• Journal of Korea Multimedia Society
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• v.11 no.12
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• pp.1688-1696
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• 2008

We propose a hierarchical service management method using Bloom filters for large MANETs. In this paper, a MANET is comprised of logical grid hierarchy, and each mobile node within the lowest service region multicasts the Attenuated Bloom Filter (ABF) for services itself to other nodes within the region. To advertise and discovery a service efficiently, the server node of the lowest server region sends the Summary Bloom Filter (SBF) for the ABFs to the server node of upper server region. Each upper server has the set of SBFs for lower vicinity service regions. The traffic load of the proposed method is evaluated by an analytical model, and is compared with that of two alternative advertisement solutions: complete advertisement and no advertisement. As a result, we identify that the traffic load of the proposed method is much lower than that of two alternative advertisement solutions.

• Journal of the Korea Society of Computer and Information
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• v.25 no.9
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• pp.91-100
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• 2020

This paper presents an evaluation framework for prototyping multimedia streaming services including audio and video in a distributed and/or decentralized storage that can evaluate service quality and performance under various network conditions. The evaluation framework focuses on important indicators which measure and improve service quality by applying decentralized storage to multimedia streaming services that can mimic the scalability of the existing server-client software architecture and the issue of a single point of failure. The integrated framework not only measures performance indicators for evaluating the quality and performance of multimedia streaming on open source based multimedia content streaming services, but also adjusts network quality using network virtualization technology for comprehensive evaluations. The experimental results show that the integrated framework has low overhead in building and operating a decentralized storage with multimedia streaming services on a single host computer which validates the scalability of the developed framework.

• Journal of the HCI Society of Korea
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• v.1 no.2
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• pp.59-64
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• 2006

This paper describes UPnP AV System which provides various multimedia services in home network composed of diverse multimedia devices. It is difficult to build home network where various multimedia services can be provided because there are a lot of difference devices, platforms, and network technologies. However, UPnP middleware can make up multimedia service environment in that home network. Therefore this paper describes how the multimedia service environment is built with UPnP middleware. We analyze and modify MediaServer, MediaRenderer, and Control Point, which these are the components of UPnP AV archtecture. Additionally we provide some efficient GUI to use different kind of multimedia in any place of home networks. We propose UPnP AV Framework of playback module that consist of MediaServer providing contents, MediaRenderer using contents, and Control Point providing GUI. Especially, MediaRenderer and Control Point are integrated in set-top.

• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.326-329
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• 2004

Content adaptation is an effective solution to support the quality of service over multimedia services over heterogeneous environments. This paper deals with the accuracy and the real-time requirement, two important issues in making decision on content adaptation. From our previous problem formulation, we propose an optimal algorithm and a fast approximation based on the Viterbi algorithm of dynamic programming. Through extensive experiments, we show that the proposed algorithms can enable accurate adaptation decisions, and especially they can support the real-time processing.

• Journal of Korea Multimedia Society
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• v.23 no.10
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• pp.1258-1269
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• 2020

The IoT(Internet of Things) service provides users with valuable services by collecting and analyzing data using Internet-connected IoT devices. Currently, IoT service platforms are accomplished by using edge computing to reduce the delay time required to collect data from IoT devices. However, if a user moves to another network with IoT device, the connection will be lost and IoT service will be suspended. To solve this problem, we proposes a service that automatically roaming IoT service when IoT device makes move. IoT roaming service provides a device automatic tracking management technique designed to continue receiving IoT services even if users move to other networks. To check if the proposed roaming service was effective, we implemented IoT roaming service and measured the data transfer time while move between networks along with devices while using IoT service. As a result, the average data transfer time was 124.62ms, and the average service interrupt time was 812.12ms. with this result, we can assume that the user could feel service interruption time very shortly and it will not affect the service experience. with IoT roaming service, we expect that it will present a method that stably providing IoT services even if user moves networks.

• Journal of the Korea Computer Industry Society
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• v.3 no.9
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• pp.1223-1234
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• 2002

RTP payload must be encrypted for providing commercial VOD service or private video conference over the Internet. Encryption/decryption delay is minimized because there are constraints in transporting a multimedia data through the Internet. Therefore, encryption algorithm is changed with considering network traffic md load. During many users participate in the same multimedia service, an user who already left the service can receive and decrypt the RTP payload because of knowing the encryption key. In this paper, Security Control Protocol for RTP is designed and implemented for changing the encryption algorithm and the key.

• ETRI Journal
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• v.26 no.4
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• pp.367-370
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• 2004

A new transmission system is necessary for the Digital Multimedia Broadcasting (DMB) service in Korea. Therefore, in this paper, we propose a new architecture for the implementation of a DMB transmission system based on Eureka-147. We describe the design and implementation of the Ensemble remultiplexer, which is essential to the proposed system for remultiplexing ETI frames and MPEG-2 transport streams. The proposed system provides a solution with high flexibility and low cost for multimedia broadcasting service. The functions of this transmission system have been verified by using our DMB receiver and other related systems.

• 한국정보통신설비학회:학술대회논문집
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• 2004.08a
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• pp.81-85
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• 2004

내용기반 질의법 (Content-based Query Method)은 멀티미디어 데이터가 가지고 있는 고유의 특성을 검색의 단서로 하여 질의하는 방법이다. 따라서 이러한 내용 기반의 디지털 오디오 콘텐츠 시스템은 유저가 데이터베이스 내에서 찾고자 하는 오디오 관련 정보의 질의 방법으로써 그 노래의 멜로디 정보를 입력함으로써 이루어지게 된다. 본 논문에서는 가수명이나 노래 제목, 혹은 가사의 일부 등 기존의 음악 검색에 필수적인 텍스트 정보인 키워드를 전혀 모르는 상태에서, 휴대폰이나 컴퓨터의 마이크를 통해 자신이 기억하고 있는 노래의 일부분을 흥얼거리는 것만으로, 각종 오디오 정보를 손쉽게 찾아주는 내용기반 질의법을 이용한 디지털오디오 검색시스템 (MuseFinder)을 소개한다. 또한 실제 유저의 편이성을 고려한 GUI에 기초한 고성능의 검색시스템을 구현하는데 있어 주요 이슈와 고려사항에 대해서 살펴보고 그 해결 방법을 제안한다.

• Journal of Korea Multimedia Society
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• v.3 no.6
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• pp.643-651
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• 2000

ATM network technology is generally used for the integration of multimedia services in high-speed Internet. ABR (Available Bit Rate) and UBR (Unspecified Bit Rate) service classes have been developed specifically to support data application. In this paper, through the result of simulation, we analyzed the effect of TCP data transmission performance by using FRR (Fast Retransmission and Recovery) and Nagle's Algorithm on the UBR service, and by adjusting EFCI switch parameter on the ABR service. As a result of our study, performance improvement of TCP over ATM network is observed by adjusting TCP parameters and setting of effective switch parameter.

• Journal of Korea Multimedia Society
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• v.20 no.7
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• pp.1030-1037
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• 2017

Traffic flows of real-time multimedia services such as Internet phone and IPTV are bounded on the end-to-end delay. Packets violating their delay limits will be dropped at a router because of not useful anymore. Service providers promise the quality of their providing services in terms of SLA(Service Level Agreement), and they, especially, have to guarantee the packet loss rates listed in the SLA. This paper is about a method to guarantee the required packet loss rate of each traffic flow keeping the high network resource utilization as well. In details, it assures the required loss rate by adjusting adaptively the timestamps of packets of the flow according to the difference between the required and measured loss rates in the lossy Weighted Fair Queuing(WFQ) scheduler. The proposed method is expected to be highly applicable because of assuring the packet loss rates regardless of the fluctuations of offered traffic load in terms of quality of services and statistical characteristics.