• The Journal of Information Systems
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• v.24 no.1
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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.

• Journal of Korea Multimedia Society
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• v.16 no.1
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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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.9
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• pp.4125-4132
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• 2011

The research of image quality estimation standard and the image quality change according to the network traffic load increase at IPTV multicasting service is necessary because the concern of IPTV(Internet Protocol TV) service become active recently. In the research, for finding out the threshold value of network performance elements giving the effect to the image quality according to the network traffic load, we developed S/W to operate the test bed network and make the test scenario through test bed network test and then we expand the test environment scope to the college network and try to measure the image quality change of IPTV multicasting service according to the network traffic load increase at the college network similar to the real IPTV service environment.

• The Journal of the Acoustical Society of Korea
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• v.28 no.2E
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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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.150-153
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• 2001

Today Internet is only Best-Effort service. During the past few years, new types of internet applications which require performance beyond the best-effort service that is provided by the current internet have emerged. These applications required QoS(Quality of Services) guarantee and Security between end-to-end. In this paper simulations Differentiated Services that IETF(Internet Engineering Task Forte) has proposed one of QoS(Quality of Services) guarantee VPN(Virtual private Network) using QoS(Quality of Services) guarantee and IP Security between end-to-end.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.5B
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• pp.850-858
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• 2000

Increased network reliability is required as the size of communication network becomes larger and the bandwidth requirement is increasing. And preparing of backup path is required to protect the network from serious network failures in high speed network. In this paper, we construct multiple logical networks on a physical ATM network according to the ATM bearer service category(CBR, rt-VBR, nrt-VBR, ABR, UBR) defined by ATM Forum to support the required QoS(Quality of Service) and to manage the network more efficiently. We use backup path restoration algorithm rather than dynamic restoration to achieve rapid restoration when active path fails and we use fault management function in TINA. We propose a restoration scheme that is suitable for high-speed network.

• Journal of the Korea Safety Management & Science
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• v.10 no.3
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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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• v.6 no.11
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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.

• Journal of Korea Society of Industrial Information Systems
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• v.3 no.1
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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.

• Journal of Korean Society for Quality Management
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• v.18 no.1
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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.