• Journal of Conservation Science
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• v.37 no.6
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• pp.723-737
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• 2021

This study analyzed the composition and structure of materials with Buddhist paper scriptures excavated from architectural sites in 'Sum Tolgoi' of the 17^th century and carried out conservation treatment base on the result of the analysis. The scriptures were covered in dust and foreign sub stances, and were so crumpled that it was impossible to identify the form. The damage, loss, and discoloration have been identified. Buddhist scriptures written in Tibetan used indigo and ink sticks on paper as a result of UV-Vis analysis, and ink sticks as black character materials from scriptures written ancient Mongolian. SEM-EDS and Micro-XRF analyses revealed that the outlines were drawn with red lines using a mix of Minium (Pb₃O₄) and Cinnabar (HgS), or Cinnabar (HgS) alone, and the contents of the scriptures were written with silver paint. Silver chloride (AgCl) and Calcium (Ca) were identified in the silver paint component of the characters, while Calcium and Orpiment (As₂S₃) were identified in the yellow lines. Concerning the paper ground, Buddhist scriptures written in ancient Mongolian were characterized by herbal plant fiber and bast fiber, and those written in Tibetan, by bast fiber. Radiocarbon dating indicates that the paper for the scriptures was produced between the 15^th and 17^th centuries. Conservation treatment of the scriptures was carried out based on the experiment on the production of pre-coated paper and how to coat that to prevent the second damage due to the deformation and fragility of the excavated paper. The scriptures were preserved and mounted, and a neutral box was made to identify the contents of the scriptures recorded on both sides after the treatment. This conservation treatment is the result of a study that applied new conservation treatment materials and methods according to the principle of conservation treatment reversibility.

• Journal of Bio-Environment Control
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• v.31 no.3
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• pp.194-203
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• 2022

Cultivation of tomatoes in Korea grown in soil covers 89% of the total area for tomato cultivation. Tomatoes grown in soil often encounter various environment stresses including not only salt stress and soil-borne diseases but also cold stress in the winter season. This study was conducted to comparatively analyze the performance of rootstocks with cold stress by measuring the growth, yield, and photosynthetic efficiency in tomatoes grown in soil. The rootstocks were used 'Powerguard', 'IT173773', and '20LM' for the domestic rootstock cultivars and 'B-blocking' for a control cultivar. The tomato cultivar 'Red250' was used as the scion and the non-grafted tomatoes. Stem diameter, flowering position, leaf length, and leaf width were investigated for the growth parameters. The stem diameter of the non-grafted tomatoes decreased by 15% compared to the grafted tomatoes at 80 days after transplanting when exposed to low temperatures of 9-14℃ for 14 days. The leaf length and width of the non-grafted tomatoes were the lowest with 42.4 cm and 41.8 cm at 80 days after transplanting. The total yield per plant was the highest in tomato plants grafted on 'Powerguard' with 1,615 g and lowest in non-grafted tomatoes with 1,299 g. As the result of measuring the chlorophyll fluorescence parameters, PI_ABS and DI₀/RC, which mean the performance index and dissipated energy flux, 'Powerguard' was the highest with 3.73 in PI_ABS and the lowest with 0.34 in DI₀/RC, whereas non-grafted tomatoes was the lowest with 2.62 in PI_ABS and the highest with 0.41 in DI₀/RC at 80 days after transplanting. The stem diameter has positive correlation with PI_ABS, while it has negative correlation with DI₀/RC. The results indicate that can be analyzed by chlorophyll fluorescence parameters can be used for analyzing the differences in the growth of tomato plants grafted on different rootstocks when exposed to cold stress.

• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.157-164
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• 2023

Codonopsis lanceolata (S. et Z.) Trautv. is mainly cultivated in Korea and China as a medicinal crop. C. lanceolata is difficult to produce plug seedlings in the summer, because C. lanceolata has a low germination rate and is vulnerable to high temperatures. Cold treatment is effective in breaking dormancy of seeds and increasing the germination rate. Shading cultivation can control the solar irradiance received by plants and reduce the damage by high temperatures and strong light. This study was conducted to examine the appropriate cold treatment period for the improving germination of C. lanceolata, and shading level during the summer seedling period. Cold treatment experiments were conducted for 0 (control), 1, 2, 3, and 4 weeks at 4℃ before sowing. In the shading experiment, C. lanceolata was grown for 45 days with 0 (non-treatment), 45, 75% shading levels. Cold treatment for one week significantly improved the germination energy. The plant height, leaf area, and fresh and dry weights of C. lanceolata seedlings were significantly increased under the 45% shading level. Total root length, root surface area, and the number of root tips were significantly higher in shading treatment (45 and 75%) than in non-treatment. The C. lanceolata seedling's compactness and Dickson's quality index were the highest at 45% shading level. Therefore, these results recommended sowing C. lanceolata after cold treatment for one week at 4℃, and 45% shading level could stably culture C. lanceolata plug seedlings during the high temperature period.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.216-217
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• 2022

Gulpur 수력발전 프로젝트는 전력난을 겪고 있는 파키스탄에 102 MW 규모의 수력발전소를 건설하여 30년 동안 운영 관리한 후 파키스탄 정부로 양도하는 IPP(Independent Power Producing) 형식의 투자사업이다. 남동발전과 DL E&C, 롯데건설이 Sponsor로서 출자한 자본금과, ADB, IFC, K-EXIM 등의 대주단로부터의 차입금을 재원으로 하여 소요 사업비를 조달하고 사업을 개발하였다. DL E&C와 롯데건설이 EPC(Engineering, Procurement, Construction)를 수행하였고, 이산이 Design consultant의 역할을 수행하였다. Gulpur 수력발전 프로젝트의 발전형식은 수로식(run-of-river)으로 201 m³/s의 발전유량과 102 MW의 발전 시설용량을 이용하여 연평균예상발전량은 398 GWh이다. 주요 구조물로는 설계 재현빈도 1년의 유수전환시설(가물막이댐 & 가배수터널)과 콘크리트 중력식댐(H 67 m, L 205 m), 도수터널(D 6.7 m, L 215 m, 2기), 옥외형 발전소 (H 51 m, W 60 m, L 38 m, Kaplan 2기)가 있으며, 2015년 10월 착공하여 2020년 3월 상업발전을 시작하였다. 본 프로젝트는 DL E&C의 첫 번째 EPC 해외수력발전 프로젝트이다. 따라서 프로젝트의 성공적 수행을 위한 경제적 설계, 시공의 효율성 및 안정성 확보 등을 위하여 많은 연구를 수행하는 과정에서 다양한 기술 개선을 이룰 수 있었다. 본고에서는 Gulpur 프로젝트를 통하여 도출된 성공 사례들을 소개 및 공유하고자 한다. 첫 번째로 콘크리트 중력식댐 시공을 위한 유수전환시설의 최적 설계빈도를 산정하였다. 일반적으로 유수전환시설의 규모는 설계기준에 제시된 설계 재현빈도를 이용하는데, 해외 설계기준에서는 10년, 국내 설계기준에서는 1~2년으로 다르게 제시되어 있는 문제점이 있다. 유수전환시설의 규모는 프로젝트의 경제성에 큰 영향을 미치기 때문에 최적 설계빈도의 결정이 필요하며, 위험도분석기법(Risk Analysis)과 기대화폐가치법(Expected Monetary Value)을 이용하여 유수전환시설의 최적 설계 재현빈도와 이에 영향을 미치는 인자를 분석하였다. 위험도는 몬테카를로 시뮬레이션으로 산정된 가물막이댐 파괴확률과 재현빈도를 이용하여 산정된 가물막이댐 월류확률을 고려하였으며, 비용 및 피해액으로는 유수전환시설의 공사비, 가물막이댐 파괴시의 재건설비용과 지체보상금, 가물막이댐 월류시의 복구비용을 고려하였다. 이에 대한 연구결과로, 유수전환시설의 사용기간과 월류시의 복구비용이 유수전환시설의 설계 재현기간 결정에 가장 큰 영향을 미치는 것으로 나타났고, 특히 월류시의 복구비용이 작을수록 낮은 설계 재현빈도를 선택하는 것이 타당한 것으로 나타났다. 예를 들어, 유수전환시설의 사용기간이 3 ~ 5년, 복구비용이 0.5 ~ 1.0 mil USD 이하인 조건에서 가물막이시설의 최적 설계빈도는 1년 ~ 2년인 것으로 나타났다. 또한, 유수전환시설의 사용기간은 본댐의 규모와 시공기간 등을 고려하여 결정되는 사항으로 설계자가 임의 조정할 수 없지만, 복구비용은 시공 관리자에 따라 결정되는 부분으로, 적극적 홍수 피해 저감 및 복구방안을 마련하는 것이 프로젝트의 경제성을 향상시킬 수 있다는 것을 알 수 있었다. 두 번째로 프로젝트의 경제성 향상, 홍수기 댐 시공시의 안전성 확보를 위하여 홍수 조기경보시스템(Early Warning System)을 개발 및 활용하였다. 수로식(Run-of-river) 수력발전댐은 대부분 산악지역에 위치하기 때문에 국지성 강우 및 급한 지형 경사로 인하여 돌발홍수(flash flood)의 발생 가능성이 높다. 따라서 시공 중 홍수(월류) 발생을 미리 감지하고 현장에 전파할 수 있는, 수로식(Run-of-river) 수력발전댐 현장을 위한 홍수 조기경보시스템이 필요하며, 이를 리스크 인식, 모니터링 및 경보, 전파 및 연락, 반응 능력 향상의 4가지 부분으로 나누어 구축하였다. 리스크 인식 부분에서는 가물막이댐 월류 발생 상황에 대한 위험도, 취약성, 리스크를 제시하였으며, 모니터링 및 경보 부분에서는 상류 측정수위에서 유도된 현장 예상수위와 실제 현장 측정 수위를 대상으로 경보홍수위와 위험홍수위로 나누어 관리하였다. 전파 및 연락 부분에서는 현장 시공 조직을 활용하여 홍수시를 대비한 비상연락체계도(Emergency communication flow chart)를 운영하였으며, 반응 능력 향상을 위해 비상연락체계도의 팀별 Action plan을 상세화 하였다. 세 번째로 현장의 지질특성과 50여 차례 발파시험으로 현장 고유의 발파진동감쇄곡선을 도출하였으며, 이를 통해 현장의 시공성과 콘크리트 품질 확보를 동시에 달성할 수 있는 방안을 제시하였다. 콘크리트댐 공사에서는 제한된 공기 내에 공사를 완료하기 위해 사면부 굴착과 콘크리트 타설이 동시에 수행될 수밖에 없는 문제점을 가지고 있다. 그러나 신규 콘크리트 타설면 근처에서 발파를 수행하는 경우 발파로 발생되는 탄성파가 일정 수준을 초과하게 되면, 콘크리트 양생에 영향을 주게 된다. 따라서 다수의 현장 발파시험을 통해 발파거리와 최대진동속도의 상관관계 즉, 발파진동감쇄곡선을 도출함으로써 현장의 발파진동특성을 도출할 수 있었다. 또한, 기존 연구 논문들을 통해 콘크리트 재령기간 별 안전진동속도를 선정하고, 해당 안전진동속도를 초과하지 않는 범위에서 콘크리트 타설면과 발파위치의 거리에 따라 1회 발파 가능한 장약량을 산정하여 적용하였다. 이와 같은 체계적인 접근을 통해 콘크리트 타설과 발파 작업 동시 수행에 대한 논란을 해소할 수 있었다.

• Korean Journal of Remote Sensing
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• v.40 no.1
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• pp.19-31
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• 2024

Ports are vital social infrastructures that significantly influence both people's lives and a country's economy. In South Korea, the aging of port infrastructure combined with the increased frequency of various natural disasters underscores the necessity of displacement monitoring for safety management of the port. In this study, the time-series displacements of Yeongilman Port and surrounding areas in Pohang, South Korea, were measured by applying Permanent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR) to Sentinel-1 SAR images collected from the satellite's ascending (February 2017-July 2023) and descending (February 2017-December 2021) nodes, and the displacement associated with the 2017 Pohang earthquake in the port was analyzed. The southern (except the southernmost) and central parts of Yeongilman Port showed large displacements attributed to construction activities for about 10 months at the beginning of the observation period, and the coseismic displacement caused by the Pohang earthquake was up to 1.6 cm of the westward horizontal motion and 0.5 cm of subsidence. However, little coseismic displacement was observed in the southernmost part of the port, where reclamation was completed last, and in the northern part of the oldest port. This represents that the weaker the consolidation of the reclaimed soil in the port, the more vulnerable it is to earthquakes, and that if the soil is very weakly consolidated due to ongoing reclamation, it would not be significantly affected by earthquakes. Summer subsidence and winter uplift of about 1 cm have been repeatedly observed every year in the entire area of Yeongilman Port, which is attributed to volume changes in the reclaimed soil due to temperature changes. The ground of the 1st and 2nd General Industrial Complexes adjacent to Yeongilman Port subsided during the observation period, and the rate of subsidence was faster in the 1st Industrial Complex. The 1st Industrial Complex was observed to have a westward horizontal displacement of 3 mm and a subsidence of 6 mm as the coseismic displacement of the Pohang earthquake, while the 2nd Industrial Complex was analyzed to have been little affected by the earthquake. The results of this study allowed us to identify the time-series displacement characteristics of Yeongilman Port and understand the impact of earthquakes on the stability of a port built by coastal reclamation.

• The Korean Journal of Ecology
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• v.28 no.5
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• pp.335-345
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• 2005

A study on changes on the distribution of vascular hydrophytes and the growth pattern of Schenoplectus triqueter (Scirpus triqueter) was undertaken at the Nakdong River estuary from 2002 to 2004. The change was due to physical alteration of the estuary for the past 25 years. These plant species are the major food sources for winter waterfowl. A total of 32 species of vascular hydrophytes from 17 families were found in the West Nakdong River (freshwater), the main channel of Nakdong River (freshwater) and the Nakdong River Estuary (brackish water). After the construction of the barrage on the estuary in 1987, the number of hydrophytes has remarkably increased to 17 species (5 species in 1985) in the main channel of the River. In particular, a community of Eurale ferox was found at the backwater wetland of the Daejeo side of the main channel. The introduced species of Eichhornia crassipes and Pistia stratiotes that were epidemic in 2001 at West Nakdong River was not found any more. The other species such as Nymphoides indica, Myriophyllum spicatum, Ruppia spp. were rediscovered. The large area (about 1,300ha) of Zostera spp. was the main sources of food for swans, but disappeared because of direct and indirect impacts of reclamation in the River estuary. Currently, there remains a small patch of Zostera spp. and about 250ha of S. triqueter. Schenoplectus triqueter grew mostly between April-September and tuber formed, between September-October. The growth of S. triqueter up to $60\sim80cm$ in length was observed in 5 sites out of the 7 sites in brackish area. Tubers of S. triqueter were eaten by waterfowls such as swans as winter food. In five sites, tubers took $44\sim57%$ of total biomass in October. Tubers were found in deep layers; $5\sim15cm$ (9%), $15\sim25cm$ (28%), $25\sim40cm$ (55%), below 40cm $(6\sim7%)$. The distribution of vascular hydrophytes has remarkably changed in the Nakdong River Estuary due to the reclamation of the area. In order to determine the extent of changes of the distribution of these plants and the carrying capacity of the area for waterfowl, an intensive research is urgently needed.

• Korean Journal of Heritage: History & Science
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• v.52 no.3
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• pp.172-187
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• 2019

Knowledge of intangible cultural heritage is usually disseminated through word-of-mouth and actions rather than written records. Thus, people assemble to teach others about it and form communities. Accordingly, to understand and spread information about intangible cultural heritage properly, it is necessary to understand not only their attributes but also a community's relational characteristics. Community members include specialized transmitters who work under the auspices of institutions, and general transmitters who enjoy intangible cultural heritage in their daily lives. They converse about intangible cultural heritage in close relationships. However, to date, research has focused only on professionals. Thus, this study focused on the roles of general transmitters of intangible cultural heritage information by investigating intangible cultural heritage communities centering around Jeongseon Arirang; a social network analysis was performed. Regarding the research objectives presented in the introduction, the main findings of the study are summarized as follows. First, there were 197 links between 74 members of the Jeongseon Arirang Transmission Community. One individual had connections with 2.7 persons on average, and all were connected through two steps in the community. However, the density and the clustering coefficient were low, 0.036 and 0.32, respectively; therefore, the cohesiveness of this community was low, and the relationships between the members were not strong. Second, 'Young-ran Yu', 'Nam-gi Kim' and 'Gil-ja Kim' were found to be the prominent figures of the Jeongseon Arirang Transmission Community, and the central structure of the network was concentrated around these three individuals. Being located in the central structure of the network indicates that a person is popular and ranked high. Also, it means that a person has an advantage in terms of the speed and quantity of the acquisition of information and resources, and is in a relatively superior position in terms of bargaining power. Third, to understand the replaceability of the roles of Young-ran Yu, Nam-gi Kim, and Gil-ja Kim, who were found to be the major figures through an analysis of the central structure, structural equivalence was profiled. The results of the analysis showed that the positions and roles of Young-ran Yu, Nam-gi Kim, and Gil-ja Kim were unrivaled and irreplaceable in the Jeongseon Arirang Transmission Community. However, considering that these three members were in their 60s and 70s, it seemed that it would be necessary to prepare measures for the smooth maintenance and operation of the community. Fourth, to examine the subgroup hidden in the network of the Jeongseon Arirang Transmission Community, an analysis of communities was conducted. A community refers to a subgroup clearly differentiated based on modularity. The results of the analysis identified the existence of four communities. Furthermore, the results of an analysis of the central structure showed that the communities were formed and centered around Young-ran Yu, Hyung-jo Kim, Nam-gi Kim, and Gil-ja Kim. Most of the transmission TAs recommended by those members, students who completed a course, transmission scholarship holders, and the general members taught in the transmission classes of the Jeongseon Arirang Preservation Society were included as members of the communities. Through these findings, it was discovered that it is possible to maintain the transmission genealogy, making an exchange with the general members by employing the present method for the transmission of Jeongseon Arirang, the joint transmission method. It is worth paying attention to the joint transmission method as it overcomes the demerits of the existing closed one-on-one apprentice method and provides members with an opportunity to learn their masters' various singing styles. This study is significant for the following reasons: First, by collecting and examining data using a social network analysis method, this study analyzed phenomena that had been difficult to investigate using existing statistical analyses. Second, by adopting a different approach to the previous method in which the genealogy was understood, looking at oral data, this study analyzed the structures of the transmitters' relationships with objective and quantitative data. Third, this study visualized and presented the abstract structures of the relationships among the transmitters of intangible cultural heritage information on a 2D spring map. The results of this study can be utilized as a baseline for the development of community-centered policies for the protection of intangible cultural heritage specified in the UNESCO Convention for the Safeguarding of Intangible Cultural Heritage. To achieve this, it would be necessary to supplement this study through case studies and follow-up studies on more aspects in the future.