• Tribology and Lubricants
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• v.35 no.2
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• pp.87-93
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• 2019

This work aims to develop a dry lubricant for oilless bush, especially a solid lubricant, thereby creating a coating method with improved properties of anti-friction and load-carrying capacity without oil lubrication. In this work, spherical-shaped powders of thermosetting resin such as polyimide (PI) are mixed with a binder matrix obtained by mixing a fluorocarbon compound resin such as Polytetrafluoroethylene (PTFE) or Ethylene tetra fluoro ethylene (ETFE) with itself or with a non-fluorocarbon thermoplastic resin such as Polyether ether ketone (PEEK). And these dry lubricant mixtures are thickly coated (200-300 mm in the thickness) on the inner surface of the bush by using a wet-typed air-spray deposition method. It was found that the load-carrying capacity of the solid lubricant for excavator bush (60 mm in diameter) that operates under a high load condition (at 40 MPa) is greatly improved owing to the spherical-shaped powders of thermosetting resin. In addition, the coefficient of friction at the sliding surface is also reduced less than 0.1. Thick coating also lowers the contact stress at the edge of a bush that results in better tribological performances. The result suggests that the lubrication performance and durability life of the bush can be remarkably improved even without lubrication (oil or grease).

• Journal of the Society of Naval Architects of Korea
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• v.59 no.2
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• pp.64-71
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• 2022

In this paper, we simulate the collision of a solitary wave on a vertical wall in a uniform water channel and investigate the effect of damping on the amplitude attenuation. In order to take into account the damping effect, we introduce the Stokes damping whose dissipation is dependent on the velocity of wave motion on the surface of a thin layer of oil. That is, we use the improved Boussinesq equation with Stokes damping to describe the damped wave motion. Our work mainly focuses on the amplitude attenuation of a propagating solitary wave, which may depend on the Stokes damping together with the initial position and initial amplitude of the wave. We utilize the method of images and a powerful numerical tool (functional iteration method) for solving the improved Boussinesq equation, yielding an effective numerical simulation. This enables us to find the amplitudes of the incident wave and reflected one, whose ratio is a measure of the (wave) amplitude attenuation. Accordingly, we have shown that the reflection of a solitary wave by a vertical wall is dependent on not only the initial amplitude and position of a solitary but the Stokes damping.

• 주택과사람들
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• s.11
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• pp.88-92
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• 1991

1. 이 자료는 최초입주하게 되는 2,500여세대 주민들에게 불편이 없도록 공공시설과 생활편익 시설을 차질없이 설치하고자, 분당현지에서 건설부장관이 주재하에 3월 8일 오후 2시 관계기관 차관회의를 개최한 내용임. - 회의일시: 1991.3.8 $14:00{\~}16:00$. - 회의장소: 분당신도시내 토지개발공사 건설현장사무소 . - 참석: 12개기관 국무총리 행정조정실장 경제기획원차관 내무부차관 교육부차관 동력자원부차관 체신부차관 환경처차관 철도청장 경기도지사 서울특별시 부시장 경기도교육위 교육감 한국토지개발공사 사장. 2. 이번 회의에서는 다음 사항들을 중점 논의할 계획이다. - 분당신도시 건설사업의 종합적인 추진대책의 협의. - 최초 입주자에게 불편이 없도록 편익시설$\cdot$기반시설의 적기 설치. $\cdot$ 학교, 동사무소, 우체국, 파출소 등 필수 공공시설. $\cdot$ 도로, 상하수도, 난방 등 도시기반시설. $\cdot$ 병원, 상가 등 생활편익시설.

• Geotechnical Engineering
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• v.12 no.6
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• pp.101-114
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• 1996

Even though the Coulomb's earth pressure theory has been mainly used in practice, the general equation does not exist yet, which is applicable to retaining wall backfilled by cohesive soils. Here, for gravity walls backfilled by cohesive soils, some equations have been derived by newly using the Coulomb's theory, for the cases oi drained and untrained analyses. and for the cases of neglecting and considering the tension crack, respectively. Both the active earth thrust and the depth of tension crack under different conditions were tabulated.

• Computational Structural Engineering
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• v.1 no.1
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• pp.95-102
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• 1988

I-BUILDS is the building design expert system conceptually modeled for synthesizing the conventional CAD programs (BUILDS; an integrated BUILding Desing System) and the knowledge base into an unified system. As a part of the efforts to build this system, this paper presents the conceptual model by which the data items generated by inference are transformed into a formatted input file to be used for several BUILDS subsystems, each of which is assigned to have various computational capabilities and to perform specialized task.

• Journal of Welding and Joining
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• v.5 no.2
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• pp.35-43
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• 1987

The effect of post weld heat treatment (P.W.H.T) on the propagation rate of stress corrosion cracking(S.C.C) and threshold stress intensity factor ($K_{IC}.c.c$) for stress corrosion cracking of 304 stainless steel has been investigated in boiling 45% $MgCl_2$ solutions with W.O.L specimens. Specimens were precracked by turning a pair of Cr-Mo steel bolts into a machined slot at the end of the specimen. The fracture surface was examined fractographically by Scanning Electron Microscope(S.E.M.)

• Journal of environmental and Sanitary engineering
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• v.20 no.2 s.56
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• pp.21-28
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• 2005

Soy sauce is one of the most Korean representative and traditional seasoning sauce, which occupied about 150 million won of 550 billion won in the domestic sauce market. There are many arguments over the safety of the soy sauce made from acid-hydrolyzate. This study on the use pattern of soy sauce in the popular restaurants. Surveyed restaurants were 106 places in Uijeongbu-city The results of this study showed that the highest number of chemical soy sauce which was mixed with acid-hydrolyzated and commercial fermented soy sauce on surveyed restaurants. These results suggest that necessitate the requirements of establish of concerns for food safety again.

• Journal of The Korean Digital Architecture Interior Association
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• v.4 no.2
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• pp.19-25
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• 2004

This study is to furnish basic data for establishing the improvement counterplan of Housing environment and to solve the problem of Housing supply resulting from the continuous increase of population and to examine the historical flowing, the present condition and problems of Housing in Uijeongbu city. Including of the multi-house to the number of Housing, the supply ratio of Housing is 95% in quantity of the Housing in Uijeongbu city in 2004. Now, it is important time in the respect of quality as well as the quantity in supply matter of Housing. In fact, the main viewpoint in housing supply policy has been brought focus into the economic profits more than public interests. As a result of that, the residence environment has been worse. From now on, a Local autonomous entity including the construction authorities and Uijeongbu city authorities must focus on the public interests in solving problems of Housing.

• 정보화사회
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• s.18
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• pp.44-50
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• 1989

미국 상무성의 전기통신정보국(NTIA)은 지난해 말 새대통령이 실행해야 할 미국 전기통신 정책과 정책결정기구의 개혁에 관한 제안문서(NTIA TELECOM 2000: CHARTING THE COURSE FOR A NEW CENTURY)를 발표하였다. 이 제안보고서는 1989년 1월 발족한 부시 새정권의 산업정책을 선도할 것이며 앞으로 미국 통신정책의 구체적 방향의 근간이 될 것으로 보인다. 또한 이달부터는 재개될 것으로 보이는 한미간 통신협상에서도 미국 무역대표부는 이 보고서에 근간하여 협상전략을 짤 것으로 예상된다. 이 보고서는 제1부 "전기통신, 정보정책에 있어서의 중요과제"와 제2부 "전기통신, 정보분야의 연구"로 구성되어 있는데 본란에서는 제1부의 정책제언 중 각 분야의 권고내용을 중심으로 소개한다.

• Defense and Technology
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• no.10 s.296
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• pp.48-55
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• 2003

미 안보지원역사는 좁은 의미로는 무기와 물품의 지원 및 판매 역사이며, 우리 의지와는 상관없이 세계정세 변화에 따라 국익을 극대화할 수 있도록 변화해 있다. 현 부시 행정부의 안보지원정책은 미래를 위한 "능력에 기초한(Capacity Based)" 모델을 추구하고 있다. 이를 뒷받침하기 위해 기존 NATO 위주에서 구매국 위주 정책으로 변환을 천명하고, 기동성이 떨어지고 유지비용이 많이 드는 무기는 과감히 도태시키고 있다. 이를 추진하기 위해 주요 핵심보직에는 전력기획 및 협상을 주도할 전문가를 보직하고, 대외 군사판매(FMS : Foreign Military Sales)를 자국 경제발전에 적극 활용하고 있다. 이러한 변화의 와중에서 미국은 어떤 특정국가를 챙겨 줄 여유가 없다. 우리 스스로 미국ㄱ의 전략변화와 안보지원관련 법규.제도와 업무수행 절차를 명확히 이해하여 미국의 변화 속에서 민첩히 대응하여 국가이익 차원에서 실리를 추구하는 방향으로 정책이 지향되어야 한다. 미국의 안보지원정책 변화를 정확히 이해하고 지혜롭게 활용함에 따라 국가의 위기가 될 수도 있고 도약의 기회가 될 수도 있다.