• Journal of Microbiology and Biotechnology
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• v.32 no.3
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• pp.278-286
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• 2022

Live bacterial vector vaccines are one of the most promising vaccine types and have the advantages of low cost, flexibility, and good safety. Meanwhile, protein secretion systems have been reported as useful tools to facilitate the release of heterologous antigen proteins from bacterial vectors. The twin-arginine translocation (Tat) system is an important protein export system that transports fully folded proteins in a signal peptide-dependent manner. In this study, we constructed a live vector vaccine using an engineered commensal Escherichia coli strain in which amiA and amiC genes were deleted, resulting in a leaky outer membrane that allows the release of periplasmic proteins to the extracellular environment. The protective antigen proteins SLY, enolase, and Sbp against Streptococcus suis were targeted to the Tat pathway by fusing a Tat signal peptide. Our results showed that by exploiting the Tat pathway and the outer membrane-defective E. coli strain, the antigen proteins were successfully secreted. The strains secreting the antigen proteins were used to vaccinate mice. After S. suis challenge, the vaccinated group showed significantly higher survival and milder clinical symptoms compared with the vector group. Further analysis showed that the mice in the vaccinated group had lower burdens of bacteria load and slighter pathological changes. Our study reports a novel live bacterial vector vaccine that uses the Tat system and provides a new alternative for developing S. suis vaccine.

• Journal of Korean Society on Water Environment
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• v.28 no.2
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• pp.255-268
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• 2012

Nonpoint source pollution has become a concern for water quality in the Han River system, especially during the high runoff events during the monsoon season. The patterns in nonpoint source runoff the relationships with land use, rainfall intensity, and stream nutrients concentrations were surveyed in 19 streams in the Han River watershed. The results show that the magnitude of NPS inputs of nutrients and sediment in the Han River watershed are of a serious concern. In the South Han River watershed, event mean concentrations (EMC) for biochemical oxygen demand (BOD), suspended sediment (SS), dissolved organic carbon (DOC), dissolved total phosphorus (DTP), total nitrogen (TN) Nitrate ($NO_3$-N) and total phosphorus (TP) were $1.94mg{\cdot}L^{-1},\;251mg{\cdot}L^{-1},\;2.75mg{\cdot}L^{-1},\;0.076mg{\cdot}L^{-1},\;2.82mg{\cdot}L^{-1},\;2.40mg{\cdot}L^{-1}$ and $0.232mg{\cdot}L^{-1}$, respectively. In the North Han River watershed, EMCs for BOD, SS, DOC, DTP, TN, $NO_3$-N and TP were $1.34mg{\cdot}L^{-1},\;172mg{\cdot}L^{-1},\;2.63mg{\cdot}L^{-1},\;0.032mg{\cdot}L^{-1},\;1.97mg{\cdot}L^{-1},\;1.55mg{\cdot}L^{-1}$ and $0.148mg{\cdot}L^{-1}$, respectively. The specific export coefficients of nutrient and sediments were much higher than those of other reports. Our study also found that the proportion of agricultural field area was significantly correlated with the EMCs for nutrients. Therefore, efforts to reduce NPS loading must focus on agricultural practices in the watershed. The relationships between land use and nutrient and sediment export found in this study can be used to derive estimates of runoff coefficients for agricultural field and as input data for modeling works and to develop total maximum daily load and best management practices in the Han River watershed.

• Current Research on Agriculture and Life Sciences
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• v.31 no.3
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• pp.182-192
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• 2013

Since the Korean apple industry needs to expand its export market in Southeast Asia, this study investigates the attributes of Korean apples affecting consumer preference in Indonesia, Malaysia, Singapore, and Thailand. Based on an Importance-Preference analysis, the results are summarized as follows. First, price is the most important determinant for purchasing Korean apples by Southeast Asian consumers, except in Malaysia. Second, managing the intrinsic(sweetness and chewing texture) and extrinsic(surface and color) factors needs to be well maintained. Third, the priority of the marketing factor(wrapping) should be lowered. Fourth, while the importance of extrinsic factors(shape and size) is low, satisfaction is high, so these factors need to be managed to avoid overkill. Overall, Korean apples should have their own merits with an appropriate proper price, while maintaining a high quality. The results of this paper may provide suitable strategies for promoting apple exports to Southeast Asia.

• Korean Journal of Agricultural Science
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• v.33 no.1
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• pp.43-56
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• 2006

In this thesis we aim at analyzing international competitive power of Chinese ginseng in comparison with Korean ginseng and searching policy direction for Korea to compete Chinese ginseng industry. We summarized the research results as follows; First, we examine the structural change of ginseng industry of China. Second, we review the theories for international competitiveness and apply the method of analyzing competitiveness to ginseng industry. Third, we compared the international competitive power of the ginseng industry between China and Korea and found that Chinese ginseng, estimated by Revealed Comparative Advantage(RCA) at about 15, still remains high competitiveness in terms of cost and price but lowering price competitiveness recently. Based on the research results, we suggest export promotion strategies of the Korean ginseng as follows; 1) Korean government should enforce trade cooperation with China so as to register Korean root ginseng an importable medicine. 2) Korean ginseng producer should develop various products such as capsules, powders and etc. according to China's consumer purchasing power and taste. 3) Korean ginseng should be sold as an differentiated commodity so that it will contribute to building consumer loyalty to Korean ginseng, makes market share superior to other cheaper ginseng products in China. 4) In order to be effective brand marketing and product advertisement, there should be established reliable networks to process and distribute Korean ginseng products exclusively.

• The Journal of the Convergence on Culture Technology
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• v.6 no.3
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• pp.377-380
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• 2020

The increase in single households, changes in consumption behavior, and the size of marts are becoming larger, whereas the packaging form is being changed to small packaging containers, small packages are being exported when exporting agricultural products, especially fruits and related crops, leading to CO2 at the time of export. Although it was processed, it was difficult to guarantee the freshness of the crops inside the package during the transportation period. Therefore, it is necessary to provide a new method of maintaining freshness for application to agricultural products distributed in small packaging containers as a freshness retention agent to prevent deterioration of crops by microorganisms due to changes in product temperature during transportation or display during distribution of agricultural products. I was researching ways to bring about innovation.

• Journal of Mushroom
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• v.16 no.3
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• pp.140-146
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• 2018

Pleurotus eryngii is one of the most commercially important mushrooms cultivated in Korea. However, the shelf-life of the fruiting body is short, limiting its export. A new hybrid strain H17 of P. eryngii was developed to extend the shelf-life by mono-mono crossing between monokaryotic strains derived from DanBi and KNR2774. Although the cultivation period of H17 was slightly longer than that of the reference cultivar Kenneutari No.2, the quality did not change and remained normal after a period of 65.0 days at $4^{\circ}C$. This result was significantly different from that of the reference cultivar Kenneutari No.2. Analysis of the genetic characteristics of the new hybrid strain H17 revealed a different profile from that of the parental and reference cultivars when random amplification of polymorphic DNA (RAPD) primers was used. These results demonstrate that H17 is a new cultivar with improved storability after harvesting.

• Journal of Korea Trade
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• v.27 no.3
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• pp.1-20
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• 2023

Purpose - Using trade data from 2008 to 2019, this study analyzes the impact of trade facilitation on China's agricultural exports under the RCEP framework using a gravity model based on the level of trade facilitation in 13 RCEP countries. Design/methodology - This study constructs a complete set of trade facilitation index systems, comprehensively measures the trade facilitation level of RCEP member countries, and uses a gravity model to verify the critical role of trade facilitation level in enhancing the trade volumes of RCEP member countries. Findings - We found that trade facilitation has a significant impact on China's agricultural exports as a whole. The effect of each primary indicator varies in magnitude, with finance and e-commerce (F) having the most significant impact, followed by customs efficiency (C) and infrastructure development (1); the institutional environment has no significant effect. Originality/value - This study analyzes the impact of trade facilitation on China's agricultural exports from the perspective of exports, and uses the latest data to study the degree of the impact of trade facilitation in importing countries. Measures to jointly enhance trade facilitation among member countries under the RCEP framework are proposed.

• Korean Journal of Plant Resources
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• v.31 no.1
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• pp.90-94
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• 2018

The 'Hongsil' strawberry ($Fragaria{\times}ananassa$ Duch.) is a new cultivar released by Gyeongsangnam-do Agricultural Research & Extension Services in 2015. This cultivar originated from a 2011 cross between '802a312' and 'Okmae' and exhibited suitable fruit characteristics for export due to the high soluble solids content and firmness of the fruit. The breeding line '1116-74-15' was selected as an elite line after examining its characteristics and productivity from 2013 to 2014. A field trial of this line was conducted on a farm in 2015, and it was registered as 'Hongsil' thereafter. The 'Hongsil' strawberry demonstrates intermediate plant type and moderate vigor in growth. It is suitable for forcing culture due to its early flower bud differentiation and low chilling requirement. The soluble solids content of 'Hongsil' is $10.0^{\circ}Brix$, which is approximately $0.4^{\circ}Brix$ higher than that of 'Seolhyang' The Fruit firmness of 'Hongsil' is $13.1g{\cdot}mm^{-2}$, similar to that of 'Maehyang'. Fruits of 'Hongsil' are long conical having a red skin color and marketable yield is $4,269kg{\cdot}10a^{-1}$ which is 16% higher than that of 'Maehyang'. The 'Hongsil' cultivar is sensitive to powdery mildew, and it therefore warrants further investigation regarding disease control.

• Korean Journal of Agricultural Science
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• v.24 no.1
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• pp.85-93
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• 1997

This paper is aimed to study on sales promotion strategies for the increment of farm income by cultivating Boxthron in Chongyang Area. Marketing Survey was done in Chongyang Boxthron market, Kyoung-dong herb market in Seoul. The results are as follows ; Reviewing the Boxthron market prices, the price of direct transaction was the highest one and that of Agricultural Cooperatives was next one, Chongyang market price was lowest one. Therefore, the efforts including exclusive labeling, high class packing strategies of Boxthron with lower pollution would be necessary. The seasonal variation Boxthron prices were lowest in Aug.-Sept., harvesting season, and highest in april-june prices, off-crop season. Farmers have sold 45% of all products in Aug.-Oct. at lowest price and the remaining 15% of that sold in april-june at the highest prices. On account of the above reasons, loan for Boxthron production, government purchasing and storage program of it especially in harvesting season from Aug. to Oct. should be adopted to increase Boxthron producer income. Finally, the strategies for sales promotion, enforcement of government supporting activities including export strategies and the development of new processed products of Boxthron should be propelled considering the products cycle.

• Korean Journal of Agricultural Science
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• v.32 no.2
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• pp.181-195
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• 2005

This study is to provide a comprehensive overview of the changing vegetable sector of Chinese agriculture and to analyse the competitiveness of Chinese vegetable production. China now produces more than 60% of the world's vegetable supply and that 150 million people are engaged in vegetable production, processing and marketing since the reform of vegetable industry structure started in the late 1980s. As a labour abundant industry, China also features more comparative advantages in the vegetable trade. Although China's vegetable exports still accounts for only 1% of total production, the 5 million tons of export in 2003 makes China one of the largest vegetable players in the international markets. When estimating competitiveness of China's vegetable industry, China's producers' prices for vegetables are founded to be only from 10%~40% of what they are in Korea, while most of China's vegetables have also strong competitiveness in quality. As China joined the WTO in 2001 and expects to increase market share in vegetable trade, the development strategy for Korea's vegetable industry are suggested as follows; 1) focusing on the technology for the growth of vegetable productivity, 2) developing the higher value added vegetable industry through processing, 3) expanding the exported area and leading vegetable varieties.