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Effect of Signal filtering on Image Quality of Projection-Based Magnetic Particle Imaging

Open Journal of Medical Imaging 2017年第2期7卷 43-55页

作者： Kazuki Shimada Kenya Murase Department of Medical Physics and Engineering Division of Medical Technology and Science Faculty of Health Science Graduate School of Medicine Osaka University Osaka Japan

Purpose: Magnetic particle imaging (MPI) allows for imaging of the spatial distribution of magnetic nanoparticles (MNPs) in positive contrast, with high sensitivity, high spatial resolution, and high imaging speed. It is necessary to increase the signal-to-noise ratio to enhance the reliability of MPI. The purpose of this study was to investigate the effect of signal filtering on the image quality and quantitativity in projection-based MPI using phantoms. Materials and Methods: We fabricated two kinds of phantom (cylindrical tube phantom with a diameter of 6 mm and A-shaped phantom) and evaluated the effect of signal filtering in terms of root-mean-square (RMS) granularity and the correlation coefficient between iron concentrations of MNPs and average MPI values for four filter modes (THRU, BPF, BEF, and LPF). In the THRU mode, the signal input was output without passing through the filter. In the BPF mode, only the third-harmonic signal was passed using a band-pass filter (central frequency: 1200 Hz, band width: 1/3 octave). In the BEF mode, the first-harmonic signal was eliminated using a band-elimination filter (central frequency: 400 Hz, band width: 1/3 octave). In the LPF mode, only the signal with a frequency less than the third-harmonic frequency was passed using a low-pass filter (cut-off frequency: 1200 Hz, -24 ± 2 dB/octave). The RMS granularity was obtained by calculating standard deviations of the pixel values in the MPI image without MNPs, whereas average MPI values were obtained by drawing a circular region of interest with a diameter of 6 mm on the MPI image of the cylindrical tube phantom. Results: When using the filtered back-projection (FBP) method with a ramp filter for image reconstruction, the RMS granularity and correlation coefficient decreased in the order of THRU, BPF, BEF, and LPF. In the BPF mode, however, some artifacts were observed. When using the maximum likelihood-expectation maximization (ML-EM) algorithm with an iteration number of 15, the correlation coefficient decreased in the

关键词： Magnetic Particle Imaging (MPI) Magnetic Nanoparticles (MNPs) Signal filtering Image Quality Root-Mean-Square (RMS) Granularity

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A Novel filtering Method for Infrared Image

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国际计算机前沿大会会议论文集 2016年第1期 15-16页

作者： Jian Kang Chunxiao Zhou Weiqiang Xia Chaopeng Shen Guanglu Sun Beijing Institute of Astronautical Systems Engineering BeijingChina School of Computer Science and Technology Harbin University of Science and TechnologyHarbinHeilongjiangChina

The image filtering technology is widely used in many fields, such as environmental monitoring and assessment, space remote sensing, recognition and tracking of infrared target. In this paper, aiming at the problem of poor generalization capability and over-fitting with artificial neutral network for infrared image filtering, a new filtering method is presented. The structure elements are used to set up the training samples. And then, based on support vector machine theory, it builds the learning ma-chine with proper model and trains the samples. The result can be used to suppress the background SNR of following image. The experimental result with infrared image shows that the method can obtain higher SNR than conventional neutral network and fixed Top-Hat operator method, especially in low SNR.

关键词： Image filtering Neutral network Support vector machine Top-Hat operator

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TIME-SPACE 3D MATCHED filtering FOR PERFORMANCE ANALYSIS OF SYNTHETIC IMPULSE AND ANTENNA RADAR

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Journal of Electronics(China) 1995年第1期12卷 48-57页

作者：张庆文保铮张玉洪 Institute of Electronics Engineering Xidian University Xi'an 710071

The principle and performance of Synthetic Impulse and Antenna Radar(SIAR) are analyzed with the concept of 3D matched filtering. The discussion here is concentrated on the characteristics of SIAR in the case of three... 详细信息

关键词： Synthetic impulse Synthetic antenna 3D matched filtering Synthetic impulse and antenna radar (SIAR)

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Personalized Tag Recommendation Based on Transfer Matrix and Collaborative filtering

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Journal of Computer and Communications 2015年第9期3卷 9-17页

作者： Shaowu Zhang Yanyan Ge School of Computer Science and Technology Dalian University of Technology Dalian China School of Computer Science and Engineering Xinjiang University of Finance and Economics Urumqi China

In social tagging systems, users are allowed to label resources with tags, and thus the system builds a personalized tag vocabulary for every user based on their distinct preferences. In order to make the best of the personalized characteristic of users’ tagging behavior, firstly the transfer matrix is used in this paper, and the tag distributions of query resources are mapped to users’ query before the recommendation. Meanwhile, we find that only considering the user’s preference model, the method cannot recommend new tags for users. So we utilize the thought of collaborative filtering, and produce the recommend tags based on the query user and his/her nearest neighbors' preference models. The experiments conducted on the Delicious corpus show that our method combining transfer matrix with collaborative filtering produces better recommendation results.

关键词： Tag Recommendation Collaborative filtering Transfer Tensor

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A TIME filtering SCHEME FOR THE SHORT RANGE CLIMATE PREDICTION MODEL PRODUCTS AND ITS REAL CASE ANALYSIS

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Journal of Tropical Meteorology 2000年第1期6卷 29-36页

作者：闫敬华 Guangzhou Institute of Tropical and Oceanic Meteorology Guangzhou 510080 China

A filtering / extracting scheme for various timescale processes in short range climate model out-put is established by using the scale scattering method. And the climatological meanings as well as the impor-tance of the filtered series are discussed. In the latter part of work, the effectiveness of the filtering method and the performance of the prediction model are analyzed through a real case.

关键词： products of short-range climate model scale filtering scheme factors describing the predicted cli-mate performance of model

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A STATISTICAL NOISE MODEL AND MATHEMATICAL MODEL OF SPECKLE PATTERN AND ADAPTIVE filtering APPROACH

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Journal of Electronics(China) 1995年第1期12卷 24-32页

作者：杨亦兵何振亚 Southeast University Nanjing 210096

A statistical noise model and a mathematical model for real speckle pattern are presented in this paper, and then, in view of the models, a new adaptive suboptimal image filtering approach is proposed. The proposed approach, with the local direction features of speckle pattern, combines the characteristics of optimal linear filter with non-linear filter and is an adaptive approximation to linear minimum mean square error filter. Experimental results show that the proposed approach has fairly good edge-preserved performance, compared with other present image filters, as well as much better filtering performance and robustness for speckle pattern.

关键词： Speckle pattern Noises Adaptive filtering

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A sequential estimation problem with control and discretionary stopping

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Probability, Uncertainty and Quantitative Risk 2022年第3期7卷 151-168页

作者： Erik Ekström Ioannis Karatzas Department of Mathematics Uppsala UniversityBox 25675105 UppsalaSweden Departments of Mathematics and Statistics Columbia University2990 BroadwayNew YorkNY 10027USA

We show that“full-bang”control is optimal in a problem which combines features of(i)sequential least-squares estimation with Bayesian updating,for a random quantity observed in a bath of white noise;(ii)bounded control of the rate at which observations are received,with a superquadratic cost per unit time;and(iii)“fast”discretionary stopping.We develop also the optimal filtering and stopping rules in this context.

关键词： Sequential analysis filtering Optimal stopping Stochastic control Bold play

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AlN MEMS filters with extremely high bandwidth widening capability

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Microsystems & Nanoengineering 2020年第1期6卷 460-470页

作者： Anming Gao Kangfu Liu Junrui Liang Tao Wu Department of Electrical and Computer Engineering University of Illinois at Urbana-ChampaignUrbanaIL 61820USA School of Information Science and Technology(SIST) ShanghaiTech UniversityShanghai 201210China University of Chinese Academy of Sciences No.19(A)Yuquan RoadShijingshan DistrictBeijingChina

This paper presents radio frequency(RF)microelectromechanical system(MEMS)filters with extremely high bandwidth widening capability.The proposed filtering topologies include hybrid configurations consisting of piezoelectric MEMS resonators and surface-mounted lumped elements.The MEMS resonators set the center frequency and provide electromechanical coupling to construct the filters,while the lumped-element-based matching networks help widen the bandwidth(BW)and enhance the out-of-band rejection.Aluminum nitride(AlN)S0 Lamb wave resonators are then applied to the proposed filtering topologies.AlN S0 first-and second-order wideband filters are studied and have shown prominent performance.Finally,the AlN S0 first-order wideband filter is experimentally implemented and characterized.The demonstrated first-order filter shows a large fractional bandwidth(FBW)of 5.6%(achieved with a resonator coupling of 0.94%)and a low insertion loss(IL)of 1.84 dB.The extracted bandwidth widening factor(BWF)is 6,which is approximately 12 times higher than those of the current ladder or lattice filtering topologies.This impressive bandwidth widening capability holds great potential for satisfying the stringent BW requirements of bands n77,n78,and n79 of 5G new radio(NR)and will overcome an outstanding technology hurdle in placing 5G NR into the marketplace.

关键词： filters filtering coupling

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Approach Development Accelerate of Process Special Traffic filtering

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Journal of Computer and Communications 2015年第9期3卷 68-82页

作者： Karimov Madjit Malikovich Gulomov Sherzod Rajaboevich Yusupov Bakhodir Karomatovich Department of Information Security Faculty of Computer Engineering Tashkent University of Information Technologies Tashkent Uzbekistan

This article is dedicated to the analysis list of a set of rules to traffic filtering, which is a multi-dimensional structure, where each dimension is a set of networking field or the field of action, measuring the cost of the rules to traffic filtering on computer networks, allowing to determine the difference between definition of the rules and the control of the packet fields. Furthermore, the article was considered a hierarchical model to optimize traffic filtering, which reduces the overhead traffic filtering rules and provides the semantic integrity of the original set of rules to traffic filtering. The hierarchical structure of the design and optimization of traffic filtering was researched. And also was developed the hierarchical approach to optimize traffic filtering for reducing set of rules traffic filtering. Analyzed the algorithm optimal solutions and algorithm of random search filters that, allowing you to find the shortest way to a set of rules to traffic filtering. Moreover, in this article was presented the effectiveness evaluation of the process accelerating traffic filtering proposed by HAOTF.

关键词： Traffic filtering Hierarchical Structure Model HAOTF Heuristic Method

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AN ADAPTIVE filtering ALGORITHM OF VELOCITY ESTIMATION

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Journal of Electronics(China) 2000年第3期17卷 248-253页

作者： Tao Weigang Feng Xinxi(Dept. of the Computer and Command Automation, Telecom. Eng. Iust., Air Force Eng. University, Post Box No.111, Xi’an 710077)

In this paper, a novel adaptive filtering algorithm using real-time deviation of velocity estimation is presented for maneuvering target tracking. This new algorithm will be called adaptive filtering algorithm of velocity estimation. A number of simulation results indicate that the algorithm not only has good performance on tracking maneuvering target, but also greatly improves the capacity for tracking non-maneuvering target. So it is worthy to be applied widely in practice.

关键词： Target tracking Adaptive filtering Velocity estimation

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