• Journal of KIISE:Computer Systems and Theory
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• v.31 no.7
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• pp.387-396
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• 2004

In this paper, we propose an algorithm that distributes processor time to the tasks decoding encoded frames with a goal maximizing total QoS (quality of services) of video conference system. An encoded frame has such a characteristic that the QoS of recovered frame image also increases as the processor time given for decoding the frame gets to increase. Thus, the quality of decoded image for each frame can be represented as a QoS function of the amount of service time given to decode. In addition, every stream of video conference has close time-dependency between continuous frames belonging to the same stream. Based on the time-dependency and QoS functions, we propose an on-line frame scheduling algorithm which does not schedule all frames in the system but just a few frames while maximizing total QoS of video streams in the conference. The simulation results show that, as the system load gets to increase, the proposed algorithm compared to the existing EDF algorithm can reduce the quality of decoded frame images more smoothly and show the movements of conference attendees more naturally without short cutting.

• Journal of Scientific & Technological Knowledge Infrastructure
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• s.4
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• pp.80-93
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• 2001

본 고에서는 멀티미디어 서비스를 위한 인터넷 QoS(Quality of Service) 기술요소를 살펴보았다. 즉 Intserv/RSVP 기반의 플로우 단위의 품질보장기술, Diffserv에 의한 CoS(class of service) 기술, SBM과 같은 대역폭관리기술 등을 살펴보고 이들 요소기술이 조합된 예를 살펴보았다. 또한 차세대 인터넷에서의 SLS(Service Level Specification)를 고찰했다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1998.05a
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• pp.282-287
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• 1998

최근 인터넷에서는 Mbone, 인터넷 폰과 같이 End-to-End QoS (Quality of Service) 보장을 요구하는 많은 실시간 멀티미디어 응용들이 출현하고 있다[1]. 인터넷 표준 기구인 IETF (Internet Engineering Task Force)에서는 과거 수년간, 이러한 실시간 멀티미디어 응용들을 지원하기 위한 Integrated Service 구조를 개발하고 자원 예약 프로토콜로서 RSVP (Resource Reservation Protocol)를 개발하였다. 하지만, flow를 기본 단위로 하여 자원을 예약하고 패킷을 처리하는 Integrated Service 모델은 인터넷에 광역적으로 구축되기에는 너무 복잡한 것으로 드러났다. 이에 따라, 큰 규모의 인터넷 전달망에 적용할 경우 scalability 문제를 안고 있는 Integrated Service 모델의 대안 또는 보완책으로, Differentiated Service 구조가 작년부터 IETF에서 활발히 논의되어 왔다. [2,3,4]. 본 논문에서는 Differentiated Service의 구조 및 구성요소의 개념을 살펴보고, RSVP/Integrated Service 구조와 어떻게 공존하여 광역 인터넷에서 End-to-End QoS를 제공할 수 있을지를 고찰한 다음, 향후 기술 발전을 전망한다.

• International Journal of Computer Science & Network Security
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• v.21 no.4
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• pp.115-122
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• 2021

In the recent past enormous enterprise applications have migrated into the cloud computing (CC). The researchers have contributed to this ever growing technology and as a result several innovations strengthened to offer the quality of service (QoS) as per the demand of the customer. It was treated that management of resources as the major challenge to offer the QoS while focusing on the trade-offs among the performance, availability, reliability and the cost. Apart from these regular key focuses to meet the QoS other key issues in CC are data integrity, privacy, transparency, security and legal aspects (DIPTSL). This paper aims to carry out the literature survey by reflecting on the prior art of the work with regard to QoS in CC and possible implementation of block chain to implement decentralised CC solutions governing DIPTSL as an integral part of QoS.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.129-132
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• 2003

In this paper, we propose the DQM - CBRP( Distributed QoS Monitoring - Cluster Based Routing Protocol ) routing protocol to provide Quality of Service guarantee for multimedia service in Ad hoc mobile network. This paper proves the DQM-CBRP can avoid message loss and is suitable to guarantee of QoS thru simulation of COMNET III.

• Journal of Communications and Networks
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• v.15 no.6
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• pp.614-634
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• 2013

The proliferation of real-time multimedia services requires huge amounts of data transactions demanding strict quality-of-service (QoS) guarantees. Multicast transmission is a promising technique because of its efficient network resource utilization. However, high head-of-line (HOL) blocking probability and lack of service-specific QoS control should be addressed for practical implementations of multicast networks. In this paper, a topology aware fanout set division (TAFD) scheme is proposed to resolve these problems. The proposed scheme is composed of two techniques that reduce HOL blocking probability and expedite packet delivery for large-delay branches regarding multicast tree topology. Since management of global topology information is not necessary, scalability of the proposed scheme is guaranteed. Mathematical analysis investigates effects of the proposed scheme and derives optimal operational parameters. The evaluation results show that the TAFD scheme achieves significant delay reduction and satisfies required delay bounds on various multicast networks.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.775-777
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• 2004

본 논문은 다수의 DiffServ(Differentiated Service) 도메인을 지나가는 Assured Forwarding(AF) 서비스 클래스의 종단간 QoS(Quality of Service)툴 향상시키는 새로운 Marking Mechanism을 제안한다. 기본적인 개념은 패킷들이 최초 DiffServ 도메인으로 들어갈 때 부여받은 Marking 정보를 종단까지 유지하고, 이 정보를 근간으로 Marking을 수행하여 종단간 QoS를 보장받도록 해주는 것이다.

• IE interfaces
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• v.12 no.4
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• pp.496-505
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• 1999

Quality of Service(QoS) is the collective effect of service performances and has a direct impact on customer satisfaction. Although QoS is subjective, network performance parameters contributing to QoS can be measured physically. Therefore overall customer satisfaction for each test condition of the performance parameters is evaluated by asking respondents to indicate his or her opinion on a five-category rating scale i.e., excellent, good, fair, poor, and unsatisfactory. The opinion data resulting from the test can then be used to measure and analyze QoS from the customers' viewpoints. In this papaer, we consider two methods for analyzing the opinion data: MOS method and Cumulative Probability Curve method. The former evaluates an arithmetic mean of the opinion scores which quantify the surveyed opinions of respondents. The latter uses graphical and analytical models which are based on the distribution of the opinions rather than an arithmetic mean. The advantages, disadvantages, and an alternative of each method are discussed, together with future directions of research.

• Journal of Communications and Networks
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• v.8 no.4
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• pp.410-421
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• 2006

In this work, we propose an analytic framework for dimensioning the link capacity of broadband access networks which provide universal broadband access services to a diverse kind of customers such as patient and impatient customers. The proposed framework takes into account the flow-level quality of service (QoS) of a connection as well as the packet-level QoS, via which a simple and systematic provisioning and operation of the network are provided. To that purpose, we first discuss the necessity of flow-aware network dimensioning by reviewing the networking technologies of the current and future access network. Next, we propose an analytic model for dimensioning the link capacity for an access node of broadband convergence networks which takes into account both the flow and packet level QoS requirements. By carrying out extensive numerical experiment for the proposed model assuming typical parameters that represent real network environment, the validity of the proposed method is assessed.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.3-6
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• 1998

This paper considers the analysis of QoS(Quality of Service) routing mechanisms to support the NGIs(Next Generation Internets). NGIs are constructing high-speed IP layer networks to support all data services. To support real time multimedia services on NGIs, it is important to satisfy the required QoS parameters on networks. To support QoS requirements for NGI networks, new QoS routing methods are essential. In this paper, serveral new QoS routing algorithms are explained. Some problems for the high speed QoS routing will be explained and possible solutions are suggested.