• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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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.

• Tunnel and Underground Space
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• v.24 no.2
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• pp.120-130
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• 2014

Recently, a few mega projects of subsea tunneling are completed or ongoing or under planning stage all across the world. In Korea, subsea tunnels connecting to Japan and China have been considered in the past decades. At the same time, subsea tunnels connecting to domestic islands were planned with preliminary design concepts. Development and improvement of indigenous techniques regarding subsea tunneling are essential in light of current technical level in Korea and their future impact on tunneling industry. In this paper, distinct features of subsea tunnel and construction trend of subaqueous tunnels are analyzed via case studies. Also, case studies about incidents related to subsea tunneling and required techniques to secure safety are presented.

• Nuclear Engineering and Technology
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• v.31 no.6
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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.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.11 no.1
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• pp.1-6
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• 1999

Nearshore and offshore pipelines are often applied to carry oil, gas, water and combined products. The thermal and pressure gradients of the fluid inside pipeline cause pipeline expansion. This expansion produces stress to connecting structures with pipeline. Should this stress exceeds the yield strength of connecting components or the allowable displacement of the system, a damage can occur. As most pipelines contain hazardous and toxic fluids, the damage usually leads to fatal accidents involving great economic loss as well. Even subsea pipelines can be easily applied to transport liquid type fluid without time and space constraint, they should be designed and maintained carefully to be functional safely during design lifetime. In this paper, various theories estimating pipeline thermal expansion are investigated and the effects of pipe components to expansion are studied.

• Journal of the Korean Institute of Educational Facilities
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• v.28 no.5
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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.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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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.

• Journal of the Korean Professional Engineers Association
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• v.33 no.6
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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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• v.12 no.3
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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).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.10A
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• pp.996-1002
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• 2006

USB(Universal Serial Bus) is one of the most popular communication interfaces. When USB is used in an extended range, especially configurating In-home network by connecting multiple digital devices each other, USB interface uses the bandwidth in the way of TDM (Time Division Multiplexing) so that the bottleneck of bus bandwidth can be brought. In this paper, the more effective usage of bus bandwidth to overcome this situation is introduced.

• Molecules and Cells
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• v.28 no.2
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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.