• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.245-245
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• 2006

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.1
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• pp.11-14
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• 2015

WSN (Wireless Sensor Network) based on low-power is one of the core technologies in the ubiquitous society. In this paper, we present a border surveillance and control system in WSN environment. The system consists of static sensor node, mobile sensor node, static gateway, mobile gateway, server and mobile application. Mobile applications are divided into user mode and manager mode. So users monitor border surveillance through mobile phone and get information of border network environment without time and space constraints. In manager mode, for the flexible operation of nodes, manager can update to the software remotely and adjust the position of the mobile node. And also we implement a suitable multi-hop routing protocol for scalable low-power sensor nodes and confirm that the system operates well in WSN environment.

• KIPS Transactions on Computer and Communication Systems
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• v.1 no.3
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• pp.193-204
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• 2012

This paper specifies a low-cost global mobility management architecture and protocol procedure called LC-$GM^2$, which is based on Proxy Mobile IPv6. In LC-$GM^2$, mobility management is performed by the network entity. The benefit is the elimination of the wireless link data delivery tunnel overhead between a mobile node and the access router. To compare with the well-known Hierarchical Mobile IPv6 mobility management protocol and GPMIP, the location update, packet delivery, and total cost functions generated by a mobile node during its average domain residence time are formulated for each protocol based on Fluid-flow mobility model. Then, the impacts of various system parameters on the cost functions are analyzed. The analytical results indicate that the proposed global mobility management protocol can guarantee lower total costs.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.433-435
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• 2002

All IP Mobile Network 하에서의 효율적인 멀티캐스트 전송의 필요성이 부각되고있다. Mobile IP프로토콜은 기본적으로 유니캐스트전송을 지원하며, 멀티캐스트 전송에 대해서는 효과적으로 정의하지 못하고 있다. 본 연구는 Mobile IP 망에 명시적 라우팅 프로토콜을 적용할 경우 기존 멀티캐스트 라우팅 도매인과의 연동을 하기 위한 미디어 게이트웨이(MGEM)를 설계하고 개발한다. 기존 멀티캐스트 트래픽을 1:N tunnel 의 특성을 가지는 명시적 멀티캐스트 전송방식을 사용하여 멀티캐스트 패킷을 이동단말들에 전송하기 위해서는 Mobile IP 홈에이젼트가 MGEM으로 확장되어야 하며, 이는 IGMP, SDP, 확장 HA 및 멀티캐스트 라우터 기능을 갖도록 요구된다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.920-922
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• 2012

논문은 기존의 헬스케어 서비스의 한계를 극복하기 위해 최근 대두되고 있는 스마트 헬스케어서비스(smart healthcare service)에 관한 연구이다. 스마트 헬스케어는 스마트폰의 기능에 맞추어 기초체력 운동 지수, 섭취 칼로리, 심박 체크 등의 다양한 서비스를 제공할 수 있지만, 최근에는 보건의료서비스에 특화시켜 환자와 의사가 직 간접적으로 진료를 할 수 있게끔 하는 스마트폰 환경에서의 원격진료 서비스가 부각되고 있다. 이에 본 논문에서는 게이트웨이 기능의 스마트폰을 기반으로 스마트 헬스케어 시스템을 설계 구현하였다.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.5
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• pp.286-299
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• 2006

Due to the continuing technical progress in the capabilities of modeling, simulation, and sensor devices, huge volume data with very high resolution are common. In scientific visualization, various interactive real-time techniques on high performance parallel computers to effectively render such large scale volume data sets have been proposed. In this paper, we present a mobile volume visualization system that consists of mobile clients, gateways, and parallel rendering servers. The mobile clients allow to explore the regions of interests adaptively in higher resolution level as well as specify rendering / viewing parameters interactively which are sent to parallel rendering server. The gateways play a role in managing requests / responses between mobile clients and parallel rendering servers for stable services. The parallel rendering servers visualize the specified sub-volume with rendering contexts from clients and then transfer the high quality final images back. This proposed system lets multi-users with PDA simultaneously share commonly interesting parts of huge volume, rendering contexts, and final images through CSCW(Computer Supported Cooperative Work) mode.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.11a
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• pp.349-351
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• 2014

최근 정부 및 의료산업계에서 원격진료에 대한 관심이 매우 대두되고 있다. 본 연구에서는 모바일 PACS 시스템을 개선한 XC(External Photography Camera) 유형의 DICOM 영상획득 장치 설계 및 개발 결과를 제시하며, 또한 고용량의 DICOM 이미지를 스마트기기에 효율적인 전송하기 위한 모바일 게이트웨이 설계 결과를 제시한다.

• Journal of the Korea Society of Computer and Information
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• v.19 no.1
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• pp.31-41
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• 2014

This paper proposes a virtual mobile ad-hoc network (VMANET) model that automatically divides heterogeneous mobile devices of a MANET into a number of network groups depending on the communication capacity(data rate) of different network operational models such as IEEE 802.11g, IEEE 802.11b, and Frequency Hopping. In addition, it supports a distinct routing protocol for each network group of VMANETs, resulting in running multiple routing protocols concurrently on different groups of VMANETs. To reduce the network congestion and improve the network load balance, a default MANET gateway is configured in each VMANET and these gateways are responsible for integrating the MANET and IP networks. Experiment results show that the proposed model outperforms the conventional IMANET by significantly increasing throughput and reducing network congestion and network delay.

• KSCI Review
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• v.14 no.2
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• pp.123-127
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• 2006

In this paper, we designed and implemented home gateway system for remote control of home appliances and devices using cellular phone. The system communicate home devices through Zigbee protocol and home server based on Linux operating system communicate cellular phone through external networks. We expect that the system apply various fields as home automations, home network, smart offices, and ubiquious environments.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.6 s.348
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• pp.9-22
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• 2006

When the legacy multicast routing protocols are adopted in If-based mobile core networks, there are some problems such as traffic injection from unnecessary sources, traffic overhead by group management and router performance degradation by large amount of multicast session information. In this paper, we propose a stateless multicast mechanism which has no need to maintain multicast information for session status and reduces redundant network overhead for maintaining multicast tree. In addition interworking with IGMPv3 gets rid of traffic from unnecessary sources which have no registration from receivers. The operations of essential components including a gateway node for interworking with the legacy Internet multicast network, a gateway node for transparency to radio access network and a intermediate node in mobile core networks, are definitely defined and the proposed communication architecture is completed. Finally we evaluate and approve the performance of the proposed architecture by means of well-designed network simulation.