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三角形网格基活动图像编码研究——基本框架和I帧编码 被引量:6
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作者 卢朝阳 周幸妮 +1 位作者 高西全 樊昌信 《通信学报》 EI CSCD 北大核心 2002年第10期66-70,共5页
本文结合实验结果,深入讨论了三角形网格基活动图像编码方法的基本框架和帧内编码问题。文中全面比较了DTM+MD的帧内编码方法和JPEG方法的性能,表明采用DTM+MD作帧内编码具有更好的主客观质量。
关键词 本框架 I帧编码 图像编码 网格基 DELAUNAY三角形 帧内编码
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MPEG标准中的三角形网格基运动补偿方法
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作者 卢朝阳 周幸妮 +1 位作者 高西全 樊昌信 《西安电子科技大学学报》 EI CAS CSCD 北大核心 2001年第6期816-819,共4页
运动补偿技术是视频编码的关键和难点 ,文中从技术角度比较了传统的分块匹配算法和新的MPEG标准所支持的三角形网格基算法的各自优势 ,并给出一种实现三角形网格基的方法和相关的实验结果 .
关键词 视频编码 MPEG标准 运动补偿 三角形网格基 图像编码
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高精度复杂网格基板的数控加工
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作者 曹永新 《航天制造技术》 2003年第2期33-36,共4页
介绍了高精度复杂网格基板数控编程设计和数控加工工艺。在编程中灵活应用了子程序及自变量的设定,提高了数控编程的技巧。同时解决了面积大易变形、网格密易翘曲的高精度微波元件的加工难题,具有一定的推广价值。
关键词 复杂网格基 数控加工 数控编程 天线
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塑料网格砂基透水砖铺装系统的径流控制试验研究 被引量:6
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作者 王俊岭 秦全城 +2 位作者 张玉玉 张雅君 李俊奇 《新型建筑材料》 北大核心 2015年第12期13-16,共4页
塑料网格砂基透水砖铺装是一种结合网格和透水砖特点的创新型透水铺装,对其径流控制方面的效果进行了试验研究,结果表明,塑料网格砂基透水砖道路比普通道路产流时间延长10~45min。各重现期下塑料网格砂基透水砖道路和普通道路的产... 塑料网格砂基透水砖铺装是一种结合网格和透水砖特点的创新型透水铺装,对其径流控制方面的效果进行了试验研究,结果表明,塑料网格砂基透水砖道路比普通道路产流时间延长10~45min。各重现期下塑料网格砂基透水砖道路和普通道路的产流时间分别介于13~53min和3—8min。1年重现期下,塑料网格砂基透水砖道路比普通道路的产流时间延长约45rain,其对洪峰流量的削减率是32.9%,峰现时间比普道路延迟约20min。当重现期从1年增到100年时,洪峰流量削减率有所降低,同时峰现延迟时间从20min缩短到14min。 展开更多
关键词 塑料网格透水砖 重现期 径流控制 洪峰流量削减率 峰现延迟时间
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用于DT网格模型基视频编码的三角形分割准则
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作者 郭大波 卢朝阳 +1 位作者 焦卫东 胡星星 《通信学报》 EI CSCD 北大核心 2009年第5期88-93,共6页
在分析DT(Delaunay triangulation)网格已有的2种分割准则——灰度误差最小化准则和灰度分布均匀化准则在网格基编码不足的基础上,提出了一种新的DT网格分割准则——灰度误差平方和最小化准则,使三角形分割更加合理有效,编码性能比以前... 在分析DT(Delaunay triangulation)网格已有的2种分割准则——灰度误差最小化准则和灰度分布均匀化准则在网格基编码不足的基础上,提出了一种新的DT网格分割准则——灰度误差平方和最小化准则,使三角形分割更加合理有效,编码性能比以前的方法有明显提高。在此基础上提出了帧内变换编码/帧间网格基运动估计的混合编码方案,该方案可应用于复杂运动和背景的视频序列中,突破了以往模型基编码只能应用于视频会议的限制。实验结果表明,该编码方案在复杂运动和背景的应用场合高出了H.263的编码性能。 展开更多
关键词 DELAUNAY三角化 网格模型编码 图像分割准则 彩色视频编码
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基于时空无网格法的两种算法求解电报方程
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作者 朱妍红 宋灵宇 盖梦琳 《内蒙古师范大学学报(自然科学汉文版)》 CAS 2023年第5期512-520,共9页
从时空距离的角度出发,分别用时空MQ径向基无网格法和时空MQ径向基耦合时空多项式基的无网格法在时空尺度框架下离散电报方程,将问题转化为求解线性方程组问题,求出电报方程的数值解,并比较两种方法的精度。然而大多数情况下,会造成系... 从时空距离的角度出发,分别用时空MQ径向基无网格法和时空MQ径向基耦合时空多项式基的无网格法在时空尺度框架下离散电报方程,将问题转化为求解线性方程组问题,求出电报方程的数值解,并比较两种方法的精度。然而大多数情况下,会造成系数矩阵本身是病态而无法求得稳定解,因此引入了奇异值分解技术求解线性方程组。数值实验结果表明:两种方法都可以得到逼近效果较好的数值解,耦合时空多项式基可以提高精度和稳定性,更适合用来数值计算。 展开更多
关键词 电报方程 时空径向网格 时空径向耦合时空多项式网格 奇异值分解
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特征距离和扩充无网格法分析多裂纹相互作用 被引量:2
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作者 许艳 马文涛 《应用力学学报》 CAS CSCD 北大核心 2015年第3期490-495,12,共6页
提出特征距离这一概念对内部基扩充无网格法进行修正,并数值模拟了多裂纹之间的相互作用。特征距离法用于选择内部基扩充无网格Galerkin法的奇异基函数,该方法仅对传统的内部基扩充无网格Galerkin法作了很小的改进,即可方便地应用于求... 提出特征距离这一概念对内部基扩充无网格法进行修正,并数值模拟了多裂纹之间的相互作用。特征距离法用于选择内部基扩充无网格Galerkin法的奇异基函数,该方法仅对传统的内部基扩充无网格Galerkin法作了很小的改进,即可方便地应用于求解多裂纹问题;给出了相互作用能量积分计算混合型模式下的应力强度因子,数值模拟了三条内部裂纹和六条边裂纹问题,并与杂交位移不连续边界元法的计算结果进行比较。数值结果表明:修正的内部基扩充无网格法可以方便、有效地求解多裂纹问题,在不增加附加节点和自由度的情况下与杂交位移不连续方法的计算精度非常接近。 展开更多
关键词 特征距离 多裂纹相互作用 内部扩充无网格 应力强度因子
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基于RPIM法的圆极化天线特性参数快速测试 被引量:2
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作者 张晓燕 李利卫 +1 位作者 展爱云 赵艺萌 《微波学报》 CSCD 北大核心 2019年第4期66-71,共6页
为提高圆极化天线特性参数的测试精度,线极化分量法往往需要对线分量场进行多次测量。文中在天线测试系统中引入插值算法,减少采样点,提高圆极化天线测试效率。将径向基函数的点插值无网格(RPIM)法引入圆极化天线参数合成算法中,首先使... 为提高圆极化天线特性参数的测试精度,线极化分量法往往需要对线分量场进行多次测量。文中在天线测试系统中引入插值算法,减少采样点,提高圆极化天线测试效率。将径向基函数的点插值无网格(RPIM)法引入圆极化天线参数合成算法中,首先使用RPIM拟合出测试场的幅值和相位,然后再使用解析的方式合成圆极化天线的轴比和方向图,算法性能与基于分段线性插值技术的模型参数估计法(MBPE)和基于三次样条插值的移动最小二乘法(MLS)进行比较,数值实验显示,当采样点数仅为测试点数的4%时,MLS失效,MBPE和RPIM误差均为10-3量级;而当采样点数减少为测试点数的2%时,MBPE和MLS均失效,RPIM的误差虽然增大到10-1量级,但仍能保持稳定。数值实验证明,在采样点数较少情况下,RPIM性能优于其它两种算法。 展开更多
关键词 线极化分量法 径向函数点插值无网格 圆极化天线 特性参数
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玻纤网格增强聚酯毡在改性沥青防水卷材中的应用研究
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作者 侯尚民 李连功 《中国建筑防水》 2023年第5期1-4,共4页
研发了一种玻纤网格增强聚酯毡,介绍了其结构特点和生产工艺。与其他类型的聚酯毡材料相比,玻纤网格增强聚酯毡在热尺寸稳定性方面具有明显优势。在相同生产条件下,以玻纤网格增强聚酯毡为胎基制备的改性沥青防水卷材性能指标符合标准要... 研发了一种玻纤网格增强聚酯毡,介绍了其结构特点和生产工艺。与其他类型的聚酯毡材料相比,玻纤网格增强聚酯毡在热尺寸稳定性方面具有明显优势。在相同生产条件下,以玻纤网格增强聚酯毡为胎基制备的改性沥青防水卷材性能指标符合标准要求,并且可以大幅提升生产速度从而大幅提高生产效率,降低生产成本。 展开更多
关键词 改性沥青防水卷材 玻纤网格增强聚酯毡胎 热尺寸稳定性 生产速度
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碳-玻混杂纤维网格增强水泥基材料板轴拉性能与力阻响应特性研究
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作者 林旭华 张大伟 +2 位作者 刘嘉荣 谢志禹 武于森 《建筑结构学报》 EI CAS CSCD 北大核心 2024年第8期83-92,共10页
为研究碳-玻混杂纤维网格增强水泥基材料(carbon-glass hybrid fiber grid reinforced cementitious matrix,C-GFRCM)板的轴拉性能与力阻响应,开展12组C-GFRCM板单轴拉伸试验,分析砂浆类型、预应力水平、黏合剂以及玻璃纤维布粘贴方式... 为研究碳-玻混杂纤维网格增强水泥基材料(carbon-glass hybrid fiber grid reinforced cementitious matrix,C-GFRCM)板的轴拉性能与力阻响应,开展12组C-GFRCM板单轴拉伸试验,分析砂浆类型、预应力水平、黏合剂以及玻璃纤维布粘贴方式对其受拉性能和纤维利用率的影响,研究C-GFRCM板拉伸过程中碳纤维束的电阻变化与试件受力状态的响应机制,以及力阻响应与裂缝发生位置的规律。结果表明:预应力C-GFRCM板多为单裂缝破坏模式,环氧树脂黏合CGFRCM板多为纤维拉断破坏,地聚物黏合C-GFRCM板纤维发生滑移而拉断-拔出破坏;预应力工艺主要提升C-GFRCM板的开裂荷载,且预应力水平越高提升效果越明显,最大可提高267%;采用环氧树脂黏合剂分散粘贴玻璃纤维布可显著增强C-GFRCM板的极限荷载,最大可提高320%;拉伸过程中C-GFRCM板的力阻响应呈现三阶段特征,即弹性阶段电阻无明显变化;裂缝发展阶段在裂缝产生处电阻开始增长与波动;裂缝扩大与破坏阶段在主裂缝处电阻增长显著,采用力阻响应可以准确表征C-GFRCM板的受力状态并判断裂缝发生位置,不同设计参数C-GFRCM板的电阻变化对受力状态的敏感性不同。 展开更多
关键词 碳-玻混杂纤维网格增强水泥材料 预应力 单轴拉伸 力阻响应 裂缝
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修正的内部基扩充无网格法求解多裂纹应力强度因子 被引量:18
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作者 马文涛 许艳 马海龙 《工程力学》 EI CSCD 北大核心 2015年第10期18-24,共7页
修正的内部基扩充无网格Galerkin法求解了多裂纹应力强度因子。采用特征距离对内部基扩充无网格法进行修正,应用变分原理推导了系统离散方程,给出相互作用能量积分计算混合型模式下的应力强度因子的公式。求解3个平面应力条件下的多裂... 修正的内部基扩充无网格Galerkin法求解了多裂纹应力强度因子。采用特征距离对内部基扩充无网格法进行修正,应用变分原理推导了系统离散方程,给出相互作用能量积分计算混合型模式下的应力强度因子的公式。求解3个平面应力条件下的多裂纹问题,并与其他数值方法的计算结果进行比较。数值算例表明:修正的内部基扩充无网格Galerkin法可以方便、有效地求解多裂纹问题,在不增加附加节点和自由度的情况下便可以得到较高精度的计算结果。 展开更多
关键词 断裂力学 多裂纹 内部扩充无网格 特征距离 应力强度因子
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3D Engineering Model Retrieval Based on Enhanced Shape Distributions 被引量:1
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作者 侯鑫 张旭堂 +1 位作者 刘文剑 冉洋 《Journal of Donghua University(English Edition)》 EI CAS 2009年第4期413-422,共10页
To reuse and share the valuable knowledge embedded in repositories of engineering models for accelerating the design process, improving product quality, and reducing costs, it is crucial to devise search engines capab... To reuse and share the valuable knowledge embedded in repositories of engineering models for accelerating the design process, improving product quality, and reducing costs, it is crucial to devise search engines capable of matching 3D models efficiently and effectively. In this paper, an enhanced shape distributions-based technique of using geometrical and topological information to search 3D engineering models represented by polygonal meshes was presented. A simplification method of polygonal meshes was used to simplify engineering model as the pretreatment for generation of sample points. The method of sampling points was improved and a pair of functions that was more sensitive to shape was employed to construct a 2D shape distribution. Experiments were conducted to evaluate the proposed algorithm utilizing the Engineering Shape Benchmark (ESB) database. The experiential results suggest that the search effectiveness is significantly improved by enforcing the simplification and enhanced shape distributions to engineering model retrieval. 展开更多
关键词 shape retrieval polygonal mesh simplification shape distribution 3D engineering model
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Evaluation methods of man-machine-environment system for clean and safe production in phosphorus mines: A case study 被引量:5
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作者 DONG Long-jun ZHOU Ying +2 位作者 DENG Si-jia WANG Mei SUN Dao-yuan 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第12期3856-3870,共15页
Phosphorus is an essential element in agricultural production and chemical industry. However, since the risk of casualties and economic loss by mining accidents, the application of clean and safe production in phospho... Phosphorus is an essential element in agricultural production and chemical industry. However, since the risk of casualties and economic loss by mining accidents, the application of clean and safe production in phosphorus mines encounters great challenges. For this purpose, a man-machine-environment system composed of evaluation indexes was established, and the grading standards of indexes were defined. Firstly, the measurements of 39 qualitative indexes were obtained through the survey data. According to the measured values of 31 quantitative indexes, the measurements of quantitative indexes were calculated by linear measurement function(LM) and other three functions. Then the singleindex measurement evaluation matrixes were established. Secondly, the entropy weight method was used to determine the weights of each index directly. The analytic hierarchy process(AHP) was also applied to calculate the weights of index and index factor hierarchies after the established hierarchical model. The weights of system hierarchies were given by the grid-based fuzzy Borda method(GFB). The comprehensive weights were determined by the combination method of AHP and GFB(CAG). Furthermore, the multi-index comprehensive measurement evaluation vectors were obtained.Thirdly, the vectors were evaluated by the credible degree recognition(CDR) and the maximum membership(TMM)criteria. Based on the above functions, methods, and criteria, 16 combination evaluation methods were recommended.Finally, the clean and safe production grade of Kaiyang phosphate mine in China was evaluated. The results show that the LM-CAG-CDR is the most reasonable method, which can not only determine the clean and safe production grade of phosphorus mines, but also improve the development level of clean and safe mining of phosphorus mines for guidance.In addition, some beneficial suggestions and measures were also proposed to advance the clean and safe production grade of Kaiyang phosphorus mine. 展开更多
关键词 phosphorus mines clean and safe production man-machine-environment system unascertained measurement evaluation grid-based fuzzy borda method analytic hierarchy process
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Study on Classification of Personality-Based Brand Archetype from the Perspective of Internet 被引量:1
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作者 CHEN Fei YUE Xin YANG Xuecheng GE Tingting 《China Communications》 SCIE CSCD 2014年第7期153-160,共8页
Due to the rapid development,Internet has become the main field for brand building.Under this circumstance,the image of the brand is always consistent with the consumers' perception.Therefore,this study uses the m... Due to the rapid development,Internet has become the main field for brand building.Under this circumstance,the image of the brand is always consistent with the consumers' perception.Therefore,this study uses the method of text mining of search engine to explore the categories of brand archetype based on Brand Personality Theory from the perspective of Internet.The results find that 12 brand archetypes,including caregiver,sage,hero,innocent,dominator,creator,vitality,explorer,stylish woman,lover,cooperator,and vogue gentleman,have a high degree explanation.Deeper study uses case study to verify the reasonability and effectiveness of the classification standard. 展开更多
关键词 brand archetype brandpersonality brand positioning SE text mining
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Solving Two-Dimensional Moving-Boundary Problems with Meshless and Level Set Method
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作者 L. Vrankar G. Turk F. Runovc 《Journal of Energy and Power Engineering》 2010年第1期51-55,共5页
During the past decade, increasing attention has been given to the development of meshless methods using radial basis functions for the numerical solution of Partial Differential Equations (PDEs). A level set method... During the past decade, increasing attention has been given to the development of meshless methods using radial basis functions for the numerical solution of Partial Differential Equations (PDEs). A level set method is a promising design tool for tracking, modelling and simulating the motion of free boundaries in fluid mechanics, combustion, computer animation and image processing. In the conventional level set methods, the level set equation is solved to evolve the interface using a capturing Eulerian approach. The solving procedure requires an appropriate choice of the upwind schemes, reinitialization, etc. Our goal is to include Multiquadric Radial Basis Functions (MQ RBFs) into the level set method to construct a more efficient approach and stabilize the solution process with the adaptive greedy algorithm. This paper presents an alternative approach to the conventional level set methods for solving moving-boundary problems. The solution was compared to the solution calculated by the exact explicit lime integration scheme. The examples show that MQ RBFs and adaptive greedy algorithm is a very promising calculation scheme. 展开更多
关键词 Moving boundary problems level set method MULTIQUADRIC greedy algorithm exact time integration scheme
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图书与情报工作
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《电子科技文摘》 2002年第5期3-3,共1页
Y2001-62925-337 0207881因特网上基于内容的图象查询有效方法=Effecriveways for querymg images by contenE over the Internet[会,英]/Vlachos.M.& Vardangals,G.//2000IEEE Mediterranean Electrotechnical Conference.Vol 1of 3:R... Y2001-62925-337 0207881因特网上基于内容的图象查询有效方法=Effecriveways for querymg images by contenE over the Internet[会,英]/Vlachos.M.& Vardangals,G.//2000IEEE Mediterranean Electrotechnical Conference.Vol 1of 3:Regional Communication and Information Technol- 展开更多
关键词 情报工作 信息检索 链码 检索方法 运动补偿 网格基 电视技术 联第 会议概况
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编码理论、信道理论与技术、编译码器
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《电子科技文摘》 2003年第4期36-39,共4页
Y2002-63328-2649 0307395GSM 的迭代信源和信道译码=Iterative source andchannel decoding for GSM[会,英]/Perkert,R.&Kaindl,M.//The 2001 IEEE International Conferenceon Acoustics,Speech,and Signal Processing Vol.Ⅳ of... Y2002-63328-2649 0307395GSM 的迭代信源和信道译码=Iterative source andchannel decoding for GSM[会,英]/Perkert,R.&Kaindl,M.//The 2001 IEEE International Conferenceon Acoustics,Speech,and Signal Processing Vol.Ⅳ ofⅥ.—2649~2652(HE) 展开更多
关键词 编译码器 信道接入协议 信道译码 DECODING 编码理论 视频编码 网格基 密码算法 密码学 编码系统
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A spherical parameterization approach based on symmetry analysis of triangular meshes 被引量:2
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作者 Jian-ping HU Xiu-ping LIU +2 位作者 Zhi-xun SU Xi-quan SHI Feng-shan LIU 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2009年第7期1009-1017,共9页
We present an efficient spherical parameterization approach aimed at simultaneously reducing area and angle dis-tortions. We generate the final spherical mapping by independently establishing two hemisphere parameteri... We present an efficient spherical parameterization approach aimed at simultaneously reducing area and angle dis-tortions. We generate the final spherical mapping by independently establishing two hemisphere parameterizations. The essence of the approach is to reduce spherical parameterization to a planar problem using symmetry analysis of 3D meshes. Experiments and comparisons were undertaken with various non-trivial 3D models, which revealed that our approach is efficient and robust. In particular, our method produces almost isometric parameterizations for the objects close to the sphere. 展开更多
关键词 Triangular mesh Spherical parameterization Symmetry analysis
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Road Density Analysis Based on Skeleton Partitioning for Road Generalization 被引量:2
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作者 艾廷华 刘耀林 《Geo-Spatial Information Science》 2009年第2期110-116,共7页
This paper proposes an algorithm for road density analysis based on skeleton partitioning. Road density provides metric and statistical information about overall road distribution at the macro level. Existing measurem... This paper proposes an algorithm for road density analysis based on skeleton partitioning. Road density provides metric and statistical information about overall road distribution at the macro level. Existing measurements of road density based on grid method, fractal geometry and mesh density are reviewed, and a new method for computing road density based on skeleton partitioning is proposed. Experiments illustrate that road density based on skeleton partitioning may reveal the overall road distribution. The proposed measurement is further tested against road maps at 1:10k scale and their generalized version at 1:50k scale. By comparing the deletion percentage within different density interval, a road density threshold can be found, which indicate the need for further operations during generalization. Proposed road density may be used to examine the quality of road generalization, to explore the variation of road network through temporal and spatial changes, and it also has future usage in urban planning, transportation and estates evaluation practice. 展开更多
关键词 multiple-representation map generalization road density skeleton partitioning
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Biologically inspired model of path integration based on head direction cells and grid cells 被引量:1
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作者 Yang ZHOU De-wei WU 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2016年第5期435-448,共14页
Some neurons in the brain of freely moving rodents show special firing pattern. The firing of head direction cells(HDCs) and grid cells(GCs) is related to the moving direction and distance, respectively. Thus, it is c... Some neurons in the brain of freely moving rodents show special firing pattern. The firing of head direction cells(HDCs) and grid cells(GCs) is related to the moving direction and distance, respectively. Thus, it is considered that these cells play an important role in the rodents' path integration. To provide a bionic approach for the vehicle to achieve path integration, we present a biologically inspired model of path integration based on the firing characteristics of HDCs and GCs. The detailed implementation process of this model is discussed. Besides, the proposed model is realized by simulation, and the path integration performance is analyzed under different conditions. Simulations validate that the proposed model is effective and stable. 展开更多
关键词 Head direction cells (HDCs) Grid cells (GCs) Path integration Bionic navigation
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