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- 摘要
- 关键词
- 实验方案
- 产品
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Remote Vital Sign Recognition through Machine Learning augmented UWB
摘要： This paper describes an experimental demonstration of machine learning (ML) techniques supplementing radar to distinguish and detect vital signs of users in a domestic environment. This work augments an intelligent location awareness system previously proposed by the authors. That research employed Ultra-Wide Band (UWB) radar complemented by supervised machine learning techniques to remotely identify a person’s room location via ?oor plan training and time stamp correlations. Here, the remote breathing and heartbeat signals are analyzed through Short Term Fourier Transformation (STFT) to determine the Micro-Doppler signature of those vital signs in different room locations. Then, Multi-Class Support Vector Machine (MC-SVM) is implemented to train the system to intelligently distinguish between vital signs during different activities. Statistical analysis of the experimental results supports the proposed algorithm. This work could be used to further understand, for example, how active older people are by engaging in typical domestic activities.
关键词： Short Term Fourier Transform (STFT),Breathing,Ultra-Wide Band (UWB),Multi-Class Support Vector Machine (MC-SVM),Heartbeat,Indoor Positioning System (IPS)
更新于2025-09-23 15:22:29
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Hyperspectral Face Recognition with Patch-Based Low Rank Tensor Decomposition and PFFT Algorithm
摘要： Hyperspectral imaging technology with sufficiently discriminative spectral and spatial information brings new opportunities for robust facial image recognition. However, hyperspectral imaging poses several challenges including a low signal-to-noise ratio (SNR), intra-person misalignment of wavelength bands, and a high data dimensionality. Many studies have proven that both global and local facial features play an important role in face recognition. This research proposed a novel local features extraction algorithm for hyperspectral facial images using local patch based low-rank tensor decomposition that also preserves the neighborhood relationship and spectral dimension information. Additionally, global contour features were extracted using the polar discrete fast Fourier transform (PFFT) algorithm, which addresses many challenges relevant to human face recognition such as illumination, expression, asymmetrical (orientation), and aging changes. Furthermore, an ensemble classifier was developed by combining the obtained local and global features. The proposed method was evaluated by using the Poly-U Database and was compared with other existing hyperspectral face recognition algorithms. The illustrative numerical results demonstrate that the proposed algorithm is competitive with the best CRC_RLS and PLS methods.
关键词： spectral and spatial information,polar discrete fast Fourier transform,band fusion,ensemble classifier,global and local features,tensor decomposition,hyperspectral images
更新于2025-09-23 15:22:29
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[IEEE 2017 International Renewable and Sustainable Energy Conference (IRSEC) - Tangier (2017.12.4-2017.12.7)] 2017 International Renewable and Sustainable Energy Conference (IRSEC) - Solar Panels Frames Quality Assessment
摘要： Maintaining solar plant maximum energy production requires a regular inspection of solar panels. Images stitching technique of captured videos is usually used to form panoramic image view of the solar plant. Analyze of those images help supervisors to detect cracks, dust accumulation, …. Often captured videos are done using moveable devices, such as vehicle robots and drones. Usually, motion and shaking of devices provoke some blur captured frames which affect drastically the stitching process. In this paper, we study, experiment, and compare a set of techniques allowing to detect and discard blurred frames. As result, the algorithm based on Fourier Transform allows an efficient (i.e. accuracy of about 98%) and rapid treatment which can be easily integrated into online stitching process.
关键词： Blur estimation,Magnitude Fourier transform,DCT analysis,Image edges,SVD decomposition,Frame quality,Frames stitching
更新于2025-09-23 15:22:29
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[IEEE 2018 China International SAR Symposium (CISS) - Shanghai (2018.10.10-2018.10.12)] 2018 China International SAR Symposium (CISS) - 3D Velocity Estimation for Moving Targets via Geosynchronous Bistatic SAR
摘要： Recently, geosynchronous synthetic aperture radar (GEO-SAR), which can achieve continuous Earth observation missions with large coverage and short revisit period, has drawn extensive attention. The wide-swath imaging mode of GEO-SAR presents great potentials for bistatic observation applications. Geosynchronous bistatic SAR (GEO-BiSAR) can not only imaging task, but also provide the complete conditions for ground moving-target indication (GMTI). In this paper, the 3D velocity estimation for moving target via GEO-BiSAR are investigated. And the velocity estimation problem is extended to three-dimensional (3D) domain, considering that targets always move in a 3D space. To solve the 3D velocity of moving targets via GEO-BiSAR, the 3D velocity raw signal model is established, and a method based on fractional Fourier transform (FrFT) is proposed. First, the Doppler centroids and Doppler rates in the GEO-BiSAR are estimated by the FrFT. Second, one of the Doppler rates is used to estimate the azimuth velocity. Then, the range and height velocity are obtained by solving a Doppler centroid equation set. Finally, simulation experiments are presented to demonstrate the effectiveness of the method.
关键词： 3D Velocity Estimation,GMTI,fractional Fourier transform,Geosynchronous bistatic SAR
更新于2025-09-23 15:22:29
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High Resolution and Fast Processing of Spectral Reconstruction in Fourier Transform Imaging Spectroscopy
摘要： High-resolution spectrum estimation has continually attracted great attention in spectrum reconstruction based on Fourier transform imaging spectroscopy (FTIS). In this paper, a parallel solution for interference data processing using high-resolution spectrum estimation is proposed to reconstruct the spectrum in a fast high-resolution way. In batch processing, we use high-performance parallel-computing on the graphics processing unit (GPU) for higher efficiency and lower operation time. In addition, a parallel processing mechanism is designed for our parallel algorithm to obtain higher performance. At the same time, other solving algorithms for the modern spectrum estimation model are introduced for discussion and comparison. We compare traditional high-resolution solving algorithms running on the central processing unit (CPU) and the parallel algorithm on the GPU for processing the interferogram. The experimental results illustrate that runtime is reduced by about 70% using our parallel solution, and the GPU has a great advantage in processing large data and accelerating applications.
关键词： parallel computing,high performance,GPU,Fourier transform imaging spectrometer,spectrum reconstruction
更新于2025-09-23 15:22:29
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Tunable fractional Fourier transform implementation of electronic wave functions in atomically thin materials
摘要： A tunable fractional Fourier transform of the quantum wave function of electrons satisfying either the Schr?dinger or the Dirac equation can be implemented in an atomically thin material by a parabolic potential distribution applied on a direction transverse to that of electron propagation. The difference between the propagation lengths necessary to obtain a fractional Fourier transform of a given order in these two cases could be seen as a manifestation of the Berry phase. The Fourier transform of the electron wave function is a particular case of the fractional Fourier transform. If the input and output wave functions are discretized, this configuration implements in one step the discrete fractional Fourier transform, in particular the discrete Fourier transform, and thus can act as a coprocessor in integrated logic circuits.
关键词： Fourier transform,atomically thin materials,tunable devices
更新于2025-09-23 15:22:29
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Near-infrared remote sensing of Los Angeles trace gas distributions from a mountaintop site
摘要： The Los Angeles basin is a significant anthropogenic source of major greenhouse gases (CO2 and CH4) and the pollutant CO, contributing significantly to regional and global climate change. We present a novel approach for monitoring the spatial and temporal distributions of greenhouse gases in the Los Angeles basin using a high-resolution spectroscopic remote sensing technique. A new Fourier transform spectrometer called CLARS-FTS has been deployed since May, 2010, at Jet Propulsion Laboratory (JPL)'s California Laboratory for Atmospheric Remote Sensing (CLARS) on Mt. Wilson, California, for automated long-term measurements of greenhouse gases. The instrument design and performance of CLARS-FTS are presented. From its mountaintop location at an altitude of 1673 m, the instrument points at a programmed sequence of ground target locations in the Los Angeles basin, recording spectra of reflected near-IR solar radiation. Column-averaged dry-air mole fractions of greenhouse gases (XGHG) including XCO2, XCH4, and XCO are retrieved several times per day for each target. Spectra from a local Spectralon? scattering plate are also recorded to determine background (free tropospheric) column abundances above the site. Comparisons between measurements from LA basin targets and the Spectralon? plate provide estimates of the boundary layer partial column abundances of the measured species. Algorithms are described for transforming the measured interferograms into spectra, and for deriving column abundances from the spectra along with estimates of the measurement precision and accuracy. The CLARS GHG measurements provide a means to infer relative, and possibly absolute, GHG emissions.
关键词： column abundances,remote sensing,greenhouse gases,Fourier transform spectrometer,Los Angeles basin
更新于2025-09-23 15:22:29
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Assessment of Fringe Pattern Decomposition with a Cross-Correlation Index for Phase Retrieval in Fringe Projection 3D Measurements
摘要： Phase retrieval from single frame projection fringe patterns, a fundamental and challenging problem in fringe projection measurement, attracts wide attention and various new methods have emerged to address this challenge. Many phase retrieval methods are based on the decomposition of fringe patterns into a background part and a fringe part, and then the phase is obtained from the decomposed fringe part. However, the decomposition results are subject to the selection of model parameters, which is usually performed manually by trial and error due to the lack of decomposition assessment rules under a no ground truth data situation. In this paper, we propose a cross-correlation index to assess the decomposition and phase retrieval results without the need of ground truth data. The feasibility of the proposed metric is verified by simulated and real fringe patterns with the well-known Fourier transform method and recently proposed Shearlet transform method. This work contributes to the automatic phase retrieval and three-dimensional (3D) measurement with less human intervention, and can be potentially employed in other fields such as phase retrieval in digital holography.
关键词： parameter selection,cross-correlation,Fourier transform,phase retrieval,Shearlet transform,fringe pattern decomposition
更新于2025-09-23 15:21:21
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Recent progress in all-fiber non-Gaussian optical beam shaping technologies
摘要： Rapid development of fiber lasers are being followed by wide ranges of applications in laser processing technologies. One of the key parameters to determine the laser-matter interaction is beam shape and there have been intense research activities on beam shaping using bulk-optics. However, fiber optic solutions would take clear advantages over bulk-optics especially for fiber laser sources in terms of the beam conversion efficiency, the throughput power, and the compact footprint. In this article, all-fiber optical beam shaping technologies are reviewed and they are categorized as the phase front modification on the fiber facet, the surface plasmonics on fiber, all-fiber Fourier transformation, and multimode interference. Their physical principles, beam shaping capability, and some of the novel applications are explained
关键词： Phase front engineering,Laser beam,Surface plasmon polariton,Beam Shaping,Multimode Interference,Fourier Transform,Fiber Optics,Single mode optical fiber
更新于2025-09-23 15:21:21
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[IEEE 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - Chengdu, China (2018.3.26-2018.3.28)] 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - A Vector Parabolic Equation Method for Propagation Predictions Over 3-D Irregular Terrains
摘要： In this paper, a vector parabolic equation (PE) method based on perfectly absorbing thin screen is applied to predicting the propagation of electromagnetic waves over three-dimensional (3-D) irregular terrains. Under the assumption of forward propagation, the 3-D PE is obtained and the split-step Fourier transform algorithm is adopted to march the potentials from one aperture plane to the next. Terrains are equivalent to a series of perfectly absorbing thin screens arranged along the direction of propagation and the Tukey window is used to attenuate the fields smoothly at the upper boundary without reflections. Finally, in order to validate the proposed method, several numerical simulations are made and the results are compared with the two-dimensional PE method. As a result, good agreements are observed and the proposed method was confirmed to take the effect of lateral terrains into account.
关键词： split-step Fourier transform,vector parabolic equation,propagation prediction,irregular terrain
更新于2025-09-23 15:21:21