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[Communications in Computer and Information Science] Advances in Signal Processing and Intelligent Recognition Systems Volume 968 (4th International Symposium SIRS 2018, Bangalore, India, September 19–22, 2018, Revised Selected Papers) || Pre-processed Hyperspectral Image Analysis Using Tensor Decomposition Techniques
摘要： Hyperspectral remote sensing image analysis has always been a challenging task and hence there are several techniques employed for exploring the images. Recent approaches include visualizing hyperspectral images as third order tensors and processing using various tensor decomposition methods. This paper focuses on behavioural analysis of hyperspectral images processed with various decompositions. The experiments includes processing raw hyperspectral image and pre-processed hyperspectral image with tensor decomposition methods such as, Multilinear Singular Value Decomposition and Low Multilinear Rank Approximation technique. The results are projected based on relative reconstruction error, classification and pixel reflectance spectrums. The analysis provides correlated experimental results, which emphasizes the need of pre-processing for hyperspectral images and the trend followed by the tensor decomposition methods.
关键词： Low Multilinear Rank Approximation,Remote sensing image,Pixel reflectance spectrums,Multilinear Singular Value Decomposition,Relative reconstruction error,Tensor decomposition
更新于2025-09-19 17:15:36
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Wave Polarization Analyzed by Singular Value Decomposition of the Spectral Matrix in the Presence of Noise
摘要： Analysis of wave polarization provides wave propagation parameters and enables an identification of modes in space plasmas. It is based on measurements of several components of fluctuating electromagnetic fields. This technique has become a conventional part of modern instrumentation onboard scientific spacecraft. A definition of the degree of polarization can be reduced to a very basic form, i.e., the ratio of a signal’s polarized power to its total power. However, this simple definition can have several different realizations which depend mainly on the underlying assumptions about separating the polarized (coherent) part from the unpolarized part (noise). After reviewing polarization of a plane wave in two and three dimensions, we examine the singular value decomposition technique for a complex spectral matrix as well as for a real spectral matrix. The meaning of singular values is explained, and we show to what extent the singular values are able to contribute to a separation between polarized signal and noise. Finally, our theoretical findings are verified with synthetic data as well as with whistler-mode chorus wave observations from the THEMIS spacecraft.
关键词： Singular value decomposition,Wave normal vector,Hermitian spectral matrix,Spectral averaging,Stokes parameters,Degree of polarization,Planarity,Singular values,Ellipticity,Plane wave,Eigenvalues,Polarization analysis
更新于2025-09-19 17:15:36
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A Novel Weighted Integral Energy Functional (WIEF) Algorithm: Augmented Reality (AR) for Visualising the Blood Vessels in Breast Implant Surgeries
摘要： The use of Augmented Reality (AR) for visualising blood vessels in surgery is still at the experimental stage and has not been implemented due to limitations in terms of accuracy and processing time. The AR also hasn't applied in breast surgeries yet. As there is a need for a plastic surgeon to see the blood vessels before he cuts the breast and before putting the implant, this paper aims to improve the accuracy of augmented videos in visualising blood vessels during Breast Implant Surgery. The proposed system consists of a Weighted Integral Energy Functional (WIFE) algorithm to increase the accuracy of the augmented view in visualising the occluded blood vessels that covered by fat in the operating room. The results on breast area shows that the proposed algorithm improves video accuracy in terms of registration error to 0.32 mm and processing time to 23 sec compared to the state-of-the-art method. The proposed system focuses on increasing the accuracy in augmented view in visualising blood vessels during Breast Implant Surgery as it reduces the registration error. Thus, this study concentrates on looking at the feasibility of the use of Augmented Reality technology in Breast Augmentation surgeries.
关键词： Breast Augmentation,Augmented Reality,Random Decision Forests,Surgical Planning,Vascular Pulsation,Wavelet Decomposition
更新于2025-09-19 17:15:36
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On the Decomposition of Carbonate-Based Lithium-Ion Battery Electrolytes Studied Using Operando Infrared Spectroscopy
摘要： A novel infrared diagnostic for operando measurements of electrolyte decomposition is reported. The diagnostic was used to study the decomposition of LiPF6/EC/DEC electrolyte in LCO/graphite Li-ion cells. During formative cycles spectra revealed electrochemical reduction of the EC carbonyl group, which corresponded to simultaneous SEI formation on the graphite anode. This observation supplements current theories of EC decomposition during SEI formation. Operating LCO half-cells at voltages above 4.2 V caused permanent battery capacity loss but no observable electrolyte degradation, indicating the LCO electrode is degraded at high voltage. Infrared thermometry was used to measure the temperature of the electrolyte during heated tests. Operating cells at temperatures above 70°C resulted in SEI and electrolyte decomposition. Operando spectra collected during heating revealed EC ring-opening as the mechanism of thermal degradation, which resulted in permanent capacity loss. EC thermal decomposition was identical in all cells tested, indicating a homogeneous decomposition reaction independent of electrode material or potential. Thermal stability decreased with increased salt concentration indicating that decomposition is likely catalyzed by LiPF6 decomposition products. Thus, thermal decomposition is not caused by continued reduction reactions on the anode due to SEI failure, as EC reduction and EC thermal decomposition have different mechanisms.
关键词： SEI formation,operando infrared spectroscopy,thermal stability,lithium-ion batteries,electrolyte decomposition
更新于2025-09-19 17:15:36
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Dynamic and quasi-static signal separation method for bridges under moving loads based on long-gauge FBG strain monitoring
摘要： Structural health monitoring is an important means of obtaining the state information of bridges, and the extracted quasi-static strain signal can reflect the stress state of bridges directly. However, the strain signals acquired during the operation stage of bridges are dynamic, and the strain gauges used in the health monitoring system are short (no more than 10 cm), which means they are easily affected by small damage at the installation parts of bridges and thereby the monitoring signal abnormalities occur. A type of externally affixed long-gauge fiber strain gauge is used to monitor the health of bridges, and the dynamic and quasi-static signal separation method for long-gauge strain sensors is studied under different vehicle loads; at the same time, the dynamic monitoring performance of the long-gauge sensor is investigated in this paper. The quasi-static strain signal extracted from the dynamic macro-strain signal can be used to directly monitor the stress status of the bridge. The results show that the method proposed in this paper is feasible for extracting the quasi-static macro-strain from a dynamic long-gauge strain signal.
关键词： signal processing,bridge engineering,empirical mode decomposition method,macro-strain,Bridge health monitoring
更新于2025-09-19 17:15:36
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Photocuring of Radically Polymerizable Hyperbranched Polymers Having Degradable Linkages
摘要： Hyperbranched polymers having a number of reductive disulfide bonds and radically reactive vinyl groups were synthesized by the bulk radical homopolymerization of bis(2-methacryloyloxyethyl)disulfide (disulfide based dimethacrylate, DSDMA) as a divinyl monomer in the presence of methyl 2-(bromomethyl)acrylate as an addition-fragmentation chain transfer agent. The resulting hyperbranched polymers (HB-DSDMAs) were photocured by irradiated at 365 nm in the presence of 2,2-dimethoxy-2-phenylacetophenone as a photo radical initiator. The photocured HB-DSDMA exhibited high transparency in the visible region and good solvent resistance for various organic solvents. Reduction of the disulfide groups smoothly proceeded in the presence of tributylphosphine as a reductant, and the cured HB-DSDMAs were completely solubilized. HB-DSDMAs were also photocured by irradiation at 254 nm due to the homolysis of the disulfide groups with subsequent initiation of the radical polymerization.
关键词： Photo cleavage,Reductive decomposition,Hyperbranched,Degradable,Curable,polymer,Photopolymerization
更新于2025-09-19 17:15:36
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Chloro- and Dichloro-methylsulfonyl Nitrenes: Spectroscopic Characterization, Photoisomerization, and Thermal Decomposition
摘要： Chloro- and dichloro-methylsulfonyl nitrenes, CH2ClS(O)2N and CHCl2S(O)2N, have been generated from UV laser photolysis (193 and 266 nm) of the corresponding sulfonyl azides CH2ClS(O)2N3 and CHCl2S(O)2N3, respectively. Both nitrenes have been characterized with matrix-isolation IR and EPR spectroscopy in solid N2 (10 K) and glassy toluene (5 K) matrices. Triplet ground-state multiplicity of CH2ClS(O)2N (|D/hc| = 1.57 cm?1 and |E/hc| = 0.0026 cm?1) and CHCl2S(O)2N (|D/hc| = 1.56 cm?1 and |E/hc| = 0.0042 cm?1) has been confirmed. In addition, dichloromethylnitrene CHCl2N (|D/hc| = 1.57 cm?1 and |E/hc| = 0 cm?1), formed from SO2-elimination in CHCl2S(O)2N, has also been identified for the first time. Upon UV light irradiation (365 nm), the two sulfonyl nitrenes R–S(O)2N (R = CH2Cl and CHCl2) undergo concomitant 1,2-R shift to N-sulfonlyamines R–NSO2 and 1,2-oxygen shift to S-nitroso compounds R–S(O)NO, respectively. The identification of these new species with IR spectroscopy is supported by 15N labeling experiments and quantum chemical calculations at the B3LYP/6-311++G(3df,3pd) level. In contrast, the thermally-generated sulfonyl nitrenes CH2ClS(O)2N (600 K) and CHCl2S(O)2N (700 K) dissociate completely in the gas phase, and in both cases, HCN, SO2, HCl, HNSO, and CO form. Additionally, ClCN, OCCl2, HNSO2, ?NSO2, and the atmospherically relevant radical ?CHCl2 are also identified among the fragmentation products of CHCl2S(O)2N. The underlying mechanisms for the rearrangement and decomposition of CH2ClS(O)2N and CHCl2S(O)2N are discussed based on the experimentally-observed products and the calculated potential energy profile.
关键词： decomposition,nitrenes,azides,reaction mechanism,photoisomerization,matrix isolation
更新于2025-09-19 17:15:36
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Phase-locking particle image velocimetry measurement of unsteady flow behaviors: Online dynamic mode decomposition using field-programmable gate array
摘要： A novel online dynamic mode decomposition (DMD) approach using a field-programmable gate array (FPGA), which takes full advantage of the DMD to extract multiple unsteady events and the FPGA system for signal sampling and fast computation, was developed for phase-locking particle image velocimetry (PIV) measurements of unsteady flow behaviors. The turbulent separated and reattaching flow around a finite blunt plate with a length-to-height-ratio L/D = 6.0 was examined to demonstrate this novel approach. The wall-pressure field and the velocity field were measured using arrayed microphones and the conventional planar PIV setup, respectively. Offline DMD analysis of the wall-pressure fluctuation field was first used to identify the dominant modes corresponding to the energetically unsteady events. For each mode, the eigenmode and its mode coefficient reflected the spatial footprint pattern and temporal strength of the unsteady event, respectively. Next, trained machine learning of the mode coefficient was used to establish a phase prediction strategy. Finally, in the online analysis, the relevant eigenmode was cast into the FPGA device to serve as the reference mode for reconstruction with the sampled wall-pressure data, determining the phase signal to fire the PIV setup. High-resolution spatiotemporal evolutions of the dominant flow structures (i.e., the flapping separation bubble, the impinging leading-edge vortex, and the trailing-edge vortex street) were separately assembled. Further measurements demonstrated a clear panoramic view of the synchronous behavior of the enlarging separation bubble and the impinging leading-edge vortex. The proposed online FPGA-DMD approach can serve as a sophisticated strategy for phase-locking PIV measurements of unsteady flow behaviors.
关键词： phase-locking,dynamic mode decomposition,unsteady flow,particle image velocimetry,field-programmable gate array
更新于2025-09-19 17:15:36
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Theoretical evaluation of thermal decomposition of dichlorosilane for plasma-enhanced atomic layer deposition of silicon nitride: the important role of surface hydrogen
摘要： Silicon nitride (SiN) thin films have been widely employed for various applications including microelectronics, but their deposition presents a challenge especially when highly conformal layers are necessary on nanoscale features with high aspect ratios. Plasma-enhanced atomic layer deposition (PEALD) has been demonstrated to be a promising technique for controlled growth of SiN thin films at relatively low temperatures (o400 1C), in which thermal decomposition of Si-containing precursors on a N-rich surface is a critical step. Based on periodic density functional theory calculations, we present potential underlying mechanisms leading to facile thermal decomposition of dichlorosilane (DCS, SiH2Cl2) on the N-rich b-Si3N4(0001) surface. Our study highlights the importance of high hydrogen content on the N-rich surface, rendering primary and secondary amine groups. When the N-rich b-Si3N4(0001) surface is fully hydrogenated, the molecular adsorption of DCS is predicted to be exothermic by 0.6 eV. In this case, DCS decomposition appears to be initiated by nucleophilic attack by an amine lone-pair on the electrophilic Si, leading to the formation of a DCS-amine adduct intermediate followed by release of a Cl(cid:2) anion and a proton. The predicted activation barrier for the DCS decomposition reaction is only 0.3 eV or less, depending on its adsorption configuration. We also discuss the formation and desorption of HCl, the subsequent formation and nature of Si–N bonds, and the interaction between adsorbed DCS molecules. While clearly demonstrating the advantageous features of DCS as a Si precursor, this work suggests that the thermal decomposition of Si precursors, and in turn the ALD kinetics and resulting film quality, can be strongly influenced by surface functional groups, in addition to product accumulation and precursor coverage.
关键词： silicon nitride,plasma-enhanced atomic layer deposition,dichlorosilane,surface hydrogen,thermal decomposition,density functional theory
更新于2025-09-19 17:15:36
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[IEEE 2019 10th Workshop on Hyperspectral Imaging and Signal Processing: Evolution in Remote Sensing (WHISPERS) - Amsterdam, Netherlands (2019.9.24-2019.9.26)] 2019 10th Workshop on Hyperspectral Imaging and Signal Processing: Evolution in Remote Sensing (WHISPERS) - A Coupled Retrieval Of Columnar Water Vapor and Canopy Water Content From Spaceborne Hyperspectral Measurements
摘要： Huynen decomposition (HD) as the first formalized target decomposition has not been widely accepted. The preference for symmetry and regularity restricts not only its application but also its unification with other target dichotomies. The nonuniqueness issue then arises because we may have different dichotomies of radar targets, but we have no idea on how to select them. In this paper, a unified Huynen dichotomy is developed by extending HD for a full preference for symmetry and regularity, nonsymmetry, irregularity, and their couplings. It covers all of the existing dichotomies and provides a unified selection mechanism for them. Scattering preference is identified as a main feature of target dichotomy, and its concise description is devised by relating each dichotomy to a canonical scattering. A scattering degree of preference (SDoP) parameter is defined to measure the preference of each dichotomy. In virtue of an adaptive combination and permutation of SDoPs, a scattering pyramid description of the mixed scattering is developed, which has better discrimination of target than entropy/alpha. An SDoP/alpha classification is further proposed by statistical modeling of the unified dichotomy, which is a competent alternative to entropy/alpha. The excellent performance of unified dichotomy makes us believe that the existing concerns on HD are well treated and the Huynen–Cloude controversy, in a sense, may be ended.
关键词： target decomposition,Huynen decomposition (HD),unsupervised classification,target extraction,radar polarimetry
更新于2025-09-19 17:13:59