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Lorentz force electrical impedance tomography using pulse compression technique 被引量:3
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作者 孙直申 刘国强 夏慧 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第12期355-360,共6页
Lorentz force electrical impedance tomography (LFEIT) combines ultrasound stimulation and electromagnetic field detection with the goal of creating a high contrast and high resolution hybrid imaging modality. In thi... Lorentz force electrical impedance tomography (LFEIT) combines ultrasound stimulation and electromagnetic field detection with the goal of creating a high contrast and high resolution hybrid imaging modality. In this study, pulse compression working together with a linearly frequency modulated ultrasound pulse was investigated in LFEIT. Experiments were done on agar phantoms having the same level of electrical conductivity as soft biological tissues. The results showed that:(i) LFEIT using pulse compression could detect the location of the electrical conductivity variations precisely; (ii) LFEIT using pulse compression could get the same performance of detecting electrical conductivity variations as the traditional LFEIT using high voltage narrow pulse but reduce the peak stimulating power to the transducer by 25.5 dB; (iii) axial resolution of 1 mm could be obtained using modulation frequency bandwidth 2 MHz. 展开更多
关键词 Lorentz force electrical impedance tomography Hall effect imaging magneto-acousto-electrical tomography linear frequency-modulation pulse compression
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Space debris tracking based on fuzzy running Gaussian average adaptive particle filter track-before-detect algorithm 被引量:1
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作者 Peerapong Torteeka Peng-Qi Gao +5 位作者 Ming Shen Xiao-Zhang Guo Da-Tao Yang Huan-Huan Yu Wei-Ping Zhou You Zhao 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2017年第2期51-62,共12页
Although tracking with a passive optical telescope is a powerful technique for space debris observation, it is limited by its sensitivity to dynamic background noise. Traditionally, in the field of astronomy, static b... Although tracking with a passive optical telescope is a powerful technique for space debris observation, it is limited by its sensitivity to dynamic background noise. Traditionally, in the field of astronomy, static background subtraction based on a median image technique has been used to extract moving space objects prior to the tracking operation, as this is computationally efficient. The main disadvantage of this technique is that it is not robust to variable illumination conditions. In this article, we propose an approach for tracking small and dim space debris in the context of a dynamic background via one of the optical telescopes that is part of the space surveillance network project, named the Asia- Pacific ground-based Optical Space Observation System or APOSOS. The approach combines a fuzzy running Gaussian average for robust moving-object extraction with dim-target tracking using a particle- filter-based track-before-detect method. The performance of the proposed algorithm is experimentally evaluated, and the results show that the scheme achieves a satisfactory level of accuracy for space debris tracking. 展开更多
关键词 astrometry -- space debris -- atmospheric effects -- image processing
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Multi-voltage X-ray image sequence fusion based on selection of valid region 被引量:2
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作者 WEI Jiao-tong HAN Yan CHEN Ping 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2016年第4期358-362,共5页
A key step is to extract valid information region in the fusion of multi-voltage X-ray image sequence for complicated components. To improve the self-adaption of extraction, a method is presented in this paper. In thi... A key step is to extract valid information region in the fusion of multi-voltage X-ray image sequence for complicated components. To improve the self-adaption of extraction, a method is presented in this paper. In this paper, the valid informa-tion region is selected by the grey level interval, which is computed by the optimization of image quality evaluation model. The model is based on the histogram equalization and the grey level interval. Then, every valid region of images at different voltages is extracted and they are fused according their grey level transformation function. The fusion image contains completed struc-ture information of the component. The fusion experiment of a cylinder head shows the effectiveness of the presented method. 展开更多
关键词 multi-voltage X-ray image fusion valid regioncylinder head shows the effectiveness of the presented method.
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Effects of light intensity on reflective ghost imaging 被引量:1
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作者 段徳洋 杜少将 +4 位作者 闫丽 姜盛山 刘元元 张路 夏云杰 《Chinese Optics Letters》 SCIE EI CAS CSCD 2014年第7期63-66,共4页
In this letter, we analyze the effects of light intensity find that the brightness of reflective ghost image can on reflective ghost imaging with thermal source. We be changed by modulating the light intensity of the ... In this letter, we analyze the effects of light intensity find that the brightness of reflective ghost image can on reflective ghost imaging with thermal source. We be changed by modulating the light intensity of the source and the splitting ratio of the beam splitter. The signal-to-noise ratio will be improved by increa.sing the light intensity of the source. More important, we can obtain the reflective ghost image with high image quality by adopting a low light intensity signal beam and a high light intensity reference beam, which is better than the classical optical imaging, because it can reduce the effects of light on the object. 展开更多
关键词 effects of light intensity on reflective ghost imaging
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A quick and effective multivariate statistical strategy for imaging mass spectrometry 被引量:1
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作者 Fei Tang Yi Chen +4 位作者 Tie-Gang Li Jiu-Ming He Zeper Abliz Gang Huang Xiao-Hao Wang 《Chinese Chemical Letters》 SCIE CAS CSCD 2014年第10期1331-1335,共5页
A new multivariate statistical strategy for analyzing large datasets that are produced by imaging mass spectrometry(IMS) techniques is reported.The strategy divides the whole datacube of the sample into several subs... A new multivariate statistical strategy for analyzing large datasets that are produced by imaging mass spectrometry(IMS) techniques is reported.The strategy divides the whole datacube of the sample into several subsets and analyses them one by one to obtain the results.Instead of analyzing the whole datacube at one time,the strategy makes the analysis easier and decreases the computation time greatly.In this report,the IMS data are produced by the air flow-assisted ionization IMS(AFAI-IMS).The strategy can be used in combination with most multivariate statistical analysis methods.In this paper,the strategy was combined with the principal component analysis(PCA) and partial least square analysis(PLS).It was proven to be effective by analyzing the handwriting sample.By using the strategy,the m/z corresponding to the specific lipids in rat brain tissue were distinguished successfully.Moreover the analysis time grew linearly instead of exponentially as the size of sample increased.The strategy developed in this study has enormous potential for searching for the mjz of potential biomarkers quickly and effectively. 展开更多
关键词 imaging mass spectrometry Multivariate statistical analysis Potential biomarkers Quick and effective
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Gate-to-body tunneling current model for silicon-on-insulator MOSFETs
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作者 伍青青 陈静 +4 位作者 罗杰馨 吕凯 余涛 柴展 王曦 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第10期604-607,共4页
A gate-to-body tunneling current model for silicon-on-insulator (SOl) devices is simulated. As verified by the mea- sured data, the model, considering both gate voltage and drain voltage dependence as well as image ... A gate-to-body tunneling current model for silicon-on-insulator (SOl) devices is simulated. As verified by the mea- sured data, the model, considering both gate voltage and drain voltage dependence as well as image force-induced barrier low effect, provides a better prediction of the tunneling current and gate-induced floating body effect than the BSIMSOI4 model. A delayed gate-induced floating body effect is also predicted by the model. 展开更多
关键词 gate-to-body tunneling gate-induced floating body effect image force-induced barrier low effect silicon-on-insulator
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Examining Mediating Role of Customer Loyalty for Influence of Brand Related Attributes on Customer Repurchase Intention
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作者 Zeeshan Ahmad Meng Jun +2 位作者 Imran Khan Muhammad Abdullah Tauqir Ahmad Ghauri 《Journal of Northeast Agricultural University(English Edition)》 CAS 2016年第2期89-96,共8页
The objective of current study was to investigate the influence of brand related attributes on customer loyalty and repurchase intention in agricultural product marketing in Pakistan. Results of current study would he... The objective of current study was to investigate the influence of brand related attributes on customer loyalty and repurchase intention in agricultural product marketing in Pakistan. Results of current study would help the management of branded agricultural products, in Pakistan specifically and in developing countries generally, to formulate the best strategies to enhance customer loyalty in order to induce repurchase intention of them. Future research could be conducted in the same field by adopting larger sample size and this research can be replicated with specific product category. 展开更多
关键词 brand image brand loyalty repurchase intention mediating effect agricultural product marketing
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Improved preprocessed Yaroslavsky filter based on shearlet features
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作者 吴一全 戴一冕 吴健生 《Journal of Beijing Institute of Technology》 EI CAS 2016年第1期135-144,共10页
An improved preprocessed Yaroslavsky filter(IPYF)is proposed to avoid the nick effects and obtain a better denoising result when the noise variance is unknown.Different from its predecessors,the similarity between t... An improved preprocessed Yaroslavsky filter(IPYF)is proposed to avoid the nick effects and obtain a better denoising result when the noise variance is unknown.Different from its predecessors,the similarity between two pixels is calculated by shearlet features.The feature vector consists of initial denoised results by the non-subsampled shearlet transform hard thresholding(NSST-HT)and NSST coefficients,which can help allocate the averaging weights more reasonably.With the correct estimated noise variance,the NSST-HT can provide good denoised results as the initial estimation and high-frequency coefficients contribute large weights to preserve textures.In case of the incorrect estimated noise variance,the low-frequency coefficients will mitigate the nick effect in cartoon regions greatly,making the IPYF more robust than the original PYF.Detailed experimental results show that the IPYF is a very competitive method based on a comprehensive consideration involving peak signal to noise ratio(PSNR),computing time,visual quality and method noise. 展开更多
关键词 image processing image denoising preprocessed Yaroslavsky filter shearlet features nick effect
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Electrical Homo-Junction Delineation Techniques: A Comparative Study
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作者 Nicolas Vivet Mélanie Diogo +4 位作者 Amandine Aubert Tony Moinet Fabien Allanic Raphael Perdreau Jean-Paul Rebrassé 《Materials Sciences and Applications》 2016年第6期326-347,共22页
In active semiconductor devices, the junction characteristics are critical for the electrical performance. As an alternative of the atomic force microscopy (AFM)-based electrical techniques which provide unique juncti... In active semiconductor devices, the junction characteristics are critical for the electrical performance. As an alternative of the atomic force microscopy (AFM)-based electrical techniques which provide unique junction characterization, other methods are dedicated for the delineation of the electrical junction such as the wet chemical etching, the electrochemical plating method, the Seebeck effect imaging (SEI) method, the electron-beam induced current (EBIC) technique and the secondary electron potential contrast (SEPC) method. The aim of this paper is in the one hand to compare these five techniques in term of sample preparation, spatial application range, spatial resolution, simplicity and information displayed. In the other hand, this review aims to provide some guidelines for the appropriate delineation method(s) selection. It was confirmed that chemical based techniques are the simplest junction delineation methods but exhibit some drawbacks in term of spatial resolution and reproducibility. Despite of a limited spatial resolution, it was evidenced that EBIC can provide accurate electrical characterization of the junction. Finally, it was demonstrated that SEPC is the most promising technique providing the higher spatial resolution. The effect of the sample preparation method has been described. Even if the comparison was mainly based on homo-micro-Silicon junctions (n-p and n-p-n-p), the results were also discussed for short SiC junctions. The importance of the analysis context was considered in this paper and analysis flow was suggested for specific analysis cases. 展开更多
关键词 Junction Delineation Silicon Silicon Carbide Electron Beam Induced Current Seebeck effect imaging Secondary Electron Potential Contrast
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Simple and effective method to improve the signal-to-noise ratio of compressive imaging
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作者 Yao Zhao Qian Chen +1 位作者 Guohua Gu and Xiubao Sui 《Chinese Optics Letters》 SCIE EI CAS CSCD 2017年第10期46-50,共5页
This Letter presents a simple and effective method to improve the signal-to-noise ratio(SNR) of compressing imaging. The main principles of the proposed method are the correlation of the image signals and the random... This Letter presents a simple and effective method to improve the signal-to-noise ratio(SNR) of compressing imaging. The main principles of the proposed method are the correlation of the image signals and the randomness of the noise. Multiple low SNR images are reconstructed firstly by the compressed sensing reconstruction algorithm, and then two-dimensional time delay integration technology is adopted to improve the SNR. Results show that the proposed method can improve the SNR performance efficiently and it is easy to apply the a lgorithm to the real project. 展开更多
关键词 SNR Simple and effective method to improve the signal-to-noise ratio of compressive imaging
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An effective graph and depth layer based RGB-D image foreground object extraction method
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作者 Zhiguang Xiao Hui Chen +1 位作者 Changhe Tu Reinhard Klette 《Computational Visual Media》 CSCD 2017年第4期387-393,共7页
We consider the extraction of accurate silhouettes of foreground objects in combined color image and depth map data.This is of relevance for applications such as altering the contents of a scene,or changing the depths... We consider the extraction of accurate silhouettes of foreground objects in combined color image and depth map data.This is of relevance for applications such as altering the contents of a scene,or changing the depths of contents for display purposes in 3DTV,object detection,or scene understanding.To 展开更多
关键词 RGB An effective graph and depth layer based RGB-D image foreground object extraction method
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Investigation of high resolution compact gamma camera module based on a continuous scintillation crystal using a novel charge division readout method 被引量:1
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作者 代秋声 赵翠兰 +1 位作者 张华林 漆玉金 《Chinese Physics C》 SCIE CAS CSCD 2010年第8期1148-1152,共5页
The objective of this study is to investigate a high performance and lower cost compact gamma camera module for a multi-head small animal SPECT system. A compact camera module was developed using a thin Lutetium Oxyor... The objective of this study is to investigate a high performance and lower cost compact gamma camera module for a multi-head small animal SPECT system. A compact camera module was developed using a thin Lutetium Oxyorthosilicate (LSO) scintillation crystal slice coupled to a Hamamatsu H8500 position sensitive photomultiplier tube (PSPMT). A two-stage charge division readout board based on a novel subtractive resistive readout with a truncated center-of-gravity (TCOG) positioning method was developed for the camera. The performance of the camera was evaluated using a flood 99roTe source with a four-quadrant bar-mask phantom. The preliminary experimental results show that the image shrinkage problem associated with the conventional resistive readout can be effectively overcome by the novel subtractive resistive readout with an appropriate fraction subtraction factor. The response output area (ROA) of the camera shown in the flood image was improved up to 34%, and an intrinsic spatial resolution better than 2 mm of detector was achieved. In conclusion, the utilization of a continuous scintillation crystal and a flat-panel PSPMT equipped with a novel subtractive resistive readout is a feasible approach for developing a high performance and lower cost compact gamma camera. 展开更多
关键词 compact gamma camera module truncated center-of-gravity method image shrinkage effect
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Investigation of Portevin–Le Chatelier Band Strain and Elastic Shrinkage in Al-Based Alloys Associated with Mg Contents 被引量:3
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作者 Yulong Cai Suli Yang +2 位作者 Shihua Fu Di Zhang Qingchuan Zhang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2017年第6期580-586,共7页
The Portevin–Le Chatelier(PLC) effect in Al–2.30wt%Mg, Al–4.57wt%Mg and Al–6.91wt%Mg alloys has been investigated at various applied strain rates at room temperature in this study. Three-dimensional digital imag... The Portevin–Le Chatelier(PLC) effect in Al–2.30wt%Mg, Al–4.57wt%Mg and Al–6.91wt%Mg alloys has been investigated at various applied strain rates at room temperature in this study. Three-dimensional digital image correlation(3D-DIC) technique was applied to obtaining the further insight into the spatiotemporal characteristics, in particular the influence of Mg content on deformation behaviors. Mg content has a pronounced effect on serration characteristics, including the serration type and amplitude; Mg content tends to weaken the spatial correlation of the propagative bands. Additionally, the serration amplitude linearly increases with the maximum PLC band strain; high Mg content generates a higher PLC band strain at a given serration amplitude compared with low Mg content. Mg content is found to be effective to enhance the serration amplitude, the maximum PLC band strain and also the amount of elastic shrinkage outside PLC bands. 展开更多
关键词 Mg content Al–Mg alloy Portevin–Le Chatelier effect Digital image correlation Elastic shrinkage
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