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R^s空间中Lagrange插值问题研究
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作者 李志斌 李伟 万朝燕 《大连交通大学学报》 CAS 2007年第4期1-4,共4页
研究空间Rs中多项式空间中的Lagrange插值问题.给出了R1和R2上Lagrange插值多项式的构造,同时,给出了R2上插值问题的几个例子.另外,给出了矩形网点上的Lagrange插值多项式和三角形网点上的Lagrange插值多项式.讨论了Rs空间中的Lagrange... 研究空间Rs中多项式空间中的Lagrange插值问题.给出了R1和R2上Lagrange插值多项式的构造,同时,给出了R2上插值问题的几个例子.另外,给出了矩形网点上的Lagrange插值多项式和三角形网点上的Lagrange插值多项式.讨论了Rs空间中的Lagrange插值多项式及其余项. 展开更多
关键词 lagrange插值 空间Rs 余项
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Cartesian点集Lagrange投影算子的误差公式
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作者 李喆 孙艳 《吉林大学学报(理学版)》 CAS CSCD 北大核心 2014年第5期911-915,共5页
考虑多元插值问题的插值余项估计问题.针对好误差公式的概念,给出了推广好误差公式的概念,并以三维Cartesian点集为例,利用B样条与差商的关系给出Cartesian点集Lagrange插值误差公式的积分形式.该结果可以推广到d维空间中.
关键词 Cartesian点集 lagrange投影算子 误差公式
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Examining the Use of Scott’s Formula and Link Expiration Time Metric for Vehicular Clustering
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作者 Fady Samann Shavan Askar 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期2421-2444,共24页
Implementing machine learning algorithms in the non-conducive environment of the vehicular network requires some adaptations due to the high computational complexity of these algorithms.K-clustering algorithms are sim... Implementing machine learning algorithms in the non-conducive environment of the vehicular network requires some adaptations due to the high computational complexity of these algorithms.K-clustering algorithms are simplistic,with fast performance and relative accuracy.However,their implementation depends on the initial selection of clusters number(K),the initial clusters’centers,and the clustering metric.This paper investigated using Scott’s histogram formula to estimate the K number and the Link Expiration Time(LET)as a clustering metric.Realistic traffic flows were considered for three maps,namely Highway,Traffic Light junction,and Roundabout junction,to study the effect of road layout on estimating the K number.A fast version of the PAM algorithm was used for clustering with a modification to reduce time complexity.The Affinity propagation algorithm sets the baseline for the estimated K number,and the Medoid Silhouette method is used to quantify the clustering.OMNET++,Veins,and SUMO were used to simulate the traffic,while the related algorithms were implemented in Python.The Scott’s formula estimation of the K number only matched the baseline when the road layout was simple.Moreover,the clustering algorithm required one iteration on average to converge when used with LET. 展开更多
关键词 CLUsTERING vehicular network scott’s formula FastPAM
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Huatan Qushi formula alleviates non-alcoholic fatty liver disease via PI3K/Akt signaling and gut microbiota modulation
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作者 Xiuping Zhang Linghui Zhu +7 位作者 Jinchen Ma Yi Zheng Xuejing Yang Lingling Yang Yang Dong Yan Zhang Baoxing Liu Lingru Li 《Journal of Traditional Chinese Medical Sciences》 CAS 2024年第4期443-455,共13页
Objective:To provide the mechanism-based pharmacotherapy of the Huatan Qushi formula(HTQS for-mula),for the health management and treatment of non-alcoholic fatty liver disease(NAFLD).Methods:A rat model of NAFLD was ... Objective:To provide the mechanism-based pharmacotherapy of the Huatan Qushi formula(HTQS for-mula),for the health management and treatment of non-alcoholic fatty liver disease(NAFLD).Methods:A rat model of NAFLD was employed to examine the efficacy and safety of the HTQS formula.In vivo active components and potential mechanisms of the HTQS formula were identified using UPLC‒MS/MS combined with network pharmacology.The influence of the HTQS formula on the dominating proteins in PI3K/Akt pathway was validated in vivo using western blot.Finally,16S rRNA sequencing of the gut microbiome was conducted followed by targeted metabolomics detecting fecal short-chain fatty acids(SCFAs)and bile acids to determine the impact of the HTQS formula on gut microbiota.Results:The HTQS formula reduced weight gain and hepatic steatosis in NAFLD rats and decreased serum total cholesterol(TC),triglycerides,blood glucose,and insulin resistance(IR)without causing liver or kidney injury.We detected 28 components using UPLC‒MS/MS and identified 439 shared targets be-tween NAFLD and the HTQS formula.Primarily,we focused on the PI3K/Akt signaling pathway based on protein‒protein interaction network analysis.We validated that the HTQS formula inhibited liver stea-tosis and inflammation by increasing the phosphorylation levels of PI3K,AKT,P27,GSK3b in the PI3K/Akt signaling pathway.16S rRNA sequencing revealed that the HTQS formula reduced the abundance of the genus Family_XIII_AD3011_group,which was positively correlated with IR and taurodeoxycholic acid.In addition,Lachnospiraceae_UCG_010 inversely correlated with TC and five bile acids,which could be essential to the therapeutic effect of the HTQS formula against NAFLD.Conclusions:The HTQS formula proved to be an effective pharmacotherapy for NAFLD without causing liver or kidney injury.Multiple potent components of the HTQS formula could alleviate liver steatosis and lipid metabolism disorder by modulating the PI3K/Akt signaling pathway and restoring gut microbiota composition. 展开更多
关键词 Non-alcoholic fatty liver disease Huatan Qushi formula Network pharmacology PI3K/Akt signaling pathway 16s rRNA sequencing Gut microbiota
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基于L-S Lagrange函数的神经网络方法
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作者 彭爱民 《湖北大学学报(自然科学版)》 CAS 2012年第2期231-234,共4页
利用非线性规划的Log-Sigmoid(L-S)型Lagrange函数及其对偶问题的性质,提出一种求解优化问题的神经网络方法,并讨论网络的收敛性和稳定性条件,算例表明该神经网络能有效求解.
关键词 L-s lagrange函数 神经网络 渐近稳定
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Comparison of Numerical Approximations of One-Dimensional Space Fractional Diffusion Equation Using Different Types of Collocation Points in Spectral Method Based on Lagrange’s Basis Polynomials 被引量:1
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作者 Mushfika Hossain Nova Hasib Uddin Molla Sajeda Banu 《American Journal of Computational Mathematics》 2017年第4期469-480,共12页
Recently many research works have been conducted and published regarding fractional order differential equations. There are several approaches available for numerical approximations of the solution of fractional order... Recently many research works have been conducted and published regarding fractional order differential equations. There are several approaches available for numerical approximations of the solution of fractional order diffusion equations. Spectral collocation method based on Lagrange’s basis polynomials to approximate numerical solutions of one-dimensional (1D) space fractional diffusion equations are introduced in this research paper. The proposed form of approximate solution satisfies non-zero Dirichlet’s boundary conditions on both boundaries. Collocation scheme produce a system of first order Ordinary Differential Equations (ODE) from the fractional diffusion equation. We applied this method with four different sets of collocation points to compare their performance. 展开更多
关键词 Fractional Diffusion Equation spectral METHOD COLLOCATION METHOD lagranges BAsIs Polynomial
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由O.Schlmilch-Roche式探讨Lagrange余项及Cauchy余项的由来
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作者 邹青 《苏州市职业大学学报》 2012年第3期65-67,共3页
运用Taylor展式的基本理论以及Cauchy公式推导出Taylor展式余项的O.Schlmilch-Roche式,并以O.Schlmilch-Roche式作为基础对其中的变量p进行赋值,从而探讨数学分析中Taylor展式的Lagrange余项及Cauchy余项的由来,使之更具理论依据.
关键词 O.schlmilch-Roche式 TAYLOR展式 lagrange余项 Cauchy余项
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Reciprocity Relation between Alternative Gravity Formulas
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作者 Hans Hermann Otto 《Journal of Applied Mathematics and Physics》 2024年第4期1432-1440,共9页
We compare Newton’s force law of universal gravitation with a corrected simple approach based on Bhandari’s recently presented work, where the gravitation constant G is maintained. A reciprocity relation exists betw... We compare Newton’s force law of universal gravitation with a corrected simple approach based on Bhandari’s recently presented work, where the gravitation constant G is maintained. A reciprocity relation exists between both alternative gravity formulas with respect to the distances between mass centers. We conclude a one-to-one mapping of the two gravitational formulas. We don’t need Einstein’s construct of spacetime bending by matter. 展开更多
关键词 Gravity formulas Reciprocity Distance Relation NEWTON EINsTEIN Bhandari Higgs Field Dirac’s Large Number
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Numerical Solution of Two Dimensional Fredholm Integral Equations of the Second Kind by the Barycentric Lagrange Function
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作者 Hongyan Liu Jin Huang Yubin Pan 《Journal of Applied Mathematics and Physics》 2017年第2期259-266,共8页
This paper solves the two dimensional linear Fredholm integral equations of the second kind by combining the meshless barycentric Lagrange interpolation functions and the Gauss-Legendre quadrature formula. Inspired by... This paper solves the two dimensional linear Fredholm integral equations of the second kind by combining the meshless barycentric Lagrange interpolation functions and the Gauss-Legendre quadrature formula. Inspired by this thought, we convert the equations into the associated algebraic equations. The results of the numerical examples are given to illustrate that the approximated method is feasible and efficient. 展开更多
关键词 Two Dimensional FREDHOLM Integral Equations Barycentric lagrange Interpolation Functions Gauss-Legendre QUADRATURE formula
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On Form Invariance,Lie Symmetry and Three Kinds of Conserved Quantities of Generalized Lagrange's Equations
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作者 ZHAO Shu-Hong LIANG Li-Fuoi School of Civil Engineering,Harbin Engineering University,Harbin 150001,China2 Engineering College,Northeast Agricultural University,Harbin 150030,China 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第7期37-42,共6页
In this paper,the form invariance and the Lie symmetry of Lagrange's equations for nonconservativesystem in generalized classical mechanics under the infinitesimal transformations of group are studied,and the Noet... In this paper,the form invariance and the Lie symmetry of Lagrange's equations for nonconservativesystem in generalized classical mechanics under the infinitesimal transformations of group are studied,and the Noether'sconserved quantity,the new form conserved quantity,and the Hojman's conserved quantity of system are derived fromthem.Finally,an example is given to illustrate the application of the result. 展开更多
关键词 form invariance Lie symmetry conserved quantity generalized classical mechanics lagranges equation
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Lagrange’s Spectral Collocation Method for Numerical Approximations of Two-Dimensional Space Fractional Diffusion Equation
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作者 Hasib Uddin Molla Mushfika Hossain Nova 《American Journal of Computational Mathematics》 2018年第2期121-136,共16页
Due to the ability to model various complex phenomena where classical calculus failed, fractional calculus is getting enormous attention recently. There are several approaches available for numerical approximations of... Due to the ability to model various complex phenomena where classical calculus failed, fractional calculus is getting enormous attention recently. There are several approaches available for numerical approximations of various types of fractional differential equations. For fractional diffusion equations spectral collocation is one of the efficient and most popular ap-proximation techniques. In this research, we introduce spectral collocation method based on Lagrange’s basis polynomials for numerical approximations of two-dimensional (2D) space fractional diffusion equations where spatial fractional derivative is described in Riemann-Liouville sense. We consider four different types of nodes to generate Lagrange’s basis polynomials and as collocation points in the proposed spectral collocation technique. Spectral collocation method converts the diffusion equation into a system of ordinary differential equations (ODE) for time variable and we use 4th order Runge-Kutta method to solve the resulting system of ODE. Two examples are considered to verify the efficiency of different types of nodes in the proposed method. We compare approximated solution with exact solution and find that Lagrange’s spectral collocation method gives very high accuracy approximation. Among the four types of nodes, nodes from Jacobi polynomial give highest accuracy and nodes from Chebyshev polynomials of 1st kind give lowest accuracy in the proposed method. 展开更多
关键词 lagranges sPECTRAL METHOD 2D FRACTIONAL Diffusion EQUATION COLLOCATION METHOD
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Lagrange三角平动点邻近的相空间结构 被引量:3
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作者 周礼勇 孙义燧 周济林 《天文学报》 CSCD 北大核心 1999年第3期286-293,共8页
构造描述一类特殊平面圆型限制性三体问题的一个映射,并用这个映射讨论了该类三体问题Lagrange 三角平动点邻近的相空间结构以及它的稳定性,发现当两个主天体的质量比μ< 0 .02165 时,除去μ= 0 .01440 的... 构造描述一类特殊平面圆型限制性三体问题的一个映射,并用这个映射讨论了该类三体问题Lagrange 三角平动点邻近的相空间结构以及它的稳定性,发现当两个主天体的质量比μ< 0 .02165 时,除去μ= 0 .01440 的例外情况,三角平动点被不变曲线包围,是稳定的,这与理论结果相符,由此可解释特罗央群和希腊群小行星的稳定存在. 展开更多
关键词 lagrange平动点 小行星 映射方法 相空间结构
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多点多重Lagrange型插值公式 被引量:2
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作者 盛中平 王晓辉 李冰玉 《东北师大学报(自然科学版)》 CAS CSCD 北大核心 2007年第2期136-137,共2页
讨论了一般多点多重Hermite插值问题,给出了完全展开的多点多重Lagrange型插值公式,且就各节点重度相同的情况给出了若干特例.并利用序列对偶及广义差分方程理论等给出了计算Lagrange型插值公式的多种快速算法.
关键词 显式公式 重节点 Lagange插值 切触插值
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基于Lagrange方法的平面双摆机构多体动力学研究 被引量:8
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作者 刘艳梨 朱永梅 《机械设计与制造》 北大核心 2009年第5期75-77,共3页
详细叙述了Lagrange方法的理论体系;针对一种平面双摆机构进行了动力学分析,采用Lagrange方法建立动力学模型;结合纽马克法,用VC++编制了自动建立平面双摆机构动力学模型的计算机程序,通过MATLAB软件模拟了平面双摆机构模型微振动时旋... 详细叙述了Lagrange方法的理论体系;针对一种平面双摆机构进行了动力学分析,采用Lagrange方法建立动力学模型;结合纽马克法,用VC++编制了自动建立平面双摆机构动力学模型的计算机程序,通过MATLAB软件模拟了平面双摆机构模型微振动时旋转角位移的动力学响应情况;从而为这种机构动力学特性的深入分析和结构优化设计提供了参考。 展开更多
关键词 动力学 lagrange方法 平面双摆机构 纽马克法
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New Color-Difference Formula Based on CIECAM97s 被引量:1
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作者 宦晖 李为 赵达尊 《Journal of Beijing Institute of Technology》 EI CAS 2001年第2期149-152,共4页
To deduce a new color difference formula based on CIE 1997 Color Appearance Model(CIECAM97s), a color space J a 1 b 1 is first constructed with color appearance descriptors J,a,b in CIECAM97s. The new f... To deduce a new color difference formula based on CIE 1997 Color Appearance Model(CIECAM97s), a color space J a 1 b 1 is first constructed with color appearance descriptors J,a,b in CIECAM97s. The new formula is then deduced in the space and named CDF CIECAM97s. The factors for lightness, chroma and hue correction in the formula are derived by linear regression according to BFD? CP data sets. It is found by statistical analysis that CDF CIECAM97s is in closer accordance with the visual assessments when compared with CMC(1∶1), CIE94 and CIE L *a *b * color difference formulae. Based on color appearance model, the new color difference formula can be used to predict color difference perception in a varity of different viewing conditions. 展开更多
关键词 CIECAM97s color difference formulae color space
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辅助纬度反解公式的Lagrange级数法推演 被引量:10
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作者 王瑞 李厚朴 《海洋测绘》 2008年第3期18-23,共6页
对地图投影理论中经常遇到的等距离纬度、等量纬度和等面积纬度的反解公式进行了新的研究。利用Lagrange级数公式,借助计算机代数系统强大的数学分析功能,全面给出了这些纬度用椭球偏心率幂级数形式表示的反解公式。与以往数值形式表示... 对地图投影理论中经常遇到的等距离纬度、等量纬度和等面积纬度的反解公式进行了新的研究。利用Lagrange级数公式,借助计算机代数系统强大的数学分析功能,全面给出了这些纬度用椭球偏心率幂级数形式表示的反解公式。与以往数值形式表示的反解展开式不同,这些反解公式是以符号形式给出。研究表明计算机代数系统的应用不但极大地提高了公式推演的效率和准确度,而且反解系数从此可以表示为更简单和更便于记忆的符号形式。 展开更多
关键词 地图投影 辅助纬度 计算机代数系统 lagrange级数公式
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基于Ackermann's formula的类反斜线回滞系统滑模控制 被引量:1
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作者 张达科 胡跃明 郭华芳 《机械工程学报》 EI CAS CSCD 北大核心 2005年第1期11-15,共5页
回滞现象广泛地存在于许多机械控制领域。由于回滞特性具有不可微性,从而使得对回滞系统的控制变得困难和复杂,同时由于回滞可能引起系统的振荡,甚至造成系统的不稳定,因此有必要对回滞系统的有效控制进行研究。考虑到回滞系统建模仍然... 回滞现象广泛地存在于许多机械控制领域。由于回滞特性具有不可微性,从而使得对回滞系统的控制变得困难和复杂,同时由于回滞可能引起系统的振荡,甚至造成系统的不稳定,因此有必要对回滞系统的有效控制进行研究。考虑到回滞系统建模仍然是个研究的领域,针对类反斜线回滞系统进行研究。把类反斜线回滞模型分解为确定的线性部分和已知上界的不确定非线性部分,利用Ackermann's formula给出了类反斜线回滞系统的滑模控制律。仿真表明此滑模控制律是有效的,同时此滑模控制保证了整个系统的稳定性。 展开更多
关键词 类反斜线回滞 滑模控制 Ackermann’s formula
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Lagrange插指 被引量:18
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作者 颜宁生 《北京服装学院学报(自然科学版)》 CAS 北大核心 2005年第3期50-56,共7页
提出了拉格朗日(Lagrange)插值问题的一种新形式:幂指数形式,简称Lagrange插指.应用这种插指法,可以构造出一类离散型总体的公式式分布律.
关键词 拉格朗日(lagrange)插值多项式 拉格朗日(lagrange)插指多项式 抛物线插值分布律的公式式 最大似然估计
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Lagrange支持向量机算法应用研究 被引量:2
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作者 刘太安 安新军 +1 位作者 刘欣颖 李涵 《计算机工程与设计》 CSCD 北大核心 2007年第19期4726-4728,共3页
将SVM(support vector machine)分类的思想方法应用于个人信用评估。通过比较分析银行个人信用特征数据,设计了新的通用的银行个人信用特征数据。基于LSVM(Lagrange support vector machine)分类算法分析,将LSVM算法应用于个人信用评估... 将SVM(support vector machine)分类的思想方法应用于个人信用评估。通过比较分析银行个人信用特征数据,设计了新的通用的银行个人信用特征数据。基于LSVM(Lagrange support vector machine)分类算法分析,将LSVM算法应用于个人信用评估,并与KNN(K-nearest neighbor)分类方法、OSU_SVM3.0工具分类方法比较,实验结果表明:LSVM具有较好的分类预测能力,为个人信用评估提供了一个新的有效方法。 展开更多
关键词 lagrange支持向量机 分类算法 sMW公式 个人信用特征数据 个人信用评估
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一类非完整系统的Lagrange定理及其应用 被引量:1
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作者 李刚常 何世本 《应用数学和力学》 EI CSCD 北大核心 1998年第2期127-135,共9页
本文研究一类非完整系统平衡位置流形的稳定性问题·利用Ляпунов直接法和稳定性定义将完整系统的Lagrange定理推广到一类非完整保守系统与耗散系统,并对该类非完整系统平衡位置流形的渐近稳定性与耗散力间的关系作... 本文研究一类非完整系统平衡位置流形的稳定性问题·利用Ляпунов直接法和稳定性定义将完整系统的Lagrange定理推广到一类非完整保守系统与耗散系统,并对该类非完整系统平衡位置流形的渐近稳定性与耗散力间的关系作了新的表述,最后举例说明定理的应用· 展开更多
关键词 非完整系统 稳定性 流形 拉格朗日定理
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