• Title/Summary/Keyword: geographic accessibility

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An Analysis of Accessibility to Hydrogen Charging Stations in Seoul Based on Location-Allocation Models (입지배분모형 기반의 서울시 수소충전소 접근성 분석)

  • Sang-Gyoon Kim;Jong-Seok Won;Yong-Beom Pyeon;Min-Kyung Cho
    • Journal of the Society of Disaster Information
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    • v.20 no.2
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    • pp.339-350
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    • 2024
  • Purpose: This study analyzes accessibility of 10 hydrogen charging stations in Seoul and identifies areas that were difficult to access. The purpose is to re-analyze accessibility by adding a new location in terms of equity and safety of location placement, and then draw implications by comparing the improvement effects. Method: By applying the location-allocation model and the service area model based on network analysis of the ArcGIS program, areas with weak access were identified. The location selection method applied the 'Minimize Facilities' method in consideration of the need for rapid arrival to insufficient hydrogen charging stations. The limit distance for arrival within a specific time was analyzed by applying the average vehicle traffic speed(23.1km/h, Seoul Open Data Square) in 2022 to three categories: 3,850m(10minutes), 5,775m(15minutes), 7,700m(20minutes). In order to minimize conflicts over the installation of hydrogen charging stations, special standards of the Ministry of Trade, Industry and Energy applied to derive candidate sites for additional installation of hydrogen charging stations among existing gas stations and LPG/CNG charging stations. Result: As a result of the analysis, it was confirmed that accessibility was significantly improved by installing 5 new hydrogen charging stations at relatively safe gas stations and LPG/CNG charging stations in areas where access to the existing 10 hydrogen charging stations is weak within 20 minutes. Nevertheless, it was found that there are still areas where access remains difficult. Conclusion: The location allocation model is used to identify areas where access to hydrogen charging stations is difficult and prioritize installation, decision-making to select locations for hydrogen charging stations based on scientific evidence can be supported.

Detection of Pine Wilt Disease tree Using High Resolution Aerial Photographs - A Case Study of Kangwon National University Research Forest - (시계열 고해상도 항공영상을 이용한 소나무재선충병 감염목 탐지 - 강원대학교 학술림 일원을 대상으로 -)

  • PARK, Jeong-Mook;CHOI, In-Gyu;LEE, Jung-Soo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.22 no.2
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    • pp.36-49
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    • 2019
  • The objectives of this study were to extract "Field Survey Based Infection Tree of Pine Wilt Disease(FSB_ITPWD)" and "Object Classification Based Infection Tree of Pine Wilt Disease(OCB_ITPWD)" from the Research Forest at Kangwon National University, and evaluate the spatial distribution characteristics and occurrence intensity of wood infested by pine wood nematode. It was found that the OCB optimum weights (OCB) were 11 for Scale, 0.1 for Shape, 0.9 for Color, 0.9 for Compactness, and 0.1 for Smoothness. The overall classification accuracy was approximately 94%, and the Kappa coefficient was 0.85, which was very high. OCB_ITPWD area is approximately 2.4ha, which is approximately 0.05% of the total area. When the stand structure, distribution characteristics, and topographic and geographic factors of OCB_ITPWD and those of FSB_ITPWD were compared, age class IV was the most abundant age class in FSB_ITPWD (approximately 55%) and OCB_ITPWD (approximately 44%) - the latter was 11% lower than the former. The diameter at breast heigh (DBH at 1.2m from the ground) results showed that (below 14cm) and (below 28cm) DBH trees were the majority (approximately 93%) in OCB_ITPWD, while medium and (more then 30cm) DBH trees were the majority (approximately 87%) in FSB_ITPWD, indicating different DBH distribution. On the other hand, the elevation distribution rate of OCB_ITPWD was mostly between 401 and 500m (approximately 30%), while that of FSB_ITPWD was mostly between 301 and 400m (approximately 45%). Additionally, the accessibility from the forest road was the highest at "100m or less" for both OCB_ITPWD (24%) and FSB_ITPWD (31%), indicating that more trees were infected when a stand was closer to a forest road with higher accessibility. OCB_ITPWD hotspots were 31 and 32 compartments, and it was highly distributed in areas with a higher age class and a higher DBH class.

Design and Implementation of Internet Spatial Data Service Component based Open GIS Specification (개방형 GIS 기반 인터넷 공간 데이터서비스 컴포넌트의 설계 및 구현)

  • Choi, Sang-Kil;Lee, Jin-Kyu;Lee, Jong-Won;Kim, Jang-Su
    • Journal of Korea Spatial Information System Society
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    • v.1 no.2 s.2
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    • pp.21-31
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    • 1999
  • In accordance with the completion of the spatial database building works in the central and/or local government authorities as well as the rapid popularization of various information services through internet, it is heavily required to provide spatial information services through World Wide Web. To provide a qualified spatial information service, it is crucial to have a Web-based GIS (Geographic Information Service) service system equipped with the publicity, the convenient accessibility, and the easy-to-use user interface. In this paper, we introduce a new component system for Web-based spatial information services based on the OpenGIS Simple Feature specification for OLE/COM[3] and OLE DB specification[4]. The important functionality of a Web-based spatial information service system includes its accessibility of various existing GIS server system and huge databases in addition to the resolution of response-time delay problems caused by transmitting a large amount of digital maps via internet[6]. To cope with these problems, our component system has been designed to access heterogeneous databases in transparent manner and to support vector-based and/or image-based image production techniques for shortening transmission time.

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A Study on the Extraction of a River from the RapidEye Image Using ISODATA Algorithm (ISODATA 기법을 이용한 RapidEye 영상으로부터 하천의 추출에 관한 연구)

  • Jo, Myung-Hee
    • Journal of the Korean Association of Geographic Information Studies
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    • v.15 no.4
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    • pp.1-14
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    • 2012
  • A river is defined as the watercourse flowing through its channel, and the mapping tasks of a river plays an important role for the research on the topographic changes in the riparian zones and the research on the monitoring of flooding in its floodplain. However, the utilization of the ground surveying technologies is not efficient for the mapping tasks of a river due to the irregular surfaces of the riparian zones and the dynamic changes of water level of a river. Recently, the spatial information data sets are widely used for the coastal mapping tasks due to the acquisition of the topographic information without human accessibility. In this research, we tried to extract a river from the RapidEye imagery by using the ISODATA(Iterative Self_Organizing Data Analysis) classification algorithm with the two different parameters(NIR (Near Infra-Red) band and NDVI(Normalized Difference Vegetation Index)). First, the two different images(the NIR band image and the NDVI image) were generated from the RapidEye imagery. Second, the ISODATA algorithm were applied to each image and each river was generated in each image through the post-processing steps. River boundaries were also extracted from each classified image using the Sobel edge detection algorithm. Ground truths determined by the experienced expert are used for the assessment of the accuracy of an each generated river. Statistical results show that the extracted river using the NIR band has higher accuracies than the extracted river using the NDVI.

Mapping Man-Made Levee Line Using LiDAR Data and Aerial Orthoimage (라이다 데이터와 항공 정사영상을 활용한 인공 제방선 지도화)

  • Choung, Yun-Jae;Park, Hyen-Cheol;Chung, Youn-In;Jo, Myung-Hee
    • Journal of the Korean Association of Geographic Information Studies
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    • v.14 no.1
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    • pp.84-93
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    • 2011
  • Levee line mapping is critical to the protection of environments in river zones, the prevention of river flood and the development of river zones. Use of the remote sensing data such as LiDAR and aerial orthoimage is efficient for river mapping due to their accessibility and higher accuracy in horizontal and vertical direction. Airborne laser scanning (LiDAR) has been used for river zone mapping due to its ability to penetrate shallow water and its high vertical accuracy. Use of image source is also efficient for extraction of features by analysis of its image source. Therefore, aerial orthoimage also have been used for river zone mapping tasks due to its image source and its higher accuracy in horizontal direction. Due to these advantages, in this paper, research on three dimensional levee line mapping is implemented using LiDAR and aerial orthoimage separately. Accuracy measurement is implemented for both extracted lines generated by each data using the ground truths and statistical comparison is implemented between two measurement results. Statistical results show that the generated 3D levee line using LiDAR data has higher accuracy than the generated 3D levee line using aerial orthoimage in horizontal direction and vertical direction.

An Empirical Study on the Correlation between TOD Planning Elements and Subway Ridership in Busan Metropolitan City (부산시 역세권 TOD계획요소의 공간특성과 지하철 이용객 수의 상관성에 관한 실증연구)

  • Choi, Don-Jeong;Suh, Yong-Cheol
    • Journal of the Korean Association of Geographic Information Studies
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    • v.17 no.3
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    • pp.147-159
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    • 2014
  • Public transportation ridership and walkability of urban district can be enhanced through high quality of TOD(Transit Oriented Development) elements. Generally, TOD have been evaluated several physical components such as the diversity of land use pattern, accessibility of public transportation and aspects of urban design around the station area. Especially, Spatial characteristics of TOD planning elements have many potential dependent when considering the characteristics of Rail Station-Influenced Area Development which is performing around subway station. Therefore, researchers should be considering the variation of spatial properties for planning elements according the set of spatial area and their socioeconomic factors. However, existing many cases related TOD does not consider about this point. In this paper, the changes of TOD characteristics were analyzed by different spatial units surrounding subway station in Busan Metropolitan City. Multiple Regression Analysis was performed for an investigation of effective spatial unit of TOD planning elements in this area using subway ridership data. In addition, the application validity of socioeconomic variables was examined through a comparative analysis of regression results with the multiple regression that implied only physical TOD elements. As the result, the variation of spatial properties for TOD planning elements according to the set of spatial unit was found. Furthermore, the specific spatial unit to applicable TOD elements in this area was derived. And the multiple regression model which added socioeconomic variables was derived more improved estimate results than the multiple regression model that implied only physical TOD elements.

A Study on the Validation of Vector Data Model for River-Geospatial Information and Building Its Portal System (하천공간정보의 벡터데이터 모델 검증 및 포털 구축에 관한 연구)

  • Shin, Hyung-Jin;Chae, Hyo-Sok;Hwang, Eui-Ho
    • Journal of the Korean Association of Geographic Information Studies
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    • v.17 no.2
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    • pp.95-106
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    • 2014
  • In this study, the applicability of a standard vector model was evaluated using RIMGIS vector data and a portal based river-geospatial information web service system was developed using XML and JSON based data linkage between the server and the client. The RIMGIS vector data including points, lines, and polygons were converted to the Geospatial Data Model(GDM) developed in this study and were validated by layers. After the conversion, it was identified that the attribute data of a shape file remained without loss. The GeoServer GDB(GeoDataBase) that manages a DB in the portal was developed as a management module. The XML-based Geography Markup Language(GML) standards of OGC was used for accessing to and managing vector layers and encoding spatial data. The separation of data content and expression in the GML allowed the different expressions of the same data, convenient data revision and update, and enhancing the expandability. In the future, it is necessary to improve the access, exchange, and storage of river-geospatial information through the user's customized services and Internet accessibility.

Development of Web Based GIS for Polar Ocean Research (극지 해양환경 연구를 위한 웹GIS 구축)

  • CHI, Jun-Hwa;HYUN, Chang-Uk;KIM, Hyun-Cheol;JOO, Hyoung-Min;YANG, Eun-Jin;PARK, Ho-Joon;KANG, Sung-Ho
    • Journal of the Korean Association of Geographic Information Studies
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    • v.20 no.1
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    • pp.15-25
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    • 2017
  • In recent years, polar research has been focused on climate change, natural resources, and development of a new North Pole Route. Since 2010, the Korea Polar Research Institute has been collecting various in situ data from the Arctic/Antarctic oceans using ARAON, which is the first effort of Korea toward leading global polar research. As a part of these activities, a web-based GIS service was developed to collect in situ data and to standardize data formats. Visualizations of in situ measurements and thematic maps were also developed to improve both the quantitative and qualitative quality of polar ocean research, and to increase accessibility of polar oceanographic data. This system will ultimately share all of the data acquired from the Arctic/Antarctic oceans with international research groups.

Analysis on Green Vulnerable Areas Considering the Catchment Area of Urban Parks - Focused on Nam-gu in Daegu - (도시공원 유치거리를 고려한 녹지취약지역 분석 - 대구광역시 남구를 대상으로 -)

  • EUM, Jeong-Hee;LEE, Yun-Gu
    • Journal of the Korean Association of Geographic Information Studies
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    • v.19 no.2
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    • pp.117-131
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    • 2016
  • This study aims to analyze the spatial accessibilities to urban greens considering the catchment areas of urban parks to improve those areas with lower spatial accessibility in the neighborhood units. Nam-gu in Daegu was selected as the study area. In the results of the analysis of 16 existing parks, Daemyung6-dong and Daemyung5-dong had high ratios of green service area to administrative district, with values of 94.4% and 92.3%, respectively. Low ratios of green service area(vulnerable area of green service) were recorded in Icheondong(1.6%) and Daemyung10-dong(24.1%). However, the ratio of Icheondong may increase by 88.6%, when the 12 unexecuted urban parks are established. The ratio of Daemyung10-dong can also increase up to 40.1% by establishing green spaces in public institutions such as government offices and schools. This study suggests possibilities to improve the spatial accessibilities to urban parks and indicates the policies required for enhancing the even distribution of green spaces.

A Study on Mapping 3-D River Boundary Using the Spatial Information Datasets (공간정보를 이용한 3차원 하천 경계선 매핑에 관한 연구)

  • Choung, Yun-Jae;Park, Hyen-Cheol;Jo, Myung-Hee
    • Journal of the Korean Association of Geographic Information Studies
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    • v.15 no.1
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    • pp.87-98
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    • 2012
  • A river boundary is defined as the intersection between a main stream of a river and the land. Mapping of the river boundary is important for the protection of the properties in river areas, the prevention of flooding and the monitoring of the topographic changes in river areas. However, the utilization of the ground surveying technologies is not efficient for the mapping of the river boundary due to the irregular surfaces of river zones and the dynamic changes of water level of a river stream. Recently, the spatial information data sets such as the airborne LiDAR and aerial images are widely used for coastal mapping due to the acquisition of the topographic information without human accessibility. Due to these advantages, this research proposes a semi-automatic method for mapping of the river boundary using the spatial information data set such as the airborne LiDAR and the aerial photographs. Multiple image processing technologies such as the image segmentation algorithm and the edge detection algorithm are applied for the generation of the 3D river boundary using the aerial photographs and airborne topographic LiDAR data. Check points determined by the experienced expert are used for the measurement of the horizontal and vertical accuracy of the generated 3D river boundary. Statistical results show that the generated river boundary has a high accuracy in horizontal and vertical direction.