• KIPS Transactions on Software and Data Engineering
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• v.3 no.6
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• pp.237-242
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• 2014

Current digital door lock systems are mainly designed for users' convenience, so they have weakness in security. Thus, this paper suggests a video digital doorlock system grouped with a relay device, a server, and a digital doorlock with a camera, sensors, and communication modules, which is detecting or recognizing objects approaching to the front of the door lock system and sending images and door-opening information to users' smart devices. Experiments showed that the suggested system has 96~98% recognition rate of approaching objects and requires 17.1~23.9 seconds for transmission on average, depending on network systems. Therefore, the system is thought to have enough capability for real time security response by monitoring the front area of the doorlock system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.1147-1150
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• 2007

Korean traditional houses have been developed in sympathy with natural environment and formed comfortable indoor condition by properly using surrounding natural resources including building layout, space construction and material. Or traditional wooden windows adjusting ambient temperature and humidity have both the functions of window and door, although they are clearly divided in the West. While window paper is attached from the outside in China and Japan, it is attached from the inside in Korea. The opening and closing mode of windows is similar and their dimensions are shown not to be standardized but diverse in terms of the characteristic of wooden furniture and that of components placed between columns. Thus this study is to look into the performance of band-lattice door of a typical traditional one by observing changes in sound insulation characteristics according to difference in thickness and finishing method of window paper and those in sound insulation characteristics with the changed thickness of air layer in traditional windows and doors.

• Fire Science and Engineering
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• v.28 no.5
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• pp.37-43
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• 2014

In the case of interior fire in an apartment building, contamination of vestibule area by fire smoke before air fan operating when fire doors are open makes the evacuation of people very difficult. In order to investigate the effect of heat release rate (HRR) and interior opening on fire flow velocity, numerical simulations using Fire Dynamics Simulator were carried out. In simulations, actual dimensions and configuration of an apartment building were considered and interior leakage and HRR were varied. From simulation results, it was found that fire flow velocity distribution is significantly influenced by HRR and interior opening resulting in the change of the location of a neutral plane. Also, it is shown that there is a larger difference of the fire flow velocity between upper and lower part of the fire door when the neutral plane becomes closer to the ceiling.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2546-2551
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• 2007

Weather Strip(W/S) is a rubber part to proof water, sound and dust for opening and shutting devices including vehicle doors. And it requires high dimension precision and durability to proof water, noise, vibration and etc. But ironically it itself makes some wind noise because of some protuberance with glasses. The air flow analysis of door part of vehicle makes it possible to calculate and find out the cause of wind noise. In previous analysis, we focus on the numerical air flow analysis of the automobile side part. We do 2D-C.F.D first and 3D second. Through simulations, we can calculate the amount of sound pressure level at the glass run and find out the effects of glass run to make wind noise. Finally we can improve shape of glass run to reduce wind noise although it is small amounts of sound pressure reduction compared with total vehicle noise level.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.17-20
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• 2006

Korean traditional houses have been developed in sympathy with natural environment and formed comfortable indoor condition by properly using surrounding natural resources including building layout, space construction and material our traditional wooden windows adjusting ambient temperature and humidity have both the functions of window and door, although they are clearly divided in the West. While window paper is attached from the outside in China and Japan, it is attached from the inside in Korea. The opening and closing mode of windows is similar and their dimensions are shown not to he standardized but diverse in terms of the characteristic of wooden furniture and that of components placed between columns. Thus this study is to look into the performance of band-lattice door of a typical traditional one by observing changes in sound absorption characteristics according to difference in thickness and finishing method of window paper and those in sound absorption characteristics with the changed thickness of air layer in traditional windows and doors.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.2
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• pp.81-88
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• 2020

The damping hinge of a built-in refrigerator was examined in terms of its stress and fatigue life. Analysis of the initial design showed that stress concentration occurred at the concave surface of the hinge lever, which was broken during the door opening-and-closing endurance test of the prototype. The maximum von Mises stress at this location exceeded the yield strength. In addition, Goodman fatigue analysis of the initial design showed that the fatigue life at this location was consistent with the failure observed during the endurance test. Based on these results, an improved design for the damping hinge was derived. Analysis of this improved design showed that the stress concentration in the hinge lever of the initial design was eliminated. In this case, the maximum stress occurred at the position where the hinge lever was in contact with the door stopping pin, and the maximum von Mises stress was smaller than the yield strength. Goodman fatigue analysis of the improved design indicated that the fatigue life of the entire damping hinge was infinite. It was therefore concluded that the improved design does not suffer from fatigue damage during the endurance test.

• Fire Science and Engineering
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• v.25 no.6
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• pp.178-183
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• 2011

In cold season, the elevator systems in super high-rise buildings would make noises at the door-gaps on high floors, and the elevator doors on the 1st floor would suffer from opening/closing trouble due to the pressure differences. Such pressure differences are also the main driving power of smokes through the hoistway in the case of fire. In addition, the pressure differences should be overcome to use the elevator systems as a measure of emergency escape. This paper reviews the way of hoistway pressurization to reduce the adverse influences. Simulations achieved a good result close to the requirements of NFPA 92A and IBC 2012 under the condition that the hoistway should be pressurized after pressure equalizing between floors and hoistway with the openings through the hoistway wall.

• Journal of architectural history
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• v.6 no.2 s.12
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• pp.9-22
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• 1997

The results of analyzing opening types in the rear elevations of ninety-six buddhist temples which would be existence can be summarized as follows ; 1) Opening types in the rear elevations of buddhist temples in the Koryo Dynasty were various as the type of doors and windows, and the type of combining with walls. but the fact had something in common that whole door was the swinging pannel one, and the type of the whole window was the lattice and the mullioned casement one. 2) The type of the lattice windows were disappered and the only type of the mullioned casement windows were put in an apperance in the early period of Cho-sun Dynasty. 3) The type of doors + walls and the type of doors + windows in the rear elevations of buddhist temples of the seventeenth century were absolute. Especially the mullioned casement windows were used mainly in buddhist temple of the type of doors + windows. 4) The type of doors + windows in the rear elevations of buddhist temples of the eighteenth century did not be seen, but types of doors + walls and walls + walls which were much enclosed, were mainly put to use in those.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.34 no.3
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• pp.189-192
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• 2024

Objectives: To protect researchers using chemicals, it is necessary to monitor whether the working environment is well managed through the performance evaluation of the local exhaust system in the research laboratory. These results need to be reflected in the work environment management policy of research laboratories in the future. Methods: By measuring the capture velocities of fume hoods and arm hoods, which are the most commonly used local exhaust systems in research laboratories in a domestic research institute, we tried to confirm the degree to which the actual capture velocity values and legal standards were satisfied. The capture velocities were measured using a hot wire wind speedometer (TSI 9565-P, USA, 2016 with all exhaust systems in operation in the laboratory. As for the measurement position for each local exhaust system, in the case of the fume hood, the wind speed in the center of the opening surface was measured after opening 50% of the door of the hood. For the arm hood the capture velocities were measured at a distance of 10 cm vertically from the opening surface of the hood Conclusions: The total number of arm hoods measured was 546, and the average capture velocity was 0.61 m/sec with an S.D of 0.49. Among them, 99 satisfied the capture velocity standard of 1m/sec, meaning only 18.1% of the total satisfied with the standard. The total number of fume hoods measured was 625, and the average control wind speed was 0.48 m/sec with an S.D. of 0.17. Among them, the number of fume hoods that satisfied the capture velocity standard of 0.4 m/sec was 518, meaning 82.9% of the total satisfied the standard. Therefore, research institutes that operate local exhaust systems to protect researchers from chemicals should further strengthen the capture velocity management of hoods, and government agencies need to reflect this in work environment management policies based on further evaluation results.

• Korean Journal of Human Ecology
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• v.10 no.2
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• pp.37-42
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• 2007

The scale and the extent of a aging of population of a rural are more serious than those of a urban in China. However, the welfare policy and the service for the aged in the rural are inferior. China established the different systems of social welfare policy for the city and the rural and has administered it since the china was established. Owing to an open-door policy(opening of a reform) the gap between the two got more deeply distinguished. Accordingly. the striking difference is shown in a living environment and a quality of life of the cities and the rural. I made clear the difference of services for the aged in the rural and the urban examining daily lives, medical industry, recreation systems and so on and analyzing their sources. In addition, I proposed the ways to establish synthetic social welfare policy of the urban and the rural.