Johannes Lotz

Contact Details:

• Dr. rer. nat. Dipl.-Ing. Johannes Lotz
• Phone: +49 (0)241/80 20 129
• Mail: lotz@stce.rwth-aachen.de
• Office:  Room 237, Seffenter Weg 23

Research Interest:

• dco/c++ - Derivative Code by Overloading in C++
• Hybrid Approaches to Adjoint Code Generation based on the AD Tool dco/c++.
• Joint work with TU Kaiserslautern, Chair for Scientific Computing:
  dco/c++ and TRACE / PADGE (CFD, optimization).
• Joint work with Jülich Research Center, IEK-7:
  dco/c++ and JURASSIC (atmospheric remote sensing, inverse problems).
• Joint work with RWTH, Process Systems Engineering:
  dco/c++ and NIXE (ODE integration, data fitting).
• Joint work with NAG:
  dco/c++ and CUDA (finance).
• Internally:
  • dco/c++ and dco/fortran.
  • dco/c++ and OpenFOAM (CFD, optimization).
  • dco/c++ and PETSc.

Publications:

• 2020
  • S.R. Islam, J. Lotz, J. Szumbarski, U. Naumann. Adjoint Based Output Error Estimation and Mesh Regeneration for
    Inviscid Flow. 22nd Australasian Fluid Mechanics Conference. Abstract accepted.
  • R. Langer, J. Lotz, L. Cai, F. v. Lehn, K. Leppkes, U. Naumann, H. Pitsch. Adjoint sensitivity analysis of kinetic, thermochemical, and transport data of nitrogen and ammonia chemistry. 38th International Symposium on Combustion, 2020. Accepted as presentation.
  • D. Ganellari, G. Haase, G. Zumbusch, J. Lotz, P. Peltzer, K. Leppkes and U. Naumann. Patient-specific cardiac parametrization from Eikonal simulations. 2020 International Conference on Computational Science. Accepted.
  • P. Peltzer, J. Lotz and U. Naumann. Eigen-AD: Algorithmic Differentiation of the Eigen Library. 2020 International Conference on Computational Science. Accepted.
• 2016
  
  • J. Lotz, U. Naumann, S. Mitra. Mixed Integer Programming for Call Tree Reversal. 2016 Proceedings of the Seventh SIAM Workshop on Combinatorial Scientific Computing.
  • J. Lotz. Hybrid Approaches to Adjoint Code Generation with dco/c++. PhD Thesis, 2016.
  • J. Lotz, M. Schwalbach, U. Naumann. A Case Study in Adjoint Sensitivity Analysis of Parameter Calibration. Procedia Computer Science 80, 2016 International Conference on Computational Science.
• 2015
  • J. Lotz, U. Naumann, R. Hannemann-Tamas, T. Ploch, and A. Mitsos. Higher-Order Discrete Adjoint ODE Solver in C++ for Dynamic Optimization. Procedia Computer Science, 2015 International Conference on Computational Science.
  • N. Safiran, J. Lotz, U. Naumann. Second-order Tangent Solvers for Systems of Parameterized Nonlinear Equations. Procedia Computer Science, 2015 International Conference on Computational Science.
  • U. Naumann, J. Lotz, K. Leppkes, M. Towara. Algorithmic Differentiation of Numerical Methods: First-Order Tangents and Adjoints for Solvers of Systems of Nonlinear Equations. ACM TOMS, Vol. 41.
•  2013
  • M. Sagebaum, N. R. Gauger, U. Naumann, J. Lotz, and K. Leppkes. Algorithmic Differentiation of a Complex C++ Code with Underlying Libraries. Procedia Computer Science 18, 208-217, 2013.
  • J. Lotz, U. Naumann, M. Sagebaum, M. Schanen. Discrete Adjoints of PETSc through dco/c++ and Adjoint MPI. Euro-Par 2013 Parallel Processing (pp. 497-507). Springer Berlin Heidelberg, 2013.
• 2012
  • J. d. Toit, J. Lotz, and U. Naumann. Adjoint Algorithmic Differentiation of a GPU Accelerated Application, pdf, 2012.
  • J. Lotz, U. Naumann and J. Ungermann. Hierarchical Algorithmic Differentiation: A Case Study. Recent Advances in Algorithmic Differentiation, Lecture Notes in Computational Science and Engineering, Volume 87, 187-196, 2012.
  • M. Schanen, M. Foerster, J. Lotz, K. Leppkes and U. Naumann. Adjoining Hybrid Parallel Code. Proceedings of the Eighth International Conference on Engineering Computational Technology, 2012.
• 2011
  • J. Ungermann, J. Blank, J. Lotz, K. Leppkes, T. Guggenmoser, M. Kaufmann, P. Preusse, U. Naumann, and M. Riese. A 3-D Tomographic Trajectory Retrieval for the Air-borne Limb-imager GLORIA. Atmos. Meas. Tech., 2011.