## Borg Backup May 16, 2017

An introduction to the Borg backup system, presented at DevOps Munich meetup.

An introduction to the Borg backup system, presented at DevOps Munich meetup.

Conference talk at SPIN 2016. "We define memory-efficient certificates for µ-calculus model checking problems based on the well-known correspondence between µ-calculus model checking and winning certain parity games. Winning strategies can be independently checked, in low polynomial time, by observing that there is no reachable strongly connected component in the graph of the parity game whose largest priority is odd. Winning strategies are computed by fixpoint iteration following the naive semantics of µ-calculus. We instrument the usual fixpoint iteration of µ-calculus model checking so that it produces evidence in the form of a winning strategy; for a formula φ with fixed alternation depth, these winning strategies can be computed in polynomial time in |S| and in space O(|S|²|φ|²), where |S| is the size of the state space and |φ| the length of the formula φ. On the technical level our work yields a new, simpler, and immediate constructive proof of the correspondence between µ-calculus and parity games. A prototypical implementation of a µ-calculus model checker generating these certificates has been developed."

My master thesis. "We present an implementation of a model checker for µ-calculus that certifies its result as a winning strategy for a corresponding parity game. The winning strategy is computed by means of a fixpoint iteration, similar to the well-known set semantics of µ-calculus, and can be regarded as a instrumentation thereof. The computed certificates are compact and can be checked efficiently in low polynomial time by a separate routine."

A lightning talk on elscreen, a screen manager for Emacs. Presented at "Learn yourself Emacs for Great Good" of Munich Lambda.

an exposition of my init system for Arch Linux, ignite.
Presented at the suckless conference slcon 2013.

My bachelor thesis. "This thesis consists of five parts: first, we look at set theory and the lack thereof in Minlog's typed calculus; second, we research the different kinds of sets and their uses in Bishop/Bridges Constructive Analysis; third, we formally prove some theorems, focussing about finite sets; fourth, we consider how measure theory can be formulated in a constructive setting; fifth, we conclude our work."

Material for a presentation on Emacs.

It is not a tutorial, but the idea is that you will want to learn Emacs afterwards.

It is not a tutorial, but the idea is that you will want to learn Emacs afterwards.

German seminar talk on realizability for Prof. Schwichtenberg's seminar on proof theory.

What makes code simple, why we should strive for simple code and how we can write it, interspersed with insightful quotes.
Talk given at the Central European Ruby Camp (Curucamp) 2009.

Introductory talk given in German at the Munich Rails User Group on their April meeting about what Rack is, how everyone can benefit and who already supports and implements it.

Developing general web frameworks and frameworkless web applications is difficult because lots of different ways to connect to web servers need to be implemented. Since Ruby is popular for writing web applications, we try to address this problem by proposing a lightweight abstraction mapping HTTP requests onto a simple Ruby API. This makes it possible to combine all kinds of web servers with different web applications without further change. Furthermore, our solution enables new functionality by combining and composing web applications, as well as better testability.
Talk given at the European Ruby Conference (Euruko) 2007.

A presentation about chemical evolution in German for school. After an introductory question about the beginning of life, the stepwise gain of complexity in organic molecules is analyzed. The ferrite-sulphur world is used as an example of how energy can steadily be available, then the RNA world introduces the concept of auto-catalysis. Microspheres and fatty acids are considered as the first cell membranes. After presenting the Eigen-hypercycle, an outlook at the beginnings of biological evolution encourage further discussion. Includes slides for a 40 minute presentation and an illustrated three page handout.

A presentation about expressing different programming paradigms in Ruby (prototyped-based object-orientation, Erlang-style concurrency, logic programming) with code examples and an overview of the techniques used. Every sublanguage is assessed on what's good, what's bad and what needs to be done better. Talk given at the European Ruby Conference (Euruko) 2006.

The main part of this seminar paper is a 86 page report about pesticides and their bad ramifications, seen from a social and scientific point of view. Also includes slides for a 30 minute presentation, the timesheet we had to keep during the seminar and full LaTeX sources.

A presentation about medical active agents in German for school. After a general introduction and a short history of medicine, Valerian and acetylsalicylic acid are given a closer look. Includes additional material for a 40 minute presentation and a two page handout.

A very basic set of slides about Taylor series in German for school. Features approximation of sin and e. Includes additional material for a 35 minute presentation, and a 5 page handout with diagrams.

A presentation of dynamic scoping and context-oriented programming and explanation of how it can be implemented using method slices. As a bonus, a primitive library for selector namespaces is presented. Talk given at the European Ruby Conference (Euruko) 2005.

A presentation about Bayes' Theorem in German for school. Bayesian spam-filters are used as an example application. Includes additional material for a 45 minute presentation.