@inproceedings{MuellerAltherrAholaetal.2019,
  author    = {M{\"u}ller, Tim M. and Altherr, Lena and Ahola, Marja and Schabel, Samuel and Pelz, Peter F.},
  title     = {Multi-Criteria optimization of pressure screen systems in paper recycling - balancing quality, yield, energy consumption and system complexity},
  series = {EngOpt 2018 Proceedings of the 6th International Conference on Engineering Optimization},
  booktitle = {EngOpt 2018 Proceedings of the 6th International Conference on Engineering Optimization},
  editor    = {Rodrigues, H. C.},
  publisher = {Springer International Publishing},
  address   = {Basel},
  isbn      = {978-3-319-97773-7},
  doi       = {10.1007/978-3-319-97773-7_105},
  year      = {2019},
  abstract  = {The paper industry is the industry with the third highest energy consumption in the European Union. Using recycled paper instead of fresh fibers for papermaking is less energy consuming and saves resources. However, adhesive contaminants in recycled paper are particularly problematic since they reduce the quality of the resulting paper-product. To remove as many contaminants and at the same time obtain as many valuable fibres as possible, fine screening systems, consisting of multiple interconnected pressure screens, are used. Choosing the best configuration is a non-trivial task: The screens can be interconnected in several ways, and suitable screen designs as well as operational parameters have to be selected. Additionally, one has to face conflicting objectives. In this paper, we present an approach for the multi-criteria optimization of pressure screen systems based on Mixed-Integer Nonlinear Programming. We specifically focus on a clear representation of the trade-off between different objectives.},
  language  = {en}
}
@inproceedings{LorenzAltherrPelz2019,
  author    = {Lorenz, Imke-Sophie B. and Altherr, Lena and Pelz, Peter F.},
  title     = {Graph-theoretic resilience analysis of a water distribution system's topology},
  series = {World Congress on Resilience, Reliability and Asset Management 2019},
  booktitle = {World Congress on Resilience, Reliability and Asset Management 2019},
  pages     = {106 -- 109},
  year      = {2019},
  abstract  = {Water suppliers are faced with the great challenge of achieving high-quality and, at the same time, low-cost water supply. In practice, the focus is set on the most beneficial maintenance measures and/or capacity adaptations of existing water distribution systems (WDS). Since climatic and demographic influences will pose further challenges in the future, the resilience enhancement of WDS, i.e. the enhancement of their capability to withstand and recover from disturbances, has been in particular focus recently. To assess the resilience of WDS, metrics based on graph theory have been proposed. In this study, a promising approach is applied to assess the resilience of the WDS for a district in a major German City. The conducted analysis provides insight into the process of actively influencing the resilience of WDS},
  language  = {en}
}