• Journal of the Korean Geophysical Society
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• v.8 no.3
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• pp.137-143
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• 2005

Early detection of premonitory symptom of slope movement ensures tremendous saving of lives and repair costs from catastrophic disaster. Therefore, it is essential to constantly monitor the performance and integrity of both reinforced and un-reinforced cut slopes. We developed a novel monitoring system by using tension wire sensors. It's advantages are highly sensitivity, simple installation, large displacement measurement, durability of system, capability of remote sensing. Real-time measurement of slope surface movement is shown graphically and it gives a warning when the monitored value exceeds a given threshold level so that any sign of abnormal slope movement can be easily perceived.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.557-560
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• 2003

Some well-known artificial weathering tests such as freezing-thawing, acid immersion, and salt crystallization are adopted to examine the change of rock properties during the processes of artificial weathering. Granites and other rock types of limestone, marble and basalt collected from different quarries in south Korea were sampled for this study. All tests were performed up to 30 cycles and physical properties were measured after experiencing every ten cycles of artificial weathering tests. During the tests, the variation trends of rock properties were too variable to draw generalized variation patterns but it can be concluded that weathering agents have different effect on rock properties depending on weathering circumstance and time. Even in short terms of salt crystallization tests, some rocks were severely deformed and then burst, and in the early stages of salt weathering, recrystallized salts filling pores and cracks in rocks could be a important factor affecting rock properties.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.103-108
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• 2003

In the construction of mountain tunnels, reaction forces of the legs of steel arch supports against the ground are often expected to support the ground being excavated. In these cases, a stress concentration occurs in the ground directly under the support legs. If the bearing capacity of the ground is insufficient or displacement is not effectively constrained, the local failure of the ground under the support legs or settlement of the tunnel supports due to large deformation could result. It is therefore necessary to reinforce the support legs to reduce settlement. As a means of reducing settlement, wing-ribbed steel arch supports are well used. In this study, with the aim of finding a way to quickly reduce the settlement of steel arch support legs, effectiveness of a new type of wing ribs to reinforce steel arch supports was investigated through laboratory testing.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.362-369
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• 2003

A infiltration experiment of river water has been conducted to evaluate the applicability of electrical resistivity monitoring methods in an area containing gravelly deposits in Nagaoka, Japan. Apparent resistivity data, which are inverted to obtain the resistivity distribution, are measured with a newly developed system. This system can collect 490 data in an hour and be controlled with PC to store the data. Subsurface resistivity sections, which are obtained from two-dimensional nonlinear inversion of time-lapse apparent resistivity data, enable us to estimate the direction of the flow and the rate of infiltration. The infiltration rate is estimated to be $4.4{\times}10^4m/s$ in the early stage of the experiment when the infiltration process is dominant.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.71.3-71.3
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• 2018

Asteroids represent a significant resource for space exploration and scientific research. Various scientific missions have already performed and planned to investigate and understand the characteristics of asteroids. This talk introduces many space missions to asteroids. Representing missions to asteroids are the NASA's NEAR, Deep Space-1, Dawn, OSIRIS-Rex, SCOUT, DART, and ESA's Rosetta, and JAXA's Hayabusa 1 and 2, and DESTINY+ missions, and others. Although it is a very rare event, the possibility of Earth-crossing asteroids (ECAs) colliding with the Earth can never also be ignored. Numerous mitigation concepts also have been proposed to deflect ECAs in preparing for the disasters which might occur in future days. In the early studies for mitigation schemes, most of analyses were centered on to deflect ECAs with impacting the energy to the object to change its orbit. This talk also introduces many methods to deflect the orbit of ECAs, and shows spacecraft trajectories to asteroids.

• Korean Journal of Child Studies
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• v.21 no.1
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• pp.215-234
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• 2000

This study analyzed the aims, contents, and methods of early education in Sohak(小學) a textbook for childhood education in the choson Dynasty. The analysis was based on the 6th Korean National Kindergarten Curriculum(in process) and the theories of education in Sohak. Sohak consists of Establishing the Education Process(入敎), Clarifying the Cardinal Human Relationships(明倫), Reverencing for the Self(敬身), Examining Antiquity(稽古), Admirable Sayings(嘉言), and Exemplary Deeds(善行). The aim of education in Sohak was to preserve Sheng(性), i.e. human nature inherited from heaven. The contents of education in Sohak was divided into 6 groups: distinction by age and sex, health, basic life habits, private life, family life, and group life. Methods of education in Sohak was the consolidation of knowledge and conduct, education of self control, learning of exploration, learning of constructive models, learning of keep the stages and telling stories of the sayings of the saints.

• Asian Journal for Public Opinion Research
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• v.1 no.1
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• pp.42-60
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• 2013

This article introduces the infrastructure of public opinion research in Japan by reviewing the development of polling organizations and the current situation of social surveys. In Japan, the polling infrastructure developed through the direction and encouragement of the U.S. occupation authorities. In the early 1969s, however, survey researchers began to conduct their own original polls in not only domestic but also cross-national contexts. An exploration of recent survey trends reveals that polling organizations tended to conduct more surveys during summer, in the mid-range of sample size (1,000-2,999), based on random sampling (response rates of 40-50%), and through the mail between April 2011 and March 2012. The media was the most active polling sector.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.55.2-55.2
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• 2011

We present the current research activities of the Center for the Exploration of the Origin of the Universe, a center established at Seoul National University with the Creative Research Initiative program. Our activities focus on observational studies of distant objects such as gamma-ray bursts, quasars, and proto-cluster of galaxies, but we also carry out other observational and theoretical studies in related topics. We also developed a new instrument, Camera for Quasars at Early Universe (CQUEAN) in collaboration with Kyunghee University group, and have secured observing facilities such as UKIRT and McDonald 2.1m observatory. Our research highlights include results such as the discovery of high redshift quasars and gamma ray bursts, the discovery of tidal disruption event at z=0.38 and peculiar gamma ray burst events, analysis of proto-clusters of galaxies, the discovery of brown dwarfs, and development of CQUEAN and its usage at the McDonald observatory.

• Journal of Korean Neurosurgical Society
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• v.44 no.5
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• pp.341-344
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• 2008

The authors present a case of 68-year-old woman who underwent resection of a metastatic adenocarcinoma in the left parietooccipital area. The intraoperative course was uneventful; however, after closure of the scalp incision, increased bleeding from the suture line was noted. A computerized tomography scan that was performed immediately after operation revealed acute epidural hemorrhage with mass effect under the bone flap. The patient developed disseminated intravascular coagulation and immediate re-exploration was performed. This patient was successfully treated owing to early recognition of the condition and immediate treatment with transfusion. Neurosurgeons should be alert that hypercoagulabe state is common in cancer patients and consumptive coagulopathy can occur after resection of metastatic brain tumor.

• Clinical and Experimental Pediatrics
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• v.53 no.9
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• pp.852-854
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• 2010

Testicular torsion is rare in newborn infants. However, its frequency has increased, most of which are reported in full-term infants. We diagnosed and treated testicular torsion in an extremely low birth weight infant (ELBWI). A $2{\times}2cm$ red mass was palpable in the left groin of a 24-week-old, 745 g, male newborn at 23 days of age. Left testicular torsion was diagnosed, and emergent orchiopexy was performed. Careful physical examination is needed in cases suspicious of testicular torsion in ELBWIs with cryptorchidism. Moreover, early diagnosis and emergent exploration are necessary to prevent complications such as the risk of anorchia.