• Steel and Composite Structures
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• 재36권6호
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• pp.703-710
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• 2020

This paper presents numerical and theoretical investigations on the strain rate in steel-concrete composite (SC) panels under low-velocity impact of a hemispherical rigid body. Finite element analyses were performed on five specimens with different loading rates. The impact energy was kept constant to eliminate its influence by simultaneously altering the velocity and mass of the projectile. Results show that the strain rate in most parts of the specimens was low and its influence on bearing capacity and energy dissipation was limited in an average sense of space and time. Therefore, the strain rate effect can be ignored for the analyses of global deformation. However, the strain rate effect should be considered in local contact problems. Equations of the local strain and strain rate were theoretically derived.

• 대한간호학회지
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• 제13권3호
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• pp.119-126
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• 1983

Early extra-uterine development of the newborn infant has the potential for clarifying important questions of nature and care taking environment. In this study, tactile and auditory stimulation is used on .a group of infants to determine the effects of their response. Infants were tested by EKG at 24∼48 hrs after birth ana all they are free from complication. Stimuli presented were-touch and sound (40dB, 70dB and 40∼70dB). The result of the study were as follows: 1) The heart rate was seen to depend on their sleep-wake state. (light sleep ; 125/min, eyes: open & motor activity increase ； 151/min crying ; 185/min). 2) The heart rate affected by tactile & auditory stimulus. The heart rate response was acceleration above the prestimulus level. (tactile, 231min increase, auditory ; 16∼21/min increase), and heart rate change was seen to depend on prestimulus rate. (γ=.73) 3) There was a decrease in heart rate when they were soothe. (touch ; 24.8sec, 21/min decrease, pacifier ; 14.5sec, 26/min decrease) and significant difference in time between touch and pacifier (t= 1.76, p<0.05). This result support the evaluation of newborn infant's sensory abilitics, and has even begin to influence changes in nursing care. But systemic monitoring of newborn infants response would. further define.

• The Journal of Asian Finance, Economics and Business
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• 제8권3호
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• pp.1-10
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• 2021

This study examines the dynamic pattern of the exchange rate volatilities of the ASEAN-5 currencies from January 2006 to August 2020. The exchange rates applied in this study comprise bilateral and effective exchange rates in order to investigate the influence of the US dollar on the stability of the ASEAN-5 currencies. Since a volatility model employed in this study is a natural cubic spline volatility model, the Monte Carlo simulation is consequently conducted to determine an appropriate criterion to select a number of quantile knots for this model. The simulation results reveal that, among four candidate criteria, Generalized Cross-Validation is a suitable criterion for modeling the ASEAN-5 exchange rate volatilities. The estimated volatilities showed the inconstant dynamic patterns reflecting the uncertain exchange rate risk arising in international transactions. The bilateral exchange rate volatilities of the ASEAN-5 currencies to the US dollar are more variable than their corresponding effective exchange rate volatilities, indicating the influence of the US dollar on the stability of the ASEAN-5 currencies. The findings of this study suggest that the natural cubic spline volatility model with the quantile knots selected by Generalized Cross-Validation is practical and can be used to examine the dynamic patterns of the financial volatility.

• Journal of Ceramic Processing Research
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• 제20권1호
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• pp.59-62
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• 2019

Y2O3-MgO nanocomposites are promising materials for hypersonic infrared windows and domes due to their excellent midIR transmittance and mechanical properties. In this work, influence of SPS heating rate on the microstructure, IR transmittance, and mechanical properties of Y2O3-MgO nanocomposites was investigated. It was found that the average grain size decreases with a decreasing heating rate, which can be attributed to high defect concentration by rapid heating and deformation during densification. Also, the residual porosity decreases with a decreasing heating rate, which is ascribed to the enhancement of grain boundary diffusion by a large grain-boundary area (a small grain size). Consequently, high transmittance and hardness were attained by the low heating rate. On the other hand, the mechanical strength showed little difference with the heating rate change, which is somewhat different from the general knowledge on ceramics and will be discussed in this letter.

• 산업융합연구
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• 제15권2호
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• pp.45-56
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• 2017

본 연구의 목적은 국내 증권형 크라우드펀딩의 달성률에 영향을 주는 투자자 수의 영향력을 분석하여, 일반 투자자의 참여가 필요한 이유에 대해 알아보고 일반 투자자의 참여를 높이는 방안을 제시함에 목적이 있다. 이를 위해 증권형 크라우드펀딩에서 실제 진행된 190개의 진행결과를 분석하였고, 국내 증권형 크라우드펀딩의 달성률에 영향을 주는 요인으로는 선행연구와 같이 모집금액, 목표금액, 모집기간과 사업연수의 영향력을 확인할 수 있었으며, 달성률에 대한 영향요인이 일반 투자자의 수가 증가함에 따라 더욱 더 큰 영향을 줄 수 있음을 확인하였다. 따라서, 정부에서는 일반 투자자에 대한 규제를 보다 더 완화하는 노력을 기울여야 하며 자금수요자는 일반 투자자의 자금 회수를 위하여 KSM시장을 통한 기업공개에 대한 노력을 강화하고 공시해야만 일반 투자자의 참여를 이끌어 낼 수 있으며 크라우드 펀딩을 통하여 원할한 자금 확보를 이끌어 낼 수 있을 것이다.

• 한국보육학회지
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• 제18권1호
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• pp.77-102
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• 2018

이 연구의 목적은 영아기 아버지 양육참여, 어머니 양육스트레스, 영아 심리사회발달과 유아기 또래상호작용간의 종단적 관계를 잠재성장 모형을 통해 검증하고자 하는 것이다. 이를 위해 한국아동패널조사(PSKC)자료의 0세부터 2세까지와 4세부터 6세까지의 자료인 1차 ~ 3차 년도와 5차 ~ 7차 년도의 종단 자료를 활용해 분석하였다. 분석결과 첫째, 아버지 양육참여 초기값이 유아기 놀이상호작용 초기값에 미치는 영향력에서 어머니 양육스트레스의 초기값은 매개효과가 있는 것으로 나타났다. 둘째, 아버지 양육참여 초기값과 변화율은 유아기 놀이방해 및 단절 초기값과 변화율에 미치는 영향력에서 어머니 양육스트레스의 초기값과 변화율은 매개효과가 있는 것으로 나타났다. 셋째, 아버지 양육참여의 초기값과 변화율은 유아기 놀이상호작용의 초기값과 변화율에 미치는 영향력에서 영아 심리사회발달의 초기값과 변화율은 매개효과가 있는 것으로 나타났다. 넷째, 아버지 양육참여 초기값이 유아기 놀이방해 및 단절 초기값에 미치는 영향력에서 영아 심리사회발달의 초기값은 매개효과가 있는 것으로 나타났다.

• 대한가정학회지
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• 제36권6호
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• pp.85-94
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• 1998

In this study we tested the physiological influence on human-body according to clothing pressure with reduction rate and varied posture using three kinds of belt with different width. The width of belts were 2.5cm, 3.5cm and 4.5cm, and reduction rates of belts were 0%, 2.5% and 5% of the subject/s waist size respectively. the measured postures were standing state and sitting stste in the chair. The reasults are as follows; 1. Clothing pressure was high in the order of Side part>Front part>Back part and the rate fo change in the side part was highest, according to the reductio rate of belts. The more the width of belt was wide, the less the clothing pressure was small, and this kind of phenomenon could be explained by "The Principle of the power". 2. Both the rate of reduction of belt and the change of average skin temperature in accordance with the width of belt is small, however, the more the width of belts is wider and the reduction rate is bigger, the more the skin temperature at the waist part is increased. 3. The blood pressure and pulse was influenced when the width of belt was narrow and the reduction rate was high. 4. A sense restraining was much influenced by the width of belt, especially when the width of belts was wide, the significant difference was permitted.permitted.

• 한국유체기계학회 논문집
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• 제14권1호
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• pp.42-47
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• 2011

Measurement uncertainty analysis of fuel flow using turbine flowmeter was performed for the case of altitude engine test. SAE ARP4990 was used as the fuel flow calculation procedure, as well as the mathematical model for the measurement uncertainty assessment. The assessment was performed using Sensitivity Coefficient Method. 11 parameters involved in the calculation of the flow rate were considered. For the given equipment setup, the measurement uncertainty of fuel flow was assessed in the range of 1.19~1.86 % for high flow rate case, and 1.47~3.31 % for low flow rate case. Fluctuation in frequency signal from the flowmeter had the largest influence on the fuel flow measurement uncertainty for most cases. Fuel temperature measurement had the largest for the case of low temperature and low flow rate. Calibration of K-factor and the interpolation of the calibration data also had large influence, especially for the case of very low temperature. Reference temperature, at which the reference viscosity of the sample fuel was measured, had relatively small contribution, but it became larger when the operating fuel temperature was far from reference temperature. Measurement of reference density had small contribution on the flow rate uncertainty. Fuel pressure and atmospheric pressure measurement had virtually no contribution on the flow rate uncertainty.

• 여성건강간호학회지
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• 제18권3호
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• pp.200-208
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• 2012

Purpose: This study was aimed to examine the gap between predicted cesarean section rate and real cesarean section rate and it's determining factors of 44 tertiary hospitals. Method: This study is a cross-sectional analysis using the data of 25,623 deliveries in 2009 drawn from homepage of Health Insurance Review and Assessment Service. Data were analyzed with t-test, F-test, Scheff$\acute{e}$ test, and logistic regression. Result: There were statistically significant differences in the gap of cesarean section rate (more gap indicates higher quality of delivery) by grade of nurse staffing and delivery cases. Hospitals with nurse staffing grade 1 to 2 had more possibility to be classified into higher grade in quality of delivery (OR 5.67, 95% CI 1.07-30.08). Also hospitals with over 500 delivery cases had more possibility be classified into higher grade in quality of delivery (OR 4.92, 95% CI 1.14-21.23, respectively). Conclusion: The finding suggests that grade of nurse staffing may influence the real cesarean section rate because nurses do a vital role to prevent unnecessary cesarean section. Further study is required to provide evidence that nurse staffing influence on patient outcome and cost-effectiveness in order to obtain adequate number of nursing staffs.

• 대한의용생체공학회:의공학회지
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• 제26권4호
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• pp.193-197
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• 2005

Shunt valves used to treat patients with hydrocephalus were tested to investigate influence of intracranial pressure pulsation on their flow control characteristics. Five commercial shunt valves were tested in the flow loop that simulates pulsed flow under pressure pulsation. As 20cc/hr of flow rate was adjusted at a constant pressure, application of $40mmH_2O$ of pressure pulse increased the flow rate by $67.9\%.$ As a 90cm length catheter was connected to the valve outlet, increase in the flow rate was substantially reduced to $17.5\%.$ As the flow rate was adjusted to 40cc/hr at a constant pressure, increase in the flow rate was $51.1\%$ with the same pressure pulsation of $40mmH_2O$. The results indicated that pressure-flow control characteristics of shunt valves implanted above human brain ventricle is quite different from those obtained by syringe pump test at constant pressures right after manufacture. The influence of pressure pulsation was observed to be more significant at low flow rate and the flexibility of the outlet silicone catheter was estimated to significantly reduce flow increase due to pressure pulsation.