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Constructing Three-Dimension Space Graph for Outlier Detection Algorithms in Data Mining 被引量:1
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作者 ZHANG Jing 1,2 , SUN Zhi-hui 1 1.Department of Computer Science and Engineering, Southeast University, Nanjing 210096, Jiangsu, China 2.Department of Electricity and Information Engineering, Jiangsu University, Zhenjiang 212001, Jiangsu, China 《Wuhan University Journal of Natural Sciences》 EI CAS 2004年第5期585-589,共5页
Outlier detection has very important applied value in data mining literature. Different outlier detection algorithms based on distinct theories have different definitions and mining processes. The three-dimensional sp... Outlier detection has very important applied value in data mining literature. Different outlier detection algorithms based on distinct theories have different definitions and mining processes. The three-dimensional space graph for constructing applied algorithms and an improved GridOf algorithm were proposed in terms of analyzing the existing outlier detection algorithms from criterion and theory. Key words outlier - detection - three-dimensional space graph - data mining CLC number TP 311. 13 - TP 391 Foundation item: Supported by the National Natural Science Foundation of China (70371015)Biography: ZHANG Jing (1975-), female, Ph. D, lecturer, research direction: data mining and knowledge discovery. 展开更多
关键词 OUTLIER DETECTION three-dimensional space graph data mining
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Continuous imaging space in three-dimensional integral imaging 被引量:1
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作者 张雷 杨勇 +3 位作者 王金刚 赵星 方志良 袁小聪 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第5期303-305,共3页
We report an integral imaging method with continuous imaging space. This method simultaneously reconstructs real and virtual images in the virtual mode, with a minimum gap that separates the entire imaging space into ... We report an integral imaging method with continuous imaging space. This method simultaneously reconstructs real and virtual images in the virtual mode, with a minimum gap that separates the entire imaging space into real and virtual space. Experimental results show that the gap is reduced to 45% of that in a conventional integral imaging system with the same parameters. 展开更多
关键词 three-dimensional integral imaging imaging space
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Three-dimensional numerical modeling of gravity anomalies based on Poisson equation in spacewavenumber mixed domain 被引量:6
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作者 Dai Shi-Kun Zhao Dong-Dong +3 位作者 Zhang Qian-Jiang Li Kun Chen Qing-Rui Wang Xu-Long 《Applied Geophysics》 SCIE CSCD 2018年第3期513-523,共11页
In gravity-anomaly-based prospecting, the computational and memory requirements for practical numerical modeling are potentially enormous. Achieving an efficient and precise inversion for gravity anomaly imaging over ... In gravity-anomaly-based prospecting, the computational and memory requirements for practical numerical modeling are potentially enormous. Achieving an efficient and precise inversion for gravity anomaly imaging over large-scale and complex terrain requires additional methods. To this end, we have proposed a new topography-capable By performing a two-dimensional Fourier transform in the horizontal directions, threedimensional partial differential equations in the spatial domain were transformed into a group of independent, one-dimensional differential equations engaged with different wave numbers. These independent differential equations are highly parallel across different wave numbers. differential equations with different wave numbers, and the efficiency of solving fixedbandwidth linear equations was further improved by a chasing method. In a synthetic test, a prism model was used to verify the accuracy and reliability of the proposed algorithm by comparing the numerical solution with the analytical solution. We studied the computational precision and efficiency with and without topography using different Fourier transform methods. The results showed that the Guass-FFT method has higher numerical precision, while the standard FFT method is superior, in terms of computation time, for inversion and quantitative interpretation under complicated terrain. 展开更多
关键词 Topography gravity ANOMALY space-wavenumber mixing DOMAIN three-dimensionAL NUMERICAL modeling
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Risk Assessment of Coal Mine Water Hazard Based on Three-Dimensional Model of Geology and Underground Space 被引量:1
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作者 Kai Zhang~1,Ming Huang~1,Bin Tang~2,Fan Cui~1 1.Laboratory of Coal Resources and Mine Safety,China University of Mining and Technology,Beijing 100083,China. 2.China Water Investment Co.Ltd,Beijing 100053,China 《地学前缘》 EI CAS CSCD 北大核心 2009年第S1期279-279,共1页
Mine safety have top-five disasters,which including the water,gas,fire,dust and geological dynamic disaster.The coal mine water disaster is one of the important factors which restricted the development of China’s coa... Mine safety have top-five disasters,which including the water,gas,fire,dust and geological dynamic disaster.The coal mine water disaster is one of the important factors which restricted the development of China’s coal production.It is showed by statistics that 60%of mine accidents are affected by groundwater,which not only result in the production losses,casualties and a variety of 展开更多
关键词 DISASTER risk assessment three-dimensionAL model of GEOLOGY and UNDERGROUND space emergency RESCUE
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Three-Dimensional Space Interpolation of Grey / Depth Image Sequence-A New Technique of Computer Graphics Synthesis
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作者 Wang Xincheng, Zhu Weile, Zhu Xiaokun and Gu DerenChengdu University of Electronic Science and Technology, Chengdu 610054 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1993年第3期70-77,共8页
This paper advances a three-dimensional space interpolation method of grey / depth image sequence, which breaks free from the limit of original practical photographing route. Pictures can cruise at will in space. By u... This paper advances a three-dimensional space interpolation method of grey / depth image sequence, which breaks free from the limit of original practical photographing route. Pictures can cruise at will in space. By using space sparse sampling, great memorial capacity can be saved and reproduced scenes can be controlled. To solve time consuming and complex computations in three-dimensional interpolation algorithm, we have studied a fast and practical algorithm of scattered space lattice and that of 'Warp' algorithm with proper depth. By several simple aspects of three dimensional space interpolation, we succeed in developing some simple and practical algorithms. Some results of simulated experiments with computers have shown that the new method is absolutely feasible. 展开更多
关键词 Grey / depth image three-dimensional space interpolation Computer graphics synthesis Algorithms.
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Three-dimensionally ordered macroporous cross-linked polystyrene incorporating functional group via hydrophilic spacer arm 被引量:1
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作者 Li Xia Yuan Xiao Mei Wang Xu Zhang Pan Ge Liu Wei Dong Yan 《Chinese Chemical Letters》 SCIE CAS CSCD 2010年第12期1493-1496,共4页
A versatile and effective method for incorporating functional groups on the pore wall of three-dimensionally ordered macroporous cross-linked polystyrene(3DOM CLPS) by hydrophilic spacer arm has been investigated.Th... A versatile and effective method for incorporating functional groups on the pore wall of three-dimensionally ordered macroporous cross-linked polystyrene(3DOM CLPS) by hydrophilic spacer arm has been investigated.The 3DOM CLPS with pore size 865 nm was prepared by sacrifice template method.The hydrophilic spacer arm(polyethylene glycol,molecular weight is 600) was grafted to the 3DOM CLPS via nucleophilic substitution reaction.The other side of active hydroxyl can be further converted into a lot of other functional groups.In this report,the chelating ligand 2-mercaptobenzothiazole(MBZ) group was introduced on the end of the PGE chain to evidence the versatile functionalization approach.The functionalized ordered macroporous materials were characterized by FT-IR,element analyzer,SEM.The results reveal that the pores were successfully bonded with 2-mercaptobenzothiazole groups via hydrophilic spacer arms and the original morphology of ordered macroporous materials were remained after functionalization.The MBZ group density is 0.052 mmol/m^2.The functionalized 3DOM CLPS are expected to application as heavy metal ions adsorbent. 展开更多
关键词 three-dimensionally ordered macroporous polymer FUNCTIONALIZATION Hydrophilic space arm Heterocyclic functional group
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Special Relativity in Three-Dimensional Space-Time Frames
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作者 Tower Chen Zeon Chen 《International Journal of Astronomy and Astrophysics》 2016年第4期410-424,共15页
In Newton’s classical physics, space and time are treated as absolute quantities. Space and time are treated as independent quantities and can be discussed sepa-rately. With his theory of relativity, Einstein proved ... In Newton’s classical physics, space and time are treated as absolute quantities. Space and time are treated as independent quantities and can be discussed sepa-rately. With his theory of relativity, Einstein proved that space and time are de-pendent and must be treated inseparably. Minkowski adopted a four-dimensional space-time frame and indirectly revealed the dependency of space and time by adding a constraint for an event interval. Since space and time are inseparable, a three-dimensional space-time frame can be constructed by embedding time into space to directly show the interdependency of space and time. The formula for time dilation, length contraction, and the Lorenz transformation can be derived from graphs utilizing this new frame. The proposed three-dimensional space-time frame is an alternate frame that can be used to describe motions of objects, and it may improve teaching and learning Special Relativity and provide additional insights into space and time. 展开更多
关键词 Four-dimensional space-Time Frame three-dimensional space-Time Time Contraction Length Contraction Lorenz Transformation Big Bang Multiple Big Bangs Quantum Entanglement
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Obstacle avoidance method of three-dimensional obstacle spherical cap 被引量:3
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作者 YANG Xiuxia ZHANG Yi ZHOU Weiwei 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2018年第5期1058-1068,共11页
Focusing on obstacle avoidance in three-dimensional space for unmanned aerial vehicle(UAV), the direct obstacle avoidance method in dynamic space based on three-dimensional velocity obstacle spherical cap is proposed,... Focusing on obstacle avoidance in three-dimensional space for unmanned aerial vehicle(UAV), the direct obstacle avoidance method in dynamic space based on three-dimensional velocity obstacle spherical cap is proposed, which quantifies the influence of threatening obstacles through velocity obstacle spherical cap parameters. In addition, the obstacle avoidance schemes of any point on the critical curve during the multi-obstacles avoidance are given. Through prediction, the insertion point for the obstacle avoidance can be obtained and the flight path can be replanned. Taking the Pythagorean Hodograph(PH) curve trajectory re-planning as an example, the three-dimensional direct obstacle avoidance method in dynamic space is tested. Simulation results show that the proposed method can realize the online obstacle avoidance trajectory re-planning, which increases the flexibility of obstacle avoidance greatly. 展开更多
关键词 three-dimensional direct space obstacle avoidance velocity obstacle cone velocity obstacle spherical cap
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基于Cite Space的立体绿化发展可视化分析 被引量:1
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作者 陈梦瑶 朱蓉 《设计艺术研究》 2023年第1期67-72,共6页
为了解立体绿化领域研究进展、热点及趋势,基于中国知网(CNKI)和科学引文索引数据库(Web of Science),运用文献计量法和可视化文献分析软件(Cite Space)可视化分析法,分析2002—2021年立体绿化领域中英文文献资料。发现英文文献发文量... 为了解立体绿化领域研究进展、热点及趋势,基于中国知网(CNKI)和科学引文索引数据库(Web of Science),运用文献计量法和可视化文献分析软件(Cite Space)可视化分析法,分析2002—2021年立体绿化领域中英文文献资料。发现英文文献发文量及其增长幅度均高于中文文献;目前立体绿化领域主要研究机构均集中于各大高校;英文文献相关研究涵盖的学科领域主要为环境科学与生态学、工程学、城市研究、科学技术等,中文文献相关研究主要集中在建筑科学与工程、林业、园艺等方面;立体绿化的热点研究领域集中在立体绿化生态效益、施工技术和植物研究等方面;英文文献相关研究早期关注生物多样性、气候调节等,近年来关注微气候、城市农业等,中文文献相关研究的发展趋势从早期对立体绿化的理论研究、技术探索逐渐拓展到对城市雨洪、建筑节能等层面的精细化研究。基于此,提出未来立体绿化研究应在学术交流合作、学科交叉研究、创新研究方法等层面逐步深入,以此丰富立体绿化研究对象和主题,并进一步把握其研究态势。 展开更多
关键词 Cite space 立体绿化 文献综述 计量分析 可视化
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An Improved Three-Dimensional Model for Emotion Based on Fuzzy Theory
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作者 Zijiang Zhu Junshan Li +1 位作者 Xiaoguang Deng Yi Hu 《Journal of Computer and Communications》 2018年第8期101-111,共11页
Emotion Model is the basis of facial expression recognition system. The constructed emotional model should not only match facial expressions with emotions, but also reflect the location relationship between different ... Emotion Model is the basis of facial expression recognition system. The constructed emotional model should not only match facial expressions with emotions, but also reflect the location relationship between different emotions. In this way, it is easy to understand the current emotion of an individual through the analysis of the acquired facial expression information. This paper constructs an improved three-dimensional model for emotion based on fuzzy theory, which corresponds to the facial features to emotions based on the basic emotions proposed by Ekman. What’s more, the three-dimensional model for motion is able to divide every emotion into three different groups which can show the positional relationship visually and quantitatively and at the same time determine the degree of emotion based on fuzzy theory. 展开更多
关键词 EMOTION Model FACIAL EXPRESSION FUZZY Theory three-dimensionAL STATE-space
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Three-Dimensional Exact Solution for Dynamic Damped Response of Plates with Two Free Edges
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作者 Le Wang Muchun Yu 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2019年第3期79-90,共12页
A three-dimensional state space method has been developed for the calculation of dynamic response of plates with two free edges and two simply supported edges.A complex damping model was introduced, then the exact sol... A three-dimensional state space method has been developed for the calculation of dynamic response of plates with two free edges and two simply supported edges.A complex damping model was introduced, then the exact solutions which satisfy all the governing equations and boundary conditions were obtained.In order to overcome the difficulty of satisfying all the stress conditions at free edges, the displacement functions of free edges were assumed.The boundary conditions were strictly satisfied when the convergence rate was good.The computing time was evidently less than that of finite element method.The comparison of the solution with those of finite element method show that there is an excellent agreement for displacements.When the imaginary parts of normal stress deviated, the finite element results showed existence of shear stresses at top and bottom surfaces, and the boundary conditions of FEM model were not strictly satisfied. 展开更多
关键词 three-dimensionAL EXACT solution state space method free edge RESPONSE
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Three-dimensional Analysis of Functionally Graded Piezoelectric Plate with Arbitrarily Distributed Material Properties
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作者 刘五祥 MA Shaokun 吴昊 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2014年第4期712-720,共9页
An orthotropic functionally graded piezoelectric rectangular plate with arbitrarily distributed material properties was studied, which is simply supported and grounded(electrically) on its four lateral edges. The st... An orthotropic functionally graded piezoelectric rectangular plate with arbitrarily distributed material properties was studied, which is simply supported and grounded(electrically) on its four lateral edges. The state equations of the functionally graded piezoelectric material were obtained using the state-space approach, and a Peano-Baker series solution was obtained for the coupled electroelastic fi elds of the functionally graded piezoelectric plate subjected to mechanical and electric loading on its upper and lower surfaces. The influence of different distributions of material properties on the structural response of the plate was studied using the obtained solutions. 展开更多
关键词 functionally graded piezoelectric materials peano-baker series three-dimensional analysis state-space approach
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基于三维空间面积划分的轨迹相似性度量算法 被引量:1
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作者 徐凯 高琦凯 +1 位作者 殷明 谭京京 《计算机应用》 CSCD 北大核心 2024年第1期318-323,共6页
针对大部分轨迹相似性度量算法无法区分方向相反轨迹的问题,提出了一种基于三维空间面积划分的三维三角分割(3TD)算法。首先,按照3TD算法的时间转换规则将轨迹集的绝对时间序列转变为相对时间序列;然后,在由经度、纬度以及时间三要素构... 针对大部分轨迹相似性度量算法无法区分方向相反轨迹的问题,提出了一种基于三维空间面积划分的三维三角分割(3TD)算法。首先,按照3TD算法的时间转换规则将轨迹集的绝对时间序列转变为相对时间序列;然后,在由经度、纬度以及时间三要素构成的三维空间坐标系中,通过划分规则将轨迹间面积分割成若干互不重叠的三角形,累加三角形面积并计算轨迹相似度;最后,在从船舶自动识别系统(AIS)收集的随机采样轨迹数据集上,与最长公共子序列(LCSS)算法和三角分割(TD)算法等进行了对比实验。实验结果表明:3TD算法对实验数据集中异向轨迹识别精确度达到100%;同时该算法面对海量数据集以及轨迹点部分缺失的数据集时,也能维持准确的度量结果以及较高的运算效率,能更好地适应异向轨迹相似度量工作。 展开更多
关键词 时空轨迹 三维空间 面积划分 相似性度量 轨迹方向
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基于三度空间模型的精细化护理在AECOPD并呼吸衰竭患者中的实践研究
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作者 宗海燕 朱晔 《国际医药卫生导报》 2024年第1期145-150,共6页
目的探讨基于三度空间模型的精细化护理在慢性阻塞性肺疾病急性加重期(AECOPD)并呼吸衰竭患者中的应用效果。方法选取无锡市第二人民医院2020年8月至2022年3月收治的98例AECOPD并呼吸衰竭患者进行随机对照试验,利用随机数字表法分为观察... 目的探讨基于三度空间模型的精细化护理在慢性阻塞性肺疾病急性加重期(AECOPD)并呼吸衰竭患者中的应用效果。方法选取无锡市第二人民医院2020年8月至2022年3月收治的98例AECOPD并呼吸衰竭患者进行随机对照试验,利用随机数字表法分为观察组(49例)与对照组(49例)。对照组男性31例,女性18例,年龄51~79(64.56±8.15)岁,给予常规护理;观察组男性29例,女性20例,年龄53~80(66.23±7.36)岁,在对照组的基础上给予三度空间模型的精细化护理。比较两组患者护理前后自护能力、动脉血气指标、肺功能指标、生活质量以及并发症发生情况。统计学方法采用t检验、χ^(2)检验。结果护理后,两组患者自我护理技能、健康知识水平、自我概念、自护责任感评分均较护理前升高,且观察组均高于对照组[(40.92±10.23)分比(33.56±8.39)分、(49.83±12.21)分比(39.62±9.91)分、(32.96±8.24)分比(23.49±5.87)分、(28.76±7.19)分比(22.26±5.57)分],差异均有统计学意义(t=3.89、4.55、6.55、5.00,均P<0.05)。护理后,两组患者氧饱和度(SaO_(2))、动脉血氧分压(PaO_(2))、用力肺活量占正常预计值百分比(FVC%)、第一秒用力呼气量占正常预计值百分比(FEV_(1)%)、第一秒用力呼气量占用力肺活量百分率(FEV_(1)/FVC%)均较护理前升高,且观察组均高于对照组,二氧化碳分压(PaCO_(2))低于对照组[(96.86±24.22)%比(84.12±21.03)%、(88.79±22.19)mmHg(1 mmHg=0.133 kPa)比(73.21±18.30)mmHg、(2.63±0.66)%比(2.29±0.57)%、(1.46±0.37)%比(1.28±0.32)%、(0.67±0.17)%比(0.58±0.15)%、(46.58±11.65)mmHg比(58.67±4.67)mmHg],差异均有统计学意义(t=2.78、3.78、2.73、2.58、2.78、4.52,均P<0.05);护理后,两组患者疾病影响、症状评分、圣乔治呼吸问卷(SGRQ)总分均较护理前降低,且观察组均低于对照组,活动能力评分高于对照组[(20.74±4.15)分比(29.46±5.89)分、(37.86±7.57)分比(49.58±9.92)分、(29.56±7.39)分比(38.76±9.69)分、(62.85±12.57)分比(52.32±10.46)分],差异均有统计学意义(t=8.47、6.58、6.61、4.51,均P<0.05);观察组患者并发症总发生率低于对照组[6.12%(3/49)比24.49%(12/49)],差异有统计学意义(χ^(2)=5.04,P<0.05)。结论基于三度空间模型的精细化护理应用于AECOPD并呼吸衰竭患者,有利于改善患者的肺通气、换气功能,提高患者自护能力和生活质量,降低并发症发生率,值得临床推广。 展开更多
关键词 慢性阻塞性肺疾病急性加重期 呼吸衰竭 三度空间模型 精细化护理
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基于三色球的单目相机三维空间定位算法研究
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作者 张白 许有志 +1 位作者 张巍巍 焦海波 《计算机仿真》 2024年第7期359-365,共7页
为了实现无工装夹具条件下的机器人焊接,提出基于三色球的单目相机三维空间定位方法,利用球在任意角度成像的几何不变性,结合球的半径信息实现球的深度信息的提取,解决了传统单目相机无法实现三维空间定位的难题。定位算法引入颜色滤波... 为了实现无工装夹具条件下的机器人焊接,提出基于三色球的单目相机三维空间定位方法,利用球在任意角度成像的几何不变性,结合球的半径信息实现球的深度信息的提取,解决了传统单目相机无法实现三维空间定位的难题。定位算法引入颜色滤波简化三色球的识别,改进霍夫圆检测算法,提高了三色球的识别精度。研究了球的深度信息计算模型,并推导了相关公式,实现了单目相机下球的三维坐标计算。构建了基于3个标准球的焊接工件定位模型,通过工件上3个定位点设置的标准球实现焊接工件定位。基于三维微位移平台设计了定位精度检测实验平台,并开展了相关实验。实验表明,三维空间定位算法的定位误差在±0.24mm以内,满足焊接工件定位的精度要求。 展开更多
关键词 单目相机 三维空间定位 三色球 颜色滤波 霍夫圆
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Researches on Cartographic Database-Based Interactive Three-Dimensional Topographic Map
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作者 JiangWenping XiDaping 《Journal of China University of Geosciences》 SCIE CSCD 2003年第4期374-380,共7页
With the development of computer graphics, the three-dimensional (3D) visualization brings new technological revolution to the traditional cartography. Therefore, the topographic 3D-map emerges to adapt to this techno... With the development of computer graphics, the three-dimensional (3D) visualization brings new technological revolution to the traditional cartography. Therefore, the topographic 3D-map emerges to adapt to this technological revolution, and the applications of topographic 3D-map are spread rapidly to other relevant fields due to its incomparable advantage. The researches on digital map and the construction of map database offer strong technical support and abundant data source for this new technology, so the research and development of topographic 3D-map will receive greater concern. The basic data of the topographic 3D-map are rooted mainly in digital map and its basic model is derived from digital elevation model (DEM) and 3D-models of other DEM-based geographic features. In view of the potential enormous data and the complexity of geographic features, the dynamic representation of geographic information becomes the focus of the research of topographic 3D-map and also the prerequisite condition of 3D query and analysis. In addition to the equipment of hardware that are restraining, to a certain extent, the 3D representation, the data organization structure of geographic information will be the core problem of research on 3D-map. Level of detail (LOD), space partitioning, dynamic object loading (DOL) and object culling are core technologies of the dynamic 3D representation. The object- selection, attribute-query and model-editing are important functions and interaction tools for users with 3D-maps provided by topographic 3D-map system, all of which are based on the data structure of the 3D-model. This paper discusses the basic theories, concepts and cardinal principles of topographic 3D-map, expounds the basic way to organize the scene hierarchy of topographic 3D-map based on the node mechanism and studies the dynamic representation technologies of topographic 3D-map based on LOD, space partitioning, DOL and object culling. Moreover, such interactive operation functions are explored, in this paper, as spatial query, scene editing and management of topographic 3D-map. Finally, this paper describes briefly the applications of topographic 3D-map in its related fields. 展开更多
关键词 three-dimensional (3D) visualization topographic 3D-map level of detail (LOD) space partitioning dynamic object loading (DOL) dynamic representation.
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波流环境中多孔射流三维数值模拟
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作者 徐振山 韩松 +1 位作者 张玉玲 陈永平 《河海大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第1期84-92,共9页
建立了波流环境中多孔射流的三维大涡数学模型,探讨了波流共同作用下多孔射流的扩散和稀释机制,分析了孔间距对双孔射流、射流与环境水体相互作用的影响,并给出了最优相对孔间距。模拟结果表明:在波谷相位时刻,由于横流与波浪相互作用强... 建立了波流环境中多孔射流的三维大涡数学模型,探讨了波流共同作用下多孔射流的扩散和稀释机制,分析了孔间距对双孔射流、射流与环境水体相互作用的影响,并给出了最优相对孔间距。模拟结果表明:在波谷相位时刻,由于横流与波浪相互作用强烈,流场内的三维涡旋结构丰富、尺度较大、数目众多,有利于射流与环境水体、射流与射流之间的掺混,这是波流环境比单一横流环境中多孔射流运动扩散效果更佳的主要原因;随着孔间距的增大,双孔射流之间的相互作用慢慢削弱,而射流与环境水体之间的相互作用却在不断增强;双孔射流在孔间距为7.0倍管口直径时扩散效果最好。 展开更多
关键词 多孔射流 波流环境 孔间距 大涡模拟 三维流场
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三维空间位置服务中智能语义位置隐私保护方法 被引量:1
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作者 闵明慧 杨爽 +4 位作者 胥俊怀 李鑫 李世银 肖亮 彭国军 《电子与信息学报》 EI CAS CSCD 北大核心 2024年第6期2627-2637,共11页
针对大型医院、商场及其他3维(3D)空间位置服务中敏感语义位置(如药店、书店等)隐私泄露问题,该文研究了基于3D空间地理不可区分性(3D-GI)的智能语义位置隐私保护方法。为摆脱对特定环境和攻击模型的依赖,该文利用强化学习(RL)技术实现... 针对大型医院、商场及其他3维(3D)空间位置服务中敏感语义位置(如药店、书店等)隐私泄露问题,该文研究了基于3D空间地理不可区分性(3D-GI)的智能语义位置隐私保护方法。为摆脱对特定环境和攻击模型的依赖,该文利用强化学习(RL)技术实现对用户语义位置隐私保护策略的动态优化,提出基于策略爬山算法(PHC)的3D语义位置扰动机制。该机制通过诱导攻击者推断较低敏感度的语义位置来减少高敏感语义位置的暴露。为解决复杂3D空间环境下的维度灾难问题,进一步提出基于近端策略优化算法(PPO)的3D语义位置扰动机制,利用神经网络捕获环境特征并采用离线策略梯度方法优化神经网络参数更新,提高语义位置扰动策略选择效率。仿真实验结果表明,所提方法可提升用户的语义位置隐私保护性能和服务体验。 展开更多
关键词 位置服务 3维空间 语义位置隐私 策略爬山 近端策略优化
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基于空间约束联合字典学习的三维冲击波超压场重建 被引量:1
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作者 魏晓曼 李剑 +3 位作者 刘晓佳 郭陈莉 展勇忠 刘代劲 《探测与控制学报》 CSCD 北大核心 2024年第2期108-114,共7页
针对有限测点条件下冲击波超压场全时空全区域重建的需求,提出一种基于空间约束联合字典学习的三维冲击波超压场重建方法。建立三维走时层析成像模型,利用字典学习对图像的稀疏表征优势和空间约束对图像边缘纹理保真特性,采用交替最小... 针对有限测点条件下冲击波超压场全时空全区域重建的需求,提出一种基于空间约束联合字典学习的三维冲击波超压场重建方法。建立三维走时层析成像模型,利用字典学习对图像的稀疏表征优势和空间约束对图像边缘纹理保真特性,采用交替最小化思想对目标函数进行优化解算,实现大型病态稀疏矩阵的高精度求解。试验结果表明,该方法与代数重建算法(ART)、联合代数重建算法(SART)和期望极大化算法(EM)相比,重建精度更高,全区域重建误差达到了15.81%,在时空场重建过程中具有较高的应用价值。 展开更多
关键词 三维重建 空间约束 走时层析
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考虑作业姿势舒适的三维装箱问题
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作者 徐翔斌 吁琴芳 《工业工程》 2024年第2期37-47,共11页
为降低装卸工在货物配装过程中因重复弯腰而罹患肌肉骨骼疾病的概率,同时优化其作业姿势的舒适性,进而减轻作业疲劳,提升社会整体效益,基于人因工程和运筹优化协同优化的视角,从装卸工作业姿势舒适的角度出发,提出并研究考虑作业姿势舒... 为降低装卸工在货物配装过程中因重复弯腰而罹患肌肉骨骼疾病的概率,同时优化其作业姿势的舒适性,进而减轻作业疲劳,提升社会整体效益,基于人因工程和运筹优化协同优化的视角,从装卸工作业姿势舒适的角度出发,提出并研究考虑作业姿势舒适的三维装箱问题。首先对装载作业姿势舒适性进行评价,构建问题模型;其次对货物排序优化和货物放置规则等关键问题进行研究,设计了最大空间法和有偏随机密钥遗传算法相结合的求解算法;最后通过算例进行实验验证。结果表明,提出的模型和算法可以在不增加车辆运输成本的前提下提升装卸工的作业姿势舒适性,并且对于尺寸相对较小及规模相对较少的货物类型作业姿势舒适性的优化空间更大,验证了模型和算法的有效性。 展开更多
关键词 三维装箱 作业姿势舒适 最大空间法 有偏随机密钥遗传算法
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