@article{FiedlerOrzadaFloeseretal.2021, author = {Fiedler, Thomas M. and Orzada, Stephan and Fl{\"o}ser, Martina and Rietsch, Stefan H. G. and Quick, Harald H. and Ladd, Mark E. and Bitz, Andreas}, title = {Performance analysis of integrated RF microstrip transmit antenna arrays with high channel count for body imaging at 7 T}, series = {NMR in Biomedicine}, volume = {34}, journal = {NMR in Biomedicine}, number = {7}, publisher = {Wiley}, address = {Weinheim}, issn = {0952-3480 (ISSN)}, doi = {10.1002/nbm.4515}, pages = {18 SeitenWiley}, year = {2021}, abstract = {The aim of the current study was to investigate the performance of integrated RF transmit arrays with high channel count consisting of meander microstrip antennas for body imaging at 7 T and to optimize the position and number of transmit ele- ments. RF simulations using multiring antenna arrays placed behind the bore liner were performed for realistic exposure conditions for body imaging. Simulations were performed for arrays with as few as eight elements and for arrays with high channel counts of up to 48 elements. The B1+ field was evaluated regarding the degrees of freedom for RF shimming in the abdomen. Worst-case specific absorption rate (SARwc ), SAR overestimation in the matrix compression, the number of virtual obser- vation points (VOPs) and SAR efficiency were evaluated. Constrained RF shimming was performed in differently oriented regions of interest in the body, and the devia- tion from a target B1+ field was evaluated. Results show that integrated multiring arrays are able to generate homogeneous B1+ field distributions for large FOVs, espe- cially for coronal/sagittal slices, and thus enable body imaging at 7 T with a clinical workflow; however, a low duty cycle or a high SAR is required to achieve homoge- neous B1+ distributions and to exploit the full potential. In conclusion, integrated arrays allow for high element counts that have high degrees of freedom for the pulse optimization but also produce high SARwc , which reduces the SAR accuracy in the VOP compression for low-SAR protocols, leading to a potential reduction in array performance. Smaller SAR overestimations can increase SAR accuracy, but lead to a high number of VOPs, which increases the computational cost for VOP evaluation and makes online SAR monitoring or pulse optimization challenging. Arrays with interleaved rings showed the best results in the study.}, language = {en} } @article{FiedlerOrzadaFloeseretal.2022, author = {Fiedler, Thomas M. and Orzada, Stephan and Fl{\"o}ser, Martina and Rietsch, Stefan H. G. and Schmidt, Simon and Stelter, Jonathan K. and Wittrich, Marco and Quick, Harald H. and Bitz, Andreas and Ladd, Mark E.}, title = {Performance and safety assessment of an integrated transmit array for body imaging at 7 T under consideration of specificabsorption rate, tissue temperature, and thermal dose}, series = {NMR in Biomedicine}, volume = {35}, journal = {NMR in Biomedicine}, number = {5}, publisher = {Wiley}, issn = {0952-3480 (Print)}, doi = {10.1002/nbm.4656}, pages = {1 -- 17}, year = {2022}, abstract = {In this study, the performance of an integrated body-imaging array for 7 T with 32 radiofrequency (RF) channels under consideration of local specific absorption rate (SAR), tissue temperature, and thermal dose limits was evaluated and the imaging performance was compared with a clinical 3 T body coil. Thirty-two transmit elements were placed in three rings between the bore liner and RF shield of the gradient coil. Slice-selective RF pulse optimizations for B1 shimming and spokes were performed for differently oriented slices in the body under consideration of realistic constraints for power and local SAR. To improve the B1+ homogeneity, safety assessments based on temperature and thermal dose were performed to possibly allow for higher input power for the pulse optimization than permissible with SAR limits. The results showed that using two spokes, the 7 T array outperformed the 3 T birdcage in all the considered regions of interest. However, a significantly higher SAR or lower duty cycle at 7 T is necessary in some cases to achieve similar B1+ homogeneity as at 3 T. The homogeneity in up to 50 cm-long coronal slices can particularly benefit from the high RF shim performance provided by the 32 RF channels. The thermal dose approach increases the allowable input power and the corresponding local SAR, in one example up to 100 W/kg, without limiting the exposure time necessary for an MR examination. In conclusion, the integrated antenna array at 7 T enables a clinical workflow for body imaging and comparable imaging performance to a conventional 3 T clinical body coil.}, language = {en} } @article{FoltzSchneiderWolfetal.2008, author = {Foltz, Christian and Schneider, Nicole and Wolf, Martin and Kausch, Bernhard and Schlick, Christopher and Luczak, Holger}, title = {Usability engineering}, series = {Collaborative and distributed chemical engineering : from understanding to substantial design process support; results of the IMPROVE Project. - (Lecture notes in computer science ; 4970)}, journal = {Collaborative and distributed chemical engineering : from understanding to substantial design process support; results of the IMPROVE Project. - (Lecture notes in computer science ; 4970)}, editor = {Nagl, Manfred}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-540-70552-9}, doi = {10.1007/978-3-540-70552-9_21}, pages = {527 -- 554}, year = {2008}, language = {en} } @article{FrankeStreckertBitzetal.2005, author = {Franke, Helmut and Streckert, Joachim and Bitz, Andreas and Goeke, Johannes and Hansen, Volkert and Ringelstein, E. Bernd and Nattk{\"a}mper, Heiner and Galle, Hans-Joachim and St{\"o}gbauer, Florian}, title = {Effects of Universal Mobile Telecommunications System (UMTS) electromagnetic fields on the blood-brain barrier in vitro}, series = {Radiation Research}, volume = {164}, journal = {Radiation Research}, number = {3}, issn = {1938-5404}, doi = {10.1667/RR3424.1}, pages = {258 -- 269}, year = {2005}, 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} } @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{FrauenrathNiendorfKob2008, author = {Frauenrath, Tobias and Niendorf, Thoralf and Kob, Malte}, title = {Acoustic method for synchronization of Magnetic Resonance Imaging (MRI)}, series = {Acta Acustica}, volume = {94}, journal = {Acta Acustica}, number = {1}, publisher = {Hirzel}, address = {Stuttgart}, issn = {1861-9959}, doi = {10.3813/AAA.918017}, pages = {148 -- 155}, year = {2008}, abstract = {Magnetic Resonance Imaging (MRI) of moving organs requires synchronization with physiological motion or flow, which dictate the viable window for data acquisition. To meet this challenge, this study proposes an acoustic gating device (ACG) that employs acquisition and processing of acoustic signals for synchronization while providing MRI compatibility, immunity to interferences with electro-magnetic and acoustic fields and suitability for MRI at high magnetic field strengths. The applicability and robustness of the acoustic gating approach is examined in a pilot study, where it substitutes conventional ECG-gating for cardiovascular MR. The merits and limitations of the ACG approach are discussed. Implications for MR imaging in the presence of physiological motion are considered including synchronization with other structure- or motion borne sounds.}, language = {en} } @article{Gligorevic2008, author = {Gligorevic, Snjezana}, title = {Joint channel estimation and equalisation of fast time-varying frequency-selective channels}, series = {European transactions on telecommunications}, volume = {Vol. 19}, journal = {European transactions on telecommunications}, number = {Iss. 1}, issn = {1541-8251; 2161-3915; 1120-3862; 1124-318X}, pages = {1 -- 13}, year = {2008}, language = {en} } @article{Gligorevic2013, author = {Gligorevic, Snjezana}, title = {Airport surface propagation channel in the C-Band: measurements and modeling}, series = {IEEE transactions on antennas and propagation}, volume = {Vol. 61}, journal = {IEEE transactions on antennas and propagation}, number = {Iss. 9}, publisher = {IEEE}, address = {New York}, issn = {0018-926x}, pages = {4792 -- 4802}, year = {2013}, language = {en} } @article{GrandeMeffertSchoenbergeretal.2012, author = {Grande, Marion and Meffert, Elisabeth and Schoenberger, Eva and Jung, Stefanie and Frauenrath, Tobias and Huber, Walter and Hussmann, Katja and Moormann, Mareike and Heim, Stefan}, title = {From a concept to a word in a syntactically complete sentence: An fMRI study on spontaneous language production in an overt picture description task}, series = {NeuroImage}, volume = {61}, journal = {NeuroImage}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1522-2586}, doi = {10.1016/j.neuroimage.2012.03.087}, pages = {702 -- 714}, year = {2012}, abstract = {Spontaneous language has rarely been subjected to neuroimaging studies. This study therefore introduces a newly developed method for the analysis of linguistic phenomena observed in continuous language production during fMRI. Most neuroimaging studies investigating language have so far focussed on single word or — to a smaller extent — sentence processing, mostly due to methodological considerations. Natural language production, however, is far more than the mere combination of words to larger units. Therefore, the present study aimed at relating brain activation to linguistic phenomena like word-finding difficulties or syntactic completeness in a continuous language fMRI paradigm. A picture description task with special constraints was used to provoke hesitation phenomena and speech errors. The transcribed speech sample was segmented into events of one second and each event was assigned to one category of a complex schema especially developed for this purpose. The main results were: conceptual planning engages bilateral activation of the precuneus. Successful lexical retrieval is accompanied - particularly in comparison to unsolved word-finding difficulties - by the left middle and superior temporal gyrus. Syntactic completeness is reflected in activation of the left inferior frontal gyrus (IFG) (area 44). In sum, the method has proven to be useful for investigating the neural correlates of lexical and syntactic phenomena in an overt picture description task. This opens up new prospects for the analysis of spontaneous language production during fMRI.}, 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} } @article{GspandlPillReipetal.2011, author = {Gspandl, Stephan and Pill, Ingo and Reip, Michael and Steinbauer, Gerald and Ferrein, Alexander}, title = {Belief Management for High-Level Robot Programs}, series = {Proceedings of the Twenty-Second International Joint Conference on Artificial Intelligence [electronic resource] : Barcelona, Catalonia, Spain, 16 - 22 July 2011 / sponsored by International Joint Conferences on Artificial Intelligence (IJCAI) and the Association for the Advancement of Artificial Intelligence (AAAI). Ed. by Toby Walsh}, journal = {Proceedings of the Twenty-Second International Joint Conference on Artificial Intelligence [electronic resource] : Barcelona, Catalonia, Spain, 16 - 22 July 2011 / sponsored by International Joint Conferences on Artificial Intelligence (IJCAI) and the Association for the Advancement of Artificial Intelligence (AAAI). Ed. by Toby Walsh}, pages = {900 -- 905}, year = {2011}, language = {en} } @article{HaagZontarSchleupenetal.2014, author = {Haag, S. and Zontar, D. and Schleupen, Josef and M{\"u}ller, T. and Brecher, C.}, title = {Chain of refined perception in self-optimizing assembly of micro-optical systems}, series = {Journal of sensors and sensor systems}, volume = {3}, journal = {Journal of sensors and sensor systems}, number = {1}, publisher = {Copernicus Publ.}, address = {G{\"o}ttingen}, issn = {2194-878X}, doi = {10.5194/jsss-3-87-2014}, pages = {87 -- 95}, year = {2014}, abstract = {Today, the assembly of laser systems requires a large share of manual operations due to its complexity regarding the optimal alignment of optics. Although the feasibility of automated alignment of laser optics has been shown in research labs, the development effort for the automation of assembly does not meet economic requirements - especially for low-volume laser production. This paper presents a model-based and sensor-integrated assembly execution approach for flexible assembly cells consisting of a macro-positioner covering a large workspace and a compact micromanipulator with camera attached to the positioner. In order to make full use of available models from computer-aided design (CAD) and optical simulation, sensor systems at different levels of accuracy are used for matching perceived information with model data. This approach is named "chain of refined perception", and it allows for automated planning of complex assembly tasks along all major phases of assembly such as collision-free path planning, part feeding, and active and passive alignment. The focus of the paper is put on the in-process image-based metrology and information extraction used for identifying and calibrating local coordinate systems as well as the exploitation of that information for a part feeding process for micro-optics. Results will be presented regarding the processes of automated calibration of the robot camera as well as the local coordinate systems of part feeding area and robot base.}, language = {en} } @article{Hagemann1978, author = {Hagemann, Hans-J{\"u}rgen}, title = {Loss mechanisms and domain stabilization in doped BaTiO₃}, series = {Journal of Physics C: Solid State Physics}, volume = {11}, journal = {Journal of Physics C: Solid State Physics}, number = {15}, publisher = {n.a.}, address = {London}, isbn = {0022-3719}, doi = {10.1088/0022-3719/11/15/031}, pages = {3333 -- 3344}, year = {1978}, language = {en} } @article{Hagemann1978, author = {Hagemann, Hans-J{\"u}rgen}, title = {Electrical properties of acceptor-doped BaTiO3 ceramic. Hagemann, H. J.}, series = {Berichte der Deutschen Keramischen Gesellschaft. 55 (1978)}, journal = {Berichte der Deutschen Keramischen Gesellschaft. 55 (1978)}, isbn = {0365-9542}, pages = {353 -- 355}, year = {1978}, language = {en} } @article{Hagemann1978, author = {Hagemann, Hans-J{\"u}rgen}, title = {Reduction of hysteresis losses of ferroelectric BaTiO3. Hagemann, H. J.}, series = {Ferroelectrics. 22 (1978)}, journal = {Ferroelectrics. 22 (1978)}, isbn = {0015-0193}, pages = {743 -- 743}, year = {1978}, language = {en} } @article{HagemannBachmannLadeetal.1995, author = {Hagemann, Hans-J{\"u}rgen and Bachmann, P. K. and Lade, H. and Leers, D.}, title = {Thermal properties of C/H-, C/H/O-, C/H/N- and C/H/X-grown polycrystalline CVD diamond. P. K. Bachmann, H. J. Hagemann, H. Lade, ...}, series = {Diamond and Related Material. Vol 4. (1995), H. Issue 5-6}, journal = {Diamond and Related Material. Vol 4. (1995), H. Issue 5-6}, publisher = {Elsevier Science}, address = {New York, NY [u.a.]}, pages = {820 -- 826}, year = {1995}, language = {en} } @article{HagemannBachmannLadeetal.1994, author = {Hagemann, Hans-J{\"u}rgen and Bachmann, P. K. and Lade, H. and Leers, D.}, title = {Influence of the gas phase on diamond deposition and diamond properties. Bachmann, P. K.; Hagemann, H.J.; Lade, H.; Leers, D.; Picht, F.; Wiechert, D. U.}, series = {Advanced materials '94 : proceedings of the NIRIM International Symposium on Advanced Materials '94, Tsukuba, Japan, March 13 - 17, 1994 / National Institute for Research in Inorganic Materials. Ed. by M. Kamo}, journal = {Advanced materials '94 : proceedings of the NIRIM International Symposium on Advanced Materials '94, Tsukuba, Japan, March 13 - 17, 1994 / National Institute for Research in Inorganic Materials. Ed. by M. Kamo}, publisher = {International Communications Specialists, Inc.}, address = {Tokyo}, pages = {115 -- 120}, year = {1994}, language = {en} } @article{HagemannBachmannLadeetal.1994, author = {Hagemann, Hans-J{\"u}rgen and Bachmann, P.K. and Lade, H. and Leers, D.}, title = {CVD Diamond Growth: Gas Compositions and Film Properties / P.K. Bachmann, H.J. Hagemann, H. Lade, D. Leers, D.U. Wiechert and H. Wilson}, series = {Advanced materials '94 : proceedings of the NIRIM International Symposium on Advanced Materials '94, Tsukuba, Japan, March 13 - 17, 1994 / National Institute for Research in Inorganic Materials. Ed. by M. Kamo ...}, journal = {Advanced materials '94 : proceedings of the NIRIM International Symposium on Advanced Materials '94, Tsukuba, Japan, March 13 - 17, 1994 / National Institute for Research in Inorganic Materials. Ed. by M. Kamo ...}, publisher = {International Communications Specialists}, address = {Tokyo}, pages = {115 -- 120}, year = {1994}, language = {en} } @article{HagemannBachmannLadeetal.1994, author = {Hagemann, Hans-J{\"u}rgen and Bachmann, P.K. and Lade, H. and Leers, D.}, title = {Diamond chemical vapor deposition: gas compositions and film properties / Bachmann, P.K.; Hagemann, H.-J.; Lade, H; Leers, D.; Picht, F.; Wiechert, D.U.; Wilson, H.}, series = {Diamond, SiC and nitride wide bandgap semiconductors : symposium held April 4 - 8, 1994, San Francisco, California, U.S.A. / ed.: Calvin H. Carter, Jr. ...}, journal = {Diamond, SiC and nitride wide bandgap semiconductors : symposium held April 4 - 8, 1994, San Francisco, California, U.S.A. / ed.: Calvin H. Carter, Jr. ...}, address = {Pittsburgh, Penn.}, isbn = {1-55899-239-1}, pages = {267 -- 277}, year = {1994}, language = {en} } @article{HagemannBackhausGoessner2002, author = {Hagemann, Hans-J{\"u}rgen and Backhaus, U. and Goessner, S.}, title = {Collaborative eLearning Concepts for University Level Online Laboratory Courses in Engineering. U. Backhaus, S. Goessner, H. J. Hagemann}, series = {Proceedings Online Educa Berlin: 8th International Conference on Technology Supported Learning \& Training. 2002}, journal = {Proceedings Online Educa Berlin: 8th International Conference on Technology Supported Learning \& Training. 2002}, pages = {62 -- 66}, year = {2002}, language = {en} } @article{HagemannBreitschuhGraberetal.2004, author = {Hagemann, Hans-J{\"u}rgen and Breitschuh, S. and Graber, S. and Schmitz, G{\"u}nter}, title = {Internet Laboratory Courses with Remote Access and Control of Real Measurements on Sensors and Electronic Components}, series = {Mechatronics \& Robotics 2004 : Aachen, Germany, September 13 - 15, 2004 / [APS - European Centre for Mechatronics]. P. Drews (ed.)}, journal = {Mechatronics \& Robotics 2004 : Aachen, Germany, September 13 - 15, 2004 / [APS - European Centre for Mechatronics]. P. Drews (ed.)}, publisher = {Eysoldt}, address = {Aachen}, isbn = {3-938153-30-X}, pages = {1280 -- 1284}, year = {2004}, language = {en} } @article{HagemannCassidy1994, author = {Hagemann, Hans-J{\"u}rgen and Cassidy, Wiliam D.}, title = {Diamond growth rates and quality: dependence on gas phase cpmposition / William D. Cassidy [...], Hans-Jurgen Hagemann}, series = {Diamond, SiC and nitride wide bandgap semiconductors : symposium held April 4 - 8, 1994, San Francisco, California, U.S.A. / ed.: Calvin H. Carter, Jr. ....}, journal = {Diamond, SiC and nitride wide bandgap semiconductors : symposium held April 4 - 8, 1994, San Francisco, California, U.S.A. / ed.: Calvin H. Carter, Jr. ....}, address = {Pittsburgh, Penn. ,}, isbn = {1-55899-239-1}, pages = {285 -- 291}, year = {1994}, language = {en} } @article{HagemannGeittner1990, author = {Hagemann, Hans-J{\"u}rgen and Geittner, P.}, title = {PCVD hybrid technology for single mode fibres. Hagemann, H. J.; Geittner, P.}, series = {Proceedings : papers presented at: the 8th Annual European Fibre Optic Communications and Local Area Networks Exposition}, journal = {Proceedings : papers presented at: the 8th Annual European Fibre Optic Communications and Local Area Networks Exposition}, pages = {67 -- 72}, year = {1990}, language = {en} } @article{HagemannGeittnerLeers1989, author = {Hagemann, Hans-J{\"u}rgen and Geittner, P. and Leers, D.}, title = {Intrinsic scattering and absorption losses of Ge- and F-doped optical fibres prepared by PCVD. Geittner, P.; Hagemann, H. J. ; Leers, D.}, series = {Electronics letters : an intern. publication / The Institution of Electrical Engineers. 25 (1989), H. 7}, journal = {Electronics letters : an intern. publication / The Institution of Electrical Engineers. 25 (1989), H. 7}, isbn = {0013-5194}, pages = {436 -- 437}, year = {1989}, language = {en} } @article{HagemannGeittnerLydtinetal.1988, author = {Hagemann, Hans-J{\"u}rgen and Geittner, P. and Lydtin, H. and Warnier, J.}, title = {Hybrid technology for large SM-fiber preforms. Geittner, P.; Hagemann, H. J.; Lydtin, H.; Warnier, J.}, series = {Journal of Lightwave Technology (J-LT) / Institute of Electrical and Electronics Engineers (IEEE). 6 (1988), H. 10}, journal = {Journal of Lightwave Technology (J-LT) / Institute of Electrical and Electronics Engineers (IEEE). 6 (1988), H. 10}, isbn = {0733-8724}, pages = {1451 -- 1454}, year = {1988}, language = {en} } @article{HagemannGeittnerWarnieretal.1985, author = {Hagemann, Hans-J{\"u}rgen and Geittner, P. and Warnier, J. and Weling, F.}, title = {Reduction of geometric taper losses in the PCVD process. Geittner, P.; Hagemann, H. J.; Warnier, J.; Weling, F.; Wilson, H.}, series = {Electronics letters : an intern. publication / The Institution of Electrical Engineers. 21 (1985), H. 13}, journal = {Electronics letters : an intern. publication / The Institution of Electrical Engineers. 21 (1985), H. 13}, isbn = {0013-5194}, pages = {870 -- 871}, year = {1985}, language = {en} } @article{HagemannGeittnerWarnieretal.1986, author = {Hagemann, Hans-J{\"u}rgen and Geittner, P. and Warnier, J. and Wilson, H.}, title = {PCVD at high deposition rates. Geittner, P.; Hagemann, H. J.; Warnier, J.; Wilson, H.}, series = {Journal of Lightwave Technology (J-LT) / Institute of Electrical and Electronics Engineers (IEEE). 4 (1986), H. 7}, journal = {Journal of Lightwave Technology (J-LT) / Institute of Electrical and Electronics Engineers (IEEE). 4 (1986), H. 7}, isbn = {0733-8724}, pages = {818 -- 822}, year = {1986}, language = {en} } @article{HagemannGudatKunz1974, author = {Hagemann, Hans-J{\"u}rgen and Gudat, W. and Kunz, C.}, title = {Photoabsorption of alloys of Al with transition metals V, Fe, Ni and Cu and Pr near the Al L₂,₃-edge}, series = {Solid State Communications}, volume = {15}, journal = {Solid State Communications}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {0038-1098}, doi = {10.1016/0038-1098(74)91165-X}, pages = {655 -- 658}, year = {1974}, abstract = {The onset of Al 2p transitions of VAl₃, FeAl, NiAl, NiAl₃, CuAl₂, PrAl₂ and the disordered alloys V-Al (16 at \% Al, 28\%, 41\%), Fe-Al (11\%) is shifted up to 1.1 eV. New pronounced structure develops close to the onset which for NiAl agrees with a density of states calculation by Connolly and Johnson.}, language = {en} } @article{HagemannGudatKunz1975, author = {Hagemann, Hans-J{\"u}rgen and Gudat, W. and Kunz, C.}, title = {Optical constants from the far infrared to the X-ray region: Mg, Al, Cu, Ag, Au, Bi, C, and Al₂O₃}, series = {Journal of the Optical Society of America (JOSA)}, volume = {65}, journal = {Journal of the Optical Society of America (JOSA)}, number = {6}, publisher = {Optical Society of America}, address = {New York}, isbn = {0030-3941}, doi = {10.1364/JOSA.65.000742}, pages = {742 -- 744}, year = {1975}, language = {en} } @article{HagemannGudatKunz1976, author = {Hagemann, Hans-J{\"u}rgen and Gudat, W. and Kunz, C.}, title = {Photoabsorption coefficient of alloys of Al with transition metals V, Fe, Ni and Cu and Pr from 30 to 150 eV photon energy}, series = {Physica status solidi b}, volume = {74}, journal = {Physica status solidi b}, number = {2}, publisher = {Wiley-VCH}, address = {Berlin}, isbn = {0031-8957}, doi = {10.1002/pssb.2220740211}, pages = {507 -- 521}, year = {1976}, abstract = {The absorption coefficient of VAI3, FeAI, NiAI, NiAl2, CuAI2, PrAl2, and of disordered V-AI (16 at\% AI, 28\%, 41\%) and Fe-AI (11\%) alloys has been measured in the region of the M₂,₃ absorption of the transition metals and the Labsorption of AI. The strong changes of the AI spectrum in the region of the 100 eV maximum upon alloying are explained as another evidence of the EXAFS (extended X-ray absorption fine structure) nature of these structures. The broad, prominent absorption peaks from the 3p excitations in V and Fe and from the 4d excitations in Pr are influenced only little on allyoing and thus appear to be of atomic origin. The fine structure at the onset of the Pr 4d transitions is identical in the metal and the alloy but differs from that of Pr oxide. The only M₂,₃ edge which is detectably shifted is that of Ni (up to 2.1 eV), whereas the onset of the AI L₂,₃ edge is shifted in all the alloys (up to 1.1 eV). The shifts are interpreted in accordance with X-ray fluorescence and nuclear resonance measurements as changes of the density of states in the valence band of the alloys.}, language = {en} } @article{HagemannHennings1981, author = {Hagemann, Hans-J{\"u}rgen and Hennings, D.}, title = {Reversible Weight change of acceptor-doped BaTiO3. Hagemann, H. J.; Hennings, D.}, series = {Journal of the American Ceramic Society. 64 (1981)}, journal = {Journal of the American Ceramic Society. 64 (1981)}, isbn = {0002-7820}, pages = {590 -- 594}, year = {1981}, language = {en} } @article{HagemannHenningsWernicke1984, author = {Hagemann, Hans-J{\"u}rgen and Hennings, D. and Wernicke, R.}, title = {Ceramic multilayer capacitors. Hagemann, H. J.; Hennings, D.; Wernicke, R.}, series = {Philips' technical review / Philips' Gloeilampenfabrieken. Philips' Gloeilampenfabrieken . 41 (1984)}, journal = {Philips' technical review / Philips' Gloeilampenfabrieken. Philips' Gloeilampenfabrieken . 41 (1984)}, isbn = {0031-7926}, pages = {89 -- 98}, year = {1984}, language = {en} } @article{HagemannHeroGonser1980, author = {Hagemann, Hans-J{\"u}rgen and Hero, A. and Gonser, U.}, title = {The valence change of Fe in BaTiO3 studied by M{\"o}ßbauer effect and gravimetry. Hagemann, H. J.; Hero, A.; Gonser, U.}, series = {Physica Status Solidi (A) - Applied Research. 61 (1980)}, journal = {Physica Status Solidi (A) - Applied Research. 61 (1980)}, isbn = {0031-8965}, pages = {63 -- 72}, year = {1980}, language = {en} } @article{HagemannIhrig1979, author = {Hagemann, Hans-J{\"u}rgen and Ihrig, H.}, title = {Valence change and phase stability of 3d-doped BaTiO3 annealed in oxygen and hydrogen. Hagemann, H. J.; Ihrig, H.}, series = {Physical Review B.. 20 (1979), H. 9}, journal = {Physical Review B.. 20 (1979), H. 9}, isbn = {1095-3795}, pages = {3871 -- 3878}, year = {1979}, language = {en} } @article{HagemannLadeWarnieretal.1991, author = {Hagemann, Hans-J{\"u}rgen and Lade, H. and Warnier, J. and Wiechert, D. U.}, title = {The performance of Depressed-Cladding Single-Mode Fibres with Different b/a Ratios. Hagemann, H.-J.; Lade, H.; Warnier, J.; Wiechert, D. U.}, series = {Journal of Lightwave Technology (J-LT) / Institute of Electrical and Electronics Engineers (IEEE). 9 (1991), H. 6}, journal = {Journal of Lightwave Technology (J-LT) / Institute of Electrical and Electronics Engineers (IEEE). 9 (1991), H. 6}, isbn = {0733-8724}, pages = {689 -- 694}, year = {1991}, language = {en} } @article{HagemannOBryan1987, author = {Hagemann, Hans-J{\"u}rgen and O´Bryan, H. M.}, title = {Grain boundary and surface segragation of Ba-Ti-O-Phases in rutile. O´Bryan, H. M.; Hagemann, H. J.}, series = {Journal of the American Ceramic Society. 70 (1987)}, journal = {Journal of the American Ceramic Society. 70 (1987)}, isbn = {0002-7820}, pages = {274 -- 278}, year = {1987}, language = {en} } @article{HagemannStumpeWagneretal.1985, author = {Hagemann, Hans-J{\"u}rgen and Stumpe, R. and Wagner, D. and B{\"a}uerle, D.}, title = {The influence of contact effects on the dielectric behavior of diffuse phase transitions. Stumpe, R.; Wagner, D.; B{\"a}uerle, D.; Hagemann, H. J.}, series = {Ferroelectrics : the international journal devoted to the theoretical, experimental, and applied aspects of ferroelectrics and related materials / Letters section. 4 (1985)}, journal = {Ferroelectrics : the international journal devoted to the theoretical, experimental, and applied aspects of ferroelectrics and related materials / Letters section. 4 (1985)}, isbn = {0731-5171}, pages = {143 -- 147}, year = {1985}, language = {en} } @article{HagemannUngelenkWiechert1990, author = {Hagemann, Hans-J{\"u}rgen and Ungelenk, J. and Wiechert, D. U.}, title = {Optical time domain reflectometry (OTDR) of diameter modulations in single-mode fibers. Hagemann, H. J.; Ungelenk, J.; Wiechert, D. U.}, series = {Journal of Lightwave Technology (J-LT) / Institute of Electrical and Electronics Engineers (IEEE). 8 (1990), H. 11}, journal = {Journal of Lightwave Technology (J-LT) / Institute of Electrical and Electronics Engineers (IEEE). 8 (1990), H. 11}, isbn = {0733-8724}, pages = {1641 -- 1645}, year = {1990}, language = {en} } @article{HagemannWiechert1992, author = {Hagemann, Hans-J{\"u}rgen and Wiechert, D. U.}, title = {Measurements and calculations of the LP01 intensity of SM fibres far off the core. Hagemann, H.-J.; Wiechert, D. U.}, series = {Journal of Lightwave Technology (J-LT) / Institute of Electrical and Electronics Engineers (IEEE). 10 (1992), H. 4}, journal = {Journal of Lightwave Technology (J-LT) / Institute of Electrical and Electronics Engineers (IEEE). 10 (1992), H. 4}, isbn = {0733-8724}, pages = {407 -- 412}, year = {1992}, language = {en} } @article{HammHartung2011, author = {Hamm, Laurits and Hartung, Frank}, title = {High Quality Visual Communication based on IMS}, series = {Mobilkommunikation : Technologien und Anwendungen ; Vortr{\"a}ge der 16. ITG-Fachtagung vom 18. bis 19. Mai 2011 in Osnabr{\"u}ck / Veranst.: Informationstechnische Gesellschaft im VDE (ITG) ... Tagungsleitung: Ralf T{\"o}njes. Programmkomitee/Hrsg.: Peter Roer}, journal = {Mobilkommunikation : Technologien und Anwendungen ; Vortr{\"a}ge der 16. ITG-Fachtagung vom 18. bis 19. Mai 2011 in Osnabr{\"u}ck / Veranst.: Informationstechnische Gesellschaft im VDE (ITG) ... Tagungsleitung: Ralf T{\"o}njes. Programmkomitee/Hrsg.: Peter Roer}, publisher = {VDE-Verl.}, address = {Berlin}, isbn = {978-3-8007-3352-1}, pages = {80 -- 85}, year = {2011}, language = {en} } @article{HansenBitzStreckert1999, author = {Hansen, Volkert W. and Bitz, Andreas and Streckert, Joachim R.}, title = {RF Exposure of Biological Systems in Radial Waveguides}, series = {IEEE Transactions on Electromagnetic Compatibility}, volume = {41}, journal = {IEEE Transactions on Electromagnetic Compatibility}, number = {4}, issn = {1558-187X}, doi = {10.1109/15.809852}, pages = {487 -- 493}, year = {1999}, language = {en} } @article{Hartung2003, author = {Hartung, Frank}, title = {Mobile DRM Introduction: The Need for Mobile DRM}, series = {Digital Rights Management : Technological, Economic, Legal and Political Aspects / Becker, Eberhard [u.a.]}, journal = {Digital Rights Management : Technological, Economic, Legal and Political Aspects / Becker, Eberhard [u.a.]}, publisher = {Springer}, address = {Berlin}, pages = {138 -- 149}, year = {2003}, language = {en} } @article{HartungBaldoHornetal.2004, author = {Hartung, Frank and Baldo, N. and Horn, U. and Kampmann, M.}, title = {RTCP feedback based transmission rate control for 3G wireless multimedia streaming / Baldo, N. ; Horn, U. ; Kampmann, M. ; Hartung, F. ;}, series = {15th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, 2004. PIMRC 2004. Date:5-8 Sept. 2004 ; Vol. 3}, journal = {15th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, 2004. PIMRC 2004. Date:5-8 Sept. 2004 ; Vol. 3}, pages = {1817 -- 1821}, year = {2004}, language = {en} } @article{HartungDondetiCastleford2007, author = {Hartung, Frank and Dondeti, L. and Castleford, F.}, title = {Multimedia Internet KEYing (MIKEY) General Extension Payload for Open Mobile Alliance BCAST LTKM/STKM Transport / Dondeti, L. ; Castleford, D. ; Hartung, F.}, pages = {1 -- 7}, year = {2007}, language = {en} } @article{HartungGirod1997, author = {Hartung, Frank and Girod, Bernd}, title = {Copyright protection in video delivery networks by watermarking of pre-compressed video / Hartung, Frank ; Girod, Bernd}, series = {Multimedia Applications, Services and Techniques - EMAST ´97 : Second European Conference Milan, Italy, May 21-23, 1997 Proceedings / Fdida, Serge ; Morganti, Michele}, journal = {Multimedia Applications, Services and Techniques - EMAST ´97 : Second European Conference Milan, Italy, May 21-23, 1997 Proceedings / Fdida, Serge ; Morganti, Michele}, publisher = {Springer}, address = {Berlin}, pages = {423 -- 436}, year = {1997}, language = {en} } @article{HartungGirod1996, author = {Hartung, Frank and Girod, Bernd}, title = {Statistical optimization of switched two-level quantizers with application to DPCM encoding of color video / Hartung, Frank ; Girod, Bernd}, series = {IEEE International Conference on Acoustics, Speech, and Signal Processing, 1996. ICASSP-96. Conference Proceedings., 1996}, journal = {IEEE International Conference on Acoustics, Speech, and Signal Processing, 1996. ICASSP-96. Conference Proceedings., 1996}, isbn = {0-7803-3192-3}, pages = {1974 -- 1977}, year = {1996}, language = {en} } @article{HartungGirodHorn1995, author = {Hartung, Frank and Girod, Bernd and Horn, Uwe}, title = {Subband Image Coding / Girod, Bernd ; Hartung, Frank ; Horn, Uwe}, series = {Subband and Wavelet Transforms: Design and Applications / ed. by Ali N. Akansu}, journal = {Subband and Wavelet Transforms: Design and Applications / ed. by Ali N. Akansu}, publisher = {Kluwer}, address = {Boston}, isbn = {0792396456}, pages = {213 -- 250}, year = {1995}, language = {en} } @article{HartungHornHuschkeetal.2009, author = {Hartung, Frank and Horn, Uwe and Huschke, J{\"o}rg and Kampmann, Markus}, title = {MBMS—IP Multicast/Broadcast in 3G Networks / Hartung, Frank ; Horn, Uwe ; Huschke, J{\"o}rg ; Kampmann, Markus ; Lohmar, Thorsten}, series = {International Journal of Digital Multimedia Broadcasting. 2009 (2009)}, journal = {International Journal of Digital Multimedia Broadcasting. 2009 (2009)}, isbn = {1687-7586}, pages = {1 -- 25}, year = {2009}, language = {en} } @article{HartungHornHuschkeetal.2007, author = {Hartung, Frank and Horn, Uwe and Huschke, J{\"o}rg and Kampmann, Markus}, title = {Delivery of Broadcast Services in 3G Networks / Hartung, Frank ; Horn, Uwe ; J{\"o}rg Huschke ; Kampmann, Markus ; Lohmar, Thorsten ; Lundevall, Magnus}, series = {IEEE Transactions on Broastcasting. 53 (2007), H. 1 Part: 2}, journal = {IEEE Transactions on Broastcasting. 53 (2007), H. 1 Part: 2}, isbn = {0018-9316}, pages = {188 -- 199}, year = {2007}, language = {en} }