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Efficient simulation of spatially correlated non-stationary ground motions by wavelet-packet algorithm and spectral representation method
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作者 Ji Kun Cao Xuyang +1 位作者 Wang Suyang Wen Ruizhi 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第4期799-814,共16页
Although the classical spectral representation method(SRM)has been widely used in the generation of spatially varying ground motions,there are still challenges in efficient simulation of the non-stationary stochastic ... Although the classical spectral representation method(SRM)has been widely used in the generation of spatially varying ground motions,there are still challenges in efficient simulation of the non-stationary stochastic vector process in practice.The first problem is the inherent limitation and inflexibility of the deterministic time/frequency modulation function.Another difficulty is the estimation of evolutionary power spectral density(EPSD)with quite a few samples.To tackle these problems,the wavelet packet transform(WPT)algorithm is utilized to build a time-varying spectrum of seed recording which describes the energy distribution in the time-frequency domain.The time-varying spectrum is proven to preserve the time and frequency marginal property as theoretical EPSD will do for the stationary process.For the simulation of spatially varying ground motions,the auto-EPSD for all locations is directly estimated using the time-varying spectrum of seed recording rather than matching predefined EPSD models.Then the constructed spectral matrix is incorporated in SRM to simulate spatially varying non-stationary ground motions using efficient Cholesky decomposition techniques.In addition to a good match with the target coherency model,two numerical examples indicate that the generated time histories retain the physical properties of the prescribed seed recording,including waveform,temporal/spectral non-stationarity,normalized energy buildup,and significant duration. 展开更多
关键词 non-stationarity time-varying spectrum wavelet packet transform(WPT) spectral representation method(SRM) response spectrum spatially varying recordings
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Application of Elzaki Transform Method to Market Volatility Using the Black-Scholes Model
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作者 Henrietta Ify Ojarikre Ideh Rapheal Ebimene James Mamadu 《Journal of Applied Mathematics and Physics》 2024年第3期819-828,共10页
Black-Scholes Model (B-SM) simulates the dynamics of financial market and contains instruments such as options and puts which are major indices requiring solution. B-SM is known to estimate the correct prices of Europ... Black-Scholes Model (B-SM) simulates the dynamics of financial market and contains instruments such as options and puts which are major indices requiring solution. B-SM is known to estimate the correct prices of European Stock options and establish the theoretical foundation for Option pricing. Therefore, this paper evaluates the Black-Schole model in simulating the European call in a cash flow in the dependent drift and focuses on obtaining analytic and then approximate solution for the model. The work also examines Fokker Planck Equation (FPE) and extracts the link between FPE and B-SM for non equilibrium systems. The B-SM is then solved via the Elzaki transform method (ETM). The computational procedures were obtained using MAPLE 18 with the solution provided in the form of convergent series. 展开更多
关键词 Elzaki transform method European Call Black-Scholes Model Fokker-planck Equation Market Volatility
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Research on the Digital Transformation of English Teaching in Vocational Education
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作者 Xiaochao Yao Lin Shi 《Journal of Contemporary Educational Research》 2024年第5期182-186,共5页
With the advancement of technology,exploring the impact of digital transformation on vocational education English teaching has become crucial.This study aims to investigate the effectiveness of digital transformation ... With the advancement of technology,exploring the impact of digital transformation on vocational education English teaching has become crucial.This study aims to investigate the effectiveness of digital transformation in English teaching in vocational education in China by exploring students’and teachers’attitudes,views,and experiences on the use of digital technology in English teaching.This study employed a mixed method of qualitative and quantitative analysis.The research results indicate that digital transformation has had a positive impact on vocational education English teaching,as it enhances the teaching process,promotes communication and collaboration,and increases students’enthusiasm and participation.However,implementing digital transformation in vocational education English teaching also poses challenges,including a lack of resources,infrastructure,and training.This study provides an in-depth understanding of the advantages and challenges of digital transformation in vocational education English teaching and proposes strategies to improve the implementation of digital technology in this context. 展开更多
关键词 Digital transformation Vocational education English teaching Mixed methods
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Improved calibration method for displacement transformation coefficient in optical and visual measurements
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作者 Haopeng Li Zurong Qiu 《Nanotechnology and Precision Engineering》 CAS CSCD 2023年第1期12-25,共14页
Optical and visual measurement technology is used widely in fields that involve geometric measurements,and among such technology are laser and vision-based displacement measuring modules(LVDMMs).The displacement trans... Optical and visual measurement technology is used widely in fields that involve geometric measurements,and among such technology are laser and vision-based displacement measuring modules(LVDMMs).The displacement transformation coefficient(DTC)of an LVDMM changes with the coordinates in the camera image coordinate system during the displacement measuring process,and these changes affect the displacement measurement accuracy of LVDMMs in the full field of view(FFOV).To give LVDMMs higher accuracy in the FFOV and make them adaptable to widely varying measurement demands,a new calibration method is proposed to improve the displacement measurement accuracy of LVDMMs in the FFOV.First,an image coordinate system,a pixel measurement coordinate system,and a displacement measurement coordinate system are established on the laser receiving screen of the LVDMM.In addition,marker spots in the FFOV are selected,and the DTCs at the marker spots are obtained from calibration experiments.Also,a fitting method based on locally weighted scatterplot smoothing(LOWESS)is selected,and with this fitting method the distribution functions of the DTCs in the FFOV are obtained based on the DTCs at the marker spots.Finally,the calibrated distribution functions of the DTCs are applied to the LVDMM,and experiments conducted to verify the displacement measurement accuracies are reported.The results show that the FFOV measurement accuracies for horizontal and vertical displacements are better than±15μm and±19μm,respectively,and that for oblique displacement is better than±24μm.Compared with the traditional calibration method,the displacement measurement error in the FFOV is now 90%smaller.This research on an improved calibration method has certain significance for improving the measurement accuracy of LVDMMs in the FFOV,and it provides a new method and idea for other vision-based fields in which camera parameters must be calibrated. 展开更多
关键词 Displacement transformation coefficient(DTC) Laser and vision-based displacement measuring module(LVDMM) Displacement measurement Locally weighted scatterplot smoothing(LOWESS) Calibration method
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Establishment of a New Method for Genetic Transformation of Dunaliella salina 被引量:1
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作者 柴晓杰 靳非 +2 位作者 丛玉婷 岳金荣 刘艺琼 《Agricultural Science & Technology》 CAS 2017年第8期1374-1377,共4页
The exogenous gene was integrated into Dunaliella salina successfully by using LiAc/PEG mediating method for the first time. According to the results of histochemical staining, transgenic D. salina was blue, showing t... The exogenous gene was integrated into Dunaliella salina successfully by using LiAc/PEG mediating method for the first time. According to the results of histochemical staining, transgenic D. salina was blue, showing that the exogenous GUS gene was successfully expressed in the cells of D. salina. Meanwhile, the effects of growth state of D. salina, plasmid concentration and temperature on its transformation efficiency were studied, and the transformation conditions were optimized. The results show that the optimum conditions for the genetic transformation of D. salina are shown as follows: D. salina was in the early logarithmic phase; plasmid DNA concentration was 600 μg/ml; temperature was 29 ℃, and transformation efficiency was up to 74.8‰ under the best conditions. According to the results of PCR amplification and PCR-Southern hybridization, the target gene had been integrated into genome and was hereditary. 展开更多
关键词 Dunaliela salina LiAc/PEG mediating method GUS gene Genetic transformation
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基于残差U-Net和自注意力Transformer编码器的磁场预测方法 被引量:1
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作者 金亮 尹振豪 +2 位作者 刘璐 宋居恒 刘元凯 《电工技术学报》 EI CSCD 北大核心 2024年第10期2937-2952,共16页
利用有限元方法对几何结构复杂的电机和变压器进行磁场分析,存在仿真时间长且无法复用的问题。因此,该文提出一种基于残差U-Net和自注意力Transformer编码器的磁场预测方法。首先建立永磁同步电机(PMSM)和非晶合金变压器(AMT)有限元模型... 利用有限元方法对几何结构复杂的电机和变压器进行磁场分析,存在仿真时间长且无法复用的问题。因此,该文提出一种基于残差U-Net和自注意力Transformer编码器的磁场预测方法。首先建立永磁同步电机(PMSM)和非晶合金变压器(AMT)有限元模型,得到深度学习训练所需的数据集;然后将Transformer模块与U-Net模型结合,并引入短残差机制建立ResUnet-Transformer模型,通过预测图像的像素实现磁场预测;最后通过Targeted Dropout算法和动态学习率调整策略对模型进行优化,解决拟合问题并提高预测精度。计算实例证明,ResUnet-Transformer模型在PMSM和AMT数据集上测试集的平均绝对百分比误差(MAPE)均小于1%,且仅需500组样本。该文提出的磁场预测方法能减少实际工况和多工况下精细模拟和拓扑优化的时间和资源消耗,亦是虚拟传感器乃至数字孪生的关键实现方法之一。 展开更多
关键词 有限元方法 电磁场 深度学习 U-Net transformER
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Leaching and Transformation of Nitrogen Fertilizers in Soil After Application of N with Irrigation: A Soil Column Method 被引量:59
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作者 ZHOU Jian-Bin XI Jin-Gen +1 位作者 CHEN Zhu-Jun LI Sheng-Xiu 《Pedosphere》 SCIE CAS CSCD 2006年第2期245-252,共8页
A soil column method was used to compare the effect of drip fertigation (the application of fertilizer through drip irrigation systems, DFI) on the leaching loss and transformation of urea-N in soil with that of surfa... A soil column method was used to compare the effect of drip fertigation (the application of fertilizer through drip irrigation systems, DFI) on the leaching loss and transformation of urea-N in soil with that of surface fertilization combined with flood irrigation (SFI), and to study the leaching loss and transformation of three kinds of nitrogen fertilizers (nitrate fertilizer, ammonium fertilizer, and urea fertilizer) in two contrasting soils after the fertigation. In comparison to SFI, DFI decreased leaching loss of urea-N from the soil and increased the mineral N (NH4+-N + NO3- -N) in the soil. The N leached from a clay loam soil ranged from 5.7% to 9.6% of the total N added as fertilizer, whereas for a sandy loam soil they ranged between 16.2% and 30.4%. Leaching losses of mineral N were higher when nitrate fertilizer was used compared to urea or ammonium fertilizer. Compared to the control (without urea addition), on the first day when soils were fertigated with urea, there were increases in NH4+-N in the soils. This confirmed the rapid hydrolysis of urea in soil during fertigation. NH4+-N in soils reached a peak about 5 days after fertigation, and due to nitrification it began to decrease at day 10. After applying NH4+-N fertilizer and urea and during the incubation period, the mineral nitrogen in the soil decreased. This may be related to the occurrence of NH4+-N fixation or volatilization in the soil during the fertigation process. 展开更多
关键词 FERTIGATION irrigation method N leaching N transformation nitrogen fertilizer
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COUPLED NUMERICAL SIMULATION ON COLD ROLLER'S TEMPERATURE FIFLD-PHASE TRANSFORMATION - STRESS FIELD DURING ITS QUENCHING PSOCESS 被引量:14
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作者 J. F. Gu J. S. Pan M. J. Hu and F. F. Shen (School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200030, China) 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2000年第1期254-262,共9页
Complicated changns occur inside the steel parts during quenching process. The abruptly changed boundary conditions make the temperature field,micro - structure and stress field change dramatically in very short ti... Complicated changns occur inside the steel parts during quenching process. The abruptly changed boundary conditions make the temperature field,micro - structure and stress field change dramatically in very short time, and these variables take a contact interactions in the whole process. In this paper, a three dimensional non - linear mathematical model for queeching process has been founded and the numerical simulation on temperature field,microstructre and stress field has been realized.In the FEM analysis, the incremental iteration method is used to deal with such complicated nonlinear as boundary nonlinear, physical property nonlinear,transformation nonlinear etc.The effect of stress on transformation kinetics has been considered in the calculation of microstructure. In the stress field anal- ysis,a thermo- elasto - plastic model has been founded, which considers such factors as transforma- tion strain,transformation plastic strain, themal strain and the effect of temperature and transforma- tion on mechanical propertier etc. The transient temperature field, microstructure distribution and stress field of the roller on any time can be displayed vividly,and the cooling curve and the changes of stress on any position can also be given. 展开更多
关键词 quenching phase transformation temperature field stress field finite element method (FEM) numerical simulation
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Differential transformation method for studying flow and heat transfer due to stretching sheet embedded in porous medium with variable thickness, variable thermal conductivity,and thermal radiation 被引量:5
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作者 M.M.KHADER A.M.MEGAHED 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2014年第11期1387-1400,共14页
This article presents a numerical solution for the flow of a Newtonian fluid over an impermeable stretching sheet embedded in a porous medium with the power law surface velocity and variable thickness in the presence ... This article presents a numerical solution for the flow of a Newtonian fluid over an impermeable stretching sheet embedded in a porous medium with the power law surface velocity and variable thickness in the presence of thermal radiation. The flow is caused by non-linear stretching of a sheet. Thermal conductivity of the fluid is assumed to vary linearly with temperature. The governing partial differential equations (PDEs) are transformed into a system of coupled non-linear ordinary differential equations (ODEs) with appropriate boundary conditions for various physical parameters. The remaining system of ODEs is solved numerically using a differential transformation method (DTM). The effects of the porous parameter, the wall thickness parameter, the radiation parameter, the thermal conductivity parameter, and the Prandtl number on the flow and temperature profiles are presented. Moreover, the local skin-friction and the Nusselt numbers are presented. Comparison of the obtained numerical results is made with previously published results in some special cases, with good agreement. The results obtained in this paper confirm the idea that DTM is a powerful mathematical tool and can be applied to a large class of linear and non-linear problems in different fields of science and engineering. 展开更多
关键词 Newtonian fluid stretching sheet differential transformation method(DTM) thermal radiation variable thermal conductivity variable thickness
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NONLINEAR TIME TRANSFORMATION METHOD FOR STRONG NONLINEAR OSCILLATION SYSTEMS 被引量:5
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作者 徐兆 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 1992年第3期279-288,共10页
In this paper,a nonlinear time transformation method is presented for the analysis of strong nonlinear oscillation systems.This method can be used to study the limit cycle behavior of the autonomous systems and to ana... In this paper,a nonlinear time transformation method is presented for the analysis of strong nonlinear oscillation systems.This method can be used to study the limit cycle behavior of the autonomous systems and to analyze the forced vibration of a strong nonlinear system. 展开更多
关键词 strong nonlinear oscillation nonlinear time transformation method
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Analysis and Numerical Computations of the Multi-Dimensional,Time-Fractional Model of Navier-Stokes Equation with a New Integral Transformation
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作者 Yuming Chu Saima Rashid +3 位作者 Khadija Tul Kubra Mustafa Inc Zakia Hammouch M.S.Osman 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第9期3025-3060,共36页
The analytical solution of the multi-dimensional,time-fractional model of Navier-Stokes equation using the triple and quadruple Elzaki transformdecompositionmethod is presented in this article.The aforesaidmodel is an... The analytical solution of the multi-dimensional,time-fractional model of Navier-Stokes equation using the triple and quadruple Elzaki transformdecompositionmethod is presented in this article.The aforesaidmodel is analyzed by employing Caputo fractional derivative.We deliberated three stimulating examples that correspond to the triple and quadruple Elzaki transform decomposition methods,respectively.The findings illustrate that the established approaches are extremely helpful in obtaining exact and approximate solutions to the problems.The exact and estimated solutions are delineated via numerical simulation.The proposed analysis indicates that the projected configuration is extremely meticulous,highly efficient,and precise in understanding the behavior of complex evolutionary problems of both fractional and integer order that classify affiliated scientific fields and technology. 展开更多
关键词 Caputo derivative Elzaki transform time-fractional Navier-Stokes equation decomposition method
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On the Approximation of Fractal-Fractional Differential Equations Using Numerical Inverse Laplace Transform Methods
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作者 Kamran Siraj Ahmad +2 位作者 Kamal Shah Thabet Abdeljawad Bahaaeldin Abdalla 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第6期2743-2765,共23页
Laplace transform is one of the powerful tools for solving differential equations in engineering and other science subjects.Using the Laplace transform for solving differential equations,however,sometimes leads to sol... Laplace transform is one of the powerful tools for solving differential equations in engineering and other science subjects.Using the Laplace transform for solving differential equations,however,sometimes leads to solutions in the Laplace domain that are not readily invertible to the real domain by analyticalmeans.Thus,we need numerical inversionmethods to convert the obtained solution fromLaplace domain to a real domain.In this paper,we propose a numerical scheme based on Laplace transform and numerical inverse Laplace transform for the approximate solution of fractal-fractional differential equations with orderα,β.Our proposed numerical scheme is based on three main steps.First,we convert the given fractal-fractional differential equation to fractional-differential equation in Riemann-Liouville sense,and then into Caputo sense.Secondly,we transformthe fractional differential equation in Caputo sense to an equivalent equation in Laplace space.Then the solution of the transformed equation is obtained in Laplace domain.Finally,the solution is converted into the real domain using numerical inversion of Laplace transform.Three inversion methods are evaluated in this paper,and their convergence is also discussed.Three test problems are used to validate the inversion methods.We demonstrate our results with the help of tables and figures.The obtained results show that Euler’s and Talbot’s methods performed better than Stehfest’s method. 展开更多
关键词 Fractal-fractional differential equation power law kernel exponential decay kernel Mittag-Leffler kernel Laplace transform Euler’s method Talbot’s method Stehfest’s method
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Multi-phase field simulation of grain growth in multiple phase transformations of a binary alloy 被引量:1
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作者 冯力 贾北北 +3 位作者 朱昶胜 安国升 肖荣振 冯小静 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第8期87-95,共9页
This work establishes a temperature-controlled sequence function, and a new multi-phase-field model, for liquid- solid-solid multi-phase transformation by coupling the liquid-solid phase transformation model with the ... This work establishes a temperature-controlled sequence function, and a new multi-phase-field model, for liquid- solid-solid multi-phase transformation by coupling the liquid-solid phase transformation model with the solid-solid phase transformation model. Taking an Fe-C alloy as an example, the continuous evolution of a multi-phase transformation is simulated by using this new model. In addition, the growth of grains affected by the grain orientation of the parent phase (generated in liquid-solid phase transformation) in the solid-solid phase transformation is studied. The results show that the morphology of ferrite grains which nucleate at the boundaries of the austenite grains is influenced by the orientation of the parent austenite grains. The growth rate of ferrite grains which nucleate at small-angle austenite grain boundaries is faster than those that nucleate at large-angle austenite grain boundaries. The difference of the growth rate of ferrites grains in different parent phase that nucleate at large-angle austenite grain boundaries, on both sides of the boundaries, is greater than that of ferrites nucleating at small-angle austenite grain boundaries. 展开更多
关键词 multi-phase transformation MICROSTRUCTURE multi-phase-field method grain orientation
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Synthesis and Structure Transformation of Orthorhombic LiMnO2 Cathode Materials by Sol-gel Method 被引量:1
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作者 ShixiZHAO HanxingLIU +1 位作者 QiangLI ShixiOUYANG 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2004年第1期46-48,共3页
Orthorhombic LiMnO2 cathode materials were synthesized successfully at lower temperature by sol-gel method. When LiMnO2 precursor prepared by sol-gel method was fired in air, the product was a mixture of spinel struct... Orthorhombic LiMnO2 cathode materials were synthesized successfully at lower temperature by sol-gel method. When LiMnO2 precursor prepared by sol-gel method was fired in air, the product was a mixture of spinel structure LiMn2O4 and rock-salt structure Li2MnO3, whereas in argon single-phase orthorhombic LiMnO2 could obtain at the range of 750℃ to 920℃. The substitution of Mn by Zn2+ or Co3+ in LiMnO2 led to the structure of LiMnO2 transiting to Qα-LiFeO2. The results of electrochemical cycles indicated that the discharged capacity of orthorhombic-LiMnO2 was smaller at the initial stages, then gradually increased with the increasing of cycle number, finally the capacity stabilized to certain value after about 10th cycles. This phenomenon reveals that there is an activation process for orthorhombic LiMnO2 cathode materials during electrochemical cycles, which is a phase transition process from orthorhombic LiMnO2 to tetragonal spinel Li2Mn2O4. The capacity of orthorhombic LiMnO2 synthesized at lower temperature is larger than that synthesized at high temperature. 展开更多
关键词 Orthorhombic LiMnO2 SYNTHESIS Structure transformation Sol-gel method
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On Time Fractional Partial Differential Equations and Their Solution by Certain Formable Transform Decomposition Method
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作者 Rania Saadeh Ahmad Qazza +1 位作者 Aliaa Burqan Shrideh Al-Omari 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第9期3121-3139,共19页
This paper aims to investigate a new efficient method for solving time fractional partial differential equations.In this orientation,a reliable formable transform decomposition method has been designed and developed,w... This paper aims to investigate a new efficient method for solving time fractional partial differential equations.In this orientation,a reliable formable transform decomposition method has been designed and developed,which is a novel combination of the formable integral transform and the decomposition method.Basically,certain accurate solutions for time-fractional partial differential equations have been presented.Themethod under concern demandsmore simple calculations and fewer efforts compared to the existingmethods.Besides,the posed formable transformdecompositionmethod has been utilized to yield a series solution for given fractional partial differential equations.Moreover,several interesting formulas relevant to the formable integral transform are applied to fractional operators which are performed as an excellent application to the existing theory.Furthermore,the formable transform decomposition method has been employed for finding a series solution to a time-fractional Klein-Gordon equation.Over and above,some numerical simulations are also provided to ensure reliability and accuracy of the new approach. 展开更多
关键词 Caputo derivative fractional differential equations formable transform time-fractional klein-gordon equation decomposition method
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The Natural Transform Decomposition Method for Solving Fractional Klein-Gordon Equation
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作者 Mohamed Elbadri 《Applied Mathematics》 2023年第3期230-243,共14页
In this paper, a coupling of the natural transform method and the Admoian decomposition method called the natural transform decomposition method (NTDM), is utilized to solve the linear and nonlinear time-fractional Kl... In this paper, a coupling of the natural transform method and the Admoian decomposition method called the natural transform decomposition method (NTDM), is utilized to solve the linear and nonlinear time-fractional Klein-Gordan equation. The (NTDM), is introduced to derive the approximate solutions in series form for this equation. Solutions have been drawn for several values of the time power. To identify the strength of the method, three examples are presented. 展开更多
关键词 Natural transform Adomian Decomposition method Fractional Klein-Gordon Equation
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A three-dimensional transient electromagnetic data inversion method based on a time–frequency transformation 被引量:1
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作者 Yang Yun-Jian Wang Xu-Ben +2 位作者 Liu Xue-Jun Mi Xiao-Li Mao Lifeng 《Applied Geophysics》 SCIE CSCD 2020年第3期361-376,共16页
Herein,a three-dimensional(3D)inversion method in the frequency domain based on a time–frequency transformation was developed to improve the efficiency of the 3D inversion of transient electromagnetic(TEM)data.The Fo... Herein,a three-dimensional(3D)inversion method in the frequency domain based on a time–frequency transformation was developed to improve the efficiency of the 3D inversion of transient electromagnetic(TEM)data.The Fourier transform related to the electromagnetic response in the frequency and time domains becomes a sine or cosine transform under the excitation of downward-step current.We established a transformation matrix based on the digital fi ltering calculation for the sine transform,and then the frequency domain projection of the TEM data was determined from the linear transformation system using the smoothing constrained least squares inversion method,in which only the imaginary part was used to maintain the TEM data transformation equivalence in the bidirectional projection.Thus,the time-domain TEM inversion problem was indirectly and effectively solved in the frequency domain.In the 3D inversion of the transformed frequency-domain data,the limited-memory Broyden–Fletcher–Goldfarb–Shannoquasi–Newton(L-BFGS)method was used and modifi ed with a restart strategy to adjust the regularization parameter when the algorithm tended to a local minimum.Synthetic data tests showed that our domain transformation method can stably project the TEM data into the frequency domain with very high accuracy;furthe rmore,the 3D inversion of the transformed frequency-domain data is stable,can be used to recover the real resistivity model with an acceptable effi ciency. 展开更多
关键词 Transient electromagnetic method TEM digital filtering time-frequency transformation 3D EM forward 3D EM inversion
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New Generalized Transformation Method and Its Application in Higher-Dimensional Soliton Equation 被引量:2
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作者 BAI Cheng-Lin GUO Zong-Lin ZHAO Hong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第3期447-451,共5页
A new generalized transformation method is differential equation. As an application of the method, we presented to find more exact solutions of nonlinear partial choose the (3+1)-dimensional breaking soliton equati... A new generalized transformation method is differential equation. As an application of the method, we presented to find more exact solutions of nonlinear partial choose the (3+1)-dimensional breaking soliton equation to illustrate the method. As a result many types of explicit and exact traveling wave solutions, which contain solitary wave solutions, trigonometric function solutions, Jacobian elliptic function solutions, and rational solutions, are obtained. The new method can be extended to other nonlinear partial differential equations in mathematical physics. 展开更多
关键词 new generalized transformation method exact solution (3+1)-dimensional breaking soliton equation KdV equation mKdV equation cubic nonlinear Klein-Gordon equation
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集成卷积神经网络和视觉Transformer的隧道掌子面岩性判识研究
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作者 向露露 童建军 +2 位作者 王明年 苗兴旺 叶沛 《隧道建设(中英文)》 CSCD 北大核心 2024年第5期1056-1067,I0078-I0089,共24页
为研究综合高效的隧道掌子面岩性智能分类方法,首先,通过收集高铁沿线施工隧道高清掌子面照片、地质素描图及工程地质说明,筛选并统计出灰岩、泥岩、砂岩、玄武岩4种岩性,在此基础上,采用图像增强扩充样本数量并构建岩性样本集;然后,基... 为研究综合高效的隧道掌子面岩性智能分类方法,首先,通过收集高铁沿线施工隧道高清掌子面照片、地质素描图及工程地质说明,筛选并统计出灰岩、泥岩、砂岩、玄武岩4种岩性,在此基础上,采用图像增强扩充样本数量并构建岩性样本集;然后,基于上述样本集分别构建ResNet50V2岩性分类迁移模型及VIT岩性分类模型,对比二者岩性分类效果,并采用Stacking方法集成2种模型的分类特点;最后,通过对比3种元学习器(逻辑回归、支持向量机、决策树)对2种模型的集成融合效果来选取最适用的元学习器。结果表明:采用逻辑回归集成ResNet50V2及VIT所构建的集成模型对岩性的分类效果最好,能充分融合掌子面岩性的全、局部特征来进行分类,模型准确率达到93.8%。 展开更多
关键词 隧道 掌子面岩性 卷积神经网络 视觉transformer 集成学习 Stacking方法
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The Adomian Decomposition Method and the Differential Transform Method for Numerical Solution of Multi-Pantograph Delay Differential Equations
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作者 Musa Cakir Derya Arslan 《Applied Mathematics》 2015年第8期1332-1343,共12页
In this paper, the Adomian Decomposition Method (ADM) and the Differential Transform Method (DTM) are applied to solve the multi-pantograph delay equations. The sufficient conditions are given to assure the convergenc... In this paper, the Adomian Decomposition Method (ADM) and the Differential Transform Method (DTM) are applied to solve the multi-pantograph delay equations. The sufficient conditions are given to assure the convergence of these methods. Several examples are presented to demonstrate the efficiency and reliability of the ADM and the DTM;numerical results are discussed, compared with exact solution. The results of the ADM and the DTM show its better performance than others. These methods give the desired accurate results only in a few terms and in a series form of the solution. The approach is simple and effective. These methods are used to solve many linear and nonlinear problems and reduce the size of computational work. 展开更多
关键词 Multi-pantograph Delay DIFFERENTIAL Equations Adomian DECOMPOSITION method (ADM) DIFFERENTIAL transform method (DTM) Convergence of Adomian DECOMPOSITION method
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