@article{UffmannAbichtGroteetal.2002, author = {Uffmann, Kai and Abicht, Claus and Grote, Wolfgang and Quick, Harald H. and Ladd, Mark E.}, title = {Design of an MR-compatible piezoelectric actuator for MR elastography}, series = {Concepts in Magnetic Resonance Part A: Bridging Education and Research}, volume = {15}, journal = {Concepts in Magnetic Resonance Part A: Bridging Education and Research}, number = {4}, publisher = {Wiley}, doi = {https://doi.org/10.1002/cmr.10045}, pages = {239 -- 254}, year = {2002}, abstract = {Magnetic Resonance (MR) elastography is a method for measuring tissue elasticity via phase images acquired with an MR scanner. The propagation of periodic mechanical waves through the tissue can be captured by means of a modified phase contrast sequence. These waves are generated with a mechanical oscillator (actuator) and coupled into the tissue through the skin. The actuator must be capable of generating a sinusoidal excitation with excellent phase and amplitude stability, while not disturbing the MR imaging process. In this work, an actuator based on a piezoelectric principle was developed. Based on the imaging evaluation of several material samples, the housing for the piezoelectric ceramic was constructed of aluminum. Smaller parts of the housing were manufactured from brass and titanium to fulfill the mechanical constraints. A lever was used to transfer the oscillation generated by the piezoelectric ceramic to the point of excitation. The lever amplifies the piezoelectric motion, allowing for a more compact design. Three different lever designs were characterized by an acceleration sensor both outside and inside the magnet. It was shown that the rigidity of the lever, as determined by its material and form, was decisive in determining the resonant frequency of the system and therefore the maximum practical frequency of operation. It was also shown that the motion of the oscillator is unaffected by the electromagnetic fields of the MR imager. The final design can be placed directly in the magnet bore within a few centimeters of the tissue volume to be imaged without generating significant artifacts. An amplitude range of 0-1 mm in the frequency range from 0 to over 300 Hz was achieved, sufficient for performing most MR elastography applications. © 2002 Wiley Periodicals, Inc. Concepts in Magnetic Resonance (Magn Reson Engineering) 15: 239-254, 2002}, language = {en} } @article{BeyerGroteReinig2008, author = {Beyer, Marc-Andr{\´e} and Grote, Wolfgang and Reinig, Gunter}, title = {Adaptive exact linearization control of batch polymerization reactors using a Sigma-Point Kalman Filter}, series = {Journal of Process Control}, volume = {18}, journal = {Journal of Process Control}, number = {7-8}, publisher = {Elsevier}, doi = {10.1016/j.jprocont.2007.12.002}, pages = {663 -- 675}, year = {2008}, abstract = {The Chylla-Haase polymerization reactor is widely accepted as a benchmark process for the evaluation of control strategies for batch reactors. In this contribution a control concept based on Exact I/O-Linearization is proposed and compared to a conventional cascade control structure. In order to adapt the exact linearization control strategy to various polymerization products and batch conditions, an advanced probabilistic inference algorithm (Sigma-Point Kalman Filter) is applied and investigated. Sigma-Point Kalman Filters have the major improvement of simplified implementation compared to local linearization methods (i.e. Extended Kalman Filter) because no analytical Jacobians are required. Stochastic simulation studies are introduced and show the effectiveness, accuracy and benefit of the control concept. Within several scenarios a satisfying robustness against structural errors in the underlying model equations for the nonlinear control law and the inference algorithm is demonstrated. Furthermore it is pointed out, that with little effort in reassembling the plant design, control performance can be improved significantly.}, language = {en} } @article{GalbanMaderwaldEggebrechtetal.2005, author = {Galban, Craig and Maderwald, Stefan and Eggebrecht, Holger and Grote, Wolfgang and de Greiff, A. and Uffmann, K. and Ladd, M. E.}, title = {Monitoring the Effects of Chronic Obstructive Pulmonary Disease on Muscle Elasticity by MR Elastography}, series = {Proc. Intl. Soc. Mag. Reson. Med.}, volume = {13}, journal = {Proc. Intl. Soc. Mag. Reson. Med.}, pages = {2015}, year = {2005}, abstract = {Men afflicted with chronic obstructive pulmonary disease (COPD) show signs of muscle dysfunction, such as increased muscle fatigue and acidosis during exercise. We hypothesize that muscle elasticity of the lower extremities differs between patients with COPD and age-related controls. The shear modulus of the soleus muscle was measured non-invasively using MR elastography (MRE) at 0\%, 5\%, 10\%, 15\%, and 20\% of the subject's maximum applied force. The results from this study showed statistical differences between the patients and controls, even though there were no statistical differences in the maximum applied force.}, language = {en} } @article{GalbanMaderwaldHerrmannetal.2005, author = {Galban, Craig and Maderwald, Stefan and Herrmann, Burkhard and Brauck, K. and Grote, Wolfgang and de Greiff, A. and Uffmann, K. and Ladd, M.}, title = {Measuring Skeletal Muscle Elasticity in Patients with Hypogonadism by MR Elastography}, series = {Proc. Intl. Soc. Mag. Reson. Med.}, volume = {13}, journal = {Proc. Intl. Soc. Mag. Reson. Med.}, pages = {2016}, year = {2005}, abstract = {Men afflicted with hypogonadism have reduced fat-free mass and in some cases a loss in muscle strength. We hypothesize that muscle elasticity of the lower extremities differs between patients with hypogonadism and healthy controls. The shear modulus of the soleus muscle was measured non-invasively using MR elastography (MRE) at 0\%, 5\%, 10\%, 15\%, and 20\% of the subject's maximum applied force. The results from this study showed statistical differences between the patients and controls, even though there were no statistical differences in applied force.}, language = {en} } @inproceedings{GroteRammSchoenigSchwarzboezletal.2023, author = {Grote-Ramm, Wolfgang and Sch{\"o}nig, Felix and Schwarzb{\"o}zl, Peter and Drexelius, Maximilian and Maldonado Quinto, Daniel and Binder, Matthias}, title = {Model Predictive Control and Service Life Monitoring for Molten Salt Solar Power Towers}, series = {29th SolarPACES Conference, Sydney}, booktitle = {29th SolarPACES Conference, Sydney}, year = {2023}, abstract = {A two-component system for control and monitoring of solar power towers with molten salt receivers is proposed. The control component consists of a model predictive control applica-tion (MPC) with a flexible objective function and on-line tunable weights, which runs on a In-dustrial PC and uses a reduced order dynamic model of the receiver's thermal and flow dy-namics. The second component consists of a service-life monitoring unit, which estimates the service-life consumption of the absorber tubes depending on the current mode of operation based on thermal stresses and creep fatigue in the high temperature regime. The calculation of stresses is done based on a detailed finite element study, in which a digital twin of the re-ceiver was developed. By parallelising the model solver, the estimation of service-life con-sumption became capable of real-time operation. The system has been implemented at a test facility in J{\"u}lich, Germany, and awaits field experiments. In this paper, the modeling and archi-tecture are presented along simulation results, which were validated on a hardware-in-the-loop test bench. The MPC showed good disturbance rejection while respecting process variable constraints during the simulation studies.}, language = {en} } @article{LangmannMichael2019, author = {Langmann, Reinhard and Michael, Stiller}, title = {The PLC as a Smart Service in Industry 4.0 Production System}, series = {Applied Sciences}, volume = {9}, journal = {Applied Sciences}, number = {18}, publisher = {MDPI}, issn = {2076-3417}, doi = {10.3390/app9183815}, year = {2019}, language = {en} } @misc{LessmannMeuterMueller2018, author = {Lessmann, Stephanie and Meuter, Mirko and Mueller, Dennis}, title = {Method to determine distance of an object from an automated vehicle with a monocular device}, year = {2018}, abstract = {A method of determining the distance of an object from an automated vehicle based on images taken by a monocular image acquiring device. The object is recognized with an object-class by means of an image processing system. Respective position data are determined from the images using a pinhole camera model based on the object-class. Position data indicating in world coordinates the position of a reference point of the object with respect to the plane of the road is used with a scaling factor of the pinhole camera model estimated by means of a Bayes estimator using the position data as observations and under the assumption that the reference point of the object is located on the plane of the road with a predefined probability. The distance of the object from the automated vehicle is calculated from the estimated scaling factor using the pinhole camera model.}, language = {en} } @misc{KraemerSvetlichnyEilert2017, author = {Kraemer, Marco and Svetlichny, Vitaly and Eilert, Eva}, title = {Method for producing a fermentation product: Angemeldet durch DIREVO Industrial Biotechnology GmbH}, organization = {DIREVO Industrial Biotechnology GmbH}, year = {2017}, abstract = {Priorit{\"a}tsdaten: EP15191039A·2015-10-22; US201562245054P·2015-10-22 Bibliographische IPC: C12P7/06; C12P7/14;}, language = {en} } @misc{EilertSuckowPiontek2014, author = {Eilert, Eva and Suckow, Manfred and Piontek, Michael}, title = {A method for producing ectoine or a derivative thereof and a yeast cell for use as a host cell in such a method}, organization = {Artes Biotechnology GmbH}, year = {2014}, abstract = {Klassifikationen IPC C12N15/81; C12N15/82; C12P17/12; C12P7/42; CPC C12N15/815 (EP); C12P17/12 (EP);}, language = {en} } @techreport{DeckertKeszlerSchmitzetal.2022, author = {Deckert, Carsten and Keszler, Julia and Schmitz, Helen and Mohya, Ahmed}, title = {Forecasting Game: Teaching Prospective Engineers Quantitative Forecasting Techniques with a Simulation Game}, address = {D{\"u}sseldorf}, organization = {Hochschule D{\"u}sseldorf}, issn = {2627-8375}, doi = {10.20385/opus4-3905}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-39057}, pages = {43}, year = {2022}, abstract = {In order to determine demand as precisely as possible, many businesses use several forecasting methods. The aim of forecasting is to determine future demand based on data from the past. The use of a specific method is not always easy and depends on a number of factors. To help prospective engineers find the most suitable forecasting method for a specific problem, a forecasting game was developed and then evaluated. The paper describes the design and the evaluation of the forecasting game. In order to provide an overview of existing forecasting methods, the first part of the paper examined the mathematical fundamentals of eight different forecasting methods and outlined the requirements for their application. The second part of the paper describes the creation of a forecasting game in which prospective engineers can learn how to determine the appropriate forecasting method for specific scenarios. In total, five scenarios covering the three different demand patterns (linear/stationary, trend and seasonal) as well as the forecast quality methods were developed and can be played through. For each scenario, the player has to choose the most appropriate forecasting method for a specific problem based on a self-created task description. To make the game as realistic as possible, a fictional company with a background story was designed. The last part was about the evaluation of the forecasting game. For the evaluation, a student survey to gather the opinions of the students was conducted. The results of the student survey show an overall positive evaluation of the simulation game by the students. However, the test also showed that the game takes a certain amount of time. Since only 15 of the approximately 30 students who tested the game participated in the evaluation, the results are not significant.}, language = {en} }