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1.
从地质空间数据组织与管理的发展历程出发,在研究Oracle Spatial理论的基础上,分析了地质空间数据在Oracle Spatial中的组织、存储方式和空间索引机制;应用Oracle Spatial的开发接口和JBuilder集成开发环境,开发实现了地质空间数据库管理系统,提供了管理与检索地质空间数据功能;介绍了系统部署与运行方案。 相似文献
2.
Due to the complex nature of multi-source geological data, it is difficult to rebuild every geological struc-ture through a single 3D modeling method. The multi-source data interpretation method put forward in this analysis is based on a database-driven pattern and focuses on the discrete and irregular features of geological data. The geological data from a variety of sources covering a range of accuracy, resolution, quantity and quality are classified and inte-grated according to their reliability and consistency for 3D modeling. The new interpolation-approximation fitting construction algorithm of geological surfaces with the non-uniform rational B-spline （NURBS） technique is then pre-sented. The NURBS technique can retain the balance among the requirements for accuracy, surface continuity and data storage of geological structures. Finally, four alternative 3D modeling approaches are demonstrated with reference to some examples, which are selected according to the data quantity and accuracy specification. The proposed approaches offer flexible modeling patterns for different practical engineering demands. 相似文献
3.
INTRODUCTION There is growing consensus among computa-tional scientists that observational data, result of computation and other forms of information produced by an individual or a research group need to be shared and used by other authorized groups across the world through the entire life cycle of the information (Wil-liams, 1998; Rowe et al., 2001). The Web has revo-lutionized the electronic publication of data. It has relied primarily on HTML that emphasizes a hypertext document app… 相似文献
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以厦门理工学院校园为例,基于ArcGIS Server API forFlex和City Engine技术,设计并实现了B／S结构的厦门理工学院的二、三维数字校园系统．用户可以通过浏览器漫步于虚拟校园中,实现校园快速浏览、空间与属性信息双向查询、缓冲区分析和路径分析等功能． 相似文献
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Jianyi Li Lanying Nie Zeyu Li Lijun Lin Lei Tang Jun Ouyang 《Anatomical sciences education》2012,5(6):330-339
Anatomical corrosion casts of human specimens are useful teaching aids. However, their use is limited due to ethical dilemmas associated with their production, their lack of perfect reproducibility, and their consumption of original specimens in the process of casting. In this study, new approaches with modern distribution of complex anatomical spatial information were explored to overcome these limitations through the digitalization of anatomical casts of human specimens through three‐dimensional (3D) reconstruction, rapid prototype production, and Web‐based 3D atlas construction. The corrosion cast of a lung, along with its associated arteries, veins, trachea, and bronchial tree was CT‐scanned, and the data was then processed by Mimics software. Data from the lung casts were then reconstructed into 3D models using a hybrid method, utilizing both “image threshold” and “region growing.” The fine structures of the bronchial tree, arterial, and venous network of the lung were clearly displayed and demonstrated their distinct relationships. The multiple divisions of bronchi and bronchopulmonary segments were identified. The 3D models were then uploaded into a rapid prototype 3D printer to physically duplicate the cast. The physically duplicated model of the lung was rescanned by CT and reconstructed to detect its production accuracy. Gross observation and accuracy detection were used to evaluate the duplication and few differences were found. Finally, Virtual Reality Modeling Language (VRML) was used to edit the 3D casting models to construct a Web‐based 3D atlas accessible through Internet Explorer with 3D display and annotation functions. Anat Sci Educ. © 2012 American Association of Anatomists. 相似文献
6.
从Oracle Spatial的空间查询分析出发,结合实例分析了它的查询模型、空间算子以及常用的空间函数,最后给出了Oracle Spatial中空间查询的优化建议。 相似文献
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The inherent spatial complexity of the human cerebral ventricular system, coupled with its deep position within the brain, poses a problem for conceptualizing its anatomy. Cadaveric dissection, while considered the gold standard of anatomical learning, may be inadequate for learning the anatomy of the cerebral ventricular system; even with intricate dissection, ventricular structures remain difficult to observe. Three-dimensional (3D) computer reconstruction of the ventricular system offers a solution to this problem. This study aims to create an accurate 3D computer reconstruction of the ventricular system with surrounding structures, including the brain and cerebellum, using commercially available 3D rendering software. Magnetic resonance imaging (MRI) scans of a male cadaver were segmented using both semiautomatic and manual tools. Segmentation involves separating voxels of different grayscale values to highlight specific neural structures. User controls enable adding or removing of structures, altering their opacity, and making cross-sectional slices through the model to highlight inner structures. Complex physiologic concepts, such as the flow of cerebrospinal fluid, are also shown using the 3D model of the ventricular system through a video animation. The model can be projected stereoscopically, to increase depth perception and to emphasize spatial relationships between anatomical structures. This model is suited for both self-directed learning and classroom teaching of the 3D anatomical structure and spatial orientation of the ventricles, their connections, and their relation to adjacent neural and skeletal structures. 相似文献
8.
阐述了ArcGIS作为一种综合性处理工具在三维石油数据集中的应用。同时,在石油工业中三维可视化和分析工具的应用非常广泛,通过这些工具得到的综合数据和某个组织所拥有的其他空间数据是很难直接应用的。利用地理数据库的叠置单元块特性,复杂的三维特性能够存储在地理数据库中,并且可以通过三维立体方式在ArcGIS环境下达到可视化的效果。这就实现了通过传统通用仪器资源获得来自于地质、工程或者勘测源的标准空间数据的复杂三维对象的综合化。 相似文献
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对于大角度、大范围、复杂场景的快速扫描成像系统,除了要进行任意运动和动态采集建模外,还要对激光传感器的姿态和位置进行实时精确的描述.基于此要求,文中构建了一种基于小型无人直升机机载激光扫描传感器的三维建模成像系统,并设计了一种分步式串级滤波算法,将激光测距传感器得到的距离信息,与小型无人直升机惯性导航系统解算的姿态与位置数据进行融合,实现空间扫描点到基准坐标系的映射,并完成2D行扫描到3D空间的扩展,建立现实世界的3D数字模型. 相似文献
10.
李光师 《鞍山师范学院学报》2008,10(6):80-83
分析了基于Oracle Spatial的对象关系模型来存储和管理矢量空间数据的机制,包括其采用的数据模型、元数据管理机制、空间索引机制及查询机制,并在此基础之上给出了一个典型的基于Oracle Spatial创建和操作GIS空间数据库的实例． 相似文献
11.
XING Yu-zhong FAN Tai-liang ZHENG Li-hui 《浙江大学学报(A卷英文版)》2006,7(11):1904-1910
INTRODUCTION Several fields in Liaohe Basin are host to frac- tured hydrocarbon oil reservoir, fractures are consid- ered to influence productivity significantly in these reservoirs, which not only form a large part of the overall porosity, but also are responsible for the po- tential reservoir volume. More importantly, the frac- ture system facilitates permeability and flow. Ce- mented and closed fractures act as barriers to flow, whereas open fractures intersected by the wellbore may in… 相似文献
12.
Effectiveness of three‐dimensional digital animation in teaching human anatomy in an authentic classroom context 
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下载免费PDF全文 Nady Hoyek Christian Collet Franck Di Rienzo Mickael De Almeida Aymeric Guillot 《Anatomical sciences education》2014,7(6):430-437
Three‐dimensional (3D) digital animations were used to teach the human musculoskeletal system to first year kinesiology students. The purpose of this study was to assess the effectiveness of this method by comparing two groups from two different academic years during two of their official required anatomy examinations (trunk and upper limb assessments). During the upper limb section, the teacher used two‐dimensional (2D) drawings embedded into PowerPoint® slides and 3D digital animations for the first group (2D group) and the second (3D group), respectively. The same 3D digital animations were used for both groups during the trunk section. The only difference between the two was the multimedia used to present the information during the upper limb section. The 2D group surprisingly outperformed the 3D group on the trunk assessment. On the upper limb assessment no difference in the scores on the overall anatomy examination was found. However, the 3D group outperformed the 2D group in questions requiring spatial ability. Data supported that 3D digital animations were effective instructional multimedia material tools in teaching human anatomy especially in recalling anatomical knowledge requiring spatial ability. The importance of evaluating the effectiveness of a new instructional material outside laboratory environment (e.g., after a complete semester and on official examinations) was discussed. Anat Sci Educ 7: 430–437. © 2014 American Association of Anatomists. 相似文献
13.
《天津大学学报(英文版)》2017,(6)
Single-grit grinding of a 2.5D woven composite was investigated by the finite-element method(FEM) using a unit-cell model. According to our hypotheses, the axis of the warp yarn was a sinusoidal curve and the cross section of the weft yarn was shaped like a biconvex lens. AVUMAT subroutine was used to construct the constitutive model of the 2.5D woven composite. The grinding process of the composite was analyzed using an FEM simulation with the ABAQUS/Explicit software. A validation experiment was also carried out. The simulation results showed that a grinding crack was well simulated. Furthermore, the junctions between the warp yarn and weft yarn were found to be seriously damaged and cracks were observed to extend outward along the warp fiber during grinding, in good agreement with the experimental results. In addition,the strain of weft yarns was obviously greater than that of warp yarns when the grinding direction was perpendicular to the weft yarns and parallel to the axis of the warp yarns.These results demonstrate that the mesostructure strongly influences the grinding damage inflicted on woven composites. 相似文献
14.
Daniel Preece Sarah B. Williams Richard Lam Renate Weller 《Anatomical sciences education》2013,6(4):216-224
Three‐dimensional (3D) information plays an important part in medical and veterinary education. Appreciating complex 3D spatial relationships requires a strong foundational understanding of anatomy and mental 3D visualization skills. Novel learning resources have been introduced to anatomy training to achieve this. Objective evaluation of their comparative efficacies remains scarce in the literature. This study developed and evaluated the use of a physical model in demonstrating the complex spatial relationships of the equine foot. It was hypothesized that the newly developed physical model would be more effective for students to learn magnetic resonance imaging (MRI) anatomy of the foot than textbooks or computer‐based 3D models. Third year veterinary medicine students were randomly assigned to one of three teaching aid groups (physical model; textbooks; 3D computer model). The comparative efficacies of the three teaching aids were assessed through students' abilities to identify anatomical structures on MR images. Overall mean MRI assessment scores were significantly higher in students utilizing the physical model (86.39%) compared with students using textbooks (62.61%) and the 3D computer model (63.68%) (P < 0.001), with no significant difference between the textbook and 3D computer model groups (P = 0.685). Student feedback was also more positive in the physical model group compared with both the textbook and 3D computer model groups. Our results suggest that physical models may hold a significant advantage over alternative learning resources in enhancing visuospatial and 3D understanding of complex anatomical architecture, and that 3D computer models have significant limitations with regards to 3D learning. Anat Sci Educ 6: 216–224. © 2013 American Association of Anatomists. 相似文献
15.
Dong Sun Shin Hae Gwon Jang Sung Bae Hwang Dong‐Hwan Har Young Lae Moon Min Suk Chung 《Anatomical sciences education》2013,6(5):316-323
In the Visible Korean project, serially sectioned images of the pelvis were made from a female cadaver. Outlines of significant structures in the sectioned images were drawn and stacked to build surface models. To improve the accessibility and informational content of these data, a five‐step process was designed and implemented. First, 154 pelvic structures were outlined with additional surface reconstruction to prepare the image data. Second, the sectioned and outlined images (in a browsing software) as well as the surface models (in a PDF file) were placed on the Visible Korean homepage in a readily‐accessible format. Third, all image data were visualized with interactive elements to stimulate creative learning. Fourth, two‐dimensional (2D) images and three‐dimensional (3D) models were superimposed on one another to provide context and spatial information for students viewing these data. Fifth, images were designed such that structure names would be shown when the mouse pointer hovered over the 2D images or the 3D models. The state‐of‐the‐art sectioned images, outlined images, and surface models, arranged and systematized as described in this study, will aid students in understanding the anatomy of female pelvis. The graphic data accompanied by corresponding magnetic resonance images and computed tomographs are expected to promote the production of 3D simulators for clinical practice. Anat Sci Educ 6: 316–323. © 2013 American Association of Anatomists. 相似文献
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研究了基于CityGML的多层次细节3D城市模型快速建模方法,并将其结合到3DUGIS中用于数字城市建设。建模过程中考虑空间关系、拓扑关系和语义信息。建模过程自动化程度高,能够在三维空间直接进行空间分析,方便海量数据的交换与数据挖掘。并给出了上海世博园区三维信息系统结合具体应用案例。 相似文献
17.
Based on elastoplastic model, 2D and 3D finite element method (FEM) are used to calculate the stress and displacement distribution in the soft clay slope under gravity and uniform load at the slope top. Stability analyses indicate that 3D boundary effect varies with the stress level of the slope. When the slope is stable, end effect of 3D space is not remarkable. When the stability decreases, end effect occurs; when the slope is at limit state, end effect reaches maximum. The energy causing slope failure spreads preferentially along y-z section, and when the failure resistance capability reaches the limit state, the energy can extend along x-axis direction. The 3D effect of the slope under uniform load on the top is related to the ratio of load influence width to slope height, and the effect is remarkable with the decrease of the ratio. 相似文献
18.
ZHANG Feng LI Zhi-ping WANG He-lin WU Jian TAN Zhen-hua 《浙江大学学报(A卷英文版)》2007,8(11):1858-1863
In the phase of field evaluation, the changing of interwell reservoir may be out of control if the geological model was built only on well data due to few existing wells. The uncertainty of the interwell reservoir interpolation based only on well data can be decreased by comprehensive utilization of geological, logging and seismic data, especially by using highly relative seismic properties from 3D seismic data adjusted by well point data to restrict interpolation of geological properties. A 3D-geological model which takes the sand body as the direct modeling object was built through stacking the structure, reservoir and water/oil/gas properties together in 3D space. 相似文献
19.
基于地震反射波法超前预测系统的原理及主要技术手段,以栋梁坡隧道工程为实例,针对隧道复杂的地质条件,施工过程中将超前地质预报和地质素描调查相结合,先对隧道全段范围内地形、地层岩性等进行全面核查,然后结合核查结果运用地震反射波法预报掌子面前方的节理裂隙发育情况,围岩完整性等地质信息。开挖后验证情况与预测结果基本一致,为后续预防突水塌方等隧道地质灾害事故的发生提供数据支撑,有效保证栋梁坡隧道的施工安全。 相似文献