• 한국항만학회지
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• 제12권1호
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• pp.1-8
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• 1998

If a system has a large boundary and complexity, forecast's accuracy will be very low when consider the system's substance as black box. Thus, it is necessary that analysis by structure model. To examine competition in Northeast Asia Ports, it has assumed that the form of structure model, For which the System Dynamics method is adapted in this paper. Northeast Asia Ports Model includes five ports - Pusan, Kobe, Yokohama, Kaoshiung, Keelung, - which are adjacent to each other by geographically and has a competition relation. The Northeast Asia Ports Model has several sub-systems which consists of each unit port models. And, each unit port model found by quantitive, qualititive factors and their feedback loops. All effects which components of one port have influence to components of the rest ports must be surveyed in order to construct Northeast Asia Ports Model, but it may be impossible currently. In this paper Northeast Asia Ports Model was simplified by HFP-Hierarchical Fuzzy Process Method-adapted to integration of level variables of unit port model. Container cargo volumes in Northeast Ports Model is distributed by results of HFP method. And distributed container cargo volumes effected to unit port model. Developed model can estimate change of container cargo volumes in competitive relation by alternation of simple parameter, and reflects dynamics characteristics which are included in model.

• 정보처리학회논문지A
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• 제10A권6호
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• pp.709-714
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• 2003

최근 통신기술의 발달로 교육용 컨텐츠에 있어서도 학습자와 학습 컨텐츠 사이의 상호작용이 강조되고 있다. 반면에 기존의 WBI나 CAI의 경우는 학습자와 컨텐츠 사이의 단순한 상호작용만 적용하였다. 학습자간의 상호작용을 극대화 할 수 있는 게임 형태의 플랫폼은 찾아보기 어렵다. 이에 본 연구에서 개별적 독립학습에서 발생하는 학습자간의 상호작용 부재의 문제와 협동학습에서 나타나는 공동의 목표 설정 및 프로그램 구현의 어려움을 극복하기 위한 대안으로 다자간 상호 경쟁적 학습 모형을 제시한다. 또, 이를 적용한 네트워크 게임 형태의 교육 컨텐츠를 위한 설계와 플랫폼 형태로 실제 구현해 봄으로써 상호 경쟁적 학습 모형과 함께 교육용 컨텐츠의 새로운 관점을 제시해 보았다.

• KDI Journal of Economic Policy
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• 제33권2호
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• pp.81-110
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• 2011

서브프라임 모기지 및 구조화 상품 등에 대한 부정확한 신용등급은 최근 금융위기 확산의 주요 요인으로 지적되고 있다. 본 논문은 신용평가노력을 관찰할 수 없는 숨겨진 행동모형(hidden action model)을 통해 신용평가회사의 행태 및 규제에 대한 분석을 시도하여 현재 논의되고 있는 신용평가기능 개선을 위한 논의에 보완적인 기여를 하고자 한다. 분석 결과, 도덕적 해이가 존재하면 신용평가노력이 관찰 가능하지 않음으로 인해 사회적으로 최적인 수준보다 낮은 수준의 신용평가노력을 기울임을 확인하였다. 경쟁 및 평판효과를 고려한 확장된 모형의 경우에도 신용평가회사에 사회적으로 최적의 유인을 제공하는 데는 한계가 존재한다. 그리고 부수업무의 존재는 신용평가회사의 노력수준과 사회적 최적 수준 간의 괴리를 확대함을 확인하였다. 따라서 경쟁과 평판에 의한 규율이 불완전한 경우 신용평가회사에 대한 감독 및 잘못된 정보의 제공에 따른 책임의 부과가 필요하다

• Journal of Korea Trade
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• 제25권4호
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• pp.88-107
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• 2021

Purpose - Using a model that highlights Ricardian comparative advantage and Cournot competition, I derive theoretical predictions on how bilateral measures of trade intensity, specialization, and intra-industry are interrelated, and how Ricardian productivity differences affect these measures. We test the predictions using trade and production data, and confirm them. Design/methodology - A simple two-country general equilibrium model is constructed to derive theory-based bilateral indexes. We then test the relationships among them using panel data for 35 countries and 14 industries between 1996 and 2008. Findings - Bilateral trade intensity is increasing in specialization, as in the classical trade theory, and in intra-industry trade, as in the new trade theory. However, productivity differences positively affect specialization, and negatively affect intra-industry trade. These effects cancel each other; thus productivity differences have little impact on trade intensity. Originality/value - This paper provides a comprehensive conceptual framework for understanding the relationship among trade intensity, specialization, intra-industry trade, and productivity differences. We derive theory-consistent measures of specialization, intra-industry trade, and productivity differences. Moreover, we reevaluate the empirical relevance of these variables for the study of gravity equations. This paper is also an effort to capture oligopolistic competition in a general equilibrium framework, interests in which recently resurged.

• 대한전기학회논문지:전력기술부문A
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• 제51권8호
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• pp.403-408
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• 2002

As the electricity industry undergoes a process of fundamental restructuring, horizontal market power appears as a potential obstacle to a fully competitive wholesale electricity market. Market power is the ability profitably to maintain prices above competitive levels by restricting output below competitive levels. In models for imperfect competition under the consideration of the transmission constraints, the Nash equilibrium has the form of a mixed strategy. In this paper, the models for analyzing imperfect competition are compared using the solution of pure and mixed equilibria. The relation between market power and the capacity of a transmission line is investigated by imperfect competition analysis methods: Cournot, Bertrand, and Supply Curve model.

• Asia pacific journal of information systems
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• 제15권3호
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• pp.1-7
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• 2005

This paper examines strategic competition model between offline and online retailers and draws strategic implications. Research on the price competition between conventional offline retailers and online retailers has been done through empirical approaches, however, the results are conflicting. This paper reconciles the existing conflicting empirical findings on price levels between offline and online retailers through theoretical approach. This paper analyzes how the internet market has effect on equilibrium prices of both offline and online retailers and discusses the possible reasons why there exist price differences between offline and online retailers in business to consumer electronic commerce.

• 한국경영과학회지
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• 제21권1호
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• pp.51-69
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• 1996

We consider a consumer self-selection model in which a regulated firm faces two market segments with differing valuation of quality of telecommunication services and examine some economic implications from the behaviors of the firm. In the context of a regulated monopolist, even though the results depend on the degree of privatization, the firm could lower the quality of the low-end model and reduce the price of the high-end in order to alleviate cannibalization. This justifies the provision of universal service policy in the telecommunications market. Based on this self-selection model, we also analyze an extended model of product introduction and show that the monopolist will introduce new product with the same introduction time of social planner. However, when we consider competition among firms, the market equilibrium may not guarantee the efficient time of product introduction.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.376-378
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• 2000

The current worldwide electricity market introduced competition, which is breaking up the monopoly structure and also enforcing phased structural reform in South Korea. The change of the electricity charge from cost base to price base due to the introduction of the electricity market competition causes consumer to choose a variety of charge schemes and a portion of loads to be affected by this change. Therefore, in order to find a mathematical model of the sensitively-responding-to-price loads and reflect this to the DSM demand management, the price-sensitive load model is needed. Thus, this paper first proposes the composite price-sensitive load model that is expressed as a function of price, presents the methodology to estimate price-sensitive load model at each bus by bus load compositions.

• 한국항해항만학회지
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• 제30권2호
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• pp.145-150
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• 2006

Recently we have seen a noticeable trend in ports to establish port clusters. Despite this trend, little research has actually been undertaken to fully define and analyse port clusters. A couple of exceptions have descriptively defined port clusters but the boundaries of port clusters are not apparent. Therefore, the aim of this paper is to define port clusters in terms of set theory and in particular look at them in terms of their distinct characteristics and system boundaries. The main concern of this paper is that there is a need to distinguish, from a system and a competition perspective, between port clusters, ports, maritime clusters and port ranges. This paper proposes a conceptual model relevant to the relationship among port clusters related assemblages and that has been applied to the north western europe region This model suggests six levels of competition that will help port authorities and government to develop appropriate policies and strategies for port operation and port industry.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권11호
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• pp.4557-4572
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• 2020

The Alaska competition provides an opportunity to study the practical problems of real-world steganalysis. Participants are required to solve steganalysis involving various embedding schemes, inconsistency JPEG Quality Factor and various processing pipelines. In this paper, we propose a method to ensemble multiple deep learning steganalyzers. We select SRNet and RESDET as our base models. Then we design a three-layers model ensemble network to fuse these base models and output the final prediction. By separating the three colors channels for base model training and feature replacement strategy instead of simply merging features, the performance of the model ensemble is greatly improved. The proposed method won second place in the Alaska 1 competition in the end.