• Journal of Broadcast Engineering
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• v.15 no.4
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• pp.555-562
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• 2010

After starting digital terrestrial broadcasting, there have been a number oftrials to provide new services like data broadcasting on a spare bandwidth of a DTV channel. Recently, the Push-VOD service, which provides A/V contents on that bandwidth, gets more attention and is being standardized as NRT(Non-Real-Time) by ATSC. However, it is highly probable that the contents transmitted in this way contain many errors due to the DTV receiving environment. Thus, in order to improve the reliability of transmission, the contents should be transmitted repeatedly several times, considering the unidirectional property of DTV terrestrial network. In this paper, we propose a method to calculate the optimal number of repetitions to transmit each contents in a way that minimizes the number of errors occured, when trying to transmit several contents to the receiver in a restricted time, using Markov-chain modeling and dynamic programming approach.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.545-549
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• 2002

For the efficient method for acquisition of informations suitable to user's preferences and objectives in distributed environment, various researches on push agent which automatically processes its roles and sends the results to users are continued. The existing push agent models have induced increasing network overheads and traffics by continuous transmission of informations in the network environment of limitative bandwidth. In this paper, for the solution of the problems on these existing push agent systems and their interoperability, we design a push agent model based on CORBA event service. The proposed model solves the above problems and provides the retrieved results which are more suitable for user's requirement more fast and stably through the optimal path searching and controling method. And, it also supports the filtering technique for processing the duplicated or useless data that comes from the various distributed information systems.

• Journal of Korea Multimedia Society
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• v.4 no.3
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• pp.205-214
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• 2001

As the real time multimedia data service has become available due to the rapid progress of computer and Internet technology, the users can enjoy the newly developed service, which is called Video On-Dem-and(VOD). However, most of service providers have not paid their attention much on the software for various service modes on VOD, but they are only concentrating un the hardware to provide with the high resolution video display. Therefore, the service providers are recently to pay more attention on the software to cope with the various demands of users than hardware. So this paper has designed and implemented the VOD service system for those demands. Since the VOD service system suggested by this paper enable off-line search functions through E-mail, the users can possibly get the necessary information from off-line Search without connecting to the server while the current VOD service can prominently help users to save the time and effort to sea고 and select the Video contents by using periodical current awareness service supported by PUSH technology and user oriented information booking and feedback service supported by SDI service.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3B
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• pp.503-516
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• 2010

In this paper, we propose the converged profile and authentication scheme for supporting converged media services of broadcasting & communications convergence in fixed mobile convergence networks. The proposed scheme supports the management of access, service, mobility and IPTV profiles on subscriber and a function of open API(Application Program Interface) for providing the subscriber profile for the third party service provider with the PUSH/PULL method. The open API is based on a web service and a REST(Representational State Transfer) and provides various services for the third party service provider with ease. In addition, the proposed scheme supports a function of SSO(Single Sign-on). After user succeeded in establishing an access connection, user can sustain the same authentication state with this function although connected access network is changed or IMS(IP Multimedia Subsystem) service network is attached. We evaluate and analyze the performance of the proposed scheme through the implementation of CUPS(Converged User Profile Server) system test-bed.

• The KIPS Transactions:PartD
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• v.11D no.1
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• pp.105-114
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• 2004

In this paper, we propose a collaboration method of diverse agents each others in multi-agent model and describe a node migration algorithm of Mobile-Agent (MA) using by the metadata of Naming-Agent (NA). Collaboration work of multi-agent assures stability of agent system and provides reliability of information retrieval on the distributed environment. NA, an important part of multi-agent, identifies each agents and series the unique name of each agents, and each agent references the specified object using by its name. Also, NA integrates and manages naming service by agents classification such as Client-Push-Agent (CPA), Server-Push-Agent (SPA), and System-Monitoring-Agent (SMA) based on its characteristic. And, NA provides the location list of mobile nodes to specified MA. Therefore, when MA does move through the nodes, it is needed to improve the efficiency of node migration by specified priority according to hit_count, hit_ratio, node processing and network traffic time. Therefore, in this paper, for the integrated naming service, we design Naming Agent and show the structure of metadata which constructed with fields such as hit_count, hit_ratio, total_count of documents, and so on. And, this paper presents the flow of creation and updating of metadata and the method of node migration with hit_count through the collaboration of multi-agent.

• Journal of KIISE
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• v.43 no.10
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• pp.1094-1103
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• 2016

Physical Web and Eddystone can be serviced by a single integrated application on the device by using their servers' URL. However, they have a limitation that their servers must be customized for service characteristics on a case by case basis. In other words, regardless of the service selected for BLE, it should have a modified linkage application for each device. Hence, we think that a new integrated service platform, which is able to link and support its Beacon from the central server and is also able to support its application, is needed for achieving better service quality. This platform consists of push (Broadcasting for Beacon service) parts and pull (Connection) parts to establish communication. Especially, Pull should be operated and controlled under the authorization (secure) management for safe and trustable communication. It means that BLE must have its new authorization communications protocol to protect its data as much as possible. In this paper, we propose a BLE integrated authorization protocol for a BLE device control server based on Physical Web and Eddystone.

• Journal of Information Technology Services
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• v.16 no.1
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• pp.99-118
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• 2017

Growing importance of online security on certification, many of the web-related security technology introduced day by day. Especially, using smart certificate (USIM) is recognized as one of the most safe and convenient method for the security of public certificate. The purpose of this study is to find the factors that affect the Intention of switching to smart certificate for the general public who use public certificate service. Based on migration theory, this study determined the relationship between pull factors, push factors and mooring factors which can affect the intention of switching to smart certificate. To empirically analyze the proposed hypothesis, the statistical analysis were conducted based on the response from 350 public certificate service users using SPSS 22.0 and Smart PLS 2.0. The results of this study can be summarized as follows. First, system quality, one of the pull factors has positive influence on perceived ease of use. On the other hand, the other pull factor, service quality has positive influence on both perceived ease of use and perceived usefulness. Second, push factors, user experience and information security awareness have positive influence on perceived ease of use only. Third, mooring factor, switching cost does not have influence on switching intention while perceived usefulness has positive influence on. The results of this research can be used for whom has interest to the switching intention of public certificate service for online security and provide the proper understanding about smart certificate service mechanism.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.766-767
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• 2015

In recent days, mart or department which have large parking lots provide service for finding parked cars using NFC and GPS technology. In case using NFC, users should directly tap NFC tag, and GPS does not work inside the parking garage. In this paper, garage parking indicator system using becoan served push notification is described. By using this system, users can automatically be aware where they parked car when they enter into the huge parking lot. This system overcomes the weakness of the existing parking indicator systems, such as using NFC tag system and using GPS system.

• Journal of Digital Convergence
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• v.10 no.11
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• pp.419-425
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• 2012

In these days, the trends of home networking system is implementation of easily configured system with home security of emergency alarm and visitor verification services. In this paper, we implemented push server system based on Arduino of open source physical computation platform to verify visitors for the homes without home networking services. In the suggested system, visitor verification is performed in and out of home, and home access security of the system could be constructed with low-cost price by use of windows push server system and smart devices with alarm operation in corresponding to not allowed access trying.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.5
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• pp.344-354
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• 2013

In this paper, In order to solve the traffic of the SNS to be executed on smartphone, we propose the design of the SNS integrated gateway server. Also, we capture the payload size in a variety of methods to send the MQTT protocol and QoS level of MQTT protocol for communication between the client and the Gateway. And we present the results and analysis of packet loss and end-to-end delay. By using analysis proposed, we present the results of the integrated SNS Gateway push notification protocol design.