• Journal of Information Processing Systems
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• v.13 no.1
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• pp.152-173
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• 2017

Mobile phones are the most common communication devices in history. For this reason, the number of mobile subscribers will increase dramatically in the future. Therefore, the determining the location of a mobile station will become more and more difficult. The mobile station must be authenticated to inform the network of its current location even when the user switches it on or when its location is changed. The most basic weakness in the GSM authentication protocol is the unilateral authentication process where the customer is verified by the system, yet the system is not confirmed by the customer. This creates numerous security issues, including powerlessness against man-in-the-middle attacks, vast bandwidth consumption between VLR and HLR, storage space overhead in VLR, and computation costs in VLR and HLR. In this paper, we propose a secure authentication mechanism based new mobility management method to improve the location management in the GSM network, which suffers from a lot off drawbacks, such as transmission cost and database overload. Numerical analysis is done for both conventional and modified versions and compared together. The numerical results show that our protocol scheme is more secure and that it reduces mobility management costs the most in the GSM network.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1997.10a
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• pp.239-242
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• 1997

Subscriber network investment cost is a main cost element among those constituting the access charges in telephone networks. The purpose of this paper to estimate the investment cost of installing a subscriber network in a typical metropolitan area and to develop a cost modeling framework. To this aim, a metropolitan area in Seoul was investigated. The main cost elements were identified and their relationships with the cable technology, geographical characteristics, and the number of subscribers were analyzed. The findings could be used to design an enhanced cost proxy models for estimating the access charges in a multi-operator environment.

• Journal of the Korea Society of Computer and Information
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• v.13 no.4
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• pp.133-140
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• 2008

The cable TV network has delivered downward broadcasting signals from distribution centers to subscribers. Since the traditional coaxial cable has been upgraded by the Hybrid Fiber Coaxial(HFC) cable, the upward channels has expanded broadband services such as Internet. This upward channel is vulnerable to ingress noises. When the noises from the children nodes accumulated in an amplifier exceeds a certain level, that node has to be cut off to prevent the noise propagation. The node selection problem(NSP) is defined to select nodes so that the noise in each node does not exceed the given threshold value and the sum of Profits of selected nodes can be maximized. The NSP has shown to be NP-hard. In this paper, we have proposed heuristics to find the near-optimal solution for NSP. The experimental results show that interval partitioning is better than greedy approach. Our heuristics can be used by the HFC network management system to provide privileged services to the premium subscribers on HFC networks.

• Journal of Korean Society for Quality Management
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• v.39 no.3
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• pp.422-431
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• 2011

The number of mobile telecommunication service subscribers has been over 50 millions as of the end of Nov. 2010. And the number of used mobile phones has been growing continuously caused by shortened life cycle of products and competing between service providers, which is about 21 millions for only one year, 2010 in Korea. However, the quality level of reverse logistics network for used mobile phones is very low and statistics show that the collection ratio of them has not been over 40%. The current low collection ratio can be one of the significant causes of environment destruction due to the cumulated growth. Accordingly new practical alternative recovery systems are required in addition to the current one with EPR(Extended Producers Responsibility). In this paper, suggested are alternative policies to improve the quality level of reverse logistics network for used mobile phones effectively. ENR(Extended Network service providers Responsibility) is representative of them.

• Journal of the military operations research society of Korea
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• v.28 no.1
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• pp.115-135
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• 2002

The limits of current DN(Defense networks), private and closed network, become to reality; for Example, high expense of construction and maintenance of networks, restriction of new subscribers on DN. Therefore, a network using web environment that reflect fast development of If and IS(Information Security) technology is demanded for MND. Meeting the requirement of reliable IS system and extension and improvement of DN using common network, we can reduce the expense to extend, maintain, repair DN, form the environment that makes military business cooperate better with civil company and government agency, advance implementing Defense computing and networking service for field small size units that was a exception of Defense digitalization. But it is essential to construct DN based on common network that there are security requisites; confidentiality, integrity, availability, efficiency, log, backup, restoration, that have to be realized at demanding level for IS. This thesis suggested four measurements; replacement DN with common network to resolve the requirements of building new network and improvement of performance for private DN, linkage with common network for new requirement, distribution of traffic using common network, configuration of DN using Internet and Proposed a refinement of IS management organization to treat security threat of common network flexibly, and LAN IS standard model of DN based on the web environment.

• 한국경영정보학회:학술대회논문집
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• 2007.11a
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• pp.453-459
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• 2007

The mobile telecommunication sector is increasingly gathering way becoming a key area for the economic development in Uzbekistan. One way to promote competition among providers is the introduction of a number portability service. This paper estimates subscriber's willingness to pay (WTP) for the MNP service in the mobile communication market in Uzbekistan. Consumer valuation was estimated using a conjoint analysis. Since number portability had not been introduced at the time of the study, stated preference data from the conjoint survey was used. Results indicate that currently subscribers do not attach a lot of importance to the MNP service, while price and service quality are most valuable components. The results of this study provide important implication for mobile network operators and policy developers on potential MNP implementation.

• Korean Management Science Review
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• v.26 no.1
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• pp.21-35
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• 2009

There is a controversy on Internet pricing, flat-rate vs. usage-based. This study gives a comparative analysis between flat-rate and two-part tariff which is realistic alternative of usage-based pricing. In a basic economic model, two-part tariff based on ISP's cost structure satisfies allocative efficiency and relatively expand the number of subscribers. But the characteristics of Internet service like consumers' uncertainty on cost, measurement cost of traffic and network externality induce increase of cost or decrease of marginal utility. The analysis shows that small impact of these can make flat-rate more efficient.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.4
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• pp.249-262
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• 2009

HSDPA(High Speed Downlink Packet Access) service has begun nationwide network service since the year 2007 and will be leading technology in mobile service technologies in domestic. But the ARPU(Average Revenue Per Use) from HSDPA has not increased, despite of increasing in subscribers with HSDPA service. It's important to understand why the incresing subscriber with hsdp didn't cause the increasing of its usage. The purpose of this study is to examine factors affecting the intention to adopt and to use HSDPA which refer to the new 3.5 generation communication service, and we are to analyze the relation between the two intentions based on previous studies about technology acceptance.

• Electronics and Telecommunications Trends
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• v.34 no.3
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• pp.106-113
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• 2019

Mobile traffic is one of the most important indexes of the growth of the mobile communications market, and it has a close relationship with subscribers' service usage patterns, frequency demand and supply, network management, and information communication policy. The purpose of this paper is to understand mobile data usage in Korea and to suggest the optimal steps for establishing the frequency supply and demand system by researching the traffic trends that reflect the characteristics of radio resources in the mobile communications field. To achieve this goal, attempts were made to increase the possibility of policy use by analyzing and forecasting mobile traffic trends, and to improve the accuracy of the research through the verification of the existing prediction results. The paper ends with a discussion of the necessity of a frequency management system based on data science.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.3B
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• pp.314-324
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• 2004

Recently, high-speed internet subscribers have grown continuously, and reached up to 10 millions. But existing network management that is responsible only for user access is confronted with many difficulties, since user access network(xDSL, Cable, B-WILL, and so on) has diversified and value added wired/wireless contents service has developed. In this paper propose the Agent based Inter Networking platform as object-oriented hierarchical system that can provide various service such as access QoS(Quality of Service), customized application service and security service according to user on demand. This system has divided into two parts(user agent and agent management system ＆ local and central management systems). Management system periodically receive status information such as bandwidth, download speed, delay, current service, and so on, and process them, then build a policy based on processed information. According to personal user profile that is generated by this policy, the customized service can be provided for users. And This system adopt the object-oriented modeling in case that system migration and integration, and implement a system that is robust and stable for security through hierarchical server system.