• The Korean Journal of Quaternary Research
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• v.19 no.2
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• pp.68-69
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• 2005

• Journal of the Korean Geotechnical Society
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• v.37 no.11
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• pp.93-105
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• 2021

In this study, we evaluated the effect of soil fine contents on the formation of underground cavities and ground cave-ins induced by damaged sewer pipes. Simulating the domestic rainfall conditions and ground conditions, model tests were performed under three different fine particle contents conditions (7.5%, 15%, and 25%). By repeating the groundwater supply and drainage twice, ground settlement and the amount of discharged soil were obtained. Also, digital images were taken at regular time intervals during the model tests, and internal displacement and deformation were measured using PIV technique. As the cycles were repeated, the soil with high fine content showed greater resistance to the formation of underground cavities. The ground cave-ins, identified by the collapse of the surface, occurred only when the fine particle content was 15%. It is presumed to be due to the suffusion phenomenon; further study was needed to investigate the effect of fine particle contents on the suffusion phenomenon and associated changes of soil strength.

• Korean Journal of Heritage: History & Science
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• v.33
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• pp.182-208
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• 2000

Kwan-gyongdo is a pictorial presentation of a $s{\bar{u}}tra$ that teaches the Buddhist way for a person to be reincarnated in the paradise of $Amit{\bar{a}}bha$ Buddha. It consists of a preface (Kwan-gyong sobun pyonsangdo) and 16 scenes of $S{\bar{a}}kyamuni$ preaching. The preface, a painting illustrating the motivation behind the production of tile kwan-gyongdo, illustrates the "Legend of King $Aj{\bar{a}}tasatru$", a tragic story in which the prince of India's Magadha kingdom murders his father, the king, to usurp the throne. The 16 subsequent scenes show $S{\bar{a}}kyamuni$ teaching the distressed queen how a person can be reborn in paradise through meditation and praying. In the kwan-gyongdo in the Mogao Cave No. 17 in Dunhuang, China, painted during the Tang dynasty (618-907), the preface and the 16 scenes are presented in one painting, whereas they are presented in two paintings in those painted in Korea during the Koryo period (918-1392). The difference is attributed to the stylistic disparity of the two periods. Despite the temporal gap between the Koryo paintings and the Mogao Cave paintings, a comparison of the two can show the characteristic development of kwan-gyongdo. Kwan-gyongdo of the Koryo period do not have the "enmity created in the previous life" scene featuring a heavenly figure and a hare, a result that shows the influence of the Tang school that deleted the scene. The scene of $S{\bar{a}}kyamuni$ preaching on the Mountain of Spirit is included in kwan-gyongdo of both the Koryo period and the Mogao Cave, but the scene of $S{\bar{a}}kyamuni$ emerging from the earth to the Magadha palace is not included in Koryo kwan-gyongdo. Kwan-gyongdo of Koryo are generally a simpler but more faithful rendering of the $s{\bar{u}}tra$.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1338-1348
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• 2019

The Geomunoreum Lava Tube System, declared as a UNESCO World Heritage Site, has a unique natural ecosystem. The information available about this ecosystem, which contains lava caves with secondary carbonate speleothems, is sparse. Hence, extensive research is warranted for establishing a conservation standard. We commenced microbial research on the system and have been studying the microorganisms coating the lava tube wall to acquire fundamental information for understanding the lava cave ecology of Jeju Island. Samples were collected from yellow-colored walls in six caves that are part of the system-the Bengdwi, Utsanjeon, Bukoreum, Manjang, Gimnyeong, and Yongcheon caves. This study focused on yellow walls as it is the most easily distinguished color. According to previous studies, the color of cave walls is attributed to microorganisms or their components. To determine whether the yellow mats from the Jeju lava tube walls are caused by microorganisms, we examined samples at the microscopic scale, by staining mats and analyzing bacterial isolates from glitter particles. As a result, we found that the yellow walls of lava tubes are comprised of microbial mats.

• Journal of Ecology and Environment
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• v.38 no.1
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• pp.85-93
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• 2015

In 2013, the epidemics of pine wilt disease caused by the pine wood nematodes (Bursaphelenchus xylophilus) resulted in damages to the forests of black pine (Pinus thunbergii Parl.) trees in Jeju Island, Korea. Among the affected trees, an old black pine tree at Cave Temple on Mt. Sanbangsan was included and died due to the prevalence of pine wilt disease. The tree was on Mt. Sanbangsan, which was designated as a National Scenic Place with the Number 77 and was believed to be more than 400 years old in age. By examining the disc of the tree stem obtained from the height of 2 m, we counted the tree rings from 4 different directions and cross-dated the readings by comparing the records of drought simulated from the BROOK Model. Our analysis indicates that the tree seems to have grown since late 1860s. Contrary to the belief of the general public, we can conclude that the age of the tree was estimated to be at maximum 150 years, which means that it was not the same old tree as was shown in the painting of the Tam-Ra-Sun-Ryeok-Do (an old painting book for the Inspection Tour of Jeju Island) published in 1702. Discussion was extended to the life history of the tree in growth and leaning and the measures to protect the tree species from the damages of the pine wilt disease caused by pine wood nematodes.

• Journal of Digital Convergence
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• v.19 no.11
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• pp.463-470
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• 2021

Due to natural and human factors, dunhuang frescoes in China have gradually degenerated. China has conducted digital transformation of frescoes since 1990. However, it requires expensive research costs. Most of the visitors passively accept transformation contents and lack subjective participation. The paper focuses on produces a prototype of Dunhuang frescoes on the CoSpaces EDU. It was implemented as a metaverse through procedures such as transforming the cave into 3D, mapping images to the cave model and developing CoBlocks. The research puts forward a more specific methodology without expensive costs of development. The paper makes it easier to realize the immersive and interactive virtual Dunhuang frescoes world, to improve the tourism contents and educational effect. This research carries on the statistics to the product result which develops according to the user experience of 100 different ages, has obtained the good feedback. The research results need to be improved is to strengthen the processing of graphic details. Therefore, Optimization and improvement of the result will be carried out in the future research.

• Journal of the Speleological Society of Korea
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• no.63
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• pp.21-43
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• 2004

In this study, I would like to review how our ancestors understood and used caves for which purposes, and also to research the good use of caves as residential area, myths and tales, proverbs and civilian religions through folk customs' approach to caves. in pre-historic age, I understood that the caves was used for residential area and for food life by various archeological data. I could review the meaning of caves through Dangoon myth and deeply comprehend the caves, as every cave has it's own tales related with mysterious world. Caves are spotlighting as proverbs related with unknown world, and the caves as prayer place and mental training place, and also as foods warehouse, military facility, and play space I.E sightseeing place from a viewpoint of modern living folk customs.

• Journal of the Speleological Society of Korea
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• no.67
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• pp.53-63
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• 2005

This study is basic research to present the activation of cave tourism. So first of all for establishing of this study, we examined the distribution characteristics of natural caves and monument caves. The results of this study are as follows; First, monument caves concentrate upon Gangwon-do and Jeju-do. Second, open caves concentrate upon Gangwon-do and Chungcheongbuk-do. Third, typical linkage characteristics of tourism resources surrounding open caves are very high in natural tourism resources. Fourth, It is necessary to develop tourism route though the linkage with other tourism resources. But this study have been partial and fragmentary. in order to increase the number of tourists, we should make them curious about the specific region by presenting the unique characteristics of the region, for example its cultural, social, recreational etc. in other words, in order to attract the tourists open caves should differentiate from other open caves.

• Journal of Korean Neurosurgical Society
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• v.29 no.10
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• pp.1345-1351
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• 2000

Objective : Around the sellar area, there are many important structures. But, the optimal radiation dosage for minimal toxicity to surrounding neural tissue has not been firmly established. The purpose of this study is to evaluate the radiosurgical outcome of juxtasellar tumors and to investigate the relationship between radiation dosage and toxicity to neural tissue. Method : Between May 1992 and June 2000, we treated 65 juxtasellar tumors by using the Leksell Gamma Knife. Among them, 52 patients who could be followed more than 1 year were included in this study. The radiosurgical dosage to the optic pathway, cavernous sinus, Meckel's cave, hypothalamus, pituitary gland and stalk, and brain stem was analyzed and correlated with clinical outcome. The mean follow-up period was 33.5 months(range 12.2- 99.0 months). Result : The clinical response rate was 69.2%. The volume response rate was 61.0% and the radiologic control rate was 92.7%. There were 4 complications(7.7%) of 2 trigeminal neuropathy, 1 abducens nerve palsy, and 1 trigeminal and transient abducens nerve palsy. The optic apparatus appeared to tolerate doses greater than 10Gy. The risk of cranial nerve complications in cavernous sinus seemed to be related to doses of more than 16Gy. In 3 of 4 patients who received more than 16Gy to cavernous sinus, the abducens or trigeminal neuropathy occurred. Also, one patient who received more than 15Gy to the Meckel's cave, trigeminal neuropathy developed. The hypothalamus, pituitary gland and stalk, and brain stem were relatively tolerable to radiation. Conclusion : Gamma Knife radiosurgery seems to be an effective method to control the growth of juxtasellar tumors. To avoid injury to surrounding important neural tissue, careful dose planning and further study for radiation toxicity to neural tissue were needed.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.593-600
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• 2000

Most of ground investigations can be grasped geological distribution which like rock name, geological structure, soil condition, underwater condition, land slide, ground cave-in, ground collapse by geological survey. But geological survey is limited to part region geological structure, not wide region. Therefore, Image Processing Method must need to grasp wide region geological structure. The object of this research is presented analysis data of geotechnical engineering in first step investigation.