Journal of X-Ray Science and Technology - Volume 23, issue 2

Authors: Yang, Jian | Fan, Jingfan | Fu, Tianyu | Ai, Danni | Zhu, Jianjun | Li, Qin | Wang, Yongtian

Article Type: Research Article

Abstract: This study proposes a novel hierarchical pyramid strategy for 3D registration of multimodality medical images. The surfaces of the source and target volume data are first extracted, and the surface point clouds are then aligned roughly using convex hull matching. The convex hull matching registration procedure could align images with large-scale transformations. The original images are divided into blocks and the corresponding blocks in the two images are registered by affine and non-rigid registration procedures. The …sub-blocks are iteratively smoothed by the Gaussian kernel with different sizes during the registration procedure. The registration result of the large kernel is taken as the input of the small kernel registration. The fine registration of the two volume data sets is achieved by iteratively increasing the number of blocks, in which increase in similarity measure is taken as a criterion for acceptation of each iteration level. Results demonstrate the effectiveness and robustness of the proposed method in registering the multiple modalities of medical images. Show more

Keywords: Convex hull, multimodality image, registration

DOI: 10.3233/XST-150485

Citation: Journal of X-Ray Science and Technology, vol. 23, no. 2, pp. 253-265, 2015

Authors: Agah, K. Mikaili | Ghoranneviss, M. | Elahi, A. Salar

Article Type: Research Article

Abstract: Determinations of plasma parameters as well as the Magnetohydrodynamics (MHD) activity, energetic electrons energy and energy confinement time are essential for future fusion reactors experiments and optimized operation. Also some of the plasma information can be deduced from these parameters, such as plasma equilibrium, stability, and MHD instabilities. In this contribution we investigated the relation between energetic electrons, hard x-ray emission and MHD activity in the IR-T1 Tokamak. For this purpose we …used the magnetic diagnostics and a hard x-ray spectroscopy in IR-T1 tokamak. A hard x-ray emission is produced by collision of the runaway electrons with the plasma particles or limiters. The mean energy was calculated from the slope of the energy spectrum of hard x-ray photons. Show more

Keywords: Tokamak, energetic electrons

DOI: 10.3233/XST-150486

Citation: Journal of X-Ray Science and Technology, vol. 23, no. 2, pp. 267-274, 2015