• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.316-321
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• 2007

It is difficult for a superintendent or an operator of building service systems and equipment to decide the reasonable time for management of himself due to the shortage of his specialty for repair or replacement of a part of or whole equipment. But The reliable life expectancies for various building service equipment have not been prepared yet. This study shows the difference of optimal economic life and the decrease of running cost and energy consumption according to management level of the building equipment by the LCC analysis. The numerical model for building HVAC system was composed and analyses were performed for several parameters with management.

• Journal of Applied Reliability
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• v.6 no.1
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• pp.37-50
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• 2006

The accelerated life tests of the catalytic gas sensor were performed at three different gas concentration conditions. From the test data, the power-Weibull model was estimated and the acceleration factor between test condition 25%LEL(Lowe Explosive Limit) and use condition 5%LEL was about 3 according to this acceleration model. Using this acceleration factor, life test specification for qualifying that B10 lifetime of the catalytic gas sensor meets the goal lifetime (5 years) was designed.

• YAKHAK HOEJI
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• v.39 no.1
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• pp.14-23
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• 1995

The current study was undertaken to select the crude drug showing life prolonging effect on the starved rats(Sprague-Dawley) and elucidate the reaction mechanism there of. As distilled water extracts prepared from twenty kinds of natural drugs were administered orally to female starved rats, Bupleuri Radix demonstrated the most prominent effect with 34.6% increment in the survival time. To investigate underlying mechanism of life prolonging effect of Bupleuri Radix, the concentrations of adrenocorticosteroids(corticsterone, testosterone and aldosterone) and enzyme activities of superoxide dismutase(SOD), glutamate oxaloacetate transaminase(GOT), glutamate pyrurate transaminase(GPT) were assayed in the serums of rats starved for, 2, 4 and 6 days respectively. The results manifested much elevated values of corticosterone, aldosterone(2 days) and rather decreasing tendency afterwards, specially in the late periods of starvation(6 days). With respect to such a considerable changes according to starvation periods, Bupleur Radix restored these values much near to normal suggesting that Buplerum Radix may play a life prolonging action during starvation probably through reinforcing the homeostatic properties of corticosteroids and some enzyme activities.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.9
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• pp.96-102
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• 2009

In this study, performs analysis of the life of parallel opening type pneumatic chucks that are usually applied in the factory automation line. Pneumatic chucks have complicated failure cause because they are organized as a complex of various elements. Therefore, we analyzed the main failure mode of pneumatic chuck, and then performed life test and performance test according to the international standards. On the basis of these processes, shape parameter of pneumatic chuk is proposed that is the main factor for the calculation of zero failure test time for the reliability of pneumatic chuck and their data analysis of life distribution.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.3
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• pp.460-473
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• 2015

This study aimed to create a standardized recipe using three cultivars of tomatoes (Chal-tomato, Daejeo-tomato, Blacktomato) and select an appropriate tomato for producing tomato Jangajii through quality and sensory evaluation. With regard to the proximate composition of tomato Jangajii, moisture and ash contents of Chal-tomato were highest in the early stage of storage, whereas moisture, crude protein and ash contents of Black-tomato were highest in the final stage of storage. Daejeotomato showed minimal changes in pH, but showed the highest salt and sugar contents. L value increased with increasing storage time and then decreased thereafter (p<0.001). The a and b values decreased with increasing storage time and then increased thereafter (p<0.001). The reducing sugar content increased with increasing storage time and then decreased thereafter (p<0.001). With regard to Daejeo-tomato, hardness was the highest (p<0.001), and total microbial counts were lowest (p<0.001). Daejeo-tomato showed the lowest activities of PME as a softening enzyme and PG. For sensory properties, Daejeo-tomato showed a relatively high preference for all items except aroma. Based on the above results, Daejeo-tomato Jangajii showed superior quality characteristics and high preference in general among tomato Jangajii from all three cultivars of tomatoes. Therefore, Daejeo-tomato Jangajii is useful as low-sodium tomato Jangajii in light of quality characteristics and preference.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.6
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• pp.68-74
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• 2014

During the life firing test of 1 N-class thruster development model, pulse mode performance and performance changes were examined. The deviation of pulse mode response time according to thruster feed pressure was relatively small and the resultant ignition delay, response time, tail-off time were 32-35 ms, 86-91 ms, 89-98 ms, respectively. For the stabilized pulse region the impulse bit revealed the outstanding reproducibility of 1.41, 1.32, 2.10% at $3{\sigma}$. During the life firing test, the impulse bit was decreased with limited amounts, therefore the pulse mode performance could be considered to be maintained. The thrust centroid was also maintained during the life firing test.

• Journal of People, Plants, and Environment
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• v.24 no.4
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• pp.355-363
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• 2021

Background and objective: This study was conducted on Forsythia velutina, a special plant, in Gyeongsangnam-do Arboretum under the Gyeongsangnam-do Forest Environment Research Institute, which is located in the southern part of Korea. Methods: The research aimed to analyze the flowering characteristics of the plant by calculating the optimal temperature and humidity according to the flowering time and flowering period for 8 years from 2010 to 2017 in order to provide basic data for bioclimate studies of endemic plants. Results: It was observed that the Forsythia velutina showed a life cycle from mid-March and to mid-November. Average growth period was 243 (± 6.5) days. In testing the reliability of a single variable according to the meteorological factors, the Cronbach's Alpha was 0.701, which indicates that the findings were relatively reliable. The average date of flowering was March 16 (SD = 5.8) and the average date on which blossoms fall was March 29 (SD = 5.2). A substantial difference in flowering period was observed from year to year 11 to 23 days, with an average of 16 days (± 4.7). The temperature and humidity in February to March, which affect the flowering, were 2.9-5.5℃, and 66.5-73.0%, respectively, and showed differences every year. Conclusion: The correlation between flowering time and meteorological factors was positive, and the highest daily temperature and average daily temperature had the highest significance. When establishing basic data on plant species for the conservation of endemic plants, the changes in life cycle events and weather conditions are identified. It is believed that it will be helpful in establishing a conservation strategy for the plant species in the future.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.4
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• pp.467-472
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• 2010

In this study, an analysis of the used RCD's condition is conducted to assess the effect on environment of installation area, terms of use, corrosion, contamination etc. According to KS C 4613, the used RCDs were tested to get date which is the RCD's life time. And then, the date is analysed using Minitab which is a statistical program for reliability analysis. As a result, The RCD's MTTF for the all samples is $12.7{\pm}0.23$ years. and the MTTF of RCDs which are used indoor area is $12.9{\pm}0.34$ years, the MTTF of RCDs which are used outdoor area is $11.9{\pm}0.30$ years. Futhermore, the MTTF of RCDs which are used in dry area is a $13.1{\pm}0.26$ years, the MTTF of RCDs which are used in dust area is $13.0{\pm}0.57$ years, the MTTF of RCDs which are used in moisture area is $8.4{\pm}0.77$ years.

• The Korean Journal of Emergency Medical Services
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• v.24 no.1
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• pp.67-76
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• 2020

Purpose: Effective time management, as well as life-saving care, are important in maximizing the prognosis of patients who have sustained major traumas. This study evaluated the appropriateness of emergency medical system (EMS) provider's essential care and how this care impacted on-scene time in patients with major traumas. Methods: This retrospective observational study analyzed the EMS major trauma documents, classified according to the physiological criteria (Glasgow coma scale <14, systolic blood pressure <90mmHg, Respiration rate <10 or >29) in Daejeon, from January, 2015 to December, 2018. Results: Of the 707 major trauma cases, the mean on-scene time was 7.75±4.64 minutes. According to EMS guidelines, essential care accuracy was 67.5% for basic airway, 36.4% for advanced airway, 91.2% for cervical collar, 81.5% for supplemental oxygen, 47.0% for positive pressure ventilation, 19.9% for intravenous access and fluid administration, and 96.0% for external hemorrhage control. Factors affecting on-scene time were positive pressure ventilation (p<.004), and intravenous access and fluid administration (p<.002). Conclusion: Adherence to guidelines was low during advanced airway procedures, positive pressure ventilation, intravenous access, and fluid administration. In addition, the on-scene time was prolonged when the practitioner provided positive pressure ventilation, intravenous access, and fluid administration; however, these durations did not exceed the recommended 10 minutes.

• 한국노년학
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• v.40 no.1
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• pp.23-32
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• 2020

The purpose of this study is to identify lifestyle types for Koreans' time use through the 2014 National Time Survey. In this 2014 national life time survey data, the required maintenance time, mandatory time, and free time presented in the triangle model were divided into three areas, and compared and analyzed by age and region. In this type of lifestyle, teenagers, people in their 20s and 50s were given reasonable life-seeking, people in their 30s and 40s were given achievement-seeking, and people in their 60s, 70s and 80s were given passive real-life seeking. The required maintenance time of each regional lifestyle activity was Jeonbuk, Ulsan, and Gangwon took up the most time during free time. The higher the age, the higher the satisfaction level of each age, the higher the satisfaction level of life, while the satisfaction level of each region was the highest in Daejeon and the lowest in Ulsan. The satisfaction level for each lifestyle type was higher, followed by rational life pursuit, achievement pursuit and passive reality. It seems that systematic research on lifestyle will be needed in future studies through the diversification of areas of time, classification according to leisure characteristics, and type of lifestyle.