• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.130.1-130.1
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• 2011

Since the direct normal insolation is a main factor for designing any solar thermal power system, it is necessary to evaluate its characteristics all over the country. We have begun collecting direct normal insolation data since December 1992 at 16 different locations and considerable effort has been made for constructing a standard value from measured data at each station. KIER(Korea Institute of Energy Research)'s new data will be extensively used by solar thermal concentrating system users or designers as well as by research institutes. From the results, we can conclude that 1) Yearly mean $2.67kWh/m^2/day$ of the all day's direct normal insolation was evaluated for all days all over the 16 areas in Korea. 2) All day's direct normal insolation of spring and summer were $2.91kWh/m^2/day$ and $2.23kWh/m^2/day$, and for fall and winter their values were $2.78kWh/m^2/day$ and $2.77kWh/m^2/day$ respectively. So, spring, fall and winter were higher, and summer was lower than the yearly mean value.

• Proceedings of the Safety Management and Science Conference
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• 2010.04a
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• pp.141-147
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• 2010

Risk level for each construction work can be very important factors to establish advanced preventionmeasures. But it is important how to produce it. There are three different methods to set it up for consturuction situation. They are as follows; 1) occurrence frequency = the number of accident workers of each work kind / yearly accident workers 2) occurrence frequency = the number of accident workers of each work kind / yearly workers 3) occurrence frequency = the number of accident workers of each work kind / the total workers All these three concepts(=averaged concept)are analyzed. Additionally frequency based on discrete curve, and severity based on continuous curve are also combined for producing risk level with more scientific approach. This risk level can be very useful to make prevention plan or take measures at construction sites. This is study result can change existing risk level concept to new concept of it, namely rail way work and in-water work showed be high risk level and RC work be low risk level, different from the situation which we have thought commonly, so far.

• Solar Energy
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• v.20 no.2
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• pp.31-42
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• 2000

Since the direct normal insolation is a main factor for designing any focusing solar system, it is necessary to evaluate its characteristics all over the country. We have begun collecting direct normal insolation data since December 1990 at 16 different locations and considerable effort has been made for constructing a standard value from measured data at each station. KIER(Korea Institute of Energy Research)'s new data will be extensively used by concentrating system users or designers as well as by research institutes. From the results, we can conclude that 1) Yearly mean $4,576kcal/m^2.day$ of the direct normal insolation was evaluated for clear day all over 16 areas in Korea. 2) Clear day's direct normal insolation of spring and summer were $4,710kcal/m^2.day$ and $4,960kcal/m^2.day$, and for fall and winter their values were $4,484kcal/m^2.day$ and $4,151kcal/m^2.day$ respectively. So, spring and summer were higher, and fall and winter were lower than the yearly mean value.

• Journal of the Korean Solar Energy Society
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• v.28 no.3
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• pp.45-52
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• 2008

In order to clarify characteristics of variation in wind energy over a long-term period, an investigation was carried out at Seoguang site on Jeju island. The wind data for 10 years from Automatic Weather System (AWS) were analyzed for each year. The variation in the annual energy production (AEP) for the 2 MW wind turbine was estimated through statistical work. The result shows that the range of the yearly average wind speed at 15 m above ground level for 10 years was from -22.6% to +13.7%, which is wider range than that in Japan. The coefficient of variation for the AEP was 22.7%, which is about twice of that for the yearly average wind speed. Therefore, for estimating the wind energy potential accurately at a given site, the wind data should be analyzed over a long-term period based on the data from the meteorological station.

• Journal of the Korean Solar Energy Society
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• v.28 no.1
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• pp.51-56
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• 2008

Since the direct normal insolation is a main factor for designing any solar thermal power system, it is necessary to evaluate its characteristics all over the country. We have begun collecting direct normal insolation data since December 1992 at 16 different locations and considerable effort has been made for constructing a standard value from measured data at each station. KIER(Korea Institute of Energy Research)'s new data will be extensively used by solar thermal concentrating system users or designers as well as by research institutes. From the results, we can conclude that 1) Yearly mean $2.67\;kWh/m^2/day$ of the direct normal insolation was evaluated for all days all over the 16 areas in Korea. 2) All day's direct normal insolation of spring and summer were $2.91\;kWh/m^2/day$ and $2.23\;kWHm^2/day$, and for fall and winter their values were $2.78\;kWh/m^2/day$ and $2.77\;kWh/m^2/day$ respectively. So, spring, fall and winter were higher, and summer was lower than the yearly mean value.

• 보존과학연구
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• s.24
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• pp.169-184
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• 2003

Yearly mean temperature and relative-humidity of the Seokguram Grotto was measured $19~23^{\circ}C$, 40~44% from May, 1998 to December,2002. The measurement has little differences comparing to the optimum guideline (temperature : $20^{\circ}\pm2^{\circ}C$, relative-humidity : $50^{\circ}\pm5%$). It is necessary to increase humidity in the Seokguram Grotto during winter because of heating and decrease the temperature during summer because of a higher temperature of outside. In addition, the diurnal range keep in $4^{\circ}C$ of temperature and in 10% of relative-humidity. Yearly mean concentration of $CO_2$(carbon dioxide) was measured538~658ppm that is higher than concentration of normal atmosphere(360 ppm). The $CO_2$ has an cumulative effect on the surface of stone cultural properties as a form of carbonic acid($H_2CO_3$) after reaction with water. HVAC (Heating, Ventilation and Air Conditioning) system should be operated to maintain ideal state for the preservation according to the optimum guideline. Also, the entrance into the Seokguram Grotto should be controlled to prevent a sudden fluctuation of humidity and temperature. Human could carry small particles like a microdust, microbe, etc., into the Seokguram Grotto and also could damage the surface by a direct touch.

• Journal of the Korean Operations Research and Management Science Society
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• v.40 no.4
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• pp.49-63
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• 2015

Keyword indexed in multidisciplinary journals show trends about science and technology innovation. Nature and Science were selected as multidisciplinary journals for our analysis. In order to reduce the effect of plurality of keyword, stemming algorithm were implemented. After this process, we fitted growth curve of keyword (stem) following bass model, which is a well-known model in diffusion process. Bass model is useful for expressing growth pattern by assuming innovative and imitative activities in innovation spreading. In addition, we construct keyword co-occurrence network and calculate network measures such as centrality indices and local clustering coefficient. Based on network metrics and yearly frequency of keyword, time series analysis was conducted for obtaining statistical causality between these measures. For some cases, local clustering coefficient seems to Granger-cause yearly frequency of keyword. We expect that local clustering coefficient could be a supportive indicator of emerging science and technology.

• Journal of Pharmaceutical Investigation
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• v.37 no.1
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• pp.27-37
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• 2007

Proficiency test is an essential tool far ensuring analytical ability of analytical chemists and analytical institutes. Usually, the standard protocol for proficiency test is focused on acceptability of reported analytical results of participants by calculating z-scores and related diagnostic parameters. The ultimate goal of this process is to reveal the sources of variability of analytical results and to find the way to reduce their influence. In this study, the method of analysis of variance (ANOVA) was applied to the analytical data collected from qualify control departments of pharmaceutical companies in KyungIn province in Korea in the year of 2000. As influencing factors of variability of analytical results, the use of internal standards for liquid and gas chromatograpy, the educational and professional background of participants, geological locations and yearly production sizes of participating companies were evaluated. To evaluate the variability in accuracy of analytical results, absolute differences from sample mean and sample median were used and to evaluate variability in precision of individual participants, the reported standard deviation of each participant was used. As a result, the use of internal standards in gas chromatographic analysis, participants' academic background and the yearly production sizes of pharmaceutical companies showed statistically significant influence to the accuracy and the precision of the reported analytical results used in this study.

• Applied Biological Chemistry
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• v.18 no.2
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• pp.61-64
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• 1975

Soil residues in a tobacco field yearly treated with a soil insecticide, Heptachlor, was analyzed by GLC equipped with electron capture detector(ECD). In addition, translocation of the heptachlor residues into two staple vegetables, radish and chinese cabbage was also studied under field conditions. The results were summarized as follows; 1. The Heptachlor residues in the soil of tobacco plots were less than 0.010 ppm. 2. The Heptachlor residues in radish and chinese cabbages cultivated in the tobacco plot were also below 0.010 ppm. 3. Amount of Heptachlor residues translocated into the vegetables were not related to the concentrations of the residues in the soil.

• Journal of Astronomy and Space Sciences
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• v.29 no.2
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• pp.97-101
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• 2012

Monitoring sunspots consistently is the most basic step required to study various aspects of solar activity. To achieve this goal, the observers must regularly calculate their own correction factor $k$ and keep it stable. Relatively recently, two observing teams in South Korea have presented interesting papers which claim that revisions that take the yearly-basis $k$ into account lead to a better agreement with the international relative sunspot number $R_i$, and that yearly $k$ apparently varies with the solar cycle. In this paper, using artificial data sets we have modeled the sunspot numbers as a superposition of random noise and a slowly varying background function, and attempted to investigate whether the variation in the correction factor is coupled with the solar cycle. Regardless of the statistical distributions of the random noise, we have found the correction factor increases as sunspot numbers increase, as claimed in the reports mentioned above. The degree of dependence of correction factor $k$ on the sunspot number is subject to the signal-to-noise ratio. Therefore, we conclude that apparent dependence of the value of the correction factor $k$ on the phase of the solar cycle is not due to a physical property, but a statistical property of the data.