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基于EMD-SSSC分解的振动信号去势 被引量:2
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作者 杨穹 秦仙蓉 +2 位作者 刘兆航 孙远韬 张氢 《噪声与振动控制》 CSCD 北大核心 2024年第1期187-191,共5页
提出一种基于经验模态分解和软筛分准则的振动信号去势方法EMD-SSSC(Empirical Mode Decomposition-Soft Sifting Stopping Criterion,EMD-SSSC),根据软筛分准则自适应控制筛分过程,改善本征模态函数的混叠问题,提高经验模态分解的精度... 提出一种基于经验模态分解和软筛分准则的振动信号去势方法EMD-SSSC(Empirical Mode Decomposition-Soft Sifting Stopping Criterion,EMD-SSSC),根据软筛分准则自适应控制筛分过程,改善本征模态函数的混叠问题,提高经验模态分解的精度与效率,从而有效去除振动信号的趋势项。通过解析函数和两自由度弹簧-质量-阻尼系统验证该方法的有效性和精度,并进一步将其应用于实际岸桥结构健康监测中加速度响应的去势。结果表明:采用EMD-SSSC方法可以准确剔除振动信号中的趋势项,去势精度远高于最小二乘法;所提出方法既可有效用于数值积分中因积分常数的存在而出现的趋势项,也可合理去除工程实际监测信号中的趋势项。 展开更多
关键词 振动与波 经验模态分解 软筛分停止准则 信号去势 信号分析 岸桥监测
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新疆北疆滴灌机采棉田杂草生态位机理研究 被引量:1
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作者 孙利忠 马保建 刘彤 《棉花学报》 CSCD 北大核心 2024年第1期66-78,共13页
【目的】探究新疆北疆滴灌机采棉田杂草生态位机理。【方法】运用七级目测法调查了新疆北疆5个地区(新疆生产建设兵团第八师143团、145团和147团,昌吉市,奎屯市)25个滴灌机采棉田样点的杂草优势度等级,依据优势度等级转换为重要值,进而... 【目的】探究新疆北疆滴灌机采棉田杂草生态位机理。【方法】运用七级目测法调查了新疆北疆5个地区(新疆生产建设兵团第八师143团、145团和147团,昌吉市,奎屯市)25个滴灌机采棉田样点的杂草优势度等级,依据优势度等级转换为重要值,进而计算出主要杂草(20种)的生态位宽度及重叠值;依据20种主要杂草的优势度及生态位重叠值,采用去趋势对应分析(detrended correspondence analysis,DCA)排序和最小生成树法(图论聚类分析),制作反映杂草生态学相似关系的排序图和最小生成树。【结果】田旋花、藜、反枝苋、龙葵、芦苇、狗尾草、苘麻、野西瓜苗和稗的实际生态位较宽,是新疆北疆滴灌机采棉田的优势种群(恶性杂草)。龙葵与藜、苘麻与反枝苋、野西瓜苗与稗、反枝苋与稗等杂草间的生态位重叠值较大,对资源的竞争较为激烈。依据生态位重叠值的大小关系制作的最小生成树中,20种主要杂草被分为4组。在25个样点中,针对20种主要杂草的综合生态需求DCA排序表明:9种恶性杂草几乎都聚集于排序图中央,与居于排序图周边的一般杂草区分较为明显,且20种主要杂草的DCA排序图与最小生成树对应关系较好。【结论】随着滴灌年限的增加,龙葵、田旋花、藜等9种恶性杂草的优势度值与滴灌年限之间存在极显著或显著的回归关系,其中除田旋花、狗尾草2种杂草的优势度值与滴灌年限之间存在极显著的非线性回归关系外,其他7种杂草的优势度值与滴灌年限之间存在极显著的线性回归关系。 展开更多
关键词 棉花 杂草 滴灌 生态位 最小生成树 去趋势对应分析
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New seismic attribute:Fractal scaling exponent based on gray detrended fluctuation analysis 被引量:1
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作者 黄亚平 耿建华 郭彤楼 《Applied Geophysics》 SCIE CSCD 2015年第3期343-352,467,共11页
Seismic attributes have been widely used in oil and gas exploration and development. However, owing to the complexity of seismic wave propagation in subsurface media, the limitations of the seismic data acquisition sy... Seismic attributes have been widely used in oil and gas exploration and development. However, owing to the complexity of seismic wave propagation in subsurface media, the limitations of the seismic data acquisition system, and noise interference, seismic attributes for seismic data interpretation have uncertainties. Especially, the antinoise ability of seismic attributes directly affects the reliability of seismic interpretations. Gray system theory is used in time series to minimize data randomness and increase data regularity. Detrended fluctuation analysis (DFA) can effectively reduce extrinsic data tendencies. In this study, by combining gray system theory and DFA, we propose a new method called gray detrended fluctuation analysis (GDFA) for calculating the fractal scaling exponent. We consider nonlinear time series generated by the Weierstrass function and add random noise to actual seismic data. Moreover, we discuss the antinoise ability of the fractal scaling exponent based on GDFA. The results suggest that the fractal scaling exponent calculated using the proposed method has good antinoise ability. We apply the proposed method to 3D poststack migration seismic data from southern China and compare fractal scaling exponents calculated using DFA and GDFA. The results suggest that the use of the GDFA-calculated fractal scaling exponent as a seismic attribute can match the known distribution of sedimentary facies. 展开更多
关键词 Seismic attribute gray system theory detrended fluctuation analysis fractal scaling exponent
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融合图卷积和卷积自注意力的股票预测方法
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作者 田红丽 崔姚 闫会强 《计算机工程与应用》 CSCD 北大核心 2024年第4期192-199,共8页
随着我国股票市场的不断发展,一只股票的走势往往受其企业上下游产业发展的影响。针对主流股票预测模型忽略了股票间关联关系的不足,提出了融合图卷积和多头卷积自注意力的股票趋势预测模型。首先使用互相关系数计算多只关联股票的关系... 随着我国股票市场的不断发展,一只股票的走势往往受其企业上下游产业发展的影响。针对主流股票预测模型忽略了股票间关联关系的不足,提出了融合图卷积和多头卷积自注意力的股票趋势预测模型。首先使用互相关系数计算多只关联股票的关系矩阵,再使用图卷积神经网络结合关系矩阵对关联股票进行特征提取,其次使用多头卷积自注意力提取时间特征,最后使用分类损失函数多项式展开框架对损失函数进行优化,并进行趋势预测。实验结果表明,所提模型在准确率、查全率、召回率以及F1分数上均优于门控循环单元、时间卷积网络等模型。 展开更多
关键词 股票趋势预测 卷积自注意力 去趋势互相关系数
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线性和非线性去趋势化对土性波动范围影响分析
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作者 吴杰 吴道祥 +1 位作者 林飞 李汶修 《合肥工业大学学报(自然科学版)》 CAS 北大核心 2024年第10期1412-1418,1426,共8页
文章基于合肥市黏土层静力触探(cone penetration test,CPT)数据建立土性剖面随机场模型,探究线性和非线性去趋势化对土性波动范围计算结果的影响。利用线性和非线性去趋势方法对原始CPT数据进行去趋势化处理,对得到的波动分量进行平稳... 文章基于合肥市黏土层静力触探(cone penetration test,CPT)数据建立土性剖面随机场模型,探究线性和非线性去趋势化对土性波动范围计算结果的影响。利用线性和非线性去趋势方法对原始CPT数据进行去趋势化处理,对得到的波动分量进行平稳性和遍历性检验,采取相关函数法和空间递推法计算波动分量对应的土性波动范围,并讨论计算方法和取样间距对不同去趋势化方法的敏感性。结果表明:对于具有非线性趋势的数据,采用线性去趋势来处理会使得到的波动分量平稳性变差,导致最终计算得到的波动范围均值、标准差和变异系数增大,计算结果稳定性明显变差;相比于线性去趋势,非线性去趋势的适应性更强;此外相关函数法对不同去趋势化方法的敏感性要大于空间递推法,而取样间距不会影响数据整体的趋势性及对去趋势化处理方法的选择。 展开更多
关键词 静力触探(CPT) 去趋势化 波动范围 相关函数法 空间递推法
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基于去趋势多重互相关的深度回声状态网络剪枝算法
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作者 孙晓川 王宇 +1 位作者 李莹琦 黄天宇 《郑州大学学报(工学版)》 CAS 北大核心 2024年第4期38-45,共8页
针对储备池中存在的冗余结构导致深度回声状态网络预测精度不佳的问题,提出了一种基于去趋势多重互相关的深度回声状态网络剪枝算法。首先,根据去趋势协方差函数和去趋势方差函数,依次计算所选储备池中每2个神经元之间的去趋势互相关系... 针对储备池中存在的冗余结构导致深度回声状态网络预测精度不佳的问题,提出了一种基于去趋势多重互相关的深度回声状态网络剪枝算法。首先,根据去趋势协方差函数和去趋势方差函数,依次计算所选储备池中每2个神经元之间的去趋势互相关系数,构建去趋势互相关矩阵,基于该矩阵评估该储备池中所选神经元与所有剩余神经元之间的去趋势多重互相关性。其次,依次删除每个储备池中高相关性神经元到输出层的连接,从而去除网络中的冗余结构。最后,通过最小二乘回归重新训练剪枝后的网络,以获得最优的深度回声状态网络拓扑结构。仿真结果表明:经过所提算法优化后的深度回声状态网络在Mackey-Glass时间序列上的预测精度和记忆能力分别提高了89.80%和30.93%,在Call时间序列上的预测精度和记忆能力分别提高了14.34%和0.10%。 展开更多
关键词 深度回声状态网络 结构优化 剪枝 去趋势多重互相关 时间序列预测
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甘肃祁连山国家自然保护区植物群落多样性与海拔的响应关系
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作者 李国霞 苏军德 赵晓冏 《自然保护地》 CSCD 2024年第1期110-122,共13页
【目的】探求祁连山自然保护区植物群落多样性与海拔的响应关系及其驱动机制,为区域森林生态系统的保育和恢复提供一定的理论基础,同时也为区域生物多样性的保护利用及生态建设提供参考依据。【方法】本研究在野外样方调查的基础上,综... 【目的】探求祁连山自然保护区植物群落多样性与海拔的响应关系及其驱动机制,为区域森林生态系统的保育和恢复提供一定的理论基础,同时也为区域生物多样性的保护利用及生态建设提供参考依据。【方法】本研究在野外样方调查的基础上,综合运用除趋势典范对应分析法(Detrended canonical correspondence analysis,DCCA)、相关分析法及回归分析法,对甘肃祁连山自然保护区内(99°30′~100°53′E,38°12′~39°17′N,海拔1500~3700 m)植物群落多样性与海拔的响应关系进行了深入分析。【结果】结果表明:①不同层次植物群落丰富度指数、多样性指数在不同海拔表现出明显的差异,草本层和灌木层Patrick丰富度指数和Shannon-Wiener多样性指数随环境梯度和海拔梯度均表现出“单峰型”变化格局,除高海拔(2950~3700 m)外,在其余海拔梯度上,草本层丰富度指数和多样性指数均显著高于灌木层(P<0.01),且在中海拔(2400~2950 m)地带达到最高;②植物群落各层次Pielou均匀度并未随环境梯度和海拔梯度表现出明显的差异,表明植物群落均匀度受环境响应较小,而主要受群落自身的结构类型和稳定程度的影响;③草本、灌木和乔木植被分布格局被环境因子解释部分分别占29.32%,23.24%和9.05%,被空间因子解释部分分别占15.21%,11.08%和7.52%,被空间和环境因子交叉作用的解释部分分别占11.04%、8.42%和5.31%,未被空间因子和环境因子解释部分分别占44.43%,57.26%和78.12%。【结论】植物群落物种多样性除受海拔引起的水热梯度影响外,还受生物间相互作用、人类活动、发育程度等因素的影响,在未来生态系统的保护与管理中,在减少人类活动影响的同时,应增强应对气候变化的保护措施和力度。 展开更多
关键词 植物群落 海拔 祁连山 植物多样性 除趋势典范对应分析法
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基于近红外高光谱成像技术的地方鸡品种鉴别
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作者 金航峰 于昌昊 +3 位作者 范锴萍 吴健清 颜菲菲 汪涵 《现代食品科技》 CAS 北大核心 2024年第5期247-254,共8页
我国拥有丰富的地方鸡遗传资源,不同品种的地方鸡在营养、口感和风味上表现出显著区别。该研究利用近红外高光谱成像技术研究地方鸡品种的鉴别方法。以龙游麻鸡、江山乌骨鸡和丝羽乌骨鸡为研究对象,采集3个品种鸡肉在900~1700 nm波段的... 我国拥有丰富的地方鸡遗传资源,不同品种的地方鸡在营养、口感和风味上表现出显著区别。该研究利用近红外高光谱成像技术研究地方鸡品种的鉴别方法。以龙游麻鸡、江山乌骨鸡和丝羽乌骨鸡为研究对象,采集3个品种鸡肉在900~1700 nm波段的高光谱图像并提取光谱数据。对光谱数据进行预处理后选取特征波长,建立PLS和SVM鉴别模型。结果显示,Detrending-SNV为最优预处理方法,ACCc、ACCp和ACCt分别为94.17%、95%和94.59%。基于MCUVE-SPA算法选取的16个特征波长建立的PLS鉴别模型为最优模型,ACCc、ACCp和ACCt分别为95.83%、100%和97.92%,与全光谱模型相比分别提高了1.76%、5.26%和3.52%。研究结果表明,利用近红外高光谱成像技术鉴别地方鸡品种具有一定的可行性。 展开更多
关键词 地方鸡 近红外高光谱 去趋势 标准正态变量变换 连续投影算法 支持向量机
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基于去趋势波动分析方法的直拉单晶硅拉速曲线研究
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作者 汤辉 吴彦国 《计算机应用文摘》 2024年第18期154-156,共3页
直拉单晶硅的生长是半导体工业中的关键步骤,其过程具有动态连续性。提拉速度的波动直接影响最终产品的成品率和质量。在直拉单晶硅的等径生长过程中,稳定的提拉速度有助于提高晶体的质量;而提拉速度波动过大会导致晶体中出现原生缺陷,... 直拉单晶硅的生长是半导体工业中的关键步骤,其过程具有动态连续性。提拉速度的波动直接影响最终产品的成品率和质量。在直拉单晶硅的等径生长过程中,稳定的提拉速度有助于提高晶体的质量;而提拉速度波动过大会导致晶体中出现原生缺陷,甚至可能引发晶体直径控制的失效。采用去趋势波动分析法(DFA)对直拉单晶硅的拉速曲线进行处理,结合具体的单晶硅生长过程,分析了拉速出现较大波动的原因。结果表明,DFA对研究直拉单晶硅拉速曲线具有较好的适用性,并且结合工艺过程开展的研究对优化工艺和提高生产稳定性具有重要的指导意义。 展开更多
关键词 单晶硅 拉速 MATLAB 去趋势波动分析
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计划烧除影响下的大气O_(3)和PM_(2.5)/PM_(10)多尺度互相关性的多重分形表征
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作者 钟心宇 陈智荣 +4 位作者 罗静 梅小莉 樊彬鑫 李友平 刘春琼 《西华师范大学学报(自然科学版)》 2024年第5期466-474,共9页
为揭示计划烧除期间烟羽区中O_(3)和二次气溶胶之间的复杂大气光化学行为,基于多重分形去趋势互相关分析(MFDCCA)方法对凉山彝族自治州西昌市5个大气监测点(凉山州政府、青龙寺、邛海宾馆、西昌市政府和长安)不同时间尺度上O_(3)和PM_(2... 为揭示计划烧除期间烟羽区中O_(3)和二次气溶胶之间的复杂大气光化学行为,基于多重分形去趋势互相关分析(MFDCCA)方法对凉山彝族自治州西昌市5个大气监测点(凉山州政府、青龙寺、邛海宾馆、西昌市政府和长安)不同时间尺度上O_(3)和PM_(2.5)/PM_(10)序列之间互相关性的多重分形强度(Δh)进行研究。结果发现:(1)计划烧除期间(2020年12月—2021年2月和2021年12月—2022年2月)和非计划烧除期间(2016年—2019年同期)各监测点的O_(3)或PM_(2.5)/PM_(10)的日变化规律一致,并且计划烧除期间的O_(3)浓度小于非计划烧除期间,PM_(2.5)/PM_(10)大于非计划烧除期间,其中,青龙寺监测点PM_(2.5)/PM_(10)的增涨幅度最高,而O_(3)浓度的下降幅度最低。(2)各监测点O_(3)和PM_(2.5)/PM_(10)序列之间的互相关性在2016—2022年均具有多重分形特征,各监测点的Δh值均表现出冬春高、夏秋低的季节变化规律,且青龙寺监测点的Δh值最高。(3)各监测点的Δh值均在2020与2021年冬季出现峰值,计划烧除期间的Δh值均高于非计划烧除期间,且青龙寺监测点的增涨幅度最大。研究结果有助于从新的角度理解计划烧除对大气光化学作用的影响,并为进一步研究野火对大气环境的影响并制定相应的措施提供一定的科学依据。 展开更多
关键词 计划烧除 多重分形去趋势互相关分析 日变化规律 O_(3) PM_(2.5)/PM_(10) 二次气溶胶 西昌市
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浅谈电机轴承振动信号的采集与处理
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作者 张雪玲 《防爆电机》 2024年第4期87-90,共4页
基于实际电机运维和故障检测技术,对电机轴承的故障检测,提出了轴承振动信号的采集与处理的一些经验方法。基于振动信号的采样理论,讨论了采样控制方法和信号预处理方法,以及电机的轴承信号故障检测与分析方法。
关键词 电机轴承振动信号 去趋势项 五点三次平滑法 快速傅里叶变换
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Detrended cross-correlation analysis of electroencephalogram 被引量:5
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作者 Wang Jun Zhao Da-Qing 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第2期577-580,共4页
In the paper we use detrended cross-correlation analysis (DCCA) to study the electroencephalograms of healthy young subjects and healthy old subjects. It is found that the cross-correlation between different leads o... In the paper we use detrended cross-correlation analysis (DCCA) to study the electroencephalograms of healthy young subjects and healthy old subjects. It is found that the cross-correlation between different leads of a healthy young subject is larger than that of a healthy old subject. It was shown that the cross-correlation relationship decreases with the aging process and the phenomenon can help to diagnose whether the subject's brain function is healthy or not. 展开更多
关键词 detrended cross-correlation analysis ELECTROENCEPHALOGRAM brain function aging process
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Extracting a seizure intensity index from one-channel EEG signal using bispectral and detrended fluctuation analysis 被引量:4
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作者 Pegah Tayaranian Hosseini Reza Shalbaf Ali Motie Nasrabadi 《Journal of Biomedical Science and Engineering》 2010年第3期253-261,共9页
Epilepsy is a medical condition that produces seizures affecting a variety of mental and physical functions. Seizures can last from a few seconds to a few minutes. They can have many symptoms, from convulsions and los... Epilepsy is a medical condition that produces seizures affecting a variety of mental and physical functions. Seizures can last from a few seconds to a few minutes. They can have many symptoms, from convulsions and loss of consciousness to blank staring, lip smacking, or jerking movements of arms and legs. If early warning signals of an upcoming seizure (diagnosis of preictal period) are detected, proper treatment can be applied to the patient to help prevent the seizure. In this research, an epileptic disorder has been divided into three subsets: Normal, Preictal (just before the seizure), and Ictal (during seizure). By using Detrended Fluctuation Analysis (DFA), Bispectral Analysis (BIS), and Standard Deviation (SD) three features from single-channel EEG signals have been derived in the foresaid groups. A fuzzy classifier is used to separate the three groups which can successfully separate them with a separation degree of 100% and further a fuzzy inference engine is used to extract a Seizure Intensity Index (SII) from the Electroencephalogram (EEG) signals of the three different states. One can apparently see the distinction of SII amounts between the three states. It is more important when one remembers that these results are just from single-channel EEG signal. 展开更多
关键词 EPILEPSY Fuzzy INFERENCE Engine BISPECTRUM detrended FLUCTUATION Analysis
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Relationships of exponents in multifractal detrended fluctuation analysis and conventional multifractal analysis 被引量:2
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作者 周煜 梁怡 喻祖国 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第9期98-106,共9页
Multifractal detrended fluctuation analysis (MF-DFA) is a relatively new method of multifractal analysis. It is extended from detrended fluctuation analysis (DFA), which was developed for detecting the long-range ... Multifractal detrended fluctuation analysis (MF-DFA) is a relatively new method of multifractal analysis. It is extended from detrended fluctuation analysis (DFA), which was developed for detecting the long-range correlation and the fractal properties in stationary and non-stationary time series. Although MF-DFA has become a widely used method, some relationships among the exponents established in the original paper seem to be incorrect under the general situation. In this paper, we theoretically and experimentally demonstrate the invalidity of the expression r(q) = qh(q) - 1 stipulating the relationship between the multifractal exponent T(q) and the generalized Hurst exponent h(q). As a replacement, a general relationship is established on the basis of the universal multifractal formalism for the stationary series as .t-(q) = qh(q) - qH - 1, where H is the nonconservation parameter in the universal multifractal formalism. The singular spectra, a and f(a), are also derived according to this new relationship. 展开更多
关键词 fractals Hurst exponent multifractal detrended fluctuation analysis time series analysis
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Detrended Fluctuation Analysis on Correlations of Complex Networks Under Attack and Repair Strategy 被引量:4
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作者 CHI Li-Ping YANG Chun-Bin MAKe CAI Xu 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第4期765-768,共4页
We analyze the correlation properties of the Erd6s-Rdnyi random graph (RG) and the Barabdsi-Albert scale-free network (SF) under the attack and repair strategy with detrended fluctuation analysis (DFA). The maxi... We analyze the correlation properties of the Erd6s-Rdnyi random graph (RG) and the Barabdsi-Albert scale-free network (SF) under the attack and repair strategy with detrended fluctuation analysis (DFA). The maximum degree kmax, representing the local property of the system, shows similar scaling behaviors for random graphs and scale-free networks. The fluctuations are quite random at short time scales but display strong anticorrelation at longer time scales under the same system size N and different repair probability pre. The average degree 〈k〉, revealing the statistical property of the system, exhibits completely different scaling behaviors for random graphs and scale-free networks. Random graphs display long-range power-law correlations. Scale-free networks are uncorrelated at short time scales; while anticorrelated at longer time scales and the anticorrelation becoming stronger with the increase of pre. 展开更多
关键词 CORRELATIONS detrended fluctuation analysis complex networks
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Correlation between detrended fluctuation analysis and the Lempel-Ziv complexity in nonlinear time series analysis 被引量:1
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作者 唐友福 刘树林 +1 位作者 姜锐红 刘颖慧 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第3期219-225,共7页
We study the correlation between detrended fluctuation analysis(DFA) and the Lempel-Ziv complexity(LZC) in nonlinear time series analysis in this paper.Typical dynamic systems including a logistic map and a Duffin... We study the correlation between detrended fluctuation analysis(DFA) and the Lempel-Ziv complexity(LZC) in nonlinear time series analysis in this paper.Typical dynamic systems including a logistic map and a Duffing model are investigated.Moreover,the influence of Gaussian random noise on both the DFA and LZC are analyzed.The results show a high correlation between the DFA and LZC,which can quantify the non-stationarity and the nonlinearity of the time series,respectively.With the enhancement of the random component,the exponent α and the normalized complexity index C show increasing trends.In addition,C is found to be more sensitive to the fluctuation in the nonlinear time series than α.Finally,the correlation between the DFA and LZC is applied to the extraction of vibration signals for a reciprocating compressor gas valve,and an effective fault diagnosis result is obtained. 展开更多
关键词 nonlinear time series detrended fluctuation analysis Lempel-Ziv complexity correlation coefficient
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Detrended Fluctuation Analysis of the Human EEG during Listening to Emotional Music 被引量:2
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作者 Ting-Ting Gao Dan Wu Ying-Ling Huang De-Zhong Yao 《Journal of Electronic Science and Technology of China》 2007年第3期272-277,共6页
A nonlinear method named detrended fluctuation analysis (DFA) was utilized to investigate the scaling behavior of the human electroencephalogram (EEG) in three emotional music conditions (fear, happiness, sadness... A nonlinear method named detrended fluctuation analysis (DFA) was utilized to investigate the scaling behavior of the human electroencephalogram (EEG) in three emotional music conditions (fear, happiness, sadness) and a rest condition (eyes-closed). The results showed that the EEG exhibited scaling behavior in two regions with two scaling exponents β1 and β2 which represented the complexity of higher and lower frequency activity besides α band respectively. As the emotional intensity decreased the value of β1 increased and the value of β2 decreased. The change of β1 was weakly correlated with the 'approach-withdrawal' model of emotion and both of fear and sad music made certain differences compared with the eyes-closed rest condition. The study shows that music is a powerful elicitor of emotion and that using nonlinear method can potentially contribute to the investigation of emotion. 展开更多
关键词 detrended fluctuation analysis (DFA) electroencephalogram(EEG) EMOTION MUSIC scaling.
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A Multifractal Detrended Fluctuation Analysis of the Ising Financial Markets Model with Small World Topology 被引量:1
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作者 张昂辉 李晓温 +1 位作者 苏桂锋 张一 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第9期13-16,共4页
We present a multifractal detrended fluctuation analysis (MFDFA) of the time series of return generated by our recently-proposed Ising financial market model with underlying small world topology. The result of the M... We present a multifractal detrended fluctuation analysis (MFDFA) of the time series of return generated by our recently-proposed Ising financial market model with underlying small world topology. The result of the MFDFA shows that there exists obvious multifractal scaling behavior in produced time series. We compare the MFDFA results for original time series with those for shuffled series, and find that its multifractal nature is due to two factors: broadness of probability density function of the series and different correlations in small- and large-scale fluctuations. This may provide new insight to the problem of the origin of multifractality in financial time series. 展开更多
关键词 A Multifractal detrended Fluctuation Analysis of the Ising Financial Markets Model with Small World Topology
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INVESTIGATION OF THE SPATIAL AND TEMPORAL DISTRIBUTION OF EXTREME HIGH TEMPERATURE IN CHINA WITH DETRENDED FLUCTUATION AND PERMUTATION ENTROPY
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作者 尹继福 郑有飞 +2 位作者 吴荣军 傅颖 王维 《Journal of Tropical Meteorology》 SCIE 2013年第4期349-356,共8页
With temperatures increasing as a result of global warming,extreme high temperatures are becoming more intense and more frequent on larger scale during summer in China.In recent years,a variety of researches have exam... With temperatures increasing as a result of global warming,extreme high temperatures are becoming more intense and more frequent on larger scale during summer in China.In recent years,a variety of researches have examined the high temperature distribution in China.However,it hardly considers the variation of temperature data and systems when defining the threshold of extreme high temperature.In order to discern the spatio-temporal distribution of extreme heat in China,we examined the daily maximum temperature data of 83 observation stations in China from 1950 to 2008.The objective of this study was to understand the distribution characteristics of extreme high temperature events defined by Detrended Fluctuation Analysis(DFA).The statistical methods of Permutation Entropy(PE)were also used in this study to analyze the temporal distribution.The results showed that the frequency of extreme high temperature events in China presented 3 periods of 7,10—13 and 16—20 years,respectively.The abrupt changes generally happened in the 1960s,the end of 1970s and early 1980s.It was also found that the maximum frequency occurred in the early 1950s,and the frequency decreased sharply until the late 1980s when an evidently increasing trend emerged.Furthermore,the annual averaged frequency of extreme high temperature events reveals a decreasing-increasing-decreasing trend from southwest to northeast China,but an increasing-decreasing trend from southeast to northwest China.And the frequency was higher in southern region than that in northern region.Besides,the maximum and minimum of frequencies were relatively concentrated spatially.Our results also shed light on the reasons for the periods and abrupt changes of the frequency of extreme high temperature events in China. 展开更多
关键词 EXTREME high temperature EVENTS detrended FLUCTUATION analysis PERMUTATION ENTROPY spatial and TEMPORAL distribution
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Effects of quantization on detrended fluctuation analysis
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作者 朱松盛 徐泽西 +1 位作者 殷奎喜 徐寅林 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第5期153-158,共6页
Detrended fluctuation analysis (DFA) is a method foro estimating the long-range power-law correlation exponent in noisy signals. It has been used successfully in many different fields, especially in the research of ... Detrended fluctuation analysis (DFA) is a method foro estimating the long-range power-law correlation exponent in noisy signals. It has been used successfully in many different fields, especially in the research of physiological signals. As an inherent part of these studies, quantization of continuous signals is inevitable. In addition, coarse-graining, to transfer original signals into symbol series in symbolic dynamic analysis, can also be considered as a quantization-like operation. Therefore, it is worth considering whether the quantization of signal has any effect on the result of DFA and if so, how large the effect will be. In this paper we study how the quantized degrees for three types of noise series (anti-correlated, uncorrelated and long-range power-law correlated signals) affect the results of DFA and find that their effects are completely different. The conclusion has an essential value in choosing the resolution of data acquisition instrument and in the processing of coarse-graining of signals. 展开更多
关键词 detrended fluctuation analysis QUANTIZATION
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