Talks
lmonade
 ÖMGDMV Congress 2013, Innsbruck, Austria, September 2327, 2013 Reproducibility, software in experimental mathematics and lmonade [slides]
 SciPy 2013, Austin, USA,
June 2429, 2013
lmonade: a distribution for scientific software [slides] [video]  FOSDEM 2013, Brussels,
Belgium,
Feb. 23, 2013
lmonade: a distribution for scientific software [slides] [video]  SingularPolymakeGAP meeting, St. Andrews, Scotland,
Aug. 2731, 2012
lmonade: a platform for development and distribution of mathematical software [slides]  Efficient Linear Algebra for Gröbner Basis Computations, Kaiserslautern, Germany, June 48, 2012 Short presentation on lmonade. [slides] [video]
 Annual Meeting of DFG Priority Program
SPP1489,
Hannover, Germany,
Feb. 27  March 1, 2012 Presentation on the architecture of lmonade. [slides]  Annual Meeting of DFG Priority Program
SPP1489, Aachen, Germany,
Feb. 2125, 2011
A platform for the distribution and development of mathematical software [slides]
Sage
 Symbolic Computation and its Applications
2012, Aachen, Germany,
May 1720, 2012
Presentation on Sage and lmonade  polymake
Workshop, Darmstadt, Germany,
March 2223, 2012
Short presentation on pypolymake, a Sage interface to polymake.  Industrial Applications and Prospects of Computer
Algebra, Kaiserslautern, Germany,
June 2122, 2011
Presentation on Sage.  Sage Days 24, Hagenberg, Austria,
July 1722, 2010
Two tutorials on basic Python programming and implementing arithmetic types in Sage.  SCIEnce Training School in Symbolic
Computation, Hagenberg, Austria,
July, 2010
A short course as an introduction to Sage.  Software Workshop Geometry and Combinatorics
2010, Kaiserslautern, Germany,
Feb. 1114, 2010
Sage and connecting mathematical software  Sage workshop
*Combinat, Hagenberg, Austria,
July 2529, 2009
Two talks on Sage titled Introduction to Sage and How to get started developing Sage?
Maths
 Difference Equations and
Applications
session of the Joint Mathematics
Meetings, New Orleans,
Jan. 69, 2011
Algebraic Extensions for Summation in Finite Terms [slides]  ISSAC 2010, Munich, Germany,
July 2528, 2010
Software presentation titled Summation in finite terms using Sage. [abstract]  Sage Days 24, Hagenberg, Austria,
July 1722, 2010
talk on algebraic extensions of difference fields. [slides]  Applications of Computer Algebra
2010, Vlore, Albania,
June 2427, 2010
Talk in the Computation of Special Functions session.  Sage Days
20.5, Fields Institute, Toronto, Canada,
May 37, 2010
Algebraic Extensions for Summation in Finite Terms  Sage workshop
*Combinat, Hagenberg, Austria,
July 2529, 2009
A presentation titled Difference Fields and Symbolic Summation in Sage.
Cryptography
 Sage Days 10, Nancy, France,
Oct. 1015, 2008
SCrypt: Symbolic computation assists algebraic cryptanalysis [slides]  Symbolic Computation and Cryptography
2008, Beijing, China,
April 2830, 2008
SCrypt: Bridging the Gap Between Algebra and Cryptography
Refereed Conference Contributions
 (with William Stein) The Sage project: Unifying free mathematical software to create a viable alternative to Magma, Maple, Mathematica and MATLAB, in K. Fukuda, J. Hoeven, M. Joswig, N. Takayama (Eds.), Proc. of International Conference on Mathematical Software (ICMS) 2010, LNCS 6327, 1227. [pdf]
 Summation in finite terms using Sage, software presentation at International Symposium on Symbolic and Algebraic Computation (ISSAC) 2010. [abstract]
 (with Arne Storjohann) Nullspace computation over rational function fields for symbolic summation, poster presentation at ISSAC 2010. (won Best Poster Award from Fachgruppe Computeralgebra) [abstract]
 SCrypt: Bridging the gap between algebra and cryptography, in: J.C. Faugere, D.Wang (Eds.), Proc. First Intl. Conf. on Symbolic Computation and Cryptography (SCC) 2008. [pdf]
Publications
 Algebraic Extensions in Symbolic Summation, PhD Thesis, RISC, Johannes Kepler University, Linz, February 2011. [pdf]
 Some Sequence Synthesis Algorithms, MSc Thesis, Middle East Technical University, Institute of Applied Mathematics, July 2006.
 A Survey of Primality Testing, Senior Thesis, Istanbul Bilgi University, Department of Mathematics, July 2003.
Workshops
 Sage Days 53: Computational Number Theory, Geometry, and Physics, University of Oxford, UK, September 2329 2013
 Open Science Summit, Mountain View, USA, Oct. 1920, 2012
 SingularPolymakeGAP meeting, St. Andrews, Scotland, Aug. 2731, 2012
 Efficient Linear Algebra for Gröbner Basis Computations, Kaiserslautern, Germany, June 48, 2012
 polymake Workshop, Darmstadt, Germany, March 2223, 2012

Sage Days 35: SageFlint Days, Warwick, UK, Dec. 1722, 2011
Implemented fast linear algebra mod p^n for small primes in Cython based on Python code written by Martin Albrecht and Simon King. The code, faster than Magma, is available on Sage trac ticket #12177.
 Sage  Singular Days 34, Kaiserslautern, Germany, Sep. 2630, 2011
 Sage Days 31, Seattle, USA, June 1317, 2011
 polymake Workshop, Darmstadt, Germany, March 31April 1, 2011
 Software Workshop: Fast linear algebra, Gröbner Bases and Parallelization in Singular, Kaiserslautern, Germany, July 1722, 2010

Sage Days 24, Hagenberg, Austria, July 1722, 2010
As an organizer, I did not get a chance to do much real work. Though, I still managed to learn a lot about algorithms for solving differential equations from Felix Ulmer and started implementing Kovacic’s algorithm in Sage. We also had some useful discussions with Frédéric Chyzak, Fredrik Johansson and Flavia Stan about how to handle hypergeometric functions in Sage.
 Sage Days 23.5, Kaiserslautern, Germany, July 1722, 2010

Sage Days 20.5, Fields Institute, Toronto, Canada, May 37, 2010
Besides giving a talk and fixing bugs here and there, I learnt a lot about the design of the category framework in Sage from Florent Hivert and Nicolas Thiéry.

Software Workshop Geometry and Combinatorics 2010, Kaiserslautern, Germany, Feb. 1114, 2010
Worked with Anders Jensen to make gfan call Singular’s Gröbner basis computation functions through Sage. This led to sage_link, an example of how to embedd Sage in C/C++ programs.

Sage Days 19, Seattle, USA, Jan. 1620, 2010
Squashed some Pynac and symbolics related bugs.
 Sage workshop *Combinat, Hagenberg, Austria, July 2529, 2009

Sage Days 16, Barcelona, Spain, June 2227, 2009
Started writing templated wrappers for FFLAS in Sage (#4260). Here is the status reports page.

Sage Days 12, San Diego, USA, Jan. 2124, 2009
I concentrated mainly on Pynac with the aim of implementing features needed to use it as the main symbolics backend in Sage.

Sage Days 10, Nancy, France, Oct. 1015, 2008
A rather productive week, as the status reports page reflects. Here is a summary:
 Initial prototype wrapper for Singular’s noncommutative part Plural from Sage with Michael Brickenstein. This became #4539, which was completed with help from Oleksandr Motsak, Alexander Dreyer, and especially Simon King to be merged into Sage 3 years later.
 Started working on fast linear algebra over univariate polynomial rings based on a xadic lifting algorithm suggested by Arne Storjohann.
 Moved Sage’s fraction field code to the new coercion framework and made the element classes customizable. This was useful for my implementation of Karr’s algorithm in Sage.

Sage Developer Days 1, Seattle, USA, June 1320, 2008
A totally awesome weeklong coding sprint, where I started out with the aim to make linear algebra over polynomial rings faster and ended up writing a wrapper for Sage to use Flint for operations on univariate polynomials over the integers. Here is the complete status report.

Sage Days 6, Bristol, UK, Nov. 1014, 2007
This was my first real world meeting with Sage developers. I spent most of the time working with Michael Brickenstein to debug the Cython interface to PolyBoRi I had written.
Activities
Helped with the organization of
 Efficient Linear Algebra for Gröbner Basis Computations, June 48, 2012, Kaiserslautern, Germany
 Sage/Singular Days 34, September 2630, 2011, Kaiserslautern, Germany
 Sage Days 24, July 1722, 2010, Hagenberg, Austria
 *combinat days, July 2529, 2009, Hagenberg, Austria
 Formal Power Series and Algebraic Combinatorics (FPSAC) 2009, July 2024, 2009, Hagenberg, Austria
 International Symposium on Symbolic and Algebraic Computation (ISSAC) 2008, July 20–23, 2008, Hagenberg, Austria