• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.11a
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• pp.59-60
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• 2023

현재 우리나라는 연안수역에 급증하는 해양시설물 설치사업에 따라 해상교통로를 보존하고 연안수역 해상교통망 수역을 기존에 구축된 지리정보 시스템(GIS)와 연계할 수 있는 방법을 연구중에 있다. 이에 따라 Postgres SQL 기반의 PostGIS를 활용하여 해상교통 밀집분석을 시공간 형태로 구축 하였으며 표출 방법에 따라 최적의 해상교통로를 선정하고자 한다. 표출 방법은 등도수 분할을 활용하여 10개의 등급으로 구분한 후 상위 1개 등급을 우선적으로 선정하였으며, 이를 기반으로 GIS에서 제공하는 다양한 알고리즘을 활용하여 좌표로 구축하고자 하였다. 수많은 격자 데이터와 벡터형태로 저장된 해상교통밀집 분석 결과는 폴리곤 결합, 폴리곤 부분 제거, 폴리곤 스무싱, 폴리곤 단순화를 활용하여 해상교통망을 구축하였다.

• Journal of Korean Society for Geospatial Information Science
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• v.14 no.4 s.38
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• pp.3-10
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• 2006

This study proposes a method to measure the positional accuracy of the implemented GIS polygon data. Also, it aims to present a possibility to analyze the occurrence types of positional errors by improving the measuring methods of positional accuracy based on the existing individual methods and by linking individual methods. As a result of the actual application of the methodology to the test area, it was possible to measure the positional accuracy in target test areas and to analyze the occurrence causes (types) of positional errors through each index linking (linking methodologies). Also, research results allowed confirming the applicability of the methodology. However, complementary research for each standard numerical value is recommended in order to ensure the validity of methodology.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.06a
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• pp.419-426
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• 2008

본 논문에서는, 건설도면의 건물 경계선을 이용하여 기존 지형도의 건물 레이어를 자동 갱신하는 과정에서 건물 객체간 유사를 측정하는 과정에서 Hausdorff 거리 측정 방법을 적용해 보았다. 서로 다른 축척에 의하여 발생하는 형상의 세일도 차이에서 발생하는 오차를 최소화하기 위하여 partial Hausdorff 거리를 적용하였다. 이 때 partial fraction을 정의하기 위한 기준으로 폴리곤 절점, 경계선 길이, 폴리곤 면적을 이용한 세 가지 방법을 적용하였다. 이 기준을 실제 데이터에 적용한 결과, 경계선 기준과 폴리곤 면적 기준 방법이 절점 기준에 비하여 안정적이라는 것과, 적용 기준에 따라 적절한 partial fraction 값을 사용하면 잡음에 의한 영향을 최소화할 수 있다는 것을 확인할 수 있었다.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.639-640
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• 2008

본 논문은 지리정보시스템(GIS, geographic information system) 상에서 GIS 데이터의 구조와 기하학적 특성을 바탕으로 GIS 속성 집합들의 평균 면적(MAAG, meanareas of attribute group)을 이용한 워터마킹 기법을 제안한다. 워터마크는 소유권 정보를 포함하는 이진 비트열로 사용하였으며, GIS 데이터 내의 MAAG를 결정한 후, 각 MAAG의 적응적 임계치를 이용하여 은닉되며, 워터마크 검출 시, 원래의 GIS 데이터가 필요 없는 블라인드 워터마킹 기법을 적용한다. 실험 결과, 제안한 워터마킹 기법이 기하학적 공격에 견고하며 워터마크의 비가시성을 확인하였다.

• Journal of Korea Multimedia Society
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• v.14 no.2
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• pp.210-218
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• 2011

Generally, GIS digital map has been represented and transmitted by ASCII and Binary data forms. Among these forms, Binary form has been widely used in many GIS application fields for the transmission of mass map data. In this paper, we present a hierarchical compression technique of polyline and polygon components for effective storage and transmission of vector map with various degree of decision. These components are core geometric components that represent main layers in vector map. The proposed technique performs firstly the energy compaction of all polyline and polygon components in spatial domain for the lossless compression of detailed vector map and compress independently integer parts and fraction parts of 64bit floating points. From experimental results, we confirmed that the proposed technique has superior compressive performance to the conventional data compression of 7z, zip, rar and gz.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.3
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• pp.15-26
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• 2012

Recently, due to applicability increase of vector data based digital map for geographic information and evolution of geographic measurement techniques, large volumed GIS(geographic information service) services having high resolution and large volumed data are flowing actively. This paper proposed an efficient vector map compression technique using the SEC(spatial energy compaction) based on classified bins for the vector map having 1cm detail and hugh range. We encoded polygon and polyline that are the main objects to express geographic information in the vector map. First, we classified 3 types of bins and allocated the number of bits for each bin using adjacencies among the objects. and then about each classified bin, energy compaction and or pre-defined VLC(variable length coding) were performed according to characteristics of classified bins. Finally, for same target map, while a vector simplification algorithm had about 13%, compression ratio in 1m resolution we confirmed our method having more than 80% encoding efficiencies about original vector map in the 1cm resolution. Also it has not only higher compression ratio but also faster computing speed than present SEC based compression algorithm through experimental results. Moreover, our algorithm presented much more high performances about accuracy and computing power than vector approximation algorithm on same data volume sizes.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.6
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• pp.599-610
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• 2020

The AED (Automated External Defibrillator) is not evaluated for spatial accuracy and temporal availability even if it is located within a building or a specific area that needed necessary to partition by spatial analysis and location allocation analysis. As a result of the analysis, the spatial analysis was performed using the existing public data of AED with applied the GIS location analysis method. A public institution (119 safety center, police box) was selected as a candidate for a public AED base that can operate 24 hours a day, 365 days a year according to the characteristics of each residential area. In addition, Thiessen Polygons were created for each candidate site and divided by regions. In the analysis of the service was analyzed regional in terms of accessibility to emergency medical services in consideration of the characteristics of AED, that emergency vehicles could arrive within 4 minutes of the time required for emergency medical treatment in most areas of the study area, but it did not areas outside of the city center. As a result, It was found that the operation of the AED base service center centered on vehicles of public institutions is effective for responding to AED patients at night and weekend hours. 19 Safety Center under and police box the jurisdiction of Daegu City to establish an AED service center for public institutions, location-based distance, attribute analysis, and minimization of overlapping areas that the method of using a vehicle appeared more efficient than using the existing walking type AED.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.2
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• pp.227-238
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• 2006

Line density index(LDI) was developed to quantify a densely isothermal line rate as standard index in the ocean environment. Theoretical background on the LDI development process restricting index range 0 to 100 was described. And validation test was done for the LDI application condition that total line length is not greater than 1/10 of unit area. NOAA SST(Sea Surface Temperature) data were used for the experimental application of LDI in the South Sea of Korea. Using GIS, $0.1^{\circ}C$ isothermal lines were linearized as vector data form SST raster data, and unit area were built as polygon data. For the LDI calculation, spatial overlapping(line in polygon) was implemented. To analyze the effect of unit area size for the LDI distribution, two cases of unit area size were designed and descriptive statistics was calculated including performing normality test. The results showed no change of LDI's essential characteristics such as mean and normality except for the range of value, variance and standard deviation. Accordingly, it was found that complex structure of thermal front and even smaller scale of front width than unit area size could influence on the LDI distribution. Also, correlation analysis performed between LDI and difference of temperature(${\Delta}T^{\circ}C$), and horizontal thermal gradient(${\Delta}T^{\circ}C/km$) on the front was obtained from linear regression model. This obtained value was compared with the results from previous researches. Newly developed LDI can be used to compare the thermal front regions changing spatio-temporally in the ocean environment using absolute index value. It is considered to be significant to analyze the relationship between thermal front and marine environment or front and marine organisms in a quantitative approach described in this study.