TY - JOUR A1 - Faßbender, Heinz A1 - Vogler, Heiko T1 - A narrowing machine for the functional logic language BABEL, restricted to primitive recursion : abstract JF - Granada Workshop on the Integration of Functional and Logic Programming / Granada Workshop on the Integration of Functional and Logic Programming <1990>. K. Indermark ... (ed.) Y1 - 1991 SP - 95 EP - 96 PB - RWTH, Fachgruppe Informatik CY - Aachen ER - TY - CHAP A1 - Altherr, Lena A1 - Dörig, Bastian A1 - Ederer, Thorsten A1 - Pelz, Peter Franz A1 - Pfetsch, Marc A1 - Wolf, Jan T1 - A mixed-integer nonlinear program for the design of gearboxes T2 - Operations Research Proceedings 2016 N2 - Gearboxes are mechanical transmission systems that provide speed and torque conversions from a rotating power source. Being a central element of the drive train, they are relevant for the efficiency and durability of motor vehicles. In this work, we present a new approach for gearbox design: Modeling the design problem as a mixed-integer nonlinear program (MINLP) allows us to create gearbox designs from scratch for arbitrary requirements and—given enough time—to compute provably globally optimal designs for a given objective. We show how different degrees of freedom influence the runtime and present an exemplary solution. Y1 - 2017 SN - 978-3-319-55701-4 U6 - https://doi.org/10.1007/978-3-319-55702-1_31 SP - 227 EP - 233 PB - Springer CY - Cham ER - TY - JOUR A1 - Orzada, Stephan A1 - Ladd, Mark E. A1 - Bitz, Andreas T1 - A method to approximate maximum local SAR in multichannel transmit MR systems without transmit phase information JF - Magnetic Resonance in Medicine N2 - Purpose To calculate local specific absorption rate (SAR) correctly, both the amplitude and phase of the signal in each transmit channel have to be known. In this work, we propose a method to derive a conservative upper bound for the local SAR, with a reasonable safety margin without knowledge of the transmit phases of the channels. Methods The proposed method uses virtual observation points (VOPs). Correction factors are calculated for each set of VOPs that prevent underestimation of local SAR when the VOPs are applied with the correct amplitudes but fixed phases. Results The proposed method proved to be superior to the worst-case calculation based on the maximum eigenvalue of the VOPs. The mean overestimation for six coil setups could be reduced, whereas no underestimation of the maximum local SAR occurred. In the best investigated case, the overestimation could be reduced from a factor of 3.3 to a factor of 1.7. Conclusion The upper bound for the local SAR calculated with the proposed method allows a fast estimation of the local SAR based on power measurements in the transmit channels and facilitates SAR monitoring in systems that do not have the capability to monitor transmit phases Y1 - 2016 U6 - https://doi.org/10.1002/mrm.26398 SN - 1522-2594 VL - 78 IS - 2 SP - 805 EP - 811 PB - International Society for Magnetic Resonance in Medicine ER - TY - CHAP A1 - Heuermann, Holger A1 - Harzheim, Thomas A1 - Mühmel, Marc T1 - A maritime harmonic radar search and rescue system using passive and active tags T2 - 2020 17th European Radar Conference (EuRAD) N2 - This article introduces a new maritime search and rescue system based on S-band illumination harmonic radar (HR). Passive and active tags have been developed and tested attached to life jackets and a rescue boat. This system was able to detect and range the active tags up to a range of 5800 m in tests on the Baltic Sea with an antenna input power of only 100 W. All electronic GHz components of the system, excluding the S-band power amplifier, were custom developed for this purpose. Special attention is given to the performance and conceptual differences between passive and active tags used in the system and integration with a maritime X-band navigation radar is demonstrated. KW - Harmonic Radar KW - Rescue System KW - Frequency Doubler KW - Transponder KW - Tag Y1 - 2021 SN - 978-2-87487-061-3 U6 - https://doi.org/10.1109/EuRAD48048.2021.00030 N1 - 17th European Radar Conference, 13th - 15th January 2021, Utrecht, Netherlands SP - 73 EP - 76 PB - IEEE CY - New York, NY ER - TY - JOUR A1 - Bragard, Michael A1 - van Hoek, H. A1 - De Doncker, R. W. T1 - A major design step in IETO concept realization that allows overcurrent protection and pushes limits of switching performance JF - IEEE transactions on power electronics N2 - This paper presents the latest prototype of the integrated emitter turn-off thyristor concept, which potentially ranks among thyristor high-power devices like the gate turn-off thyristor and the integrated gate-commutated thyristor (IGCT). Due to modifications of the external driver stage and mechanical press-pack design optimization, this prototype allows for full device characterization. The turn-off capability was increased to 1600 A with an active silicon area of 823mm2 . This leads to a transient peak power of 672.1kW/cm² . Within this paper, measurements and concept assessment are presented and a comparison to state-of-the-art IGCT devices is provided. Y1 - 2012 U6 - https://doi.org/10.1109/TPEL.2012.2189136 SN - 0885-8993 VL - 27 IS - 9 SP - 4163 EP - 4171 PB - IEEE CY - New York ER - TY - JOUR A1 - Niemüller, Tim A1 - Ferrein, Alexander A1 - Lakemeyer, Gerhard T1 - A Lua-based Behavior Engine for Controlling the Humanoid Robot Nao JF - RoboCup 2009: Robot Soccer World Cup XIII Y1 - 2010 N1 - Lecture Notes in Computer Science ; 5949 SP - 240 EP - 251 ER - TY - JOUR A1 - Ferrein, Alexander A1 - Rens, Gavin A1 - Meyer, Thomas A1 - Lakemeyer, Gerhard T1 - A Logic for Specifying Partially Observable Stochastic Domains / Rens, Gavin ; Meyer, Thomas ; Ferrein, Alexander ; Lakemeyer, Gerhard JF - Proceedings of the Ninth International Workshop pn non-Monotonic Reasoning, Action and Change (NRAC`11) Y1 - 2011 N1 - Technical Report RMIT-TR-11-02 SP - 15 EP - 22 ER - TY - JOUR A1 - Rens, Gavin A1 - Varzinczak, Ivan A1 - Meyer, Thomas A1 - Ferrein, Alexander T1 - A Logic for Reasoning about Actions and Explicit Observations JF - AI 2010: Advances in Artificial Intelligence 23rd Australasian Joint Conference, Adelaide, Australia, December 7-10, 2010. Proceedings Y1 - 2010 SN - 978-3-642-17431-5 N1 - Lecture Notes in Computer Science ; 6464 SP - 395 EP - 404 PB - Springer CY - Berlin ER - TY - CHAP A1 - Limpert, Nicolas A1 - Schiffer, Stefan A1 - Ferrein, Alexander T1 - A Local Planner for Ackermann-Driven Vehicles in ROS SBPL T2 - Proceedings of the International Conference on Pattern Recognition Association of South Africa and Robotics and Mechatronics (PRASA-RobMech), 2015 Y1 - 2015 U6 - https://doi.org/10.1109/RoboMech.2015.7359518 SP - 172 EP - 177 ER - TY - JOUR A1 - Czarnecki, Christian A1 - Spiliopoulou, Myra T1 - A holistic framework for the implementation of a next generation network JF - International Journal of Business Information Systems N2 - As the potential of a next generation network (NGN) is recognised, telecommunication companies consider switching to it. Although the implementation of an NGN seems to be merely a modification of the network infrastructure, it may trigger or require changes in the whole company, because it builds upon the separation between service and transport, a flexible bundling of services to products and the streamlining of the IT infrastructure. We propose a holistic framework, structured into the layers ‘strategy’, ‘processes’ and ‘information systems’ and incorporate into each layer all concepts necessary for the implementation of an NGN, as well as the alignment of these concepts. As a first proof-of-concept for our framework we have performed a case study on the introduction of NGN in a large telecommunication company; we show that our framework captures all topics that are affected by an NGN implementation. KW - next generation network KW - telecommunication KW - NGN KW - IP-based networks KW - product bundling Y1 - 2012 U6 - https://doi.org/10.1504/IJBIS.2012.046291 SN - 1746-0972 VL - 9 IS - 4 SP - 385 EP - 401 PB - Inderscience Enterprises CY - Olney, Bucks ER - TY - JOUR A1 - Rausch, Lea A1 - Friesen, John A1 - Altherr, Lena A1 - Meck, Marvin A1 - Pelz, Peter F. T1 - A holistic concept to design optimal water supply infrastructures for informal settlements using remote sensing data JF - Remote Sensing N2 - Ensuring access to water and sanitation for all is Goal No. 6 of the 17 UN Sustainability Development Goals to transform our world. As one step towards this goal, we present an approach that leverages remote sensing data to plan optimal water supply networks for informal urban settlements. The concept focuses on slums within large urban areas, which are often characterized by a lack of an appropriate water supply. We apply methods of mathematical optimization aiming to find a network describing the optimal supply infrastructure. Hereby, we choose between different decentral and central approaches combining supply by motorized vehicles with supply by pipe systems. For the purposes of illustration, we apply the approach to two small slum clusters in Dhaka and Dar es Salaam. We show our optimization results, which represent the lowest cost water supply systems possible. Additionally, we compare the optimal solutions of the two clusters (also for varying input parameters, such as population densities and slum size development over time) and describe how the result of the optimization depends on the entered remote sensing data. KW - water supply design KW - mathematical optimization KW - slum classification KW - remote sensing Y1 - 2018 SN - 2072-4292 U6 - https://doi.org/10.3390/rs10020216 VL - 10 IS - 2 SP - 1 EP - 23 PB - MDPI CY - Basel ER - TY - JOUR A1 - Heuermann, Holger A1 - Schiek, Burkhard T1 - A Generalization of the Txx Network Analyzer Self-Calibration Procedure JF - Conference proceedings : monday 24th to thursday 27th august 1992, Helsinki University of Technology, Espoo, Finland ; [the international conference and exhibition designed for the Microwave Community]. Vol. 2 Y1 - 1992 SN - 0-946821-77-1 N1 - European Microwave Conference <22, 1992, Espoo> ; Teknillinen Korkeakoulu SP - 907 EP - 912 PB - Microwave Exhibitions and Publishers CY - Tunbridge Wells ER - TY - JOUR A1 - Ferrein, Alexander A1 - Schiffer, Stefan A1 - Lakemeyer, Gerhard T1 - A Fuzzy Set Semantics for Qualitative Fluents in the Situation Calculus / Ferrein, Alexander ; Schiffer, Stefan ; Lakemeyer, Gerhard JF - Intelligent Robotics and Applications : First International Conference, ICIRA 2008 Wuhan, China, October 15-17, 2008 Proceedings, Part I Y1 - 2008 N1 - Lecture Notes in Computer Science ; 5314 SP - 498 EP - 509 PB - Springer CY - Berlin ER - TY - CHAP A1 - Engels, Elmar T1 - A field bus library for MATLAB based on open core engineering T2 - Proceedings to the 14th International Workshop on Research and Education in Mechatronics, REM 2013, Wien, 05.06.-06.06.2013. Y1 - 2013 SN - 978-3-90275-907-8 ER - TY - JOUR A1 - Heuermann, Holger A1 - Schiek, Burkhard T1 - A Fast and Robust Procedure for the Determination of the Scattering Parameters for Network Analyzer Calibration Y1 - 1992 N1 - Precision electromagnetic measurements : conference Paris, 9-12 June 1992 = Conférence sur les Mesures Electromagnétiques de Précision. SP - 373 EP - 374 CY - Paris ER - TY - CHAP A1 - Walenta, Robert A1 - Schellekens, Twan A1 - Ferrein, Alexander A1 - Schiffer, Stefan T1 - A decentralised system approach for controlling AGVs with ROS T2 - AFRICON, Proceedings Y1 - 2017 SN - 978-1-5386-2775-4 U6 - https://doi.org/10.1109/AFRCON.2017.8095693 SN - 2153-0033 N1 - AFRICON <2017, 18-20 Sept., Cape Town, South Africa> SP - 1436 EP - 1441 PB - IEEE ER - TY - CHAP A1 - Steuer-Dankert, Linda T1 - A crazy little thing called sustainability T2 - 51st Annual Conference of the European Society for Engineering Education (SEFI) N2 - Achieving the 17 Sustainable Development Goals (SDGs) set by the United Nations (UN) in 2015 requires global collaboration between different stakeholders. Industry, and in particular engineers who shape industrial developments, have a special role to play as they are confronted with the responsibility to holistically reflect sustainability in industrial processes. This means that, in addition to the technical specifications, engineers must also question the effects of their own actions on an ecological, economic and social level in order to ensure sustainable action and contribute to the achievement of the SDGs. However, this requires competencies that enable engineers to apply all three pillars of sustainability to their own field of activity and to understand the global impact of industrial processes. In this context, it is relevant to understand how industry already reflects sustainability and to identify competences needed for sustainable development. KW - Transformative Competencies KW - Future Skills KW - Transdisciplinarity KW - Interdisciplinarity KW - Sustainability Y1 - 2023 U6 - https://doi.org/10.21427/9CQR-VC94 N1 - 51st Annual Conference of the European Society for Engineering Education, Technological University Dublin, 10th-14th September, 2023 ER - TY - JOUR A1 - Köhler, Klemens T1 - A conflict theory perspective of IT attacks – consequences for IT security education N2 - Cyberspace is "the environment formed by physical and non-physical components to store, modify, and exchange data using computer networks" (NATO CCDCOE). Beyond that, it is an environment where people interact. IT attacks are hostile, non-cooperative interactions that can be described with conflict theory. Applying conflict theory to IT security leads to different objectives for end-user education, requiring different formats like agency-based competence developing games. Y1 - 2020 IS - Preprint ER - TY - CHAP A1 - Rausch, Lea A1 - Leise, Philipp A1 - Ederer, Thorsten A1 - Altherr, Lena A1 - Pelz, Peter F. ED - Papadrakakis, M. ED - Ppadopoulos, V. ED - Stefanou, G. ED - Plevris, V. T1 - A comparison of MILP and MINLP solver performance on the example of a drinking water supply system design problem T2 - ECCOMAS Congress 2016 VII European Congress on Computational Methods in Applied Sciences and Engineering N2 - Finding a good system topology with more than a handful of components is a highly non-trivial task. The system needs to be able to fulfil all expected load cases, but at the same time the components should interact in an energy-efficient way. An example for a system design problem is the layout of the drinking water supply of a residential building. It may be reasonable to choose a design of spatially distributed pumps which are connected by pipes in at least two dimensions. This leads to a large variety of possible system topologies. To solve such problems in a reasonable time frame, the nonlinear technical characteristics must be modelled as simple as possible, while still achieving a sufficiently good representation of reality. The aim of this paper is to compare the speed and reliability of a selection of leading mathematical programming solvers on a set of varying model formulations. This gives us empirical evidence on what combinations of model formulations and solver packages are the means of choice with the current state of the art. KW - Technical Operations Research KW - Mixed-Integer Nonlinear Optimisation KW - Solver Per- formance KW - Drinking Water Supply KW - System Design Problem Y1 - 2016 SN - 978-618-82844-0-1 N1 - ECCOMAS Congress 2016 VII European Congress on Computational Methods in Applied Sciences and Engineering, 5–10 June 2016.Crete Island, Greece SP - 8509 EP - 8527 ER - TY - CHAP A1 - Wolf, Martin A1 - Wiese, Ute T1 - A comparative transformation model for process changes using serious games T2 - 2013 IEEE 2nd International Conference on Serious Games and Applications for Health (SeGAH): proceedings of a meeting held 2-3 May 2013, Algarve, Portugal Y1 - 2013 SN - 978-1-4673-6164-4 U6 - https://doi.org/10.1109/SeGAH.2013.6665307 SP - 64 EP - 70 PB - Institute of Electrical and Electronics Engineers (IEEE) CY - Piscataway, NJ ER -