@misc{EhrhardtSteinbach, author = {Ehrhardt, Klaus and Steinbach, Marc}, title = {KKT Systems in Operative Planning for Gas Distribution Networks}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-7962}, number = {04-21}, abstract = {Operative planning in gas networks with prescribed binary decisions yields large scale nonlinear programs defined on graphs. We study the structure of the KKT systems arising in interior methods and present a customized direct solution algorithm. Computational results indicate that the algorithm is suitable for optimization in small and medium-sized gas networks.}, language = {en} } @misc{EhrhardtSteinbach, author = {Ehrhardt, Klaus and Steinbach, Marc}, title = {Nonlinear Optimization in Gas Networks}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-7687}, number = {03-46}, abstract = {The operative planning problem in natural gas distribution networks is addressed. An optimization model focusing on the governing PDE and other nonlinear aspects is presented together with a suitable discretization for transient optimization in large networks by SQP methods. Computational results for a range of related dynamic test problems demonstrate the viability of the approach.}, language = {en} }