• Journal of Applied Reliability
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• v.6 no.2
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• pp.173-186
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• 2006

This paper presents a study on the failure mechanism for optical engine of Projection TV. The lenses of which optical engine composes are failed by various environmental conditions, that is, thermal effect, moisture effect, mechanical shock or chemical effect. By surveying on actual TV working condition, the major factor of failure was turned out the thermal effect. Because the actual surface temperature of optical engine rose at max. $51^{\circ}C$ during it worked, the relative humidity around optical engine was kept at less than 20% that is difficult to do chemical reaction with humidity. Therefore we can make a conclusion that the major failure of optical engine resulted from thermal effect.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.596-598
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• 2000

This paper presents a new accelerating aging test facility for distribution lightning arresters. Aging parameters of lightning arrester are moisture ingress, electrical stress and surge absorption and so on. In this system, we applied 13.2kV to 6 samples and controled temperature and humidity of chamber and measured leakage currents of the all samples. Also we developed accelerating aging cycle which consists of -35$^{\circ}C$∼90$^{\circ}C$ temperature and 40%∼90% humidity. Through the aging test we found out the leakage current of aged sample increases rapidly according to the temperature rising. Hereafter we can determine the replacement guide of leakage current for field operating arresters and condition assessment of aged samples through this aging test.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.2068-2069
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• 2007

This study describes a compairison leakage current properties between a polluted insulator and insulator subjected to salt polluted condition. Exposure tests at a sea coast test and the leakage current of insulators, climate conditions, and salt deposit density were measured during the tests. Appearance of leakage current for the insulator was affected by the humidity and the salt deposition on the surface. comparison of leakage current under salt polluted conditions. salt polluted test and humidity tests were carried out in laboratory using the same insulator profiles in oder to determine the leakage current patterns during critical conditions

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.1166-1170
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• 2004

The leakage currents of transmission insulator were investigated as a function of environmental conditions, such as temperature, humidity, and rainfall. The insulators were artificially contaminated with insoluble yellow soil and kaolin which helped salt to stick on the surface of insulator. The insulators contaminated with the grade of B, C, and D were installed in the KoChang Testing Center. The leakage currents were measured and compared with non-contaminated insulators. The results indicated that the most important factor affecting leakage current was humidity. After heavy rain, the artificially contaminated salt was dissolved, resulting in similar characteristics between with and without contamination

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.38 no.5 s.118
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• pp.60-65
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• 2006

The physical and mechanical properties of linerboard were shown to be affected by changing atmospheric conditions. Two atmospheric conditions were measured in order to investigate how they were affected by different atmospheric conditions on the physical and mechanical properties of domestic linerboard. The basis data set for the standardization research was provided in this study. It is confirmed that the relative humidity seemed to be a major factor on the quality deterioration of a linerboard. Experimental results have shown that the short span compression test (SCT) could be used to evaluate the quality characteristics of linerboardat different moisture content and relative humidity.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.31-32
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• 2020

Concrete changes its internal moisture distribution depending on the external environment, and changes in the condition of the material's interior over time affect the performance of the concrete. These effects are closely related to the long-term behavior and durability of concrete, and the degree of deterioration varies from climate to climate in each region. In this study, we use actual climate data from each region with distinct climates. A multi-physical analysis based on the method was conducted to predict the difference and degree of deterioration rate by climate.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.16 no.6
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• pp.613-619
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• 1987

In a room air conditioning cooling system, if the room-sensible-heat-factor as plotted on a Psychrometric Chart intersects the saturation curve below the apparatus leaving air dewpoint, reheat must be used to maintain the design room air conditions. However, if the design room humidity is permitted to be raised to some degree, the cooling system will not require reheat as a new room-sensible-heat-factor line is developed between the apparatus leaving air dew-Point and the adjusted design room air conddition point. The advantages to this are the cost of reheat equipment and operation can be avoided. The cycle of this system can be shown on a Psychrometric Chart to plot the design condition points.

• Korean Journal of Veterinary Service
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• v.25 no.1
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• pp.15-22
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• 2002

This experiment was carried out to investigate the changes of egg qualify during storage in order to find out the proper storage condition. Fresh eggs were stored at cold condition ($5^{\circ}C$, relative humidity ; RH :$65\pm$3%) and room condition($25^{\circ}C$, RH :$40\pm$3%) during 10 weeks and examined microbiological quality, weight loss and interior quality periodically. Weight loss was indicated 17.93% at room condition and 2.56% at cold condition. The pH of egg white and yolk were increased from 7.94 to 9.03(average 13.72%) and from 6.16 to 6.57(average 6.65%) at cold condition and from 7.94 to 9.54(average 20.15%) and from 6.16 to 6.90(average 12.01%) at room condition respectively. But pH of egg white and yolk did not showed significant difference between before molting and after molting. Haugh unit was decreased from 82.0 to <30 at room condition after 3 weeks. The most frequent bacteria isolated were E coli, Staphylococcus leutus, S saprophyticus, Citrobacter freundii, Klebsiella oxytoca, Providencia rettgeri, and Pontoea spp. It was recommended that shelf life of unrefrigerated eggs would not be longer than 21 days at room temperature in summer.

• Journal of the Korean Geographical Society
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• v.43 no.3
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• pp.312-323
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• 2008

The purpose of this paper is to analyze thermal sensation which is measured by human physioclimatic reactions in South Korea. Relationships between Temperature-Humidity Index(THI) and human thermal sensation scale are derived from a questionnaire, which investigates degree of volunteer's thermal sensation with respect to each biometeorological condition. Analyses of these empirical relationships make it possible to calculate thermal sensational indices and to classify bioclimatic types for individual weather stations based on long-term(1971-2000) averages of monthly temperature and humidity data. A generalized annual physioclimatic maps for each Annual Cumulative Thermal Sensation Index for the 68 stations are constructed to show men tend to feel in various areas. The Monthly thermal sensations are affected by latitude, altitude, orographic effects and systems of airmasses. The Annual Cumulative Thermal sensations are increasing towards northern areas and inland, and that the major factors are largely derived from cold stress in winter. The Annual Physioclimatic Types are grouped 8 climatic types(M, ES, M-ES, M-S, W-ES, C-ES, C-M, C-M-ES) according to climatic stress. Results of this study can be applied for evaluation of thermal environment in our daily activities, and for searching relevant sports training-sites, climatherapy etc.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.7 no.2
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• pp.19-24
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• 2001

The design criteria of ventilating container is not provided yet in Korea. This caused strength reduction due to the ventilating hole and bad ventilating performance. The purposes of this study were to survey the present situation of ventilating container in Korea, to analyze the strength reduction on the atmosphere condition variation, and to provide the criteria for the optimum design of ventilating container. The ventilating area of container was $1.41{\sim}2.65%$, and strength reduction due to the varied pattern, size and location of ventilating hole was $8.5{\sim}20.2%$. The effect on the strength reduction from the pattern and location of ventilating hole was bigger than that from the ventilating area. Equilibrium arrival time of temperature and relative humidity was shorter as the ventilating area was bigger, and temperature reached to the equilibrium state earlier than the relative humidity. There was no significant difference on the ventilating hole pattern between equilibrium arrival time of temperature and relative humidity and equilibrium arrival temperature and relative humidity if the ventilating area was the same.