• Journal of the Korean Society of Safety
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• v.14 no.3
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• pp.40-47
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• 1999

A numerical study on gaseous explosion was carried out to predict the transient pressure behavior with the partial rupture in confined vessels. Equations, assumptions and solutions for central ignition of premixed gases in closed spherical vessels are proposed with various equivalence ratios of gas fuel, as $CH_4$ and $C_3H_8$, vent areas and vent opening pressures. Given vent opening pressure in a vessel, the magnitude of second peak pressure results from the vent areas and burning velocity, varied by equivalence ratio of gas fuel. In a living room of an apartment, the higher second peak pressure than the vent pressure is not appeared due to its large window areas. As vent opening pressure is higher, the larger damage by gaseous explosion is expected and the larger vent area is necessary for relieving the damage. In the same concentration, the gaseous explosion by propane rather than methane shows the larger damage due to its higher adiabatic flame temperature and equivalence ratio.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.3
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• pp.232-238
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• 2018

Flabby ridges adversely affect the stability of complete dentures. For the management it is suggested that soft tissues reconditioned before making definitive dentures, and modified impression techniques used for the flabby ridges. Also, correct record of centric relation is important in complete dentures. This case of 67-year-old edentulous female patient had atrophied ridges on the mandible and the flabby ridge on the maxilla. Treatment dentures were fabricated using gothic arch tracing method and tissue conditioner. Definitive dentures were made using window opening impression technique, the gothic arch tracing method, and lingualized occlusion. The patient was satisfied with the function and esthetic quality of the new prostheses.

• KIEAE Journal
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• v.8 no.5
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• pp.3-10
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• 2008

The Korean traditional architecture has developed by adapting to the natural environment, and has successfully created a comfortable indoor settings by using the surrounding natural resources. This is reflected in the building layout, space design and even materials. 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. The opening and closing method of our traditional 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 aims to research the sound insulation and absorption performance of traditional windows to be varied with thickness, finishing method of window paper and thickness of air layer. Despite increase of the thickness of window paper, sound absorption was reduced, and the same result was shown when both sides of the structure were finished with thick window paper. The sound insulation performance of the windows could be evaluated to be inappropriate with $R_w$ 0 ~ $R_w$ 14.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.19 no.2
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• pp.61-65
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• 2013

Modified atmosphere (MA) of reduced $O_2$ and elevated $CO_2$ concentrations has been used for keeping the quality of fresh produce and extending the shelf life. As a way to attain the beneficial MA package around the produce, a gas diffusion tube or perforation can be attached onto the container and controlled on real time in its opening/closing responding to $O_2$ and $CO_2$ concentrations measured by gas sensors. The timely-controlled opening of the gas diffusion tube can work in harmony with the produce respiration and help to create the desired MA. By use of the mathematical modeling, the effect of tube dimension on the controlled container atmosphere was figured out in this study. Spinach and king oyster mushroom were used as typical commodities for designing the model container system (0.35 and 0.9 kg in 13 L, respectively) because of their respiration characteristics and the optimal MA condition ($O_2$ 7~10%/$CO_2$ 5~10% for spinach; $O_2$ 2~5%/$CO_2$ 10~15% for mushroom). With a control logic for the gas composition to stay as close as possible to optimum MA window without invading injurious low $O_2$ and/or high $CO_2$ concentrations, the atmosphere of the sensor-controlled container could stay at its lower $O_2$ boundary or upper $CO_2$ limit under certain tube dimensional conditions. There were found to be the ranges of the tube diameter and length allowing the beneficial MA. The desired range of the tube dimension for spinach consisted of combinations of larger diameter and shorter length in the window of 0.3~2 cm diameter and 0.2~10 cm length. Similarly, that for king oyster mushroom was combinations of larger diameter and shorter length in the window of 0.9~2 cm diameter and 0.2~3 cm in length. Clear picture on generally affordable tube dimension range may be formulated by further study on a wide variety of commodity and pack conditions.

• Journal of Biomedical Engineering Research
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• v.34 no.4
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• pp.189-196
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• 2013

Dielectrophoresis(DEP) is useful in manipulation and separation of micro-sized particles including biological samples such as bacteria, blood cells, and cancer cells in a micro-fluidic device. Especially, those separation and manipulation techniques using DEP in combination of micro fabrication technique have been researched more and more. Recently, it is revealed that a window structure of insulating layer in microfluidic DEP chip is key role in trap of micro-particles around the window structure. However, the trap phenomenon-driven by DEP force gradient did not fully understand and is still illusive. In this study, we characterize the trap mechanism and efficiency with different shapes of window in a microfluidic DEP chip. To do this characterization, we fabricated 4 different windows shapes such as rhombus, circle, squares, and hexagon inside a micro-fluidic chip, and performed micro-sized particles manipulation experiments as varying the frequency and voltage of AC signal. Moreover, the numerical simulation with the same parameters that were used in the experiment was also performed in order to compare the simulation results and the experimental results. Those comparison shows that both results are closely matched. This study may be helpful in design and development of microfluidic DEP chip for trapping micro-scaled biological particle.

• KIEAE Journal
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• v.4 no.3
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• pp.79-85
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• 2004

There is something valuable in Korean traditional architecture that does not change even after more than a number of years. Each design element of traditional houses has its own role to embody natural, healthy, and environment-friendly architectural planning. With traditional already-built examples located in the northern area of Gyeongbuk province, this study attempts to untangle some of the daylighting control issues in opening design. By looking at more than just photometric materials, at some threshold level, the whole of daylighting control characteristics of their openings is being surveyed from the viewpoint of geometric relationship between their roof structures and windows. As a glazing material, in addition, Korean traditional window covering paper, Changhoji, is evaluated for its transmittal performance under artificial and real skies as well.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.2-4
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• 2014

The preferred dimensions of the test opening for a window are $1250mm{\times}1500mm$ according to ISO 10140-1:2010. But tests done at actual size generally because not standardized for windows. In this study, we know the sound insulation characteristics by the size of windows using the single windows and double windows, consider the more effective performance evaluation method.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.8-9
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• 2018

In recent years, the fire risk in the aged housing facilities in high-rise building has been closing up due to the fire in the Grenfell Tower. In the case of these high-rise residential facilities, fire cases of residential facilities such as Uijeongbu Apartment Fire The fire hazard has been reexamined mainly. Especially, the fire of these residential facilities is very closely related to the window, so measures are needed. On the other hand, in Korea, there is almost no fire safety measures against these openings. Therefore, this study suggests improvement measures by comparison with advanced countries based on fire safety measures for domestic windows.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.1
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• pp.151-158
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• 2008

Upper and lower cuspids are very important teeth in point of function as well as esthetic. However, failure of eruption of the canine sometimes happens and is frequently encountered clinical problems. Upper cuspids are more frequently impacted as compared with lower cuspis and palatally impaction is more frequent event than labially impaction. Impaction of the mandibular canine is unusual event, especially crossing the midline (transmigration) is very rare. Because of, in most cases, there is no signs and symptoms, impacted teeth can be detected by periodic radiograph examination. The etiology of impaction is unclear and multifactorial. The treatment of impacted canine is influenced by presence of obstacles, location and direction of impaction, space for alignment and development of root. There are several treatment options; (1) Surgical removal and/or observation, (2) Window opening and orthodontic traction, (3) Autotransplantation. The first patient (impaction of upper right cuspid) is treated with window opening and orthodontic traction. The second patient (bilaterally impaction of lower cuspids) is treated with autotransplantation, because of transmigration.

• Computational Structural Engineering
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• v.3 no.4
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• pp.133-141
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• 1990

The nature of fluctuating air pressure inside building was studied by testing a building model in a wind tunnel. The model has a single room and a window opening. Various opening conditions were tested in both laminar uniform wind and turbulent boundary-layer wind. The RMS and the spectra of the fluctuating internal pressure were measured. The test results support a recent theory which predicts the behavior of internal pressure under high wind based on aerodynamic analysis.