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THz-TDS signal analysis and substance identification via the conformal split

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Science china(Information Sciences) 2012年第1期55卷 49-63页

作者： xie weixin1.2,LI Jing1,2&PEI JiHong2 1School of electronic engineering,xidian university,xi'an 710071,china 2Intelligent Information institute,Shenzhen university,Shenzhen 518060,china 1. School of electronic engineering Xidian University Xi’an 710071 China2. Intelligent Information Institute Shenzhen University Shenzhen 518060 China

A terahertz time-domain spectroscopy(THz-TDS)imaging system can obtain high-dimensional signals with substance fingerprint *** introducing geometric algebra,a novel signal analysis approach to THz-TDS signals is developed based on an optical physical *** this approach,signals are represented with vectors in the high-dimensional real vector *** distribution properties and algebraic relationships of THz-TDS signals are *** is proved that every complex refractive index of substances relates to a unique 2-blade,the vectors corresponding to the samples of the same substance are collinear and belong to the intrinsic 2-blade of the *** decomposed through the conformal split with respect to a 2-blade,THz-TDS signals of high dimensionality can be related to vectors in a 2-dimensional *** on the conformal split properties we deduced,two criteria for substance identification on the basis of THz-TDS signals are ***,a novel substance identification method via the conformal split is *** the method,the 2-blade related to each "known" substance is calculated with two vectors corresponding to THz-TDS signals measured from samples of the substance but with dierent *** the conformal split with respect to those 2-blades,an identified vector corresponding to a THz-TDS signal is linearly related to the vector in a 2-dimensional *** substance of a sample can be identified using criteria on the projected vectors in the *** method can contribute to accurate classification and ***,two experiments are presented that show the feasibility and accuracy of this method.

关键词： terahertz time-domain spectroscopy substance identification geometric algebra conformal split

FUZZY PARTITIONING OF FEATURE SPACE FOR PATTERN CLASSIFICATION BASED ON SUPERVISED C1USTERING

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Journal of electronics(china) 2000年第2期17卷 170-177页

作者： gao xinbo Xu Chunguang xie weixin (School of electronic engineering, xidian university, xi’an 710071)

The choice of a fuzzy partitioning is crucial to the performance of a fuzzy system based on if-then rules. However, most of the existing methods are complicated or lead ,o too many subspaces, which is unfit for the applications of pattern classification. A simple but effective clustering approach is proposed in this paper, which obtains a set of compact subspaces and is applicable for classification problems with higher dimensional feature. Its effectiveness is demonstrated by the experimental results.

关键词： Pattern classification Fuzzy if-then rules Fuzzy clustering Fuzzy partitioning

Fabrication and evaluation of high-performance 3D interpenetrated network structures SiC/Al composites with high-purity plate-like a-SiC framework

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Journal of Materiomics 2024年第2期10卷 499-510页

作者： Jiawei xie Jinhui Zou Liangcheng Tong Syieluing Wong xin Guo Hang Qin Pengzhao gao Wenming Guo Hanning xiao College of Materials Science and engineering Hunan UniversityChangsha410082China Department of Chemical engineering and Chemistry Eindhoven University of TechnologyEindhoven5612 AZNetherlands College of Automation and Information engineering Xi'an University of TechnologyXi'an710048China

To reinforce compatibility with the thermophysical and mechanical properties of SiC/Al composites for electronic packaging to improve the stability and reduce fatigue failure of electronic integrated devices,a novel 3D SiC reinforced framework with interpenetrated plate-like a-SiC grains was synthesized.A small amount of doped a-SiC was seeded to induce the transformation of b-SiC to plate-like a-SiC at 2,300℃,forming a high-purity a-SiC strongly bonded ***/gas pressure infiltration of Al alloy was subsequently used to manufacture the 3D interpenetrated network structure SiC/Al(SiC3D/Al)*** results showed that 15%(in mass)seeds provided the composite with the optimal comprehensive performance,including a low coefficient of thermal expansion(CTE)of 5.54×10^(-6)K^(-1),a high thermal conductivity(l)of 239.08 W·m^(-1)·K^(-1),the highest flexural strength of 326.84 MPa,and a low thermal deformation parameter(TDP)of ***-purity plate-like grains enhanced the purity of the framework promoting a significant improvement in *** the seed content increased to 20%(in mass),both CTE and l reached optimal values of 5.22×10^(-6)K^(-1)and 243.14 W·m^(-1)·K^(-1),but the mechanical properties declined by 10.30%.The synergistic effect of the well-bonded interface and the high-purity 3D SiC framework balanced excellent mechanical properties and multiple thermal functions.

关键词： α-SiC seed Phase transformation Thermophysical properties SiC_(3D)/Al composites electronic packaging

LOCALIZED RADON-WIGNER TRANSFORM AND GENERALIZED-MARGINAL TIME-FREQUENCY DISTRIBUTIONS

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Journal of electronics(china) 2000年第2期17卷 116-122页

作者： Xu Chunguang gao xinbo xie weixin (School of electronic engineering, xidian university, xi’an, 71007l)

This paper introduces the localized Radon transform (LRT) into time-frequency distributions and presents the localized Radon-Wigner transform (LRWT). The definition of LRWT and a fast algorithm is derived, the properties of LRWT and its relationship with Radon-Wigner transform, Wigner distribution (WD), ambiguity function (AF), and generalized-marginal time-frequency distributions are analyzed.

关键词： Time-frequency distributions Localized Radon-Wigner transform Generalized-marginal time-frequency distributions

Inhibiting oxygen vacancies and twisting NbO_(6) octahedron in erbium modified KNN-based multifunctional ceramics

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Journal of Materiomics 2024年第1期10卷 179-189页

作者： Lulu gao Zhiyong Liu Pengrong Ren Renhong Liang Ting Li Kun Guo Bing xie Jinshan Lu Pu Mao Jun Tian Longlong Shu School of Materials Science and engineering Nanchang Hangkong UniversityNanchang330063China School of Materials Science and engineering Xi'an University of TechnologyXi'an710048China School of Physics and Materials Science Nanchang UniversityNanchang330031China institute of Applied Chemistry Jiangxi Academy of SciencesNanchang330096China

It is a challenge to obtain highly tunable multifunctional performances in one ferroelectric system by a simple approach to meet the miniaturization,integration,and functionalization requirements of advanced electronic ***,rare earth erbium(Er)modulated 0.9K_(0.5)Na_(0.5)NbO_(3)-0.1Sr(1-x)Er_(x)Ti_((1-x/4))O_(3),(0.9KNN-0.1ST:xEr)transparent-photoluminescent-ferroelectric energy storage multifunctional ceramics are prepared to solve this *** effect of lattice distortion and oxygen vacancies by Er doping on the optical and electrical properties is systematically *** Er^(3+)ions can introduce a large distortion of the NbO_(6) octahedron by replacing the A-site in KNN-based *** to the higher c/a ratio and lower oxygen vacancy content are simultaneously obtained in 0.9KNN-0.1ST:0.1Er *** effective energy storage density(Wrec)of 0.86 J/cm^(3),excellent near-infrared transmittance of 51.7%(1100 nm)and strong green upconversion photoluminescence are achieved in this multifunctional *** study provides a solid basis for rare earth ions doped ferroelectric ceramics with tunable multifunctional properties and has significant potential for applications in optoelectronic devices.

关键词： KNN Upconversion photoluminescence Multifunctional ceramics Oxygen vacancy Octahedron

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图像重定向质量评价的研究进展

中国图象图形学报 2024年第1期29卷 22-44页

作者：胡波谢国庆李雷达李静杨嘉琛路文高新波重庆邮电大学图像认知重庆市重点实验室重庆400065 广阳湾实验室重庆脑与智能科学中心重庆400064 西安电子科技大学人工智能学院西安710071 阿里巴巴集团北京100020 天津大学电气自动化与信息工程学院天津300072 西安电子科技大学电子工程学院西安710071

随着移动显示设备的普及,人们可以使用不同的终端设备来获取图像信息。为了适配不同尺寸的设备,图像重定向技术应运而生,并成为当前研究的热点。尽管该技术在近年来取得了长足进步,但没有算法能够保证在不降低视觉内容质量的前提下满足... 详细信息

随着移动显示设备的普及,人们可以使用不同的终端设备来获取图像信息。为了适配不同尺寸的设备,图像重定向技术应运而生,并成为当前研究的热点。尽管该技术在近年来取得了长足进步,但没有算法能够保证在不降低视觉内容质量的前提下满足多种显示设备的要求。换句话说,在图像重定向的过程中,不可避免地会引入失真,降低用户的视觉体验。因此,如何客观、准确地评价重定向图像质量对图像重定向算法的选择、优化及发展至关重要。当前,研究人员已针对图像重定向质量评价开展了一系列研究,并取得了一定的研究成果。但是缺乏对图像重定向质量评价的综述,因此本文对当前图像重定向质量评价的研究进展进行了较为全面的回顾和总结。首先简单介绍了图像重定向以及传统图像质量评价;然后分别介绍图像重定向质量评价的数据集和客观质量评价方法,将现有的客观质量评价分为基于传统特征相似性的方法和基于图像配准的方法两类,并分析了两类方法的优缺点;接着在3个数据集上对具有代表性的算法的性能进行了对比分析;最后,总结了当前图像重定向质量评价领域面临的问题和挑战,并指明了未来可能的发展方向。

关键词：图像质量评价(IQA) 图像重定向图像配准内容损失几何失真

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基于自适应参数估计的微动时频表征重构方法

空军工程大学学报 2024年第5期25卷 107-114页

作者：李开明王欢解岩陈卓高泽岳空军工程大学信息与导航学院西安710077 信息感知技术协同创新中心西安710077 西安电子工程研究所总体二部西安710100 四川省政府服务和公共资源交易服务中心成都610000 95894部队北京112211

针对数据缺失条件下的目标微动回波时频表征重构问题,提出了一种基于自适应参数估计的微动时频表征重构方法。首先,将缺失的微动时频表征重构问题建模为基于L_P范数最小化的稀疏重构问题,其次,引入哈达玛积参数将L_P范数最小化稀疏重构... 详细信息

针对数据缺失条件下的目标微动回波时频表征重构问题,提出了一种基于自适应参数估计的微动时频表征重构方法。首先,将缺失的微动时频表征重构问题建模为基于L_P范数最小化的稀疏重构问题,其次,引入哈达玛积参数将L_P范数最小化稀疏重构问题转化为多个L_2范数联合最小化问题,并采用迭代吉洪诺夫正则化求解,同时在每次迭代过程中根据重构结果自适应估计正则化参数,最后,采用除偏处理减小了重构时频表征的振幅衰减。与传统微动回波时频表征重构方法相比,所提方法避免了需要人工设置正则化参数不足的问题,并且重构的时频表征更加完整。仿真实验和实测数据处理结果验证了所提方法的有效性和稳健性。

关键词：微多普勒效应信号重构稀疏优化参数估计时频分析

基于X射线图像与稀疏描述的管道环焊缝缺陷自动识别法

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油气储运 2024年第9期43卷 1048-1055,1079页

作者：贾韶辉李亚平高炜欣彭云超张新建王玉霞国家管网集团科学技术研究总院分公司河北省廊坊市065000 西安石油大学电子工程学院国家管网集团东部原油储运有限公司

【目的】环焊缝焊接质量是影响管道安全运行的重要因素,X射线则为焊缝缺陷检测的关键技术之一,但管道环焊缝缺陷及噪声的X射线图像特征值存在难以区分的问题。【方法】提出了一种高准确度的管道环焊缝缺陷X射线图像自动识别方法:在疑似... 详细信息

【目的】环焊缝焊接质量是影响管道安全运行的重要因素,X射线则为焊缝缺陷检测的关键技术之一,但管道环焊缝缺陷及噪声的X射线图像特征值存在难以区分的问题。【方法】提出了一种高准确度的管道环焊缝缺陷X射线图像自动识别方法:在疑似缺陷区域(SuspectedDefectRegion,SDR)与灰度密度定义的基础上,构建了一种基于聚类的SDR分割算法,可以准确分割任意形状的SDR。为保证分割后图像识别的成功率,将判断X射线SDR图像是否为缺陷作为一种模式识别问题处理,并将待检测SDR图像视为样本SDR图像(即字典矩阵)的线性组合,通过求取系数向量判断分割后的SDR图像是否为缺陷。为使系数向量稀疏化方便判断,通过零范数最优化求解系数向量。同时,利用一种光滑可导的0-1惩罚项函数,使采用罚函数方法求零范数最优问题变为可能。为使字典矩阵能够包含尽可能多的图像特征,建立基于正交最优的环焊缝X射线SDR图像最优字典矩阵模型,并提出了一种正交最优字典矩阵求解算法。【结果】基于所建模型及算法,开发了稀疏描述与X射线图像检测技术相结合的管道环焊缝缺陷检测软件,通过对管径762mm、壁厚10.3mm的某管道环焊缝缺陷进行X射线图像识别,缺陷检出率可达98%。【结论】新提出的缺陷识别方法可大幅提升管道环焊缝安全隐患检测的质量与效率,具备工业化应用前景。(图7,表3,参22)

关键词：管道环焊缝 X射线图像缺陷识别稀疏描述

Galvanic replacement reaction for in situ fabrication of litchi-shaped heterogeneous liquid metal-Au nano-composite for radio-photothermal cancer therapy

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Bioactive Materials 2021年第3期6卷 602-612页

作者： Zhenhu Guo Jingsong Lu Dan Wang Wensheng xie Yongjie Chi Jianzhong Xu Nonaka Takuya Junxin Zhang Wanling Xu Fei gao Hong Wu Lingyun Zhao State Key Laboratory of Powder Metallurgy Powder Metallurgy Research InstituteCentral South UniversityChangshaHunan410083China Key Laboratory of Advanced Materials Ministry of Education of ChinaSchool of Materials Science and EngineeringTsinghua UniversityBeijing100084China State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing100084China Research Center of Magnetic and electronic Materials College of Materials Science and EngineeringZhejiang University of TechnologyHangzhouZhejiang310014China Department of Nanoengineering Chemical Engineering Programand Moores Cancer CenterUniversity of California San DiegoLa JollaCA92093United States The Key Laboratory of Bioorganic Phosphorus Chemistry&Chemical Biology(Ministry of Education) Department of ChemistryTsinghua UniversityBeijing100084China School of Earth Sciences and Resources China University of Geosciences(Beijing)Beijing100083China Shaanxi university of Chinese Medicine Xi'anShanxi712046China

With tremendous research advances in biomedical application,liquid metals(LM)also offer fantastic chemistry for synthesis of novel ***,as a pioneering trial,litchi-shaped heterogeneous eutectic gallium indium-Au nanoparticles(EGaIn-Au NPs),served as effective radiosensitizer and photothermal agent for radio-photothermal cancer therapy,have been successfully prepared using in situ interfacial galvanic replacement *** enhanced photothermal conversion efficiency and boosted radio-sensitization effect could be achieved with the reduction of Au nanodots onto the eutectic gallium indium(EGaIn)NPs *** importantly,the growth of tumor could be effectively inhibited under the combined radio-photothermal therapy mediated by EGaIn-Au *** by this approach,in situ interfacial galvanic replacement reaction may open a novel strategy to fabricate LM-based nano-composite with advanced multi-functionalities.

关键词： Au nanodots Gallium Galvanic replacement reaction Indium Radio-photothermal therapy