• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.477-484
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• 2015

Environmental effect of water-saving irrigation on the emissions of greenhouse gases (GHGs) has not been well investigated. The objective of this study was to measure the effect of water-saving irrigation on GHGs as well as water use and rice production yield in paddy field condition in Korea. Four experimental runoff plots of 4x35 m in size were prepared at an existing paddy field. GHGs emission was measured during the 2012~2013 growing seasons while a Japonica rice variety was cultivated. Four different water management methods, 1) Continuous Flooding (CF), 2) Intermittent Drainage (ID), 3) Water Saving (WS), and 4) CF+WS, were used during a rice growing season to compare the effects of water management methods on GHGs emission. CF method is flooding all the time, ID method makes paddy water drained 40 days after transplanting for about two weeks, WS method maintains 2~3 cm water-level, which should be refilled when the water-level decreased to about 0 cm, and CF+WS method combines CF method before 30 days after transplanting (DAT) and WS method after 30 DAT. Regardless of water management methods, paddy field water was drained about 30 days before harvest. Amount of GHGs emission from WS plot was reduced by 69.3% compared to that from CF plot and by 59.0% compared to that from ID plot. Amount of GHGs emission from CF+WS plot was reduced by 60.7% compared to that from CF plot and by 47.5% compared to that from ID plot. Weed occurrence in CF+WS plots was reduced to 62.2% in comparison with the WS plot, implying that CF+WS plot showed the best effect to mitigation of the greenhouse gas emission in the atmosphere.

• Korean Journal of Agricultural Science
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• v.42 no.3
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• pp.167-175
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• 2015

The present study aimed to investigate the effects of drought stress on the accumulation of glucosinolates (GSLs) in the leaves of Kale cultivated in autumn and spring. HPLC analysis guided to identify seven GSLs including progoitrin, glucoraphanin, sinigrin, gluconapin, glucobrassicin, 4-methoxyglucobrassicin and neoglucobrasscin. Quantification of GSLs revealed that the contents of sigirin was the highest (45%) followed by the level of progoitrin (24%) in terms of total GSLs. The ranges of total GSL contents was 1.16 (84)-15.88 (89 DAS, ${\mu}mol/g$ dry wt. (DW)) in treatment plot and 1.23 (84)-7.05 (74 DAS, ${\mu}mol/g$ dry wt.) in control plot showed the enhancement in the contents of GSLs in treatment than in the control plot. The present results evidenced that the variation of total GSL contents were depending on the harvest period. In 105 DAS, comparatively no differences in the GSL contents on each sample in autumn season, whereas in spring season, although there was decrease in the GSLs tendency from 74 DAS to 84 DAS in both control and treatment plot, the GSL contents of treatment plot was dramatically increased in 89 DAS. In treatment plot, the GSL contents on 89 DAS (1.16) was 15 fold higher to 84 DAS ($15.88{\mu}mol/g$ DW). The variation in the contents of GSL in spring and autumn did not documented significant differences because of their differences in the growth time and cultivation conditions. In conclusion, the GSL contents in kale was likely to be affected by drought stress treatment. Scrutiny and further research for exact relation between drought stress and GSL contents in kale should be needed.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.4
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• pp.63-73
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• 2020

The area of paddy fields for upland crop cultivation is gradually increasing. In this context, we developed a chain type mole drainer that can be attached to a tractor to prevent the wet injury of crops. To conduct a field test, we formed underdrains at 2 m intervals in a paddy field wherein soybeans are cultivated, and we investigated the status of the soil moisture, groundwater level, and soybean growth during the cultivation period. The soil moisture content decreased by 22.3~26.8% in the test plot and by 5.9~6.9% in the control plot during a period of 57~88 hour after a rainfall of 41.5~157.0 mm. The effect of underdrainage was clear as the hourly groundwater level decreased approximately 2.8 times faster in the test plot compared with the control plot. Moreover, the soybean yield was greater by 78.6 kg/10a in the test plot than in the control plot. Therefore, for soybean cultivation in paddy fields, the use of the developed mole drainer is expected to help in improving the drainage and increasing the soybean yield.

• The Korean Journal of Food And Nutrition
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• v.30 no.4
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• pp.703-709
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• 2017

This study analyzed the effect on weight and average daily gain, carcass grade, and blood characteristics and immunity in case of dietary addition of pegmatite to Hanwoo steers. Relative to Hanwoo steers, initial body weight was $257.3{\pm}11.74kg$ (8-months old after birth). Forty-eight Hanwoo steers were fed for 24 months using random arrangement (4 treatment plots${\times}$4 heads${\times}$3 repeat). The treatment plot (498.75~500.82 kg) had higher weight during the early fattening stage compared with that of the control plot (474.37 kg) (p<0.05). Regarding total cholesterol of the blood, the value was similar to one during initiation of testing, but the value increased gradually based on the progress of fattening. In addition, the triglyceride was considerably low in T2~T3 plots with high addition of pegmatite during the late fattening stage compared with other treatment plots (p<0.05). This study revealed a tendency in the IgG content that represented immunity as the addition of pegmatite became higher (p>0.05). This study found that the treatment plot (441.55~452.10 kg) had higher carcass weight compared with the control plot (436.30 kg). However, this study revealed that the treatment plot (2.30~2.55 points) had higher carcass quantity grade compared with the control plot (2.11 points). This study found that the control plot (3.55 points) had higher carcass quality grade compared with the treatment plot (2.67~3.09 points) (p>0.05). With studies combined, it was determined that dietary addition of pegmatite to the feed as clay minerals in fattening Hanwoo steers would improve feed intake, body weight gain and carcass quantity grade.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.5
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• pp.285-292
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• 2008

To investigate the effect of tillage methods on the silage barely growth and the soil environment in paddy field, liquid pig manure(LPM) was applied after harvesting rice at Jisan series soil for 2 years. Five plots, a LPM applied rate as N%; 0, 100, 150, 200(basal dressing) and 100(basal dressing)+50(additional fertilizer) were divided by tillage methods; non-tillage, non-tillage+rice straw and rotary tillage method. Emission amounts of $NH_3$ gas highly decreased in the rotary tillage and the non-tillage+rice straw plot compared to non-tillage plot. The contents of soil organic matter and exchangeable cation were increased in the applied LPM plot. $NH_4-N$ and $NO_3-N$ contents in soil were the highest in the non-tillage+rice straw plot and followed by the rotary tillage and highly decreased along with the growth of plant. Run-off rate of mineral components were higher in order of the rotary tillage plot£æthe non-tillage plot£æthe non-tillage+rice straw plot and then leached to $SO_4$, $NO_3-N$, K plentifully. The yield of silage barley in dry weight was higher in order of the non-tillage+rice straw plot>the rotary tillage plot>the non-tillage plot. To estimate the feed value of silage barley, crude protein, acid detergent fiber(ADF) and neutral detergent fiber(NDF) contents were analyzed. Crude protein and ADF contents were the highest at rotary tillage N150% plot as 9.7 and 29.4%, respectively. NDF contents was the highest at non-tillage+rice straw N150% plot as 56.7%. In conclusion, we recommend not to incinerate rice straw and to apply LPM at non-tillage status in cultivating the silage barley. This may prevent water pollution and increase barley yields.

• The Korean Journal of Applied Statistics
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• v.31 no.1
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• pp.155-165
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• 2018

Outliers and influential observations often distort many numerical measures for data analysis. Jang and Anderson-Cook (Quality and Reliability Engineering International, 30, 1409-1425, 2014) proposed a graphical firework plot method for exploratory analysis purpose to provide a possible visualization of the trace of the impact of the possible outlying and influential observations on the univariate/bivariate data analysis and regression. They developed 3-D plot as well as pairwise plot for the appropriate measures of interest. We use firework plots as a graphical exploratory data analysis tool to detect outliers and evaluate the impact of outliers in statistical inference.

• Journal of the Korean Data and Information Science Society
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• v.23 no.6
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• pp.1103-1115
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• 2012

In this study, we studied the effect of onion on hyperlipidemia in terms of factors, such as body weight, liver weight, kidney weight, heart weight, blood glucose, total cholesterol, triglycerides, HDL-cholesterol, and LDL-cholesterol. The hyperlipidemia supplement was significantly effective on the liver weight, kidney weight, blood glucose, total cholesterol, triglycerides, and LDL-cholesterol with the fixed effect model. However, the liver weight, blood glucose, total cholesterol, and triglycerides were significantly decreased with the random effect model on the heterogeneous factors selected by Galbraith plot. The existence of publication bias was checked by using a funnel plot.

• The Korean Journal of Applied Statistics
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• v.29 no.2
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• pp.355-368
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• 2016

Outliers and influential data points distort many data analysis measures. Jang and Anderson-Cook (2014) proposed a graphical method called a rework plot for exploratory analysis purpose so that there could be a possible visualization of the trace of the impact of the possible outlying and/or influential data points on the univariate/bivariate data analysis and regression. They developed 3-D plot as well as pairwise plot for the appropriate measures of interest. This paper further extends their approach to identify its strength. We can use rework plots as a graphical exploratory data analysis tool to evaluate the impact of outliers in skewness and kurtosis of univariate data.

• Journal of Korean Society of Forest Science
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• v.80 no.4
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• pp.379-382
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• 1991

Tree height at age 10 was used to estimate the statistical efficiencies of sampling size in the progeny test of Pinus koraiensis S. et Z. Experimental design was RCB design which consists of 25 half-sib families in each of three blocks. The number of families and blocks were fixed, therefore, the number of trees sampled per plot was the only factor that influences the environmental portion of the family mean height. Coefficient of variation, the estimate of the standard error of the family mean height, decreased with increase of sampling plot size, and became stable from 4-tree plot sampling (6.97%). The experimental error was significant from 7-tree sampling plot size. Nonlinear relationship (${\hat{Y}}=10.425e-^{0.073x}$ ; $R^2$=0.840) was found between the sampling plot size and the standard error of family mean height.

• Bulletin of the Korean Chemical Society
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• v.34 no.9
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• pp.2781-2786
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• 2013

We examined the effect of electrode fingers and gaps of coplanar interdigitated electrode (IDE) structures to characterize the ammonium salt-containing polyelectrolyte film of resistance-based humidity sensors. IDEs designed for this purpose were flexible gold electrodes deposited on a polyimide substrate using a printing process because the geometry presents a potential for tunable sensitivity over other electrode designs. The basic design of the sensors consisted of IDEs with a different number of electrode fingers such as 3, 4, and 5 and gap sizes of 310, 360, 410, and $460{\mu}m$. Details of the AC complex impedance characteristics such as the Nyquist plot, Bode plot, and activation energy based on electrode construction were investigated.