• Proceedings of the Korean Radioactive Waste Society Conference
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• 2011.10a
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• pp.81-82
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• 2011

• Proceedings of the Korean Society of Crop Science Conference
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• 2023.04a
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• pp.18-18
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• 2023

• Journal of Sericultural and Entomological Science
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• v.18 no.1
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• pp.11-15
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• 1976

These surveys were designed to know decreasing rate of cocoon production all over the country and purchased amount of cocoons at public market which had been caused by various diseases in autumn of 1975. The results can be summarized as follows; 1. Percentage of sericuitural houses which sustain disease damage was 18.5 percent, and cocoon yield per box in bad crop houses was 8.8kg smaller than that in normal houses. 2. About 838M/T of decreased cocoons and 5.6 percent of damaging rate can be estimated in this autumn throughout the country. 3. In our country, it was 40.9 per cent of Grasseril and 34.5 per cent of Flacherie of silkworm diseases.

• Journal of Environmental Policy
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• v.12 no.4
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• pp.119-132
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• 2013

Hosta longipes is one of the most popular ornamental perennials in use in Korea today, and is mainly used as a groundcover plant in urban shaded places. In this study, the pytoremediation effect of Hosta longipes was tested using four concentrations (Control, 100, 250 and $500mg{\cdot}kg^{-1}$) of Cd, Pb and Zn in soil. The plants were planted in $300mm{\times}200mm{\times}250mm$ drainless-containers, which were filled with a artificial amended soil for 7 months. The results showed that the contents of heavy metals cadmium and lead in the shoot of Hosta longipes increased with increasing heavy metal concentration levels exception of zinc. The amount of zinc, cadmium, and lead accumulated in roots were increased with heavy metal concentration levels up in soil. The shoot/root ratios(TF; translocation factor) values were found to be more than 80% of total Zn, Cd, and Pb take up by Hosta longipes. These results indicated that root is the major part for accumulation of heavy metal. The removal contents of zinc, cadmium, and lead increased significantly with the increasing heavy metal concentration in the soil, which was planted with Hosta longipes. The heavy metal concentration accumulation in plant/soil ratios (BF; bioaccumulation factor) values for three metals were found to be more than 30% in cadmium and lead, but lower in zinc treatments. The different responses of Hosta longipes suggest that in heavy metal contaminated soils the plant adsorbs available metals depending on the concentration soils in which they are present. Therefore, this species can be an efficient phytoremediator for soils contaminated with cadmium and lead in urban shaded places.

• Horticultural Science & Technology
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• v.29 no.5
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• pp.433-440
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• 2011

In head lettuce seedlings, NaCl stress was treated with hydroponic culture containing 0, 50, or with 100 mM NaCl in the seedling grown up to two leaf stages. Our focus was on the effect of NaCl on fresh and dry weights, antioxidant materials, and inorganic ion level. Fresh and dry weights of head lettuce seedlings increased with the increase in salinity while the optimal growth occured at 50 mM NaCl. The chlorophyll a (Chl a), total Chl and Chl a/b ratio increased 6 days after treatment with 100 mM NaCI. However, the Chl b content decreased. Total glutathione increased only in the root of head lettuce seedlings, whereas significant increase of total arcorbate content was observed in both shoot and root after the treatment with 100 mM NaCl. In addition, the NaCl treatment resulted in the decreased level of spermidine content, and a increased spermine content. Furthermore, $Na^+$ content in shoot and root increased significantly while $K^+$, $Ca^{2+}$, and $Mg^{2+}$ content decreased. The alteration of inorganic ion level after treatment with NaCl caused the reduction of $K^+/Na^+$, $Ca^{2+}/Na^+$, and $Mg^{2+}/Na^+$ ratio with the increase of NaCl concentration. Taken together, these findings indicate that the treatment of NaCl causes the induction of oxidative stress, and results in the alteration of metabolic mechanism in head lettuce seedlings.

• Horticultural Science & Technology
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• v.34 no.4
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• pp.587-595
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• 2016

Salt stress in crops in reclaimed tidal lands can be reduced by applying soil amendments. To evaluate the effects of compost, gypsum, and phosphate on the growth of Chinese cabbage in saline-sodic soil conditions, we conducted a pot experiment in 2013 and 2014. The treatments consisted of a standard fertilizer application of a mix of compost and N-P-K fertilizer (S) and standard fertilizer applications with additional compost (S + C), gypsum (S + G), phosphate (S+P), and gypsum and phosphate (S + GP). The mean dry matter yield of cabbage in 2014 was three times as great as that in 2013, although soil EC (Electrical conductivity) in 2014 was not decreased. However, the mean ratio of sodium ion in soil solution ($SAR_{1:5}$) significantly decreased from $17.3{\pm}1.1$ in 2013 to $11.2{\pm}2.7$ in 2014. Application of gypsum had the greatest positive impact on the growth of Chinese cabbage. The S + G treatment increased dry matter yield by 7.0 (48.2) and 7.9 g/plant (16.6%) in 2013 and 2014, respectively, compared to the S treatment. Applying gypsum increased soil EC, but decreased $SAR_{1:5}$ by 14 and 38% in 2013 and 2014, respectively. The application of compost and phosphate had a small effect on the growth of Chinese cabbage. These results suggest that applying gypsum in reclaimed tidal lands can reduce the sodicity of the soil and improve crop growth.

• Journal of Applied Biological Chemistry
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• v.61 no.1
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• pp.25-31
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• 2018

This study investigated the effect of different $O_2$ transmission rate (OTR) of films on surface temperature, weight loss, pH, $O_2$, $CO_2$ and sensory characteristics, microbial quality, total phenolic contents and 1,1-diphenyl-2-picryl hydrazyl radical scavenging activity of fresh-cut lettuce during storage at $10^{\circ}C$ for 7 days. $80{\pm}5g$ of fresh-cut lettuce were packaged with oriented polypropylene films respectively. The OTR of packaging materials was 5,000, 8,000 and $10,000cc/m^2{\cdot}day{\cdot}atm$. Quality characteristics showed significant differences during storage. The surface temperature was averaged 13 and lower in higher OTR of films. The weight loss of lettuce ranged from 2.8 to 5.4% and the highest loss showed in $5,000cc/m^2{\cdot}day{\cdot}atm$ of film. pH was increased during storage and the highest pH was found in $5,000cc/m^2{\cdot}day{\cdot}atm$. The $O_2$ content in the packaging was decreased with increasing $CO_2$ content during storage. The lowest $CO_2$ was found in $10,000cc/m^2{\cdot}day{\cdot}atm$. As OTR was decreased, antioxidant profile of lettuce was decreased. Total aerobic bacteria showed from 5.48 to 6.59 log CFU/g. From the result of the overall sensory test, the marketability of fresh-cut lettuce stored at $10^{\circ}C$ seemed to be maintained effectively over 5 days.

• The Korean Journal of Applied Statistics
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• v.28 no.5
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• pp.907-920
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• 2015

Charts based on geometric distribution are effective to monitor the proportion of nonconforming items in high-quality processes where the in-control proportion nonconforming is low. The implementation of this chart is often based on the assumption that in-control proportion nonconforming is known or accurately estimated. However, accurate parameter estimation is very difficult and may require a larger sample size than that available in practice for high-quality process where the proportion of nonconforming items is very small. An inaccurate estimate of the parameter can result in estimated control limits that cause unreliability in the monitoring process. The maximum likelihood estimator (MLE) is often used to estimate in-control proportion nonconforming. In this paper, we recommend a Bayes estimator for the in-control proportion nonconforming to incorporate practitioner knowledge and avoid estimation issues when no nonconforming items are observed in the Phase I sample. The effects of parameter estimation on the geometric chart and the geometric CUSUM chart are considered when the MLE and the Bayes estimator are used. The results show that chart performance with estimated control limits based on the Bayes estimator is generally better than that based on the MLE.

• Horticultural Science & Technology
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• v.31 no.1
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• pp.1-7
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• 2013

In this study, the resistance to ozone and characteristics of ozone-induced damage were investigated on the perennial ground cover plant species. Sedum kamtschaticum and Hosta longipes were exposed to $200{\mu}g{\cdot}kg^{-1}$ ozone for 8 hours per day (from 08:00 to 16:00) in the naturally irradiated phytotron. The extent of ozone-induced damage was measured through the analysis of physiological parameters, such as water use efficiency (WUE), chlorophyll content (Chl. a, Chl. b, Chl. a + b, and Chl. a/b ratio), carotenoid contents, and the induction of reactive oxygen species (ROS). Ozone exposure significantly reduced the daytime WUE in both species. The contents of chlorophyll and carotenoid were also decreased and ROS, such as hydrogen peroxide ($H_2O_2$) and superoxide radical ($O_2{^-}$) were accumulated after ozone exposure. The above results of this study suggested that S. kamtschaticum is more resistant to atmospheric ozone than Hosta longipes. Considering its fast responses to ozone, it was also assumed that Hosta longipes can be used as an indicator plant of an increase in atmospheric ozone concentration.

• Journal of vocational education research
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• v.35 no.4
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• pp.1-18
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• 2016

The purposes of this study is to verify additional demand of students for secondary vocational education, and draw political implications. To meet the purposes, firstly we analyzed current policies on the secondary vocational education. Second, we divided additional demand of students for secondary vocational education into practical and potential demand. Practical demand by students who would like to take further vocational education in secondary education system includes students who hoped to enter vocational high school however they failed to go, the first or second year students who transferred from general high school to vocational high school, and the third year students who are in general high school would like to take commissioned vocational courses. Potential demand is an additional demand for secondary vocational education in a society perspective. This includes a student who downgraded employment even though they entered college or university after graduated general high-school. Comparing the result of this study with the entrance quota of vocational high-school, additional demand of students for secondary vocational education showed that accounted for 61.2 percent of the entrance quota year 2015. Specifically, potential demand accounts for 31.7 percent of the entrance quota for vocational high school and practical demand accounts for 29.5 percent.