• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.551-556
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• 2018

The material normally used in hot dip galvanizing facilities is SM45C (carbon steel for mechanical structure, KS standard), mainly because of its price. During this process, the oxidation of the plating facility occurs due to the heat of the Zn fumes coming from the molten zinc. Since the cycle time of the current facilities is 6 months, much time and money are wasted. In this study, the corrosive properties of various materials (Inconel625, STS304, SM45C) were investigated by oxidation in a high temperature and Zn fumes environment. The possibility of applying the hot-dip galvanizing equipment was investigated for each material. The Zn fumes were generated by directly bubbling Ar gas into Zn molten metal in a 650 degree furnace. High-temperature, Zn fumes corrosion was conducted for 30 days. The sample was removed after 30 days and the oxidation of the surface was confirmed with EDS and SEM, and the corrosion properties were examined using potentiodynamic polarization tests.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.2
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• pp.73-79
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• 2014

The sandwich shell with Egg-box core has been used for the combustion chamber case of air breathing propulsion system. The alteration on pitch length and thickness of Egg-box core was required to be lighter and save manufacturing time and cost of combustion chamber case. In this paper, the finite element analysis method which simulated bending test was used to predict the equivalent shear modulus which affect structural stability of sandwich shell in short time. The result of FE calculation on sandwich panel with homogeneous material, H130-foam core, showed a good agreement with the values available in the reference. The equivalent shear modulus of Egg-box core according to the variation of pitch length and thickness can be obtained.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.3
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• pp.237-247
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• 2005

It is necessary to forecast the various dismantling activities prior to dismantling nuclear facilities by using various software instead of a physical mock-up system because the dismantling in a contaminated with radioactivity cause the results of an unexpected situation. The component that needs to develop a dismantling mock-up system was examined. There are many component systems such as a decommissioning database system,3D dosimetric mapping that represents a distribution of a radionuclide contamination, a component of modeling for nuclear facility and devices include the decontamination and decommissioning. The research of software architecture about these components was carried out because these component systems that have been independently doesn't describe not only to visual an activities of Decontamination and Decommissioning(D&D) but also to evaluate it. The result was established an architecture that consist of an visualization module which could be visualized an D&D activities and a simulation module which can be evaluated a dismantling schedule and decommissioning cost.

• The Journal of the Korea Contents Association
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• v.13 no.8
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• pp.52-59
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• 2013

Recently, the importance of the efficient production pipeline design has been increased for 3D animation, which becomes more delicate. In this paper, we propose 3D animation character development pipeline using 3D printing technology. We introduce 3D printing procedure into each step of the classical 3D animation and character development pipeline to incorporate the feed-back from the designer immediately. Specially, during the production step, we can find the design errors and minimize the period of production by using 3D printing of approximate shape of designed character. Using proposed method, eight DreaMegg characters were developed and their quality was very high with respect to 3D virtual graphics and real product. Using our method, high-quality 3D animation character can be developed with the minimized time and cost for development by reflecting the feed-back into production line from designers and researchers immediately.

• Journal of Biomedical Engineering Research
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• v.24 no.3
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• pp.233-239
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• 2003

Falling related injuries are categorized as the most serious and common medical problems experienced by the elderly, hip joint fracture, one of the most serious consequences of falling in the elderly, occurs in only about 1% of falling. Nevertheless, hip fracture accounts for a considerable part of the disability, death, and medical costs associated with falling. In this study, we considered the impact angle and displacement rate in falling as another factor affecting femoral strength. Using a fresh-frozen human femur, we developed system to simulate the falling condition and then conducted the experiments changing the impact angle (0$^{\circ}$, 15$^{\circ}$, 30$^{\circ}$) of proximal femur. Also, in order to analyze the relative risk due to falling to normal situation in proximal femur, we did the static test simulating the two-legged stance condition. The results showed that the change in impact angle affected the strain distribution in proximal femur, and that a large deformation in femoral neck than in other sites. Furthermore despite low impact velocity, a large deformation in proximal femur occurred in the impact test and different strain distribution was observed compare to the static case.

• Journal of Advanced Navigation Technology
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• v.19 no.5
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• pp.354-362
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• 2015

In this study, for integrated management and inter-exchange of operational data generated by ships and land-side information on safe and business, a vessel communication system with modular functions was designed that applied high efficiency compression, least-cost algorithms and Inmarsat FBB connection automation system. Performance test at the KTsat Kumsan satellite earth station; system was found to delivered an average transfer speed of 7 kB/S, which was significant improvement from the existing commercial product's average speed of 5 kB/S. It also delivered twice the efficiency of the existing product in terms of compression rate and transfer of the most widely used office files in maritime businesses.

• Proceedings of the Korea Technology Innovation Society Conference
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• 1999.05a
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• pp.409-419
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• 1999

전기기술은 기술의 특성상 민간에 대한 유인이 적은 공유성 기술이나 대학 또는 기업이 감당하기 어려운 대형복합기술의 비중이 높으며, 최근 들어 전력산업의 구조개편 등에 따라 국가적 기술개발수요가 확대됨과 동시에 전기기술의 이용분야 확대와 타 기술과의 융합화 및 대형화로 신기술수요가 늘어나고 있다. 현재 우리 나라의 전기기술 R&D체제에서는 공공기술에 대한 사각지대가 발생하고 있음에도 불구하고 국가차원의 R&D 공급이 미약하여, 거대한 시험설비와 첨단고가장비를 필요로 하는 시스템기술로 일부 기기나 시스템운용을 제외하고는 개별기업이나 전력회사에 대한 기술개발 유인이 크지 않으며, 따라서 전기기술분야의 R&D 실태 파악과 역할에 대한 검토를 통해 R&D 주체별 기관특성에 맞는 국가 R&D체계의 정립이 필요한 실정이다. 따라서, 앞으로는 전기기술분야의 국가 R&D 목표 및 기본전략에 따라 국가 R&D 자원의 규모, R&D 주체간의 역할분담 등 전반적인 R&D 체계의 구축이 선행되어야 하며, 이를 통해 기관별 Mission 및 고유기능을 토대로 전문성 제고와 특성화를 유도할 수 있는 연구여건의 조성이 시급하다 하겠다. 특히, 장기대형연구, 원천기술연구, 기초기반연구, 연구기반구축, 인력양성 등 필수적 국가기능에 대해서는 기관별 특성에 따라 안정적인 역할수행이 가능하도록 역할분담 및 정책적 지원을 하되, 그 밖의 영역이나, 민간 및 전력회사의 독자적인 R&D에 대해서는 경쟁 및 협력을 통한 연구효율성 향상을 유도하는 방향으로 나가는 것이 바람직할 것이다. 국가적 전력기술 R&D의 효과적인 수행과 실효성 확보를 위해서는 재원확보가 선행되어야 하며, 이를 위한 방안으로는 기존의 전력사업자에게는 기술개발충당금 또는 전기요금 중 일정비율을 국가적 R&D 재원으로 설정할 수 있을 것이며. 신규 사업자에게도 규제비용의 차원에서 일정 부담금을 부과하는 방법이 가능할 것이다. 이러한 재원을 가지고 사업성격 및 R&D 유형에 따라 역할분담에 따른 지원, 정책적 사업, 경쟁적 사업공모 등을 통해 지원분야 및 규모, 대상기관 등에 대한 선별적인 지원이 이루어져야할 것이다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.3
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• pp.530-536
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• 2017

The accident of the small vessel is increasing due to the growth of the sea and service industry. According to data from National Statistical Office, for 100 ton less than small ship accident, the most of the shipping incident generated in the small ship by 84% of the total shipping incident in 2015. The radar obligatory mounting is enforced to the small vessel in order to conclude this problem. However, the problems including the maintenance cost and transmission power etc. happens high if the existing pulse radar is mounted in the small vessel. In this development, the development is for small ship fixed type radar the object. And in this paper, by using the phase array antenna revolving electronically around the beam, the antenna which it is applicable to the marine fixed type radar which can solve above problem was made and it tested.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.770-774
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• 2008

현장 계측을 통한 오염부하량 산정은 많은 시간, 노력, 비용을 필요로 한다. 이러한 어려움을 해결하기 위해 오염부하 추정에 관한 많은 방법론들이 제시되고 있으며 개발되고 있는 중이다. 논오염부하 추정을 위한 일환으로 강우사상평균농도(Event Mean Conentration, EMC)에 관한 연구가 많이 진행되고 있다. 하지만, 오염부하량 산정을 위해서는 농도이외의 주요 매개변수인 유출량 산정 또한 중요하다. 하지만 논의 경우 실제 유출량 자료는 흔치 않다. 우리나라의 경우 영농활동이 시기별, 지역별로 비슷한 형태를 가지고 있으므로 이러한 점을 이용하면 유출율을 추정하는데 용이할 것으로 판단된다. 따라서 본 연구는 2004년부터 2007년 영농기 강우-유출량 실측 자료를 이용하여 시기별 유출특성을 파악하고, 논의 시기별 유출율을 제안하였다. 논의 시기별 유출율을 산정하기 위한 시험지구는 영산강 수계내에 위치한 전라남도 함평군 엄다면 화양리 13.69 ha 논지구이며, 2004년부터 2007년 영농기(5월$\sim$9월)동안 모니터링을 실시하였다. 논 배수로 말단에 수위계를 설치하여 수위-유량관계식을 이용하여 유량을 구하였고, 직선분리법을 이용하여 직접유출과 기저유출을 분리한후 강우량과 유출량의 비를 통하여 월별 평균 유출율을 산정하였다. 5월, 6월, 7월, 8월, 9월에 내린 평균 강수량은 각각 40.2, 50.1, 75.4, 75.8, 136.8 mm로 나타났고, 영농기 월별 평균 직접유출량은 각각 9.1, 26.6, 34.6, 42.9, 79.6 mm로 나타났다. 강우량과 유출량의 비를 통해 4개년 5월, 6월 7월 8월 9월 평균 유출율은 각각 0.18, 0.42, 0.40, 0.44, 0.49로 나타나 논의 경우 시기별로 유출율이 차이가 있는 것으로 조사되었다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.4
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• pp.395-402
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• 2010

Baffle injectors are protruded into the combustion chamber and form an anti-pulsating baffle to prevent high-frequency combustion instabilities in transverse modes. Being exposed to a high heat-flux environment, the baffle injector has self-cooling passages through which kerosene is convected and heated. The baffle injector with 20 spiral cooling channels has been developed and successfully applied to 30 $ton_f$-class combustors without any performance loss due to an additional cooling. In this work, numerical analysis of conjugate heat transfer in baffle injectors with various cooling channel designs has been performed in order to reduce the fabrication cost which would be considerably increased for the 75 $ton_f$-class combustor. Prior to the application to a full-scale combustor, the thermal durability of the modified design has been verified through the subscale hot-firing tests.