• 한국컴퓨터정보학회논문지
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• 제3권1호
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• pp.125-148
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• 1998

ATM망으로 유입되는 트래픽을 제어하는 리키버킷 알고리즘을 구현한 트래픽 성형 메카니즘의 사용으로 ATM망 자원의 이용율을 향상시킬 수 있고 사용자들이 요구하는ATM망의 서비스 품질을 보장할 수 있다. 리키버킷 알고리즘의 구현 트래픽 성형 메카니즘의 성능은 토큰풀 크기와 입력 큐 크기에 의해 좌우되어진다. 본 논문에서는 시뮬레이션을통해 이들 파라미터의 변화가 ATM망의 서비스 품질에 미치는 영향을 분석해 보고자 한다.

• 통상정보연구
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• 제10권4호
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• pp.125-151
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• 2008

Website service quality is widely accepted as one of the key determinants of online business success. Several studies identified key factors that determine the website service quality factors appropriate for online business environments. A convention and visitors bureau (CVB) website is a service portal that delivers information online about a destination so users can develop an overall image of the location. CVBs struggle to deliver positive destination images because the competition among destinations to host conventions is intense. In spite of the important role of CVBs and the beneficial spillover effect of CVBs, there are few studies available reporting on the unique service qualities of a CVB website. The primary purpose of this study was to examine the determining factors that are appropriate for CVB websites from the meeting planners' perspective. The research questions arc: What are the determining factors of service quality of a CVB website? Do the determining factors of CVB website service quality positively influence meeting planners' satisfaction? The new conceptual framework was developed from a variety of destination marketing and Internet marketing concepts: e-servicescape management, web community network, Internet service encounter management, and online system quality. Empirical results indicate that three of the four factors, that is, e-servicescape, web community network, and online system quality are important determinants in evaluating CVB website service quality. The findings also show that three determinants have significant and positive influence on meeting planners' satisfaction. The findings from this study will provide meaningful advice for CVB website quality management. To enhance the CVB website service quality and satisfaction level of meeting planners, these three determinants' should be considered of the utmost strategic importance and priority.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권8호
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• pp.2783-2804
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• 2021

In the network function virtualization environment, dynamic changes in network traffic will lead to the dynamic changes of service function chain resource demand, which entails timely dynamic adjustment of service function chain resource configuration. At present, most researches solve this problem through virtual network function migration and link rerouting, and there exist some problems such as long service interruption time, excessive network operation cost and high penalty. This paper proposes a dynamic adjustment method of service function chain resource configuration for the dynamic changes of network traffic. First, a dynamic adjustment request of service function chain is generated according to the prediction of network traffic. Second, a dynamic adjustment strategy of service function chain resource configuration is determined according to substrate network resources. Finally, the resource configuration of a service function chain is pre-adjusted according to the dynamic adjustment strategy. Virtual network functions combination and virtual machine reusing are fully considered in this process. The experimental results show that this method can reduce the influence of service function chain resource configuration dynamic adjustment on quality of service, reduce network operation cost and improve the revenue of service providers.

• 한국정밀공학회지
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• 제26권10호
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• pp.40-46
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• 2009

Recently CAN (Controller Area Network) is widely used as an in-vehicle networking protocol for intelligent vehicle. The identifier field (ID) of CAN is used not only to differentiate the messages but also to give different priorities to access the bus. This paper presents a dynamic 10 allocation algorithm in order to enhance the real-time quality-of-service (QoS) performance. When the network traffic is increased, this algorithm can allocate a network resource to lower priority message without degradation of the real-time QoS performance of higher priority message. In order to demonstrate the algorithm's feasibility, message transmission delays have been measured with and without the algorithm on an experimental network test bed.

• 대한전자공학회논문지TC
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• 제46권8호
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• pp.59-66
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• 2009

최근 국내 인터넷망의 개선과 TPS(Triple Play Service : 데이터+영상+음성) 서비스를 위한 가입자망의 고도화로 IPTV(Internet Protocol TV) 서비스의 품질에 대한 기대치가 급격히 높아지고 있다 따라서, 가입자의 실시간 동영상 품질을 보장할 수 있는 IPTV 서비스 품질에 대한 국내 품질 기준 및 국제 표준의 재정이 시급히 필요하다. 본 논문은 서비스 사업자 네트워크의 특성과 유사한 환경에서 시험하기 위해 방송/VoD(Video on demand)를 제공하는 헤드엔드 영역과 상용 네트워크 특성을 나타내는 트래픽/라우팅 부하 생성 장비와 네트워크 Impairment 장비 및 다수의 이기종 라우터를 포함하는 네트워크 영역과 가입자 셋탑박스 영역으로 테스트베드를 구축하였다. 그리고 구축된 환경을 이용하여 서비스 환경의 변화에 따른 품질 시험으로 IPTV 서비스의 품질기준 결정에 필요한 특성을 제시한다.

• 정보처리학회논문지C
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• 제16C권6호
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• pp.717-724
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• 2009

IPTV 서비스의 품질은 IPTV 서비스가 성공적으로 정착되기 위한 가장 중요한 요소라 할 수 있다. 본 논문에서는 IPTV 서비스가 전달되는 계층적인 구조에 있어서 각 계층을 대표하는 서비스 품질 지표들을 선정하고 이들 간의 상관관계를 분석한다. 이를 위하여 IPTV 서비스가 전달되는 과정을 최대한 실제와 가깝게 구현하기 위한 시험 네트워크를 구축하고 선정된 품질 지표들에 대한 반복적인 측정을 수행한다. 측정을 통한 분석 결과 네트워크 계층의 대표적인 서비스 품질 지표 가운데 패킷손실률이 지연이나 지터에 비해 IPTV 서비스의 비디오 품질에 더 큰 영향을 미친다는 점을 보인다.

• 한국콘텐츠학회논문지
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• 제13권8호
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• pp.371-385
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• 2013

대학 도서관의 지식문헌정보서비스는 대학 교육 및 교수의 연구를 지원하는 중요한 역할을 수행하고 있다. 이에 따라, 서비스 품질요소를 계층적 관점에서 정의하고 이들의 중요성을 분석함으로써 대학 도서관의 서비스를 개선하기 위한 연구들이 선행되어 왔다. 그러나 기존 연구들은 서비스 품질을 구성하는 하위요소들 간의 상호 영향관계, 그리고 서비스 이용자와 제공자 두 집단간의 서비스 품질요인에 대한 인식차를 파악하여 서비스를 개선하는 측면에서는 연구가 미흡한 실정이다. 따라서 본 연구는 SERVQUAL의 관점을 바탕으로 도서관 서비스를 구성하는 서비스 품질요소 간 상관관계를 네트워크 모델로 도출하고, Analytic Network Process를 활용하여 서비스 이용자와 제공자 집단간의 서비스 품질요소에 대한 인식차이를 도출, 분석하였다. 그 결과 제공자는 요소들을 비교적 균일하게 중요하게 인식하지만 이용자는 특정 몇 가지 요소들을 중요하게 인식하는 것을 확인하였다. 도서관 서비스 품질요소들간의 상관관계와 집단간의 인식차이를 파악하는 본 연구의 접근방법은 추후 대학 도서관의 지식문헌서비스 경쟁력 확보에 기여할 것으로 기대된다.

• Journal of Information Processing Systems
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• 제13권3호
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• pp.546-558
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• 2017

The amount of multimedia traffic over the Internet has been increasing because of the development of networks and mobile devices. Accordingly, studies on multicast, which is used to provide efficient multimedia and video services, have been conducted. In particular, studies on centralized multicast tree construction have attracted attention with the advent of software-defined networking. Among the centralized multicast tree construction algorithms, the group Takahashi and Matsuyama (GTM) algorithm is the most commonly used in multiple multicast tree construction. However, the GTM algorithm considers only the network-cost overhead when constructing multicast trees; it does not consider the temporary service disruption that arises from a link change for users receiving an existing service. Therefore, in this study, we propose a multiple multicast tree construction algorithm that can reduce network cost while avoiding considerable degradation of service quality to users. This is accomplished by considering both network-cost and link-change overhead of users. Experimental results reveal that, compared to the GTM algorithm, the proposed algorithm significantly improves the user-experienced quality of service by substantially reducing the number of linkchanged users while only slightly adding to the network-cost overhead.

• Journal of Communications and Networks
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• 제17권2호
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• pp.110-117
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• 2015

In mobile social network, it is a critical challenge to select an optimal set of devices to supply high quality service constantly under dynamic network topology and the limit of device capacity in mobile ad-hoc network (MANET). In this paper, a multi-devices composition and maintenance problem is proposed with ubiquitous service model and network model. In addition, a multi-devices composition and maintenance approach with dynamic planning is proposed to deal with this problem, consisting of service discovery, service composition, service monitor and service recover. At last, the simulation is implemented with OPNET and MATLAB and the result shows this mechanism is better applied to support complex ubiquitous service.

• 한국통신학회논문지
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• 제34권3B호
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• pp.225-234
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• 2009

Recently IPTV service is penetrating to the ordinary home users very swiftly. One of the first phase of IPTV service is considered to be VoD, and a nationwide availability of the VoD service imposes tremendous pressure to the network resource due to its requirements for the broad bandwidth, the inherent nature of unicast technology, and the large scalability, etc. This work suggests a novel and practical method to the design of network resource for the VoD service. Especially, we explore the distributed content storage problem that takes into account the popularity of the video contents and its corresponding link dimensioning problem that takes into account the grade of service for the flow level quality of service about the VoD service. By assuming a realistic topology for the nationwide IP backbone network of Korea, which is a typical tree topology, we suggest an analytic method for the design of VoD service.