• Journal of Navigation and Port Research
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• v.29 no.6 s.102
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• pp.555-560
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• 2005

Recently, many control systems are replaced with digital control systems in an effort to optimize the overall performance. In order to operate these systems efficiently, the conventional point-to-point connection method must be changed to the signal exchange via a communication network. This paper investigates the technical feasibility of the crane system using CAN protocol which is a part NMEA 2000 by implementing a network-based control system emulating the crane control system.

• Journal of KIISE:Information Networking
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• v.37 no.5
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• pp.363-373
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• 2010

The existing QoS mechanisms for video streaming are short of the consideration for various user environments and the characteristic of streaming applying programs. In order to overwhelm this problem, studies on the video streaming protocols exploiting scalable video coding (SVC), which provide spatial, temporal, and qualitative scalability in video coding, are progressing actively. However, these protocols also have the problem to deepen network congestion situation, and to lower fairness between other traffics, as they are not equipped with congestion control mechanisms. SVC based streaming protocols also have the problem to overlook the property of videos encoded in SVC, as the protocols transmit the streaming simply by extracting the bitstream which has the maximum bit rate within available bandwidth of a network. To solve these problems, this study suggests TCP-friendly network adaptive SVC streaming(T-NASS) protocol which considers both network status and SVC bitstream property. T-NASS protocol extracts the optimal SVC bitstream by calculating TCP-friendly transmission rate, and by perceiving the network status on the basis of packet loss rate and explicit congestion notification(ECN). Through the performance estimation using an ns-2 network simulator, this study identified T-NASS protocol extracts the optimal bitstream as it uses TCP-friendly transmission property and perceives the network status, and also identified the video image quality transmitted through T-NASS protocol is improved.

• IEMEK Journal of Embedded Systems and Applications
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• v.8 no.6
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• pp.329-337
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• 2013

In multihop routed ad hoc networks, the conventional store-and-forward delivery has been used. However, we may ask a question: "Is the store-and-forward delivery still the best?" This paper presents a pipeline-through MAC (PT-MAC) protocol for ad hoc networks, in which nodes have two 3-channel interfaces in order to use limited radio resources efficiently and improve network performance. The proposed protocol reduces end-to-end delay significantly in multihop routed transmission by exploiting a novel pipeline-through technique rather than using the conventional store-and-forward. This results in improved network performance without increasing control overhead. Our extensive performance study shows that the proposed PT-MAC shows 20-40 percent shorter end-to-end delay and 25-55 percent better goodput compared to the IEEE 802.11 DCF with two 3-channel interfaces.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.6
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• pp.1104-1109
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• 2001

In this paper, we describe a method for real-time transmitting video streams based on RTP. In order to guarantee synchronous video streams, we propose a method to grasp network situations by analyzing end-to-end network traffic. In addition, we present an algorithm for satisfying QoS requirements of real-time multimedia transmission and maintaining continuity of transmission. It describes a buffering method for overcoming bandwidth limitations and an analyzing method based on RTCP for grasping network traffic situation to resolve the problem of real-time transmission of video streams.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1545-1549
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• 2005

According as computer is supplied in a lot of homes and offices and Internet use increases, various service based on the Internet. Including wireless PDA in the future, many devices such as Internet telephone, TV, refrigerator and oven will be connected on the Internet and Internet address exhaustion will be raised to serious problem gradually. Today, the IPv4 address exhaustion problem has been solved partially using NAT (Network Address Translation) however, the transition to next Generation Internet will be accelerated because of advantages such as mobility, security service, QoS, and abundant IP addresses. In IPv6, all hosts are designed to create and set their address automatically without manager's intervention using Neighbor Discovery Protocol. But, when an IPv6 host sets its address automatically, there are serious security vulnerabilities. In this paper, we analysis security vulnerabilities in auto-configuration and provide security requirements for secure auto-configuration.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.505-507
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• 2005

In this paper, a timing analysis is performed for the CAN-based simulator system for a fuel cell hybrid electric vehicles. The CAN protocol is recently being used for conventional vehicles, however, the network-induced delay can make the in-vehicle network system unstable. This problem may be occurred in the future vehicles because more ECUs are being required than recent vehicles. In order to develop a stable network-based control system, timing analysis is required at the design process. Throughout this analysis, timing parameters that affect transmission delay are examined and an effective method of predicting a sampling time for a stable communication via CAN protocol. In order to show the validityof suggested timing analysis. some experiments are performed using DSPs with CAN module.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.133-133
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• 2000

This paper implements Message Service of TCN or IEC 61375-1. TCN is divided into two services, Variable and Message Service. Variable Service uses the broadcasting method with Source Address, but Message Service uses peer-to-peer method with Destination Address and has OSI 7 Layer. In TCN, interface between Transport and Network Layer has not been defined and Meaning of Packet Pool has not been defined exactly. Therefore, this paper proposes the Implementation method for both the interface between Transport and Network Layer and the packet pool for Message Service of TCN.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.272-272
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• 2004

홈 네트워크(home network)란 집안과 밖에서 언제든지 편리하고 안전하며 경제적인 생활서비스를 즐길 수 있도록 다양한 디지털 가전 기기들이 서로 연결된 네트워크를 의미한다. 디지털 신호 처리 기술의 발전으로 인하여 백색 가전으로 불리우던 냉장고나 세탁기 등이 점차 디지털화되고, 가전용 운영 체제 기술과 고속 멀티미디어 통신 기술 등이 디지털 가전에 응용되고 있다. 이로 인하여, 새로운 형태의 정보 가전이 등장하고, 홈 네트워크 분야의 _관심도가 높아지고 있다.(중략)

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.129-132
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• 2001

The ad hoc network was composed of Mobile hosts. Due to the limited transmission range of each mobile node hosts, in such an environment, it is essential for other hosts to coorperate to transfer packet to destination. Moreover, the existing routing protocol algorithms are not efficient on the ad hoc network because a mobile host operates router without fixed router. In this paper, we will compare and analysis for the performance of existing ad hoc network routing protocols through simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.169-172
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• 2001

In this paper, we describe a method for real-time transmitting video streams based on RTP In order to guarantee synchronous video streams, we propose a method to grasp network situations by analyzing end-to-end network traffic. In addition, we present an algorithm for satisfying QoS requirements of real-time multimedia transmission and maintaining continuity of transmission. It describes a buffering method for overcoming bandwidth limitations and an analyzing method based on RTCP for grasping network traffic situation to resolve the problem of real-time transmission of video streams.