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High-Order Spatial FDTD Solver of Maxwell’s Equations for Terahertz Radiation Production
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作者 Abdelrahman Mahdy 《Journal of Applied Mathematics and Physics》 2024年第4期1028-1042,共15页
We applied a spatial high-order finite-difference-time-domain (HO-FDTD) scheme to solve 2D Maxwell’s equations in order to develop a fluid model employed to study the production of terahertz radiation by the filament... We applied a spatial high-order finite-difference-time-domain (HO-FDTD) scheme to solve 2D Maxwell’s equations in order to develop a fluid model employed to study the production of terahertz radiation by the filamentation of two femtosecond lasers in air plasma. We examined the performance of the applied scheme, in this context, we implemented the developed model to study selected phenomena in terahertz radiation production, such as the excitation energy and conversion efficiency of the produced THz radiation, in addition to the influence of the pulse chirping on properties of the produced radiation. The obtained numerical results have clarified that the applied HO-FDTD scheme is precisely accurate to solve Maxwell’s equations and sufficiently valid to study the production of terahertz radiation by the filamentation of two femtosecond lasers in air plasma. 展开更多
关键词 The Finite-Difference-Time-Domain Terahertz Radiation production Filamentation of Femtosecond Laser Maxwell’s equations Solution
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GLOBAL CLASSICAL SOLUTIONS OF SEMILINEAR WAVE EQUATIONS ON R^(3)×T WITH CUBIC NONLINEARITIES
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作者 陶飞 《Acta Mathematica Scientia》 SCIE CSCD 2024年第1期115-128,共14页
In this paper,we establish global classical solutions of semilinear wave equations with small compact supported initial data posed on the product space R^(3)×T.The semilinear nonlinearity is assumed to be of the ... In this paper,we establish global classical solutions of semilinear wave equations with small compact supported initial data posed on the product space R^(3)×T.The semilinear nonlinearity is assumed to be of the cubic form.The main ingredient here is the establishment of the L^(2)-L^(∞)decay estimates and the energy estimates for the linear problem,which are adapted to the wave equation on the product space.The proof is based on the Fourier mode decomposition of the solution with respect to the periodic direction,the scaling technique,and the combination of the decay estimates and the energy estimates. 展开更多
关键词 semilinear wave equation product space decay estimate energy estimate global solution
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Assessment of Relationship of Some Causal Factors Associated with Productivity of Longwall Mining Using Structured Equation Modeling
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作者 Sidharth Talan Ashis Bhattacherjee 《Journal of Minerals and Materials Characterization and Engineering》 2021年第4期375-389,共15页
Enhancement of productivity optimization is steadily gaining the priority in mining companies especially in the underground coal mining industry which faces a daunting task to balance marginal profit generation with a... Enhancement of productivity optimization is steadily gaining the priority in mining companies especially in the underground coal mining industry which faces a daunting task to balance marginal profit generation with a comparatively high cost of production, volatile market price and rapid grade variation. This paper is aimed to analyze some of the causal factors both technical and site specific which are directly or indirectly impacting the productivity of the longwall coal mining system such as downtime of equipment system in longwall panel, overloading of conveyors and bin, preventive maintenance, gas management practices and injury severity rate. Structured Equation Modelling (SEM) was used to study the causal relationships between the above-mentioned factors and mine productivity. The equipment considered for analysis included shearer, armored face conveyor, crusher, bridge stage loader, chock supports, main gate drive, gate conveyor, hydraulic pumps and crusher. SEM was applied to relate the correlations existing among these causal variables in order to assess their direct or indirect impact on mining productivity. Based on the data extracted over a period of 10 months which included the extraction of 2 longwall panels, the study revealed a significant negative causal relationship between injury severity rate (p < 0.01) and equipment downtime (p = 0.001), with mine productivity. However, preventive maintenance delay time, gas management delay time and conveyor overloading delay time were found to have an insignificant direct influence on mine productivity but indirectly modify it through a significant mediator relationship with equipment downtime. This information would assist mine management to take proper preventive measures. 展开更多
关键词 Structured equation Modelling Longwall Mining Operational Equipment productivity
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Coupling Relationship Analysis on Households′ Production Behaviors and Their Influencing Factors in Nature Reserves:A Structural Equation Model 被引量:6
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作者 WANG Changhai WEN Yali +1 位作者 DUAN Wei HAN Feng 《Chinese Geographical Science》 SCIE CSCD 2013年第4期506-518,共13页
A households′production behavior directly influences the quality of the environment and determines the successful development of nature reserves.Meanwhile,the households′production behaviors are complicated by inter... A households′production behavior directly influences the quality of the environment and determines the successful development of nature reserves.Meanwhile,the households′production behaviors are complicated by interrelated factors,such as protection attitudes,resource endowment,and family wealth.This research evaluated households near the Crested Ibis National Nature Reserve in Shaanxi Province,acquiring data from 436 households around Yang County and Ningshan County in the south slope of Qinling Mountains,China.Based on the collected data,we developed a structural equation model to evaluate the coupling relationships among households′ protection attitudes,production behaviors,resource endowment,and family wealth.The results showed that:1) households with great resource endowment had more negative attitudes,probably due to their greater protection costs;2) the households with higher education levels had worse protection attitudes;3) the households with more family wealth were likely to use fewer fertilizers,pesticides,and firewood;4) the households with more resource endowment showed less production and management behaviors;5) the enhancement of households' attitudes improved production behaviors to protection the environment,but the effects were not statistically significant.Our results provide a basis for the government's protection policy making,exploring the effective management measures that are beneficial for both nature reserve management and community development. 展开更多
关键词 family wealth protection attitudes production behaviors resource endowment structural equation model Crested Ibis National Nature Reserve
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Intuitionistic Menger inner product spaces and applications to integral equations
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作者 张石生 M.GOUDARZI +1 位作者 R.SAADATI S.M.VAEZPOUR 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2010年第4期415-424,共10页
In this paper, first introduce and define an intuitionistic Menger inner product space, and then, obtain a new fixed point theorem in a complete intuitionistic Menger inner product space. As an application, the result... In this paper, first introduce and define an intuitionistic Menger inner product space, and then, obtain a new fixed point theorem in a complete intuitionistic Menger inner product space. As an application, the results are used to study the existence and uniqueness of the solution to a linear Volterra integral equation. 展开更多
关键词 intuitionistic Menger inner product space Volterra integral equation h-type t-norm fixed point theorem
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Two Dimensional Tensor Product B-Spline Wavelet Scaling Functions for the Solution of Two-Dimensional Unsteady Diffusion Equations
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作者 XIONG Lei LI haijiao ZHANG Lewen 《Journal of Ocean University of China》 SCIE CAS 2008年第3期258-262,共5页
The fourth-order B spline wavelet scaling functions are used to solve the two-dimensional unsteady diffusion equation. The calculations from a case history indicate that the method provides high accuracy and the compu... The fourth-order B spline wavelet scaling functions are used to solve the two-dimensional unsteady diffusion equation. The calculations from a case history indicate that the method provides high accuracy and the computational efficiency is enhanced due to the small matrix derived from this method.The respective features of 3-spline wavelet scaling functions,4-spline wavelet scaling functions and quasi-wavelet used to solve the two-dimensional unsteady diffusion equation are compared. The proposed method has potential applications in many fields including marine science. 展开更多
关键词 wavelet analysis B-spline wavelet tensor product RESOLUTION diffusion equations
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A New Method to Construct Integrable Coupling System for Burgers Equation Hierarchy by Kronecker Product
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作者 YU Fa-Jun LI Li 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第1期23-26,共4页
It is shown that the Kronecker product can be applied to construct a new integrable coupling system of soliton equation hierarchy in this paper. A direct application to the Burgers spectral problem leads to a novel so... It is shown that the Kronecker product can be applied to construct a new integrable coupling system of soliton equation hierarchy in this paper. A direct application to the Burgers spectral problem leads to a novel soliton equation hierarchy of integrable coupling system. It indicates that the Kronecker product is an efficient and straightforward method to construct the integrable couplings. 展开更多
关键词 Kronecker product integrable coupling system soliton equation hierarchy
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Mathematical Equations for Reducing Water Pollution Problems among Poultry Production Clusters in Nong Khai Province, Thailand
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作者 Worapol Aengwanich Thongchai Boonsorn Komvut Thammasar 《Journal of Geoscience and Environment Protection》 2014年第2期48-51,共4页
Poultry production clusters (PPC) in Nong Khai raise layer chickens in the poultry houses constructed over fish ponds. Layer farmers use chicken manure to feed their fish. However, unbalance between chicken raising an... Poultry production clusters (PPC) in Nong Khai raise layer chickens in the poultry houses constructed over fish ponds. Layer farmers use chicken manure to feed their fish. However, unbalance between chicken raising and the size of fish pond or number of fish results in low water quality, which affects fish production and the community’s public water resource. In this field study, data was collected from layer farms in three poultry production clusters in Nong Khai province in the northeast of Thailand (a total of 90 farms) between April and August 2013. Data collected consisted of observations of dissolved oxygen (DO) values of water in the fish ponds, the number of egg-laying chickens raised above the fish ponds, the number of fish and size of the fish ponds. When all of these four observations were analyzed, mathematical equations for calculating the number of chickens raised, the number of fish per one rai (1600 m2), and the size of pond suitable for the number of chickens and fish were obtained as follows: 1) number of fish/rai = 5796 + 1097(size of pond) (R2 = 0.71), 2) number of chicken/rai = 513 + 223(size of pond) (R2 = 0.48) and 3) size of pond =-0.328474 + 0.000262(Fish) + 0.00117(Chicken) (R2 = 0.40). When pond = desired pond size, fish = number of fish to be raised and chicken = number of chickens to be raised. 展开更多
关键词 Mathematic equation Water Pollution POULTRY production CLUSTERS PPCS FISH POND Thailand
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Tree Network Formation in Poisson Equation Models and the Implications for the Maximum Entropy Production Principle
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作者 Hiroshi Serizawa Takashi Amemiya Kiminori Itoh 《Natural Science》 2014年第7期514-527,共14页
This paper presents not only practical but also instructive mathematical models to simulate tree network formation using the Poisson equation and the Finite Difference Method (FDM). Then, the implications for entropic... This paper presents not only practical but also instructive mathematical models to simulate tree network formation using the Poisson equation and the Finite Difference Method (FDM). Then, the implications for entropic theories are discussed from the viewpoint of Maximum Entropy Production (MEP). According to the MEP principle, open systems existing in the state far from equilibrium are stabilized when entropy production is maximized, creating dissipative structures with low entropy such as the tree-shaped network. We prepare two simulation models: one is the Poisson equation model that simulates the state far from equilibrium, and the other is the Laplace equation model that simulates the isolated state or the state near thermodynamic equilibrium. The output of these equations is considered to be positively correlated to entropy production of the system. Setting the Poisson equation model so that entropy production is maximized, tree network formation is advanced. We suppose that this is due to the invocation of the MEP principle, that is, entropy of the system is lowered by emitting maximal entropy out of the system. On the other hand, tree network formation is not observed in the Laplace equation model. Our simulation results will offer the persuasive evidence that certifies the effect of the MEP principle. 展开更多
关键词 DISSIPATIVE Structure Far from Equilibrium Fractal POISSON equation Maximum ENTROPY productION (MEP) PRINCIPLE Minimum ENTROPY productION (MinEP) PRINCIPLE Tree Network
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Constructing New Discrete Integrable Coupling System for Soliton Equation by Kronecker Product
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作者 YU Fa-Jun ZHANG Hong-Qing 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第9期561-564,共4页
It is shown that the Kronecker product can be applied to constructing new discrete integrable couplingsystem of soliton equation hierarchy in this paper.A direct application to the fractional cubic Volterra lattice sp... It is shown that the Kronecker product can be applied to constructing new discrete integrable couplingsystem of soliton equation hierarchy in this paper.A direct application to the fractional cubic Volterra lattice spectralproblem leads to a novel integrable coupling system of soliton equation hierarchy.It is also indicated that the study ofdiscrete integrable couplings by using the Kronecker product is an efficient and straightforward method.This methodcan be used generally. 展开更多
关键词 Kronecker product fractional cubic Volterra lattice equation discrete integrable couplings
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The Exact Solutions of Such Coupled Linear Matrix Fractional Differential Equations of Diagonal Unknown Matrices by Using Hadamard Product
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作者 Zayed Al-Zuhiri Zeyad Al-Zhour Khaled Jaber 《Journal of Applied Mathematics and Physics》 2016年第2期432-442,共11页
In this paper, we present the general exact solutions of such coupled system of matrix fractional differential equations for diagonal unknown matrices in Caputo sense by using vector extraction operators and Hadamard ... In this paper, we present the general exact solutions of such coupled system of matrix fractional differential equations for diagonal unknown matrices in Caputo sense by using vector extraction operators and Hadamard product. Some illustrated examples are also given to show our new approach. 展开更多
关键词 Fractional Operators Matrix Fractional Differential equations Hadamard product Vector Extraction Operator
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On the Product of Integro Differential Equations and Their Solutions in Direct Sum Spaces
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作者 Sobhy El-sayed Ibrahim 《Journal of Mathematics and System Science》 2013年第5期231-245,共15页
In this paper, we consider a general quasi-differential expressions t1,t2 Tn, each of order n with complex coefficients and their formal adjoints are t1+,t2+- x+ on [0, b) respectively. We show in the direct sum s... In this paper, we consider a general quasi-differential expressions t1,t2 Tn, each of order n with complex coefficients and their formal adjoints are t1+,t2+- x+ on [0, b) respectively. We show in the direct sum spaces LZ(Ip), p = 1,2 N of functions defined on each of the separate intervals with the case of one singular end-points and under suitable conditions on the function F that all solutions of the product quasi-integro differential equations are bounded and LZw -bounded on [0,b). 展开更多
关键词 Quasi-integro differential equation product differential expressions direct sum spaces bounded and square integrablesolutions.
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Calculation of Combustion Products by the New Iteration Method of Non-linear Equations
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作者 Paramust Juntarakod Thanakom Soontomchainacksaeng 《Journal of Mathematics and System Science》 2013年第1期15-25,共11页
For a specific combustion problem involving calculations of several species at the equilibrium state, it is simpler to write a general computer program and calculate the combustion concentration. Original work describ... For a specific combustion problem involving calculations of several species at the equilibrium state, it is simpler to write a general computer program and calculate the combustion concentration. Original work describes, an adaptation of Newton-Raphson method was used for solving the highly nonlinear system of equations describing the formation of equilibrium products in reacting of fuel-additive-air mixtures. This study also shows what possible of the results. In this paper, to be present the efficient numerical algorithms for. solving the combustion problem, to be used nonlinear equations based on the iteration method and high order of the Taylor series. The modified Adomian decomposition method was applied to construct the numerical algorithms. Some numerical illustrations are given to show the efficiency of algorithms. Comparisons of results by the new Matlab routines and previous routines, the result data indicate that the new Matlab routines are reliable, typical deviations from previous results are less than 0.05%. 展开更多
关键词 Non-linear equation Newton-Raphson method Adomian decomposition method Householder's iteration method highorder iteration method chemical equilibrium fuel and combustion products.
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Movement Differential Equation of Seed Roller which Has Been Installed Stake Accelerator on the Roll Box of Gin Machine 被引量:7
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作者 Sarimsakov Akramjon Muradov Rustam +1 位作者 Umarov Akmal Kurbanov Dilmurat 《Engineering(科研)》 2018年第8期521-529,共9页
In the article stake accelerator has proposed on the side of the roll box in order to increase the productivity of the gin machine. The effect to the raw material of the proposed stakes was studied. Movement different... In the article stake accelerator has proposed on the side of the roll box in order to increase the productivity of the gin machine. The effect to the raw material of the proposed stakes was studied. Movement differential equation of the seed roller was made up and necessary graphics were taken based on laws. 展开更多
关键词 The Cotton Gin SEED Fiber Saw Gridiron ROLL Box SEED ROLLER Speed Quality Efficiency productivity equation Pressure Density Strength
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ON HYPERSTABILITY OF THE BIADDITIVE FUNCTIONAL EQUATION 被引量:1
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作者 Iz-iddine EL-FASSI Janusz BRZDEK +1 位作者 Abdellatif CHAHBI Samir KABBAJ 《Acta Mathematica Scientia》 SCIE CSCD 2017年第6期1727-1739,共13页
We present results on approximate solutions to the biadditive equationf(x+y,z-w)+f(x-y,z+w)=2f(x,z)-2f(y,w)on a restricted domain. The proof is based on a quite recent fixed point theorem in some function s... We present results on approximate solutions to the biadditive equationf(x+y,z-w)+f(x-y,z+w)=2f(x,z)-2f(y,w)on a restricted domain. The proof is based on a quite recent fixed point theorem in some function spaces. Our main results state that, under some weak natural assumptions, functions satisfying the equation approximately (in some sense) must be actually solutions to it. In this way we obtain inequalities characterizing biadditive mappings and inner product spaces. Our outcomes are connected with the well known issues of Ulam stability and hyperstability. 展开更多
关键词 HYPERSTABILITY Ulam stability biadditive functional equation fixed point the-orem characterization of inner product space
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Master equation describing the diffusion process for a coherent state 被引量:1
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作者 刘堂昆 单传家 +1 位作者 刘继兵 范洪义 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第3期112-114,共3页
The evolution of a pure coherent state into a chaotic state is described very well by a master equation, as is validated via an examination of the coherent state's evolution during the diffusion process, fully utiliz... The evolution of a pure coherent state into a chaotic state is described very well by a master equation, as is validated via an examination of the coherent state's evolution during the diffusion process, fully utilizing the technique of integration within an ordered product (IWOP) of operators. The same equation also describes a limitation that maintains the coherence in a weak diffusion process, i.e., when the dissipation is very weak and the initial average photon number is large. This equation is dp/dt = -κ[a+ap -a+pa -apa+ + paa+]. The physical difference between this diffusion equation and the better-known amplitude damping master equation is pointed out. 展开更多
关键词 master equation describing diffusion coherent state evolution chaotic state integration within anordered product (IWOP) of operators
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On a Matrix Equation AX+XB=C over a Skew Field 被引量:1
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作者 王卿文 秦建国 《Chinese Quarterly Journal of Mathematics》 CSCD 1993年第3期97-102,共6页
In this paper we study a matrix equation AX+BX=C(I)over an arbitrary skew field,and give a consistency criterion of(I)and an explicit expression of general solutions of(I).A convenient,simple and practical method of s... In this paper we study a matrix equation AX+BX=C(I)over an arbitrary skew field,and give a consistency criterion of(I)and an explicit expression of general solutions of(I).A convenient,simple and practical method of solving(I)is also given.As a particular case,we also give a simple method of finding a system of fundamental solutions of a homogeneous system of right linear equations over a skew field. 展开更多
关键词 matrix equation over a skew field fundamental system of solutions basic solution matrix subdirect product homogeneous system of right linear equations
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MAURER-CARTAN EQUATION OF A_∞-ALGEBRAS
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作者 HeJiwei 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2004年第1期27-36,共10页
The axioms of A ∞ algebras can be written as Maurer Cartan equation.Infi nitesimal multiplication of a graded associative algebra is defined and the integrability of infinitesimal multiplication is discussed throu... The axioms of A ∞ algebras can be written as Maurer Cartan equation.Infi nitesimal multiplication of a graded associative algebra is defined and the integrability of infinitesimal multiplication is discussed through the Massey F product. 展开更多
关键词 minimal A algebra Maurer Cartan equation Massey F product infinitesimal multiplication integrability.
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Parameterized Solution to a Class of Sylvester Matrix Equations
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作者 Yu-Peng Qiao Hong-Sheng Qi Dai-Zhan Cheng 《International Journal of Automation and computing》 EI 2010年第4期479-483,共5页
A class of formulas for converting linear matrix mappings into conventional linear mappings are presented. Using them, an easily computable numerical method for complete parameterized solutions of the Sylvester matrix... A class of formulas for converting linear matrix mappings into conventional linear mappings are presented. Using them, an easily computable numerical method for complete parameterized solutions of the Sylvester matrix equation AX - EXF = BY and its dual equation XA - FXE = YC are provided. It is also shown that the results obtained can be used easily for observer design. The method proposed in this paper is universally applicable to linear matrix equations. 展开更多
关键词 Sylvester matrix equation parameterized solution Kronecker product linear matrix equation Luenberger observers
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AUTOMATIC AUGMENTED GALERKIN ALGORITHMS FOR FREDHOLM INTEGRAL EQUATIONS OF THE FIRST KIND
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作者 S.Abbasbandy E.Babolian 《Acta Mathematica Scientia》 SCIE CSCD 1997年第1期69-84,共16页
In recent papers, Babolian & Delves [2] and Belward[3] described a Chebyshev series method for the solution of first kind integral equations. The expansion coefficients of the solution are determined as the soluti... In recent papers, Babolian & Delves [2] and Belward[3] described a Chebyshev series method for the solution of first kind integral equations. The expansion coefficients of the solution are determined as the solution of a mathematical programming problem.The method involves two regularization parameters, Cf and r, but values assigned to these parameters are heuristic in nature. Essah & Delves[7] described an algorithm for setting these parameters automatically, but it has some difficulties. In this paper we describe three iterative algorithms for computing these parameters for singular and non-singular first kind integral equations. We give also error estimates which are cheap to compute. Finally, we give a number of numerical examples showing that these algorithms work well in practice. 展开更多
关键词 Fredholm integral equations Galerkin method Regularization parameters Error estimation Ill-Posed problems product of chebyshev series
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