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Generalized regular points of a C^1 map between Banach spaces
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作者 史平 马吉溥 《Journal of Southeast University(English Edition)》 EI CAS 2007年第1期148-150,共3页
Let f be a C^1 map between two Banach spaces E and F. It has been proved that the concept of generalized regular points of f, which is a generalization of the notion of regular points of f, has some crucial applicatio... Let f be a C^1 map between two Banach spaces E and F. It has been proved that the concept of generalized regular points of f, which is a generalization of the notion of regular points of f, has some crucial applications in nonlinearity and global analysis. We characterize the generalized regular points of f using the three integer-valued (or infinite) indices M(x0), Mc(x0) and Mr(x0) at x0 ∈ E generated by f and by analyzing generalized inverses of bounded linear operators on Banach spaces, that is, iff '(x0) has a generalized inverse in the Banach space B(E, F) of all bounded linear operators on E into F and at least one of the indices M(x0), Mc(x0) and Mr(x0) is finite, then xo is a generalized regular point off if and only if the multi-index (M(x), Me(x), Mr(x)) is continuous at X0. 展开更多
关键词 Banach space bounded linear operator generalized inverse index generalized regular point semi- Fredholm mao
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A remark on regular points of Ricci limit spaces 被引量:1
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作者 Lina CHEN 《Frontiers of Mathematics in China》 SCIE CSCD 2016年第1期21-26,共6页
Let Y be a Gromov-Hausdorff limit of complete Riemannian nmanifolds with Ricci curvature bounded from below. A point in Y is called k-regular, if its tangent is unique and is isometric to a k-dimensional Euclidean spa... Let Y be a Gromov-Hausdorff limit of complete Riemannian nmanifolds with Ricci curvature bounded from below. A point in Y is called k-regular, if its tangent is unique and is isometric to a k-dimensional Euclidean space. By Cheeger-Colding and Colding-Naber, there is k 〉 0 such that the set of all k-regular point :Rk has a full renormalized measure. An open problem is if Rl = 0 for all l 〈 k? The main result in this paper asserts that if R1 ≠ 0, then Y is a one-dimensional topological manifold. Our result improves Honda's result that under the assumption that 1 ≤ dimH(Y) 〈 2. 展开更多
关键词 Ricci curvature regular point Gromov-Hausdorff limit
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Regular-Singular Crossings on Nonlinear Systems with Turning Point
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作者 Zhang Hanlin (Beijing Polytechnic University) Zhang Heping (Beijing Electric Power College) 《Advances in Manufacturing》 SCIE CAS 1998年第3期21-23,共3页
We consider in this paper the boundary value problems of nonlinear systems the form εY″=F(t,Y,Y′,ε), -1<t<1, Y(-1,ε)=A(ε), Y(1,ε)=B(ε). Supoosing some or all of the components of F , that is, ... We consider in this paper the boundary value problems of nonlinear systems the form εY″=F(t,Y,Y′,ε), -1<t<1, Y(-1,ε)=A(ε), Y(1,ε)=B(ε). Supoosing some or all of the components of F , that is, f i satisfy 2 f y′ 2 i t =0 =0, we say that F possesses a generalized turning point at t =0. Our goal is to give sufficient conditions for the existence of solution of the problems and to study the asymptotic behavior of the solution when F possesses a generalized turning point at t =0. We mainly discuss regular singular crossings. 展开更多
关键词 turning point regular singular crossing differential inequality
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FIXED POINTS OF A PAIR OF ASYMPTOTICALLY REGULAR MAPPINGS 被引量:1
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作者 B. K. Sharma B. S. Thakur(School of Studies in Mathematics.Pt. Ravishankar Shukla University. Raipur-492010 India)(Received Nov. 20. 1996. Communicated by Ding Xieping) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1997年第8期771-778,共8页
In this paper some theorems on fixed points of pair of asymptotically regularmappings in p-uniformly convex Banach space are proved For these mappings somefixed point theorems in a Hilbert space.in Lp spaces in Hardy ... In this paper some theorems on fixed points of pair of asymptotically regularmappings in p-uniformly convex Banach space are proved For these mappings somefixed point theorems in a Hilbert space.in Lp spaces in Hardy spaces Hp and in Sobolev spaces Hpk for 1<P<+∞ and K>0 are also established.Thus resultsof Gornicki Kruppel and others are extended. 展开更多
关键词 asymptotically regular mappings p-uniformly convex Banach space asymptotic center fixed points
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HAMILTON-JACOBI EQUATIONS FOR A REGULAR CONTROLLED HAMILTONIAN SYSTEM AND ITS REDUCED SYSTEMS 被引量:1
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作者 王红 《Acta Mathematica Scientia》 SCIE CSCD 2023年第2期855-906,共52页
In this paper,we give the geometric constraint conditions of a canonical symplectic form and regular reduced symplectic forms for the dynamical vector fields of a regular controlled Hamiltonian(RCH)system and its regu... In this paper,we give the geometric constraint conditions of a canonical symplectic form and regular reduced symplectic forms for the dynamical vector fields of a regular controlled Hamiltonian(RCH)system and its regular reduced systems,which are called the Type I and Type II Hamilton-Jacobi equations.First,we prove two types of Hamilton-Jacobi theorems for an RCH system on the cotangent bundle of a configuration manifold by using the canonical symplectic form and its dynamical vector field.Second,we generalize the above results for a regular reducible RCH system with symmetry and a momentum map,and derive precisely two types of Hamilton-Jacobi equations for the regular point reduced RCH system and the regular orbit reduced RCH system.Third,we prove that the RCH-equivalence for the RCH system,and the RpCH-equivalence and RoCH-equivalence for the regular reducible RCH systems with symmetries,leave the solutions of corresponding Hamilton-Jacobi equations invariant.Finally,as an application of the theoretical results,we show the Type I and Type II Hamilton-Jacobi equations for the Rp-reduced controlled rigid body-rotor system and the Rp-reduced controlled heavy top-rotor system on the generalizations of the rotation group SO(3)and the Euclidean group SE(3),respectively.This work reveals the deeply internal relationships of the geometrical structures of phase spaces,the dynamical vector fields and the controls of the RCH system. 展开更多
关键词 regular controlled Hamiltonian system Hamilton-Jacobi equation regular point reduction regular orbit reduction RCH-equivalence
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“平急两用”理念下城市地震应急物资储备点选址研究 被引量:1
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作者 陈瑞琪 刘刚 +2 位作者 张博骞 马东辉 王威 《武汉理工大学学报(信息与管理工程版)》 2025年第2期133-140,共8页
为响应城市建设“存量优先”的政策导向,推动“平急两用”设施建设,提升震后应急物资供给的运行效率,首先,建立应急物资需求点紧迫度评估指标体系,采用熵权-TOPSIS综合评估应急物资需求点的紧迫度并进行分级,为“平急两用”理念下设施... 为响应城市建设“存量优先”的政策导向,推动“平急两用”设施建设,提升震后应急物资供给的运行效率,首先,建立应急物资需求点紧迫度评估指标体系,采用熵权-TOPSIS综合评估应急物资需求点的紧迫度并进行分级,为“平急两用”理念下设施选址提供准确的需求紧迫度评估基础。其次,将“平急两用”理念融入候选点筛选和选址优化模型中,构建“平急两用”理念下的城市地震应急物资储备点多目标优化选址模型,并采用快速非支配排序遗传算法NSGA-Ⅱ求解。最后,以华东某城市地震应急物资储备点的优化选址为例进行分析。结果表明,优化后的应急物资储备点的总成本相较于仅追求覆盖率的情况共优化了582.250~8 540.333万元,同时优化选址方案保障了震后应急物资供给的时效性、公平性和经济性,可为“平急两用”理念下公共基础设施的选址布局提供规划决策支撑。 展开更多
关键词 地震应急物资储备点 “平急两用” 优化选址 应急需求紧迫度 遗传算法
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基于数据挖掘探析穴位贴敷治疗化疗相关性恶心呕吐选穴规律
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作者 宋红梅 张金花 《智慧健康》 2025年第24期1-4,共4页
目的探讨穴位贴敷治疗化疗相关性恶心呕吐(CINV)的选穴规律。方法系统检索CNKI、VIP、WanFang和SinoMed数据库,筛选65篇文献建立处方数据库,运用聚类分析和关联规则挖掘技术进行数据挖掘。结果纳入55条有效处方,涉及23个腧穴,总频次184... 目的探讨穴位贴敷治疗化疗相关性恶心呕吐(CINV)的选穴规律。方法系统检索CNKI、VIP、WanFang和SinoMed数据库,筛选65篇文献建立处方数据库,运用聚类分析和关联规则挖掘技术进行数据挖掘。结果纳入55条有效处方,涉及23个腧穴,总频次184次。高频穴位(≥5次)包括足三里、内关、中脘等7穴,76.3%分布于任脉。腧穴归经以任脉(34.8%)、足阳明胃经(21.7%)为主。特定穴中五输穴占比最高(43.5%)。关联规则挖掘显示中脘-神阙为核心配伍组合。结论穴位贴敷治疗CINV以任脉及胃经腧穴为主,通过和胃降逆、补益胃气实现疗效,可为临床选穴提供参考依据。 展开更多
关键词 化疗相关性恶心呕吐 数据挖掘 穴位贴敷 选穴规律
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一种基于电路板点云数据的预处理综合解决方案
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作者 钱宇亮 《制造业自动化》 2025年第10期54-63,共10页
随着物联网技术和逆向工程的深入发展,表面网格划分等细分技术应用场景快速增加,电路板点云数据的三维重建在帮助多种产品定制和改进设计、快速定位微小问题、缺陷和损坏检测等过程中发挥重要作用,但其无规则性离散点及庞大数据量给工... 随着物联网技术和逆向工程的深入发展,表面网格划分等细分技术应用场景快速增加,电路板点云数据的三维重建在帮助多种产品定制和改进设计、快速定位微小问题、缺陷和损坏检测等过程中发挥重要作用,但其无规则性离散点及庞大数据量给工业应用带来了繁杂问题。因此,提出了一种点云预处理的综合解决方案,将原始点云进行离散及生长方向拟合,提出一种基于Logistic模型函数的多特征因子加权分类法进行特征点提取,并提出一种基于R邻域及栅格化的数据处理法对分类结果进行分治正则化。实验结果表明,该方案使得数据量大幅度减少,生成点云数据质量高,重建后表现效果良好。 展开更多
关键词 点云预处理 点云分类 正则化 点云重建
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基于少测点噪声数据重构问题的改进GappyPOD算法
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作者 韩佳洁 苑清扬 +3 位作者 张博 赵鑫 兰天 李郁 《应用科学学报》 北大核心 2025年第5期740-756,共17页
基于数据驱动的GappyPOD(GP)算法是一种解决流动、传热等物理现象中反问题的方法,然而实际数据通常因受到多种噪声污染而影响了GappyPOD算法的精度。伯格斯方程含有流动和传热方程的部分重要形态,以此构建数据库,并对高斯噪声和无规则... 基于数据驱动的GappyPOD(GP)算法是一种解决流动、传热等物理现象中反问题的方法,然而实际数据通常因受到多种噪声污染而影响了GappyPOD算法的精度。伯格斯方程含有流动和传热方程的部分重要形态,以此构建数据库,并对高斯噪声和无规则噪声下,基于普通最小二乘法(ordinary leastsquares,OLS)、加权最小二乘法(weightedleast squares,WLS)、总体最小二乘法(total leastsquares,TLS)及L1正则化的GappyPOD算法的重构精度与稳定性展开研究。研究结果表明,GappyPOD算法可以在仅利用少量残缺数据条件下对一维伯格斯方程实现较高精度的重构;与GP-OLS相比,GP-WLS、GP-TLS和GP-L1的均方根误差显著降低,最大误差明显减小,相关系数更接近于1;在噪声条件下,GP-WLS重构均方根误差比GP-OLS减小到原来的1/27,提高了重构精度;GP-TLS重构均方根误差和最大误差均为最小,分别是0.0141和0.0130,数据矩阵和观测向量均存在噪声时的重构性能最好;GP-L1重构的相关系数接近1,提高了算法趋势预测能力,且从添加噪声前后来看,其重构能力变化程度不大,说明GP-L1算法对于异常值和噪声具有较强的抗干扰能力,提高了模型的鲁棒性能。 展开更多
关键词 GappyPOD算法 最小二乘法 正则化 有限测点 噪声处理
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一种顾及几何约束的机载LiDAR点云建筑物轮廓线提取方法
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作者 石义煌 蔡湛 《测绘科学技术学报》 2025年第1期68-73,共6页
建筑物是城市区域的主要地物之一。建筑物轮廓线的有效提取对于建筑物三维建模十分重要。机载激光雷达技术是近年来较为新颖的直接获取地表信息的手段,用其生成的点云数据可直接提取建筑物轮廓线。针对点云数据提取轮廓线中阈值半径不... 建筑物是城市区域的主要地物之一。建筑物轮廓线的有效提取对于建筑物三维建模十分重要。机载激光雷达技术是近年来较为新颖的直接获取地表信息的手段,用其生成的点云数据可直接提取建筑物轮廓线。针对点云数据提取轮廓线中阈值半径不易控制的问题,提出一种直接从机载激光雷达点云数据提取建筑物轮廓线的方法。首先,进行建筑物轮廓点提取,利用三角函数和斜率来获取初始轮廓点;然后采用多项式和最小二乘原理对轮廓线进行拟合;接着进行轮廓线规则化和轮廓线扩展;最后计算角点。根据实验结果得到的角点中误差可知,该方法能够准确地从点云数据中提取完整的建筑物轮廓线。 展开更多
关键词 机载激光雷达 轮廓点提取 轮廓线拟合 轮廓线规则化 几何约束
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基于机器学习的城镇满水排水管网三维模型重建技术
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作者 封小宇 朱洁明 +1 位作者 胡臻臻 张人航 《智能物联技术》 2025年第1期120-124,共5页
针对城镇满水排水管网的三维模型重建问题,提出一种基于声呐点云数据的高精度建模方法。首先,预处理原始点云数据,包括去噪、补全和优化,并引入PointMixup技术实现数据增强,以提升模型训练的健壮性和泛化能力;其次,采用基于梯度分析的... 针对城镇满水排水管网的三维模型重建问题,提出一种基于声呐点云数据的高精度建模方法。首先,预处理原始点云数据,包括去噪、补全和优化,并引入PointMixup技术实现数据增强,以提升模型训练的健壮性和泛化能力;其次,采用基于梯度分析的权重分配法与随机森林模型结合对满水排水管道进行形状拟合,以准确还原管道几何特征;最后,通过提取多分辨率信息,结合Poisson重建技术,在拟合管道形状和原始点云数据的双重约束下,生成细节丰富的三维排水管网模型。以实测水下机器人搭载断面声呐获取的点云数据为实验对象,验证了所提方法的有效性。实验结果表明,该方法能够完整提取管道内部沉积物和水面特征信息,精准重建管道三维结构,同时清晰展示管道的功能性缺陷,具有较高的工程应用价值。 展开更多
关键词 声呐点云数据 机器学习 城镇排水管网 点云分类 规则化处理 三维重建
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Robust elastic impedance inversion using L1-norm misfit function and constraint regularization 被引量:1
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作者 潘新朋 张广智 +3 位作者 宋佳杰 张佳佳 王保丽 印兴耀 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第1期227-235,共9页
The classical elastic impedance (EI) inversion method, however, is based on the L2-norm misfit function and considerably sensitive to outliers, assuming the noise of the seismic data to be the Guassian-distribution.... The classical elastic impedance (EI) inversion method, however, is based on the L2-norm misfit function and considerably sensitive to outliers, assuming the noise of the seismic data to be the Guassian-distribution. So we have developed a more robust elastic impedance inversion based on the Ll-norm misfit function, and the noise is assumed to be non-Gaussian. Meanwhile, some regularization methods including the sparse constraint regularization and elastic impedance point constraint regularization are incorporated to improve the ill-posed characteristics of the seismic inversion problem. Firstly, we create the Ll-norm misfit objective function of pre-stack inversion problem based on the Bayesian scheme within the sparse constraint regularization and elastic impedance point constraint regularization. And then, we obtain more robust elastic impedances of different angles which are less sensitive to outliers in seismic data by using the IRLS strategy. Finally, we extract the P-wave and S-wave velocity and density by using the more stable parameter extraction method. Tests on synthetic data show that the P-wave and S-wave velocity and density parameters are still estimated reasonable with moderate noise. A test on the real data set shows that compared to the results of the classical elastic impedance inversion method, the estimated results using the proposed method can get better lateral continuity and more distinct show of the gas, verifying the feasibility and stability of the method. 展开更多
关键词 elastic impedance (EI) inversion Ll-norm misfit function sparse constraint regularization elastic impedance point constraint regularization IRLS strategy
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新时代深入贯彻中央八项规定精神的进程及其经验
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作者 梁静 张荣臣 《理论建设》 2025年第5期45-55,共11页
中央八项规定精神的形成和贯彻,是党的自我革命在作风建设领域的集中体现和生动实践。新时代深入贯彻中央八项规定精神,取得了教育引导不断强化、制度体系日益健全、监督执行显著增强,党风政风为之一新、社风民风持续性向好、政治生态... 中央八项规定精神的形成和贯彻,是党的自我革命在作风建设领域的集中体现和生动实践。新时代深入贯彻中央八项规定精神,取得了教育引导不断强化、制度体系日益健全、监督执行显著增强,党风政风为之一新、社风民风持续性向好、政治生态持续改善,自我革命不断推进、党群关系更加密切、执政根基稳如磐石的实践成效。常态化长效化推动中央八项规定精神贯彻落实,必须深化马克思主义执政党建设规律认识,秉持自我革命的政治勇气和历史自觉,把贯彻落实中央八项规定精神的好经验好做法转化为常态长效机制,巩固好拓展好现有理论成果、文化成果、制度成果和实践成果,为党的自我革命引领社会革命提供坚强作风保障。 展开更多
关键词 中央八项规定精神 自我革命 作风建设 常态化长效化
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机载LiDAR点云建筑物边界提取算法
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作者 闫花英 赖海明 《北京测绘》 2025年第5期653-658,共6页
为了提升基于机载雷达(LiDAR)点云的建筑物边界提取精度,本文设计并实现了一种渐进式建筑物边界提取算法。首先,借助布料模拟滤波方法,有效区分地面点、非地面点;随后,通过最大类间方差法(Otsu)对非地面点云进行阈值分析,识别出潜在的... 为了提升基于机载雷达(LiDAR)点云的建筑物边界提取精度,本文设计并实现了一种渐进式建筑物边界提取算法。首先,借助布料模拟滤波方法,有效区分地面点、非地面点;随后,通过最大类间方差法(Otsu)对非地面点云进行阈值分析,识别出潜在的建筑物点云,融合阿尔法形状(alpha-shape)算法和道格拉斯-普克算法(Douglas-Peucker algorithm,D-P)获取建筑物的轮廓线,结合边界线的关键特征确定轮廓线角点;最后,对轮廓线进行标准化处理,得到最终建筑物边界线信息。选取杭州某地区机载LiDAR点云数据进行试验测试,试验结果的第一类误差率为8.04%,第二类误差率为10.39%,总误差率为8.84%,同时Kappa系数高达80.54%,验证了本文方法的有效性。 展开更多
关键词 机载雷达(LiDAR)点云 建筑物边界 最大类间方差法 边界线规则化
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A Fixed Point Method for Convex Systems
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作者 Morteza Kimiaei Farzad Rahpeymaii 《Applied Mathematics》 2012年第10期1327-1333,共7页
We present a new fixed point technique to solve a system of convex equations in several variables. Our approach is based on two powerful algorithmic ideas: operator-splitting and steepest descent direction. The quadra... We present a new fixed point technique to solve a system of convex equations in several variables. Our approach is based on two powerful algorithmic ideas: operator-splitting and steepest descent direction. The quadratic convergence of the proposed approach is established under some reasonable conditions. Preliminary numerical results are also reported. 展开更多
关键词 CONVEX EQUATIONS Least SQUARES -regularization Problems Fixed point Quadratically CONVERGENCE
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ON THE EXISTENCE OF COMMON FIXED POINTS FOR A PAIR OF LIPSCHITZIAN MAPPINGS IN BANACH SPACES
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作者 曾六川 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2003年第3期344-354,共11页
The existence of common fixed points for a pair of Lipschitzian mappings in Banach spaces is proved. By using this result, some common fixed point theorems are also established for these mappings in Hilbert spaces, in... The existence of common fixed points for a pair of Lipschitzian mappings in Banach spaces is proved. By using this result, some common fixed point theorems are also established for these mappings in Hilbert spaces, in L p spaces, in Hardy spaces H p, and in Sobolev spaces H r,p , for 1<p<+∞ and r≥0. 展开更多
关键词 asymptotic regularity common fixed point Lipschitzian mapping p- uniformly convex Banach space weak ω-limit set
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Accelerated RHSS Iteration Method for Stabilized Saddle-Point Problems
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作者 Zhenghui Song Pingping Zhang 《Journal of Applied Mathematics and Physics》 2022年第4期1019-1027,共9页
For stabilized saddle-point problems, we apply the two iteration parameters idea for regularized Hermitian and skew-Hermitian splitting (RHSS) method and establish accelerated RHSS (ARHSS) iteration method. Theoretica... For stabilized saddle-point problems, we apply the two iteration parameters idea for regularized Hermitian and skew-Hermitian splitting (RHSS) method and establish accelerated RHSS (ARHSS) iteration method. Theoretical analysis shows that the ARHSS method converges unconditionally to the unique solution of the saddle point problem. Finally, we use a numerical example to confirm the effectiveness of the method. 展开更多
关键词 Stabilized Saddle-point Problems regularized Hermitian and Skew-Hermitian Splitting Iteration Parameters Convergence Property
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Delight and Frustration with Number “Seven” in Plane Geometry and the Regular Heptagon
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作者 A. Wünsche 《Advances in Pure Mathematics》 2021年第1期63-100,共38页
As starting point for patterns with seven-fold symmetry, we investigate the basic possibility to construct the regular heptagon by bicompasses and ruler. To cover the whole plane with elements of sevenfold symmetry is... As starting point for patterns with seven-fold symmetry, we investigate the basic possibility to construct the regular heptagon by bicompasses and ruler. To cover the whole plane with elements of sevenfold symmetry is only possible by overlaps and (or) gaps between the building stones. Resecting small parts of overlaps and filling gaps between the heptagons, one may come to simple parqueting with only a few kinds of basic tiles related to sevenfold symmetry. This is appropriate for parqueting with a center of seven-fold symmetry that is illustrated by figures. Choosing from the basic patterns with sevenfold symmetry small parts as elementary stripes or elementary cells, one may form by their discrete translation in one or two different directions periodic bordures or tessellation of the whole plane but the sevenfold point-group symmetry of the whole plane is then lost and there remains only such symmetry in small neighborhoods around one or more centers. From periodic tiling, we make the transition to aperiodic tiling of the plane. This is analogous to Penrose tiling which is mostly demonstrated with basic elements of fivefold symmetry and we show that this is also possible with elements of sevenfold symmetry. The two possible regular star-heptagons and a semi-regular star-heptagon play here a basic role. 展开更多
关键词 Bicompasses and Ruler Construction regular Heptagon regular and Semi-regular Star-Heptagons point-Group Symmetry C7 and C7v Parqueting Tiling Tessellation Penrose Tiles Symmetry and Antisymmetry Magnetic and Non-Magnetic Classes Time Inversion Color Groups
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利用点电流源和Tikhonov正则化的潜艇稳恒电场反演方法
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作者 张建春 刘春阳 赵玉龙 《国防科技大学学报》 EI CAS CSCD 北大核心 2024年第4期212-221,共10页
为了评估潜艇水下腐蚀相关稳恒电场分布特性,从潜艇水下腐蚀相关稳恒电场产生机理出发,基于等效点电流源建立潜艇水下腐蚀相关稳恒电场正演模型,并利用Tikhonov正则化根据已知电场数据求解等效点电流源电流强度,对潜艇周围海水空间的腐... 为了评估潜艇水下腐蚀相关稳恒电场分布特性,从潜艇水下腐蚀相关稳恒电场产生机理出发,基于等效点电流源建立潜艇水下腐蚀相关稳恒电场正演模型,并利用Tikhonov正则化根据已知电场数据求解等效点电流源电流强度,对潜艇周围海水空间的腐蚀相关稳恒电场进行推算。将某型潜艇的COMSOL软件仿真结果作为模拟试验数据,对所提方法有效性进行验证。结果表明:由水深38 m电场值向水深42.5 m和水深33.5 m进行反演时,相对均方根误差、最大值相对误差、峰峰值相对误差均不超过0.06;由较近平面向较远平面进行反演时,即使推算深度达到45 m,相对均方根误差仍然在0.21以内;噪声标准差为实际电场最大值的0.1倍时,反演误差仍然小于0.1。该算法抗噪声能力强,精度较高,能较好地用于工程实践。 展开更多
关键词 潜艇电场 反演 点电流源 TIKHONOV正则化
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轻质烷烃混合流体固液平衡状态预测与致密化规律
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作者 刘柏文 王磊 +3 位作者 上官石 厉彦忠 谢福寿 马原 《低温工程》 CAS CSCD 北大核心 2024年第5期67-72,86,共7页
对比分析了多种轻质烷烃类混合流体凝固温度预测模型,发现正规溶液模型具有较高精度。采用该模型分别针对甲烷-乙烷、甲烷-丙烷二元混合流体的凝固温度及密度提升率开展了仿真分析。结果表明,对甲烷-乙烷体系,当甲烷摩尔含量为0.72时,... 对比分析了多种轻质烷烃类混合流体凝固温度预测模型,发现正规溶液模型具有较高精度。采用该模型分别针对甲烷-乙烷、甲烷-丙烷二元混合流体的凝固温度及密度提升率开展了仿真分析。结果表明,对甲烷-乙烷体系,当甲烷摩尔含量为0.72时,体系达到最低凝固点,温度约72.90 K,相较于三相点纯甲烷,密度提升率为21.62%;对甲烷-丙烷体系,最低凝固温度存在于甲烷含量为0.66时,凝固温度为71.55 K,密度提升率34.48%。采用理想溶液模型预估了甲烷-乙烷-丙烷三元体系的混合特征。结果发现,当混合比为0.63∶0.17∶0.20时,凝固温度降至63.11 K,甲烷推进剂过冷潜能进一步提高。提供了3种混合流体相图,为液甲烷推进剂过冷制备、深度致密化提供了理论支撑。 展开更多
关键词 固液相平衡 共晶点 致密化 正规溶液模型
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