• Information and Communications Magazine
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• v.31 no.6
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• pp.3-11
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• 2014

Mobile operators today face yet another critical challenge as technology lifecycle becomes increasingly short and also as heterogeneous and complex network becomes exceedingly expensive and difficult to manage. With extremely competitive market and demanding users, the overall revenue structure is expected to get worse. A network architecture based on software-defined networking (SDN) and virtualization techniques gives operators greater opportunity to build cost-effective and efficient alternative to the legacy. In this work we review our Carrier Cloud as a future mobile network infrastructure that exploits both SDN and NFV in order to increase the operator agility, reduce the cost, and even disrupt the vendor landscape. This new architecture will not be fully adopted by the conservative operators at once. Technological hurdles have to be overcome, and a clear understanding of operational differences must be preceded.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.4 no.1
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• pp.23-29
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• 2005

This study is about designing mobile phone display in consideration of elder people's preferences by reason of their optical weakness. The research is closely connected with designing user-friendly interface by considering user characteristics. The criteria for first experiment are font sizes, font types, line spacing and background colors. With the experiment result, relative importance of each attribute and subjective preference are investigated by conjoint analysis. Secondly, an optimal display design for elder people is presented by response surface method on the basis of the result of conjoint analysis, other statistical analyses, and user interviews.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.402-405
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• 2006

Mobile IP has been designed to have mobile host users move from place to plate without changing their IP address. Ad-hoc network is a provisional network whose mobile host users construct networks by themselves without any assistance of infra structure network, using wireless interface. In this paper we discuss the scheme with which Ad-hoc network users ran access the Internet freely, using mobile IP protocol, and Ad-hot networks are access networks in the spotlight. In this paper we propose algorithm that support enhanced mobility between two Ad-hoc networks applying mobile IP at Ad-hoc routing protocol.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.146-151
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• 2008

새로운 사용자 경험의 향상을 위해 UI 의 개선방안을 모색할 때, 기존에 수행해 오던 일반적 사용성 평가 방법만으로는 모바일과 같이 복합적 컨텍스트를 가진 서비스 이용환경을 파악하는데 적지 않은 한계가 있다. 가령 특정 Task 수행시 Lead Time 측정과 같은 계량화된 사용성 평가방법을 통해서는 실제 사용자의 컨텍스트를 고려한 사용성의 수준(혹은 오류의 수준)에 대한 분석이 어려운 반면, In-depth Interview 로 대표되는 통상의 정성적인 사용자 리서치 방법은 장애의 요인과 결과간의 논리적인 상관관계를 명확화하거나 실측적인 개선 성과로써 도출해 내는데 어려움이 있다. 본 연구에서는 정량적인 사용성 평가방법에 정성적인 사용자 리서치 수행기법 및 통계적 기법을 결합하여, 실측 가능하고 설득력을 가진 근거 데이터를 지지하는 한편 한계로 남겨져 왔던 행위결과에 대한 요인에도 적절한 인사이트를 제시할 수 있는 대안적 사용성 평가 방법을 제시하고자 한다.

• Journal of Advanced Navigation Technology
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• v.12 no.6
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• pp.591-597
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• 2008

With the established voice service, the data service is increasing in the field of mobile telecommunications in these days. Also, the data service develops into the form of multimedia service which combines various media. However, it is limited to provide QoS(Quality of Service) for the multimedia using the established network which manages all the data in sam: rule. So, this paper suggests the network architecture which assures QoS of multimedia data by applying MPLS(Multi-Protocol Label Switching) to the core network. Especially, we analyze the efficiency of the network combining Mobile IP network based on the WLAN(Wireless LAN) and core network based on MPLS through by network simulations using QualNet.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.39-42
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• 2006

There are various analysis functions(including prediction of path loss, analyzing of capacity and coverage, etc.) of simulation tool to design and optimize the mobile communication network. Its reliability absolutely effects the performance of mobile communication network. Especially as the wireless network highly advancing focused on data service, it more needs to research and develop on the standard establishment of reliability of the simulation tool. Also it is important the systematic research how to improve the reliability of simulation tool. In this paper, to give the concrete process and skill about how to improve reliability, we define the kinds of reliability at first. And then we explain the comparison results between real field measurement data and theoretic simulation data.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.743-746
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• 2004

This study is generally purposed to develop a mobile augmentative and alternative communication system (hereinafter referred to as 'a mobile AAC system'). Also the device is aimed as a mobile AAC system for helping communication of persons who suffer from speech disorders in a free and convenient manner. One thing firstly considered for a successful AAC system is selection of vocabularies. For this purpose, the above researchers collected utterances in actual situations to select vocabularies of higher frequencies. For generation of sentences by maximizing the use of limited space in the AAC system, this study specifically presents a method of predicting predictions. This method includes selecting vocabulary and classifying it by domains so as to meet the characteristics of the mobile AAC communication, using a noun thesaurus for semantic analysis, and building a sub-category dictionary. Predicting predicates by selecting symbols in accordance with this method is tested and the utility thereof is confirmed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.6
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• pp.1191-1196
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• 2017

Lately, the three mobile telecom companies in Korea are competing for the launch of Internet of Things services for using home. Typical launched services are in the smart home related fields. However, Internet of Things as mobile telecom based are at an early stage, expected that various services will be started continuously. At this point, we have been planning to analyze the preference of Internet of Things for objects based on the services already launched. In order to apply the analytic hierarchy method, the first stage factors were designed as Safety, Security, Health care, Intelligence and Home appliances. In addition, the second stage factors were organized into 18 detailed services presented in the conceptual model. As a result, Health care (23.2%) was the most preferred priority. These results can be interpreted as the result of interest in health by improving income. We presented the theoretical and practical implications of these results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.140-143
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• 2017

Lately, the three mobile telecom companies in Korea are competing for the launch of internet of things services for using home. Typical launched services are in the smart home related fields. However, internet of things as mobile telecom based are at an early stage, expected that various services will be started continuously. At this point, we have been planning to analyze the preference of Internet of things for objects based on the services already launched. In order to apply the AHP (analytic hierarchy process) analysis method, the first stage factors were designed as safety, security, health care, intelligence and home appliances. In addition, the second stage factors were organized into 18 detailed services presented in the conceptual model. Thus, we present the theoretical and practical implications of these results.

• IE interfaces
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• v.17 no.spc
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• pp.111-121
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• 2004

In this paper, we propose an urgency and efficiency based wireless packet scheduling (UEPS) algorithm that is able to schedule real time (RT) and non-real time (NRT) traffics at the same time. The proposed UEPS algorithm is designed to support wireless downlink packet scheduling in the OFDMA system which is a strong candidate wireless system for the next generation mobile communications. The UEPS algorithm uses the time-utility function as a scheduling urgency factor and the relative status of the current channel to the average one as an efficiency indicator of radio resource usage. The design goal of the UEPS algorithm is to maximize throughput of NRT traffics with satisfying QoS requirements of RT traffics. The simulation study shows that the proposed UEPS algorithm is able to give better throughput performance than existing wireless packet scheduling algorithms such as proportional fair (PF) and modified-largest weighted delay first (M-LWDF) while satisfying QoS requirements of RT traffics such as the average delay and the packet loss rate under various traffic loads.