Yiping Tian

Decomposition tree: a spatio-temporal indexing method for movement big data

Movement is a complex process that evolves through both space and time. Movement data generated by moving objects is a kind of big data, which has been a focus of research in science, technology, economics, and social studies. Movement database is also at the forefront of geographic information science research. Developing efficient access methods for movement data stored in movement databases is of critical importance. Tree-like indexing structures such as the R-tree, Quadtree, Octree are not suitable for indexing multi-dimensional movement data because they all have high space cost of their inner nodes. In addition, it is difficult to use them for parallel access to multi-dimensional movement data because they thereof, are in hierarchical structures, which have severe overlapping problems in high dimensional space. In this paper, we propose a novel access method, the Decomposition Tree (D-tree), for indexing multi-dimensional movement data. The D-tree is a virtual tree without inner nodes, instead, through an encoding method based on integer bit-shifting operation, and can efficiently answer a wide range of queries. Experimental results show that the space cost and query performance of D-tree are superior to its best known competitors.

Three-dimensional oil and gas pool-forming dynamic simulation system: principle, method and applications

Based on the theories and methods of system engineering, the reconstruction of physical space for oil and gas generation, expulsion, migration, accumulation and diffusion is realised by combining the dynamics simulation with topological structure simulation and applying the topological structure simulation. The integral non-linear process of petroleum system is described successfully with the combination of general and system dynamic simulation. The integration of numerical simulation and artificial intelligence simulation solves the non-linear process description of petroleum generation, expulsion, migration, accumulation and diffusion. At the same time, the basin geological body and its oil and gas generation, expulsion, migration, accumulation process of the three-dimensional visualisation of dynamic modelling, spatial analysis and trap evaluation technologies were further developed in this system. The software has been applied successfully in modelling petroleum systems of Tarim River Oilfield, Zhu III Depression, Linqing Depression, Baise Basin and Dongying Depression, China.

Three-dimensional reconstruction of geological solids based on section topology reasoning

In order to solve the dynamic reconstruction and local updating problem of three-dimensional geological solids, topology reasoning is used for three-dimensional geological modeling. This can advance the level of the corresponding section automation in implementing the 3D geological solid dynamical reconstruction by the construction of and reasoning on topology on the 3D curved surface. This method has been successfully used in the Nanjing city geological modeling and the Zijin gold mine modeling. The results prove that this method adapts to coplanar section and noncoplanar section data, and improves the efficiency of 3D geological modeling.

A virtual globe-based integration and visualization framework for aboveground and underground 3D spatial objects

The construction of a large-scale integrated information system has been a hot issue in the field of geoinformatics. It aims to integrate aboveground and underground spatial information and objects in a unified visual environment. Virtual globe, as the most commonly used technology in the construction of Digital Earth, can provide a platform and framework for the integration and visualization of worldwide spatial objects and models. However, the existing works mainly focused on terrains and aboveground spatial entities, and there is still little research on the integration and visualization of large-scale underground geological models and entities in a virtual globe. In this work, the data organizations of aboveground and underground 3D spatial objects were analyzed in detail according to the technical characteristics of the virtual globe. Improved strategies were proposed to achieve the integrated visualization of aboveground and underground 3D spatial objects in a virtual globe-based spherical coordinate. In this process, the terrain surface based on Triangulated Irregular Network (TIN) was used as an intermediate layer to unify the spatial coordinate system. An improved scene cutting approach was used to overcome the challenge that underground geological structures cannot be integrated and visualized with aboveground spatial entities, terrains and landforms. Finally, we developed a virtual globe-based prototype system using OpenSceneGraph (OSG) and osgEarth as the 3D visualization engine. The aboveground and underground spatial models of Fuzhou, a coastal city of eastern China, were applied in this system to verify the validity of the strategies proposed in this paper. In addition, the efficiency of this system in terms of scheduling and visualizing was tested by using the massive models of Fuzhou.

A transmission architecture for massive 3D geospatial data dynamic dispatch based on ACE

Becoming development trend of GIS, three-dimensional visualization makes the amount of spatial data grown inevitably. Therefore, the study on storage and management of massive three-dimensional geospatial data is necessary and significant. The C/S framework, which consists of massive three-dimensional geospatial database for server and a large number of low-profile PC for clients, has become a basic idea to solve the problem. However, the development of server software witnesses plenty of challenges, such as error detection and recovery, intercurrent control and real time dispatch of spatial data etc. Based on ACE, how to apply the framework and pattern of communications software for building up a powerful application framework and constructing a high-performance server called adaptive communication server of massive three-dimensional geospatial data, is presented. The paper discusses massive three-dimensional data server related technology to achieve a thorough exploration and research, analyses the domain of 3D GIS thoroughly, identifies the problem space and the core design challenges, and proposes a feasible solution. Reducing the difficulty and workload of 3D GIS server development, this solution can have the developer focus on the development of data visualization. In addition, this paper described the object oriented architecture which supports multiple server policy configurations. Being a dynamically ordered structure, it can be ordered systematically these strategies and can be statically and dynamically change their behavior, so that it can provide the most effective strategies for a given software or hardware platform and work load.