• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.155-158
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• 2003

This paper proposes a quality-of-service(QoS)-adaptive proxy-switching scheme for multimedia streaming over the Internet. characteristic of multimedia-object about that effect on weight and transport-time causes Streaming Application is restricted to high-quality-service. But using of Proxy or Cache can reduce restraint of media stream. However previous scheme propose only structure of proxy and skill of streaming-object. It couldn't propose proper scheme about limited cache and proxy error occasion. We propose adaptive-proxy-switching mechanism for solution about some problems that caused by single-proxy and limited cache in case of streaming service.

• 한국ITS학회:학술대회논문집
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• v.2007 no.10
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• pp.7-10
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• 2007

• The KIPS Transactions:PartA
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• v.10A no.6
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• pp.723-728
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• 2003

In this paper, we propose the two-tiered proxy system that offers a seamless media service to mobile nodes in mobile computing environment. This proxy system is composed of a media proxy and a mobile proxy. We also propose the handoff protocol and the transmission mechanism for the seamless media service. The simulation result shows that the media service is improved in the two-tiered proxy system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.5
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• pp.1229-1240
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• 1998

In this paper, we provide a design of DAVIC VOD service system with proxy servers which perform caching of video streams. Proxy servers are placed between a service provider system and service consumer systems. They provide video services to consumers on behalf of the service provider, therefore they reduce the loads of service providers and network. The operation of a proxy server depends on whether the requested program is in its storage. If this is the case, the prosy servere takes all the controls, but if the proxy does not have the program, it forwards the service request the proxy server takes all the controls, but if the prosy does not have the program, it forwards the service request to a service provider. While the service provider system provides the program to the consumer, the proxy copies and caches the program. The proxy server executes cache replacement, if necessary. We show by simultion that the LFU is the most efficiency caching replacement algorithm among the typical algorithms such as LRU, LFU, FIFO.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.2
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• pp.317-326
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• 2012

Internet service provider is able to collect personal information to prevent the violations of the rights of service providers and customers using internet. But there are still many debates going on between a personal privacy and a regulation. Proxy servers are used in various technical purposes include bypass access. Although the proxy server users are increasing but there are not any proper institutional mechanisms and regulations to protect users. In this study, we discuss the two sides of a proxy service includes its privacy protection function and the cyber-crime threat and propose supplementary measures to mediate between the interests of public and private.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.296-301
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• 2000

This paper provides the solution for supporting H.323 services through firewalls with proxy server. The paper Provides a survey of H.323 Protocol, and framework for firewalls. The Paper also discusses the issues of H.323 and proxy server - why H.323 is hard for firewalls, and service scenarios with H.323 terminals and proxy server. Finally, the paper propose an application proxy service architecture for supporting H.323 protocol.

• Journal of Internet Computing and Services
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• v.13 no.6
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• pp.55-62
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• 2012

Grid web applications by standard Web technology are increasingly used to provide grid service to users as normal Web user interface and service. It is however difficult to integrate a grid security system such as Grid Security Infrastructure (GSI) into Web applications because the delegation way of standard Web security is not the same as the one of Grid security. This can be solved by allowing Web applications to get a Grid credential by using an online credential repository system such as MyProxy. In this paper, we investigate the problem that occurs when MyProxy, which assumes mutual trust between a user and Grid web application, is adapted for achieving security integration between Web and Grid, and we propose a new Grid proxy delegation service to delegate a Grid credential to the Web without assuming mutual trust. In the service, the X.509 proxy delegation process is added to OAuth protocol for credential exchange, and authentication can be done by an external service such as OpenID. So, users can login onto the Grid web application in a single sign-on manner, and are allowed to securely delegate and retrieve multiple credentials for one or more Virtual Organizations.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.351-354
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• 2002

NAPTR(Naming Authority Pointer) is a type of resource record specified IETF RFC 2915. NAPTR enables to register various services in tile domain name systems and thus Provides a way to discover services available on specific hosts. This paper describes the design and implementation of a proxy DNS system aimed at supporting NAPTRS. The goal of this work is to study on the feasibility of the service discovery registered in DNS via NAPTR records. This research result can be applied to service discovery in the resource information management for high performance GRID environments as well as to implement generic ENUM services

• 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 KIISE:Computing Practices and Letters
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• v.9 no.1
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• pp.47-59
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• 2003

The Internet telephony service is one of the commercially successful Internet application services. VoIP technology makes the service come true. VoIP deploys H.323 or SIP as the standard protocol for the distributed multimedia services over the Internet in which QoS is not guaranteed. VoIP carries the packetized voice over the RTP/UDP/IP protocol stack. The data transmission trouble is caused by UDP when the service is provided in private networks and some ISP-provided Internet access networks in the private address space. The Internet telephony users in such networks cannot listen the voices of the other parties in the public Internet or PSTN. Making the problem more difficult, the Internet telephony service considered in this paper gets the incoming voice packets of every session through only one UDP port number. In this paper, three schemes including the terminal proxy, the gateway proxy, and the protocol translation are suggested to solve the problems. The design and implementation of the NAT proxy server based on gateway proxy scheme are described in detail.