• Journal of environmental and Sanitary engineering
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• v.19 no.3 s.53
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• pp.13-21
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• 2004

This study was focused on the evaluation of Nanjido landfill site by leachate analysis. Several parameters, for example pH, BOD, $COD_{Mn},\;COD_{Cr}$, SS, TP, $NH_3-N$, Color, were selected as major leachate quality parameters. $BOD/COD_{Cr}$. was used to estimate the biodegradable portion in organic matter. Samples were collected at the leachate storage wells and leachate treatment facility inflow in each quarter of 2003. The results were as follows : 1. Inflow quality of treatment plant in 2003 was analysed as $pH\;7.3\~8.0,\;BOD\;12.4\~30.0mg/L,\;COD_{Mn}\;101.2\~130.3mg/L,\;COD_{Cr}\;122.5\~238.0mg/L,\;SS\;16.1\~115.3mg/L$, $T-P\;0.27\~0.80mg/L,\;NH_3-N\;208.0\~~354.0mg/L$, Color $110.3\~129.0$ unit. 2. $BOD/COD_{Cr}$ of inflow ranged between $0.07\~0.16$ indicating that the landfill had the properties of old-fill and organic portion in leachate was mostly persistent organic matter. 3. Though concentrations of BOD, COD, $NH_3-N$, Color in leachate storage wells were mostly higher in first landfill than in second landfill, $BOD/COD_{Cr}$ ranging from 0.03 to 0.20, showed reversely. 4. Correlation coefficient$(R^2)$ between color and other parameters related to organic matter showed mostly above 0.7 and especially highest value with $COD_{Mn}$ of 0.7985.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.2
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• pp.45-49
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• 2006

Electrochemical hydrogenation/dehydrogenation properties were studied for a single particle of a Mm-based(Mm : minh metal) hydrogen storage alloy($MmNi_{3.55}Co_{0.75}Mn_{0.4}Al_{0.3}$) for fuel cell and Ni-MH batteries. A carbon fiber microelectrode was manipulated to make electrical contact with an alloy particle, and the potential-step experiment was carried out to determine the apparent chemical diffusion coefficient of hydrogen atom($D_{app}$) in the alloy. Since the alloy particle we used here was a dense, conductive sphere, the spherical diffusion model was employed for data analysis. $D_{app}$ was found to vary the order between $10^{-9}\;and\;10^{-10}[cm^2/s]$ over the course of hydrogenation and dehydrogenation process. Compared with the conventional composite film electrodes, the single particle measurements using the microelectrode gave more detailed, true information about the hydrogen storage alloy.

• Korean journal of food and cookery science
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• v.15 no.3
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• pp.249-257
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• 1999

Jeung-Pyun is a traditional fermented Korean food with rice flour, water, sugar, salt and unrefined rice wine(Takju). In order to investigate how the addition of soybean has an influence on Jeung-Pyun fermentation, changing to adding amount of soybean 0%, 5%, l0%. 15%, 20% based on rice weight, we carried out sensory evaluation and measured the physicochemical properties, instrumental characteristics and degree of gelatinization. The specific volume of Jeung-Pyun was increased as the more soybean was added. The pH of Jeung-Pyun batter was decreased as the fermentation time was longer, but it was increased as more soybean was added. The degree of gelatinization of Jeung-Pyun was decreased as storage day was longer, but it was high as more soybean was added compared to control(0%). In sensory evaluation, Jeung-Pyun added 5∼10% of soybean was good generally. Correlation coefficient between hardness and degree of gelatinization was high. In instrumental characteristics, hardness was increased only in control for room temperature storage(20$^{\circ}C$), but at 4$^{\circ}C$ it was less increased than control(0%) as more soybean was added. Cohesiveness was decreased generally as storage day was longer at 4$^{\circ}C$, but it was less decreased as more soybean was added. In brittleness at 4$^{\circ}C$, Jeung-Pyun of adding soybean was higher compared to control. In surface structure of Jeung-Pyun observerd by SEM. air pore size was small and distributed regularly as more soybean added. In conclusion. it can be suggested that the addition of soybean improve the quality of Jeung-Pyun.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1060-1063
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• 2003

Electron spin resonance (ESR) spectroscopy was used to investigate the effects of irradiation doses and storage times on three spices. Three imported spices (Brassica juncea, Origanum vulgare, Laurus nobilis) were irradiated with doss of 0, 1, 5 and 10 kGy using a Co-60 irradiator at room temperature. ESR signals were measured from each sample by a Bruker-EPR spectrometer. The gamma-irradiated Brassica and Laurus nobilis exhibited characteristic signals, which were different from those of the non-irradiated ones. Non-irradiated and irradiated Origanum vulgare exhibited single lines, with higher ESR signals in irradiated sample than in non-irradiated sample. The ESR signals increased linearly with increasing irradiation doses $(1{\sim}10kGy)$. A strong positive correlation coefficient $(R^2=0.9939{\sim}0.9993)$ was obtained between the irradiation doses and the corresponding ESR signal intensities. Although the ESR signal intensities decreased with storage time, signals from the three irradiated spices were observed even after 12 weeks of storage at room temperature.

• Korean Journal of Food Science and Technology
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• v.19 no.6
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• pp.463-470
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• 1987

In order to develop a rapid predicting method of the shelf-life of moisture sensitive foods and establish their proper packaging methods, the qualify changes and shelf-life of dired laver as a model food were studied by the computer simulation. A mathematical model of the relationship between the rate constants of chlorophyll a and water activity was established at $10^{\circ}C,\;25^{\circ}C$ and $40^{\circ}C$. Computer simulation to predict water activity and chlorophyll a was developed by considering the simultaneous influence of storage conditions such as water content of products, storage temperature and relative humidity, packaging materials. Simulated quality changes of dried laver was in good agreement with the experiment data. Chlorophyll a and sensory score decreased as the water activity increased. And correlation coefficient between the sensory scores and the contents of chlorophyll a was very high as 0.991. The critical water activity by sensory evaluation was around 0.55. The shelf-life of dried laver packaged with plastic films could be predicted from the above results in various storage conditions.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.7
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• pp.64-73
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• 2002

This study was performed to evaluate effects of physical characteristics of both watershed and reservoir on nutrient-chlorophyll relationship in Korean reservoirs. Simple linear models were developed with published data in Korea including 415 reservoirs and 11 multi-purpose dams, and physico-chemical parameters of reservoirs and characteristics relationship of models were analyzed. Theoretical residence time in Korean reservoirs was strongly correlated with the ratio of TA/ST (drainage area + surface area / storage volume) in the logarithmic function. As a result of monthly nutrients-chlorophyll-a regression analysis, significant Chl-a-TP relationship appeared during May～July. The high Chl-a yields per total phosphorus appeared during this time (R$\^$2/=0.51, p<0.001, N= 1088). Chlorophyll-a demonstrated much stronger relationship with TP. than TN. Seasonal algal-nutrient coupling were closely related with N:P ratio in the reservoir water, and it was, in turn, dependent on the monsoon climatic condition (precipitation). Based on the results of regression analysis and high N:P ratio, a major limiting factor of algal growth appeared to be phosphorus during this time. Unlikely TA/ST ratio, DA/SA ratio (drainage area f surface area) was likely to influence directly on the nutrient-Chl-a relationship, indicating that if storage volume and inflowing water volume were the same, algal biomass could be developed more in reservoirs with large surface area. Thus, DA/SA ratio seemed to be an important factor to affect the development of algal biomass in Korean reservoirs. With low determination coefficient of TP-Chl-a relationship, our findings indicated not only nutrient (phosphorus) but also other physical factors, such as DA/SA ratio, may affect algal biomass development in Korean reservoirs, where actual residence time appears to be more closely related to reservoir surface area rather than storage volume.

• Journal of Power Electronics
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• v.15 no.4
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• pp.1105-1118
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• 2015

Battery energy storage devices (ESDs) have become more and more commonplace to maintain the stability of islanded power systems. Considering the limitation in inverter capacity and the requirement of flexibility in the ESD, the droop control was implemented in paralleled ESDs for higher capacity and autonomous operation. Under the conventional droop control, state-of-charge (SoC) errors between paralleled ESDs is inevitable in the discharging operation. Thus, some ESDs cease operation earlier than expected. This paper proposes an adaptive accelerating parameter to improve the performance of the SoC error eliminating droop controller under the constraints of a microgrid. The SoC of a battery ESD is employed in the active power droop coefficient, which could eliminate the SoC error during the discharging process. In addition, to expedite the process of SoC error elimination, an adaptive accelerating parameter is dedicated to weaken the adverse effect of the constraints due to the requirement of the system running. Moreover, the stability and feasibility of the proposed control strategy are confirmed by small-signal analysis. The effectiveness of the control scheme is validated by simulation and experiment results.

• Journal of Soil and Groundwater Environment
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• v.9 no.3
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• pp.27-32
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• 2004

The oceanic tides have an effect on groundwater levels in coastal fractured rock aquifers. The observed groundwater table fluctuations caused by the effective stress through an aquifer are shown as sine curves similar with tidal fluctuation. To estimate a hydrogeologic parameter, tidal method is utilized with groundwater level fluctuations of two monitoring wells. Cross correlation function is used to calculate time lags between observed groundwater levels and tide, and the deeper well shows longer time lag. The storage coefficients calculated by using tidal efficiency and time lag show large differences. The storage coefficients obtained by using time lags are close to the result of slug test, and that of the deeper well shows closer value by slug test. The tidal efficiency is unsatisfied to apply in the tidal method because of an effect of phreatic aquifer and the vertical flow of groundwater through fractured confining bed. This tidal method can be an economical and effective way to define the parameter by considering the location of observation well and hydrogeologic characteristics of a coastal aquifer.

• Journal of Veterinary Clinics
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• v.4 no.1
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• pp.395-401
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• 1987

In this study, the effect of ambient temperature on the 45$^{\circ}$micro ESR/hr of cattle blood were observed, and a correction chart for correcting observed values at any ambient temperature to standard values at 20$^{\circ}C$ was plotted. Besides, the effect of storage temperature of blood on the 45$^{\circ}$micro ESR/hr was surveyed. The results were as follows: 1. The values of the 45$^{\circ}$micro ESR/hr were increased as the ambient temperature were elevated(P<0.01), and lower the value of PCV, higher the effect of temperature on the 45$^{\circ}$micro ESR/hr was observed(P<0.01). 2. Regression of values of 45$^{\circ}$micro ESR to ambient temperature in all the group of different level of blood PCV showed linear regression with the highly significant coefficient of correlation. With the results, correction chart was drawn as in Fig. 1. 3. In the purpose to verify the reliability of correction chart, observed values of 45$^{\circ}$micro ESR/hr in field(out door) were corrected to values at 20$^{\circ}C$ by the correction chart(Fig. 1), comparing with the observed values at 20$^{\circ}C$ of standard temperature. No significant differences were found between two groups mentioned above. 4. In the study on the effect of storage temperature of the blood on the 45$^{\circ}$micro ESR/hr, group of storage temperature at 5$^{\circ}C$ showed statistically no significant differences untill 24 hours in contrast with standard control group.

• Journal of agriculture & life science
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• v.46 no.1
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• pp.43-51
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• 2012

This study was conducted to develop growth model and to estimate carbon storage of Quercus variablis stands. The study sites were located in the Yangpyeong and Gangneung regions. A total of 30 sample trees were harvested for data collection. According to the results of the application of Chapman-Richards model in this study, the coefficient of determination($R^2$) for the DBH-height model in Yangpyeong region was 97% while 94% in Gangneung regions. For the age-height relationship, the $R^2$ in Yangpyeong regions was 99% while 94% in Gangneung regions. The total carbon stored in Yangpyeong region was $83.0Mg\;C\;ha^{-1}$ while $137.3Mg\;C\;ha^{-1}$ in Gangneung.