The Experts below are selected from a list of 3780 Experts worldwide ranked by ideXlab platform
Eric Michielssen - One of the best experts on this subject based on the ideXlab platform.
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a wavelet enhanced pwtd accelerated time domain integral equation solver for analysis of transient scattering from electrically large conducting objects
IEEE Transactions on Antennas and Propagation, 2018Co-Authors: Abdulkadir C. Yücel, Anna C Gilbert, Hakan Bagci, Eric MichielssenAbstract:A wavelet-enhanced plane-wave time-domain (PWTD) algorithm for efficiently and accurately solving time-domain surface integral equations (TD-SIEs) on electrically large conducting objects is presented. The proposed scheme reduces the memory requirement and computational cost of the PWTD algorithm by representing the PWTD ray data using Local Cosine wavelet bases (LCBs) and performing PWTD operations in the wavelet domain. The memory requirement and computational cost of the LCB-enhanced PWTD-accelerated TD-SIE solver, when applied to the analysis of transient scattering from smooth quasi-planar objects with near-normal incident pulses, scale nearly as $O(N_{s} \log N_{s})$ and $O(N_{s}^{1.5})$ , respectively. Here, $N_{s} $ denotes the number of spatial unknowns. The efficiency and accuracy of the proposed scheme are demonstrated through its applications to the analysis of transient scattering from a 185-wavelength long NASA almond and a 123-wavelength long Airbus A-320 model.
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a wavelet based pwtd algorithm accelerated time domain surface integral equation solver
USNC-URSI Radio Science Meeting, 2015Co-Authors: Abdulkadir C. Yücel, Anna C Gilbert, Hakan Bagci, Eric MichielssenAbstract:The multilevel plane-wave time-domain (PWTD) algorithm allows for fast and accurate analysis of transient scattering from, and radiation by, electrically large and complex structures. When used in tandem with marching-on-in-time (MOT)-based surface integral equation (SIE) solvers, it reduces the computational and memory costs of transient analysis from equation and equation to equation and equation, respectively, where N t and N s denote the number of temporal and spatial unknowns (Ergin et al., IEEE Trans. Antennas Mag., 41, 39–52, 1999). In the past, PWTD-accelerated MOT-SIE solvers have been applied to transient problems involving half million spatial unknowns (Shanker et al., IEEE Trans. Antennas Propag., 51, 628–641, 2003). Recently, a scalable parallel PWTD-accelerated MOT-SIE solver that leverages a hiearchical parallelization strategy has been developed and successfully applied to the transient problems involving ten million spatial unknowns (Liu et. al., in URSI Digest, 2013). We further enhanced the capabilities of this solver by implementing a compression scheme based on Local Cosine wavelet bases (LCBs) that exploits the sparsity in the temporal dimension (Liu et. al., in URSI Digest, 2014). Specifically, the LCB compression scheme was used to reduce the memory requirement of the PWTD ray data and computational cost of operations in the PWTD translation stage.
Abdulkadir C. Yücel - One of the best experts on this subject based on the ideXlab platform.
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a wavelet enhanced pwtd accelerated time domain integral equation solver for analysis of transient scattering from electrically large conducting objects
IEEE Transactions on Antennas and Propagation, 2018Co-Authors: Abdulkadir C. Yücel, Anna C Gilbert, Hakan Bagci, Eric MichielssenAbstract:A wavelet-enhanced plane-wave time-domain (PWTD) algorithm for efficiently and accurately solving time-domain surface integral equations (TD-SIEs) on electrically large conducting objects is presented. The proposed scheme reduces the memory requirement and computational cost of the PWTD algorithm by representing the PWTD ray data using Local Cosine wavelet bases (LCBs) and performing PWTD operations in the wavelet domain. The memory requirement and computational cost of the LCB-enhanced PWTD-accelerated TD-SIE solver, when applied to the analysis of transient scattering from smooth quasi-planar objects with near-normal incident pulses, scale nearly as $O(N_{s} \log N_{s})$ and $O(N_{s}^{1.5})$ , respectively. Here, $N_{s} $ denotes the number of spatial unknowns. The efficiency and accuracy of the proposed scheme are demonstrated through its applications to the analysis of transient scattering from a 185-wavelength long NASA almond and a 123-wavelength long Airbus A-320 model.
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a wavelet based pwtd algorithm accelerated time domain surface integral equation solver
USNC-URSI Radio Science Meeting, 2015Co-Authors: Abdulkadir C. Yücel, Anna C Gilbert, Hakan Bagci, Eric MichielssenAbstract:The multilevel plane-wave time-domain (PWTD) algorithm allows for fast and accurate analysis of transient scattering from, and radiation by, electrically large and complex structures. When used in tandem with marching-on-in-time (MOT)-based surface integral equation (SIE) solvers, it reduces the computational and memory costs of transient analysis from equation and equation to equation and equation, respectively, where N t and N s denote the number of temporal and spatial unknowns (Ergin et al., IEEE Trans. Antennas Mag., 41, 39–52, 1999). In the past, PWTD-accelerated MOT-SIE solvers have been applied to transient problems involving half million spatial unknowns (Shanker et al., IEEE Trans. Antennas Propag., 51, 628–641, 2003). Recently, a scalable parallel PWTD-accelerated MOT-SIE solver that leverages a hiearchical parallelization strategy has been developed and successfully applied to the transient problems involving ten million spatial unknowns (Liu et. al., in URSI Digest, 2013). We further enhanced the capabilities of this solver by implementing a compression scheme based on Local Cosine wavelet bases (LCBs) that exploits the sparsity in the temporal dimension (Liu et. al., in URSI Digest, 2014). Specifically, the LCB compression scheme was used to reduce the memory requirement of the PWTD ray data and computational cost of operations in the PWTD translation stage.
Jiaqing Miao - One of the best experts on this subject based on the ideXlab platform.
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image segmentation based on an active contour model of partial image restoration with Local Cosine fitting energy
Information Sciences, 2018Co-Authors: Jiaqing Miao, Tingzhu Huang, Xiaobing Zhou, Yugang Wang, Jun LiuAbstract:Abstract In this paper, we use the Cosine function to express the data energy fitting of a traditional active contours model and propose a model based on sectional image recovery Local Cosine-fitting energy active contours, which is used to segment medical and synthetic images . The algorithm is a single level image segmentation method. It can process synthetic images with intensity inhomogeneity . Moreover, our model for the images with noise and the fuzzy ones is more efficient and robust, and the computational speed was similar or faster, compared with Convex Variant of the Mumford–Shah Model and Thresholding (CVMST) model, a Local binary fitting (LBF) model and L0 Regularized Mumford–Shah (L0MS) model. In addition, we describe the model in a discrete form, which is more convenient to add a regular term to control the segmentation. Therefore the massive calculation is reduced by re-initializing the level set curve. At the end of the paper, the modified algorithm has been utilized to segment medical images and three-dimensional visualization results are obtained. The experimental results indicate that the segmentation results are accurate and efficient when applied to different kinds of images.
Hakan Bagci - One of the best experts on this subject based on the ideXlab platform.
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a wavelet enhanced pwtd accelerated time domain integral equation solver for analysis of transient scattering from electrically large conducting objects
IEEE Transactions on Antennas and Propagation, 2018Co-Authors: Abdulkadir C. Yücel, Anna C Gilbert, Hakan Bagci, Eric MichielssenAbstract:A wavelet-enhanced plane-wave time-domain (PWTD) algorithm for efficiently and accurately solving time-domain surface integral equations (TD-SIEs) on electrically large conducting objects is presented. The proposed scheme reduces the memory requirement and computational cost of the PWTD algorithm by representing the PWTD ray data using Local Cosine wavelet bases (LCBs) and performing PWTD operations in the wavelet domain. The memory requirement and computational cost of the LCB-enhanced PWTD-accelerated TD-SIE solver, when applied to the analysis of transient scattering from smooth quasi-planar objects with near-normal incident pulses, scale nearly as $O(N_{s} \log N_{s})$ and $O(N_{s}^{1.5})$ , respectively. Here, $N_{s} $ denotes the number of spatial unknowns. The efficiency and accuracy of the proposed scheme are demonstrated through its applications to the analysis of transient scattering from a 185-wavelength long NASA almond and a 123-wavelength long Airbus A-320 model.
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a wavelet based pwtd algorithm accelerated time domain surface integral equation solver
USNC-URSI Radio Science Meeting, 2015Co-Authors: Abdulkadir C. Yücel, Anna C Gilbert, Hakan Bagci, Eric MichielssenAbstract:The multilevel plane-wave time-domain (PWTD) algorithm allows for fast and accurate analysis of transient scattering from, and radiation by, electrically large and complex structures. When used in tandem with marching-on-in-time (MOT)-based surface integral equation (SIE) solvers, it reduces the computational and memory costs of transient analysis from equation and equation to equation and equation, respectively, where N t and N s denote the number of temporal and spatial unknowns (Ergin et al., IEEE Trans. Antennas Mag., 41, 39–52, 1999). In the past, PWTD-accelerated MOT-SIE solvers have been applied to transient problems involving half million spatial unknowns (Shanker et al., IEEE Trans. Antennas Propag., 51, 628–641, 2003). Recently, a scalable parallel PWTD-accelerated MOT-SIE solver that leverages a hiearchical parallelization strategy has been developed and successfully applied to the transient problems involving ten million spatial unknowns (Liu et. al., in URSI Digest, 2013). We further enhanced the capabilities of this solver by implementing a compression scheme based on Local Cosine wavelet bases (LCBs) that exploits the sparsity in the temporal dimension (Liu et. al., in URSI Digest, 2014). Specifically, the LCB compression scheme was used to reduce the memory requirement of the PWTD ray data and computational cost of operations in the PWTD translation stage.
Anna C Gilbert - One of the best experts on this subject based on the ideXlab platform.
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a wavelet enhanced pwtd accelerated time domain integral equation solver for analysis of transient scattering from electrically large conducting objects
IEEE Transactions on Antennas and Propagation, 2018Co-Authors: Abdulkadir C. Yücel, Anna C Gilbert, Hakan Bagci, Eric MichielssenAbstract:A wavelet-enhanced plane-wave time-domain (PWTD) algorithm for efficiently and accurately solving time-domain surface integral equations (TD-SIEs) on electrically large conducting objects is presented. The proposed scheme reduces the memory requirement and computational cost of the PWTD algorithm by representing the PWTD ray data using Local Cosine wavelet bases (LCBs) and performing PWTD operations in the wavelet domain. The memory requirement and computational cost of the LCB-enhanced PWTD-accelerated TD-SIE solver, when applied to the analysis of transient scattering from smooth quasi-planar objects with near-normal incident pulses, scale nearly as $O(N_{s} \log N_{s})$ and $O(N_{s}^{1.5})$ , respectively. Here, $N_{s} $ denotes the number of spatial unknowns. The efficiency and accuracy of the proposed scheme are demonstrated through its applications to the analysis of transient scattering from a 185-wavelength long NASA almond and a 123-wavelength long Airbus A-320 model.
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a wavelet based pwtd algorithm accelerated time domain surface integral equation solver
USNC-URSI Radio Science Meeting, 2015Co-Authors: Abdulkadir C. Yücel, Anna C Gilbert, Hakan Bagci, Eric MichielssenAbstract:The multilevel plane-wave time-domain (PWTD) algorithm allows for fast and accurate analysis of transient scattering from, and radiation by, electrically large and complex structures. When used in tandem with marching-on-in-time (MOT)-based surface integral equation (SIE) solvers, it reduces the computational and memory costs of transient analysis from equation and equation to equation and equation, respectively, where N t and N s denote the number of temporal and spatial unknowns (Ergin et al., IEEE Trans. Antennas Mag., 41, 39–52, 1999). In the past, PWTD-accelerated MOT-SIE solvers have been applied to transient problems involving half million spatial unknowns (Shanker et al., IEEE Trans. Antennas Propag., 51, 628–641, 2003). Recently, a scalable parallel PWTD-accelerated MOT-SIE solver that leverages a hiearchical parallelization strategy has been developed and successfully applied to the transient problems involving ten million spatial unknowns (Liu et. al., in URSI Digest, 2013). We further enhanced the capabilities of this solver by implementing a compression scheme based on Local Cosine wavelet bases (LCBs) that exploits the sparsity in the temporal dimension (Liu et. al., in URSI Digest, 2014). Specifically, the LCB compression scheme was used to reduce the memory requirement of the PWTD ray data and computational cost of operations in the PWTD translation stage.