welcome on my personal website. You can find some information concerning my scientific work and interests, mainly covering the areas of computer science, space science and technology, and math, as well as information on myself here.
Students of the Merseburg University of Applied Sciences may find some materials that I prepared during my study time for the courses mentioned above within the category “Science”.
Please do not hesitate to contact me in case of questions, criticism, errors or any other concerns. You may find my contact information here.
— M.Eng. René Schwarz
New Blog Posts
New Memorandum "Quaternions and Spatial Rotation" Released
René Schwarz (talk), 29 October 2014 17:42
- brief introduction into quaternions, their components, notations, and properties
- quaternion algebra formulary summarizing
- basic properties (quaternion equality, hypercomplex conjugate, norm, and inverse)
- basic operations (quaternion addition and subtraction, multiplication, division, normalization, cross and dot product)
- exponential and logarithmic functions (quaternion exponential function, natural logarithm, logarithmic functions, power and root functions)
- trigonometric and hyperbolic functions of quaternions
- application of quaternions in the context of spatial rotations, quaternion rotation operators, rotations and transformations
- conversion algorithms:
- Euler Angles to Quaternion (for all 12 possible rotation sequences)
- Quaternion to Euler Angles (for all 12 possible rotation sequences)
- Direction Cosine Matrix (DCM) to Quaternion
- Quaternion to Direction Cosine Matrix (DCM)
- Euler Angles to Rotation Matrix (for all 12 possible rotation sequences)
- time derivative of a rotation quaternion
- quaternion interpolation algorithms
- linear interpolation (LERP)
- spherical linear interpolation (SLERP)
Have a look here if you are also interested into other Memoranda out of my Memorandum Series.
In the light of the recent occurences in the domain of computer security, I will hereby replace my old OpenPGP key by a new and stronger key. The old key is invalid with immediate effect and I recommend to use my new one for all future correspondence. Please see my key transition notice here for further details:
Unfortunately, Moxa's NPort Real TTY Driver for Linux is currently (version 1.18, released 2012/03/20) not compatible with Linux kernel 3.8.0. When I tried to install this driver for the NPort 5450 Serial to IP Server on my Ubuntu 13.04 machine (currently with kernel 3.8.0-27), the driver didn't compile. It turned out, that it is possible to patch the driver source code in order to get it work with Linux kernel 3.8.0 – here is a short documentation what I did.
In endeavor to extend my Memorandum Series, I published a new Memorandum on astrodynamical constants, listing commonly used constants in astrodynamics as well as in space science and engineering with their latest values according to recent publications. This Memorandum is going to be updated with new constants from time to time.
Have a look here if you are also interested into other Memoranda out of my Memorandum Series:
- M001: Keplerian Orbit Elements to Cartesian State Vectors
- M002: Cartesian State Vectors to Keplerian Orbit Elements
- M003: Trigonometric Functions
- M005: Astrodynamical Constants
- M004: Conversion between Gregorian and Julian Dates
- M006: Quaternions and Spatial Rotation
After one year of having missed to update the page on my Master's Thesis, I am finally pleased to announce the availability of my master's thesis „Development of an illumination simulation software for the Moon's surface: An approach to illumination direction estimation on pictures of solid planetary surfaces with a significant number of craters“ as book both in form of a free download (PDF file) and in form of a printed paperback copy over the book trade.
For details see this page.
php_mailparse.dll for PHP 5.4.x (VC9 version) available
René Schwarz (talk), 17 May 2012 14:45
I'm pleased to announce the immediate availability of a precompiled php_mailparse.dll for the PHP 5.4.x series, built with VC9. This version is compatible with the standard 32-bit binaries of PHP for Windows.
Please notice the instructions written here (they are valid for the new version too).
Breathtaking Time-Lapse Aurora Video in Norway 2012
René Schwarz (talk), 7 February 2012 14:56
Today I've seen this breathtaking time-lapse aurora video made in Norway, January 2012, by Christian Mülhauser. It is so fascinating, that it would be a shame not to share it with you.
Many thanks to Christian Mülhauser for his efforts!
During the ongoing work on my Master's Thesis I noticed a bug in the MySQL profiling feature: The output of the
SHOW PROFILEstatement is misleading, since the presented durations are not given for the status in the same row, but the durations are given for the previous status!