• Korean Journal of Remote Sensing
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• v.28 no.6
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• pp.683-691
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• 2012

High resolution satellite images are now widely used for a variety of mapping applications including photogrammetry, GIS data acquisition and visualization. As the spectral and spatial data size of satellite images increases, a greater processing power is needed to process the images. The solution of these problems is parallel systems. Parallel processing techniques have been developed for improving the performance of image processing along with the development of the computational power. However, conventional CPU-based parallel computing is often not good enough for the demand for computational speed to process the images. The GPU is a good candidate to achieve this goal. Recently GPUs are used in the field of highly complex processing including many loop operations such as mathematical transforms, ray tracing. In this study we proposed a technique for parallel processing of high resolution satellite images using GPU. We implemented a spectral radiometric processing algorithm on Landsat-7 ETM+ imagery using CUDA, a parallel computing architecture developed by NVIDIA for GPU. Also performance of the algorithm on GPU and CPU is compared.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.2
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• pp.189-197
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• 2012

This research attempted to find possibilities of the practical use utilizing geospatial methods for the balanced promotion of sustainable coastal development and preservation through a case study of Jekyll Island, one of Georgia's barrier islands. In response, this research provided ways for practical use in sustainable development and preservation plans. First this research thoroughly investigated the 1996 master plan of Jekyll Island and tried to recalculate developed and undeveloped areas. Second, new estimations for developed areas were investigated through field survey. Third, this research proposed the use of the satellite images with different levels of spatial resolutions and tested different classification schemes to find possibilities for practical use. For these purposes, first, we classified developed and undeveloped features by manual digitization using an aerial photo image with 0.5m spatial resolution. Second, a Landsat 7 ETM+ and a QuickBird satellite images with mid- and high-levels of spatial resolutions were applied to identify developed and undeveloped areas using both the National Land Cover Data (NLCD) and the Coastal Change Analysis Program (CCAP) classification schemes. Also, GEOBIA (Geographic Object-Based Image Analysis) was conducted to accurately identify developed and undeveloped areas.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.198-198
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• 2022

최근 도시화에 따른 토지 피복 변화와 열섬현상 등의 원인으로 상승하는 도시의 기온이 식물 계절에 미치는 영향에 관한 연구들이 다수 진행되고 있다. 본 연구는 수도권인 서울과 경기도 지역을 대상으로 도시 내 열섬현상으로 인한 기온 상승과 도시 지역 내 식생 생장기간 변화의 관계성을 분석하였다. 식물계절 모니터링에 사용한 개량식생지수(Enhanced Vegetation Index, EVI)는 Google Earth Engine (GEE)에서 제공하는 30 m 해상도의 2000-2021년 NASA-USGS Landsat 위성(TM5, ETM+7, OLI8)의 지표면 반사율(surface reflectance, SR) 자료에서 도출하여 생장기간 산정에 사용하였다. 또한 PRISM (Parameter-elevation Regressions on Independent Slopes Model)을 각 기상관측지점의 일별 지상 기온 자료에 적용하여 30 m 해상도로 생성한 격자형 지표면 온도의 공간적 패턴을 분석하였다. 연구 지역 내 도시화 정도(magnitude)를 도심으로부터의 거리와 환경부 토지피복도 및 인구 밀도를 종합하여 특정하였고, 최종적으로 기후변화 및 도시화 정도와 생장기간 변화의 특징을 분석하였다. 비선형 로지스틱 회귀를 사용하여 EVI 데이터를 종합하여 분석한 결과, 수도권 지역에서 전반적으로 식물계절 개엽일(Start of Season)은 앞당겨지며 낙엽일(End of Season, EOS)은 늦춰져 생장기간(Length of Growing Season, LOS)이 길어짐을 발견하였다.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.3
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• pp.339-344
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• 2016

This study is conducted for analysis of distribution of macrobenthic by using satellite image and in-situ data in the intertidal zone of Suncheon bay. The satellite images on low tide on July 7, 2010 and high tide on Sept. 25, 2010, respectively, are classified into sea water, tidal flat and land. It is to extract for intertidal zone overlaying at low tide and high tide image from previously classified image. Total number of species emergence are 196 species in the intertidal zone, and most species are emergence in the right part of the subtidal zone. The Sigambra tentaculata is the dominant species and emergence the Mediomastus californiensis, Magelona japonica, etc. It is noticed that many kind of macrobenthic distribution in the subtidal zone more than the supralittoral zone. It find out that contamination due to organic through the macrobenthic distribution with a strong resistance to organic in the subtidal zone of Suncheon Bay.

• Forest Science and Technology
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• v.14 no.4
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• pp.181-191
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• 2018

This study was carried out in the teaching and research forest of the University of Dschang in Belabo, with the aim of analysing land-cover and land-use changes as well as carbon stocks dynamic. The databases used are composed of three Landsat satellite images (5TM of 1984, 7ETM + of 2000 and 8OLI of 2016), enhanced by field missions. Satellite images were processed using ENVI and ArcGIS software. Interview, focus group discussion methods and participatory mapping were used to identify the activities carried out by the local population. An inventory design consisting of four transects was used to measure dendrometric parameters and to identify land-use types. An estimation of carbon stocks in aboveground and underground woody biomass was made using allometric models based on non-destructive method. Dynamic of land-cover showed that the average annual rate of deforestation is 0.48%. The main activities at the base of this change are agriculture, house built-up and logging. Seven types of land-use were identified; adult secondary forests (64.10%), young secondary forests (7.54%), wetlands (7.39%), fallows (3.63%), savannahs (9.59%), cocoa farms (4.28%) and mixed crop farms (3.47%). Adult secondary forests had the highest amount of carbon ($250.75\;t\;C\;ha^{-1}$). This value has decreased by more than 60% for mixed crop farms ($94.67\;t\;C\;ha^{-1}$), showing the impact of agricultural activities on both forest cover and carbon stocks. Agroforestry systems that allow conservation and introduction of woody species should be encouraged as part of a participatory management strategy of this forest.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.426-429
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• 2007

One of the widely used applications of remote sensing studies is environmental change detection and biodiversity conservation. The study area Hustai Mountain is situated in the transition zone between the Siberian taiga forest and Central Mongolian arid steppe. Hustai National Park carries out one of several reintroduction programs of takhi (wild horse or Equus ferus przewalskii) from various zoos in the world and it represents one of a few textbook examples of successful reintroduction of an animal extinct in the wild. In this paper we describe the results of an analysis on the change of remaining forest area over the 7-year period since Hustai Mountain was designated as a protected area for reintroduction to wild horses. Today the forested area covers approximately 5% of the Hustai National Park, mostly the north-facing slopes above 1400 m altitude. Birch (Betula platyphylla) and aspen (Populus tremula) trees are predominant in the forest. We used Landsat ETM+ images from two different years and multi temporal MODIS NDVI data. Land types were determined by supervised classification methods (Maximum Likelihood algorithm) verified with ground-truthing data and the Land Change Modeler (LCM) which was developed by Clark Labs. Forested area was classified into three different land types, namely the forest land, mountain meadow and mountain steppe. The study results illustrate that the remaining birch forest has rapidly changed to fragmented forest land and to open areas. Underlying causes for such a rapid change during the 15-year period may be manifold. However, the responsible factors appear to be the drying off and outbreak of forest pest species (such as gypsy moth or Lymantria dispar) in the area.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.471-474
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• 2007

Eucalyptus plantations play a major role in the China's ecological, social, economic and other aspects and presently China is the second largest producer of Eucalyptus in the world next to Brazil. It was introduced as an ornamental tree during 1890 but later it became a commercial crop. During 1960s large number of Eucalyptus timber were used for railway sleepers and it was also used as shelter belt for rubber trees. It becomes one of the important national resources of commercial timber once the production reached to 5 million $m^{3}/yr$. Through Eucalyptus oil, it brought about 20% of foreign exchange. In the present study, it was aimed to estimate the Eucalyptus growing area in the southern Guangdong in China in terms of aerial extent and changes between 1991 and 2001 using Landsat TM and ETM+ data. Object based classification technique and subsequent temporal change detection analysis were followed to identify the changes between the periods. In the present study, the total area was divided into three classes viz., plantation area with trees, plantation area without trees and others. Object oriented classification was found to be more accurate in the present study. Overall increase of about 23.62 $km^{2}$ was noted between 1991 and 2001 in the plantation area. With reference to the present study area, the growth of Eucalyptus growing area was 7.4% in the 10 year periods. From this study it is clear that the area under Eucalyptus cultivation is growing considerably year by year in China. However, elaborate study must be conducted considering larger areas to accurately predict the growth of Eucalyptus growing areas.

• Korean Journal of Remote Sensing
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• v.20 no.6
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• pp.361-368
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• 2004

Hydraulic models has a module to calculate SCS-CN values in order to estimate amount of water flow, which can be done with remotely sensed data and GIS data. The choice of the ancillary data tends to determine the range of SCS-CN values. We compare the results of SCS-CN value with satellite data of different spatial resolution and with soil maps of different scale. Mokhyun river basin was chosen,partly because of availbility of water quality and quantity data, partly because of rapid changes in land use and land cover since last ten years. The average CN values were calculated with spatial resolutions of 2.5 meter and 30 meter, We could not find any different result due to spatial resolution of CN resolution but due to both soil maps and to land cover maps. Further studies should be done for more than two kinds of satellite data.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.4
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• pp.95-104
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• 2006

The DMZ is a 248km long thin green line which has various landscapes of fields, hills and mountains. This study focused on western part of DMZ and vicinity which consist of abandoned rice paddy, wetlands and fields. The main purpose of this study is to detect the vegetation vitality from the western part of MDL to DMZ vicinity and identify and quantify ecological buffer(ecotone) width adopting logistic function derived from 'Vegetation Index-distance curve' using an Landsat ETM+ image acquired on June of 2002. Green leaf vegetation was quantified to identify the ecotone buffer in western DMZ and vicinity(civilian control area: CCA) using Transformed Vegetation Index(TVI) which is one of common measurement among various indices. Vegetation measurement from Military Demarcation Line(MDL) to vicinity area was investigated at 500m intervals to 10kms of southern and northern part of western DMZ and vicinity. The Logistic function models the sigmoid curve of growth with three stages of growth of initial competition and maturity. In the TVI-distance logistic curve, the maturity is high vegetation vitality, the competition is vitality changing, and the initial is low vitality. In the TVI-distance curve, maturity area of high TVI value is core area for ecological conservation, and the competition area between inflection points can be an ecotone(ecological buffer). In case of southern part, maximum TVI value is 221.92 and minimum is 207.16, and maximum TVI of northen part is 215.32 and minimum is 188.35. That means forest devastation of north Korean part of DMZ and vicinity is severer than that of south Korea. The width of core area for ecological conservation is 2,311m, and ecotone in the southern part is 5,339m, so minimum width from MDL for ecological conservation can be computed as 7,651m. In case of Northern part, the width of core area is 1,841m, and ecotone buffer is 5,014m, so ecological conservation width can be estimated as 6,855m. In case of northen part, width of estimated core area is less than that of DMZ width, which means ecological disturbance is very severe in northern part of western DMZ.