• KIEAE Journal
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• 제15권1호
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• pp.97-102
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• 2015

Recently many buildings are airtight, deterioration takes the high stage. As this room ventilation is increasingly difficult, the importance of indoor air was emphasized. And Got a few provisions on the indoor ventilation, the building is used for other purposes also requires a lot of careful research. In this study, consisting of floor heating ventilation in the room and wants to know the impact on the human body react with the carbon dioxide concentration in the indoor air were investigated PMV. We have get the data through the experimental study like this. It can be inferred correlations of ventilation and temperature according to human comfort that you should consider when using the work of residential buildings in accordance with the changing social conditions and social. It is also determined that in the future through additional experiments related data can be established basic experimental data.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.209-212
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• 2005

Recently, since structures have become extremely airtight with the development of high-rise apartments, mixed use residential and commercial buildings and offices, large capacity range hoods have become commonly implemented. However, the high noise level caused by this range hood system made of thin plate is the cause of increased complaints among users. In this study, the level of noise emitted from this type of range hood was measured by height at the user's location in the kitchen. It was confirmed that a great deal of noise was emitted in the downward direction of the hood. In order to minimize the noise emitted from this type of range hood, a new type of fan was manufactured. This was done by changing only the material and shape of the fan, since it was determined to be the primary source of noise emission. Then a comparison and evaluation were carried out regarding the noise characteristics between the new type of fan and the existing type of fan. As a result, it was confirmed that the noise from the new fan was reduced by more than 2 dB compared to the existing fan without noise interference at the discharge end.

• The Plant Pathology Journal
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• 제27권3호
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• pp.257-265
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• 2011

During 2002-2008 in Korea, 455 extracts from myxobacteria consisting of 318 cellulolytic and 137 bacteriolytic myxobacteria were isolated, which were then screened for antifungal activity against the phytopathogens Botrytis cinerea, Colletotrichum acutatum, Penicillium sp., Pyricularia grisea, and Phytophthora capsici. 204 isolates had antifungal activity, causing both a clear zone due to blocked spore germination and inhibition of mycelial growth; most (199) were from cellulolytic (Sorangium cellulosum) and only five were from bacteriolytic myxobacteria. B. cinerea, the best controlled among the five tested pathogens, had a unique group of antifungal isolates of myxobacterial extracts compared to the other pathogens' groups. Among seventy-nine bioactive myxobacteria, four isolates, KYC 3130, KYC 3247, KYC 3248 and KYC 3270, were selected and all were cellulolytic. Liquid culture filtrates of these four myxobacteria were applied to tomato, cherry tomato, strawberry, and kiwi fruits 5 h before inoculation with gray mold conidia; then the treated fruits were placed in an airtight container and the experiment was repeated six to eight times. Incidence (%) of gray mold on fruit of the infected control treatment was 84-98%, whereas it was only 5-21% after the KYC 3270 treatment. After KYC 3270 treatment of the four fruits, mold control was 79-95%, which was highest among the filtrates and statistically the same as treatment with fludioxonil, a registered chemical against gray mold of stored fruits.

• 한국안전학회지
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• 제33권5호
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• pp.51-59
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• 2018

It is difficult to determine the outdoor toxic level of hazardous chemicals that are leaked in the building, since there are no efficient ways to calculate how much percentage of the leaked chemicals is released into the outdoor atmosphere. In address to these problems, we propose a reasonable box model that can quantitatively evaluate the mass rate of the indoor chlorine leakage into the outside of the building. The proposed method assumes that the indoor chlorine leakage is fully mixed with the indoor air, and then the mixture of the chlorine and indoor air is exfiltrated into the outside of the building through effective leakage areas of the building. It is found that the exfiltration rate of the mixture of the chlorine and indoor air is strongly dependent on the temperature difference between inside and outside the building than the atmospheric wind speed. As compared with a conventional method that uses a vague mitigation factor, our method is more effective to evaluate the outdoor toxic threat zone of the chlorine that are leaked in the building, because it can consider the degree of airtight of the building in the evaluation of the threat zone.

• 한국항해항만학회지
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• 제27권5호
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• pp.459-464
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• 2003

강제 횡동요 실험을 통하여 동요하는 탱크의 내부압력을 폭정하고, 탱크의 내부압력을 추정하는 간단한 이론식을 제시하였다. 청수로 채워진 사각 탱크를 동요실험에 사용하였으며, 탱크의 안쪽 벽과 바닥에 압력게이지를 설치하여 내부압력의 시간변화량을 측정하였다. 측정된 탱크의 내부압력의 실험값과 이론식을 이용한 계산값을 비교하였다. 횡동요 하는 탱크내부의 압력을 구하기 위해 압력중심을 고려하여 추정하는 방법을 연구하였다.

• 설비공학논문집
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• 제30권4호
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• pp.195-203
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• 2018

Mohair is widely used as an airtight material for filling the gap between a window frame and sash. The purpose of this study is to investigate infiltration rate and opening force of sliding windows according to the mohair installation conditions. Infiltration experimental apparatus was set up, and the experimental results were applied to windows to find a correlation between infiltration rates and opening forces. When 4 rows of mohair were installed, the infiltration rate increase became 27.1% per clearance length increase of 1 mm, and the infiltration rate decrease became 5.7% per shortened length increase of 0.1 mm. For 4 rows of mohair, the opening force decreased by 28.2% as the clearance increased by 1 mm, and it increased by 9.3% as the shortened length increased by 0.1 mm.

• Journal of Ginseng Research
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• 제18권2호
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• pp.128-133
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• 1994

Color characteristics were investigated for white ginseng powder immediately and during storage following treatments of gamma ray or ethylene oxide (EO) for microbial decontamination. The variation in fatand water-soluble pigments of the sample was negligible immediately after both treatments, however an apparent increase was observed in the samples stored for four months at $25^{\circ}C$ and RH 90%, in the order of nontreated control, EO-fumigated, and 5 key-irradiated samples. Hunter's color a and b values of white ginseng powder increased slightly in proportion to irradiation doses, whereas EO fumigation caused a decrease in L value and an increase in a and b values of the sample, showing overall color difference (${\delta}^E$) of 1.8. Considering the higher ${\delta}^E$ in the higher RH conditions, airtight packaging and sterilization using like gamma ray were considered an effective means for maintaining high quality of color characteristics in stored white ginseng powder.

• 한국환경보건학회지
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• 제21권4호
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• pp.56-62
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• 1995

Recently, the traffic noise around residences and schools has become a serious social problem with the increase of the amount of transportation. This study was performed to investigate the sound proof efficiency of windows for traffic noise. The results were as follows 1) The traffic noise in 19 sites among 22 sampling sites was higher value than 65 dB(A) being roadside environment standard level in the daytime when all windows were opened, while the noise in 22 sampling sites was transmitted below standard level when all windows were closed. 2) The transmission loss of sound level at single window and double windows were 10~25 dB(A) and 11~29 dB(A) respectively. 3) The transmission loss of sound level at sampled school with sound proof pannel was 7~8 dB (A), which was lower 2~7 dB(A) than the theoretical value of the influence assessment . 4) The construction cost of double windows was lower 28% even if include the cost of setting up air conditioner for the summer season and the power consuming cost for its operation than that of sound proof pannel for traffic noise. 5) The effect of transmission loss of windows was more influenced by airtight than materials of windows.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1294-1297
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• 2003

With the development of medical field, many kinds of operations have been performed on human articulation. Arthroscopic surgery, which has Irrigation Pumping System for security of operator vision and washing spaces of operation, has been used for more merits than others. In this paper, it is presented that the research on a reliable control algorithm of the pumping system instrument for arthroscopic surgery. Before clinical operation, the flexible artificial articulation model is used for realizing the model the most same as human's and the algorithm has been exploited for it. This system is considered of the following; limited sensing point, dynamic effect by compliance, time delay by fluid flow and so on. The system is composed with a pressure controller, a regulator for keeping air pressure, an airtight tank that can have distilled water packs, artificial articulation and a measuring system, and has controlled by the feedback of pressure sensor on the artificial articulation. Also the system has applied to Smith Predictor for time delay and the parameter estimation method for the most suitable system with both the experiment data and modeling. In this paper, the pressure error that is between an air pressure tank and an artificial articulation was measured so that the system could be presumed and then the controller had developed for performing State-Feedback. Finally, the controller with a real microprocessor has realized. The confidence of system can be proved by applying this control algorithm to an artificial articulation experiment material.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.321-325
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• 2000

Gasket of vehicle engine maintains airtight between cylinder head and engine block under high temperature and pressure, and plays important role in heat conduction of engine. And the characterization of the nonlinear behavior of metal gasket fer various bead shapes is very important as basic research for estimation of gasket durability. But it is very difficult to analyze the behavior of gasket In real experiment. In this paper, to analysis effects of the bead shape on the nonlinear behavior of cylinder head gasket under uniform pressure, the virtual experiment using the nonlinear finite element method was performed. Results are analyzed with residual deformation and the sealing pressure. With the increase of the height and the width of bead, the residual deformation and the sealing pressure increase. And if the height is very high and the width is very narrow, the wrinkles are occurred in the gasket while working.