• Journal of information and communication convergence engineering
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• v.4 no.2
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• pp.58-61
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• 2006

A key issue toward mobile multimedia communications is to create technologies for broadband signal transmission that can support high quality services. Such a broadband mobile communications system should be able to overcome severe distortion caused by timevarying multi-path fading channel, while providing high spectral efficiency and low power consumption. For these reasons, an adaptive suboptimum decision feedback equalizer (DFE) for the single-carrier shortburst transmissions system is considered as one of the feasible solutions. For the performance improvement of the system with the short-burst format including the short training sequence, in this paper, the multiple-training least mean square (MTLMS) based DFE scheme with soft decision feedback is proposed and its performance is investigated in mobile wireless channels throughout computer simulation.

• Asia-Pacific Journal of Business
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• v.3 no.2
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• pp.16-22
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• 2012

Korean mobile telecommunications market is shifting from 2G to 3G service. Considering the revenue of voice-based communication has reached its maximum, 3G services can provide telecommunication companies with the opportunity to increase their revenues. As the competition in the market is becoming fierce, mobile carriers are trying to increase their profits by preventing their customers from switching to rivals. In this regard, managing customer can be a key success factor of the mobile telecommunications business by retaining existing customer. In this research, we tried to develop and test a model that aids further understanding of the determinants of continuance intention to use the current 3G service. We conducted empirical study through the analysis of 3G service users' data in Korea. The results indicated that continuance intention to use the current 3G is dependent on the customer's satisfaction with the service quality, handset, and brand image. We hope that analysis results will have significant implications in terms of both practical and theoretical aspects.

• Journal of Family Resource Management and Policy Review
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• v.10 no.3
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• pp.23-43
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• 2006

The purpose of this study is to identify the types of consumer problems involving the use of online game services in Korea. This study analyzed the consumer damage cases by age and type that were reported to the Korea Consumer Protection Board (KCPB). The results of this study are as follows: The online game complaints varied by age. In the case of children, most complaints involved phone charging online game fees without parents' consent. There were similarities in the victimization of teens and children according to reason for complaint, handling result and type of damage. However, based on method of charging, mobile phone and credit card payments were causes in the case of teen victimization. Meanwhile, complaints among adults showed more complexity than the previous two groups such as cases relating to online game companies illegally seizing game items and game accounts, and charging fees for unused services caused by identity theft. By type of charging method, most complaints involved phone and mobile phone payments. According to the analysis result of online game victims, the monetary damage of consumers did not differ among socio-demographic variables such as age, residence, gender and occupation but there was difference in the method of charging. In the handling period, differences could be seen by age, year, gender and type of damage.

• Journal of the Korea Computer Industry Society
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• v.5 no.9
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• pp.1101-1110
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• 2004

In the first quarter of 2004, there were about 1 billion 348 million mobile phone users worldwide with a penetration rate of only 29%. Korea ranks among the highest in the use of mobile communication, having over 36 million mobile phone subscribers with a mobile phone penetration rate of 75% as of May 2004. Since the introduction of wireless Internet service in May 1999, the number of subscribers rose to 34.5 million with 95.3% of the total mobile phone subscribers using wireless Internet services in May 2004, largely due to continued investments by telecommunication service providers, improvement of mobile handsets (color and digital camera phones) and implementation of policies on mobile number portability. In the Korean wireless Internet market, there are many user complaints since the service providers are competing with each other through TV commercial sales and phone discounts rather than improving their call quality, services and billing systems. therefore there is a growing need to improve the billing systems through means such as the implementation of reasonable payment plans according to consumer use, development of a wireless Internet billing system that can predict the number of users and establishment of pricing standards for controlled data (head, tail, etc...) as well as menu information by testing the texts. multimedia, video and other types of content provided by the three major mobile communication companies. The purpose of this study is to promote wireless Internet services and protect user rights by proposing a reasonable way to improve the billing systems for wireless Internet services after conducting a comparative analysis of file size and billing data of each of the service providers through a verification test on a packet billing system for wireless Internet services.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.663-666
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• 2009

The usage of fixed call services and public payphones decreased due to the mobile services became general communications tools and the new VoIP services are emerging. Public phone services are included in the scope of universal services and the prices of services is low and the services are easy to access anywhere. However the telecommunication markets are changed then the loss of public payphone services gets worse and the importance of public payphone have decreased. This paper reviewed the universal services regulations of public payphones in overseas countries and proposed the implications of improving the universal service regulations for public payphones.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10a
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• pp.282-284
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• 1998

차세대 무선 이동통신인 IMT-2000(International Mobile Telecommunication 2000)의 고유 서비스들 중 하나인 글러벌 로밍 서비스는 전 세계의 단일 표준안에 따라서 서로다른 IMT-2000훼밀리 멤버들 간에 로밍을 가능하게 한다는 개념이다. 본 논문에서는 글로벌 로밍의 네트워크 측면의 기능들 중에서 이동성과 밀접한 관련이 있는 위치 정보관리 서비스와 위치 정보 관리 기능을 정의하였다. 본 연구의 결과는 상용화를 앞에 두고 있는 IMT-2000 망의 운용자가 효율적인 글로벌 로밍 서비스를 제공할수 있게 하는 망 관리 수단의 기반이 될 것이다.

• Journal of the Korean Operations Research and Management Science Society
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• v.32 no.1
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• pp.105-124
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• 2007

CRM (Customer Relationship Management) becomes a crucial paradigm as the environment of the market changes. About the CRM actively maintaining and managing customers that have been already acquired, the research has been done as a plan to lure loyal customers who bring lucrative profits in the long term for the company in order to increase the value to the customers. However, in practice, the focus is on putting spurs to attracting new customers in a short term rather than retaining existing customers who give profitable revenues. If the company puts high emphasis on drawing the new customers, in a CRM's point of view in relation to the value of the customers, it can incur a loss in the long run. The reason is that if the firm conducts discriminative sales promotion, the existing clients with high loyalty will feel relatively treated inappropriately and they will have negative feelings such as being betrayed from the company they prefer. This occurrence of negative emotion can in-crease the possibility of highly profitable clients' secession. In consequence, this paper focusing on the process of the client segmentation at the mobile telecommunication services shows that the sales promotion strategy for the new customer attraction can lead to negative effect on the loyalty of the existing customers.

• Journal of the Korean Professional Engineers Association
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• v.27 no.1
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• pp.5-12
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• 1994

In the high degree information society of the 21st century, along with the social activity becoming much more closer, our life style will also be very much changed. Recognition for obtaining various informations rapidly will be anticipated to enhance and the progress of a mobile communication system is greatly expected. This will enable the system to give and receive ″whenever, wherever, whomever, whatsever information.″ In our country, the car telephone and personal mobile communication services of radio calling etc. are diversified by the telecommunication system reformation and by the introduction of competive principle of the hereafter of 1988. Moreover, in accordance with the tariff, the number of subscrier is rapidly increasing. On the other hand, on the utility side of business, for the realization of a mobile communication which is abundant in functional nature, not only the hitherto voice but also non voice system of data communication is being introduced. The Ministry of Communications of Korea has been expediting the effective utilization of limited frequency band of qusai microwave band etc. as a concrete measures for an ever increasing demand. At the same time, to disseminate and promote a mobile communication most effectively, convenience, economic, and safety nature of the system, and in addition to these, international standardization is considered. For constitution of a new mobile communication, the Ministry has been promoting various policies designed for the digitalization of system, utility extention for home. personal level.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.8 no.2
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• pp.72-77
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• 2009

A number of new DTV technologies have been introduced to provide crystal clear picture and enhanced sound. HDTV, in particular has four times resolution of conventional TV along with 16:9 aspect ratio. Also the introduction of the new technologies offered a valuable basis for character graphics which was only an assistant method to deliver visual images effectively. Various sizes of displays for different applications such as high definition TV and mobile multimedia services have created demands for additional features of character graphics including proper letter fonts, colors, moving effects as much. This article analyzes in what way the visual elements above can affect uses' visual perception. New CG formats designed for OSMU, one source multi use, are also suggested available to each media. For the research three groups of CG designers, art directors and productions/distribution groups are established according to production process by two Delphi surveys of TV production staff.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.525-528
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• 2009

This paper attempts to conceptually examine the potential of IPTV(Internet Protocol Television). First, this paper reviews the concept of a bridging telecommunication service and a gap-filling telecommunications service. Second, the current status of various emerging telecommunications services including mobile WiMax, called WiBro, and both satellite and terrestrial digital multimedia broadcasting service, called DMB are comprehensively analyzed. Based on those analysis, this paper analyzes whether IPTV is regared as a bridging telecommunications service or a gap-filling telecommunications service and examine the potential growth possibility of IPTV. Finally, the suggestions for policy makers are discussed.