• Title/Summary/Keyword: Geospatial Queries

Search Result 11, Processing Time 0.023 seconds

Development of a Geo Semantic Web System (Geo Semantic Web 시스템의 개발)

  • Kim, Joung-Joon;Shin, In-Su;Han, Ki-Joon
    • Spatial Information Research
    • /
    • v.18 no.5
    • /
    • pp.83-92
    • /
    • 2010
  • Recently, as the Geospatial Web is combined with the Semantic Web in order to keep pace with the recent trends of information technology emphasizing interoperability, intelligence and individualization, the Geo Semantic Web was proposed, which is an intelligent geographical information Web service technology that can provide users with suitable information by connecting and integrating various types of spatial information and extensive aspatial information on the Web efficiently. For the Geo Semantic Web service, we need to develop Geo Ontology processing technologies that enable computers to process knowledge and information scattered around in the Web environment automatically. However, standards for Geo Ontology processing technologies have nod been established yet, and standardization organizations and various groups and agencies are conducting relevant studies. This paper analyzed various base theories and technologies related to Geo Ontology and developed a Geo Semantic Web system. The Geo Semantic Web system comprises Query Processing Manager that analyzes and processes Geo Semantic queries and manages sessions, Ontology Manager that generates and queries Geo Ontology and extracts spatial/aspatial data, and Clients. Finally, this paper proved the utility of the Geo Semantic Web system by applying it to a hypothetical scenario where Geo Semantic queries are required.

Query Operations for Fuzzy Spatiotemporal Databases (퍼지 시공간 데이터베이스를 위한 질의 연산)

  • Nhan Vu Thi Hong;Chi Jeong-Hee;Ryu Keun-Ho
    • 한국공간정보시스템학회:학술대회논문집
    • /
    • 2004.12a
    • /
    • pp.81-88
    • /
    • 2004
  • GIS (geographic information system) applications increasingly require the representation of geospatial objects with fuzzy extent and querying of time-varying information. In this paper, we Introduce a FSTDB (fuzzy spatiotemporal database) to represent and manage states and events causing changes of dynamic fuzzy objects using fuzzy set theory. We also propose the algorithms for the operators to be included in a GIS to make it able to answer queries depending on fuzzy predicates during a time interval and a method to identify the development process of objects during a certain period based on the designed database. They can be used in application areas handling time-varying geospatial data, including global change (as in climate or land cover change) and social (demographic, health, ect.) application.

  • PDF

An Efficient Caching Scheme to Enhance the Response Time of Geospatial Web Services (지리공간 웹 기반 서비스에서 응답시간을 향상시키기 위한 효율적인 캐싱 기법)

  • Moon, Jin-Yong
    • Journal of Digital Contents Society
    • /
    • v.10 no.3
    • /
    • pp.395-400
    • /
    • 2009
  • The wide spread of the Internet service has brought in web GIS development. But, there are problems of the user access latencies, the network traffic, and the server overload in Internet Geographic Information System because spatial data are transferred in large volumes. In this paper, I propose a cache algorithm on client side to solve the above problems. The proposed algorithm demonstrates the performance improvement over known studies by utilizing unit time and spatial proximity. In addition, this paper conducts a performance evaluation to measure the improvement in algorithm efficiency and analyzes the results of the performance evaluation. When spatial data queries are conducted, according to our performance evaluation, hit rate has been improved over the existing algorithms.

  • PDF

Developing a 3D Indoor Evacuation Simulator using a Spatial DBMS (공간 DBMS를 활용한 3차원 실내 대피 경로 안내 시스템)

  • Kim, Geun-Han;Kim, Hye-Young;Jun, Chul-Min
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.16 no.4
    • /
    • pp.41-48
    • /
    • 2008
  • Currently used 3D models, which are mostly focused on visualization of 3D objects and lack topological structure, have limitation in being used for 3D spatial analyses and applications. However, implementing a full topology for the indoor spatial objects is less practical due to the increase of complexity and computation time. This study suggests an alternative method to build a 3D indoor model with less complexity using a spatial DBMS. Storing spatial and nonspatial information of indoor spaces in DB tables enables faster queries, computation and analyses. Also it is possible to display them in 2D or 3D using the queried information. This study suggests a 2D-3D hybrid data model, which combines the 2D topology constructed from CAD floor plans and stored in a spatial DBMS and the 3D visualization functionality. This study showed the process to build the proposed model in a spatial DBMS and use spatial functions and queries to visualize in 2D and 3D. And, then, as an example application, it illustrated the process to build an indoor evacuation simulator.

  • PDF

Spatial Filtering Techniques for Geospatial AR Applications in R-tree (R-tree에서 GeoSpatial AR 응용을 위한 공간필터링 기법)

  • Park, Jang-Yoo;Lee, Seong-Ho;Nam, Kwang-Woo
    • Spatial Information Research
    • /
    • v.19 no.1
    • /
    • pp.117-126
    • /
    • 2011
  • Recently, AR applications provide location-based spatial information by GPS. Also, the spatial information is displayed by the angle of the camera. So far, traditional spatial indexes in spatial database field retrieve and filter spatial information by the minimum bounding rectangle (MBR) algorithm.(ex. R-tree) MBR strategy is a useful technique in the geographic information systems and location based services. But MBR technique doesn't reflect the characteristics of spatial queries in AR. Spatial queries of AR applications have high possibility of the dead space area between MBRs of non-leaf node and query area. We propose triangle node filtering algorithm that improved efficiency of spatial retrieval used the triangle node filtering techniques by exclusion the dead space. In this paper, the proposed algorithm has been implemented on PostgreSQL/PostGIS. Experimental results show the spatial retrieval that using the proposed algorithm better performance than the spatial retrieval that of the minimum bounding rectangle algorithm.

Implementation of User Interface for Geo-spatail Information Processing Toolkit using Open Source-based PostGIS (공개소스 PostGIS 기반 공간정보 처리 툴 킷 사용자 인터페이스 구현)

  • Han, Sun-Mook;Lee, Ki-Won
    • Korean Journal of Remote Sensing
    • /
    • v.25 no.2
    • /
    • pp.185-192
    • /
    • 2009
  • Recently, open sources for geo-spatial information processing and analysis are being developed, and they are widely adopted for the various application development projects. Open sources in the geo-spatial communities consist in several levels or types: viewer, API-level, engine sources of SDK-level, or toolkits. Among them, spatial database engine of PostgreSQL-PostGIS is used in this study for the portable multi-geospatial information processing toolkit. This work can be extended to target-based applications with domain-specific spatial queries and analyses. Design and implementation are based on C Language Interface (LIBPQ) to PostGIS and OGC library on PostgreSQL database. Conclusively, PostGIS according to this approach is an important alternative to develop most applications dealing with multi-geospatial information due to its availability, extensibility, scalability, and stability.

Determining Spatial Neighborhoods in Indoor Space using Integrated IndoorGML and IndoorPOI data

  • Claridades, Alexis Richard;Lee, Jiyeong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.38 no.5
    • /
    • pp.467-476
    • /
    • 2020
  • Indoor space has been one of the focal points for geospatial research as various factors such as increasing demands for application and demand for adaptive response in emergencies have arisen. IndoorGML (Indoor Geography Markup Language) has provided a standardized method of representing the topological aspect of micro-scale environments, with its extensive specifications and flexible applicability. However, as more real-world problems and needs demand attention, suggestions to improve this standard, such as representing IndoorPOI (Indoor Points of Interest), have arisen. Hence, existing algorithms and functionalities that we use on perceiving these indoor spaces must also adapt to accommodate said improvements. In this study, we explore how to define spatial neighborhoods in indoor spaces represented by an integrated IndoorGML and IndoorPOI data. We revisit existing approaches to combine the aforementioned datasets and refine previous approaches to perform neighborhood spatial queries in 3D. We implement the proposed algorithm in three use cases using sample datasets representing a real-world structure to demonstrate its effectiveness for performing indoor spatial analysis.

Design and Implementation of Extended Web Map Service Interfaces for Mobile Applications (모바일 응용을 위한 웹 맵 서비스 확장 인터페이스의 설계 및 구현)

  • Jo, Dae-Soo;Oh, Byung-Woo
    • Journal of Korea Spatial Information System Society
    • /
    • v.7 no.3 s.15
    • /
    • pp.93-106
    • /
    • 2005
  • Recently, the web map services with standard interfaces have been developed to a high degree for the purpose of sharing of spatial data through the web. Among the various kinds of works related, the specification for the web map service released by Open Geospatial Consortium (OGC) is the most prominent, and is nearly adopted as international standard (ISO/DIS 19128) in developing the web map servers. The web map server of OGC, however, provides the insufficient capabilities for mobile applications. Unlike the wired applications, the mobile applications would require the map server to minimize of size of data transferred, because the size of data is very important factor in communication cost and the response time of map clients. And the mobile applications require different quality of map according to the screen size of mobile devices. The mobile application, also require some application specific queries. In this paper, We have Proposed the interfaces for mobile web map services (M-WMS) which fully comply with the standard interfaces proposed in OGC. And we have designed and implemented the web map server for mobile map services. This paper has contributed to construction and practical use of the web map servers in mobile applications, such as LBS and telematics.

  • PDF

3D Object Modeling for Laser Radar Simulation (레이저레이더 시뮬레이션을 위한 3차원 객체 모델링)

  • Kim, Geun-Han;Jun, Chul-Min
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.16 no.2
    • /
    • pp.57-65
    • /
    • 2008
  • The improvement of the performance in laser radar simulation requires fast retrievals of the spatial locations and attributes of objects in response to the laser signals of the simulators. Since the data used in simulation are complex 3D objects such as terrain, buildings and vehicles, and are of large sizes, commonly used 3D modeling tools are not suitable for this use. We proposed a method to store such 3D objects in a database, perform required queries and integrate with visualization tools. We showed the processes for the data modeling based on 3D topological concepts and then building a spatial DBMS. Also, we illustrated the process for accessing and visualizing the stored data using VRML and performed test computations using some laser signal data. With further enhancement on data modeling and LOD problems in visualization, the proposed method will be practically applied in different situations including laser simulation.

  • PDF

Information Service of Real-time Emergency Room Location using MongoDB (MongoDB를 활용한 실시간 응급실 위치 정보 서비스)

  • Shin, Dong-Jin;Hwang, Seung-Yeon;Jang, Seok-Woo
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.22 no.6
    • /
    • pp.63-68
    • /
    • 2022
  • Currently, there are a total of 68 emergency rooms based on Seoul, South Korea, and there is a portal site that allows you to inquire the location of the emergency room, but it is difficult to use in an actual emergency situation because it consists of selecting a gu and a self-governing dong. In addition, it may be more efficient to go to the emergency room directly because you may miss the golden time necessary for survival in a situation where you call 119 and wait for the rescue team. Therefore, in this paper, we propose a service that can quickly search the location of the emergency room based on a specific location through various functions supported by MongoDB. After downloading emergency room location data based on Seoul Metropolitan City, storing it in MongoDB, processing the data through various processing techniques, and applying a spatial index, you can query the emergency room based on distance from a specific location in real time.