TY  - JOUR
A1  - Orzada, S.
A1  - Maderwald, S.
A1  - Poser, B. A.
A1  - Johst, S.
A1  - Kannengiesser, S.
A1  - Ladd, M. E.
A1  - Bitz, Andreas
T1  - Time-interleaved acquisition of modes: an analysis of SAR and image contrast implications
JF  - Magnetic Resonance in Medicine
N2  - s the magnetic field strength and therefore the operational frequency in MRI are increased, the radiofrequency wavelength approaches the size of the human head/body, resulting in wave effects which cause signal decreases and dropouts. Especially, whole-body imaging at 7 T and higher is therefore challenging. Recently, an acquisition scheme called time-interleaved acquisition of modes has been proposed to tackle the inhomogeneity problems in high-field MRI. The basic premise is to excite two (or more) different Burn:x-wiley:07403194:media:MRM23081:tex2gif-stack-1 modes using static radiofrequency shimming in an interleaved acquisition, where the complementary radiofrequency patterns of the two modes can be exploited to improve overall signal homogeneity. In this work, the impact of time-interleaved acquisition of mode on image contrast as well as on time-averaged specific absorption rate is addressed in detail. Time-interleaved acquisition of mode is superior in Burn:x-wiley:07403194:media:MRM23081:tex2gif-stack-2 homogeneity compared with conventional radiofrequency shimming while being highly specific absorption rate efficient. Time-interleaved acquisition of modes can enable almost homogeneous high-field imaging throughout the entire field of view in PD, T2, and T2*-weighted imaging and, if a specified homogeneity criterion is met, in T1-weighted imaging as well.
Y1  - 2012
U6  - https://doi.org/10.1002/mrm.23081
SN  - 1522-2594
VL  - 67
IS  - 4
SP  - 1033
EP  - 1041
PB  - Wiley-Liss
CY  - New York
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  - Noureddine, Yacine
A1  - Kraff, Oliver
A1  - Ladd, Mark E.
A1  - Wrede, Karsten
A1  - Chen, Bixia
A1  - Quick, Harald H.
A1  - Schaefers, Georg
A1  - Bitz, Andreas
T1  - Radiofrequency induced heating around aneurysm clips using a generic birdcage head coil at 7 Tesla under consideration of the minimum distance to decouple multiple aneurysm clips
JF  - Magnetic Resonance in Medicine
Y1  - 2019
U6  - https://doi.org/10.1002/mrm.27835
SN  - 1522-2594
IS  - Early view
SP  - 1
EP  - 17
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Noureddine, Yacine
A1  - Bitz, Andreas
A1  - Ladd, Mark E.
A1  - Thürling, Markus
A1  - Ladd, Susanne C.
A1  - Schaefers, Gregor
A1  - Kraff, Oliver
T1  - Experience with magnetic resonance imaging of human subjects with passive implants and tattoos at 7 T: a retrospective study
JF  - Magnetic Resonance Materials in Physics, Biology and Medicine
Y1  - 2015
U6  - https://doi.org/10.1007/s10334-015-0499-y
SN  - 1352-8661
VL  - 28
IS  - 6
SP  - 577
EP  - 590
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Niemüller, Tim
A1  - Lakemeyer, Gerhard
A1  - Ferrein, Alexander
A1  - Reuter, S.
A1  - Ewert, D.
A1  - Jeschke, S.
A1  - Pensky, D.
A1  - Karras, Ulrich
T1  - Proposal for advancements to the LLSF in 2014 and beyond
Y1  - 2013
SP  - Publ. online
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  - Niemüller, Tim
A1  - Ferrein, Alexander
A1  - Eckel, Gerhard
A1  - Pirro, David
A1  - Podbregar, Patrick
A1  - Kellner, Tobias
A1  - Rath, Christoph
A1  - Steinbauer, Gerald
T1  - Providing Ground-truth Data for the Nao Robot Platform
JF  - RoboCup 2010: Robot Soccer World Cup XIV
Y1  - 2011
SN  - 978-3-642-20217-9
N1  - Lecture Notes in Computer Science ; 6556
SP  - 133
EP  - 144
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Niemüller, Tim
A1  - Ferrein, Alexander
A1  - Beck, Daniel
A1  - Lakemeyer, Gerhard
T1  - Design Principles of the Component-Based Robot Software Framework Fawkes
JF  - Simulation, Modeling, and Programming for Autonomous Robots
Y1  - 2010
N1  - Lecture Notes in Computer Science ; 6472 ; Second International Conference, SIMPAR 2010, Darmstadt, Germany, November 15-18, 2010. Proceedings
SP  - 300
EP  - 311
ER  - 
TY  - JOUR
A1  - Ndoumbè Mbonjo Mbonjo, H.
A1  - Streckert, J.
A1  - Bitz, Andreas
A1  - Hansen, V.
A1  - Glasmachers, A.
A1  - Gencol, S.
A1  - Rozic, D.
T1  - Generic UMTS test signal for RF bioelectromagnetic studies
JF  - Bioelectromagnetics
Y1  - 2004
U6  - https://doi.org/10.1002/bem.20007
SN  - 1521-186X
VL  - 25
IS  - 6
SP  - 415
EP  - 425
ER  - 
TY  - JOUR
A1  - Müller, Tim M.
A1  - Leise, Philipp
A1  - Lorenz, Imke-Sophie
A1  - Altherr, Lena
A1  - Pelz, Peter F.
T1  - Optimization and validation of pumping system design and operation for water supply in high-rise buildings
JF  - Optimization and Engineering
N2  - The application of mathematical optimization methods for water supply system design and operation provides the capacity to increase the energy efficiency and to lower the investment costs considerably. We present a system approach for the optimal design and operation of pumping systems in real-world high-rise buildings that is based on the usage of mixed-integer nonlinear and mixed-integer linear modeling approaches. In addition, we consider different booster station topologies, i.e. parallel and series-parallel central booster stations as well as decentral booster stations. To confirm the validity of the underlying optimization models with real-world system behavior, we additionally present validation results based on experiments conducted on a modularly constructed pumping test rig. Within the models we consider layout and control decisions for different load scenarios, leading to a Deterministic Equivalent of a two-stage stochastic optimization program. We use a piecewise linearization as well as a piecewise relaxation of the pumps’ characteristics to derive mixed-integer linear models. Besides the solution with off-the-shelf solvers, we present a problem specific exact solving algorithm to improve the computation time. Focusing on the efficient exploration of the solution space, we divide the problem into smaller subproblems, which partly can be cut off in the solution process. Furthermore, we discuss the performance and applicability of the solution approaches for real buildings and analyze the technical aspects of the solutions from an engineer’s point of view, keeping in mind the economically important trade-off between investment and operation costs.
KW  - Technical Operations Research
KW  - MINLP
KW  - MILP
KW  - Experimental validation
KW  - Pumping systems
Y1  - 2020
U6  - https://doi.org/10.1007/s11081-020-09553-4
SN  - 1573-2924
VL  - 2021
IS  - 22
SP  - 643
EP  - 686
PB  - Springer
ER  -