Author: Johannes Ernst

  • Bye, Diamond!

    June, 2007 – May 2, 2019.

  • A cool research project for somebody aspiring with a 3D printer

    Back in the days when I went to (the German equivalent of) high school, we had to write the famous “Facharbeit”: a thesis in the field of your specialization for which you had a whole year. I wrote about infrared remote controls and built a bunch of electronics — which was great fun, except that […]

  • A Process Model (updated)

    Update August 6: added Operations (and moved Environment on to the top) The other day I was trying to analyze a rather complex system, and realized I don’t have the tools for it. So I came up with this. Posted here for others to use (and improve?), and for me to remember how it worked! […]

  • The best seasonal allergy medicine is … and here is the proof

    It’s actually not a medicine. It’s better: It’s an air filter. Over 30 years of allergies, and two continents, no allergy doctor ever mentioned air filters to me, but it makes all the difference in the world. And has no side effects, other than a little bit of noise and a little bit of electricity […]

  • Simple Notes on RSA encryption with Python’s Cryptography module

    I might as well publish my notes. First, about RSA: You need three numbers and calculate the rest. p and q must be (large) primes. They need to be secret. e needs to be chosen so that a certain function (that indirectly depends on p and q) evaluates to 1. e becomes public. You calculate […]