Research and innovation have always been very important for Stefan Michaelis. His professional experience concentrates on the areas: Communication Networks, especially mobile networks, Embedded Systems and Pattern Recognition.
Stefan Michaelis has worked for many years as a researcher on these topics and published several international publications.
In his dissertation (Ph.D. thesis) he worked on recognition of user mobility in cellular mobile networks. The thesis is based on the assumption, that mobile network users are constrained in their movements and therefore can not change randomly between neighbouring cells. Geographic topology and users moving towards specific destinations lead to partially deterministic behaviour. This macroscopic mobility resembles a fingerprint of mobile network coverage, user behaviour and topology of street and railway networks.
The sequences of traversed cells by all users deliver a data set in which mobility patterns can be extracted through application of knowledge discovery algorithms. The patterns are generalised and saved without any specific user identification. Afterwards, the derived models can be used to predict the next cell for any mobile user with an active connection. The knowledge about future cells helps reserving resources before the user enters the cell in question. Especially real-time services like video calls or online games benefit from this approach, minimizing latency and connection loss.
For the upcoming trend in transferring video games from the local computer into the cloud and just streaming the picture, the demand for highly reliable networks even during high speed movement raises. Effective resource reservation based on next-cell predictions guarantees the needed quality of service.
The thesis has been published as a book (in German only) and is available directly via the publisher or Amazon. A one-page abstract macromobility prediction in English is available as a PDF download here.
Beside professional life there always is a bit of time left for private experimental projects.
The first program published by me was a remote control for digital cameras, running on PDAs and implemented in Java Personal Profile: RemoteShot. Tested on Compaq iPAQs and Casion QV digital cameras the program was a nice example for write once, run anywhere. Today, smartphones replaced the concept to a huge extent.
A box, locked, content unknown, and opens only at a certain location. This is the concept of the Geocache Transposed. Based on the Puzzle Box by Mikal Hart this is my own version.
The box enables a new variant of the treasure hunt, as the receiver has the treasure with him all the time. A nice present for weddings, anniversaries and birthdays.
The first time this box was used, it was a present for my wife with visits to several stations of our shared life.
The box includes GPS and an Arduino controlling the lock. On activation the only information displayed is the distance to the next destination. The full story is available on Google+, source code on GitHub.
Time management techniques like the Pomodoro technique often separate work into small time slots. Instead of the proposed kitchen timer, I implemented the Polar Timer using SVG to provide three easily configurable timers.
For easy conversion from csv to the Vowpal Wabbit format for machine learning a tool implement in Go can be found here: csv2vw
This web site also started as an experiment when HTML5 and CSS3 were still in their early stages. My digital home initially got implemented using HTML5 Boilerplate, JQuery, Mirah and Dubious. You can find the source code running this site as an example on Github: Homepage Source. Today the web page is running as a Go-Backend with a responsive design based on Bootstrap.