• Journal of Korea Water Resources Association
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• v.34 no.4
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• pp.317-326
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• 2001

This study evaluates the errors involved in the area average rainfall amounts estimated by the arithmetic mean method, the Thiessen's weighting method, and the optimal weighting method from the estimation theory. This study was applied to the upstream part of Nam-Han river basin (upper part of Youngwal) and the following results could be obtained. First, in case the raingauges are located evenly over the basin, no obvious difference can be found in the area average rainfall amounts from the arithmetic mean method or from the Thiessen's weighting method. However, as these two methods cannot consider the spatial variability of rainfall, the estimation error could be higher when the spatial variability of rainfall is high. In our application the estimation error from the arithmetic mean method or the Thiessen's weighting method was also found to be higher than that from the method from the information theory, which considers the spatial variability of rainfall. Thus, we could conclude that for the rainy season of Korea or for the mountain area when and where the spatial variability of rainfall is high, a proper method of considering the spatial variability of rainfall should be used regardless of the basin size. The isohyetal method generally used for the large basins or the optimal weighting method from the estimation theory used in this study could be good alternatives for this case.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.3
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• pp.151-161
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• 2003

The spatiotemporal distribution of resuspended solid on the shelf of the southern Yellow Sea and the northern East China Sea was studied. The sea surface reflectance imageries obtained by remote sensing using satellite at channels of red (620~670nm), green(545~565nm) and blue(459~479nm) from Terra MODIS were used to explain the front of the high concentration suspended solid(SS) on the shelf in the East China Sea. The horizontal distribution of the resuspended solid was depended on the wind force, tidal current and stratification of water. The horizontal distribution areas of the resuspended solid in winter season during January~April, 2002 were three times wider than those in summer season during June~September, 2001.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.1
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• pp.35-47
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• 2022

Expansion of potato production areas can improve the food security in North Korea because the given crop has less requirements for agricultural materials and facilities. The Global Agro-Ecological Zones (GAEZ) model, which was developed to evaluate climate suitability under different cultivation conditions, was used to identify potential areas for the potato production. The spatial estimates of crop suitability under low and high input management conditions were downloaded from the GAEZ data portal. The values of suitability were obtained at the potato occurrence sites retrieved from the Global Biodiversity Information Facility (GBIF) database. The suitable areas for the potato production were identified using a threshold value derived from the suitability estimates at the occurrence sites. It was found that 90% of the occurrence sites had the suitability index value >3,333, which was set to be the threshold value. The suitable areas in North Korea were summarized by province and county. Rice cultivation areas were excluded from the analysis. The reported relative acreage of potato production was better represented by the suitable areas under the low input management options than the high input conditions. The suitable areas also had a similar distribution to the reported acreage of potato production by county. These results indicated that the GAEZ model would be useful to identify the candidate production areas, which would facilitate the increases in potato production especially under future climate conditions. Furthermore, monthly maps of crop suitability can be used to design cropping systems that would improve crop production under the limited use of agricultural materials and facilities.

• Korean Journal of Remote Sensing
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• v.39 no.6_3
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• pp.1731-1745
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• 2023

Within the framework of the post-2020 climate regime, the Paris Agreement's emphasis on Nationally Determined Contributions and Biennial Transparency Reporting is paramount in addressing its long-term temperature goal. A salient issue is the treatment of wetland ecosystems within the context of Land Use, Land-Use Change, and Forestry, as defined by the Intergovernmental Panel on Climate Change. In the 2019 National Inventory Report, wetlands were recategorized as emission sources due to their designation as inundated areas. This study employs C-band radar imagery to discriminate between inundated and non-inundated regions of wetlands, enabling the quantification of their spatial dynamics. The research capitalizes on 24-period Sentinel-1 satellite data to cover both the inundation and desiccation phases while centering its attention on Ungok Wetland, a Ramsar-designated inland wetland conservation area in Korea. The inundated area is quantitatively assessed through the integration of multi-temporal Sentinel-1 Single-Look Complex (SLC) data, aerial orthophotography, and inland wetland spatial information. Furthermore, the study scrutinizes fluctuations in the maximum and minimum inundated areas, with substantial changes corroborated via drone aerial reconnaissance. The outcomes of this investigation hold the potential to make substantive contributions to the refinement of national greenhouse gas absorption and emission factors, thereby informing the development of comprehensive greenhouse gas inventories. These efforts align directly with the overarching objectives of the Paris Agreement.

• The KIPS Transactions:PartD
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• v.11D no.1
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• pp.23-30
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• 2004

In order to approximate the spatial query result size we partition the input rectangles into subsets and estimate the query result size based on the partitioned spatial area. In this paper we examine query result size estimation in skewed data. We examine the existing spatial partitioning techniques such as equi-area and equi-count partitioning, which are analogous to the equi-width and equi-height histograms used in relational databases, and examine the other partitioning techniques based on spatial indexing. In this paper we propose a new spatial partitioning technique based on the Hilbert space filling curve. We present a detailed experimental evaluation comparing the proposed technique and the existing techniques using synthetic as well as real-life datasets. The experiments showed that the proposed partitioning technique based on the Hilbert space filling curve achieves better query result size estimation than the existing techniques for space query size, bucket numbers, skewed data, and spatial data size.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.991-999
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• 2018

In urban areas, the proportion of railway traffic in public transport is increasing. The congestion situation is repeated as the passengers concentrate on station and transfer facilities and the inconvenience of the passengers is increasing in terms of safety and convenience. Therefore, the importance of estimating the appropriate area of the station has been emphasized. The area estimation formula used in the metropolitan railway stations currently is a partial modification of the area estimation formula of Japan in the 1970s. It does not reflect changes in the social and cultural environment and patterns of passengers. The technical basis for major decision variables is insufficient. Therefore, the theoretical basis of the area estimation formula and the pedestrian environment satisfaction of the design guideline of metropolitan railway stations were analyzed in order to suggest improvement formula. The improved area estimation formula was verified by conducting field surveys on 5 stations of metropolitan railways and 15 stations of urban railways. The existing area estimation formula is LOS E grade for the main space. However, the LOS D grade is implemented when the improved area estimation formula is applied. Based on the results, the design factors for the area estimation formula are suggested.

• Korean Journal of Environment and Ecology
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• v.33 no.5
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• pp.578-586
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• 2019

The purpose of this study was to investigate the change of spatial distribution of Korean red pine (Pinus densiflora Siebold & Zucc.) in Hallasan National Park by surveying the distribution and crown density and analyzing by the elevation, slope, orientation, and regional habitat in 2006 and 2015. The total area of the Korean red pine forest was 1,259.9 ha in 2015, which increased by 51.4 ha, or 4.1%, compared to 1,208.5 ha in 2006. For the past 10 years, the area of sparse density with crown density of 11% to 40% of Korean red pine increased by 59.8 ha, the area of moderate density with crown density of 41% to 70% increased by 59.0 ha, and the area of dense density with 71% or more crown density increased by 67.3 ha. In terms of the altitude above sea level, the Korean red pine forest area between 1,010 m and 1,400 m was the largest at 1,003.0 ha or 79.6% of the total area in 2015. The area between 1,100 m and 1,300 m increased, and the area of dense density decreased significantly while the areas of moderate density and sparse density increase. There was no notable change according to the land slope, and the area increased from 2006 regardless of the slope. By direction, 56.4% were distributed in the southwest and southeast directions centered on the south-facing slope with the increase of 27.8 ha over the 10 years while the northwest and northeast directions centered on the north-facing slope decreased by 7.6 ha. Regarding the distribution change of the Korean red pine forest by the region, the Yeongsil area showed an increase of 25.5 ha, or 49.6% of the total area increase, in 2006 while the Ibseog-oreum area including the right side on the Sanbeoleum mountain valley increased by 20.4 ha. The distribution in the Gaemideung area that includes Jogeundeule increased by 7.4 ha while that of Sogbat in Sungpanak Trail decreased by 1.9 ha. This study analyzed the changes in the distribution area and crown density of the Korean red pine forest according to the altitude, slope, direction, and regional habitat in Hallasan National Park. The expansion of Korean red pine forest distribution was limited to the areas where the grass and the shrub was the dominating vegetation structure, or the forest gap was created by the disturbance. On the other hand, the distribution area of the Korean red pine forest surrounded by deciduous broad-leaved forests or mixed vegetation structure is considered to result from the change in density more than the area due to competition with deciduous broad-leaved trees.

• Korean Institute of Interior Design Journal
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• v.19 no.2
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• pp.216-224
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• 2010

This study aims to examine a special type of hospital known as Western Oriental medicine treatment designed to provide the best treatment by combining the advantages of Western and Oriental medicine, The actual conditions of the organizations and operations of O.P.D and how the cooperative treatment between Western and Oriental medicine is conducted at general hospitals that operate the cooperative treatment by applying a drawing analysis and an area analysis, and provide materials that help design hospitals that offers the cooperative treatment based on the information. According to the results of this study, the forms of the cooperative treatment between Western and Oriental medicine included several methods; to operate the cooperative center separately between an Oriental hospital and a general hospital, to operate the cooperative hospital, using several floors for an Oriental hospital inside a general hospital, and to operate the cooperative center in specialized centers inside a general hospital and the type of cluster that offers the cooperative treatment in specialized centers is known as the best appropriate treatment.

• 한국공간정보시스템학회:학술대회논문집
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• 2007.06a
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• pp.436-440
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• 2007

ArcView와 연동하는 SWAT(Soil and Water Assessment Tool)은 수문평가 도구로써 사용되는 모형이다. 이러한 SWAT모형은 유역의 서로 다른 표면 특성을 반영할 수 있도록 대상유역을 몇 개의 소유역으로 나누고 소유역 내에서 유사한 특성을 나타내는 HRU으로 세분화한다. 모형에서는 유역부분과 수체부분으로 나누어 모의가 이루어지며 각 소유역에서 물수지식에 따라 강우량, 지하수로의 침투량, 증발산량, 그리고 표면 유출량을 산정한다. SWAT 모형은 많은 입력 자료가 있으며 그 중에서도 소유역 개수와 HRU개수가 SWAT 모형의 결과에 많은 영향을 미칠 것으로 생각되어 본 논문에서는 이에 대한 영향을 분석하였다. 연구 대상지역은 함평천 유역으로 전라남도 함평군과 무안군 사이에 위치하고 있으며 유역의 면적은 $196.4km^2$이고 유역의 대부분이 산지와 농업지역으로 이루어져 있다. SWAT 모형을 모의하기 위한 지형자료는 1:25,000 수치지도, 농업과학기술원의 1:25,000 정밀토양도, 환경부의 토지피복도를 사용하였고 기상자료와 강우자료는 목포기상관측소의 자료를 사용하였다. 매개변수를 추정하기위해 환경부의 오염총량관리 세유역을 사용하였으며 모의 결과를 실측치와 비교함으로서 매개변수를 추정하였다. 추정된 매개변수를 이용하고 연구대상지역의 소유역 개수와 HRU개수를 여러 가지로 변화시켜 모의하였으며 그 결과를 실측치와 비교하여 최적 소유역 개수와 HRU 개수를 추정하였다. 본 연구의 결과는 SWAT모형 수행시 소유역의 면적에 대한 객관적인 기준을 제시할 수 있을 것이다.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.371-371
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• 2011

본 연구에서는 한강유역 내 관측기간이 충분한 기상청 지상관측소 10개소를 선정하고 CCCma(Canadian Century for Climate modeling and analysis)에서 제공하는 자료에 대한 인공신경망기법 상세화 적용을 실시하였다. 인공신경망의 학습을 위해 CGCM3.1/T63 20C3M시나리오(reference scenario)의 22개 2D변수 중 물리적으로 민감도가 높다고 판단되는 GCM_Prec, huss, ps를 입력변수로 선정하였으며 인공신경망 학습기간은 1991년~1995년, 검증기간은 1996년~2000년, 예측기간은 2011년~2100년으로 A1B, A2 B1 시나리오 등 다양한 기후변화 시나리오를 통해 예측band를 제시하고자 하였다. 하지만 공간상관을 고려하기 위하여 각 관측소에 대하여 인공신경망 학습을 하는 경우 관측소간 spatial correlation 및 spatial cluster구현이 어렵기 때문에 Spatial Rectangular Pulse모형을 이용하고자 하였으나, 강수면적에 대한 scale의 결정이 어렵다는 단점을 확인 하고 본 연구에서는 Random Cascade 모형을 이용하여 ${\beta}$를 통한 강수면적 scale(rainy area fraction)을 결정하고자 하였다. Random Cascade모형의 기법은 격자단위의 downscaling기법으로 강수대의 공간적 형상을 재현하며 스케일에 비종속적인(scale-invariant)프랙탈 특성을 이용하여 매개변수를 최소화 할 수 있는 장점을 가진 기법으로 한강유역 1Km내외 강우장을 만들어 topographic effect를 첨가하고자 한다.