• Journal of Korea Multimedia Society
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• v.10 no.2
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• pp.278-287
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• 2007

Even though a variety of types of multimedia data are being used on the basis of user characteristics and demands, all devices do not always support playing all multimedia data. Accordingly, a multimedia transcoder is used to create media suitable for each environments. This is due to the dissimilarity between the source QoS and the target QoS. Therefore, we need to consider adapting the two dissimilar QoS. Therefore in this paper, we create a suitable application-specific transcoding path with unit transcoders before performing the media transcoding in consideration of source QoS and target QoS. and the created transcoding path performs the transcoding. Here, creating a UTR(Unit Transcoder) conversion path that considers the transcoding possibility and the minimum of the UTR will allow the playback of various multimedia data with convenience. and The consideration of QoS allows users to use the multimedia easily.

• The KIPS Transactions:PartC
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• v.9C no.5
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• pp.757-764
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• 2002

This Paper describes our experiences with the design and implementation of a networked multimedia information management system in an object-oriented framework for distributed multimedia applications, and an integrated QoS-resource negotiation protocol which has been applied to a video server in our networked multimedia infrastructure. The salient features of our framework to support efficient multimedia streaming are explained. Next the paper explores the challenges faced in integrating the proposed QoS negotiation policy into the framework.

• The Journal of the Korea Contents Association
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• v.10 no.4
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• pp.45-54
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• 2010

In this paper, we propose a quality interworking control system to enhance user's quality satisfaction in NGN environment by controling QoS parameters related with QoE in network layer when service user's QoE using variance multimedia service is poor. The proposed system gathers QoS parameter information in network layer through control packet such as RTCP, and evaluates QoE of multimedia service using these QoS parameter information. Comparing the evaluated QoE with the measured QoE in application layer, QCS judges quality degradation, deduces related QoS parameters and decides relative importance of each parameter when QoE is lower than threshold value. QCS generates QoS control values which is based on routing and switching policy in service quality control system(SCS) and forwards them to SCS. Through this proposed system, service and network providers can provide multimedia services of enhanced quality to service users taking account of service characteristic and network performance.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.96-99
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• 2003

현재 블루투스(Bluetooth) 표준(Specification)에서는 QoS 지원에 대해 L2CAP, LMP 계층(Layer)에서의 QoS 지원 파라미터(parameter)와 협상(Negotiation) 순서에 대해서만 정의되어 있다. 본 논문에서는 블루투스 기기간의 통신시 QoS를 지원하기 위해 현재 블루투스 표준에 정의되어 있는 요소들을 기반으로 한 새로운 QoS 제어 메커니즘(Control Mechanism)을 제안한다.

• Journal of Digital Contents Society
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• v.3 no.1
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• pp.101-111
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• 2002

Lately development of network around Internet expands range of data traffic to multimedia information, and so for the guarantee of multimedia services end-to-end QoS(Quality of Service) must service because comparing with existing Internet service can not support For satisfying those QoS requirements, network have to guarantee not only network on parameter, such as delay, jitter, throughput but also system resources like CPU utilization, memory usage. Therefore it is urgent to develop QoS based middleware to distribute multimedia data and maximize network utilization in the limited resource environment. And it must be necessary of network to provide end-to-end QoS(Quality of Service) for multimedia applications. Multimedia applications want that QoS which satisfy their own service properties be guaranteed Then, We must analyze those necessary QoS requirements md define QoS parameter which specify as two viewpoint, user's and network's perspective. Therefore network provider supplying network for usual user and university, enterprise must want to find about their own network performance and problem. It is essential for network manager to want to use a tool like this. On the basis of technique about QoS test-bed in the AIM network, We studied on the method of QoS measurement and management about end-to-end connection in the Internet. We measured network status about end-to-end connection and analyze the result of performance.

• Convergence Security Journal
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• v.7 no.1
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• pp.77-82
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• 2007

Supporting Quality of Service (QoS) for multimedia services in heterogeneous mobile networks is a part of key issue for Beyond Three Generation (B3G) development. In particular, if QoS degradation are occurred because cell overload and error late patterns of wireless links during the transmission of multimedia data, the efficient QoS management is necessary to maintain the same QoS of transmitted multimedia data because the QoS may be defected by some delay and information loss. This paper deals with QoS Degradation reason Intra-System Handover (D-ISHO) for handling QoS of multimedia services over heterogeneous mobile networks. For this aim, the function modules for supporting QoS of D-ISHO are proposed. The sequence diagram showing interaction between the modules is described and then a scenario for D-ISHO is considered. Simulation is focused on the average delay and packet loss rate. The proposed heterogeneous mobile system using the QoS-Guaranteed Resource Management (QGRM) provides a better performance than each different access system.

• Journal of Korea Multimedia Society
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• v.11 no.5
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• pp.673-684
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• 2008

In this paper, we propose a signaling protocol which can support QoS for multimedia applications continuously after handover of a mobile node in the network environment where IP-based wireless access networks co-exist. Since existing RSVP-based signaling protocols can cause the waste of network resources due to double reservation and do not provide fast resource reservation/release, they are not suitable for mobile networks. The proposed QoS signaling protocol can support QoS for multimedia applications using the fast reservation of necessary resources after handover and avoid the waste of resources by resolving the double reservation problem. This paper presents design and implementation architectures of the proposed signaling protocol and analyzes its performance via a physical testbed. Based on the analysis results, it was shown that the proposed protocol is able to support seamless QoS for multimedia applications.

• Proceedings of the Korea Multimedia Society Conference
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• 2000.11a
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• pp.41-44
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• 2000

분산 멀티미디어 시스템은 이식성을 보장하고 동적인 자원 변화를 수용하고 올바른 시간에 올바른 데이터 인도를 보장해야 한다. 따라서 분산 멀티미디어 시스템의 각 구성 요소들은 멀티미디어 응용에서 QoS(Quality of Service)를 제공하기 위한 자원 관리 기법과 다양한 종류의 QoS 요구를 수용할 수 있어야 한다. 본 연구에서 가변 전송율을 갖는 비디오에 대한 여러 종류의 QoS 요구를 만족하기 위한 비디오 배치 및 검색 방법을 제안한다. 제안된 방법은 여러 종류의 해상도 요구에서 개선된 성능을 보였다.

• Journal of Korea Multimedia Society
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• v.6 no.2
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• pp.208-215
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• 2003

For playing a multimedia presentation in a Internet, the case that the presentation QoS(Quality of Services) at a destination nay be different from the QoS of multimedia data at the source occurs frequently. In this case, the process of trancoding the multimedia data at the source Into the multimedia data satisfying the QoS at the destination should be requited. In addition, even the presentation description having the homogeneous QoS at both sides may have different transcoding paths due to the limitation of display terminals or network bandwidth. That is, for a multimedia description, it is required to regenerate a proper transcoding path whenever the displaying terminals or the network environment gets decided. And the delay time required to go through the transcoding path may affect the playability of the give presentation. Therefore it should be checked whether the presentation requiring a transcoding process is able to be played in a real time. In this paper, the algorithm for generating all the possible transcoding paths for a given multimedia description under a fixed set of transcoders and the network environment is proposed. The algorithm adopts the concept of QoS transition diagram to Prevent from a trancoding Path being cycled by the repetition of a cyclic Path which generates the same QoS of multimedia data as its input QoS. By eliminating all the cyclic Paths, the algorithm can guarantee the termination of the process. And for the playability check, a method of computing the transcoding time and the delay lime between logical data units are proposed.Finally all the proposed methods were implemented in the stream engine, called TransCore and the presentation-authoring tool, called VIP, we had developed. And the test results with sample scenarios were presented at the last.

• The KIPS Transactions:PartA
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• v.15A no.2
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• pp.101-110
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• 2008

Ubiquitous computing has extended the computer system into the whole physical space and has ushered the emergence of more dynamic distributed systems. This environment require unique QoS parameters for various devices, resources and user requirements. In this paper, we propose a new hybrid QoS management model which defines a static-dynamic QoS parameter that is more appropriate to the ubiquitous computing environment. This model consists of the QoS Control Management Module(QoS CMM) in the client side and the Resource QoS Management Module (RQoS MM) in the server side. The RQoS MM deals with the static QoS parameters and the whole QoS control of the distributed control(QoS CMM) in order to minimize server load in cases of multiple communication. Finally, we present the experimental result of our location based application using a graphical user interface that shows the multimedia service execution of selected client device types such as desktop PC, notebook and PDA.