• Transactions on Electrical and Electronic Materials
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• v.11 no.1
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• pp.33-36
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• 2010

$MgF_2$ is a current material used for optical applications in the ultraviolet and deep ultraviolet range. Process variables for manufacturing $MgF_2$ thin film were established in order to clarify the optimum conditions for the growth of the thin film, dependant upon the process conditions, and then by changing a number of the vapor deposition conditions, substrate temperatures, and heat treatment conditions, the structural and optical characteristics were measured. Then, optimum process variables were thus derived. Nevertheless, modern applications still require improvement in the optical and structural quality of the deposited layers. In the present work, in order to understand the composition and microstructure of $MgF_2$, single layers grown on a slide glass substrate using an Electron beam Evaporator (KV-660), were analyzed and compared. The surface substrate temperature, having an effect on the quality of the thin film, was changed from $200^{\circ}C$ to $350^{\circ}C$ at intervals of $50^{\circ}C$. The heat treatment temperature, which also has an effect on the thin film, was changed from $200^{\circ}C$ to $400^{\circ}C$ at intervals of $50^{\circ}C$. The physical properties of the thin film were investigated at various fabrication conditions, such as the substrate temperature, the heat treatment temperature, and the heat treatment time, by X-ray diffraction, and field emission-scanning electron microscopy.

• Journal of Haehwa Medicine
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• v.18 no.2
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• pp.131-140
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• 2009

The aim of this study is to find out benefits of symptom questionnaire for oriental medical treatments. We analyzed symptom questionnaire of Korean association of abdomen diagnosis and treatment. Conclusions are as below. 1. Appetite, taste and digestion have a deep connection with accumulation and muscular contracture, with which the method of reinforcement and reduction is decided. 2. Feces, urine and, sweat have a deep connection with accumulation and water, with which the method of diaphoresis, emesis and purgation is decided. 3. Thirst and chillness and fever have a deep connection with water poisons and feverish feeling, based on which the cold and heat is classified. 4. we can find out the lesions with departmentalized physical sections of the head and the face, the chest, the abdomen, the articulations, the limbs and the skin. 5. It is possible to select appropriate prescription and assess before & after treatment through the questionnaire.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.776-778
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• 2015

논문에서는 DNN(Deep Neural Network)의 dropout 기법을 이용하여 산란계가 고온 스트레스를 받고 있는지 여부를 닭의 울음소리 정보를 통해 탐지하는 방법을 제안한다. 실험에서는 $21^{\circ}C$ 정상 온도에서 100개의 소리 데이터, $35^{\circ}C$ 고온에서 200개의 소리 데이터를 사용한다. 먼저, DNN의 학습을 위해서 취득한 울음소리에서 54개의 소리 특징 정보를 추출한다. 둘째, CFS(Correlation Feature Selection)을 이용하여, 추출된 특징 중 온도 구분을 위한 중요한 특정 10개를 선택한다. 셋째, 선택된 소리특징을 DNN에 적용하여 온도 환경을 구분하는 시스템이다. DNN의 과적합(over-fitting) 영향을 감소시키고, 성능 향상을 위하여 dropout 비율을 조정하여 실험을 진행하였다. 본 연구에서는 실제 계사에서 수집된 소리 정보를 이용하여 모의실험을 수행한 결과 매우 우수한 성능을 보임을 확인하였다.

• Ocean Systems Engineering
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• v.2 no.1
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• pp.17-31
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• 2012

This study investigated the behavior of a non-isothermal $CO_2$ bubble formed through a leak process from a high-pressure source in a deep sea. Isenthalpic interpretation was employed to predict the state of the bubble just after the leak. Three modes of mass loss from the rising bubble were demonstrated: dissolution induced by mass transfer, condensation by heat transfer and phase separation by pressure decrease. A graphical interpretation of the last mode was provided in the pressure-enthalpy diagram. A threshold pressure (17.12 bar) was identified below which the last mode was no longer present. The second mode was as effective as the first for a bubble formed in deep water, leading to faster mass loss. To the contrary, only the first mode was active for a bubble formed in a shallow region. The third mode was insignificant for all cases.

• Journal of Welding and Joining
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• v.15 no.2
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• pp.54-63
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• 1997

For the purpose of establishing laser welding condition (laser power, welding speed and beam focus) and of evaluating tailored blanks for two kinds of thin steel sheets SPCC and SK5M using in the thin plate structure such as automobile, train, and so on, investigated their $CO^2$ laser weldability under various initial welding conditions. SPCC thin sheet showed good weldability under some welding conditions. But, high carbon steel sheet SK5M needed heat treatment after welding to obtain ductility of the welded joint. And next, tailored blank was tested through deep drawing to evaluate reliability of their obtained laser welding conditions. The forming depths by tailored blank were SPCC+SPCC=22-25mm and SK5M+SK5M=13-25mm.

• Journal of the korean society of oceanography
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• v.38 no.1
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• pp.11-16
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• 2003

The three dimensional structure of thermohaline circulation in a D-plane is investigated using a conceptual two layer model and a scaling argument. In this simple model, the water mass formation region is excluded. The upper layer represents the oceans above the main thermocline. The lower layer represents the deep ocean below the thermocline and is much thicker than the upper layer. In each layer, geostrophy and the linear vorticity balance are assumed. The cross interfacial velocity that compensates for the deep water mass formation balances downward heat diffusion from the top. From the above relations, we can determine the thickness of the upper layer, which is the same as thermocline depth. The results we get is basically the same as that we get for an f-plane ocean or the classical thermocline theory. Mass budget using the velocity scales from the scaling argument shows that western boundary and interior transports are much larger than the net meridional transport. Therefore in the thermohaline circulation, horizontal circulation is much stronger than the vertical circulation occuring on a meridional plane.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1998.10a
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• pp.221-226
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• 1998

The processing conditions for the mass production of platelet WS$_2$ lubricant powder were optimized. The mixture of tungsten and sulfur powders was sealed in a vacuum of 10$^{-3}$ torr and heat-treated at 850$\circ$C for 2 h. The internal pressure of reaction chamber was maintained at certain level by controlling the release valve automatically. The reaction product was the platelet WS$_2$ powder with an average size of 15 $\mu$m. The synthesized WS$_2$ powder was then coated on the wiper-blade of automobiles and the commercial deep-grooved ball bearing using wet and dry coating methods, respectively. High lubricity and wear resistance of wet coated wiper-blade were confirmed by the life test of 70,000 cycles. The life-time of the ball bearing assembled after WS$_2$ coating onto each part increased 50 times compared to the non-coated ball bearing.

• Journal of Power System Engineering
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• v.9 no.3
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• pp.66-70
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• 2005

Structural components for aerospace, electronics and automobile industry are the main applications for magnesium alloys due to their lightweight and high specific strength. The adoption of magnesium alloys in sheet forming processes is still limited, due to their low formability at room temperature caused by the hexagonal crystal structure. In this paper, the authors aim to improve the formability of AZ31 magnesium alloy. For this, experiment and finite element analysis on used warm deep drawing process with a local heating and cooling technique were done. Both die and blank holder were heated at various warm temperature while the punch was kept at room temperature by cooling water.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.1001-1004
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• 2021

Pain is an unpleasant experience for the patient. The recognition and assessment of pain help tailor the treatment to the patient, and they are also challenging in the medical. In this paper, we propose an approach for pain recognition through a deep neural network applied to pre-processed physiological. The proposed approach applies the idea of shortcut connections to concatenate the spatial information of a convolutional neural network and the temporal information of a recurrent neural network. In addition, our proposed approach applies the attention mechanism and achieves competitive performance on the BioVid Heat Pain dataset.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.4
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• pp.470-476
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• 2010

The thermodynamic performance of closed ocean thermal energy conversion (OTEC) cycle with 1 MW gross power was evaluated to obtain the basic data for the optimal design of OTEC. The basic thermodynamic model for OTEC is Rankine cycle and the thermal effluent from power plant was used for the heat source of evaporator. The cycle performance such as efficiency, heat exchanger capacity, etc. was analyzed on the temperature variation of thermal effluent. The saturated pressure of evaporator increased with respect to the increase of thermal effluent temperature, so the cycle efficiency increased and necessary capacity of evaporator and condenser decreased under 1 MW gross power. As the thermal effluent temperature increases about $15^{\circ}C$, the cycle efficiency increased approximately 44%. So, it was revealed that thermal effluent from power plant is important heat source for OTEC plant. Also, if there is an available waste heat, it can be transferred heat to the working fluid form the evaporator through heat exchanger and cycle efficiency will be increased.