• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.10
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• pp.1011-1017
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• 2012

We report the development of an optical micro-nanolithography method by using a roll-type mask. It includes phase-shift lithography and photolithography for realizing various target dimensions. For sub-wavelength resolution, a structure is achieved using the near-field exposure of a photoresist through a cylindrical phase-mask, allowing high-throughput continuous patterning. By using a film-type metal mask, continuous photolithography was achieved, and this method could be used to control the period of resultant patterns in real time by changing the rotating speed of the cylinder mask. As an application, we present the fabrication of a transparent electrode in the form of a metallic mesh by using the developed roll-type photolithography process. As a result, a transparent conductor with good properties was achieved by using a recently built cylindrical phase-shift lithography prototype, which was designed for patterning on 100-mm2 substrates.

• International Journal of Naval Architecture and Ocean Engineering
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• v.5 no.3
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• pp.333-347
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• 2013

The present study numerically models the interaction between a regular wave and the roll motion of a rectangular floating structure. In order to simulate two-dimensional incompressible viscous two-phase flow in a numerical wave tank with the rectangular floating structure, the present study used the volume of fluid method based on the finite volume method. The sliding mesh technique is adopted to handle the motion of the rectangular floating structure induced by fluid-structure interaction. The effect of the wave period on the flow, roll motion and forces acting on the structure is examined by considering three different wave periods. The time variations of the wave height and the roll motion of the rectangular structure are in good agreement with experimental results for all wave periods. The present response amplitude operator is in good agreement with experimental results with the linear potential theory. The present numerical results effectively represent the entire process of vortex generation and evolution described by the experimental results. The longer wave period showed a different mechanism of the vortex evolution near each bottom corner of the structure compared to cases of shorter wave periods. In addition, the x-directional and z-directional forces acting on the structure are analyzed.

• Korean journal of food and cookery science
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• v.27 no.5
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• pp.507-522
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• 2011

In this study, samples of wheat flour and dough were prepared by adding of 1, 3, or 5% branched dextrin, which is produced from the amylopectin of waxy corn starch using a cyclization reaction with a branching enzyme. The samples were then evaluated qualitatively in terms of farinogram, viscogram, and extensogram characteristics. The fermentation power of dough expansion, extensogram characteristics, specific volume, baking loss, external/internal surface appearance, and sensory qualities were also examined after 4 weeks of storage at -20$^{\circ}C$ to determine the effect on freeze-thaw stability and quality improvement of branched dextrins in the soft roll bread formulation. Furthermore, the samples along with a control were compared regarding their quality characteristics, including changes in moisture content, water activity, color, and textural characteristics during a storage period of 4 days at 20$^{\circ}C$ to determine the effect on preventing retrogradation of the branched dextrin. As the branched dextrin content increased, area and extensibility increased, whereas water absorption, fermentation power of dough expansion, resistance/extensibility ratio, baking loss, and brownness of the crust decreased. However, the control group presented significantly higher peak viscosity, resistance, specific volume, taste, overall acceptability, moisture content, water activity, springiness, cohesiveness, and resilience values than those of the branched dextrin samples, whereas lightness, hardness, and chewiness showed the reverse effect. As the storage period increased, lightness, hardness, and chewiness increased, whereas cohesiveness decreased. In conclusion, the results indicate that adding 1~3% branched dextrin into a soft roll bread formulation from frozen dough had no positive effect on freeze-thaw stability or preventing retrogradation but may provide good nutritional properties.

• Journal of Navigation and Port Research
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• v.28 no.5
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• pp.353-358
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• 2004

A transient irregular wave was designed based on ISSC spectrum The designed wave was generated in the towing tank and ,the roll motion of a model was measured A method to predict the maximum roll motion, expected in the short-term sea state, was investigated with comparison of the theoretical and experimental results.

• Journal of Ship and Ocean Technology
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• v.7 no.1
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• pp.19-28
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• 2003

The systematic results of anti-rolling tanks tests obtained by bench tester and roll test in towing tank have been examined. The effects on the oscillating period of fluid transfer through the duct of U-tube tank due to damper plates and the effects on roll damping moment of the tank due to swash plates are alto evaluated from the results. A simple control algorithm for a forced fluid transfer in U-tube tanks if devised to active operation of the tank by air blower. The active performances of the tank are confirmed very effective through the tank tests carried out in the irregular waves.

• Journal of Ship and Ocean Technology
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• v.7 no.1
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• pp.29-35
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• 2003

Intensive experimental investigation has been conducted on the characteristics of model tank with intruded flow. The remaining flow inside tank contribute to the dynamic behavior and further closely related to the stability of vessel as well. To understand the importance of the trapped flow and its dynamic effects a series of systematic tests were conducted using a bench tester that could generate periodic roll motion and also complex motions of combined roll-heave-sway. To accommodate experimental conditions and to create three degree freedom of motions, a bench tester was fabricated and verified. Having similarities in terms of flow trapped inside tank, theoretical approaches for A.R.T. were applied to the study. The major parameters including roll angle, period and flow height were varied in the experiments to obtain the characteristics of model tank.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.05a
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• pp.70-75
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• 2001

Intensive experimental investigations were carried out to provide information of the effects of inflow on the rolling characteristics and stability of ships, which becomes great concern in relation to ship's capsizing. A series of systematic experiments have been performed considering the effects cf combined motion of roll-heave-sway and relevant parameters, such as roll angle and period, tank water height etc. To accommodate this type of experiments with 3-degree of freedom of motion, a bench tester has been developed and verified using existing data. Also, theoretical application of anti-roll tank has been incorporated to support the process of investigation. A model of Ro-Ro ships is used in the present study as this type of vessels, as well as fishing vessels, with large open decks, can loose stability rapidly when there is inflow on the decks.

• Journal of Ocean Engineering and Technology
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• v.24 no.3
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• pp.64-71
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• 2010

This paper summarizes the development of an ART control system panel with a touch screen and sensors to measure the roll and roll rate of ships. The control system hardware consists of two micro-processors, analog and digital I/O circuits, various relay circuits, etc. Sensor fusion and moving cross algorithms are implemented to accurately estimate the roll angle and roll period. In addition, the control system adopts a fault detection algorithm to inform users of ART system faults. A touch screen in the control panel can display the ART system states and faults. The performance of the developed system was verified on real sea trials.

• Journal of Ship and Ocean Technology
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• v.9 no.2
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• pp.21-28
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• 2005

Recently moored offshore vessels like as FPSO(Floating Production Storage Offloading) are frequently deployed in seas for a long time. For successful operation, the motion behavior of such a vessel in waves must be clarified in advance either theoretically or experimentally. It is of particular interest to examine the behavior, when swells are superposed to seas with different incident angle. Such a situation is actually reported in some offshore oilfield. In this paper, the motion of a FPSO in irregular waves including swells is studied in time domain. Hydrodynamic coefficients and wave forces are calculated in frequency domain using three-dimensional singularity distribution method. Time memory function and added mass at infinite frequency are derived by Fourier transform utilizing hydrodynamic damping coefficients. In the process, the numerical accuracy of added mass at infinite frequency is carefully examined in association with free decay simulations. It is found from numerical simulations that swells significantly affect the vertical motion of FPSO mainly because of their longer period compared to the ordinary sea waves. In particular, the roll motion is largely amplified because the dominant period of swell is closer to the roll natural period than that of seas.

• Journal of the Korean Vacuum Society
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• v.10 no.2
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• pp.145-154
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• 2001

A new type of modular mirror manipulator with independent adjustability was developed for the EPU6 beamline under construction at the Pohang Accelerator Laboratory. The mirror manipulator was designed so that the angular displacements of roll and pitch rotations do not introduce translational displacements and are independent with each other by positioning the mirror center to the center of a newly devised spherical joint. Manipulating its roll and pitch micrometers, the rotation angles of a dummy mirror were measured at an accuracy of 5 $\mu$rad using a gravity-referenced inclinometer. While the designed angular resolution was 3.937 $\mu$rad/$\mu\textrm{m}$, measured angular resolutions were 3.94 $\mu$rad/$\mu\textrm{m}$ for roll rotation and 3.85 $\mu$rad/$\mu\textrm{m}$ for pitch rotation. The effect of roll rotation on pitch angles was measured to be -3.18% and the effect of pitch rotation on roll angles was measured to be -5.21%. As the mirror manipulator was designed with emphases on independent adjustability and standardization, it results in eases of manufacturing, installation and adjustment as well as reductions of development period and design cost of mirror manipulators for various types of mirrors.