• The Korean Publising Journal, Monthly
• /
• s.382
• /
• pp.34-35
• /
• 2007

• Korean Architects
• /
• s.563
• /
• pp.64-77
• /
• 2016

• Railway Journal
• /
• v.14 no.4
• /
• pp.18-26
• /
• 2011

• Railway Journal
• /
• v.16 no.4
• /
• pp.47-51
• /
• 2013

• Korean Architects
• /
• s.499
• /
• pp.24-29
• /
• 2010

• Railway Journal
• /
• v.18 no.4
• /
• pp.29-34
• /
• 2015

• Clean Technology
• /
• v.19 no.1
• /
• pp.8-12
• /
• 2013

Phase behavior of carbon dioxide + surfactant binary system and carbon dioxide + surfactant + water ternary system was investigated at the temperatures from 318 K to 348 K by using high pressure vapor liquid equilibrium apparatus containing variable-volume view cell. Sorbitan monopalmitate was used as the surfactant. The cloud point pressures for the binary mixture of carbon dioxide + sorbitan monopalmitate increased with an increasing of system temperatures and the maximum cloud point pressure was observed at the composition of 0.226 wt% of sorbitan monopalmitate. On the other hand, as the temperatures and compositions of water increased, the cloud point pressures for ternary system containing 0.1 wt% of sorbitan monopalmitate increased significantly. For the ternary system of constant 0.2 wt% of water, the cloud point pressure curves show relatively flat according to the change of compositions of surfactant. The cloud point pressures increased when the temperatures and compositions of water increased.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.28 no.4
• /
• pp.343-350
• /
• 2015

Extensive discussion on the optimal types of offshore wind turbine(OWT) among monopile, tripod and jacket in the intermediate depth of water has been actively carried out in worldwide wind turbine industry. Selecting the optimal types of OWT among several substructural types, it is required to consider the economic and technical feasibility including dynamically stable design of a wind turbine system. In this study, the effects of loading levels and uncertainties of soil properties on the natural frequency of OWT have been quantitatively investigated. In conclusion, the natural frequency of monopile-type OWTs has a significant level of uncertainty, hence it is very important to minimize the level of uncertainties in soil properties when the monopile is selected as a foundation for an OWT.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.15 no.4
• /
• pp.211-215
• /
• 2015

In this paper, we propose a internal antenna for wirless HDMI dongle device using the folded monopole structure. The proposed antenna is for 2.4GHz and 5.8GHz. The antenna optimized for parameters length, gap, width, and radius of semicircular of monopole antenna using the 'F' structure. To confirm the characteristics of the antenna parameters, HFSS from ANSYS Inc. was used for the analysis. We used an FR4 dielectric substrate with a dielectric constant of 4.4. The HDMI dongle size of the proposed antenna is $45{\times}20{\times}1mm$, and the size of the antenna area is $5{\times}20mm$. There is a value of return loss less then -10dB in 2.4GHz and 5.8GHz, band and the maximum antenna gain is -4.13dBi. The result proved the possibility of the practical using 'F' structure that came frin comparing and analyzing the measured and simulated data of the antenna.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.20 no.2
• /
• pp.84-90
• /
• 2017

In this research, a three-dimensional Computational Fluid Dynamics(CFD), scour characteristics around monopile was grasped and the effect of circular ring type scour protection on reducing protection was assessed. When Torsethaugen(1975) found that the scour area and its depth were coincided quantitatively On the ground of previous findings, after scour was assessed in terms of sea current velocity, we also found that the tendency of maximum scour depth and its width were increased as the sea current velocity was increased. The experiments were performed by attaching ring-circular typed scour protection under the bottom in order to reducing scour around the constructs of monopile type and showed reduced scour approximately by 68.5%. In addition, there were reduction of downward flow and bottom velocities, suggesting that scour protection reduce the effect of downward flow on scour.