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基于Fisher-SVM特征选择的负荷辨识研究

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电力科学与技术学报 2023年第4期38卷 230-239,264页

作者：栾开宁杨世海黄艺璇方凯杰程含渺黄时国网江苏省电力有限公司江苏南京210028 江苏智臻能源科技有限公司江苏南京211111

针对当前非侵入式负荷辨识中不同设备特征选择上主观性、盲目性的问题,提出基于Fisher-SVM特征选择的非侵入式负荷辨识算法。首先,基于高频采样终端提取入户侧电流、电压原始数据,使用傅里叶变换对原始信号分解得有功、无功及谐波时间序... 详细信息

针对当前非侵入式负荷辨识中不同设备特征选择上主观性、盲目性的问题,提出基于Fisher-SVM特征选择的非侵入式负荷辨识算法。首先,基于高频采样终端提取入户侧电流、电压原始数据,使用傅里叶变换对原始信号分解得有功、无功及谐波时间序列;其次,将负荷波形分为4个阶段并计算得到负荷波形暂稳态特征;然后,通过Fisher-SVM算法在不同分类器中对特征进行选择,得到最优分类特征子集,并利用Sigmoid函数对结果进行概率校准;最后,根据贝叶斯理论对各分类器进行融合从而实现对不同负荷的辨识。以3类台区831户实际用户进行算法测试。结果表明,该算法能够有效利用不同电器负荷印记的独特性,克服特征选择上的盲目性,提高负荷辨识能力。

关键词：非侵入式负荷辨识 Fisher 支持向量机特征提取

Probing Nonclassicality of Two-Mode SU (2) Generator Based on Quantum Fisher Information

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Communications in Theoretical Physics 2018年第11期69卷 552-558页

作者：张丹郑强王晓光 School of Chemistry and Material Science Guizhou Normal University School of Mathematics Guizhou Normal University Quantum Physics and Quantum Information Division Beijing Computational Science Research Center Zhejiang Institute of Modern Physics Department of Physics Zhejiang University

Nonclassicality is an essential but still open question in quantum mechanics. Here, utilizing the maximum value of quantum Fisher information, we suggest a new version of the nonclassical criterion for SU(2) generator realized by two bosonic modes. As an application of the criterion, the system of two coupled nonlinear nanomechanical resonators is considered. And the nonclassicality of the phonon state in the dynamical evolution is explored. The system has a dynamical phase transition from the tunnelling phase to the self-trapping phase by tuning the coupling strength. It is found that for the tunnelling phase, the phonon state is nonclassical in the full time evolution. And for the self-trapping phase, the evolved phonon state is still nonclassical in the full time with a relatively large coupling strength, while it is nonclassical i n the most of time (but not all) with a small coupling strength. Quantum coherence has distinct different behaviors in the two phases.

关键词： quantum Fisher information nonclassicality coherence

Wright-Fisher-like models with constant population size on average

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International Journal of Biomathematics 2017年第6期10卷 51-72页

作者： Nicolas Grosjean Thierry Huillet Laboratoire de Physique Theorique et Modelisation CNRS-UMR 8089 et Universite de Cergy-Pontoise 2 Avenue Adolphe Chauvin 95302 Cergy-Pontoise France

We first recall some basic facts from the theory of discrete-time Markov chains arising from two types neutral and non-neutral evolution models of population genetics with constant size. We then define and analyze a version of such models whose fluctuating total population size is conserved on average only. In our model, the population of interest is seen as being embedded in a frame process which is a critical Galton–Watson process. In this context, we address problems such as extinction, fixation, size of the population at fixation and survival probability to a bottleneck effect of the environment.

关键词：平均模型人口规模 Fisher 马尔可夫链理论恒定瓶颈效应生存概率波动

A numerical study by using the Chebyshev collocation met hod for a problem of biological invasion: Fractional Fisher equation A numerical study by using the Chebyshev collocation met hod for a problem of biological invasion: Fractional Fisher equation

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International Journal of Biomathematics 2018年第8期11卷 71-85页

作者： Mohamed M. Khader Khaled M. Saad Department of Mathematics and Statistics College of Science Al Imam Mohammad Ibn Saud Islamic University (IMSIU) Riyadh Saudi Arabia Department of Mathematics Faculty of Science Benha University Benha Egypt Department of Mathematics College of Arts and Sciences Najran University Najran Saudi Arabia Department of Mathematics Faculty of Applied Science Taiz University Taiz Yemen

In this paper, an efficient numerical method is introduced for solving the fractional (Caputo sense) Fisher equation. We use the spectral collocation method which is based upon Chebyshev approximations. The properties of Chebyshev polynomials of the third kind are used to reduce the proposed problem to a system of ODEs, which is solved by the finite difference method (FDM). Some theorems about the convergence analysis are stated and proved. A numerical simulation is given and the results are compared with the exact solution.

关键词： Fractional Fisher equation FDM Chebyshev polynomials convergence analysis

Quantum Fisher Information Gap for Systems with Nonlinear Hamiltonians

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Communications in Theoretical Physics 2019年第1期71卷 43-48页

作者：刘博黄奕筱王晓光 Zhejiang Institute of Modern Physics Department of Physics Zhejiang University School of Physics Changchun Normal University School of Science Zhejiang University of Science and Technology

Quantum Fisher information(QFI) gap characterizes the stability of QFI to space directions. We study the QFI distributions and QFI gap for quantum states generated from nonlinear Hamiltonians for both spin and bosonic systems. We find that the same spin-squeezing parameter(or principle squeezing parameter) corresponds to two different values QFI gap, and the locations of all extreme points of the QFI are explicitly given.

关键词： quantum Fisher information metrology nonlinear Hamiltonians

Discontinuity and Protection of Quantum Fisher Information for a Two-Qubit System

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Communications in Theoretical Physics 2015年第11期64卷 495-500页

作者：王国友袁季兵曾浩生 College of Science Hunan University of Technology Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Department of PhysicsHunan Normal University State Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of Sciences

We analytically investigate the dynamics of quantum Fisher information of two qubits in independent environments for both uncorrelated and entangled input states.Especially,we observe that,in the non-Markovian regime and resonant case,quantum Fisher information of uncorrelated input state vanishes only at discrete time point whereas that of entangled input state can disappear during finite time interval.It shows that quantum Fisher information,which determines the parameter estimation precision,is strongly affected by the environment memory effects,and the advantage of entanglement-enhance metrology no longer exists even for a very short time.We also note that quantum Fisher information for two kinds of input states can be preserved under appropriate qubit-reservoir detuning.

关键词： quantum Fisher information discontinuity protectio

Silhouettes Based Human Action Recognition in Video via Procrustes Analysis and Fisher Vector Coding

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Journal of Donghua University(English Edition) 2019年第2期36卷 140-148页

作者：蔡加欣钟然旭李俊杰 School of Applied Mathematics Xiamen University of TechnologyXiamen 361024China Department of Software Research and Development Guangdong Grandmark Automotive Systems Co.Ltd.Dongguan 523000China

This paper proposes a framework for human action recognition based on procrustes analysis and Fisher vector coding(FVC).Firstly,we applied a pose feature extracted from silhouette image by employing Procrustes analysis and local preserving projection(LPP).Secondly,the extracted feature can preserve the discriminative shape information and local manifold structure of human pose and is invariant to translation,rotation and scaling.Finally,after the pose feature was extracted,a recognition framework based on FVC and multi-class supporting vector machine was employed to classify the human action.Experimental results on benchmarks demonstrate the effectiveness of the proposed method.

关键词： human action recognition Procrustes analysis local preserving projection Fisher vector coding(FVC)

基于多层感知器-Fisher判别分析的车用保险杠红外光谱鉴别

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中国测试 2019年第5期45卷 74-78,92页

作者：何欣龙王继芬李青山何亚姜晓佳李超彭山珊中国人民公安大学刑事科学技术学院北京102600 中国人民解放军92635部队山东青岛266041

利用光谱检测和数据分析实现不同种类汽车保险杠碎片的快速无损检测和精确识别与分类具有重要的意义,采集 8 个品牌共计 38 个汽车保险杠碎片的红外谱图,预处理采用自动基线校正、峰面积归一化、多元散射校正和 Savitzky-Golay 平滑,通... 详细信息

利用光谱检测和数据分析实现不同种类汽车保险杠碎片的快速无损检测和精确识别与分类具有重要的意义,采集 8 个品牌共计 38 个汽车保险杠碎片的红外谱图,预处理采用自动基线校正、峰面积归一化、多元散射校正和 Savitzky-Golay 平滑,通过小波阈值进行去噪处理,借助主成分分析(PCA)提取特征变量,建立基于多层感知器(MLP)的 Fisher 判别分析(FDA)分类模型。实验结果表明:数据在 20 维矩阵上特征提取最好,包含的信息量足够大,MLP 模型对样本种类的识别准确率为 74.70%,在 20 维特征数据上构建 FDA 模型,求得 Z1 和 Z2 判别函数式以及各样本分布散点图,其中 35 个样本实现了正确的区分和归类,分类准确率为 92.1%,相比较单一 MLP 模型,MLP-FDA 区分能力更强、精度更高。综上,将红外光谱技术与 MLP-FDA 模型结合可以实现对车用保险杠碎片的快速无损鉴别,且模型检测精度高,方法具有普适性和借鉴意义。

关键词：车用保险杠碎片红外光谱多层感知器 Fisher 判别分析鉴别

A Meshless LBIE/LRBF Method for Solving the Nonlinear Fisher Equation: Application to Bone Healing

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Computer Modeling in Engineering & Sciences 2015年第6期105卷 87-122页

作者： K.N.Grivas M.G.Vavva E.J.Sellountos D.I.Fotiadis D.Polyzos Department of Mechanical Engineering and Aeronautics University of PatrasPatrasGreece Instituto Seperior Tecnico CEMAT LisbonPortugal Department of Materials Science and Engineering University of Ioannina

A simple Local Boundary Integral Equation(LBIE)method for solving the Fisher nonlinear transient diffusion equation in two dimensions(2D)is reported.The method utilizes,for its meshless implementation,randomly distributed nodal points in the interior domain and nodal points corresponding to a Boundary Element Method(BEM)mesh,at the global boundary.The interpolation of the interior and boundary potentials is accomplished using a Local Radial Basis Functions(LRBF)scheme.At the nodes of global boundary the potentials and their fluxes are treated as independent variables.On the local boundaries,potential fluxes are avoided by using the Laplacian companion solution.Potential gradients are accurately evaluated without RBFs via a LBIE,valid for gradient of potentials.Nonlinearity is treated using the Newton-Raphson scheme.The accuracy of the proposed methodology is demonstrated through representative numerical examples.Fisher equation is solved here via the LBIE/LRBF method in order to predict cell proliferation during bone healing.Cell concentrations and their gradients are numerically evaluated in a 2D model of fractured bone.The results are demonstrated and discussed.

关键词： Fisher equation Local Boundary Integral Equation Method LBIE Local Radial Basis Functions Bone healing