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Auto-parametric resonance of a continuous-beam-bridge model under two-point periodic excitation:an experimental investigation and stability analysis
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作者 Li Yuchun Shen Chao +1 位作者 Liu Wei Li Dong 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第2期445-454,共10页
The auto-parametric resonance of a continuous-beam bridge model subjected to a two-point periodic excitation is experimentally and numerically investigated in this study.An auto-parametric resonance experiment of the ... The auto-parametric resonance of a continuous-beam bridge model subjected to a two-point periodic excitation is experimentally and numerically investigated in this study.An auto-parametric resonance experiment of the test model is conducted to observe and measure the auto-parametric resonance of a continuous beam under a two-point excitation on columns.The parametric vibration equation is established for the test model using the finite-element method.The auto-parametric resonance stability of the structure is analyzed by using Newmark's method and the energy-growth exponent method.The effects of the phase difference of the two-point excitation on the stability boundaries of auto-parametric resonance are studied for the test model.Compared with the experiment,the numerical instability predictions of auto-parametric resonance are consistent with the test phenomena,and the numerical stability boundaries of auto-parametric resonance agree with the experimental ones.For a continuous beam bridge,when the ratio of multipoint excitation frequency(applied to the columns)to natural frequency of the continuous girder is approximately equal to 2,the continuous beam may undergo a strong auto-parametric resonance.Combined with the present experiment and analysis,a hypothesis of Volgograd Bridge's serpentine vibration is discussed. 展开更多
关键词 auto-parametric resonance continuous beam bridge model two-point excitation experimental investigation stability analysis vibration of Volgograd Bridge
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Stochastic Programming for Hub Energy Management Considering Uncertainty Using Two-Point Estimate Method and Optimization Algorithm
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作者 Ali S.Alghamdi Mohana Alanazi +4 位作者 Abdulaziz Alanazi Yazeed Qasaymeh Muhammad Zubair Ahmed Bilal Awan M.G.B.Ashiq 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第12期2163-2192,共30页
To maximize energy profit with the participation of electricity,natural gas,and district heating networks in the day-ahead market,stochastic scheduling of energy hubs taking into account the uncertainty of photovoltai... To maximize energy profit with the participation of electricity,natural gas,and district heating networks in the day-ahead market,stochastic scheduling of energy hubs taking into account the uncertainty of photovoltaic and wind resources,has been carried out.This has been done using a new meta-heuristic algorithm,improved artificial rabbits optimization(IARO).In this study,the uncertainty of solar and wind energy sources is modeled using Hang’s two-point estimating method(TPEM).The IARO algorithm is applied to calculate the best capacity of hub energy equipment,such as solar and wind renewable energy sources,combined heat and power(CHP)systems,steamboilers,energy storage,and electric cars in the day-aheadmarket.The standard ARO algorithmis developed to mimic the foraging behavior of rabbits,and in this work,the algorithm’s effectiveness in avoiding premature convergence is improved by using the dystudynamic inertia weight technique.The proposed IARO-based scheduling framework’s performance is evaluated against that of traditional ARO,particle swarm optimization(PSO),and salp swarm algorithm(SSA).The findings show that,in comparison to previous approaches,the suggested meta-heuristic scheduling framework based on the IARO has increased energy profit in day-ahead electricity,gas,and heating markets by satisfying the operational and energy hub limitations.Additionally,the results show that TPEM approach dependability consideration decreased hub energy’s profit by 8.995%as compared to deterministic planning. 展开更多
关键词 Stochastic energy hub scheduling energy profit UNCERTAINTY Hong’s two-point estimate method improved artificial rabbits optimization
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Existence of solutions and positive solutions to a fourth-order two-point BVP with second derivative 被引量:12
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作者 姚庆六 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2004年第3期104-108,共5页
Several existence theorems were established for a nonlinear fourth-order two-point boundary value problem with second derivative by using Leray-Schauder fixed point theorem, equivalent norm and technique on system of ... Several existence theorems were established for a nonlinear fourth-order two-point boundary value problem with second derivative by using Leray-Schauder fixed point theorem, equivalent norm and technique on system of integral equations. The main conditions of our results are local. In other words, the existence of the solution can be determined by considering the height of the nonlinear term on a bounded set. This class of problems usually describes the equilibrium state of an elastic beam which is simply supported at both ends. 展开更多
关键词 Nonlinear fourth-order equation two-point boundary value problem Solution and positive solution EXISTENCE Fixed point theorem
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HIGH ACCURACY FINITE VOLUME ELEMENT METHOD FOR TWO-POINT BOUNDARY VALUE PROBLEM OF SECOND ORDER ORDINARY DIFFERENTIAL EQUATIONS 被引量:4
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作者 Wang Tongke(王同科) 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 2002年第2期213-225,共13页
In this paper, a high accuracy finite volume element method is presented for two-point boundary value problem of second order ordinary differential equation, which differs from the high order generalized difference me... In this paper, a high accuracy finite volume element method is presented for two-point boundary value problem of second order ordinary differential equation, which differs from the high order generalized difference methods. It is proved that the method has optimal order error estimate O(h3) in H1 norm. Finally, two examples show that the method is effective. 展开更多
关键词 SECOND order ordinary differential equation two-point boundary value problem high accuracy finite volume element method error estimate.
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Existence and iteration of monotone positive solutions for a third-order two-point boundary value problem 被引量:5
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作者 SUN Yong-ping 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2008年第4期413-419,共7页
The existence of nondecreasing positive solutions for the nonlinear third-order twopoint boundary value problem u′″(t) + q(t)f(t,u(t),u′(t)) = 0, 0 〈 t 〈 1, u(0) = u″(0) = u′(1) = 0 is studied.... The existence of nondecreasing positive solutions for the nonlinear third-order twopoint boundary value problem u′″(t) + q(t)f(t,u(t),u′(t)) = 0, 0 〈 t 〈 1, u(0) = u″(0) = u′(1) = 0 is studied. The iterative schemes for approximating the solutions are obtained by applying a monotone iterative method. 展开更多
关键词 third-order two-point boundary value problem monotone iterative method positive solution existence iterative scheme
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Two-point compression ultrasonography: Enough to rule out lower extremity deep venous thrombosis? 被引量:2
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作者 Ralphe Bou Chebl Nader El Souki +3 位作者 Mirabelle Geha Imad Majzoub Rima Kaddoura Hady Zgheib 《World Journal of Emergency Medicine》 SCIE CAS CSCD 2021年第4期268-273,共6页
BACKGROUND: Deep venous thrombosis(DVT) is a major cause of morbidity and is a common presenting complaint to the emergency department(ED). Point-of-care two-point compression ultrasonography has evolved as a quick an... BACKGROUND: Deep venous thrombosis(DVT) is a major cause of morbidity and is a common presenting complaint to the emergency department(ED). Point-of-care two-point compression ultrasonography has evolved as a quick and effective way of diagnosing DVT. The purpose of this study is to validate the prevalence and distribution of venous thrombi isolated to proximal lower extremity veins, other than common femoral and popliteal veins in patients with DVT.METHODS: This is a single-center retrospective study that looked at patients presenting to the ED of a tertiary care hospital between January 2014 and August 2018. The clinical presentation and laboratory and imaging results were obtained using the hospital's electronic medical record.RESULTS: A total of 2,507 patients underwent a lower extremity duplex ultrasound during the study period. Among them, 379(15%) were included in the study. The percentages of isolated thrombi to the femoral vein and deep femoral vein were 7.92% and 0.53%, respectively. When the patients were stratified into the two groups of isolated DVT and two-point compression DVT, there were no statistically significant differences in the laboratory results between both groups. However, immobilized patients and patients with recent surgeries were more likely to have an isolated DVT.CONCLUSIONS: Thrombi isolated to proximal lower extremity veins other than the common femoral and popliteal veins make up 8.45% of DVTs. Given this significant number of missed DVTs, the authors recommend the addition of the femoral and deep femoral veins to the two-point compression exam. 展开更多
关键词 Lower extremity Deep venous thrombosis Emergency department two-point compression ultrasonography
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Investigation of Divertor Detachment in EAST by‘Two-Point’Model 被引量:1
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作者 金乐 朱思铮 《Plasma Science and Technology》 SCIE EI CAS CSCD 2007年第4期403-406,共4页
Divertor plasma detachment offers one of the most promising operating modes for fusion devices because of low target power loading. In this article a 'two-point' model is used to investigate the formation of detachm... Divertor plasma detachment offers one of the most promising operating modes for fusion devices because of low target power loading. In this article a 'two-point' model is used to investigate the formation of detachment and explore the route to detachment in EAST, in order to find an ideal operation window. The simulation results show that impurity radiation and ionneutral friction are the main causes of divertor plasma detachment at the target plates. Raising the safety factor and reducing the upstream power density provide effective means to achieve the detachment due to the increased radiation power fraction. Puffing Ar and Ne impurities and raising the safety factor can bring the upstream high plasma temperature region (above 100 eV) and the low target plasma temperature region (below 10 eV) close to each other in terms of the separatrix density. But it is difficult to find a common operating region which satisfies both conditions. High recycling and detached regimes provides an ideal operation window because of the steady upstream condition and low target power load. 展开更多
关键词 DETACHMENT two-point model DIVERTOR
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Two-Point Statistics of Coherent Structure in Turbulent Flow 被引量:1
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作者 Jun Chen 《Journal of Flow Control, Measurement & Visualization》 2019年第4期153-173,共21页
This review summarizes the coherent structures (CS) based on two-point correlations and their applications, with a focus on the interpretation of statistic CS and their characteristics. We review studies on this topic... This review summarizes the coherent structures (CS) based on two-point correlations and their applications, with a focus on the interpretation of statistic CS and their characteristics. We review studies on this topic, which have attracted attention in recent years, highlighting improvements, expansions, and promising future directions for two-point statistics of CS in turbulent flow. The CS is one of typical structures of turbulent flow, transporting energy from large-scale to small-scale structures. To investigate the CS in turbulent flow, a large amount of two-point correlation techniques for CS identification and visualization have been, and are currently being, intensively studied by researchers. Two-point correlations with examples and comparisons between different methods are briefly reviewed at first. Some of the uses of correlations in both Eulerian and Lagrangian frames of reference to obtain their properties at consecutive spatial locations and time events are surveyed. Two-point correlations, involving space-time correlations, two-point spatial correlations, and cross correlations, as essential to theories and models of turbulence and for the analyses of experimental and numerical turbulence data are then discussed. The velocity-vorticity correlation structure (VVCS) as one of the statistical CS based on two-point correlations is reiterated in detail. Finally, we summarize the current understanding of two-point correlations of turbulence and conclude with future issues for this field. 展开更多
关键词 two-point Correlation Coherent Structure Boundary Layer Wall-Bounded FLOW TURBULENT SHEAR FLOW
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ASYMPTOTIC ERROR EXPANSIONS OF QUADRATIC SPLINE COLLOCATION SOLUTIONS FOR TWO-POINT BOUNDARY VALUE PROBLEMS
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作者 韩国强 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 1994年第2期120-125,共6页
In this paper, we consider the following problem:The quadratic spline collocation, with uniform mesh and the mid-knot points are taken as the collocation points for this problem is considered. With some assumptions, w... In this paper, we consider the following problem:The quadratic spline collocation, with uniform mesh and the mid-knot points are taken as the collocation points for this problem is considered. With some assumptions, we have proved that the solution of the quadratic spline collocation for the nonlinear problem can be written as a series expansions in integer powers of the mesh-size parameter. This gives us a construction method for using Richardson’s extrapolation. When we have a set of approximate solution with different mesh-size parameter a solution with high accuracy can he obtained by Richardson’s extrapolation. 展开更多
关键词 ASYMPTOTIC error expansion QUADRATIC SPLINE COLLOCATION method two-point boundary value problem Richardson’s extrapolation.
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Nonlinear Coupled Motions for a Given Two-Point Tension Mooring System
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作者 Sun, MG Long, J 《China Ocean Engineering》 SCIE EI 1998年第3期253-264,共12页
The nonlinear behaviors of plane coupled motions for a given two-point tension mooring system, are discussed in the present paper. For a cylinder moored by two taut lines under the action of gravity, buoyance and forc... The nonlinear behaviors of plane coupled motions for a given two-point tension mooring system, are discussed in the present paper. For a cylinder moored by two taut lines under the action of gravity, buoyance and forces due to wave-current and mooring lines, a mathematical model of motions with three degrees of freedom is established. The steady solution and stability are analyzed. By integrating the equations of motions, history, phase map and Poincare map are obtained. The Liapunov exponents are also computed. The numerical results show that: the horizontal movement will increase, and stability will also increase as the steady force increases. The amplitude of responses will decrease as time-dependent forces decrease. Because of the geometric nonlinearity, there exist many windows bifurcating to pseudo-periodic or multi-periodic solution. The bifurcating patterns may be different. The behaviors are very complex. Under wave excitation alone, the motions are nonsymmetrical but still symmetrical statistically. 展开更多
关键词 two-point mooring time-domain simulation Poincare map phase map Liapunov exponent
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Two-point model analysis of SOL plasma in EAST
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作者 Jie HUANG Yasuhiro SUZUKI +2 位作者 Kunpei NOJIRI Naoko ASHIKAWA EAST Team 《Plasma Science and Technology》 SCIE EI CAS CSCD 2021年第8期1-5,共5页
A two-point model is used to investigate the characteristics of scrape-off layer(SOL)plasma with the field line tracing method in the experimental advanced superconducting tokamak.The profiles of plasma density,temper... A two-point model is used to investigate the characteristics of scrape-off layer(SOL)plasma with the field line tracing method in the experimental advanced superconducting tokamak.The profiles of plasma density,temperature and particle flux on the divertor target calculated by the model are in reasonable agreement with experimental observation.Moreover,the profiles of plasma parameters on the divertor target strongly depend on the SOL magnetic topology or the equilibrium configuration from the modeling. 展开更多
关键词 scrape-off layer two-point model field line tracing TOKAMAK
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Several New Types of Fixed Point Theorems and Their Applications to Two-Point Ordinary Differential Equations
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作者 Congjun Zhang Jinlu Li +1 位作者 Yan Zhang Xiaoliang Feng 《Applied Mathematics》 2012年第10期1109-1116,共8页
The present paper is mainly concerned with several new types of fixed point theorems in different spaces such as cone metric spaces and fuzzy metric spaces. By using these obtained fixed point theorems, we then prove ... The present paper is mainly concerned with several new types of fixed point theorems in different spaces such as cone metric spaces and fuzzy metric spaces. By using these obtained fixed point theorems, we then prove the existence and uniqueness of the solutions to two classes of two-point ordinary differential equation problems. 展开更多
关键词 Expansive Mapping CONE METRIC SPACE Fuzzy METRIC SPACE two-point Ordinary Differential Equations
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A Special Case of Variational Formulation for Two-Point Boundary Value Problem in L2(Ω)
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作者 Pedro Pablo Cárdenas Alzate 《Applied Mathematics》 2015年第4期700-706,共7页
We consider the nonlinear boundary value problems for elliptic partial differential equations and using a maximum principle for this problem we show uniqueness and continuous dependence on data. We use the strong vers... We consider the nonlinear boundary value problems for elliptic partial differential equations and using a maximum principle for this problem we show uniqueness and continuous dependence on data. We use the strong version of the maximum principle to prove that all solutions of two-point BVP are positives and we also show a numerical example by applying finite difference method for a two-point BVP in one dimension based on discrete version of the maximum principle. 展开更多
关键词 two-point BOUNDARY VARIATIONAL Problem Stability RESTRICTION
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A Two-Point Boundary Value Problem by Using a Mixed Finite Element Method
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作者 Pedro Pablo Cárdenas Alzate José Rodrigo González Granada 《Applied Mathematics》 2015年第12期1996-2003,共8页
This paper describes a numerical solution for a two-point boundary value problem. It includes an algorithm for discretization by mixed finite element method. The discrete scheme allows the utilization a finite element... This paper describes a numerical solution for a two-point boundary value problem. It includes an algorithm for discretization by mixed finite element method. The discrete scheme allows the utilization a finite element method based on piecewise linear approximating functions and we also use the barycentric quadrature rule to compute the stiffness matrix and the L2-norm. 展开更多
关键词 two-point BVP Galerkin’s METHOD Non-Symmetric PROBLEM
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A rapid and accurate two-point ray tracing method in horizontally layered velocity model
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作者 田玥 陈晓非 《Acta Seismologica Sinica(English Edition)》 EI CSCD 2005年第2期154-161,254,共9页
A rapid and accurate method for two-point ray tracing in horizontally layered velocity model is presented in this paper. Numerical experiments show that this method provides stable and rapid convergence with high accu... A rapid and accurate method for two-point ray tracing in horizontally layered velocity model is presented in this paper. Numerical experiments show that this method provides stable and rapid convergence with high accuracies, regardless of various 1-D velocity structures, takeoff angles and epicentral distances. This two-point ray tracing method is compared with the pseudobending technique and the method advanced by Kim and Baag (2002). It turns out that the method in this paper is much more efficient and accurate than the pseudobending technique, but is only applicable to 1-D velocity model. Kim's method is equivalent to ours for cases without large takeoff angles, but it fails to work when the takeoff angle is close to 90°. On the other hand, the method presented in this paper is applicable to cases with any takeoff angles with rapid and accurate convergence. Therefore, this method is a good choice for two-point ray tracing problems in horizontally layered velocity model and is efficient enough to be applied to a wide range of seismic problems. 展开更多
关键词 two-point ray tracing horizontally layered velocity model
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Analytical Solutions of Some Two-Point Non-Linear Elliptic Boundary Value Problems
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作者 Vembu Ananthaswamy Lakshmanan Rajendran 《Applied Mathematics》 2012年第9期1044-1058,共15页
Several problems arising in science and engineering are modeled by differential equations that involve conditions that are specified at more than one point. The non-linear two-point boundary value problem (TPBVP) (Br... Several problems arising in science and engineering are modeled by differential equations that involve conditions that are specified at more than one point. The non-linear two-point boundary value problem (TPBVP) (Bratu’s equation, Troesch’s problems) occurs engineering and science, including the modeling of chemical reactions diffusion processes and heat transfer. An analytical expression pertaining to the concentration of substrate is obtained using Homotopy perturbation method for all values of parameters. These approximate analytical results were found to be in good agreement with the simulation results. 展开更多
关键词 two-point ELLIPTIC Boundary Value Problems Bratu’s Equation Troesch’s Problem NON-LINEAR Equations HOMOTOPY PERTURBATION Method Porous Catalyst Numerical Simulation
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A study on the surface overpressure distribution and formation of a double curvature liner under a two-point initiation
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作者 Jie Liu Xi Chen Zhong-hua Du 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2022年第1期148-157,共10页
The formation mechanism of an EFP(explosively formed projectile)using a double curvature liner under the overpressure effect generated by a regular oblique reflection was investigated in this paper.Based on the detona... The formation mechanism of an EFP(explosively formed projectile)using a double curvature liner under the overpressure effect generated by a regular oblique reflection was investigated in this paper.Based on the detonation wave propagation theory,the change of the incident angle of the detonation wave collision at different positions and the distribution area of the overpressure on the surface of the liner were calculated.Three dimensional numerical simulations of the formation process of the EFP with tail.as well as the ability to penetrate 45#steel were performed using LS-DYNA software,and the EFP ve locity,the penetration ability,and the forming were assessed via experiments and x_ray photographs.The experimental results coincides with those of the simulations.Results indicate that the collision of the detonation wave was controlled to be a regular oblique reflection acting on the liner by setting the di-mensions of the unit charge and maintai ning the pressure at the collision point region at more than 2.4 times the CJ detonation when the incident angle approached the cnitical angle.The distance from the liner midline to the boundary of the area within which the pressure ratio of the regular oblique reflection pressure to the qJ detonation pressure was greater than 2.5,2,and 15was approximately 0.66 mm,132 mm,and 3.3 mm,respectively.Itis noted that pressure gradient caused the liner to turn inside out in the middle to form the head of the EFP and close the two tails of the EFP at approximately 120μs.The penetration depth of the EFP into a 45#steel target exceeded 30 mm,and there was radial expansion between the head and tail of the EFP,increasing the penetration resistance of the EFP.Therefore,the structural size of the unit charge and the liner can be further optimized to reduce resist ance to increase the penetration ability of the EFP. 展开更多
关键词 Unit-shaped charge Double curvature liner Regular oblique reflection two-point initiation Pene tra tion Numerical simulation
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A Pseudo-Spectral Scheme for Systems of Two-Point Boundary Value Problems with Left and Right Sided Fractional Derivatives and Related Integral Equations
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作者 I.G.Ameen N.A.Elkot +2 位作者 M.A.Zaky A.S.Hendy E.H.Doha 《Computer Modeling in Engineering & Sciences》 SCIE EI 2021年第7期21-41,共21页
We target here to solve numerically a class of nonlinear fractional two-point boundary value problems involving left-and right-sided fractional derivatives.The main ingredient of the proposed method is to recast the p... We target here to solve numerically a class of nonlinear fractional two-point boundary value problems involving left-and right-sided fractional derivatives.The main ingredient of the proposed method is to recast the problem into an equivalent system of weakly singular integral equations.Then,a Legendre-based spectral collocation method is developed for solving the transformed system.Therefore,we can make good use of the advantages of the Gauss quadrature rule.We present the construction and analysis of the collocation method.These results can be indirectly applied to solve fractional optimal control problems by considering the corresponding Euler–Lagrange equations.Two numerical examples are given to confirm the convergence analysis and robustness of the scheme. 展开更多
关键词 Spectral collocation method weakly singular integral equations two-point boundary value problems convergence analysis
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Existence of Solutions of Two-Point Boundary Value Problems for 4n th-Order Nonlinear Differential Equation
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作者 高永馨 石新华 《Transactions of Tianjin University》 EI CAS 2004年第2期158-161,共4页
By using the method of upper and lower solution, some conditions of the existence of solutions of nonlinear two-point boundary value problems for 4nth-order nonlinear differential equation are studied.
关键词 nth-order nonlinear differential equation nonlinear two-point boundary value problem existence of solutions
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Numerical Solution of Singularly Perturbed Two-Point Boundary Value Problem via Liouville-Green Transform
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作者 Hradyesh Kumar Mishra Sonali Saini 《American Journal of Computational Mathematics》 2013年第1期1-5,共5页
In this paper, authors describe a Liouville-Green transform to solve a singularly perturbed two-point boundary value problem with right end boundary layer in the interval [0, 1]. They reply Liouville-Green transform i... In this paper, authors describe a Liouville-Green transform to solve a singularly perturbed two-point boundary value problem with right end boundary layer in the interval [0, 1]. They reply Liouville-Green transform into original given problem and finds the numerical solution. Then they implemented this method on two linear examples with right end boundary layer which nicely approximate the exact solution. 展开更多
关键词 Singular Perturbation Ordinary Differential Equation BOUNDARY Layer two-point BOUNDARY Value Problem Liouville-Green TRANSFORM
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