• The Journal of the Petrological Society of Korea
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• v.26 no.1
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• pp.83-91
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• 2017

In order to determine the runout range of pyroclastic density currents on Jeju island, lava dome collapse on 8 locations of outer rim of Baekrokdam crater were simulated by TITAN2D numerical simulation program. We set parameters as internal friction angle as $30^{\circ}$ and bed friction angle as $20^{\circ}$ to control velocity of currents occurred by lava dome collapse. Then we set the height and radius of lava dome, initial speed of collapse and simulation times. And we carried out numerical simulations for a total of 96 scenarios. The result shows that the maximum runout distance was 13.4 km in case of lava dome collapse. This study can be used database for manufacturing of hazard map to minimize damages caused by pyroclastic density currents occurred on Jeju island.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1722-1729
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• 2005

In this paper, we used the quadruped walking robot Titan-VIII in order to carry out this simulation of sway compensation trajectory. The attitude angle ${\phi}_r$ and ${\phi}_p$ is obtained from 3-D motion sensor that is attached at the center of robot body and the attitude control carried out at every 10[ms] for stable gait of robot. Duty factor, that is fixed at 0.5. When we change period T into 1.5, 2.0, 3.0[sec] each and moving distance per period is changed into 0.2, 0.3(m), we sim띠ate several walking experiment of robot. and then we analyze the experiment results if there are any difference between the imaginary ZMP and actual ZMP of robot and the stable gait of robot is realized.

• The Journal of the Petrological Society of Korea
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• v.23 no.4
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• pp.351-366
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• 2014

We assumed the situation where an eruption column had been formed by the explosive Plinian eruption from Mt. Baekdu and that the collapse of eruption column had caused pyroclastic density currents to occur. Based on this assumption, we simulated by using a Titan2D model. To find out about the range of the impacts of pyroclastic density currents by volcanic eruption scenarios, we studied the distance for the range of the impacts by VEIs. To compare the results by each volcanic eruption scenario, we set the location of the vent on the 8-direction flank of the outer rim and on the center of the caldera, the internal friction angle of the pyroclastic density currents as $35^{\circ}$, the bed friction angle as $16^{\circ}$. We set the pile height of column collapse and the vent diameter with various VEIs. We properly assumed the height of the column collapse, the diameter of the vent, the initial rates of the column collapse and the simulation period, based on the VEIs, gravity and the volume of the collapsed volcanic ash. According to the comparative analysis of the simulation results based on the increase of the eruption, the higher VEI by the increase of eruption products, the farther the pyroclastic density currents disperse. To the northwest from the vent on the northeast slope of the outer rim of the caldera, the impact range was 3.3 km, 4.6 km, 13.2 km, 24.0 km, 50.2 km, 83.4 km or more from VEI=2 to VEI=7, respectively. Once the database has been fully constructed, it can be used as a very important material in terms of disaster prevention and emergency management, which aim to minimize human and material damages in the vicinity of Mt. Baekdu when its eruption causes the pyroclastic density currents to occur.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.4
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• pp.259-263
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• 2010

We measured and compared the partition coefficients and absorption levels of preservative phenoxyethanol (PE), antimicrobial ethylhexylglycerin (EG) and UV-filters widely used in cosmetic products and more specifically evaluated the relative absorption level of PE depending on various packaging materials. The resulting partition coefficients of 11 UV filters in relation to PE and EG displayed EG with a relatively higher partition coefficients. The partition coefficients of Tinsorb M and Solaveil CT434 were also high. Among the UV-filter ingredients with EG absorption levels exceeding 40 % were Gransil PSQ, UV Titan M 160 and Micro $TiO_2$ MT 100 TV, whereas Gransil PSQ and Scadder showed PE absorption levels above 40 %. In addition, we confirmed that PE had displayed an absorption level of 7 ~ 8 % as a result of 1 month-long exposure to packaging material polyoxymethylene. This extensive research illustrates the possibility of producing the most potent preservative contents based on studying the relative compatibility between UV-filters and preservatives and selecting the adequate preservatives to be used. Furthermore, preservative level can also decline with passage of time depending on the type of packaging material used.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05b
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• pp.103-106
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• 2002

The applicability of models based on fractal morphology to characterize $(Ba\;Sr)TiO_{3}$ thin film surfaces was investigated. The fractal morphology of coated barium strontium titan oxide thin film surfaces was described using fractal dimension from scanning electro microscopy image. The $(Ba\;Sr)TiO_{3}$ coating were deposited on silicon wafers using $(Ba\;Sr)TiO_{3}$ solution and spin coater. BST solution was composited by mol ratio, and then spin-coated from 3 times to 5 times coating on $Pt/SiO_{2}/Si$ substrate. Qualitative thin film analysis was performed with scanning electro microscopy (SEM), and surfaces parameters such as average grain diameter, roughness exponent and fractal dimension were determined.

• The Journal of the Korea Contents Association
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• v.10 no.6
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• pp.222-235
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• 2010

After its remarkable success, "Avatar" brought another way of creating cinematic story; the stereoscopic 3-D cinema. Comparing conventional 2-D filmmaking, you need twice as much of budget and manpower in 3-D filmmaking because of the complicated process and slow production speed. The 3-D hardware like 3-D TV and 3-D projector are already showing at the retail stores while 3-D filmmaking is still in veil, and no major educational institution is yet to start 3-D related education. As 3-D movies get popular and demand more 3-D filmmaking professional crew, educating 3-D filmmaking to 2-D based film students will improve their hiring rate in the market. The successful result of the box office showing 3-D films like "Alice in Wonderland 3D" and "Titan 3D" forecasts that there will be more demand on 3-D related jobs very soon.

• Journal of the Korean earth science society
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• v.34 no.7
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• pp.615-625
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• 2013

Many eruptions of Mt. Baekdusan volcano have been recorded in the historical literatures, and there were unrest precursors in 2002. Based on the geological survey results, it has been recognized that Mt. Baekdusan's Plinian eruptions had caused ashfall, followed by the occurrence of pyroclastic flows, which were caused by the collapse of eruption column. Therefore, we simulated the range of the impacts of pyroclastic flows, which were caused by small eruptions from a specific crater. Based on the simulation results, it can be interpreted that, when the pyroclastic flows are caused by the eruption column collapse from an eruption with less than VEI 3, the impacts will range from the outer rim of the caldera to the mountain slope 7 km at the maximum distance. Furthermore, it is interpreted that, when the eruption column occurs by the crater located inside the caldera, most will be deposited inside the caldera and what overflows will be deposited thickly mostly in the north valley, the upper stream region of Erdaobaihe.