• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2292-2294
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• 2004

At satellite communication system for flood forecasting and warning, VSAT system needs to good performance for aquisition of rainfall and water-level data. But, it has difficult for obtaining good performance because of the rainfall attenuation. Thus, in this paper, we introduced the efficiency plan of the transmission power control for Mini-Hub Station.

• 한국항해항만학회지
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• 제44권2호
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• pp.73-78
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• 2020

The cruise industry in the Mediterranean region increased from 2000-2018, being the second most important region after the Caribbean. The purpose of this study was to analyze the networks and hub ports of the Mediterranean. This paper used the SNA (Social Network Analysis) methodology, which includes Hub and Authority Combined Centrality (HACC) that has been used to analyze cruise port centrality, as well as degree centrality such as In-Degree, Out-Degree, and Betweenness. This empirical study suggests that the top three ports of the Mediterranean ports' network in terms of hub index are Barcelona, Civitavecchia, and Palma de Mallorca. The academic implications are the suggestion for data integration based on real itineraries and numbers of POC (Port of Calls), as well as the selection of the hubs of the targeted areas. The practical implications are suggested such as a clear requirement for cruise industry, as a way to widen the scope for the Mediterranean region and a valuable reference for cruise ship companies to select the best fit home ports.

• 대한교통학회지
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• 제28권1호
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• pp.7-14
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• 2010

세계화의 진전에 따라 항만위주의 국제무역 관행이 공항으로 전이되고 있으며, 공항에서 물류기능의 비중은 이전보다 훨씬 커지고 있다. 공항은 한 국가의 경제수준과 과학기술수준을 총체적으로 나타내주는 사회간접자본의 역할과 다국적 기업들의 생산, 판매, 운송 과정을 통합적으로 관리해주는 물류중심지로서 기능이 확대되고 있다. 공항의 경쟁력은 국제물류거점으로서 배후단지 기능과 해당 공항의 경쟁 우위 요소에 대한 지속적인 관리에서 나온다. 이 논문에서는 국제물류거점으로서 허브공항이 되기 위한 요인과 인천, 나리타, 간사이, 나고야, 창이, 타이페이 공항으로 허브공항으로서의 경쟁력을 연구하였다.

• 한국산학기술학회논문지
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• 제10권1호
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• pp.122-127
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• 2009

본 본 논문은 항공 교통 체계에서 가장 중요하게 고려되는 안전한 항공체계에 대한 연구를 중심으로 보안구조를 검토하고 보안모델을 제시하였다. 분석된 내용은 항공서비스 분야 관련 보안기술을 기반으로 국제적인 기술 동향과 함께 국내의 항공체계에 대한 보안모델을 다루고 있다. 항공통신 네트워크의 보안 프레임워크에서는 항공과 지상 데이터링크 보안기술, 항공체계에 따른 보안구조를 분석하였고 U-information HUB 모델의 보안구조를 제시하였다. U-information HUB 보안구조는 항공사, 공항 네트워크, 항공기, 관련 정부기관 등과 연동범위를 포함하고 있다.

• 한국컴퓨터정보학회논문지
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• 제21권1호
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• pp.59-64
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• 2016

This paper suggests heuristic algorithm with O(mn) polynomial time complexity using Excel for partially survivable networks optimization problem of cellular telecommunication systems with m cells and n hubs. This problem only can be get the solution using linear programming or LINGO software package. The proposed algorithm connects the cell to hubs in ring network with minimum cost as the connection diversity of each cell. If the traffic of ring network (T) is T>2K for ring capacity (K), we adjust the maximum cost hub to MTSO that has a ascending order of (D/DC)/${\Delta}^+$ cell with each cell traffic demand (D) and ${\Delta}^+$=(MTSO cost-maximum cost hub) than we get the $T{\leq}2K$. Finally, we adjust MTSO to the removed maximum cost hub for the cell with 2K-$T{\geq}$(D/DC) and $_{max}{\Delta}^-$. While we using like this simple method, the proposed algorithm can be get the same optimal solution for experimental data as linear programing and LINGO software package.

• 한국항만학회지
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• 제13권1호
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• pp.11-26
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• 1999

The subject of port efficiency is one of the important issues facing port authorities and policy makers today. A number of studies have been undertaken which compare ports in terms of their efficiency. But any port comparison can only be valid and meaningful if a port’s efficiency is compared with a similar port. The main objective of this paper is to introduce a systematic approach to identifying similar ports based on the technique of principal component analysis and cluster analysis. And it seeks to identify the most important factors underlying the port classification. Lack of awareness of which factors differentiate ports has resulted in an unnecessary collection of data which are of limited use in port classification. This paper has identified five groupings of similar ports within which port comparision can be justifiably made. This approach can be used for any future port comparision.

• 유통과학연구
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• 제14권1호
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• pp.59-66
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• 2016

Purpose - The purpose of this study is to find out how shipping company recognizes making partnership with the third party logistics provider and to give implication. Research design, data and methodology - Personal interview and questionnaire by E-mail, Fax, Mail, and telephone were used. 700 copies of the questionnaires were distributed and 155 copied were returned. Among collected questionnaires, 20 copies were excluded because of insufficient content, and therefore 135 copies were used. Results - Korea should change into new paradigm from old one based on current economic and social systems which has stemmed from bureaucracy, inflexibility chauvinism and equalitarianism. Flexible policies, administration and systems will be needed for better business practices. The Domestic logistics corporation needs to preoccupy strategic logistics hub and network. Conclusions - To be a center of North East Logistics, Korea needs more reasonable business law, systems and policies. Social norms and orders should be established to accomplish political and social security. A paradigm of the policy ruling over development of capital city and satellite cities shall make change.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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• pp.402-408
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• 2003

Now many major airports in the world which operate strategic alliance or Hub & Spoke system have met capacity restriction and confusion problems. And the time and the walking distance for boarding to flight are important standard to measure customer convenience. And the effective gate assignment guarantees customers convenience as well as increasing airport capacity without expanding established airport equipments. So it can be a major concern to manage airports. So this paper formulate gate assignment problem in the hub airport not quadratic assignment problem but a improved single-period integer problem which is minimize local and transit passengers I walking distance. As a result, this study will present a method producing optimal gate assignment result using optimization software. We use real flights and gates data in the national airport, so we will compare a assignment results with a real airport assignment results and previous researches and analyze those results.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1795-1798
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• 2003

This paper presents a method for impeller modeling by the reverse engineering and the 5-axis machining. The impeller is composed of pressure surface, suction surface and leading edge, and so on. The impeller is modeled by using the characteristic curves of impeller such as hub curves, shroud curves and leading edge. The characteristic curves are extracted from the scanned data. The hub curves and shroud curves are generated by intersection between blade surface and hub boundary and shroud boundary. respectively. A sample impeller machining is performed by tool path plan and post-processing with inverse kinematic solution.

• 한국유통학회지:유통연구
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• 제7권1호
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• pp.1-20
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• 2002

Many of logistics-related research in automobile industry has focused on inbound logistics and procurement. Research into outbound logistics is relatively few. As a starting research into outbound logistics in automobile industry, this paper examined its logistics network problems with three aspects - location strategy, inventory strategy and transportation strategy. We proposed alternatives of logistics network design resolution, and presented three practical scenarios based on those alternatives. Based on interview, on-site visit and internal data collection processes, we identified major domestic outbound logistics problems such as redundant logistics bases, inefficient delivery policy, insufficient inventory capacity, inventory stock quality deterioration, inefficient transportation system, and etc. In order to cope with those problems, we proposed such strategic alternatives as introduction of hub-and-spoke system, integration of logistics bases, introduction of (automatic) parking building, diversification of transportation mode, and etc. At the same time, we constructed three practically executable scenarios based on those ideas. The first is "Center Hub" scenario, the second is "Metropolitan Hub" scenario. The third and last scenario is "Regional Consolidation of Warehouses (distribution centers)".