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一种改进型脉冲耦合神经网络及其图像分割

计算机工程与应用 2003年第8期39卷 7-8,44页

作者：张军英樊秀菊董继扬石美红西安电子科技大学雷达信号处理国家重点实验室西安710071 西安电子科技大学计算机学院西安710071 西安工程科技学院信息与控制系西安710048

文章结合人类视觉系统(HVS)对图像各个区域敏感度不同这一特性,对通常的脉冲耦合神经网络模型(PC-NN--PulseCoupledNeuralNetwork)进行了改进,分析了改进模型的特性及其参数优化原理,提出了一种基于这种改进PCNN的图像分割算法。该算法... 详细信息

文章结合人类视觉系统(HVS)对图像各个区域敏感度不同这一特性,对通常的脉冲耦合神经网络模型(PC-NN--PulseCoupledNeuralNetwork)进行了改进,分析了改进模型的特性及其参数优化原理,提出了一种基于这种改进PCNN的图像分割算法。该算法可根据像素周边区域的灰度梯度大小发放不同值的脉冲,从而自适应地将图像分为多个不同等级的高低信息区域,较好地仿真了人类视觉系统特性。并将该算法应用于图像压缩,在压缩比和重建图像主观视觉感知质量上均达到了较好的性能。

关键词：脉冲耦合神经网络图像分割图像信息图像压缩

TREM-2 Drives Development of Multiple Sclerosis by Promoting Pathogenic Th17 Polarization

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Neuroscience Bulletin 2024年第1期40卷 17-34页

作者： Siying Qu Shengfeng Hu Huiting Xu Yongjian Wu Siqi Ming xiaoxia Zhan Cheng Wang xi Huang Center for Infection and Immunity and Guangdong Provincial Engineering Research Center of Molecular Imaging The Fifth Affiliated Hospital of Sun Yat-sen UniversityZhuhai 519000China The State key laboratory of Respiratory Disease Guangdong Provincial Key Laboratory of Allergy and Clinical ImmunologyThe Second Affiliated HospitalGuangzhou Medical UniversityGuangzhou 510260China Department of laboratory Medicine The First Affiliated Hospital of Sun Yat-sen UniversityGuangzhou 510080China Division of Nephrology Department of Medicinethe Fifth Affliated Hospital of Sun Yat-sen UniversityZhuhai 519000China

Multiple sclerosis(MS)is a neuroinflammatory demyelinating disease,mediated by pathogenic T helper 17(Th17)***,the therapeutic effect is accompa-nied by the fluctuation of the proportion and function of Th17 cells,which prompted us to find the key regulator of Th17 differentiation in ***,we demonstrated that the triggering receptor expressed on myeloid cells 2(TREM-2),a modulator of pattern recognition receptors on innate immune cells,was highly expressed on pathogenic CD4-positive T lymphocyte(CD4^(+)T)cells in both patients with MS and experimental autoimmune encephalomyelitis(EAE)mouse *** knockout of Trem-2 in CD4^(+)T cells significantly alleviated the disease activity and reduced Th17 cell infiltration,activation,differentiation,and inflammatory cytokine production and secretion in EAE ***,with Trem-2 knockout in vivo experiments and in vitro inhibitor assays,the TREM-2/zeta-chain associated protein kinase 70(ZAP70)/signal transducer and activator of transcription 3(STAT3)signal axis was essential for Th17 activation and differentiation in EAE *** conclusion,TREM-2 is a key regulator of pathogenic Th17 in EAE mice,and this sheds new light on the potential of this therapeutic target for MS.

关键词： Multiple sclerosis Experimental autoimmune encephalomyelitis T helper 17 Triggering receptor expressed on myeloid cells 2

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一种小波域HMT模型参数初始化方法

计算机科学 2003年第1期30卷 85-86,77页

作者：汪西莉刘芳焦李成西安电子科技大学雷达信号处理国家重点实验室西安电子科技大学计算机学院西安710071

Wavelet transformation and hidden Markov model are used in wavelet-based HMT model for analyzing andprocessing images. Expected Maximization(EM) algorithm used in training model results in slow convergence. Thepersistence, exponential decay characteristics of wavelet coefficient are analyzed. A model parameter initializationmethod is proposed. This method provides reasonable initial model value, reduces training time greatly. Its applica-tion in image de-noising demonstrates is validity.

关键词：小波域 HMT模型参数初始化图像去噪图像处理小波理论信号分析

Parameters Estimation of LFM signals Based on STTFD

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Parameters Estimation of LFM Signals Based on STTFD

Fabrication of sub-micro size PZT array and their ferroelectric properties

2008 9th International Conference on signal processing(ICSP’2008)

作者： Long Zhang 1 2 xiao-hui He 2 Ya-chao Li 1 Meng-dao xing 1 Zheng Bao 1 1 the State key Lab for radar signal processing xidian university Shaanxi 710071 P.R.china 2 xi’an Polytechnic university Shaanxi 710048 P.R.china

The accurate estimation of the center frequency and the chirp rate of a linear frequency-modulated（LFM） signal palys an important role in radar signal *** WVD transform can show the characteristic of the center frequency and the chirp rate of a LFM signal,but the cross-terms of signals deteriorates the precision of the estimation of the center frequency and the chirp ***,in order to estimate those parameters of the LFM signals better,this paper proposes a new method based on the scaling transform in time-frequency distribution plane（STTFD） for the parameters estimation of the LFM signals,by which the frequency of each LFM signal in timefrequency plane changes from the linear distribution along the time axis to the constant distribution along the time axis,then the coupling effect between the signal time and the correlation function delay can be removed and the center frequencies and the chirp rates of the LFM signals can be accurately estimated by the peak value locations of accumulated signals realized by the Fourier transform with respect to the time *** the same time,the analysis of the characteristic of STTFD is given in ***,the simulated result shows that the method proposed in this paper can effectively weaken the effect of the cross-terms and accurately estimate the center frequencies and the chirp rates of the LFM signals.

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Science china(Technological Sciences) 2006年第6期49卷 693-700页

作者： ZHAO Gaoyang1, ZHANG Weihua1, XU Guomin1, DENG xiaocui1, JIANG Bailing1 & ZHAO Wei2 1. School of Materials Science and Engineering, xi’an university of Technology, xi’an 710048, china 2. xi’an Institute of Optics and Precision Mechanics of CAS, xi’an 710048, china 1. School of Materials Science and Engineering Xi’an University of Technology Xi’an 710048 China 2. xi’an Institute of Optics and Precision Mechanics of CAS Xi’an 710048 China

The photosensitive PZT sols and their gel films were prepared by sol-gel process. Based on the photosensitivity of the PZT gel films, two-dimensional (2D) array of the PZT gel film was fabricated using twice-exposure of double-beam interference on the gel film. PZT gel films coated on ITO/quartz substrate were exposed to an interference fringe of 325 He-Cd laser beams, the substrate was rotated by 90° between the first and second irradiation steps. Island type periodic 2D array structures with a pitch of 1 μm and cell size of about 480 nm × 480 nm × 40 nm were formed after the irradiation, and followed by leaching with organic solvent, and then by heat treatment at 600°C for 15 min. The hysteresis loops of the cell in PZT array were in-situ measured by the online-operation of TF analyzer and atomic force microscope (AFM). The probe can be located on the locked cell of PZT array in the AFM image. The alternating voltage applied to the locked cell is supplied by the TF analyzer through the conductive coating probe, and then the test signal is fed back to the TF analyzer to obtain the hysteresis loop of the locked cell of array in the absence of top electrode. The results show that the sub-micro size PZT arrays prepared in this way are of polarization reversal characteristics with the alternating electric fields, thereby exhibiting obvious ferroelectricity.

关键词： PZT, ferroelectric films, photosensitivity, hysteresis loop.

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免疫规划+K均值混合聚类算法

计算机科学 2003年第4期30卷 150-152,158页

作者：行小帅潘进焦李成西安电子科技大学雷达信号处理国家重点实验室西安通信学院计算机与信息工程系西安710106

A novel Hybrid Clustering Algonthm (HCA) that incorporates the K-means into the canonical immune programming algorithm is proposed after analyzing the advantages and disadvantages of the classical k-means clustering algorithm in the paper. The theory analyse and experimental results show, the algorithm not only avoids the local optima and is robust to imtialization, but also increases the convergent speed, meanwhile evidently restrains the degenerating phenomenon during the evolutionary process.

关键词：模式识别免疫规划 K均值混合聚类算法全局寻优算法目标函数

Electrogenerated chemiluminescence aptasensor for thrombin incorporating poly(pyrrole-co-pyrrole propylic acid) nanoparticles loaded with aptamer and ruthenium complex

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Science china Chemistry 2011年第8期54卷 1357-1364页

作者： MA Fen, JIA LiJuan, ZHANG Yu, SUN Bo, QI HongLan, GAO Qiang & ZHANG Chengxiao key laboratory of Applied Surface and Colloid Chemistry, Ministry of Education School of Chemistry and Materials Science, Shaanxi Normal university, xi’an 710062, china 1. key laboratory of Applied Surface and Colloid Chemistry Ministry of Education School of Chemistry and Materials Science Shaanxi Normal University Xi’an 710062 China

A novel electrogenerated chemiluminescence （ECL） aptasensor for highly sensitive detection of thrombin was developed on the basis of poly（pyrrole-co-pyrrole propylic acid） nanoparticles loaded with aptamer and ruthenium complex. Thrombin binding aptamers served as the molecular recognition elements and ruthenium bis（2,2＇-bipyridine）（2,2＇-bipyridine-4,4＇-dicarboxylic acid）-ethylenediamine （Rul） was used as an ECL signal complex. Novel electroactive polymers poly（pyrrole-co-pyr- role propylic acid） nanoparticles （Ppy-pa NPs） were synthesized by a simple alcohol-assisted microemulsion polymerization. Rul-Ppy-pa NPs were synthesized by covalently coupling Rul with the Ppy-pa NPs. Ppy-pa NPs and Rul-Ppy-pa NPs were characterized using a fourier transform infrared spectrometer, super-conducting fourier digital NMR spectrometer, and trans- mission electron microscope. One ECL chemical sensor fabricated by immobilizing the Rul-Ppy-pa NPs on PIGE was developed for the determination of TprA with a high sensitivity and stability. The ECL aptasensor was fabricated by covalenfly coupling the thrombin binding aptamer-I （TBA-I） onto the surface of the paraffin-impregnated graphite electrode, which had been covalently modified with a monolayer of 4-aminobenzene sulfonic acid via electrochemical oxidations, for capturing thrombin onto the electrode and then the TBA-II labeled with Rul-Ppy-pa NPs was bound with epitope of thrombin. The ECL aptasensot showed an extremely low detection limit of 3.0×10^-16 mol/L for thrombin and a good selectivity. This work demonstrated that using Ppy-pa NPs as a carrier of ruthenium complex and molecular recognition element was a promising approach for the fabrication of ECL biosensor with high sensitivity.

关键词： biosensor electrogenerated chemiluminescence poly(pyrrole-co-pyrrole propylic acid) nanoparticles conducting polymer,aptamer thrombin

An efficient ranging method based on Chinese remainder theorem for RIPS measurement

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Science china(Information Sciences) 2010年第6期53卷 1233-1241页

作者： WANG Chen , YIN QinYe & WANG WenJie Ministry of Education key Lab for Intelligent Networks and Network Security, xi’an Jiaotong university, xi’an 710049, china 1. Ministry of Education key Lab for Intelligent Networks and Network Security Xi’an Jiaotong University Xi’an 710049 China

The radio interferometric positioning system(RIPS) measures the phase difference of the interference signal to provide high accuracy and at the same time maintain simple hardware configuration for wireless sensor ***, it suffers from phase ambiguity problem because of the periodicity of phase, which makes it hard to determine the actual distance difference only from a single phase *** solve the problem, RIPS makes multiple measurements at different frequencies so as to determine the distance difference from multiple ***, this is a computationally intensive searching process and not suitable for energyconstrained wireless sensor *** this paper, we introduce the Chinese remainder theorem(CRT) to RIPS to solve the phase ambiguity ***, we utilize some properties of the coefficients in the CRT algorithm to avoid the over-sensitivity of the traditional CRT, which increases the robustness of the *** apply this robust CRT algorithm to the ranging process which calculates the distance difference directly from a closed-form equation and therefore reduces the response time and the energy consumption of the ranging procedure.

关键词： ranging phase ambiguity Chinese remainder theorem robustness energy efficiency wireless sensor networks

GAUSSIAN PRINCIPLE COMPONENTS FOR NONLOCAL MEANS IMAGE DENOISING

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Journal of Electronics(china) 2011年第Z1期 539-547页

作者： Li xiangping Wang xiaotian Shi Guangming(key laboratory of Intelligent Perception and Image Understanding of the Ministry of Education of china,xidian university,xi’an 710071,china)

NonLocal Means(NLM),taking fully advantage of image redundancy,has been proved to be very effective in noise ***,high computational load limits its wide *** on Principle Component Analysis(PCA),Principle Neighborhood Dictionary(PND) was proposed to reduce the computational load of ***,as the principle components in PND method are computed directly from noisy image neighborhoods,they are prone to be inaccurate due to the presence of *** this paper,an improved scheme for image denoising is *** scheme is based on PND and uses preprocessing via Gaussian filter to eliminate the influence of *** is then used to project those filtered image neighborhood vectors onto a lower-dimensional *** the preproc-essing process,the principle components computed are more accurate resulting in an improved de-noising performance.A comparison with some NLM based and state-of-art denoising methods shows that the proposed method performs well in terms of Peak signal to Noise Ratio(PSNR) as well as image visual *** experimental results demonstrate that our method outperforms existing methods both subjectively and objectively.

关键词： Image denoising NonLocal Means(NLM) Gaussian filter Principle Component Analysis(PCA)