• Proceedings of the KIEE Conference
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• 2005.07d
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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.

• Journal of Korea Port Economic Association
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• v.20 no.2
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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.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.2
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• pp.206-218
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• 2002

In this paper, we design and implement a system that presents a method for selecting and providing personalized services independently without unifying the existing system platform with shopping malls joined in the hub site. This system provides a mechanism for gathering information left behind by many clients visiting Web sites for analysis of customers property, vector model for selecting personalized services, and mechanism for providing them to customers who visited in a shopping mall joined to the hub site. In a position of shopping mall site, this kind of personalization system can provide target advertisement, point marketing, and point share service etc. without changing existing shopping mall's environment through wrapper web server. Hub site customers can get personalized services from many shopping mall sites with only once registration for the hub site.

• The Journal of the Korea Contents Association
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• v.9 no.1
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• pp.446-454
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• 2009

In this paper, we propose u-learning hub site systems which are designed and implemented based on learning activities oriented components. The proposed systems are composed of component which can process the functionalities for coming into action of learning activities through various devices. Specially, each component is broken into class units by which learning activities of users can be performed on various devices. When users try to connect u-learning system in hub site, the system explores devices of users and connection program and then selects components that are fit to the activities and combines them in realtime. Through the methodology of u-learning hub site, the system proposed in this paper provides u-learning environment so that users can use the learning activity services taking no influence on time, place, devices and programs under the consistent system. That is different to traditional e-learning system which cannot support various devices of users directly.

• Journal of Industrial Technology
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• v.22 no.A
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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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• v.18 no.12
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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.

• Journal of the Korean Operations Research and Management Science Society
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• v.24 no.3
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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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• v.17 no.1
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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.

• Journal of Korean Society of Rural Planning
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• v.15 no.3
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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.

• Journal of Distribution Research
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• v.7 no.1
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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)".