• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.2
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• pp.140-145
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• 2007

This study was carried out to develop effective test method by soybean stink bug and to screen resistant genetic resources against soybean stink bug. The damage pod rate by stink bug showed 40% of most soybean varieties and was selected about 10% low of 10 varieties by 298 variety and degree in soybean at first year Stink bug damage rate research for 102 varieties that stink bug damage rate lowed at first year showed 10% low of 12 varieties and from 20% to 30% of the other varieties. So testing material is "Ilpumgeumjeongkong" to develop for effective test method soybean stink bug and result for stink bug damage rate research of according to growth stage showed rapidly high more full seed than full pod. Full seed stage (R6) was highest to 35.5% for stink bug damage rate. Result of resistant genetic resources selection according to stink bug damage pod rate was lowed of best to 10.3% for "Peking, Sorogkong, Hwangsaegjunjeari and Sobaeknamulkong" in the order. Also, stink bug damage seed rate was similar too. So "Peking, Sorogkong, Hwangsaegjunjeari and Sobaeknamulkong" were thought resistant variety against stink bug. Additional study carried out with "Peking and Sorogkong" so that concretely investigate about stink bug's refuse reaction. This result showed 10.0% for Peking and 14.2% for Sorogkong at R6 stage. But, damage pod rate was rapidly lowed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.747-756
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• 1995

To find out the optimum application method of slow-releasing fertilizer(SRF) and conventional fertilizer(CF) with different fertilization rate under two culture methods[l0-day old seedling machine transplanting(MT) and direct-sowing on dry paddy(DS)] in the south-western region(clay loam soil) of Korea, used were Chosun slow-releasing fertilizer(silicate latex coated fertilizer: N-P$_2$O$_{5}$-K$_2$O =18-12-13) and conventional fertilizer. Plant height and number of tillers with different two culture methods were higher at MT than DS in early growth. The ratio of dry weight in heading stage was higher at CF than SRF in MT than DS and especially, SRF 80% + CF 20% than SRF 100% or CF 100%. Leaf area index (LAI) in heading stage was higher at CF in MT but higher at SRF in DS than their counterparts. Chlorophyll content was higher at SRF than in CF expect for heading stage(HS), especially in DS. It was highest at HS in CF without its difference during maximum tillering stage(MTS) and panicle formation stage(PFS), while highest at PFS in SRF with tendency of gradual increase and decrease before and after PFS, respectively. Heading was delayed 2~3 days at SRF in two cultrue methods and 4~5 days at SRF in DS in comparison with CF in MT with delay of 2 days at DS compared with MT. Culm length was longer at CF in MT and at SRF in DS than their counterparts. Panicle number per m was more at SRF and in DS. Filled grain ratio was higher at CF and in MT. Yield was obtained 101 and 100% at 100% and 80% level of SRF in DS respectively, and 96% at 80% level of CF in MT, compared with conventional application method (516kg /l0a), and increased 2~4% at DS and 0~3% at MT in SRF. Yield was high in order of 100%(SRF) =80%(SRF) + 20%(CF) > 100%(SRF) + 20%(CF) > 80%(SRF) at MT and 80%(SRF) + 20%(CF) =100%(SRF) > 80%(SRF) =100%(SRF) + 20%(CF) at DS.

• Horticultural Science & Technology
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• v.29 no.1
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• pp.29-35
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• 2011

Individual ion concentrations and ionic contributions to EC reading in the circulated nutrient solution are the important factors to be considered for stable EC-based closed-loop soilless culture. This study was conducted to determine appropriate ion-analysis intervals of the circulated nutrient solutions based on ion concentration, ion balance, and ion electrical conductivity under different renewal intervals in EC-based nutrient control systems for sweet peppers (Capsicum annum L. 'Fiesta') in early growth stage. Average node numbers of the plants were 13 and 18 when the experiment started and finished, respectively, and three plants were grown in each rockwool slab. Four different renewal intervals of circulated nutrient solutions such as 1, 2, 3, and 4 weeks were used as treatment. Nutrient solutions were supplied to the plants based on integrated radiation. Drainage was collected into drain tanks after irrigation ended in the day and then mixed with fresh water until the EC reaches 2.69 $dS{\cdot}m^{-1}$. The replenished nutrient solution was supplied to the plants in the next day. Ion concentrations of the individual ions periodically analyzed in the circulated nutrient solutions showed no significant differences among the treatments during the experimental period. Ion concentrations of $K^+$, $Ca^{2+}$, $Mg^{2+}$, $Na^+$, $NO_3{^-}$, ${SO_4}^{2-}$, ${PO_4}^{3-}$, and $Cl^-$ varied within 5-8, 11-14, 2.0-2.7, 0.5-0.6, 14-19, 4-5, 1-4, and 0.3-0.5 $meq{\cdot}L^{-1}$, respectively. Ion balance showed a consistent tendency over all the treatments and especially $K^+$ : $Ca^{2+}$ and ${SO_4}^{2-}$ : ${PO_4}^{3-}$ played great roles in the cation and anion balances in the nutrient solutions, respectively. Activity coefficients of ions such as $K^+$, $NO_3{^-}$, and $H_2PO_4{^-}$ varied within 0.8-0.9 and those of $Ca^{2+}$, $Mg^{2+}$, ${SO_4}^{2-}$ varied within 0.5-0.6, showing little changes with time. Ionic contributions of $K^+$ and $NO_3{^-}$ to EC reading were the greatest followed by $Ca^{2+}$, ${SO_4}^{2-}$, and $Mg^{2+}$ in the order. From the results, we thought that allowable ranges in ion concentration, ion balance, and subsequent individual ionic contributions to EC reading would be obtained within 4-week renewal interval of nutrient solution in EC-based closed-loop soilless culture for sweet pepper plants.

• Food Science and Preservation
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• v.11 no.1
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• pp.79-87
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• 2004

To investigate antioxidative effects of phenolic compounds separated from persimmon leaves(PL)(Diospyros kaki Thunb.) on the ethanol-induced hepatotoxicity in rat, Sprague-Dawley rats weighing 100-150 g were divided into 5 groups; control group(CON), PL(70 mg/kg) administered group(PEl), ethanol(5 mL/kg, 25％) administered group(ETH), PL(70 mg/kg) and ethanol administered group (PE2), and PL(140 mg/kg) and ethanol administered group(PE3), respectively. The antioxidative activity of persimmon leaves decreased in order of ethylacetate>interphase materials>n-butanol>chloroform>n-hexane>water fraction. The growth rate and feed efficiency ratio decreased by ethanol were gradually increased to the adjacent level of CON by administering PL. The serum activities of ALT, alkaline phosphatase and lactic acid dehydrogenase elevated by ethanol were decreased significantly. It was also observed that the activities of SOD, catalase, and GSH-Px of rat liver increased by ethanol were markedly decreased in PL administered group as compared to ETH. The GSH content of liver was decreased by ethanol, but that was increased in PE1 and PE2 compared with ETH as a dose-dependant manner. These results suggested that phenolic compounds separated from persimmon leaves have a possible protective and relievable effect on the ethanol-induced hepatotoxicity in rats.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.688-695
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• 2011

This study was carried out for some survey about soil compaction in the multi-cropping system of paddy field. Investigated sites were 90 farmer's fields in south-eastern part of Korea. The tillage practices season was different according to cropping system of paddy; in spring for mono rice cultivation and in autumn for the multi-cropping field. The average tillage depth in investigated sites was about 25 cm, however, it is different between the farmer's tillage practices and soil characteristics. It is high correlation to tillage deep and minimum resistance of penetration. The reaching soil deep to maximum resistance of penetration was about 27 cm, and average penetration resistance of the deep is 1.8~2.0 MPa for moderately fine-textured soils and more than 3.0 MPa for moderately coarse-textured soils. The difference of penetration resistance between cultivating and compacted layer was in order to sandy loam > clayey loam > clayey, and the difference was lesser in poorly drained soils than somewhat poorly ones. In the rice mono cropping field, the maximum resistance in no-tillage for 15 years was 1.18~1.25 Mpa at 20~25 cm in soil deep, however, the resistance of field with every year tillage practices was 2.03~2.21 Mpa. In the extremely compacted sandy loam textured soils, the penetration resistance at 30 cm in soil depth was drastically reduced by the subsoil from 5.2 Mpa to 3.2 Mpa, and the watermelon root in plastic film house was deep elongated.

• Journal of Life Science
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• v.31 no.12
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• pp.1079-1087
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• 2021

To analyze gut microbiota of livestock in Korea and compare taxonomic differences, we conducted 16S rRNA metagenomic analysis through next-generation sequencing. Fecal samples from broiler chickens, pigs, and cattle were collected from domestic feedlots randomly. α-diversity results showed that significant differences in estimated species richness estimates (Chao1 and ACE, Abundance-based coverage estimators) and species richness index (OUTs, Operational taxonomic units) were identified among the three groups. However, NPShannon, Shannon, and Simpson indices revealed that abundance and evenness of the species were statistically significant only for poultry (broiler chickens) and mammals (pigs and cattle). Firmicutes was the most predominant phylum in the three groups of fecal samples. Linear discriminant (LDA) effect size (LEfSe) analysis was conducted to reveal the ranking order of abundant taxa in each of the fecal samples. A size-effect over 2.0 on the logarithmic LDA score was used as a discriminative functional biomarker. As shown by the fecal analysis at the genus level, broiler chickens were characterized by the presence of Weissella and Lactobacillus, as well as pigs were characterized by the presence of provetella and cattele were characterized by the presence of Acinetobacter. A permutational multivariate analysis of variance (PERMANOVA) showed that differences of microbial clusters among three groups were significant at the confidence level. (p=0.001). This study provides basic data that could be useful in future research on microorganisms associated with performance growth, as well as in studies on the livestock gut microbiome to increase productivity in the domestic livestock industry.

• Journal of Wetlands Research
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• v.24 no.3
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• pp.204-212
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• 2022

The LID technique began to be applied in Korea after 2009, and LID facilities are installed and operated for rainwater management in business districts such as the Ministry of Environment, the Ministry of Land, Infrastructure and Transport, and LH Corporation, public institutions, commercial land, housing, parks, and schools. However, looking at domestic cases, the application cases and operation periods are insufficient compared to those outside the country, so appropriate design standards and measures for operation and maintenance are insufficient. In particular, LID facilities constructed using LID techniques need to maintain the environment inside LID facilities because hydrological and environmental effects are expressed by material circulation and energy flow. The LID facility is designed with the treatment capacity planned for the water circulation target, and the proper maintenance, vegetation, and soil conditions are periodically identified, and the efficiency is maintained as much as possible. In other words, the soil created in LID is a very important design element because LID facilities are expected to have effects such as water pollution reduction, flood reduction, water resource acquisition, and temperature reduction while increasing water storage and penetration capacity through water circulation construction. In order to maintain and manage the functions of LID facilities accurately, the current state of the facilities and the cycle of replacement and maintenance should be accurately known through various quantitative data such as soil contamination, snow removal effects, and vegetation criteria. This study was conducted to investigate the current status of LID facilities installed in Korea from 2009 to 2020, and analyze soil changes through the continuity and current status of LID facilities applied over the past 10 years after collecting soil samples from the soil layer. Through analysis of Saturn, organic matter, hardness, water contents, pH, electrical conductivity, and salt, some vegetation-type LID facilities more than 5 to 7 years after construction showed results corresponding to the lower grade of landscape design. Facilities below the lower level can be recognized as a point of time when maintenance is necessary in a state that may cause problems in soil permeability and vegetation growth. Accordingly, it was found that LID facilities should be managed through soil replacement and replacement.

• Journal of Korean Home Economics Education Association
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• v.26 no.1
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• pp.101-118
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• 2014

"Career maturity" is very crucial for high school students since it has an impact on their career path and decision-making. Not only that, it is also important in self-realization and happiness as well as maximizing human resources. When it comes to understanding high school students' career path, it is necessary to know how they perceive school life since they spend most of their time in school. It's also vital to observe in the perspective of students' personal growth. This study seeks to understand the relationship between "adaptation to school life" "self-esteem" and "career maturity". To accomplish this, the 7th additional surveys conducted by Welfare Panel Study were used. The survey was conducted among 496 high school students in order to come up with descriptive statistics and correlation between "adaptation to school life" and "self-esteem" as well as the level of "career maturity". Hierarchical multiple regression analysis was used to understand the effects of "adaptation to school life" and "self-esteem" on "career maturity." The Baron and Kennny mediation analysis were used to understand the effects when the mediating role of "self-esteem" comes into the relationship between "adaptation to school life" and "career maturity". The results of the analysis are as follows: First, the average age for high school students' "career maturity" is 2.07, while it is 1.91 for "self-esteem". For "adaptation to school life," the relationship between "obedience to school regulations" and "relationship with friends" was relatively higher than the relationship between "attitude toward school life" and "interest in school life" Second, high school students' "career maturity" "adaptation to school life" and "self-esteem" were thought to be statistically meaningful since it showed that they had a positive relationship with each other. Third, "interest in school life" "attitude toward school life" and "obedience to school life" and "relationship with friends" in which all of these are the sub factors for "adaptation to school life" together with "self-esteem" had an influence on high school students' "career maturity". Lastly, the relationship between "adaptation to school life" and "career maturity" was proved to be influenced by the partial mediating role of "self-esteem". As the study seeks to find relationships and the factors that affect high school students' "career maturity" meaningful information is given out for the development and progress of educational programs for "career maturity". This was done by understanding the fundamental and systematic approach towards "career maturity" in the students' perspective.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.18
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• pp.28-53
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• 1975

Experiments on the physiological root activity and its related characteristics of rice varieties were carried out in order to obtain some basic informations for the application of the results obtained to a rice breeding program. A significant positive correlation was found not only among the various characteristics related to conducting and ventilating systems which connects top and root of rice plant, but also between these characteristics and root activity. On the other hand, a significant difference in physiological root activity was recognized among different varieties and also between different groups of recognized 7 rice varieties differing in the their origin. It was also found that varieties with higher root activity (root activity indices) after ear formation stage tended to have more number of lower green leaves and consequently resulted in higher grain yield. Therefore, it may be possible to diagnose indirectly the root activity by examining the number of green leaves of the rice plant at later growth stage when breeders make selections of parent material for crossing or of hybrid lines in pedigree nurseries.

• Journal of the Korean Applied Science and Technology
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• v.32 no.3
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• pp.427-438
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• 2015

The effects of different feeding times, using a diet containing 800 ppm betaine, on production, blood profile, and the short-chain fatty acid (SCFA), was investigated using 240 Cherry Valley (Anas platyrhynchos) meat ducks exposed to a scorching heat wave. The animals were randomly assigned to four groups, each of which was replicated three times with twenty ducks per replicate. The experimental period was 42 days for each group. Four groups were assigned into C (heat wave control group without betaine), T1 (ad libitum group fed a diet containing 800 ppm betaine), T2 (diet-restricted group fed twice daily between 05:00-10:00 and 17:00-20:00, using a diet containing 800 ppm betaine), and T3 (night-restricted group, fed from 17:00-10:00, with a diet containing 800 ppm betaine). At 42 days, body weight increased in order of T2, T1, T3 compared to the heat wave control group although. However, these differences were not found between the groups of T1 and T3. The heat wave control group, provided an ad libitum diet without betaine (C), showed an elevated feed conversion ratio compared to the groups fed a diet containing betaine. However, these differences were not found between the groups of T1, T2 and T3. RBC and platelet profiles except for PLT and MPV showed statistically significant differences between study groups fed a diet containing betaine. T2 presented significantly higher blood electrolytes $Na^+$ and $Cl^-$ than the other groups. T2 also showed a blood gas level that was generally higher than the other groups. Total SCFA, acetic acid and propionic acid concentration has been the increasing trend in T2, but butyric acid, isobutyric acid and valeric acid concentration has been the decreasing trend in T2 compared to the other groups. It is concluded that the feeding-restricted group, fed two times daily between 05:00-10:00 and 17:00-20:00, with a diet containing 800 ppm betaine may improve growth performance in meat ducks exposed to a scorching heat wave.