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Phase Shift Migration With SIMO Superposition for MIMO-Sidelooking Imaging at Terahertz Band

IEEE ACCESS 2020年 8卷 208418-208426页

作者： Yang, Guan Li, Chao Gao, Hang Fang, Guangyou Chinese Acad Sci Aerosp Informat Res Inst Beijing 100190 Peoples R China Chinese Acad Sci Key Lab Electromagnet Radiat & Sensing Technol Beijing 100190 Peoples R China Univ Chinese Acad Sci Sch Elect Elect & Commun Engn Beijing 100039 Peoples R China

In this paper, the enhanced phase shift migration (PSM) algorithm for multi-input-multi-output (MIMO) side-looking (SL) scheme was proposed for the 2-dimension (2D) fast image reconstruction in the terahertz (THz) band. By decomposing the MIMO imaging problem into a superposition of several single-input-multiple-output (SIMO) sub-arrays, the proposed algorithm can be applied to systems with randomly distributed transmitting array. By deriving and applying the modified phase shift factor and necessary phase compensation, zero-padding in the transmitting array and data reorganization in the spatial-frequency domain of the conventional wavenumber domain MIMO algorithm can be totally avoided, which will hopefully further reduce the amount of calculation. A comprehensive MIMO-SL-EPSM algorithm was established in the wavenumber domain. Proof-of-principle experiments in the 0.1-THz band were performed based on a MIMO-SL prototype system. The reconstructed images for different targets with high efficiency and quality demonstrate the theoretical results and the effectiveness of the proposed algorithm.

关键词： Interpolation Imaging Prototypes Explosions Arrays MIMO communication image reconstruction Multiple-input-multiple-output (MIMO) phase shift migration (PSM) terahertz (THz) image reconstruction algorithm

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ITERATIVE FILTERING reconstruction algorithm FOR GAMMA COMPUTERIZED TOMOGRAPHY: APPLICATION TO TWO-PHASE FLOW VISUALIZATION

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INSTRUMENTATION SCIENCE & TECHNOLOGY 2012年第1期40卷 1-16页

作者： Xue, Qian Wang, Huaxiang Hao, Kuihong Xin, Shan Tianjin Univ Sch Elect Engn & Automat Tianjin 300072 Peoples R China Civil Aviat Univ China Mech & Elect Engn Coll Tianjin Peoples R China

Considering the influence of the limited measurement data on the effectiveness of the image reconstruction algorithms in industrial multiphase flow tomography, an iterative filtering reconstruction algorithm is proposed by redefining inverse problem in this article. In order to improve the image quality in iterative reconstruction algorithm, Wiener filter and soft-threshold algorithm are employed as constraints for the reconstructed image. The developed algorithm is applied to gamma-CT based two-phase flow measurements, both simulated and experimental. The results demonstrate that the proposed method cannot only realize the flow regime identification on horizontal pipe, but also improve the iterative reconstruction process, i.e., the reconstructed image quality is enhanced and the iteration number is reduced.

关键词： computerized tomography (CT) image reconstruction algorithm two-phase flow

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An imaging algorithm of planar array capacitance sensor for defect detection

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MEASUREMENT 2021年 168卷

作者： Zhang, Yuyan Sun, Yurong Wen, Yintang Yanshan Univ Key Lab Measurement Technol & Instrumentat Hebei Qinhuangdao 066004 Hebei Peoples R China

Planar array capacitance imaging is a feasible solution for detecting defects in composite components. However, the coplanar arrangement of electrodes in the imaging system renders a soft field effect, which results in unstable or susceptible imaging. The inverse problem of a planar array capacitance sensor system is ill-posed. Hence, a wavelet fusion combined multi-objective threshold programming imaging algorithm is proposed for a planar array capacitive imaging system. Furthermore, initial values of conjugate gradient (CG) and Newton-Raphson (NR) algorithms are optimized using the Tikhonov regularization algorithm. Subsequently, wavelet fusion is introduced to fuse images obtained using the CG and NR algorithms to acquire more detailed information. To further improve the reconstructed quality, a multi-objective threshold programming strategy is proposed. The final reconstruction image is obtained using the optimal threshold. Experimental results show a significantly improved quality of the reconstructed image, thereby verifying the effectiveness of the presented algorithm.

关键词： Planar array capacitance sensor image reconstruction algorithm Wavelet fusion Multi-objective threshold programming

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Implementation method for magneto-acoustic concentration tomography with magnetic induction (MACT-MI) based on the method of moments

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COMPUTERS IN BIOLOGY AND MEDICINE 2021年 128卷 104105-104105页

作者： Yan, Xiaoheng Xu, Zhengyang Chen, Weihua Pan, Ye Liaoning Tech Univ Fac Elect & Control Engn Huludao 125105 Liaoning Peoples R China

Magneto-acoustic concentration tomography of magnetic nanoparticles with magnetic induction (MACT-MI) is a new imaging technology that combines the advantages of the high sensitivity of magnetic particle imaging and the high resolution of ultrasonic imaging. This technique has broad application prospects in the biomedical and molecular imaging fields. In this study, a reconstruction algorithm based on the method of moments (MoM) is proposed for the MACT-MI inverse problem. image reconstructions of the acoustic source and superparamagnetic nanoparticle (SPN) concentration were performed using different shape models, and the reconstructed images were analyzed. In addition, the effect of the radius of the tissue region loaded with SPNs on the quality of the reconstructed images was evaluated. The results demonstrated that the new method could reconstruct the SPN concentration distribution well, and a negative correlation existed between the radius of the imaging model and reconstructed image quality. The finding of this research can potentially contribute to the development of MACT-MI in medicine.

关键词： Magneto-acoustic concentration tomography with magnetic induction (MACT-MI) Method of moments Inverse problem image reconstruction algorithm

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A learnable end-edge-cloud cooperative network for driving emotion sensing

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COMPUTERS & ELECTRICAL ENGINEERING 2022年 103卷

作者： Ding, Cheng Ding, Fei Gorbachev, Sergey Yue, Dong Zhang, Dengyin Nanjing Univ Posts & Telecommun Sch Int Things Nanjing 210003 Peoples R China Nanjing Univ Posts & Telecommun Jiangsu Key Lab Broadband Wireless Commun & Int Nanjing 210003 Peoples R China Chongqing Univ Educ Sch Artificial Intelligence Chongqing 400065 Peoples R China Russian Acad Engn Moscow Russia Nanjing Univ Posts & Telecommun Coll Automat & Coll Artificial Intelligence Nanjing 210003 Peoples R China

The driver's emotional state directly affects safe driving. Under the "vehicle-human-road-cloud" integrated control framework, we propose an end-edge-cloud collaborative emotion perception network model (EEC-Net). The end side extracts the key frames of the driver's face video stream and performs batch compression;the edge side extracts the region of interest (ROI) of the reconstructed images as the input of the emotion recognition model (tiny_Xception) for classification;the cloud control terminal receives abnormal ROI image data and performs online training to dynamically adjust the operating parameters of the edge model. Finally, we test on open and self-built datasets, and the results show tiny_Xception has a significant improvement in accuracy of 2.45% compared to mini_Xception;the EEC-Net model can reliably perceive the negative emotion period, and the overall system memory consumption is reduced by about 5%, and the network transmission data volume and the computation time of emotion recognition are reduced by 95%, 60% respectively.

关键词： End -edge -cloud human -machine collaboration Video stream key frames extraction image reconstruction algorithm Region of interest Driver emotion recognition

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Using passive and active acoustic methods for impact damage assessment of composite structures

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COMPOSITE STRUCTURES 2019年 226卷

作者： Saeedifar, Milad Mansvelder, Jasmijn Mohammadi, Reza Zarouchas, Dimitrios Delft Univ Technol Struct Integr & Composites Grp Fac Aerosp Engn Delft Netherlands Amirkabir Univ Technol Nondestruct Testing Lab Dept Mech Engn Tehran Iran

This study aims to use the passive and active acoustic-based health monitoring methods for impact damage assessment of composite structures. To this aim, a Carbon Fiber Reinforced Polymer (CFRP) composite plate was fabricated and subjected to a simulated low-velocity impact by performing repeated quasi-static indentation tests where a loading-unloading-reloading test profile with 5 repetitions was adopted. Two Acoustic Emission (AE) broadband sensors and a network of eight piezoelectric (PZT) sensors were attached on the composite plate surface. AE (passive method) was employed during the loading and reloading phases of the indentation tests to online monitor the critical damage occurrence and also specify the damage type while scanning of the plate with Lamb waves (active method) was done to localize the damage when the structure was unloaded. Felicity Ratio (FR) index which was calculated based on the AE data could accurately detect that critical damage occurred during the 5th loading-unloading-reloading stage when the structural integrity dropped to 60% of its initial stage. Furthermore, Lamb wave signals of central frequency 150 kHz localized the impact damage with error of 0.89 cm (3.6% error respect to the shortest dimension of the scanned area).

关键词： Structural Health Monitoring Impact damage diagnostics Acoustic Emission Lamb waves image reconstruction algorithm

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Novel muon imaging techniques

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PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES 2019年第2137期377卷 20180062页

作者： Yang, Guangliang Clarkson, Tony Gardner, Simon Ireland, David Kaiser, Ralf Mahon, David Al Jebali, Ramsey Shearer, Craig Ryan, Matthew Univ Glasgow Sch Phys & Astron Glasgow G12 8QQ Lanark Scotland Univ Glasgow Lynkeos Technol Ltd Glasgow G12 8QQ Lanark Scotland Natl Nucl Lab Cent Lab Seascale CA20 1PG Cumbria England

Owing to the high penetrating power of high-energy cosmic ray muons, muon imaging techniques can be used to image large bulky objects, especially objects with heavy shielding. Muon imaging systems work just like CT scanners in the medical imaging field-that is, they can reveal information inside of a target. There are two forms of muon imaging techniques: muon absorption imaging and muon multiple scattering imaging. The former is based on the flux attenuation of muons, and the latter is based on the multiple scattering of muons in matter. The muon absorption imaging technique is capable of imaging very large objects such as volcanoes and large buildings, and also smaller objects like spent fuel casks;the muon multiple scattering imaging technique is best suited to inspect smaller objects such as nuclear waste containers. Muon imaging techniques can be applied in a broad variety of fields, i.e. from measuring the magma thickness of volcanoes to searching for secret cavities in pyramids, and from monitoring the borders of countries checking for special nuclear materials to monitoring the spent fuel casks for nuclear safeguards applications. In this paper, the principles of muon imaging are reviewed. image reconstruction algorithms such as Filtered Back Projection and Maximum Likelihood Expectation Maximization are discussed. The capability of muon imaging techniques is demonstrated through a Geant4 simulation study for imaging a nuclear spent fuel cask. This article is part of the Theo Murphy meeting issue 'Cosmic-ray muography'.

关键词： muon imaging inverse problem image reconstruction algorithm

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Investigation of gas-solid bubbling fluidized beds using ECT with a modified Tikhonov regularization technique

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AICHE JOURNAL 2018年第1期64卷 29-41页

作者： Guo, Qiang Meng, Shuanghe Wang, Dehu Zhao, Yinfeng Ye, Mao Yang, Wuqiang Liu, Zhongmin Chinese Acad Sci Dalian Inst Chem Phys Dalian Natl Lab Clean Energy Dalian 116023 Peoples R China Chinese Acad Sci Dalian Inst Chem Phys Natl Engn Lab MTO Dalian 116023 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China Univ Manchester Sch Elect & Elect Engn Manchester M13 9PL Lancs England

Electrical capacitance tomography (ECT) provides a non-intrusive means to visualize cross-sectional material distribution of gas-solid bubbling fluidized beds. Successful application of ECT strongly depends on the image reconstruction algorithm used. For on-line measurements of bubbling fluidized beds, employing an algorithm that can produce high-quality images without extensive computation is necessary. Using the conventional Tikhonov regularization algorithm, image quality in the central area is basically satisfied but suffers from artifacts in the near-wall region. To solve this problem, a similar division operation learned from linear back projection was introduced to modify the conventional Tikhonov algorithm. Both numerical simulations and experiments were performed to evaluate the modified technique. The results indicate that the artifacts can be effectively removed and the reconstructed image quality is similar to Landweber method with dozens of iterations. Furthermore, the modified Tikhonov technique shows high accuracy when obtaining important hydrodynamic parameters in gas-solid bubbling fluidized beds. (c) 2017 American Institute of Chemical Engineers AIChE J, 63: 29-41, 2018

关键词： gas-solid bubbling fluidized bed electrical capacitance tomography image reconstruction algorithm Tikhonov regularization hydrodynamic parameter

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Modified algebraic reconstruction technique based on circular scanning geometry to improve processing time in photoacoustic tomography

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MICROWAVE AND OPTICAL TECHNOLOGY LETTERS 2023年第8期65卷 2456-2463页

作者： Darband, Maryam Ahangar Qorbani, Omid Aghdam, Esmaeil Najafi Sahand Univ Technol Dept Elect Engn Tabriz *** Iran

Photoacoustic imaging is low-risk, and noninvasive tool for imaging biological tissues that acoustically respond to absorbed irradiating nonionized short laser pulse by tissue, then the image of light energy absorption distribution in the tissue has been reconstructed by image reconstruction algorithms. Indeed, photoacoustic tomography is a hybrid imaging modality that combines pure optical and acoustic imaging methods to take advantage of them, therefore, it contains high optical contrast with good ultrasonic resolution. However, improving its main parts is challenging. One of the most important parts of photoacoustic imaging is image reconstruction using appropriate algorithms. There are various image reconstruction methods. image reconstruction based on an algebraic algorithm can reconstruct a clear image without artifact, but the algorithm is typically time-consuming. This paper deals with this drawback of the algorithm. Simulations demonstrate significant improvement in the processing time of reconstructed images achieved by our proposed algorithm as compared to the phase-controlled algorithm. Based on the image reconstruction algorithm in circular scanning geometry presented in this article, the processing time required to create a 2D tomographic image is reduced from 60 to 3.89 s compared to our previous work, which was based on a phase-controlled algorithm. This improvement was based on inspiration from the experiences of our past works in dealing with various image reconstruction algorithms, which ultimately led to improvement in the calculation time.

关键词： breast cancer image reconstruction algorithm photoacoustic tomography ultrasonic

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High-resolution three-dimensional ANGIE T1 mapping of the whole heart

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Journal of Cardiovascular Magnetic Resonance 2015年第SUPPL 1期17卷 W4-W4页

作者： Bhairav B Mehta Michael Salerno Frederick H Epstein Department of Biomedical Engineering University of Virginia Charlottesville VA USA Medicine (Cardiology) University of Virginia Charlottesville VA USA Department of Radiology and Medical Imaging University of Virginia Charlottesville VA USA

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