• Title/Summary/Keyword: Geo-information

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Status and Development of Geomatic s in China

  • Li, Li
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2002.04a
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    • pp.17-24
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    • 2002
  • Mechanization is the characteristic of the industrial era and computerization is the characteristic of the Information Era. Now we are facing on the transition from Industrial Era to information Era. Established the National Geo-spatial Data Infrastructures is the fundamental base for information society and is one part of the national basic economic development plan. From 1980's China started his successful transition from traditional methods to high-tech based mapping. China has laid out a high accuracy national GPS (global Positioning System) network, and completed the geographic information databases for scale of 1:1million and 1:250,000. Now it is working on the databases for scales of 1:50,000 and 1:10,000, the world highest level. The massive national programmed has been dubbed "Digital China," since it involves massive quantities of digitized geographical information. Simultaneity, GIS technology and the geo-spatial data have been used widely in electronic government affair, environmental protection, disaster control, ITS and etc. The users have realized the benefits more and more widely. Internet is an efficient way to distribute the geo-information, the State Bureau of Surveying and Mapping has give great effort to settle down the rules and standards to establish the clearing house. Some National Geo-standards have issued, and some of them are on the way. The GIS software is another important factor in the GIS industry. Chinese government working-out some good policy to supports the GIS software developer to have their own copyright. This paper is based on the above to introduce the status and development of Geomatics in China. in China.

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A Study on the Web-Based Representation of Thematic Maps Using GeoWeb Platform (GIS와 지오웹 플랫폼을 활용한 웹기반 주제도 표현에 관한 연구)

  • Kim, Nam-Shin;Jin, Shizhu
    • Journal of the Korean Association of Geographic Information Studies
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    • v.14 no.1
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    • pp.107-117
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    • 2011
  • This study aimed to inquire into possibilities of the web-based representation of thematic maps by geo-information mashup in the geoweb platform. In the Web2.0, Google platform leads the geoweb by offering effective mashup functions for geo-information. Geo-information mashup is opening a new horizon of map applications in fusion with a great of data in the Internet. Geo-information mashup by the available data method can be classified as two type; one is linkage of sources of platform itself(satellite images) and external data, the other is linkage of platform itself and user created contents. This study made heatmap, proportional map, and choropleth map based on Google satellite images by the linkage of platform itself and external data. As a result, thematic map of Google mashup expected to give us to a flexibility for difference interpretations of geographical distribution by representing overlap with satellite images.

Questionnaire Analysis of Geo-Spatial Open Source Application (공간정보 오픈소스 활용 설문조사에 따른 현황 분석)

  • Yoo, Hee-Young;Lee, Ki-Won;Lee, Kwang-Jae;Kim, Yong-Seung
    • Journal of the Korean Association of Geographic Information Studies
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    • v.16 no.4
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    • pp.106-119
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    • 2013
  • As open source can reduce costs and apply to various fields rapidly, many countries have actively adopted open source. However, geo-spatial open source in Korea is not actively promoted yet comparing to other countries having similar infra environments. In this study, we analyzed the perception of geo-spatial open source, utilization status, the development possibility and future direction using questionnaire survey completed by experts dealing with spatial information. The survey result shows that many experts have experiences of using geo-spatial open source but they got a lack of understanding about open source license or regulations and only a few people got professional training. Insufficient references, the difficulty of maintenance, lack of support and low technical reliability have hindered the adoption of geo-spatial open source. Only some part of geo-spatial open source software or libraries in some field have been used in the country. However, many researchers rate highly development potential and plan to use geo-spatial open source soon. If user's convenience, reference materials, technical trust and policy support are improved, open source field for spatial information will be developed greatly in the future.

A study on GEO satellite signals in L - to Ka-band affected by Asian Sand Dust

  • Hong Wan-Pyo
    • Journal of information and communication convergence engineering
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    • v.3 no.3
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    • pp.146-151
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    • 2005
  • This paper represents an attempt to bring together and analyses the measurement data measured by the Satellite Signal Monitoring Center in Korea and the Korea Meteorological Administration/Korea Meteorological Research Institute in close cooperation with this study team. This paper presents the signal characteristic of GEO satellite operating in frequency range 1 to 20GHz associated with Asian Sand Dust (the so-called Yellow Sand Dust). The downlink signal power (dBm) for L-, S-, C-, Ku-, and Ka-band frequencies from GEO satellites were measured in a clear weather and in Asian Sand Dust weather by the Satellite Signal Monitoring Center. The measured signal power(dBm) were compared to the total number concentration and size distribution of Sand Dust that were measured by the Korea Meteorological Administration/Korea Meteorological Research Institute and the possible correlation between these sets data were analyzed. The results demonstrate that the downlink signal level (dBm) of GEO satellite is attenuated by Asian Sand Dust. Hitherto, merger information has been reported as to the influence of sand dust on satellite communications operating in regions affected by sand dust.

GML-based Strategic Approach and Its Application for Geo-scientific Infrastructure Building

  • Moon, Sun-Hee;Lee, Ki-Won;Kwon, Byung-Doo
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.235-237
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    • 2003
  • GIS became increasingly important in information-oriented society as social indirect capital and many GIS data are developed. To use these data effectively standard format that enables easy to transport and store is needed. For this purpose, OGC developed GML based on XML as web standard format of geographical information. In this study, web based mapping with respect to digital geologic map and gravity anomaly map was accomplished using GML. While, styling methods were implemented in XSLT to make the visualizing suitable for the character of each layer, so it is possible to make dynamic maps in the SVG. GML-base map produced in this study can be transferred and represented without loss of the meaning and degrading on the web.

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Research on Geo-Referencing Methodology of Point Clouds Data in Urban Area (포인트 클라우드 자료의 도심지 Geo-Referencing 방안 연구)

  • Cho, Hyung-Sig;Sohn, Hong-Gyoo;Han, Soo-Hee;Hwang, Sae-Mi-Na
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2010.04a
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    • pp.285-287
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    • 2010
  • It is recently enlarged to necessity of 3D spatial information model in urban areas. and in order to that, It is increased to use the terrestrial LiDAR. The Point clouds which are received by terrestrial LiDAR take a relateive coordinate. For transform into absolute coordinate, it carry out GPS surveying. However, it is difficult to geo-referencing of point clouds using the GPS due to high buildings and facilities in urban area. This study suggests a methodology, that is geo-referencing of point clouds which is received from terresstrial LiDAR in urban area and then verified accuracy of geo-referencing of point clouds. In order to geo-Referencing of point clouds which are received in Engineering building of Yonsei Univ., it was be setout through GPS surveying, and then obtained absolute coordinate of real building. Using this coordinate, It was operated geo-referencing of point clouds, verified accuracy between check point and geo-referenced point clouds. As a result, RMSE of check point shows that GPS surveying is 6.9~8.0cm.

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A Dual Processing Load Shedding to Improve The Accuracy of Aggregate Queries on Clustering Environment of GeoSensor Data Stream (클러스터 환경에서 GeoSensor 스트림 데이터의 집계질의의 정확도 향상을 위한 이중처리 부하제한 기법)

  • Ji, Min-Sub;Lee, Yeon;Kim, Gyeong-Bae;Bae, Hae-Young
    • Journal of the Korea Society of Computer and Information
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    • v.17 no.1
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    • pp.31-40
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    • 2012
  • u-GIS DSMSs have been researched to deal with various sensor data from GeoSensors in ubiquitous environment. Also, they has been more important for high availability. The data from GeoSensors have some characteristics that increase explosively. This characteristic could lead memory overflow and data loss. To solve the problem, various load shedding methods have been researched. Traditional methods drop the overloaded tuples according to a particular criteria in a single server. Tuple deletion sensitive queries such as aggregation is hard to satisfy accuracy. In this paper a dual processing load shedding method is suggested to improve the accuracy of aggregation in clustering environment. In this method two nodes use replicated stream data for high availability. They process a stream in two nodes by using a characteristic they share stream data. Stream data are synchronized between them with a window as a unit. Then, processed results are merged. We gain improved query accuracy without data loss.

Rainfall-Runoff Analysis in the Whangryong River Basin Using HEC-HMS and HEC-GeoHMS (HEC-HMS, HEC-GeoHMS를 이용한 황룡강유역의 유출분석)

  • Kim, Chul;Park, Nam-Hee
    • Spatial Information Research
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    • v.10 no.2
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    • pp.275-287
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    • 2002
  • Rainfall-Runoff Analysis in Whangryong River Basin was made using HEC-HMS and HEC-GeoHMS. The Basin was divided into three sub-basins using HEC-CeoHMS and GIS. Then, GIS input data were derived from each sub-basins. SCS CN runoff-volume model, Snyder's UH direct-runoff model, exponential recession baseflow model and Muskingum routing model in HEC-HMS were used to simulate the runoff volume using selected rainfall event and the parameters were optimized. Peak flowrate calculated using optimized parameters was compared to the observed flowrate in the basin. The result proved to be good agreement with each other. Optimized parameters in this local basin can be used to calculate the peak flowrate in the future.

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Strategies and Cost Model for Spatial Data Stream Join (공간 데이터스트림을 위한 조인 전략 및 비용 모델)

  • Yoo, Ki-Hyun;Nam, Kwang-Woo
    • Journal of Korea Spatial Information System Society
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    • v.10 no.4
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    • pp.59-66
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    • 2008
  • GeoSensor network means sensor network infra and related software of specific form monitoring a variety of circumstances over geospatial. And these GeoSensor network is implemented by mixing data stream with spatial attribute, spatial relation. But, until a recent date sensor network system has been concentrated on a store and search method of sensor data stream except for a spatial information. In this paper, we propose a definition of spatial data stream and its join strategy model at GeoSensor network, which combine data stream with spatial data. Spatial data stream s defining in this paper are dynamic spatial data stream of a moving object type and static spatial data stream of a fixed type. Dynamic spatial data stream is data stream transmitted by moving sensor as GPS, while static spatial data stream is generated by joining a data stream of general sensor and a relation with location values of these sensors. This paper propose joins of dynamic spatial data stream and static spatial data stream, and cost models estimating join cost. Finally, we show verification of proposed cost models and performance by join strategy.

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