• The Journal of the Korea Contents Association
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• v.5 no.6
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• pp.65-73
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• 2005

Request about fast diffusion of internet and high-capacity multimedia service is increasing day after day. Because existent wireless LAN is short range, if subscriber is far away in base station transceiver system(Base Station), subscriber's quality of service becomes low, and wileless internet is expensive. Lately, WiBro(Wireless Broadband Internet) system that is developed in domestic by world first, is high-speed portable internet service that is situated in middle area of mobile phone and wireless LAN. In this paper, service traffic model and characteristics are analyzed to provide multimedia service based on IEEE 802.16 BWA accomplishes base of WiBro and simulation is conducted according to various traffic mixing ratio. Finally, on the basis of these simulation results, maximum allowable number of subscriber per cell is calculated.

• Journal of the Korean Society for Library and Information Science
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• v.50 no.1
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• pp.101-132
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• 2016

This study aims at developing subject guides for the disabled to provide service effectively. Subject guide and service models are developed on the basis of reference, case study, and user requests analysis and information types in areas are determined. Information types for collecting and building information resources are classified into types are subordinate and also metadata by information types are developed. Subject guides based on customized services contain information, disability type, service target, life-cycle, media type, and organizations.

• Journal of Information Technology Services
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• v.20 no.3
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• pp.87-101
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• 2021

Since the introduction of block chain technology, its potential use in financial service area have been increasing, and financial firms are seeking ways to take advantage of the benefits of it. The purpose of this study is to present an approach to prioritize block chain-based services for bank. Toward this, we picked out potential financial services through focus group interview and derived the criteria that can be used in evaluating the priorities of block chain-based banking services in the same way. Then, we propose an analytic hierarchy process model to help decision makers prioritize the banking services while considering multiple criteria of technology issues, governmental regulations in the financial industry, cost, managerial issues, customers' needs, and the business opportunity for the bank. By using the analytic hierarchy process model, we can estimate the weighting coefficients to be assigned to each criteria and determine the order of priority in determining the best block chain-based service for the case study bank. The results show that banking login authentication would be forefront service, followed by money transfer, document notarization, and trade financing service in the order, and the trade financing could be most important service in terms of the business profitability for the bank in the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.503-514
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• 2019

This paper proposes a blockchain-based urban service-operation model that can enhance usability by integrating several data-driven services operated in a city. In the proposed model, in order to encourage the participation of service users, the providers of data and values that can be consumed and utilized by each service acquire incentives, and consumers can use various services by paying the incentives. In this way, the proposed service model provides a structure in which various services can be interworked within the incentive system. The characteristics of blockchain technology can also guarantee service operation and management transparency. In addition, in this paper, by establishing and operating a prototype, the efficiency and operability of the proposed model are verified. As a result, three implemented data-driven urban management services are organically inter-compatible based on the concept of the proposed integrated incentive system. In the future, the proposed service model can be applied as an elemental technology of urban operational and management architectures based on citizen participation using local currency, and by cooperating with local economic revitalization projects of interest to many local governments. It is expected that the expansion of the blockchain technology area will also be possible through convergence with smart city services.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.500-504
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• 2008

The objective of this paper is to evaluate the feasibility of using an optimization model as a effective way to search conjunctive operation scheme to meet two conditions; one is to minimize the electric cost for pumping and another is to meet the water demand for satisfying customers. The feasibility is confirmed as comparing the best combinations of pumps between multi-regional water supply networks from multiple sources which are obtained through an optimization modeling and EPAnet modeling. KModsim model, a network optimization model, was used to determine conjunctive operation scheme in the pipe system. KModsim, based on Lagrangian Relaxation algorithm, is useful for modeling network system and obtaining simultaneously pump combination and water allocation with given input option such as energy unit cost supplying from a source into a consumer, operating pumping combination. This study develops the procedure of determining optimal conjunctive operation scheme with using KModsim model. As a study region, the water supplying systems of the Geojae-city in the Geongsang Namdo Province was selected and investigated. The EPAnet hydraulic simulation result(Ryu et al, 2007, KSWW) gave input data for optimization model; energy unit price(won/$m^3$), water service available area etc.. It was assured that the combination of pump operation through optimum conjunctive operation is to be optimum scheme to obtain the best economic water allocation with comparison to the hydraulic simulation result such as electric cost and pump combination cases. The results obtained through the study are as follows. First, It was found that a well-allocated water supply scheme, the best combination of pump operation through optimum joint operation, promises to save the electric cost and satisfy all operational goals such as stability and revenues during the period. Second, an application of KModSim, a network model, gave the amount of water allocation from each source to a consumer with consideration of economic supply. Finally, in a service area available to supply through conjunctive operation of existing inter-regional water supply networks within short distance, a conjunctive operation is useful for determining each transmission pipeline's service area and maximizing the effectiveness of optimizations in pumping operation time.

• 한국노년학
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• v.31 no.3
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• pp.691-709
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• 2011

The purpose of this study is to measure the utilization of a day care service and service quality by SERVQUAL model, also to discuss policy implications based on this. The data analysis is conducted with 208 users of a day care service in Deajeon metropolitan city, Chungnam and Chungbuk area. The analysis result is as follows. First, it shows positive definiteness on tangibles, reliability, responsiveness, assurance, empathy in all categories because perceived level is higher than expectations. Perceived level after using the service is more highly rated than expectations before using it by most of seniors who use the service. Second, service quality is examined in accordance with demographic characteristics, but the difference is not statistically significant. Third, examining service quality in terms of characteristics of centers, it shows statistically significant difference in perceived level depending on management type of location, a number of provided programs per week, and the size of a facility and in expectations depending on established institution. Forth, as a result of examining service quality in accordance with characteristics of service users, there is no meaningful difference statistically.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.35T no.1
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• pp.111-119
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• 1998

To predict propagation environments of antenna radiation pattern, it is very important for deceision of service area, selection of the best station location and design of cell etc. By analyzing the propagation prediction model that is varied acceding to the kind of antenna, beam angle, terrain and obstacles, we expect that the economic operating of communication networks, calling quality and service of subscriber will be enhanced. It was measured the fields strength to propose the optimal propargation predicted model of the zone of Seji base station in Naju-city. The simulations of field test are 4 types Hata model, the Egri model, the Carey model and the proposed model. Finally the proposed model are more close agreement with experimental test than other models.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.427-430
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• 2007

The Shiwa is developed by banwol special area and it is holding a many problem for a residential area. It controls about 80% of the waste in the capital region area and it is urgent to life environment improvement. thus, It is necessary to effort for the development of ecological intelligence city from the planning of a new town. In this study, it is intended to create the City specialization Model of a shiwa zone using Ubiquitous Technology which is considered IT-based service. It is aimed to provide city life style which is fine and convenient

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.8
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• pp.760-766
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• 2008

This paper proposes an efficient location technique to find an indoor location under the IEEE 802.11 wireless local area networks. The proposed method is based on the range measurements obtained from a simple radio frequency propagation model. Thus, unlike the radio frequency fingerprint correlation method, it does not suffer from the computational burden during the real-time location service period and can quickly reply the location requests of many users at the same time. To increase the location accuracy in spite of the frequent non-line-of-sight error occurrences, the proposed method calibrates the distortion of the non-line-of-sight error by a simple measurement surveying procedure that does not require the surveyor's manual interaction. Experimental results show the capability of the proposed method.

• Convergence Security Journal
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• v.11 no.6
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• pp.67-72
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• 2011

A system that provides a ubiquitous service is a networked system that has to overcome their circumstances that the service survivability is weak. the survivability of a networked system is defined as an ability of the system that can offer their services without interruption, regardless of whether components comprising the system are under failures, crashes, or physical attacks. This paper presents an approach that end users can obtain a quantitative evaluation of U-service survivability to reflect intended cyber attacks causing the networked system to fall into byzantine failures in addition to the definition of the survivability. In this paper, a Jini system based on wireless local area networks is used as an example for quantitative evaluation of U-service survivability. This paper also presents an continuous time markov chain (CTMC) Model for evaluation of survivability of U-service that a Jini system provides, and an approach to evaluate the survivability of the U-service as a blocking probability that end users can not access U-services.