• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.3
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• pp.252-259
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• 2008

The deep-sea mining system is generally composed of surface vessel, lifting system, buffer, flexible pipe and miner. The mining system can be regarded as a large-scale system in which each subsystem is interconnected to other ones. In order to control a large-scale system, decentralized control approaches have been proposed recently. In this paper, as a basic study on application of decentralized control, firstly, the mining system was modeled in a simplified way. Lifting system and buffer were regarded as a spherical pendulum and the flexible pipe was taken as a two-dimensional linear spring connection. Based on the simplified model dynamics, the mining system can be decentralized two subsystems, the one consisting of surface vessel, lifting system and buffer, and the other, the miner. Next, this paper proposed the design of controller for each decentralized subsystem by regarding the interacting terms as disturbances. The controllers kept the constant distance between two subsystems during the miner was moving on the specified track. Finally, the efficiency of proposed controller was proven through the numerical simulation of the derived model.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2002.02a
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• pp.215-218
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• 2002

HTS motors and generators have some advantages over LTS machines because of higher operating temperature. Very low temperature nakes LTS machines need higher refrigeration cost and large facilities. However, HTS machines are expected to be comparable with conventional counterparts at smaller machine ratings than LTS generators in terms of efficiency and size. As the operating temperature increases, the magnetic flux density generated by HTS field coils decreases relatively. For example, 1000hp HTS synchronous motor developed in a few years ago has maximum field density of 1.5T. At this point, magnetic material used in conventional machines is able to pass magnetic flux easily with high permeability. In order to investigate the effect, we arranged magnetic core only inside of magnet vessel of a 100hp target machine. By way of FEM analysis, we concluded that the magnetic core can reduce amount of expensive BSCCO conductor so much.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.5
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• pp.520-526
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• 2009

Efficient stowage plan is required for handling large number of containers in a container terminal. Before a ship enters port, most of container terminals prepare a stowage plan based on information received from the shipping company. If this information does not have the accurate information of containers in the vessel, the stowage plan might be often changed or sometimes it becomes useless. In order to avoid this problem, we apply RFID system in the container ship and we propose a framework for communication between ships and terminals using RFID and Web Services technology.

• Journal of the Korea Furniture Society
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• v.18 no.4
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• pp.312-316
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• 2007

A study was conducted to know 99.5% ethyl alcohol penetration depth in radial and longitudinal direction of Castanea crenata. Alcohol penetration depth was found higher in longitudinal direction by about 12.47 times. In both earlywood and latewood, fiber conducted alcohol in higher depth than that of large and small vessel. Penetration depth of alcohol after 15.0 second of penetration in longitudinal direction, there was no significant difference among fiber in sapwood and heartwood, and vessel in sapwood. At the beginning of penetration the speed was high and then gradually decreased.

• Journal of the Korean Society of Safety
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• v.14 no.3
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• pp.40-47
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• 1999

A numerical study on gaseous explosion was carried out to predict the transient pressure behavior with the partial rupture in confined vessels. Equations, assumptions and solutions for central ignition of premixed gases in closed spherical vessels are proposed with various equivalence ratios of gas fuel, as $CH_4$ and $C_3H_8$, vent areas and vent opening pressures. Given vent opening pressure in a vessel, the magnitude of second peak pressure results from the vent areas and burning velocity, varied by equivalence ratio of gas fuel. In a living room of an apartment, the higher second peak pressure than the vent pressure is not appeared due to its large window areas. As vent opening pressure is higher, the larger damage by gaseous explosion is expected and the larger vent area is necessary for relieving the damage. In the same concentration, the gaseous explosion by propane rather than methane shows the larger damage due to its higher adiabatic flame temperature and equivalence ratio.

• 한국연소학회:학술대회논문집
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• 2002.06a
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• pp.95-98
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• 2002

A numerical investigation on the flame propagation and extinction in a micro combustor is described. Previous measurements of $H_2-air$ flame propagation in a submilimeter scale combustor exhibited significance of wall effects on burning velocity and extinction. The heat transfer to wall becomes important not only in the cooling of burnt gases but also during the flame ropagation, which has be by and large ignored in macro scale combustor calculations. In order to take the heat loss into account the combustion calculation, we developed a numerical code with a heat transfer model that was determined empirically from measured data. PISO algorithm was used for differencing of conservation equations. $H_2-air$ reaction was modeled with 10 species - 16 steps. Comparison with measured data showed good agreement in flame propagation speed. Also the pressure decrease after flame extinction was accurately predicted by the model. A further study is desirable for a better quenching model that can predict the quenching location.

• Archives of Reconstructive Microsurgery
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• v.23 no.1
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• pp.33-35
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• 2014

Mondor's disease is an uncommon condition characterized by a palpable, cord-shaped structure, which causes pain when pressed. Its known pathophysiology is thrombophlebitis of the superficial venous system. Although reported repeatedly, its definite cause is unknown and various possible causes have been identified, including surgery, irradiation, infection, malignancy, and trauma. We diagnosed this case to be Mondor's disease of the antecubital venous system, probably due to thermal injury of the proximal tributaries of the basilic or cephalic vein. Risk of thermal injury to the skin flap or the portal site remains a common complication, and as thermal injury to the blood vessel might also be considered, attention must be given when suctioning the area near a large superficial vessel.

• Journal of Navigation and Port Research
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• v.42 no.5
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• pp.317-322
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• 2018

Marine weather information provided for vessels is mainly offered by radio devices such as NAVTEX, Weather Fax., and others. However, the information is too general for large areas, and lacks more detail. So, many seafarers are disinclined to use the information to initiate proper readiness of vessels' safety, avoiding marine accidents such as grounding, hull and cargo damage, but cannot develop an optimal and economical navigation plan, considering the inadequate level of low precision weather information. The purpose of this paper is to develop a strong wind warning system, based on the digital anemometer installed on the bridge. This study analyzed the data on 10-minutes average wind speed, when the vessel's grounding accidents happened in Korean ports. Results reveal that the vessel's strong wind warning algorithm, can estimate the growing of wind speed two-three hours in advance.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05a
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• pp.574-579
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• 1995

Saturated boiling heat transfer experiment in a hemispherical narrow space is conducted using Freon-113 to investigate an additional heat removal capability through a hypothetical gap between lower head and degraded core. The narrow space of 1mm consists of a 124mm diameter heated stainless steel hemisphere and a glass outer vessel. Within the hemispherical narrow space large coalesced bubbles are produced and these bubbles rise in random direction, causing liquid flow in from the opposite side to fill the region. Such flow in random direction makes the flow field in the narrow space very chaotic and thus enhance heat transfer. The heat transfer coefficient is higher at lower angle and at higher heat flux. The present study shows that the liquid from upper region can effectively penetrate into the gap and augment the heat removal capability through tile gap.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.5
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• pp.583-589
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• 2012

This Paper contained Managing the Memory With Virtual Server, building Database for Broadcast and statistics, architecture Can Easily Build up Each Analysis algorism and How to Broadcast Analysis outcome for Inteligent Vessel Navigation Analysis System. Also concrete Algorism and formula for each navigation analysis that we studed(Collision, Patten, Traffic separation, Danger Area So on).