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模糊拓扑空间的m-紧(Ⅰ)
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作者 李庆国 《湖南大学学报(自然科学版)》 EI CAS CSCD 2000年第4期1-6,共6页
在模糊拓扑空间中利用强开覆盖的概念引进一个称作 m-紧的紧性定义 ,并研究了它与模糊网的 m-收敛之间的关系 .证明了 Tychonoff乘积定理对 m-紧性成立 .
关键词 强开覆盖 模型 模型拓扑空间
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室内实景三维重建技术综述
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作者 康志忠 杨俊涛 《时空信息学报》 2024年第1期1-10,共10页
构建语义丰富、几何精确且拓扑完备的室内三维模型是实景三维中国建设中一项富有挑战性的任务,在室内导航与位置服务、虚拟现实、智能家居等领域都有重要的应用价值。室内空间结构布局复杂、实体要素类型多样及杂乱遮挡等因素给室内实... 构建语义丰富、几何精确且拓扑完备的室内三维模型是实景三维中国建设中一项富有挑战性的任务,在室内导航与位置服务、虚拟现实、智能家居等领域都有重要的应用价值。室内空间结构布局复杂、实体要素类型多样及杂乱遮挡等因素给室内实景三维重建带来诸多挑战。近些年,室内实景三维重建受到广泛关注,然而关于现有方法的系统性总结仍较为欠缺。本文对室内实景三维重建最新技术的研究进展进行整理和归纳。首先,简要总结当前主流的室内空间三维数据采集手段;其次,从室内实景三维模型构建过程中涉及的关键环节出发,从实体要素语义识别和分类、实体要素几何模型生成、空间拓扑特征组织与表达方面对现有方法及其优缺点进行综述;最后,对室内实景三维重建相关研究现存的技术挑战进行分析总结,并对未来研究趋势进行展望。 展开更多
关键词 室内实景三维 数据配准 实体要素分类 空间拓扑模型 实体要素几何模型
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深圳市轨道交通复杂网络特性分析 被引量:1
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作者 孔攀登 《交通与运输》 2023年第1期44-48,共5页
为了研究深圳市轨道交通网络的特点,对深圳市轨道交通网络建立基于复杂网络理论的L空间及P空间网络模型。通过对网络路径长度的分析,发现P空间网络模型不完全适用于深圳市轨道交通网络。通过对节点度、节点介数、聚类系数等参数及其分... 为了研究深圳市轨道交通网络的特点,对深圳市轨道交通网络建立基于复杂网络理论的L空间及P空间网络模型。通过对网络路径长度的分析,发现P空间网络模型不完全适用于深圳市轨道交通网络。通过对节点度、节点介数、聚类系数等参数及其分布规律的分析,得到深圳市轨道交通网络具有较高的聚类系数和较小的平均路径长度,但节点度分布在L空间及P空间下均服从高斯分布,说明深圳市轨道交通网络属于具有一定小世界网络特征的混合结构网络。通过分析深圳市轨道交通网络的复杂网络特性及存在的部分问题,可以为优化轨道交通网络的连通性提供一定的理论基础和科学依据。 展开更多
关键词 轨道交通 复杂网络 混合结构网络 拓扑空间模型 高斯分布
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第三次国土调查的图斑自动综合方法 被引量:8
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作者 梁磊 周启 +1 位作者 任东宇 文学虎 《测绘通报》 CSCD 北大核心 2021年第12期124-129,共6页
从第三次国土调查数据库快速缩编派生出多尺度数据库,是地图制图的重要任务。本文针对大量图斑,首先通过研究图斑栅格综合,减少碎图斑数量;然后构建图斑语义邻近度模型、空间几何拓扑模型,分析了顾及拓扑和地区地理特征约束下的地类图... 从第三次国土调查数据库快速缩编派生出多尺度数据库,是地图制图的重要任务。本文针对大量图斑,首先通过研究图斑栅格综合,减少碎图斑数量;然后构建图斑语义邻近度模型、空间几何拓扑模型,分析了顾及拓扑和地区地理特征约束下的地类图斑制图综合方法;最后形成了自动化图斑缩编生产工艺流程。基于上述方法,采用计算机编程技术研发国土三调缩编系统,并应用于四川省某县23万图斑量的三调数据并试验验证。试验结果表明,通过本文方法的成果符合专题制图要求,极大地提高了三调图斑的自动综合效率。 展开更多
关键词 多尺度数据库 图斑栅格综合 语义邻近度 空间几何拓扑模型 图斑缩编
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Kinematic Model Extraction for Serial Manipulators Which Have in Different Topologies in Vpython Environment
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作者 Ece Yildirim 《Journal of Mechanics Engineering and Automation》 2015年第9期503-509,共7页
In this study, we aim at obtaining inverse kinematic model of a serial manipulator using spatial operator algebra. For testing the inverse kinematic algorithm, the Vpython software program which has simultaneous view ... In this study, we aim at obtaining inverse kinematic model of a serial manipulator using spatial operator algebra. For testing the inverse kinematic algorithm, the Vpython software program which has simultaneous view and software working, is used. The aim is to measure the inverse kinematics modeling work on different serial manipulator mechanisms with spatial vector algebra. The algorithm is used with the same reference inputs on the recursive, exact and nonrecursive manipulators. During the tests, the permitted error tolerance is 0.01 cm. The graph plots show that the algorithm is fit for the error tolerance. 展开更多
关键词 Spatial operator algebra inverse kinematic Vpython.
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The Extension of Infinitesimal Prolongation Theorem and Its Application
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作者 陈东立 《Journal of Mathematical Research and Exposition》 CSCD 北大核心 2003年第2期221-224,共4页
Infinitesimal prolongation theorem is extended from sequences to nets based on κ-saturated nonstandard model. As its an application, a main property about topology of uniform convergence is proved. The proof is much ... Infinitesimal prolongation theorem is extended from sequences to nets based on κ-saturated nonstandard model. As its an application, a main property about topology of uniform convergence is proved. The proof is much simpler than it was, meanwhile the nonstandard characteristics of convergence with respect to u.c. topology is given. 展开更多
关键词 Infinitesimal Prolongation Theorem κ-saturation monad of uniformity topology of uniform convergence.
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Building 3D Cadastral System Based on 2D Survey Plans with SketchUp 被引量:7
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作者 YING Shen LI Lin GUO Renzhong 《Geo-Spatial Information Science》 2011年第2期129-136,共8页
Three-dimensional (3D) land development and utilization has become the trend for urban planning in the current metropolis.This paper presents a method for building a 3D cadastral management system from survey plans wi... Three-dimensional (3D) land development and utilization has become the trend for urban planning in the current metropolis.This paper presents a method for building a 3D cadastral management system from survey plans with SketchUp.It concentrates on the geometric representation and topological consistent maintenance of 3D cadastral objects.In this system a complete topological model is built to express the body construction and spatial relationships among 3D property units.SketchUp is used to automatically construct 3D models with attributes and thematic information from 2D survey plans.Spatial topologic relationships and operations are analyzed with the programming and development of Ruby language.The resulting system can manage 3D cadastral objects and manipulate them with spatial operations to support spatial analysis. 展开更多
关键词 3D cadastre topological model spatial operation
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Simulation of higher-order topological phases and related topological phase transitions in a superconducting qubit 被引量:4
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作者 Jingjing Niu Tongxing Yan +9 位作者 Yuxuan Zhou Ziyu Tao Xiaole Li Weiyang Liu Libo Zhang Hao Jia Song Liu Zhongbo Yan Yuanzhen Chen Dapeng Yu 《Science Bulletin》 SCIE EI CSCD 2021年第12期1168-1175,M0003,共9页
Higher-order topological phases give rise to new bulk and boundary physics,as well as new classes of topological phase transitions.While the realization of higher-order topological phases has been confirmed in many pl... Higher-order topological phases give rise to new bulk and boundary physics,as well as new classes of topological phase transitions.While the realization of higher-order topological phases has been confirmed in many platforms by detecting the existence of gapless boundary modes,a direct determination of the higher-order topology and related topological phase transitions through the bulk in experiments has still been lacking.To bridge the gap,in this work we carry out the simulation of a twodimensional second-order topological phase in a superconducting qubit.Owing to the great flexibility and controllability of the quantum simulator,we observe the realization of higher-order topology directly through the measurement of the pseudo-spin texture in momentum space of the bulk for the first time,in sharp contrast to previous experiments based on the detection of gapless boundary modes in real space.Also through the measurement of the evolution of pseudo-spin texture with parameters,we further observe novel topological phase transitions from the second-order topological phase to the trivial phase,as well as to the first-order topological phase with nonzero Chern number.Our work sheds new light on the study of higher-order topological phases and topological phase transitions. 展开更多
关键词 Higher-order topological phases Quantum simulation Topological phase transitions Superconducting circuits
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Separation axioms under crossover operator and its generalized
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作者 M. M. El-Sharkasy M. Shokry 《International Journal of Biomathematics》 2016年第4期169-191,共23页
The purpose of this work is to construct a new crossover operator using the properties of DNA and RNA by using topological concepts in constructing flexible mathematical models in the field of biomathematics. Also, we... The purpose of this work is to construct a new crossover operator using the properties of DNA and RNA by using topological concepts in constructing flexible mathematical models in the field of biomathematics. Also, we investigate and study topological prop- erties of the constructed operators and the associated topological spaces of DNA and RNA. Finally we use the process of exchange for sequence of genotypes structures to construct new types of topological concepts to investigate and discuss several examples and some of their properties. 展开更多
关键词 DNA and RNA GENOTYPES TOPOLOGY (To T1 T2)-crossover space.
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