• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.78-82
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• 2003

Development of hematite-coated sand was evaluated for the application of the PRB (permeable reactive barrier) in the arsenic-contaminated subsurface of the metal mining areas. The removal efficiency of As(III) and As(V), the effect of anion competition and the capability of arsenic removal in the flow system were investigated through the experiments of adsorption isotherm, arsenic removal kinetics against anion competition and column removal. Hematite-coated sand followed a linear adsorption isotherm with high adsorption capacity at low level concentrations of arsenic (< 1.0 mg/l). When As(III) and As(V) underwent adsorption reactions in the presence of anions (sulfate, nitrate and bicarbonate), sulfate caused strong inhibition of arsenic removal, and bicarbonate and nitrate caused weak inhibition due to specific and nonspecific adsorption onto hematite, respectively. In the column experiments, high content of hematite-coated sand enhance the arsenic removal, but the amount of the arsenic removal decreased due to the higher affinity of As(V) than As(III) and reduced adsorption kinetics in the flow system, Therefore, the amount of hematite-coated sand, the adsorption affinity of arsenic species and removal kinetics determined the removal efficiency of arsenic in the flow system. arsenic, hematite-coated sand, permeable reactive barrier, anion competition, adsorption.

• Journal of Navigation and Port Research
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• v.38 no.3
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• pp.307-315
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• 2014

This paper aims to empirically examine how shipping companies can effectively acquire knowledge from their strategic alliance partners. This paper adopts cooperative network embeddedness mechanism, such as network density and tie closeness, as a channel through which to acquire more knowledge for shipping participants within a strategic alliance network. This study also examines the moderating role of competition between alliance partners in reinforcing the effectiveness of the cooperative relationships on the knowledge acquisition. Based on the literature, hypotheses to predict the aforementioned associations between cooperative network embeddedness and knowledge acquisition and the moderating role of competition in facilitating that association are established. A quantitative research method using survey data conducted in the Korean shipping industry was employed in order to empirically test the presented hypotheses. The results show that if players in a shipping alliance network are embedded in a dense network and have close relationships with their alliance partners, this helps to facilitate a greater degree of knowledge acquisition from the partners; and the impact of network density on the knowledge acquisition would be intensified with the higher level of competition between shipping companies.

• Environmental and Resource Economics Review
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• v.19 no.1
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• pp.3-21
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• 2010

By the significant structural change in 1999, a partial privatization has occurred in Korean fossil-fuel power generation sector. Under the current price scheme wholesale electricity price is dependent on output size, and hence, may not satisfy the assumption of price-taking producers. The purpose of our study is constructing the productivity change measurements of Korean power generation sector taking into account possibly imperfect competition and variable returns to scale. Our approach based on Harrison (1994) and Levinsohn (1993) derives the plant-level productivity measurements of the period between 2001 and 2007, as well as the measurements of mark-ups and returns to scale. It is shown that the mark-up size is dependent on the plants' fuel type and is decreasing over time. Allowing for imperfect competition and variable returns to scale adjusts the productivity measurements substantially.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.4 no.1
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• pp.73-79
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• 1968

In order to investigate varietal competition effects on yield of rice, two experiments were conducted under paddy field condition. In experiment I, two leading varieties were grown in pure and mixed stands and examined the influence of spacings and nitrogen levels on the varietal competition effects and competitive ability of two varieties. In experiment II, three leading varieties were grown in pure and mixed stands with different combinations and examined the competition effects on yield in different combinations. The results are summarized as follows: 1. No significant differences were found in grain yield between varietal mixture and pure stands, though the level of nitrogen and spacings affected plot yield. 2. In the mixture of Suwon ＃82 and Shin ＃2, Suwon ＃82 appeared to be a better competitor to the Shin #2 in terms of grain yield. 3. The performance of mixtures were determined by the balance of the increment of better competitor and the decrement of poorer competitor. Here, the increment of Suwon ＃82 due to competition did not much exceeded the decrement of Shin ＃2. 4. Spacings and Nitrogen levels, tested here, did not affect significantly to the varietal competition effects. 5. Jaekun, Paltal and Norin ＃6 showed no varietal difference in competing ability.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.6
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• pp.62-71
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• 2013

This study is conducted for the purpose of analyzing and contemplating the problems with the competition in current landscape design, with the goal of improving the landscape design competition system by using the AHP technique. The result of this study, first describe the Landscape design competition system that formed the problems and show the most important problem followed by other problems shown in order of importance, which are 'design changes after winning', 'Guidelines for design competition' and 'Landscape design competition manner'. Secondly, in the low rank article make up the level one -From a total 12 elements from the low rank article corresponding in 'process of winner selection' the 'Unprofessional landscape participate the screening' collected comments for the biggest problem, 'lack of expertise in judgement', 'problems with the examination scoring system' and other articles, the corresponding in 'process of winner selection' appears at the highest ranks. It also happens that after making the choice in the landscape design competition, the importance of 'client's design change symptoms' appears high. As a result the overlooked details of the landscape design competition's problems were analyzed. This study has prioritized the problems by problems which landscape design competition institutions most frequently have. Based on this ranking, there is significance purpose to create proactive system improvements in the future. By analyzing these problems, we will be better able to develop improvements to the future system.

• Korean Journal of Weed Science
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• v.5 no.1
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• pp.24-34
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• 1985

To estimate the fundamental situation of weed emergence and it's competition to paddy rice (critical competition period and threshold level) in the southern paddy area in Korea, two rice cultivars (Pungsanbyo and Tongjinbyo) under two cropping periods (Mono- and After-barley-cropping) were experimented. As a result, the dominant weed species (Monochoria vaginalis and Scirpus juncoides Roxb.) and the better emerging conditions (rather at the monocropping and cv. Punsanbyo) were identified. Also, the main components of yield decrease (25-55% of the weed-free check) of both cultivars as affected by weed competition were the number of spikelets, panicle and ripening rate in monocropping, and the ripening rate and grain weight in after-barley-cropping, respectively. Under the situation of combinated dominance with Monochoria v. and Scirpus j. among others, the duration of critical competition periods was enlarged.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7788-7793
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• 2015

Both export and import sides of grain trade market are analyzed and compared in terms of the static levels and dynamic trends to make new empirical inference on the imperfect competition degree. Export concentration level is high compared to import concentration level. And such states have been sustained since 2001 until 2014. Unlike public concerns, the concentration level of export side seems to be easing by small degree. However, the grain trade market remains imperfect competitive market. Furthermore, overall imperfective competition condition over 2002-2014 has been worsened compared to 2001 level. It is because the reduction level of imports concentration is higher than that of the export concentration. Gini and Atkinson Inequality Index based on Lorenz Curve are newly utilized to analyze market concentration level, instead of the commonly used concentration ratio.

• The Journal of the Korea Contents Association
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• v.15 no.7
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• pp.128-137
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• 2015

Going through rapid changes, the field of information technology (IT) has launched many innovative products. Some of those products have spread, forming a stable market, whereas others have disappeared. The purpose of the study is to purpose a theoretical model to show changes in the importance of competition factors over the three stages. Our study applied the innovation adoption stage model of the Innovation Diffusion Theory (IDT) to the industry life cycle of the Industry Life Cycle (ILC) Theory resulting in three stage of introduction, growth, and maturity, and defined a model of market characteristics according to time. By using the model, we analyzed the case of notebook computers and tablet and checked the fitness of the model. Results show that five competition factors worked differently according to time. In the introduction stage, relative functionality and relative playfulness are important competition factors. In the growth stage, compatibility is added to those two factors. In the last maturity stage, compatibility, complexity, and cost level are important competition factors.

• International Journal of Computer Science & Network Security
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• v.22 no.3
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• pp.53-60
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• 2022

The article examines the problems of ensuring the effectiveness of the economic security system in the face of increasing competition. The relevance of the study is determined by the intensification of competition between enterprises and the threats arising from this phenomenon. The methodological basis is the methods used: analysis and synthesis - to identify the main trends in the development of tools for economic security of the enterprise; systematization - to highlight the main characteristics of the economic security of the enterprise in the intensification of competition; generalization - to form the general conclusions of the study. The purpose of scientific research is to substantiate the feasibility of using the tools of the economic security system to increase its efficiency in the face of intensifying competition. The main components of the economic security system of the enterprise, which have the greatest impact on the formation of an effective level of economic security. The defining characteristics of the system of economic security of the enterprise are investigated. Special characteristics of the economic security system of the enterprise are considered. The offered directions of tools of maintenance of system of economic safety of the enterprise in competitive conditions: objective, subjective external, subjective internal. For each area, specific tools for ensuring the system of economic security, which affect its efficiency, have been identified.

• Journal of Korean Society of Forest Science
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• v.89 no.1
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• pp.49-54
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• 2000

Stand level survival prediction model was developed that incorporated the incidence of fusiform rust(Cronartium quercuum [Berk.] Miyabe ex Shirai f. sp. fusiforme) and allowed the transition of trees from an uninfected stage to an infected stage. The influence of hardwood interspecific competition on the survival of unthinned planted stands of loblolly pine (Pinus taeda L.) was analyzed by using of information from twelve years of tracking a set of permanent plots representing a broad range of plantation parameters. Significant interaction effects between site index and hardwood basal area per acre were revealed in the survival model. Survival of the planted pines decreased with increasing density of hardwood trees per acre and site index as the productivity rating of the forest land. The effects of hardwood trees interspecific competition on loblolly pine tended to show a negative effect on predicted future number of planted pine trees.