• Animal cells and systems
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• 제7권2호
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• pp.127-132
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• 2003

Effects of genotype, settlement density and irradiane on the growth, mortality and population structure of Fucus serratus germlings were examined in the laboratory. The growth of F. serratus germlings was influenced by genotype of parent plants, which is likely to occur by microclimatic differentiation of substrata. The growth of germlings were greater at lower densities than higher densities indicating that intraspecific competition between germlings occurred within three weeks. Also, the growth of F. serratus germlings was better at $120\mumol\;m^-2/s^-1$ than at $60\mumol\;m^-2/s^-1$. However, mortality of germlings was determined by settlement density rather than irradiance. In population structure, skewness was increased at low irradiance and high density indicating that population structure could be changed by intraspecific competition. Thus, it is concluded that genotypic differentiation of F. serratus germlings occurred in a microgeographic scale, and the experimental density and irradiance level affected the growth of germlings.

• 대한전기학회논문지:전력기술부문A
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• 제54권4호
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• pp.199-204
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• 2005

In an electricity market with an imperfect competition, participants make plans of bidding and transaction strategies to maximize their own profits. The market price and the quantity are concerned with the operation reserve as well as the bidding system and demand curves in an electricity market. This paper presents a market model combined by an energy market and an operating reserve market. The competition of the generation producers in the combined market is formulated as a gaming of selecting bid parameters such as intersections and slopes in bid functions. The Nash Equilibrium(NE) is analyzed by using a hi-level optimization; maximization of Social Welfare(SW) and maximization of the producers' profits.

• 한국항해항만학회지
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• 제29권9호
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• pp.801-806
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• 2005

The world of container shipping and container terminal business is changing and container ports need to know what the changes are in order to plan how to respond. In particular, the container transport industry has noticed two major developments such as globalization and consolidation. The purpose of this paper is to review the current trend towards globalization and consolidation of container liner shipping and container terminal business. It also investigates the impact of these market developments on container ports and presents its implications for port development, management and operation, and port competition policy. According to the discussion of this paper a greater exercise of market power of container terminal operators will have negative impacts on international trade and national economy, especially port users, including container lines, exporters and importers. An empirical evidence on the exercise of market power is required to develop competition rules on market dominance at a national and international level. This paper suggests 'port coopetition' as a solution for smaller and regional container terminal operators to survive in a competitive business environment.

• 무역학회지
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• 제44권5호
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• pp.161-174
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• 2019

Recent studies on trade payment methods have suggested various alternatives to replace remittance payments. However, these studies theoretically provided the possibilities and limitations of each alternative. To check recent changes in trade practices, our research analyzed payment methods in international trade e-marketplace. Using company and product information obtained from Alibaba.com, we analyzed payment methods used in this e-marketplace and examined determination factors for new payment methods. According to the results of logistic regression analysis, we found a relationship between new payment method and factors such as market competition and the age of the company. Also, providing Paypal payments showed a correlation with market competition and price level of products as well as e-commerce infrastructure. Though these study results feature limitations in the generalization of results, it contributes to the research on payment method trends in international trade.

• 한국수산과학회지
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• 제40권1호
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• pp.39-49
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• 2007

Species competition among the toxic dinoflagellates Alexandrium tamarense and Gymnodinium catenatum and the diatom Skeletonema costatum was simulated using a mathematical model. Prior to the model simulation competition experiments using the three species were conducted to obtain data for validation by the simulation model. S. costatum dominated at a density of ${\sim}10^{4}\;cells/mL$ compared to the other species in the medium with dissolved inorganic phosphorus (DIP). The growth of S. costatum was also stimulated by the addition of dissolved organic phosphorus (DOP), such as uridine-5-monophosphate (UMP) or glycerophosphate (Glycero-P), although this species is unable to take up DOP. This implies that the growth of S. costatum may be supported by DIP, which is hydrolyzed by alkaline phosphatase produced from A. tamarense and G. catenatum. The species competition model was run assuming the environmental conditions of northern Hiroshima Bay, Japan, during spring and summer. G. catenatum increased in cell density and neared the level of S. costatum at the end of the calculation. In the sensitivity analyses by means of doubling and halving parameters, depleted DIP had little effect on the cell density of G. catenatum. However the growth of A. tamarense and S. costatum was significantly affected by changes in the parameter values. These results indicate that if DIP depletion is ongoing, species that have a large phosphate pool in their cells, such as G. catenatum, will predominate in the community.

• 정보교육학회논문지
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• 제19권3호
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• pp.311-322
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• 2015

본 연구는 교사가 개발한 콘텐츠의 설계 동향과 문제들을 분석하고, 개선방안을 모색하였다. 교육정보화연구 대회에서 최근 3년 동안 1등급을 받은 콘텐츠들을 분석하였다. 콘텐츠를 8가지 교수 학습 활동 유형과 6가지 지식 유형으로 나누어 살펴보았을 때, 대부분의 콘텐츠가 개인교수 유형과 개념 및 원리 학습 유형에 치중되어 있었다. 한편, 교육용 소프트웨어 품질인증 기준을 적용한 결과, 다수의 준거들에서 미흡하게 설계된 것으로 밝혀졌다. 이와 더불어서, 내용 분석 방법을 적용하여 설계의 특성을 심층적으로 분석한 결과, 평가, 피드백, 학습목표 등과 관련하여 다수의 문제들이 발견되었으며, 이 외에도 수준별 학습 지원, 학습자와 내용 간의 상호작용, 텍스트와 내레이션 제시, 학습자 정보 처리, 화면 설계, 학습자의 수준을 고려한 내용 선정 등에서 몇 가지 공통된 문제들이 발견되었다. 분석 결과로 발견된 문제들과 관련하여 평가 문항 선정 및 안내, 피드백 내용 및 종류, 학습목표 기술, 학습내용 선정, 상호작용, 텍스트 제시, 화면 설계 등에 대한 개선 방안들이 제안되었다.

• Journal of Korea Trade
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• 제26권4호
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• pp.1-22
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• 2022

Purpose - This paper empirically investigates the effect of a rise in the global value chain (GVC) on the industry-level efficiency of resource allocation (based on plant-level inefficiency measures) in Korea, with a focus on various channels through which a rise in the GVC can increase competition among firms and thus induce resources to be allocated more efficiently across firms. Design/methodology - We empirically investigate the relationship between the industry-specific importance of GVC and the industry-level allocative inefficiency that is measured as the dispersion of the plant-level marginal revenue of capital (MRK) as in Hsieh and Klenow's (2009) influential model. We compute MRK dispersion for industries sorted by various characteristics that are closely related to firm/industry sensitivity to the GVC. In other words, we compute the average industry-level MRK dispersion for industries sorted by industry-specific importance of GVC and compute the difference between the two groups of industries (higher vs. lower than the median GVC); we also calculate the difference between industries sorted by industry-specific export (import) intensity. This is our difference-in-difference estimate of the MRK dispersion associated with the GVC for the export (import)-intensive industry versus the non-export (non-import)-intensive industry. This difference-in-difference estimate of the MRK dispersion conditional vs. unconditional on firm-level productivity is then calculated further (triple-difference estimate). Findings - A rise in GVC is associated with a decrease in the MRK dispersion in the export-intensive industry compared to the non-export-intensive industry. The same is true for industries that rely heavily on imports versus those that do not (i.e., import intensive vs. non-intensive). Furthermore, the reduction in the MRK dispersion in the export-intensive industry associated with an increase in the GVC is disproportionately greater for high-productivity firms. In contrast, the negative relationship between GVC and MRK dispersion in the import-intensive industry is disproportionately smaller for high-productivity firms. Originality/value - Existing studies focus on the relationship between GVC and aggregate output, exports, and imports at the country level. We investigate detailed firm/industry-level mechanisms that determine the relationship between GVC, trade, and productivity. Using the plant-level data in South Korea, we investigate how GVC is related to the cross-firm MRK dispersion, an important measure of allocative inefficiency, based on Hsieh and Klenow's (2009) influential economic theory. This is the first study to provide plant-level evidence of how GVC affects MRK dispersion. Furthermore, we examine how the relationship between GVC and MRK-dispersion varies across export intensity, import intensity, and firm-level productivity, providing insight into how GVC can affect firms' exposure to competition in the global market differently depending on market conditions and thus generate trade-related productivity gains.

• 한국위성정보통신학회논문지
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• 제8권4호
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• pp.105-110
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• 2013

방송이 아날로그방식에서 디지털방식으로 전환되면서 방송 음량의 다이나믹 레인지가 확대되나, 방송 음량에 대해 어떤 규제가 없는 상황에서 방송사 간 혹은 프로그램 간의 경쟁 등에 방송 음량이 점차 커지고 있다. 방송 시청 중 채널 간에 음량 변화가 큰 경우, 시청자들의 정서장애 등이 유발될 수도 있으며, 이를 해결하기 위해 ITU에서는 방송 음량 기준을 제정했다. 본 연구에서는 ITU-R에서 제시하는 음량 측정 알고리즘을 적용하여, 국내 주요 방송채널들의 음량을 측정 분석하고 음량을 관리하기 위한 방안을 제시하고자 한다.

• 경영과학
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• 제11권1호
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• pp.73-90
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• 1994

Recently the recongnition of Logistics becomes important to enterpries as a means for improving their competition, but the Korea enterpries falls for far behind in management techniques for analyzing realities and problems in the Logistics compare to the advanced countries. Especially the function of inventory control which is most undeveloped in them should be improved in Korea. Inventory is very important in Logistics, but there exists trade-off between inventory level and customer in the service level. It is difficult to coordinate both the reduction in the inventory level and the enhancement in the service level. Its effective technique is a DRP system. In general, it deals with arborescent distribution network in which a given channel member has a single source of supply. This article aims to present a DRP system, and more a DRP system which is flexible and responsive in the multisourcing, multi-echelon distribution network. Related research issues are discussed. Finally, using a DRP system on logistics and the management performance. So we can help the physical distribution improvement of the Korean enterprises.

• KDI Journal of Economic Policy
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• 제13권4호
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• pp.31-57
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• 1991

본 연구는 과잉투자(過剩投資)나 과당경쟁(過當競爭)이 발생할 수 있는 객관적인 기준과 경제적 조건들을 분석하고, 정부규제(政府規制)의 근거로서 제시되는 과잉투자(過剩投資)-과당경쟁(過當競爭)의 개념과 논리의 타당성 및 이에 대한 정책적(政策的) 대응방향(對應方向)을 검토하였다. 본고(本稿)에서 필자(筆者)들은 유지불가능한 자연독점의 경우를 제외하면 시장수요(市場需要)의 사전적(事前的) 불확실성(不確實性)으로 인해 발생하는 사후적(事後的) 설비부족(設備不足)이나 유휴설구(遊休設構)는 발생할 수 있지만, 투자시점에서의 과잉투자는 발생할 수 없음을 모형의 분석을 통해 보였다. 설비투자 완료후 생산(生産)-판매단계(販賣段階)에서 유휴설비가 발생하였을 경우에 정부(政府)가 경쟁을 제한할 수 있다는 예상이 오히려 과잉설비투자를 초래하는 중요한 원인임을 보이고, 일관성 있는 정부불개입정책(政府不介入政策)의 유지가 과잉설비투자를 억제하는 최선의 정책임을 보였다.