期刊文献+
共找到8,743篇文章
< 1 2 250 >
每页显示 20 50 100
Application of Elzaki Transform Method to Market Volatility Using the Black-Scholes Model
1
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
下载PDF
Research on the Digital Transformation of English Teaching in Vocational Education
2
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
下载PDF
Improved calibration method for displacement transformation coefficient in optical and visual measurements
3
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
下载PDF
基于残差U-Net和自注意力Transformer编码器的磁场预测方法
4
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
下载PDF
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
5
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
下载PDF
NONLINEAR TIME TRANSFORMATION METHOD FOR STRONG NONLINEAR OSCILLATION SYSTEMS 被引量:5
6
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
下载PDF
Analysis and Numerical Computations of the Multi-Dimensional,Time-Fractional Model of Navier-Stokes Equation with a New Integral Transformation
7
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
下载PDF
On the Approximation of Fractal-Fractional Differential Equations Using Numerical Inverse Laplace Transform Methods
8
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
下载PDF
On Time Fractional Partial Differential Equations and Their Solution by Certain Formable Transform Decomposition Method
9
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
下载PDF
Synthesis and Structure Transformation of Orthorhombic LiMnO2 Cathode Materials by Sol-gel Method 被引量:1
10
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
下载PDF
The Natural Transform Decomposition Method for Solving Fractional Klein-Gordon Equation
11
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
下载PDF
A three-dimensional transient electromagnetic data inversion method based on a time–frequency transformation 被引量:1
12
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
下载PDF
Leaching and Transformation of Nitrogen Fertilizers in Soil After Application of N with Irrigation: A Soil Column Method 被引量:59
13
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 土壤成分 转移方法 肥料
下载PDF
集成卷积神经网络和视觉Transformer的隧道掌子面岩性判识研究
14
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
下载PDF
基于CNN-Swin Transformer Network的LPI雷达信号识别
15
作者 苏琮智 杨承志 +2 位作者 邴雨晨 吴宏超 邓力洪 《现代雷达》 CSCD 北大核心 2024年第3期59-65,共7页
针对在低信噪比(SNR)条件下,低截获概率雷达信号调制方式识别准确率低的问题,提出一种基于Transformer和卷积神经网络(CNN)的雷达信号识别方法。首先,引入Swin Transformer模型并在模型前端设计CNN特征提取层构建了CNN+Swin Transforme... 针对在低信噪比(SNR)条件下,低截获概率雷达信号调制方式识别准确率低的问题,提出一种基于Transformer和卷积神经网络(CNN)的雷达信号识别方法。首先,引入Swin Transformer模型并在模型前端设计CNN特征提取层构建了CNN+Swin Transformer网络(CSTN),然后利用时频分析获取雷达信号的时频特征,对图像进行预处理后输入CSTN模型进行训练,由网络的底部到顶部不断提取图像更丰富的语义信息,最后通过Softmax分类器对六类不同调制方式信号进行分类识别。仿真实验表明:在SNR为-18 dB时,该方法对六类典型雷达信号的平均识别率达到了94.26%,证明了所提方法的可行性。 展开更多
关键词 低截获概率雷达 信号调制方式识别 Swin transformer网络 卷积神经网络 时频分析
下载PDF
Measurement Method of Graviton Velocity and Thought on Correcting Lorentz Transformation——The Superluminal Neutrino’s Influence on Special Relativity and Other Physical Theories
16
作者 Ping’an Luo 《Journal of Modern Physics》 2012年第4期297-303,共7页
After discovery of the superluminal particle and consideration on development of contemporary physical theory research, also on the existing errors and omissions, the principle of constant light speed is found not a n... After discovery of the superluminal particle and consideration on development of contemporary physical theory research, also on the existing errors and omissions, the principle of constant light speed is found not a necessary condition in derivation of Lorentz Transformation;instead, this thesis proposes the velocity of graviton may feature superluminal, constant velocity in different directions, and independence of inertial reference frame speeds. This is an optional thought of correction. According serial hypothesis, an equation of graviton’s motion trace, i.e., the central curve of nebula density, is established for spiral galaxy. Thus we gain the method to measure velocity of graviton. If to totally avoid problem of limit speed, we have to search for independent of inertia frames, and relevant to space-time properties. Regarding current difficulties of singular points in the Theory of Limited Universe, this thesis points out that the document [1] is the best solution to these difficulties. 展开更多
关键词 Special RELATIVITY LORENTZ transformation SUPERLUMINAL Graviton Measurement method of Graviton VELOCITY Singular Point The Theory of Limited Universe
下载PDF
Auto-Backlund Transformation and Extended Tanh-Function Methods to Solve the Time-Dependent Coefficients Calogero-Degasperis Equation
17
作者 Rehab M. El-Shiekh 《American Journal of Computational Mathematics》 2015年第2期215-223,共9页
In this paper, the Auto-B?cklund transformation connected with the homogeneous balance method (HB) and the extended tanh-function method are used to construct new exact solutions for the time-dependent coefficients Ca... In this paper, the Auto-B?cklund transformation connected with the homogeneous balance method (HB) and the extended tanh-function method are used to construct new exact solutions for the time-dependent coefficients Calogero-Degasperis (VCCD) equation. New soliton and periodic solutions of many types are obtained. Furthermore, the soliton propagation is discussed under the effect of the variable coefficients. 展开更多
关键词 Auto-Backlund transformation Homogeneous Balance method The Extended Tanh-Function method The Time-Dependent Coefficients Calogero-Degasperis Equation Exact Solutions
下载PDF
A Study on the Effects of Internal Heat Generation on the Thermal Performance of Solid and Porous Fins using Differential Transformation Method
18
作者 M.G.Sobamowo O.A.Adedibu +1 位作者 O.A.Adeleye A.O.Adesina 《Semiconductor Science and Information Devices》 2020年第1期29-36,共8页
In this study,the impacts of internal heat generation on heat transfer enhancement of porous fin is theoretical investigated using differential transform method.The parametric studies reveal that porosity enhances the... In this study,the impacts of internal heat generation on heat transfer enhancement of porous fin is theoretical investigated using differential transform method.The parametric studies reveal that porosity enhances the fin heat dissipating capacity but the internal heat generation decreases the heat enhancement capacity of extended surface.Also,it is established that when the internal heat parameter increases to some certain values,some negative effects are recorded where the fin stores heat rather than dissipating it.This scenario defeats the prime purpose of the cooling fin.Additionally,it is established in the present study that the limiting value of porosity parameter for thermal stability for the passive device increases as internal heat parameter increases.This shows that although the internal heat parameter can help assist higher range and value of thermal stability of the fin,it produces negative effect which greatly defeats the ultimate purpose of the fin.The results in the work will help in fin design for industrial applications where internal heat generation is involved. 展开更多
关键词 Thermal analysis Solid and porous fins Thermal performance Temperature-dependent internal heat generation Differential transformation method
下载PDF
Mean Square Solutions of Second-Order Random Differential Equations by Using the Differential Transformation Method
19
作者 Ayad R. Khudair S. A. M. Haddad Sanaa L. Khalaf 《Open Journal of Applied Sciences》 2016年第4期287-297,共11页
The differential transformation method (DTM) is applied to solve the second-order random differential equations. Several examples are represented to demonstrate the effectiveness of the proposed method. The results sh... The differential transformation method (DTM) is applied to solve the second-order random differential equations. Several examples are represented to demonstrate the effectiveness of the proposed method. The results show that DTM is an efficient and accurate technique for finding exact and approximate solutions. 展开更多
关键词 Random Differential Equations Stochastic Differential Equation Differential transformation method
下载PDF
New Generalized Transformation Method and Its Application in Higher-Dimensional Soliton Equation 被引量:2
20
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
一个新概括转变方法被介绍发现更多非线性的部分微分方程的准确答案。作为方法的应用,我们选择(3+1 ) 说明方法的维的碎 soliton 方程。作为结果,明确、准确的 travehng 波浪解决方案的许多类型,包含独居的波浪解决方案,三角法的函... 一个新概括转变方法被介绍发现更多非线性的部分微分方程的准确答案。作为方法的应用,我们选择(3+1 ) 说明方法的维的碎 soliton 方程。作为结果,明确、准确的 travehng 波浪解决方案的许多类型,包含独居的波浪解决方案,三角法的函数解决方案, Jacobian 椭圆形的函数解决方案,和合理解决方案,被获得。Thenew 方法能在数学物理被扩大到另外的非线性的部分微分方程。 展开更多
关键词 转化方法 高维孤立子方程 精确解法 立方非线性Klein-Gordon方程 KDV方程
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部