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Faculty of Engineering and Information Sciences - Papers: Part A

Field

2013

Articles 1 - 3 of 3

Full-Text Articles in Social and Behavioral Sciences

Spherical, Cylindrical And Tetrahedral Symmetries; Hydrogenic States At High Magnetic Field In Si:P, R A. Lewis, A Bruno-Alfonso, G V B De Souza, R E M Vickers, J A Colla, E Constable Jan 2013

Spherical, Cylindrical And Tetrahedral Symmetries; Hydrogenic States At High Magnetic Field In Si:P, R A. Lewis, A Bruno-Alfonso, G V B De Souza, R E M Vickers, J A Colla, E Constable

Faculty of Engineering and Information Sciences - Papers: Part A

Phosphorous donors in silicon have an electronic structure that mimics the hydrogen atom, albeit on a larger length, smaller energy and smaller magnetic field scale. While the hydrogen atom is spherically symmetric, an applied magnetic field imposes cylindrical symmetry, and the solid-state analogue involves, in addition, the symmetry of the Si crystal. For one magnetic field direction, all six conduction-band valleys of Si:P become equivalent. New experimental data to high laboratory fields (30 T), supported by new calculations, demonstrate that this high symmetry field orientation allows the most direct comparison with free hydrogen.


Impact Of The Mlc On The Mri Field Distortion Of A Prototype Mri-Linac, Stefan Kolling, Brad Oborn, Paul Keall Jan 2013

Impact Of The Mlc On The Mri Field Distortion Of A Prototype Mri-Linac, Stefan Kolling, Brad Oborn, Paul Keall

Faculty of Engineering and Information Sciences - Papers: Part A

Purpose: To cope with intrafraction tumor motion, integrated MRI-linac systems for real-time image guidance are currently under development. The multileaf collimator (MLC) is a key component in every state-of-the-art radiotherapy treatment system, allowing for accurate field shaping and tumor tracking. This work quantifies the magnetic impact of a widely used MLC on the MRI field homogeneity for such a modality. Methods: Results: Conclusions: This work shows that the MRI field distortions caused by the MLC cannot be ignored and must be thoroughly investigated for any MRI-linac system. The numeric distortion values obtained for our1.0T magnet may vary for other magnet …


Inter-Occlusion Reasoning For Human Detection Based On Variational Mean Field, Duc Thanh Nguyen, Wanqing Li, Philip O. Ogunbona Jan 2013

Inter-Occlusion Reasoning For Human Detection Based On Variational Mean Field, Duc Thanh Nguyen, Wanqing Li, Philip O. Ogunbona

Faculty of Engineering and Information Sciences - Papers: Part A

Detecting multiple humans in crowded scenes is challenging because the humans are often partially or even totally occluded by each other. In this paper, we propose a novel algorithm for partial inter-occlusion reasoning in human detection based on variational mean field theory. The proposed algorithm can be integrated with various part-based human detectors using different types of features, object representations, and classifiers. The algorithm takes as the input an initial set of possible human objects (hypotheses) detected using a part-based human detector. Each hypothesis is decomposed into a number of parts and the occlusion status of each part is inferred …