• 한국환경농학회지
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• 제41권1호
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• pp.65-70
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• 2022

BACKGROUND: The Geomunoreum Lava Tube System (GLTS) is both vast and culturally valuable. The Jeju Volcanic Island and Lava Tubes, which are partly composed of the GLTS, have been declared as a United Nations Educational, Scientific, and Cultural Organization (UNESCO) World Heritage Site. Exploration of the caves is strictly regulated to conserve these vulnerable environments. Photographs provide limited information and do not describe the entire environment comprehensively. Therefore, we created several illustrations of the lava tubes to display their environmental features. METHODS AND RESULTS: We explored six lava caves (upstream and downstream) in the GLTS and photographed their geological features and yellow walls, the colors of which are influenced by microbial mats. We compared the hex codes of the wall colors using the Clip Studio v1.10.5 software and created illustrations that accurately represent the scale and features of the caves. CONCLUSION(S): Upstream and downstream caves of the GLTS differ in scale and volcanic features. We illustrated various characteristics of the caves including lava cave features, vegetation, and microbial mats. We also described the internal and external cave environments.

• 한국지반공학회논문집
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• 제37권11호
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• pp.93-105
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• 2021

본 연구에서는 매립토의 세립분 함량이 파손된 하수관으로 인해 유발되는 지하 공동 및 지반함몰에 미치는 영향을 평가했다. 국내 강우 조건 및 지반 조건을 모사하였으며, 서로 다른 세 가지 세립분 함량(7.5%, 15%, 25%)을 적용해 지반함몰 모사시험을 수행했다. 모형지반을 조성한 뒤 하수관 손상부를 모사한 부분을 통해 지하수를 유입하고 배출시키는 과정을 두 차례 반복하며, 지표면 침하량 및 배토량을 측정했다. 또한 모형시험 중에 일정 시간 간격으로 디지털 이미지를 촬영하고 이를 PIV 기법을 통해 분석하여 내부 변위 및 변형(지하 공동 형성 과정)을 측정하였다. 시험 결과, 지하수 유입 및 배출 단계가 반복됨에 따라, 세립분 함량이 높을수록 배토량이 적고 지하 공동 형성이 억제되는 것으로 나타났다. 다만, 지표면 붕괴로 확인되는 지반함몰은 세립분 함량이 15%인 경우에만 발생했다. 이는 배토된 흙의 세립분 함량 변화를 통해 서퓨전(suffusion) 현상에 기인한 것으로 분석되어, 세립분 함량이 서퓨전 현상 발현에 미치는 영향과 이에 따른 지반 강도 변화에 대한 추가연구가 필요함을 확인했다.

• Journal of Ecology and Environment
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• 제32권3호
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• pp.191-195
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• 2009

We monitored 38 hibernation sites of Myotis formosus in South Korea and recorded the number of bats occupying each site and assessed the micro-climate at the sites during four winters from 2005 to 2009 at. The mean rock temperature of the bat roosting sites was $13.2{\pm}1.4^{\circ}C$ and the mean body temperature of the hibernating bats was $13.3{\pm}1.3^{\circ}C$. The number of hibernating bats was negatively related to the size of the entrance and positively related to the minimum ambient temperature and humidity in the site interior. More bats hibernated in roosts with smaller entrances and higher minimum ambient temperatures, and more bats selected sites presenting a narrow temperature range. This study showed that the internal environments of hibernacula of M. formosus were highly stable despite dramatic variation in the external environment.

• Journal of Korean Neurosurgical Society
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• 제54권6호
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• pp.477-483
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• 2013

Objective : Although surgical techniques for clipping paraclinoid aneurysms have evolved significantly in recent times, direct microsurgical clipping of large and giant paraclinoid aneurysms remains a formidable surgical challenge. We review here our surgical experiences in direct surgical clipping of large and giant paraclinoid aneurysms, especially in dealing with anterior clinoidectomy, distal dural ring resection, optic canal unroofing, clipping techniques, and surgical complications. Methods : Between September 2001 and February 2012, we directly obliterated ten large and giant paraclinoid aneurysms. In all cases, tailored orbito-zygomatic craniotomies with extradural and/or intradural clinoidectomy were performed. The efficacy of surgical clipping was evaluated with postoperative digital subtraction angiography and computed tomographic angiography. Results : Of the ten cases reported, five each were of ruptured and unruptured aneurysms. Five aneurysms occurred in the carotid cave, two in the superior hypophyseal artery, two in the intracavernous, and one in the posterior wall. The mean diameter of the aneurysms sac was 18.8 mm in the greatest dimension. All large and giant paraclinoid aneurysms were obliterated with direct neck clipping without bypass. With the exception of the one intracavenous aneurysm, all large and giant paraclinoid aneurysms were occluded completely. Conclusion : The key features of successful surgical clipping of large and giant paraclinoid aneurysms include enhancing exposure of proximal neck of aneurysms, establishing proximal control, and completely obliterating aneurysms with minimal manipulation of the optic nerve. Our results suggest that internal carotid artery reconstruction using multiple fenestrated clips without bypass may potentially achieve complete occlusion of large paraclinoid aneurysms.

• 한국위성정보통신학회논문지
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• 제12권3호
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• pp.41-49
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• 2017

본 연구에서는 달의 동굴에 대한 거주환경에 잠재적 요건이 될 수 있는 지질과 지형, 내부탐사, 안정성, 통신, 거주요건 등의 5분야에 대한 분석을 시도 하였다. 달 동굴관련 정성적 정량적인 자료 분석에서 다음과 같은 결과를 도출하였다. 달 동굴의 지질과 지형환경에서는 지구의 용암동굴의 규모와 형상에서 큰 차이를 확인하였다. 달의 지질은 내인적인 분화나 지진 보다 외인적인 환경인 운석의 낙하와 방사선의 공격 및 급격한 온도차에 의한 영향이 크다. 달 동굴의 지형과 내부형상은 중력의 차로 인한 대규모의 위험한 동굴지형으로 함몰구(skylight)와 사행 열구(sinuous rilles)에 대한 접근과 내부 지형형상 취득에 기술적인 한계가 있었다. 달 동굴의 안정성 분석에서는 대형의 동굴에 대한 지질과 지형적인 위험성에 두었다. 함몰에 대한 저 위험도 빈도, 저 중력, 동굴의 대규모와 두께 등의 안정성 인자 등으로 지구보다 상대적인 안정성이 확인되었다. 달 동굴내외의 통신환경은 동굴내부에서의 무선통신 운영의 경우 태양열 충전식에만 한계가 있을 것이나 전력의 무선전송기술로 이를 극복할 수 있을 것이다. 따라서 본 연구를 통하여 달 동굴에 대한 거주 가능성에 대한 학설과 기술의 대비 중에서 학술적이고 기술적인 차별성이 다양하게 확인되었다. 특히 무중력, 우주방사선의 피폭과 먼지 등의 외인적인 한계와 거칠고 급경사인 함몰구 등의 접근기술에 대한 통신과 토목 및 GIS기술 등에 대한 내인적인 한계의 극복의 필요성으로 이에 대한 향후의 연구개발에 기대감이 증폭되었다.

• Applied Microscopy
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• 제16권2호
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• pp.61-74
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• 1986

The anatomy of the renal papilla and pelvis of the bat(Pipistrellus abramus abramus Temminck) and their ultrastructure of the epithelium has been studied by means of light, scanning and transmission electron microscopy. The bats were captured at Ondal cave located in Yangchun-Myun, Tanyang-Kun, Chungchongpuk-Do, Korea in the active(July) and hibernating(January) phases. A conical renal papilla with several papillary foramina at the apex was curved toward the ureter. At the margin of the funnel-shaped renal pelvis, the fornix extended deeply into the kidney parenchyme was formed between the outer zone of the medulla and the cortex. The epithelium of the papilla covered the inner zone of the medulla. The epithelium of the fornix medially overlayed the outer zone of the medulla, and laterally the cortex. The surface epithelium of the papilla was simple columnar in shape with the scanty organelles and the short microvilli on their luminal surface. The fornix was Jined with $1{\sim}2$ cell layered squamous epithelium. On the medial surface of the fornix, two types of the superficial epithelial cells were identified; one had numerous short microvilli and the other had the microplicae and plaques on their luminal surface. The lateral surface of the fornix lined with the epithelial cells showed microridges and plaques on the luminal surface. The epithelial cells on the medial and lateral surfaces of the fornix were similar to their internal ultrastructures. The pelvic epithelium was a typical transitional type, which was composed of a layer of basal cells, one or two layers of intermediate cells, and a layer of superficial(facet) cells. The fusiform vesicles were observed in the cytoplasm of the intermediate and facet cells. There were no noticeable morphological changes in the epithelium of the papilla, fornix and pelvis except the medial epithelium of the fornix in the hibernating cycle. The microvillar cells were more numerous in the hibernating phase than in the active phase. The morphology, of the renal papilla and fornix of bats, indicates that a functional relationship may exist between the pelvic urine and the renal parenchyme.

• Journal of Astronomy and Space Sciences
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• 제33권1호
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• pp.21-28
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• 2016

Caves can serve as major outposts for future human exploration of the Moon and Mars. In addition, caves can protect people and electronic equipment from external hazards such as cosmic ray radiation and meteorites impacts and serve as a shelter. Numerous pit craters have been discovered on the Moon and Mars and are potential entrances to caves; the principal topographic features of pit craters are their visible internal floors and pits with vertical walls. We have devised two topographical models for investigating the relationship between the topographical characteristics and the inner void of pit craters. One of our models is a concave floor void model and the other is a convex floor tube model. For each model, optical photographs have been obtained under conditions similar to those in which optical photographs have been acquired for craters on the Moon and Mars. Brightness profiles were analyzed for determining the profile patterns of the void pit craters. The profile patterns were compared to the brightness profiles of Martian pit craters, because no good-quality images of lunar pit craters were available. In future studies, the model profile patterns will be compared to those of lunar pit craters, and the proposed method will likely become useful for finding lunar caves and consequently for planning lunar bases for manned lunar expeditions.