• Title/Summary/Keyword: Geospatial technique

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Site Suitability Assessment for Joint Forest Management(JFM) - a Geospatial Approach

  • Jayakumar, S.;Ramachandran, A.;Bhaskaran, G.;Heo, Joon;Kim, Woo-Sun
    • Korean Journal of Remote Sensing
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    • v.23 no.5
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    • pp.473-481
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    • 2007
  • Joint Forest Management(JFM) is a concept of developing partnerships between fringe forest user groups and the Forest Department(FD) on the basis of mutual trust and jointly defined roles and responsibilities with regard to forest protection and development. In India, JFM was started during 1992 and it was implemented in many states. However success rate of JFM activity was not promising. Though there are many factors attributed to the failures, one of the main factors is the JFM site. This paper deals with the significant ground works to be done before planning for JFM using recent technologies such as remote sensing(RS) and Geographic Information System(GIS). Also it deals with the advantages of weighted overlay analysis in selecting suitable sites for JFM taking into consideration the various criteria. As a result of weighted overlay analysis, there were four types of suitability classes viz., less, moderate, highly and un-suitable. The moderately suitable class occupied maximum area(13209.64 ha) than less and highly suitable classes. If JFM is implemented on the suitability area, then the failure could be avoided in the future.

Three-dimensional geostatistical modeling of subsurface stratification and SPT-N Value at dam site in South Korea

  • Mingi Kim;Choong-Ki Chung;Joung-Woo Han;Han-Saem Kim
    • Geomechanics and Engineering
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    • v.34 no.1
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    • pp.29-41
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    • 2023
  • The 3D geospatial modeling of geotechnical information can aid in understanding the geotechnical characteristic values of the continuous subsurface at construction sites. In this study, a geostatistical optimization model for the three-dimensional (3D) mapping of subsurface stratification and the SPT-N value based on a trial-and-error rule was developed and applied to a dam emergency spillway site in South Korea. Geospatial database development for a geotechnical investigation, reconstitution of the target grid volume, and detection of outliers in the borehole dataset were implemented prior to the 3D modeling. For the site-specific subsurface stratification of the engineering geo-layer, we developed an integration method for the borehole and geophysical survey datasets based on the geostatistical optimization procedure of ordinary kriging and sequential Gaussian simulation (SGS) by comparing their cross-validation-based prediction residuals. We also developed an optimization technique based on SGS for estimating the 3D geometry of the SPT-N value. This method involves quantitatively testing the reliability of SGS and selecting the realizations with a high estimation accuracy. Boring tests were performed for validation, and the proposed method yielded more accurate prediction results and reproduced the spatial distribution of geotechnical information more effectively than the conventional geostatistical approach.

Application Technique of Geospatial Information for Pre-Environment Survey in Construction Site (건설현장 사전 환경조사를 위한 공간정보의 적용기법)

  • Yeon, Sang-Ho
    • Journal of the Korean Association of Geographic Information Studies
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    • v.17 no.1
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    • pp.119-128
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    • 2014
  • The environmental survey in advance in the construction works is very important for planning and designing as well as the service of field survey before carrying out construction. The topographical application of spatial information coupled with USN is the very economical method for the survey and research every processing stage of construction field in advance. Therefore the execution of very important role for environmental planning and fundamental designing of construction reduces the unnecessary trial and error through the environmental survey in advance. In this research the environment of existent construction field is transformed to that of digital spatial information by fusing the sensor network with wireless technique on the base of spatial position. In addition, the sink sensor cumulates the environmental data measured from each USN sensor using small wireless environmental sensors installed at the construction site and changes of various environmental data at the present constructing site are able to be monitored at 3-D topographical space in real time by using the method for transmitting the image of PC output based on TinyOS.

Applicability Analysis of Measurement Data Classification and Spatial Interpolation to Improve IUGIM Accuracy (지하공간통합지도의 정확도 향상을 위한 계측 데이터 분류 및 공간 보간 기법 적용성 분석)

  • Lee, Sang-Yun;Song, Ki-Il;Kang, Kyung-Nam;Kim, Wooram;An, Joon-Sang
    • Journal of the Korean Geotechnical Society
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    • v.38 no.10
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    • pp.17-29
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    • 2022
  • Recently, the interest in integrated underground geospatial information mapping (IUGIM) to ensure the safety of underground spaces and facilities has been increasing. Because IUGIM is used in the fields of underground space development and underground safety management, the up-to-dateness and accuracy of information are critical. In this study, IUGIM and field data were classified, and the accuracy of IUGIM was improved by spatial interpolation. A spatial interpolation technique was used to process borehole data in IUGIM, and a quantitative evaluation was performed with mean absolute error and root mean square error through the cross-validation of seven interpolation results according to the technique and model. From the cross-validation results, accuracy decreased in the order of nonuniform rational B-spline, Kriging, and inverse distance weighting. In the case of Kriging, the accuracy difference according to the variogram model was insignificant, and Kriging using the spherical variogram exhibited the best accuracy.

Hypothesis Tests For Performances of a New Spline Interpolation Technique (신 스플라인보간법의 퍼포먼스 가설점정)

  • Yu, Ki-Yun
    • Journal of Korean Society for Geospatial Information Science
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    • v.7 no.1 s.13
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    • pp.29-40
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    • 1999
  • In vector GIS, natural linear entities (called linear entitles) are usually represented by a set of line segments. As an alternative of the line segments, curve segments can be used to represent the linear entities. The curve segments, as one-dimensional spatial objects, we generated by spline interpolation technique such as Bezier technique. In an effort to improve its accuracy in resembling the linear entities, the Bezier technique was modified generating a new technique (called New technique) (Kiyun, 1998). In this paper, validity of the New technique was tested. Test focused on answering two questions: (1) whether or not the curve segments from the New technique replace line segments so as to enhance the accuracy of representations of linear entities, and (2) whether or not the curve segments from the New technique represent the linear entities more accurately than curve segments from the Bezier technique. Answering these two questions entailed two hypothesis tests. For test data, a series of hydrologic lines on 7.5-minute USGS map series were selected. Test were done using t-test method and statistical inferences were made from the results. Test results indicated that curve segments from both the Bezier and New techniques represent the linear entities more accurately than the line segments do. In addition, curve segments from the New technique represent the linear entities more accurately than the line segments from the Bezier technique do at probability level 69% or higher.

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A Study on the Accuracy Analysis of Parcel Coordinate by RTK-GPS (RTK-GPS에 의한 일필지 좌표 결정의 정확도 분석에 관한 연구)

  • Kang, Tae-Seok;Hong, Sung-Eon
    • Journal of Korean Society for Geospatial Information Science
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    • v.10 no.1 s.19
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    • pp.37-49
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    • 2002
  • RTK-GPS(Real Time Kinematic GPS) surveying technique which allows centimeter level three-dimensional coordinates in real time has been recognized as a major advance in the science of GPS positioning. And no longer is it necessary to wait until post-processed results are computed after the surveying has been completed in field. The purpose of this study is to present the accuracy and effectiveness of the determinated parcel coordinate by RTK-GPS surveying technique, through the analysis and comparison of the surveying results both in Total Station and RTK-GPS.

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The Development of Automatic Map-Publishing Technique for Military Map Production (군 래스터지도 제작을 위한 자동 복원도시기법 개발)

  • Song, Hyun-Seung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.28 no.5
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    • pp.539-546
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    • 2010
  • A program which can produce military standard raster maps was developed. This includes the functions that classify the types of geospatial data, publish automatically based on paper map schema, and convert products with military standard raster formats. Especially, this paper presents the automatic map-publishing technique with mathematical modeling and controling the line width, color, shape that ever not used.

Soil Resource Inventory and Mapping using Geospatial Technique

  • Jayakumar, S.;Ramachandran, A.;Lee, Jung-Bin;Heo, Joon
    • Journal of Korean Society for Geospatial Information Science
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    • v.17 no.3
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    • pp.3-12
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    • 2009
  • Soil is one of the Earth's most important resources. There are many differences among the soils of plains.like and hilly terrains, and therefore, accurate and comprehensive information on soil is essential for optimum and sustainable soil utilization. However, information on the soil of the hilly terrains of the Eastern Ghats of Tamil Nadu, India, is limited or absent. In the present study, Kolli hill, one among the hills of the Eastern Ghats, was soil.inventoried and mapped using a ground survey and remote sensing. Soil samples were collected and their physico.chemical properties analyzed according to the United States Department of Agriculture (USDA) standards. The soils were classified up to the family level. As a result of this study, 30 soil series belonging to ten sub.groups of five great groups and three sub.orders and orders each, were identified (classified to the family level) and mapped. Entisols, Inseptisols and Alfisols were the three orders, among which Entisols was the major one, occupying 75% of the area. Among the five great groups, Ustorthents occupied majority of the area (73%). Lithic Ustorthents and Typic Ustorthents were the two major sub.groups, occupying 40% and 26% of the total area, respectively. The present soil resource mapping of the Eastern Ghats of Tamil Nadu is a pioneer study, which yielded valuable information on the soil in this region.

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Detection of Surface Water Bodies in Daegu Using Various Water Indices and Machine Learning Technique Based on the Landsat-8 Satellite Image (Landsat-8 위성영상 기반 수분지수 및 기계학습을 활용한 대구광역시의 지표수 탐지)

  • CHOUNG, Yun-Jae;KIM, Kyoung-Seop;PARK, In-Sun;CHUNG, Youn-In
    • Journal of the Korean Association of Geographic Information Studies
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    • v.24 no.1
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    • pp.1-11
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    • 2021
  • Detection of surface water features including river, wetland, reservoir from the satellite imagery can be utilized for sustainable management and survey of water resources. This research compared the water indices derived from the multispectral bands and the machine learning technique for detecting the surface water features from he Landsat-8 satellite image acquired in Daegu through the following steps. First, the NDWI(Normalized Difference Water Index) image and the MNDWI(Modified Normalized Difference Water Index) image were separately generated using the multispectral bands of the given Landsat-8 satellite image, and the two binary images were generated from these NDWI and MNDWI images, respectively. Then SVM(Support Vector Machine), the widely used machine learning techniques, were employed to generate the land cover image and the binary image was also generated from the generated land cover image. Finally the error matrices were used for measuring the accuracy of the three binary images for detecting the surface water features. The statistical results showed that the binary image generated from the MNDWI image(84%) had the relatively low accuracy than the binary image generated from the NDWI image(94%) and generated by SVM(96%). And some misclassification errors occurred in all three binary images where the land features were misclassified as the surface water features because of the shadow effects.

Object-based Change Detection using Various Pixel-based Change Detection Results and Registration Noise (다양한 화소기반 변화탐지 결과와 등록오차를 이용한 객체기반 변화탐지)

  • Jung, Se Jung;Kim, Tae Heon;Lee, Won Hee;Han, You Kyung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.37 no.6
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    • pp.481-489
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    • 2019
  • Change detection, one of the main applications of multi-temporal satellite images, is an indicator that directly reflects changes in human activity. Change detection can be divided into pixel-based change detection and object-based change detection. Although pixel-based change detection is traditional method which is mostly used because of its simple algorithms and relatively easy quantitative analysis, applying this method in VHR (Very High Resolution) images cause misdetection or noise. Because of this, pixel-based change detection is less utilized in VHR images. In addition, the sensor of acquisition or geographical characteristics bring registration noise even if co-registration is conducted. Registration noise is a barrier that reduces accuracy when extracting spatial information for utilizing VHR images. In this study object-based change detection of VHR images was performed considering registration noise. In this case, object-based change detection results were derived considering various pixel-based change detection methods, and the major voting technique was applied in the process with segmentation image. The final object-based change detection result applied by the proposed method was compared its performance with other results through reference data.