Efficiently capturing large,complex cultural heritage sites with a handheld mobile 3D laser mapping system     

《Journal of Cultural Heritage》2014,15(6):670-678

Accurate three-dimensional representations of cultural heritage sites are highly valuable for scientific study, conservation, and educational purposes. In addition to their use for archival purposes, 3D models enable efficient and precise measurement of relevant natural and architectural features. Many cultural heritage sites are large and complex, consisting of multiple structures spatially distributed over tens of thousands of square metres. The process of effectively digitising such geometrically complex locations requires measurements to be acquired from a variety of viewpoints. While several technologies exist for capturing the 3D structure of objects and environments, none are ideally suited to complex, large-scale sites, mainly due to their limited coverage or acquisition efficiency. We explore the use of a recently developed handheld mobile mapping system called Zebedee in cultural heritage applications. The Zebedee system is capable of efficiently mapping an environment in three dimensions by continually acquiring data as an operator holding the device traverses through the site. The system was deployed at the former Peel Island Lazaret, a culturally significant site in Queensland, Australia, consisting of dozens of buildings of various sizes spread across an area of approximately 400 × 250 m. With the Zebedee system, the site was scanned in half a day, and a detailed 3D point cloud model (with over 520 million points) was generated from the 3.6 hours of acquired data in 2.6 hours. We present results demonstrating that Zebedee was able to accurately capture both site context and building detail comparable in accuracy to manual measurement techniques, and at a greatly increased level of efficiency and scope. The scan allowed us to record derelict buildings that previously could not be measured because of the scale and complexity of the site. The resulting 3D model captures both interior and exterior features of buildings, including structure, materials, and the contents of rooms.  相似文献   

激光扫描技术在自由式滑雪运动员三维人体模型建立中的应用     

关欣  王新  白巍  付彦铭 《广州体育学院学报》2014,(1):92-95

为了缩短体育运动中人体运动技能分析过程人体模型构建周期和提高构建精度。采用激光扫描 技术,对自由式滑雪运动员在助滑阶段的几个主要动作进行数据采集,以“实物-设计意图-三维重构-再 设计”框架为流程,建立自由式滑雪运动员三维人体模型。研究发现在采用激光扫描技术得到表面的几何 数据基础上,人体模型的构建还要经过数据拼合、简化、三角化、去噪等预处理,再进行测量数据分块、 曲面拟合,最终进行模型重构。探讨了运动生物力学研究领域人体模型构建的新方法,提高人体模型构建 效率,为体育科学人体运动研究提供基础模型。  相似文献   

Probing transient protein-mediated DNA linkages using nanoconfinement     

Maedeh Roushan  Parminder Kaur  Alena Karpusenko  Preston J. Countryman  Carlos P. Ortiz  Shuang Fang Lim  Hong Wang  Robert Riehn 《Biomicrofluidics》2014,8(3)

We present an analytic technique for probing protein-catalyzed transient DNA loops that is based on nanofluidic channels. In these nanochannels, DNA is forced in a linear configuration that makes loops appear as folds whose size can easily be quantified. Using this technique, we study the interaction between T4 DNA ligase and DNA. We find that T4 DNA ligase binding changes the physical characteristics of the DNA polymer, in particular persistence length and effective width. We find that the rate of DNA fold unrolling is significantly reduced when T4 DNA ligase and ATP are applied to bare DNA. Together with evidence of T4 DNA ligase bridging two different segments of DNA based on AFM imaging, we thus conclude that ligase can transiently stabilize folded DNA configurations by coordinating genetically distant DNA stretches.  相似文献   

New Life to Old Serials: Digitizing Back Volumes     

《期刊图书馆员》2012,62(1-4):180-182

Wendy Robertson shared her experience with digitization projects in which she had been involved at the University of Iowa Libraries. She emphasized the need for serialists to take a participatory role in any digitization projects that include serials. Serialist participation is necessary due to the complications that may occur when digitizing serial runs. Robertson provided practical information regarding digitization projects in general terms, while also mentioning some of the specific technical aspects. She presented a wide variety of existing serial digitization projects in order to show how they are organized. Robertson concluded that a serial digitization project will benefit greatly, by being better organized and more accessible, when a serialist is included in its production.  相似文献   

环境扫描系统模型设计与研究     

张军亮 《图书馆学研究》2012,(11):62-67

文章首先介绍了环境扫描概念及环境扫描信息行为模型,环境扫描已经成为企业经理人制定企业决策必不可少的一个步骤,随着网络的发展,为实现企业的互联互通打开了方便之门。企业经理人需要一个有助于他们环境扫描的系统出现。文章根据这种需求通过环境扫描概念和企业经理人信息查询模式的研究,尝试建立一个企业经理人环境扫描系统模型框架。  相似文献   

Polar or nonpolar? That is not the question for perovskite solar cells     

Boyuan Huang  Zhenghao Liu  Changwei Wu  Yuan Zhang  Jinjin Zhao  Xiao Wang  Jiangyu Li 《国家科学评论(英文版)》2021,8(8)

Perovskite solar cells (PSC) are promising next generation photovoltaic technologies, and there is considerable interest in the role of possible polarization of organic-inorganic halide perovskites (OIHPs) in photovoltaic conversion. The polarity of OIHPs is still hotly debated, however. In this review, we examine recent literature on the polarity of OIHPs from both theoretical and experimental points of view, and argue that they can be both polar and nonpolar, depending on composition, processing and environment. Implications of OIHP polarity to photovoltaic conversion are also discussed, and new insights gained through research efforts. In the future, integration of a local scanning probe with global macroscopic measurements in situ will provide invaluable microscopic insight into the intriguing macroscopic phenomena, while synchrotron diffractions and scanning transmission electron microscopy on more stable samples may ultimately settle the debate.  相似文献   

纳米流体结晶过程的DSC法实验研究     

陈颖  贾莉斯  莫松平 《东南大学学报》2010,26(2):359-363

以质量分数5%、平均粒径75nm的水基二氧化钛（TiO2）纳米流体为材料,利用差示扫描量热仪,分别在3,5,7,9℃/min4个冷却速率下研究了TiO2纳米粒子对去离子水结晶和熔化行为的影响.实验结果表明,与去离子水相比,水基TiO2纳米流体具有更低的过冷度和更快的结晶速率.随着冷却速率的增大,TiO2纳米粒子对去离子水过冷度的影响增强,对其结晶速率的影响则减弱.在熔化过程中,与去离子水相比,水基TiO2纳米流体具有更低的熔化温度、更小的熔化潜热和更大的熔化速率.  相似文献   

力竭运动大鼠心肌心钠素表达的变化   总被引：36，自引：4，他引：36  

潘珊珊  张炎  陆爱云  姜宗来  杨向群 《体育科学》2000,20(3):66-69

为了探讨力竭运动对大鼠心脏心钠素表达的影响,采用４月龄雄性ＸＤ大鼠,体重２２０ｇ－３６０ｇ,随机分为（１）正常对照组（Ａ组）,（２）有训练游泳力竭组（Ｂ组）、（３）无训练游力竭组（Ｃ组）,每组各１４只。灌注后取出整心,用免疫组化ＡＢＣ法,结果是：心钠素免疫阳性反应为：右心耳〉右心房〉左心房〉右心室近心房处,与Ａ组相比,Ｂ组大鼠心房肌心钠素阳性择应明显增强,心钠素电子致密颗粒大量增加;Ｃ组大鼠心房钠  相似文献   

碱金属气室参数测试教学实验平台搭建北大核心     

韩邦成  陆吉玺  张少文  翟跃阳  胡朝晖 《实验技术与管理》2022,(1):56-58

碱金属气室是原子磁强计、原子陀螺仪、原子钟等量子传感器的核心敏感元件,其内部的碱金属原子蒸汽通过与激光、磁场等相互作用,实现对物理量的高精度测量。实验室搭建了针对一类高温、高压碱金属气室的参数测试教学实验平台,该平台通过测量激光吸收光谱,获得气室内部缓冲气体的压强以及碱金属原子蒸汽的原子数密度。该平台使学生能够直接观察到激光与原子的相互作用,有助于学生加深对碱金属气室的理解以及培养学生的实验动手能力,同时也为研究生和本科生的相关课程提供了有力支撑。  相似文献