• 산업경영시스템학회지
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• 제33권2호
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• pp.81-88
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• 2010

This paper presents an application of heuristic approach to problem of designing reliable network expansion. The problem essentially consists in finding the network topology that satisfies given set of reliability constraints. To efficiently solve the problem, a scatter search approach is proposed. The results of the two experiments show that scatter search is a more suitable approach for finding a good solution or near optimal solution in comparison with genetic algorithm.

• 한국시뮬레이션학회논문지
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• 제7권1호
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• pp.1-14
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• 1998

In this paper, we propose an efficient network communication scheme tailored to the network virtual reality(NVR) system. We first present the architecture and implementation of CVRAT (collaborative virtual reality authoring tool). The design goal of CVRAT is to provide consistent and scalable shared virtual environments. To achieve this goal, we classify the network messages according to their reliability and latency requirements. These conflicting requirements lead us to conceive a heterogeneous communication scheme which provides the unicast and three different multicast transport services; unreliable multicast, receiver-driven reliable multicast, fast reliable multicast. Each protocol has trade-offs in reliability, latency and bandwidth usage. The characteristics are analyzed by several experiments. Finally, applying this communication method to multi-participant battle-field tank simulation, we show the efficacy of proposed heterogeneous transport mechanism.

• 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.

• 전자공학회논문지B
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• 제28B권12호
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• pp.1-8
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• 1991

Given the set of minimal paths between two vertices in a network, this paper shows that the system reliability can be obtained by using a Binary Decision Digram. It can be done by transforming a Boolean sum of products into a Binary Decision Diagram and the reliability can be directly derived from it. The resulting reliability expression is compact and requires relatively fewer arithmetic opersations in its evaluation. Several examples are given to show that the method using Binary Decision Diagram is conceptually casy, simple and efficient.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.332-336
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• 1991

Network management is responsible for gathering information on the usage of the network media by the network devices, ensuring the correct operation of the network, and providing reports. MAP network management must provide the high reliability of the media and signaling method, even in very harsh environments, providing a very low bit error rate and minimum number of retransmission. In this paper, we analysed the framework of OSI management and MAP network management and discussed the implementation method of fault management and remote management mechanism in the Mini-MAP controller developed for IBM-PC.

• 정보처리학회논문지D
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• 제14D권6호
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• pp.649-656
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• 2007

오늘날 차량네트워크(CAN)는 전기적 강인, 저가격과 접근지연 때문에 분산 임베디드 시스템에서 널리 사용되는 버스형 필드이다. 그러나 버스토폴로지에서 발생하는 의존적인 제한 때문에 차량네트워크가 어플리케이션상에서 안전적으로 사용되는지는 논쟁되어왔다. 그래서 차량네트워크(CAN) 디자인 단계 동안 데이터 버스의 부하와 최대 지연, 경쟁 우선순위와 같은 네트워크의 성능을 분석하는 것이 중요하게 되었다. 이 논문은 차량네트워크의 성능을 평가하기 위해 사용된 시뮬레이션 알고리즘과 고장 기법 기술을 적용을 소개한다. 이는 차량네트워크의 어떤 산만한 구현의 줄임과 시스템의 신뢰성을 향상 시켜 줄 것이다.

• 전기학회논문지
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• 제64권10호
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• pp.1448-1453
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• 2015

In this paper, we propose an alternative method of communication to improve the reliability of in-vehicle networks by jointly using wireless communication networks. Wired Communication networks have been used in vehicles for the monitoring and the control of vehicle motion, however, the disconnection of wires or hardware fault of networks may cause a critical problem in vehicles. If the network manager detects a disconnection or faults in wired in-vehicle network like the Controller Area Network(CAN), it can redirect the communication path from the wired to the wireless communication like the Zigbee network. To show the validity and the effectiveness of the proposed in-vehicle network architecture, we implement the Electronic Stability Control(ESC) system as ECU-In-the-Loop Simulation(EILS) and verify that the control performance can be kept well even if some hardware faults like disconnection of wires occur.

• 전기학회논문지P
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• 제64권4호
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• pp.281-285
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• 2015

Electrical energy supply interruption degrades reliability of power supply as well as social costs and economic loss. It is important to assess the reliability of the power system. Nowadays IEC61850 based substation automation system(SAS) has been developed for an updating of automation and interoperability. In this study, three kinds of reliability block diagram(RBD) were proposed to examine of network availability of the three types SAS. And reliability and unreliability of the SAS was formulated using the RBD. Finally, while varying the value of reliability and unreliability, the reliability and the unreliability of the overall system were evaluated.

• 한국신뢰성학회지:신뢰성응용연구
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• 제10권1호
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• pp.11-24
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• 2010

Lighting industry is rapidly being developed as the ubiquitous society based on sensor network emerges. This kind of paradigm shift brings the society convergence of technologies which leads to smart lighting system as well as the integration of interior and sensibility control. However, standards for sensors have not been firmly established, and problems related to quality and malfunction have been brought up, thereby calling for careful approach to the enhancement and assessment of reliability of the item. In this article reliability assessment criteria for sensor module for lighting fixtures is established in terms of performance assessment criterion and reliability assessment criterion.

• 조명전기설비학회논문지
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• 제24권6호
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• pp.52-59
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• 2010

지속적인 전력수요 증가에 따라 대단위 발전설비가 증설되고 있다. 특히, 국제적인 친환경 기조에 따라 배전계통 내에 신재생 에너지를 기반으로 하는 분산전원이 급속히 확산되고 있다. 또한, 전력공급의 신뢰도 향상 및 계통 운영의 유연성을 위해서 배전계통이 망상 형태로 점점 복잡해지고 있는 실정이다. 이러한 변화는 사고시의 고장전류 크기를 증가시킨다. 따라서, 앞으로 고장전류는 현재 설치된 차단기의 차단 한계용량을 넘어설 것으로 예상된다. 이를 위한 해결책으로 보호설비의 교체나 용량증대 등을 들 수 있다. 하지만, 기술적 경제적인 측면을 고려해 볼 때 초전도한류기가 그 대안이 될 수 있다. 본 논문에서는 초전도한류기의 최적 위치를 선정하는 기법을 제안한다. 최적 위치는 초전도한류기의 복합배전계통 내 설치 위치에 따른 설비별 고장전류의 저감에 기초해 설비별 고장율을 재산정하고 이를 통한 수용가별 신뢰도 향상을 신뢰도 민감도 지수를 이용하여 산정한다. 또한, 수지형 계통 및 망상형 계통에 제안한 초전도한류기의 최적 위치 기법을 적용함으로써 그 타당성을 입증하였다.