• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.664-667
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• 2015

사물인터넷(IoT)은 시간과 장소의 제약 없이 모든 사물이 인터넷을 기반으로 정보 교환 및 의사소통을 지원하는 지능형 기술 및 서비스를 의미한다. IoT 기술의 발전과 이를 활용한 서비스 분야는 새로운 융합 서비스 형태로 발전함에 따라 리소스 서비스에 대한 모델 관리 방안 연구가 필요하다. 본 논문에서는 CapSG(Capability Service Gateway)를 이용한 IoT 서비스 접근 제어 플랫폼을 살펴보고, IoT 테스트베드 환경에서 리소스 서비스에 대한 모델 관리 방안을 제시한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.580-582
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• 2012

네트워크 기반의 이동성 관리 프로토콜인 PMIPv6(Proxy Mobile IPv6)에서 방송이나 비디오 스트리밍과 같은 서비스를 제공할 때 멀티캐스트 방식을 이용하여 데이터 패킷을 전송하는 기법이 제안되었다. 제안되었던 기법은 MN(Mobile Node)이 핸드오버할 때 nMAG(new Mobile Access Gateway) 내에 같은 멀티캐스트 멤버인 또 다른 MN이 존재할 경우를 고려하지 않았다. 본 논문에서는 같은 멀티캐스트 멤버인 MN이 존재할 경우 버퍼링된 패킷들의 중복 전송을 막는 기법에 대해 제안한다. 이 후 MN이 nMAG로 핸드오버했을 때 같은 멀티캐스트 멤버를 가진다면 버퍼링된 패킷을 현재 핸드오버한 MN에만 포워딩하여 중복 전송되는 것을 방지한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.594-596
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• 2011

PMIPv6 (Proxy Mobile IPv6)은 MN (Mobile Node)를 대신하여 액세스 망에서 MN의 이동성을 지원하는 네트워크 기반의 이동성 관리 프로토콜이다. 기존의 PMIPv6는 MN과 Corespondent Node (CN) 간 통신을 할 때, 교환하는 데이터 패킷은 LMA (Local Mobility Anchor)를 경유하고 MAG (Mobile Access Gateway)를 경유해서 전송하기 때문에 시그널링 코스트가 증가하고 전송 지연 문제가 발생한다. 따라서 본 논문은 MN이 도메인 내 핸드오버를 했을 시, LMA에서 MAG를 경유하지 않는 경로 최적화를 제시한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.05a
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• pp.875-878
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• 2008

Proxy MIPv6 환경에서 Local Mobility Anchor는 이동 단말에 대해 이동성을 제공하기 위한 등록과정과 데이터의 터널링을 제공한다. 다수의 Mobile Access Gateway에 위치하는 모든 이동 단말에 대해 서비스를 제공하여야 하기 때문에 Local Mobility Anchor는 병목현상을 일으킬 수 있으며 이것은 Local Mobility Anchor에 의해 관리되는 모든 이동 단말에 대해 전체적인 이동 서비스의 실패로 이어질 수 있다. 본 논문에서는 이러한 문제를 해결하기 위해 다수의 Local Mobility Anchor에 부하를 분배하며 특정한 Local Mobility Anchor에 부하가 집중될 경우 효과적으로 재분배하기 위한 기법을 소개한다. 본 논문에서 제안하는 기법을 통해 다수의 이동 단말에게 서비스를 제공하는 Proxy MIPv6 환경에서도 안정적이고 양질의 서비스를 제공하며 자원을 효율적으로 이용할 수 있을 것으로 기대된다.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.855-857
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• 2007

In recent years, Wireless Mesh Network (WMN) is a compelling topic to many network researchers due to its low cost in deployment, ease and simplicity in installation and scalability and robustness in operation. In WMN, Gateway nodes (Access Point-AP) are in charge of steering the traffic from the external network (e.g. Internet...) to client devices or mesh clients. The limited bandwidth of wireless links between Gateways and intermediate mesh routers makes the Gateways becomes the bottleneck of the mesh network in both uplink stream and downlink stream. In this paper, we propose a mechanism to permit Gateways collaboratively work to manipulate the traffic to fit our network. They will move the traffic from congested links to the unused capacity on other links.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.3
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• pp.605-614
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• 2012

Nowadays u-healthcare which is very sensitive to the character of user's information among other ubiquitous computing field is popular in medical field. u-healthcare deals extremely personal information including personal health/medical information so it is exposed to various weaknees and threats in the part of security and privacy. In this paper, RFID based patient's information protecting protocol that prevents to damage the information using his or her mobile unit illegally by others is proposed. The protocol separates the authority of hospital(doctor, nurse, pharmacy) to access to patient's information by level of access authority of hospital which is registered to management server and makes the hospital do the minimum task. Specially, the management server which plays the role of gateway makes access permission key periodically not to be accessed by others about unauthorized information except authorized information and improves patient's certification and management.

• Journal of Satellite, Information and Communications
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• v.11 no.2
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• pp.23-28
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• 2016

In this paper, we proposed the novel algorithm which controls the resolution of the HDMI(High Definition Multimedia Interface) by the channel estimation from WiFi-AP(Access Point) in the ISM(Industry-Science-Medical) band. The 2.4 and 5 GHz channel models are widely used since they have identical RF property as RSSI(Received Signal Strength Indication). Especially, the performance degradation of signal-transmission and streaming of WiFi will be occurred by the co-channel interference between AP(Access Point) and increased number of smart devices. Therefore, the optimization scheme of video format timing was designed by HDMI-CEC(Consumer Electronics Control) which considers the transmission speed of radio channel. The HDMI resolution, video quality of home-gateway and digital TV and the decision of PIP position can be maintained by the protocols between smart devices and DLNA(Digital Living Network Alliance) via proposed technique.

• Journal of Broadcast Engineering
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• v.10 no.2
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• pp.182-189
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• 2005

In this paper, an asymmetric WDM-EPON transmission scheme is proposed to be used in a high speed access network system, which is required to implement the convergence of broadcast and communication. WDM is used for downstream transmission from OLT to access nodes, satisfying wide bandwidth requirement for broadcasting and various multimedia services. And an EPON scheme, which is cheaper than WDM, is applied to upstream transmission where less bandwidth is required. A transmission test in physical layer was performed successfully and the results are provided. If ONUs are to be used in a home gateway, its protocol should be appropriate to its traffic pattern. Voice is sensitive to a time delay while data is not. A new dynamic bandwidth assignment protocol for PON system, which can cope with various types of data in access network is proposed and its performance is analysed. A maximum cycle time is specified to achieve the QoS of signals sensitive to time delay. And a minimum window is specified to prevent the downstream control signals from uprising. It is shown by simulation that the proposed EPON protocol can provide a better performance than previous ones.

• The Transactions of the Korea Information Processing Society
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• v.7 no.1
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• pp.156-165
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• 2000

This paper proposes an integrated system for interworking different network management protocols. The interworking system between SNMP(Simple Network Management Protocol) and CMIP(Common Management Information Protocol) has been designed. We defined new managed object architecture using MOVI(Managed Object View Interface) concept and implemented an extended GDMO(EGDMO) compiler. An access mechanism for consistency control and atomic action on the sharing resources has been defined. Thus, even if a new management protocol would be introduced, new gateway system need not to be redesigned. It can be achieved with minimum modification of the view interface of managed objects. As a managed object can support various view interfaces, several network management protocols can directly access it. This approach, therefore, provides some benefits. For instance, manager can access managed objects without additional functions and tools. Ti, also, could be achieved interworking between SNMP and CMIP with minimum modification on the view interface of the managed objects defined previously. It is able to interwork more complicated network management protocols and to increase usefulness of SNMP and CMIP.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1023-1026
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• 2005

In the ubiquitous computing environment, an intelligent vehicle is defined as a sensor node with a capability of intelligence and communication in a wire and wireless network space. To make it real, a lot of problems should be addressed in the aspect of vehicle mobility, in-vehicle communication, common service platform and the connection of heterogeneous networks to provide a driver with several intelligent information services beyond the time and space. In this paper, we present an intelligent information system for managing in-vehicle sensor network and a vehicle gateway for connecting the external networks. The in-vehicle sensor network connected with several sensor nodes is used to collect sensor data and control the vehicle based on CAN protocol. Each sensor node is equipped with a reusable modular node architecture, which contains a common CAN stack, a message manager and an event handler. The vehicle gateway makes vehicle control and diagnosis from a remote host possible by connecting the in-vehicle sensor network with an external network. Specifically, it gives an access to the external mobile communication network such as CDMA. Some experiments was made to find out how long it takes to communicate between a vehicle's intelligent information system and an external server in the various environment. The results show that the average response time amounts to 776ms at fixed place, 707ms at rural area and 910ms at urban area.