• Journal of Korean Society of Disaster and Security
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• v.17 no.1
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• pp.1-8
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• 2024

In Korea, mountainous areas cover 60% of the land, leading to increased factors such as concentrated heavy rainfall and typhoons, which can result in debris flow and landslide. Despite the high risk of disasters like landslides and debris flow, there has been a tendency in most regions to focus more on post-damage recovery rather than preventing damage. Therefore, in this study, precise topographic data was constructed by conducting on-site surveys and drone measurements in areas where debris flow actually occurred, to analyze the risk zones for such events. The numerical analysis program RAMMS model was utilized to perform debris flow analysis on the areas prone to debris flow, and the actual distribution of debris flow was compared and analyzed to evaluate the applicability of the model. As a result, the debris flow generation area calculated by the RAMMS model was found to be 18% larger than the actual area, and the travel distance was estimated to be 10% smaller. However, the simulated shape of debris flow generation and the path of movement calculated by the model closely resembled the actual data. In the future, we aim to conduct additional research, including model verification suitable for domestic conditions and the selection of areas for damage prediction through debris flow analysis in unmeasured watersheds.

• Journal of the Korean GEO-environmental Society
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• v.25 no.6
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• pp.19-24
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• 2024

Urban densification has necessitated the development of subterranean spaces such as subway networks and underground tunnels to facilitate the dispersal and movement of populations. Development of these underground spaces requires excavation from the ground surface, which can induce groundwater flow and potentially lead to ground subsidence and sinkholes, damaging structures. To mitigate these risks, it is essential to model groundwater flow prior to construction, analyze its characteristics, and predict potential groundwater discharge during excavation. In this study, we collected meteorological, topographical, and soil conditions data for the city of ○○, where tunnel construction was planned. Using the Visual MODFLOW program, we modeled the groundwater flow. Excavation sections were set as drainage points to monitor groundwater discharge during the excavation process, and the effectiveness of seepage control measures was assessed. The model was validated by comparing measured groundwater levels with those predicted by the model, yielding a coefficient of determination of 0.87. Our findings indicate that groundwater discharge is most significant at the beginning of the excavation. Additionally, the presence of seepage barriers was found to reduce groundwater discharge by approximately 59%.

• Journal of the Society of Disaster Information
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• v.20 no.1
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• pp.93-105
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• 2024

Purpose: This study aims to quantitatively determine the impact on nearby risidents by selecting the amount of chemicals emitted from the workplace among the substances subject to the chemical emission plan and predicting the concentration with the atmospheric diffusion program. Method: The selection of research materials considered half-life, toxicity, and the presence or absence of available monitoring station data. The areas discharged from the materials to be studied were selected as the areas to be studied, and four areas with floating populations were selected to evaluate health risks. Result: AERMOD was executed after conducting terrain and meteorological processing to obtain predicted concentrations. The health hazard assessment results indicated that only dichloromethane exceeded the threshold for children, while tetrachloroethylene and chloroform appeared at levels that cannot be ignored for both children and adults. Conclusion: Currently, in the domestic context, health hazard assessments are conducted based on the regulations outlined in the "Environmental Health Act" where if the hazard index exceeds a certain threshold, it is considered to pose a health risk. The anticipated expansion of the list of substances subject to the chemical discharge plan to 415 types by 2030 suggests the need for efficient management within workplaces. In instances where the hazard index surpasses the threshold in health hazard assessments, it is judged that effective chemical management can be achieved by prioritizing based on considerations of background concentration and predicted concentration through atmospheric dispersion modeling.

• Journal of Korea Water Resources Association
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• v.57 no.9
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• pp.615-626
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• 2024

To accurately and efficiently monitor soil moisture (SM) across South Korea, this study developed a SM estimation model that integrates the cloud computing platform Google Earth Engine (GEE) and Automated Machine Learning (AutoML). Various spatial information was utilized based on Terra MODIS (Moderate Resolution Imaging Spectroradiometer) and the global precipitation observation satellite GPM (Global Precipitation Measurement) to test optimal input data combinations. The results indicated that GPM-based accumulated dry-days, 5-day antecedent average precipitation, NDVI (Normalized Difference Vegetation Index), the sum of LST (Land Surface Temperature) acquired during nighttime and daytime, soil properties (sand and clay content, bulk density), terrain data (elevation and slope), and seasonal classification had high feature importance. After setting the objective function (Determination of coefficient, R² ; Root Mean Square Error, RMSE; Mean Absolute Percent Error, MAPE) using AutoML for the combination of the aforementioned data, a comparative evaluation of machine learning techniques was conducted. The results revealed that tree-based models exhibited high performance, with Random Forest demonstrating the best performance (R² : 0.72, RMSE: 2.70 vol%, MAPE: 0.14).

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.1
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• pp.91-106
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• 2014

This study tries to cluster the 795 standard watersheds of Korea Water Resources Unit Map using multivariate statistical analysis technique. The 30 factors of watershed characteristics related to topography, stream, meteorology, soil, land cover and hydrology were selected for comprehensive analysis. From the factor analysis, 16 representative factors were selected. The significant factors in order were the pedological feature, scale and geological location and meteorological and hydrological features of the watershed. As a next step, the 73 gauged watersheds were selected for cluster analysis. They are scattered properly to the whole country and the discharge data were within a confidential level. Based on the 73 watersheds, the other ungaged watersheds were clustered by applying the 16 factors and calculating Euclidian distances. The clustering results showed that the similarity between standard watersheds within the same river basin were 87%, 69%, 41%, 52%, and 27% for Han, Nakdong, Geum, Seomjin, and Yeongsan river basins respectively.

• Journal of the Korean earth science society
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• v.27 no.4
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• pp.416-424
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• 2006

Because there is no generally accepted definition of a geographic center and no completely satisfactory method to determine one, there may be as many geographic centers of a country as there are many definitions. The geographic center of an area may be defined as the center of gravity on a surface, or that point on which the surface of an area would balance if it were a plane of uniform thickness. This research uses geographic information system (GIS) analysis and there are places where it defines the geographical and the geological centers in the inland of South Korea. To compute the geo-centers in South Korea: 1) firstly, we collected existing reaserch data related to digital map data. 2)Secondly, we analyzed a geological center and data collection examples of Korea and other nations-the Europe and America. 3) Thirdly, we carried out numerous processes to build a geodatabase, short for geograhic database, so that GIS analysis and the constructed geodatabase is covered within the inland in South Korea. Where geodatabase is a kind of spatial database. 4) Fourthly, in order to determine the geographical center, we supposed that the condition of continental surface is the plane of homogeneous or irregular density. 5) Consequently, we chose a few resonable conditions and produced a variety of geographical centers that is geometric and gravitational in South Korea. As a result of the analysis, center points are massed to southern part of Chungbuk province, Korea.

• Research in Plant Disease
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• v.16 no.3
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• pp.266-273
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• 2010

Bacterial pustule of soybean (Glycines max) caused by Xanthomonas axonopodis pv. glycines is one of the most prevalent bacterial diseases of soybean. This bacterium shows strong pathogenicity to the plants and distributes throughout Korea. However, no good control measures including bactericides and resistant cultivars are available to control the disease in Korea. Therefore, this study was conducted to develop chemical control method against soybean bacterial pustule. The present study was undertaken to find out the growth inhibitory effect bactericides (8 antibiotics, 2 copper compounds, quinoline, 18 agro-chemicals) on bacterial pustule pathogen. Antibiotics test showed that tetracycline and streptomycin sulfate significantly suppressed the growth of bacterial pustule pathogen. Also, application of oxolinic acid was found to be effective for pathogen inhibition. However, vancomycin, polymyxin B sulfate and copper compounds did not show the positive suppressive effect on growth of the pathogen. Among the eighteen agro-chemicals, streptomycin sulfate + oxytetracyclin (18.8 + 1.5%) WP, oxytetracycline (17%) WP and oxolinic acid (20%) WP were found to be effective for the inhibition of the pathogen in vitro. The selected 5 agro-chemicals were also applied on soybean in field and their control effects against the soybean bacterial pustule were tested. The foliar application of streptomycin sulfate + oytetracyclin WP and oxytetracycline WP on the naturally infected soybean (Taekwangkong) showed high control value (above 70%). Therefore, it is concluded that the bactericides used in this study showed strong inhibitory effect to soybean bacterial pustule and they can be recommend to farmers to control the disease.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.4
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• pp.257-266
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• 2000

A vertically-averaged, two-dimensional version of the Princeton Ocean Model has been applied to the South Sea to simulate the circulation driven by tides and inflows/outflows across open boundaries. To incorporate both forcing properly, a two-step modeling approach is adopted, in which the tidal circulation is first simulated by specifying the tides along the open boundaries, and then both the calculated tidal currents and the observed steady mean currents are prescribed across the open boundaries. Model results show that the steady, subtidal circulation of the South Sea is different from the residual circulation due to tidal rectification, and subtidal currents become locally as strong as tidal currents. The Cheju Current entering the model domain across the Cheju Strait flows eastward in general while shifting onshore or offshore areas following local isobaths. The Tsushima Current entering across the southern boundary reaches farther to the north in the eastern vicinity of Cheju-Do as compared to that entering across other parts of the southern boundary. The Tsushima Current turns to the east, merges with the Cheju Current, and both the Cheju and Tsushima Current exit to the East Sea through the western channel of the Korea Strait. An intensification of the outflow occurs over the deep trough adjacent to the Tsushima Island, which appears to be due to the formation of the frictional boundary layer in order to remove excess positive relative vorticity generated by an increase in the layer thickness. The circulation driven by both the tidal and inflows/outflows is different from that driven by each forcing separately in coastal areas, which implies that both forcings should be considered simultaneously in the simulation of more realistic coastal circulation.

• Journal of Biosystems Engineering
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• v.9 no.1
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• pp.62-70
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• 1984

가축배설물(家畜排泄物)의 콤포스트화(化) 작업(作業)의 공학적(工學的)인 국면(局面)은 축산(畜産) 경영(經營)의 축산물(畜産物) 생산성(生産性), 에너지 보전(保全), 공해방지(公害防止)와 분뇨처리(糞尿處理)의 노력(勞力) 절약(節約)에 긴밀(緊密)한 관계(關係)가 있다. 그러나 우리나라에 있어서 축산업(畜産業)의 사양(飼養) 규모(規模)와 두수(頭數)는 매년(每年) 증가(增加)하고 있는 경향(傾向)인바 전통적(傳統的)인 가축(家畜) 배설물(排泄物) 처리(處理) 및 재이용(再利用) 과정(科程)에서 발생(發生)되는 문제점(問題點)에 대(對)한 연구(硏究) 자료(資料)가 없고 특(特)히 콤포스트화(化) 작업(作業)이 원시적(原始的)이므로 개선(改善) 확립(確立)이 절실(切實)히 요구(要求)되는 실정(實定)이다. 본(本) 연구(硏究)의 목적(目的)은 가축(家畜) 분뇨(糞尿)의 콤포스트화(化) 작업(作業) 과정(科程)에서 공학적(工學的)인 제(諸) 문제점(問題點)을 조사(調査) 분석(分析)하여 현상(現狀)을 평가(評價)하고 개선(改善) 방안(方案)을 모색(摸索)하기 위한 기본자료(基本資料)를 제공(提供)하고져 수행(遂行)하였다. 이에 관한 조사(調査)와 분석(分析) 결과(結果)를 요약(要約)하면 다음과 같다. 1. 축산농가(畜産農家)의 가축(家畜) 배설물(排泄物) 처분(處分) 방법(方法)은 대부분(大部分)이 자연건조(自然乾燥), 퇴적(堆積), 혐기적(嫌氣的)인 고형(固形) 또는 액상(液狀) 퇴비화(堆肥化)에 의하여 실시(實施)되고 있었으며 가축분뇨(家畜糞尿)로 인(因)한 공해(公害)는 심각(深刻)하다는 것을 알 수 있었다. 2. 호기성(好氣性) 야적(野積) 콤포스트의 통기작업(通氣作業)은 트랙터에 부착(附着)되어진 전후(前後) 작동식(作動式) 로우더가 바람직하다. 3. 농축산(農畜産) 폐기물(廢棄物)의 콤포스트화(化) 작업(作業)은 축산농가(畜産農家)를 중심(中心)으로 한 콤포스트 센타에서 전체 농가(農家)가 지방(地方) 증진(增進)과 오염(汚染) 방지(防止)를 하기 위해 참여(參與)하여 완전(完全) 공동(共同) 이용(利用) 체계에 따라 일관성(一貫性)있게 수행(遂行)되어야 한다. 4. 호기성(好氣性) 야적(野積) 콤포스트 작업(作業)은 다른 방법(方法)에 비하여 운영비(運營費)가 적게 들어 영세적(零細的)인 축산업(畜産業)의 경우(境遇)에 가장 적당(適當)하고 공해(公害)를 방지(防止)함으로서 한국(韓國) 축산농가(畜産農家)의 콤포스트화(化) 시설(施設)로 전망(展望)이 밝다고 판단(判斷)된다.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.33 no.1
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• pp.31-40
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• 2015

This study aims to comprehend that Seokpajeong garden for aspect of space change. Spatial characteristics according to the transfer of ownership are classified as period. And investigate the aspect of space change in Seokpajeong garden based on literature and painting, newspaper, photo. The results were as follows. First, Investigate the construction and change of Seokpajeong garden. Accordingly, spatial characteristics of Seokpajeong garden are classified into three period. 1st period is Kim-Heung Keun owned Samgyedong-jungsa garden. 2nd period is Daewongun hold Seokpajeong garden. 3rd period is damaged original form of Seokpajeong garden from Korean War to current time inclusive. Secondly, Kim-Heung Keun owned Samgyedong-jungsa garden has characteristics of water system centric space and many buildings. In addition accept foreign culture like chinese pavilion and Byeoldang Villa. and plant unique flower and leaf in garden. Thirdly, According to Seokpajeong garden folding screen, Daewongun owned Seokpajeong garden accept organization of space in Samgyedong garden. But different locations of Sarangchae in folding screen means possibility of move building to current position. So, additional historical research is required with representation of chinese pavilion location. Fourthly, Seokpajeong garden was damaged from original form to frequent changes of ownership. Transform of geographical features and water system as well as Anchae and Sarangchae, back side of a outbuilding are only the remained among many buildings. Also, Seokpajeong garden is more fell to the subsidiary facility of Seoul Museum than Wonrim. Therefore restoration and recovery of original form are urgent.