• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
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• pp.2661-2663
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• 2005

To construct the stable back-up system between mini-hubs, we propose the plan of site diversity of asynchronous mini-hub by monitoring outlink carriers and error data. In this paper, we made hardware and software to control mini-hub system for site diversity back-up by switching SDBS equipment through communication between master mini-hub and slave mini-hub.

• 한국항만경제학회지
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• 제20권2호
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• pp.89-100
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• 2004

Because of a recent trend of the open and globalized world economy, international trade is getting bigger and there is a trade competition among many countries, resulting in competition between harbor industries. Therefore, as hub-port development of China, Japan and Taiwan is more actively progressing than any other times, Korea should prepare a powerful management system to take the initiative over them. Above all, a new recognition of the governmental officers in charge of political management about hub-port industry and early development of the northeast hub-port are needed. To maximize its distinctiveness from competitive ports, port sale should be actively managed. As well, as port functions are diverse, accompanied site development should be prepared. In conclusion, in order to improve functions of a port and develop the port as a general complex of physical distribution, the government should encourage the accompanied site development and support preparation of a customs-free area and a general system of physical distribution.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제8권2호
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• pp.206-218
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• 2002

본 논문에서는 서로 다른 플랫폼으로 구성된 허브 사이트 가맹점들이 지역적으로 분산되어 있는 분산 이기종 환경에서 각 가맹점들의 기존 플랫폼을 통일시키지 않고 독립적으로 고객이 관심을 가질만한 맞춤 정보 및 광고를 선정하여 제공하기 위한 시스템 설계 및 구현 내용을 서술한다. 본 논문에서 제안하는 시스템은 각 가맹점을 방문하는 고객들의 정보를 수집하기 위한 모니터링 기능, 고객 개개인의 특성에 맞는 서비스를 선정하기 위한 벡터 모델, 그리고 벡터 모델을 이용하여 선정된 서비스를 허브사이트 또는 각 가맹점을 방문하는 고객 개개인에게 제공하기 위한 기능을 지원한다. 본 시스템은 상점 입장에서는 허브 사이트 가맹점이 됨으로써 기존 플랫폼을 바꾸지 않고도 통합 서비스 및 개인화 서비스 제공이 가능하며, 고객 입장에서는 한번의 고객 등록으로 맞춤 서비스를 제공받을 수 있다는 장점을 갖는다.

• 한국콘텐츠학회논문지
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• 제9권1호
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• pp.446-454
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• 2009

본 논문에서는 학습활동 중심의 컴포넌트를 기반으로 설계 구현한 u-러닝 허브사이트 시스템을 제안한다. 제안된 시스템은 u-러닝 환경에서 다양한 단말기를 통하여 교육활동이 이루어 질수 있도록 u-러닝 허브사이트의 기능을 컴포넌트 단위로 세분화 하며, 각 컴포넌트는 클래스들의 상속과 조합을 통하여 실시간으로 허브 사이트의 기능을 구성한다. 즉 접속하는 단말기와 프로그램의 특성을 파악하여 기본이 되는 부모 클래스를 바탕으로 자식 클래스를 추가하거나 조합하여 하나의 컴포넌트를 동적으로 구성하게 된다. 이러한 방식을 통해, 본 논문에서 제안한 시스템은 다양한 단말기를 지원 할 수 없는 기존의 e-러닝 시스템과 달리 동일한 시스템 하에서 시간, 장소, 단말기와 프로그램에 구애받지 않고 교육활동 서비스를 이용할 수 있는 유비쿼터스 러닝 환경을 제공한다.

• 산업기술연구
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• 제22권A호
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• pp.49-57
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• 2002

The accurate wind speed information at the hub height of a wind turbine is very essential to the exact estimation of the wind turbine power performance testing. Several methods on the site calibration, which is a technique to estimate the wind speed at the wind turbine's hub height based on the measured wind data using a reference meteorological mast, are introduced. A site calibration result and the wind resource assessment for the Taekwanryung test site are presented using a one-month wind data from a reference meteorological mast and a temporal mast installed at the site of wind turbine. From this analysis, it turns out that the current location of the reference meteorological mast is wrongly determined, and the self-developed codes for the site calibration are working properly. Besides, an analysis on the uncertainty allocation for the wind speed correction using site calibration is performed.

• Journal of Mechanical Science and Technology
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• 제18권12호
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• pp.2250-2257
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• 2004

The accurate wind speed information at the hub height of a wind turbine is very essential to the exact estimation of the wind turbine power performance testing. Several methods on the site calibration, which is a technique to estimate the wind speed at the wind turbine's hub height based on the measured wind data using a reference meteorological mast, are introduced. A site calibration result and the wind resource assessment for the TaeKwanRyung test site are presented using three-month wind data from a reference meteorological mast and the other mast temporarily installed at the site of wind turbine. Besides, an analysis on the uncertainty allocation for the wind speed correction using site calibration is performed.

• 한국경영과학회지
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• 제24권3호
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• pp.93-107
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• 1999

We consider the development of an integer programming model and algorithm for the ATM switching node location problem. There are two kinds of facilities, hub facilities and remote facilities, with different capacities and installation costs. Each customer needs to be connected to one or more hub facilities via remote facilities, where the hub(remote) facilities need to be installed at the same candidate installation site of hub(remote) facility. We are given a set of customers with each demand requirements, a set of candidate installation sites of facilities, and connection costs between facilities, We need to determine the locations to place facilities, the number of facilities for each selected location, the set of customers who are connected to each installed hub facilities via installed remote facilities with minimum costs, while satisfying demand requirements of each customer. We formulate this problem as a general integer programming problem and solve it to optimality. In this paper, we develop a branch-and-cut algorithm with path variables. In the algorithm, we consider the integer knapsack polytope and derive valid inequalities. Computational experiments show that the algorithm works well in the real world situation. The results of this research can be used to develop optimization algorithms to solve capacitated facility location problems.

• Asia Marketing Journal
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• 제17권1호
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• pp.69-95
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• 2015

This paper examines a highly used social networking site (SNS) by studying the behavior of more than 11 million members over a 20 month period. The importance of the most highly active members to the overall network is demonstrated by the significant fraction of total visits by extremely active members in a given period but such members have surprisingly short lifespans (an average of only 2.5 months) as social hubs. We form and test a number of hypotheses concerning these social hubs and the determinants of their lifespan. We find that the speed of achieving social hub status increases the lifespan of a social hub. The norm of reciprocity is strongly confirmed to be present in the social hub population as visits are reciprocated. We also find that increasing local dominance in terms of activities over neighboring agents leads to a longer lifespan of a social hub. Contrary to expectations, local clustering in the vicinity of social hubs is smaller (rather than larger) than overall clustering. We discuss managerial implications in the paper.

• 농촌계획
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• 제15권3호
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• pp.33-45
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• 2009

This study tried to establish a tentative renewal guideline on spatial structure of the Hub-myun's center villages which would be positioned as sub-centers in the rural settlement hierarchy in Korea. Space Syntax Method was used to analyze the locational characteristics of community facilities in the center villages of 8 pilot project areas which were selected in the nationwide scale. The base-maps for spatial analysis works were prepared firstly from satellite pictures and adjusted through field check. Generally, connectivity and global integration values of center villages were calculated as higher than hinterland villages, which would mean better accessible spatial characteristics in the center villages. And a tentative renewal guideline was proposed for road route improvement and relocation of community facilities in the Hub-myun's center villages.

• 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)".