• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.489-492
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• 2013

각종 스마트 모바일 기기들의 보급이 활성화되면서 사용자들이 전송하는 정보들의 종류가 다양해지고 있다. 이러한 정보들 가운데 가장 큰 트래픽을 차지하는 비디오 콘텐츠의 전송은 이동통신망의 병목현상을 일으키는 주요한 원인으로 꼽힌다. 이동 통신망 기반의 콘텐츠 전송의 근본적인 문제들과 더불어 병목현상으로 인한 과부하 문제를 해결하기 위해서 D2D 기반의 콘텐츠 전송을 위한 연구들이 진행되고 있으나 대부분은 동일망을 전제로 하거나 이동, 배터리 문제등과 같은 모바일 환경에서 일어나는 상황에 대응하지 못하였다. 본 논문에서는 D2D 기반 스마트 에이전트의 콘텐츠 전송기법을 적용하여 이종망을 지원하게 하였다. 또한 콘텐츠를 전송하는 기기이외에 이들을 관리하는 에이전트를 따로 두어 모바일 환경에 대응하도록 하였다. 스마트 에이전트는 크게 콘텐츠를 요청하는 요청 에이전트와 콘텐츠를 제공하는 제공 에이전트, 마지막으로 이들은 중개하는 중개 에이전트로 나누어진다. 각각의 에이전트는 사용자의 기기에 독립적으로 탑재되어 콘텐츠를 요청, 전송, 관리하며 지능레벨에 따른 서비스의 범위를 다양하게 할 수 있도록 설계하였다. 끝으로 스마트 에이전트의 역할이 효과적으로 나타날 다양한 활용방안을 제시하였다.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.6
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• pp.36-45
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• 1998

This paper discusses multiple access control aspects for a wireless extension of high-speed asynchronous transfer mode(ATM) networks. One challenging requirement is that mobile systems convey of diverse types of information including voice, computer data, facsimile, and video data that have different quality of service constraints. Basically, a centralized control scheme for a coordinated multiple access is required in order to efficiently accommodate multimedia traffic on wireless links. The proposed scheme dynamically scheduling the mobile terminal, which has data to transfer according to the service, types at base station. In this scheme, the scheduling algorithm is performed on the basis of traffic descriptors and QoS parameters, which required in the connection set up phase. As a consequence, the transmission scheduling is very flexible and can account for the different traffic rate and delay constraints that emerge from voice and data integration. The simulation result shows that the proposed scheme has better performance over other scheduling algorithms.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.4
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• pp.312-333
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• 2005

SIP(Session Initiation Protocol) has been proposed for session control protocol of Internet multimedia communication system like VoIP(Voice over IP). SIP has complicated session control steps to support various kinds of audio and video formats and to assure service quality of real time data communication. Up until now, existing protocol analyzers can not provide such detailed information of SIP based communication system. In this paper, therefore, we propose a new protocol analyzer as a tool that can analyze and diagnose SIP based multimedia communication system throughout the session initiation, data exchange and session change steps. The propose traffic analyzer, which is called STAT(SIP based Traffic Analysis Tool), Is implemented on Winder's environment so that it is generally usable and extensible. Since STAT analyze low level packets captured via Ethernet broadcasting property, it is able to provide session status and real time traffic monitoring information without any affection to the communication system. The STAT which is implemented in this paper. therefore, is expected to be a useful tool for developing and managing of a SIP based multimedia communication system.

• Journal of the Korea Society of Computer and Information
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• v.17 no.7
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• pp.97-106
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• 2012

Management of biosignal data in mobile devices causes many problems in real-time transmission of large volume of multimedia data or storage devices. Therefore, this research paper intends to suggest an m-Health system, a clinical data processing system using mobile in order to provide quick medical service. This system deployed health system on IP network, compounded outputs from many bio sensing in remote sites and performed integrated data processing electronically on various bio sensors. The m-health system measures and monitors various biosignals and sends them to data servers of remote hospitals. It is an Android-based mobile application which patients and their family and medical staff can use anywhere anytime. Medical staff access patient data from hospital data servers and provide feedback on medical diagnosis and prescription to patients or users. Video stream for patient monitoring uses a scalable transcoding technique to decides data size appropriate for network traffic and sends video stream, remarkably reducing loads of mobile systems and networks.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.38 no.1
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• pp.1-13
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• 2001

In this paper, we propose a new dynamic bandwidth allocation and call admission control for VBR video sources with QoS constraints to support an efficient resource management and at the same Lime to satisfy the user's quality or service requirements. For the dynamic bandwidth allocation, first the next amount of traffic is predicted using a modified adaptive linear prediction method that considers abrupt scene change effects. And then, we dynamically allocate the necessary bandwidth to each connection based on the currently provided quality degree by the network with respect to the user's QoS requirements in terms of average delay and loss ratio. For the admission control, we determine the acceptance or rejection or a new connection based on the quality satisfaction degrees of the existing connections. Simulation results show that our proposed dynamic schemes are able to provide a stable service, which well meets the user's quality requirements.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.3
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• pp.285-289
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• 2004

Recently, due to the high development of the internet, needs for multimedia streams such as digital audio and video is increasing much more. In case of transmitting multimedia streams using the User Datagram Protocol (UDP), it may cause starvation of TCP traffic on the same transmission path, thus resulting in congestion collapse and enormous delay because UDP does not perform TCP-like congestion control. Because of this problem, diverse researches are being conducted on new transmission schemes and protocols intended to efficiently reduce the transmission delay of real-time multimedia streams and perform congestion control. The TCP-friendly congestion control schemes can be classified into the window-based congestion control, which uses the general congestion window management function, and the rate-based congestion control, which dynamically adjusts transmission rate by using TCP modeling equations and the like. In this paper, we suggest the square-root congestion avoidance algorithm with the hybrid TCP-friendly congestion control scheme which the window-based and rate-based congestion controls are dealt with in a combined way. We apply the proposed algorithm to the existing TEAR. We simulate the performance of the proposed TEAR by using NS, and the result shows that it gives better improvement in the stability needed for providing congestion control than the existing TEAR.

• Journal of the Korea Society of Computer and Information
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• v.26 no.3
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• pp.1-7
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• 2021

In this paper, optimized media data retrieval and transmission based on the Hybrid CDN/P2P architecture and selective storage through user's prediction of requestability enable seamless data transfer to users and reduction of unnecessary traffic. We also propose a new media management method to minimize the possibility of transmission delay and packet loss so that media can be utilized in real time. To this end, we construct each media into logical segments, continuously compute weights for each segment, and determine whether to store segment data based on the calculated weights. We also designate scattered computing nodes on the network as local groups by distance and ensure that storage space is efficiently shared and utilized within those groups. Experiments conducted to verify the efficiency of the proposed technique have shown that the proposed method yields a relatively good performance evaluation compared to the existing methods, which can enable both initial latency reduction and seamless transmission.

• Journal of Satellite, Information and Communications
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• v.12 no.2
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• pp.71-78
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• 2017

A network neutrality is the concept that ISP assures users non-discrimination, interconnection, accessibility for ensuring users without control or interference of equal services in the network. But today a network traffic is growing rapidly in sensitive buffering services as P2P service diffusion and mass video stream service. To manage this problem, ISP violates a net neutrality by control, change and interfere with service. And then the debate about net neutrality is happening. Therefore in this paper, we compare and analyze net neutrality principles, concepts, and legislative policy in the native and foreign. Based on this, we suggested the issues and improvement plan of net neutrality guard line.

• Journal of Digital Contents Society
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• v.15 no.2
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• pp.251-261
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• 2014

In the typical P2P VOD system, it is very important to develop the fast and efficient peer searching scheme since the peers frequently join and leave to/from P2P system. This paper proposes a new peer searching scheme for P2P VOD system based on DHT network environment. The proposed scheme constructs DHT network by managing the peers having close playback starting times and close network locations into a peer all together. The peer information is mapped onto DHT nodes by hashing the key values each of which consists of the starting time and network location of the peer. From the simulation results, the number of messages required to search the partner peers are decreased, and the number of buffer maps exchanging among the peers are also decreased. The proposed scheme can reduce the average network distances among the partner peers. As a result, the proposed scheme makes routing more efficient and it saves the network resources by decreasing communication traffic overhead.

• Convergence Security Journal
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• v.12 no.1
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• pp.35-42
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• 2012

Increase of data traffic and the advent of new real-time services require to change from the traditional TDM-based (Time Division Multiplexing) networks to the optical networks that soft and dynamic configuration. Voice and lease line services are main service area of the traditional TDM-based networks. This optical network became main infrastructure that offer many channel that can convey data, video, and voice. To provide high resilience against failures, Packet-optical networks must have an ability to maintain an acceptable level of service during network failures. Fast and resource optimized lightpath restoration strategies are urgent requirements for the near future Packet-optical networks with a Generalized Multi-Protocol Label Switching(GMPLS) control plane. The goal of this paper is to provide packet-optical network with a hierarchical multi-layer recovery in order to fast and coordinated restoration in packet-optical network/GMPLS, focusing on new implementation information. The proposed schemes do not need an extension of optical network signaling (routing) protocols for support.