M.Sc. Stefan Kögel

My main interests are Graph Transformations, Machine Learning, Functional Programming (mainly Haskell), and Compilers. I have published papers and supervised several theses on these topics and am always happy to talk about them :)

My research focus is the development of a recommender system for structured data (EMF models, XML files, serialized UML diagrams, etc.) that is formalism agnostic. I achieve this by learning common changes in a set of noisy before and after examples. Such a set of examples could, for example, be extracted from the version history of an XML file in a version control system. The learned common changes can then be used to generate recommendations tailored to the example data set.

I try to do as much of my work as possible in Haskell: I once implemented a web crawler that finds and mines git repositories and stores its results in a SQLite data base; all in Haskell. (Results published here: 10.18725/OPARU-9850)

Outside of work I enjoy cycling, go/baduk/weiqi, and playing walking simulators.

Research Projects

Ensure

ENsurance of Software evolUtion by Run-time cErtification

Other Projects

  • A visual interpreter for a Haskell-like language for teaching purposes: ClickyEvaluation.
  • Distributing students into groups according to their preferences. Available as a Moodle Plugin.
  • Several projects for industry partners

Publications

2018

6.
Kögel, Stefan; Tichy, Matthias
A Dataset of EMF Models from Eclipse Projects
Herausgeber: Open Access Repositorium der Universität Ulm
September 2018
DOI:10.18725/OPARU-9850
5.
Kögel, Stefan; Tichy, Matthias; Groner, Raffaela; Stegmaier, Michael; Götz, Stefan; Rechenberger, Sascha
Developing an Optimizing Compiler for the Game Boy as a Software Engineering Project
Software Engineering Education and Training Track of the 40th International Conference on Software Engineering (ICSE SEET 2018), Gothenburg, Sweden
Mai 2018
DOI:10.1145/3183377.3183388
Datei:https://www.icse2018.org/event/icse-2018-software-engineering-education-and-training-developing-an-optimizing-compiler-for-the-game-boy-as-a-software-engineering-project

2017

4.
Kögel, Stefan
Recommender system for model driven software development
Proceedings of the 2017 11th Joint Meeting on Foundations of Software Engineering, ESEC/FSE 2017, Paderborn, Germany,
September 2017
DOI:10.1145/3106237.3119874
3.
Tichy, Matthias; Beaucamp, Luis; Kögel, Stefan
Towards Debugging the Matching of Henshin Model Transformations Rules
1st International Workshop on Debugging in Model-Driven Engineering (MDEbug), Austin, Texas
Juli 2017
Datei:https://msdl.uantwerpen.be/conferences/MDEbug/wp-content/uploads/2017/08/MDEbug_2017_paper_2.pdf

2016

2.
Kögel, Stefan; Tichy, Matthias; Groner, Raffaela
Automatic Change Recommendation of Models and Meta Models Based on Change Histories
ME 2016 – Models and Evolution Workshop Proceedings (MODELS 2016), Saint-Malo, France
Oktober 2016
Datei:http://ceur-ws.org/Vol-1706/paper3.pdf
1.
Kögel, Stefan; Cüppers, Joscha; Tichy, Matthias
ClickyEvaluation: A Step‐by‐Step Evaluator for Functional Programming Expressions
2nd European Conference of Software Engineering Education (ECSEE), 30 June and 1 July 2016, Seeon Monastery, Germany
Juni 2016

Teaching

Supervised theses

  • Adding type checking and do notation to ClickyEvaluation
    (2016)
  • Statische Analyse einer Automotive Embedded Software: Automatische Abstraktion einer Strukturdarstellung von Sourcecode zur Komplexitätsreduktion
    (2017)
  • Abstraction of version changes in models
    (2017)
  • Converting EMF Ecore Meta Models to Haskell Algebraic Data Types
    (2017)
  • Erweiterungen des "Automatic recommenders" für Ecore Metamodelle
    (2017)
  • Exploiting dependent types for representing Graph-constraints in GADTs
    (2018)
  • Recommending Model Transformations via Subgraph Matching
    (2019)
  • Measuring and improving the performance of PureScript applications
    (2019)