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Image Hiding with High Robustness Based on Dynamic Region Attention in the Wavelet Domain
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作者 Zengxiang Li Yongchong Wu +3 位作者 Alanoud Al Mazroa Donghua Jiang Jianhua Wu Xishun Zhu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第10期847-869,共23页
Hidden capacity,concealment,security,and robustness are essential indicators of hiding algorithms.Currently,hiding algorithms tend to focus on algorithmic capacity,concealment,and security but often overlook the robus... Hidden capacity,concealment,security,and robustness are essential indicators of hiding algorithms.Currently,hiding algorithms tend to focus on algorithmic capacity,concealment,and security but often overlook the robustness of the algorithms.In practical applications,the container can suffer from damage caused by noise,cropping,and other attacks during transmission,resulting in challenging or even impossible complete recovery of the secret image.An image hiding algorithm based on dynamic region attention in the multi-scale wavelet domain is proposed to address this issue and enhance the robustness of hiding algorithms.In this proposed algorithm,a secret image of size 256×256 is first decomposed using an eight-level Haar wavelet transform.The wavelet transform generates one coefficient in the approximation component and twenty-four detail bands,which are then embedded into the carrier image via a hiding network.During the recovery process,the container image is divided into four non-overlapping parts,each employed to reconstruct a low-resolution secret image.These lowresolution secret images are combined using densemodules to obtain a high-quality secret image.The experimental results showed that even under destructive attacks on the container image,the proposed algorithm is successful in recovering a high-quality secret image,indicating that the algorithm exhibits a high degree of robustness against various attacks.The proposed algorithm effectively addresses the robustness issue by incorporating both spatial and channel attention mechanisms in the multi-scale wavelet domain,making it suitable for practical applications.In conclusion,the image hiding algorithm introduced in this study offers significant improvements in robustness compared to existing algorithms.Its ability to recover high-quality secret images even in the presence of destructive attacksmakes it an attractive option for various applications.Further research and experimentation can explore the algorithm’s performance under different scenarios and expand its potential applications. 展开更多
关键词 Image hiding ROBUSTNEss wavelet transform dynamic region attention
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People Recognition by RGB and NIR Analysis from Digital Image Database Using Cross-Correlation and Wavelets
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作者 David Martínez-Martínez Yedid Erandini Niño-Membrillo +3 位作者 José Francisco Solís-Villarreal Oscar Espinoza-Ortega Lizbeth Sandoval-Juárez Francisco Javier Núñez-García 《Engineering(科研)》 2024年第10期353-359,共7页
This document presents a framework for recognizing people by palm vein distribution analysis using cross-correlation based signatures to obtain descriptors. Haar wavelets are useful in reducing the number of features ... This document presents a framework for recognizing people by palm vein distribution analysis using cross-correlation based signatures to obtain descriptors. Haar wavelets are useful in reducing the number of features while maintaining high recognition rates. This experiment achieved 97.5% of individuals classified correctly with two levels of Haar wavelets. This study used twelve-version of RGB and NIR (near infrared) wavelength images per individual. One hundred people were studied;therefore 4,800 instances compose the complete database. A Multilayer Perceptron (MLP) was trained to improve the recognition rate in a k-fold cross-validation test with k = 10. Classification results using MLP neural network were obtained using Weka (open source machine learning software). 展开更多
关键词 Palm Vein Recognition CROss-CORRELATION Haar wavelets Multilayer Perceptron
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基于ICEEMDAN-SSA-Wavelet的声发射信号降噪研究
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作者 姚慧栋 金永 +1 位作者 王江 李玉珠 《现代电子技术》 北大核心 2024年第5期93-97,共5页
针对粘接件声发射(AE)信号含有噪声分量难以滤除的问题,提出一种改进ICEEMDAN的方法。该方法首先使用ICEEMDAN分解原始AE信号,并通过相关系数和能量差值的方法筛选出低频分量和高频分量;运用麻雀优化算法(SSA)优化后的改进小波阈值去噪... 针对粘接件声发射(AE)信号含有噪声分量难以滤除的问题,提出一种改进ICEEMDAN的方法。该方法首先使用ICEEMDAN分解原始AE信号,并通过相关系数和能量差值的方法筛选出低频分量和高频分量;运用麻雀优化算法(SSA)优化后的改进小波阈值去噪算法对其进行去噪;最后将保留的低频分量和去噪后的高频分量重构成一个新的信号,通过实验数据对比和分析评估降噪效果。实验结果表明,相较于改进小波阈值去噪和ICEEMDAN去噪,文中提出的方法对金属与非金属粘接件AE信号的降噪效果更好,能够保护原始信号的频域信息,进而提高脱粘检测精度。 展开更多
关键词 ICEEMDAN去噪 小波阈值去噪 声发射信号 金属与非金属粘接件 ssA 信号降噪
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美标碳素钢SS钢轨成分及轧制工艺优化
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作者 赵桂英 梁正伟 +2 位作者 李永强 王嘉伟 边影 《包钢科技》 2024年第3期81-85,98,共6页
通过60E1和115RE断面钢轨对比,优化钢轨化学成分,采取窄成分控制,提高C含量,控制Mn、Cr元素含量,优化轧制工艺,小批量生产了60E1断面SS钢轨,钢轨性能达到R_(p0.2)≥512 MPa,R_(m)≥982 MPa,A≥10%,踏面硬度(HB)≥310。小批量工业生产实... 通过60E1和115RE断面钢轨对比,优化钢轨化学成分,采取窄成分控制,提高C含量,控制Mn、Cr元素含量,优化轧制工艺,小批量生产了60E1断面SS钢轨,钢轨性能达到R_(p0.2)≥512 MPa,R_(m)≥982 MPa,A≥10%,踏面硬度(HB)≥310。小批量工业生产实践证明,60E1断面SS钢轨生产工艺顺行,性能稳定,满足用户需要,可以扩量生产。 展开更多
关键词 ss钢种 60E1断面 钢轨 优化
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基于ICEEMDAN和分布熵的SS-Y伸缩仪信号随机噪声压制方法
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作者 吴林斌 《大地测量与地球动力学》 CSCD 北大核心 2024年第4期429-435,共7页
结合改进的自适应噪声完备集合经验模态分解(ICEEMDAN)与分布熵(DistEn),提出一种无需自定义算法参数、去噪效果较好的伸缩仪信号随机噪声压制方法。首先将伸缩仪信号进行ICEEMDAN处理,得到若干个本征模态函数(IMF);然后计算各IMF分量... 结合改进的自适应噪声完备集合经验模态分解(ICEEMDAN)与分布熵(DistEn),提出一种无需自定义算法参数、去噪效果较好的伸缩仪信号随机噪声压制方法。首先将伸缩仪信号进行ICEEMDAN处理,得到若干个本征模态函数(IMF);然后计算各IMF分量的分布熵值,根据不同分布熵值的大小和表征的分量信号混乱程度,有针对性地对各IMF进行取舍;最后进行线性重构。设计仿真信号去噪实验和SS-Y伸缩仪信号去噪实验,结果表明,基于ICEEMDAN-DistEn去噪模型的伸缩仪信号重构还原度较好,去噪效果显著,明显优于CEEMDAN-DistEn、小波去噪和卡尔曼滤波等去噪模型。 展开更多
关键词 ss-Y伸缩仪 随机噪声压制 改进的自适应噪声完备集合经验模态分解 分布熵 信噪比
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灰毡毛忍冬SS基因的克隆及表达分析
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作者 陈勋 王珊 +3 位作者 龙雨青 曾娟 周日宝 刘湘丹 《安徽农业科学》 CAS 2024年第21期71-77,共7页
[目的]克隆灰毡毛忍冬SS基因全长序列,并进行生物信息学和表达模式分析。[方法]提取灰毡毛忍冬花总RNA,通过RT-PCR和RACE技术克隆LmSS基因的全长cDNA序列;运用相关软件对该基因序列进行生物信息学分析;利用qRT-PCR测定灰毡毛忍冬茎、叶... [目的]克隆灰毡毛忍冬SS基因全长序列,并进行生物信息学和表达模式分析。[方法]提取灰毡毛忍冬花总RNA,通过RT-PCR和RACE技术克隆LmSS基因的全长cDNA序列;运用相关软件对该基因序列进行生物信息学分析;利用qRT-PCR测定灰毡毛忍冬茎、叶和不同花期花中该基因的相对表达量。[结果]克隆的LmSS基因开放阅读框(ORF)长度为1245 bp,编码414个氨基酸,属于亲水性蛋白,定位于细胞质中,具有典型的多聚异戊二烯基合成酶活性结构域,与其他植物SS基因具有较高同源性。LmSS基因在灰毡毛忍冬不同花期和器官中表达有组织特异性。[结论]该研究成功地克隆灰毡毛忍冬中的SS基因,为进一步研究该基因的功能奠定基础,同时为探究灰毡毛忍冬皂苷生物合成和调节机制提供了科学依据。 展开更多
关键词 灰毡毛忍冬 鲨烯合酶(ss) 基因克隆 生物信息学 表达分析
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基于CEEMDAN-VSSLMS的滚动轴承故障诊断
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作者 江莉 向世召 《计算机集成制造系统》 EI CSCD 北大核心 2024年第3期1138-1148,共11页
针对传统机械轴承故障诊断模型易受系统噪声干扰、特征识别效率低等问题,提出一种基于信号固有模式深度建模分析的轴承故障诊断方法。首先,将采集到的轴承振动信号进行噪声自适应完全经验模态分解(CEEMDAN),获得不同时间尺度的局部特征... 针对传统机械轴承故障诊断模型易受系统噪声干扰、特征识别效率低等问题,提出一种基于信号固有模式深度建模分析的轴承故障诊断方法。首先,将采集到的轴承振动信号进行噪声自适应完全经验模态分解(CEEMDAN),获得不同时间尺度的局部特征信号,使用相关系数判别并去除虚假模态分量,再利用可变步长最小均方算法(VSSLMS)对剩余IMF分量降噪并进行重构;然后,将降噪后的振动信号进行离散小波变换(DWT)得到时频谱图,并利用形态学开运算进行特征增强;最后利用改进GoogLeNet网络模型对特征图进行训练,通过Softmax分类器完成特征归类,从而实现轴承故障诊断。将提出的故障诊断方法应用于不同工况下的轴承故障数据集,试验结果表明,所提方法在噪声干扰下具有较高的诊断精度。 展开更多
关键词 轴承故障诊断 经验模态分解 最小均方算法 离散小波变换 GoogLeNet模型
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基于MDS和改进SSA-SVM的高速铁路道岔故障诊断方法研究
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作者 王彦快 米根锁 +2 位作者 孔得盛 杨建刚 张玉 《铁道学报》 EI CAS CSCD 北大核心 2024年第1期81-90,共10页
针对高速铁路道岔设备故障频繁,现场维修工作量大等问题,提出基于多维尺度缩放法(MDS)和改进麻雀搜索算法(SSA)优化支持向量机(SVM)的高速铁路道岔故障诊断模型。首先以ZDJ9道岔转换功率曲线为研究对象,总结现场典型道岔故障类型及故障... 针对高速铁路道岔设备故障频繁,现场维修工作量大等问题,提出基于多维尺度缩放法(MDS)和改进麻雀搜索算法(SSA)优化支持向量机(SVM)的高速铁路道岔故障诊断模型。首先以ZDJ9道岔转换功率曲线为研究对象,总结现场典型道岔故障类型及故障原因,分别提取道岔功率曲线的时域、频域特征指标以及小波包能量熵,组成特征指标向量;其次采用MDS方法进行多维特征指标的降维优化,建立道岔故障特征指标样本数据库;最后利用改进Circle混沌映射初始化种群,并通过自适应t分布增强麻雀种群的多样性,再以改进SSA算法优化SVM模型中的惩罚因子和核函数方差2个关键参数,构建改进SSA-SVM的道岔故障诊断模型。故障诊断结果表明,本模型的故障诊断正确率高达96.25%,诊断效果优于其他方法,可以为道岔设备的故障维修提供理论依据。 展开更多
关键词 高速铁路道岔 故障诊断 改进麻雀搜索算法-支持向量机 Circle混沌映射 自适应t分布 小波包能量熵 多维尺度缩放法
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T6SS阳性CRKP临床感染特征及毒力基因分析
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作者 刘莉娟 储雯雯 +4 位作者 王梦 闫涛 龚真 周强 刘周 《中国感染控制杂志》 CAS CSCD 北大核心 2024年第4期488-493,共6页
目的分析T6SS阳性耐碳青霉烯类肺炎克雷伯菌(CRKP)临床感染特征,以及其耐药、毒力基因检出率和生物膜形成能力,为临床防控CRKP感染提供参考数据。方法收集2019年1月—2022年12月安徽某三甲医院临床分离的CRKP菌株及患者资料,PCR法检测T... 目的分析T6SS阳性耐碳青霉烯类肺炎克雷伯菌(CRKP)临床感染特征,以及其耐药、毒力基因检出率和生物膜形成能力,为临床防控CRKP感染提供参考数据。方法收集2019年1月—2022年12月安徽某三甲医院临床分离的CRKP菌株及患者资料,PCR法检测T6SS基因、毒力基因、耐药基因和分子分型,96孔板结晶紫染色法检测生物膜形成能力。结果共纳入160株CRKP。标本来源以痰(46.9%)和血(26.3%)为主。CRKP菌株呈现多重耐药表型,以携带bla KPC(80.6%)为主,其次为bla NDM(17.5%)。根据是否携带T6SS将CRKP分为T6SS阳性组(129株,80.6%)和T6SS阴性组(31株,19.4%)。T6SS阳性组患者患慢性肺部疾病和心脏疾病比例高于T6SS阴性组(P<0.05),且预后较阴性组差(P<0.05)。T6SS阳性组中,iuc A、mrk D、rmp A2、peg 344、wab G、fim H检出率均高于T6SS阴性组(均P<0.05)。CRKP中以ST11型(68.8%)为主,其中K64-ST11型占比70.9%,K47-ST11型占比25.5%。T6SS阳性组ST11型和K64-ST11型CRKP占比均高于T6SS阴性组(均P<0.05)。T6SS阳性组CRKP生物膜形成能力强于T6SS阴性组(P<0.001)。两组除bla OXA-48基因外,在携带其他碳青霉烯类耐药基因和抗菌药物耐药率方面差异无统计学意义。结论该地区CRKP呈现多重耐药,CRKP菌株T6SS检出率高,T6SS阳性CRKP毒力基因检出率更高,且生物膜形成能力更强。 展开更多
关键词 肺炎克雷伯菌 T6ss 毒力基因 耐碳青霉烯类 碳青霉烯酶
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基于Renyi熵和ISSA-SVM的轴承故障诊断分析
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作者 吴会咏 李洪坤 +1 位作者 周子潍 杨童童 《工业控制计算机》 2024年第11期53-55,58,共4页
在工业系统中,旋转机械的信号通常是非平稳的、非线性的,并且带有噪声干扰。为了提高异常检测分析的准确性,克服优化方法的局限性,提出了一种基于Renyi熵的滚动轴承故障诊断方法和一种基于飞行策略的改进麻雀搜索算法(ISSA)来优化支持... 在工业系统中,旋转机械的信号通常是非平稳的、非线性的,并且带有噪声干扰。为了提高异常检测分析的准确性,克服优化方法的局限性,提出了一种基于Renyi熵的滚动轴承故障诊断方法和一种基于飞行策略的改进麻雀搜索算法(ISSA)来优化支持向量机(SVM)。首先,小波包分析对原始信号进行分解,从分解后的频带中选取最佳频带进行重构,然后利用重构后的频带计算Renyi熵,形成特征向量,输入到具有动态逆向学习因子的麻雀搜索算法进行故障诊断。该方法提高了种群的多样性。通过采用飞行策略初始化种群,调整步长因子,避免了麻雀搜索算法陷入局部最优的问题。与灰狼优化算法和粒子群优化算法相比,麻雀搜索算法在故障诊断方面具有最高的准确性。三种算法准确率分别为88.89%、93.94%和96.97%。采用Lévy飞行策略对三种算法进行优化,ISSA-SVM的准确率最高达到99%,IPSO-SVM的准确率达到98%,IGWO-SVM的准确率达到95%。实验数据表明,利用Lévy飞行算法优化的麻雀搜索算法具有最高的故障诊断精度。因此,将Renyi熵与ISSA-SVM相结合提出的非线性故障诊断方法可行。 展开更多
关键词 故障诊断 支持向量机 小波包分解 RENYI熵 滚动轴承
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SS-OCT在角膜成像中的应用进展
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作者 赵丽丽 宋继科 +1 位作者 卢秀珍 毕宏生 《国际眼科杂志》 CAS 2024年第7期1058-1063,共6页
成像技术的进步彻底改变了眼科领域,改变了我们对眼科疾病的理解、诊断和治疗。扫频源光学相干断层扫描(SS-OCT)是一种最新的非接触式高分辨率成像技术。它进一步提高了成像深度和扫描速度,增加了新的算法和功能。SS-OCT允许对角膜结构... 成像技术的进步彻底改变了眼科领域,改变了我们对眼科疾病的理解、诊断和治疗。扫频源光学相干断层扫描(SS-OCT)是一种最新的非接触式高分辨率成像技术。它进一步提高了成像深度和扫描速度,增加了新的算法和功能。SS-OCT允许对角膜结构进行三维评估,提供角膜前、后表面的曲率和高度图以及角膜厚度图。这可以帮助眼科医生筛查和诊断角膜病变,如圆锥角膜、角膜营养不良和变性。SS-OCT更快、更精准和更灵敏的角膜测量有助于对即将进行角膜和屈光手术的患者做好术前计划和术后监测。文章总结SS-OCT技术的发展及其在角膜疾病中潜在的临床效用与在手术中的应用进展,以支持更多未来可能的研究和临床治疗。 展开更多
关键词 扫频源光学相干断层扫描(ss-OCT) 屈光手术 角膜移植 散光
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ASTER Data Processing by Discrete Wavelets Transform and Band Ratio Techniques for the Identification of Lineaments and Hydrothermal Alteration Zones in Poli, North Cameroon
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作者 Mohamadou Ahamadou May Nome Stella Meying Arsène 《Journal of Geoscience and Environment Protection》 2023年第9期216-232,共17页
The aim of this study is to carry out hydrothermal alteration mapping and structural mapping using ASTER images in order to identify indices that could guide mining exploration work in the Poli area and its surroundin... The aim of this study is to carry out hydrothermal alteration mapping and structural mapping using ASTER images in order to identify indices that could guide mining exploration work in the Poli area and its surroundings. To achieve this, the ASTER images were first preprocessed to correct atmospheric effects and remove vegetation influence. Secondly, a lineament mapping was conducted by applying Discrete Wavelet Transform (DWT) algorithms to the First Principal Component Analysis (PCA1) of Visible Near-Infrared (VNIR) and Shortwave Infrared (SWIR) bands. Lastly, band ratio methods were applied to the VNIR, SWIR, and Thermal Infrared (TIR) bands to determine indices of iron oxides/hydroxides (hematite and limonite), hydroxyl-bearing minerals (chlorite, epidote, and muscovite), and the quartz index. The results obtained showed that the lineaments were mainly oriented NE-SW, ENE-WSW, and E-W, with NE-SW being the most predominant direction. Concerning hydrothermal alteration, the identified indices covered almost the entire study area and showed a strong correlation with lithological data. Overlaying the obtained lineaments with the hydrothermal alteration indices revealed a significant correlation between existing mining indices and those observed in the field. Mineralized zones generally coincided with areas of high lineament density exhibiting significant hydrothermal alteration. Based on the correlation between existing mining indices and the results of hydrothermal and structural mapping, the results obtained can then be used as a reference document for any mining exploration in the study area. 展开更多
关键词 Discrete wavelets Transform Band Ratio LINEAMENTS Hydrothermal Alteration
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Dual-stream coupling network with wavelet transform for cross-resolution person re-identification
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作者 SUN Rui YANG Zi +1 位作者 ZHAO Zhenghui ZHANG Xudong 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第3期682-695,共14页
Person re-identification is a prevalent technology deployed on intelligent surveillance.There have been remarkable achievements in person re-identification methods based on the assumption that all person images have a... Person re-identification is a prevalent technology deployed on intelligent surveillance.There have been remarkable achievements in person re-identification methods based on the assumption that all person images have a sufficiently high resolution,yet such models are not applicable to the open world.In real world,the changing distance between pedestrians and the camera renders the resolution of pedestrians captured by the camera inconsistent.When low-resolution(LR)images in the query set are matched with high-resolution(HR)images in the gallery set,it degrades the performance of the pedestrian matching task due to the absent pedestrian critical information in LR images.To address the above issues,we present a dualstream coupling network with wavelet transform(DSCWT)for the cross-resolution person re-identification task.Firstly,we use the multi-resolution analysis principle of wavelet transform to separately process the low-frequency and high-frequency regions of LR images,which is applied to restore the lost detail information of LR images.Then,we devise a residual knowledge constrained loss function that transfers knowledge between the two streams of LR images and HR images for accessing pedestrian invariant features at various resolutions.Extensive qualitative and quantitative experiments across four benchmark datasets verify the superiority of the proposed approach. 展开更多
关键词 cross-resolution feature invariant learning person re-identification residual knowledge transfer wavelet transform
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偃松PpSS和PpSE基因过表达载体构建
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作者 王思瑶 于宏影 +2 位作者 刘洋 梁雪 南方 《温带林业研究》 2024年第2期68-71,共4页
【目的】构建偃松甾醇代谢途径关键基因SS和SE过表达载体,为促进偃松甾醇高效合成奠定基础,为药用偃松遗传改良提供重要基因资源。【方法】以偃松的cDNA为模板,将SS和SE基因克隆至pNC-Cam1304-35s载体;重组质粒通过PCR及测序鉴定正确后... 【目的】构建偃松甾醇代谢途径关键基因SS和SE过表达载体,为促进偃松甾醇高效合成奠定基础,为药用偃松遗传改良提供重要基因资源。【方法】以偃松的cDNA为模板,将SS和SE基因克隆至pNC-Cam1304-35s载体;重组质粒通过PCR及测序鉴定正确后,三亲杂交转入根瘤农杆菌LBA4404。【结果】抗性农杆菌PCR产物长度与预期一致,阳性菌液测序结果与目标基因序列相同。【结论】成功构建SS和SE过表达载体,重组载体的获得为进一步挖掘其在偃松甾醇代谢中的调控机制研究奠定了基础。 展开更多
关键词 偃松 ss SE 过表达
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Anomaly Detection Based on Discrete Wavelet Transformation for Insider Threat Classification
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作者 Dong-Wook Kim Gun-Yoon Shin Myung-Mook Han 《Computer Systems Science & Engineering》 SCIE EI 2023年第7期153-164,共12页
Unlike external attacks,insider threats arise from legitimate users who belong to the organization.These individuals may be a potential threat for hostile behavior depending on their motives.For insider detection,many... Unlike external attacks,insider threats arise from legitimate users who belong to the organization.These individuals may be a potential threat for hostile behavior depending on their motives.For insider detection,many intrusion detection systems learn and prevent known scenarios,but because malicious behavior has similar patterns to normal behavior,in reality,these systems can be evaded.Furthermore,because insider threats share a feature space similar to normal behavior,identifying them by detecting anomalies has limitations.This study proposes an improved anomaly detection methodology for insider threats that occur in cybersecurity in which a discrete wavelet transformation technique is applied to classify normal vs.malicious users.The discrete wavelet transformation technique easily discovers new patterns or decomposes synthesized data,making it possible to distinguish between shared characteristics.To verify the efficacy of the proposed methodology,experiments were conducted in which normal users and malicious users were classified based on insider threat scenarios provided in Carnegie Mellon University’s Computer Emergency Response Team(CERT)dataset.The experimental results indicate that the proposed methodology with discrete wavelet transformation reduced the false-positive rate by 82%to 98%compared to the case with no wavelet applied.Thus,the proposed methodology has high potential for application to similar feature spaces. 展开更多
关键词 Anomaly detection CYBERSECURITY discrete wavelet transformation insider threat classification
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Meta-Heuristic Optimized Hybrid Wavelet Features for Arrhythmia Classification
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作者 S.R.Deepa M.Subramoniam +2 位作者 R.Swarnalatha S.Poornapushpakala S.Barani 《Intelligent Automation & Soft Computing》 SCIE 2023年第7期745-761,共17页
The non-invasive evaluation of the heart through EectroCardioG-raphy(ECG)has played a key role in detecting heart disease.The analysis of ECG signals requires years of learning and experience to interpret and extract ... The non-invasive evaluation of the heart through EectroCardioG-raphy(ECG)has played a key role in detecting heart disease.The analysis of ECG signals requires years of learning and experience to interpret and extract useful information from them.Thus,a computerized system is needed to classify ECG signals with more accurate results effectively.Abnormal heart rhythms are called arrhythmias and cause sudden cardiac deaths.In this work,a Computerized Abnormal Heart Rhythms Detection(CAHRD)system is developed using ECG signals.It consists of four stages;preprocessing,feature extraction,feature optimization and classifier.At first,Pan and Tompkins algorithm is employed to detect the envelope of Q,R and S waves in the preprocessing stage.It uses a recursive filter to eliminate muscle noise,T-wave interference and baseline wander.As the analysis of ECG signal in the spatial domain does not provide a complete description of the signal,the feature extraction involves using frequency contents obtained from multiple wavelet filters;bi-orthogonal,Symlet and Daubechies at different resolution levels in the feature extraction stage.Then,Black Widow Optimization(BWO)is applied to optimize the hybrid wavelet features in the feature optimization stage.Finally,a kernel based Support Vector Machine(SVM)is employed to classify heartbeats into five classes.In SVM,Radial Basis Function(RBF),polynomial and linear kernels are used.A total of∼15000 ECG signals are obtained from the Massachusetts Institute of Technology-Beth Israel Hospital(MIT-BIH)arrhythmia database for performance evaluation of the proposed CAHRD system.Results show that the proposed CAHRD system proved to be a powerful tool for ECG analysis.It correctly classifies five classes of heartbeats with 99.91%accuracy using an RBF kernel with 2nd level wavelet coefficients.The CAHRD system achieves an improvement of∼6%over random projections with the ensemble SVM approach and∼2%over morphological and ECG segment based features with the RBF classifier. 展开更多
关键词 Arrhythmia classification abnormal heartbeats waveletS meta-heuristics algorithm neural network signal classification
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Efficient Authentication System Using Wavelet Embeddings of Otoacoustic Emission Signals
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作者 V.Harshini T.Dhanwin +2 位作者 A.Shahina N.Safiyyah A.Nayeemulla Khan 《Computer Systems Science & Engineering》 SCIE EI 2023年第5期1851-1867,共17页
Biometrics,which has become integrated with our daily lives,could fall prey to falsification attacks,leading to security concerns.In our paper,we use Transient Evoked Otoacoustic Emissions(TEOAE)that are generated by ... Biometrics,which has become integrated with our daily lives,could fall prey to falsification attacks,leading to security concerns.In our paper,we use Transient Evoked Otoacoustic Emissions(TEOAE)that are generated by the human cochlea in response to an external sound stimulus,as a biometric modality.TEOAE are robust to falsification attacks,as the uniqueness of an individual’s inner ear cannot be impersonated.In this study,we use both the raw 1D TEOAE signals,as well as the 2D time-frequency representation of the signal using Continuous Wavelet Transform(CWT).We use 1D and 2D Convolutional Neural Networks(CNN)for the former and latter,respectively,to derive the feature maps.The corresponding lower-dimensional feature maps are obtained using principal component analysis,which is then used as features to build classifiers using machine learning techniques for the task of person identification.T-SNE plots of these feature maps show that they discriminate well among the subjects.Among the various architectures explored,we achieve a best-performing accuracy of 98.95%and 100%using the feature maps of the 1D-CNN and 2D-CNN,respectively,with the latter performance being an improvement over all the earlier works.This performance makes the TEOAE based person identification systems deployable in real-world situations,along with the added advantage of robustness to falsification attacks. 展开更多
关键词 Person identification system cochlea:transient evoked otoacoustic emission wavelet transform convolutional neural network
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基于WT和黏菌算法的LSSVM短期风功率预测 被引量:1
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作者 赵卿 高文华 +1 位作者 石慧 董增寿 《计算机仿真》 2024年第7期166-170,226,共6页
针对风电出力存在随机性、波动性等问题,建立基于小波变换(WT)与黏菌算法(Slime mould algorithm, SMA)优化最小二乘支持向量机(LSSVM)关键参数的风功率预测模型。首先利用小波变换将风功率信号以及风速信号分解为多个不同频率的平稳的... 针对风电出力存在随机性、波动性等问题,建立基于小波变换(WT)与黏菌算法(Slime mould algorithm, SMA)优化最小二乘支持向量机(LSSVM)关键参数的风功率预测模型。首先利用小波变换将风功率信号以及风速信号分解为多个不同频率的平稳的子序列,并提出采用一种黏菌优化算法优化LSSVM的参数,同时引入气象因素,包括风速、风向、温度、气压、湿度作为输入,分别建立模型来预测风电功率。通过将各个模型预测结果加和得到完整的风功率预测值。使用某风电厂数据进行仿真验证,实验结果表明,所提出的WT-SMA-LSSVM预测模型在短期风功率预测中具有更高的预测精度。 展开更多
关键词 风功率预测 最小二乘支持向量机 小波变换 黏菌算法
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110SS油管钢在高酸性气藏环境下的腐蚀行为
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作者 陈治宇 黄本生 +1 位作者 唐景黎 左寒阳 《材料保护》 CAS CSCD 2024年第10期27-34,共8页
110SS钢因其优异的耐腐蚀性能和强度,在酸性环境的气藏油管材料中被广泛应用。为深入理解其在高酸性气藏环境中的腐蚀行为,将110SS油管挂片放置于高温高压反应釜中进行CO_(2)/H_(2)S环境模拟腐蚀实验,并利用扫描电子显微镜(SEM)、X射线... 110SS钢因其优异的耐腐蚀性能和强度,在酸性环境的气藏油管材料中被广泛应用。为深入理解其在高酸性气藏环境中的腐蚀行为,将110SS油管挂片放置于高温高压反应釜中进行CO_(2)/H_(2)S环境模拟腐蚀实验,并利用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、能谱仪(EDS)、电化学测量等手段对其腐蚀产物形貌、腐蚀速率、物相、元素含量及电化学行为进行研究。结果表明,在72~168 h腐蚀时间内,110SS油管的腐蚀速率呈幂函数变化规律,并随着腐蚀时间的延长而降低;72 h时试样表面出现黄褐色的点状腐蚀产物,120 h时黄褐色腐蚀产物出现大面积脱落,以新出现的灰色腐蚀产物为主,168 h时呈现出分布均匀的青色腐蚀产物;110SS钢腐蚀产物主要有S、FeS_(1-x)、Fe_(1-x)S、FeS、Fe_2O_(3)、Fe_3O_4、FeCl_3、FeCO_(3)等;此外,自腐蚀电流密度随着腐蚀时间的延长而增加。研究结果有助于更好地了解110SS油管钢在高酸性气藏环境中的腐蚀行为。 展开更多
关键词 110ss油管钢 CO_(2)/H_(2)S 高酸性 电化学
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高盐饮食通过激活盐皮质受体引发Dahl SS大鼠肾损伤和高血压的新机制
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作者 李曦 王蕊 李洪林 《华东理工大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第3期391-399,共9页
盐敏感高血压作为一种顽固性高血压,其发病机制十分复杂。虽然盐皮质激素受体激活和肾损伤在盐敏感高血压的发展中起关键作用,但具体的病理机制目前并不明确。通过高盐饮食诱导建立达尔盐敏感(Dahl SS)大鼠高血压模型,探究盐敏感高血压... 盐敏感高血压作为一种顽固性高血压,其发病机制十分复杂。虽然盐皮质激素受体激活和肾损伤在盐敏感高血压的发展中起关键作用,但具体的病理机制目前并不明确。通过高盐饮食诱导建立达尔盐敏感(Dahl SS)大鼠高血压模型,探究盐敏感高血压及肾损伤产生的病理机制。与盐不敏感的SS-13BN大鼠相比,长期高盐饮食会造成Dahl SS大鼠肾脏中交感神经和肾素-血管紧张素-醛固酮系统(RAAS)的局部激活,最终激活盐皮质激素受体(MR),导致上皮钠通道(ENaC)表达增加、氧化应激与炎症反应增强,从而发生肾纤维化病变,并引发肾脏中磷酸化肌动蛋白(P-Cofilin)与足蛋白(Podocin)表达增加,造成足细胞损伤,最终引发肾损伤与高血压症状。 展开更多
关键词 高盐饮食 Dahl ss大鼠 盐敏感高血压 肾损伤 盐皮质激素受体
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