• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.1
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• pp.133-149
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• 2022

Existing domestic studies on estimating rice yield were mainly implemented at the level of cities and counties in the entire nation using MODIS satellite images with low spatial resolution. Unlike previous studies, this study tried to estimate rice yield at the level of eup-myon-dong in Gimje-si, Jeollabuk-do using Sentinel-2 satellite images with medium spatial resolution, rainfall and soil data, and then to evaluate its accuracy. Five vegetation indices such as NDVI, LAI, EVI2, MCARI1 and MCARI2 derived from Sentinel-2 images of August 1, 2018 for Gimje-si, Jeollabuk-do, rainfall and paddy soil-type data were aggregated by the level of eup-myon-dong and then rice yield was estimated with gamma generalized linear model, an expanded variant of multi-variate regression analysis to solve the non-normality problem of dependent variable. In the rice yield model finally developed, EVI2, rainfall days in September, and saline soils ratio were used as significant independent variables. The coefficient of determination representing the model fit was 0.68 and the RMSE for showing the model accuracy was 62.29kg/10a. This model estimated the total rice production in Gimje-si in 2018 to be 96,914.6M/T, which was very close to 94,470.3M/T the actual amount specified in the Statistical Yearbook with an error of 0.46%. Also, the rice production per unit area of Gimje-si was amounted to 552kg/10a, which was almost consistent with 550kg/10a of the statistical data. This result is similar to that of the previous studies and it demonstrated that the rice yield can be estimated using Sentinel-2 satellite images at the level of cities and counties or smaller districts in Korea.

• Korean Journal of Ecology and Environment
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• v.55 no.2
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• pp.132-144
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• 2022

The fish community in the Seomjin River-Seomjin River Estuary-Gwangyang Bay coast continuum was investigated three times from March 2019 to October 2019. The collected species at the eight sites during the survey period were 49 species belonging to 31 families, including two endangered species. According to Bray-Curtis similarities, observations were divided into four groups based on the fish community composition; two groups (group 1, 2) and two uncategorized groups (group 3, 4). ANOSIM based on spatial and temporal groupings indicated that the spatial differences in fish communities (R=0.398, P=0.001) were relatively more important than the temporal differences (analysis of similarities, R=0.273, P=0.002). In particular, there were significant differences between groups 1 and 2 (analysis of similarities, R=0.556, P=0.001), and similarity percentage analysis revealed that Argyrosomus argentatus (9.4%), Favonigobius gymnauchen (6.9%) and Konosirus punctatus (5.9%) contributed to these differences of fish assemblages for each group. The fish fauna distributed in the Seomjin River-Gwangyang Bay ecosystem were spatially divided and the number of species and number of individuals showed seasonal differences. This study could be a basis for understanding changes in the fish community and implementing conservation and management strategies on major species within a continuous environment of the river-estuary-ocean continuum.

• Journal of the Korean Geotechnical Society
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• v.39 no.5
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• pp.51-63
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• 2023

Numerical analysis was conducted to determine the effect of soil behavior by thawing and freezing of seasonal frozen soil on pile foundations. The analysis was performed using the finite element method (FEM) to simulate soil-pile interaction based on the atmosphere temperature change. Thermomechanical coupled modeling using FEM was applied with the temperature-dependent nonlinear properties of the frozen soil. The analysis model cases were applied to the MCR and HDP models to simulate the elastoplastic behavior of soil. The numerical analysis results were analyzed and compared with various conditions having different length and width sizes of the pile. The results of the numerical analysis showed t hat t he HDP model was relat ively passive, and t he aspect and magnit ude of t he bearing capacit y and displacement of the pile head were similar depending on the length and width of the pile conditions. The vertical displacement of the pile head by thawing and freezing of the ground showed a large variation in displacement for shorter length conditions. In the MCR model, the vertical displacement appeared in the maximum thaw settlement and frost heaving of 0.0387 and 0.0277 m, respectively. In the HDP model, the vertical displacement appeared in the maximum thaw settlement and frost heaving of 0.0367 and 0.0264 m, respectively. The results of the pile bearing capacity for the two elastoplastic models showed a larger difference in the width condition than the length condition of the pile, with a maximum of about 14.7% for the width L condition, a maximum of about 5.4% for M condition, and a maximum of about 5.3% for S condition. The significance of the effect on the displacement of the pile head and the bearing capacity depended on the pile-soil contact area, and the difference depended on the presence or absence of an active layer in the soil and its thickness.

• Korean Journal of Heritage: History & Science
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• v.55 no.4
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• pp.118-135
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• 2022

The primary purpose of this study is to estimate the structure of Byeongpungsadaseok (屛風莎臺石) and Nanganseok (欄干石) in Geonwonneung (建元陵) and Heonneung (獻陵), which were built in the early of 15th century, based on the Annals of King Sejong. In addition, the ultimate purpose of this study is to reveal structural changes and their significance by comparing the differences with the contents of the dismantlement survey. Geonwonneung, Jereung(齊陵), and Heonneung were repaired at the same time in 1442, and the structural changes were the similar. The purpose of the repair in 1442 was to prevent water from flowing into the underground palace with smooth drainage. As a result of estimating the structure of Geonwonneung and Heonneung according to the records of the Annals of King Sejong, it was created in a very similar form to the Hyeonneung and Jeongneung of Goryeo. And it was clearly recognized that the Royal Tomb of Goryeo was followed. However, as the structure was improved in 1442, the unique characteristics of the Royal Tomb of the Joseon Dynasty were formed. First is the appearance of the Bokbuhyeong lime (覆釜形石灰, which is a convex roof on the Byeongpungsadaseok that serves to prevent rainwater from penetrating into the burial mound. It also plays a role in connecting and fixing the Manseok (滿石) and the Inseok (引石), which are the upper structures of the Sadaseok (莎臺石). Second, the Bakseok (薄石) between the nanganseok and the sadaseok has been transformed into the Sangseok (裳石) with a slope. This plays a role in protecting the inner stone chamber by expanding the length of the bakseok, which forms an overall slope, like the eaves of the roof. After both of these features were first attempted in 1442, they were applied to all Royal Tombs of the Joseon Dynasty and became unique features of these Royal Tombs.

• Journal of the Daesoon Academy of Sciences
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• v.21
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• pp.157-195
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• 2013

대순진리회는 '구천응원뇌성보화천존강성상제(이하 '구천상제')'를 주신(主神)으로 신앙하는 종교단체이다. 그렇다면 대순진리회의 '구천상제'와 중국 도교에서 모셔지는 '구천응원뇌성보화천존'(이하 '보화천존')은 어떤 연관성이 있는 것인가? 이런 질문을 토대로 본 글에서는 이 신들의 기원과 칭호, 도세법문(度世法門 : 세상을 제도하고자 펼친 법도) 등의 관점에서 그 차이점과 공통점을 하나씩 비교해 보았다. 먼저 기원이라는 측면에서 '구천상제'와 '보화천존'을 비교해보면, '구천상제'는 천지인 삼계의 최고신으로서 강씨 가문을 선택하여 인간의 육신으로 태어났다. 강씨 성은 상고 신농씨에서 시작되었는데, 고대 문헌에 근거하면 신농씨는 태양신, 남쪽, 불(火) 등으로 상징화된다. 이런 상징들은 '구천상제'가 인간으로 태어날 때 나타난 "하늘이 남북으로 갈라지다", "큰 불덩이가 몸을 덮치다", "천지가 밝아지는도다" 등의 현상들에서 찾아볼 수 있다. 도교의 '보화천존'은 뇌신의 특징을 가지면서 일신(日神), 월신(月神)과 관계를 맺고 있는데, 이런 면들은 신농씨로부터 분석한 '구천상제'의 신적 기원과 일치하고 있다. 또한 도교에서는 신농씨가 다스리던 세상을 중국 상고시대의 가장 이상적인 사회형태로 보고 있는데, 이것을 '구천상제'가 건설하려는 후천선경과 연관 지어 생각해보면 '구천상제'가 신농씨의 후손인 강씨 종가에서 태어난 배경을 이해할 수 있다. 도교의 '보화천존' 역시 중생의 이익을 도모하고, 조화로운 인간세상을 만드는 것을 목표로 삼고 있으며, 이것은 대순진리회 '구천상제'가 행한 대순의 목적과 거의 비슷하다고 볼 수 있다. 다음으로 '구천상제'와 '보화천존'은 칭호에서도 공통점과 차이점을 살펴볼 수 있다. 단적으로 말하자면, '구천상제'에는 '보화천존'에 비해 '강성상제'라는 칭호가 추가되어 있다는 것이다. 또한 도교에서는 '보화천존'을 최고신으로 모시지 않으며, '구천상제' 신앙에서는 '보화천존' 신앙에서와 달리 뇌신과의 관계에 대한 설명을 찾아볼 수 없다. 마지막으로 '구천상제'와 '보화천존'의 도세법문을 비교해보면 첫째, 구천상제는 세상이 혼란, 불공평, 죄악에 빠졌기에 육신으로 인간 세상에 강림한 후 대순진리를 선포하였다. 이와 유사하게 보화천존도 천하와 인간세상을 순시하여 죄악과 겁액을 없앤다는 '순시천하(巡視天下)' 사상이 있다. 물론 여기에는 차이점이 존재하는데, 그 중 하나는 '보화천존'은 순시할 때 인간의 육신으로 화하지 않았다는 점이다. 또 다른 하나는 '보화천존'이 인간 세상에 창교의 방법을 통하여 선경을 건설하고자 하는 목표를 전해주지 않았다는 점이다. '보화천존'은 교리를 가르치거나 신통을 발휘하는 데에만 중점을 두고 있다. 둘째, '구천상제'가 내린 가르침인 해원상생은 후천선경을 건설하기 위한 수단과 과정이다. 도교의 '보화천존'도 인간이 지은 많은 죄악과 겁액은 세상 사람들이 맺은 원한과 관계가 있으므로, 이런 겁액과 죄를 해소하려면 해원부터 해야 한다는 것을 수차례에 걸쳐 언급하고 있다. 도교에서 말하는 '해원'의 구체적인 내용은 주로 인간의 시비, 질병, 겁액에 관한 것이며, 그 해결 방법으로는 주로 마음속으로 『옥추보경』을 읽는 것이다. 이를 '구천상제'의 '해원상생' 가르침과 비교하면 그 사상의 폭이나 깊이, 중요성, 이론적 측면 등에서 비교적 간단한 형태로서 체계적인 면모로까지 나아가지는 못하였다. 셋째, '구천상제' 는 곤경에 처한 사람이 신명의 호칭을 부르면 그에 상응하는 신명이 달려와서 구원해준다는 '소리감응' 방법을 사용하고 있는데, 이 방법은 도교의 '보화천존' 역시 사용하고 있는 것이다. 넷째, '구천상제'는 과오를 범한 사람이 자신의 과오를 뉘우치면, 그 다음에 상제의 용서를 받음으로써 그 원한이 풀리게 된다는 참법(懺法 : 懺悔法)을 세인(世人) 교화에 자주 사용하였다. 물론 이것은 해원상생의 구체적인 적용이라 할 수 있다. 기능면에서 보면 이 방법은 『구천응원뇌성보화천존옥추보참(九天應元雷聲普化天尊玉樞寶懺)』의 참의(懺儀)와 공통되는 점이 있다. 참의는 수도자 스스로 자신의 잘못을 뉘우치고, 수도에 정진하며, 사회의 안정을 도모하고, 포덕에 힘쓰고, 악을 물리치고 선을 널리 펼친다는 것인데, 이런 의미에서 양자는 일치한다고 생각된다. 필자가 생각하건대, 대순진리회의 '구천응원뇌성보화천존강성상제'와 도교의 '구천응원뇌성보화천존' 사이에는 공통점이 아주 많지만 동시에 차이점 또한 적지 않다. 만약 더욱 다양한 자료들을 수집하여 더욱 깊고 광범위한 연구를 진행한다면 한국 대순진리회와 중국 도교, 특히 도교의 뇌법종파(雷法宗派)와의 상관관계를 해석하는 데 큰 도움이 될 것이라 생각한다.

• Korean Journal of Remote Sensing
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• v.39 no.5_3
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• pp.1031-1042
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• 2023

In this study, a deep learning model was developed to predict the yield of cabbage and radish, one of the five major supply and demand management vegetables, using satellite images of Landsat 8. To predict the yield of cabbage and radish in Gangwon-do from 2015 to 2020, satellite images from June to September, the growing period of cabbage and radish, were used. Normalized difference vegetation index, enhanced vegetation index, lead area index, and land surface temperature were employed in this study as input data for the yield model. Crop yields can be effectively predicted using satellite images because satellites collect continuous spatiotemporal data on the global environment. Based on the model developed previous study, a model designed for input data was proposed in this study. Using time series satellite images, convolutional neural network, a deep learning model, was used to predict crop yield. Landsat 8 provides images every 16 days, but it is difficult to acquire images especially in summer due to the influence of weather such as clouds. As a result, yield prediction was conducted by splitting June to July into one part and August to September into two. Yield prediction was performed using a machine learning approach and reference models , and modeling performance was compared. The model's performance and early predictability were assessed using year-by-year cross-validation and early prediction. The findings of this study could be applied as basic studies to predict the yield of field crops in Korea.

• Korean Journal of Remote Sensing
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• v.39 no.6_2
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• pp.1605-1613
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• 2023

The physical properties of the ocean interior are determined by temperature and salinity. To observe them, we rely on satellite observations for broad regions of oceans. However, the satellite for salinity measurement, Soil Moisture Active Passive (SMAP), has low temporal and spatial resolutions; thus, more is needed to resolve the fast-changing coastal environment. To overcome these limitations, the algorithm to use the Geostationary Ocean Color Imager-II (GOCI-II) of the Geo-Kompsat-2B (GK-2B) was developed as the inputs for a Multi-layer Perceptron Neural Network (MPNN). The result shows that coefficient of determination (R²), root mean square error (RMSE), and relative root mean square error (RRMSE) between GOCI-II based sea surface salinity (SSS) (GOCI-II SSS) and SMAP was 0.94, 0.58 psu, and 1.87%, respectively. Furthermore, the spatial variation of GOCI-II SSS was also very uniform, with over 0.8 of R² and less than 1 psu of RMSE. In addition, GOCI-II SSS was also compared with SSS of Ieodo Ocean Research Station (I-ORS), suggesting that the result was slightly low, which was further analyzed for the following reasons. We further illustrated the valuable information of high spatial and temporal variation of GOCI-II SSS to analyze SSS variation by the 11th typhoon, Hinnamnor, in 2022. We used the mean and standard deviation (STD) of one day of GOCI-II SSS, revealing the high spatial and temporal changes. Thus, this study will shed light on the research for monitoring the highly changing marine environment.

• Journal of Dental Rehabilitation and Applied Science
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• v.40 no.2
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• pp.46-54
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• 2024

Purpose: The purpose of this study was to compare the periodontal status of end-stage renal disease patients undergoing dialysis and referred for intraoral evaluation prior to renal transplantation surgery with those having normal kidney function. Materials and Methods: Patients who had been undergoing dialysis for end-stage renal disease and been referred to the Dental Clinic Center by the Department of Nephrology at University Hospital for intraoral evaluation prior to kidney transplantation surgery. For comparison of periodontal status, subjects without abnormalities in kidney function were matched with the patients by age and gender and selected as healthy controls. The patients' age, gender, comorbidities, type of dialysis received, and duration of dialysis were investigated by reference to their medical records, and data on their periodontal status were analyzed via the relevant periodontal records. Results: A total of 102 patients, including 51 dialyzed patients and 51 healthy control group subjects, participated in this study. In the patients with end-stage renal disease undergoing dialysis with periodontal probing depth of 5 mm or more, percentage of sites with clinical attachment level of 4 mm or more, percentage of teeth with bleeding on probing, number of missing teeth, and ratio of moderate to severe periodontitis were all significantly greater than in the healthy controls. Conclusion: The periodontal status of end-stage renal disease patients undergoing dialysis and referred for intraoral evaluation prior to kidney transplantation was worse than that of healthy controls.

• Korean Journal of Ecology and Environment
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• v.57 no.1
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• pp.1-16
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• 2024

Most wetlands worldwide have suffered from extensive human exploitation. Unfortunately they have been less explored compared to river and lake ecosystems despite their ecological importance and economic values. This is the same case in Korea. This study was aimed to estimate the assemblage attributes and distribution characteristics of benthic macroinvertebrates for fifty wetlands distributed throughout subtropical Jeju Island in 2021. A total of 133 taxa were identified during survey periods belonging to 53 families, 19 orders, 5 classes and 3 phyla. Taxa richness ranged from 4 to 31 taxa per wetland with an average of 17.5 taxa. Taxa richness and abundance of predatory insect groups such as Odonata, Hemiptera and Coleoptera respectively accounted for 67.7% and 68.2% of the total. Among them Coleoptera were the most diverse and abundant. Taxa richness and abundance did not significantly differ from each wetland type classified in accordance with the National Wetland Classification System. There were three endangered species (Clithon retropictum, Lethocerus deyrolli and Cybister (Cybister) chinensis) and several restrictively distributed species only in Jeju Island. Cluster analysis based on the similarity in the benthic macroinvertebrate composition largely classified 50 wetlands into two major clusters: small wetlands located in lowland areas and medium-sized wetlands in middle mountainous regions. All cluster groups displayed significant differences in wetland area, long axis, percentage of fine particles and macrophyte composition ratio. Indicator Species Analysis selected 19 important indicators with the highest indicator value of Ceriagrion melanurum at 63%, followed by Noterus japonicus (59%) and Polypylis hemisphaerula (58%). Our results are expected to provide fundamental information on the biodiversity and habitat environments for benthic macroinvertebrates in wetland ecosystems, consequently helping to establish conservation and restoration plans for small wetlands relatively vulnerable to human disturbance.

• Korean Journal of Heritage: History & Science
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• v.57 no.1
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• pp.82-108
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• 2024

With the transition of archaeological recording method's transition from analog to digital, the 3D scanning technology has been actively adopted within the field. Research on the digital archaeological digital data gathered from 3D scanning and photogrammetry is continuously being conducted. However, due to cost and manpower issues, most buried cultural heritage organizations are hesitating to adopt such digital technology. This paper aims to present a digital recording method of relics utilizing open-source software and photogrammetry technology, which is believed to be the most efficient method among 3D scanning methods. The digital recording process of relics consists of three stages: acquiring a 3D model, creating a joining map with the edited 3D model, and creating an digital drawing. In order to enhance the accessibility, this method only utilizes open-source software throughout the entire process. The results of this study confirms that in terms of quantitative evaluation, the deviation of numerical measurement between the actual artifact and the 3D model was minimal. In addition, the results of quantitative quality analysis from the open-source software and the commercial software showed high similarity. However, the data processing time was overwhelmingly fast for commercial software, which is believed to be a result of high computational speed from the improved algorithm. In qualitative evaluation, some differences in mesh and texture quality occurred. In the 3D model generated by opensource software, following problems occurred: noise on the mesh surface, harsh surface of the mesh, and difficulty in confirming the production marks of relics and the expression of patterns. However, some of the open source software did generate the quality comparable to that of commercial software in quantitative and qualitative evaluations. Open-source software for editing 3D models was able to not only post-process, match, and merge the 3D model, but also scale adjustment, join surface production, and render image necessary for the actual measurement of relics. The final completed drawing was tracked by the CAD program, which is also an open-source software. In archaeological research, photogrammetry is very applicable to various processes, including excavation, writing reports, and research on numerical data from 3D models. With the breakthrough development of computer vision, the types of open-source software have been diversified and the performance has significantly improved. With the high accessibility to such digital technology, the acquisition of 3D model data in archaeology will be used as basic data for preservation and active research of cultural heritage.