• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.5
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• pp.353-360
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• 2014

The model ice is created at KRISO (Korea Research Institute for Ships and Ocean Engineering) ice basin where model ship is tested to obtain the necessary data in order to design the ice breaking vessels and ocean structures operating in the northern pole sea area. Through the model ship test, ice breaking, clearing, ice-ship and ice-propeller interaction behavior can be obtained. Since mechanical properties of ice plate are required for the model test, some tests are performed to obtain the properties in this paper. First, ultrasonic devide is used to measure the thickness of the model ice plate and the results show the possibility of using ultrasonic method, yet more sophisticated device or special sensors are required to measure the ice thickness completely. And the defection of ice plate is measured using LVDT to compute the characteristic length of ice plate on the fluid, which is used to get the effective Young's modulus of model ice.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.1
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• pp.1-7
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• 2015

The environmental regulations for CO2 emissions from the ship have been established recently, and fuel oil price has been increased continuously. In order to overcome these circumstances, Energy Saving Devices (ESDs) have been developed continuously to reduce the fuel oil consumption and improve the propulsive efficiency. This paper describes the trial performance of PBCF (Propeller Boss Cap Fins), SCHNEEKLUTH duct, Asymmetric rudder bulb and Mewis duct applied to handy-size bulk carriers. As a result, SCHNEEKLUTH duct is more effective than other energy saving devices at the reducing the fuel oil consumption and the improvement of the propulsive efficiency. In addition, it is confirmed that SCHNEEKLUTH duct is really effective in the vibration of the deck house. And the fuel oil consumption can also be reduced through main engine de-rating.

• Journal of Advanced Navigation Technology
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• v.16 no.1
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• pp.1-7
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• 2012

In this research, a single-axis attitude control test bed is developed, and simulation and tests experiments are performed, as a preliminary research of a quad-rotor aerial vehicle development. A single-axis test bed with seesaw configuration is manufactured using two motors and propellers, and the aerodynamic parameters are derived by thrust tests. The response of the system is estimated with Matlab/Simulink, and experiments are performed with attitude control computer and an attitude sensor onboard the test bed. Comparing the results of simulated and tested data, factors of steady-state errors during experiments are found, and performances of used attitude control algorithm and the control computer were verified. In these process, essential preliminary data for attitude control of a quad-rotor unmanned aerial vehicle were acquired.

• Archives of Reconstructive Microsurgery
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• v.25 no.2
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• pp.37-42
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• 2016

Purpose: Soft tissue coverage of the distal leg and ankle region represents a surgical challenge. Beside various local and free flaps, the perforator flap has recently been replaced as a reconstructive choice because of its functional and aesthetic superiority. Although posterior tibial artery perforator flap (PTAPF) has been reported less often than peroneal artery perforator flap, it also provides a reliable surgical option in small to moderate sized defects especially around the medial malleolar region. Materials and Methods: Seven consecutive patients with soft tissue defect in the ankle and foot region were enrolled. After Doppler tracing along the posterior tibial artery, the PTAPF was elevated from the adjacent tissue. The average size of the flap was $28.08{\pm}9.31cm^2$ (range, 14.25 to $37.84cm^2$). The elevated flap was acutely rotated or advanced. Results: Six flaps survived completely but one flap showed partial necrosis because of overprediction of the perforasome. No donor site complications were observed during the follow-up period and all seven patients were satisfied with the final results. Conclusion: For a small to medium-sized defect in the lower leg, we conducted the close-by islanded PTAPF using a single proper adjacent perforator. Considering the weak point of the conventional propeller flap, this technique yields much better aesthetic results as a simple and reliable technique especially for defects of the medial malleolar region.