• Journal of agriculture & life science
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• v.45 no.1
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• pp.109-117
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• 2011

The antioxidant activities of 60% ethanol extracts from different parts (leaf, stem, and root) of Artemisia argyi using an in vitro system were examined to find a possibility as natural antioxidant substances. The highest total phenolics (23.08 mg/g) was obtained by 60% ethanol extract of leaf. The scavenging activity of 60% ethanol extract from different parts of A. argyi on the DPPH and ABTS radical was raised with increasing amount of extracts, and 60% ethanol extract from leaf showed the highest radical scavenging activities. The leaf extract presented the highest reducing power and strong inhibitory effect on autooxidation of linoleic acid. In MDA formation using mouse brain homogenates, the 60% ethanol extracts of A. argyi also exhibited antioxidant activity as inhibition of MDA (71.38% at $200{\mu}g/mL$). Therefore, these results suggest that the 60% ethanol extract of A. argyi leaf possess excellent antioxidant activities and thus it has great potential as a source for natural antioxidant.

• Journal of agriculture & life science
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• v.46 no.3
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• pp.37-45
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• 2012

To select bacterial strains with antifungal activity against an anthracnose fungal disease causing damage severely on hot pepper, previous isolates obtained from plant root samples were screened. Among 457 isolates, IA70-5 isolate was finally selected and identified as Streptomyces padanus based on 16S rDNA sequence analysis. Strain IA70-5 is non-pigmenteous, non-mobile, and filamentous. S. padanus IA70-5 inhibited effectively the mycelium growth, spore germination, and appressorium formation of Colletotrichum acutatum in vitro. The results of this study demonstrated that IA70-5 strain, especially applied on fruit of hot pepper, decreased disease incidence 90% for pre-inoculation before pathogen treatment. Taken together, S. padanus IA70-5 strain is a promising biological control agent to control of a major fungal pepper disease, anthracnose.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.319-325
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• 2015

The safety of plant species used as a source for herbal medicines and dietary supplements has recently been questioned due to poisonings associated with the presence of cadmium (Cd) in these plants. These plants can derive Cd from their presence in the soil. Organic matter (OM) concentrations in soils could affect the availability of Cd for plants. To determine the effect of OM concentration in soil on the concentration of plant available Cd and uptake of this toxic element by medicinal plants, soil and plant samples were collected from 102 fields supporting for 5 species of medicinal plants in 6 province of South Korea. Concentrations of OM and dissolved organic carbon (DOC) in soils affected the phytoavailability of Cd. One M $NH_4OAc$ extractable Cd concentration in soil increased with increasing OM concentrations. There were significantly positive relationships between 1 M $NH_4OAc$ extractable Cd concentration and OM concentration in soil and between 1 M $NH_4OAc$ extractable Cd concentration and DOC concentration. Likewise, OM and DOC concentrations significantly affected Cd concentration in medicinal plant soils. Cadmium concentration in medicinal plants increased with increasing OM concentration in soil [Cd concentration $(mg\;kg^{-1})= 0.179+1.424{\times}10^{-3}$ OM concentrations, $R^2=0.042*$] and with DOC concentration [Cd concentration $(mg\;kg^{-1})= 0.150+5.870{\times}10^{-4}$ DOC concentrations, $R^2=0.124***$]. These results might result from Cd-DOC complex which is easily absorbed Cd form by plant root. Dissolved organic carbon concentration had more positive relationship with Cd concentration in medicinal plants and 1 M $NH_4OAc$ extractable Cd concentration in soils than OM. Cadmium concentration in all 5 species of medicinal plant (Atractylodes macrocephala Koidzumi, Astragalus membranaceus, Codonopsis lanceolata, Platycodon grandiflorum, and Rehmannia glutinosa) significantly increased with increasing DOC concentration in soil. From the above results, formation of Cd-DOC complex caused by OM application might be mainly attributed to increase in Cd concentration in medicinal plants.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.397-403
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• 2015

Heavy metals reduce the photosynthetic efficiency and disrupt metabolic reactions in a concentration-dependent manner. Moreover, by replacing the metal ions in metalloproteins that use essential metal ions, such as Cu, Zn, Mn, and Fe, as co-factors, heavy metals ultimately lead to the formation of reactive oxygen species (ROS). These, in turn, cause destruction of the cell membrane through lipid peroxidation, and eventually cause the plant to necrosis. Given the aforementioned factors, this study was aimed to understand the physiological responses of rice to cadmium (Cd) and arsenic (As) toxicity and the effect of essential metal ions on homeostasis. In order to confirm the level of physiological inhibition caused by heavy metal toxicity, hydroponically grown rice (Oryza sativa L. cv. Dongjin) plants were exposed with $0-50{\mu}M$ cadmium (Cd, $CdCl_2$) and arsenic (As, $NaAsO_2$) at 3-leaf stage, and then investigated malondialdehyde (MDA) contents after 7 days of the treatment. With increasing concentrations of Cd and As, the MDA content in leaf blade and root increased with a consistent trend. At 14 days after treatment with $30{\mu}M$ Cd and As, plant height showed no significant difference between Cd and As, with an identical reduction. However, As caused a greater decline than Cd for shoot fresh weight, dry weight, and water content. The largest amounts of Cd and As were found in the roots and also observed a large amount of transport to the leaf sheath. Interestingly, in terms of Cd transfer to the shoot parts of the plant, it was only transported to upper leaf blades, and we did not detect any Cd in lower leaf blades. However, As was transferred to a greater level in lower leaf blades than in upper leaf blades. In the roots, Cd inhibited Zn absorption, while As inhibited Cu uptake. Furthermore, in the leaf sheath, while Cd and As treatments caused no change in Cu homeostasis, they had an antagonist effect on the absorption of Zn. Finally, in both upper and lower leaf blades, Cd and As toxicity was found to inhibit absorption of both Cu and Zn. Based on these results, it would be considered that heavy metal toxicity causes an increase in lipid peroxidation. This, in turn, leads to damage to the conductive tissue connecting the roots, leaf sheath, and leaf blades, which results in a reduction in water content and causes several physiological alterations. Furthermore, by disrupting homeostasis of the essential metal ions, Cu and Zn, this causes complete heavy metal toxicity.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.574-583
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• 2021

Predicting shipping markets is an important issue. Such predictions form the basis for decisions on investment methods, fleet formation methods, freight rates, etc., which greatly affect the profits and survival of a company. To this end, in this study, we propose a shipping freight rate prediction model for container ships using gated recurrent units (GRUs) and long short-term memory structure. The target of our freight rate prediction is the China Container Freight Index (CCFI), and CCFI data from March 2003 to May 2020 were used for training. The CCFI after June 2020 was first predicted according to each model and then compared and analyzed with the actual CCFI. For the experimental model, a total of six models were designed according to the hyperparameter settings. Additionally, the ARIMA model was included in the experiment for performance comparison with the traditional analysis method. The optimal model was selected based on two evaluation methods. The first evaluation method selects the model with the smallest average value of the root mean square error (RMSE) obtained by repeating each model 10 times. The second method selects the model with the lowest RMSE in all experiments. The experimental results revealed not only the improved accuracy of the deep learning model compared to the traditional time series prediction model, ARIMA, but also the contribution in enhancing the risk management ability of freight fluctuations through deep learning models. On the contrary, in the event of sudden changes in freight owing to the effects of external factors such as the Covid-19 pandemic, the accuracy of the forecasting model reduced. The GRU1 model recorded the lowest RMSE (69.55, 49.35) in both evaluation methods, and it was selected as the optimal model.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.1
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• pp.34-41
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• 2019

Platelet aggregation is essential for the formation of a hemostatic plug in the case of blood vessel damage. On the other hand, excessive platelet aggregation may cause cardiovascular disorders, such as thrombosis, atherosclerosis, and myocardial infarction. Scopoletin, which found in the root of plants in the genus Scopolia or Artemisia, has anti-coagulation and anti-malaria effects. This study examined the effects of scopoletin on human platelet aggregation induced by collagen. Scopoletin had anti-platelet effects via the down-regulation of thromboxane $A_2$ ($TXA_2$) production and intracellular $Ca^{2+}$ mobilization ($[Ca^{2+}]_i$), which are aggregation-inducing molecules produced in activated platelets. On the other hand, scopoletin increased both the cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) levels, which are known as intracellular $Ca^{2+}$-antagonists and aggregation-inhibiting molecules. In particular, scopoletin increased the potently cAMP level more than cGMP, which led to suppressed fibrinogen binding to ${\alpha}IIb/{\beta}_3$ in collagen-induced human platelet aggregation. In addition, scopoletin inhibited collagen-elevated adenosine triphosphate (ATP) release in a dose-dependent manner. The results suggest that aggregation amplification through granule secretion is inhibited by scopoletin. Therefore, scopoletin has potent anti-platelet effects and may have potential for the prevention of platelet-derived vascular diseases.

• Korean Journal of Medicinal Crop Science
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• v.27 no.3
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• pp.202-207
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• 2019

Background: Rehmannia glutinosa is a perennial herb belonging to the family Scrophulariaceae and is used in traditional oriental medicine. This study was conducted to evaluate the appropriateness of plug-seedling cultivation for replanting of R. glutinosa. Methods and Results: The seed rhizomes of Rehmannia glutinosa 'Jihwang 1' were harvested in the middle of March, 2018. Direct seedling cultivation was conducted after air curing for 3 days. The seedlings for transplanting were cultivated for 30 (30D), 45 (45D), and 60 days (60D). The mat formation rates of the 30D, 45D and 60D treatment seedling were 81.3%, 100%, and 100%, respectively. Of the tree treatment groups, flowering occurred only in the 45D and 60D treatment groups, and their flowering rates were $7.3{\pm}3.06%$ and $13.3{\pm}1.15%$, respectively. The agronomic characteristics and active components of the three treatment groups were evaluated in comparison with the DS1 (directly seeded group, control) and DS2 (directly seeded group, replanting) groups. As a result, the leaf length and leaf width of the 30D seedlings were higher than other treatment groups, but the number of leaves per plant was statistically the same. In addition, root diameter and yield of the 30D seedling were statistically the same as DS1. Moreover the catalpol contents of 30D, 45D, DS1 and DS2 group seedlings were 2.23%, 1.86%, 2.50% and 2.08%, respectively. Conclusions: Taken together, these findings suggest it is feasible to use the plug-seedling cultivation method for replanting of R. glutinosa. seedlings. However, further evaluation of the economic aspect is needed.

• The Journal of Korean Philosophical History
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• no.58
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• pp.139-160
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• 2018

'Gyeokmulchiji' (格物致知), coming to knowledge based on the investigation of things) is a starting point for any study and politics of Confucianism. Much emphasis was placed on the conception of 'Gyeokchi' as a root of every learning and adminstration in the early Joseon period. As Confucianism established itself as a salient value system of the government, a mighty change and paradigm shift happened in its governmental system which had depended upon Buddhism up to that time. Thus, Confucian statecraft also stood out. Daehakyeonui (大學衍義) was preached as a model of regal learning and politics in the governmental agon, and its conceptual starting point was 'Gyeokchi.' The various interpretations and arguments about this concept shows the process in which Zhu Xi NeoConfucianism was deepened into Neo-Confucianism of Joseon's own. This conception reached the essence of 'Li' beyond the problem of cognitive subject and object, and provided a watershed which divided Giho (畿湖) and Yeongnam (嶺南) schools. Confucian method of study, which incorporates knowledge and practice, has great implications for our times when there are many voices of concern over humanities. The enhancement of universities and humanities is much needed to adjust the direction and pace of scientific technology, which is now entirely left with the logic of market. Accordingly, it is quite urgent for us to examine our object of learning again, which should integrate 'Sugi' (修己, cultivating oneself) with 'Chi-in' (治人, governing others), and knowledge with practice.

• (The)Study of the Eastern Classic
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• no.32
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• pp.311-362
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• 2008

This study aimed to make clear the education process, from antenatal training to early childhood education, of Joseon Royal Family. Centered on the successors to the throne and reviewed also the education of other Royal Family members, this study carried out comparative analysis on them. Antenatal training is pregnant woman's essential physical and mental attitude. It is indispensable to the health and good nature of unborn baby. Antenatal training had been based on the theory of Oriental medical science that fetus can sympathize what mother see and feel. Such theory, combined with Confucian self-culture theory, had taken very important position in Confucianism. Not to speak of Royal Family, noble family regarded antenatal training very essential as beginning of education and root of nature formation. For firstborn son and firstborn grandson, Boyangcheong (輔養廳, special nursery agency) was set up before their age became three, but not for other sons and grandsons of Royal Family. When firstborn son or firstborn grandson grew up to read letters, Ganghakcheong (講學廳) was set up for their early education. Other sons of king also learned in their early ages at Ganghakcheong while other grandsons of king learned at Gyohakcheong (敎學廳). Education courses were almost same between successors and non-successors but there were wide difference in the ranks of their tutors; firstborn son's tutor marked 2nd Jeong(正) class, firstborn grandson's tutor marked 2nd Jong(從) class and other royal sons' tutors were just 9th Jong(從) class.

• Korean Journal of Metals and Materials
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• v.49 no.2
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• pp.180-186
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• 2011

Isothermal annealing and electromigration tests were performed at $125^{\circ}C$ and $125^{\circ}C$, $3.6{\times}10_4A/cm^2$ conditions, respectively, in order to compare the growth kinetics of the intermetallic compound (IMC) in the Cu/thin Sn/Cu bump. $Cu_6Sn_5$ and $Cu_3Sn$ formed at the Cu/thin Sn/Cu interfaces where most of the Sn phase transformed into the $Cu_6Sn_5$ phase. Only a few regions of Sn were not consumed and trapped between the transformed regions. The limited supply of Sn atoms and the continued proliferation of Cu atoms enhanced the formation of the $Cu_3Sn$ phase at the Cu pillar/$Cu_6Sn_5$ interface. The IMC thickness increased linearly with the square root of annealing time, and increased linearly with the current stressing time, which means that the current stressing accelerated the interfacial reaction. Abrupt changes in the IMC growth velocities at a specific testing time were closely related to the phase transition from $Cu_6Sn_5$ to $Cu_3Sn$ phases after complete consumption of the remaining Sn phase due to the limited amount of the Sn phase in the Cu/thin Sn/Cu bump, which implies that the relative thickness ratios of Cu and Sn significantly affect Cu-Sn IMC growth kinetics.