• 한국정보시스템학회지:정보시스템연구
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• 제24권1호
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• pp.67-94
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• 2015

Recently, the popularity of Social Network Service (SNS) along with the spread of smart phone, personal computer and tablet PC helps personal network to construct new forms of services in cyberspace. As such, SNS plays a significant role in constructing diverse online networks and there is a growing interest on SNS at societal level. In this vein, the purpose of the research was to find the factors affecting the continuance intention to use social network services. The major findings are summarized as follows. First, "System Quality", "Contents Quality", "Personal Innovativeness", "Self-Efficiency", "Honor Benefit" has significant effects on "Relationship Quality". Yet, "Economic Benefit" is not statistically significant on "Relationship Quality". Second, "Relationship Quality" has a significant effect on "Continuous Usage Intention". Last, our research discovered the relationship between exogenous variables which would serve as valuable inputs in the development of strategic guideline and plan for SNS companies and related services.

• 한국멀티미디어학회논문지
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• 제16권1호
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• pp.50-55
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• 2013

This article presents a simple and reasonable in-service, real-time, and continuous single-ended objective video quality assessment model for DTV broadcasting using a multiburst signal at the bottom of the transient effect area, similar to Vertical Interval Test Signals. The issue of in-service video-quality monitoring in DTV broadcasting is addressed, and an effective method of quality monitoring is presented. The proposed method is also implemented and tested in a range of situations using a simulated HDTV broadcasting network.

• 한국산학기술학회논문지
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• 제12권9호
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• pp.4125-4132
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• 2011

IPTV 멀티캐스팅 서비스에서 증가되는 네트워크 트래픽 로드에 따른 화상 품질 측정과 화상 품질 변화에 대한 연구는 IPTV 서비스에 대한 관심이 현실화됨에 따라 필요하게 되었다. 본 연구에서는 네트워크 트래픽 로드에 따른 화상 품질의 효과가 주어지는 네트워크 성능 요소의 최적의 값을 파악하기 위하여, 테스트 베드 네트워크를 통하여 테스트 하는 S/W를 개발하였다. 그리고 테스트 환경을 학교 네트워크로 확장하여 실제 IPTV 서비스 환경과 비슷한 학교 네트워크에서 네트워크 트래픽 로드 증가에 따른 IPTV 멀티캐스팅 서비스의 화상 품질 변화를 측정하고자 하였다.

• The Journal of the Acoustical Society of Korea
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• 제28권2E호
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• pp.35-42
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• 2009

In this paper, we present criteria of objective measurement of speech quality to provide the mobile-VoIP services efficiently over wireless mobile internet. The mobile-VoIP service, which is based on mobility and is error-prone compared to conventional VoIP over wired network, is about to be launched, but there have not been adequate quality indexes and the Quality of Service (QoS) standards for evaluating speech quality of Mobile-VoIP. In addition, there are many factors influencing on the speech quality in packet network of which packet loss contribute directly to the overall voice communication quality. For this reason, we adopt the Gilbert-Elliot Channel Model for modeling packet network based on IP and assess the voice quality through the objective speech method of ITU-T P. 862 PESQ and ITU-T P. 862.1 MOS-LQO under various packet loss rates in the transmission channel environments. Our simulation results address the specific criteria and QoS for the mobile-VoIP services in terms of the various packet loss environments.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 추계종합학술대회
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• pp.150-153
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• 2001

현재의 인터넷은 Best-Effort 서비스만을 지원한다. 그러나 지난 몇 년 동안 인터넷 환경의 지속적인 발전으로 인해 Best-Effort 서비스의 한계를 넘어선 새로운 형태의 Application들이 등장하게 되었고, 이러한 Application들은 end-to-end간에 QoS(Quality of Services)보장 및 보안을 요구한다. 본 논문에서는 IETF에서 제안한 QoS 보장 기술중 하나인 Differentiated Services를 이용하여 end-to-end 간의 QoS보장 및 IP Security 적용한 가상사설망(VPN) 구현방안에 관해 연구하였다.

• 한국통신학회논문지
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• 제25권5B호
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• pp.850-858
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• 2000

최근 통신망의 규모가 커지고 대역폭이 증가됨에 따라서 통신망에 요구되는 신뢰도가 증가하게 되었다. 통신망에 있어서 대체 경로의 지정은 통신망의 장애 발생으로부터 통신망을 보호하는데 필수적이다. 본 논문에서는 다양한 서비스들이 가지는 상이한 트래픽 파라메터와 QoS(Quality of Service)를 제공하고 통신망의 관리를 용이하게 하기 위해서 동일한 물리매체 위에 ATM 베어러 서비스 유형(CBR, rt-VBR, nrt-VBR, ABR, UBR)에 따라 논리적으로 구분된 통신망을 구성한다. 또한 사용중인 노드 또는 링크에 장애가 발생했을 때, 보다 바른 자동복구를 위해서 대체경로를 이용한 자동북구 방법을 사용하고, TINA 기반의 장애관리 기능을 사용하여 초고속 통신망에 적합한 자동복구 방법을 제안한다.

• 대한안전경영과학회지
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• 제10권3호
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• pp.203-216
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• 2008

As the service quality measurement has been developed, various fields of service quality measurement have evolved. Especially the development of the mobile communication service and its status has been watched with keen interest. The growth of mobile communications has not developed alone. It evolved with the growth of the mobile communications company and the device manufacturer. This research investigates the mutual relation sand influence between the service quality and the device quality. This is a distinguished phenomenon within the existing research. Currently in Korea mobile devices can be purchased independently of network provider; however, there are also arrangements whereby the manufacturer supplies devices through only selected service providers. The model of service quality measurement is not a simple fragment model for the service quality anymore. It is required to establish the ultimate model for the service quality to determine if the customer differentiates between the device and service quality. Knowing if a customer differentiates between device and service can aid strong brands when deciding which partners to select for collaborative strategies. The aim of this research is to determine the significant difference between the models of service quality measurement based on differing levels of brand awareness.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권11호
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• pp.2764-2783
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• 2012

Network virtualization supports future Internet environments and cloud computing. Virtualization can mitigate many hardware restrictions and provide variable network topologies to support variable cloud services. Owing to several advantages such as low cost, high flexibility, and better manageability, virtualization has been widely adopted for use in network virtualization platforms. Among the many issues related to cloud computing, to achieve a suitable cloud service quality we specifically focus on network and performance isolation schemes, which ensure the integrity and QoS of each virtual cloud network. In this study, we suggest a virtual network platform that uses Xen-based virtualization, and implement multiple virtualized networks to provide variable cloud services on a physical network. In addition, we describe the isolation of virtual networks by assigning a different virtualized network ID (VLAN ID) to each network to ensure the integrity of the service contents. We also provide a method for efficiently isolating the performance of each virtual network in terms of network bandwidth. Our performance isolation method supports multiple virtual networks with different levels of service quality.

• 한국산업정보학회논문지
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• 제3권1호
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• pp.49-65
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• 1998

The trend toward globalization and competitive advantage is increasing the importance of international data communication . The more companies attempt to be globalized and competitive, the more critical the problems of the computer networks are. To improve computer networks in the business world, it is believed that the network shoud be approached from the viewpoint of service quality : we need to understand what network quality means to network users, those who use the network. The purpose of this study is to develop a dimension that captures the aspects of network quality that are important to network users. Many articles show that speed is very important factor in network systems. But the more important thing is that speed is just one of the factors contributing to network quality. It is suggested that a quality network meet nine dimensions : (1) speed (2) accessibility (3) connectivity (4) security (5) compatibility, (6) government restrictions (7) complexity (8) sustainability and (9) sharability.

• 품질경영학회지
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• 제18권1호
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• pp.21-28
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• 1990

In this paper, the capacity of system which provides the real time response call service to the customer is studied. The quality of call service depends on the response time of the service in the system. Therefore, the focus of this paper is to investigate the capacity of system under the restriction of response time. In this paper, the system is modeled by queueing network. The analytical method is applied to solve this queueing network. The solution of the model has product form solution. To get the reasonable capacities, nonlinear programming problem is formulated and is solved by GINO.