• Title/Summary/Keyword: Overlay analysis

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A Fundamental Study on the Maintenance of Administrative Boundaries based on Spatial Information (공간정보기반의 행정경계 정비를 위한 기초연구)

  • Yun, Ji-Ye;Park, Hong-Gi;Choi, Yun-Soo;Nam, Dae-Hyun
    • Spatial Information Research
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    • v.20 no.1
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    • pp.47-57
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    • 2012
  • An Administrative Boundary is the basic of spatial information to cover geographical and regional area. Its importance has arisen in our society at the Smart world era. However, it is difficult to serve exact boundary's lines as administrative boundaries are based on the cadastre lines of land register ; these partly are overlay each other or has gaps. So, it Should be adjusted. But, the maintenance work of administration boundaries causes a conflict or confusion unless we offer concrete procedures and detailed plans previously. Therefore, a rational method is required to prevent side-effects such as confusion, disagreem ent and a conflict etc. In this Study, we present a method and 5 step procedures to make better use in a practical maintenance work. we researched on basic studies of Administrative boundary's concept, history. And we performed a field survey as well as analysis of current problems. considering these results, we suggest usage of various spatial data sources, stake-holders' participation, a method of Nearest district's boundaries to maintain administrative boundaries. Throughout the method, we expect it to serve correct boundary-data to various fields without a big confusion. it is also useful to apply its results not only for re-surveying our land but for recording appropriate boundary-data as rational lines.

The Evaluation of Architectural Density on Urban District using Airborne Laser Scanning Data (항공레이저측량 자료를 이용한 시가지 건축밀도 평가에 관한 연구)

  • Lee, Geun-Sang;Koh, Deuk-Koo;Cho, Gi-Sung
    • Journal of the Korean Association of Geographic Information Studies
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    • v.6 no.3
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    • pp.95-106
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    • 2003
  • This study evaluated the architectural density of urban district using airborne laser scanning(ALS) that is a method used in urban planning, water resources and disaster prevention with high interest recently. First, digital elevation model(DEM) and digital surface model(DSM) was constructed from Light detection and ranging(LiDAR). For getting the height of building, ZONALMEAN filter was used in DEM and ZONALMAJORITY filter was used in DSM. This study compared the floor from filtering with the floor from survey and got standard error, which is ${\pm}0.199$ floor. Also, through the overlay and statistical analysis of total-area layer and zone layer, we could present floor area ratio by zone. As a result of comparison with floor area ratio between airborne laser scanning data and survey data, the standard error of floor area ratio shows ${\pm}2.68%$. Therefore, we expect that airborne laser scanning data can be a very efficient source to decision makers who set up landuse plan in near future.

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The Comparison of Water Quality of Daecheong-Dam basin According to the Data Sources of Land Cover Map (토지피복도 자료원에 따른 대청댐유역 수질특성 비교)

  • Lee, Geun Sang;Park, Jin Hyeog;Choi, Yun Woong
    • Spatial Information Research
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    • v.20 no.5
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    • pp.25-35
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    • 2012
  • This study compared the influence of water quality according to the data sources of spatial information. Firstly, land cover map was constructed through image classification of Daecheong-dam basin and the accuracy of image classification from satellite image showed high as 88.76% in comparison with the large-scaled land cover map in Ministry of Environment, to calculate Event Mean Concentration (EMC) by land cover that impact on the evaluation of nonpoint source pollutant loads. Also curve number and direct runoff were calculated by spatial overlay with soil map and land cover map from image classification. And Seokcheon and Daecheong-Dam basin showed high in the analysis of curve number and direct runoff. Samgacheon-Joint and Sokcheon-Downstream basin showed high in the nonpoint source pollutant loads of BOD from direct runoff and EMC. And Samgacheon-Joint and Bonghwangcheon- Downstream basin showed high in the nonpoint source pollutant loads of TN and TP. Nonpoint source pollutant loads from image classification were compared with those by the land cover map from Ministry of Environment to present the effectivity of nonpoint source pollutant loads from satellite image. And Daecheong-Dam Upstream basin showed high as 10.64%, 11.70% and 20.00% respectively in the errors of nonpoint source pollutant loads of BOD, TN, and TP. Therefore, it is desirable that spatial information including with paddy and dry field is applied to the evaluation of nonpoint source pollutant loads in order to simulate water quality of basin effectively.

Confidence Improvement of Serial Cadastral Map Edit Using Ortho Image (정사영상을 이용한 연속지적도 편집의 신뢰성 향상 방안)

  • Kim Kam Lae;Ra Yong Hwa;Ahn Byung Gu;Park Se Jin
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.22 no.3
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    • pp.253-259
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    • 2004
  • The sheetwise cadastral map data needs to become a Serial Cadastral Map (SCM) database for the promotion of the reliability of cadastral surveying, for the efficient operation of the Parcel Based Land Information System, and for the convenient use of land information as well. A large amount of money and time are required for the editing process of producing SCM DB in accordance with the $\ulcorner$Guideline for the Production of Serial Cadastral Maps$\lrcorner$ by the Ministry of Construction & Transportation if any of field surveying techniques is accompanied by. In addition, a boundary line that extends to a neat line does not meet the counterpart of the neighboring map sheet at a point. Such cases frequently occur and are much dependent upon the decisions of individuals in charge of editing or inspecting. The core processes of the research, firstly overlay SCM produced by the edition of the sheetwise cadastral maps with Autodesk Map on orthophoto images, secondly adjust the parcel boundaries which are delineated over more than one map sheet, and lastly compare the original boundary coordinates and areas with the corresponding adjusted ones and calculate root mean square errors (RMSEs). The research aims at promoting the quality of SCM by minimizing the inconsistency of parcel boundaries by means of the comparative analysis of the calculated RMSEs.

Extraction of Individual Trees and Tree Heights for Pinus rigida Forests Using UAV Images (드론 영상을 이용한 리기다소나무림의 개체목 및 수고 추출)

  • Song, Chan;Kim, Sung Yong;Lee, Sun Joo;Jang, Yong Hwan;Lee, Young Jin
    • Korean Journal of Remote Sensing
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    • v.37 no.6_1
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    • pp.1731-1738
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    • 2021
  • The objective of this study was to extract individual trees and tree heights using UAV drone images. The study site was Gongju national university experiment forest, located in Yesan-gun, Chungcheongnam-do. The thinning intensity study sites consisted of 40% thinning, 20% thinning, 10% thinning and control. The image was filmed by using the "Mavic Pro 2" model of DJI company, and the altitude of the photo shoot was set at 80% of the overlay between 180m pictures. In order to prevent image distortion, a ground reference point was installed and the end lap and side lap were set to 80%. Tree heights were extracted using Digital Surface Model (DSM) and Digital Terrain Model (DTM), and individual trees were split and extracted using object-based analysis. As a result of individual tree extraction, thinning 40% stands showed the highest extraction rate of 109.1%, while thinning 20% showed 87.1%, thinning 10% showed 63.5%, and control sites showed 56.0% of accuracy. As a result of tree height extraction, thinning 40% showed 1.43m error compared with field survey data, while thinning 20% showed 1.73 m, thinning 10% showed 1.88 m, and control sites showed the largest error of 2.22 m.

The Distribution Characteristics of Topographical Relieves at Each Geological Area in Gyeongsangbuk-do Province using GIS (GIS를 이용한 경상북도 지질 지역별 지형 기복의 분포 특성)

  • KIM, Dae-Sik;LEE, Gwang-Ryul
    • Journal of The Geomorphological Association of Korea
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    • v.17 no.3
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    • pp.49-57
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    • 2010
  • The topographical rolling distribution characteristics of 10 geological areas in Gyeongsangbuk-do are analyzed using GIS. PEs, PEgrgn, Pp2, Kav·Kiv, and Khgr regions occupy the more than 60% that are a steep slope-a high elevation and a steep slope-a middle elevation region, and form high moutains in Gyeongsangbuk-do. Meanwhile, Ke1-9 and Te1-2 regions take possession of the more than 70% that are a low elevation region. Ke1-9 region form landward flatlands and hills around Nakdong river and tributaries of Nakdong river in Gyeongsangbuk-do. Then, Te1-2 region form coastal lowlands adjacent the East sea in Gyeongsangbuk-do. Also, Jgr region take possession of the more than 70% that are a middle elevation region, and form low moutains or flatlands in Gyeongsangbuk-do. Finally, Ols1 region take possession of the more than 50% that are a steep slope region, and form landward moutains in Gyeongsangbuk-do.

Analyzing Priority Management Areas for Domestic Cats (Felis catus) Using Predictions of Distribution Density and Potential Habitat (고양이(Feliscatus)의 분포밀도와 잠재서식지 예측을 이용한 우선 관리 대상 지역 분석)

  • Ahmee Jeong;Sangdon Lee
    • Journal of Environmental Impact Assessment
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    • v.32 no.6
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    • pp.545-555
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    • 2023
  • This study aimed to predict the distribution density and potential habitat of domestic cats (Felis catus) in order to identify core distribution areas. It also aimed to overlay protected areas to identify priority areas for cat management. Kernel density estimation was used to determine the distribution density, and areas with high density were classified in Greater Seoul, Chungnam, Daejeon, and Daegu. Elevation, distance from the used area and roughness were identified as important variables in predicting potential habitat using the MaxEnt model. In addition, the classification of suitable and unsuitable areas based on thresholds showed that the predicted presence of habitat was more extensive in Seoul, Sejong, Daejeon, Chungnam, and Daegu. Core distribution areas were selected by overlapping high-density areas with suitable areas. Priority management areas were identified by overlaying core distribution areas with designated wildlife sanctuaries. As a result, Gyeonggi, and Chungnam have the largest areas. In addition, buffer zones will be implemented to effectively manage the core distribution area and minimize the potential for additional introductions in areas of high management priority, such as protected areas. These results can be used as a basis for investigating the status of the cat's habitat and developing more effective management strategies.

Subjective and Objective Assessment of Monoenergetic and Polyenergetic Images Acquired by Dual-Energy CT in Breast Cancer

  • Xiaoxia Wang;Daihong Liu;Shixi Jiang;Xiangfei Zeng;Lan Li;Tao Yu;Jiuquan Zhang
    • Korean Journal of Radiology
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    • v.22 no.4
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    • pp.502-512
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    • 2021
  • Objective: To objectively and subjectively assess and compare the characteristics of monoenergetic images [MEI (+)] and polyenergetic images (PEI) acquired by dual-energy CT (DECT) of patients with breast cancer. Materials and Methods: This retrospective study evaluated the images and data of 42 patients with breast cancer who had undergone dual-phase contrast-enhanced DECT from June to September 2019. One standard PEI, five MEI (+) in 10-kiloelectron volt (keV) intervals (range, 40-80 keV), iodine density (ID) maps, iodine overlay images, and Z effective (Zeff) maps were reconstructed. The contrast-to-noise ratio (CNR) and the signal-to-noise ratio (SNR) were calculated. Multiple quantitative parameters of the malignant breast lesions were compared between the arterial and the venous phase images. Two readers independently assessed lesion conspicuity and performed a morphology analysis. Results: Low keV MEI (+) at 40-50 keV showed increased CNR and SNRbreast lesion compared with PEI, especially in the venous phase ([CNR: 40 keV, 20.10; 50 keV, 14.45; vs. PEI, 7.27; p < 0.001], [SNRbreast lesion: 40 keV, 21.01; 50 keV, 16.28; vs. PEI, 10.77; p < 0.001]). Multiple quantitative DECT parameters of malignant breast lesions were higher in the venous phase images than in the arterial phase images (p < 0.001). MEI (+) at 40 keV, ID, and Zeff reconstructions yielded the highest Likert scores for lesion conspicuity. The conspicuity of the mass margin and the visual enhancement were significantly better in 40-keV MEI (+) than in the PEI (p = 0.022, p = 0.033, respectively). Conclusion: Compared with PEI, MEI (+) reconstructions at low keV in the venous phase acquired by DECT improved the objective and subjective assessment of lesion conspicuity in patients with malignant breast lesions. MEI (+) reconstruction acquired by DECT may be helpful for the preoperative evaluation of breast cancer.

A Study on the Vulnerability Assessment of Solar Power Generation Facilities Considering Disaster Information (재해정보를 고려한 태양광발전시설의 취약성 평가에 관한 연구)

  • Heejin Pyo
    • Land and Housing Review
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    • v.15 no.2
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    • pp.57-71
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    • 2024
  • This study aims to develop an evaluation method for solar power facilities considering disaster impacts and to analyse the vulnerabilities of existing facilities. Haenam-gun in Jeollanam-do, where the reassessment of existing facilities is urgent, was selected as the study area. To evaluate the vulnerability from a more objective perspective, principal component analysis and entropy methods were utilised. Seven vulnerability assessment indicators were selected: maximum hourly rainfall, maximum wind speed, number of typhoon occurrence days, number of rainfall days lasting more than five days, maximum daily rainfall, impermeable area ratio, and population density. Among these, maximum hourly rainfall, maximum wind speed, maximum daily rainfall, and number of rainfall days lasting more than five days were found to have the highest weights. The overlay of the derived weights showed that the southeastern regions of Haenam-eup and Bukil-myeon were classified as Grade 1 and 2, whereas the northern regions of Hwawon-myeon, Sani-myeon, and Munnae-myeon were classified as Grade 4 and 5, indicating differences in vulnerability. Of the 2,133 facilities evaluated, 91.1% were classified as Grade 3 or higher, indicating a generally favourable condition. However, there were more Grade 1 facilities than Grade 2, highlighting the need for countermeasures. This study is significant in that it evaluates solar power facilities considering urban disaster resilience and is expected to be used as a basic resource for the installation of new facilities or the management and operation of existing ones.

GIS Spatial Analysis of Vulnerability of Protected Cultivation Area to Meteorological Disaster : A Case Study of Jeollanambuk Province, South Korea (GIS를 이용한 시설재배의 기상재해 취약지역 해석 - 전라남북도의 사례를 중심으로 -)

  • Kim, Dong Hyeon;Kang, Dong Hyeon;Lee, Si Young;Son, Jin Kwan;Park, Min Jung;Yoon, Yong-Cheol;Yun, Sung-Wook
    • Journal of Bio-Environment Control
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    • v.26 no.2
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    • pp.87-99
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    • 2017
  • Recently the increase in an abnormal climate events and meteorological disasters which causes a great damage to greenhouse facilities. To minimize and evaluate the expected damages it is necessary to prepare countermeasures and a management system in advance. For this purpose, a quantitative analysis of weather and abnormal climate are needed to investigate protected cultivation areas which are vulnerable to natural disasters. This study focused on protected cultivation areas in Jeolla province, South Korea. Surrogate variables were calculated to analyze the vulnerable areas to meteorological disasters, and spatial distribution analysis was also performed by using GIS to present vulnerable areas on map. The map thus created and was compared with actual data of damages by meteorological disasters which occurred in target areas. The result of the comparison is as follows: About 50% of the target areas showed an agreement between the map created in this study and the actual data, these areas includes Gwangju metropolitan city, Naju city, Yeongam County, Jangseong County, Hampyeong County, and Haenam County. On the other hand, other areas, including Gunsan city, Mokpo city, and Muan County, suffered low damage in spite of high levels of vulnerability to meteorological disasters. This result was considered to be affected by such variables as different structural designs and management systems of greenhouses by region. This study carried out an analysis of meteorological data to find out more detailed vulnerability to protected cultivation area and to create a map of vulnerable protected cultivation areas. In addition, the map was compared with the record of natural disasters to identify actual vulnerable areas. In conclusion, this study can be utilized as basic data for preventing and reducing damages by meteorological disasters in terms of design and management of greenhouses.