• Proceedings of the KSR Conference
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• 2011.10a
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• pp.656-662
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• 2011

Recently, rolling stock technology has rapidly developed. Nevertheless, ride quality and vibration vibration on vehicle still need more study. EMU to be operated on SMRT Line 7(SR001) extension section is applied to oil-free reciprocating air compressor considering maintainability and convenience of inspection. But reciprocating air compressor compresses the air by back-and-forth motion of piston, and spreads the vibration to surrounding structures by its force of inertia. Optimum design of mounting bracket is able to reduce the vibration. As a result, we analyzed the frequency spectrum on vibration upon value by measuring vibration during operation of air compressor. On this study, we comprehend the vibration transmission process of reciprocating air compressor and consider the measure for reducing vibration by minimizing propagation of vibration.

• Health Policy and Management
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• v.22 no.1
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• pp.49-64
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• 2012

With the burden of chronic diseases mounting among the population as a result of its aging, the importance of health examination is being stressed in order to identify and manage diseases in the early stage. Health examination in Korea is divided largely into periodic health examination provided as a national health screening program and individual physical checkups. The advantages of the former include little economic burden on the examined and those of the latter include the freedom of the individual to select various examination headings depending on the individual's characteristics and preferences. With both examinations now being expanded, empirical analyses from various standpoints are needed. This study proposes to analyze traits of the examined and non-examined as shown in the facts and figures of the 1st and 2nd Korean Longitudinal Study of Ageing (KLoSA), thereby make the determinant factors clear leading to the acceptance of the examinations, and analyze the effects of the examinations upon maintaining or moving to healthy lifestyle. It was confirmed that demographic features such as gender and age, socioeconomic features such as the level of education, place of residence and household income, physical and mental state of health such as chronic disease and dementia, and daily living habits are significantly related with whether to accept physical examination. It is also confirmed that physical examination leads to non-smoking, regular physical exercises and regular dietary habits. It is suggested that, to enhance effects of health examinations, follow-up management programs making use of results of health examinations be further expanded, and the national health screening program be more actively put into operation for the bracket lying in the blind spot of the program.

• The korean journal of orthodontics
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• v.36 no.3 s.116
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• pp.198-206
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• 2006

With the introduction of the xenon plasma arc curing light and the LED curing light as orthodontic curing lights, the polymerizing time of orthodontic composites has clearly decreased. In contrast to various research cases regarding the polymerization time and bond strength of the xenon plasma arc curing light, not enough research exists on the LED curing light, including the appropriate polymerization time. The objective of this research was to compare the bond strength of the plasma curing light and the LED curing light in regards to the polymerization time. The polymerization time needed to achieve an appropriate adhesion strength of the bracket has also been studied. After applying orthodontic brackets using composite resin onto 120 human premolars, the plasma arc curing light and the LED curing light were used for polymerization for 4, 6, and 8 seconds accordingly. This research proved that the LED curing light provided appropriate bond strength for mounting orthodontic brackets even with short seconds of polymerization. The expensive cost and large size of the device limits the use of the plasma arc curing light, whereas the low cost and easy handling of the LED curing light may lead to greater use in orthodontics.