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2-D NONSEPARABLE SCALING FUNCTIONINTERPOLATION AND APPROXIMATION 被引量:1
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作者 En-Bing, Lin Yi Ling (Department of Mathematics. University of Toledo, Toledo, OH .43606, USA) 《Acta Mathematica Scientia》 SCIE CSCD 2002年第1期19-31,共13页
The authors introduce nonseparable scaling function interpolation and show that its approximation can provide similar convergence properties as scalar wavelet system. Several equivalent statements of accuracy of nonse... The authors introduce nonseparable scaling function interpolation and show that its approximation can provide similar convergence properties as scalar wavelet system. Several equivalent statements of accuracy of nonseparable scaling function are also given. In the numerical experiments, it appears that nonseparable scaling function interpolation has better convergence results than scalar wavelet systems in some cases. 展开更多
关键词 WAVELETS nonseparable scaling function interpolation accuracy of scaling function. 2-D MRA
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A comparison of piecewise cubic Hermite interpolating polynomials,cubic splines and piecewise linear functions for the approximation of projectile aerodynamics 被引量:4
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作者 C.A.Rabbath D.Corriveau 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2019年第5期741-757,共17页
Modelling and simulation of projectile flight is at the core of ballistic computer software and is essential to the study of performance of rifles and projectiles in various engagement conditions.An effective and repr... Modelling and simulation of projectile flight is at the core of ballistic computer software and is essential to the study of performance of rifles and projectiles in various engagement conditions.An effective and representative numerical model of projectile flight requires a relatively good approximation of the aerodynamics.The aerodynamic coefficients of the projectile model should be described as a series of piecewise polynomial functions of the Mach number that ideally meet the following conditions:they are continuous,differentiable at least once,and have a relatively low degree.The paper provides the steps needed to generate such piecewise polynomial functions using readily available tools,and then compares Piecewise Cubic Hermite Interpolating Polynomial(PCHIP),cubic splines,and piecewise linear functions,and their variant,as potential curve fitting methods to approximate the aerodynamics of a generic small arms projectile.A key contribution of the paper is the application of PCHIP to the approximation of projectile aerodynamics,and its evaluation against a set of criteria.Finally,the paper provides a baseline assessment of the impact of the polynomial functions on flight trajectory predictions obtained with 6-degree-of-freedom simulations of a generic projectile. 展开更多
关键词 Aerodynamic coefficients PIECEWISE POLYNOMIAL functionS CUBIC splines Curve fitting PIECEWISE linear functionS PIECEWISE CUBIC HERMITE interpolating POLYNOMIAL PROJECTILE modelling and simulation Fire control inputs Precision Ballistic computer software
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INTERPOLATION OF LORENTZ-ORLICZ MARTINGALE SPACES 被引量:3
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作者 张传洲 潘誉 张学英 《Acta Mathematica Scientia》 SCIE CSCD 2015年第6期1467-1474,共8页
In this paper, we apply function parameters to real interpolation of Lorentz- Orlicz martingale spaces. Some new interpolation theorems are formulated which generalize some known results in Lorentz spaces An introduce... In this paper, we apply function parameters to real interpolation of Lorentz- Orlicz martingale spaces. Some new interpolation theorems are formulated which generalize some known results in Lorentz spaces An introduced by Sharpley. 展开更多
关键词 MARTINGALE Lorentz-Orlicz space interpolation function parameter
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UNIVERSAL INTERPOLATING SEQUENCES ON SPACES OF ANALYTIC FUNCTIONS 被引量:1
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作者 B.Yousefi 《Acta Mathematica Scientia》 SCIE CSCD 2011年第1期68-72,共5页
This article derives the relation between universal interpolating sequences and some spectral properties of the multiplication operator by the independent variable z in case the underlying space is a Hilbert space of ... This article derives the relation between universal interpolating sequences and some spectral properties of the multiplication operator by the independent variable z in case the underlying space is a Hilbert space of functions analytic on the open unit disk. 展开更多
关键词 Hilbert spaces of analytic functions universal interpolating sequence multiplication operator invariant subspaces spectral properties
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An improved local radial point interpolation method for transient heat conduction analysis
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作者 王峰 林皋 +1 位作者 郑保敬 胡志强 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第6期127-134,共8页
The smoothing thin plate spline (STPS) interpolation using the penalty function method according to the optimization theory is presented to deal with transient heat conduction problems. The smooth conditions of the ... The smoothing thin plate spline (STPS) interpolation using the penalty function method according to the optimization theory is presented to deal with transient heat conduction problems. The smooth conditions of the shape functions and derivatives can be satisfied so that the distortions hardly occur. Local weak forms are developed using the weighted residual method locally from the partial differential equations of the transient heat conduction. Here the Heaviside step function is used as the test function in each sub-domain to avoid the need for a domain integral. Essential boundary conditions can be implemented like the finite element method (FEM) as the shape functions possess the Kronecker delta property. The traditional two-point difference method is selected for the time discretization scheme. Three selected numerical examples are presented in this paper to demonstrate the availability and accuracy of the present approach comparing with the traditional thin plate spline (TPS) radial basis functions. 展开更多
关键词 thin plate splines transient heat conduction penalty function method local radial point interpolation method
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A GENERALIZATION OF BOYD’S INTERPOLATION THEOREM
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作者 Kwok-Pun HO 《Acta Mathematica Scientia》 SCIE CSCD 2021年第4期1263-1274,共12页
Boyd^interpolation theorem for quasilinear operators is generalized in this paper,which gives a generalization for both the Marcinkiewicz interpolation theorem and Boyd^interpolation theorem.By using this new interpol... Boyd^interpolation theorem for quasilinear operators is generalized in this paper,which gives a generalization for both the Marcinkiewicz interpolation theorem and Boyd^interpolation theorem.By using this new interpolation theorem,we study the spherical fractional maximal functions and the fractional maximal commutators on rearrangement-invariant quasi-Banach function spaces.In particular,we obtain the mapping properties of the spherical fractional maximal functions and the fractional maximal commutators on generalized Lorentz spaces. 展开更多
关键词 interpolation of operator quasilinear operator rearrangement-invariant function space spherical fractional maximal function fractional maximal commutator generalized Lorentz space
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The Mean Convergence Order of Extended Hermite-Fejér Interpolation Operators
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作者 文成林 田继善 《Chinese Quarterly Journal of Mathematics》 CSCD 1997年第4期70-74, ,共5页
Weighted Lp mean convergence of Extended Hermite-Fejer operators based on the zeros of orthogonal polynomials with respct to the general weight and Jacobi weight is investigated. Suf ficient conditions for such conve... Weighted Lp mean convergence of Extended Hermite-Fejer operators based on the zeros of orthogonal polynomials with respct to the general weight and Jacobi weight is investigated. Suf ficient conditions for such convergence for all continuous functions are given. 展开更多
关键词 interpolation orthogonal polynomial weight function mean convergence
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COMPLEX INTERPOLATION OF L_(p)(C,H)SPACES WITH RESPECT TO CULLEN-REGULAR
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作者 Kaili HE Jianxun HE Zhenzhen LOU 《Acta Mathematica Scientia》 SCIE CSCD 2022年第2期774-788,共15页
The aim of this paper is to prove a new version of the Riesz-Thorin interpolation theorem on L^(P)(C,H).In the sense of Cullen-regular,we show Hadamard’s three-lines theorem by means of the Maximum modulus principle ... The aim of this paper is to prove a new version of the Riesz-Thorin interpolation theorem on L^(P)(C,H).In the sense of Cullen-regular,we show Hadamard’s three-lines theorem by means of the Maximum modulus principle on a symmetric slice domain.In addition,two applications of the Riesz-Thorin theorem are presented.Finally,we investigate two kinds of Calderón’s complex interpolation methods in LP(C,H). 展开更多
关键词 Hadamard’s three-lines theorem complex interpolation quaternion valued function space Cullen-regular
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基于ICESat-2/ATLAS的景东彝族自治县森林生物量估测研究
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作者 饶昕 舒清态 +2 位作者 王继雄 罗绍龙 杨正道 《西南林业大学学报(自然科学)》 北大核心 2025年第2期159-168,共10页
以云南省景东彝族自治县为研究区,星载激光雷达ICESat-2/ATLAS为主要信息源,在对ATLAS数据进行去噪和分类的基础上,基于地统计学的克里格插值实现ATLAS光子参数指标点由“点”到“面”的空间扩展,结合地面265块生物量调查样地,建立研究... 以云南省景东彝族自治县为研究区,星载激光雷达ICESat-2/ATLAS为主要信息源,在对ATLAS数据进行去噪和分类的基础上,基于地统计学的克里格插值实现ATLAS光子参数指标点由“点”到“面”的空间扩展,结合地面265块生物量调查样地,建立研究区森林生物量估测模型。结果表明:基于随机森林重要性排序,ATLAS光子与森林生物量具有较强相关性的5个参数为最大冠层高度、平均冠层高度、光子关联参数、太阳高度角、太阳方向角。对5个参数进行变异函数分析,根据决定系数和空间自相关性选择最优变异函数模型,最大冠层高度、太阳高度角、太阳方向角3种参数以球状模型进行空间插值效果最优,平均冠层高度、光子关联参数2种参数以指数模型效果最优。以地面265块样地地上生物量为被解释变量,对应的5种参数为解释变量,基于随机森林回归,建立了研究区森林生物量遥感估测模型,建模精度R^(2)=0.794 1、RMSE=23.004 7 t/hm^(2),可作为研究区森林地上生物量估测模型。基于验证后的RF模型估测研究区森林生物总量,估计值为31 269 874.76 t,估测精度为85.3%,与实际计算结果空间分布基本一致,表明基于ICESat-2/ATLAS数据进行森林生物量估测有较好效果。 展开更多
关键词 ICESat-2/ATLAS 特征优选 变异函数 克里格插值 随机森林 生物量
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A meshless model for transient heat conduction analyses of 3D axisymmetric functionally graded solids 被引量:3
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作者 李庆华 陈莘莘 曾骥辉 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第12期51-57,共7页
A meshless numerical model is developed for analyzing transient heat conductions in three-dimensional (3D) axisymmetric continuously nonhomogeneous functionally graded materials (FGMs). Axial symmetry of geometry ... A meshless numerical model is developed for analyzing transient heat conductions in three-dimensional (3D) axisymmetric continuously nonhomogeneous functionally graded materials (FGMs). Axial symmetry of geometry and boundary conditions reduces the original 3D initial-boundary value problem into a two-dimensional (2D) problem. Local weak forms are derived for small polygonal sub-domains which surround nodal points distributed over the cross section. In order to simplify the treatment of the essential boundary conditions, spatial variations of the temperature and heat flux at discrete time instants are interpolated by the natural neighbor interpolation. Moreover, the using of three-node triangular finite element method (FEM) shape functions as test functions reduces the orders of integrands involved in domain integrals. The semi-discrete heat conduction equation is solved numerically with the traditional two-point difference technique in the time domain. Two numerical examples are investigated and excellent results are obtained, demonstrating the potential application of the proposed approach. 展开更多
关键词 meshless method transient heat conduction problem axisymmetric functionally graded materials natural neighbor interpolation
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Static and free vibration analyses of functionally graded porous variable-thickness plates using an edge-based smoothed finite element method 被引量:3
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作者 Trung Thanh Tran Quoc-Hoa Pham Trung Nguyen-Thoi 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2021年第3期971-986,共16页
The main purpose of this paper is to present numerical results of static bending and free vibration of functionally graded porous(FGP) variable-thickness plates by using an edge-based smoothed finite element method(ES... The main purpose of this paper is to present numerical results of static bending and free vibration of functionally graded porous(FGP) variable-thickness plates by using an edge-based smoothed finite element method(ES-FEM) associate with the mixed interpolation of tensorial components technique for the three-node triangular element(MITC3), so-called ES-MITC3. This ES-MITC3 element is performed to eliminate the shear locking problem and to enhance the accuracy of the existing MITC3 element. In the ES-MITC3 element, the stiffness matrices are obtained by using the strain smoothing technique over the smoothing domains formed by two adjacent MITC3 triangular elements sharing an edge. Materials of the plate are FGP with a power-law index(k) and maximum porosity distributions(U) in the forms of cosine functions. The influences of some geometric parameters, material properties on static bending, and natural frequency of the FGP variable-thickness plates are examined in detail. 展开更多
关键词 functionally graded porous(FGP)plates Edge-based smoothed finite element method(ES-FEM) Mixed interpolation of tensorial components(MITC) Static bending Free vibration
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The choosing of reproducing kernel particle shape function with mathematic proof
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作者 夏茂辉 李金 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第10期3067-3071,共5页
Many mechanical problems can be induced from differential equations with boundary conditions; there exist analytic and numerical methods for solving the differential equations. Usually it is not so easy to obtain anal... Many mechanical problems can be induced from differential equations with boundary conditions; there exist analytic and numerical methods for solving the differential equations. Usually it is not so easy to obtain analytic solutions. So it is necessary to give numerical solutions. The reproducing kernel particle (RKP) method is based on the Carlerkin Meshless method. According to the Sobolev space and Fourier transform, the RKP shape function is mathematically proved in this paper. 展开更多
关键词 point of interpolation PARTICLE reproducing kernel particle shape function
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UNIFORM APPROXIMATION OF ENTIRE FUNCTIONS OF SLOW GROWTH ON COMPACT SETS
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作者 G.S.Srivastava S.Kuma 《Acta Mathematica Scientia》 SCIE CSCD 2012年第6期2401-2410,共10页
In the present paper, we study the polynomial approximation of entire functions of several complex variables. The characterizations of generalized order and generalized type of entire functions of slow growth are obta... In the present paper, we study the polynomial approximation of entire functions of several complex variables. The characterizations of generalized order and generalized type of entire functions of slow growth are obtained in terms of approximation and interpolation errors. 展开更多
关键词 entire function generalized order generalized type approximation errors interpolation errors
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A B-Spline Method Used to Calculate Added Resistance in Waves
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作者 Razieh Zangeneh Mahmood Ghiasi 《Journal of Marine Science and Application》 CSCD 2017年第1期20-26,共7页
Making an exact computation of added resistance in sea waves is of high interest due to the economic effects relating to ship design and operation. In this paper, a B-spline based method is developed for computation o... Making an exact computation of added resistance in sea waves is of high interest due to the economic effects relating to ship design and operation. In this paper, a B-spline based method is developed for computation of added resistance. Based on the potential flow assumption, the velocity potential is computed using Green's formula. The Kochin function is applied to compute added resistance using Maruo's far-field method, the body surface is described by a B-spline curve and potentials and normal derivation of potentials are also described by B-spline basis functions and B-spline derivations. A collocation approach is applied for numerical computation, and integral equations are then evaluated by applying Gauss–Legendre quadrature. Computations are performed for a spheroid and different hull forms; results are validated by a comparison with experimental results. All results obtained with the present method show good agreement with experimental results. 展开更多
关键词 Added resistance b-spline Kochin function Maruo's far-field method Gauss–Legendre quadrature
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融合趋势面函数的多重二次曲面法恢复图形数字化数据
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作者 杨学顺 陈煜烽 +5 位作者 胡贺松 赖志丹 刘海飞 张宇豪 李小强 刘春明 《矿产勘查》 2024年第9期1750-1756,共7页
为方便对一些老的纸质等值线图件进行数据再处理,首先需要对图件进行数字化,然后再进行二维网格化,网格化数据质量直接影响后续数据的处理效果。由于等值线图的数字化数据具有不均匀的特点,网格化后容易产生数据畸变的问题,本文提出了... 为方便对一些老的纸质等值线图件进行数据再处理,首先需要对图件进行数字化,然后再进行二维网格化,网格化数据质量直接影响后续数据的处理效果。由于等值线图的数字化数据具有不均匀的特点,网格化后容易产生数据畸变的问题,本文提出了融合趋势面函数的多重二次曲面网格化方法。该方法首先根据已知离散点构建低阶趋势面函数,然后利用已知离散点与低阶趋势面函数的差构建多重二次曲面函数,再将低阶趋势面与多重二次曲面叠加构造出新曲面,两者结合可较好地消除多重二次曲面函数在数据稀疏区的畸变效应。通过对磁法等值线图数字化数据进行插值测试,验证了融合趋势面函数的多重二次曲面插值方法具有良好的保真性。 展开更多
关键词 趋势面函数 多重二次曲面函数 二维插值
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基于径向基函数拟插值法的水轮机传递系数曲面构建
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作者 王俊杰 周明明 +5 位作者 周国胜 许仁山 杨奎 孔祥宇 赵坤杰 袁晓辉 《水电能源科学》 北大核心 2024年第12期171-175,共5页
水电机组调节系统仿真计算中水轮机模型多采用简化模型,忽略了水轮机非线性特性,难以准确反映水轮机实际运行过程。水轮机非线性模型构建的难点在于精确获取水轮机不同工况传递系数。对此,首先基于水轮机模型综合特性曲线推导了水轮机... 水电机组调节系统仿真计算中水轮机模型多采用简化模型,忽略了水轮机非线性特性,难以准确反映水轮机实际运行过程。水轮机非线性模型构建的难点在于精确获取水轮机不同工况传递系数。对此,首先基于水轮机模型综合特性曲线推导了水轮机传递系数的表达式;再引入径向基函数拟插值法对水轮机模型综合特性曲面重建和网格化加密处理,比较不同核函数对水轮机模型综合特性曲线拟插值精度的影响;最后构建了水轮机传递系数曲面,分析了水轮机模型综合特性曲线拟插值误差对水轮机6个传递系数求解精度的影响。结果表明,使用径向基函数拟插值法对水轮机模型综合特性曲面进行重建,重采样平均相对误差能控制在0.005以内,水轮机在不同工况下的传递系数的精度较高。 展开更多
关键词 水轮机 径向基函数 拟插值 传递系数
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导数推广的拉格朗日插值公式及其在密文训练神经网络中的应用 被引量:1
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作者 杨舒雅 李晓东 张健毅 《北京电子科技学院学报》 2024年第1期50-59,共10页
拉格朗日多项式插值公式被用于经过若干点的未知函数的多项式刻画,也被用于对已有的非多项式函数进行多项式函数逼近,在许多领域有着广泛的应用。本文探索了拉格朗日多项式插值公式在导数情况下的一般性推广。推广的多项式插值公式不仅... 拉格朗日多项式插值公式被用于经过若干点的未知函数的多项式刻画,也被用于对已有的非多项式函数进行多项式函数逼近,在许多领域有着广泛的应用。本文探索了拉格朗日多项式插值公式在导数情况下的一般性推广。推广的多项式插值公式不仅可以在插值点的函数值逼近目标函数,同时也能在插值点的变化趋势上对目标函数进行逼近。在已知插值点上给定某个阶数以内导数的情况下,能够使用推广的拉格朗日多项式插值公式获得对目标函数的深度多项式逼近。实验结果表明,用导数推广拉格朗日多项式代替逻辑回归函数重新构建的密文神经网络的训练准确率更高,均方误差更小。扩展后的拉格朗日多项式插值公式能够适用于更一般的场景。 展开更多
关键词 拉格朗日插值公式导数推广 密文训练神经网络 多项式逼近 激励函数
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高阶剪切变形理论下Pasternak地基上FG-CNTRC梁自由振动及屈曲分析
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作者 杨立军 彭林欣 陈卫 《振动与冲击》 EI CSCD 北大核心 2024年第2期1-11,共11页
功能梯度碳纳米管增强复合材料(functionally graded carbon nanotube-reinforced composite,FG-CNTRC)作为新一代先进复合材料,因其优越的力学性能而被研究者们广泛关注。该研究以Pasternak地基上FG-CNTRC梁为研究对象,基于不同高阶剪... 功能梯度碳纳米管增强复合材料(functionally graded carbon nanotube-reinforced composite,FG-CNTRC)作为新一代先进复合材料,因其优越的力学性能而被研究者们广泛关注。该研究以Pasternak地基上FG-CNTRC梁为研究对象,基于不同高阶剪切变形理论,将一种具有插值特性的无网格法——稳定移动克里金插值(stabilized moving Kriging interpolation,SMKI)应用于求解Pasternak地基上FG-CNTRC梁的自由振动及屈曲问题。基于稳定移动克里金插值和不同高阶剪切变形理论给出FG-CNTRC梁的位移场,利用Hamilton原理和最小势能原理分别推导了Pasternak地基上FG-CNTRC梁的自由振动和屈曲控制方程。采用MATLAB软件编制了相关程序,将该研究解与解析解或文献解对比,证明了该方法在计算Pasternak地基上FG-CNTRC梁自由振动与屈曲的有效性及准确性。最后,还讨论了不同高阶剪切变形理论、地基系数、碳纳米管体积分数等对其自振频率和屈曲临界荷载的影响。 展开更多
关键词 功能梯度碳纳米管增强复合材料(FG-CNTRC)梁 稳定移动克里金插值(SMKI) 不同高阶剪切变形理论 PASTERNAK地基 自由振动 屈曲
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参数化流动传热问题的模型降阶方法研究
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作者 杨迪 段承杰 +3 位作者 丁鹏 宋菊青 宋子凡 张纯禹 《原子能科学技术》 EI CAS CSCD 北大核心 2024年第7期1440-1451,共12页
高精度的数值模型是构建反应堆堆芯数字孪生的基础,但传统的高分辨率数值模型的计算效率无法满足数字孪生的需求。为显著提高计算效率,综合利用伽辽金投影法和径向基函数插值法构造了参数化流动传热问题的降阶模型。该模型以典型的数值... 高精度的数值模型是构建反应堆堆芯数字孪生的基础,但传统的高分辨率数值模型的计算效率无法满足数字孪生的需求。为显著提高计算效率,综合利用伽辽金投影法和径向基函数插值法构造了参数化流动传热问题的降阶模型。该模型以典型的数值解作为学习样本,通过本征正交分解获得各物理场分布的主模态作为缩减基,然后将控制方程在缩减基张成的空间上进行投影以获得自由度个数显著降低的降阶模型。螺旋十字型燃料冷却剂的测试算例表明,相较于全阶模型,该降阶模型可实现高达3~4个数量级的加速效果,降阶模型的速度场与压力场的相对误差均小于10%。 展开更多
关键词 流动传热 降阶模型 本征正交分解 径向基函数插值
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基于Roberts算子的激光夜视图像自动分割方法
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作者 李星军 邵志伟 梁嘉怡 《激光杂志》 CAS 北大核心 2024年第5期110-114,共5页
激光夜视图像分辨率较低,边缘信息难以检测,导致图像分割过程存在效率低、精度较差等问题,为此设计基于Roberts算子的激光夜视图像自动分割方法。使用相机采集夜间场景色彩信息,采用加权平均法重构图像数据,输出完整的激光夜视图像。拟... 激光夜视图像分辨率较低,边缘信息难以检测,导致图像分割过程存在效率低、精度较差等问题,为此设计基于Roberts算子的激光夜视图像自动分割方法。使用相机采集夜间场景色彩信息,采用加权平均法重构图像数据,输出完整的激光夜视图像。拟合图像周边相邻像素,利用三次样条插值函数平滑处理图像,运用Roberts算子计算图像梯度,实现激光夜视图像边缘检测,得到图像插值后的平滑信息,提升夜视图像分辨率。通过模糊C均值聚类明确聚类范围,引入混沌粒子群算法实现图像分割。实验结果表明,所提方法分割差异率在3%以下,图像分割Dice相似性系数在0.97以上,图像分割平均耗时为9 s。 展开更多
关键词 ROBERTS算子 三次样条插值函数 激光夜视图像 图像分割 模糊C均值聚类
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