• Journal of Photoscience
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• 제9권2호
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• pp.454-456
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• 2002

It is important to determine the action spectrum of UV-B radiation contained in the sunlight to estimate the risk of skin cancer. We have investigated action spectra for induction of apoptosis and reproductive cell death in L5178Y cells using the Okazaki Large Spectrograph at NIBB. L5178Y cells were exposed to light at different wavelengths in UV-B or UV-A region. Frequencies of apoptosis induction and reproductive cell death were determined by counting cells with chromatin condensation, and by the colony formation assay, respectively. The measured sensitivity spectra for the two end-points were in very good agreement. Sensitivity decreased steeply with increase of wavelength in UV-B region and remains nearly constant in UV-A region. The action spectra were also slightly steeper than that for the minimum erythematic dose (MED), but very similar to the light absorption spectrum of DNA in UV-B region. On the other hand, the spectra for both endpoints were similar to MED spectrum but not DNA spectrum in the UV-A region. Also different time-course and morphological difference of apoptosis were found between UV-B (long time, fragmentation) and UV-A (short time, shrinkage) region. These results suggest that DNA damage induced by UV-B light triggers apoptosis and reproductive cell death, but other damaged targets (membrane, protein and so on) trigger these effects in UV-A region.

• 신재생에너지
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• 제7권4호
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• pp.10-17
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• 2011

Recently, electricity industry is facing high market uncertainty which has ever had and which increase risks in power market. In this study, we analyze risk factors such as discount rates, initial investment (overnight cost), plant factor, fuel cost, carbon price, etc, for the perspective of investor. For the analysis of risk factors, we used LCOE method. The results of this study show that renewable energy is more affected by plant factor and overnight cost than other risk factors. First, Renewable energy has higher proportion of overnight cost in the total investment than that of other technologies. Second, renewable energy is free of fuel cost and carbon price so plant factor is the most important factor, in other words, competitiveness of renewable energy depends on plant factor. Furthermore, we conducted economic feasibility of wind power and PV in domestic case study. The minimum requirement condition to get profitability is that plant factor 15% and overnight cost \6,000,000/kW and 26%, \2,200,000/kW for PV and Wind Power, respectively.

• 대한간호학회지
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• 제45권3호
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• pp.429-438
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• 2015

Purpose: This study was conducted to develop key performance indicators (KPIs) for home care nursing (HCN) based on a balanced scorecard, and to construct a performance prediction model of strategic objectives using the Bayesian Belief Network (BBN). Methods: This methodological study included four steps: establishment of KPIs, performance prediction modeling, development of a performance prediction model using BBN, and simulation of a suggested nursing management strategy. An HCN expert group and a staff group participated. The content validity index was analyzed using STATA 13.0, and BBN was analyzed using HUGIN 8.0. Results: We generated a list of KPIs composed of 4 perspectives, 10 strategic objectives, and 31 KPIs. In the validity test of the performance prediction model, the factor with the greatest variance for increasing profit was maximum cost reduction of HCN services. The factor with the smallest variance for increasing profit was a minimum image improvement for HCN. During sensitivity analysis, the probability of the expert group did not affect the sensitivity. Furthermore, simulation of a 10% image improvement predicted the most effective way to increase profit. Conclusion: KPIs of HCN can estimate financial and non-financial performance. The performance prediction model for HCN will be useful to improve performance.

• 한국생산제조학회지
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• 제21권4호
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• pp.532-540
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• 2012

In this study, some considerations have been suggested in developing on-site techniques to evaluate the sensitization of stainless steels. Electrochemical potentiokinetic reactivation (EPR) technique is known to be a candidate tool for field applications since it enables quantitative assessment in reasonable test time, compared to oxalic etching (ditch) technique. The on-site application of the test method imposes additional restrictions on the selection of the test method (for example, minimum surface preparation requirement, insensitivity to testing temperature, etc.). The EPR and etching techniques have been compared in order to sensitization of stainless steel structures. It has been widely reported that the maximum sensitivity in the welded structure of stainless steel is shown at heat-affected zone (HAZ) than weldments with cast structure. In this work, sectioned weldments and external surfaces were investigated to reveal the degree of sensitization by the etching and the results were compared with those of EPR test. The EPR test showed little sensitivity to surface roughness and test temperature.

• 센서학회지
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• 제22권3호
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• pp.191-196
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• 2013

A particulate matter sensor fabricated by MEMS process is proposed. It is developed to accommodate Euro6 on-board diagnostics regulation for diesel automobile. In the regulation, emission of diesel particulate matter is restricted to 9 mg/km. Particulate matter sensor is designed to use induced charges by charged particulate matter. To increase sensitivity of the sensor, groove is formed on sensor surface because wider surface area generates more induced charges. Sensitivity of the sensor is measured 10.6 mV/(mg/km) and the sensor shows good linearity up to 15.7 mg/km. Also its minimum detectable range is about 0.25 mg/km. It is suitable to detect failure of a diesel particulate filter which should filter particulate matter more than 9 mg/km. For removing accumulated particulate matter on the sensor which can disturb normal operation, platinum heater is designed on the backside of the sensor. The developed sensor can sense very low amount of particulate matter from exhaust gas in real-time with good linearity.

• 한국안전학회지
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• 제29권6호
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• pp.94-98
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• 2014

본 연구는 구조물의 최적안전수준과 수명기간동안 투자되는 총비용과의 상관관계를 연구하였다. 설계, 건설 및 공용 중 투자되는 총비용을 최소화하면서 최적의 안전수준을 결정하기 위하여 신뢰성해석을 수행하였다. 신뢰성해석에는 설계인자들의 불확실성과 설계 및 공사, 유지관리를 수행하는 인간의 오류 등 인적 불확실성을 확률변수로 고려하였다. 이러한 확률해석을 통한 안전지수와 생애주기비용의 상관관계를 연구하고, 생애주기비용의 분산도에 따른 안전지수의 민감도해석을 통하여 최적의 안전수준을 결정하였다. 해석결과는 이러한 평가방법이 교통시설물에 투자되는 비용을 최소화하면서 최적의 안전수준을 결정할 수 있는 정확하고 유용한 방법임을 보여주었다.

• 대한기계학회논문집A
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• 제21권11호
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• pp.1765-1772
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• 1997

The layered composites have a character to change of structure stiffness with respect to the layup angles. The deformations in the fan-blades to be initially designed by considering efficiency and noise, etc., which arise due to the pressure during the fan operation, can make the fan inefficient. Thus, so as to minimize the deformations of the blades, it is needed to increase the stiffness of the blades. An investigation has been performed to develop the three dimensional layered composite shell element with the drilling degree of freedom and the optimization module for finding optimal layup angles with sensitivity analysis. And then they have been verified. In this study, the analysis model is engine cooling fan of automobile. In order to analyzes the stiffness of the composite fan blades, finite element analysis is performed. In addition, it is linked with optimal design process, and then the optimal angles that can maximize the stiffness of the blades are found. In the optimal design process, the deformations of the blades are considered as multiobjective functions, and this results minimum bending and twisting simultaneously.

• 한국환경과학회지
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• 제22권5호
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• pp.591-597
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• 2013

For Kangjeong stream and Akgeun stream in the central part of the southern Jeju Island, on-site discharge estimation was carried out for approximately 10 months (July 2011-April 2012) twice a month on a regular basis by using ADCP (acoustic doppler current profiler) and long term rate of discharge was calculated by using SWAT (soil and water assessment tool) model. The discharge was $0.28-1.30m^3/sec$ for Kangjeong stream and $0.10-1.54m^3/sec$ for Akgeun stream. It showed the maximum in the summer and the minimum in the winter. As a result of parameter sensitivity analysis of SWAT model, CN (NRCS runoff curve number for moisture condition II), SOL_AWC (available water capacity of the soil layer), and ESCO (soil evaporation compensation factor) showed sensitive responses. By using the result, the model was corrected and the rate of discharge was calculated. As a result, the annual discharge rate was 27.12-31.86(%) at the Akgeun basin and 23.55-28.43(%) at the Kangjeong basin.

• Journal of Microbiology and Biotechnology
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• 제19권11호
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• pp.1470-1474
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• 2009

This paper describes the development a of direct multiplex reverse transcription-nested polymerase chain reaction (PCR) method, devised for simultaneous detection and typing of influenza viruses. This method combines the direct reverse transcription reaction without RNA purification with the enhancement of sensitivity and specificity of nested PCR. The method successfully detected three major human influenza viruses: influenza virus A subtype 1 (H1N1) and subtype 3 (H3N2), and influenza B virus (B). The minimum number of virus particles (pfu/ml) necessary for detection in spiked saliva samples was 200 (H1N1), 140 (H3N2), and 4.5 (B). The method's sensitivity and simplicity will be convenient for use in clinical laboratories for the detection and subtyping of influenza and possibly other RNA viruses.

• 경영과학
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• 제26권1호
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• pp.77-91
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• 2009

It is the most important sucess factor for the electricity generation industry to minimize operations cost of surplus electricity generation through accurate demand forecasts. Temperature forecast is a significant input variable, because power demand is mainly linked to the air temperature. This study estimates the information value of the temperature forecast by analyzing the relationship between electricity load and daily air temperature in Korea. Firstly, several characteristics was analyzed by using a population-weighted temperature index, which was transformed from the daily data of the maximum, minimum and mean temperature for the year of 2005 to 2007. A neural network-based load forecaster was derived on the basis of the temperature index. The neural network then was used to evaluate the performance of load forecasts for various types of temperature forecasts (i.e., persistence forecast and perfect forecast) as well as the actual forecast provided by KMA(Korea Meteorological Administration). Finally, the result of the sensitivity analysis indicates that a $0.1^{\circ}C$ improvement in forecast accuracy is worth about $11 million per year.