• Proceedings of the KSLP Conference
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• 1996.11a
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• pp.89-89
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• 1996

정상인 20명을 대상으로 하여, 우리말의 양순 파열음인 /ㅂ, ㅃ, ㅍ/의 발음시, 각각의 음소에서의 구강내압의 크기와 폐쇄기 및 VOT의 길이를 측정하고, 목표 자음이 어두에 나올 때 및 음절 초에 나올 때, 그리고 어음을 보통 소리로 말했을 때와 큰 소리로 말했을 때, 그 세 측정치가 어떻게 변화하는지를 파악하기 위한 실험을 실시하였다 채취된 어음의 구강내압은 발음시 Pressure sensor를 사용함으로써 산출된 파형을 이용하여 측정하였고, 폐쇄기와 VOT는 컴퓨터에 입력된 음성신호를 Spectrogram으로 분석하여 측정하였다. 그 결과, 양순 파열음 중 구강내압은 /ㅍ/＞/ㅃ/＞/ㅂ/의 순이었고, 폐쇄기의 길이는 /ㅃ/＞/ㅍ/＞/ㅂ/, 그리고, VOT의 길이는 /ㅍ/＞/ㅂ/＞/ㅃ/의 순이었다. 양순 파열음이 어두에 올 패보다 음절 초에 올 때 더 큰 구강내압을 보였으며, 폐쇄기의 길이는 더 짧아지는 경향을 보였고, VOT의 길이도 폐쇄기와 마찬가지로 짧아지는 경향을 보였다 그리고, 양순 파열음을 큰 소리로 발음했을 때, 목표 자음의 위치에 상관없이, 구강내압의 크기는 의미 있게 커졌으며, 폐쇄기와 VOT는 짧아지는 경향을 보였다.

• The Korean Journal of Zoology
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• v.35 no.2
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• pp.136-143
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• 1992

돼지 난포의 폐쇄기 작을 규명하고 폐쇄난포의 판정기준을 보완, 확립하기 위하여 난포의 크기 및 상태 그리고 난소주기에 따라 Acid phosphatase(Acpase)의 활성부위와 활성도를 조사하였다. Acpase의 활성부위는 과립세포와 난포막내층이었고, 반응정도는 난포 :극 대난포와 중난포의 경우 정상군에 비해 폐쇄군에서 강한 반응을 보였다. 황체기난포의 과립세포에서는 중난포와 소난포 모두 반응이 미약하였고, 난포막층에서는 정상군과 폐쇄군 모두 강하게 나타났다. Acpase의 활성도는 난포기 난포의 과립세포에서 난포가 커짐에 따라 증가하였는데 난포막층의 활성도는 감소하였으며 , 폐쇄군이 높은 활성도를 보f:다. 황체기의 경우 반포기와는 달리 과립세포와 난포막층에서 난포가 커짐에 따라 활성도는 감소하였으나 폐쇄군은 역시 높았다. 이상의 결과에서 폐쇄난포의 Acpase의 활성부위와 활성도는 정상난포에 비하여 뚜렷하고 강하여서 이 방법은 폐쇄의 판정기준으로 이용 가능한 것으로 사료된다. 또한 난소주기에 따라 상이한 결과를 나타낸 것은 폐쇄기 작이 서로 다름을 시사하였다.

• Economic and Environmental Geology
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• v.52 no.4
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• pp.299-312
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• 2019

This study analyzed variation of tidal channels associated with Shihwa reclamation project for corresponding observation period based on remote sensing approaches. The project period was subdivided to developing period, closed period, and open period based on developing and management plan of Shiwa lake, and number, length, width, and direction of tidal channels for each period were analyzed using CORONA, Landsat 5 TM, Landsat 7 ETM+, and orthorectified aerial photographs. Number of tidal channels decreased from developing to opening period while $3^{rd}$ order channles did not show noticeable changes. The length of tidal channels decreased during developing to closed period, and increasing trend of $2^{nd}$ and $3^{rd}$ order channels was observed for the opening period. The average widtrh of $2^{nd}$ and $3^{rd}$ order channels decreased from developing to closed period, and increased during open period. The direction of tidal channels showed NW and NE direction in general, while the rose diagram showed deacrased frequency of NE direction and increased frequency of NW direction during the open period. These variations in tidal channels are considered to be related to changes in tidal energy environment, where stable energy environment before the project was changed to disconnection of tidal energy by closed environment, and re-connection of the energy during the open period.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.47-53
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• 2020

The purpose of this study was to increase product reliability by improving the durability of the breech block for a 30mm Automatic Gun. The breech block is a key component of a gun that functions as chambering, closing, and extracting. The breech block requires high reliability, which needs to be improved because cracks of a breech block can occur early in operation. Cause analysis confirmed that the crack is caused by repeated impacts. Therefore, the following improvement measures were studied, and the effects were demonstrated using a firing test. The energy of impact absorption was increased by changing the material, and the stress concentration was mitigated by increasing the value of R. In addition, the fatigue life was increased by adding Shot-peening, deleting chromium plating, and changing the forging method. The firing test did not show firing trouble for up to 5,000 rounds. The start timing of the crack was delayed, and the depth was small. Therefore, the improved product was more durable than the existing product. This study can be used as a useful reference when assessing the improvement of the durability of similar products, life study, and criteria for crack acceptance.

• Nuclear industry
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• v.36 no.6
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• pp.45-50
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• 2016

미국의 전력회사 Entergy는 향후 4년 내에 비등수형(BWR) 원자로 3기의 운영을 중단하고 영구 폐쇄에 들어갈 계획이다. 무엇 때문에 Entergy가 그런 조기 폐쇄 결정을 내리게 되었는지, 그리고 그러한 결정이 결과적으로 어떤 문제를 초래할 수 있는지 등에 대해 알아보고자 한다.

• Tuberculosis and Respiratory Diseases
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• v.41 no.3
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• pp.205-214
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• 1994

만성 폐쇄성 폐질환(COPD)은 하부 기도 즉 말초기도의 지속적인 미만성 폐쇄로 인하여 불가역성 기류폐쇄를 나타내는 질환을 말하며, 임상적으로 만성 기관지염과 폐기종으로 분류할 수 있으나, 이들은 기능적으로나 병리적으로 서로 중첩되어 임상적으로 명확하게 구별할 수 없기 때문에 만성적, 비특이적으로 진행하는 기류폐쇄의 포괄적인 용어로 COPD를 사용한다. COPD의 특징적인 병리변화는 소기도 즉 막성 세기관지염과 호흡세기관지염이며, 호흡세기관지염을 동반하는 폐기종의 중증도가 기류폐쇄의 정도를 결정하는 중요한 인자로 작용한다.

• 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.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.1
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• pp.46-52
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• 2011

A study on the improvement for cycle efficiency of closed-type ocean thermal energy conversion (OTEC) was studied to obtain the basic data for the optimal design of cycle. For that, OTEC cycle with a generator, a reheater and a multi-turbine was simulated and analyzed. The basic thermodynamic model for OTEC is Rankine cycle and the surface seawater of $26^{\circ}C$ and deep seawater of $5^{\circ}C$ were used for the heat source of evaporator and condenser, respectively. Ammonia is used as the working fluid. The cycle efficiency increased when generator is added with 0.9 generator effectiveness. When the reheater and multi-turbine are applied in the basic cycle, the cycle efficiency showed 3.14% and the capacity of heat exchanger decreased for same total cycle power. For the OTEC cycle with the generator, the reheater and the multi-turbine showed the highest cycle efficiency and increased the efficiency by more than 6.5% comparing with the basic OTEC cycle.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.116.2-116.2
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• 2005

• The Korean Journal of Applied Statistics
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• v.31 no.3
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• pp.329-342
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• 2018

Nomogram is a statistical tool that visualizes the risk factors of the disease and then helps to understand the untrained people. This study used risk factors of chronic obstructive pulmonary disease (COPD) and compared with logistic regression model and naïve Bayesian classifier model. Data were analyzed using the Korean National Health and Nutrition Examination Survey 6th (2013-2015). First, we used 6 risk factors about COPD. We constructed nomogram using logistic regression model and naïve Bayesian classifier model. We also compared the nomograms constructed using the two methods to find out which method is more appropriate. The receiver operating characteristic curve and the calibration plot were used to verify each nomograms.