• 대한조선학회 특별논문집
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• 대한조선학회 2017년도 특별논문집
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• pp.63-66
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• 2017

All passenger ships aboard more than 36 passengers are to be able to easily find escape routes when the escape way by fire with flame spread were onboard vessel (incl. Ferry, Passenger, Ro-pax, Inland Ferry) It should be impossible by ordinary emergency lights. The international Maritime Organization (IMO) gives special requirement for luminescent evaluation onboard test procedure and applicable location of low location lighting. In order to maintain the residual light source for a certain time in the low location lighting with a strip-shaped light source, the light source material must be sufficiently exposed to the light due to the proper placement of the escape route. The lighting arrangement influence how maintain low location lighting strip luminescent which measured onboard in connection with what elements are mainly sustain luminescent.

• 한국생산제조학회지
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• 제20권4호
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• pp.452-457
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• 2011

The internal temperature of an operating room had to keep within $20^{\circ}C$. However, the doctor who is wearing operating gown and mask caused to rise temperature because of the thermal occurrence of dental LED light source. At first, the surgery environment is getting worse. And then last, it would increase bleeding rate by the expansion of patient's exposured blood vessel. A surgical operator can distribute the patient's tissue through such surgery environment, exactly. It can do accurate surgery. So, it gave to effect that surgical operator's eye condition is getting better and it could keep a mutual assistance system. For this research, we develop the LED dental light source module of high color rendition. It performed simulation for replacing established the method of Halogen lamp and Plazma lamp of light source. We analyzed intensity of illumination and the change of viability by changing the height of light source module.

• Journal of Advanced Marine Engineering and Technology
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• 제40권4호
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• pp.342-347
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• 2016

본 논문에서는 실습선과 함정의 광원으로 80 % 이상을 차지하는 백열등 및 형광등기구를 대체하기 위한 선박용 LED 등기구의 경제성 분석에 관하여 기술하였다. 소비전력, 초기투자비용, 유지비용 및 유류비에 대한 절감률을 분석하였고, 탄소배출량과 손익분기점을 산출하였다. 실습선의 초기투자비용은 3.8배 상승하였지만, 5년간 유지비용은 51 % 절감되었다. 40 %, 50 % 및 60 %의 점등률에 따른 손익분기점은 각각 11개월, 9개월 및 7개월로 산출하였다. 함정의 초기 투자비용은 3.5배 상승하였지만, 5년간 유지비용은 55 % 절감되었다. 40 %, 50 % 및 60 %의 점등률에 따른 손익분기점은 각각 15개월, 12개월 및 10개월로 산출하였다. 또한 실습선과 함정의 탄소배출량은 각각 69 % 및 65 % 절감되었다. 이러한 결과를 통하여 실습선과 함정에 LED 등기구를 적용한다면, 50 % 이상의 유지비용 절약과 60 % 이상의 소비전력, 유류비 절감 및 탄소배출량이 감소될 것으로 판단된다.

• 대한조선학회논문집
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• 제38권1호
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• pp.99-107
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• 2001

어선 제작시 어선의 고속화 및 어로작업 등에 의한 내구성을 향상시키기 위해 선각재질이 가볍고, 강도, 화재 및 해수의 부식 등에 뛰어난 재료의 사용이 요구되어지고 있다. 이러한 어선으로서는 크게 FRP어선과 Al어선으로 대별할 수 있다. 그러나 FRP어선은 가볍고 강도는 우수하나 인화성이 높아서 열에 매우 약하고 선박 제작 과정에 있어 인체에 해로운 유해성분이 발생할 뿐만 아니라, 폐선의 경우 산업폐기물로써 환경 오염에 큰 영향을 미치고 있다. 그런 반면에, Al어선은 FRP어선의 단점을 보완할 수 있는 재료로써, 고강도 및 경량화의 효과를 낼 수 있고, FRP어선보다 인화성이 낮아서 열에 강하고, 내구성이 높아 해수의 부식방지에 뛰어나므로 Al 어선의 개발이 시급한 실정이다. 그러나, 알루미늄 합금은 용접성이 좋지 않고 용접변형 및 균열이 발생하고, 건조 비용이 비싸다는 단점이 있다. 따라서, 본 연구에서는 Al 합금 접합시의 문제점 해결방안으로 용접이음부의 새로운 형상을 개발하고 개발한 신형상에 대한 역학적 거동을 규명하고자 하였다. 이를 위해, 먼저 평판 이론을 이용하여 구조부재를 단순화하여 평판, 보강판, 신형상에 대하여 해석함으로써 강도를 비교 검토하고, 이러한 결과를 토대로 자체 개발된 용접열전도 및 용접열응력 수치해석 프로그램을 사용하여 평판과 신형상의 온도분포, 용접잔류응력, 인장, 압축시의 강도를 수치시뮬레이션을 통하여 비교, 검토하였다. 또한, 인장 시험편을 제작하여 실험을 통하여 강도를 비교함으로써 신형상에 대한 적용 가능성 및 역학적 우수성을 입증하고자 하였다.

• 수산해양기술연구
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• 제49권4호
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• pp.385-394
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• 2013

This study has conducted a comparative analysis on the fishing efficiency of LED fishing lamps by squid jigging vessels, the Yeongrak-ho (16 tons) and Somang-ho (9.77 tons), which operated during September and October 2010 and during October 2011, comparing with MH (Metal Halide) fishing lamp-equipped fishing vessels. This study has also examined vessel's fuel consumption level. The light powers of LED fishing lamps of the Yeongrak-ho and Somang-ho were 25.8kW and 32kW, respectively. Those of the MH fishing vessels, that is, the MH fishing lamp-equipped fishing vessels, were 105kW and 81kW, respectively. The average squid catch in number of an LED vessel, Yeongrak-ho, was 39.2% of the MH fishing lamp-equipped fishing vessels; however, that of the Somang-ho improved to 78.7% of the MH fishing lamp-equipped vessels. Average catch in number by Yeongrak-ho crew was 2.6 times more than catch in number by automatic jigging machines. Average catch in number by MH fishing vessel crew was 1.8 times more than that by automatic jigging machines. An LED vessel, Yeongrak-ho's fishing rate was 17.5%~152.2% of the MH fishing vessels, that is, 61.1% on average, in comparison of combined catch in number per automatic jigging machine and per crewmember. Somang-ho's fishing rate was 6.7%~127.6% of the MH fishing vessels, that is, 73.1% on average. The average fuel consumption level of the Somang-ho, throughout its departure from to arrival at the port, was 475.7l, and that during fishing hours was 109.6l, or 23.0% of the total fuel consumption level. Somang-ho's fuel consumption level per fishing hour was 9.7l on average.

• Journal of Plant Biotechnology
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• 제7권1호
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• pp.67-74
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• 2005

To overcome various disadvantages of conventional cul-ture vessels for micropropagation, a novel disposable vessel, the 'Vitron', made of a multi-layered $OTP^{(R)}$ film and supported by a polypropylene frame, was developed. The film possesses superior properties such as: high light transmittance, low water vapor transmittance and thermal stability and in particular, high gas-permeability. Single nodal explants, which were excised from the multiple shoots derived from shoot-tip culture, were cultured in Vitron and polycarbonate vessels on $3\%$ sugar-containing agar on MS medium and placed at 3000 ppm $CO_2$-enrichment at a low photosynthetic photon flux density (PPFD) ($45{\mu}mol\;m^{-2}\;s^{-1}$). The in vitro and ex vitro growth, and the net photosynthetic rate of in vitro and ex vitro plantlets were significantly enhanced in the Vitron compared to those cultured in a polycarbonate vessel. Explants that were cultured on the same MS medium under low PPFD at various $CO_2$ concentrations were also cultured at 3000 ppm $CO_2$- enrichment at various PPFD: 30, 45, 60, 75 and $90{\mu}mol\;m^{-2}\;s^{-1}$. The best in vitro and ex vitro growth obtained for 3000 ppm $CO_2$-enrichment at $75{\mu}mol\;m^{-2}\;s^{-1}$ PPFD. The novel Vitron vessel, when placed under the two conditions, may replace conventional culture vessels for the successful micropropagation of sweetpotato.

• 한국압력기기공학회 논문집
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• 제10권1호
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• pp.113-121
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• 2014

In this work, an integrated model including molecular dynamics and chemical rate theory was implemented to calculate the growth of point defect clusters(PDC) and copper-rich precipitates(CRP) which could change the mechanical properties of reactor pressure vessel(RPV) steels in a nuclear power plant. A number of time-dependent differential equations were established and numerically integrated to estimate the evolution of irradiation defects. The calculation showed that the concentration of the vacancies was higher than that of the self-interstitial atoms. The higher concentration of vacancies induced a formation of the CRPs in the later stage. The size of the CRPs was used to estimate the mechanical property changes in RPV steels, as is the same case with the PDCs. The calculation results were compared with the measured values of yield strength change and Charpy V-notch transition temperature shift, which were obtained from the surveillance test data of Korean light water reactors(LWRs). The estimated values were in fair agreement with the experimental results in spite of the uncertainty of the modeling parameters.

• Nuclear Engineering and Technology
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• 제41권1호
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• pp.11-20
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• 2009

Radiation effects on materials are inherently multiscale phenomena in view of the fact that various processes spanning a broad range of time and length scales are involved. A multiscale modeling approach to embrittlement of pressure vessel steels is presented here. The approach includes an investigation of the mechanisms of defect accumulation, microstructure evolution and the corresponding effects on mechanical properties. An understanding of these phenomena is required to predict the behavior of structural materials under irradiation. We used molecular dynamics (MD) simulations at an atomic scale to study the evolution of high-energy displacement cascade reactions. The MD simulations yield quantitative information on primary damage. Using a database of displacement cascades generated by the MD simulations, we can estimate the accumulation of defects over diffusional length and time scales by applying kinetic Monte Carlo simulations. The evolution of the local microstructure under irradiation is responsible for changes in the physical and mechanical properties of materials. Mechanical property changes in irradiated materials are modeled by dislocation dynamics simulations, which simulate a collective motion of dislocations that interact with the defects. In this paper, we present a multi scale modeling methodology that describes reactor pressure vessel embrittlement in a light water reactor environment.

• 대한기계학회논문집B
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• 제30권7호
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• pp.682-691
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• 2006

This study was conducted to assess the effect of mixed fuel composition and mass fraction on spray inner structure in evaporating transient spray under the various ambient conditions. Spray structure and spatial distribution of liquid phase concentration are investigated using a thin laser sheet illumination technique on the multi-component mixed fuels. A pulsed Ar+ laser was used as a light source. The experiments were conducted in a constant volume vessel with optical access. Fuel was injected into the vessel with electronically controlled common rail injector. Used fuel contain $i-octane(C_8H_{18}),\;n-dodecane(C_{12}H_{26})$ and $n-hexadecane(C_{16}H_{34})$ that are selected as low-, middle- and high-boiling point fuel, respectively. Experimental conditions are 25Mpa, 42MPa, 72MPa and 112MPa in injection pressure, $5kg/m^3,\;15kg/m^3\;and\;20kg/m^3$ in ambient gas density, 400K, 500K, 600K and 700K in ambient gas temperature, 300K and 368K in fuel temperature, and different fuel mass fraction. Experimental results indicate that the more high-boiling point component, the longer the liquid phase it were closely related to fuel physical properties, but injection pressure had no effect on. And there was a high correlation between the liquid phase length and boiling temperature at 75% distillation point.

• 한국항해항만학회지
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• 제43권6호
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• pp.437-443
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• 2019

항로표지는 선박에 대하여 등광, 형상, 색채, 음향, 전파 등을 수단으로 운항 선박에게 위치, 방향 및 장애물의 위치 등을 알려주는 항행보조시설 일체를 의미하며, 주야간 선박항행의 안전을 위한 기본 수단이다. 예인선은 안전을 위해 종류별 최소 설비요건을 마련하여 사고를 대비하고 있지만, 예인삭의 길이, 조류의 영향, 상대적으로 중량이 큰 부선의 타력으로 인한 영향 등으로 예인선과 선회권이 달라, 변침 시 부선이 예인선을 따라가지 못하여 등부표와 추돌하는 사고가 발생하기도 한다. 본 연구의 목적은 두 선박의 물리적 관계를 분석하여 예인선열을 식별하고 등부표와의 위험을 항로표지 관리운영 시스템을 통해 전파하는 기초 시스템을 제시하는데 있다. 연구를 통해 예부선의 사전 식별 가능성을 확인하였고, 위험 전파를 위한 메시지를 설계하고 모의 시스템을 통한 위험 전파 및 전자해도 상에 위험을 표시하였다.