attributes, like the type of the highway, "foot=yes/no/...", "access="yes/no/....", etc. and if I use something like geofabrik, these attributes do not appear. How is floating point stored? When does it matter? In follow up to , it appears that some numbers cannot be represented by floating point at all, and instead are approximated.  How are floating point numbers stored?  Is there a common standard for the different sizes?  What kind of gotchas do I need to watch out for if I use floating point?  Are they cross-language compatible (ie, what conversions do I need to deal with to send a floating point number from a python program to a C program over TCP/IP)? How to make an ext4 formatted usb drive with full RW permissions for any linux machine? I want to format my USB stick to ext4 and just use as I would any other typical non-linux format drive (FAT32, exFAT, NTFS).   That is to say, I want to be able to plug the usb stick into any of my linux machines, and read/write to it without needing to adjust permissions, like doing chmod or chown stuff.  I would prefer to use GUI partition software like GParted, rather than command-line commands, though I welcome any solution!  I'm sure a post like this is duplicate flag heaven for some, but after browsing 6~10 SO and forum posts from google, I didn't find a simple solution to my question. Seemed like everything was about adjusting permissions on a per-user basis. Maybe you just cannot use ext4 drives with the same brainless convenience as NTFS. What is the value of $\sum\limits_{i=1}^\infty\frac{1}{p_{p_i}}$ where $p_{i}$ is the $i$th prime? I am aware there are many questions similar to this on MSE but I am having trouble following any of the solutions given.   I have the function given by   $f(x) = \dfrac{xy}{x^2+y^2}\;$ for $(x,y)\neq (0,0)$ and $f(0,0)=0$  I have calculated the partial derivatives and found:   $$\frac{\partial f}{\partial x} = \frac{y(-x^2+y^2)}{(x^2+y^2)^2}, \quad \frac{\partial f}{\partial y} = \frac{x(-y^2+x^2)}{(y^2+x^2)^2}$$  Now I need to show the partial derivatives exist for $(x,y) = (0,0)$.  I am also asked to show it is not continuous at $(x,y)=(0,0)$, based on other answers I've seen it seems like this follows from solving the first part but I fail to see how that follows through as well.   I could just copy the solutions with my function in place as I have seen a lot of answers using the definition of the derivative, but realistically I do want to understand what the thinking behind this is.   Any help would be appreciated. product of two uniformly continuous functions is uniformly continuous Suppose that $f$ and $g$ are uniformly continuous functions defined on $(a,b)$. Prove that $fg$ is also uniformly continuous on $(a,b)$.   My attempt: Since $f$ is uniformly continuous on $(a,b)$, for all $\epsilon&gt;0$, we have $\delta_f(\epsilon)&gt;0$ such that for all $x,y \in (a,b)$, $|x-y|&lt;\delta_f$, $|f(x)-f(y)|&lt;\epsilon$  Since $g$ is uniformly continuous on $(a,b)$, for all $\epsilon&gt;0$, we have $\delta_g(\epsilon)&gt;0$ such that for all $x,y \in (a,b)$, $|x-y|&lt;\delta_g$, $|g(x)-g(y)|&lt;\epsilon$  Notice that $$|f(x)g(x)-f(y)g(y)|=|f(x)g(x)-f(x)g(y)+f(x)g(y)-f(y)g(y)| \leq |f(x)||g(x)-g(y)| + |g(y)||f(x)-f(y)|$$  Here I don't know how to bound $|f(x)|$ and $|g(y)|$. I have proven that uniformly continuous functions preserve boundedness of an interval , i.e. $f$ is bounded on $(a,b)$. Can anyone help me? How do I check if an array includes a value in JavaScript? I am trying to print a List of Appendices (LoA) for my thesis, separate from the Table of Contents (ToC).   I wish for my ToC to look like this, with depth up to subsections (2?):  CONTENTS  CHAPTER   I. Introduction......1    1.1 Section title...1     1.1.1 Subsection...1  Appendices ..... 2   and for an LoA on a new page, with depth 0, thus:  APPENDICES  APPENDIX A. Proof of Theorem 1...1 B. Proof of Theorem 2...1   I am trying to achieve this using the report class, in a way that allows me to type appendices using the hierarchy that I obtain from the chapter, section commands. This is as opposed to defining a custom myappendix command into which I insert my appendix content. (I realize that I only need the titles from the appendix chapters for the LoA, but I'd like for the appendix content to have such structure.)   For instance, this approach would solve my problem:   \chapter{Introduction} \section{Section title} \subsection{Subsection} % \begin{appendices} is also acceptable \appendix   % Some settings are changed now \chapter{Proof of Theorem 1} \chapter{Proof of Theorem 2} % \end{appendices} if environment is begun   whereas the following approach would not:  \chapter{Introduction} \section{Section title} \subsection{Subsection} \myappendix{Proof of Theorem 1} \myappendix{Proof of Theorem 2}   I realize several questions have been asked regarding this before, but none of them quite solved my problem. Notably,  defines a custom appendix command;  defines two custom commands to maintain some hierarchy, but I will have to do more work to handle the inclusion of another layer (subsection) into the appendix.    is the closest to what I want: it does give me a separate LoA, but it also adds appendices to ToC and I can't quite figure out how to suppress the entires in ToC. The moment I use   \addcontentsline{toc}{\setcounter{tocdepth}{-1}}   the line   \xpatchcmd{\@chapter}{\addcontentsline{toc}}{\addcontentsline{toa}}{}{}%   fails because I am not adding anything to the ToC anymore.   My approach: Since I was using titlesec and tocloft packages anyway, I tried to do the following:   Stop ToC once appendix command is issued Start a new counter for appendices using tocloft Using the &lt;after-code&gt; option of titlesec, add contents line after every chapter.    My MWE   \documentclass[a4paper]{report} \usepackage{lipsum} % for arbitrary text  \usepackage{tocloft,etoolbox,titlesec} \newcommand{\listappendixname}{List of Appendices} \newlistof{appendix}{apc}{\listappendixname}  \makeatletter \g@addto@macro{\appendix}{     \clearpage     \addcontentsline{toc}{chapter}{Appendices}     \addtocontents{toc}{\protect\setcounter{tocdepth}{-1}}     \titleformat      {\chapter}      [display]     {\huge\bfseries\filcenter}      {\Large \MakeUppercase{\@chapapp} \thechapter}      {1.5ex}{}     {\refstepcounter{appendix} \addcontentsline{apc}{appendix}{\protect{\@chapapp \thechapter}}} } \makeatother  \title{Title} \author{Author}  \begin{document} \maketitle \tableofcontents \clearpage \listofappendix  \chapter{Introduction} \lipsum[1] \section{Section} \lipsum[2] \subsection{Subsection} \lipsum[3]  \appendix  \chapter{Proof of Theorem One} \lipsum[4] \chapter{Proof of Theorem Two} \lipsum[5]  \end{document}   produces the following LoA:  List of Appendices  Appendix...... 5   It doesn't get the Appendix title or number, and fails after the first one.  Could you please help me obtain a separate LoA in a way that I can still use LaTeX's chapter, section, ... hierarchy? (I am okay with using different packages, the book class, or any approach other than mine.) Up until now, I implemented all-against-all collision detection in my games. It worked fine.  But I reached a point where implementing this kind of collision detection, makes the game run poorly, because there are two many objects to iterate through and check for collision.  I have searched this site and found something about 'uniform grids'. But I didn't completely understand what it is and how to implement it. Tried to Google it but nothing easy enough to understand came up.  I am a beginner to 2D-game programming. Do you mind trying to explain to uniform-grids, or link me to some good tutorial?  Thanks a lot Identify a story about a teen boy who learns to use magic with his lizard companion Difference in System. exit(0) , System.exit(-1), System.exit(1 ) in Java Linear regression best polynomial (or better approach to use)? Any ideas on other polynomials I could successfully use for applying regression? My goal is a solution that has fit error strictly based on the noise. Is this possible since it is a bell-like curve? The tails can be long, short or non-existent. Am I looking for the impossible? Please note it has been a while since I have plunged this far into linear regression.   Anyway, my data points do not fit the $ax+bx^2+c$ polynomial well enough. I would like a replacement for this polynomial to apply regression (or different approach). In the following example, each point misses the fit curve by $20\%$ of the $Y$ range on average (of the data points). I looked at splines, but I do not know how to apply the regression since they look piece-wise.   Example $Y$ values (evenly spaced in $X$). It looks kind of like a bell curve. I would be applying 5 to 50 data points to determine the polynomial coefficients. Ultimately, I am interested in the best $X$ location for the peak based on the data points.     X      Y -40    -21142.1111111111 -30    -21330.1111111111 -20    -12036.1111111111 -10      7255.3888888889   0     32474.8888888889  10     32474.8888888889  20      9060.8888888889  30    -11628.1111111111  40    -15129.6111111111 How to control fan speed? How can I control the computer's fan speed?  On Windows there is a wonderful program called . HTTP vs HTTPS performance If I leave fully-cooked food (particularly meat) out at warm temperature - say on the counter or in a crock pot that's been turned off -  how long will it stay safe to eat?  Does it make any difference if I re-cook the food afterward? How can I switch between starting a coroutine vs running the routine all at once? I'm generating a level, and I have an optional delay to show the steps level generation one by one.  If my generationDelay boolean is true, I want to use StartCoroutine to spread the generation out over time. If it's false, I want to call the same method but without StartCoroutine.  The problem is that the method is type IEnumerator.  I can make two methods one type of IEnumerator and one not. But I wonder if there is a way to use one method.  In the first script top i did:  public bool generationDelay = false;   Then in a method:  private void BeginGame()     {         mazeInstance = Instantiate(mazePrefab) as Maze;          if (generationDelay == true)         {             StartCoroutine(mazeInstance.Generate(generationDelay));         }         else         {             mazeInstance.Generate(generationDelay);         }     }   Then the other script where the method Generate is: In the top:  public float generationStepDelay = 0.01f;   Then the method Generate:  public IEnumerator Generate (bool generationDelay) {          if (generationDelay == true)             WaitForSeconds delay = new WaitForSeconds(generationStepDelay);         cells = new MazeCell[size.x, size.z];         List&lt;MazeCell&gt; activeCells = new List&lt;MazeCell&gt;();         DoFirstGenerationStep(activeCells);         while (activeCells.Count &gt; 0) {             yield return delay;             DoNextGenerationStep(activeCells);         }     }   I'm getting an error on the line:   WaitForSeconds delay = new WaitForSeconds(generationStepDelay);      "Embedded statement cannot be a declaration or labeled statement"   And an error on the line:  yield return delay;      "The name 'delay' does not exist in the current context"   The reason I want to use a bool variable is that when i'm using StartCoroutine it's kind of slow, even if I change the value of generationStepDelay to 0 it's kind of slow. And if I'm not using StartCoroutine and not using the Generate method as IEnumerator it will work fast.  So i wonder what should I do and how? Which countries require a 24-hour transit visa in China? I'm transiting through China in Kunming, China.  I'm a South African national and do NOT fall under the 72-hour visa free program. However on [their official (travelchina) website][1] it says:     Nationals of most countries are eligible for the 24-hour direct   transit, while a visa is needed for the passengers transiting on   Afghanistan, Azerbaijan, Iran, Iraq, Kazakhstan, Kyrgyzstan, Malaysia,   Nigeria, Oman, Pakistan, Saudi Arabia, Sri Lanka, Thailand, Turkey,   United Arab Emirates and Yemen passports.   I'm sorry if I'm missing this, but the above is rather badly worded for me does "nationals of most countries" include ALL countries except those mentioned in the list shown?  Also again sorry if I'm missing this but again it is rather badly worded for me. I will fly via Thailand to China and then via China to Canada with an 8-hour layover in China. I see Thailand is mentioned on the list. I have a Thailand residency permit where I currently reside... Would that affect me at all?  Also, any idea if I can exit the airport in China and come back under the 24-hour visa exemption (should I be exempt)?  Many thanks.