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Related papers: Parallel transmit PUlse design for Saturation Homo…

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Existing optimal control protocols for mitigating the effects of relaxation and/or RF inhomogeneity on broadband pulse performance are extended to the more difficult problem of designing robust, refocused, frequency selective excitation…

Instrumentation and Detectors · Physics 2015-06-03 Thomas E. Skinner , Naum I. Gershenzon , Manoj Nimbalkar , Steffen J. Glaser

RF pulse design via optimal control is typically based on gradient and quasi-Newton approaches and therefore suffers from slow convergence. We present a flexible and highly efficient method that uses exact second-order information within a…

Optimization and Control · Mathematics 2017-02-27 Christoph Aigner , Christian Clason , Armin Rund , Rudolf Stollberger

Spatial multiplexing (SM) gains in multiple input multiple output (MIMO) cellular networks are limited when used in combination with ultra-dense small cell networks. This limitation is due to large spatial correlation among channel pairs.…

Information Theory · Computer Science 2016-11-15 Amir H. Jafari , Vijay Venkateswaran , David Lopez-Perez , Jie Zhang

Permanent magnet-assisted synchronous reluctance motors (PMSynRM) have a significantly higher average torque than synchronous reluctance motors. Thus, determining an optimal design results in a multi-material topology optimization problem,…

Optimization and Control · Mathematics 2026-04-01 Thomas Gauthey , Peter Gangl , Maya Hage Hassan

Background: Parallel transmit (pTx) has introduced many benefits to MRI with regard to decreased specific absorption rates and improved transmit field homogeneity, of particular importance in applications at higher magnetic field strengths.…

The efficiency of dipole-dipole coupling driven coherence transfer experiments in solid-state NMR spectroscopy of powder samples is limited by dispersion of the orientation of the internuclear vectors relative to the external magnetic…

Quantum Physics · Physics 2009-11-13 N. Khaneja , C. Kehlet , S. J. Glaser , N. C. Nielsen

We present a method for characterizing the propagation of the magnetic flux in an artificially drilled bulk high-temperature superconductor (HTS) during a pulsed-field magnetization. As the magnetic pulse penetrates the cylindrical sample,…

Superconductivity · Physics 2015-05-13 Gregory P Lousberg , J-F Fagnard , E Haanappel , X Chaud , M Ausloos , B Vanderheyden , Ph Vanderbemden

The simulation of large-scale high-temperature superconducting (HTS) magnets is a computational challenge due to the multiple spatial scales involved, from the magnet to the detailed turn-to-turn geometry. To reduce the computational cost…

Accelerator Physics · Physics 2025-10-13 Louis Denis , Benoît Vanderheyden , Christophe Geuzaine

This paper proposes a bidirectional multibeam hybrid transmitarray (HTA) employing a transmission polarization-rotating metasurface (TPRM). A novel configuration is introduced to facilitate bidirectional beam scanning by combining the…

Systems and Control · Electrical Eng. & Systems 2024-08-05 Fan Qin , Yifei Liu , Chao Gu , Linfeng Zeng , Wenchi Cheng , Hailin Zhang , Steven Gao

In ultra-dense small cell networks, spatial multiplexing gain is a challenge because of the different propagation conditions. The channels associated with different transmitreceive pairs can be highly correlated due to the i) high…

Information Theory · Computer Science 2016-11-08 Amir H. Jafari , Vijay Venkateswaran , David Lopez-Perez , Jie Zhang

Inductive wireless power transfer (WPT) systems can be effectively described as non-Hermitian systems using the coupled-mode theory. In these systems, parity-time (PT) symmetric states facilitate efficient power transfer. Traditionally,…

Applied Physics · Physics 2023-12-22 Hanwei Wang , Joshua Yu , Xiaodong Ye , Yang Zhao

Waveguides have been successfully used to generate magnetic resonance images at 7 T with whole-body systems. The bore limits the magnetic resonance signal transmitted because its specific cut-off frequency is greater than the majority of…

Medical Physics · Physics 2015-06-12 F. Vazquez , R. Martin , O. Marrufo , A. O. Rodriguez

Ultrahigh-field MRI, such as those operating at 7 Tesla, enhances diagnostic capabilities but also presents unique challenges, including the need for advanced RF coil designs to achieve an optimal signal-to-noise ratio and transmit…

Medical Physics · Physics 2025-02-11 Yunkun Zhao , Komlan Payne , Leslie Ying , Xiaoliang Zhang

Purpose: Magnetization transfer saturation (MTsat) mapping is commonly used to examine the macromolecular content of brain tissue. This study compared variable flip angle (VFA) T1 mapping against compressed sensing (cs)MP2RAGE T1 mapping…

Multi-pass cell (MPC) compressors have proven to be the method of choice for compression of high average power long-pulse Yb lasers. Yet, generating sub-30 fs pulses at high pulse energy with compact and simple components remains a…

The root raised-cosine pulse commonly used in linear digital modulations yields exactly two intersymbol interference components from the preceding and the subsequent data symbols, provided that the roll-off factor is $100\%$ and the…

Information Theory · Computer Science 2023-01-05 Pavel Loskot

The temporal shape of a pulse in transcranial magnetic stimulation (TMS) influences which neuron populations are activated preferentially as well as the strength and even direction of neuromodulation effects. Furthermore, various pulse…

Medical Physics · Physics 2022-02-15 Z. Li , J. Zhang , A. V. Peterchev , S. M. Goetz

We optimize the pulse shape and polarization of time-dependent electric fields to maximize the production of electron-positron pairs via strong field quantum electrodynamics processes. The pulse is parametrized in Fourier space by a…

High Energy Physics - Phenomenology · Physics 2017-08-02 François Fillion-Gourdeau , Florian Hebenstreit , Denis Gagnon , Steve MacLean

Broadband inversion pulses that rotate all magnetization components 180 degrees about a given fixed axis are necessary for refocusing and mixing in high-resolution NMR spectroscopy. The relative merits of various methodologies for…

Tsinghua University has designed an X-band (11.424 GHz) slow-wave parallel-coupling accelerating structure, and demonstrated the high performance of the over-coupled structure operating with ultrashort pulse. In this study, we redesigned a…

Accelerator Physics · Physics 2025-01-07 Weihang Gu , Hao Zha , Jiaru Shi , Yuliang Jiang , Jiayang Liu , Xiancai Lin , Focheng Liu , Huaibi Chen