• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.118.2-118
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• 2002

Uncertain time delay happens when the process reads the sensor data and sends the control input to the plant located at a remote site in distributed control system. As in the case of data network using TCP/IP, VDN that integrates both device network and data network has uncertain tim e delay. Uncertain time delay can cause degradation in stability of distributed control system based on VDN. This paper investigates the transmission characteristic of VDN and suggests a control scheme based on the Smith's predictor to minimize the effect of uncertain time delay. The validity of the proposed control scheme is demonstrated with tracking position control of experiments.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.4
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• pp.334-340
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• 2004

In this paper, a Web-based management system for the building network is described. A multi-protocol converter based on SoC and embedded Linux is designed. The open source licensing, reliability, and broad hardware support are key reasons for use of embedded Linux in embedded industry. The multi-protocol converter integrates control network of RS-485 and LonWorks devices through TCP/IP protocol for a client with Java applet. The system consists of three-tier architecture, such as a client, a server that is performed on a multi-protocol converter, and control devices. The developed system includes the inverter motor control system with modbus protocol for the RS-485 network. The experiment results show that the multi-protocol converter using embedded Linux is a flexible and effective way to builda Web -based monitoring and control system.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.145-148
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• 2003

본 논문에서는 TCP/IP 기반에서 웨이블릿 변환과 신경회로(Neural Network)를 이용하여 실시간으로 동영상 전송을 위한 알고리즘에 대해 연구하였다. 우선, 서버에서 카메라를 이용하여 영상을 획득한다. 획득한 영상에 대해 2 단계 웨이블릿 변환을 한 후, 인터넷을 통하여 수신 측으로 전송한다. 그 다음, 수신 측에서는 동영상을 보이기 위해, 제한된 시간 안에 수신한 이미지 프레임(image frame)만을 가지고 역웨이블릿변환을 하여 보여주게 된다. 만약 네트워크에 혼잡이 발생하게 되면 소량의 이미지 프레임 만을 전송하도록 하였다. 수신 측에서는 네트워크의 혼잡 정도를 송신 측에 특별한 목적으로 제안된 프레임을 전송함으로써 알려주도록 하였으며, 송신 측에서는 이러한 정보를 수신한 후 역전파 신경회로(back-propagation neural network)를 이용하여 송신할 데이터의 양(data rate)을 조절하여줌으로써 네트워크 속도에 대처하도록 하였다. 이러한 방법을 통해서 우리는 네트워크의 혼잡에 알맞게 조정된 동영상의 스트림(stream)을 보낼 수 있었다.

• Journal of the Korea Society of Computer and Information
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• v.15 no.11
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• pp.185-193
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• 2010

In this paper, we Provide context-aware services based on UPnP Device Module including sensor unit in existing PLC network without additional infrastructure. so existing PLC devices are controlled based on knowledge context and can be used in a ubiquitous environment. And efficient remote control and device management based on UPnP can also be provided.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2298-2300
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• 2002

In this paper, we introduced a fault tolerant control system with the aim of achieving higher degree of reliability for a PLC control system in the field network. The system reliability was evaluated by MTBF(Mean Time Between Failure). The design of the fault tolerant system through CC-Link of Mitsubisi's MELSEC network was presented. In addition, the PLC data is transmitted from the field network's PC to the host PC by TCP/IP Window socket.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1998.04a
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• pp.304-308
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• 1998

Technical advances in computer networks and the Internet bring a new communication era and provide effective solutions for cooperative works and research. These technological advances introduced the concept of cyberspace that many people involve reseach and a project at different locations at the same time. In this paper, we present a fast and effective interaction protocol that is aeapted to the COLAB(COIIaborative LABoratory) Systems which use a high-speed ATM Network. The CCOLAB systems is developed for researchers those who are doing a large project on the collaborative research environment. The interaction protocol that we developed supports multi-session and multi-channel on the TCP/IP Network and provides more flexible solution to control multimedia data on the network.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.07a
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• pp.330-333
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• 2017

본 논문에서는 기존 인터넷 체계의 문제점을 보완하고 근본적인 대안을 제시하기 위해 CCN개념을 이용한 보안 강화 기법을 제안하고 이를 통해 네트워크의 안전한 전송 시스템을 제안한다. 또한 기존의 복잡한 구조와 사이버 공격 및 해킹에 쉽게 노출되는 TCP/IP 체계의 현재 인터넷 구조에서 네트워크 시스템구조를 단순화하고 획기적 성능 향상과 더불어 사이버 공격에 대응할 수 있는 기술을 제안하고 이를 프로토타입으로 설계하여 증명하고자 한다. 본 논문에서는 파일롯 시스템의 실험을 통하여 제안하는 CCN개념을 이용한 네트워크 보안 변환 시스템 기법의 우수함을 보인다.

• Journal of the military operations research society of Korea
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• v.18 no.2
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• pp.44-55
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• 1992

According to the plan on Defense Computer Network, hundreds of troops and ten thousands of end users will be joined in the Defense Computer Networn the near future. Thus, we need hierarchical addressing methods between source station and destination station in order to send a message efficiently. On the basis of the above background, we proposed the addressing methods for both TCP/IP environment which is a current standard protocol and OSI environment which will be a future protocol in this paper. The network interface. routings and address management have considered in our proposed addressing methods.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05c
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• pp.2141-2144
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• 2003

최근 인터넷의 급속한 보급 확대 및 대중화에 따라 네트워크상의 서비스 속도와 정보보안은 인터넷 사용자에게 중요한 문제로 대두되고 있고, 이로 인해 네트워크의 트래픽 증가와 공격자로부터의 공격이 점점 증가하고 있는 현실이다. 인터넷 사용자의 급속한 증가로 인한 복잡한 TCP 반응과 연관되어 네트워크 서비스에 많은 패킷 손실을 야기하게 되었다. 이러한 문제를 해결하기 위하여 대학 연구소와 기업체에서는 패킷에 임의의 정보를 마킹하고, 마킹된 정보를 추출하는 기법들을 연구하는 중이다. 그러한 기법은 네트워크 트래픽 제어를 위하여 패킷에 우선순위를 두어 차등 서비스 제공을 목적으로 패킷마킹 기법을 사용하기도 한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.3
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• pp.1298-1310
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• 2019

Network coding (NC) is a promising technology that can improve available bandwidth and packet throughput in wireless sensor networks (WSNs). Sliding window is an improved technology of NC, which is a supplement of TCP/IP technology and can improve data throughput and network lifetime on WSNs. This paper proposes a network coding-based maximum lifetime algorithm for sliding window in WSNs (NC-MLSW) which improves the throughput and network lifetime in WSN. The packets on the source node are sent on the WSNs. The intermediate node encodes the received original packet and forwards the newly encoded packet to the next node. Finally, the destination node decodes the received encoded data packet and recovers the original packet. The performance of the NC-MLSW algorithm is studied using NS2 simulation software and the network packet throughput, network lifetime and data packet loss rate were evaluated. The simulations experiment results show that the NC-MLSW algorithm can obviously improve the network packet throughput and network lifetime.