期刊文献+
共找到253篇文章
< 1 2 13 >
每页显示 20 50 100
Passive Steganalysis Based on Higher Order Image Statistics of Curvelet Transform 被引量:1
1
作者 S.Geetha Siva S.Sivatha Sindhu N.Kamaraj 《International Journal of Automation and computing》 EI 2010年第4期531-542,共12页
Steganographic techniques accomplish covert communication by embedding secret messages into innocuous digital images in ways that are imperceptible to the human eye. This paper presents a novel passive steganalysis st... Steganographic techniques accomplish covert communication by embedding secret messages into innocuous digital images in ways that are imperceptible to the human eye. This paper presents a novel passive steganalysis strategy in which the task is approached as a pattern classification problem. A critical part of the steganalyser design depends on the selection of informative features. This paper is aimed at proposing a novel attack with improved performance indices with the following implications: 1) employing higher order statistics from a curvelet sub-band image representation that offers better discrimination ability for detecting stego anomalies in images, as compared to other conventional wavelet transforms; 2) increasing the sensitivity and specificity of the system by the feature reduction phase; 3) realizing the system using an efficient classification engine, a neuro-C4.5 classifier, which provides better classification rate. An extensive experimental evaluation on a database containing 5600 clean and stego images shows that the proposed scheme is a state-of-the-art steganalyser that outperforms other previous steganalytic methods. 展开更多
关键词 Image steganalysis curvelet higher order statistics neuro-C4.5 classifier information forensics information security
下载PDF
Identification of the Wave-Particles Interaction in Space Plasma Using Higher-Order Statistics
2
作者 Zhao Zhengyu, Shi Xianqing, F. Lefeuvre, A. Masson(College of Electronic Information, Wuhan University, Wuhan 430072, China)(LPCE/CNRS, 45100 Orleans Cedex 02, France) 《Wuhan University Journal of Natural Sciences》 EI CAS 1998年第1期41-45,共5页
The interaction of wave-particles and wave-wave in the space plasmas are essentially non-linear or non-Gaussian processes. Using the higher-order statistical analyses methods (higher-order moments and bi-tri correlati... The interaction of wave-particles and wave-wave in the space plasmas are essentially non-linear or non-Gaussian processes. Using the higher-order statistical analyses methods (higher-order moments and bi-tri correlation or bi-tri spectrum), its physical properties can be described. The question addressed in this paper is that of the usefulness of higher-order statistical analysis for identification of the wave-particles interaction in space plasmas. The signals handled are from the ARCAD-3 ISOPROBE experiment on ELF frequency range, then strong electrostatic turbulence and electron density irregularities. Second and third order statistical analyses are applied: first, on time series associated with each type of measurement, then, on the two types. All results are presented for one typical case. Correlation functions estimated over the corresponding time intervals point out the existence of a, non-linear interaction between these fluctuations and electrostatic filed. 展开更多
关键词 Key words wave particles interaction space plasmas higher order statistics
下载PDF
Classification of Multi-User Chirp Modulation Signals Using Wavelet Higher-Order-Statistics Features and Artificial Intelligence Techniques
3
作者 Said E. El-Khamy Hend A. Elsayed 《International Journal of Communications, Network and System Sciences》 2012年第9期520-533,共14页
Higher order statistical features have been recently proved to be very efficient in the classification of wideband communications and radar signals with great accuracy. On the other hand, the denoising properties of t... Higher order statistical features have been recently proved to be very efficient in the classification of wideband communications and radar signals with great accuracy. On the other hand, the denoising properties of the wavelet transform make WT an efficient signal processing tool in noisy environments. A novel technique for the classification of multi-user chirp modulation signals is presented in this paper. A combination of the higher order moments and cumulants of the wavelet coefficients as well as the peaks of the bispectrum and its bi-frequencies are proposed as effective features. Different types of artificial intelligence based classifiers and clustering techniques are used to identify the chirp signals of the different users. In particular, neural networks (NN), maximum likelihood (ML), k-nearest neighbor (KNN) and support vector machine (SVMs) classifiers as well as fuzzy c-means (FCM) and fuzzy k-means (FKM) clustering techniques are tested. The Simulation results show that the proposed technique is able to efficiently classify the different chirp signals in additive white Gaussian noise (AWGN) channels with high accuracy. It is shown that the NN classifier outperforms other classifiers. Also, the simulations prove that the classification based on features extracted from wavelet transform results in more accurate results than that using features directly extracted from the chirp signals, especially at low values of signal-to-noise ratios. 展开更多
关键词 Artificial Intelligence TECHNIQUES CLASSIFICATION Discrete WAVELET Transform higher order statistics MULTI-USER CHIRP Modulation SIGNALS
下载PDF
Higher-Order Statistics and Nonlinear Processes in Space Plasmas
4
作者 Zhao Zhengyu Dai Honggang Shi Xianqing 《Wuhan University Journal of Natural Sciences》 EI CAS 1998年第2期181-186,共6页
Statistics of order 2 (variance, auto and cross-correlation functions, auto and cross-power spectra) and 3 (skewness, auto and cross-bicorrelation functions, auto and cross-bispectra) are used to analyze the wave-part... Statistics of order 2 (variance, auto and cross-correlation functions, auto and cross-power spectra) and 3 (skewness, auto and cross-bicorrelation functions, auto and cross-bispectra) are used to analyze the wave-particle interaction in space plasmas. The signals considered here are medium scale electron density irregularities and ELF/ULF electrostatic turbulence. Nonlinearities are mainly observed in the ELF range. They are independently pointed out in time series associated with fluctuations in electronic density and in time series associated with the measurement of one electric field component. Peaks in cross-bicorrelation function and in mutual information clearly show that, in well delimited frequency bands, the wave-particle interactions are nonlinear above a certain level of fluctuations. The way the energy is transferred within the frequencies of density fluctuations is indicated by a bi-spectra analysis. 展开更多
关键词 higher-order statistics nonlinear processes space plasmas
下载PDF
Higher-order nonclassical effects generated by multiple-photon annihilation-then-creation and creation-then-annihilation coherent states
5
作者 袁洪春 徐学翔 +2 位作者 肖进 熊超 朱锡芳 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第5期186-191,共6页
We explore two observable nonclassical properties of quantum states generated by repeatedly operating annihilationthen-creation(AC) and creation-then-annihilation(CA) on the coherent state, respectively, such as h... We explore two observable nonclassical properties of quantum states generated by repeatedly operating annihilationthen-creation(AC) and creation-then-annihilation(CA) on the coherent state, respectively, such as higher-order subPoissonian statistics and higher-order squeezing-enhanced effect. The corresponding analytical expressions are derived in detail depending on m. By numerically comparing those quantum properties, it is found that these states above have very different nonclassical properties and nonclassicality is exhibited more strongly after AC operation than after CA operation. 展开更多
关键词 non-Gaussian operation sub-Poissonian statistics higher-order squeezing
下载PDF
平坦慢衰落信道下基于HOS的PSK调制盲信道估计 被引量:11
6
作者 李啸天 雷菁 +2 位作者 刘伟 李艳斌 张润生 《通信学报》 EI CSCD 北大核心 2015年第5期140-147,共8页
提出一种基于符号高阶统计量(HOS,high-order statistics)的MPSK调制信道衰落系数盲估计算法。针对平坦慢衰落信道模型,首先分析了MPSK调制符号高阶统计量特征,证明了MPSK调制符号的M次方符号的值是唯一的,而当1≤M′<M时,调制符号的... 提出一种基于符号高阶统计量(HOS,high-order statistics)的MPSK调制信道衰落系数盲估计算法。针对平坦慢衰落信道模型,首先分析了MPSK调制符号高阶统计量特征,证明了MPSK调制符号的M次方符号的值是唯一的,而当1≤M′<M时,调制符号的M′次方符号在复平面上是对称分布的;之后利用此特征推导出MPSK调制阶数、初始相位和衰落系数估计算法。仿真实验表明,信噪比高于12 d B条件下,HOS算法估计性能与目前平坦慢衰落信道盲估计的主流方法 Lloyd-Max算法相同,而算法复杂度为Lloyd-Max算法的1/50,并且在接收样本符号较少的条件下HOS算法的均方误差曲线收敛于最小二乘估计理论下界。 展开更多
关键词 平坦慢衰落 盲估计 高阶统计量 PSK调制 Lloyd-Max算法
下载PDF
基于HOS奇异值谱的SVDD轴承故障检测方法 被引量:18
7
作者 陶新民 杜宝祥 徐勇 《振动工程学报》 EI CSCD 北大核心 2008年第2期203-208,共6页
针对轴承故障检测中异常样本不易收集、数据分布不均以及阈值设定等问题,提出了基于支持向量数据描述(SVDD)的轴承故障检测方法。该方法只需对正常样本进行训练,以高阶统计矩阵奇异值谱为故障诊断特征,解决了高阶统计特征(HOS)数据冗余... 针对轴承故障检测中异常样本不易收集、数据分布不均以及阈值设定等问题,提出了基于支持向量数据描述(SVDD)的轴承故障检测方法。该方法只需对正常样本进行训练,以高阶统计矩阵奇异值谱为故障诊断特征,解决了高阶统计特征(HOS)数据冗余且受噪声影响的不足。实验分析了不同参数对检测性能的影响,并将本方法与多层感知机(MLP)方法及K均值聚类方法进行了比较,验证了方法的有效性和正确性。 展开更多
关键词 故障诊断 高阶统计特征 支持向量数据描述 奇异值谱 核参数
下载PDF
基于HOS和Radon变换的图像盲复原算法改进 被引量:1
8
作者 曲振峰 陈朝辉 《郑州轻工业学院学报(自然科学版)》 CAS 2010年第6期95-99,共5页
针对一般图像复原算法中噪声在高频下放大的问题,提出了用高阶统计量对模糊系统进行辨识、估计出MA模型参数、再用反卷积算法估计出原始图像的复原算法.同时引入Radon变换将二维图像投影为某一角度下的一维投影,大大降低了算法的运算复... 针对一般图像复原算法中噪声在高频下放大的问题,提出了用高阶统计量对模糊系统进行辨识、估计出MA模型参数、再用反卷积算法估计出原始图像的复原算法.同时引入Radon变换将二维图像投影为某一角度下的一维投影,大大降低了算法的运算复杂度.仿真实验表明,该算法取得了良好的效果. 展开更多
关键词 图像盲复原 高阶统计量 RADON变换 ARMA参数估计法 点扩散函数
下载PDF
基于HOS的雷达目标分类新算法
9
作者 李会方 俞卞章 梁志恒 《西北工业大学学报》 EI CAS CSCD 北大核心 2001年第2期270-273,共4页
提出一种基于高阶谱 ( HOS)的雷达目标分类方法 ,将双谱概念从频域推广到时域和距离域 ,并给出了将双谱和双相干函数的“均值”及“重心”作为特征量的特征提取新算法 ,在目标散射信号中含有加性噪声和指数噪声的情况下 ,进行了模拟 ,... 提出一种基于高阶谱 ( HOS)的雷达目标分类方法 ,将双谱概念从频域推广到时域和距离域 ,并给出了将双谱和双相干函数的“均值”及“重心”作为特征量的特征提取新算法 ,在目标散射信号中含有加性噪声和指数噪声的情况下 ,进行了模拟 ,同时对 BSB( Brain State in Box)模型的人工神经网络进行了学习训练和分类仿真 。 展开更多
关键词 信号处理 目标分类 高阶统计量 人工神经网络 雷达 高阶谱
下载PDF
HOS运动目标分割算法在视频监控中的应用 被引量:3
10
作者 范欣楠 朱玉文 +1 位作者 刘万春 刘建君 《微电子学与计算机》 CSCD 北大核心 2005年第1期66-69,共4页
为了提高视频监控中运动目标分割的速度和准确度,研究并实现了一种基于高阶统计量HOS(HigherOrderStatistics)的分割算法。首先根据HOS假设检验处理帧差图,判定像素点是否属于运动区域,阈值通过灰度共生矩阵获得,考虑了背景纹理的慢变... 为了提高视频监控中运动目标分割的速度和准确度,研究并实现了一种基于高阶统计量HOS(HigherOrderStatistics)的分割算法。首先根据HOS假设检验处理帧差图,判定像素点是否属于运动区域,阈值通过灰度共生矩阵获得,考虑了背景纹理的慢变化。然后,用矩形框聚类法大致确定运动目标的范围,在该范围内使用形态运算法和首尾扫描法去除空洞。最后,使用模板相与法获得帧图像的运动目标模板,从原图像中分割运动区域。算法采用了由粗到精的分析策略,实验表明,是一种快速稳健的算法。 展开更多
关键词 运动目标分割 视频监控 高阶统计量 灰度共生矩阵
下载PDF
基于HOS的未知雷达辐射源信号分选 被引量:2
11
作者 杨志祥 朱元清 +1 位作者 徐光华 任静波 《电子对抗》 2008年第6期10-13,共4页
对未知雷达辐射源信号进行准确分选是电子对抗领域迫需解决的一个难题。当前用于分选的特征参数主要有相像系数、小波包变换、熵值等,它们普遍存在的问题是在低信噪比下难以获得令人满意的准确率。基于高阶统计量(HOS)可以实现多种... 对未知雷达辐射源信号进行准确分选是电子对抗领域迫需解决的一个难题。当前用于分选的特征参数主要有相像系数、小波包变换、熵值等,它们普遍存在的问题是在低信噪比下难以获得令人满意的准确率。基于高阶统计量(HOS)可以实现多种不同雷达辐射源信号的分类,且具有抑制高斯噪声的优点。文章提出一种基于HOS的未知雷达辐射源信号分选新方法,通过计算机仿真验证,在相同的信噪比条件下,利用HOS进行分选可以获得更高的准确率。 展开更多
关键词 高阶统计量(hos) KOHONEN神经网络 分选
下载PDF
Modulation recognition of MIMO radar signal based on joint HOS and SNR algorithm 被引量:3
12
作者 Xiaojing Wang Ying Xiong +1 位作者 Yunhao Li Bin Tang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2014年第2期226-236,共11页
This paper presents a joint high order statistics (HOS) and signal-to-noise ratio (SNR) algorithm for the recognition of multiple-input multiple-output (MIMO) radar signal without a priori knowledge of the signa... This paper presents a joint high order statistics (HOS) and signal-to-noise ratio (SNR) algorithm for the recognition of multiple-input multiple-output (MIMO) radar signal without a priori knowledge of the signal parameters. This method is capable of recognizing the MIMO radar signal as well as discriminating it from single-carrier signal adopted by conventional radar. Meanwhile, the sub-carrier number of the none-coding MIMO radar signal is estimated. Extensive simulations are carried out in different operating conditions. Simulation results prove the feasibility and indicate that the recognition probability could reach over 90% when the value of SNR is above 0 dB. 展开更多
关键词 modulation recognition multiple-input multiple-output(MIMO) radar signal high order statistics hos).
下载PDF
Monte Carlo study of single-barrier structure based on exclusion model full counting statistics
13
作者 陈华 杜磊 +3 位作者 曲成立 何亮 陈文豪 孙鹏 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第1期553-556,共4页
Different from the usual full counting statistics theoretical work that focuses on the higher order cumulants computation by using cumulant generating function in electrical structures, Monte Carlo simulation of singl... Different from the usual full counting statistics theoretical work that focuses on the higher order cumulants computation by using cumulant generating function in electrical structures, Monte Carlo simulation of single-barrier structure is performed to obtain time series for two types of widely applicable exclusion models, counter-flows model, and tunnel model. With high-order spectrum analysis of Matlab, the validation of Monte Carlo methods is shown through the extracted first four cumulants from the time series, which are in agreement with those from cumulant generating function. After the comparison between the counter-flows model and the tunnel model in a single barrier structure, it is found that the essential difference between them consists in the strictly holding of Pauli principle in the former and in the statistical consideration of Pauli principle in the latter. 展开更多
关键词 Monte Carlo simulation higher order cumulant exclusion model full counting statistics
下载PDF
BLIND ADAPTIVE XPIC BASED ON HOS
14
作者 Fu Haiyang Yang Longxiang (Dept. of Comm. Eng., Nanjing University of Posts and Telecomm., Nanjing 210003)Peng Jianglong (Qingdao TeJecommunication Bureau, Qingdao 266000) 《Journal of Electronics(China)》 2001年第2期113-120,共8页
This paper presents a new blind XPIC and a new adaptive blind deconvolutional algorithm based on HOS processing, which separates and equalizes the signals in real time. The simulation results demonstrate that the perf... This paper presents a new blind XPIC and a new adaptive blind deconvolutional algorithm based on HOS processing, which separates and equalizes the signals in real time. The simulation results demonstrate that the performance of the proposed adaptive blind algorithm,compared with the conventional algorithms, is outstanding with the feature of feasibility, stability and fast convergence rate. 展开更多
关键词 HIGH order statistics(hos) BLIND deconvolutional ALGORITHMS CROSS-POLARIZATION INTERFERENCE canceller (XPIC)
下载PDF
HOS AND GA BASED INTERFERENCE REJECTION IN DS SS COMMUNICATION SYSTEMS
15
作者 Gong Xiangyang Hu Guaugrui Li Taijie (Department of Electronic Engineering, Shanghai Jiaotong University, Shanghai 200030) 《Journal of Electronics(China)》 2002年第2期175-177,共3页
A new interference rejection filter based on Higher Order Statistics (HOS) and Genetic Algorithm (GA) is introduced. The advantages over the adaptive filters based on secondorder statistics or gradient algorithm are s... A new interference rejection filter based on Higher Order Statistics (HOS) and Genetic Algorithm (GA) is introduced. The advantages over the adaptive filters based on secondorder statistics or gradient algorithm are shown through computer simulation. 展开更多
关键词 higher order statistics Genetic algorithm Adaptive filter Interference rejection
下载PDF
HOS AND GA BASED INTERFERENCE REJECTION IN DIRECT SEQUENCE SPREAD SPECTRUM COMMUNICATION SYSTEMS
16
作者 Gong Xiangyang Hu Guangrui Li Taijie (Department of Electronic Engineering, Shanghai Jiaotong University, Shanghai 200030) 《Journal of Electronics(China)》 2003年第2期97-101,共5页
A new Higher Order Statistics (HOS) and Genetic Algorithm (GA)-based interference rejection filter is introduced. Compared with the adaptive filters based on second-order statistics and gradient algorithm, the HOS and... A new Higher Order Statistics (HOS) and Genetic Algorithm (GA)-based interference rejection filter is introduced. Compared with the adaptive filters based on second-order statistics and gradient algorithm, the HOS and GA-based filter can reject the interference more efficiently, is independent of uncorrelated Gaussian noise, tends to converge to the optimum solution and is much less sensitive to the choice of the step size parameter. Computer simulations show that the method can reject narrowband interference efficiently. 展开更多
关键词 higher order statistics Genetic algorithm Adaptive filter Interference rejection
下载PDF
基于连续小波变换和高阶统计量的心律失常识别算法
17
作者 李刚 高广帅 +3 位作者 张珍珍 巴任伟 李春雷 刘洲峰 《中国医学物理学杂志》 CSCD 2024年第3期365-374,共10页
针对可变持续时间心电图(ECG)数据信号的非平稳性和时序性问题,提出一种基于连续小波变换(CWT)和高阶统计量(HOS)的心律失常识别算法。首先,针对可变持续时间ECG数据中每个样本的数据点数量不同,采用RR间期插值法预处理数据,并通过CWT... 针对可变持续时间心电图(ECG)数据信号的非平稳性和时序性问题,提出一种基于连续小波变换(CWT)和高阶统计量(HOS)的心律失常识别算法。首先,针对可变持续时间ECG数据中每个样本的数据点数量不同,采用RR间期插值法预处理数据,并通过CWT将信号分解为不同的时频分量,从而使网络能够更好地提取心电信号中的时间和频率特征。其次,针对时序信息利用不充分的问题,提出基于HOS和长短期记忆网络的时序挖掘模块,以捕捉和学习ECG信号中的长期依赖关系,从而有助于识别和理解特定的心律失常类别。通过在公开的ECG数据集MIT-BIN上进行的大量实验,验证所提方法的有效性和优越性。 展开更多
关键词 心律失常识别 连续小波变换 高阶统计量 长短期记忆网络 RR间隔
下载PDF
高阶网络统计指标综述
18
作者 刘波 曾钰洁 +1 位作者 杨荣湄 吕琳媛 《物理学报》 SCIE EI CAS CSCD 北大核心 2024年第12期60-77,共18页
复杂网络是描述和理解现实世界中复杂系统的有力工具.近年来,为了更准确地描述复杂网络中的交互关系,或者从高阶视角分析成对交互作用网络,许多学者开始使用高阶网络进行建模,并在研究其动力学过程中发现了与成对交互作用网络不同的新现... 复杂网络是描述和理解现实世界中复杂系统的有力工具.近年来,为了更准确地描述复杂网络中的交互关系,或者从高阶视角分析成对交互作用网络,许多学者开始使用高阶网络进行建模,并在研究其动力学过程中发现了与成对交互作用网络不同的新现象.然而,与成对交互作用网络相比,高阶网络的研究相对较少;而且,高阶网络结构相对复杂,基于结构的统计指标定义较为分散且形式不统一,这些都给描述高阶网络的拓扑结构特征带来了困难.鉴于此,本文综述了两种最常见的高阶网络——超图和单纯形网络——常用的统计指标及其物理意义.本文有助于加深对高阶网络的理解,促进对高阶网络结构特征的定量化研究,也有助于研究者在此基础上开发更多适用于高阶网络的统计指标. 展开更多
关键词 高阶网络 超图 单纯形网络 统计指标
下载PDF
公众媒体素养评估:如何侦测假信息及提供评估学习工具
19
作者 赵明明 林思明(译) 《考试研究》 2024年第4期1-8,共8页
为帮助公众识别假新闻,研究使用人工智能和高级统计技术检测假新闻,在此基础上探讨开发学生媒体素养的评估和学习工具。通过人工智能、计算语言学和高级统计,分析用户或推特属性是否能区分4165条纠正过拼写错误的英文推文的真、假新闻,... 为帮助公众识别假新闻,研究使用人工智能和高级统计技术检测假新闻,在此基础上探讨开发学生媒体素养的评估和学习工具。通过人工智能、计算语言学和高级统计,分析用户或推特属性是否能区分4165条纠正过拼写错误的英文推文的真、假新闻,这些推文与20条匹配的相关新闻报道之一(10条真,10条假)关联。相较而言,使用常用词、负面情绪、更高情感激励、更高支配力、第一人称单数代词、第三人称代词或拥有更多关注用户的推文,是真新闻的可能性更大;使用第二人称代词、以无主语句开头或使用委婉语的推文,是假新闻的可能性更大。结果表明,一些通用的预测因素(如代词、礼貌用语、关注用户人数等)和特定主题的预测因素(如常用词、情绪、委婉语等)可以有效识别真假新闻。最后提出用简单易懂的媒体素养仪表盘模拟假新闻的传播范围、速度和形状,以帮助学生学习和评估自身媒体素养。 展开更多
关键词 媒体素养 假新闻 人工智能 高阶统计
下载PDF
基于JT-AR转换模型的非高斯风荷载特性分析
20
作者 孙芳锦 阳立云 +2 位作者 路明璟 张大明 曾倩 《兰州工业学院学报》 2024年第1期64-70,共7页
为了研究大跨度屋盖结构的非高斯风荷载特性,提出一种采用JT-AR转换模型模拟大跨度球面屋盖结构非高斯脉动风压的方法。基于JT变换和AR模型理论进行耦合,提出并构建JT-AR转换模型,模拟生成非高斯脉动风压时程样本数据,与目标功率谱及高... 为了研究大跨度屋盖结构的非高斯风荷载特性,提出一种采用JT-AR转换模型模拟大跨度球面屋盖结构非高斯脉动风压的方法。基于JT变换和AR模型理论进行耦合,提出并构建JT-AR转换模型,模拟生成非高斯脉动风压时程样本数据,与目标功率谱及高阶统计量对比验证;通过已有风洞试验结果与作用在大跨度球面屋盖结构表面的非高斯分布特性作对比验证。结果表明:JT-AR转换模型的模拟结果与风洞试验作用在建筑上的非高斯脉动风具有同等作用效应,其模拟仿真结果具备可靠性及普适性。研究结论为大跨度结构抗风设计提供一种新的模拟方法,可代替复杂的风洞试验。 展开更多
关键词 大跨度屋盖结构 Johnson变换 AR自回归模型 高阶统计量 非高斯脉动风压
下载PDF
上一页 1 2 13 下一页 到第
使用帮助 返回顶部