• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.354-358
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• 2007

This article presents several methods of mobile communication network to access technologies utilizing unlicensed spectrum interworking. Generic Access Network (GAN) technology was already specified in GERAN (GSM EDGE Radio Access Network) and Interworking WLAN (I-WLAN) was standardized for WCDMA system for WLAN user to access WCDMA packet based services through WLAN access point. Voice Call Continuity is not access network dependent technology but is a kind of domain change scheme for voice call from Circuit Switching (CS) network to IP Multimedia Subsystem (IMS) and vice versa.

• Journal of Information Technology Applications and Management
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• v.22 no.2
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• pp.123-148
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• 2015

Today the mobile devices including smart phones have influenced on the users' daily activities in the mobile internet society, and the expansion of social media has also affected on the purchasing behavior of consumers. This study examines whether the quality of corporate twitter, a typical social network service for call centers influences on the customer satisfaction, and brand loyalty. In order to achieve the research goal, the quality of twitter has been divided into four variables; information quality, service quality, system quality, and social quality. The results of our empirical analysis show that the three variables except service quality have significantly influenced on the customer satisfaction and the customer satisfaction also significantly has a casual effect on the brand loyalty. The empirical results are expected as a guideline to contribute on the practical improvement of customer service, satisfaction, and brand loyalty through corporate social network services such as corporate twitters in the future.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.07a
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• pp.115-116
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• 2017

본 논문에서는 스포츠 경기장에서 응원 그룹 서비스를 제공하기 위한 사용자가 밀집된 그룹 통신을 위한 효율적인 CCN 멀티캐스트 라우팅 및 캐싱 기법을 사용한 스포츠 모바일 서비스 플랫폼과 모바일 응원 어플리케이션을 개발하였다. 응원 그룹 운영을 위해 CCN 코어 라우터는 경기 시작 전에 서비스 서버로부터 콘텐츠 이름, 데이터, 콘텐츠의 라이프타임이 포함된 경기 관련 콘텐츠를 전달받아, 경기가 시작되면 서비스한고, 경기가 끝나면 라이프타임 후에 삭제할 수 있도록 설계하였다.

• ETRI Journal
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• v.29 no.5
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• pp.569-595
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• 2007

Particularly in wireless communications, link errors severely affect the quality of the services due to the high error probability and the specific error characteristics (burst errors) in the radio access part of the network. In this work, we show that thorough analysis and appropriate modeling of radio-link error behavior are essential to evaluate and optimize higher layer protocols and services. They are also the basis for finding network-aware cross-layer processing algorithms which are capable of exploiting the specific properties of the link error statistics, such as predictability. This document presents the analysis of the radio link errors based on measurements in live Universal Mobile Telecommunication System (UMTS) radio access networks as well as new link error models originating from that analysis. It is shown that the knowledge of the specific link error characteristics leads to significant improvements in the quality of streamed video by applying the proposed novel network- and content-aware cross-layer scheduling algorithms. Although based on live UMTS network experience, many of the conclusions in this work are of general validity and are not limited to UMTS only.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.959-962
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• 2005

Recently, business integration and interoperability of between the heterogeneous applications are requested by rapid growth of web. Web Services that self-contained for platform and programming language is appeared used to XML of standard data format. Such amid Fast Web Services attract attention at fields necessary to bring rapid communication like Mobile and RFID. In this paper, we inquired about ASN.1 of ITU-T and IS0/IEC standard that a central role of data transform. And we studied encoding process of between ASN.1 and XML for transform SOAP massage of a massage transfer mode of Web Services to binary data.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.4
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• pp.357-367
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• 2005

According to the recent advancement of mobile computing technology and the hardware technology, the mobile device has rapidly come into wide use.'rho data in the central management server needs to confirm to that in mobile devices in order for the mobile device users to access the needed data regardless of time and place. This is called Data Synchronization. Currently, major mobile device manufacturing companies provide the data synchronization solutions, but these solutions are not compatible with other mobile devices/other applied services. In order to solve this problem, OMA(Open Mobile Alliance), mainly composed of mobile telecommunication companies, has suggested using the SyncML(Synchronization Markup Language) data synchronization method. This is an attempt to make a public standard. In this paper, the data synchronization client that synchronizes the PIMS (Personal Information Management System) data in mobile devices like PDA is developed, complying with the SyncML standard requirements.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.10
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• pp.1256-1262
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• 2016

As the population of camping is increased in campsites and auto camp sites, the electrical equipment can safely supply electricity to users in a variety of electricity bill policy is required in the campsite. In this paper, we develop the vending machine for electricity that can control the outdoor electrical outlet from the management server using the Z-Wave WPAN and android mobile application. The developed vending machine for electricity consists of the management server, the controller, the outdoor outlet box, and the mobile application. The management server provides reservation and electricity bill payment to users. The management server controls the electrical outlet box through the controller to safely supply electricity to users. The controller that is a relay device between the management server and the switch controls switches based on Z-Wave mesh network. Outdoor electrical outlet box has 2 meter switches. We receive the relevant authorization to provide commercial electricity services using the outdoor electrical outlet box in the campsite.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.581-584
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• 2006

Cellular phones have been popularized and some of them even have access to the Internet. But the utilization of mobile phones has not been for education but only focused on particular services due to the text-based low capacity. This thesis proposes a multimedia education system using cell phones with SMIL. We can decrease the size of the parser and refute the resources of CPU by designing SMIL tag only, which is needed for multimedia education. In addition, the macro method for producing information for lectures will make possible decreased transmission quantity of multimedia contents and increased transmission efficiency. This will lead to overcoming the matter of insufficient CPU and memory, which is common to most mobile phone terminals.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.321-324
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• 2018

Recently, the evolution of V2X (Vehicle to Everything) technology is accelerating. In particular, it can be seen that C-V2X (Cellular V2X) technology and services combined with mobile telecommunication network are developing rapidly. However, in Korea, e-Call and emergency communication services are inferior to the developed communication technologies and the proportion of vehicles arriving at Golden Hour is considerably low. Therefore, this paper designed the communication architecture with C-V2X and Android operating systems, and presented ways to improve existing e-Call services using V2N (Vehicle to Nomadic Device) communication based on it.

• Journal of Internet Computing and Services
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• v.24 no.2
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• pp.1-10
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• 2023

The Multi-access Edge Computing (MEC) paradigm equips network edge telecommunication infrastructure with cloud computing resources. It seeks to transform the edge into an IT services platform for hosting resource-intensive and delay-stringent services for mobile users, thereby significantly enhancing perceived service quality of experience. However, erratic user mobility impedes seamless service continuity as well as satisfying delay-stringent service requirements, especially as users roam farther away from the serving MEC resource, which deteriorates quality of experience. This work proposes a deep reinforcement learning based service mobility management approach for ensuring seamless migration of service instances along user mobility. The proposed approach focuses on the problem of selecting the optimal MEC resource to host services for high mobility users, thereby reducing service migration rejection rate and enhancing service availability. Efficacy of the proposed approach is confirmed through simulation experiments, where results show that on average, the proposed scheme reduces service delay by 8%, task computing time by 36%, and migration rejection rate by more than 90%, when comparing to a baseline scheme.