• ETRI Journal
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• v.32 no.2
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• pp.241-247
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• 2010

We propose and experimentally demonstrate a service-aware optical transport system. The proposed service-aware optical transport system makes a flow based on service type and priority of traffic. The generated flow is mapped to a corresponding sub-${\lambda}$ for transport over an optical network. Using sub-${\lambda}$ provided by the centralized control plane, we could effectively provide quality-of-service guaranteed Ethernet service and best-effort service simultaneously in a single link. The committed information rate (CIR) traffic and best-effort traffic are assigned to different sub-${\lambda}s$. The bandwidth of the CIR traffic is guaranteed without being affected by violation traffic because the bandwidth is managed per each sub-${\lambda}$. The failure detection time and restoration time from a link failure is measured to be about 60 ${\mu}s$ and 22 ms, respectively, in the ring network. The measured restoration time is much smaller than the 50 ms industry requirement for real-time services. The fast restoration time allows the proposed service-aware optical transport system to offer high availability and reliability which is a requirement for transport networks.

• International Journal of Contents
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• v.2 no.2
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• pp.10-16
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• 2006

In this paper, we propose a predictive resource metric region (RMR) based radio resource metric estimation (RRME) mechanism, which utilizes a resource metric mapping function (RMMF), both of which permit efficient inter-working between the physical layer and higher layers for envisaging multimedia service applications over a CDMA communication system platform. The RMR can provide the acceptable resource region where QoS and acceptable link quality can be guaranteed with an achievable resource margin to be utilized in terms of capacity margin, the degree of confidence (DCL) of user, second-order statistics of Eb/Io. With predicted capacity margin and variance, DCL can deliver decision parameters with which an adaptive QoS based admission control can perform well taking capacity and resource availability into account in a dynamic and predictive manner. Combined with advanced techniques such as adaptive modulation or rate control and power control, the proposed mechanism can adjust the conventional stringent link quality information efficiently, and deliver accurate information of the resource availability. Thus, these can guarantee the maximization of resource utilization of multimedia service applications.

• Journal of the Korea Society of Computer and Information
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• v.13 no.5
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• pp.247-253
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• 2008

Web 2.0 and Semantic Web technology will be merged to be a next generation Web that leads presentation-oriented Web to data-centric Web. In the next generation Web. semantic processing. Web Platform, and data fusion are most important technology factors. Resolving the Link Rot is the one of the essential technologies to enable these features. The Link Rot causes not only simple annoyances to users but also more serious problems including data integrity. loss of knowledge. breach of service. and so forth. We have suggested a new XRI-based persistent Web link architecture to cure the Link Rot that has been considered as a deep-seated Problem of the Web. The Proposed architecture is based on the XRI suggested by OASIS and it is designed to support a persistent link by using URL rewriting. Since the architecture is designed as a server-side technology, it is superior to existing research especially in Interoperability. Transparency and Adoptability. In addition to this, the architecture provides a metadata identification to be used fer context-aware link resolution.

• Journal of Korea Technology Innovation Society
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• v.1 no.1
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• pp.69-82
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• 1998

As a new medium for knowledge diffusion, E-Journal is expected to be a general type of scholarly communication. However, the techno - economic problems have hindered the advancement of the E-Journal. For the technical aspects, there are problems such as the standardization of document format, automatization of the document preparation, forward and backward link between documents. Also there are necessities for the support of the information infrastructure of digital library and information superhighway. For the economic domain, reengineering of total publishing cycle is considered and the new paradigm of peer review is analyzed. We pointed out that the main difficulties in the diffusion of E-Journal are on the promotion of service and technological advance, not the price and marketing strategy.

• Journal of Information Processing Systems
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• v.13 no.3
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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 information and communication convergence engineering
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• v.14 no.1
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• pp.21-25
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• 2016

N-screen is a promising technology to improve support for multimedia multicasting, content sharing, content mobility, media scalability, and seamless mobility. In this paper, the WiMedia distributed-MAC (D-MAC) protocol is adopted for development of a seamless N-screen wireless service. Furthermore, to provide a multi-hop, one source multi-use N-screen service through point to point streaming in a seamless D-MAC protocol, a dynamic multi-frame transmission technology is proposed. In this technology, a dynamic time slot allocation scheme and a multi-hop resource reservation scheme are combined. In the proposed dynamic time slot allocation scheme, two thresholds, a hard threshold and a soft threshold, are included to satisfy the power consumption and delay requirements. A multi-frame DRP reservation scheme is proposed to minimize end-to-end delay during the multi-hop transmissions between N-screen devices. The proposed dynamic multi-frame transmission scheme enhances N-screen performance in terms of the multi-hop link establishment success rate and link establishment time compared to the conventional WiMedia D-MAC system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.10B
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• pp.841-848
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• 2004

In case of failure in the IP network services should be provided via a backup path which fully meets QoS requirements. In this regard, we in this paper suggest simple-PFC(5-PFC) to restore single link failure, iterative-PFC(i-PFC) for multiple link failures, and fault_node Avoidance-PFC(a-PFC) for failures of nodes such as routers. Taking the minimum cost rerouting problem into account, we compare and analyze performance of those three mechanisms carrying out Direct_destination Rerouting(DR).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.9A
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• pp.2165-2172
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• 1998

Existing premises telecommucation wiring ad been installed for efficient telephone service. But premises wiring is currently ready to be reused as media for wideband digital services and Fiber-to-the-curb architecture. Electrical properties of premises wiring link have not characateized above frequencies for voice service. Accurte measurement of these characteristics are exssential for studies fof wideband ditital transmission system. On the other hand, the transmission qualities of premises wiring have been known to be worst in telecommunications access networks. So the knowledge of premises wiring sturucture as well as electrical properties is needed to improve the performance of premises wiring. In this paper, the structure of premises wiring is described in detail and electrical characteristics (characteristic impedance, SRL, attnuation, NEXT) about premises cables and stelecommucations link of representative apartment complex sare measured and naalyzed ove r16MHz range which is UTP Cat3 bandwidth.

• Journal of Korean Library and Information Science Society
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• v.46 no.1
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• pp.115-133
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• 2015

This study investigates the contents of twitters serviced by metropolitans and citizens' questions to propose improvements. Using content analysis as a research method, this study recorded and analyzed all the tweets of six metropolitans (Seoul, Busan, Daegu, Incheon, Daejeon, Gwangju) for three months. As the results, the frequency analysis of tweets revealed that Busan posted more tweets than other cities, and Seoul posted the highest number of tweet using URL link. The results of content analysis showed that the most frequently provided information from tweeters was about convenience of citizens living. Tweets using URL link were focused on information about citizen living, prize contest, and service announcement. Citizens had a request for information about their life and traffic. For public information service using tweeter in the future, this study provided several important suggestions.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.129-132
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• 1999

In this Paper, new congention control schemes using the adaptive rate control for ATM LANs are presented. If is preferable for hosts in LANs to be able to send bursts at the same speed as the interface link speed in a lightly loaded condition, and as the network load increases, to reduce their traffic rate adaptively in order to avaid network congestion. We propose to apply such a rate control concept for two different traffic classed in the ATM LANs. For the first traffic class requiring no bandwidth reservation, i.e, a best effort service class, a combination of the end-to-end adaptive peak rate control with the link-by-link backpressure control is proposed. For the second traffic class, requiring the bandwidth reservation for the burst transmission, i.e. guaranteed burst service class, a combination of he adaptive peak rate control with the fast bandwidth reservation is proposed.