• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.30-35
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• 2004

Several roll motion reduction devices are reviewed and suggested for the application in FPSO. The firstly suggested solution is the shape of the bilge. The next is a bilge keel. The last suggestion is the ART (anti-rolling tank). Typical U-tube type ART is designed for a FPSO and examined extensively by model experiment. The model section was made of transparent acryl. Free decay test, forced oscillation test and wave test were carried out at a two-dimensional wave flume. U-tube type ART is effective only when the natural periods of ART and ship are same. Therefore, the divided U-tube type ART with split plate is suggested for the reduction of the roll motion of a FPSO over the wide range of the roll period.

• Journal of Power System Engineering
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• v.13 no.3
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• pp.59-64
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• 2009

This study presents a new approach to pressure control of a impression cylinder for roll coater which is a kind of face pressure control between blanket roll and impression roll. Roll-to-Roll method for printing is a very useful tool for mass production such as RFID elements, smart sensors and solar cell devices. In this study, a decupling control strategy of the roll coater which is a combination of a cylinder system, a dry system and two pressure regulators with two pneumatic cylinders was discussed. Also, the characteristics of component such as a pressure regulator having a pressure reducing function and the movement of a blanket roll and a impression cylinder were analyzed using the Matlab software. From this results, the techniques of a shock and a vibration reduction were suggested.

• Journal of Navigation and Port Research
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• v.34 no.4
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• pp.271-279
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• 2010

The Mobile Harbor(MH) is a new transportation platform that can load and unload containers to and from very large container ships in the sea. This loading and unloading by crane can be performed with only very small movements of the MH in waves because MH is operated outside of the harbor. For this reason, an anti-rolling tank(ART) and an active mass driving system(AMD) were designed to reduce MH's roll motion, especially at the natural frequency of MH. In the conceptual design stage, it is difficult to confirm the design result of theses anti-rolling devices without modeling and simulation tools. Therefore, the coupled MH and anti-rolling devices' dynamic equations in waves were derived and a simulation program that can analyze the roll reduction performance in various conditions, such as sea state, wave direction, and so on, was developed. The coupled equations are constructed as an eight degrees of freedom (DOF) motion that consists of MH's six DOF dynamics and the ART's and AMD's control variables. In order to conveniently include the ART's and AMD's control dynamics in the time domain, MH's radiated wave force was described by an impulse response function derived by the damping coefficient obtained in the frequency domain, and wave exciting forces such as Froude-Krylov force and diffraction force and nonlinear buoyancy were calculated at every simulation time interval. Finally, the roll reduction performances of the designed anti-rolling devices were successfully assessed in the various loading and wave conditions by using a developed simulation program.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.47 no.3
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• pp.248-256
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• 2011

The inherent efficiency of a ship would be prior to any other quality factors in ship's safety, because lack of it may give rise to a serious sea casuality even if it were a light mistake in operation. And the representative casualty comes from a deficiency of stability and an operating error combined would be capsizing. The Korean offshore large purseiner looks to have a structural weak point with small range of stability in spite of her big initial metacentric height, and have various type of roll reduction devices in order to cover up the defect. The aim of this study is to grasp for the roll reduction characteristics of the purseiner with bilge keel only and a stern keel additionally attached. The results are summarized as follows; The rolling angle of the model ship was increased in accordance with increase of the wave period and height, especially at close to the natural wave period of her, and the trends were more distinguished in the situation of bilge keel only installation than in the stern keel additionally installed. And stern keel has not noticeable effect on the reduction of the roll in the light ship condition, but has a little effect in full load condition.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.4
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• pp.9-14
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• 2004

This paper reports the measurement and analysis of the short channel effects and the punchthrough voltage of SOI-MOSFET with a self-aligned ground plane electrode in the silicon mechanical substrate underneath the buried oxide. When the channel length is reduced below 0.2${\mu}{\textrm}{m}$ it is observed that the threshold voltage roll-off and the subthreshold swing with channel length are reduced and DIBL is improved more significantly in GP-SOI devices than FD-SOI devices. It is also observed from the dependence of threshold voltage with substrate biases that the body factor is a higher in GP-SOI devices than FD-SOI devices. From the measurement results of punchthrough voltage, GP-SOI devices show the higher punchthrough voltages than FD-SOI devices

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1654-1657
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• 2007

We demonstrate that the reduction of quantum efficiency with increasing current density in phosphorescent light emitting diodes (PhOLEDs) is related to the formation of excitons in hole transporting layer based on the analysis of emission spectra and exciton formation zone. By employing dual emitting layerm we could achieve maintaining quantum efficiency at high current density up to $10000\;cd/m^2$ as 13.1% compared to the devices with single emitting layer (S-EML) (${\eta}_{ext}$= 6.9% at $10000\;cd/m^2$).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.727-730
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• 2004

Reduction of a ship's rolling is the most important performance requirement for improving the safety of the crew on board and preventing damage to cargos as well as improving the comfort of the ride. A mass driving anti-rolling system (MD-ARS) might be one candidate of several systems against the ship's rolling. In this paper, three types of MD-ARS, two passive and one active devices, are developed for small ships. After they are installed on the cabin of the small leisure boat, respectively, a series of test is conducted before and after operating them. Through the test, it is confirmed that the roll responses of the ship are pretty well reduced by the system.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.6 s.144
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• pp.666-672
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• 2005

Reduction of a ship's rolling is the most important performance requirement for improving the safety of the crew on board and preventing damage to cargos as well as improving the comfort of the ride. A mass driving anti-rolling system (MO-ARS) might be one candidate of several systems against the ship's rolling. In this paper, three types of MD-ARS, two passive and one active devices, are developed for small ships. After they are installed on the cabin of the small leisure boat, respectively, a series of performance test is conducted before and after operating them. Through the test, it is confirmed that the roll responses of the ship are pretty well reduced by the MO-ARS.