• Journal of Digital Contents Society
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• v.15 no.1
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• pp.87-91
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• 2014

This paper suggested a web based error manager for societal security service. This is a system that is suitable for detecting, sharing and recovering software error based on multimedia CSCW(Computer Supportes Cooperated Work). With error sharing system, a group cooperating users can share error applications. Our a web based error manager for societal security service enables user to share error objects through interaction awareness. This method has a file sharing, a window copy, a window overlay, or a window sharing. We implemented the web based error manager for societal security service so that the users participated in collaborative work may refer shared error objects as the same view to others.

• The KIPS Transactions:PartC
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• v.11C no.4
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• pp.419-428
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• 2004

Due to the deployment problem of the IP Multicast service, the Application Layer Multicast (or Overlay Multicast) has appeared as an alter-native of the If Multicast. However, even though plenty of the Application Layer Multicast (ALM) Protocols were designed and their applications were developed according to the diverse requirements of each multicast service, researches on the ALM Protocols are focused on only a protocol design or an efficient multicast group management algorithm. And there is little effort to provide a unified guideline for development of the ALM Protocols and provide an environment for running multiple protocols simultaneously in a system. In this paper, we propose socket APIs to be a reference in developing new ALM Protocols which enables a system to support multiple protocols in a system with other ALM Protocols and which gives an environment to support efficient protocol management.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.6 s.336
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• pp.9-16
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• 2005

In this paper, we focus on supporting the convergence of broadcasting and communication in home network systems with E-PON based home gateway. We propose a new architecture to provide broadcasting and data services in integrated home network using overlay transport mechanism in access network and If multicast techniques of IGMP and IGMP snooping in home network. We also detail a set of mechanisms and procedures for home broadcasting service through the home gateway system. Our new scheme is composed of three parts: a) an overlay transmission model of video broadcasting signals (satellite and/or cable TV) and Internet data, b) to select a specific video broadcasting channel and to make of the selected video broadcasting stream into IP multicast packets in tuner/conversion module using multiple tuner system and c) to transfer the converted If multicast packets to L2 switch of home gateway's core module and to send them out to target port(s) by L2 multicast using IGMP snooping.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.7
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• pp.630-642
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• 2013

To transmit vital signal stream of mobile patients remotely, it requires mobility of patient and watcher, sensing function of patient's abnormal symptom and self-organizing service binding of related computing resources. In the existing relative researches, the vital signal stream is transmitted as a centralized approach which exposure the single point of failure itself and incur data traffic to central server although it is localized service. Self-organizing middleware platform based on heterogenous overlay network is a middleware platform which can transmit real-time data from sensor device(including vital signal measure devices) to Smartphone, TV, PC and external system through overlay network applied self-organizing mechanism. It can transmit and save vital signal stream from sensor device autonomically without arbitration of management server and several receiving devices can simultaneously receive and display through interaction of nodes in real-time.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.10
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• pp.42-51
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• 1998

This paper suggests a congestion control scheme for CL (ConnectionLess) overlay network using the feedback loops between CL user and CL server, between CL servers, and between end-to-end CL users, and the header translation table of CL server. The CL overlay network for CBDS(Connectionless Broadhand Data Service) defined by ITU-T((International Telecommunication Union-Telecommunication) consists of CL servers which route frames and links which connect between CL user and CL server or between CL servers. In the CL overlay network, two kinds of congestion, CL link congestion and CL server congestion, may occur. We considered the schemes to solve the congestion. link-by-link method[18] has used the ABR feedback loops of ATM layer between CL user and CL server or between CL servers, and the congestion table using header translation table of CL server. As in congestion of output virtual channel this method has an effect on all the traffic transmitting through the link, then it has an effect on the traffic that has not caused the congestion. As a result, the link utilization of output virtual channel that does not bring the congestion and outputs the traffic is decreased. To overcome this drawback of link-by-link, we proposed the hybrid method that are using the ABR feedback loops of link-by-link method, the feedback loop between CL users in end-to-end, the congestion table using and the header translation table. This scheme deals with teh congestion immediately by link-by-link loops and the header translation table, and then regulates the sending rate of CL user that causes the congestion by end-to-end loop.

• Annual Conference of KIPS
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• 2011.11a
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• pp.1146-1149
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• 2011

N-screen 은 여러 단말을 통한 콘텐츠 소비형 서비스로써 이용자 환경과 요구사항에 반응하여 연속성을 가지고 이용자가 원하는 단말을 통해 제공될 수 있다. 자신이 가지고 있는 다양한 단말만 아니라 인증을 거친 다른 사용자가 가진 단말에도 N-screen 을 제공할 수 있다. 서로 다른 서비스 이용자 간 N-screen 을 제공하기 위한 플랫폼으로써 웹 플랫폼을 이용할 수 있다. 웹은 N-screen 을 제공하기 위해 가장 우선시 되는 요구사항인 플랫폼의 통합을 이끌어 낼 수 있으며 서비스 플랫폼과 협업을 통해 서비스 이용자의 요구사항을 만족시키고 동시에 Community 융합을 통해 전혀 새로운 서비스로 제공될 수 있다. 이에 본 논문에서는 웹 기반 N-screen 환경에서 Community 서비스 제공을 위한 서비스 제어기능 모델을 제안하고 그에 따른 서비스 시나리오를 설명한다.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.4
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• pp.104-113
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• 2012

Followed by that HTML5(Hypertext Markup Language5) was introduced, many kinds of program and services based on this have been developed and released. HTML5 is technical standard specifications for cross platform for personal computers and mobile devices so that it is expected that continuing progress and wide application in the both sides of the academic and the industrial fields increase. This study is to design and implement a mobile application program for overlay rendering with DEM and other geo-based image sets using HTML5 WebGL for 3D graphic processing on web environment. Particularly, the blending technique was used for overlay processing with multiple images. Among available WebGL frameworks, CubicVR.js was adopted, and various blending techniques were provided in the user interface for general users. For the actual application in the study area around the Sejong city, serveral types of geo-based data sets were used and processed: KOMPSAT-2 images, ALOS PALSAR SAR images, and grid data by environment measurements. While, DEM for 3D viewing with these geo-based images was produced using contour information of the digital map sets. This work demonstrates possibilities that new types of contents and service system using geo-based images can be extracted and applied.

• 한국벤처창업학회:학술대회논문집
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• 2010.08a
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• pp.71-89
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• 2010

It is strongly believed that multicast will become one of the most promising services on internet for the next generation. Multicast service can be deployed either on network-layer or application-layer. IP multicast (network-layer multicast) is implemented by network nodes (i.e., routers) and avoids multiple copies of the same datagram on the same link. Despite the conceptual simplicity of IP multicast and its obvious benefits, it has not been widely deployed since there remain many unresolved issues. As an alternative to IP multicast, overlay multicast (application-layer multicast) implements the multicast functionality at end hosts rather than routers. This may require more overall bandwidth than IP multicast because duplicate packets travel the same physical links multiple times, but it provides an inexpensive, deployable method of providing point-to-multipoint group communication. In this paper we develop an efficient method applied greedy algorithm for solving two models of overlay multicast tree building problem that is aimed to construct MDST (Minimum Diameter Spanning Tree : minimum cost path from a source node to all its receivers) and MST (Minimum Spanning Tree : minimum total cost spanning all the members). We also simulate and analyze MDST and MST.

• Information and Communications Magazine
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• v.13 no.3
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• pp.61-70
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• 1996

In this paper, the architecture of the LAN Emulation service defined by the ATM Forum is introduced. In order to use the vast base of the existing LAN application software in ATM network. LAN Emulation provides a MAC layer service emulating connectionless services of legacy LANs on ATM networks. LAN Emulation forms a logical overlay network, called and emulated LAN, on top of an ATM network. LAN Emulation service comprises a set of LAN Emulation Clients(LECs) residing in end stations of an emulated LAN and three logical service entities : LAN Emulation Configuration Server (LECS), LAN Emulation Server(LES). and Broadcast and Unknown Server(BUS). LEC utilizes the services provided by these three servers to provide seamless interworking between legacy LANs and ATM networks, and to support transparent communications between LAN applications over ATM.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.9
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• pp.1947-1954
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• 2009

Service discovery mechanism is a core technique for getting a desired service in MANET(Mobile Ad-Hoc NETwork) environment. However, As feature of MANET, existing mechanisms have some problem that service requester search for trustable service. also it can not support scalability. in this paper, how to reliably support applications such as service discovery on top of MANET. we are firstly finding a trustable service provider and configure DHT(Distributed Hash Table). P2P's DHT can be adopted to service discovery mechanism because P2P and MANET share certain similarities, primarily the fact that both are instances of self-organizing decentralized systems. Especially, Proposed DHT systems used for P2P overlay network can be effective in reducing the communication overhead in service discovery. So proposed mechanism can support for reliably searching required service and scalability. Simulation results show that our mechanism is scalable and outperforms existing service discovery mechanism.