TY  - JOUR
A1  - Schlamann, Marc
A1  - Yoon, Min-Suk
A1  - Maderwald, Stefan
A1  - Pietrzyk, Thomas
A1  - Bitz, Andreas
A1  - Gerwig, Marcus
A1  - Forsting, Michael
A1  - Ladd, Susanne C.
A1  - Ladd, Mark E.
A1  - Kastrup, Oliver
T1  - Short term effects of magnetic resonance imaging on excitability of the motor cortex at 1.5T and 7T
JF  - Academic Radiology
N2  - Rationale and Objectives
The increasing spread of high-field and ultra-high-field magnetic resonance imaging (MRI) scanners has encouraged new discussion of the safety aspects of MRI. Few studies have been published on possible cognitive effects of MRI examinations. The aim of this study was to examine whether changes are measurable after MRI examinations at 1.5 and 7 T by means of transcranial magnetic stimulation (TMS).

Materials and Methods
TMS was performed in 12 healthy, right-handed male volunteers. First the individual motor threshold was specified, and then the cortical silent period (SP) was measured. Subsequently, the volunteers were exposed to the 1.5-T MRI scanner for 63 minutes using standard sequences. The MRI examination was immediately followed by another TMS session. Fifteen minutes later, TMS was repeated. Four weeks later, the complete setting was repeated using a 7-T scanner. Control conditions included lying in the 1.5-T scanner for 63 minutes without scanning and lying in a separate room for 63 minutes. TMS was performed in the same way in each case. For statistical analysis, Wilcoxon's rank test was performed.

Results
Immediately after MRI exposure, the SP was highly significantly prolonged in all 12 subjects at 1.5 and 7 T. The motor threshold was significantly increased. Fifteen minutes after the examination, the measured value tended toward normal again. Control conditions revealed no significant differences.

Conclusion
MRI examinations lead to a transient and highly significant alteration in cortical excitability. This effect does not seem to depend on the strength of the static magnetic field.
Y1  - 2010
U6  - https://doi.org/10.1016/j.acra.2009.10.004
SN  - 1076-6332
VL  - 17
IS  - 3
SP  - 277
EP  - 281
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Kraff, Oliver
A1  - Bitz, Andreas
A1  - Kruszona, Stefan
A1  - Orzada, Stephan
A1  - Schaefer, Lena C.
A1  - Theysohn, Jens M.
A1  - Maderwald, Stefan
A1  - Ladd, Mark E.
A1  - Quick, Harald H.
T1  - An eight-channel phased array RF coil for spine MR imaging at 7 T
JF  - Investigative Radiology
Y1  - 2009
U6  - https://doi.org/10.1097/RLI.0b013e3181b24ab7
SN  - 1536-0210
VL  - 44
IS  - 11
SP  - 734
EP  - 740
PB  - Lippincott Williams & Wilkins
ER  - 
TY  - JOUR
A1  - Klomp, D. W. J.
A1  - Bitz, Andreas
A1  - Heerschap, A.
A1  - Scheenen, T. W. J.
T1  - Proton spectroscopic imaging of the human prostate at 7 T
JF  - NMR in Biomedicine
Y1  - 2009
U6  - https://doi.org/10.1002/nbm.1360
SN  - 1099-1492
VL  - 22
IS  - 5
SP  - 495
EP  - 501
ER  - 
TY  - JOUR
A1  - Lerchl, Alexander
A1  - Krüger, Heike
A1  - Niehaus, Michael
A1  - Streckert, Joachim R.
A1  - Bitz, Andreas
A1  - Hansen, Volkert
T1  - Effects of mobile phone electromagnetic fields at nonthermal SAR values on melatonin and body weight of Djungarian hamsters (Phodopus sungorus)
JF  - Journal of Pineal Research
Y1  - 2008
U6  - https://doi.org/10.1111/j.1600-079X.2007.00522.x
SN  - 1600-079X
VL  - 44
IS  - 3
SP  - 267
EP  - 272
ER  - 
TY  - JOUR
A1  - Fiedler, Thomas M.
A1  - Ladd, Mark E.
A1  - Bitz, Andreas
T1  - SAR Simulations & Safety
JF  - NeuroImage
Y1  - 2017
U6  - https://doi.org/10.1016/j.neuroimage.2017.03.035
SN  - 1053-8119
IS  - Epub ahead of print
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Noureddine, Yacine
A1  - Kraff, Oliver
A1  - Ladd, Mark E.
A1  - Wrede, Karsten H.
A1  - Chen, Bixia
A1  - Quick, Harald H.
A1  - Schaefers, Gregor
A1  - Bitz, Andreas
T1  - In vitro and in silico assessment of RF-induced heating around intracranial aneurysm clips at 7 Tesla
JF  - Magnetic Resonance in Medicine
Y1  - 2017
U6  - https://doi.org/10.1002/mrm.26650
SN  - 1522-2594
IS  - Early view
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Fiedler, Thomas M.
A1  - Ladd, Mark E.
A1  - Bitz, Andreas
T1  - RF safety assessment of a bilateral four-channel transmit/receive 7 Tesla breast coil: SAR versus temperature limits
JF  - Medical Physics
Y1  - 2017
U6  - https://doi.org/10.1002/mp.12034
N1  - This article is corrected by:
Errata: Erratum: “RF safety assessment of a bilateral four-channel transmit/receive 7 Tesla breast coil: SAR versus tissue temperature limits” [Med. Phys. 44(1), 143–157 (2017)] Volume 44, Issue 2, 772
VL  - 44
IS  - 1
SP  - 143
EP  - 157
ER  - 
TY  - JOUR
A1  - Lagemaat, Miriam W.
A1  - Vos, Eline K.
A1  - Maas, Marnix C.
A1  - Bitz, Andreas
A1  - Orzada, Stephan
A1  - Uden, Mark J. van
A1  - Kobus, Thiele
A1  - Heerschap, Arend
A1  - Scheenen, Tom W. J.
T1  - Phosphorus magnetic resonance spectroscopic imaging at 7 T in patients with prostate cancer
JF  - Investigative Radiology
N2  - Objectives 
The aim of this study was to identify characteristics of phosphorus (³¹P) spectra of the human prostate and to investigate changes of individual phospholipid metabolites in prostate cancer through in vivo ³¹P magnetic resonance spectroscopic imaging (MRSI) at 7 T.

Materials and Methods 
In this institutional review board–approved study, 15 patients with biopsy-proven prostate cancer underwent T₂-weighted magnetic resonance imaging and 3-dimensional ³¹P MRSI at 7 T. Voxels were selected at the tumor location, in normal-appearing peripheral zone tissue, normal-appearing transition zone tissue, and in the base of the prostate close to the seminal vesicles. Phosphorus metabolite ratios were determined and compared between tissue types.

Results 
Signals of phosphoethanolamine (PE) and phosphocholine (PC) were present and well resolved in most ³¹P spectra in the prostate. Glycerophosphocholine signals were observable in 43% of the voxels in malignant tissue, but in only 10% of the voxels in normal-appearing tissue away from the seminal vesicles. In many spectra, independent of tissue type, 2 peaks resonated in the chemical shift range of inorganic phosphate, possibly representing 2 separate pH compartments. The PC/PE ratio in the seminal vesicles was highly elevated compared with the prostate in 5 patients. A considerable overlap of ³¹P metabolite ratios was found between prostate cancer and normal-appearing prostate tissue, preventing direct discrimination of these tissues. The only 2 patients with high Gleason scores tumors (≥4+5) presented with high PC and glycerophosphocholine levels in their cancer lesions.

Conclusions 
Phosphorus MRSI at 7 T shows distinct features of phospholipid metabolites in the prostate gland and its surrounding structures. In this exploratory study, no differences in ³¹P metabolite ratios were observed between prostate cancer and normal-appearing prostate tissue possibly because of the partial volume effects of small tumor foci in large MRSI voxels.
Y1  - 2014
U6  - https://doi.org/10.1097/RLI.0000000000000012
SN  - 1536-0210
VL  - 49
IS  - 5
SP  - 363
EP  - 372
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia, Pa.
ER  - 
TY  - JOUR
A1  - Maas, Marnix C.
A1  - Vos, Eline K.
A1  - Lagemaat, Miriam W.
A1  - Bitz, Andreas
A1  - Orzada, Stephan
A1  - Kobus, Thiele
A1  - Kraff, Oliver
A1  - Maderwald, Stefan
A1  - Ladd, Mark E.
A1  - Scheenen, Tom W. J.
T1  - Feasibility of T₂-weighted turbo spin echo imaging of the human prostate at 7 tesla
JF  - Magnetic Resonance in Medicine
N2  - Purpose
To demonstrate that high quality T₂-weighted (T2w) turbo spin-echo (TSE) imaging of the complete prostate can be achieved routinely and within safety limits at 7 T, using an external transceive body array coil only.

Methods
Nine healthy volunteers and 12 prostate cancer patients were scanned on a 7 T whole-body system. Preparation consisted of B₀ and radiofrequency shimming and localized flip angle calibration. T₁ and T₂ relaxation times were measured and used to define the T2w-TSE protocol. T2w imaging was performed using a TSE sequence (pulse repetition time/echo time 3000–3640/71 ms) with prolonged excitation and refocusing pulses to reduce specific absorption rate.

Results
High quality T2w TSE imaging was performed in less than 2 min in all subjects. Tumors of patients with gold-standard tumor localization (MR-guided biopsy or prostatectomy) were well visualized on 7 T imaging (n = 3). The number of consecutive slices achievable within a 10-g averaged specific absorption rate limit of 10 W/kg was ≥28 in all subjects, sufficient for full prostate coverage with 3-mm slices in at least one direction.

Conclusion
High quality T2w TSE prostate imaging can be performed routinely and within specific absorption rate limits at 7 T with an external transceive body array.
Y1  - 2014
U6  - https://doi.org/10.1002/mrm.24818
SN  - 1522-2594
VL  - 71
IS  - 5
SP  - 1711
EP  - 1719
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Umutlu, Lale
A1  - Kraff, Oliver
A1  - Fischer, Anja
A1  - Kinner, Sonja
A1  - Maderwald, Stefan
A1  - Nassenstein, Kai
A1  - Nensa, Felix
A1  - Grüneisen, Johannes
A1  - Orzada, Stephan
A1  - Bitz, Andreas
A1  - Forsting, Michael
A1  - Ladd, Mark E.
A1  - Lauenstein, Thomas C.
T1  - Seven-Tesla MRI of the female pelvis
JF  - European Radiology
Y1  - 2013
U6  - https://doi.org/10.1007/s00330-013-2868-0
SN  - 1432-1084
VL  - 23
IS  - 9
SP  - 2364
EP  - 2373
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Bitz, Andreas
A1  - Felder, Jorg
A1  - Wittig, Tilmann
T1  - Designing MRI Coils with Aid of Simulation
JF  - Microwaves & RF
Y1  - 2013
SN  - 0745-2993
VL  - 52
IS  - 7
SP  - 56
PB  - Penton
CY  - Cleveland, Ohio
ER  - 
TY  - JOUR
A1  - Kraff, Oliver
A1  - Wrede, Karsten H.
A1  - Schoemberg, Tobias
A1  - Dammann, Philipp
A1  - Noureddine, Yacine
A1  - Orzada, Stephan
A1  - Ladd, Mark E.
A1  - Bitz, Andreas
T1  - MR safety assessment of potential RF heating from cranial fixation plates at 7 T
JF  - Medical Physics
Y1  - 2013
U6  - https://doi.org/10.1118/1.4795347
SN  - 2473-4209
VL  - 40
IS  - 4
SP  - 042302-1
EP  - 042302-10
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Umutlu, L.
A1  - Maderwald, S.
A1  - Kinner, S.
A1  - Kraff, O.
A1  - Bitz, Andreas
A1  - Orzada, S.
A1  - Johst, S.
A1  - Wrede, K.
A1  - Forsting, M.
A1  - Ladd, M. E.
A1  - Lauenstein, T. C.
A1  - Quick, H. H.
T1  - First-pass contrast-enhanced renal MRA at 7 Tesla: initial results
JF  - European Radiology
Y1  - 2013
U6  - https://doi.org/10.1007/s00330-012-2666-0
SN  - 1432-1084
VL  - 23
IS  - 4
SP  - 1059
EP  - 1066
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Umutlu, Lale
A1  - Orzada, Stephan
A1  - Kinner, Sonja
A1  - Maderwald, Stefan
A1  - Bronte, Irina
A1  - Bitz, Andreas
A1  - Kraff, Oliver
A1  - Ladd, Susanne C.
A1  - Antoch, Gerald
A1  - Ladd, Mark E.
A1  - Quick, Harald H.
A1  - Lauenstein, Thomas C.
T1  - Renal imaging at 7 Tesla: preliminary results
JF  - European Radiology
N2  - Objective
To investigate the feasibility of 7T MR imaging of the kidneys utilising a custom-built 8-channel transmit/receive radiofrequency body coil.

Methods
In vivo unenhanced MR was performed in 8 healthy volunteers on a 7T whole-body MR system. After B0 shimming the following sequences were obtained: 1) 2D and 3D spoiled gradient-echo sequences (FLASH, VIBE), 2) T1-weighted 2D in and opposed phase 3) True-FISP imaging and 4) a T2-weighted turbo spin echo (TSE) sequence. Visual evaluation of the overall image quality was performed by two radiologists.

Results
Renal MRI at 7T was feasible in all eight subjects. Best image quality was found using T1-weighted gradient echo MRI, providing high anatomical details and excellent conspicuity of the non-enhanced vasculature. With successful shimming, B1 signal voids could be effectively reduced and/or shifted out of the region of interest in most sequence types. However, T2-weighted TSE imaging remained challenging and strongly impaired because of signal heterogeneities in three volunteers.

Conclusion
The results demonstrate the feasibility and diagnostic potential of dedicated 7T renal imaging. Further optimisation of imaging sequences and dedicated RF coil concepts are expected to improve the acquisition quality and ultimately provide high clinical diagnostic value.
Y1  - 2011
SN  - 1432-1084
VL  - 21
IS  - 4
SP  - 841
EP  - 849
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Fiedler, Thomas M.
A1  - Orzada, Stephan
A1  - Flöser, Martina
A1  - Rietsch, Stefan H. G.
A1  - Schmidt, Simon
A1  - Stelter, Jonathan K.
A1  - Wittrich, Marco
A1  - Quick, Harald H.
A1  - Bitz, Andreas
A1  - Ladd, Mark E.
T1  - 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
JF  - NMR in Biomedicine
N2  - 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.
KW  - body imaging at 7 T MRI
KW  - thermal dose
KW  - tissue temperature
KW  - transmit antenna arrays
Y1  - 2022
U6  - https://doi.org/10.1002/nbm.4656
SN  - 0952-3480 (Print)
SN  - 1099-1492 (Online)
VL  - 35
IS  - 5
SP  - 1
EP  - 17
PB  - Wiley
ER  - 
TY  - JOUR
A1  - Coll-Perales, Baldomero
A1  - Schulte-Tigges, Joschua
A1  - Rondinone, Michele
A1  - Gozalvez, Javier
A1  - Reke, Michael
A1  - Matheis, Dominik
A1  - Walter, Thomas
T1  - Prototyping and evaluation of infrastructure-assisted transition of control for cooperative automated vehicles
JF  - IEEE Transactions on Intelligent Transportation Systems
N2  - Automated driving is now possible in diverse road and traffic conditions. However, there are still situations that automated vehicles cannot handle safely and efficiently. In this case, a Transition of Control (ToC) is necessary so that the driver takes control of the driving. Executing a ToC requires the driver to get full situation awareness of the driving environment. If the driver fails to get back the control in a limited time, a Minimum Risk Maneuver (MRM) is executed to bring the vehicle into a safe state (e.g., decelerating to full stop). The execution of ToCs requires some time and can cause traffic disruption and safety risks that increase if several vehicles execute ToCs/MRMs at similar times and in the same area. This study proposes to use novel C-ITS traffic management measures where the infrastructure exploits V2X communications to assist Connected and Automated Vehicles (CAVs) in the execution of ToCs. The infrastructure can suggest a spatial distribution of ToCs, and inform vehicles of the locations where they could execute a safe stop in case of MRM. This paper reports the first field operational tests that validate the feasibility and quantify the benefits of the proposed infrastructure-assisted ToC and MRM management. The paper also presents the CAV and roadside infrastructure prototypes implemented and used in the trials. The conducted field trials demonstrate that infrastructure-assisted traffic management solutions can reduce safety risks and traffic disruptions.
KW  - Automated driving
KW  - automated vehicles
KW  - connected automated vehicles
KW  - CAV
KW  - experimental evaluation
Y1  - 2021
U6  - https://doi.org/10.1109/TITS.2021.3061085
SN  - 1524-9050 (Print)
SN  - 1558-0016 (Online)
VL  - 23
IS  - 7
SP  - 6720
EP  - 6736
PB  - IEEE
ER  - 
TY  - JOUR
A1  - Fiedler, Thomas M.
A1  - Orzada, Stephan
A1  - Flöser, Martina
A1  - Rietsch, Stefan H. G.
A1  - Quick, Harald H.
A1  - Ladd, Mark E.
A1  - Bitz, Andreas
T1  - Performance analysis of integrated RF microstrip transmit antenna arrays with high channel count for body imaging at 7 T
JF  - NMR in Biomedicine
N2  - 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.
KW  - body imaging at UHF MRI
KW  - integrated transmit coil arrays
KW  - VOP compression
Y1  - 2021
U6  - https://doi.org/10.1002/nbm.4515
SN  - 0952-3480 (ISSN)
SN  - 1099-1492 (eISSN)
VL  - 34
IS  - 7
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Kowalewski, Paul
A1  - Bragard, Michael
A1  - Hüning, Felix
A1  - De Doncker, Rik W.
T1  - An inexpensive Wiegand-sensor-based rotary encoder without rotating magnets for use in electrical drives
JF  - IEEE Transactions on Instrumentation and Measurement
N2  - This paper introduces an inexpensive Wiegand-sensor-based rotary encoder that avoids rotating magnets and is suitable for electrical-drive applications. So far, Wiegand-sensor-based encoders usually include a magnetic pole wheel with rotating permanent magnets. These encoders combine the disadvantages of an increased magnet demand and a limited maximal speed due to the centripetal force acting on the rotating magnets. The proposed approach reduces the total demand of permanent magnets drastically. Moreover, the rotating part is manufacturable from a single piece of steel, which makes it very robust and cheap. This work presents the theoretical operating principle of the proposed approach and validates its benefits on a hardware prototype. The presented proof-of-concept prototype achieves a mechanical resolution of 4.5 ° by using only 4 permanent magnets, 2Wiegand sensors and a rotating steel gear wheel with 20 teeth.
KW  - Rotary encoder
KW  - Wiegand sensor
Y1  - 2023
U6  - https://doi.org/10.1109/TIM.2023.3326166
SN  - 0018-9456 (Print)
SN  - 1557-9662 (Online)
VL  - 72
SP  - 10 Seiten
PB  - IEEE
CY  - New York
ER  - 
TY  - JOUR
A1  - Elsen, Ingo
A1  - Kraiss, Karl-Friedrich
T1  - System concept and realization of a scalable neurocomputing architecture
JF  - Systems Analysis Modelling Simulation
N2  - This paper describes the realization of a novel neurocomputer which is based on the concepts of a coprocessor. In contrast to existing neurocomputers the main interest was the realization of a scalable, flexible system, which is capable of computing neural networks of arbitrary topology and scale, with full independence of special hardware from the software's point of view. On the other hand, computational power should be added, whenever needed and flexibly adapted to the requirements of the application. Hardware independence is achieved by a run time system which is capable of using all available computing power, including multiple host CPUs and an arbitrary number of neural coprocessors autonomously. The realization of arbitrary neural topologies is provided through the implementation of the elementary operations which can be found in most neural topologies.
Y1  - 1999
SN  - 0232-9298
SN  - 1029-4902
VL  - 35
IS  - 4
SP  - 399
EP  - 419
PB  - Gordon and Breach Science Publishers
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Elsen, Ingo
A1  - Kraiss, Karl-Friedrich
A1  - Krumbiegel, Dirk
A1  - Walter, Peter
A1  - Wickel, Jochen
T1  - Visual information retrieval for 3D product identification: a midterm report
JF  - KI - Künstliche Intelligenz
Y1  - 1999
SN  - 1610-1987
SN  - 0933-1875
VL  - 13
IS  - 1
SP  - 64
EP  - 67
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Elsen, Ingo
A1  - Hartung, Frank
A1  - Horn, Uwe
A1  - Kampmann, Markus
A1  - Peters, Liliane
ED  - Voas, Jeffrey
T1  - Streaming technology in 3G mobile communication systems
JF  - Computer : innovative technology for computer professionals
N2  - Third-generation mobile communication systems will combine standardized streaming with a range of unique services to provide high-quality Internet content that meets the specific needs of the rapidly growing mobile market.
Y1  - 2001
SN  - 0018-9162
SN  - 1558-0814
VL  - 34
IS  - 9 Seiten
SP  - 46
EP  - 52
PB  - IEEE
CY  - New York
ER  - 
TY  - JOUR
A1  - Wolf, Martin R.
T1  - Groupware related task design
JF  - ACM SIGGROUP Bulletin. 21 (2000), H. 2
Y1  - 2000
SP  - 5
EP  - 8
PB  - -
ER  - 
TY  - JOUR
A1  - Ferrein, Alexander
T1  - golog.lua: Towards a Non-Prolog Implementation of Golog for Embedded Systems
Y1  - 2010
SP  - 20
EP  - 28
ER  - 
TY  - JOUR
A1  - Ferrein, Alexander
T1  - golog.lua: Towards a Non-Prolog Implementation of Golog for Embedded Systems
JF  - Cognitive Robotics / Lakemeyer, Gerhard (ed.)
Y1  - 2010
N1  - Dagstuhl Seminar Proceedings ; 10081
SP  - 1
EP  - 15
ER  - 
TY  - JOUR
A1  - Schiffer, Stefan
A1  - Ferrein, Alexander
T1  - Decision-Theoretic Planning with Fuzzy Notions in GOLOG
JF  - International Journal of Uncertainty, Fuzziness and Knowledge-Based Systems
N2  - In this paper we present an extension of the action language Golog that allows for using fuzzy notions in non-deterministic argument choices and the reward function in decision-theoretic planning. Often, in decision-theoretic planning, it is cumbersome to specify the set of values to pick from in the non-deterministic-choice-of-argument statement. Also, even for domain experts, it is not always easy to specify a reward function. Instead of providing a finite domain for values in the non-deterministic-choice-of-argument statement in Golog, we now allow for stating the argument domain by simply providing a formula over linguistic terms and fuzzy uents. In Golog’s forward-search DT planning algorithm, these formulas are evaluated in order to find the agent’s optimal policy. We illustrate this in the Diner Domain where the agent needs to calculate the optimal serving order.
Y1  - 2016
U6  - https://doi.org/10.1142/S0218488516400134
SN  - 1793-6411
VL  - 24
IS  - Issue Suppl. 2
SP  - 123
EP  - 143
PB  - World Scientific
CY  - Singapur
ER  - 
TY  - JOUR
A1  - Ferrein, Alexander
A1  - Steinbauer, Gerald
T1  - The Interplay of Aldebaran and RoboCup
JF  - KI - Künstliche Intelligenz
Y1  - 2016
U6  - https://doi.org/10.1007/s13218-016-0440-1
SN  - 1610-1987
VL  - 30
IS  - 3-4
SP  - 325
EP  - 326
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Köhler, Klemens
A1  - Röpke, René
A1  - Wolf, Martin R.
T1  - Through a mirror darkly – On the obscurity of teaching goals in game-based learning in IT security
JF  - ISAGA 2019: Simulation Gaming Through Times and Disciplines
N2  - Teachers and instructors use very specific language communicating teaching goals. The most widely used frameworks of common reference are the Bloom’s Taxonomy and the Revised Bloom’s Taxonomy. The latter provides distinction of 209 different teaching goals which are connected to methods. In Competence Developing Games (CDGs - serious games to convey knowledge) and in IT security education, a two- or three level typology exists, reducing possible learning outcomes to awareness, training, and education. This study explores whether this much simpler framework succeeds in achieving the same range of learning outcomes. Method wise a keyword analysis was conducted. The results were threefold: 1. The words used to describe teaching goals in CDGs on IT security education do not reflect the whole range of learning outcomes. 2. The word choice is nevertheless different from common language, indicating an intentional use of language. 3. IT security CDGs use different sets of terms to describe learning outcomes, depending on whether they are awareness, training, or education games. The interpretation of the findings is that the reduction to just three types of CDGs reduces the capacity to communicate and think about learning outcomes and consequently reduces the outcomes that are intentionally achieved.
KW  - IT security education
KW  - Competence Developing Games
KW  - Game-based learning
KW  - Keyword analysis
KW  - Bloom’s Taxonomy
Y1  - 2021
U6  - https://doi.org/10.1007/978-3-030-72132-9_6
N1  - ISAGA 2019 - International Simulation and Gaming Association Conference. 26-30 August 2019. Warsaw, Poland.

Part of the Lecture Notes in Computer Science book series (LNCS, volume 11988)
SP  - 61
EP  - 73
PB  - Springer
CY  - Cham
ER  - 
TY  - JOUR
A1  - Wolf, Martin R.
A1  - Luczak, Holger
T1  - Computer Supported Communication and Cooperation – Making Information Aware / Luczak, H. ; Wolf, M.
JF  - Human-computer interaction : proceedings of HCI International '99 (the 8th International Conference on Human-Computer Interaction), Munich, Germany, August 22 - 26, 1999
Y1  - 1999
N1  - HCI - International Conference on Human-Computer Interaction ; 8 (Munich, Germany) : 1999.08.22-26 ; in 2 Bänden
SP  - 298
EP  - 302
PB  - Erlbaum
CY  - Mahwah, NJ
ER  - 
TY  - JOUR
A1  - Ferrein, Alexander
A1  - Dylla, Frank
A1  - Lakemeyer, Gerhard
A1  - Murray, Jan
T1  - Approaching a formal soccer theory from behaviour specifications in robotic soccer / Dylla, Frank ; Ferrein, Alexander ; Lakemeyer, Gerhard ; Murray, Jan ; Obst, Oliver ; Röfer, Thomas ; Schiffer, Stefan ; Stolzenburg, Frieder ; Visser, Ubbo ; Wagner, Tho
JF  - Computers in sport / editors: P Dabnichki
Y1  - 2008
SN  - 978-1-8456-4064-4
SP  - 161
EP  - 185
PB  - WIT Press
CY  - Southampton
ER  - 
TY  - JOUR
A1  - Booysen, Tracy
A1  - Rieger, Michael
A1  - Ferrein, Alexander
T1  - Towards inexpensive robots for science & technology teaching and education in Africa
Y1  - 2011
SN  - 978-1-61284-992-8
N1  - AFRICON, 2011
SP  - 1
EP  - 6
PB  - IEEE
CY  - New York
ER  - 
TY  - JOUR
A1  - Gspandl, Stephan
A1  - Pill, Ingo
A1  - Reip, Michael
A1  - Steinbauer, Gerald
A1  - Ferrein, Alexander
T1  - Belief Management for High-Level Robot Programs
JF  - 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
Y1  - 2011
N1  - International Joint Conference on Artificial Intelligence ; (22 : ; 2011.07.16-22 : ; Barcelona, Spain) ; IJCAI ; (22 : ; 2011.07.16-22 : ; Barcelona, Spain)
SP  - 900
EP  - 905
ER  - 
TY  - JOUR
A1  - Ferrein, Alexander
T1  - Towards applying soccer moves in the RoboCup Standard Platform League
JF  - ÖGAI-Journal
Y1  - 2008
SN  - 0254-4326
VL  - Bd. 27
IS  - H. 3
SP  - 4
EP  - 9
ER  - 
TY  - JOUR
A1  - Heuermann, Holger
A1  - Erkens, H.
T1  - Mixed-Mode Chain Scattering Parameters: Theory and Verification
JF  - IEEE Transactions on Microwave Theory and Techniques
N2  - Chain scattering parameters or T-parameters are a useful tool for calculating cascaded two-ports. With the increasing importance of mixed-mode S-parameters, a need for converting the T-parameters from their unbalanced form into a balanced form emerges for suiting both common and differential mode waves, as well as the mode conversion. This paper presents the derivation of the equations for transformations between mixed-mode S- and T-parameters for a mixed-mode two-port. Although derived in a way very similar to monomode T-parameters, no simplifications were necessary. Measurement results exemplify the quality of the T-parameter transformation under real-life conditions.
Y1  - 2007
SN  - 0018-9480
U6  - https://doi.org/10.1109/TMTT.2007.902587
VL  - 55
IS  - 8
SP  - 1704
EP  - 1708
PB  - IEEE
CY  - New York
ER  - 
TY  - JOUR
A1  - Rens, Gavin
A1  - Ferrein, Alexander
T1  - Belief-node condensation for online POMDP algorithms
N2  - Slightly extended version of the paper accepted at the Robotics and Artificial Intelligence Workshop, a special track of IEEE AFRICON-2013, held in Mauritius, 9-12 September 2013
Y1  - 2013
SP  - 1
EP  - 7
PB  - IEEE
CY  - New York
ER  - 
TY  - JOUR
A1  - Heuermann, Holger
A1  - Sadeghfam, Arash
T1  - Electrically tunable bandpass filter with integrated carrier suppression for UHF RFID systems / Sadeghfam, Arash ; Heuermann, Holger
JF  - European Microwave Conference, 2008, EuMC 2008, 38th
Y1  - 2008
SN  - 978-2-87487-006-4
SP  - 1727
EP  - 1730
ER  - 
TY  - JOUR
A1  - Ritz, Thomas
T1  - Modelling mass customization of digital news services
JF  - International journal of e-business strategy management
Y1  - 2002
VL  - 3
IS  - 3
ER  - 
TY  - JOUR
A1  - Turdumamatov, Samat
A1  - Belda, Aljoscha
A1  - Heuermann, Holger
T1  - Shaping a decoupled atmospheric pressure microwave plasma with antenna structures, Maxwell’s equations, and boundary conditions
JF  - IEEE Transactions on Plasma Science
N2  - This article addresses the need for an innovative technique in plasma shaping, utilizing antenna structures, Maxwell’s laws, and boundary conditions within a shielded environment. The motivation lies in exploring a novel approach to efficiently generate high-energy density plasma with potential applications across various fields. Implemented in an E01 circular cavity resonator, the proposed method involves the use of an impedance and field matching device with a coaxial connector and a specially optimized monopole antenna. This setup feeds a low-loss cavity resonator, resulting in a high-energy density air plasma with a surface temperature exceeding 3500 o C, achieved with a minimal power input of 80 W. The argon plasma, resembling the shape of a simple monopole antenna with modeled complex dielectric values, offers a more energy-efficient alternative compared to traditional, power-intensive plasma shaping methods. Simulations using a commercial electromagnetic (EM) solver validate the design’s effectiveness, while experimental validation underscores the method’s feasibility and practical implementation. Analyzing various parameters in an argon atmosphere, including hot S -parameters and plasma beam images, the results demonstrate the successful application of this technique, suggesting its potential in coating, furnace technology, fusion, and spectroscopy applications.
KW  - 3-D printing
KW  - Furnace
KW  - Fusion
KW  - Hot S-parameter
KW  - Mode converter
Y1  - 2024
U6  - https://doi.org/10.1109/TPS.2024.3383589
SN  - 0093-3813 (Print)
SN  - 1939-9375 (Online)
IS  - Early Access
SP  - 1
EP  - 9
PB  - IEEE
ER  - 
TY  - JOUR
A1  - Heuermann, Holger
T1  - A 14 W SPST Switch with Four PIN-Diodes In a 0402-SMD-Package
Y1  - 2008
SN  - 978-3-8007-3086-5
N1  - Microwave Conference (GeMIC), 2008 German
SP  - 318
EP  - 321
ER  - 
TY  - JOUR
A1  - Niemüller, Tim
A1  - Ferrein, Alexander
A1  - Lakemeyer, Gerhard
T1  - A Lua-based Behavior Engine for Controlling the Humanoid Robot Nao
JF  - RoboCup 2009: Robot Soccer World Cup XIII
Y1  - 2010
N1  - Lecture Notes in Computer Science ; 5949
SP  - 240
EP  - 251
ER  - 
TY  - JOUR
A1  - Heuermann, Holger
A1  - Schiek, Burkhard
T1  - The In-Fixture Calibration Procedure Line-Network-Network-LNN
JF  - Conference proceedings : monday 6th to thursday 9th september 1993, Palacio de Congresos, Madrid, Spain ; [the international conference and exhibition designed for the Microwave Community]
Y1  - 1992
SN  - 0-946821-23-2
N1  - European Microwave Conference <23, 1993, Madrid>
SP  - 500
EP  - 505
PB  - Reed Exhibition Companies
CY  - Tunbridge Wells
ER  - 
TY  - JOUR
A1  - Heuermann, Holger
A1  - Schiek, B.
T1  - Robust Algorithms for Txx Network Analyzer Self-Calibration Procedures
JF  - IEEE transactions on instrumentation and measurement : IM / Institute of Electrical and Electronics Engineers, Instrumentation and Measurement Group. 43 (1994), H. 1
Y1  - 1994
SN  - 0018-9456
SP  - 18
EP  - 23
ER  - 
TY  - JOUR
A1  - Ferrein, Alexander
A1  - Siebel, Nils T.
A1  - Steinbauer, Gerald
T1  - Hybrid control for autonomous systems — Integrating learning, deliberation and reactive control
JF  - Robotics and Autonomous Systems
Y1  - 2010
SN  - 0921-8890
VL  - 58
IS  - 9
SP  - 1037
EP  - 1038
ER  - 
TY  - JOUR
A1  - Heuermann, Holger
A1  - Ibrahim, Irfan
T1  - Improvements in the flicker noise reduction technique for osillator designs / Ibrahim, Irfan ; Heuermann, Holger
JF  - European Microwave Conference, 2009 : EuMC 2009 ; Sept. 29, 2009 - Oct. 1, 2009, Rome, Italy ; part of European Microwave Week (EuMW) / sponsored by EuMA, European Microwave Association ... Endorsed by IEEE
Y1  - 2009
SN  - 978-1-4244-4748-0
N1  - EuMC 2009
SP  - 1215
EP  - 1218
PB  - IEEE
CY  - Piscataway, NJ
ER  - 
TY  - JOUR
A1  - Heuermann, Holger
T1  - A Synthesis Technique for Mono- and Mixed-Mode Symmetrical Filter
JF  - 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
Y1  - 2004
SN  - 1-580-53992-0
N1  - European Microwave Conference ; (34, 2004, Amsterdam) ; European Microwave Week ; (7, 2004, Amsterdam)
SP  - 309
EP  - 312
PB  - Horizon House Publ
CY  - London
ER  - 
TY  - JOUR
A1  - Schiffer, Stefan
A1  - Ferrein, Alexander
A1  - Lakemeyer, Gerhard
T1  - Reasoning with Qualitative Positional Information for Domestic Domains in the Situation Calculus
JF  - Journal of Intelligent & Robotic Systems
Y1  - 2011
SN  - 0921-0296
VL  - 63
IS  - 2
SP  - 273
EP  - 300
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Harzheim, Thomas
A1  - Mühmel, Marc
A1  - Heuermann, Holger
T1  - A SFCW harmonic radar system for maritime search and rescue using passive and active tags
JF  - International Journal of Microwave and Wireless Technologies
N2  - This paper 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 while attached to life jackets and a small boat. In this demonstration test carried out on the Baltic Sea, the system was able to detect and range the active tags up to a distance of 5800 m using an illumination signal transmit-power of 100 W. Special attention is given to the development, performance, and conceptual differences between passive and active tags used in the system. Guidelines for achieving a high HR dynamic range, including a system components description, are given and a comparison with other HR systems is performed. System integration with a commercial maritime X-band navigation radar is shown to demonstrate a solution for rapid search and rescue response and quick localization.
KW  - Radar
KW  - microwave measurements
KW  - harmonic radar
KW  - harmonic radar tags
KW  - nonlinear VNA measurements
Y1  - 2021
U6  - https://doi.org/10.1017/S1759078721000520
VL  - 13
IS  - Special Issue 7
SP  - 691
EP  - 707
PB  - Cambridge University Press
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Schiffer, Stefan
A1  - Ferrein, Alexander
A1  - Lakemeyer, Gerhard
T1  - Caesar: an intelligent domestic service robot
JF  - Intelligent service robotics
N2  - 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
Y1  - 2012
U6  - https://doi.org/10.1007/s11370-012-0118-y
SN  - 1861-2776
N1  - Special Issue on Artificial Intelligence Techniques for Robotics: Sensing, Representation and Action, Part I
VL  - 5
IS  - 4
SP  - 259
EP  - 276
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Ferrein, Alexander
A1  - Schiffer, Stefan
A1  - Lakemeyer, Gerhard
T1  - Embedding fuzzy controllers in golog  / Ferrein, Alexander ; Schiffer, Stefan ; Lakemeyer, Gerhard
JF  - IEEE International Conference on Fuzzy Systems, 2009. FUZZ-IEEE 2009
Y1  - 2009
SN  - 978-1-4244-3596-8
SP  - 894
EP  - 899
PB  - IEEE
CY  - New York
ER  - 
TY  - JOUR
A1  - Heuermann, Holger
A1  - Rumiantsev, A.
A1  - Schott, S.
T1  - Advanced on-wafer multiport calibration methods for mono- and mixed-mode device characterization
JF  - 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]
Y1  - 2004
SN  - 0-7803-8371-0
N1  - Microwave Theory and Techniques Society. ; Automatic RF Techniques Group ; ARFTG conference ; (63 : ; 2004.06.11 : ; Fort Worth, Tex.)
SP  - 91
EP  - 96
PB  - IEEE Operations Center
CY  - Piscataway, NJ
ER  - 
TY  - JOUR
A1  - Heuermann, Holger
A1  - Erkens, Holger
T1  - Blocking structures for mixed-mode systems. / Erkens, Holger ; Heuermann, Holger
JF  - 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
Y1  - 2004
SN  - 1-580-53992-0
N1  - European Microwave Conference ; (34, 2004, Amsterdam) ; European Microwave Week ; (7, 2004, Amsterdam)
SP  - 297
EP  - 300
PB  - Horizon House Publ.
CY  - London
ER  -