• Journal of the Institute of Electronics Engineers of Korea CI
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• v.39 no.4
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• pp.10-18
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• 2002

Network topology design is a multiobjective problem with various design components. The components such as cost, message delay and reliability are important to gain the best performance. Recently, Genetic Algorithms(GAs) have been widely used as an optimization method for real-world problems such as combinatorial optimization, network topology design, and so on. This paper proposed a method of Multi-objective GA for Design of the network topology which is to minimize connection cost and message delay time. A common difficulty in multiobjective optimization is the existence of an objective conflict. We used the prufer number and cluster string for encoding, parato elimination method and niche-formation method for the fitness sharing method, and reformation elitism for the prevention of pre-convergence. From the simulation, the proposed method shows that the better candidates of network architecture can be found.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.4B
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• pp.700-707
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• 2000

In this paper, we address vulnerabilities of legacy VOD system and implement secure-VOD system to protect security holes of it. Our secure-VOD system provide user authentication using one-time password, message authentication and encryption/decryption for video server information. To improve security of existing fixed password system, our secure-VOD system use one-time password. Also, our secure-VOD system provides integrity for video server information by generating and verifying message authentication code using HMAC-HAS 160 algorithm. Finally, our secure-VOD system uses RC5 encryption algorithm to guarantee confidentiality for video server information.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 1997.11a
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• pp.387-400
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• 1997

본 논문에서는 기존의 방송망에서의 다양한 한정 액세스 방식들을 살펴보고, ETSI 표준 한정 액세스 방식을 분석한다. 또한 스마트 카드 활용이 가능하고 다중 송신자 구조를 갖는 ECM(Entitlement Control Message) 과 EMM(Entitlement Management Message) 등의 메시지 분배를 위한 암호키 분배 방식을 살펴보고, 지상파 디지털 방송에 적용할 수 있는 공개키 알고리듬과 키된 MAC 를 이용한 자격 메시지 분배 기법을 제안한다.

• IE interfaces
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• v.13 no.3
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• pp.548-555
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• 2000

TAn E-Mail system is one of the most important services for enterprise and electronic commerce end users on the Internet. However, security for an E-Mail service is not satisfied yet, an E-Mail system with security service is definitely required especially in electronic commerce system. In this paper, an E-Mail system with confirmation of e-mail delivery is proposed, The certification of delivery of E-Mail message is not provided in conventional E-Mail systems. The proposed E-Mail system is composed of this certification of delivery and basic security services. The certification of delivery can prove sender's E-Mail message is securely sent to legitimate receivers. The system is designed and implemented by Java Cryptography API.

• International Journal of Contents
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• v.1 no.1
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• pp.45-49
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• 2005

If the service provider provides mobile service with mobile switching centers that use different handoff message format, the soft-handoff between mobile switching centers is not available and the hard-handoff scheme is used instead. When this occurs, calls are often disconnected or there is an interruption of service. This can be very annoying to a mobile user. We propose the handoff subsystem of the ATM switch which provides the soft-handoff between wireless cells under the control of different MSCs. The proposed handoff subsystem transforms the handoff message format of the source MSC to that of the destination MSC. It also provides efficient routing scheme that distributes handoff packets to balance the traffic load.

• IEMEK Journal of Embedded Systems and Applications
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• v.10 no.3
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• pp.119-127
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• 2015

In the IoT(Internet of Things) environment, methods that user can access sensor node directly to collect sensing data or manage sensor in a gateway have a limitations. To solve this problem, cloud based sensor network architectures are proposed. In this paper, we proposed CoAP based IoT architecture that a lightweight gateway is used for data gathering instead of using a heavy traditional one and users can request sensing data through IoT applications running in the cloud environment and analyze signaling message cost. By doing so, our system can reduce message cost compared to the traditional gateway based system.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.12
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• pp.145-154
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• 2003

In this paper we propose service schemes for the control message of voice and data connections served by a Softswitch in NGN (next generation networks). After that we propose a method of evaluating the performance of a Softswitch that provides a limited delay to voice connections. Via numerical experiments, we verify the implication of the proposition in the design of a Softswitch, which simultaneously incorporates voice and data services in the NGN framework.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.6
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• pp.506-513
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• 2002

Distributed control systems(DCS) using fieldbus such as CAN have been applied to process systems but it is very difficult to design the DCS while guaranteeing the given end-to-end constraints such as precedence constraints, time constraints, and periods and priorities of tasks and messages. This paper presents a scheduling method to guarantee the given end-to-end constraints. The presented scheduling method is the integrated one considering both tasks executed in each node and messages transmitted via the network and is designed to be applied to a general DCS that has multiple loops with several types of constraints, where each loop consists of sensor nodes with multiple sensors, actuator nodes with multiple actuators and controller nodes with multiple tasks. An assignment method of the optimal period of each loop and a heuristic assignment rule of each message's priority are proposed and the integrated scheduling method is developed based on them.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.757-766
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• 2005

A speed of a train is controlled by Automatic Train Control system and the continuous transmission system provide the speed related information in the Korean High Speed Line. The primary objective of this paper is to measure the level of continuous signal and to calculate the message of that signal. A measuring equipment is introduced and the equipment provide the base line of the level of current and the correction information of the message.

• Annual Conference of KIPS
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• 2005.05a
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• pp.1189-1192
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• 2005

컴퓨터와 네트워크의 보급이 일반화되면서 인터넷을 통한 정보 전달이 일상 생활처럼 되고 있다. 또한 인터넷, 무선통신, 그리고 자료 교환에 대한 증가로 인해 다른 사용자와 접속하기 위한 방식은 빠르게 변화하고 있다. 그러나 기존의 침입 차단 시스템과 침입 탐지 시스템과 같은 시스템 외부방어 개념의 보안 대책은 전산망 내의 중요한 정보 및 자원을 보호함에 있어서 그 한계를 갖는다. 본 논문에서는 해킹으로 판단되는 침입에 대하여 라우터의 구조적 변경 없이 효율적으로 역추적 하기 위해서 ICMP 역추적 메시지(ICMP Traceback Message)를 이용한 ICMP 기반의 역추적 시스템을 설계한다.