• 전기학회논문지P
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• 제58권4호
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• pp.541-545
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• 2009

This study evaluated the contact resistance, insulation resistance, withstand voltage characteristics and insertion force, etc., of the wire connector used inside an integrated LITE WAY lighting fixture developed for efficient installation. Since the connector connecting the lighting fixture's internal wires is housed, it is easily connected and separated and has a structure enabling a close-fitting connection. The temperature and time applied to the high temperature characteristics test of the connector are $105^{\circ}C$ and 16 hours, respectively. The measured contact resistance of the high temperature tested connector was 3.258 mV/A, and its measured insulation resistance was greater than $10\;G{\Omega}$ All specimens demonstrated uniform insulation characteristics, which could be seen to be in good condition. From the withstand voltage test results found before and after performing the high temperature operation test on the connector for cable connection, it was confirmed that the withstand voltage characteristics between all terminals were good. The insertion force of the connector connecting the internal wiring averaged 9.67 kgf. It was observed that the insertion force between the plug housing and the female terminal, and that between the plug housing and the male terminal, were 0.680 kgf and 1.27 kgf on average, respectively.

• 터널과지하공간
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• 제24권2호
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• pp.120-130
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• 2014

최근 전 세계적으로 여러 건의 대규모 해저터널 건설 사업이 완료되었거나 진행 혹은 계획 중에 있다. 우리나라 역시 한중, 한일 해저터널에 대한 기본 구상이 이루어지고 있으며 동시에 국내 도서 지역을 연결하는 해저터널이 구상 단계에 있다. 국내 기술수준과 해저터널 건설이 갖는 파급효과를 고려할 때, 해저터널 관련 기술의 확보 및 개선이 요구되어진다. 이 논문은 사례연구를 통하여 해저터널이 갖는 특징과 국내외 해 하저터널 건설동향을 분석하였고 해저터널과 관련된 사고 발생 사례를 수집하여 이로부터 요구되는 관련기술에 대하여 정리하였다.

• Nuclear Engineering and Technology
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• 제31권6호
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• pp.572-585
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• 1999

The characteristics of two-phase flow instability in a vertical boiling channel connecting with an unheated riser are investigated through the linear stability analysis model. Various two-phase flow models, including thermal non-equilibrium effects, are taken into account for establishing a physical model in the time domain. A classical approach to the frequency response method is adopted for the stability analysis by employing the D-partition method. The adequacy of the linear model is verified by evaluating experimental data at high quality conditions. It reveals that the flow-pattern-dependent drift velocity model enhances the prediction accuracy while the homogeneous equilibrium model shows the most conservative predictions. The characteristics of density wave oscillations under low-power and low-quality conditions are investigated by devising a simple model which accounts for the gravitational and frictional pressure losses along the channel. The necessary conditions for the occurrences of type-I instability and flow excursion are deduced from the one-dimensional D-partition analysis. The parametric effects of some design variables on low quality oscillations are also investigated.

• 한국해안해양공학회지
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• 제11권1호
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• pp.1-6
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• 1999

해안 및 해양에 설치되어 있는 해저관로는 원유, 가스, 물과 이들의 혼합된 유체들을 전달하기 위한 수단으로 사용되고 있다. 관로 내부 유체의 열과 압력 차이는 해저관로의 팽찰을 야기시킨다. 해전관로 팽창은 관로와 연결되는 구조물들에 응력을 유발시킨다. 작용 응력이 연결 부재의 항복점을 초과하거나 전체 시스템의 허용변형을 초과할 경우 구조물에 손상이 발생된다. 해안 및 해양에 설치되는 해저관로는 주로 위험 물질이나 유독 유체를 포함하기 때문에 만약 이런 유체의 유출이 발생될 경우 인명 피해는 물론 큰 경제적 손실을 가져온다. 비록 해저관로는 시간적/공간적 제약 없이 유체를 전달할 수 있지만, 이런 관로 설계시 안전하게 그 기능을 수행할 수 있도록 고려되어야 한다. 본 논문에서는 해저관로의 열변형 해석에 사용되는 여러 개의 이론을 조사하였고, 관로의 요소들이 관로 팽창에 미치는 영향에 대해 조사하였다.

• 교육시설 논문지
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• 제28권5호
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• pp.3-8
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• 2021

The purpose of this study was exploring perceptions of people in community towards community use and multiple-use of special school facilities and providing implications for connecting school to the communities. Survey was conducted to special education teachers, parents of children receiving special education, and local residents. Total 5,702 people participated in this study and general finds were as following: (1) All 3 groups of study participants reported that there was a generally positive perception of special schools within the community, however, at the same time, almost quarter of parents having children with disabilities reported negative perceptions of special schools in the community; (2) among the special school facilities, sports facilities appeared to be the most open to the community and difficulties related to the community-open of school facilities included facility management and safety issues, and inteference with students' school activities; (3) facilities suitable for the multi-use of special schools facilities included sports facilities, cultural and creative spaces, and commercial areas, and those facilities could be open to community during non-class hours such as after-school, weekends, and vacations. Based on the results from survey, implications for planning, designing, and implementing multi-use facilities of special schools were provided.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2009년도 추계학술발표논문집
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• pp.989-993
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• 2009

Wireless LAN(WLAN) is a rather mature communication technology connecting mobile terminals. IEEE 802.11 is a representative protocol among WLAN technologies. With the rising popularity of delay-sensitive real-time multimedia applications(video, voice and data) in IEEE 802.11 wireless LAN, it is important to study the MAC layer delay performance of WLANs. In this paper, performance for packet delay that recently have been proposed schemes is analysed in wireless LAN and proved performance results via simulation.

• 기술사
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• 제33권6호
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• pp.51-56
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• 2000

Recently we cannot almost pass a day without watching a word internet on TV or in the magazings; but the history of internet is considerably old and it has passed more than 30 years. The internet (internetworking), as we know from the words "international"or "interstate", meant originally to connect computer network, but at the present time generally it means one particular network connecting the world. We are being surrounded by the internet so rapidly that I would like to describe its historical background, present status, further it′s subjects, future prospect of th internet.

• Journal of Chest Surgery
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• 제12권3호
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• pp.225-232
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• 1979

A 15-year-old girl underwent successful surgical correction of double-outlet right ventricle [S.D.L.] subaortic ventricular septal defect, patent foramen ovale, and pulmonary hypoplasia with valvular stenosis. The operation consisted of an internal baffling connecting the left ventricle to the aorta through the ventricular septal defect. The pulmonary stenosis was corrected with the method of connection the right ventricle to the pulmonary artery bifurcation using the Hancock valve[18mm] contained conduit. This rare type of DORV seemed to be suitable for corrective surgery, and the patient`s condition is very good until present time (post operative 7 months).

• 한국통신학회논문지
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• 제31권10A호
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• pp.996-1002
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• 2006

USB(Universal Serial Bus)는 최근 컴퓨터시스템에서 가장 인기 있는 인터페이스 중의 하나인데 이를 보다 확대하여 사용 시 즉, 다수의 디바이스들이 서로 연결되는 댁내망을 구성할 때는 버스대역을 시분할 다중화(TDM, Time Division Multiplexing) 방식으로 사용하는 USB의 특징상 버스대역의 병목현상을 초래하게 되는 데 이러한 상황을 보다 효율적으로 대처할 수 있는 버스 대역 사용방안을 제안한다.

• Molecules and Cells
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• 제28권2호
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• pp.75-80
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• 2009

The cyclic environmental conditions brought about by the 24 h rotation of the earth have allowed the evolution of endogenous circadian clocks that control the temporal alignment of behaviour and physiology, including the uptake and processing of nutrients. Both metabolic and circadian regulatory systems are built upon a complex feedback network connecting centres of the central nervous system and different peripheral tissues. Emerging evidence suggests that circadian clock function is closely linked to metabolic homeostasis and that rhythm disruption can contribute to the development of metabolic disease. At the same time, metabolic processes feed back into the circadian clock, affecting clock gene expression and timing of behaviour. In this review, we summarize the experimental evidence for this bimodal interaction, with a focus on the molecular mechanisms mediating this exchange, and outline the implications for clock-based and metabolic diseases.