• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.07a
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• pp.316-320
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• 2003

본 논문에서는 우리가 개발한 IPsec 시스템의 효율성을 위해 인터넷 키 교환 서버를 중심으로 모듈간 연동 구조와 이에 따른 수행 절차를 다룬다. 개발한 IPsec 시스템은 IP기반 단대단 보안을 위해 IPsec 엔진을 중심으로 키 관리, SADB, SPDB 모듈이 통합된 구조로 되어 있다. 따라서 각 모듈간의 효율적인 연동구조는 시스템의 전체 효율에 매우 큰 영향을 줄 수 있다. 특히, 우리의 IPsec 시스템에서 IPsec 엔진은 커널과의 통합방식으로 구현되었기 때문에 SPDB와 SADB의 구현 위치에 따른 조회의 효율성을 위해 여러 고려 사항들이 필요하다. 우리는 이러한 문제를 풀기 위해 IKE 서버에 의해 생성된 SPI를 사용한다 최종적으로 우리는 SPDB 엔트리와 SADB 엔트리 조회의 최적화 방법에 기인한 모듈간 연동구조를 제안한다.

• Journal of Korea Game Society
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• v.20 no.5
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• pp.89-98
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• 2020

In MMO game servers, NUMA (Non-Uniform Memory Access) architecture is generally used to achieve high performance. Furthermore, such servers normally use hash tables as internal data structure which have constant time complexity for insert, delete, and search operations. In this study, we proposed a concurrent hash table optimized for NUMA system to make MMO game servers improve their performance. We tested our hash table on 4 socket NUMA system, and the hash table shows at most 100% speedup over another high-performance hash table.

• The Journal of the Korea Contents Association
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• v.19 no.7
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• pp.192-198
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• 2019

We propose an emergency rescue support communication system to quickly rescue passenger ships, such as large cruise ships, when a ship sinks or a disaster such as a fire occurs. A beacon is installed in the inside of the vessel, and the position and the status of the passenger are detected in real time through the Bluetooth communication in the mobile terminal carried by the passenger and transmitted to the server. When an emergency occurs, the server sends information on the passenger to the rescue agency, informs the passenger of the emergency, and guides evacuation. As a result of simulations using the designed system, it was confirmed that the server immediately notifies all terminals when an emergency occurred in more than half of the area. This system, which detects the accident in real time and notifies all terminals in the vessel, unlike the existing system that notifies the position of the accident vessel or simply the position of the passenger in the vessel, will be helpful for the rapid evacuation and rescue of the passenger.

• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3B
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• pp.517-525
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• 2010

The IPTV Service provides various interactive services beyond the level of being able to substitute cable TV. The IPTV system is to be decentralized gradually in which one server conducts all tasks. Primarily, deliberation of media needs to be changed into a system in which relayer and peer from the central server is utilized. Secondarily, the way of controling IPTV network need to be decentralized. Unlike the current client-server system, P2P(Peer To Peer), the main technology of decentralized IPTV is able to provide a service by cooperation of each node. Dealing with live streaming IPTV system which is based on the P2P protocol, this paper design the pure P2P IPTV structure and does verify the performance of P2P IPTV structure by realizing real system.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.5
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• pp.567-577
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• 2003

We usually applied PPP CHAP (Point-to-Point Protocol Challenge Handshake Authentication Protocol) when the visited ISP subscriber accesses to authentication server in own home ISP network and IP Assignment for remote Internet service. But PPP CHAP doesn't support in case of visited ISP subscriber in GPRS network accesses to authentication server in own home ISP network for wireless Internet service. We suggest solution this problem with PPP CHAP improvement. For this we propose the modified PPP CHAP message format, PCO Message format at MT, and interworking message and format between GGSN and RADIUS in home ISP network for wireless internet service of mobile ISP subscriber at GPRS network in this paper. We also show authentication results when visited mobile ISP subscriber via PPP CHAP at GPRS network accesses the RADIUS server in home ISP network.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04b
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• pp.3-5
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• 2000

최근 지리 정보 시스템(GIS)이 전 국가적으로 대중화되면서 서로 다른 분야에서 구축되어 서로 다른 환경에 분산되어 있는 이질적인 공간 데이터의 상호운용성에 대한 필요성이 증가하고 있다. 이러한 상호운용성을 위해 OGC에 의해 표준 사양인 OpenGIS이 개발되었고, 이 사양을 바탕으로 개방형 지리 정보 시스템을 개발하여 다양한 데이터 소스간의 상호운용성을 얻고자 하는 연구가 활발히 이루어지고 있다. 그러나, OpenGIS 사양을 따르는 상호운용성 지원 방법에서는 다양한 형태의 데이터 소스별로 데이터 제공자의 개발이 필요하다. 따라서 이러한 부담을 줄이고 효율적인 데이터 저장 및 관리를 위한 단일 처리 모델의 제시가 필요하다 이에 본 논문에서는 표준 데이터 언어인 XML과 기타 다른 관련기술을 OpenGIS 서버의 데이터 제공자 컴포넌트에 도입하여, OpenGIS 사양을 따르는 기존의 이질적인 데이터 소스와의 연등을 지원할 뿐 아니라 표준화된 저장 구조의 데이터 소스에 대한 하나의 효율적인 데이터 제공자를 갖는 OpenGIS 서버를 설계 및 구현한다. 본 시스템은 OpenGIS의 지리 데이터 구조와 처리에 대한 인터페이스의 표준화를 통해 상호운용성을 보장하고, OLE/COM 사양을 이용하여 각 컴포넌트들의 재사용성을 지원하며, 또한 문서 저장 및 전달을 위한 데이터 형식의 표준인 XML을 사용하여 문서구조의 검증 기능과 문서접근 방식의 단일화를 지원한다.

• Journal of KIISE:Information Networking
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• v.29 no.5
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• pp.573-582
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• 2002

We propose centralized server based QoS routing schemes, where a route server is responsible for determining QoS paths on behalf of all the routers in a routing domain. In the proposed server based schemes, the dynamic link QoS state information, which is required for a QoS path computation, is implicitly maintained at route server as it assigns or gets back QoS paths. By maintaining the network state information this way, we may not only eliminate the overhead to exchange network state update message but also achieve higher routing performance by utilizing accurate network state information in path computation. We discuss path caching techniques for reducing the amount of path computation overhead at the route server, and evaluate the performance of the proposed schemes using simulation. The simulation results show that the path caching schemes may significantly reduce the route server load. The proposed schemes are also compared to the distributed QoS routing schemes proposed in the literature. It has been shown that the proposed server based schemes not only enhance the routing performance, but they are also competitive with respect to routing overheads.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.3
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• pp.55-61
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• 2024

In a hybrid architecture that combines the technological advantages of P2P(peer-to-peer) and cloud computing, it is possible to efficiently supply resources and allocate loads. In other words, by appropriately utilizing the processing power of the players constituting P2P as well as the server in the cloud computing environment, MMOG(Massively Multiplayer Online Game) can be configured that considers the scale of economic cost and service quality. In fact, the computing power and communication bandwidth of servers in the cloud are important demand-based resources. The more it is used when renting, the higher the cost, while the quality of service improves. On the other hand, if the player's processing power is utilized a lot, the quality of service deteriorates relatively while the economic cost decreases. In this paper, a bandwidth adjustment technique between servers and players for MMOG based on this hybrid structure is described. When the number of players running at the same time increases, the players' actions are appropriately distributed to servers and players to effectively utilize the server's computing power and communication volume. Simulation results show that in the MMOG based on cloud and P2P hybrid architecture, the bandwidth of the server is proportionally decreased as the bandwidth directly handled by players is increased.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.6
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• pp.1106-1118
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• 2006

The Internet has become an important instrument for providing many pieces of information to us. And server systems offer the various services after processing a volume of information, it's network topology also has been complex for providing information. Therefore this expansion means the importance of fast and sustained management of server systems. But most of server systems are located in fire-walls to allow only restricted access. Moreover, due to the difference of management based on the different operating system of each server system, management of server system is not to efficiency. That is, sever administrators have to manage by themselves many kinds of servers by using local-based or socket-based single access applications. Therefore, we design and implement a middleware system which allows to manage many kinds of severs integrally ruling XML-based Web Services which have distributed object technology such as CORBA, Java RMI and DCOM, but are free from platforms or development languages. System also provides location transparency and terminal independence and calls a server system management command to manage systems.