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An Optimal Subspace deconvolution algorithm for Robust and High-Resolution Beamforming

SENSORS 2022年第6期22卷 2327-2327页

作者： Su, Xiruo Miao, Qiuyan Sun, Xinglin Ren, Haoran Ye, Lingyun Song, Kaichen Zhejiang Univ Coll Biomed Engn & Instrument Sci Hangzhou 310058 Peoples R China Zhejiang Univ Sch Earth Sci Hangzhou 310058 Peoples R China Zhejiang Univ Sch Aeronaut & Astronaut Hangzhou 310058 Peoples R China

Utilizing the difference in phase and power spectrum between signals and noise, the estimation of direction of arrival (DOA) can be transferred to a spatial sample classification problem. The power ratio, namely signal-to-noise ratio (SNR), is highly required in most high-resolution beamforming methods so that high resolution and robustness are incompatible in a noisy background. Therefore, this paper proposes a Subspaces deconvolution Vector (SDV) beamforming method to improve the robustness of a high-resolution DOA estimation. In a noisy environment, to handle the difficulty in separating signals from noise, we intend to initial beamforming value presets by incoherent eigenvalue in the frequency domain. The high resolution in the frequency domain guarantees the stability of the beamforming. By combining the robustness of conventional beamforming, the proposed method makes use of the subspace deconvolution vector to build a high-resolution beamforming process. The SDV method is aimed to obtain unitary frequency matrixes more stably and improve the accuracy of signal subspaces. The results of simulations and experiments show that when the input SNR is less than -27 dB, signals of decomposition differ unremarkably in the subspace while the SDV method can still obtain clear angles. In a marine background, this method works well in separating the noise and recruiting the characteristics of the signal into the DOA for subsequent processing.

关键词： Direction of Arrival Estimation (DOA) subspace vector deconvolution algorithm

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Full cycle rapid scan EPR deconvolution algorithm

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JOURNAL OF MAGNETIC RESONANCE 2017年 281卷 272-278页

作者： Tseytlin, Mark West Virginia Univ Sch Med Dept Biochem Morgantown WV 26506 USA West Virginia Univ Robert C Byrd Hlth Sci Ctr In Vivo Multifunct Magnet Resonance Ctr Morgantown WV 26506 USA

Rapid scan electron paramagnetic resonance (RS EPR) is a continuous-wave (CW) method that combines narrowband excitation and broadband detection. Sinusoidal magnetic field scans that span the entire EPR spectrum cause electron spin excitations twice during the scan period. Periodic transient RS signals are digitized and time-averaged. deconvolution of absorption spectrum from the measured full-cycle signal is an ill-posed problem that does not have a stable solution because the magnetic field passes the same EPR line twice per sinusoidal scan during up- and down-field passages. As a result, RS signals consist of two contributions that need to be separated and postprocessed individually. deconvolution of either of the contributions is a well-posed problem that has a stable solution. The current version of the RS EPR algorithm solves the separation problem by cutting the full-scan signal into two half-period pieces. This imposes a constraint on the experiment;the EPR signal must completely decay by the end of each half-scan in order to not be truncated. The constraint limits the maximum scan frequency and, therefore, the RS signal-to-noise gain. Faster scans permit the use of higher excitation powers without saturating the spin system, translating into a higher EPR sensitivity. A stable, full-scan algorithm is described in this paper that does not require truncation of the periodic response. This algorithm utilizes the additive property of linear systems: the response to a sum of two inputs is equal the sum of responses to each of the inputs separately. Based on this property, the mathematical model for CW RS EPR can be replaced by that of a sum of two independent full-cycle pulsed field-modulated experiments. In each of these experiments, the excitation power equals to zero during either up- or down-field scan. The full-cycle algorithm permits approaching the upper theoretical scan frequency limit;the transient spin system response must decay within the scan period.

关键词： Rapid scan EPR EPR imaging deconvolution algorithm Ill-posed problem Linear systems

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An improved deconvolution algorithm using B-splines for well-test data analysis in petroleum engineering

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JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING 2017年 149卷 306-314页

作者： Liu, Wenchao Liu, Yuewu Han, Guofeng Zhang, Jianye Wan, Yizhao Chinese Acad Sci Inst Mech Beijing 100190 Peoples R China Petro China Tarim Oilfield Co Res Inst Explorat & Dev Korla 841000 Xinjiang Peoples R China

Ilk et al.'s deconvolution algorithm using B-splines involves the Laplace transformation of the convolution equation with respect to production rate and wellbore pressure based on Duhamel principle. However, for common cases, the production rate function has "discontinuity" with respect to production time;it does not satisfy the precondition that the function to be transformed by Laplace transformation should be continuous. This inherent defect may directly cause enormous amount of computational time or even the failure of the numerical Laplace inversion in the deconvolution process. Based on these concerns, a fundamentally improved deconvolution algorithm using B-splines is presented here. In the convolution equation, the wellbore pressure derivative corresponding to constant unit production rate as the target of deconvolution is still represented by weighted summation of second-order B-splines;however, the computation process of the deconvolution is kept in the level of integral in the real time space instead of the Laplace space, for the reason that there will be no continuity requirement for the production rate function in the application of Duhamel principle for the deconvolution computation problem. According to the real production rate history, a technique of piecewise analytical integration is adopted for obtaining the elements of sensitivity matrix of a linear system with respect to weight coefficients;the linear system is generated by substituting the measured wellbore pressure data and corresponding variable 'production rate data into the convolution equation containing B-splines. The proposed direct analytical solution method of the integration for calculating the elements of the sensitivity matrix can not only guarantee the success of the deconvolution computation, but also can largely enhance the deconvolution computation speed. Moreover, in order to further improve the computation speed, a binary search method is also applied to find which production

关键词： deconvolution algorithm Well testing Duhamel principle Least square method

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Finding the optimal deconvolution algorithm for MR perfusion in carotid stenosis: Correlations with angiographic cerebral circulation time

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JOURNAL OF NEURORADIOLOGY 2016年第4期43卷 290-296页

作者： Lin, Chung-Jung Hung, Sheng-Che Chang, Feng-Chi Guo, Wan-Yuo Luo, Chao-Bao Kowarschik, Markus Chu, Wei-Fa Liou, Adrian J. Y. Kang Taipei Vet Gen Hosp Dept Radiol 201Shipai RdSect 2 Taipei 11217 Taiwan Natl Yang Ming Univ Sch Med Taipei Taiwan Siemens AG Healthcare Sect Angiog & Intervent Xray Syst Forchheim Germany

Purpose: The aim of our study is to explore the impacts of different deconvolution algorithms on correlations between CBF, MTT, CBV, TTP, Tmax from MR perfusion (MRP) and angiography cerebral circulation time (CCT). Methods: Retrospectively, 30 patients with unilateral carotid stenosis, and available prestenting MRP and angiography were included for analysis. All MRPs were conducted in a 1.5-T MR scanner. Standard singular value decomposition, block-circulant, and two delay-corrected algorithms were used as the deconvolution methods. All angiographies were obtained in the same bi-plane flat-detector angiographic machine. A contrast bolus of 12 mL was administrated via angiocatheter at a rate of 8 mL/s. The acquisition protocols were the same for all cases. CCT was defined as the difference between time to peak from the cavernous ICA and the parietal vein in lateral view. Pearson correlations were calculated for CCT and CBF, MTT, CBV, TTP, Tmax. Results: The correlation between CCT and MTT was highest with Tmax (r= 0.65), followed by MTT (r= 0.60), CBF (r=-0.57), and TTP (r=0.33) when standard singular value decomposition was used. No correlation with CBV was noted. Conclusions: MRP using a singular value decomposition algorithm confirmed the feasibility of quantifying cerebral blood flow deficit in steno-occlusive disease within the angio-room. This approach might further improve patient safety by providing immediate cerebral hemodynamics without extraradiation and iodine contrast. (C) 2016 Elsevier Masson SAS. All rights reserved.

关键词： Carotid stenosis Cerebral blood flow Cerebral circulation time deconvolution algorithm Quantitative DSA MR perfusion Time density curve

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High Spatial Resolution BOTDA Based on deconvolution and All Phase Digital Filtering

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IEEE SENSORS JOURNAL 2024年第7期24卷 10024-10030页

作者： Peng, Jiaxin Wang, Tao Zhang, Qian Ge, Xiaopeng Zhu, Yaqi Zhang, Yongqi Zhang, Jianzhong Li, Jian Zhang, Mingjiang Taiyuan Univ Technol Minist Educ Key Lab Adv Transducers & Intelligent Control Syst Taiyuan 030024 Peoples R China Univ Macau State Key Lab Internet Things Smart City Macau Peoples R China Shanxi Zheda Inst Adv Mat & Chem Engn Taiyuan 030032 Peoples R China

Brillouin optical time-domain analysis (BOTDA) technology plays an important role in distributed monitoring fields. However, the signal-to-noise ratio (SNR) is often degraded in the process of improving the sensing spatial resolution. Therefore, we propose a high spatial resolution BOTDA demodulation scheme based on a deconvolution algorithm complemented by all phase discrete Fourier transform (APDFT) digital filter. Initially, deconvolution algorithm is employed to improve the spatial resolution of the system. Subsequently, APDFT is used to filter out the noise in the signal, thereby improving the SNR while maintaining high spatial resolution. The results show that the sensing spatial resolution is optimized to 43 cm under a 40 ns pulsewidth in a 5.1 km sensing fiber and an enhancement in SNR by 6.5 dB is achieved compared to without denoising. The proposed scheme has a capability to achieve a heightened spatial resolution without upgrading the hardware devices of the BOTDA system.

关键词： All phase DFT digital filter Brillouin optical time-domain analysis deconvolution algorithm signal-to-noise ratio (SNR) spatial resolution

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Frequency Diverse Array and Spotlight Synthetic Aperture Radar 2D Imaging Based on Multiple Repeated Subpulses

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SENSORS 2025年第4期25卷 1075-1075页

作者： Li, Qinlin Liao, Kefei Xie, Ningbo Chen, Hanbo Guilin Univ Elect Technol Sch Informat & Commun Guilin 541004 Peoples R China Guangxi Intelligent Electromagnet Spectrum Percept Guilin 541004 Peoples R China

Frequency diverse array (FDA) beams show an "S" shape in space and cannot form a spot beam;thus, they cannot be directly combined with spotlight synthetic aperture radar (SSAR). In this paper, we propose a 2D imaging system emitting multiple repeated subpulses using an FDA and spotlight synthetic aperture radar (MRS-FDA-SSAR). This system carries the FDA on an airborne platform and uses the frequency difference between the array elements to synthesize broadband signals and obtain the distance-direction resolution, and then it uses a synthetic aperture technique to obtain the azimuth-direction resolution. Subsequently, 2D imaging results are obtained using the BP algorithm. A deconvolution algorithm is introduced to address the problem of high target sidelobes in the BP imaging results, which can result in the masking of weak targets. This allows 2D imaging results to be obtained with lower sidelobes. Finally, the MRS-FDA-SSAR model was simulated in experiments to verify its effectiveness.

关键词： frequency diverse array higher energy accumulation BP algorithm spotlight synthetic aperture radar deconvolution algorithm

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Influence of light spatial coherence on speckle imaging through scattering layers

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OPTICAL ENGINEERING 2025年第2期64卷

作者： Zhou, Yuanyuan Zhu, Dabo Soochow Univ Appl Technol Coll Suzhou Peoples R China

This work investigates the influence of light coherence on speckle imaging through a scattering layer. A focused laser is incident on a rotating ground glass (RGG). By changing the distance from the focus to the RGG, the degree of coherence of partially spatially coherent light can be controlled. Speckle correlation technique with iterative phase-retrieval algorithm and deconvolution method using point spread function are employed, and their results indicate that the lower the spatial coherence of the light, the higher the quality of the reconstructed object. Moreover, similar conclusions are obtained using an LED as light source. The results suggest that the coherence of light source should be carefully examined and selected to achieve high-quality speckle imaging through scattering layers.

关键词： speckle imaging spatial coherence of light speckle correlation technique deconvolution algorithm rotating ground glass

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Comparison of stromal vascular fraction cell composition between Coleman fat and extracellular matrix/stromal vascular fraction gel

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ADIPOCYTE 2024年第1期13卷 2360037页

作者： Li, Xiaoyun Zhang, Guohong Wang, Mengmeng Lu, Changhao Zhang, Guangping Chen, Zhehui Ji, Yingchang Shantou Univ Med Coll Dept Pathol Shantou Peoples R China Shantou Univ Affiliated Hosp 1 Med Coll Med Cosmet Ctr 57 Changping Rd Shantou 515041 Guangdong Peoples R China

As a mechanically condensed product of Coleman fat, extracellular matrix/stromal vascular fraction gel (ECM/SVF-gel) eliminates adipocytes, concentrates SVF cells, and improves fat graft retention. This study aims to compare SVF cell composition between Coleman fat and ECM/SVF-gel. Matched Coleman fat and ECM/SVF-gel of 28 healthy women were subjected to RNA-seq, followed by functional enrichment and cell-type-specific enrichment analyses, and deconvolution of SVF cell subsets, reconstructing SVF cell composition in the transcriptome level. ECM/SVF-gels had 9 upregulated and 73 downregulated differentially expressed genes (DEGs). Downregulated DEGs were mainly associated with inflammatory and immune responses, and enriched in fat macrophages. M2 macrophages, resting CD4(+) memory T cells, M1 macrophages, resting mast cells, and M0 macrophages ranked in the top five most prevalent immune cells in the two groups. The proportions of the principal non-immune cells (e.g., adipose-derived stem cells, pericytes, preadipocytes, microvascular endothelial cells) had no statistical differences between the two groups. Our findings reveal ECM/SVF-gels share the same dominant immune cells beneficial to fat graft survival with Coleman fat, but exhibiting obvious losses of immune cells (especially macrophages), while non-immune cells necessary for adipose regeneration might have no significant loss in ECM/SVF-gels and their biological effects could be markedly enhanced by the ECM/SVF-gel's condensed nature.

关键词： Coleman fat ECM/SVF-gel RNA-seq SVF cells deconvolution algorithm

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A deconvolutional Reconstruction Method Based on Lucy-Richardson algorithm for Joint Scanning Laser Thermography

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IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT 2021年 70卷 1-8页

作者： He, Zhiyi Wang, Hongjin Li, Yiwen Zhang, Zhenjun Zhang, Yudong Bi, Hanbo He, Yunze Hunan Univ Coll Elect & Informat Engn Changsha 410082 Peoples R China Air Force Engn Univ Sci & Technol Plasma Dynam Lab Xian 710038 Peoples R China

Joint scanning laser thermography (JLST) is well-known for its efficiency to overcome the field of view (FOV) limitation of thermal imagers. However, JSLT requires a data reconstruction to reveal the location of the defective area straightforwardly. Moreover, its detection capacity is limited by the lack of a deconvolution algorithm adaptive to the reconstructed data. In this study, a deconvolutional reconstruction method based on the Lucy-Richardson (LR) algorithm has been developed for JST, which is effective in suppressing random noise and the blur effect caused by the thermal diffusion. A JSLT inspection is carried out on a functional coating material with cylinder-like defects to test the performance of the proposed method. In comparison to the directly processed method on the original data, the proposed method is processed on the reconstructed data and then compared with principal component analysis (PCA), restored pseudo heat flux (RPHF), fast Fourier transform (FFT) methods and non-negative matrix factorization (NMF). The experimental results indicated that our proposed LR method exhibited a higher signal-to-noise ratio. Besides, it can detect the cylinder-mocked debonding defects with a diameter of 1.5 mm and a depth of 2.0 mm buried under the 1.0-mm coating. In addition, the defect detection diameter-to-depth ratio reached 1.5, while the defect detection rate of the test specimens can approach 90%.

关键词： deconvolution algorithm functional coating materials infrared thermography joint laser scanning nondestructive testing (NDT) and evaluation

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Determination of Water and Oil in Contaminated Coastal Sand by Low-Field Hydrogen-1 Nuclear Magnetic Resonance (¹H NMR)

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ANALYTICAL LETTERS 2021年第9期54卷 1496-1509页

作者： Bai, Ningchen Wang, Diansheng Zhang, Yingpeng Sui, Hongguang China Univ Petr East China Coll Sci Qingdao Peoples R China

This study presents a low-field hydrogen-1 nuclear magnetic resonance (H-1 NMR) method to accurately determine water and oil in oil-contaminated coastal sand. Rapid, efficient separation of water and oil signals in the overlapping transverse relaxation (T-2) spectra was achieved using a novel approach combining physical (paramagnetic ions Mn2+) and mathematical separation (deconvolution algorithm). High correlation coefficients of 0.998 and 0.982 were obtained between the prepared and NMR determined contents for water and oil together with the maximum errors of 0.84% and 0.54% for the water and oil content separately, which suggests NMR measurement of water and oil contents in oil-contaminated coastal sand is fairly accurate.

关键词： deconvolution algorithm hydrogen-1 nuclear magnetic resonance (1H NMR oil and water contents oil-contaminated coastal sands) paramagnetic ions transverse relaxation

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