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Real-Time Patient-Specific ECG Arrhythmia Detection by Quantum Genetic Algorithm of Least Squares Twin SVM 被引量:3
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作者 Duan Li Ruizheng Shi +2 位作者 Ni Yao Fubao Zhu Ke Wang 《Journal of Beijing Institute of Technology》 EI CAS 2020年第1期29-37,共9页
The automatic detection of cardiac arrhythmias through remote monitoring is still a challenging task since electrocardiograms(ECGs)are easily contaminated by physiological artifacts and external noises,and these morph... The automatic detection of cardiac arrhythmias through remote monitoring is still a challenging task since electrocardiograms(ECGs)are easily contaminated by physiological artifacts and external noises,and these morphological characteristics show significant variations for different patients.A fast patient-specific arrhythmia diagnosis classifier scheme is proposed,in which a wavelet adaptive threshold denoising is combined with quantum genetic algorithm(QAG)based on least squares twin support vector machine(LSTSVM).The wavelet adaptive threshold denoising is employed for noise reduction,and then morphological features combined with the timing interval features are extracted to evaluate the classifier.For each patient,an individual and fast classifier will be trained by common and patient-specific training data.Following the recommendations of the Association for the Advancements of Medical Instrumentation(AAMI),experimental results over the MIT-BIH arrhythmia benchmark database demonstrated that our proposed method achieved the average detection accuracy of 98.22%,99.65%and 99.41%for the abnormal,ventricular ectopic beats(VEBs)and supra-VEBs(SVEBs),respectively.Besides the detection accuracy,sensitivity and specificity,our proposed method consumes the less CPU running time compared with the other representative state of the art methods.It can be ported to Android based embedded system,henceforth suitable for a wearable device. 展开更多
关键词 WEARABLE ECG monitoring systems PATIENT-SPECIFIC ARRHYTHMIA classification quantum genetic algorithm least squareS TWIN SVM
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Impacts of Heat Flux Distribution, Sloping Magnetic Field and Magnetic Nanoparticles on the Natural Convective Flow Contained in a Square Cavity 被引量:2
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作者 Latifa M.Al-Balushi M.M.Rahman 《Fluid Dynamics & Materials Processing》 EI 2020年第3期441-463,共23页
In the present paper,the effect of the heat flux distribution on the natural convective flow inside a square cavity in the presence of a sloping magnetic field and magnetic nanoparticles is explored numerically.The no... In the present paper,the effect of the heat flux distribution on the natural convective flow inside a square cavity in the presence of a sloping magnetic field and magnetic nanoparticles is explored numerically.The nondimensional governing equations are solved in the framework of a finite element method implemented using the Galerkin approach.The role played by numerous model parameters in influencing the emerging thermal and concentration fields is examined;among them are:the location of the heat source and its lengthH,the magnitude of the thermal Rayleigh number,the nanoparticles shape and volume fraction,and the Hartmann number.It is found that the nanofluid velocity becomes higher when the thermal source length,the nanoparticles volume fraction and/or the thermal Rayleigh number are increased,while it decreases as the Hartmann number Ha grows and the position of the heat source moves toward the center of the lower wall of the cavity.Moreover,the temperature of the nanofluid grows with the extension of the thermal source and decreases slowly when the heat flux position moves toward the center of the lower wall.The outcomes of the research also indicate that the average Nusselt number becomes smaller on increasing Hartmann number Ha and heat source length H^(*).The addition of Fe_(3)O_(4) to engine oil leads to a higher rate of heat transfer with respect to the addition of SiO_(2) particles.Blade-shaped nanoparticles generate the highest value of the Nusselt number compared to all the other considered shapes. 展开更多
关键词 Nanofluids magnetic nanoparticles heat source natural convection finite element method square enclosure
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TRANSIENT-STATE RESPONSE OF WAVE PROPAGATION IN MAGNETO-ELECTRO-ELASTIC SQUARE COLUMN 被引量:2
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作者 Jianping Wei Xianyue Su 《Acta Mechanica Solida Sinica》 SCIE EI 2008年第6期491-499,共9页
This is a continued work in studying the wave propagation in a magneto-electroelastic square column (MEESC). Based on the analytic dispersive equation, group velocity equation and steady-state response obtained in o... This is a continued work in studying the wave propagation in a magneto-electroelastic square column (MEESC). Based on the analytic dispersive equation, group velocity equation and steady-state response obtained in our previous paper 'Steady-state response of the wave propagation in a magneto-electro-elastic square column' published in CME, the dynamical behavior of MEESC was studied in this paper. The unlimited column is an open system. The transientstate response in the open system subjected by arbitrary external fields was derived when the propagating wave pursuing method was introduced. 展开更多
关键词 magneto-electro-elastic square column open system transient-state response propagating wave pursuing method
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Adaptive control of machining process based on extended entropy square error and wavelet neural network 被引量:2
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作者 赖兴余 叶邦彦 +1 位作者 李伟光 鄢春艳 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2007年第3期349-353,共5页
Combining information entropy and wavelet analysis with neural network,an adaptive control system and an adaptive control algorithm are presented for machining process based on extended entropy square error(EESE)and w... Combining information entropy and wavelet analysis with neural network,an adaptive control system and an adaptive control algorithm are presented for machining process based on extended entropy square error(EESE)and wavelet neural network(WNN).Extended entropy square error function is defined and its availability is proved theoretically.Replacing the mean square error criterion of BP algorithm with the EESE criterion,the proposed system is then applied to the on-line control of the cutting force with variable cutting parameters by searching adaptively wavelet base function and self adjusting scaling parameter,translating parameter of the wavelet and neural network weights.Simulation results show that the designed system is of fast response,non-overshoot and it is more effective than the conventional adaptive control of machining process based on the neural network.The suggested algorithm can adaptively adjust the feed rate on-line till achieving a constant cutting force approaching the reference force in varied cutting conditions,thus improving the machining efficiency and protecting the tool. 展开更多
关键词 machining process adaptive control extended entropy square error wavelet neural network
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Noise cancellation of a multi-reference full-wave magnetic resonance sounding signal based on a modified sigmoid variable step size least mean square algorithm 被引量:1
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作者 TIAN Bao-feng ZHOU Yuan-yuan +2 位作者 ZHU Hui JIANG Chuan-dong YI Xiao-feng 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第4期900-911,共12页
Nano-volt magnetic resonance sounding(MRS) signals are sufficiently weak so that during the actual measurement, they are affected by environmental electromagnetic noise, leading to inaccuracy of the extracted characte... Nano-volt magnetic resonance sounding(MRS) signals are sufficiently weak so that during the actual measurement, they are affected by environmental electromagnetic noise, leading to inaccuracy of the extracted characteristic parameters and hindering effective inverse interpretation. Considering the complexity and non-homogeneous spatial distribution of environmental noise and based on the theory of adaptive noise cancellation, a model system for noise cancellation using multi-reference coils was constructed to receive MRS signals. The feasibility of this system with theoretical calculation and experiments was analyzed and a modified sigmoid variable step size least mean square(SVSLMS) algorithm for noise cancellation was presented. The simulation results show that, the multi-reference coil method performs better than the single one on both signal-to-noise ratio(SNR) improvement and signal waveform optimization after filtering, under the condition of different noise correlations in the reference coils and primary detecting coils and different SNRs. In particular, when the noise correlation is poor and the SNR<0, the SNR can be improved by more than 8 dB after filtering with multi-reference coils. And the average fitting errors for initial amplitude and relaxation time are within 5%. Compared with the normalized least mean square(NLMS) algorithm and multichannel Wiener filter and processing field test data, the effectiveness of the proposed method is verified. 展开更多
关键词 magnetic resonance SOUNDING SIGNAL MULTI-REFERENCE coils adaptive noise CANCELLATION SIGMOID variable step size least mean square (SVSLMS)
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Application of neural network model coupling with the partial least-squares method for forecasting watre yield of mine 被引量:2
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作者 陈南祥 曹连海 黄强 《Journal of Coal Science & Engineering(China)》 2005年第1期40-43,共4页
Scientific forecasting water yield of mine is of great significance to the safety production of mine and the colligated using of water resources. The paper established the forecasting model for water yield of mine, co... Scientific forecasting water yield of mine is of great significance to the safety production of mine and the colligated using of water resources. The paper established the forecasting model for water yield of mine, combining neural network with the partial least square method. Dealt with independent variables by the partial least square method, it can not only solve the relationship between independent variables but also reduce the input dimensions in neural network model, and then use the neural network which can solve the non-linear problem better. The result of an example shows that the prediction has higher precision in forecasting and fitting. 展开更多
关键词 water yield of mine partial least square method neural network forecasting model
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Factors influencing the internet banking adoption decision in North Cyprus: an evidence from the partial least square approach of the structural equation modeling 被引量:2
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作者 Hiba Alhassany Faisal Faisal 《Financial Innovation》 2018年第1期422-442,共21页
Purpose:This paper aims to examine how the adoption decision of the internet banking in North Cyprus would be affected based on the following dimensions;the technology features,the personal characteristics,the social ... Purpose:This paper aims to examine how the adoption decision of the internet banking in North Cyprus would be affected based on the following dimensions;the technology features,the personal characteristics,the social environment and the expected risk.Design/methodology/approach:A self-administered survey was conducted with 291 participants responded to it.The partial least square approach of the structural equation modeling(PLS-SEM)is employed to investigate the direct effects of the proposed factors on the adoption decision.Additionally,the mediation test is used to examine indirect effects.Findings:Results showed that even though the participants appreciated the benefits of the online banking as the perceived usefulness factor exerts the greatest direct effect,they would rather use clear and easy-to-use websites,adding to that their assessments of the usefulness of these services are significantly influenced by the surrounding people’s views and prior experience.This is demonstrated by the total effects of the perceived ease of use and the subjective norm factors,which are greater than the direct effect of the perceived usefulness factor since both of these factors have significant direct and indirect effects mediated by the perceived usefulness factor.The negative impact of the perceived risk factor is weak compared to the previous factors.While the personal innovativeness factor showed the weakest effect among the proposed factors. 展开更多
关键词 Behavioral theories Technology adoption TAM Subjective norm Personal innovativeness Perceived risk Partial least square Structural equation modeling
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Neural Network inverse Adaptive Controller Based on Davidon Least Square 被引量:2
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作者 Chen, Zengqiang Lu, Zhao Yuan, Zhuzhi 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2000年第1期47-52,共6页
General neural network inverse adaptive controller has two flaws: the first is the slow convergence speed; the second is the invalidation to the non-minimum phase system. These defects limit the scope in which the neu... General neural network inverse adaptive controller has two flaws: the first is the slow convergence speed; the second is the invalidation to the non-minimum phase system. These defects limit the scope in which the neural network inverse adaptive controller is used. We employ Davidon least squares in training the multi-layer feedforward neural network used in approximating the inverse model of plant to expedite the convergence, and then through constructing the pseudo-plant, a neural network inverse adaptive controller is put forward which is still effective to the nonlinear non-minimum phase system. The simulation results show the validity of this scheme. 展开更多
关键词 ALGORITHMS Backpropagation Convergence of numerical methods Feedforward neural networks Inverse problems Least squares approximations Mathematical models Multilayer neural networks
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Design and implementation of square Helmholtz coil for uniform magnetic field generation 被引量:1
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作者 Wang Chao Yuan Bin +1 位作者 Mao Junfa Zhang Shuang 《Journal of Southeast University(English Edition)》 EI CAS 2019年第1期16-21,共6页
In order to calibrate electrical instruments and generate a constant magnetic field, a novel design method for square Helmholtz coil is proposed. According to the superposition principle in electromagnetics, the theor... In order to calibrate electrical instruments and generate a constant magnetic field, a novel design method for square Helmholtz coil is proposed. According to the superposition principle in electromagnetics, the theory of the square Helmholtz coil is established, and the design method is verified by Matlab calculation. Compared with conventional circular Helmholtz coil, the novel square one is with a larger uniform region. Simulation work is conducted in Maxwell, and the distribution of the magnetic field is obtained. The results demonstrate the validation of the applied calculation method of the proposed Helmholtz model. The space utilization rate η is used to make a comparison between the square and circular coils for the uniform region. The square Helmholtz coil is fabricated, the length of a single square coil is 1.5 m, and the amplitude of the magnetic field is controlled by the current. The GSM-19 T proton magnetometer is used to measure the amplitude of the magnetic field generated by the square Helmholtz coil. Experimental results indicate that a wide-range variable uniform magnetic field from 0 to 120 μT is generated in the center of Helmholtz coils. 展开更多
关键词 proton magnetometer square Helmholtz coils space utilization rate uniform magnetic field
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Consistency and Asymptotic Property of a Weighted Least Squares Method for Networked Control Systems 被引量:1
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作者 张聪 叶昊 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2014年第7期754-761,共8页
In this paper, we study the problems related to parameter estimation of a single-input and single-output networked control system, which contains possible network-induced delays and packet dropout in both of sensor-to... In this paper, we study the problems related to parameter estimation of a single-input and single-output networked control system, which contains possible network-induced delays and packet dropout in both of sensor-to-controller path and controller-to-actuator path. A weighted least squares(WLS) method is designed to estimate the parameters of plant, which could overcome the data uncertainty problem caused by delays and dropout. This WLS method is proved to be consistent and has a good asymptotic property. Simulation examples are given to validate the results. 展开更多
关键词 networked control system network-induced delay Packet dropout Weighted least squares CONSISTENCY Asymptotic property
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Quantitative structure-property relationship study of the solubility of thiazolidine-4-carboxylic acid derivatives using ab initio and genetic algorithm-partial least squares 被引量:1
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作者 Ali Niazi Saeed Jameh-Bozorghi Davood Nori-Shargh 《Chinese Chemical Letters》 SCIE CAS CSCD 2007年第5期621-624,共4页
A quantitative structure-activity relationships (QSAR) study is suggested for the prediction of solubility of some thiazolidine-4- carboxylic acid derivatives in aqueous solution. Ab initio theory was used to calcul... A quantitative structure-activity relationships (QSAR) study is suggested for the prediction of solubility of some thiazolidine-4- carboxylic acid derivatives in aqueous solution. Ab initio theory was used to calculate some quantum chemical descriptors including electrostatic potentials and local charges at each atom, HOMO and LUMO energies, etc. Modeling of the solubility of thiazolidine- 4-carboxylic acid derivatives as a function of molecular structures was established by means of the partial least squares (PLS). The subset of descriptors, which resulted in the low prediction error, was selected by genetic algorithm. This model was applied for the prediction of the solubility of some thiazolidine-4-carboxylic acid derivatives, which were not in the modeling procedure. The relative errors of prediction lower that -4% was obtained by using GA-PLS method. The resulted model showed high prediction ability with RMSEP of 3.8836 and 2.9500 for PLS and GA-PLS models, respectively. 展开更多
关键词 Ab initio Partial least squares Genetic algorithm SOLUBILITY THIAZOLIDINE
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Utilizing partial least square and support vector machine for TBM penetration rate prediction in hard rock conditions 被引量:11
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作者 高栗 李夕兵 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第1期290-295,共6页
Rate of penetration(ROP) of a tunnel boring machine(TBM) in a rock environment is generally a key parameter for the successful accomplishment of a tunneling project. The objectives of this work are to compare the accu... Rate of penetration(ROP) of a tunnel boring machine(TBM) in a rock environment is generally a key parameter for the successful accomplishment of a tunneling project. The objectives of this work are to compare the accuracy of prediction models employing partial least squares(PLS) regression and support vector machine(SVM) regression technique for modeling the penetration rate of TBM. To develop the proposed models, the database that is composed of intact rock properties including uniaxial compressive strength(UCS), Brazilian tensile strength(BTS), and peak slope index(PSI), and also rock mass properties including distance between planes of weakness(DPW) and the alpha angle(α) are input as dependent variables and the measured ROP is chosen as an independent variable. Two hundred sets of data are collected from Queens Water Tunnel and Karaj-Tehran water transfer tunnel TBM project. The accuracy of the prediction models is measured by the coefficient of determination(R2) and root mean squares error(RMSE) between predicted and observed yield employing 10-fold cross-validation schemes. The R2 and RMSE of prediction are 0.8183 and 0.1807 for SVMR method, and 0.9999 and 0.0011 for PLS method, respectively. Comparison between the values of statistical parameters reveals the superiority of the PLSR model over SVMR one. 展开更多
关键词 tunnel boring machine(TBM) performance prediction rate of penetration(ROP) support vector machine(SVM) partial least squares(PLS)
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Modelling of the Relaxation Least Squares-Based Neural Networks and Its Application 被引量:1
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作者 Lu Kongkuo, Chen Zengqiang & Yuan ZhuzhiDepartment of Automation, Nankai University, Tianjin 300071, P.R.China(Received July 5, 2001) 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2002年第2期16-21,共6页
A relaxation least squares-based learning algorithm for neual networks is proposed. Not only does it have a fast convergence rate, but it involves less computation quantity. Therefore, it is suitable to deal with the ... A relaxation least squares-based learning algorithm for neual networks is proposed. Not only does it have a fast convergence rate, but it involves less computation quantity. Therefore, it is suitable to deal with the case when a network has a large scale but the number of training data is very limited. It has been used in converting furnace process modelling, and impressive result has been obtained. 展开更多
关键词 Backpropagation Learning systems Least squares approximations
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Design of Radial Basis Function Network Using Adaptive Particle Swarm Optimization and Orthogonal Least Squares 被引量:1
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作者 Majid Moradi Zirkohi Mohammad Mehdi Fateh Ali Akbarzade 《Journal of Software Engineering and Applications》 2010年第7期704-708,共5页
This paper presents a two-level learning method for designing an optimal Radial Basis Function Network (RBFN) using Adaptive Velocity Update Relaxation Particle Swarm Optimization algorithm (AVURPSO) and Orthogonal Le... This paper presents a two-level learning method for designing an optimal Radial Basis Function Network (RBFN) using Adaptive Velocity Update Relaxation Particle Swarm Optimization algorithm (AVURPSO) and Orthogonal Least Squares algorithm (OLS) called as OLS-AVURPSO method. The novelty is to develop an AVURPSO algorithm to form the hybrid OLS-AVURPSO method for designing an optimal RBFN. The proposed method at the upper level finds the global optimum of the spread factor parameter using AVURPSO while at the lower level automatically constructs the RBFN using OLS algorithm. Simulation results confirm that the RBFN is superior to Multilayered Perceptron Network (MLPN) in terms of network size and computing time. To demonstrate the effectiveness of proposed OLS-AVURPSO in the design of RBFN, the Mackey-Glass Chaotic Time-Series as an example is modeled by both MLPN and RBFN. 展开更多
关键词 RADIAL BASIS Function network ORTHOGONAL Least squareS Algorithm Particle SWARM Optimization Mackey-Glass CHAOTIC Time-Series
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Development a Spectrophotometric of Fe(Ⅲ), Al(Ⅲ) and Cu(Ⅱ) Using Eriochrome Cyanine R Ligand and Assessment of the Obtained Data by Partial Least-Squares and Artificial Neural Network Method-Application to Natural Waters
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作者 A. Hakan AKTAS 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2018年第8期2638-2644,共7页
Simultaneous determination of heavy metal cations and accurate quantitative prediction of them are of great interest in analytical chemistry.This work has focused on a comprehensive comparison of partial least squares... Simultaneous determination of heavy metal cations and accurate quantitative prediction of them are of great interest in analytical chemistry.This work has focused on a comprehensive comparison of partial least squares(PLS-1)and artificial neural networks(ANN)as two types of chemometric methods.For this purpose,aluminum,iron and copper were studied as three analytes whose UV-Vis absorption spectra highly overlap each other.Accordance with determined parameters(ligand concentration,pH,waiting times,the relationship between absorbance and concentration of metal ion effect and foreign ions)are provided and the optimum conditions.After establishing the optimum conditions for Fe^(3+),Al^(3+) and Cu^(2+) containing mixtures spectrophotometric determinations and the data calibration method of least squares(PLS-1)regression,and artificial neural network(ANN)methods were used.Chemometric methods are applied in a fast,simple,and the results are applicable. 展开更多
关键词 UV-Vis spectrophotometry Partial least squares Artificial neural network ALUMINUM IRON COPPER
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Effect of Bath pH on the Squareness of Electroless CoNiWP Magnetic Films
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作者 Haibin CHENG Shuai XU Wenyu ZHAO Suling ZHAO Pengcheng ZHAI Zhigang SUNand Qingjie ZHANGt Pengcheng ZHAI Zhigang SUN Qingjie ZHANG 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2008年第5期712-714,共3页
Electroless CoNiWP magnetic films were prepared by varying the bath pH and then characterized by energy dispersive X-ray analysis, X-ray diffraction and magnetic force microscopy, it has been found that the microstruc... Electroless CoNiWP magnetic films were prepared by varying the bath pH and then characterized by energy dispersive X-ray analysis, X-ray diffraction and magnetic force microscopy, it has been found that the microstructure and the magnetic properties of films were influenced greatly by the bath pH. At the bath pH 8.06, the grain size and coercivity of the films reach maximuml while the squareness (Mr/Ms) of MH curves reaches minimum. The Henkel plots indicates that the exchange-coupling interaction is very weak at this pH, which may be caused by phase-separation and large grain size, and then results in the lowest squareness. At pH above 8.5, obvious exchange-coupling interaction is observed because of the inexistence of phase-separation and the refinement of grain size. 展开更多
关键词 CoNiWP magnetic film Bath pH squareNESS Exchange-coupling interaction
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Algorithm of neural-network about solving nonlinear least squares adjustment by parameters
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作者 QING Xi-hong~1, NING Wei~(1,2), TAO Hua-xue~1 (1. Shandong University of Science and Technology, Tai’an 271019, China 2. Shandong Agriculture University, Tai’an 271018, China) 《中国有色金属学会会刊:英文版》 CSCD 2005年第S1期145-147,共3页
Study on solving nonlinear least squares adjustment by parameters is one of the most important and new subjects in modern surveying and mapping field . Many researchers have done a lot of work and gained some solving ... Study on solving nonlinear least squares adjustment by parameters is one of the most important and new subjects in modern surveying and mapping field . Many researchers have done a lot of work and gained some solving methods. These methods mainly include iterative algorithms and direct algorithms mainly. The former searches some methods of rapid convergence based on which surveying adjustment is a kind of problem of nonlinear programming. Among them the iterative algorithms of the most in common use are the Gauss-Newton method, damped least quares, quasi-Newton method and some mutations etc. Although these methods improved the quantity of the observation results to a certain degree, and increased the accuracy of the adjustment results, what we want is whether the initial values of unknown parameters are close to their real values. Of course, the model of the latter has better degree in linearity, that is to say, they nearly have the meaning of deeper theories researches. This paper puts forward a kind of method of solving the problems of nonlinear least squares adjustment by parameters based on neural network theory, and studies its stability and convergency. The results of calculating of living example indicate the method acts well for solving parameters problems by nonlinear least squares adjustment without giving exact approximation of parameters. 展开更多
关键词 NEURAL network nonlinear least squareS adjustment by PARAMETERS stability convergency
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Factors Affecting the Squareness of Hysteresis Loops of Sintered NdFeB Magnets
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作者 王占勇 王现英 金鸣林 《Journal of Rare Earths》 SCIE EI CAS CSCD 2007年第S2期109-112,共4页
Investigation into the magnets with different squareness of hysteresis loop(SHL) reveals that the microstructure of sintered NdFeB magnets has great effects on the SHL of the magnets. The abnormal grain growth deterio... Investigation into the magnets with different squareness of hysteresis loop(SHL) reveals that the microstructure of sintered NdFeB magnets has great effects on the SHL of the magnets. The abnormal grain growth deteriorates the SHL seriously. The shape of the grain and the grain boundary affect the intensity of demagnetization field, and consequently on the SHL. The added elements have effects on the phase structures and distributions in the magnets, which influences the uniform of demagnetization field. 展开更多
关键词 NDFEB squareness of hysteresis loop abnormal grain growth magnetizing reversal
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Galerkin-Petrov least squares mixed element method for stationary incompressible magnetohydrodynamics
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作者 罗振东 毛允魁 朱江 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2007年第3期395-404,共10页
The Galerkin-Petrov least squares method is combined with the mixed finite element method to deal with the stationary, incompressible magnetohydrodynamics system of equations with viscosity. A Galerkin-Petrov least sq... The Galerkin-Petrov least squares method is combined with the mixed finite element method to deal with the stationary, incompressible magnetohydrodynamics system of equations with viscosity. A Galerkin-Petrov least squares mixed finite element format for the stationary incompressible magnetohydrodynamics equations is presented. And the existence and error estimates of its solution are derived. Through this method, the combination among the mixed finite element spaces does not demand the discrete Babuska-Brezzi stability conditions so that the mixed finite element spaces could be chosen arbitrartily and the error estimates with optimal order could be obtained. 展开更多
关键词 equation of magnetohydrodynamics mixed element method GalerkinPetrov least squares method error estimate
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Prediction of Axial Capacity of Concrete-Filled Square Steel Tubes Using Neural Networks
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作者 朱美春 王清湘 冯秀峰 《Journal of Southwest Jiaotong University(English Edition)》 2005年第2期151-155,共5页
The application of artificial neural network to predict the ultimate bearing capacity of CFST ( concrete-filled square steel tubes) short columns under axial loading is explored. Input parameters consiste of concret... The application of artificial neural network to predict the ultimate bearing capacity of CFST ( concrete-filled square steel tubes) short columns under axial loading is explored. Input parameters consiste of concrete compressive strength, yield strength of steel tube, confinement index, sectional dimension and width-to-thickness ratio. The ultimate bearing capacity is the only output parameter. A multilayer feedforward neural network is used to describe the nonlinear relationships between the input and output variables. Fifty-five experimental data of CFST short columns under axial loading are used to train and test the neural network. A comparison between the neural network model and three parameter models shows that the neural network model possesses good accuracy and could be a practical method for predicting the ultimate strength of axially loaded CFST short columns. 展开更多
关键词 Concrete-filled square steel tubes Neural networks Axial capacity Short columns
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