• 한국산학기술학회논문지
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• 제20권11호
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• pp.44-55
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• 2019

본 연구는 간호사를 대상으로 초기 심정지 5분 간 수행능력, 자신감 향상을 위해 전통적 시뮬레이션 교육 방법과 Rapid Cycle Deliberate Practice(RCDP) 시뮬레이션 교육 방법을 받은 전·후 변화를 확인하고 두 그룹 간의 수행 능력, 자신감, 만족도를 비교 하고자 시도되었으며 연구 대상자는 서울 소재 병원의 간호사로 그룹 1은 62명으로 RCDP 시뮬레이션 방법을 그룹 2는 60명으로 전통적 시뮬레이션 교육 방법으로 총 122명의 간호사에게 전문 소생술 교육을 진행 하였다. 2019년 3월 18일부터 29일 까지 자료 수집을 하였으며 자료 분석은 SPSS Version 23.0 프로그램으로 서술적 통계, Fisher's exact test, t-test, Wilcoxon sign rank test, Mann-Whitney U-test를 활용하여 분석하였다. 연구 결과 RCDP와 전통적 시뮬레이션 교육의 두 그룹 간에는 수행 능력의 일부 항목(z=-2.02, p=0.044 / z=-2.42, p=0.015 / z=-3.03, p=0.002)은 유의한 차이를 보였으나 수행 자신감(z=0.388, p=0.699)과 만족도(t=.72, p=0.476)에서 두 그룹간의 차이는 없었다. 본 연구는 전통적 시뮬레이션 교육 방법과 RCDP 시뮬레이션 교육 방법 모두 간호사의 전문 소생술 수행 능력 및 자신감을 높이는데 효과적인 교육 방법임을 확인하였다. 따라서 간호사 대상 전문 소생술 교육시 교육 대상 및 내용에 따라 적절한 시뮬레이션 방법을 적용하고 다양한 분야에 RCDP 시뮬레이션 교육 방법을 활용하여 효과성을 확인 해 볼 것을 제언한다.

• Nuclear Engineering and Technology
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• 제55권2호
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• pp.546-554
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• 2023

The cyclical behavior of Alloy 617 was examined at 25 ℃ and high temperatures of 800, 850, 900, and 950 ℃ in air to obtain its fatigue life curves. The specimens tested at 25, 800, and 850 ℃ cyclically hardened, whereas those tested above 900 ℃ cyclically softened from the first cycle, that is, their fatigue life was reduced at high temperatures owing to loss of strength. Parameters of the typical Coffin-Manson-Basquin relationship were determined for each test temperature. Interestingly, no significant difference in fatigue life was observed for the specimens tested in the range of 800-950 ℃. Owing to the similarity in fatigue life, we determined fatigue strength and fatigue ductility exponents that could be applied for this temperature range. The parameters obtained were close to the universal slopes, although the fatigue ductility exponent was slightly different. The proposed fatigue life curves were compared with those presented in ASME code.

• KEPCO Journal on Electric Power and Energy
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• 제7권2호
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• pp.241-248
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• 2021

High cycle fatigue life for the cables with two different types of clamps is estimated comparatively through acceleration testing. The high cycle fatigue fracture of overhead lines is caused mainly by the aeolian vibration which is induced by vortex shedding. It is necessary to manage the integrity of cables continuedly considering that the aeolian vibration is unavoidable since it occurs in steady and relatively low wind velocity. Two types of clamps which are largely used for overhead lines of the distribution grids are selected and failure data are obtained by step stress testing with a electrodynamic shaker with them. The inverse power law is assumed to describe the stress-life relationship and the fatigue limit at any specified life is supposed to follow Weibull distribution. The life of the cable is defined as the number of cycles to the time that one of strands is completely broken. Finally, the fatigue limits of the cables with two clamp types are estimated at the reference life of 500 Mcycles and compared each other based on a bending vibration amplitude.

• 대한수의학회지
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• 제37권1호
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• pp.189-194
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• 1997

The life cycle of Theileria sergenti(T sergenti) in cattle, especially Korean native cattle, was not proved clearly. To find schizont stage in the life cycle of T sergenti in Korean cattle, T sergenti schizonts in the cells of parotid lymph nodes from 10 adult Korean cattle were examined. Lymphoid cells which were separated from these lymph nodes were cytocentrifuged to observe the parasites in the cells. T sergenti schizonts were detected in the cells of lymph nodes of 6 cattle out of them by IFA(Indirect Fluorescent Antibody) test and Giemsa stain. By peroxidase stain, the cells which contain schizonts were proved lymphoid cells. T sergenti schizonts identified by IFA test were able to be restained by Giemsa stain. Also, merozoites were observed in peripheral blood of the same 6 cattle that had schizonts, by giemsa stain, but not observed in the 4 cattle that had not been detected schizonts. As a part of life cycle of T sergenti, schizonts were observed in the lymphoid cells of Korean cattle.

• 한국표면공학회지
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• 제40권5호
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• pp.225-233
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• 2007

Effects of alloying elements on the corrosion layer formation of Pb-grid/active materials interface has been researched for improvement of corrosion resistance of Pb-Ca alloy. For this research, various amounts of alloying elements such as Sn, Ag and Ba were added to the Pb-Ca alloys and investigated their corrosion behaviors. Batteries fabricated by using these alloys as cathode grids were subjected to life cycle test. Overcharge life cycle test was carried out at $75^{\circ}C$, 4.5 A, for 110 hrs. with KS standard (KSC 8504). And then, after keeping the battery with open circuit state for 48 hr, discharge was carried out at 300A for 30 sec. Corrosion morphology and interface between Pb-grid and active materials were investigated by using ICP, SEM, WDX, and LPM. Corrosion layer of Pb-Ca alloy got thicken with increasing Ca content. For Pb-Ca-Sn alloy, thickness of corrosion layer decreased as Sn and Ag content increased gradually. In case of Pb-Ca-Sn-Ba alloy, thickness of corrosion layer decreased up to 0.02 wt% Ba addition, whereas, it was not changed in case of above 0.02 wt% Ba addition.

• 한국의류학회지
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• 제33권7호
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• pp.1050-1060
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• 2009

This study develops a scale for consumer clothing satisfaction based on Lee et al. 's (2002) five stages of the consumer life cycle (acquisition, possession, consumption, maintenance, and disposal). Data were gathered by surveying college students using convenience sampling, and 419 questionnaires were used in the statistical analysis. In analyzing the data, an exploratory factor analysis and a confirmatory factor analysis using a structural equation modeling were conducted. The proposed scale, which identified various sources of satisfaction and dissatisfaction associated with the 5 consumption cycles of clothing, suggests some guidelines for marketers in enhancing consumer clothing satisfaction across consumption stages. The model test for the scale also identified that consumption satisfaction had the greatest effect on consumer clothing satisfaction showing the strongest loading and squared multiple correlation.

• 한국정밀공학회지
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• 제21권12호
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• pp.109-118
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• 2004

Life cycle assessment (LCA) usually involves some uncertainty. These uncertainties are generally divided in two categories such lack of data and data inaccuracy in life cycle inventory (LCI). This paper explo.es a methodology on dealing with uncertainty due to lack of data in LCI. In order to treat uncertainty of LCI data, a model for data uncertainty is proposed. The model works with probabilistic curves as inputs and with Monte Carlo Simulation techniques to propagate uncertainty. The probabilistic curves were derived from the results of survey in expert network and Monte Carlo Simulation was performed using the derived probabilistic curves. The results of Monte Carlo Simulation were verified by statistical test. The proposed approach should serve as a guide to improve data quality and deal with uncertainty of LCI data in LCA projects.

• 산업경영시스템학회지
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• 제20권43호
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• pp.365-379
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• 1997

Currently the problem of air pollution caused by the motor vehicle emission is of the most serious problems to be solved. Life Cycle Assessment is a process to evaluate the environmental burdens associated with a product or process by identifying and quantifying energy and materials used and wasters to the environment. This paper establishes a Life Cycle Assessment Systems which satisfies the criteria motor vehicle emission for the automobile producers who are currently producing the automobiles with catalytic convert. This plan also considered the constraint of the effective motor vehicle emission by way of the exhaust gas recirculation, electronic fuel injection, closed loop carburetor. In order to develope the performance of the LCA systems, the recent emissions test data have also been applied. The result of the development LCA systems has proved that the LCA plans presented in this paper satisfies the criteria motor vehicle emission and will be contributed to constrain the motor vehicle emission most effectively.

• Earthquakes and Structures
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• 제25권1호
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• pp.69-78
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• 2023

Life-cycle performance analysis of a reinforced concrete box section bridge was generated. Moreover, Monte Carlo simulation with important sampling (IS) was used to simulate the bridge material and load uncertainties. The bridge deterioration model was generated with the basic probabilistic principles and updated according to the measurement data. A genetic algorithm (GA) with the response surface model (RSM) was used to determine the deterioration rate. The importance of health monitoring systems to sustain the bridge to give services economically and reliably and the advantages of fiber-optic sensors for SHM applications were discussed in detail. This study showed that the most effective loss of strength in reinforced concrete box section bridges is corrosion of the reinforcements. Due to reinforcement corrosion, the use of the bridge, which was examined, could not meet the desired strength performance in 25 years, and the need for reinforcement. In addition, it has been determined that long-term health monitoring systems are an essential approach for bridges to provide safe and economical service. Moreover the use of fiber optic sensors has many advantages because of the ability of the sensors to be resistant to environmental conditions and to make sensitive measurements.

• 농약과학회지
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• 제10권3호
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• pp.196-200
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• 2006

국내서식 물벼룩종을 이용한 표준생태독성시험법 개발을 위한 기초연구로서 국내환경에서의 대표성, 실내사육가능성 및 독성시험에 적합한 크기 등을 고려하여 선발된 4종의 한국산 물벼룩 Daphnia sp., Daphnia obtusa, Moina macrocopa, S.imocephalus vetulus과 Daphnia magna에 대한 실내사육조건에서의 life cycle을 조사하였다. 국내산 물벼룩 4종과 D. magna에 대한 실내사육조건에서의 전 생애에 걸친 생육특성을 조사한 결과 D. magna가 어미 1마리당 평균 358마리의 새끼를 출산하였고 국내산 물벼룩 중에는 Daphnia sp.가 297마리의 새끼를 출산하여 가장 출산새끼수가 많았으며 그 다음으로는 M. macrocopa, S. vetulus, D. obtusa 순이었다. 평균수명은 D. magna가 50일로 가장 길었으며 국내산 물벼룩 중에는 Daphnia sp.가 39일로 조사되었으며 그 다음으로는 S. vetulus, D. obtusa M. macrocopa, 순이었다. 특히 M. macrocopa의 경우 번식력이 우수하면서도 세대기간이 짧아 기존의 번식독성시험법에서 제시하는 21일보다 짧은 10일 정도의 단기간에 번식영향을 평가할 수 있을 것으로 판단된다.