@article{SchifferFerreinLakemeyer2012, author = {Schiffer, Stefan and Ferrein, Alexander and Lakemeyer, Gerhard}, title = {Caesar: an intelligent domestic service robot}, series = {Intelligent service robotics}, volume = {5}, journal = {Intelligent service robotics}, number = {4}, publisher = {Springer}, address = {Berlin}, issn = {1861-2776}, doi = {10.1007/s11370-012-0118-y}, pages = {259 -- 276}, year = {2012}, abstract = {In this paper we present CAESAR, an intelligent domestic service robot. In domestic settings for service robots complex tasks have to be accomplished. Those tasks benefit from deliberation, from robust action execution and from flexible methods for human-robot interaction that account for qualitative notions used in natural language as well as human fallibility. Our robot CAESAR deploys AI techniques on several levels of its system architecture. On the low-level side, system modules for localization or navigation make, for instance, use of path-planning methods, heuristic search, and Bayesian filters. For face recognition and human-machine interaction, random trees and well-known methods from natural language processing are deployed. For deliberation, we use the robot programming and plan language READYLOG, which was developed for the high-level control of agents and robots; it allows combining programming the behaviour using planning to find a course of action. READYLOG is a variant of the robot programming language Golog. We extended READYLOG to be able to cope with qualitative notions of space frequently used by humans, such as "near" and "far". This facilitates human-robot interaction by bridging the gap between human natural language and the numerical values needed by the robot. Further, we use READYLOG to increase the flexible interpretation of human commands with decision-theoretic planning. We give an overview of the different methods deployed in CAESAR and show the applicability of a system equipped with these AI techniques in domestic service robotics}, language = {en} } @incollection{PriedeFerrein2013, author = {Priede, Gareth and Ferrein, Alexander}, title = {Towards passive walking for the fully-actuated biped robot Nao}, series = {Emerging trends in computing, informatics, systems sciences, and engineering. (Lecture notes in electrical engineering : vol. 151)}, booktitle = {Emerging trends in computing, informatics, systems sciences, and engineering. (Lecture notes in electrical engineering : vol. 151)}, publisher = {Springer}, address = {New York, NY}, isbn = {978-1-4614-3557-0 ; 978-1-4614-3558-7}, doi = {10.1007/978-1-4614-3558-7_18}, pages = {225 -- 236}, year = {2013}, abstract = {Many biped robots deploy a form of gait that follows the zero moment point (ZMP) approach, that is, the robot is in a stable position at any point in time. This requires the robot to be fully actuated. While very stable, the draw-backs of this approach are a fairly slow gait and high energy consumption. An alternative approach is the so-called passive-dynamic walking, where the gait makes use of the inertia and dynamic stability of the robot. In this paper we describe our ongoing work of combining the principles of passive-dynamic walking on the fully-actuated biped robot Nao, which is also deployed for robotic soccer applications. We present a simple controller that allows the robot to stably rock sidewards, showing a closed limit-cycle. We discuss first results of superimposing a forward motion on the sidewards motion. Based on this we expect to endow the Nao with a fast, robust, and stable passive-dynamic walk on the fully-actuated Nao in the future.}, language = {en} } @article{FerreinSchifferLakemeyer2009, author = {Ferrein, Alexander and Schiffer, Stefan and Lakemeyer, Gerhard}, title = {Embedding fuzzy controllers in golog / Ferrein, Alexander ; Schiffer, Stefan ; Lakemeyer, Gerhard}, series = {IEEE International Conference on Fuzzy Systems, 2009. FUZZ-IEEE 2009}, journal = {IEEE International Conference on Fuzzy Systems, 2009. FUZZ-IEEE 2009}, publisher = {IEEE}, address = {New York}, isbn = {978-1-4244-3596-8}, pages = {894 -- 899}, year = {2009}, language = {en} } @incollection{RahierRitzWallenborn2015, author = {Rahier, Michael and Ritz, Thomas and Wallenborn, Ramona}, title = {Information and communication technology for integrated mobility concepts such as E-carsharing}, series = {E-Mobility in Europe : trends and good practice}, booktitle = {E-Mobility in Europe : trends and good practice}, publisher = {Springer}, address = {Cham [u.a.]}, isbn = {978-3-319-13193-1}, doi = {10.1007/978-3-319-13194-8_17}, pages = {311 -- 326}, year = {2015}, abstract = {During the past decade attitude towards sharing things has changed extremely. Not just personal data is shared (e.g. in social networks) but also mobility. Together with the increased ecological awareness of the recent years, new mobility concepts have evolved. E-carsharing has become a symbol for these changes of attitude. The management of a shared car fleet, the energy management of electric mobility and the management of various carsharing users with individual likes and dislikes are just some of the major challenges of e-carsharing. Weaving it into integrated mobility concepts, this raises complexity even further. These challenges can only be overcome by an appropriate amount of well-shaped information available at the right place and time. In order to gather, process and share the required information, fleet cars have to be equipped with modern information and communication technology (ICT) and become so-called fully connected cars. Ensuring the usability of these ICT systems is another challenge that is often neglected, even though it is usability that makes carsharing comfortable, attractive and supports users' new attitudes. By means of an integrated and consistent concept for human-machine interaction (HMI), the usability of such systems can be raised tremendously.}, language = {en} } @inproceedings{NeumannDuelbergSchifferetal.2016, author = {Neumann, Tobias and D{\"u}lberg, Enno and Schiffer, Stefan and Ferrein, Alexander}, title = {A rotating platform for swift acquisition of dense 3D point clouds}, series = {Intelligent Robotics and Applications: 9th International Conference, ICIRA 2016, Tokyo, Japan, August 22-24, 2016, Proceedings, Part I}, volume = {9834}, booktitle = {Intelligent Robotics and Applications: 9th International Conference, ICIRA 2016, Tokyo, Japan, August 22-24, 2016, Proceedings, Part I}, publisher = {Springer}, isbn = {978-3-319-43505-3 (Print)}, doi = {10.1007/978-3-319-43506-0_22}, pages = {257 -- 268}, year = {2016}, language = {en} } @article{HeuermannRumiantsevSchott2004, author = {Heuermann, Holger and Rumiantsev, A. and Schott, S.}, title = {Advanced on-wafer multiport calibration methods for mono- and mixed-mode device characterization}, series = {On wafer characterization : 63rd ARFTG conference digest, spring 2004, 11 June 2004, Fort Worth, TX / Automatic RF Techniques Group. [Conference chair: John Cable. Publication chair: J. G. Burns]}, journal = {On wafer characterization : 63rd ARFTG conference digest, spring 2004, 11 June 2004, Fort Worth, TX / Automatic RF Techniques Group. [Conference chair: John Cable. Publication chair: J. G. Burns]}, publisher = {IEEE Operations Center}, address = {Piscataway, NJ}, isbn = {0-7803-8371-0}, pages = {91 -- 96}, year = {2004}, language = {en} } @article{HeuermannErkens2004, author = {Heuermann, Holger and Erkens, Holger}, title = {Blocking structures for mixed-mode systems. / Erkens, Holger ; Heuermann, Holger}, series = {Conference proceedings : Tuesday 12th, Wednesday 13th and Thursday 14th October, [RAI International Exhibition and Congress Centre, Amsterdam ; part of European Microwave Week 2004] / EuMA, European Microwave Association. Vol. 1}, journal = {Conference proceedings : Tuesday 12th, Wednesday 13th and Thursday 14th October, [RAI International Exhibition and Congress Centre, Amsterdam ; part of European Microwave Week 2004] / EuMA, European Microwave Association. Vol. 1}, publisher = {Horizon House Publ.}, address = {London}, isbn = {1-580-53992-0}, pages = {297 -- 300}, year = {2004}, language = {en} } @article{HeuermannSchiek1992, author = {Heuermann, Holger and Schiek, Burkhard}, title = {A Fast and Robust Procedure for the Determination of the Scattering Parameters for Network Analyzer Calibration}, address = {Paris}, pages = {373 -- 374}, year = {1992}, language = {en} } @article{FerreinFritzLakemeyer2004, author = {Ferrein, Alexander and Fritz, Christian and Lakemeyer, Gerhard}, title = {On-Line Decision-Theoretic Golog for Unpredictable Domains / Ferrein, Alexander ; Fritz, Christian ; Lakemeyer, Gerhard}, series = {KI 2004: Advances in Artificial Intelligence : 27th Annual German Conference on AI, KI 2004, Ulm, Germany, September 20-24, 2004. Proceedings}, journal = {KI 2004: Advances in Artificial Intelligence : 27th Annual German Conference on AI, KI 2004, Ulm, Germany, September 20-24, 2004. Proceedings}, publisher = {Springer}, address = {Berlin}, pages = {322 -- 336}, year = {2004}, language = {en} } @incollection{AlhwarinFerreinScholl2014, author = {Alhwarin, Faraj and Ferrein, Alexander and Scholl, Ingrid}, title = {IR stereo kinect: improving depth images by combining structured light with IR stereo}, series = {PRICAI 2014: Trends in artificial intelligence : 13th Pacific Rim International Conference on Artificial Intelligence : Gold Coast, QLD, Australia, December 1-5, 2014 : proceedings. (Lecture notes in computer science ; vol. 8862)}, booktitle = {PRICAI 2014: Trends in artificial intelligence : 13th Pacific Rim International Conference on Artificial Intelligence : Gold Coast, QLD, Australia, December 1-5, 2014 : proceedings. (Lecture notes in computer science ; vol. 8862)}, publisher = {Springer}, address = {M{\"u}nchen}, isbn = {978-3-319-13559-5 (Print) ; 978-3-319-13560-1 (E-Book)}, doi = {10.1007/978-3-319-13560-1_33}, pages = {409 -- 421}, year = {2014}, abstract = {RGB-D sensors such as the Microsoft Kinect or the Asus Xtion are inexpensive 3D sensors. A depth image is computed by calculating the distortion of a known infrared light (IR) pattern which is projected into the scene. While these sensors are great devices they have some limitations. The distance they can measure is limited and they suffer from reflection problems on transparent, shiny, or very matte and absorbing objects. If more than one RGB-D camera is used the IR patterns interfere with each other. This results in a massive loss of depth information. In this paper, we present a simple and powerful method to overcome these problems. We propose a stereo RGB-D camera system which uses the pros of RGB-D cameras and combine them with the pros of stereo camera systems. The idea is to utilize the IR images of each two sensors as a stereo pair to generate a depth map. The IR patterns emitted by IR projectors are exploited here to enhance the dense stereo matching even if the observed objects or surfaces are texture-less or transparent. The resulting disparity map is then fused with the depth map offered by the RGB-D sensor to fill the regions and the holes that appear because of interference, or due to transparent or reflective objects. Our results show that the density of depth information is increased especially for transparent, shiny or matte objects.}, language = {en} } @inproceedings{HeuermannFinger2014, author = {Heuermann, Holger and Finger, Torsten}, title = {2.45 GHz Plasma Powered Spark Plug by Thermal and EM-Optimization}, pages = {30 Folien}, year = {2014}, language = {en} } @article{HeuermannEmmrichBongartz2022, author = {Heuermann, Holger and Emmrich, Thomas and Bongartz, Simon}, title = {Microwave spark plug to support ignitions with high compression ratios}, series = {IEEE Transactions on Plasma Science}, journal = {IEEE Transactions on Plasma Science}, number = {Early Access}, publisher = {IEEE}, issn = {1939-9375}, doi = {10.1109/TPS.2022.3183690}, pages = {1 -- 6}, year = {2022}, abstract = {Upcoming gasoline engines should run with a larger number of fuels beginning from petrol over methanol up to gas by a wide range of compression ratios and a homogeneous charge. In this article, the microwave (MW) spark plug, based on a high-speed frequency hopping system, is introduced as a solution, which can support a nitrogen compression ratio up to 1:39 in a chamber and more. First, an overview of the high-speed frequency hopping MW ignition and operation system as well as the large number of applications are presented. Both gives an understanding of this new base technology for MW plasma generation. Focus of the theoretical part is the explanation of the internal construction of the spark plug, on the achievable of the high voltage generation as well as the high efficiency to hold the plasma. In detail, the development process starting with circuit simulations and ending with the numerical multiphysics field simulations is described. The concept is evaluated with a reference prototype covering the frequency range between 2.40 and 2.48 GHz and working over a large power range from 20 to 200 W. A larger number of different measurements starting by vector hot-S11 measurements and ending by combined working scenarios out of hot temperature, high pressure and charge motion are winding up the article. The limits for the successful pressure tests were given by the pressure chamber. Pressures ranged from 1 to 39 bar and charge motion up to 25 m/s as well as temperatures from 30◦ to 125◦.}, language = {en} } @article{Ritz2000, author = {Ritz, Thomas}, title = {Personalized information services : an electronic information commodity and its production}, series = {International Journal of E-Business Strategy Management}, volume = {2}, journal = {International Journal of E-Business Strategy Management}, number = {2}, issn = {1467-0305}, year = {2000}, language = {en} } @inproceedings{SchoppHeuermannHoltrup2014, author = {Schopp, Christoph and Heuermann, Holger and Holtrup, S.}, title = {Investigation on efficacy optimization of RF-driven automotive D-lamps}, series = {44th European Microwave Conference (EuMC),2014, Rome}, booktitle = {44th European Microwave Conference (EuMC),2014, Rome}, doi = {10.1109/EuMC.2014.6986645}, pages = {1154 -- 1157}, year = {2014}, language = {en} } @article{FerreinJacobsLakemeyer2005, author = {Ferrein, Alexander and Jacobs, Stefan and Lakemeyer, Gerhard}, title = {Unreal Golog Bots / Jacobs, Stefan ; Ferrein, Alexander ; Lakemeyer, Gerhard}, series = {IJCAI-05 Workshop on Reasoning, Representation, and Learning in Computer Games}, journal = {IJCAI-05 Workshop on Reasoning, Representation, and Learning in Computer Games}, pages = {31 -- 36}, year = {2005}, language = {en} } @article{HeuermannSchiek1997, author = {Heuermann, Holger and Schiek, B.}, title = {Results of network analyzer measurements with leakage errors-corrected with direct calibration techniques}, series = {IEEE transactions on instrumentation and measurement : IM / Institute of Electrical and Electronics Engineers, Instrumentation and Measurement Group. 46 (1997), H. 5}, journal = {IEEE transactions on instrumentation and measurement : IM / Institute of Electrical and Electronics Engineers, Instrumentation and Measurement Group. 46 (1997), H. 5}, isbn = {0018-9456}, pages = {1120 -- 1127}, year = {1997}, language = {en} } @article{FerreinBoehnstedtLakemeyer2007, author = {Ferrein, Alexander and B{\"o}hnstedt, Lutz and Lakemeyer, Gerhard}, title = {Options in readylog reloaded -- generating decision-theoretic plan libraries in golog / B{\"o}hnstedt, Lutz ; Ferrein, Alexander ; Lakemeyer, Gerhard}, series = {KI 2007: advances in artificial intelligence : 30th Annual German Conference on AI, KI 2007, Osnabr{\"u}ck, Germany, September 10 - 13, 2007 ; proceedings}, journal = {KI 2007: advances in artificial intelligence : 30th Annual German Conference on AI, KI 2007, Osnabr{\"u}ck, Germany, September 10 - 13, 2007 ; proceedings}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-540-74564-8}, pages = {352 -- 366}, year = {2007}, language = {en} } @inproceedings{NeumannFerreinKallweitetal.2014, author = {Neumann, Tobias and Ferrein, Alexander and Kallweit, Stephan and Scholl, Ingrid}, title = {Towards a mobile mapping robot for underground mines}, series = {7th Conference of Robotics and Mechatronics : RobMech 2014 : 27th and 28th Nov. 2014, Cape Town}, booktitle = {7th Conference of Robotics and Mechatronics : RobMech 2014 : 27th and 28th Nov. 2014, Cape Town}, organization = {Conference of Robotics and Mechatronics <7, 2014, Cape Town, South Africa>}, pages = {1 -- 6}, year = {2014}, language = {en} } @article{Heuermann1995, author = {Heuermann, Holger}, title = {LZY: A Self-Calibration Approach in Competition to the LRM Method for On-Wafer Measurements}, pages = {129 -- 136}, year = {1995}, language = {en} } @article{WolfFoltzSchlicketal.2002, author = {Wolf, Martin R. and Foltz, Christian and Schlick, Christopher and Luczak, Holger}, title = {Development and evaluation of a groupware system to support chemical design processes / Wolf, Martin ; Foltz, Christian ; Schlick, Christopher ; Luczak, Holger}, series = {International Journal of Human-Computer Interaction . 14 (2002), H. 2}, journal = {International Journal of Human-Computer Interaction . 14 (2002), H. 2}, publisher = {-}, isbn = {1044-7318}, pages = {181 -- 198}, year = {2002}, language = {en} } @inproceedings{NethSchubaBrodkorbetal.2023, author = {Neth, Jannik and Schuba, Marko and Brodkorb, Karsten and Neugebauer, Georg and H{\"o}ner, Tim and Hack, Sacha}, title = {Digital forensics triage app for android}, series = {ARES '23: Proceedings of the 18th International Conference on Availability, Reliability and Security}, booktitle = {ARES '23: Proceedings of the 18th International Conference on Availability, Reliability and Security}, publisher = {ACM}, isbn = {9798400707728}, doi = {10.1145/3600160.3605017}, pages = {6 Seiten}, year = {2023}, abstract = {Digital forensics of smartphones is of utmost importance in many criminal cases. As modern smartphones store chats, photos, videos etc. that can be relevant for investigations and as they can have storage capacities of hundreds of gigabytes, they are a primary target for forensic investigators. However, it is exactly this large amount of data that is causing problems: extracting and examining the data from multiple phones seized in the context of a case is taking more and more time. This bears the risk of wasting a lot of time with irrelevant phones while there is not enough time left to analyze a phone which is worth examination. Forensic triage can help in this case: Such a triage is a preselection step based on a subset of data and is performed before fully extracting all the data from the smartphone. Triage can accelerate subsequent investigations and is especially useful in cases where time is essential. The aim of this paper is to determine which and how much data from an Android smartphone can be made directly accessible to the forensic investigator - without tedious investigations. For this purpose, an app has been developed that can be used with extremely limited storage of data in the handset and which outputs the extracted data immediately to the forensic workstation in a human- and machine-readable format.}, language = {en} } @inproceedings{NeugebauerBrutschyMeyeretal.2014, author = {Neugebauer, Georg and Brutschy, Lucas and Meyer, Ulrike and Wetzel, Susanne}, title = {Privacy-preserving multi-party reconciliation secure in the malicious model}, series = {DPM 2013, SETOP 2013: Data Privacy Management and Autonomous Spontaneous Security}, booktitle = {DPM 2013, SETOP 2013: Data Privacy Management and Autonomous Spontaneous Security}, editor = {Garcia-Alfaro, Joaquin and Lioudakis, Georgios and Cuppens-Boulahia, Nora and Foley, Simon and Fitzgerald, William M.}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-642-54567-2 (Print)}, doi = {10.1007/978-3-642-54568-9_12}, pages = {178 -- 193}, year = {2014}, abstract = {The problem of fair and privacy-preserving ordered set reconciliation arises in a variety of applications like auctions, e-voting, and appointment reconciliation. While several multi-party protocols have been proposed that solve this problem in the semi-honest model, there are no multi-party protocols that are secure in the malicious model so far. In this paper, we close this gap. Our newly proposed protocols are shown to be secure in the malicious model based on a variety of novel non-interactive zero-knowledge-proofs. We describe the implementation of our protocols and evaluate their performance in comparison to protocols solving the problem in the semi-honest case.}, language = {en} } @article{HeuermannSadeghfam2009, author = {Heuermann, Holger and Sadeghfam, Arash}, title = {Enhanced system architecture for rugged wide band data transmission / Sadeghfam, A. ; Heuermann, H.}, series = {European Radar Conference, 2009 : EuRAD 2009 ; Sept. 30 - Oct. 2 2009, Rome, Italy ; part of the European Microwave Week (EuMW) / sponsored by EuMA, European Microwave Association}, journal = {European Radar Conference, 2009 : EuRAD 2009 ; Sept. 30 - Oct. 2 2009, Rome, Italy ; part of the European Microwave Week (EuMW) / sponsored by EuMA, European Microwave Association}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-2-87487-014-9}, pages = {347 -- 350}, year = {2009}, language = {en} } @inproceedings{ChircuCzarneckiFriedmannetal.2023, author = {Chircu, Alina and Czarnecki, Christian and Friedmann, Daniel and Pomaskow, Johanna and Sultanow, Eldar}, title = {Towards a Digital Twin of Society}, series = {Proceedings of the 56th Hawaii International Conference on System Sciences 2023}, booktitle = {Proceedings of the 56th Hawaii International Conference on System Sciences 2023}, publisher = {University of Hawai'i}, address = {Honolulu}, isbn = {978-0-9981331-6-4}, pages = {6748 -- 6757}, year = {2023}, abstract = {This paper describes the potential for developing a digital twin of society- a dynamic model that can be used to observe, analyze, and predict the evolution of various societal aspects. Such a digital twin can help governmental agencies and policy makers in interpreting trends, understanding challenges, and making decisions regarding investments or policies necessary to support societal development and ensure future prosperity. The paper reviews related work regarding the digital twin paradigm and its applications. The paper presents a motivating case study- an analysis of opportunities and challenges faced by the German federal employment agency, Bundesagentur f¨ur Arbeit (BA), proposes solutions using digital twins, and describes initial proofs of concept for such solutions.}, language = {en} } @inproceedings{StenderRitz2003, author = {Stender, Michael and Ritz, Thomas}, title = {Modeling of business-to-business mobile commerce processes}, series = {Electronic proceedings / ICPR 17, 17th International Conference on Production Research [Blacksburg, Virginia, USA, August 3 - 7, 2003]}, booktitle = {Electronic proceedings / ICPR 17, 17th International Conference on Production Research [Blacksburg, Virginia, USA, August 3 - 7, 2003]}, edition = {CD-ROM-Ausg.}, address = {Blacksburg, Va.}, isbn = {0-9721257-3-6}, year = {2003}, language = {en} } @inproceedings{BuxbaumSchwarteRingbeck1999, author = {Buxbaum, Bernd and Schwarte, Rudolf and Ringbeck, Thorsten}, title = {PMD-PLL: receiver structure for incoherent communication and ranging systems}, series = {Optical wireless communications II / [SPIE Conference on Optical Wireless Communications II], 22 September 1999, Boston, Massachusetts. - (SPIE proceedings series ; 3850)}, booktitle = {Optical wireless communications II / [SPIE Conference on Optical Wireless Communications II], 22 September 1999, Boston, Massachusetts. - (SPIE proceedings series ; 3850)}, editor = {Korevaar, Eric John}, publisher = {SPIE}, address = {Bellingham, Wash.}, isbn = {0-8194-3443-4}, issn = {0038-7355}, pages = {116 -- 130}, year = {1999}, language = {en} } @misc{BragardBuddeHenteetal.2008, author = {Bragard, Michael and Budde, W. O. and Hente, D. and Jacobs, J. H. A. M. and Waffenschmidt, E.}, title = {Lighting system : [patent of invention]}, publisher = {WIPO / United States Patent and Trademark Office}, address = {Geneva / Alexandria, VA}, pages = {32 S. : graph. Darst.}, year = {2008}, language = {en} } @inproceedings{KoellenspergerBragardPlumetal.2007, author = {K{\"o}llensperger, P. and Bragard, Michael and Plum, T. and De Doncker, R. W.}, title = {The dual GCT : a new high-power device using optimized GCT technology}, series = {Conference record of the 2007 IEEE Industry Applications Conference : 42. IAS annual meeting ; September 23 - 27, 2007, New Orleans, Louisiana, USA}, booktitle = {Conference record of the 2007 IEEE Industry Applications Conference : 42. IAS annual meeting ; September 23 - 27, 2007, New Orleans, Louisiana, USA}, publisher = {IEEE Operations Center}, address = {Piscataway, NJ}, isbn = {978-1-4244-1260-0 (Online)}, doi = {10.1109/07IAS.2007.76}, pages = {358 -- 365}, year = {2007}, language = {en} } @phdthesis{Bragard2012, author = {Bragard, Michael}, title = {The integrated emitter turn-off thyristor : an innovative MOS-gated high-power device. - (Aachener Beitr{\"a}ge des ISEA ; 62)}, publisher = {Shaker}, address = {Aachen}, isbn = {978-3-8440-1152-4}, pages = {III, 164 S. : Ill., graph. Darst.}, year = {2012}, abstract = {This thesis introduces the Integrated Emitter Turn-Off (IETO) Thyristor as a new high-power device. Known state-of-the-art research activities like the Dual GCT, the ETO thyristor and the ICT were presented and critically reviewed. A comparison with commercialized solutions identifies the pros and cons of each type of device family. Based on this analysis, the IETO structure is proposed, covering most benefits of each device class. In particular the combination of a MOS-assisted turn-off with a thyristor-based device allows a voltage-controlled MOS switching and the low on-state voltage of the thyristors. The following synthesis of an IETO device stands on a three-dimensional field of optimization spanned by electric, mechanical and thermal aspects. From an electric point of view, the lowest possible parasitic inductance and resistance within the commutation path are optimization criteria. The mechanical construction has to withstand the required contact pressure of multiple kilo Newtons. Finally, thermal borders limit the maximum average current of the device. FEM simulations covering these three aspects are performed for several design proposals. An IETO prototype is constructed and measurements on various test benches attest thermal, mechanical and electric performance. A local decoupling of the external driver stage and the presspack housing is presented by a cable connection. This separation enables a thermal and mechanical independence, which is advantageous in terms of vibrations and thermal cycles including increased reliability. The electric pulse performance of the prototype device is a factor of 3.1 above today''s solutions. In single-pulse measurements, a current up to 1600 A was successfully turned off at 115°C with an active silicon area of 823 mm². One reason for this increased turn-off capability is the extremely low-inductive construction. Additional functionality of the IETO thyristor like over-current self-protection and defined short-circuit failure state are successfully verified.}, language = {en} } @article{vonKnobelsdorfBrenkenhoffFrauenrathProthmannetal.2010, author = {von Knobelsdorf-Brenkenhoff, Florian and Frauenrath, Tobias and Prothmann, Marcel and Dieringer, Matthias A. and Hezel, Fabian and Renz, Wolfgang and Kretschel, Kerstin and Niendorf, Thoralf and Schulz-Menger, Jeanette}, title = {Cardiac chamber quantification using magnetic resonance imaging at 7 Tesla—a pilot study}, volume = {20}, publisher = {Springer}, address = {Berlin, Heidelberg}, issn = {0938-7994}, doi = {10.1007/s00330-010-1888-2}, pages = {2844 -- 2852}, year = {2010}, abstract = {Objectives Interest in cardiovascular magnetic resonance (CMR) at 7 T is motivated by the expected increase in spatial and temporal resolution, but the method is technically challenging. We examined the feasibility of cardiac chamber quantification at 7 T. Methods A stack of short axes covering the left ventricle was obtained in nine healthy male volunteers. At 1.5 T, steady-state free precession (SSFP) and fast gradient echo (FGRE) cine imaging with 7 mm slice thickness (STH) were used. At 7 T, FGRE with 7 mm and 4 mm STH were applied. End-diastolic volume, end-systolic volume, ejection fraction and mass were calculated. Results All 7 T examinations provided excellent blood/myocardium contrast for all slice directions. No significant difference was found regarding ejection fraction and cardiac volumes between SSFP at 1.5 T and FGRE at 7 T, while volumes obtained from FGRE at 1.5 T were underestimated. Cardiac mass derived from FGRE at 1.5 and 7 T was larger than obtained from SSFP at 1.5 T. Agreement of volumes and mass between SSFP at 1.5 T and FGRE improved for FGRE at 7 T when combined with an STH reduction to 4 mm. Conclusions This pilot study demonstrates that cardiac chamber quantification at 7 T using FGRE is feasible and agrees closely with SSFP at 1.5 T.}, language = {en} } @misc{LindelGreiserWaxmanetal.2012, author = {Lindel, Tomasz Dawid and Greiser, Andreas and Waxman, Patrick and Dietterle, Martin and Seifert, Frank and Fontius, Ulrich and Renz, Wolfgang and Dieringer, Matthias A. and Frauenrath, Tobias and Schulz-Menger, Jeanette and Niendorf, Thoralf and Ittermann, Bernd}, title = {Cardiac CINE MRI at 7 T using a transmit array}, series = {2012 ISMRM Annual Meeting Proceedings}, journal = {2012 ISMRM Annual Meeting Proceedings}, issn = {1545-4428}, year = {2012}, abstract = {With its need for high SNR and short acquisition times, Cardiac MRI (CMR) is an intriguing target application for ultrahigh field MRI. Due to the sheer size of the upper torso, however, the known RF issues of 7T MRI are also most prominent in CMR. Recent years brought substantial progress but the full potential of the ultrahigh field for CMR is yet to be exploited. Parallel transmission (pTx) is a promising approach in this context and several groups have already reported B1 shimming for 7T CMR. In such a static pTx application amplitudes and phases of all Tx channels are adjusted individually but otherwise imaging techniques established in current clinical practice 1.5 T and 3 T are applied. More advanced forms of pTx as spatially selective excitation (SSE) using Transmit SENSE promise additional benefits like faster imaging with reduced fields of view or improved SAR control. SSE requires the full dynamic capabilities of pTx, however, and for the majority of today's implemented pTx hardware the internal synchronization of the Tx array does not easily permit external triggering as needed for CMR. Here we report a software solution to this problem and demonstrate the feasibility of CINE CMR at 7 T using a Tx array.}, language = {en} } @article{HueningHeuermannWacheetal.2018, author = {H{\"u}ning, Felix and Heuermann, Holger and Wache, Franz-Josef and Jajo, Rami Audisho}, title = {A new wireless sensor interface using dual-mode radio}, series = {Journal of Sensors and Sensor Systems : JSSS}, volume = {Volume 7}, journal = {Journal of Sensors and Sensor Systems : JSSS}, number = {2}, publisher = {Copernicus Publ.}, address = {G{\"o}ttingen}, doi = {10.5194/jsss-7-507-2018}, pages = {507 -- 515}, year = {2018}, abstract = {The integration of sensors is one of the major tasks in embedded, control and "internet of things" (IoT) applications. For the integration mainly digital interfaces are used, starting from rather simple pulse-width modulation (PWM) interface to more complex interfaces like CAN (Controller Area Network). Even though these interfaces are tethered by definition, a wireless realization is highly welcome in many applications to reduce cable and connector cost, increase the flexibility and realize new emerging applications like wireless control systems. Currently used wireless solutions like Bluetooth, WirelessHART or IO-Link Wireless use dedicated communication standards and corresponding higher protocol layers to realize the wireless communication. Due to the complexity of the communication and the protocol handling, additional latency and jitter are introduced to the data communication that can meet the requirements for many applications. Even though tunnelling of other bus data like CAN data is generally also possible the latency and jitter prevent the tunnelling from being transparent for the bus system. Therefore a new basic technology based on dual-mode radio is used to realize a wireless communication on the physical layer only, enabling a reliable and real-time data transfer. As this system operates on the physical layer it is independent of any higher layers of the OSI (open systems interconnection) model. Hence it can be used for several different communication systems to replace the tethered physical layer. A prototype is developed and tested for real-time wireless PWM, SENT (single-edge nibble transmission) and CAN data transfer with very low latency and jitter.}, language = {en} } @inproceedings{BragardRongeDeDoncker2011, author = {Bragard, Michael and Ronge, C. and De Doncker, R. W.}, title = {Sandwich design of high-power thyristor based devices with integrated MOSFET structure}, series = {Proceedings of the 2011 - 14th - European Conference on Power Electronics and Applications (EPE 2011) : Aug. 30, 2011 - Sept. 1, 2011, Birmingham, United Kingdom}, booktitle = {Proceedings of the 2011 - 14th - European Conference on Power Electronics and Applications (EPE 2011) : Aug. 30, 2011 - Sept. 1, 2011, Birmingham, United Kingdom}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-61284-167-0 (Print)}, year = {2011}, language = {en} } @misc{WiegnerVolkerMainzetal.2022, author = {Wiegner, J. and Volker, H. and Mainz, F. and Backes, A. and L{\"o}ken, M. and H{\"u}ning, Felix}, title = {Wiegand-Effect-Powered Wireless IT Sensor Node}, year = {2022}, abstract = {With the growing interest in small distributed sensors for the "Internet of Things", more attention is being paid to energy harvesting techologies. Reducing or eliminating the need for external power sources or batteries make devices more self-sufficient, more reliable, and reduces maintenance requirements. The Wiegand effect is a proven technology for harvesting small amounts of electrical power from mechanical motion.}, language = {en} } @misc{WaicziesKuehneWinteretal.2013, author = {Waiczies, Helmar and K{\"u}hne, Andr{\´e} and Winter, Lukas and Frauenrath, Tobias and Hoffmann, Werner and Ittermann, Bernd and Waiczies, Sonia and Niendorf, Thoralf}, title = {Towards theranostics of rheumatoid arthritis: 1H/19F imaging of non-steroidal anti-inflammatory drugs in hand and wrist at 7 Tesla}, series = {2013 ISMRM Annual Meeting Proceedings}, journal = {2013 ISMRM Annual Meeting Proceedings}, issn = {1545-4428}, year = {2013}, abstract = {We have developed a double-tuned ¹H/¹⁹F birdcage resonator dedicated for hand and wrist imaging at 7 T to locally image non-steroidal anti-inflammatory drugs (NSAID) such as 2-{[3-(Trifluoromethyl) phenyl]amino}benzoic acid. The preliminary in vivo images acquired by the double-tuned ¹H/¹⁹F birdcage resonator demonstrate the feasibility for ¹H/¹⁹F hand- and wrist-imaging at 7 T. While the diagnostic quality of the coil needs to be assessed in patients with inflammatory rheumatoid disease, first ¹⁹F images of the NSAID are encouraging, and point towards the prospect of applying ¹⁹F-MRI to visualize and quantify the concentration of therapeutically-active compound at the sites of inflammation.}, language = {en} } @article{HeinrichsUttingFrauenrathetal.2009, author = {Heinrichs, Uwe and Utting, Jane F. and Frauenrath, Tobias and Hezel, Fabian and Krombach, Gabriele A. and Hodenius, Michael A. J. and Kozerke, Sebastian and Niendorf, Thoralf}, title = {Myocardial T2 mapping free of distortion using susceptibility-weighted fast spin-echo imaging: A feasibility study at 1.5 T and 3.0 T}, series = {Magnetic Resonance in Medicine}, volume = {62}, journal = {Magnetic Resonance in Medicine}, number = {3}, publisher = {Wiley-Liss}, address = {New York}, issn = {1522-2594}, doi = {10.1002/mrm.22054}, pages = {822 -- 828}, year = {2009}, abstract = {This study demonstrates the feasibility of applying free-breathing, cardiac-gated, susceptibility-weighted fast spin-echo imaging together with black blood preparation and navigator-gated respiratory motion compensation for anatomically accurate T₂ mapping of the heart. First, T₂ maps are presented for oil phantoms without and with respiratory motion emulation (T₂ = (22.1 ± 1.7) ms at 1.5 T and T₂ = (22.65 ± 0.89) ms at 3.0 T). T₂ relaxometry of a ferrofluid revealed relaxivities of R2 = (477.9 ± 17) mM⁻¹s⁻¹ and R2 = (449.6 ± 13) mM⁻¹s⁻¹ for UFLARE and multiecho gradient-echo imaging at 1.5 T. For inferoseptal myocardial regions mean T₂ values of 29.9 ± 6.6 ms (1.5 T) and 22.3 ± 4.8 ms (3.0 T) were estimated. For posterior myocardial areas close to the vena cava T₂-values of 24.0 ± 6.4 ms (1.5 T) and 15.4 ± 1.8 ms (3.0 T) were observed. The merits and limitations of the proposed approach are discussed and its implications for cardiac and vascular T₂-mapping are considered.}, language = {en} } @inproceedings{WolfLenz2015, author = {Wolf, Martin R. and Lenz, Laura L.}, title = {The economic effectiveness of serious games in the healthcare environment : application and evaluation of the Comparative Transformation Model (CTM)}, series = {IEEE 3rd International Conference on Serious Games and Applications for Health : SeGAH 2014 ; Rio de Janeiro, Brazil, May 14 - 16}, booktitle = {IEEE 3rd International Conference on Serious Games and Applications for Health : SeGAH 2014 ; Rio de Janeiro, Brazil, May 14 - 16}, publisher = {IEEE [u.a.]}, address = {Piscataway, NJ}, isbn = {978-1-4799-4823-9}, doi = {10.1109/SeGAH.2014.7067089}, pages = {135 -- 142}, year = {2015}, language = {en} } @article{FerreinMeyer2012, author = {Ferrein, Alexander and Meyer, Thomas}, title = {A Brief Overview of Artificial Intelligence in South Africa}, series = {AI Magazine}, volume = {33}, journal = {AI Magazine}, number = {1}, publisher = {AAAI}, address = {Menlo Park}, issn = {0738-4602}, doi = {10.1609/aimag.v33i1.2357}, pages = {99 -- 101}, year = {2012}, abstract = {South Africa in recent years is the establishment of a number of research hubs involved in AI activities ranging from mobile robotics and computational intelligence, to knowledge representation and reasoning, and human language technologies. In this survey we take the reader through a quick tour of the research being conducted at these hubs, and touch on an initiative to maintain and extend the current level of interest in AI research in the country.}, language = {en} } @inproceedings{RingbeckSchwarteBuxbaum1999, author = {Ringbeck, Thorsten and Schwarte, Rudolf and Buxbaum, Bernd}, title = {Introduction of a new opto-electrical phase-locked loop in CMOS technology: the PMD-PLL}, series = {Optical wireless communications II / [SPIE Conference on Optical Wireless Communications II], 22 September 1999, Boston, Massachusetts. - (SPIE proceedings series ; 3850)}, booktitle = {Optical wireless communications II / [SPIE Conference on Optical Wireless Communications II], 22 September 1999, Boston, Massachusetts. - (SPIE proceedings series ; 3850)}, editor = {Korevaar, Eric John}, publisher = {SPIE}, address = {Bellingham, Wash.}, isbn = {0-8194-3443-4}, issn = {0038-7355}, pages = {108 -- 116}, year = {1999}, language = {en} } @article{BragardvanHoekDeDoncker2012, author = {Bragard, Michael and van Hoek, H. and De Doncker, R. W.}, title = {A major design step in IETO concept realization that allows overcurrent protection and pushes limits of switching performance}, series = {IEEE transactions on power electronics}, volume = {27}, journal = {IEEE transactions on power electronics}, number = {9}, publisher = {IEEE}, address = {New York}, issn = {0885-8993}, doi = {10.1109/TPEL.2012.2189136}, pages = {4163 -- 4171}, year = {2012}, abstract = {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.}, language = {en} } @inproceedings{BragardGottschlichDeDoncker2011, author = {Bragard, Michael and Gottschlich, J. and De Doncker, R. W.}, title = {Design and realization of a credit card size driver stage for high power thyristor based devices with integrated MOS structure}, series = {2011 IEEE 8th International Conference on Power Electronics and ECCE Asia (ICPE \& ECCE 2011) : Jeju, South Korea, 30 May 2011 - 3 June 2011 / [co-sponsored by the Korean Institute of Power Electronics ...]}, booktitle = {2011 IEEE 8th International Conference on Power Electronics and ECCE Asia (ICPE \& ECCE 2011) : Jeju, South Korea, 30 May 2011 - 3 June 2011 / [co-sponsored by the Korean Institute of Power Electronics ...]}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-61284-958-4 (Print)}, doi = {10.1109/ICPE.2011.5944661}, pages = {1182 -- 1189}, year = {2011}, language = {en} } @article{FrauenrathHezelRenzetal.2010, author = {Frauenrath, Tobias and Hezel, Fabian and Renz, Wolfgang and de Geyer d'Orth, Thibaut and Dieringer, Matthias and von Knobelsdorf-Brenkenhoff, Florian and Prothmann, Marcel and Schulz-Menger, Jeanette and Niendorf, Thoralf}, title = {Acoustic cardiac triggering: a practical solution for synchronization and gating of cardiovascular magnetic resonance at 7 Tesla}, series = {Journal of Cardiovascular Magnetic Resonance}, volume = {12}, journal = {Journal of Cardiovascular Magnetic Resonance}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1532-429X}, doi = {10.1186/1532-429X-12-67}, year = {2010}, abstract = {Background To demonstrate the applicability of acoustic cardiac triggering (ACT) for imaging of the heart at ultrahigh magnetic fields (7.0 T) by comparing phonocardiogram, conventional vector electrocardiogram (ECG) and traditional pulse oximetry (POX) triggered 2D CINE acquisitions together with (i) a qualitative image quality analysis, (ii) an assessment of the left ventricular function parameter and (iii) an examination of trigger reliability and trigger detection variance derived from the signal waveforms. Results ECG was susceptible to severe distortions at 7.0 T. POX and ACT provided waveforms free of interferences from electromagnetic fields or from magneto-hydrodynamic effects. Frequent R-wave mis-registration occurred in ECG-triggered acquisitions with a failure rate of up to 30\% resulting in cardiac motion induced artifacts. ACT and POX triggering produced images free of cardiac motion artefacts. ECG showed a severe jitter in the R-wave detection. POX also showed a trigger jitter of approximately Δt = 72 ms which is equivalent to two cardiac phases. ACT showed a jitter of approximately Δt = 5 ms only. ECG waveforms revealed a standard deviation for the cardiac trigger offset larger than that observed for ACT or POX waveforms. Image quality assessment showed that ACT substantially improved image quality as compared to ECG (image quality score at end-diastole: ECG = 1.7 ± 0.5, ACT = 2.4 ± 0.5, p = 0.04) while the comparison between ECG vs. POX gated acquisitions showed no significant differences in image quality (image quality score: ECG = 1.7 ± 0.5, POX = 2.0 ± 0.5, p = 0.34). Conclusions The applicability of acoustic triggering for cardiac CINE imaging at 7.0 T was demonstrated. ACT's trigger reliability and fidelity are superior to that of ECG and POX. ACT promises to be beneficial for cardiovascular magnetic resonance at ultra-high field strengths including 7.0 T.}, language = {en} } @article{MartinFrauenrathOezerdemetal.2011, author = {Martin, Conrad and Frauenrath, Tobias and {\"O}zerdem, Celal and Renz, Wolfgang and Niendorf, Thoralf}, title = {Development and evaluation of a small and mobile Magneto Alert Sensor (MALSE) to support safety requirements for magnetic resonance imaging}, series = {European Radiology}, volume = {21}, journal = {European Radiology}, publisher = {Springer}, address = {Berlin, Heidelberg}, issn = {1432-1084}, doi = {10.1007/s00330-011-2153-z}, pages = {2187 -- 2192}, year = {2011}, abstract = {Objective The purpose of this study is to (i) design a small and mobile Magnetic field ALert SEnsor (MALSE), (ii) to carefully evaluate its sensors to their consistency of activation/deactivation and sensitivity to magnetic fields, and (iii) to demonstrate the applicability of MALSE in 1.5 T, 3.0 T and 7.0 T MR fringe field environments. Methods MALSE comprises a set of reed sensors, which activate in response to their exposure to a magnetic field. The activation/deactivation of reed sensors was examined by moving them in/out of the fringe field generated by 7TMR. Results The consistency with which individual reed sensors would activate at the same field strength was found to be 100\% for the setup used. All of the reed switches investigated required a substantial drop in ambient magnetic field strength before they deactivated. Conclusions MALSE is a simple concept for alerting MRI staff to a ferromagnetic object being brought into fringe magnetic fields which exceeds MALSEs activation magnetic field. MALSE can easily be attached to ferromagnetic objects within the vicinity of a scanner, thus creating a barrier for hazardous situations induced by ferromagnetic parts which should not enter the vicinity of an MR-system to occur.}, language = {en} } @inproceedings{PenneProfittlichRingbecketal.2010, author = {Penne, Jochen and Profittlich, Martin and Ringbeck, Thorsten and Buxbaum, Bernd}, title = {Touchless detailed 3D scan of human hand anatomy using time-of-flight cameras}, series = {Proceedings of the International Conference on 3D Body Scanning Technologies : Lugano, Switzerland, 19-20 October 2010}, booktitle = {Proceedings of the International Conference on 3D Body Scanning Technologies : Lugano, Switzerland, 19-20 October 2010}, editor = {D, Nicola D'Apuzzo}, publisher = {Hometrica Consulting}, address = {Z{\"u}rich}, isbn = {978-3-033-02714-5}, pages = {361 -- 369}, year = {2010}, language = {en} } @inproceedings{SchwarteBuxbaumHeinoletal.1998, author = {Schwarte, Rudolf and Buxbaum, Bernd and Heinol, Horst-Guenther and Xu, Zhanping and Ringbeck, Thorsten and Zang, Zhigang}, title = {Novel 3D-vision systems based on layout optimized PMD-structures}, series = {Proceedings / OPTO 98, Internationaler Kongress und Fachausstellung f{\"u}r Optische Sensorik, Messtechnik und Elektronik, 18. - 20. Mai 1998, Kongreßzentrum Erfurt}, booktitle = {Proceedings / OPTO 98, Internationaler Kongress und Fachausstellung f{\"u}r Optische Sensorik, Messtechnik und Elektronik, 18. - 20. Mai 1998, Kongreßzentrum Erfurt}, publisher = {ACS Organisations GmbH}, address = {Wunsdorf}, pages = {197 -- 202}, year = {1998}, language = {en} } @article{DieringerRenzLindeletal.2011, author = {Dieringer, Matthias A. and Renz, Wolfgang and Lindel, Tomasz D. and Seifert, Frank and Frauenrath, Tobias and von Knobelsdorf-Brenkenhoff, Florian and Waiczies, Helmar and Hoffmann, Werner and Rieger, Jan and Pfeiffer, Harald and Ittermann, Bernd and Schulz-Menger, Jeanette and Niendorf, Thoralf}, title = {Design and application of a four-channel transmit/receive surface coil for functional cardiac imaging at 7T}, series = {Journal of Magnetic Resonance Imaging}, volume = {33}, journal = {Journal of Magnetic Resonance Imaging}, number = {3}, publisher = {Wiley-Liss}, address = {New York}, issn = {1522-2586}, doi = {10.1002/jmri.22451}, pages = {736 -- 741}, year = {2011}, abstract = {Purpose To design and evaluate a four-channel cardiac transceiver coil array for functional cardiac imaging at 7T. Materials and Methods A four-element cardiac transceiver surface coil array was developed with two rectangular loops mounted on an anterior former and two rectangular loops on a posterior former. specific absorption rate (SAR) simulations were performed and a Burn:x-wiley:10531807:media:JMRI22451:tex2gif-stack-1 calibration method was applied prior to obtain 2D FLASH CINE (mSENSE, R = 2) images from nine healthy volunteers with a spatial resolution of up to 1 × 1 × 2.5 mm3. Results Tuning and matching was found to be better than 10 dB for all subjects. The decoupling (S21) was measured to be >18 dB between neighboring loops, >20 dB for opposite loops, and >30 dB for other loop combinations. SAR values were well within the limits provided by the IEC. Imaging provided clinically acceptable signal homogeneity with an excellent blood-myocardium contrast applying the Burn:x-wiley:10531807:media:JMRI22451:tex2gif-stack-2 calibration approach. Conclusion A four-channel cardiac transceiver coil array for 7T was built, allowing for cardiac imaging with clinically acceptable signal homogeneity and an excellent blood-myocardium contrast. Minor anatomic structures, such as pericardium, mitral, and tricuspid valves and their apparatus, as well as trabeculae, were accurately delineated.}, language = {en} } @misc{TkachenkovonKnobelsdorffBrenkenhoffKleindienstetal.2012, author = {Tkachenko, Valeriy and von Knobelsdorff-Brenkenhoff, Florian and Kleindienst, Denise and Winter, Lukas and Rieger, Jan and Frauenrath, Tobias and Dieringer, Matthias A. and Santoro, Davide and Niendorf, Thoralf and Schulz-Menger, Jeanette}, title = {Cardiovasular MR at 7Tesla: assessment of the right ventricle}, series = {2012 ISMRM Annual Meeting Proceedings}, journal = {2012 ISMRM Annual Meeting Proceedings}, issn = {1545-4428}, year = {2012}, abstract = {The assessment of the right ventricle (RV) is a challenge in today's cardiology, but of growing clinical impact regarding patient prognosis in different cardiac diseases. The detection and differentiation of small wall motion abnormalities may help to enhance the differentiation of cardiomyopathies including Arrhythmogenic Rightventricular Cardiomyopathy. Cardiovascular magnetic resonance (CMR) at 1.5T is the accepted gold standard for RV quantification. The higher spatial resolution achievable at ultrahigh field strength (UHF) offers the potential to gain new insights into the structure and function of the RV. To approach this goal accurate RV chamber quantification at 7T has to be proven. Consequently this study examines the feasibility of assessment of RV dimensions and function at 7T using improved spatial resolution enabled by the intrinsic sensitivity gain of UHF CMR. For this purpose, a dedicated 16 channel TX/RX RF coil array is used together with 2D CINE fast gradient echo (FGRE) imaging. For comparison RV chamber quantification is conducted at 1.5T using a SSFP based state of the art clinical protocol.}, language = {en} } @inproceedings{LenzWolf2014, author = {Lenz, Laura L. and Wolf, Martin R.}, title = {Economic evaluation of serious games with the comparative assessment framework COSEGA}, series = {The shift from teaching to learning : individual, collective and organizational learning through gaming simulation ; proceedings of the 45th conference of the International Simulation and Gaming Association, Dornbirn 2014}, booktitle = {The shift from teaching to learning : individual, collective and organizational learning through gaming simulation ; proceedings of the 45th conference of the International Simulation and Gaming Association, Dornbirn 2014}, editor = {Kritz, Willy Christian}, publisher = {Bertelsmann}, address = {[Bielefeld]}, isbn = {978-3-7639-5422-3}, pages = {374 -- 386}, year = {2014}, language = {en} } @misc{GraesslRenzHezeletal.2012, author = {Gr{\"a}ßl, Andreas and Renz, Wolfgang and Hezel, Fabian and Frauenrath, Tobias and Pfeiffer, Harald and Hoffmann, Werner and Kellmann, Peter and Martin, Conrad and Niendorf, Thoralf}, title = {Design, evaluation and application of a modular 32 channel transmit/receive surface coil array for cardiac MRI at 7T}, series = {2012 ISMRM Annual Meeting Proceedings}, journal = {2012 ISMRM Annual Meeting Proceedings}, issn = {1545-4428}, year = {2012}, abstract = {Cardiac MR (CMR) at ultrahigh (≥7.0 T) fields is regarded as one of the most challenging MRI applications. At 7.0 T image quality is not always exclusively defined by signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Detrimental effects bear the potential to spoil the signal-to-noise (SNR) and contrast-to-noise (CNR) benefits of cardiac MR (CMR) at 7.0 T. B₁⁺-inhomogeneities and signal voids represent the main challenges. Various pioneering coil concepts have been proposed to tackle these issues, enabling cardiac MRI at 7.0 T. This includes a trend towards an ever larger number of transmit and receive channels. This approach affords multi-dimensional B₁⁺ modulations to improve B₁⁺ shimming performance and to enhance RF efficiency. Also, parallel imaging benefits from a high number of receive channels enabling two-dimensional acceleration. Realizing the limitations of existing coil designs tailored for UHF CMR and recognizing the opportunities of a many element TX/RX channel architecture this work proposes a modular, two dimensional 32-channel transmit and receive array using loop elements and examines its efficacy for enhanced B¹+ homogeneity and improved parallel imaging performance.}, language = {en} } @article{SchulteTiggesFoersterNikolovskietal.2022, author = {Schulte-Tigges, Joschua and F{\"o}rster, Marco and Nikolovski, Gjorgji and Reke, Michael and Ferrein, Alexander and Kaszner, Daniel and Matheis, Dominik and Walter, Thomas}, title = {Benchmarking of various LiDAR sensors for use in self-driving vehicles in real-world environments}, series = {Sensors}, volume = {22}, journal = {Sensors}, number = {19}, publisher = {MDPI}, address = {Basel}, issn = {1424-8220}, doi = {10.3390/s22197146}, pages = {20 Seiten}, year = {2022}, abstract = {Abstract In this paper, we report on our benchmark results of the LiDAR sensors Livox Horizon, Robosense M1, Blickfeld Cube, Blickfeld Cube Range, Velodyne Velarray H800, and Innoviz Pro. The idea was to test the sensors in different typical scenarios that were defined with real-world use cases in mind, in order to find a sensor that meet the requirements of self-driving vehicles. For this, we defined static and dynamic benchmark scenarios. In the static scenarios, both LiDAR and the detection target do not move during the measurement. In dynamic scenarios, the LiDAR sensor was mounted on the vehicle which was driving toward the detection target. We tested all mentioned LiDAR sensors in both scenarios, show the results regarding the detection accuracy of the targets, and discuss their usefulness for deployment in self-driving cars.}, language = {en} } @inproceedings{RitzIzquierdoTelloDamm2014, author = {Ritz, Thomas and Izquierdo Tello, C{\´e}sar and Damm, Sebastian}, title = {Connecting a pedelec to the cloud as basis for gamification in multi modal mobility planning}, series = {MobileCloud 2014 : 2nd IEEE International Conference on Mobile Cloud Computing, Services, and Engineering Oxford, United Kingdom 7-10 April 2014}, booktitle = {MobileCloud 2014 : 2nd IEEE International Conference on Mobile Cloud Computing, Services, and Engineering Oxford, United Kingdom 7-10 April 2014}, publisher = {IEEE Service Center}, address = {Piscataway, NJ}, isbn = {978-1-4799-2504-9}, doi = {10.1109/MobileCloud.2014.25}, pages = {101 -- 108}, year = {2014}, language = {en} } @article{FrauenrathFuchsDieringeretal.2012, author = {Frauenrath, Tobias and Fuchs, Katharina and Dieringer, Matthias A. and {\"O}zerdem, Celal and Patel, Nishan and Renz, Wolfgang and Greiser, Andreas and Elgeti, Thomas and Niendorf, Thoralf}, title = {Detailing the use of magnetohydrodynamic effects for synchronization of MRI with the cardiac cycle: A feasibility study}, series = {Journal of Magnetic Resonance Imaging}, volume = {36}, journal = {Journal of Magnetic Resonance Imaging}, number = {2}, publisher = {Wiley-Liss}, address = {New York}, issn = {1522-2586}, doi = {10.1002/jmri.23634}, pages = {364 -- 372}, year = {2012}, abstract = {Purpose: To investigate the feasibility of using magnetohydrodynamic (MHD) effects for synchronization of magnetic resonance imaging (MRI) with the cardiac cycle. Materials and Methods: The MHD effect was scrutinized using a pulsatile flow phantom at B0 = 7.0 T. MHD effects were examined in vivo in healthy volunteers (n = 10) for B0 ranging from 0.05-7.0 T. Noncontrast-enhanced MR angiography (MRA) of the carotids was performed using a gated steady-state free-precession (SSFP) imaging technique in conjunction with electrocardiogram (ECG) and MHD synchronization. Results: The MHD potential correlates with flow velocities derived from phase contrast MRI. MHD voltages depend on the orientation between B0 and the flow of a conductive fluid. An increase in the interelectrode spacing along the flow increases the MHD potential. In vivo measurement of the MHD effect provides peak voltages of 1.5 mV for surface areas close to the common carotid artery at B0 = 7.0 T. Synchronization of MRI with the cardiac cycle using MHD triggering is feasible. MHD triggered MRA of the carotids at 3.0 T showed an overall image quality and richness of anatomic detail, which is comparable to ECG-triggered MRAs. Conclusion: This feasibility study demonstrates the use of MHD effects for synchronization of MR acquisitions with the cardiac cycle. J. Magn. Reson. Imaging 2012;36:364-372. © 2012 Wiley Periodicals, Inc.}, language = {en} } @inproceedings{WittigRuettersBragard2024, author = {Wittig, M. and R{\"u}tters, Ren{\´e} and Bragard, Michael}, title = {Application of RL in control systems using the example of a rotatory inverted pendulum}, series = {Tagungsband AALE 2024 : Fit f{\"u}r die Zukunft: praktische L{\"o}sungen f{\"u}r die industrielle Automation}, booktitle = {Tagungsband AALE 2024 : Fit f{\"u}r die Zukunft: praktische L{\"o}sungen f{\"u}r die industrielle Automation}, editor = {Reiff-Stephan, J{\"o}rg and J{\"a}kel, Jens and Schwarz, Andr{\´e}}, publisher = {le-tex publishing services GmbH}, address = {Leipzig}, isbn = {978-3-910103-02-3}, doi = {10.33968/2024.53}, pages = {241 -- 248}, year = {2024}, abstract = {In this paper, the use of reinforcement learning (RL) in control systems is investigated using a rotatory inverted pendulum as an example. The control behavior of an RL controller is compared to that of traditional LQR and MPC controllers. This is done by evaluating their behavior under optimal conditions, their disturbance behavior, their robustness and their development process. All the investigated controllers are developed using MATLAB and the Simulink simulation environment and later deployed to a real pendulum model powered by a Raspberry Pi. The RL algorithm used is Proximal Policy Optimization (PPO). The LQR controller exhibits an easy development process, an average to good control behavior and average to good robustness. A linear MPC controller could show excellent results under optimal operating conditions. However, when subjected to disturbances or deviations from the equilibrium point, it showed poor performance and sometimes instable behavior. Employing a nonlinear MPC Controller in real time was not possible due to the high computational effort involved. The RL controller exhibits by far the most versatile and robust control behavior. When operated in the simulation environment, it achieved a high control accuracy. When employed in the real system, however, it only shows average accuracy and a significantly greater performance loss compared to the simulation than the traditional controllers. With MATLAB, it is not yet possible to directly post-train the RL controller on the Raspberry Pi, which is an obstacle to the practical application of RL in a prototyping or teaching setting. Nevertheless, RL in general proves to be a flexible and powerful control method, which is well suited for complex or nonlinear systems where traditional controllers struggle.}, language = {en} } @article{GraesslRenzHezeletal.2013, author = {Gr{\"a}ßl, Andreas and Renz, Wolfgang and Hezel, Fabian and Dieringer, Matthias A. and Winter, Lukas and {\"O}zerdem, Celal and Rieger, Jan and Kellmann, Peter and Santoro, Davide and Lindel, Tomasz D. and Frauenrath, Tobias and Pfeiffer, Harald and Niendorf, Thoralf}, title = {Modular 32-channel transceiver coil array for cardiac MRI at 7.0T}, series = {Magnetic Resonance in Medicine}, volume = {72}, journal = {Magnetic Resonance in Medicine}, number = {1}, publisher = {Wiley-Liss}, address = {New York}, issn = {1522-2594}, doi = {10.1002/mrm.24903}, pages = {276 -- 290}, year = {2013}, abstract = {Purpose To design and evaluate a modular transceiver coil array with 32 independent channels for cardiac MRI at 7.0T. Methods The modular coil array comprises eight independent building blocks, each containing four transceiver loop elements. Numerical simulations were used for B1+ field homogenization and radiofrequency (RF) safety validation. RF characteristics were examined in a phantom study. The array's suitability for accelerated high spatial resolution two-dimensional (2D) FLASH CINE imaging of the heart was examined in a volunteer study. Results Transmission field adjustments and RF characteristics were found to be suitable for the volunteer study. The signal-to-noise intrinsic to 7.0T together with the coil performance afforded a spatial resolution of 1.1 × 1.1 × 2.5 mm3 for 2D CINE FLASH MRI, which is by a factor of 6 superior to standardized CINE protocols used in clinical practice at 1.5T. The 32-channel transceiver array supports one-dimensional acceleration factors of up to R = 4 without impairing image quality significantly. Conclusion The modular 32-channel transceiver cardiac array supports accelerated and high spatial resolution cardiac MRI. The array is compatible with multichannel transmission and provides a technological basis for future clinical assessment of parallel transmission techniques at 7.0T.}, language = {en} } @inproceedings{KramerBragardRitzetal.2024, author = {Kramer, Pia and Bragard, Michael and Ritz, Thomas and Ferfer, Ute and Schiffers, Tim}, title = {Visualizing, Enhancing and Predicting Students' Success through ECTS Monitoring}, series = {2024 IEEE Global Engineering Education Conference (EDUCON)}, booktitle = {2024 IEEE Global Engineering Education Conference (EDUCON)}, publisher = {IEEE}, address = {New York, NY}, issn = {2165-9559}, doi = {10.1109/EDUCON60312.2024.10578652}, pages = {5 Seiten}, year = {2024}, abstract = {This paper serves as an introduction to the ECTS monitoring system and its potential applications in higher education. It also emphasizes the potential for ECTS monitoring to become a proactive system, supporting students by predicting academic success and identifying groups of potential dropouts for tailored support services. The use of the nearest neighbor analysis is suggested for improving data analysis and prediction accuracy.}, language = {en} } @incollection{SchultLosseCzarneckietal.2023, author = {Schult, Prince Garcia and Losse, Ann-Kathrin and Czarnecki, Christian and Sultanow, Eldar}, title = {Proposing a Framework to address the Sustainable Development Goals}, series = {EnviroInfo 2023}, booktitle = {EnviroInfo 2023}, publisher = {GI - Gesellschaft f{\"u}r Informatik}, address = {Bonn}, isbn = {978-3-88579-736-4}, issn = {1617-5468}, doi = {10.18420/env2023-022}, pages = {243 -- 249}, year = {2023}, abstract = {Reducing poverty, protecting the planet, and improving life on earth for everyone are the essential goals of the "2030 Agenda for Sustainable Development"committed by the United Nations (UN). Achieving those goals will require technological innovation as well as their implementation in almost all areas of our business and day-to-day life. This paper proposes a high-level framework that collects and structures different uses cases addressing the goals defined by the UN. Hence, it contributes to the discussion by proposing technical innovations that can be used to achieve those goals. As an example, the goal "Climate Action{\"i}s discussed in detail by describing use cases related to tackling biodiversity loss in order to conservate ecosystems.}, language = {en} } @inproceedings{BuxbaumHessRingbeck2001, author = {Buxbaum, Bernd and Hess, Holger and Ringbeck, Thorsten}, title = {The photonic mixer device : new perspectives in optical wireless communication}, series = {International Workshop on Optical MEMS and Integrated Optics : Universit{\"a}t Dortmund, Universit{\"a}tskolleg Bommerholz, 11. \& 12. June 2001}, booktitle = {International Workshop on Optical MEMS and Integrated Optics : Universit{\"a}t Dortmund, Universit{\"a}tskolleg Bommerholz, 11. \& 12. June 2001}, editor = {Voges, Edgar}, publisher = {Univ.}, address = {Dortmund}, pages = {(12)1 -- (12)5}, year = {2001}, language = {en} } @inproceedings{RingbeckAlbrechtFrey2003, author = {Ringbeck, Thorsten and Albrecht, M. and Frey, J.}, title = {Time-of-Flight 3D-camera for autonomous navigation and industrial automation}, series = {Proceedings : 11th international conference, 13 - 15 May 2003, Exhibition Centre Nuremberg, Germany ; an event of the Association for Sensor Technology, AMA}, booktitle = {Proceedings : 11th international conference, 13 - 15 May 2003, Exhibition Centre Nuremberg, Germany ; an event of the Association for Sensor Technology, AMA}, editor = {Lerch, Reinhard}, edition = {CD-ROM-Ausg.}, publisher = {AMA Service}, address = {Wunstorf/Germany}, year = {2003}, language = {en} } @inproceedings{HagebeukerRingbeckFrydlewiczetal.2007, author = {Hagebeuker, Bianca and Ringbeck, Thorsten and Frydlewicz, Paul and Jesorsky, Oliver and S{\"u}nkel, Thomas}, title = {PMD-Sensoren als Schl{\"u}sselkomponenten f{\"u}r die mehrdimensionale Umfelderfassung des Fahrzeuginnenraums}, series = {Begleittexte zum Entwicklerforum KFZ-Elektronik \& FlexRay Solution Day : 15.Mai 2007, Ludwigsburg}, booktitle = {Begleittexte zum Entwicklerforum KFZ-Elektronik \& FlexRay Solution Day : 15.Mai 2007, Ludwigsburg}, editor = {Grote, Caspar}, publisher = {WEKA-Fachzeitschr.-Verl.}, address = {Poing}, pages = {287 -- 296}, year = {2007}, language = {en} } @inproceedings{GrothofSchwarteBuxbaumetal.2002, author = {Grothof, M. and Schwarte, Rudolf and Buxbaum, Bernd and Ringbeck, Thorsten}, title = {Product monitoring with MSM-PMD-Array}, series = {Proceedings / OPTO 2002 : an event of the Association for Sensor Technology AMA ; 14 - 16 May 2002, Exhibition Centre Erfurt, Germany / International Conference Optoelectronics, Optical Sensors \& Measuring Techniques}, booktitle = {Proceedings / OPTO 2002 : an event of the Association for Sensor Technology AMA ; 14 - 16 May 2002, Exhibition Centre Erfurt, Germany / International Conference Optoelectronics, Optical Sensors \& Measuring Techniques}, editor = {Wagner, Elmar}, publisher = {AMA Service GmbH}, address = {Wunsdorf}, pages = {41 -- 47}, year = {2002}, language = {en} } @inproceedings{BuxbaumSchwarteRingbecketal.2001, author = {Buxbaum, Bernd and Schwarte, Rudolf and Ringbeck, Thorsten and Grothof, Markus and Sluiter, A. and Frey, Jochen and Hildebrand, M. and David, Klaus}, title = {Wireless LAN based on optical CDMA using a new high-speed correlation receiver (MSM-PMD)}, series = {Optical wireless communications IV : 21-22 August, 2001, Denver, USA. - (SPIE proceedings series ; 4530)}, booktitle = {Optical wireless communications IV : 21-22 August, 2001, Denver, USA. - (SPIE proceedings series ; 4530)}, editor = {Korevaar, Eric John}, publisher = {SPIE}, address = {Bellingham, Wash.}, isbn = {0-8194-4254-2}, doi = {10.1117/12.449808}, pages = {168 -- 178}, year = {2001}, language = {en} } @inproceedings{NoetzoldUphuesWegeneretal.2013, author = {N{\"o}tzold, K. and Uphues, A. and Wegener, R. and Fink, K. and Bragard, Michael and Griessel, R. and Soter, S.}, title = {Inverter based test setup for LVRT verification of a full-scale 2 MW wind power converter}, series = {15th European Conference on Power Electronics and Applications (EPE), 2013 : 2 - 6 Sept. 2013, Lille, France / [EPE Association; PELS, IEEE Power Electronics Society]}, booktitle = {15th European Conference on Power Electronics and Applications (EPE), 2013 : 2 - 6 Sept. 2013, Lille, France / [EPE Association; PELS, IEEE Power Electronics Society]}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4799-0115-9 (Online-Ausg.)}, doi = {10.1109/EPE.2013.6634752}, pages = {1037 -- 1042}, year = {2013}, language = {en} } @incollection{NiendorfWinterFrauenrath2012, author = {Niendorf, Thoralf and Winter, Lukas and Frauenrath, Tobias}, title = {Electrocardiogram in an MRI environment: Clinical needs, practical considerations, safety implications, technical solutions and fFuture directions}, series = {Advances in Electrocardiograms - Methods and Analysis}, booktitle = {Advances in Electrocardiograms - Methods and Analysis}, editor = {Millis, Richard}, publisher = {IntechOpen}, address = {London}, isbn = {978-953-307-923-3 (print)}, doi = {10.5772/24340}, pages = {309 -- 324}, year = {2012}, language = {en} } @inproceedings{EllerwegRitz2008, author = {Ellerweg, Roland and Ritz, Thomas}, title = {Tool supported requirements analysis for the user centered development of mobile enterprise software}, series = {Proceeding of Wireless Applications and Computing 2008 and Telecommunications, Networks and Systems 2008 : MCCSIS '08 ; IADIS Multi Conference on Computer Science and Information Systems ; 22 - 24 July 2008, Amsterdam, The Netherlands}, booktitle = {Proceeding of Wireless Applications and Computing 2008 and Telecommunications, Networks and Systems 2008 : MCCSIS '08 ; IADIS Multi Conference on Computer Science and Information Systems ; 22 - 24 July 2008, Amsterdam, The Netherlands}, editor = {Roth, J{\"o}rg}, publisher = {IADIS Press}, address = {[Lisboa]}, isbn = {978-972-8924-62-1}, pages = {160 -- 162}, year = {2008}, abstract = {A user centered development method has proved satisfactory for the development of mobile enterprise software. To make use of this method, detailed information about the user and the place where the user interacts with his mobile device is required. This article describes how both can be modeled by a stereotypical and conceptual extended UML extension. Finally, a software tool is presented that supports the developed UML extension.}, language = {en} } @inproceedings{LindnerKolbRingbeck2008, author = {Lindner, Marvin and Kolb, Andreas and Ringbeck, Thorsten}, title = {New insights into the calibration of ToF-sensors}, series = {2008 IEEE Computer Society Conference on Computer Vision and Pattern Recognition workshops : Anchorage, AK, 23 - 28 June 2008}, booktitle = {2008 IEEE Computer Society Conference on Computer Vision and Pattern Recognition workshops : Anchorage, AK, 23 - 28 June 2008}, publisher = {IEEE Service Center}, address = {Piscataway, NJ}, isbn = {978-1-4244-2339-2}, pages = {1 -- 5}, year = {2008}, abstract = {Time-of-flight (ToF) sensors have become an alternative to conventional distance sensing techniques like laser scanners or image based stereo. ToF sensors provide full range distance information at high frame-rates and thus have a significant impact onto current research in areas like online object recognition, collision prevention or scene reconstruction. However, ToF cameras like the photonic mixer device (PMD) still exhibit a number of challenges regarding static and dynamic effects, e.g. systematic distance errors and motion artefacts, respectively. Sensor calibration techniques reducing static system errors have been proposed and show promising results. However, current calibration techniques in general need a large set of reference data in order to determine the corresponding parameters for the calibration model. This paper introduces a new calibration approach which combines different demodulation techniques for the ToF- camera 's reference signal. Examples show, that the resulting combined demodulation technique yields improved distance values based on only two required reference data sets.}, language = {en} } @inproceedings{BragardSoltauDeDonckeretal.2010, author = {Bragard, Michael and Soltau, N. and De Doncker, R. W. and Schmiegel, A.}, title = {Design and implementation of a 5 kW photovoltaic system with li-ion battery and additional DC-DC converter}, series = {2010 IEEE Energy Conversion Congress and Exposition (ECCE 2010) : Atlanta, Georgia, USA, 12 - 16 September 2010 / [sponsored by the IEEE Power Electronics and Industry Applications Societies]}, booktitle = {2010 IEEE Energy Conversion Congress and Exposition (ECCE 2010) : Atlanta, Georgia, USA, 12 - 16 September 2010 / [sponsored by the IEEE Power Electronics and Industry Applications Societies]}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4244-5286-6 (Print)}, doi = {10.1109/ECCE.2010.5618220}, pages = {2944 -- 2949}, year = {2010}, language = {en} } @article{DroopChenRadfordetal.2023, author = {Droop, Philipp and Chen, Shaohuang and Radford, Melissa J. and Paulßen, Elisabeth and Gates, Byron D. and Reilly, Raymond M. and Radchenko, Valery and Hoehr, Cornelia}, title = {Synthesis of 197m/gHg labelled gold nanoparticles for targeted radionuclide therapy}, series = {Radiochimica Acta}, volume = {111}, journal = {Radiochimica Acta}, number = {10}, publisher = {De Gruyter}, address = {Berlin [u.a.]}, issn = {2193-3405}, doi = {10.1515/ract-2023-0144}, pages = {773 -- 779}, year = {2023}, abstract = {Meitner-Auger-electron emitters have a promising potential for targeted radionuclide therapy of cancer because of their short range and the high linear energy transfer of Meitner-Auger-electrons (MAE). One promising MAE candidate is 197m/gHg with its half-life of 23.8 h and 64.1 h, respectively, and high MAE yield. Gold nanoparticles (AuNPs) that are labelled with 197m/gHg could be a helpful tool for radiation treatment of glioblastoma multiforme when infused into the surgical cavity after resection to prevent recurrence. To produce such AuNPs, 197m/gHg was embedded into pristine AuNPs. Two different syntheses were tested starting from irradiated gold containing trace amounts of 197m/gHg. When sodium citrate was used as reducing agent, no 197m/gHg labelled AuNPs were formed, but with tannic acid, 197m/gHg labeled AuNPs were produced. The method was optimized by neutralizing the pH (pH = 7) of the Au/197m/gHg solution, which led to labelled AuNPs with a size of 12.3 ± 2.0 nm as measured by transmission electron microscopy. The labelled AuNPs had a concentration of 50 μg (gold)/mL with an activity of 151 ± 93 kBq/mL (197gHg, time corrected to the end of bombardment).}, language = {en} } @inproceedings{BragardConradDeDoncker2010, author = {Bragard, Michael and Conrad, M. and De Doncker, R. W.}, title = {The integrated emitter turn-off thyristor (IETO) : an innovative thyristor based high power semiconductor device using MOS assisted turn-off}, series = {2010 IEEE Energy Conversion Congress and Exposition (ECCE 2010) : Atlanta, Georgia, USA, 12 - 16 September 2010 / [sponsored by the IEEE Power Electronics and Industry Applications Societies]}, booktitle = {2010 IEEE Energy Conversion Congress and Exposition (ECCE 2010) : Atlanta, Georgia, USA, 12 - 16 September 2010 / [sponsored by the IEEE Power Electronics and Industry Applications Societies]}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4244-5286-6 (Print)}, doi = {10.1109/ECCE.2010.5618410}, pages = {4551 -- 4557}, year = {2010}, language = {en} } @article{HeuermannHillebrandSadeghfam2008, author = {Heuermann, Holger and Hillebrand, J{\"u}rgen and Sadeghfam, Arash}, title = {Novel Concept of a Digital SigmaDelta-PLL-Phase-Shift-Modulator / Hillebrand, J{\"u}rgen ; Sadeghfam, Arash ; Heuermann, Holger}, isbn = {978-3-8007-3086-5}, pages = {123 -- 126}, year = {2008}, language = {en} } @article{FerreinSteinbauerMcPhillipsetal.2007, author = {Ferrein, Alexander and Steinbauer, Gerald and McPhillips, Graeme and Potgieter, Anet}, title = {Establishing the RoboCup Standard League in Africa - applying for the RoboCup Standard League with a German-Austrian-South African Research Project}, pages = {1 -- 5}, year = {2007}, language = {en} } @inproceedings{Ritz2001, author = {Ritz, Thomas}, title = {Personalized information services : an electronic information commodity and its production}, series = {Electronic publishing '01 : 2001 in the digital publishing odyssey ; proceedings of an ICCC/IFIP conference held at the University of Kent at Canterbury, Kent, United Kingdom, 5 - 7 July, 2001 ; [proceedings of the Fifth Conference on Electronic Publishing]}, booktitle = {Electronic publishing '01 : 2001 in the digital publishing odyssey ; proceedings of an ICCC/IFIP conference held at the University of Kent at Canterbury, Kent, United Kingdom, 5 - 7 July, 2001 ; [proceedings of the Fifth Conference on Electronic Publishing]}, publisher = {IOS Press [u.a.]}, address = {Amsterdam}, isbn = {1-58603-191-0}, pages = {48 -- 58}, year = {2001}, language = {en} } @article{HeuermannSchiek1992, author = {Heuermann, Holger and Schiek, Burkhard}, title = {LNN (Line-Network-Network): Verfahren zur Kalibrierung von Netzwerkanalysatoren}, series = {Kleinheubacher Berichte : Vortr{\"a}ge und Berichte der gemeinsamen Tagung des U.R.S.I.-Landesausschusses in der Bundesrepublik Deutschland / Hrsg.: Deutsche Telekom AG. 36. 1992 (1992)}, journal = {Kleinheubacher Berichte : Vortr{\"a}ge und Berichte der gemeinsamen Tagung des U.R.S.I.-Landesausschusses in der Bundesrepublik Deutschland / Hrsg.: Deutsche Telekom AG. 36. 1992 (1992)}, pages = {327 -- 335}, year = {1992}, language = {en} } @article{FerreinFritzLakemeyer2005, author = {Ferrein, Alexander and Fritz, Christian and Lakemeyer, Gerhard}, title = {Using Golog for Deliberation and Team Coordination in Robotic Soccer / Ferrein, Alexander ; Fritz, Christian ; Lakemeyer, Gerhard}, series = {K{\"u}nstliche Intelligenz : KI. 19 (2005), H. 1}, journal = {K{\"u}nstliche Intelligenz : KI. 19 (2005), H. 1}, isbn = {0933-1875}, pages = {24 -- 30}, year = {2005}, language = {en} } @article{SchifferFerrein2018, author = {Schiffer, Stefan and Ferrein, Alexander}, title = {ERIKA—Early Robotics Introduction at Kindergarten Age}, series = {Multimodal Technologies Interact}, volume = {2}, journal = {Multimodal Technologies Interact}, number = {4}, publisher = {MDPI}, address = {Basel}, issn = {2414-4088}, doi = {10.3390/mti2040064}, pages = {15}, year = {2018}, abstract = {In this work, we report on our attempt to design and implement an early introduction to basic robotics principles for children at kindergarten age. One of the main challenges of this effort is to explain complex robotics contents in a way that pre-school children could follow the basic principles and ideas using examples from their world of experience. What sets apart our effort from other work is that part of the lecturing is actually done by a robot itself and that a quiz at the end of the lesson is done using robots as well. The humanoid robot Pepper from Softbank, which is a great platform for human-robot interaction experiments, was used to present a lecture on robotics by reading out the contents to the children making use of its speech synthesis capability. A quiz in a Runaround-game-show style after the lecture activated the children to recap the contents they acquired about how mobile robots work in principle. In this quiz, two LEGO Mindstorm EV3 robots were used to implement a strongly interactive scenario. Besides the thrill of being exposed to a mobile robot that would also react to the children, they were very excited and at the same time very concentrated. We got very positive feedback from the children as well as from their educators. To the best of our knowledge, this is one of only few attempts to use a robot like Pepper not as a tele-teaching tool, but as the teacher itself in order to engage pre-school children with complex robotics contents.}, language = {en} } @inproceedings{HofmannMatareNeumannetal.2018, author = {Hofmann, Till and Matar{\´e}, Victor and Neumann, Tobias and Sch{\"o}nitz, Sebastian and Henke, Christoph and Limpert, Nicolas and Niemueller, Tim and Ferrein, Alexander and Jeschke, Sabina and Lakemeyer, Gerhard}, title = {Enhancing Software and Hardware Reliability for a Successful Participation in the RoboCup Logistics League 2017}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-00308-1}, doi = {10.1007/978-3-030-00308-1_40}, pages = {486 -- 497}, year = {2018}, language = {en} } @article{HoltrupSadeghfamHeuermannetal.2014, author = {Holtrup, S. and Sadeghfam, Arash and Heuermann, Holger and Awakowicz, P.}, title = {Characterization and optimization technique for microwave-driven high-intensity discharge lamps using hot S-parameters}, series = {IEEE transactions on microwave theories and techniques}, volume = {62}, journal = {IEEE transactions on microwave theories and techniques}, number = {10}, publisher = {IEEE}, address = {New York}, issn = {0018-9480}, doi = {10.1109/TMTT.2014.2342652}, pages = {2471 -- 2480}, year = {2014}, abstract = {High-intensity discharge lamps can be driven by radio-frequency signals in the ISM frequency band at 2.45 GHz, using a matching network to transform the impedance of the plasma to the source impedance. To achieve an optimal operating condition, a good characterization of the lamp in terms of radio frequency equivalent circuits under operating conditions is necessary, enabling the design of an efficient matching network. This paper presents the characterization technique for such lamps and presents the design of the required matching network. For the characterization, a high-intensity discharge lamp was driven by a monofrequent large signal at 2.45 GHz, whereas a frequency sweep over 300 MHz was performed across this signal to measure so-called small-signal hot S-parameters using a vector network analyzer. These parameters are then used as an equivalent load in a circuit simulator to design an appropriate matching network. Using the measured data as a black-box model in the simulation results in a quick and efficient method to simulate and design efficient matching networks in spite of the complex plasma behavior. Furthermore, photometric analysis of high-intensity discharge lamps are carried out, comparing microwave operation to conventional operation.}, language = {en} } @inproceedings{SadeghfamSadeghiAhangarElgamaletal.2019, author = {Sadeghfam, Arash and Sadeghi-Ahangar, A. and Elgamal, Abdelrahman and Heuermann, Holger}, title = {Design and Development of a Novel Self-Igniting Microwave Plasma Jet for Industrial Applications}, series = {IEEE MTT-S International Microwave Symposium Digest}, booktitle = {IEEE MTT-S International Microwave Symposium Digest}, isbn = {978-172811309-8}, pages = {63 -- 66}, year = {2019}, language = {en} } @article{Ritz2002, author = {Ritz, Thomas}, title = {Mass Customized Production of Information Services - The combination of economies-of-scale with economies-of-scope}, series = {Media firms : structures, operations, and performance ; [World Media Economics Conference, 5th : 2002 : Turku, Finland] / ed. by Robert G. Picard}, journal = {Media firms : structures, operations, and performance ; [World Media Economics Conference, 5th : 2002 : Turku, Finland] / ed. by Robert G. Picard}, publisher = {Erlbaum}, address = {Mahwah, NJ [u.a.]}, isbn = {0-8058-4165-2}, pages = {267 S. : graph. Darst.}, year = {2002}, language = {en} } @article{NiemuellerFerreinBecketal.2010, author = {Niem{\"u}ller, Tim and Ferrein, Alexander and Beck, Daniel and Lakemeyer, Gerhard}, title = {Design Principles of the Component-Based Robot Software Framework Fawkes}, series = {Simulation, Modeling, and Programming for Autonomous Robots}, journal = {Simulation, Modeling, and Programming for Autonomous Robots}, pages = {300 -- 311}, year = {2010}, language = {en} } @article{FerreinSteinbauer2010, author = {Ferrein, Alexander and Steinbauer, Gerald}, title = {On the Way to High-Level Programming for Resource-Limited Embedded Systems with Golog}, series = {Simulation, Modeling, and Programming for Autonomous Robots}, journal = {Simulation, Modeling, and Programming for Autonomous Robots}, pages = {229 -- 240}, year = {2010}, language = {en} } @article{Ferrein2010, author = {Ferrein, Alexander}, title = {Robot controllers for highly dynamic environments with real-time constraints}, series = {K{\"u}nstliche Intelligenz : KI. 24 (2010), H. 2}, journal = {K{\"u}nstliche Intelligenz : KI. 24 (2010), H. 2}, isbn = {1610-1987}, pages = {175 -- 178}, year = {2010}, language = {en} } @article{HeuermannIbrahim2008, author = {Heuermann, Holger and Ibrahim, Irfan}, title = {Novel theory and architecture of a vector signal generator implemented with two PLLs / Ibrahim, Irfan ; Heuermann, Holger}, series = {European Conference on Wireless Technology, 2008. EuWiT 2008.}, journal = {European Conference on Wireless Technology, 2008. EuWiT 2008.}, isbn = {978-2-87487-008-8}, pages = {85 -- 88}, year = {2008}, language = {en} } @article{Heuermann2008, author = {Heuermann, Holger}, title = {Dual mode radio: A new tranceiver architecture for UWB and 60 GHz-applications}, series = {European Conference on Wireless Technology, 2008. EuWiT 2008.}, journal = {European Conference on Wireless Technology, 2008. EuWiT 2008.}, isbn = {978-2-87487-008-8}, pages = {147 -- 150}, year = {2008}, language = {en} } @article{BeckBuchleitnerFerreinetal.2014, author = {Beck, Daniel and Buchleitner, Martin and Ferrein, Alexander and Niem{\"u}ller, Tim and Steinbauer, Gerald}, title = {Mostly Harmless \& AllemaniACs - mixed innovations}, pages = {1 -- 8}, year = {2014}, language = {en} } @inproceedings{ArndtConzenElsenetal.2023, author = {Arndt, Tobias and Conzen, Max and Elsen, Ingo and Ferrein, Alexander and Galla, Oskar and K{\"o}se, Hakan and Schiffer, Stefan and Tschesche, Matteo}, title = {Anomaly detection in the metal-textile industry for the reduction of the cognitive load of quality control workers}, series = {PETRA '23: Proceedings of the 16th International Conference on PErvasive Technologies Related to Assistive Environments}, booktitle = {PETRA '23: Proceedings of the 16th International Conference on PErvasive Technologies Related to Assistive Environments}, publisher = {ACM}, isbn = {9798400700699}, doi = {10.1145/3594806.3596558}, pages = {535 -- 542}, year = {2023}, abstract = {This paper presents an approach for reducing the cognitive load for humans working in quality control (QC) for production processes that adhere to the 6σ -methodology. While 100\% QC requires every part to be inspected, this task can be reduced when a human-in-the-loop QC process gets supported by an anomaly detection system that only presents those parts for manual inspection that have a significant likelihood of being defective. This approach shows good results when applied to image-based QC for metal textile products.}, language = {en} } @inproceedings{AlhwarinFerreinScholl2019, author = {Alhwarin, Faraj and Ferrein, Alexander and Scholl, Ingrid}, title = {An Efficient Hashing Algorithm for NN Problem in HD Spaces}, series = {Lecture Notes in Computer Science}, booktitle = {Lecture Notes in Computer Science}, isbn = {978-303005498-4}, doi = {10.1007/978-3-030-05499-1_6}, pages = {101 -- 115}, year = {2019}, language = {en} } @article{FerreinDyllaLakemeyer2002, author = {Ferrein, Alexander and Dylla, Frank and Lakemeyer, Gerhard}, title = {Acting and Deliberating using Golog in Robotic Soccer - A Hybrid Architecture / Dylla, Frank ; Ferrein, Alexander ; Lakemeyer, Gerhard}, series = {Proc. 3rd International Cognitive Robotics Workshop (CogRob 2002)}, journal = {Proc. 3rd International Cognitive Robotics Workshop (CogRob 2002)}, pages = {1 -- 7}, year = {2002}, language = {en} } @article{Ferrein2008, author = {Ferrein, Alexander}, title = {Logic-based robot control in highly dynamic domains / Ferrein, Alexander ; Lakemeyer, Gerhard}, series = {Robotics and Autonomous Systems. 56 (2008), H. 11}, journal = {Robotics and Autonomous Systems. 56 (2008), H. 11}, isbn = {0921-8890}, pages = {980 -- 991}, year = {2008}, language = {en} } @book{Ferrein2008, author = {Ferrein, Alexander}, title = {Robot controllers for highly dynamic environments with real-time constraints}, pages = {XVI; 247 S. : Ill., graph. Darst}, year = {2008}, language = {en} } @article{KoenigWolf2018, author = {K{\"o}nig, Johannes Alexander and Wolf, Martin R.}, title = {GHOST: An Evaluated Competence Developing Game for Cybersecurity Awareness Training}, series = {International Journal on Advances in Security}, volume = {11}, journal = {International Journal on Advances in Security}, number = {3 \& 4}, publisher = {IARIA Journals}, issn = {1942-2636}, pages = {274 -- 287}, year = {2018}, abstract = {To train end users how to interact with digital systems is indispensable to ensure a strong computer security. 'Competence Developing Game'-based approaches are particularly suitable for this purpose because of their motivation-and simulation-aspects. In this paper the Competence Developing Game 'GHOST' for cybersecurity awareness trainings and its underlying patterns are described. Accordingly, requirements for an 'Competence Developing Game' based training are discussed. Based on these requirements it is shown how a game can fulfill these requirements. A supplementary game interaction design and a corresponding evaluation study is shown. The combination of training requirements and interaction design is used to create a 'Competence Developing Game'-based training concept. A part of these concept is implemented into a playable prototype that serves around one hour of play respectively training time. This prototype is used to perform an evaluation of the game and training aspects of the awareness training. Thereby, the quality of the game aspect and the effectiveness of the training aspect are shown.}, language = {en} } @article{FerreinSteinbauerMcPhillipsetal.2008, author = {Ferrein, Alexander and Steinbauer, Gerald and McPhillips, Graeme and Potgieter, Anet}, title = {RoboCup Standard Platform League - Team Zadeat : an intercontinental research effort}, pages = {1 -- 7}, year = {2008}, language = {en} } @inproceedings{SchoppNachtrodtHeuermannetal.2012, author = {Schopp, Christoph and Nachtrodt, Frederik and Heuermann, Holger and Scherer, Ulrich W. and Mostacci, Domiziano and Finger, Torsten and Tietsch, Wolfgang}, title = {A novel 2.45 GHz/200 W Microwave Plasma Jet for High Temperature Applications above 3600 K}, series = {Journal of Physics : Conference Series}, volume = {406}, booktitle = {Journal of Physics : Conference Series}, number = {012029}, issn = {1742-6596}, pages = {5}, year = {2012}, language = {en} } @book{RitzBenzStender2003, author = {Ritz, Thomas and Benz, Axel and Stender, Michael}, title = {Marktstudie mobile CRM-Systeme}, publisher = {Fraunhofer-IRB-Verl.}, address = {Stuttgart}, isbn = {3-8167-6361-8}, pages = {244 S. : Ill., graph. Darst.}, year = {2003}, language = {en} } @inproceedings{NiemuellerLakemeyerFerrein2013, author = {Niem{\"u}ller, Tim and Lakemeyer, Gerhard and Ferrein, Alexander}, title = {Aspects of integrating diverse software into robotic systems extended abstract}, series = {ICRA 2013 - 8th Workshop on Software Development and Integration in Robotics (SDIR), Karlsruhe, Germany}, booktitle = {ICRA 2013 - 8th Workshop on Software Development and Integration in Robotics (SDIR), Karlsruhe, Germany}, pages = {1 -- 2}, year = {2013}, language = {en} } @article{FerreinKonurLakemeyer2004, author = {Ferrein, Alexander and Konur, Savas and Lakemeyer, Gerhard}, title = {Learning Decision Trees for Action Selection in Soccer Agents / Konur, Savas ; Ferrein, Alexander ; Lakemeyer, Gerhard}, pages = {1 -- 7}, year = {2004}, language = {en} } @article{Ferrein2005, author = {Ferrein, Alexander}, title = {Specifying Soccer Moves with Golog}, series = {Book of abstracts : Cologne, 15 - 17 September 2004 / 1st International Working Conference IT and Sport \& 5th conference DVS-Section Computer Science in Sport}, journal = {Book of abstracts : Cologne, 15 - 17 September 2004 / 1st International Working Conference IT and Sport \& 5th conference DVS-Section Computer Science in Sport}, publisher = {German Sport Univ.}, address = {K{\"o}ln}, isbn = {3-00-014576-1}, pages = {161 -- 165}, year = {2005}, language = {en} } @article{SchoppDollGraeseretal.2016, author = {Schopp, Christoph and Doll, Timo and Gr{\"a}ser, Ulrich and Harzheim, Thomas and Heuermann, Holger and Kling, Rainer and Marso, Michael}, title = {Capacitively Coupled High-Pressure Lamp Using Coaxial Line Networks}, series = {IEEE Transactions on Microwave Theory and Techniques}, volume = {64}, journal = {IEEE Transactions on Microwave Theory and Techniques}, number = {10}, publisher = {IEEE}, address = {New York, NY}, issn = {0018-9480}, doi = {10.1109/TMTT.2016.2600326}, pages = {3363 -- 3368}, year = {2016}, abstract = {This paper describes the development of a capacitively coupled high-pressure lamp with input power between 20 and 43 W at 2.45 GHz, using a coaxial line network. Compared with other electrodeless lamp systems, no cavity has to be used and a reduction in the input power is achieved. Therefore, this lamp is an alternative to the halogen incandescent lamp for domestic lighting. To serve the demands of domestic lighting, the filling of the lamp is optimized over all other resulting requirements, such as high efficacy at low induced powers and fast startups. A workflow to develop RF-driven plasma applications is presented, which makes use of the hot S-parameter technique. Descriptions of the fitting process inside a circuit and FEM simulator are given. Results of the combined ignition and operation network from simulations and measurements are compared. An initial prototype is built and measurements of the lamp's lighting properties are presented along with an investigation of the efficacy optimizations using large signal amplitude modulation. With this lamp, an efficacy of 135 lmW -1 is achieved.}, language = {en} } @inproceedings{HeuermannHarzheimMuehmel2021, author = {Heuermann, Holger and Harzheim, Thomas and M{\"u}hmel, Marc}, title = {A maritime harmonic radar search and rescue system using passive and active tags}, series = {2020 17th European Radar Conference (EuRAD)}, booktitle = {2020 17th European Radar Conference (EuRAD)}, publisher = {IEEE}, address = {New York, NY}, isbn = {978-2-87487-061-3}, doi = {10.1109/EuRAD48048.2021.00030}, pages = {73 -- 76}, year = {2021}, abstract = {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.}, language = {en} } @article{HeuermannSchiek1997, author = {Heuermann, Holger and Schiek, Burkhard}, title = {Line Network Network (LNN): an alternative in-fixture calibration procedure}, series = {IEEE transactions on microwave theory and techniques : MTT ; a publication of the IEEE Microwave Theory and Techniques Society. 45 (1997), H. 3}, journal = {IEEE transactions on microwave theory and techniques : MTT ; a publication of the IEEE Microwave Theory and Techniques Society. 45 (1997), H. 3}, isbn = {0018-9480}, pages = {408 -- 413}, year = {1997}, language = {en} } @article{HeuermannPetersSchmitzetal.2005, author = {Heuermann, Holger and Peters, N. and Schmitz, T. and Sadeghfam, Arash}, title = {Concept of Balanced Antennas with Load-Invariant Base Impedance Using a Two Element LC-Coupler. Peters, N., Schmitz, Th., Sadeghfam, A., Heuermann, H.}, series = {Proceedings of the European microwave association : journal of the European microwave association}, journal = {Proceedings of the European microwave association : journal of the European microwave association}, publisher = {PLUS}, address = {Pisa}, pages = {117 -- 122}, year = {2005}, language = {en} }