<p><strong>Abstract.</strong> In order to solve the problem of the long update cycle of geographical names and addresses, this paper puts forward a dynamic update technique of mobile & PC integration. The combination of related services of NewMap software and mobile APP can effectively improve the speed and accuracy of updating geographical names and addresses. Taking the mobile & PC integration model as a starting point and comprehensively using GIS-related technologies, mobile positioning technologies, offline map technologies, etc., the dynamic update of geographical names and addresses has been successfully implemented and has been successfully applied to the dynamic update of geographical names.</p>
<p><strong>Abstract.</strong> ETL (Extraction-Transform-Load) tools, traditionally developed to operate offline on historical data for feeding Data-warehouses need to be enhanced to deal with continuously increased streaming data and be executed at network level during data streams acquisition. In this paper, a scalable and web-based ETL system called NMStream was presented. NMStream is based on event-driven architecture and designed for integrating distributed and heterogeneous streaming data by integrating the Apache Flume and Cassandra DB system, and the ETL processes were conducted through the Flume agent object. NMStream can be used for feeding traditional/real-time data-warehouses or data analytic tools in a stable and effective manner.</p>
<p><strong>Abstract.</strong> At present, most of the researches on geometric change detection of vector data, they store the change detection results in the database, so they pay more attention to the accuracy of results, but not to the speed of processing. Nowadays, many applications require real-time change detection on vector data and rapid presentation of the result. Although the existing algorithms use spatial index technology to improve the processing speed, the processing time is still beyond the range that people can bear. In order to reduce processing time, this paper takes the vector surface feature set as the research object, trying to reduce the redundancy of the candidate set that seriously affects the efficiency of change detection. Based on the regular use of spatial index created with geometric Minimum Bounding Rectangle, this paper uses geometric shrinkage technique and precise query technique to reduce the size of the candidate set for detection, so as to achieve the goal of speeding up. Finally, using five years of farmland data and resident data from Ezhou City, Hubei Province, China, a change detection experiment was conducted. The experiment proved that the geometric shrinkage and precise query techniques can effectively improve the processing speed.</p>
<p><strong>Abstract.</strong> This paper presents a viewpoint-related fusion method of massive vector data and 3D terrain, in order to superpose the massive 2D vector data onto the undulating multi-resolution 3D terrain precisely and efficiently. First, the method establishes an adaptive hierarchical grid spatial index for vector data. It will determine the geographic spatial relationship between vector data and the tiles of 3D terrain in the visible area; secondly, this method will use the improved sub-pixel graphics engine AggExt to generate textures for vector data that has been bound to terrain tiles in real time; Finally, considering that a large amount of vector data will generate a lot of 2D textures in the computer memory, the method should release the “expired” vector textures. In this paper, in order to take into account the real-time convergence and the smooth interactivity of 3D scenes, this method will adopt a multi-threading strategy. The experimental results show that this method can realize the real-time and seamless fusion of massive vector objects on the 3D terrain, and has a high rendering frame rate. It can also reduce the aliasing produced by traditional texture-based methods and improve the quality of vector data fusion.</p>
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