• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.2
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• pp.125-135
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• 2005

Generation and transport of nonpoint source pollution, especially sediment-associated pollutants, are profoundly influenced by hydrologic features of runoff. In order to identify pollutant export rates, hence, clear knowledge of rainfall-runoff relationship is a pre-requisition. In this study, performance of AnnAGNPS model was assessed based on the ability of the model to predict rainfall-runoff relationship. Three catchments, each under different nearly single land use, were simulated. From the results, it was found that the model was likely to produce better predictions for larger catchments than smaller catchments. Because of using the daily time scale, the model could not account for short durations less than 24 hours, especially high intensity events with multiple peak flow that significantly contribute to the generation and transport of pollutants. Since CN information for regional areas has not been built up, a careful selection of CN is needed to achieve accurate prediction of runoff volume. Storm distribution also found to be considered as an important calibration parameter for the hydrologic simulation.

• The Plant Pathology Journal
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• v.33 no.5
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• pp.441-449
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• 2017

Citrus canker is an important bacterial disease of citrus in several regions of the world. Strains of Xanthomonas citri type-A (Xc-A) group are the primary pathogen where citrus canker occurs. After Xc-A entered the Northeast of Argentina in 1974, the disease spread rapidly from 1977 to 1980 and then slowed down and remained moving at slow pace until 1990 when it became endemic. Citrus canker was detected in Northwest Argentina in 2002. This paper presents the main steps in the fight of the disease and the management strategies that have been used to control citrus canker at this time. We think the process might be usefull to other countries with the same situation. Results from more than 40 years of research in Northeast (NE) Argentina indicate that we are at the limit of favorable environment for the disease. The severity of citrus canker is greatly affected by the environment and El $Ni{\tilde{n}}o$ Southern Oscillation (ENSO) phenomenon which causes cyclic fluctuations on the disease intensity in the NE region. Weather-based logistic regression models adjusted to quantify disease levels in field conditions showed that the environmental effect was strongly modulated by the distance from a windbreak. Production of healthy fruits in citrus canker endemic areas is possible knowing the dynamics of the disease. A voluntary Integrated Plan to Reduce the Risk of Canker has been in place since 1994 and it allows growers to export unsymptomatic, uninfested fresh fruit to countries which are free of the disease and require healthy, pathogen free fruits. The experience from Argentina can be replicated in other countries after appropriate trials.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.2
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• pp.218-225
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• 2016

This experiment was conducted in Suwon and Iksan city from 2012 to 2014 to evaluate soil erosion and nutrient loss from irrigated paddy fields during cropping period. Rainfall amount and rainfall erosivity of $EI_{30}$ were, on average, 1,026 mm and $3,922mm\;ha^{-1}yr^{-1}hr^{-1}$ for the cropping period, respectively, and the rainfall event with maximum $EI_{30}$ occurred in July. Annual average of runoff was $2,508MT\;ha^{-1}yr^{-1}$ in Suwon and $3,375MT\;ha^{-1}yr^{-1}$ in Iksan, accounting for 36% of rainfall of the cropping period. Nutrient loss by runoff, on average, was $7.0kg\;N\;ha^{-1}yr^{-1}$, $1.3kg\;P\;ha^{-1}yr^{-1}$, and $16.6kg\;K\;ha^{-1}yr^{-1}$; N, P, and K loss were 5.0, 0.6, and $8.3kg\;ha^{-1}yr^{-1}$, respectively, in Suwon and 8.9, 1.9, and $16.7kg\;ha^{-1}yr^{-1}$ in Iksan. Soil loss in Korean paddy rice was evaluated as $0.33MT\;ha^{-1}yr^{-1}$ ranging from $0.05MT\;ha^{-1}yr^{-1}$ to $0.88MT\;ha^{-1}yr^{-1}$. Amount of soil loss, however, depended on areas and year influenced by variation of rainfall amount and intensity. Interestingly, soil erosion in Iksan in 2012 was remarkably greater than those in other periods due to heavy rainfall between late May and June with soil flake dispersion right after the rice-planting season.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.88-88
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• 2018

In order to increase the germination speed and uniformity of tomato seeds, sonication and modified drum priming treatments were investigated to produce high quality seeds for export. Sonication treatment was performed for 5, 10 and 20minutes at an intensity of 5.2, 10.4 and 15.7kHz in water at $15^{\circ}C$. After sonication treatment, seeds were primed with water or 100mM $KNO_3$ for 4days. 40, 50 and 60% seed moisture content (SMC) of hydrated seeds were incubated for 60, 72 and 84h in a container with a relative humidity of 99% at 26rpm for a modified drum priming treatments. Germination speed were highly improved by sonication with osmotic priming. The seed treatment of osmotic priming or hydro priming after sonication or sonication without priming enhanced germination percentage (GP) on the $2^{rd}$day after sowing to 46%, 43% and 28%, respectively, while untreated seeds resulted in only 1% GP. These treatments also highly improved mean germination time (MGT) to 1.4, 1.8 and 2.6days, respectively, when compared to 3.5days MGT of untreated seeds. The modified drum priming treatment (72h incubation after 60% SMC hydration) significantly improved results of 74% GP(on the $3^{rd}$day after sowing), 2.6days MGT and $39%{\cdot}day^{-1}$ germination rate (GR), however, untreated seeds showed 19% GP, 4.1 MGT, and $25%{\cdot}day^{-1}$ GR. Although osmotic priming after sonication, hydro priming showed similar improved germination characteristics, however, modified drum priming is considered as an industrially promising treatment methods considering the shortening of the treatment period and environment-friendly aspects.

• International Commerce and Information Review
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• v.15 no.1
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• pp.333-356
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• 2013

The main purpose of this article is to find out the determinants of usage and performance of the uTradeHub system in Korean SMEs. To achieve the purpose of the study, the research model and the hypotheses were developed based on the previous research on uTradeHub and e-Trade. And to test the research hypotheses, empirical survey was conducted to Korean SMEs which were using uTradeHub services. The results of the empirical analyses are as follows. First, among the external factors, intra-industry competition and transaction intensity were significant determinants of uTradeHub usage level. Secondly, among the internal factors, only CEO's support was found to be a significant determinant. Thirdly, among the IT related factors, IT infrastructure and IT training were positively related to uTradeHub usage level. Finally, the uTradeHub usage level was found to have positive effect both on financial and non-financial export performance of the Korean SMEs.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.4
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• pp.111-122
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• 2018

The private sector is currently reviewing the feasibility of the project or deciding economic policies by analyzing the economic ripple effects. However, the arms acquisition project focuses on the need for the national defense weapons system by analyzing the costs and the effectiveness of the analysis and reviewing the necessity and feasibility of the project. In order to analyze the economic ripple effects, KB (the Bank of Korea) prepares and publishes an analysis table of industrial associations in a given unit. IAAR (the industrial association analysis report) is difficult to apply directly to the defense weapons system. Therefore, research on the economic ripple effects applicable to the defense arms procurement project was needed. In this study, we propose the generic methodology for estimating economical and technical ripple effects resulted in acquiring new weapon systems. Based on the analysis of inter-industrial relations, economical ripple effects are estimated with production inducing effects, value-induced effects, employment-induced effects and export-induced effects. Also, the technological ripple effects are estimated with technological intensity represented by investment cost in research and development. To show the validity of proposed methodology, a case study of acquiring new weapon systems such as GR (guided rocket), destroyer, and helicopter is accomplished. From the case study, it is concluded that these economical & technological ripple effects can be used as a reference to decision making in the course of acquiring major future defense weapons systems.

• Economic Analysis
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• v.26 no.4
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• pp.98-136
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• 2020

We empirically investigate the determinants of a firm's exit from exporting, using Korean manufacturing firm-level data for the period from 2006 to 2014. Specifically, we estimate the effects of not only firm-level and industry-level characteristics, but also macroeconomic variables on the probability that a firm stops exporting by applying a Complementary Log-Log Model analysis. The results of our estimation suggest that firm-level heterogeneity, such as workforce size, capital intensity, intangible assets and foreign ownership, industry-level variation, such as the labor displacement rate, and macroeconomic variables, such as domestic demand and world demand, significantly affect the possibility of a firm ceasing exports. Also, we show that market interest rates increase the possibility of an export cessation and that the effects of market interest rates are more pronounced on firms with a higher debt ratio. In the primary exporting industries, the probability of a firm ceasing exports decreases as productivity at the firm rises.

• Journal of Korea Trade
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• v.26 no.3
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• pp.45-62
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• 2022

Purpose - Using unexpected changes in geopolitical tensions on the Korean peninsula as a quasi-natural experimental setting, we examine whether and how geopolitical risks travel across borders through firm-level imports and exports linkages. We also test whether the effects are driven by either imports or exports and assess whether firms can effectively hedge themselves against geopolitical risks. Design/methodology - We focus on a series of unanticipated geopolitical events taken place in Korea in 2018. Making use of the shocks to geopolitical climate, we identify five milestone events toward peace talks. We employ the event studies methodology. We examine heterogenous firm-level stock price reactions around key event dates depending on firms' exposure to geopolitical risks. As a measure of firms' exposure to geopolitical risks in Korea, we utilize a text-based measure of firm-level trade links. When a firm announces and discusses its purchase of inputs from Korea or sales of outputs to Korea in their annual disclosure filings, we define a firm to have a trade relationship with Korea and have exposure to Korean geopolitical risks. Similarly, we use a measure of a firm's hedging policies based on a firm's textual mention of the use of foreign exchange derivatives in their annual disclosure. Findings - We find that U.S. firms that have direct trade links to Korea gained significantly more value when the intensity of geopolitical risks drops compared to firms without such trade links to Korea. The effects are pronounced for firms purchasing inputs from or selling outputs to Korea. We find that the effectiveness of foreign exchange hedging against geopolitical risks is limited. Originality/value - We document the international transmission of geopolitical uncertainty through trade linkages. Export links as well as import links serve as important nexus of transmission of geopolitical risks across borders. Hedging strategies involving foreign-exchanges derivatives do not seem to insulate firms again geopolitical risks. With the recent movements of localization and reshuffling of the global value chain, our results suggest a significant impact of geopolitical risks in Korea on the construction of the global value chain.

• Journal of Digital Convergence
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• v.14 no.11
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• pp.135-142
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• 2016

Although growth potential of trade between Korea and the GCC region has existed in various fields through economic and business cooperation, few data and practical study related with trade structure and cooperation between Korea and GCC region have been found and the potential for further economic expansion has not been extensively explored. In this sense, this study is to analyze trade flows between Korea and GCC region countries(Saudi Arabia, Unites Arab Emirates, Qatar) using trade intensity index, trade complementarity index and special country bias index, identify potential for further expansion of Korea's trade into the GCC region and further propose the implication of FTA between mutual countries. Our analysis of trade flows also demonstrates that there is a high level of trade complementarity between Korea and GCC region. It means that increase of trade complementarity and special country bias come from removing not only trade barrier and increasing but also capital movement. Especially, the study reveals that there is an untapped potential for Korea to increase its exports to Saudi, based on the highest complementarities. Export expansion between Korea and Saudi through FTA will create new opportunity in near future.

• Management & Information Systems Review
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• v.32 no.5
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• pp.157-174
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• 2013

In this research I investigate different firm characteristics between environment-friendly companies which are awarded by the Government and companies which violate environmental regulations. I set up three hypotheses in terms of managers' environmental attitude and firms' characteristic in technical, financial and structural aspects, considering environmental experts' opinions and findings of previous papers. Main research findings are as follows. First, both acquisition of the ISO 14001 certificate and ownership structure are used as proxy of top management attitude towards environmental decision-making. It is hypothesized that it is found that the certificates of ISO 14001 is a good proxy to represent top management environmental attitude and a firm with the certificate would have less likelihood of violation. Second, it is hypothesized that technical ability affects violation tendency of environmental regulations. It is found that as R&D investment increases, violation likelihood of environmetal regulations decrease. It can be conjectured that R&D investment may improve technical abilities of observing environment regulations. Third, it is investigated whether a firm's financial capability affects violation tendency of environmental regulations. Fourth structural aspects of a firm such as capital intensity, the number of employees and export ratio are investigated. It is found that a firm with more employees per sale amount tends to violate environmental regulations. It is not found any effects of expert ratio nor capital intensity on violation tendency of environmental regulation.