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PERIODIC SYSTEMS WITH TIME DEPENDENT MAXIMAL MONOTONE OPERATORS
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作者 Zhenhai LIU Nikolaos S.PAPAGEORGIOU 《Acta Mathematica Scientia》 SCIE CSCD 2024年第4期1280-1300,共21页
We consider a first order periodic system in R^(N),involving a time dependent maximal monotone operator which need not have a full domain and a multivalued perturbation.We prove the existence theorems for both the con... We consider a first order periodic system in R^(N),involving a time dependent maximal monotone operator which need not have a full domain and a multivalued perturbation.We prove the existence theorems for both the convex and nonconvex problems.We also show the existence of extremal periodic solutions and provide a strong relaxation theorem.Finally,we provide an application to nonlinear periodic control systems. 展开更多
关键词 periodic boundary condition time-dependent maximal monotone operator convex and nonconvex problems extremal solutions strong relaxation
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Accelerated Primal-Dual Projection Neurodynamic Approach With Time Scaling for Linear and Set Constrained Convex Optimization Problems
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作者 You Zhao Xing He +1 位作者 Mingliang Zhou Tingwen Huang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第6期1485-1498,共14页
The Nesterov accelerated dynamical approach serves as an essential tool for addressing convex optimization problems with accelerated convergence rates.Most previous studies in this field have primarily concentrated on... The Nesterov accelerated dynamical approach serves as an essential tool for addressing convex optimization problems with accelerated convergence rates.Most previous studies in this field have primarily concentrated on unconstrained smooth con-vex optimization problems.In this paper,on the basis of primal-dual dynamical approach,Nesterov accelerated dynamical approach,projection operator and directional gradient,we present two accelerated primal-dual projection neurodynamic approaches with time scaling to address convex optimization problems with smooth and nonsmooth objective functions subject to linear and set constraints,which consist of a second-order ODE(ordinary differential equation)or differential conclusion system for the primal variables and a first-order ODE for the dual vari-ables.By satisfying specific conditions for time scaling,we demonstrate that the proposed approaches have a faster conver-gence rate.This only requires assuming convexity of the objective function.We validate the effectiveness of our proposed two accel-erated primal-dual projection neurodynamic approaches through numerical experiments. 展开更多
关键词 Accelerated projection neurodynamic approach lin-ear and set constraints projection operators smooth and nonsmooth convex optimization time scaling.
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RADIAL CONVEX SOLUTIONS OF A SINGULAR DIRICHLET PROBLEM WITH THE MEAN CURVATURE OPERATOR IN MINKOWSKI SPACE 被引量:3
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作者 Zaitao LIANG 杨艳娟 《Acta Mathematica Scientia》 SCIE CSCD 2019年第2期395-402,共8页
In this paper, we study the existence of nontrivial radial convex solutions of a singular Dirichlet problem involving the mean curvature operator in Minkowski space. The proof is based on a well-known fixed point theo... In this paper, we study the existence of nontrivial radial convex solutions of a singular Dirichlet problem involving the mean curvature operator in Minkowski space. The proof is based on a well-known fixed point theorem in cones. We deal with more general nonlinear term than those in the literature. 展开更多
关键词 RADIAL convex SOLUTIONS SINGULAR Dirichlet problem mean CURVATURE operator fixed point theorem in cones
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SANDWICH-TYPE RESULTS FOR A CLASS OF CONVEX INTEGRAL OPERATORS 被引量:1
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作者 Teodor Bulboac 《Acta Mathematica Scientia》 SCIE CSCD 2012年第3期989-1001,共13页
Let H(U) be the space of analytic functions in the unit disk U. For the integral operator
关键词 Analytic function starlike and convex function differential operator differential subordination
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The Fixed Point Theorems of α-concave Covex Operators with Application 被引量:2
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作者 颜心力 《Chinese Quarterly Journal of Mathematics》 CSCD 1992年第2期88-91,共4页
The coceptions of two element α-concave convex and mixed α-concave convex operators are introduced. The fixed point theorems of the two type operators are obtained. By these theorems,the existence and uniquence of s... The coceptions of two element α-concave convex and mixed α-concave convex operators are introduced. The fixed point theorems of the two type operators are obtained. By these theorems,the existence and uniquence of solution of three type nonlinear integral equations is studied. 展开更多
关键词 semi-order space α-concave convex operator mixed α-concave convex operator
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Convexity for New Integral Operator on k-uniformly p-valent a-convex Functions of Complex Order 被引量:1
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作者 LI Shu-hai MA Li-na A O-en 《Chinese Quarterly Journal of Mathematics》 CSCD 2014年第1期88-96,共9页
In this paper, we obtain the convexity of new general integral operator on some classes of k-uniformly p-valent a-convex functions of complex order. These results extend some known theorems.
关键词 analytic functions p-valently k-uniformly STARLIKE convex integral operator
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EXISTENCE OF MULTIPLE SOLUTIONS FOR SINGULAR QUASILINEAR ELLIPTIC SYSTEM WITH CRITICAL SOBOLEV-HARDY EXPONENTS AND CONCAVE-CONVEX TERMS 被引量:6
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作者 李圆晓 高文杰 《Acta Mathematica Scientia》 SCIE CSCD 2013年第1期107-121,共15页
The main purpose of this paper is to establish the existence of multiple solutions for singular elliptic system involving the critical Sobolev-Hardy exponents and concave-convex nonlinearities. It is shown, by means o... The main purpose of this paper is to establish the existence of multiple solutions for singular elliptic system involving the critical Sobolev-Hardy exponents and concave-convex nonlinearities. It is shown, by means of variational methods, that under certain conditions, the system has at least two positive solutions. 展开更多
关键词 singular elliptic system concave-convex nonlinearities positive solution Nehari manifold critical Sobolev-Hardy exponent
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MULTIPLE POSITIVE SOLUTIONS FOR QUASILINEAR ELLIPTIC PROBLEMS INVOLVING CONCAVE-CONVEX NONLINEARITIES AND MULTIPLE HARDY-TYPE TERMS 被引量:3
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作者 Tsing-San HSU 《Acta Mathematica Scientia》 SCIE CSCD 2013年第5期1314-1328,共15页
In this paper, we deal with the existence and multiplicity of positive solutions for the quasilinear elliptic problem -△pu-∑i=1^kμi|u|^p-2/|x-ai|p^u=|u|^p^*-2u+λ|u|^q-2u,x∈Ω,where Ω belong to R^N(N ... In this paper, we deal with the existence and multiplicity of positive solutions for the quasilinear elliptic problem -△pu-∑i=1^kμi|u|^p-2/|x-ai|p^u=|u|^p^*-2u+λ|u|^q-2u,x∈Ω,where Ω belong to R^N(N ≥ 3) is a smooth bounded domain such that the different points ai∈Ω,i= 1,2,...,k,0≤μi〈μ^-=(N-p/p)^p,λ〉0,1≤q〈p,and p^*=p^N/N-p.The results depend crucially cn the parameters λ,q and μi for i=1,2,...,k. 展开更多
关键词 multiple positive solutions concave-convex nonlinearities multiple Hardy- type terms
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ON SEMILINEAR ELLIPTIC EQUATIONS WITH CONCAVE AND CONVEX NONLINEARITIES IN R^N
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作者 杨海涛 陈祖墀 《Acta Mathematica Scientia》 SCIE CSCD 2000年第2期181-188,共8页
In this paper, a class of semilinear elliptic equations with sublinear and superlinear nonlinearities in R-N is studied. By making use of variational method and L-infinity estimation, the authors obtain some results a... In this paper, a class of semilinear elliptic equations with sublinear and superlinear nonlinearities in R-N is studied. By making use of variational method and L-infinity estimation, the authors obtain some results about existence of multiple positive solutions and asymptotic behavior of the solutions. 展开更多
关键词 concave convex critical point asymptotic behavior
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CONVEX MAPPINGS ASSOCIATED WITH THE ROPER-SUFFRIDGE EXTENSION OPERATOR
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作者 Danli ZHANG Huiming XU Jianfei WANG 《Acta Mathematica Scientia》 SCIE CSCD 2019年第6期1619-1627,共9页
Let λG(z)|dz| be the hyperbolic metric on a simply connected proper domain G?C containing the origin, and let ■be the Banach norms of Cnj for j = 1, 2,…,k.This note is to prove that if f is a normalized biholomor... Let λG(z)|dz| be the hyperbolic metric on a simply connected proper domain G?C containing the origin, and let ■be the Banach norms of Cnj for j = 1, 2,…,k.This note is to prove that if f is a normalized biholomorphic convex function on G, then ■is a normalized biholomorphic convex mapping on ■where N = 1+n1 + … + nk and the branch is chosen such that ■,j = 1,…, k. Applying to the Roper-Suffridge extension operator, we obtain a new convex mappings construction of an unbounded domain and a refinement of convex mappings construction on a Reinhardt domain, respectively. 展开更多
关键词 Roper-Suffridge operator convex MAPPING HYPERBOLIC METRIC
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BERNSTEIN-TYPE OPERATORS, CONVEXITY AND LIPSCHITZ CLASSES
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作者 B. Delia Vecchia I. Rasa 《Analysis in Theory and Applications》 1995年第1期16-23,共8页
In the present paper we extend previous results about the monotoaicity of Bernstein-type operators rdtiwe to convex functions and about the preservation of Lipschitz classes.
关键词 BERNSTEIN-TYPE operatorS convexITY AND LIPSCHITZ CLASSES
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Existence of Positive Solutions to Semilinear Elliptic Systems Involving Concave and Convex Nonlinearities
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作者 Mohamed E1 Mokhtar ould El Mokhtar 《Journal of Physical Science and Application》 2015年第1期71-81,共11页
In this paper, we studied the combined effect of concave and convex nonlinearities on the number of positive solutions for a semilinear elliptic system. We prove the existence of at least four positive solutions for a... In this paper, we studied the combined effect of concave and convex nonlinearities on the number of positive solutions for a semilinear elliptic system. We prove the existence of at least four positive solutions for a semilinear elliptic system involving concave and convex nonlinearities by using the Nehari manifold and the center mass function. 展开更多
关键词 Elliptic systems concave and convex nonlinearities Nehari manifold maximum principle.
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Multiple Solutions for a Class of Variable-Order Fractional Laplacian Equations with Concave-Convex Nonlinearity
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作者 Canlin Gan Ting Xiao Qiongfen Zhang 《Journal of Applied Mathematics and Physics》 2022年第3期837-849,共13页
This paper is concerned with the following variable-order fractional Laplacian equations , where N ≥ 1 and N > 2s(x,y) for (x,y) ∈ Ω × Ω, Ω is a bounded domain in R<sup>N</sup>, s(&#8901;)... This paper is concerned with the following variable-order fractional Laplacian equations , where N ≥ 1 and N > 2s(x,y) for (x,y) ∈ Ω × Ω, Ω is a bounded domain in R<sup>N</sup>, s(&#8901;) ∈ C (R<sup>N</sup> × R<sup>N</sup>, (0,1)), (-Δ)<sup>s(&#8901;)</sup> is the variable-order fractional Laplacian operator, λ, μ > 0 are two parameters, V: Ω → [0, ∞) is a continuous function, f ∈ C(Ω × R) and q ∈ C(Ω). Under some suitable conditions on f, we obtain two solutions for this problem by employing the mountain pass theorem and Ekeland’s variational principle. Our result generalizes the related ones in the literature. 展开更多
关键词 concave-convex Nonlinearity Variable-Order Fractional Laplacian Variational Methods Fractional Elliptic Equation
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凹凸工艺在再生纸包装设计中的应用研究 被引量:2
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作者 董小丹 《文化创新比较研究》 2024年第5期120-123,129,共5页
凹凸工艺与再生纸包装结合深受人们关注,随着人们环保意识的提高,再生纸包装设计运用广泛。同时,再生纸结合凹凸工艺让包装更具有一定的审美价值及实用价值。然而,在当下市场凹凸工艺的印刷及制作成本相对较高,因此该文主要研究凹凸工... 凹凸工艺与再生纸包装结合深受人们关注,随着人们环保意识的提高,再生纸包装设计运用广泛。同时,再生纸结合凹凸工艺让包装更具有一定的审美价值及实用价值。然而,在当下市场凹凸工艺的印刷及制作成本相对较高,因此该文主要研究凹凸工艺在再生纸包装设计中与3D+AI智能技术结合,以及探讨凹凸工艺在再生纸包装设计中的应用及创新方法,让凹凸工艺与再生纸包装融合在市场上有新的突破。同时,再生纸作为环保材料,不但具有可持续性和可回收利用的优点,还可以降低成本,凹凸工艺在再生纸包装设计中的应用研究有着更重要的意义。 展开更多
关键词 凹凸工艺 再生纸包装设计 应用研究 压印 3D+AI 环保材料
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基于凸包算法的极端运行方式提取方法
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作者 许彦平 白婕 +2 位作者 施浩波 秦晓辉 张彦涛 《中国电力》 CSCD 北大核心 2024年第7期30-39,共10页
在电力系统规划与运行的安全稳定计算中,一般选择对安全稳定最不利的运行方式进行校验,但随着新能源渗透率的增加,电网越发复杂多变,人工选择场景主观性较强,针对此问题,提出了一种基于快速凸包算法的极端运行方式提取,从而满足场景选... 在电力系统规划与运行的安全稳定计算中,一般选择对安全稳定最不利的运行方式进行校验,但随着新能源渗透率的增加,电网越发复杂多变,人工选择场景主观性较强,针对此问题,提出了一种基于快速凸包算法的极端运行方式提取,从而满足场景选取进行安全校核需求。从电源规划、发输电协调规划两个角度,考虑发电充裕性、火电爬坡需求、网络传输安全3个方面,分析影响规划的极端运行方式;基于凸包算法分别从上述3个方面构建坐标系进行极端运行方式提取;采用中国西北地区电网为算例进行极端运行方式提取,并与基于K-means算法的极端场景提取做对比,结果表明:所提方法能为场景选取提供有效数据支撑,满足电网规划要求。 展开更多
关键词 凸包算法 极端运行方式 电源规划 发输电协调规划 场景提取
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开采深度对低凹陷露天矿装载扬尘运移规律和质量浓度分布特征的影响分析
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作者 柯丽华 杨玄保 +4 位作者 蒋玉文 张光权 余晓轲 贺振祥 黄兆云 《中国矿业》 北大核心 2024年第7期142-148,共7页
为减少低凹陷露天矿装载扬尘对作业人员职业健康和外部环境污染的不利影响,依据气-固两相流理论,采用Fluent数值模拟方法,对不同开采深度条件下的低凹陷露天矿采装工作面装载扬尘的运移规律和质量浓度分布特征进行研究。研究结果表明:... 为减少低凹陷露天矿装载扬尘对作业人员职业健康和外部环境污染的不利影响,依据气-固两相流理论,采用Fluent数值模拟方法,对不同开采深度条件下的低凹陷露天矿采装工作面装载扬尘的运移规律和质量浓度分布特征进行研究。研究结果表明:开采深度对装载扬尘扩散方式和呼吸带高度处装载扬尘质量浓度的影响显著;当开采深度H=0 m时,受矿车的阻挡作用发生方柱扰流,装载扬尘颗粒逸出车厢后,沿X轴方向线性扩散,扩散距离随扩散时间延长而增大;当开采深度H>0 m时,采场风流在台阶处发生流动分离,形成与开采深度同高的风流漩涡,装载扬尘颗粒逸出车厢后,随着大结构漩涡向四周扩散;随着开采深度增加,装载扬尘颗粒沿X轴扩散距离逐渐减小,沿Z轴运移扩散距离增大,矿车下风向呼吸带高度处装载扬尘质量浓度超标影响范围减小,装载扬尘在呼吸带高度上的质量浓度随扩散时间增加而逐渐降低,并在t=100 s时降低至职业接触限值8 mg/m3以下。本文研究为合理确定装载扬尘的污染影响范围和制定有效的装载扬尘治理措施提供决策参考。 展开更多
关键词 装载扬尘 低凹陷露天矿 开采深度 采装作业 气-固两相流 数值模拟
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基于拐点密集区凹凸波动特性的直流配网故障检测方法 被引量:1
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作者 王晓卫 田影 +3 位作者 高杰 王雪 梁振锋 王毅钊 《电力系统保护与控制》 EI CSCD 北大核心 2024年第9期1-15,共15页
基于模块化多电平换流器(modular multilevel converter,MMC)的柔性直流配电网具有不存在换相失败等优点。但换流器存在低惯性、弱阻尼等特性,导致故障电流上升速度快且峰值高,对系统危害极大。针对直流配电网发生单极接地故障难以准确... 基于模块化多电平换流器(modular multilevel converter,MMC)的柔性直流配电网具有不存在换相失败等优点。但换流器存在低惯性、弱阻尼等特性,导致故障电流上升速度快且峰值高,对系统危害极大。针对直流配电网发生单极接地故障难以准确选择故障馈线的问题,提出了一种基于拐点密集区凹凸波动特性的直流配网故障检测方法。首先,利用变分模态分解算法对各馈线零模电流进行分解,选取特征分量。然后,计算特征分量的二阶导数,选择拐点密集区并进行归一化处理,得到各馈线的凹凸波动性。最后,判定凹凸波动性与其他馈线相异的线路为故障线路。仿真结果表明,所提方法能够快速识别故障馈线,且受过渡电阻、采样频率、数据窗和噪声等因素影响小。 展开更多
关键词 故障检测 单极接地故障 零模电流 拐点密集区 凹凸波动性
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基于凹凸性和转向角的古陶瓷碎片二次匹配算法
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作者 刘鹏欢 周强 +4 位作者 王莹 朱建锋 罗宏杰 王露 王甜 《计算机工程》 CAS CSCD 北大核心 2024年第9期356-366,共11页
碎片拼接是古陶瓷修复的关键工作,针对古陶瓷碎片形状随机、数量大、表面纹理弱且存在局部缺损而导致算法的精度较低、匹配时间较长等问题,提出一种基于凹凸性和转向角的古陶瓷碎片二次配算法。在提取古陶瓷碎片轮廓曲线的基础上,通过... 碎片拼接是古陶瓷修复的关键工作,针对古陶瓷碎片形状随机、数量大、表面纹理弱且存在局部缺损而导致算法的精度较低、匹配时间较长等问题,提出一种基于凹凸性和转向角的古陶瓷碎片二次配算法。在提取古陶瓷碎片轮廓曲线的基础上,通过先后使用粗匹配和细匹配的二次匹配组合实现碎片的两两精确匹配。一次粗匹配先通过多边形逼近碎片轮廓曲线,以降低轮廓的复杂性,再提取多边形的顶点凹凸性和顶点转向角构建一次轮廓特征集合,最后利用凹凸互补性和遍历顶点对齐的双模态特征初次匹配算法来寻找大致匹配段,并得到粗匹配点集。二次细匹配先随机选取粗匹配点集中的任意相邻两点点对来提取碎片轮廓片段,以减少轮廓点数量并提高算法效率,再计算轮廓片段的轮廓转向角以提取二次轮廓特征集合,最后利用基于粒子群优化的二次匹配来搜索精确匹配段,并得到细匹配点集。实验结果表明,该算法对二维古陶瓷碎片的拼接效果较好,且具有较强的鲁棒性,拼接误差不超过2%,运行时间效率相比已有算法提高了8%~20%。 展开更多
关键词 碎片拼接 二次匹配算法 轮廓提取 凹凸性 转向角 粒子群优化
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湘鄂渝黔交接区隐伏型红色岩溶地貌形态成因及其区域分布
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作者 姜伏伟 赖海青 +3 位作者 杨庆坤 陈友智 于宁 杨涛 《中国岩溶》 CAS CSCD 北大核心 2024年第4期948-956,共9页
红色岩溶为新发现的隐伏型地貌,是埋藏于土下、颜色红艳、形态奇特的岩溶地貌。目前,红色岩溶研究主要集中于定义特征、形成条件、地质成因、演化模式等方面,但其独特的形态的形成机制、塑形过程及隐伏的分布范围尚未深入讨论。文章从... 红色岩溶为新发现的隐伏型地貌,是埋藏于土下、颜色红艳、形态奇特的岩溶地貌。目前,红色岩溶研究主要集中于定义特征、形成条件、地质成因、演化模式等方面,但其独特的形态的形成机制、塑形过程及隐伏的分布范围尚未深入讨论。文章从物质成分差异、节理裂隙切割及差异溶蚀作用三方面分析红色岩溶地貌形态的形成机制,并讨论了塑形的基本过程及关键地质作用。依据红色岩溶地貌发育的判定条件及地层特征,确定了湘鄂渝黔红色岩溶的分布范围。结果表明:(1)岩层中可溶性物质含量差异及层状韵律层是红色岩溶地貌形态塑形的物质条件。它的动力条件是构造节理裂隙切割与岩体差异溶蚀;(2)红色岩溶地貌形态演化经历四个基本阶段,其中节理裂隙切割、岩土界面溶蚀及节理裂隙面溶蚀是塑形的关键地质作用;(3)湘鄂渝黔四省红色岩溶地貌分布总面积达3433.83 km^(2),主要分布于湘北、湘西北、鄂西南、渝东南及黔东北。 展开更多
关键词 红色岩溶 差异溶蚀 隐伏型地貌 凹凸互层
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蜂巢组织的三维结构模拟
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作者 徐辉 朱昊 史红艳 《纺织学报》 EI CAS CSCD 北大核心 2024年第8期158-164,共7页
为解决蜂巢织物模拟时仿真度不高、经纬纱空间轨迹不准确等问题,提出一种蜂巢织物的模拟方法。将浮长线的拉拢作用与邻近组织点偏移倾向等因素相结合,分析了浮长线内组织点的偏移;在此基础上,建立了组织点偏移的数学模型,提出纱线偏移... 为解决蜂巢织物模拟时仿真度不高、经纬纱空间轨迹不准确等问题,提出一种蜂巢织物的模拟方法。将浮长线的拉拢作用与邻近组织点偏移倾向等因素相结合,分析了浮长线内组织点的偏移;在此基础上,建立了组织点偏移的数学模型,提出纱线偏移的算法。为避免偏移后不同纱线间的渗透与穿刺,依照机织物的织造规律设计了纱线的碰撞检测与处理算法;考虑蜂巢织物的凹凸外观,将织物的平纹组织划分为凸起和凹下二部分。研究结果表明:采取偏移算法后的织物模拟效果逼真,更接近实际织物中纱线的空间轨迹;经碰撞检测处理后的纱线一方面减少了渗透,另一方面也突出了织物的凹凸效果;对蜂巢织物平纹部分的划分处理使模拟织物表观的倒金字塔凹槽清晰可见,取得了预期效果。 展开更多
关键词 蜂巢组织 浮长线原理 偏移算法 碰撞处理 凹凸表观 织物模拟
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