Containerless technique has many advantages for the density measurement of melts, such as high temperature anddeep undercooling measurement. At present, many researchers focus on density measurement of melts with con...
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Containerless technique has many advantages for the density measurement of melts, such as high temperature anddeep undercooling measurement. At present, many researchers focus on density measurement of melts with containerless technique and projection imaging method. In containerless experimental processes, the sphere melt droplet rotates and changes to spheroid, due to the asymmetrical of pressure of laser light and electrostatic force. In addition, there was no depth information is included in the image acquired from the droplet. Therefore, the accurate volume of droplet is difficult to obtain. Therefore, we proposed a new 3d reconstruction algorithmwith two cameras that acquired the droplet images simultaneously at different angles. The deviation of the novel algorithm is less than 1.1%. With the proposedalgorithm, the density of liquid Zr is measured from 1800 K to 2500 K, the combined relative standard uncertainty in density is 1.80%. (C) 2020 Published by Elsevier B.V.
An all-solid-state electronic three-dimensional terahertz tomography system designed specifically for non-destructive inspection of polymer materials is demonstrated, which is capable of determining the positions and ...
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An all-solid-state electronic three-dimensional terahertz tomography system designed specifically for non-destructive inspection of polymer materials is demonstrated, which is capable of determining the positions and shapes of hidden defects accurately. The imaging radar system, based on stepped-frequency modulated continuous wave (SFMCW), with center frequency at 180 GHz, bandwidth of 60 GHz, and average power 0.5 mW, is tested against thick Teflon (polytetrafluoroethylene, PTFE) plates with internal voids as samples. The locations and shapes of the hidden holes are obtained in both electromagnetic simulation and experimental measurements with a three-dimensional image reconstructionalgorithm, which features advantages of accurate reconstructed image details and fast computation speed, demonstrating that the terahertz imaging radar system combined with the algorithmdeveloped is capable of detecting internal defects of thick polymers. Key resolution parameters are established experimentally in detail, demonstrating 2.5 mm and 1.7 mm range resolutions in free space and in Teflon separately, and lateral spot diameters ranging from 3.4 mm to 8 mm at imaging distances from 5 mm to 60 mm.
Medical image 3dreconstruction is an important research and application areas. A comprehensive survey is given in four aspects: the general process of medical image 3dreconstruction, image fusion, image segmentation...
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ISBN:
(纸本)9780819466563
Medical image 3dreconstruction is an important research and application areas. A comprehensive survey is given in four aspects: the general process of medical image 3dreconstruction, image fusion, image segmentation, and3d reconstruction algorithm.
A novel algorithm for 3dreconstruction from image sequences is presented. Global optimisation is applied to a rough model by minimising the back projection errors in each image. different weights are added to disting...
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A novel algorithm for 3dreconstruction from image sequences is presented. Global optimisation is applied to a rough model by minimising the back projection errors in each image. different weights are added to distinguish visible and occluded points. Satisfactory results on both simulateddata and real images are reported.
Helical tomography yields less invasive examination at the expense of degradations in the precision of the reconstructions and the possible presence of specific artifacts. This study presents a new reconstruction meth...
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ISBN:
(纸本)0780376129
Helical tomography yields less invasive examination at the expense of degradations in the precision of the reconstructions and the possible presence of specific artifacts. This study presents a new reconstruction method that produces significant enhancement in the precision of helical tomographic images at a. reasonable computer cost.
this paper we demonstrate that conductivity changes caused by ventilation and perfusion in a human subject can be reconstructed from electrical impedance tomography data collected on a rectangular array of electrodes ...
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this paper we demonstrate that conductivity changes caused by ventilation and perfusion in a human subject can be reconstructed from electrical impedance tomography data collected on a rectangular array of electrodes placed on a subject's chest. Currents are applied on the electrodes and the resulting voltages on the electrodes are measured. A 3d reconstruction algorithm is used to reconstruct the conductivity distribution in the region beneath the array. Time traces of the reconstructed conductivity distribution demonstrate the detected changes in conductivity due to ventilation and perfusion.
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