• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.173_174
• /
• 2009

K-EMS(한국형에너지관리시스템)용 상정고장해석(Contingency Analysis) 프로그램에 대해 설명한다. 상정고장해석 프로그램은 가상의 고장에 따른 계통의 상태변화 판정 기능과 심각한 상정고장 목록을 선별하는 기능, 그리고 선별된 고장목록의 완전해석 기능으로 구성된다. 본 논문에서는 그간의 연구에서 개발된 고장에 따른 계통의 상태변화를 판정하는 방법을 설명하며, 그러한 방법에 적용한 사례연구결과와 개발 프로그램의 성능을 기술한다.

• Proceedings of the KIEE Conference
• /
• 1999.07g
• /
• pp.2836-2838
• /
• 1999

고신뢰도의 요구를 보장하는 병렬 구조의 분산시스템의 사용이 증가함에 따라 네트워크 상에서 메시지전달을 방해하는 요소고장의 영향을 최소화시킬 수 있는 고장포용 라우팅에 대한 중요성이 부각되고 있다. 그러나, 네트워크의 복잡한 환경 때문에 요소고장을 극복하기 위한 고장포용 라우팅 알고리즘의 설계는 쉬운 일이 아니다. 본 논문에서는 2차원 메쉬 네트워크에 적용되는 최적의 고장포용 라우팅 알고리즘을 설계하기 위하여 관련 응용분야에서 그 유용성이 검증된 유전 알고리즘을 이용한다. 제안된 알고리즘은 wormhole 라우팅 방식을 사용하며, 교착상태를 없애기 위하여 하나의 물리적 채널을 공유하는 4개의 가상채널을 사용한다. 마지막으로, 시뮬레이션을 통하여 제안된 알고리즘이 기존의 다른 고장포용 라우팅 알고리즘보다 우수함을 증명한다.

• Journal of Advanced Navigation Technology
• /
• v.7 no.2
• /
• pp.171-179
• /
• 2003

In this paper a neural network-based fault tolerant control system for aircraft sensor and actuator failures is considered. By exploiting flight dynamic relations a set of neural networks is constructed to detect sensor failure and give alternative signal for the faulty sensor. For actuator failures another set of neural networks is designed to perform fault detection, identification, and accomodation which returns the aircraft to a new stable trim. Integrated system is simulated to show the performance of the system with sensor and control surface failures.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2021.10a
• /
• pp.427-428
• /
• 2021

Recently, various augmented reality(AR) methods for monitoring situations in a remote factory have been proposed. The 2D manual with a classic method is not intuitive to understand and has limitations to provide to interact with objects to be repaired in the remote factory. In our paper, we present a guide method based on a virtual human expressed in augmented reality for the remote environment. Also, the remote factory environment was periodically captured through 3D reconstruction, our virtual human was adaptively matched to the built 3D environment. According to this paper, our method makes it possible to perform repairs quickly with the feeling of being with an expert. and it is possible to provide a visualized guide for troubleshooting in various fields such as factories, offices, medical facilities, and schools in remote environments.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.12B
• /
• pp.1044-1048
• /
• 2006

This paper proposes a FTOG(Fault-Tolerant Object Group)-based recovery services through replicated objects. In the distributed system, the fault of the object component may cause an entire system failure, evidently raising the service breakdowns. Therefore, this paper proposes recovery services with the replicated objects in case of fault occurrences. Moreover, applying the FTOG model to a virtual home network simulation, we verify the consistency maintenance and the service reliability of the proposed model.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2001.04a
• /
• pp.430-434
• /
• 2001

Virtual manufacturing system is integrated computer model that represents the precise and whole structure of manufacturing system and simulates its physical and logical behavior in operation.[1] A virtual machine is computer model that represents a CNC machine tool and one of core elements of virtual manufacturing system. In this paper, it is emphasized that a virtual machine must be web-based system for serving information to all attendants in a real machine tool without the restriction of time or location, and then in the fault diagnosis, one of important modules of a virtual machine, the methods of both using the controller signal and web-based expert system are proposed.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.10a
• /
• pp.109-114
• /
• 1997

As CNC machine tool is one of core elements of manufacturing system, it is much important that it remains without troubleshoots. As a virtual machine is a recent alternative using IT for optimal utilization of CNC machine tool, it is a computer model that represents a CNC machine tool. But a virtual machine is still conceptual. So, in this paper, it is proposed that a virtual machine be a realistic model in the fault diagnosis module. For this purpose, the fault diagnosis system of machine tool using CORBA and fault diagnosis expert system has been implemented. Using this system, we have expections to diagnose exactly and prompty without the restriction of time or location, to reduce MTTR(Mean Time To Repair) and finally to increase the availability of manufacturing system.

• Journal of Korea Multimedia Society
• /
• v.7 no.8
• /
• pp.1097-1106
• /
• 2004

The typical web cluster architecture consists of replicated real servers and a virtual server that routes client requests among the real servers. In this paper, we proposed an efficient dynamic load distribution method with load prediction for the web cluster systems. The virtual server transmit status request message to real servers in other to get load states. However the load states dose not accurate during load distribution, thus the virtual server predict the load status of real servers and assign a request of the client to the minimum loaded real server. The proposed distribution methods works not related to partial breakdown of real servers, thus the system works with high availability. We also show that the proposed distribution method preserve scalable property and improve the throughput through a set of simulations.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.46 no.12
• /
• pp.73-79
• /
• 2009

With the advance of VLSI technology, the capacity and density of memories are rapidly growing. In this paper we proposed MRI (Memory built-in self Repair Imagination zone) as reallocation algorithm. All faulty cells of embedded memory are reallocated into the row and column spare memory. This work implements reallocation algorithm and BISR to verify its design.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1994.04a
• /
• pp.507-507
• /
• 1994