• The KIPS Transactions:PartC
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• v.9C no.1
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• pp.79-88
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• 2002

Transcoding proxy strategy has been widely used as a means to reduce the delay in retrieving Web pages over wireless mobile data service networks. However, this strategy has the serious drawbacks of being a potential point of failure or a bottleneck of the service. We developed a distributed proxy server system in which multiple proxy servers are installed at geographically dispersed locations and share the workloads among them by serving mobile hosts only within assigned regions. A new handoff message protocol to enable handoffs between proxies as the mobile hosts move between regions is proposed. According to the proxy server handoff protocol, a client agent at the mobile horst requests a proxy server to start handoff processing by which two proxy servers synchronize distilled data belonging to a HTTP session that must be maintained across the handoff. Also, we introduce the architecture of the proxy server and the client agent that handles the proxy server handoff. Finally, we evaluate the proposed system through performance test.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.8
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• pp.1725-1733
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• 2012

This paper describes the design and implementation of a 3-tiered proxy driving system utilizing smartphones. This system provides customers with a convenient request facility, and enables proxy drivers to provide a prompt service based on customer's location information. Implemented system supports two methods such as the existing phone-call and the online requesting method using smartphones. Performance analysis shows that the higher the ratio of online requests, the greater the effect of decreasing of phone jockey's workloads and the reduction of request processing time through the automation of receipt and processing. From a proxy driver company's standpoint, this system minimizes the increase of phone jockeys, and improves customer satisfaction through good service quality. This system also helps the company reduce the cost and increase the market share.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.11a
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• pp.171-172
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• 2014

This paper proposes a SDN based Proxy Mobile IPv6 (PMIPv6) architecture for heterogeneous vehicular networks (SDN-VANET), to provide the continuity of service during the horizontal handovers and to reduce the delay during vertical and horizontal handovers. SDN-VANET mainly relies on DSRC road side units (RSUs) for V2I communication and to overcome the coverage problem SDN-VANET performs the vertical handover between DSRC and LTE/UMTS. To date there is no standard to perform network layer vertical handovers. Therefore the proposed SDN-VANET architecture also doesn't provide any mechanism for vertical network layer handovers, but solves the horizontal network layer handovers in DSRC or LTE/UMTS through introducing PMIPv6 in the architecture.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10a
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• pp.138-139
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• 2007

기존의 MIPv6는 오랜 시간동안의 핸드오버로 인하여 많은 패킷 손실 및 오랜 세션 단절을 야기시킨다. 이러한 문제점들을 향상시키기 위하여 Fast handover for Mobile IPv6 (FMIPv6) 프로토콜이 개발되었지만 여전히 터널링에 기반한 라우팅 방법은 패킷 순서 어긋남 문제로 인하여 성능이 하락하는 문제를 야기한다. 최근 모바일 단말에서의 이동성 관리 부하를 줄여주기 위하여, 네트워크 이동성 기반인 Proxy Mobile IPv6 (PMIPv6)가 제안되었다. PMIPv6는 모바일 단말에서 수행하던 이동성 관리를 네트워크 에이전트에서 해줌으로서 단말의 부하를 줄이고 이동성 관리 지연 시간을 줄일 수 있다. 하지만 현재 제안된 PMIPv6 또한 터널링 기법에 기반한 비효율적인 라우팅 경로로 인하여 성능이 저하될 수 있다. 본 논문에서는 PMIPv6 에서 안정되고 향상된 최적화 라우팅 기술이 접목된 빠른 핸드오버 방법인 Fast Proxy Mobile IPv6 (EF-PMIPv6) 제안한다.

• Journal of the Korea Computer Industry Society
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• v.3 no.8
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• pp.1049-1062
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• 2002

As the distributed resources in the networks have become increasingly popular, the accesses to these resources having been activated. Especially, the accesses to the distributed resources using the mobile agent technologies provide the mechanisms supporting mobility with mobile users as well as the dynamic accesses to the resources in the fixed networks. Proxy-based mobile agent model is defined as mobile agent network model which allocates the hierarchical domains to the distributed resources changed dynamically, assigns one proxy server for each domain, and promotes the management and the cooperation of the mobile agents. In this paper, we introduce the architecture and the execution scenario for proxy-based mobile agent model which is suitable for the hierarchical management domains. In simulation, we evaluate the proxy server's route optimization functionality and the performance reducing execution time of the mobile agents.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.4
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• pp.747-754
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• 1999

Mobile Agent is a movable software program that autonomously runs on behalf of its operator in a network environment. It has been widely applied to various kinds of computer engineering. In this paper, a network management architecture using the mobile agent technology in the distributed network environment is proposed. After manager system creates the mobile agent, it searches a proxy, a distributed object that acts as the substitute for a SNMP agent. In order to get the management information that manager requires, the mobile agent goes to the proxy and does operations on it. So, only the concise results from the operation are sent to the managing system. The proposed architecture is based on CORBA that provides several transparent characteristics in the distributed environment. In additional, the proxy object that represents the SNMP agent enables the mobile agent and the SNMP agent to converse with themselves. In this architecture, the mobile agent can carry out an automated management function, easily change and modify management functions. Therefore, it can provide an efficient management way.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04c
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• pp.615-617
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• 2003

최근 모바일 단말기의 보급이 증가함에 따라 이를 이용한 다양한 어플리케이션이 개발되고 있다. 특히 게임 분야는 기존의 Stand-Alone 방식에서 모바일 단말기의 무선통신 기능을 이용한 네트워크 온라인 게임으로 전환이 이루어지고 있다. 하지만, 네트워크 온라인 게임은 게임로직의 처리, 랜더링 처리 같은 복잡한 계산과 비동기적인 네트워크 송.수신이 빈번하게 이루어지기 때문에 모바일 단말기에서 모두 처리하기에는 많은 문제점이 있다. 따라서, 본 논문에서는 모바일 단말기가 처리해야 할 계산 및 통신기능을 대신하여 처리할 수 있는 프록시 구조를 제안한다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.703-705
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• 2004

최근 무선 통신이 급속도로 발달하면서 무선 환경에서의 멀티미디어 전송에 관한 많은 연구가 되어지고 있고, 그 중에서도 미디어 서버를 두어 무선 멀티미디어 환경에 적용시키는 경우도 많아졌다. 그러나 기존의 연구는 멀티미디어 전송을 위한 인코딩, 압축 방법 및 무선 전송방법에 대해서 연구가 되어졌다. 네트워크 관점에서 무선 멀티미디어 환경은 미디어 서버 성능의 제약성 때문에 많은 사용자에게 서비스를 제공하지 못한다. 본 논문에서는 동적 멀티미디어 서비스 분배 아키텍쳐를 이용하여 멀티미디어 서비스를 제공해주는 미디어 서버의 오버헤드를 줄임으로 인해 보다 효율적으로 멀티미디어 서비스를 제공하기 위한 방안을 제안한다.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.442-444
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• 2007

This paper presents an architecture of UPnP Bridge that allows controlling Non-iP devices from UPnP control point, without modification to Non-IP device or UPnP control point implementations. UPnP devices must provide SSDP discovery, SOAP control and GENA event processes. To represent Non-IP devices to UPnP devices, UPnP Bridge provides these functionalities on behalf of Non-IP devices. We provides two method to interoperability between UPnP and Non-IP devices, Message Field Description, Non-UPnP Proxy devices. And solution to integrate heterogeneous networking standards(RS232C, CAN, IEEE1394, USB) is provided.

• Journal of Information Technology Services
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• v.9 no.2
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• pp.179-192
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• 2010

In order to resolve the problems of traditional Enterprise Application Integration (EAI) for system integration and to establish flexible enterprise IT environments, Enterprise Service Bus(ESB) which have distributed architecture and support Service Oriented Architecture(SOA) has introduced. Particularly, JBI which developed by the Java Community Process is most widely used to implement ESB for advantages of Java technology. In ESB based on JBI, reliable message delivery is very important to ensure stability of services and systems because it is a message driven architecture. But, it is difficult to verify messages and trace messages when system fault or service error occurred because JBI specification is not enough to address them. In this paper we has proposed the Message Monitoring Framework for JBI-based ESBs which for using in monitoring messages efficiently. It provides foundations for gathering and tracing message-related information about component installation, message exchange, service deploy by using proxy-based change tracking and delegation mechanism for data processing. The proxy which used in our solutions collects data about message automatically when it changed, and the delegation mechanism provides users flexibility for data processing. Also, we describe the performance evaluation results of our solution which is acceptable. We expect to it enables users to ensure reliability and stability of the JBI-based ESB by systematic monitoring and managing messages being used to interact among components.