• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2009년도 춘계학술대회 논문집 전기설비전문위원
• /
• pp.77-79
• /
• 2009

Nonlinear system fault detection and isolation of this paper is about the failure of unknown function approximation using neural network for fault detection and isolation techniques of induction motors were applied. observer-based fault signal residual value was used. Induction motor using the speed controller of the backstepping controller. Proposed fault detection and isolation to prove the performance of the simulation was applied to and the actual system.

• 전자공학회논문지S
• /
• 제35S권1호
• /
• pp.68-79
• /
• 1998

In this paper, we propose a model-based FDI(fault detetion and isolation) algorithm to detect and isolate fault in a linear system. The proposed algorithm is gased on an HFC(hydrid fault classifier) which consists of an FCART2(fault classifier by ART2 neural network) and an FCFM(fault classifier by fault models) which operate in parallel to isolate faults. The proposed algorithm is functionally composed of three main parts-parameter estimation, fault detection, and isolation. When a change in the system occurs, the estimated parameters go through a transition zone in which errors between the system output and the stimated output and the estimated output cross a predetermined thrseshold, and in this zone the estimated parameters are tranferred to the FCART2 for fault isolation. On the other hand, once a fault in the system is detected, the FCFM statistically isolates the fault by using the error between ach fault model out put and the system output. From the computer simulation resutls, it is verified that the proposed model-based FDI algorithm can be performed successfully to detect and isolate faults in a position control system of a DC motor.

• Journal of Information Technology Applications and Management
• /
• 제13권4호
• /
• pp.141-153
• /
• 2006

According to supply of super high way internet service, importance of security becomes more emphasizing. Therefore, flawless security solution is needed for blocking information outflow when we send or receive data. large enterprise and public organizations can react to this problem, however, small organization with limited work force and capital can't. Therefore they need to elevate their level of information security by improving their information security system without additional money. No hackings can be done without passing invasion blocking system which installed at the very front of network. Therefore, if we manage.isolation log effective, we can recognize hacking trial at the step of pre-detection. In this paper, it supports information security manager to execute isolation log analysis very effectively. It also provides isolation log analysis module which notifies hacking attack by analyzing isolation log.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2001년도 하계종합학술대회 논문집(5)
• /
• pp.115-118
• /
• 2001

In this paper we propose an FDI(fault detection and isolation) algorithm using neural network-based multi-fault models to detect and isolate single faults in nonlinear systems. When a change in the system occurs, the errors between the system output and the neural network nominal system output cross a threshold, and once a fault in the system is detected, the fault classifier statistically isolates the fault by using the error between each neural network-based fault model output and the system output.

• 전자공학회논문지SC
• /
• 제39권1호
• /
• pp.24-32
• /
• 2002

본 논문은 다중 컴퓨터 시스템(multicomputer system)에서 사용되는 상호연결망(interconnection network)의 일종인 다단계 상호연결망(multistage interconnection network)에서의 고착고장(stuck-at fault)과 관련된 고장진단(fault diagnosis)에 대해 고찰한다. 지금까지 연구된 바에 의하면 다단계 상호연결망의 고장을 검출하고 위치를 찾기 위채서는 각 고장의 유형에 따라 서로 다른 다수의 과정을 거치거나 몇 번의 테스트를 통한 진단기법을 필요로 한다. 이에 본 논문에서는 단일과정을 통해 대표적인 고착고장의 유형을 검출하고 위치를 찾아내는 고장진단 알고리즘을 제안한다. 즉, 고착고장이 존재하는 임의의 다단계상호연결망에 대하여 고장 스위치 소자의 행과 열의 위치정보 및 고착고장의 유형진단 알고리즘을 제시한다. 마지막으로 다단계 상호연결망의 일종인 16×16 베이스라인 망(baseline network)에서 고착고장이 발생한 스위치의 위치와 유형을 찾는 과정을 통해 제안하는 알고리즘의 효용성을 검증한다.

• 한국조경학회지
• /
• 제29권6호
• /
• pp.37-49
• /
• 2002

The objective of this research was an investigation of the important green spaces in Daegu and to present the basic frame of green network in Daegu. Present the condition of the significant green spaces is as follows: In the 3km radius of the city center, the isolation and discontinuation of the green spaces was extensive, caused by crowding of houses and funeral parlours. Consequently, the isolation relaxation which leads to the additional creation of the green spaces and a buffering plan were demanded. In the transfer area of a 3∼6km radius, which is located between the city center's congested area and the suburb green spaces, the significant green spaces had high connection and buffering characteristic, but in the northwest and the south, serious discontinuation appeared between the suburb green spaces and the city conte green spaces. In the 6∼9km radius, the suburb important green spaces accomplished the function which extended the back core green spaces to the city center area. But creation of buffering green spaces was necessary in part because of proximity to the resident area. The results suggest a connection between green spaces on the base of the distribution of the important green spaces, were as follows: In the 3km radius, irregular direction lines appeared while a schedule one direction line appeared in 3∼6km and 6∼9km radius. The discontinued parts of the green network were caused by industrial complexes, house crowding, and cultivation areas. Consequently, reservation and creation plans of green spaces in response to this were demanded. Through the additional creation of green spaces in the discontinued parts, the basic frame of green network in Daegu was the radiation annular form. And it was suitable to activate the parks and the general green spaces.

• 한국컴퓨터정보학회논문지
• /
• 제14권9호
• /
• pp.75-84
• /
• 2009

본 논문에서는 EPC Network의 응용 기술 분야에서 가장 중요한 기술로 연구되고 주목받고 있는 RFID를 활용하여 특수질병 감염환자를 효율적으로 관리할 수 있는 U-MAS (U-Medical Administrative Services)시스템을 설계하였다. U-MAS시스템은 질병관리본부에서 질병의 유형에 따라 감염환자들을 격리 수용과 치료, 회복, 퇴원, 격리병동 이탈 등을 집중 관리할 수 있도록 효율성을 증대시킬 수 있으며, 수작업과 단순한 컴퓨터 프로그램을 이용하는 현 수준의 질적 향상을 높이기 위해 RFID 태그를 이용하여 환자의 관리를 좀 더 면밀하고, 격리병동을 벗어나게 될 경우 관할 질병관리지역구에서 보다 빠르게 위치추적 등의 대응을 원활히 할 수 있도록 기여하는데 목적이 있다. 먼저, EPC 네트워크의 관련 기술과 모바일 RFID 시스템에 대한 관련 연구를 기술하고, U-MAS 시스템 설계를 제안한다. 제안된 U-MAS 시스템을 활용할 경우 전염성 질병환자에 대한 모니터링과 격리병동에 있는 환자가 무단으로 이탈하였을 때 위치추적에 소요되는 시간을 단축시키는 질병관리업무의 효율성을 개선할 수 있는 기대 효과를 제시하였다.

• 전자공학회논문지SC
• /
• 제39권1호
• /
• pp.42-50
• /
• 2002

본 논문에서는 비선형시스템에서 발생한 고장을 감지하고 분류하기 위한 신경회로망기반 다중고장모델을 이용한 고장감지 및 분류 방법을 제안한다. 시스템에 변화가 발생하면 시스템의 출력과 신경회로망 공칭모델 출력 사이의 오차가 고장감지를 위한 문턱값을 넘고, 고장이 감지되면 각 신경회로망 고장모델 출력과 시스템 출력 사이의 오차를 이용하여 통계적 기법으로 고장을 분류한다. 컴퓨터 시뮬레이션 결과로부터 제안한 고장진단방법이 비선형시스템에서의 고장감지 및 분류문제에 잘 적용됨을 알 수 있다.

• Journal of electromagnetic engineering and science
• /
• 제16권3호
• /
• pp.194-197
• /
• 2016

An eight-element compact low-profile multi-input multi-output (MIMO) antenna is proposed for wireless local area network (WLAN) mobile applications. The proposed antenna consists of eight inverted-F antennas with an isolation-enhanced structure. By inserting the isolation-enhanced structure between the antenna elements, the slot and capacitor pair generates additional resonant frequency and decreases mutual coupling between the antenna elements. The overall size of the proposed antenna is only $33mm{\times}33mm$, which is integrated into an area of just $0.5{\lambda}{\times}0.5{\lambda}$. The proposed antenna meets 5-GHz WLAN standards with an operation bandwidth of 4.86 - 5.27 GHz and achieves an isolation of approximately 30 dB at 5 GHz. The simulated and measured results for the proposed antenna are presented and compared.

• 상하수도학회지
• /
• 제20권1호
• /
• pp.35-43
• /
• 2006

Concerns related to protecting, identifying, and isolating of subsystems of a water distribution network have led to the realization of the increased importance of valves in the system. The most important purpose of valves in water distribution systems is to isolate a subsystem due to breakage, maintenance activities, or contamination. A subsystem called segment is isolated by the closure of adjacent valves. Minimizing the pipe failure impact, an efficient algorithm is required to identify adjacent valves quickly. In this paper, an algorithm to identify adjacent valves to be closed to isolate a subsystem from the remainder of a network when a pipe failure is presented. The algorithm is operated on a matrix called the valve location matrix containing the information of valve locations. An application to an existing water distribution system demonstrates the developed algorithm efficiently locates the adjacent valves for the isolation of a broken pipe.