• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.751-756
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• 2009

In the perspective of saving energy in buildings, the high performance of insulation and air tightness for improving the heating and the cooling efficiency, has brought economically positive effects. However, these building energy saving technologies cause the lack of ventilation, which is the direct cause of increasing the indoor contaminants, and is also very harmful to the residents, because they spend over 90% of their time indoors. Therefore, the ventilation is important to keep the indoor environment clean and it can also save the energy consumption. In this study, a HEPA type nano ceramic filter is designed as a passive ventilation system to collect airborne particles and to supply fresh outdoor air. The double layer filter, which has $30{\mu}m$ in diameter at the conditions of 10wt% of concentration and 3kV/cm of the electric intensity, is produced by electrospinning. The filtration coating technology is confirmed in the solution with $SiO_2$ nano particles using polymer nano fibers. Also double layer filters are coated with $SiO_2$ nano particles and finally the porous construction materials are made by sintering in the electric furnace at $200{\sim}1400^{\circ}C$. The efficiency is measured 96.67% at the particle size of $0.31{\mu}m$, which is slightly lower than HEPA filter. However the efficiency is turned out to be sufficient.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.11
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• pp.1683-1695
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• 2009

This study analyzes the production process of eight domestic companies that manufacture scuba diving suits for men with an emphasis on the level of consumer satisfaction in scuba diving suits purchases. One hundred fifty questionnaires were distributed and a total of 140 usable data were coded for further statistical analysis that includes descriptive statistics (frequency and ${\chi}^2$ test) through SPSSWIN 17.0. The results show that a majority of the domestic scuba diving suit companies were either small, manufactured products under original equipment manufacturer (OEM) brands, or were involved in the import business. Many of these companies have developed a local sizing system derived from a company database of customer sizing. As a result, different companies have different sizes that lead to confusion and complication among consumers in selecting the correct size for scuba diving suits. The results indicate that most high-priced diving suits are made of imported fabrics because they had superior quality, fitness, and thickness compared to domestic brands. The degree of consumer satisfaction with scuba diving suits was found to be low in comfort, stuffiness, and activity. Respondents indicated that they felt a little tightness in circumstances such as bust, wrist, and thigh in measurements of circumstances. On the other hand, the respondents showed a high degree of satisfaction with body fitness in scuba diving suits. Further research will clarify a standardized sizing system and develop patterns suitable for Korean men's scuba diving suit body sizes.

• Tunnel and Underground Space
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• v.23 no.4
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• pp.319-325
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• 2013

The objective of this study is to assess risks which might occur in connection with the storage of the highly compressed air in underground opening. Risk factors were selected throughout literature survey and analysis for the characteristic of CAES. Large risk factors were categorized in three components; planning and design phase, construction phase, and operation & maintenance phases. Large category was composed of 8 medium risk groups and 24 sub-risks. AHP technique was applied in order to analyze the questionnaires answered by experts and high-risk factors were selected by evaluating the relative importance of risks. AHP analysis showed that the operation & maintenance phases are the highest risk group among three components of large category and the highest risk group of eight medium risk groups is risk associated with the quality and safety. Risk having the highest risk level in 24 sub-risks is evaluated to be a failure of tightness security of inner containment storing compressed air.

• Journal of the Korean Ceramic Society
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• v.45 no.12
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• pp.802-806
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• 2008

A proper sealant for low temperature SOFCs should show zero or low leak rates to avoid direct mixing of the fuel and oxidant gases or leakage of fuel gas during the operation of SOFCs. Furthermore, it should be chemically and/or mechanically stable in both oxidizing and reducing environments and chemically compatible with other fuel cell components. In the present work, we developed a novel compressed seal gasket of glass-based composite reinforced with ceramic particulate particles, which can efficiently control the viscous flow of glass matrix as well as the crystallization of glass phase. This novel sealing gasket showed excellent gas tightness under very low compressive load which would be suitable for the operation of SOFCs in the temperature range $600{\sim}650^{\circ}C$.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.6
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• pp.675-682
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• 2017

New government, the market for stationary fuel cell systems in domestic is expected to expand in line with the policy for expanding new and renewable energy. In order to promote and expand the domestic market for stationary fuel cell systems, it is required to do research and develop for cost reduction and efficiency improvement technologies through the localization of BOP. In this study, the safety performance including the power consumption, flow rate, noise and air-tightness of the domestic fuel booster blower and the foreign fuel booster blower was evaluated and the performance improvement of the domestic blower was confirmed. As a result of the power consumption measurement and the flow rate according to the back pressure of the A company 2nd prototype and B company, the values were 73 W, 27 LPM, and 55 W, 25 LPM. These results are attributed to the improvement of performance through design changes such as CAM angle and diaphragm material.

• Korean Journal of Adult Nursing
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• v.14 no.3
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• pp.459-469
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• 2002

Purpose: Experience of chest pain may be different in women from that of men and this discrepancy may cause misdiagnosis of angina contribute to mortality by this disease in women. The purpose of this study was to analyze the characteristics of chest pain and responses to the symptoms in women. Method: A content analysis was conducted with interviewed data obtained from women who underwent the treadmill test Result: Seven major categories were identified from this content analysis: attributes of chest pain; accompanied symptoms; precipitating factors; relief strategies; family support; communication with physicians; and effects of chest pain on their lives. Characteristics of pain were described as heaviness, tightness, heating sensation, tearing, and others. Duration and intensity of pain varied in a wide range. Radiating pain presented in 9 patients, and the locations of radiation were throat, neck, shoulder arm and fingers. Women tended not to respond actively to their chest pain, and didn't get appropriate support either from their family or from their physicians when they reported chest pain. Conclusion: Women express non-typical as well as typical patterns of pain when they experience chest pain. Clinicians have to consider the variability of symptoms when they assess women with suspicions of angina.

• Journal of Korea Multimedia Society
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• v.17 no.11
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• pp.1363-1373
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• 2014

In this study, a hybrid multi-cup electric cupping system (HMECS) was proposed, based on the ancient cupping method. HMECS consisted of several cups that could be used simultaneously to treat different areas of the patient's body. Each cup was equipped with its own pump and pressure-monitoring system. Moreover, the vacuum pressure of the cups was controlled using fuzzy logic. Through automated control of the vacuum pressure, long-term relief of muscle tightness was achieved. To develop a scientific foundation for this alternative treatment, we compared the VAS(Visual Analog Scale) and ODI(Oswestry Disability Index) scores from conventional basic cupping to the VAS and ODI scores for our proposed HMECS. The improvement rate in the VAS and ODI scores using HMECS after three treatments was higher than that achieved by basic cupping. These results, combined with the convenience offered by enhanced IT capabilities, should increase the popularity of this device among an aging society, and facilitate the opportunity to further explore the potential of Oriental medical practices.

• Journal of the Korean Society of Physical Medicine
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• v.10 no.4
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• pp.1-7
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• 2015

PURPOSE: The purpose of this study was to compare the effects of cross-body stretching (CBS) and modified cross-body stretching (MCBS) on the range of motion (ROM) of glenohumeral joint (GHJ) in healthy subjects. METHODS: Thirty subjects were randomly assigned to 1 of 2 groups: CBS group without stabilization of scapula (n=15) and MCBS group with stabilization of scapula (n=15). We measured horizontal adduction and internal rotation ROM of GHJ in pre- and post-intervention. The data were analyzed using the analyses of covariate (ANCOVA) and least significant difference (LSD) post hoc tests (p=.05). RESULTS: In the post-intervention, the MCBS group had a significantly greater increase in horizontal adduction ROM (mean ${\pm}$ SD, $11.46^{\circ}{\pm}0.83^{\circ}$) compared to the CBS group ($7.81^{\circ}{\pm}0.83^{\circ}$) (p=.007) and a greater increase in internal rotation ROM ($62.27^{\circ}{\pm}0.74^{\circ}$) compared to the CBS group ($59.20^{\circ}{\pm}0.74^{\circ}$) (p=.004). CONCLUSION: A single session application of an MCBS provides immediate more improvements in both horizontal adduction and internal rotation ROM than CBS. These results suggest that application of MCBS with stabilization of scapula may be a more useful to gain ROM of GHJ than CBS without stabilization of scapula.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.8
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• pp.17-25
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• 1998

Aluminum alloys have low density, relatively high strength and yield strength, good plasticity, good machinability, and high corrosion and acid resistance. Therefore, they are suitable for large containers for the food, chemical and other industries. Large containers are often bodies of revolution consisting of shell courses, stiffening rings, heads and other elements joined by annular welds. Larger containers have longer welds and require greater leak-tightness and higher weld mechanical properties. The LNG tank consists of aluminum plates with various sizes, so its construction should by divided by several sections. Moreover, each section has its own sub-section consisted of several aluminum plates. To guarantee the quality of huge LNG tank, therefore, the precise control of plate dimension should by urgently needed in conjunction with the appropriate selection of process parameters such as cutting speed, depth of cut, rotational speed and so on. In this paper, a manufacturing system was developed to implement automatic circular tracking in height direction and automatic circular interpolation in depth of cut direction. Also, the neural network based on the backpropagation algorithm was used to predict the cutting quality and motor load related with the life time of the developed system. It was revealed that the manufacturing system and the neural network could be effectively applied to the bevelling process and to predict the quality of machined area and the motor load.

• Applied Chemistry for Engineering
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• v.3 no.4
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• pp.639-648
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• 1992

For recycling cement hydrate(CH) as waterproofers for mortar and concrete or a filler for rubber & plastics, the cement hydrates were treated with stearic acid(SA). And the bonding characteristics and the water repellency of the CH-SA compounds were investigated by using FT-IR, TGA, SEM, XRD, and contact angle measuring apparatus. Water tightness of the remitars used CH-SA compounds was also tested. The results are summarized as follows : 1) If the cement hydrates are treated with over 2.0% of stearic acid, the CH-SA compounds show very strong water repellency. 2) The stearic acids are solidified on the surfaces of cement hydrate in calcium stearate and aluminium stearate. 3) If CH-SA compounds which is cement hydrate treated with 5~10% of stearic acid are used 3%~6% in remitar, water absorption ratio and water permeatility ratio of remitar are decreased in below 30% of those of the ordinary remitar.