• The Transactions of the Korea Information Processing Society
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• v.5 no.4
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• pp.1033-1043
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• 1998

In this paper, we present an improved multicasting path assignment algorithm based on the minimum cost spanning tree. In the method presented in this paper, a multicasting path is assigned preferentially when a node to be received is found among the next degree nodes of the searching node in the multicasting path assignment of the constrained steiner tree (CST). If nodes of the legacy group exist between nodes of the new group, a new path among the nodes of new group is assigned as long as the nodes may be excluded from the new multicasting path assignment taking into consideration characteristics of nodes in the legacy group. In assigning the multicasting path additionally, where the source and destination nodes which can be set for the new multicasting path exist in the domain of identical network (local area network) and conditions for degree constraint are satisfied, a method of producing and assigning a new multicasting path is used. The results of comparison of CST with MCSTOP, MCSTOp algorithm enhanced performance capabilities about the communication cost, the propagation delay, and the computation time for the multicasting assignment paths more than CST algorithm. Further to this, research activities need study for the application of the international standard protocol(multicasting path assignment technology in the multipoint communication service (MCS) of the ITU-T T.120).

• Journal of Broadcast Engineering
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• v.19 no.5
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• pp.687-698
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• 2014

ATSC is currently working on standardization of hybrid 3DTV broadcasting service in heterogenous network environment after completion of service-compatible 3DTV broadcasting service standard based on broadcasting channel. This paper proposes a convergence 3D video broadcasting method on broadcasting and IP network while guaranteeing a Full-HD 3D quality without degrading the image quality of legacy DTV. Specifically, this paper describes transmission of the 3D additional video using the ISO/IEC 23009-1 DASH, robust synchronization method under heterogenous network environments and system target decoder model for hybrid 3DTV receiver. Based on experimental results, we confirm that proposed technologies can be used as a core technology in the hybrid 3DTV standardization and a reference model for a development of hybrid 3DTV encoder and receiver.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.2
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• pp.151-163
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• 2014

The recent wearable device's applications concentrates on providing diverse services such as location based service, context aware service to the users. These various services are implemented by the interactions between the wearable device and the user. In the legacy system, the interaction requires certain explicit configuration from the user. If the user is unfamiliar with the IT technology, it will be impossible to get the wanted service. Therefore, a new autonomous communication concept among neighbor devices is essential for people who is unfamiliar with the IT technology. The implicit human computer interface enables the user to acquire the services, even though the user don't know the IT technology. In this paper, we propose two BLE based protocols (B-LIDx protocol, B-PniP). B-LIDx protocol is the protocol for locationing the mobile device in indoor. B-PniP is a zero-configure opportunistic direct M2M communication protocol between neighbor devices to achieve the autonomous communication concept with zero-configuration. The protocol's evaluations are performed by measuring the time for finding the location of a mobile device in actual environment and aligning the time spent in services using the B-PniP.

• The Journal of the Korea Contents Association
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• v.5 no.1
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• pp.9-17
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• 2005

In this paper we developed e-Leaning system based on open source software. We selected the Moodle that after compared the open source learning management systems. Moodle is LAMP(Linux, Apache, MySQL, PHP) based course management system (CMS), a software package designed to help educators create quality online courses. One of the main advantages of Moodle over other systems is a strong grounding in social constructionist pedagogy. Also we integrated Moodle and legacy systems such as streaming service, webhard service, and short message service. The system operated during one semester at college using blended learning model. We had obtained showed that the students had almost all scored quite highly as preferred learning environment through COLLES(Constructivist On-Line Learning Environment Survey) and ATTLS(Attitudes to Thinking and Learning Survey). Therefore this research showed that open source based e-Loaming system is stable and possible.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.574-577
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• 2007

e-Science Service Integration Workbench is the core tool that enables IT-based computation and engineering researchers to collaborate their research activities via data sharing, by semi-automatically supporting the activities. Workbench provides the researchers with a scientific workflow by establishing the environment that is capable of finding, registering, composing, and executing services-legacy codes wrapped with grid services or web services-they need to use. In other words, designing their scientific workflow through the workbench, they can receive or share its final result with their collegues by submitting jobs they describe to computational resources such as supercomputers or grids or requesting an experiment. In this paper, we propose an implementation architecture of e-Science Service Integration Workbench to support grid services of Grid Middleware.

• Journal of Korea Multimedia Society
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• v.12 no.2
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• pp.257-271
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• 2009

In this paper, we propose a protocol compression scheme for enhancing the performance of call processing of PTT(Push-to-Talk) which is one of the important services in IMS(IP Multimedia Subsystem), a next generation integrated wired/wireless packet communication network. To service the PTT on an IMS network, it should use the same call setup procedure as legacy Mobile and TRS(Trunked Radio System) networks and have a fast call setup time and enough communication bandwidth because a number of terminals should be able to exchange same data in real time. The proposed A+SigComp scheme reduces the initial call setup delay of SIP by about 10%, which is used by PTT service for call setup. In addition, the A+ROHC scheme is proposed to compress the header of RTP packets transferred during PTT voice transmission and, as a result, about 5% of increase in communication efficiency is observed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.11
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• pp.1004-1013
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• 2012

The legacy voice broadcast systems are used to broadcast the voice over an entire space or a specific zone. these broadcast systems generate unnecessary noise and waste of resources. In this paper, we propose a ubiquitous voice message broadcast system called uPaging, by combining the technique of location-awareness and the voice message delivery service in ubiquitous sensor network environment. In uPaging system, the wire/wireless hybrid network is used to implement the network system. Also, in order to actualize the location-awareness service, we use the Bidirectional Location ID-Exchange protocol was suggested by our previous research. the uPaging system can deliver the voice to a selected user or the location in which the user is present by this location awareness.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.11
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• pp.1010-1018
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• 2013

The dual-stream based stereoscopic 3D broadcasting standard was developed in 2011. EBS broadcasted 3DTV experimental service according to this standard in April 2012. Dual-stream based 3DTV broadcasting is service-compatible and backward-compatible, so viewers who have legacy 2D HDTV can watch the broadcasting content as 2D. And 3DTV viewers can select watching 2D or 3D. Since 3D content production is not usual yet for terrestrial broadcasters, only some particular programs in specific periods will be broadcasted as 3D at the initiatory stage. For it, stable viewing condition is strongly required for both 2D viewers and 3D viewers. This paper suggests broadcasting transmission system structure and effective switching scheme for stable 2D and 3D viewing conditions in the case of dual-stream based terrestrial 3DTV broadcasting.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.6
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• pp.579-587
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• 2008

In collaborative environment, since each agent generally uses different words for the same meaning, there is an obstacle for information sharing. In collaborative product development environment, each agent has different words for representing same product information. As a result, it is hard to share product information in this situation. For solving this problem, semantic-based product information is needed. In this paper, a ontology-based semantic searching system which is able to interact with legacy PDM systems is proposed for product information sharing in collaborative environment Product ontology is represented with OWL format, and the product ontology is processed by Pellet reasoning engine for semantic searching. The system is implemented as a web service which can be integrated with other systems. This paper also introduces the approach with which a PDM system provides a function of semantic search with this search system.

• Journal of the Korea Society of Computer and Information
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• v.15 no.12
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• pp.247-253
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• 2010

The demand that needs 'Digital Legacy', a notion that an Internet user can transfer his private blogs, e-mail and financial assets to inheritors and party interested when he died suddenly in the accident, has been growing recently. This issue has become a social hot potato since Justine Ellsworth's father in USA sued Yahoo for the right to access his son's Yahoo e-mail account after Justine Ellsworth had died in Iraq, in November, 2004 and the problems happened to deal with suicide-related blogs and homepages when great entertainers in Korea committed suicide and soldiers' parents in the situation of warship Chonan tragedy in Korea demanded access to soldiers' homepages and e-mail accounts. The point at issue focuses on the property matters about the digital information of the deceased and the relationship between the deceased and the Internet Service Provider(ISP). This research looks into the trend of judicial precedents and laws related to the digital information of the deceased and suggests the preliminary data of the next research.