Thoughts and Ramblings

General things I find of interest.

GF(5^2)

I got curious about the design of a puzzle a few weeks back using \(GF(5)\), or more specifically, the extension field \(GF(5^2)\). I was hoping that I could find pre-computed examples and while I found many examples of lectures discussing \(GF(5)\), I didn’t find anything with extension fields of it. So I wrote a quick program to find primitive polynomials of degree 2 over \(GF(5)\). For what I had in mind I needed 6 primitive polynomials which could be selected for construction of this field but sadly that was not the case. Since I went through the work to find all possible polynomials and I didn’t find anyone else that had done so, I decided I’d make a blog post of them in case it’s useful to someone else.


The Appearance of Truth

I’ve had a scene from the movie “Man of the Year (2006)” rolling around in my mind for the past several weeks. For those who’ve not seen the movie, it about a comedian by the name of Tom Dobbs, played by Robin Williams, who decides to run for president as a third-party candidate. While he isn’t on the ballot in every state, he does win the states where he is on the ballot and achieves the majority of electoral votes to become the next President of the United States. Many of the voting machines used in the election were made by a company called Delacroy, and after the election one of its employees, Eleanor Green, played by Laura Linney, performs a unit test (or possibly systems test) on the devices. She discovers that when the devices are given a known set of input votes, the tally isn’t consistent with that input; it was miscounting. The reason for the error is related to the fact that the candidates have repeated letters in their names and the double b in Dobbs is the real reason why he won these states. (As a professional software developer, this is an idiotic rational unless the software is doing something really screwy with the candidates names. The names should be nothing more than an opaque string but I digress) So she first takes this to her boss, Stewart, played by Jeff Goldblum, and he decides try to supress this information presumably for he sake of the company’s reputation. Anyway, she managed to convince Dobbs of all this, he withdraws from the race, and as a result Time Magazine names him Man of the Year.


A Litany of Netflix Screw-ups

For those unaware, Netflix still does their DVD by mail service. Both my dad and I have subscribed to this in the past. Occasionally when I would visit my parents (200 miles away), I would change the shipping address on my account to his place so my DVDs would be sent there and change it back when I would leave (relevant later in this post). We both hit the point where every movie in our queue had a wait on it so we both cancelled the service. We’ve done this twice before. Now, several months later, we both decided that we should renew the service because enough movies have been released in the mean time that we should go several months until this occurs again.


Plex Media Player Appliance Using Ubuntu

Running the embedded version of Plex Media Player requires several compromises when a better experience can be obtained by using a full OS install. So I went through the steps to install PMP on an Ubuntu installation. Not only do I have a powerful playback appliance for Plex but I also have a computer where I can use a browser or any other application where I would want the computer displayed on a TV.


Using ACLs to Solve Permissions Issues

One of the more annoying issues that can impact novices on Linux systems is handling permissions across multiple users. One of the contexts where I see this the most is on the Plex forums where users have to deal with allowing the Plex Media Server to see their media when it runs as a different user. Years ago I solved this problem on my system with using ACLs and I’ve never had to deal with the permissions on my media since.