• Journal of Communications and Networks
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• v.8 no.1
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• pp.49-58
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• 2006

One of the first decisions that a radio network designer must take is the location of base stations and the distance between them in order to give the best coverage to a region and, possibly, to reduce deployment costs. In this paper, the authors give an insight to this matter by presenting a possible solution to a real problem: Planning the base stations layout for a universal mobile telecommunications system (UMTS) in the city of Barcelona. At the basis of this problem, there is the interdependence between coverage and capacity in a wideband-code division multiple access (W-CDMA) system, which is a new element in the planning of BS layout for mobile communications. This aspect has been first treated with an analytical study of the cell coverage range for a specific environment and service. The achieved results have been checked with the help of snapshot simulations together with a geographical information system (GIS) tool incorporated in the simulator that allows to perform analysis and to visualize results in a useful way. By using the simulator, it is also possible to study a more complex environment, that of a set of base stations providing multiple services to a large number of users.

• The Journal of Society for e-Business Studies
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• v.15 no.4
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• pp.197-218
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• 2010

Korean Government has invested a lot of efforts on digital contents industry. It believes that the digital contents industry enables Korea to regain the reputation of the most powerful IT country. Among its various efforts to promote the digital contents industry, a Digital Contents Identifier System, called UCI(Universal Contents Identifier), has been developed and deployed. UCI has provided a critical infrastructure for digital contents production and distribution. Thanks to Korean Government's efforts, users (companies and individuals) have currently registered 3.8 million digital contents through 25 RA organizations. Although the number of registered contents has been increased rapidly, many organizations hesitate to adopt the UCI system due to the lack of visible and short-term returns from the UCI system. Thus, this research tries to explore factors which affect UCI user satisfaction. This research finds that user's awareness, information quality, and service quality are the critical influencing factors toward UCI user satisfaction. In addition, this research finds that the critical influencing factors in public organizations are different from the critical influencing factors in private organizations. These findings hopefully provide useful guidelines for disseminating the UCI system widely.

• The KIPS Transactions:PartC
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• v.16C no.1
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• pp.125-132
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• 2009

The pre-generated web contents or various devices have to be used in order to execute UMA(UMA:Universal Multimedia Access). However, an HTLM web page for PC is not very compatible with wireless internet because of its unnecessary advertisements, high resolution, and various multimedia data. This is because the main focus when creating it was on high speed. In this paper indicates with the RSS channel, converted from the main part of the HTML web page, which users show interest in, a wireless compatible internet page can easily be created. Consequently, web administrators could create a wireless page easily and quickly, and wireless users would be able to find information in the same manner.

• ETRI Journal
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• v.27 no.4
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• pp.341-354
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• 2005

The adaptation of video according to the heterogeneous and dynamic resource constraints on networks and devices, as well as on user preferences, is a promising approach for universal access and consumption of video content. For optimal adaptation that satisfies the constraints while maximizing the utility that results from the adapted video, it is necessary to devise a systematic way of selecting an appropriate adaptation operation among multiple feasible choices. This paper presents a general conceptual framework that allows the formulation of various adaptations as constrained optimization problems by modeling the relations among feasible adaptation operations, constraints, and utilities. In particular, we present the feasibility of the framework by applying it to a use case of rate adaptation of MPEG-4 video with an explicit modeling of adaptation employing a combination of frame dropping and discrete cosine transform coefficient dropping, constraint, utility, and their mapping relations. Furthermore, we provide a description tool that describes the adaptation-constraint-utility relations as a functional form referred to as a utility function, which has been accepted as a part of the terminal and network quality of service tool in MPEG-21 Digital Item Adaptation (DIA).

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.10a
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• pp.42-43
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• 2014

As MSI(Maritime Safety Information), navigational, meteorological warnings and forecasts, was included as one of service in the MSP(Maritime Service Portfolio), which is lists of shore based service in the e-Navigation driven by IMO for safety navigation and marine protection, and was tested in the european test bed project on e-Navigation, it's considered as one of important e-Navigation service. This paper developed a prototype of MSI service to prepare e-navigation era, which is very important in a navigation environment. Current status on MSI and NAVTEX was surveyed, and several points on limitations and improvements in the NAVTEX operations were summarized. Basic study on the MSI service prototype was developed based on S-100, which is recognized as baseline to develop CMDS(Common Maritime Data Structure) of e-Navigation.

• Journal of the Korean Society for Library and Information Science
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• v.42 no.2
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• pp.87-108
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• 2008

The purpose of standards and guidelines of library service for people with disability is to provide libraries, governments and other stakeholders with a framework for developing library services for people with disability. This Paper is to Identify the constituents of standards and guidelines of library service for people with disability. These constituents are developed by analysis and investigation of foreign standards and are based on many people's advice such as members of the advisory committee. Extracted constituents of standards and guidelines of library service for people with disability are as follows: physical accessibility to library building and facilities, construction of alternative formats, access to services and programs. assistance engineering devices, web accessibility and universal design, training and staff development, cooperation and networking etc. Finally, we clarified main contents of each element to be included in standard.

• IE interfaces
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• v.11 no.3
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• pp.77-87
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• 1998

Intelligent Peripheral(IP) system is to provide specialized resource functions (SRF) such as playing announcement, collecting user information, and receiving messages in the Advanced Intelligent Network (AIN). We analyze the call processing capacity of an AIN IP system being developed in ETRI through an extensive simulation using SLAM II under a variety of AIN service scenarios. We consider televoting (VOT) and universal personal telecommunication (UPT) services which are to be provided at the fit implementation of the AIN in Korea. As the performance criteria to determine the call processing capacity, processor utilization, delay and call loss probability are considered. It turns out that the major processor called SAMP is the bottleneck processor, the service response delay dominates the delay performance, and the call loss probability becomes the primary criterion in determining the call processing capacity of the AIN IP system. It is also shown that the call processing capacity of the AIN IP system is determined by the utilization of the processor and the delay performance when the VOT ratio is below 70 percent but it is determined by the call loss probability due to the lack of service channels for providing the SRF operations.

• Journal of Digital Contents Society
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• v.5 no.2
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• pp.114-120
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• 2004

This paper proposes the wireless integrated service for controlling networked appliances. Using wireless devices such as celluar phone and PDA which can communicate through Bluetooth and CDMA technology, home appliances are accessed and controlled from outside of house. The XML and the SMS message format is designed to specify controlling information for home appliances. Also the mobile agent and the message processor for networked appliances are implemented in the home gateway. In order to verify the proposed service system, a universal remote controller for cellular phone and PDA and network appliance simulator on web browser are implemented. Correct operation is verified through simulation using them.

• International Journal of Contents
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• v.11 no.1
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• pp.41-51
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• 2015

Management systems for electronic library have been developed on the basis of Client/Server or ASP framework in domestic market for a long time. Therefore, both service provider and user suffer from their high cost and effort in management, maintenance, and repairing of software as well as hardware. Recently in addition, mobile devices like smartphone and tablet PC are frequently used as terminal devices to access computers through the Internet or other networks, sophisticatedly customized or personalized interface for n-screen service became more important issue these days. In this paper, we propose a new scheme of integrated management system for electronic library based on SaaS and Web Standard. We design and implement the proposed scheme applying Electronic Cabinet Guidelines for Web Standard and Universal Code System. Hosted application management style and software on demand style service models based on SaaS are basically applied to develop the management system. Moreover, a newly improved concept of duplication check algorithm in a hierarchical evaluation process is presented and a personalized interface based on web standard is applied to implement the system. Algorithms of duplication check for journal, volume/number, and paper are hierarchically presented with their logic flows. Total framework of our development obeys the standard feature of Electronic Cabinet Guidelines offered by Korea government so that we can accomplish standard of application software, quality improvement of total software, and reusability extension. Scope of our development includes core services of library automation system such as acquisition, list-up, loan-and-return, and their related services. We focus on interoperation compatibility between elementary sub-systems throughout complex network and structural features. Reanalyzing and standardizing each part of the system under the concept on the cloud of service, we construct an integrated development environment for generating, test, operation, and maintenance. Finally, performance analyses are performed about resource usability of server, memory amount used, and response time of server etc. As a result of measurements fulfilled over 5 times at different test points and using different data, the average response time is about 62.9 seconds for 100 clients, which takes about 0.629 seconds per client on the average. We can expect this result makes it possible to operate the system in real-time level proof. Resource usability and memory occupation are also good and moderate comparing to the conventional systems. As total verification tests, we present a simple proof to obey Electronic Cabinet Guidelines and a record of TTA authentication test for topics about SaaS maturity, performance, and application program features.

• Journal of the Korean Operations Research and Management Science Society
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• v.34 no.4
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• pp.185-204
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• 2009

The USIM(universal subscriber identity module)-unlock introducing in July 1, 2008 might be led to a significant change that mobile service provider's dominance is considerably dispersed to the handset manufacturer and distributor. Under USIM-unlock environment, mobile service provider, handset manufacturer, and distributor have to make their decisions on their handset distribution channel strategies: the closed distribution channel strategy or the open distribution channel strategy. The change of distribution channel strategy between members in distribution channel can be understood as a matter of strategy choice, and we have developed a theoretical model and analyzed how to make a decision for the member's optimal distribution strategy based on 3-person game model between members of mobile phone distribution channel, under both of '1 subscriber-1 handset' and '1 subscriber-multiple handset' assumptions. Under '1 subscriber-1 handset' assumption, the closed strategy controlled by mobile service provider is all players' optimal solution because the maximum size of the mobile phone market is limited by subscribers. But, as total expected profit by the handset and distribution subsides is a deficit, mobile service provider have to choose the open strategy and consider the conversion to MNO(mobile network operator). Under '1 subscriber-multiple handset' assumption, mobile service provider is trying to find the way how to lock-in its service and mobile phone and how to maximize ARPU(average revenue per unit), while handset manufacturer and distributor have to look for the way how to maximize the mobile phone market using their own marketing efforts, because it is expected that total mobile handset demand for the open market is bigger than demand for the closed market under '1 subscriber-multiple handset' assumption.