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Demodulation of Vernier-effect-based optical fiber strain sensor by using improved cross-correlation algorithm
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作者 LIU Bin CAO Zhi-gang +7 位作者 WANG Xing-yun LIN Zi-han CHENG Rui LIU Jun SUN Yu-han ZHENG Shu-jun ZUO Cheng LIN Ji-ping 《中国光学(中英文)》 北大核心 2025年第6期1463-1474,共12页
The improved cross-correlation algorithm for the strain demodulation of Vernier-effect-based optical fiber sensor(VE-OFS)is proposed in this article.The algorithm identifies the most similar spectrum to the measured o... The improved cross-correlation algorithm for the strain demodulation of Vernier-effect-based optical fiber sensor(VE-OFS)is proposed in this article.The algorithm identifies the most similar spectrum to the measured one from the database of the collected spectra by employing the cross-correlation operation,subsequently deriving the predicted value via weighted calculation.As the algorithm uses the complete information in the measured raw spectrum,more accurate results and larger measurement range can be obtained.Additionally,the improved cross-correlation algorithm also has the potential to improve the measurement speed compared to current standards due to the possibility for the collection using low sampling rate.This work presents an important algorithm towards a simpler,faster way to improve the demodulation performance of VE-OFS. 展开更多
关键词 improved cross-correlation algorithm fiber sensor vernier effect machine learning
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Amplitude phase control for electro-hydraulic servo system based on normalized least-mean-square adaptive filtering algorithm 被引量:5
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作者 姚建均 富威 +1 位作者 胡胜海 韩俊伟 《Journal of Central South University》 SCIE EI CAS 2011年第3期755-759,共5页
The electro-hydraulic servo system was studied to cancel the amplitude attenuation and phase delay of its sinusoidal response,by developing a network using normalized least-mean-square (LMS) adaptive filtering algorit... The electro-hydraulic servo system was studied to cancel the amplitude attenuation and phase delay of its sinusoidal response,by developing a network using normalized least-mean-square (LMS) adaptive filtering algorithm.The command input was corrected by weights to generate the desired input for the algorithm,and the feedback was brought into the feedback correction,whose output was the weighted feedback.The weights of the normalized LMS adaptive filtering algorithm were updated on-line according to the estimation error between the desired input and the weighted feedback.Thus,the updated weights were copied to the input correction.The estimation error was forced to zero by the normalized LMS adaptive filtering algorithm such that the weighted feedback was equal to the desired input,making the feedback track the command.The above concept was used as a basis for the development of amplitude phase control.The method has good real-time performance without estimating the system model.The simulation and experiment results show that the proposed amplitude phase control can efficiently cancel the amplitude attenuation and phase delay with high precision. 展开更多
关键词 amplitude attenuation phase delay normalized least-mean-square adaptive filtering algorithm tracking performance electro- hydraulic servo system
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An Improved Proportionate Normalized Least Mean Square Algorithm for Sparse Impulse Response Identification
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作者 文昊翔 赖晓翰 +1 位作者 陈隆道 蔡忠法 《Journal of Shanghai Jiaotong university(Science)》 EI 2013年第6期742-748,共7页
In this paper after analyzing the adaptation process of the proportionate normalized least mean square(PNLMS) algorithm, a statistical model is obtained to describe the convergence process of each adaptive filter coef... In this paper after analyzing the adaptation process of the proportionate normalized least mean square(PNLMS) algorithm, a statistical model is obtained to describe the convergence process of each adaptive filter coefcient. Inspired by this result, a modified PNLMS algorithm based on precise magnitude estimate is proposed. The simulation results indicate that in contrast to the traditional PNLMS algorithm, the proposed algorithm achieves faster convergence speed in the initial convergence state and lower misalignment in the stead stage with much less computational complexity. 展开更多
关键词 adaptive algorithm echo cancellation(EC) proportionate normalized least mean square(PNLMS) algorithm proportionate step-size sparse impulse response
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基于鱼群算法优化normalized cut的彩色图像分割方法 被引量:4
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作者 周逊 郭敏 马苗 《计算机应用研究》 CSCD 北大核心 2013年第2期616-618,共3页
为了克服传统的谱聚类算法求解normalized cut彩色图像分割时,分割效果差、算法复杂度高的缺点,提出了一种基于鱼群算法优化normalized cut的彩色图像分割方法。先对图像进行模糊C-均值聚类预处理,然后用鱼群优化算法替代谱聚类算法求解... 为了克服传统的谱聚类算法求解normalized cut彩色图像分割时,分割效果差、算法复杂度高的缺点,提出了一种基于鱼群算法优化normalized cut的彩色图像分割方法。先对图像进行模糊C-均值聚类预处理,然后用鱼群优化算法替代谱聚类算法求解Ncut的最小值,最后通过最优个体鱼得到分割结果。实验表明,该方法耗时少,且分割效果好。 展开更多
关键词 模糊C-均值聚类 归一化划分 鱼群优化算法 彩色图像分割
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一种基于遗传算法的Normalized Cut准则图像分割方法 被引量:1
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作者 李果 《齐齐哈尔大学学报(自然科学版)》 2016年第3期25-28,共4页
Normalized Cut准则图像分割是基于图论的方法,是一种比较典型的规范化分割,但由于其运算量较大、收敛条件难以控制等缺陷,使得图像二值化分割不均匀。本文从Normalized Cut缺陷研究入手,利用遗传算法全局快速检索特性,改进Normalized ... Normalized Cut准则图像分割是基于图论的方法,是一种比较典型的规范化分割,但由于其运算量较大、收敛条件难以控制等缺陷,使得图像二值化分割不均匀。本文从Normalized Cut缺陷研究入手,利用遗传算法全局快速检索特性,改进Normalized Cut优化函数,获得精度理想的图像分割效果。 展开更多
关键词 图像分割 遗传算法 normalized Cut准则 分割测试
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An Evolutionary Normalization Algorithm for Signed Floating-Point Multiply-Accumulate Operation
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作者 Rajkumar Sarma Cherry Bhargava Ketan Kotecha 《Computers, Materials & Continua》 SCIE EI 2022年第7期481-495,共15页
In the era of digital signal processing,like graphics and computation systems,multiplication-accumulation is one of the prime operations.A MAC unit is a vital component of a digital system,like different Fast Fourier ... In the era of digital signal processing,like graphics and computation systems,multiplication-accumulation is one of the prime operations.A MAC unit is a vital component of a digital system,like different Fast Fourier Transform(FFT)algorithms,convolution,image processing algorithms,etcetera.In the domain of digital signal processing,the use of normalization architecture is very vast.The main objective of using normalization is to performcomparison and shift operations.In this research paper,an evolutionary approach for designing an optimized normalization algorithm is proposed using basic logical blocks such as Multiplexer,Adder etc.The proposed normalization algorithm is further used in designing an 8×8 bit Signed Floating-Point Multiply-Accumulate(SFMAC)architecture.Since the SFMAC can accept an 8-bit significand and a 3-bit exponent,the input to the said architecture can be somewhere between−(7.96872)_(10) to+(7.96872)_(10).The proposed architecture is designed and implemented using the Cadence Virtuoso using 90 and 130 nm technologies(in Generic Process Design Kit(GPDK)and Taiwan Semiconductor Manufacturing Company(TSMC),respectively).To reduce the power consumption of the proposed normalization architecture,techniques such as“block enabling”and“clock gating”are used rigorously.According to the analysis done on Cadence,the proposed architecture uses the least amount of power compared to its current predecessors. 展开更多
关键词 Data normalization cadence virtuoso signed-floating-point MAC evolutionary optimized algorithm block enabling clock gating
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Up-Sampled Cross-Correlation Based Object Tracking & Vibration Measurement in Agriculture Tractor System
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作者 R.Ganesan G.Sankaranarayanan +1 位作者 M.Pradeep Kumar V.K.Bupesh Raja 《Intelligent Automation & Soft Computing》 SCIE 2023年第4期667-681,共15页
This research introduces a challenge in integrating and cleaning the data,which is a crucial task in object matching.While the object is detected and then measured,the vibration at different light intensities may influ... This research introduces a challenge in integrating and cleaning the data,which is a crucial task in object matching.While the object is detected and then measured,the vibration at different light intensities may influence the durability and reliability of mechanical systems or structures and cause problems such as damage,abnormal stopping,and disaster.Recent research failed to improve the accuracy rate and the computation time in tracking an object and in the vibration measurement.To solve all these problems,this proposed research simplifies the scaling factor determination by assigning a known real-world dimension to a predetermined portion of the image.A novel white color sticker of the known dimensions marked with a color dot is pasted on the surface of an object for the best result in the template matching using the Improved Up-Sampled Cross-Correlation(UCC)algorithm.The vibration measurement is calculated using the Finite-Difference Algorithm(FDA),a machine vision systemfitted with a macro lens sensor that is capable of capturing the image at a closer range,which does not affect the quality of displacement measurement from the video frames.Thefield test was conducted on the TAFE(Tractors and Farm Equipment Limited)tractor parts,and the percentage of error was recorded between 30%and 50%at very low vibration values close to zero,whereas it was recorded between 5%and 10%error in most high-accelerations,the essential range for vibration analysis.Finally,the suggested system is more suitable for measuring the vibration of stationary machinery having low frequency ranges.The use of a macro lens enables to capture of image frames at very close-ups.A 30%to 50%error percentage has been reported when the vibration amplitude is very small.Therefore,this study is not suitable for Nano vibration analysis. 展开更多
关键词 Vibration measurement object tracking up-sampled cross-correlation finite difference algorithm template matching macro lens machine vision
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An Algorithm for the Feedback Vertex Set Problem on a Normal Helly Circular-Arc Graph
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作者 Hirotoshi Honma Yoko Nakajima Atsushi Sasaki 《Journal of Computer and Communications》 2016年第8期23-31,共9页
The feedback vertex set (FVS) problem is to find the set of vertices of minimum cardinality whose removal renders the graph acyclic. The FVS problem has applications in several areas such as combinatorial circuit desi... The feedback vertex set (FVS) problem is to find the set of vertices of minimum cardinality whose removal renders the graph acyclic. The FVS problem has applications in several areas such as combinatorial circuit design, synchronous systems, computer systems, and very-large-scale integration (VLSI) circuits. The FVS problem is known to be NP-hard for simple graphs, but polynomi-al-time algorithms have been found for special classes of graphs. The intersection graph of a collection of arcs on a circle is called a circular-arc graph. A normal Helly circular-arc graph is a proper subclass of the set of circular-arc graphs. In this paper, we present an algorithm that takes  time to solve the FVS problem in a normal Helly circular-arc graph with n vertices and m edges. 展开更多
关键词 Design and Analysis of algorithms Feedback Vertex Set normal Helly Circular-Arc Graphs Intersection Graphs
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A Novel Black-Winged Kite Algorithm with Deep Learning for Autism Detection of Privacy Preserved Data
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作者 Kalyani Nagarajan Sasikumar Rajagopalan 《Journal of Bionic Engineering》 2025年第4期1985-2011,共27页
Autism Spectrum Disorder(ASD)is a complex neurodevelopmental condition that causes multiple challenges in behavioral and communication activities.In the medical field,the data related to ASD,the security measures are ... Autism Spectrum Disorder(ASD)is a complex neurodevelopmental condition that causes multiple challenges in behavioral and communication activities.In the medical field,the data related to ASD,the security measures are integrated in this research responsibly and effectively to develop the Mobile Neuron Attention Stage-by-Stage Network(MNASNet)model,which is the integration of both Mobile Network(MobileNet)and Neuron Attention Stage-by-Stage.The steps followed to detect ASD with privacy-preserved data are data normalization,data augmentation,and K-Anonymization.The clinical data of individuals are taken initially and preprocessed using the Z-score Normalization.Then,data augmentation is performed using the oversampling technique.Subsequently,K-Anonymization is effectuated by utilizing the Black-winged Kite Algorithm to ensure the privacy of medical data,where the best fitness solution is based on data utility and privacy.Finally,after improving the data privacy,the developed approach MNASNet is implemented for ASD detection,which achieves highly accurate results compared to traditional methods to detect autism behavior.Hence,the final results illustrate that the proposed MNASNet achieves an accuracy of 92.9%,TPR of 95.9%,and TNR of 90.9%at the k-samples of 8. 展开更多
关键词 Mobile network Neuron attention stage-by-stage Z-score normalization K-ANONYMIZATION Black-winged Kite algorithm
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基于PNCC声纹特征提取技术和POA-KNN算法的齿轮箱声纹识别故障诊断
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作者 廖力达 赵阁阳 +1 位作者 魏诚 刘川江 《机电工程》 北大核心 2026年第1期24-33,共10页
风力机齿轮箱是风力发电系统的核心组件之一,承担着将风能转化为电能的重要任务。由于运行环境的恶劣以及长期使用造成的磨损,齿轮箱常常会发生各种故障,从而导致齿轮箱运行过程中产生不同的噪声,严重影响风力机的正常运行和发电效率,因... 风力机齿轮箱是风力发电系统的核心组件之一,承担着将风能转化为电能的重要任务。由于运行环境的恶劣以及长期使用造成的磨损,齿轮箱常常会发生各种故障,从而导致齿轮箱运行过程中产生不同的噪声,严重影响风力机的正常运行和发电效率,因此,提出了一种基于功率正则化倒谱系数(PNCC)声纹特征提取技术,以及行星优化算法与K近邻算法(POA-KNN)模型的风力机齿轮箱声纹识别故障诊断方法。首先,采用LMS噪声采集仪采集了6种不同状态下的风力机齿轮箱噪声数据;然后,使用了PNCC声纹特征提取的方法,提取了齿轮箱噪声信号的声纹图谱;在KNN的基础上加入行星优化算法(POA)优化了K值,提出了性能较高的POA-KNN分类模型;最后,根据6类不同状态下的齿轮数据集,采用对比试验和消融实验验证了模型性能。研究结果表明:POA-KNN模型对齿轮箱的PNCC声纹图分类准确率达到99.4%,比KNN基线模型提升了1.9%。POA-KNN分类模型能很好地对数据集中不同状态下的齿轮箱进行分类,更高效地针对风力机齿轮箱中存在的故障进行诊断。 展开更多
关键词 齿轮箱 功率正则化倒谱系数 声纹识别 声纹特征图谱 行星优化算法与K近邻算法 分类模型
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机载激光点云数据滤波下尾矿坝位移变形监测
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作者 赵国强 《有色金属(矿山部分)》 2026年第1期49-55,共7页
尾矿坝作为矿业生产的核心设施,其稳定性对矿山安全及周边环境具有重要影响。受表面植被覆盖和复杂地形影响,机载激光点云数据在采集过程中常面临密度不均及多尺度噪声干扰的问题,导致传统方法在形变估计时出现偏差。因此,提出基于机载... 尾矿坝作为矿业生产的核心设施,其稳定性对矿山安全及周边环境具有重要影响。受表面植被覆盖和复杂地形影响,机载激光点云数据在采集过程中常面临密度不均及多尺度噪声干扰的问题,导致传统方法在形变估计时出现偏差。因此,提出基于机载激光点云数据滤波的尾矿坝位移变形监测方法,通过K邻近搜索算法建立空间索引以划分多尺度噪声,并引入空间距离权重与几何相似性权重的双重约束机制,结合双边滤波算法有效抑制噪声干扰。同时,采用对象分割技术将监测区域划分为3D网格单元,实现尾矿坝水平变形与垂直沉降的高精度监测。结果表明,该方法在水平变形和垂直沉降监测中的平均绝对误差显著减小,位移速率波动率低,最大误差仅0.4%,为尾矿坝全生命周期安全提供了毫米级感知能力。相较于传统DS-InSAR技术和时序分解模型,本研究方法在复杂植被覆盖和地形起伏区域表现出更高的监测精度和稳定性,尤其适用于尾矿坝长期安全预警及动态管理场景。 展开更多
关键词 尾矿坝位移变形 双边滤波算法 K邻近搜索算法 法向量夹角 三维单元分割
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应用Normal矩阵谱平分法的多社团发现 被引量:6
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作者 张燕平 王杨 赵姝 《计算机工程与应用》 CSCD 北大核心 2010年第27期43-45,共3页
现实世界中许多实际网络都有一个共同的性质,即社团结构。揭示网络中的社团结构,对于了解网络结构与分析网络性质都是很重要的。分析了常见的社团发现算法的特点,以及谱二分法在实际应用中必须不断迭代才能完成多社团发现的不足,提出了... 现实世界中许多实际网络都有一个共同的性质,即社团结构。揭示网络中的社团结构,对于了解网络结构与分析网络性质都是很重要的。分析了常见的社团发现算法的特点,以及谱二分法在实际应用中必须不断迭代才能完成多社团发现的不足,提出了基于Normal矩阵和k-means聚类算法的多社团发现方法。该算法能选择合适的特征向量维数,为k-means划分社团提供有效数据,相比其他算法有着较高的准确率。 展开更多
关键词 社团结构 normal矩阵 谱平分法 K-MEANS聚类算法
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Poisson Log-normal回归模型的影响评价(英文)
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作者 李泽慧 赵为华 谢晓方 《昆明理工大学学报(自然科学版)》 CAS 北大核心 2013年第4期102-108,共7页
本文利用EM算法研究了来自于Lognormal分布权重的混合Poisson模型,即Poisson Lognormal回归模型,从而利用基于完全数据似然函数的条件期望进行影响评价.基于数据删除模型和局部影响分析方法,分别得到了广义Cook距离、Q距离和三种不同扰... 本文利用EM算法研究了来自于Lognormal分布权重的混合Poisson模型,即Poisson Lognormal回归模型,从而利用基于完全数据似然函数的条件期望进行影响评价.基于数据删除模型和局部影响分析方法,分别得到了广义Cook距离、Q距离和三种不同扰动模型下的正则曲率度量等诊断统计量. 展开更多
关键词 POISSON Log-normal回归 EM算法 局部影响分析 数据删除 Gauss—Hermite积分
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三参数Normal-Ogive模型参数估计的SAEM算法
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作者 孟祥斌 刘佳 丁锐 《心理科学》 CSSCI CSCD 北大核心 2023年第2期450-460,共11页
Normal-Ogive模型是项目反应理论的代表性模型之一,其参数估计主要是基于MCMC抽样实现的,但MCMC抽样的不足是计算效率较低。针对这一问题,本文以混合模型(mixture model)的视角,通过变量扩充,提出三参数normalogive(3PNO)模型题目参数... Normal-Ogive模型是项目反应理论的代表性模型之一,其参数估计主要是基于MCMC抽样实现的,但MCMC抽样的不足是计算效率较低。针对这一问题,本文以混合模型(mixture model)的视角,通过变量扩充,提出三参数normalogive(3PNO)模型题目参数估计的随机逼近EM(stochastic approximation EM,简称SAEM)算法,并通过Monte Carlo模拟对SAEM算法的主要影响因素、计算效率、估计的返真性进行验证。模拟研究的结果表明:SAEM算法能够准确实现3PNO模型题目参数估计的计算,并且具有较高的计算效率,表现出优良的计算性质。 展开更多
关键词 项目反应理论 三参数normal-Ogive模型 SAEM算法
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基于改进浣熊优化算法的永磁同步电机参数辨识
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作者 谭志博 刘雨 +1 位作者 张巧芬 李明智 《制造技术与机床》 北大核心 2026年第1期154-161,共8页
针对表贴式永磁同步电机(permanent magnet synchronous motor, PMSM)在参数辨识过程中存在辨识精度低且收敛时间长的问题,提出一种用于电机参数辨识的改进浣熊优化算法(improved coati optimization algorithm, ICOA)。改进后的算法使... 针对表贴式永磁同步电机(permanent magnet synchronous motor, PMSM)在参数辨识过程中存在辨识精度低且收敛时间长的问题,提出一种用于电机参数辨识的改进浣熊优化算法(improved coati optimization algorithm, ICOA)。改进后的算法使用分段线性混沌映射(piecewise linear chaotic map, PWLCM)策略,提升了浣熊初始种群的随机性和多样性;使用正交Lévy全局探索器,增加了搜索路径,提升全局搜索能力;使用引入种群多样性指标与迭代进度因子的自适应正态云模型,解决了算法早熟收敛的问题。对表贴式永磁同步电机进行数学建模,并使用ICOA算法对电机永磁体磁链、d-q轴电感、定子电阻进行参数辨识。仿真结果表明,相较于传统COA算法,4种参数辨识精度分别提升了12.33%、2.75%、1.13%、0.75%,且均控制在1.7%之内。 展开更多
关键词 电机参数辨识 浣熊优化算法 混沌映射 正态云模型 正交Lévy全局探索器
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A novel algorithm of adaptive IIR lattice notch filter and performance analysis 被引量:3
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作者 秦鹏 蔡萍 《Journal of Shanghai University(English Edition)》 CAS 2007年第5期485-489,共5页
A novel adaptive algorithm of IIR lattice notch filter realized by all-pass filter is presented. The time-averaged estimation of cross correlation of the present instantaneous input signal and the past output signal i... A novel adaptive algorithm of IIR lattice notch filter realized by all-pass filter is presented. The time-averaged estimation of cross correlation of the present instantaneous input signal and the past output signal is used to update the step-size, leading to a considerably improved convergence rate in a low SNR situation and reduced steady-state bias and MSE. The theoretical expression for steady-state bounds on the step-size is derived, and the influence factors on the stable performance of the algorithm theoretically are analyzed. A normalized power factor is then introduced to control variation of step-size in its steady-state bounds. This technique prevents divergence due to the influence of large power input signal and improves robustness. Numerical experiments are performed to demonstrate superiority of the proposed method. 展开更多
关键词 lattice notch filter adaptive algorithm cross correction steady-state bounds normalized power factor.
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MI-NLMS adaptive beamforming algorithm for smart antenna system applications 被引量:7
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作者 MOHAMMAD Tariqul Islam ZAINOL Abidin Abdul Rashid 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第10期1709-1716,共8页
A Matrix Inversion Normalized Least Mean Square (MI-NLMS) adaptive beamforming algorithm was developed for smart antenna application. The MI-NLMS which combined the individual good aspects of Sample Matrix Inversion (... A Matrix Inversion Normalized Least Mean Square (MI-NLMS) adaptive beamforming algorithm was developed for smart antenna application. The MI-NLMS which combined the individual good aspects of Sample Matrix Inversion (SMI) and the Normalized Least Mean Square (NLMS) algorithms is described. Simulation results showed that the less complexity MI-NLMS yields 15 dB improvements in interference suppression and 5 dB gain enhancement over LMS algorithm, converges from the initial iteration and achieves 24% BER improvements at cochannel interference equal to 5. For the case of 4-element uniform linear array antenna, MI-NLMS achieved 76% BER reduction over LMS algorithm. 展开更多
关键词 Smart antenna Beamforming algorithm Least Mean Square (LMS) normalized LMS (NLMS) Matrix InversionNLMS (MI-NLMS)
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Finite Mixture Normal Models, with Application to Dose-Response Studies 被引量:2
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作者 陶剑 宋海燕 史宁中 《Northeastern Mathematical Journal》 CSCD 2002年第1期5-8,共4页
In this paper, we consider the risk assessment problem under multi-levels and multiple mixture subpopulations. Our result is the generalization of the results of [1-5].1 Finite Mixture Normal ModelsIn dose-response s... In this paper, we consider the risk assessment problem under multi-levels and multiple mixture subpopulations. Our result is the generalization of the results of [1-5].1 Finite Mixture Normal ModelsIn dose-response studies, a class of phenomena that frequently occur are that experimental subjects (e.g., mice) may have different responses like ’none, mild, severe’ after a toxicant experiment, or ’getting worse, no change, getting better’ after a medical treatment, etc. These phenomena have attracted the attention of many researchers in recent years. Finite 展开更多
关键词 DOSE-RESPONSE EM algorithm mixture normal models risk assessment
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Optimization method of fi rst-arrival waveform inversion based on the L-BFGS algorithm 被引量:1
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作者 Zhang Kai Xu Xin +3 位作者 Liu Hong-Xing Xu Yi-Peng Li Zhen-Chun Jiang Ping 《Applied Geophysics》 SCIE CSCD 2021年第4期515-524,593,594,共12页
The fi rst arrival waveform inversion(FAWI)has a strong nonlinearity due to the objective function using L2 parametrization.When the initial velocity is not accurate,the inversion can easily fall into local minima.In ... The fi rst arrival waveform inversion(FAWI)has a strong nonlinearity due to the objective function using L2 parametrization.When the initial velocity is not accurate,the inversion can easily fall into local minima.In the full waveform inversion method,adding a cross-correlation function to the objective function can eff ectively reduce the nonlinearity of the inversion process.In this paper,the nonlinearity of this process is reduced by introducing the correlation objective function into the FAWI and by deriving the corresponding gradient formula.We then combine the first-arrival wave travel-time tomography with the FAWI to form a set of inversion processes.This paper uses the limited memory Broyden-Fletcher-Goldfarb-Shanno(L-BFGS)algorithm to improve the computational effi ciency of inversion and solve the problem of the low effi ciency of the FAWI method.The overthrust model and fi eld data test show that the method used in this paper can eff ectively reduce the nonlinearity of inversion and improve the inversion calculation effi ciency at the same time. 展开更多
关键词 first-arrival travel-time tomography first-arrival waveform inversion cross-correlation objective function L-BFGS algorithm
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Simulations of the Performance of Maximum Power Point Tracking Algorithms Based on Experimental Data According to the Topologies of DC-DC Converters 被引量:1
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作者 Abraham Dandoussou Pierre Kenfack +1 位作者 Stève Ngoffe Perabi Martin Kamta 《Journal of Power and Energy Engineering》 2021年第5期76-92,共17页
Maximum Power Point Tracking (MPPT) algorithms are now widely used in PV systems independently of the weather conditions. In function of the application, a DC-DC converter topology is chosen without any previous perfo... Maximum Power Point Tracking (MPPT) algorithms are now widely used in PV systems independently of the weather conditions. In function of the application, a DC-DC converter topology is chosen without any previous performance test under normal weather conditions. This paper proposes an experimental evaluation of MPPT algorithms according to DC-DC converters topologies, under normal operation conditions. Four widely used MPPT algorithms <i><i><span>i.e.</span></i><span></span></i> Perturb and Observe (P & O), Hill Climbing (HC), Fixed step Increment of Conductance (INCF) and Variable step Increment of Conductance (INCV) are implemented using two topologies of DC-DC converters <i><span>i.e.</span></i><span> buck and boost converters. As input variables to the PV systems, recorded irradiance and temperature, and extracted photovoltaic parameters (ideality factor, series resistance and reverse saturation current) were used. The obtained results show that buck converter has a lot of power losses when controlled by each of the four MPPT algorithms. Meanwhile, boost converter presents a stable output power during the whole day. Once more, the results show that INCV algorithm has the best performance.</span> 展开更多
关键词 MPPT algorithms DC-DC Converters Photovoltaic Parameters normal Operating Conditions
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