Prof. Emeritus Dr. Hans Ulrich Simon
Chair of Mathematics & Computer Science

E-Mail:
hans.simon(at)rub.de

Research Interests
We consider and analyze machine learning problems from the perspective of complexity theory. We try to determine the information or computational complexity of learning problems, and to design efficient learning algorithms. Furthermore, we investigate combinatorial optimization problems and explore the possibility of designing efficient approximation algorithms. We have a general interest in finding new programming methods and in inventing new data structures. We are furthermore interested in any results that shed more light on the famous P-NP problem.
Curriculum vitae
Scientific Curriculum Vitae
| 1978 | Diploma (roughly equivalent to Masters) in Mathematics (Univ. of Saarbrücken) |
| 1981 | Doctor's degree in Computer Science (Univ. of Saarbrücken) |
| 1989 | "Habilitation degree" (Univ. of Saarbrücken) |
| 1979-1989 | Research Assistant at the Computer Science Department of the University of Saarbrücken |
| 1984-1987 | Scholarship for Work on Multiprocessor Scheduling payed by the Siemens AG intermediate stays at different institutes in the USA stay at the Siemens Research Center in Munich, 1986 |
| 87/88 | Temporary Professor Position at the Univ. of Darmstadt |
| 89 | Temporary Professor Position at the Univ. of Dortmund |
| 89 | Temporary Professor Position at the Univ. of Saarbrücken |
| 1990-1997 | Professor (tenured) at the Univ. of Dortmund |
| 1997-2020 | Professor (tenured) at the Ruhr-University-Bochum |
| since August 2020 | Retired professor (Emeritus) |
| 2025-2026 | Member of the Senior Program Committee of COLT 2026 |
| 2025-2026 | Member of the Senior Program Committee of ALT 2025 and ALT 2026 |
Further Activities
- From January 1991 until June 1995: common research project with the University in Munich, Siemens AG in Munich, and the Deutsche Forschungsanstalt für Luft und Raumfahrt (DLR) about Neural Control; funded by the Bundesministerium für Forschung und Technologie (BMFT).
- From September 1992 until March 1993: Sabbatical at the University of Graz.
- From January 1995 until December 1997: common research project with the University of Milano about relations between online learning, batch learning and combinatorial optimization; funded by the Deutsche Akademische Austauschdienst (DAAD).
- From January 1995 until December 1998: research project about Computational Learning; funded by the Deutsche Forschungsgemeinschaft (DFG).
- Spring 1997: Sabbatical at the Hebrew University in Jerusalem and at the Technion in Haifa.
- Chairman of the Steering Committee of the 3rd European Conference on Computational Learning Theory (EuroCOLT 1997).
- From January 1997 until December 2000: common research project with the University in Bonn, Hebrew University in Jerusalem and Technion in Haifa about supervised and unsupervised learning; funded by the German-Israeli Foundation (GIF).
- 1998-2005: member of the DAAD-Committee which evaluates applications for research scholarships and selects the scholars (Auswahlkommission für DAAD-Stipendiaten bzw. Lektoren).
- 1998-2005: member of the DAAD-Committee which selects projects that are funded by the Vigoni-programme.
- Co-Chair of the Program Committee and Organization (together with Prof. Dr. Paul Fischer) of the 4th European Conference on Computational Learning Theory (EuroCOLT 1999).
- Member of "Endrundenjury des 17., 19., 21., and 24. Bundeswettbewerbs Informatik" in the years 1999, 2001, 2003, and 2006.
- From May 2000 until July 2003: research project about Design of New Rules for On-line Learning, Derivation of Relative Loss Bounds, and Study of Applications; funded by the Deutsche Forschnungsgemeinsachaft.
- From October 2000 until September 2006: Member of the academic staff in the PhD-program (DFG-Graduiertenkolleg) "Mathematical and Engineering Science Methods for Secure Data Transmission".
- From November 2002 until February 2005: research project about "Application of methods from Statistical Learning Theory to selected problems from Statistical Natural Language Processing"; funded by the Deutsche Forschungsgemeinschaft.
- From 2003 until 2009 Member of the advising board of the Institute of Neuroinformatik at the Ruhr-Universität Bochum.
- From January 2004 until February 2009: Site Manager of the "IST Programme of the European Community under the PASCAL Network of Excellence".
- From August 2004 until June 2006: Member of the Board of Directors in the "Association for Computational Learning".
- Co-Chair of the Program Committee for the 16'th International Conference on Algorithmic Learning Theory (ALT 2005) together with Prof. Etsuji Tomita.
- Co-Chair of the Program Committee for the 19'th International Conference on Computational Learning Theory (COLT 2006) together with Prof. Gabor Lugosi.
- Summer 2006: Sabbatical at the University of Waterloo (Ontario) and at the University of Helsinki.
- Invited Speaker at the 17'th International Conference on Algorithmic Learning Theory (ALT 2006).
- From August 2007 until September 2010: research project about Algebraic Methods as a Tool in Algorithmic Learning Theory; funded by the Deutsche Forschnungsgemeinsachaft.
- 3.-7. September 2007: invited speaker (together with Nicolo Cesa-Bianchi, Gabor Lugosi, and Afra Zomorodian) at the summer school ADFOCS 2007, Max-Planck-Institut, Saarbrücken
- From October 2007 until September 2009: Dean of the Department of Mathematics
- From October 2009 until September 2011 and from March until September 2012: Vice-Dean of the Department of Mathematics
- From January 2011 until December 2012: research project about Distribution-dependent and Distribution-independent Learnability; funded by the Deutsche Akademische Austauschdienst (DAAD) and by the corresponding institution in Hungary (MÖB).
- From July 2014 until March 2016: Member of the Board of Directors of the Service Center Mathematics and Applications (SZMA).
- July 2015: Best Paper Award at the Conference on Learning Theory (COLT 2015).
- Co-Chair of the Program Committee for the 27'th International Conference on Algorithmic Learning Theory (ALT 2016) together with Prof. Ronald Ortner.
- From October 2015 until October 2016 member of the Steering Committee of the Conference on Algorithmic Learning Theory.
- From July 2012 until June 2017 : Principal Investigator in the PhD-program (DFG-Graduiertenkolleg) "Cryptography in Ubiquitous Computing".
- Member of Program Committees of international conferences (EuroCOLT 1993, ALT 1995, EuroCOLT 1995, EuroCOLT 1997, COLT 1999, EuroCOLT 1999, STACS 2003, ALT 2005, COLT 2005, ALT 2006, COLT 2006, ICALP 2006, COLT 2007, COCOON 2009, ALT 2009, ALT 2011, COLT 2012, COCOA 2012, ALT 2012, COLT 2013, COLT 2014, ISAIM 2014,
ICML 2015, ALT 2015, COLT 2017, CSCML 2017, LATA 2019, ALT 2019). - Referee for international journals and for the Deutsche Forschungsgemeinschaft (DFG).
- Occasionally member of the Peer Review Panel in connection with Priority Programmes funded by the DFG or DFG Research Units.
- Reviewer for the "Mathematical Reviews" of the American Mathematical Society.
- Organisor of some international research seminars about Machine Learning in Dagstuhl.
- Invited Speaker on different international research seminars in Oberwolfach and Dagstuhl.
- Member of the Horst Görtz Institute for Security in Information Technology at the Ruhr-Universität Bochum.
- Member of different organizations of computer professionals like Gesellschaft für Informatik (GI), European Association of Theoretical Computer Scientists (EATCS), and the Association for Computing Machinery.
| System. Programming | SoSe 1983 | 2+1 | FB 10, Univ. des Saarl. |
| System. Programming | SoSe 1984 | 2+1 | FB 10, Univ. des Saarl. |
| Scheduling | WS 1984/85 | 4+2 | FB 10, Univ. des Saarl. |
| The complexity classes NC and RNC | WS 1985/86 | 2+1 | FB 10, Univ. des Saarl. |
| Cryptography | SoSe 1986 | 2+1 | FB 10, Univ. des Saarl. |
| Handling of NP-hard Problems on selected Examples | WS 1986/87 | 2+1 | FB 10, Univ. des Saarl., |
| Efficient Algorithms | WS 1987/88 | 4+2 | FB 20, TH Darmstadt |
| Computational Geometry (Seminar) | WS 1987/88 | 2 | FB 20, TH Darmstadt |
| The Complexity of Learning | SoSe 1988 | 2+1 | FB 10, Univ. des Saarl. |
| Cryptography | WS 1988/89 | 2+1 | FB 10, Univ. des Saarl. |
| Basics of theor. Computer Science | SoSe 1989 | 4+2 | FB 4, Univ. Dortmund |
| Computational Learning | WS 1989/90 | 4+2 | FB 10, Univ. des Saarl. |
| Programming | WS 1990/91 | 4+2 | FB 4, Univ. Dortmund |
| Computational Learning (Seminar) | WS 1990/91 | 2 | FB 4, Univ. Dortmund |
| Pattern Matching | SoSe 1991 | 4 | FB 4, Univ. Dortmund |
| Combinatorics (Seminar) | SoSe 1991 | 2 | FB 4, Univ. Dortmund |
| Complexity Theory | WS 1991/92 | 4+2 | FB 4, Univ. Dortmund |
| Recognition of Hand-Written Letters I | WS 1991/92 | 4+2 | FB 4, Univ. Dortmund |
| Recognition of Hand-Written Letters II | SoSe 1992 | 4+2 | FB 4, Univ. Dortmund |
| Efficient Algorithms | SoSe 1992 | 4+2 | FB 4, Univ. Dortmund |
| Pattern Matching (Seminar) | WS 1992/93 | 2 | IGI, Univ. Graz |
| Basics of Theoretical Computer Science | SoSe 1993 | 4+2 | FB 4, Univ. Dortmund |
| Approx. of NP-hard Optimization Problems (Seminar) | SoSe 1993 | 2 | FB 4, Univ. Dortmund |
| Complexity Theory | WS 1993/94 | 4+2 | FB 4, Univ. Dortmund |
| Theory of Neural Networks (Seminar) | WS 1993/94 | 2 | FB 4, Univ. Dortmund |
| Learning from Counterexamples | SoSe 1994 | 4+2 | FB 4, Univ. Dortmund |
| Function Learning (Seminar) | SoSe 1994 | 2 | FB 4, Univ. Dortmund |
| Operations Research | WS 1994/95 | 4+2 | FB 4, Univ. Dortmund |
| Comb. Problems in Molecular Biology (Seminar) | WS 1994/95 | 2 | FB 4, Univ. Dortmund |
| Theory of Logic Design | SoSe 1995 | 4+2 | FB 4, Univ. Dortmund |
| Approx. of Comb. Optimization Problems (Seminar) | SoSe 1995 | 2 | FB 4, Univ. Dortmund |
| Complexity Theory | WS 1995/96 | 4+2 | FB 4, Univ. Dortmund |
| Computational Learning Theory (Seminar) | WS 1995/96 | 2 | FB 4, Univ. Dortmund |
| Basics of Theor. Computer Science | SoSe 1996 | 4+2 | FB 4, Univ. Dortmund |
| Computational Lerning Theory and Comb. Optimization | SoSe 1996 | 8 | FB 4, Univ. Dortmund |
| Complexity Theory | WS 1996/97 | 4+2 | FB 4, Univ. Dortmund |
| Computational Learning Theory and Comb. Optimization | WS 1996/97 | 8 | FB 4, Univ. Dortmund |
| Introduction to Computer Science | WS 1997/98 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| PCP-Theorem and Applications (Seminar) | WS 1997/98 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Data Structures | SoSe 1998 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Introduction to Computer Science | WS 1998/99 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Public Key Crypto Systems (Seminar) | WS 1998/99 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Efficient Algorithms | SoSe 1999 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Algorithmic Biology (Seminar) | SoSe 1999 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Complexity Theory | WS 1999/00 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Efficient Approximation Alg. for NP-hard Optimization Problems (Seminar) | WS 1999/00 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Data Structures | SoSe 2000 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Perfect Hashing (Seminar) | SoSe 2000 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Introduction to Computer Science | WS 2000/01 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Complexity Theory | WS 2000/01 | 4 | Fak. 15, Ruhr-Uni-Bochum |
| Efficient Algorithms | SoSe 2001 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Introduction to Cryptography (Seminar) | SoSe 2001 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Complexity Theory | SoSe 2002 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Cryptography and its compl. th. Basics (Seminar) | SoSe 2002 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Discrete Mathematics | WS 2002/03 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Introduction to Computer Science | WS 2002/03 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Efficient Algorithms | SoSe 2003 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Support Vector Machines (Seminar) | SoSe 2003 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Theoretical Computer Science | WS 2003/04 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Discrete Mathematics | WS 2003/04 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Efficient Algorithms | SoSe 2004 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| The P-NP Problem (Seminar) | SoSe 2004 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Theoretical Computer Science | WS 2004/05 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Discrete Mathematics | WS 2004/05 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Efficient Algorithms | SoSe 2005 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Convex Optimization (Seminar) | SoSe 2005 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Theoretical Computer Science | WS 2005/06 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Algorithmic Learning | WS 2005/06 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Theoretical Computer Science | WS 2006/07 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Discrete Mathematics | WS 2006/07 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Efficient Algorithms | SoSe 2007 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Algorithmic Learning | SoSe 2007 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Theoretical Computer Science | WS 2007/08 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Complexity Theory | SoSe 2008 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Theoretical Computer Science | WS 2008/09 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Complexity Theory | SS 2009 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Discrete Mathematics | WS 2009/10 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Theoretical Computer Science | WS 2009/10 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Complexity Theory | SoSe 2010 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Communication Complexity (Seminar) | SoSe 2010 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Discrete Mathematics | WS 2010/11 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Theoretical Computer Science | WS 2010/11 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Discrete Mathematics | WS 2011/12 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Theoretical Computer Science | WS 2011/12 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Data Structures | SoSe 2012 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Computational Learning (Seminar) | SoSe 2012 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Theoretical Computer Science | WS 2012/13 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Complexity Theory | WS 2012/13 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Theory of Machine Learning | SoSe 2013 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Algorithmic Learning (Seminar) | SoSe 2013 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Differential Privacy | SoSe 2013 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Discrete Mathematics | WS 2013/14 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Complexity Theory | WS 2013/14 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Theory of Machine Learning | SoSe 2014 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Minimization of Submodular Functions (Proseminar) | SoSe 2014 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Discrete Mathematics | WS 2014/15 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Algorithmic Learning (Seminar) | WS 2014/15 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Data Structures | SoSe 2015 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Complexity Theory | SoSe 2015 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Theory of Machine Learning | SoSe 2016 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Discrete Mathematics (Seminar) | SoSe 2016 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Complexity Theory | WS 2016/17 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Algorithmic Learning (Seminar) | WS 2016/17 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Theory of Machine Learning | SoSe 2017 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Set Theory (Seminar) | SoSe 2017 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Complexity Theory | WS 2017/18 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Theoretical Computer Science | WS 2017/18 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Theory of Machine Learning | SoSe 2018 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Data Sructures | SoSe 2018 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Complexity Theory | WS 2018/19 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Theoretical Computer Science | WS 2018/19 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Data Structures | SoSe 2019 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Graphs and Matrices (Seminar) | SoSe 2019 | 2 | Fak. 15, Ruhr-Uni-Bochum |
| Complexity Theory | WS 2019/20 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Algebraic Graph Theory | WS 2019/20 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Theory of Machine Learning | SoSe 2020 | 4+2 | Fak. 15, Ruhr-Uni-Bochum |
| Complexity of Boolean Functions (Seminar) | SoSe 2020 | 2 | Fak. 15, Ruhr-Uni-Bochum |
Former team members

- Professors
- Team assistant
- Former team members
- Dr. Francesco Aldà
- Dr. Andreas Birkendorf
- Dr. Christian Brandl
- Simon Damm
- Dr. Malte Darnstädt
- Sina Däubener
- Dr. Juergen Forster
- Dr. Michael Kallweit
- Dr. Bernhard Kilgus
- Prof. Dr. Eike Kiltz
- Dr. Thorsten Kiss (geb. Doliwa)
- Dr. Norbert Klasner
- Dr. Edgar Korthauer
- Prof. Dr. Christian Kuhlmann
- Mike Laszkiewicz
- Florian Linsner
- Dr. Nikolas List
- Denis Lukovnikov
- Alexander Neuhaus
- Matías Pizarro
- Lukas Plätz
- Dr. Christoph Ries
- Dr. Dennis Rohde
- Dr. Leonie Ryvkin
- Dr. Michael Schmitt
- Dr. Leonie Selbach
- Dr. Stef Sijben
- Dr. Balazs Szoerenyi
- Dr. Filipp Valovich