• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.157.1-157
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• 2001

A new methodology is presented to diagnose faults in equipment plasma. This is accomplished by using neural networks as a pattern recognizer of radio frequency(rf) impedance match data. Using a realtime match monitor system, the match data were collected. The monitor system consisted mainly of a multifunction board and a signal flow diagram coded by Visual Designer. Plasma anomaly was effectively represented by electrical match positions. Twenty sets of fault-symptom patterns were experimentally simulated with experimental variations in process factors, which include rf source power, pressure, Ar and O$_2$ flow rates. As the inputs to neural networks, two means and standard deviations of positions were used ...

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.157.4-157
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• 2001

An effective approach to detect and diagnose multiple failures in a dynamic system is proposed for the case where the measurement noise is correlated sequentially in time. It is based on the modified interacting multiple-model (MIMM) estimation algorithm in which a generalized decorrelation process is developed by employing the autoregressive (AR) model for the correlated measurement noise. Numerical example for the nuclear steam generator is provided to illustrate the enhanced performance of the proposed algorithm.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.281-286
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• 1992

This paper describes a duplexed process control system for a boiler-turbine system of power plant, which is composed of supervisor, controller, and simulater subsystems. Its embeded POL(Problem oriented language) as a structured control language enables this system to do a real-time distributed control and fault diagnosis by simple programming with the actual implementation of advanced control algorithms such as PID autotuning and GPC, etc, the performance of overall system has been greatly enhanced.

• 한국가스학회:학술대회논문집
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• 2005.05a
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• pp.212-212
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• 2005

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.190-192
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• 2005

EAI(Enterprise Application Integration : 전사적 애플리케이션 통합)는 기업간 또는 기업 내부의 다양하고 이질적인 시스템과 애플리케이션 그리고 비즈니스 프로세서을 통합 하는것[1]이며, 본 논문에서는 어느 한쪽 프로세서가 중단되어도 다른 프로세서가 그 처리를 이어 받아서 중단없는 데이터 및 프로세스를 처리함으로써 기업의 전체 프로세스에는 영향이 없게하는 방법을 C API 프로그램의 구현을 통하여 증명함으로써 무중단 실시간 처리 시스템 구축에 도움이 될 것이며. 로그파일 모니터링 방법을 통한 실시간 모니터링에 대해서 설명하고, 앞으로의 발전방향에 대하여 논할것이다.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1997.11a
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• pp.383-394
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• 1997

이 논문에서 우리는 결함허용 실시간 소프트웨어 설계를 위한 명세언어를 제안한다. 특히, 현재 가장 인기있는 소프트웨어 기법인 후향 오류 복구를 위한 명세언어로 N-modular redunduncy나 voted-process pairs등에도 사용 가능하다. 지금까지의 명세 언어로서는 시스템의 정상 개발 차원에서의 명세만 가능했다. 그래서 본 논문에서는 시스템의 오류시에도 복구 가능한 논리 전달을 위한 명세를 제공한다. 복잡함을 피하기 위해 객체단위로 시스템을 이끌며, 명세서 작성시 주요한 부시스템 단위로 이 방법을 적용하면 명세 기술에 따른 오버헤드를 감소시킬 수 있다.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1006-1008
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• 1998

This paper describes the possible undesier-able side effects that thyristor controlled compensation may have upon in several relays. This process consisted of calculating line conditions for each of the fault, compensation and loading levels. In some cases their effectiveness at coordinating compensated lines is lost, as they no longer can always accurately determine "distances" to faults.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1516-1519
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• 1997

With disseminationof Distributed Control Systems(DCS), the huge amounts of process operation data could have been available and led to figure out process behaviors better on the statistical basis. Until now, the statistical modeling technology has been susally applied to process monitoring and fault diagnosis. however, it has been also thought that these process information, extracted from statistical analysis, might serve a great opportunity for process operation improvements and process improvements. This paper proposed a general methodolgy for process operation improvements including data analysis, backing up the result of analysis based on the methodology, and the mapping physical physical phenomena to the Principal Components(PC) which is the most distinguished feature in the methodology form traditional statistical analyses. The application of the proposed methodology to the Balst Furnace(BF) process has been presented for details. The BF process is one of the complicated processes, due to the highly nonlinear and correlated behaviors, and so the analysis for the process based on the mathematical modeling has been very difficult. So the statisitical analysis has come forward as a alternative way for the useful analysis. Using the proposed methodology, we could interpret the complicated process, the BF, better than any other mathematical methods and find the direction for process operation improvement. The direction of process operationimprovement, in the BF case, is to increase the fludization and the permeability, while decreasing the effect of tapping operation. These guide directions, with those physical meanings, could save fuel cost and process operator's pressure for proper actions, the better set point changes, in addition to the assistance with the better knowledge of the process. Open to set point change, the BF has a variety of steady state modes. In usual almost chemical processes are under the same situation with the BF in the point of multimode steady states. The proposed methodology focused on the application to the multimode steady state process such as the BF, consequently can be applied to any chemical processes set point changing whether operator intervened or not.

• Science of Emotion and Sensibility
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• v.11 no.2
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• pp.207-214
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• 2008

The inspection processing is for reducing loss which occurs fault because of fabric appearance. Up to now inspection machine which is used from inspection process is classified with the macrography inspection machine and the full automatic inspection machine. The macrography inspection machine is low price and efficient equipment but does not record information of fault. On the other side, the automatic inspection machine is high price, also the detection rate of one changes with effect of environment variable but able to record information of fault. It developed semi-automatic cloth inspection machine with the weak point of the macrography inspection machine and the automatic inspection machine was complemented. And when it uses information which was collected by semi-automatic cloth inspection machine, the loss rate of original fabric is able to calculate. So sewing factories will be able to predict fabric consuming quantity.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.2
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• pp.258-266
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• 2012

Recently, Acoustic Emission (AE) technique is widely applied to develop the early fault detection system, and the problem about a signal processing method for AE signal is mainly focused on. In the signal processing method, envelope analysis is a useful method to evaluate the rolling element bearing problems and Wavelet transform is a powerful method to detect faults occurred on gearboxes. However, exact method for AE signal is not developed yet. Therefore, in this paper, two methods, which is Hilbert transforms (HT) and Hilbert-Huang transforms (HHT), will be compared for development a signal processing method for early fault detection system by using AE. AE signals were measured through a fatigue test. HHT has better advantages than HT because HHT can show the time-frequency domain result. But, HHT needs long time to process a signal, which has a lot of data, and has a disadvantage in de-noising filter.