The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
Min Kang - One of the best experts on this subject based on the ideXlab platform.
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Magnetic-field-assisted fabrication of micro-convex Domes using long pulse laser
Applied Physics A, 2017Co-Authors: Xingsheng Wang, Meifu Jin, Weiteng Xu, Zhengwei Zhang, Lu Liu, Min KangAbstract:Surfaces with mimic micro-convex Domes offer superior functions such as superhydrophobicity, self-cleaning, anti-wear and drag reduction. In this paper, magnetic-filed-assisted laser surface texturing (LST) using long pulse laser was employed to create micro-convex Domes on 304L stainless steel. Spherical cap shaped Domes with ripples around the bottom were fabricated through LST. The effects of laser power and magnetic flux density on surface morphologies of the created convex Domes were investigated. It was found that the height and diameter of the created convex Dome increased with the increment of the laser power without magnetic field. Moreover, the height of the created convex Dome grew up gradually with the increase of magnetic flux density due to the induced Lorentz force. The height of the convex Dome was increased by as much as 14.5% as compared to LST without the applied magnetic field at a laser power of 54 W. However, the applied magnetic field had no evident effect on the diameter of the created convex Dome.
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Fabrication of micro-convex Domes using long pulse laser
Applied Physics A, 2016Co-Authors: Xingsheng Wang, Jieyu Xian, Meifu Jin, Yongnian Zhang, Ling Wang, Min KangAbstract:Micro-convex Domes inspired from nature can be machined by chemical and physical routes to achieve specific functions. Laser surface texturing (LST) is the front runner among the current material micro-processing technologies. However, most of the studies relating to LST dealt with the formation of micro-dimples. In this paper, LST using long pulse laser was used to create micro-convex Domes on 304L stainless steel. Spherical-cap-shaped Domes with diameters of 30–75 μm and height of 0.9–5.5 μm were created through LST. The effects of laser-processing parameters on surface morphologies of the created convex Domes were investigated. The height of the convex Dome increased at first and then decreased with the increasing laser power. The change tendency of the height with the pulse duration varied at different laser powers. The diameter of the convex Dome increased almost linearly with the laser power or pulse duration. The superior micro-convex Domes were achieved at a pulse energy of 5.6 mJ with a laser power of 80 W and pulse duration of 70 μs.
Mohamed Deriche - One of the best experts on this subject based on the ideXlab platform.
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Salt-Dome Detection Using a Codebook-Based Learning Model
IEEE Geoscience and Remote Sensing Letters, 2016Co-Authors: Asjad Amin, Mohamed DericheAbstract:In this letter, we present a novel supervised codebook-based learning model for salt-Dome detection in seismic imaging using texture-based attributes. The proposed algorithm is data driven and overcomes the limitations of existing texture-attributes-based salt-Dome detection techniques which are heavily dependent upon the relevance of attributes to the geological nature of salt Domes and the number of attributes used for classification. The algorithm works by combining the attributes from the gray-level cooccurrence matrix (GLCM) and those from the Gabor filter, with a codebook-based learning approach to delineate salt boundaries in seismic data. The combination of GLCM- and Gabor-filter-based attributes ensures that the algorithm works well even in the absence of strong reflectors along the salt boundary. Contrary to existing salt-Dome detection techniques, our algorithm works with a codebook of small size and is shown to be robust and computationally efficient. The learning properties of the codebook-based model make the algorithm flexible and adaptable to the nature of time-scale varying data acquired in seismic surveys. We used the Netherlands F3 block to evaluate the performance of the proposed algorithm. Our experimental results show that the proposed codebook-based workflow can detect salt Domes with good accuracy, superior to existing salt-Dome detection techniques.
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A Novel Approach for Salt Dome Detection using A Dictionary-based Classifier
SEG New Orleans Annual Meeting, 2015Co-Authors: Asjad Amin, Tamir Hegazy, Mohamed Deriche, Zhen Wang, Ghassan AlregibAbstract:© 2015 SEG. In this paper, we present a dictionary based classification approach for salt Dome detection using texture based attributes. The proposed algorithm overcomes the drawbacks of existing texture attributes based salt Dome detection techniques which are heavily dependent upon the relevance of attributes to the geological nature of salt Domes and the number of attributes used for classification. The algorithm works by combining the attributes from the Gray Level Co-occurrence Matrix (GLCM) and those from the Gradient of Texture (GoT) attributes with a dictionary-based learning approach to classify the boundaries of salt regions. The combination of GLCM and GoT attributes ensures that the proposed algorithm works well even if the salt boundary is represented only by a weak reflector. Contrary to other texture attributes based salt Dome detection techniques, our algorithm works with a minimum set of features and is shown to be independent of the amplitude variations in seismic data. We tested the proposed algorithm on the Netherlands offshore F3 block. Our experimental results show that the proposed algorithm can detect salt bodies with high accuracy superior to existing gradient based as well as texture based techniques when used separately.
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A hybrid approach for salt Dome detection in 2D and 3D seismic data
2015 IEEE International Conference on Image Processing (ICIP), 2015Co-Authors: Asjad Amin, Mohamed DericheAbstract:Salt bodies play an important role in subsurface geology, therefore accurate salt Dome detection is essential for any seismic interpretation task. Detecting salt body boundary and shape accurately, however, is very difficult due to large noise and amplitude variations in seismic data. Due to the limitations of manual picking, automatic segmentation algorithms are preferred to locate salt Domes within the seismic images. In this work, we propose a robust salt Dome detection technique based on combined edge and texture attributes. The proposed algorithm overcomes the drawbacks of existing texture attributes based salt Dome detection techniques which are heavily dependent upon the relevance of attributes to the geological nature of salt Domes, and the number of attributes used for classification. The combination of edge based and texture based attributes ensures that the proposed algorithm works well even if the salt boundary is represented only by a weak reflector. We tested the proposed algorithm on the Netherlands offshore F3 block. Our experimental results show that the proposed algorithm can detect salt boundaries with high accuracy superior to existing gradient based as well as texture based techniques when used separately.
A Gaudric - One of the best experts on this subject based on the ideXlab platform.
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morphologic characterization of Dome shaped macula in myopic eyes with serous macular detachment
American Journal of Ophthalmology, 2013Co-Authors: Violaine Caillaux, David Gaucher, Vincent Gualino, P Massin, Ramin Tadayoni, A GaudricAbstract:Purpose To analyze Dome-shaped maculas topographic features and related serous retinal detachment (SRD) in eyes with myopic staphyloma. Design Retrospective, observational case series. Methods We reviewed the records of 48 eyes in 33 patients with Dome-shaped maculas who were referred because of decreased vision. Ophthalmologic examination included axial length measurement, spectral domain optical coherence tomography (OCT), and fluorescein and indocyanine green angiography. The height of the macular bulge was measured, and the choroidal thickness was mapped. Results Patient mean age was 55.0 ± 13.6 years. Mean axial length was 27.49 ± 2.53 mm. Mean best-corrected visual acuity (BCVA) was 0.50 ± 0.33 logMAR. Three Dome-shaped macula patterns were observed: round Dome in 10/48 (20.8%) eyes; horizontal oval-shaped Dome in 30/48 (62.5%) eyes; and vertical oval-shaped Dome in 8/48 (16.7%) eyes. The mean macular bulge height was 407.7 ± 215.1 μm (120–1130) and was significantly greater in vertical oval-shaped Domes. The mean central choroidal thickness (CCT) was 146.5 ± 56.0 μm, significantly greater than at 3 mm nasal and temporal to the fovea ( P P = 0.0047). BCVA was significantly lower when SRD was present ( P = 0.043). Conclusions Most Dome-shaped maculas did not display a round but a horizontal or vertical oval-shaped Dome and could be missed on a single OCT scan. Chronic foveal SRD was associated with decreased vision and was more common when the macular bulge was highly elevated.
Robert Arrieux - One of the best experts on this subject based on the ideXlab platform.
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Multi-sequence Dome lay-up simulations for hydrogen hyper-bar composite pressure vessels.
Composites Part A: Applied Science and Manufacturing, 2013Co-Authors: David Leh, Philippe Saffré, Pascal Francescato, Robert ArrieuxAbstract:The aim of this study is to propose a calculation method for predicting the geometrical characteristics of the end-closures of composite pressure vessels used in gaseous hydrogen storage applications. We present here a method for predicting the characteristics of Domes made by multi-sequence lay-up and subject to changes in winding angle and thickness. In the proposed model, winding angle and thickness calculations are based on two existing methods that have been investigated in a single Dome lay-up context. Using them for multi-sequence Dome lay-up calculation is the originality of this work. The first predictive results are compared with experimental pressure vessel data and discussed. A good correlation between the theoretical approach and the experiments was found, indicating that the predictions could be helpful in a procedure of overall optimisation.
Xingsheng Wang - One of the best experts on this subject based on the ideXlab platform.
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Magnetic-field-assisted fabrication of micro-convex Domes using long pulse laser
Applied Physics A, 2017Co-Authors: Xingsheng Wang, Meifu Jin, Weiteng Xu, Zhengwei Zhang, Lu Liu, Min KangAbstract:Surfaces with mimic micro-convex Domes offer superior functions such as superhydrophobicity, self-cleaning, anti-wear and drag reduction. In this paper, magnetic-filed-assisted laser surface texturing (LST) using long pulse laser was employed to create micro-convex Domes on 304L stainless steel. Spherical cap shaped Domes with ripples around the bottom were fabricated through LST. The effects of laser power and magnetic flux density on surface morphologies of the created convex Domes were investigated. It was found that the height and diameter of the created convex Dome increased with the increment of the laser power without magnetic field. Moreover, the height of the created convex Dome grew up gradually with the increase of magnetic flux density due to the induced Lorentz force. The height of the convex Dome was increased by as much as 14.5% as compared to LST without the applied magnetic field at a laser power of 54 W. However, the applied magnetic field had no evident effect on the diameter of the created convex Dome.
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Fabrication of micro-convex Domes using long pulse laser
Applied Physics A, 2016Co-Authors: Xingsheng Wang, Jieyu Xian, Meifu Jin, Yongnian Zhang, Ling Wang, Min KangAbstract:Micro-convex Domes inspired from nature can be machined by chemical and physical routes to achieve specific functions. Laser surface texturing (LST) is the front runner among the current material micro-processing technologies. However, most of the studies relating to LST dealt with the formation of micro-dimples. In this paper, LST using long pulse laser was used to create micro-convex Domes on 304L stainless steel. Spherical-cap-shaped Domes with diameters of 30–75 μm and height of 0.9–5.5 μm were created through LST. The effects of laser-processing parameters on surface morphologies of the created convex Domes were investigated. The height of the convex Dome increased at first and then decreased with the increasing laser power. The change tendency of the height with the pulse duration varied at different laser powers. The diameter of the convex Dome increased almost linearly with the laser power or pulse duration. The superior micro-convex Domes were achieved at a pulse energy of 5.6 mJ with a laser power of 80 W and pulse duration of 70 μs.
