• Journal of the Korean Society of Safety
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• v.10 no.4
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• pp.13-21
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• 1995

On mini-bus with diesel engine, at idle rpm for taking measurement to reduce gear rattle noise, was tested by the three clutch disc samples by turns, then measured the fluctuation of revolution of engine & transmission and parallel vibration of differential gear & transmission. By analyzing the measured data, the gear rattle noise, the matching design and tuning technic of transmission are comprehended and established. Conclusions of this test are as follows ; (1) Fluctuation of revolution on transmission is greatly affected by torsion of clutch disc according to fluctuation of engine revolution transmit to transmission through clutch system. Especially, gear rattle noise can be reduced by minimaizing the fluctuation of the revolution of transmission using pre-damper type clutch disc. (2) The reason of gear rattle noise is higher in summer than winter and driving longer period than initial driving is due to affection by drag torque changing. So, it is necessary for manufacturer to choose proper oil to transmission. (3) It can be occurred jumping and crash noise by applying the pre-damper type clutch disc for reducing the gear rattle noise. So, it is necessary to do test with actual vehicle according to test procedure.

• Journal of the Korean Wood Science and Technology
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• v.18 no.4
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• pp.41-52
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• 1990

Experimental external collector type solar lumber dryer with $1.6m^2$ of collector area and $1.0m^3$ of maximum dryer capacity was designed and constructed to investigate the conditions inside and outside the dryer and collector. The efficiency of collector was calculated and numbers of drying-days and collector areas required to dry $0.2m^3$ and $1.0m^3$ of pine and oak at various an flow rate inside collector were estimated for eight cities in Korea. Average temperatures of collector-inlet and -outlet air and heat absorber were $52.5^{\circ}C$ $57.9^{\circ}C$, and $71.1^{\circ}C$. respectively at 4m/sec of an flow rate inside collector on sunny day in summer. Overall heat transfer coefficient of collector was 4.875W/$m^2^{\circ}C $ and collector efficiency was 52%. Estimated numbers of drying-days required to dry $0.2m^3$ of pine and oak from 80% to 15% moisture content at various air flow rate inside collector were 38 and 66 days. respectively. Areas of collector required to dry $1.0m^3$ of lumber at desired safe drying rate were estimated as $13.7m^2$ for pine and $16.0m^2$ for oak.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.2
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• pp.190-195
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• 2012

In this study, as a complementary study of the former study on indoor thermal environment in a tower type apartment house at tropical nights, a field measurement was conducted in winter season. Mainly, characteristics of heat storage and heat emission in apartment structures, in this study, were investigated. As results, indoor air temperature was changed in the range of $22.5^{\circ}C{\pm}1.0^{\circ}C$, and followed not the change of outdoor air temperature but the changed pattern of floor surface temperature. Wall surface temperature was unresponsive to the change of floor surface temperature compared with the change of indoor air temperature because wall structure was composed of concrete which has large heat capacity, and was changed in the range of $22.3^{\circ}C{\pm}0.6^{\circ}C$. Heat was stored continuously into the structures of wall and ceiling through the measurement term. and this means that a large heat capacity of the apartment structure acts as a disadvantage in winter season, too. As a total review of the study with the former study, a large heat capacity of the apartment structure acts against indoor thermal comfort in winter season as well as in summer season.

• Parasites, Hosts and Diseases
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• v.39 no.3
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• pp.223-226
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• 2001

In South Korea, the north border area has been under vivax malaria epidemic since 1993. However, Jeollabuk-do, which is about 300 kms from the border, has not experienced the same epidemic. 1 investigated a total of 58 notified cases of malaria in Jeollabuk-do in the year 2000. All of the cases had an exposure history in the epidemic area. Among them were 49 ex-soldiers, 3 soldiers who served near the border area and 6 civilians who traveled there. The causal agent of all cases was Plasmodium vivax. Except the civilians, the soldiers and ex-soldiers were aged in their twenty's. In the present study, the incubation period was from 6 to 520 days with a median of 157 days, and the latent onset type (92%) was more prevalent than the early onset type. illness onset of most cases (86%) peaked during the summer season (June to September) despite of variable incubation periods. The time lag for diagnosis ranged from 2 to 42 days with a median of 11 days. Jeollabuk-do has not been an area of epidemic untill now, but incidences have been increasing annually since 1996. In Jeollabuk-do, early diagnosis and treatment can be a feasible disease control measure to prevent spreading from the epidemic area.

• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.336-339
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• 2008

A new spray chrysanthemum cultivar, 'Moon Festival' was released by National Horticultural Research Institute (NHRI), Rural Development Administration (RDA), Korea in 2007. A cross was made in 2002 between '01B1-559', a breeding line of NHRI and 'Baeksokuk', a spray cultivar with white petals. Trials were conducted from 2005 to 2007 for evaluation and selection of this cultivar, including shading culture in summer and retarding culture in autumn. The natural flowering time of "Moon Festival" is late October, but year-round flowering is possible by shading and lighting treatment. The cultivar is semi- double type flowers with light-ivory white petals and green flower center. Flower neck and stem are very hardy. The diameter of flower is 67.5 mm. The number of flowers per stem and petals per flower is 11.5 and 100.5, respectively. The days to flowering under the short day is about 54 in autumn season.

• Journal of Korean Society for Quality Management
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• v.47 no.3
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• pp.425-435
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• 2019

Purpose: The purpose of this study was to resolve the Naval ship's Local Operation Panel(LOP) malfunction problems which caused by overheating in summer season and dispatching to equatorial regions. Methods: Instead of using dual type heat insulation materials(consist with ceramic wool and glass wool), aerogel heat insulation materials were used for decreasing heat emissions from gas-turbine heat waste steam pipes passing water-jet- room. Experiment and Computational analysis of heat flow were conducted to analyze the internal room temperature changes. Results: The results of this study are as follows; The aerogel heat insulation materials suppress heat emission more efficiently than dual type insulation materials. The cold surface temperature of insulation was far more decreased and internal room, LOP surface temperature also showed significant results too. Conclusion: The substituted heat insulation materials appeared remarkable performance in decreasing room temperature that it could be used for suppressing the LOP overheatings and malfunctions.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1726-1735
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• 2008

Seoulmetro has operated the air cooling equipment for 57 stations to improve services focused on our customers who use Seoulmetro during the summer season and has established every year. However, a new set of problems has arisen with the cooling tower to support a heat exchange of cooling water. The most important matter is loss of efficiency in the cooling tower. The leading cause of this problem is that we use an indoor type. As the cooling tower room is located in the underground of the city because of the residents near the station. Therefore It is difficult to establish the cooling tower on the ground. But it is unsuitable for the location requirements of the underground type because it has a limited space to set up the air cooling equipment, for example, the cooling tower and a ventilating opening. As a result of such an unfavorable condition, the cooling tower doesn't work efficiently and the warmth of cooling water because of insufficiency of a heat exchange and a refrigerator's technical obstacle such as a high-temperature and a high-pressure has arisen. To prevent this situation, the operator tend to reduce refrigerant. Accordingly, the efficiency of the air conditioning is getting lower and lower. Study wishes to analyze the matter to improve indoor cooling tower efficiency and recommend a best practice for a person who manage the establishment.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.725-730
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• 2006

The purpose of this study is on the performance evaluation of horizontally installed GHEX(Geothermal Heat Exchanger, HGHEX) which has been operated for 5 years successfully. Followings are the results. Firstly, in summer season, on Aug. 2000, $33^{\circ}C$ water was flowing out from HGHEX with continuous operating method, and $27{\sim}29^{\circ}C$ with interval operating method on Jul. 2005. But $2.5{\sim}3.0^{\circ}C$ temperature differences are gained from HGHEX. Secondly, in winter season, on Nov. 2000, $25^{\circ}C$ water was flowing out from HGHEX with continuous operating method, and $13{\sim}15^{\circ}C$ with interval operating method on Jan. 2006. But with each operating method, only $0.1^{\circ}C$ and $0.7^{\circ}C$ temperature differences are gained from HGHEX respectively. As the conclusion of this study, at the point of continuos operating method, seasonal balance of heating and cooling loads, and at the point of interval operating method, balance for geothermal restoring time respectively must be considered for better system performances.

• Korean Journal of Breeding Science
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• v.41 no.2
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• pp.173-176
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• 2009

A new spray chrysanthemum cultivar 'Pure Angel' was released by National Institute of Horticultural and Herbal Science (NIHHS), Rural Development Administration (RDA), Korea in 2007. The cross was made in 2004 between 'Innocence', a breeding cultivar of NIHHS, and 'Baeksokuk', a spray cultivar with white petals. Trials were conducted from 2005 to 2007 for the evaluation and selection of this cultivar, including shade cultures in summer and retarding cultures in autumn. The natural flowering time of 'Pure Angel' is late October, but year-round flowering is possible by photo-periodic control. The cultivar has single type flowers with pure white petals and a green flower center. It shows long vase life and resistance to white rust. The diameter of flower is 52.5 mm. The numbers of flowers per stem and petals per flower are 12 and 22.5, respectively. Days to flowering under the short day treatment is about 52 days in spring seasons.

• Korean Journal of Breeding Science
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• v.42 no.6
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• pp.595-599
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• 2010

A new spray chrysanthemum cultivar 'Prima Donna' was released by National Institute of Horticultural and Herbal Science (NIHHS), Rural Development Administration (RDA), in 2008. The cross was made between 'Plano' and 'Yeonja' in 2005. Trials were conducted from 2006 to 2008 for the evaluation and selection of this cultivar, including shading cultures in summer and retarding cultures in spring. The natural flowering time of 'Prima Donna' is late October, but year-round flowering is possible by photo-periodic control. The cultivar has single type flowers with pink petals, green center and good inflorescence. The growth of plant is very vigorous. The diameter of flower is 7.0cm. The number of flowers per stem and petals per flower are 13 and 42, respectively. Days to flowering under the short day treatment is about 59 and its vase life is 26.1 days in autumn season.