• Journal of The Korean Astronomical Society
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• v.37 no.5
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• pp.477-482
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• 2004

Shock waves form in the intergalactic space as an ubiquitous consequence of cosmic structure formation. Using N-body/hydrodynamic simulation data of a ACDM universe, we examined the properties of cosmological shock waves including their morphological distribution. Adopting a diffusive shock acceleration model, we then calculated the amount of cosmic ray energy as well as that of gas thermal energy dissipated at the shocks. Finally, the dynamical consequence of those cosmic rays on cluster properties is discussed.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.09a
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• pp.53-58
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• 2000

The KOESWall system that minimizes the horizontal deformation of reinforced wall effectively was developed bt E&S Eng. Co., Ltd. in 1999. Due to its systematical feature i.e. isolated construction method. KOESWall system is able to use as temporary structures more economically without the facing block. In this report, it is shown that the case history of KOESWall as a temporary soil retaining structure and the field measuremnets.

• 한국지구과학회:학술대회논문집
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• 2001.09a
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• pp.37-37
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• 2001

• 한국지구물리탐사학회:학술대회논문집
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• 2009.10a
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• pp.129-129
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• 2009

• 한국지구과학회:학술대회논문집
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• 2006.02a
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• pp.140-142
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• 2006

• 한국지구물리탐사학회:학술대회논문집
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• 2010.10a
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• pp.17-20
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• 2010

• Journal of the Korean Geotechnical Society
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• v.30 no.7
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• pp.41-53
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• 2014

This study examined the magnitude and distribution of the earth pressure on the support system in a jointed rock mass by considering different joint shear strength, rock type, and joint inclination angle. The study particularly focused on the effect of joint cohesive strength for a certain condition. Based on a physical model test (Son and Park, 2014), extended parametric studies were conducted considering rock-structure interactions based on the discrete element method, which can consider the rock and joint characteristics of rock mass. The results showed the earth pressure was strongly affected by the joint cohesive strength as well as the rock type and joint inclination angle. The study indicated that the effect of joint cohesive strength was particularly significant when a rock mass was under the condition of joint sliding. This paper investigates the magnitude of joint cohesive strength to prevent a joint sliding for each different condition. The test results were also compared with Peck's earth pressure, which has been frequently used for soil ground. The comparison indicated that the earth pressure in a jointed rock mass can be significantly different from that in soil ground. This study is expected to provide a better understanding of the earth pressure on the support system in a jointed rock mass.

• Journal of the Korean earth science society
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• v.27 no.2
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• pp.177-187
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• 2006

Due to a lack of reproducibility and visibility of the conventional equipment for westerly wave simulation, it is difficult to have indoor experiments at high school that show the stream of Hadley cell. A modified improvement of the old one improves the problem. The side wall and bottom of the new equipment is made by copper and acrylic resin, respectively, in order to clarify the difference between the water temperature inside and outside of the water tank. The equipment also has a high quality digital record for generating exact analysis of the results. And we also carried out several experiments that relate theoretical and experimental aspection of westerly wave. Temperature Detected Sheet (TDS) in flow visualization unit provides not only visual information of liquid flow, but also clear understanding of the relation between upper and lower wind flow structure. And the liquid stream simulated in indoor experiment using proposed equipment is commensurate with westerly wave in real atmosphere. The efficiency of educational properties of the proposed equipment is verified indirectly by Likert Scales survey of high school teachers.

• Journal of the Korean earth science society
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• v.28 no.7
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• pp.775-788
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• 2007

This study was aimed to understand the structures of preservice secondary school teachers' alternative conceptions on radioactive isotopes in the interior of earth. The structure of their conceptions were analyzed by the suggestions of Niaz (1988) based on the Lakatosian frameworks. The survey was carried out on a group of seventeen students who were major in science education. The research method was open-ended written questionnaire. The results of this study show that students had apparent alternative conceptions. The high temperature and pressure' explanation for radioactive decay in earth's interior had most import effects on their alternative conceptions. It was also intended to survey their conceptional change by our teaching strategies of the philosophy of science in order to construct science concepts.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.41-50
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• 2006

The crustal structure of Korean Peninsula have been investigated by analyzing group velocity dispersion data of surface wave. Cross.correlation of seismic background motions (Campillo and Paul, 2003; Shapiro et al., 2005) has been applied to estimate the short.period Rayleigh. and Love.wave group velocity dispersion characteristics of the region. Standard processing procedures were applied to the cross.correlation, except that signal whitening was used in place of one.bit sampling equalize power in signals from different times. Multiple.filter analysis was used to extract the group velocities from the estimate Green's functions, which were then use to image the spatially varying dispersion at periods between 0.5 and 20 seconds. The tomographic inversion technique used inverted all periods simultaneously to provide a smooth dispersion curve as a function of period in addition to the usual smooth spatial image for a given period. The Gyeongsang Basin in the southeastern part of the peninsula is clearly resolved with lower group velocities.