TY - JOUR A1 - Reemtsen, Rembert T1 - Design approximation problems for linear-phase nonrecursive digital filters KW - digital filters KW - linear-phase filters KW - Remez algorithm KW - Parks-McClellan algorithm Y1 - 2002 ER - TY - JOUR A1 - Reemtsen, Rembert T1 - Frequency and magnitude response design approximation problems for nonlinear-phase nonrecursive digital filters KW - filter design KW - digital filters KW - complex approximation KW - complete systems Y1 - 2002 ER - TY - JOUR A1 - Potchinkov, Alexander A1 - Reemtsen, Rembert T1 - Bicriterial design of digital filters KW - bicriterial optimization KW - reference point approximation KW - filter design KW - digital filters KW - compromise filters Y1 - 2002 ER - TY - JOUR A1 - Görner, Stephan A1 - Potchinkov, Alexander A1 - Reemtsen, Rembert T1 - The direct solution of nonconvex nonlinear FIR filter design problems by a SIP method KW - filter design KW - SQP methods KW - semi-infinite programming KW - FIR filters Y1 - 2000 ER - TY - JOUR A1 - Reemtsen, Rembert T1 - FIR filter design problems of simultaneous approximation of magnitude and phase and magnitude and group delay KW - filter design KW - digital filters KW - simultaneous approximation KW - magnitude-phase problem KW - magnitude-group delay problem Y1 - 2001 ER - TY - BOOK A1 - Reemtsen, Rembert T1 - Lineare Optimierung : Eine Vorlesung KW - Lineare Optimierung KW - Simplex-Algorithmus KW - Innere-Punkte-Verfahren Y1 - 2001 SN - 3-8265-9615-3 PB - Aachen : Shaker ER - TY - CHAP A1 - Reemtsen, Rembert T1 - Semi-infinite programming : discretization methods KW - semi-infinite programming KW - discretization methods Y1 - 2001 ER - TY - JOUR A1 - Alber, Markus A1 - Meedt, G. A1 - Nüsslin, F. A1 - Reemtsen, Rembert T1 - On the degeneracy of the IMRT optimisation problem KW - radiation therapy planning KW - intensity modulated radiation therapy Y1 - 2002 ER - TY - JOUR A1 - Gomez Bofil, W. T1 - On generic quadratic penalty embeddings for nonlinear optimization problems Y1 - 2001 ER - TY - GEN A1 - Reemtsen, Rembert A1 - Alber, Markus T1 - Optimierungsgestützte Bestrahlungsplanung für die Krebsbehandlung T2 - Forum der Forschung Y1 - 2005 SN - 0947-6989 VL - 9 IS - 18 SP - 107 EP - 114 ER - TY - JOUR A1 - Alber, Markus A1 - Reemtsen, Rembert T1 - Intensity modulated radiotherapy treatment planning by use of a barrier-penalty multiplier method N2 - The use of nonlinear functions describing biological effects has recently become a major goal in connection with intensity modulated radiotherapy (IMRT) planning models for cancer treatment. In this paper, we present a new biological model for this purpose and discuss the solution of the large-scale nonlinear optimization problems originating from it. The model includes equivalent uniform dose and partial volume constraints and employs the tumor control probability as the objective. The resulting optimization problems are convex and nonconvex constrained optimization problems with several thousands of variables, for which gradients of the involved functions are available, but the computation of Hessians is numerically too costly. It is suggested to solve these problems with a barrier-penalty multiplier method by Polyak, Ben-Tal and Zibulevsky, where this algorithm is modified according to ideas which are motivated by a related Lagrangian barrier algorithm of Conn, Gould, and Toint. In particular, the subproblems in the algorithm are solved by a conjugate gradient method, since the spectrum of the Hessian of the Lagrangian at a solution of such problem indicates fast (local) convergence of the objective function values to a good approximate (locally) optimal value. Some characteristic numbers showing the average numerical performance of the algorithm are tabulated for various types of tumors and a set of 127 clinical cases in total. Its capabilities and typical behavior also are illustrated explicitly by a computed therapy plan for a difficult clinical case of a larynx tumor. KW - radiation therapy treatment planning KW - intensity modulated radiation therapy KW - IMRT KW - barrier algorithms KW - multiplier methods KW - nonlinear rescaling method KW - barrier-penalty functions Y1 - 2007 ER - TY - CHAP A1 - Reemtsen, Rembert A1 - Alber, Markus T1 - Continuous optimization of beamlet intensities for intensity modulated photon and proton radiotheraphy. Y1 - 2009 ER - TY - THES A1 - Fügenschuh, Armin T1 - The Integrated Optimization of School Starting Times and Public Bus Services Y1 - 2005 SN - 3-8325-1037-0 N1 - Darmstadt, Technische Universität, Dissertation, 2005 PB - Logos Verlag CY - Berlin ER - TY - GEN A1 - Fügenschuh, Armin A1 - Ward, Hauke A1 - Radebach, Alexander A1 - Vierhaus, Ingmar A1 - Steckel, Jan Christoph T1 - Reducing global CO2 emissions with the technologies we have T2 - Resource and Energy Economics Y1 - 2017 SN - 0928-7655 VL - 49 SP - 201 EP - 217 ER - TY - GEN A1 - Fügenschuh, Armin A1 - Humpola, Jesco A1 - Koch, Thorsten T1 - Valid inequalities for the topology optimization problem in gas network design T2 - OR Spectrum Y1 - 2016 SN - 1436-6304 SN - 0171-6468 VL - 38 IS - 3 SP - 597 EP - 631 ER - TY - GEN A1 - Dósa, György A1 - Fügenschuh, Armin A1 - Tan, Zhiyi A1 - Tuza, Zsolt A1 - Węsek, Krzysztof T1 - Tight Upper Bounds for Semi-Online Scheduling on Two Uniform Machines with Known Optimum T2 - Central European Journal of Operations Research Y1 - 2018 SN - 1613-9178 VL - Vol. 26 IS - 1 SP - 161 EP - 180 ER - TY - GEN A1 - Vierhaus, Ingmar A1 - van Veldhuizen, Roel A1 - Fügenschuh, Armin T1 - Strategic Uncertainty in Markets for Non-renewable Resources: a Level-k Approach T2 - Discrete dynamics in nature and society Y1 - 2017 U6 - https://doi.org/10.1155/2017/2768045 SN - 1607-887X SN - 1026-0226 VL - 2017 ER - TY - GEN A1 - Nomani, Mohammad Asim A1 - Ali, Irfan A1 - Fügenschuh, Armin A1 - Ahmed, Aquil T1 - A Fuzzy Goal Programming Approach to Analyze Sustainable Development Goals of India T2 - Applied Economics Letters Y1 - 2017 SN - 1350-4851 VL - 24 IS - 7 SP - 443 EP - 447 ER - TY - GEN A1 - Börndörfer, Ralf A1 - Klug, Torsten A1 - Schlechte, Thomas A1 - Fügenschuh, Armin A1 - Schang, Thilo A1 - Schülldorf, Hanno T1 - The Freight Train Routing Problem for Congested Railway Networks with Mixed Traffic T2 - Transportation Science Y1 - 2016 U6 - https://doi.org/10.1287/trsc.2015.0656 SN - 1526-5447 SN - 0041-1655 VL - 50 IS - 2 SP - 363 EP - 761 ER - TY - GEN A1 - Humpola, Jesco A1 - Fügenschuh, Armin T1 - Convex reformulations for solving a nonlinear network design problem T2 - Computational Optimization and Applications Y1 - 2015 U6 - https://doi.org/10.1007/s10589-015-9756-2 SN - 1573-2894 SN - 0926-6003 VL - 62 IS - 3 SP - 717 EP - 759 ER -