• Journal of Korean Institute of Industrial Engineers
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• v.34 no.2
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• pp.205-215
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• 2008

convergence networks (BcN). The problem seeks to minimize the total cost of switch and cable while satisfying the requirement of demand and quality of service (QoS). We develop mixed integer programming models to obtain the optimal switch location of the access network. We develop a Tabu Search (TS) heuristic algorithm for finding a good feasible solution within a reasonable time limit. We propose real networks with up to 25 nodes and 180 demands. In order to demonstrate the effectiveness of the proposed algorithm, we generate lower bounds from nonlinear QoS relaxation problem. Computational results show that the proposed heuristic algorithm provides upper bounds within 5% optimality gap in 10 seconds.

• Journal of Korea Multimedia Society
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• v.11 no.3
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• pp.341-352
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• 2008

The dedicated line linked up with the internet maintains generally the efficiency of network by using Best Effort Model. But it is the problem that we allocate the higher bandwidth to services which request high bandwidth regardless of service types or purposes. To overcome this weak point, we use the Session QoS System which distinguish between business services such as E-mail, Web, etc. and non-business services. But, a recent session QoS system is not adequate to the environment similar to university, because that has many users who have various requests. In this paper, to satisfy various requirements of many user's in session QoS system which support services of research, education, business, etc., we analyze types of service in the environment of education and research network and propose a necessity of management strategies of session Qos system.

• Journal of the Korea Society of Computer and Information
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• v.18 no.2
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• pp.59-68
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• 2013

Efficient resource management and hand-over schemes are necessary to maintain consistent QoS because it may be severely defected by some delay and information loss during hand-over in LTE-Advanced networks. This paper proposes a resource management scheme based on the load control to support consistent QoS for heterogeneous services during hand-over in OFDMA based systems. Various multimedia services with different requirements for resource are able to be serviced simultaneously because service continuity can be provided by our proposed scheme. Simulation results show that it provides better performances than the conventional one with the measure of hand-over failure rate and packet loss rate.

• Annual Conference of KIPS
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• 2000.10b
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• pp.1617-1620
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• 2000

최근 다양한 멀티미디어 서비스와 스트림 서비스의 급증과 사용자의 서비스 기대 증가로 인해 기존의 컴퓨팅 환경도 인터넷 기반의 분산 멀티미디어 환경으로 변화되고 있다. 이러한 다양한 요구를 만족시키기 위해서는 인터넷 환경과 실시간 특성들이 혼합된 폭넓은 범위의 분산 애플리케이션을 지원해야 하고, 이들 서비스간의 QoS(Quality of Service)를 보장해야 한다. 이를 위해 본 논문에서는 분산환경인 CORBA기반에서 자원들의 효과적인 관리와 서비스들간의 QoS를 보장하는 분산 QoS 관리 구조를 제시한다 즉, 클라이언트 측에 QoS 제어 관리 모들(QoS Control Management Module)을, 서버측에는 QoS 관리 모듈(QoS Management Module)을 각각 분산시켜 QoS 관리 및 제어를 분산 구조화함으로써 서버 시스템의 부하를 줄이고, 분산 서비스 응용에 지원을 확장할 수 있도록 하며 모듈들의 재사용이 가능하도록 하였다. 또한 분산 QoS 제어를 위해 실시간 협약(Negotiation) 및 동적 적응(Dynamic Adaptation)과정이 분산환경에서 수행되도록 기능 설계를 하였다. 이들 기능수행의 전반과정을 UML(Unified Modeling Lang uage)을 이용하여 순차적 다이어그램으로 기술하였다.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.2
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• pp.193-204
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• 2010

Since Wireless Multimedia Sensor Network(WMSN) needs to process various multimedia data such as audio, image and video data as well as scalar data, it requires a mechanism that can support Quality of Service(QoS) to handle efficiently. This paper classifies traffic in WMSN as periodic monitoring traffic, event traffic, multimedia traffic and query-based traffic, proposes marking algorithm and queue management mechanism that guarantee differentiated QoS in terms of delay, energy efficiency and credibility on each traffic and conduct performance analysis with simulation.

• Proceedings of the Korea Multimedia Society Conference
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• 2000.11a
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• pp.323-326
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• 2000

시간에 의존적인 대용량의 멀티미디어 데이터를 다양한 네트웍 환경에 맞도록 전송하는 방법이 다양하게 연구되고 있다. 또한 멀티미디어 데이터를 실시간으로 전송하기 위한 프로토콜로 RTP(Real-time Transport Protocol)을 적용하여 하고 있으며, 다양한 상태의 네트웍을 통한 전송에 대한 피드백(feedback) 정보인 RTCP(Real-time Transport Control Protocol) 정보를 이용하여 QoS(Quality of Service)를 관리하는 메커니즘이 연구되고 있다. 본 논문에서는 RTP/RTCP 기반의 실시간 멀티미디어 데이터 전송을 위하여 멀티캐스팅(multicasting) 환경 하에서 각기 다른 대역 폭에 대한 동적인 QoS 관리 플랫폼을 제안한다.

• Journal of Information Technology Applications and Management
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• v.12 no.3
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• pp.129-150
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• 2005

Due to the advance of the Internet, the electronic commerce is getting more widely used, and customer's demand for the e-Commerce service quality is rapidly increasing. On the other hand, e-Commerce companies required the Internet services whose quality is provided more reliable service to their customers. Therefore, it is very important to provide both e-Commerce companies and customers with the measurement and service quality in real-life network environment. But the research on the service quality measurement method for electronic commerce systems has been limited because ISP and e-Commerce providers seldom disclose detailed service measures such as, where and how much service delay incurred. In this paper, we construct sample e-Commerce systems and try to measure the service quality of the systems in real network environment. We have analyzed the delay zones and causes using a measurement tool. We must reflect the improvement method against delay causes. Accordingly, the customers can be experiences the better service quality. We hope that this research will be the groundwork for future research on the service quality of various types of e-Commerce systems and online services.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.10B
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• pp.613-620
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• 2007

Recently, due to the developing of broadband convergence networks, the high quality multimedia services which are converged with communication and broadcasting can be provided. These high quality communication and broadcasting convergence service needs reliable multicasting mechanism in IP networks. However, multicasting mechanism recently deployed is difficult to guarantee the end-to-end QoS. For the reliable high quality If multimedia IPTV service, the QoS guaranteed multicasting mechanism should be provided. Therefore, we proposed a probing packet based multicasting admission control mechanism using centralized multicasting control management block in this paper. And for the performance evaluation of the proposed mechanism, we used ns-2 simulator.

• Journal of Communications and Networks
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• v.9 no.4
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• pp.511-523
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• 2007

In broadband convergence network(BcN), heterogeneous broadband wired & wireless subnetworks and various terminal equipments will be interconnected. In order to provide end-to-end realtime multimedia services on such heterogeneous networking environment, as a result, two major problems should be resolved: i) Multimedia session establishment & negotiation that adjusts the differences in the capability of multimedia data processing at the end terminal nodes, ii) quality of service(QoS)-guaranteed connection establishment or resource reservation with connection admission control(CAC) in each heterogeneous subnetworks along the path. The session layer signaling(e.g., SIP/SDP) should be extended for QoS negotiation, and must be tightly cooperating with network layer signaling or resource reservation with CAC function. In this paper we propose a session and connection management architecture for the QoS-guaranteed realtime multimedia service provisioning on BcN, with Q-SIP/SDP, resource reservation protocol with traffic engineering extension, and CAC functions. The detailed interaction scenario and related algorithms for QoS-guaranteed realtime multimedia session, resource reservation and connection establishment are explained and analyzed. From the experimental implementation of the proposed scheme on a small scale BcN testbed, we verified that the proposed architecture is applicable for the realtime multimedia service provisioning. We analyze the network performance and QoS parameters in detail.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.11
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• pp.3030-3049
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• 2023

With the development and wide application of hybrid network computing modes like cloud computing, edge computing and fog computing, the customer service requests and the collaborative optimization of various computing resources face huge challenges. Considering the characteristics of network environment resources, the optimized deployment of service resources is a feasible solution. So, in this paper, the optimal goals for deploying service resources are customer experience and service cost. The focus is on the system impact of deploying services on load, fault tolerance, service cost, and quality of service (QoS). Therefore, the alternate node filtering algorithm (ANF) and the adjustment factor of cost matrix are proposed in this paper to enhance the system service performance without changing the minimum total service cost, and corresponding theoretical proof has been provided. In addition, for improving the fault tolerance of system, the alternate node preference factor and algorithm (ANP) are presented, which can effectively reduce the probability of data copy loss, based on which an improved cost-efficient replica deployment strategy named ICERD is given. Finally, by simulating the random occurrence of cloud node failures in the experiments and comparing the ICERD strategy with representative strategies, it has been validated that the ICERD strategy proposed in this paper not only effectively reduces customer access latency, meets customers' QoS requests, and improves system service quality, but also maintains the load balancing of the entire system, reduces service cost, enhances system fault tolerance, which further confirm the effectiveness and reliability of the ICERD strategy.