• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.4
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• pp.308-312
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• 2001

This study was carried out to develop a basic form of planning hull type fishing boat. G/T 10ton class is selected as object hull form, and hull form is designed in Chosun University. A series of test results of LCG variations for S different LCG points are presented in this paper. The test was performed in Davidson Laboratory, and the scope of tests include resistance, trim and sinkage.

• Journal of Sensor Science and Technology
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• v.5 no.3
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• pp.17-24
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• 1996

In order to reduce the offset and its temperature drift by the different properties of the piezoresistors and the residual stress of the piezoresistive pressure sensor, a double Wheatstone-bridge pressure sensor was studied. Because the compensation bridge was arranged near by the pressure sensitive bridge, which have the similar offset component, reduction of the offset and its temperature drift was realized by the mathematical subtraction of the output of two bridges. It was configured the compensation of the offset and its temperature drift. By this compensation method, the offset and its temperature drift were reduced approximately 95% respectively. The sensitivity of the fabricated pressure sensor was $11.7\;mV/Vkg/cm^{-2}$ for $0.9\;kgfcm^{-2}$ full-scale pressure range.

• Proceeding of EDISON Challenge
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• 2016.11a
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• pp.35-43
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• 2016

본 연구에서는 EDISON의 해석자를 활용하여 선박의 최적 운항 자세 도출과 같은 실용적 문제 해석뿐 만 아니라 자유 수면 및 대칭 경계 조건이 수직한 몰수 익형 주위 유동에 미치는 영향을 분석하는 학술적 연구를 수행하였다. 선박의 자세에 따른 저항 변화를 분석한 결과 0.5m 선수 트림에서 선체 저항이 가장 작은 것으로 나타났으며, 이는 유동 가속에 의한 선수 어깨부의 낮은 압력 및 선미부에서의 압력 회복에 의한 것이다. 반면, 1.0m 선미 트림에서 선체 저항이 가장 큰 것으로 나타났는데, 평형 상태보다 선미부의 압력 회복이 약하기 때문이다. 또한 자유 수면과 대칭 경계 조건이 날개 성능에 미치는 영향을 분석한 결과, 비현실적 대칭경계 조건으로 인해 날개 양력이 13%~16% 크게 나타났으므로 대칭경계조건을 사용할 경우에는 이러한 오차를 감안해야 한다.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.10a
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• pp.159-162
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• 1998

폐수의 형태 및 성장과 막의 특성에 의해 한외여과는 처리수의 직접배출 또는 재 이용을 위해 사용되고 있다. 일본의 Masuda등은 1축 RDM을 사용하여 순수에서 회전에 따른 압력 강하를 관찰하고, 또 도시 하수처리 공정의 활성슬러지를 분리하기 위해 Aqua Renaissance '90프로젝트의 일환으로 도시 하수처리에 2축 RDM이 사용되었다. 동력학적 여과의 투과모델은 김제우 등에 의해 정립된 식을 이용하여 동력학적 여과기의 투과율(J)은 일반적으로 유효압력차($\DeltaP_T$), 벌크의 농도($C_B$) 그리고 회전속도 등에 의해 결정되어진다. 기존에 제시된 회전원판 모듈의 순수 투과에서 permeate side의 저항(Rp)값은 막자체의 저항(Rm)에 비해 상대적 작아 무시되었다. 본 연구는 1축 RDM 한외여과에서 투과율에 영향을 미치는 저항(R)에서 판자체에 변형을 주어 permeate side에서 저항(Rp)에 대한 영향에 관하여 연구를 수행하였다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.7
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• pp.601-605
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• 2014

Porous conductors are known to demonstrate excellent electrical, mechanical, and chemical resistance. These porous conductors demonstrated potential applications in various fields such as electrodes for supercapacitors, flexible heaters, catalytic electrodes, and sorbents. In this study, we described a pressure sensitive device using conductive and porous sponges. With an extremely simple "dipping and drying" process using a single-walled carbon nanotube (SWCNT) solution, we produced conductive sponges with sheet resistance of < $30k{\Omega}/sq$. These carbon nanotube sponges can be deformed into any shape elastically and repeatedly compressed to large strains without collapse. The pressure sensors developed from these sponges demonstrated high resistance change under pressure of up to a half of their initial resistance.

• Journal of Biomedical Engineering Research
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• v.24 no.1
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• pp.9-13
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• 2003

An assist device was developed to identify the epidural space by continously monitoring the air-filled catheter pressure. The pressure signal appropriately amplified and filtered enabled to alarm the needle introduction into the epidural space by thresholding detection. Ten LEDs provided a visual change of catheter pressure before alarming for user convenience. Clinical trials were performed in 30 patients with 83% success rate at the first trial. When failed, the second trial was enough for successful anesthesia. The air volume introduced during each anesthesia was less than 1ml, causing side effects. Air filling of the catheter could also minimize infection possibility. Therefore, the present device guarantees safe anesthesia with user convenience.

• Korean Chemical Engineering Research
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• v.46 no.4
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• pp.676-680
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• 2008

TiN thin films were deposited on a $SiO_2(2000{\AA})/Si$ substrate by radio-frequency(rf) magnetron sputtering. TiN films were prepared under varying $N_2$ concentration in $N_2/Ar$ gas mix, rf power and gas pressure, and investigated in terms of deposition rate, resistivity and surface morphology. As $N_2$ concentration increased, the deposition rate and the surface roughness of the films decreased and the resistivity increased. With increasing rf power, the deposition rate increased but the resistivity was decreased. As gas pressure increased, little change in deposition rate was obtained but the resistivity rapidly increased. TiN film with resistivity of $2.46{\times}10^{-4}{\Omega}cm$ at 1 mTorr was formed. It was observed that there existed a correlation between the deposition rate and resistivity. In particular, the gas pressure has a strong influence on the resistivity of thin films.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.4
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• pp.482-488
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• 2019

Leisure and business facilities have been steadily developing in Korea. Among waterborne leisure vessels and equipment, the distribution and sale of kayaks and canoes have significantly increased. Previously, (FRP) materials were primarily employed for constructing kayaks. However, owing to global warming and depletion of natural resources, the demand for non-polluting renewable energy is rapidly increasing, which has increased the demand for carbon fibers. To meet the requirements of changing social consciousness, a carbon fiber-based commercial kayak was designed in this study. Resistance analysis and structural safety were conducted by employing software tool for verifying the reliability of the proposed kayak. The pressure resistance and frictional resistance were examined in a wide range of speed. Obtained results indicate that at speeds greater than 2.6 m/s, the pressure resistance significantly increases and the total resistance also increases. Furthermore, the results corroborate that the proposed kayak structure has a adequate safety with respect to the design loads that are considered during operating conditions.

• Journal of the Society of Naval Architects of Korea
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• v.31 no.3
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• pp.100-111
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• 1994

This study was carried out for understanding the characteristics of the spray around high speed vessels. Prismatic planing hull made of an acrylate board was used to the tests. The distribution of local spray velocity were estimated from the analysis of the spray visualization. A new test system for measuring the spray thickness is proposed, and was used to estimate the local spray thickness in the model. The pressure distributions on the bottom of the hull are measured and integrated to estimate the pressure drag of the model in the towing tests. Finally. the spray drag/lift component is separated from the total drag/lift on the prismatic hull. These test results show that the spray drag component on high speed vessels is relatively large and important in total drag.

• Food Science and Preservation
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• v.6 no.4
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• pp.424-428
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• 1999

The performance of a 30K polysulfone membrane for clarification of depectinized peach juice was studied Ultrafiltration of peach juice could minimize to loss of flavor and many compounds and was expected to effectively remove precipitation and suspended solid. The results showed that permeate flux increased with the increase of operating pressure and temperature. The permeate flux declined continuously as the process time increased. The values of soluble solid and titratable acidity of permeate were decreased or were at the same level, the turbidity was largely decreased. Total resistance decreased with lower temperature and lower pressure.