• 한국정보통신학회논문지
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• 제18권10호
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• pp.2382-2388
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• 2014

인도어 무선 통신 시스템에서 무선 네트워크의 신뢰성 보장을 위하여, 갑작스런 네트워크 결함 문제의 발생을 신속하게 해결해야 한다. 본 논문에서는, 사용자들에게 끊김없는 연결성 제공을 위하여 적응적 자원관리 (ARM: Adaptive Resource Management) 기법을 제안한다. 시스템 용량 및 사용자 공평성을 동시에 고려하여, ARM 기법에서는 적응적으로 힐링 서브채널 세트를 결정하고, non-convex 최적화 문제를 기반으로 서브채널과 파워를 반복적으로 할당한다. 시뮬레이션을 통하여 평균 셀 용량과 사용자 공평성 관점에서 제안하는 기법의 우수성을 증명한다.

• 경영과학
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• 제15권1호
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• pp.63-76
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• 1998

Reliability evaluation methodologies of the multipath MIN system are reviewed and critically compared. Some guidelines are proposed to select efficient evaluation method for the system designers to use. Considering the switch failure and repair characteristics of the MIN system, three types of Markov models are proposed for the MIN system availability models. These models can be used for the MIN performance analysis. The performance of the MIN system are supposed to vary according to the failure state of the system.

• 한국전자거래학회지
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• 제5권1호
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• pp.93-104
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• 2000

Domestic automotive industry is also facing the moment it should be with a competitively priced and highly qualified automotive ta compete with worldwide automotive makers of world market through global marketing and global sourcing. At this point, weve been studying xNX model of USA, Japan and Europe with OEMs, suppliers and KAMA(Korea Automotive Manufacturers Association) to give a network infrastructure of guaranteed service quality network performance, reliability, security and trouble handling. We hope all efforts above mentioned will make the whole industry more competitive and powerful.

• 한국시뮬레이션학회논문지
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• 제23권1호
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• pp.11-20
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• 2014

본 논문은 차세대 열차제어 시스템인 KRTCS (Korea Radio Train Control System)의 네트워크의 안정성에 대해여 연구한다. KRTCS는 철로 상에 운행중인 모든 열차들의 위치, 이동속도, 정위치 정차, 차량 문 개폐, 차량 내부 상황 등을 전체적으로 관리 감독하는 시스템으로 시스템의 동작 오류는 열차 운행에 지장을 초래할 뿐만 아니라 경우에 따라서 큰 사고로 이어질 수 있기 때문에 안정성에 대한 다각적인 검증을 반드시 필요로 한다. 이를 위해 본 논문이서는 실제 열차 운행이 이루어지는 환경과 운행 방식, 그리고 네트워크 장비에서 발생할 수 있는 동작 오류 패턴을 조사하고 이를 토대로 QualNet [1]을 활용해 다양한 환경에서 시뮬레이션을 실행한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.334-337
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• 2005

This paper describes the implementation of DCS communication network that provides high bandwidth and reliability. The network for DCS in this paper adopts the Reflective Memory (RM) architecture and Fast Ethernet physical media that have 100Mbps bandwidth. Also, this network uses Ring Enhancement Device (RED) which was invented to reduce the time delay of each node. The DCS network that is introduced in this paper is named as ERCNet(Ethernet based Real-time Control Network). This paper describes the architecture and working algorithms of ERCNet and performs numerical analysis. In addition, the performance of ERCNet is evaluated by experiment using the developed ERCNet network.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.2
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• pp.117-122
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• 2006

Modernized GNSS such as new GPS signals updated GLONASS and coming Galileo promises higher quality and higher reliability for users. Powerful technologies such as Internet, ubiquitous network technology and sensor network has been used to promote a safe and more secure lifestyle. This report describes experimental trials to combine these technologies namely GPS and Sensor Network into a high-performance system. GPS is used to enlarge the communication range, resolving the service area limitations, as a wider service area is required at shore areas compared to urban area. GPS position datum is also used as primary network routing information to get practical Sensor Network. Another application is the under water Sensor Network. Accurate GPS position and time are used to establish stable and high reliability underwater acoustic Sensor Network. This paper describes the background of the project 'Harbor area Marine Ubiquitous Sensor Network', preliminary consideration and testing. Radio and acoustic communication is the main focus of this preliminary experiment.

• 전자통신동향분석
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• 제38권3호
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• pp.20-28
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• 2023

Wireless communication technology has mainly been used to fulfill the demands of industrial sites at which performance is not a critical concern. However, ongoing discussions and efforts are now focused on securing core wireless communication technologies to enable the transformation or expansion of wired industrial IoT (Internet of Things) network technology into a flexible and dynamic smart manufacturing system. This paper provides an overview of current wireless industrial IoT network technology and the recent wireless time-sensitive networking technology. It outlines the challenging level of reliability required for wireless communication technology to coexist with or replace its wired counterpart in future smart manufacturing systems. Additionally, we introduce ultra-reliable time deterministic network as the core technology of wireless industrial communications and focus on its reliability and delay characteristics.

• 한국통신학회논문지
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• 제39C권11호
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• pp.1159-1166
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• 2014

본 논문에서는 무선 USB 시스템에서 신뢰성과 연결성을 향상하기 위한 기법을 제안하였다. 무선USB 프로토콜은 고속의 전송속도를 지원하기 때문에, 실시간 멀티미디어 서비스 제공과 같은 응용분야에 적합하다. 하지만, 디바이스의 이동은 네트워크 토폴로지와 디바이스간 링크 상태의 급격한 변화를 야기하며, 네트워크의 성능 저하의 원인이 되기도 한다. 특히 사람의 이동이 빈번한 선박 네트워크 환경에서는 디바이스의 이동성이 더 심해진다. 본 논문에서는 기존의 무선 USB 표준에서 무선 채널의 상태 변화를 적절하게 대처하지 못하여 발생하는 네트워크 성능 저하 문제를 해결하는 릴레이 통신을 위한 자원 관리 기법을 제안하여 성능을 분석하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.114-116
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• 2006

XCP (eXtensive Control Protocol) is an information oriented protocol which delivers information with high reliability according to the predefined rule. XCP network system can be implemented on top of several physical layer such as power line, IEEE 802.15.4 and so on. In this paper. a monitoring software that evaluates the reliability and performance of the XCP network is designed and implemented. This paper presents the structure and method of the packet monitoring in the network through several interfaces such as RS-232, ethernet.

• Journal of Electrical Engineering and Technology
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• 제13권6호
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• pp.2456-2467
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• 2018

Wireless multimedia sensor networks (WMSNs) require real-time quality-of-service (QoS) guarantees to be provided by the network. The end-to-end delay is very critical metric for QoS guarantees in WMSNs. In WMSNs, due to the transmission errors incurred over wireless channels, it is difficult to obtain reliable delivery of data in conjunction with low end-to-end delay. In order to improve the end-to-end delay performance, the system has to drop few packets during network congestion. In this article, our proposal is based on optimization of end-to end delay for WMSNs. We optimize end-to-end delay constraint by assuming that each packet is allowed fixed number of retransmissions. To optimize the end-to-end delay, first, we compute the performance measures of the system, such as end-to-end delay and reliability for different network topologies (e.g., linear topology, tree topology) and against different choices of system parameters (e.g., data rate, number of nodes, number of retransmissions). Second, we study the impact of the end-to-end delay and packet delivery ratio on indoor and outdoor environments in WMSNs. All scenarios are simulated with multiple run-times by using network simulator-2 (NS-2) and results are evaluated and discussed.