• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.12
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• pp.969-976
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• 2020

Urban Air Mobility is attracting attention as a future innovation industry around the world, and leading industries are considering the application of composite materials for structural robustness and lightening in the designing and manufacturing new concept eVTOL aircraft. To apply composite materials to the new concept of eVTO aircraft, this paper was analyzed about composite material qualification system of FAA & EASA and institutionalized by Korea Government, including the procedures and methods, the organization to carry out the material verification for domestic conditions. The domestic composite material qualification system will not only make it easier for manufacturers of eVTOL aircraft with a new concept to apply composite materials to domestic aircraft through pre-material qualification, but also reduce the burden of material qualification within the period of type certification. In addition, domestic manufacturers of composite materials with qualified material quality and performance will be easy to enter for domestic aircraft applications and composite material manufacturers with experience in applying to aircraft will have a positive impact on overseas exports. This system will be able to promote the development eVTOL aircraft industry of a new concept and enhance international credibility of made aircraft in Korea.

• Journal of Korea Port Economic Association
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• v.37 no.4
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• pp.13-31
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• 2021

Since the signing of the Korea-Europe Free Trade Agreement, the volume of trade transactions between South Korea and Europe has increased. The traditional single-mode transport system has been transformed into an intermodal transport system using two or more modes of transport. In addition, the conventional sea and air transport routes have been restricted, leading to a decline in Korean exports to Europe, and the rail transport mode is becoming mainstream in the market due to the influence of COVID-19. This paper focuses on the China-Railway Express to explore a new intermodal transport route from Korea to Europe. First, the fuzzy analytic hierarchy process (AHP) is used to evaluate the factor weights when selecting intermodal transport routes from Korea to Europe. Then, the TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) method is used to rank three alternatives. The results show that among the four factors (total cost, total time, transportation capability, and service reliability), the total cost is the most significant factor, followed by the total time, service reliability, and transportation capability. Furthermore, the alternative route 1 (Incheon-Dalian-Manchuria-Hamburg) is preferred.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.4
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• pp.201-217
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• 2022

The United States is one of the largest producers of major crops such as wheat, maize, and soybeans, and is a major exporter of these crops. Therefore, it is important to estimate the crop production of the country in advance based on reliable long- term weather forecast information for stable crops supply and demand in Korea. The purpose of this study is to improve the seasonal predictability of the agro-climatic indices over the United States by using regional-scale daily temperature. For long-term numerical weather prediction, a dynamical downscaling is performed using Weather Research and Forecasting (WRF) model, a regional climate model. As the initial and lateral boundary conditions of WRF, the global hourly prediction data obtained from the Pusan National University Coupled General Circulation Model (PNU CGCM) are used. The integration of WRF is performed for 22 years (2000-2021) for period from June to December of each year. The empirical quantile mapping, one of the bias correction methods, is applied to the timeseries of downscaled daily mean, minimum, and maximum temperature to correct the model biases. The uncorrected and corrected datasets are referred WRF_UC and WRF_C, respectively in this study. The daily minimum (maximum) temperature obtained from WRF_UC presents warm (cold) biases over most of the United States, which can be attributed to the underestimated the low (high) temperature range. The results show that WRF_C simulates closer to the observed temperature than WRF_UC, which lead to improve the long- term predictability of the temperature- based agro-climatic indices.

• The Journal of the Convergence on Culture Technology
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• v.9 no.2
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• pp.553-560
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• 2023

The study is about domestic industries following the migration of hubs (innovation, manufacturing) to other countries and the hub-oriented US industries (batteries, semiconductors, electric vehicles). Additionally, the ongoing trade tensions between the United States and China may have also played a role in companies moving their operations to the United States. The result of such a move could potentially include job creation in the United States, as well as increased investment in the U.S. manufacturing sector. However, it is also possible that there could be negative consequences, such as higher prices for consumers or disruptions to supply chains during the relocation process. However, such IRA, Chips Act scenario would likely also have negative consequences (Inflation in the home country) for the countries whose industries moved to the US, as they would lose jobs, investment, and possibly face economic difficulties as a result. As the result of the empirical analysis of the export scale of Korea and the United States, changes in the movement of global supply hubs are related to factors such as geopolitical price increases and consumption declines. In order to respond to these changes, this paper emphasizes the need to prevent the result of de-advantage by moving the production area of the scale.

• The Korean Journal of Pesticide Science
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• v.17 no.3
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• pp.145-154
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• 2013

Flonicamid was a water-soluble and systemic insecticide. It was applied to control neonicotinod pesticide-resistant cotton aphid in sweet peppers. However, the residue levels of total flonicamid in sweet pepper exported to Japan in 2009 were exceeded the maximum residue limit (MRL). This study was conducted to elucidate residual properties of flonicamid parent compound and its metabolites in sweet peppers. It was carried out to compare the variation of residues in sweet pepper in three different greenhouses for 21 days after 3 times application with 7 days interval. The mean residues were 0.176, 0.152 and 0.108 mg $kg^{-1}$ and the residue levels in sweet pepper among three greenhouses show significant difference. The maximum residue levels were detected 10 days later after last treatments. The overall residue levels were lower than MRL 2.0 mg $kg^{-1}$ (by Korea) and 0.4 mg $kg^{-1}$ (by Japan in 2009 but now revised MRL is 2.0 mg $kg^{-1}$). But the residue level of total flonicamid at the 21th day after 3 times treatment with 7 days interval was 0.429 mg $kg^{-1}$ restricted by the application of double rate than recommended rate. The amounts of metabolites, TFNA, 4-Trifluoro methyl nicotinic acid and TFNG, N-(4-trifluoro methyl nicotinoyl) glycine were increased while flonicamid parent compound was decreased over time. Therefore the longer trial period should be needed for flonicamid in sweet peppers.

• Journal of Mushroom
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• v.13 no.2
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• pp.119-124
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• 2015

This study was carried out to characterize the chemical components of Flammulina velutipes during storage by different packaging film application for developing export winter mushroom to south east asia area. Changes of weight and growth rate from Flammulina velutipes were the lowest in testing packaging film at $15^{\circ}C$ among the films. The pH changes of Flammulina velutipesg was the highest in imported packaging film at $25^{\circ}C$. The changes of colors was measured by Hunter's color value, L value and yellowness (+b) were slightly decreased during storage. But the L value and yellowness (+b) were not affected by packaging films. Six organic acids were detected such as oxalic acid, lactic acid, malic acid, citric acid, acetic acid and succinic acid. The content of total organic acids were increased by storage period.

• Korean Journal of Plant Resources
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• v.36 no.5
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• pp.435-445
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• 2023

The aim of this study was to explore the effects of vinegar extract from seed of common buckwheat (Fagopyrum esculentum Moench) and seed of tartary buckwheat (F. tataricum Gaertner) on acute ethanol-induced hangover in Sprague-Dawley rats. Vinegar extract from buckwheat is rich choline, quercetin and its glycoside, rutin known as flavonoid antioxidants. The test extract containing buckwheat was proven to alleviate hangovers through a significant reduction in the concentration of alcohol and acetaldehyde in the context of an alcohol-induced hangover model. Hepatic alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) activities were significantly higher in buckwheat vinegar-treated rats than in ethanol-treated rats. Moreover, tartary buckwheat vinegar upregulated antioxidant enzyme such as superoxide dismutase and Catalase activities in liver tissues. These results suggest that buckwheat vinegar extract could alleviate ethanol-induced hangover symptoms by elevating activities related to hepatic ethanol-metabolizing enzymes against ethanol induced metabolites, and in particular, tartary buckwheat should be further developed to be a novel anti-hangover material.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.4
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• pp.1-15
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• 2016

Startups in Korea are experiencing for themselves the laws of survival through competition in the local and international market, and are performing active business movements based on these. Korea's economic growth rate is 2.6% due to the slump in the domestic demand and reduced exports brought by the MERSC incident in 2015. The Korea Development Institute has estimated the economic growth rate in 2016 to be around 3.0%. South Korea's economy is facing the crisis of low-growth solidification due to the decrease in economic growth, and it is forecasted that growth without employment and polarization will worsen. Startups in the high-tech industrial generation of a particular field wherein the market environment is rapidly changing must maintain a competitive advantage with the capabilities and functions exclusive to them. It is very important that they maintain a competitive edge by utilizing the capabilities exclusive to startup companies. Likewise, the accumulation of resources is also crucial in determining the success of a startup business. In a poor local startup ecosystem, majority of the startup companies are performing their business activities while striving for survival, rather than success. About 80% are struggling to survive and are failing to overcome the "Death Valley" faced 3-5 years after establishing the company. Since majority of the startups fail to achieve results during the initial stages of foundation, the importance of research on business activities and achievement during the early stages of establishment is being raised. In accordance to this, this research has performed an actual analysis on how the activities of startups during their preparation phase and early stages affect their achievements. A survey was done on the CEOs or executives (people in a position to make decisions) of local small and medium-sized enterprises that are considered start-ups, and 203 valid data were collected and analyzed. Results showed that the discoveries and utilized activities necessary for the businesses of startups have a significant impact on their achievement through the entrepreneur resources and external partners' cooperation; additionally, the related implications were discussed.

• Journal of Korean Society of Forest Science
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• v.107 no.1
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• pp.71-80
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• 2018

The effect of $SO_2$ treated pads (Sodium metabisulphate 0, 0.5, 1.0, 2.0 g/kg) on the quality of dried persimmons and dried persimmons slices were investigated. The $SO_2$ treated pads did not affect to weight, moisture loss rate, and soluble solid contents of dried persimmons and dried persimmons slices. The color change (${\Delta}E$) of dried persimmons and dried persimmons slices after storage for 8 weeks were the highest (value=6.0, 6.2) in control, whereas that was the lowest (value=4.8, 4.7) under $SO_2$ pad 2.0 g/kg condition, respectively. When we measured the browning degree of dried persimmons, they showed O.D. 0.65, 0.57, 0.29, and 0.18 in serial dilution treated pads with $SO_2$ pad 0, 0.5, 1.0, and 2.0 g/kg. The browning degree data from aforementioned dried persimmons after 8 weeks was similar to that from dried persimmons slices. The decay rate of dried persimmons and dried persimmons slices after storage for 8 weeks were the highest (value=33.3%, 36.7%) in control, whereas that was the lowest (value=3.3%, 6.7%) under $SO_2$ pad 2.0 g/kg condition, respectively. The concentration of residual $SO_2$ in dried persimmons and dried persimmons slices were detected within a safe range of 15.3~30.0 ppm. Therefore, the shelf-life of dried persimmons and dried persimmons slices were lengthened in $SO_2$ treated pads (especially in $SO_2$ pad 2.0 g/kg) for inhibiting of browning and decay.

• Journal of Bio-Environment Control
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• v.26 no.1
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• pp.1-6
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• 2017

The paprika has emerged as one of the highest-income crops by increase in dimestic and export demand in the greenhouse crops. Nevertheless, there is no standard for fertigation in soil, because general culture system is soilless culture. This study was conducted to establish the optimum nitrogen and potassium application level for paprika fertigation. Four different levels of nitrogen and potassium were applied, treatment levels were 0.5, 1.0, 1.5, 2.0 times of pimiento fertilization recommendations based on soil testing. Experiment to instigate the optimum amounts of nitrogen and potassium were carried out in 2012 and 2013, respectively13. Nitrogen application : stem diameter of 0.5 times was significantly lower than other treatments, but stem length was not affected by nitrogen fiertigation levels. Number of fruit and yield of first fruiting group harvest were not significant difference. but those of the second fruiting group were decreased by increasing nitrogen level beyond 1.0 times treatment and were the lowest in 0.5 times treatment. Overall, the optimum level of nitrogen for fertigation was judged 1.0 times of pimiento fertilization recommendations based on soil testing. Potassium application : Growth was no signigicant trend except stem length. Number of locule, fresh thickness and sugar content were not significant difference. Number of fruit and yield were not significant difference at the first and second fruiting group harvest. But those were significant difference at third fruiting group harvest, maximum yield was obtained by 1.5 times fertigation level. The optimum level of potassium for fertigation was judged 1.5 times of pimiento fertilization recommendations based on soil testing.