• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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• pp.1862-1863
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• 2006

In this paper, A new tuning method for IMC-PID controller is proposed with the identification using the relay method from closed-loop transfer function. It is considered a second-order plus delay time(SOPDT) model and selected a third-order plus delay time transfer function model as a target function. The filter function is derived from the suitable target function to satisfy the design specifications. A robustness test was done to verify the robust-stability.

• International Journal of Control, Automation, and Systems
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• 제5권2호
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• pp.212-217
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• 2007

A new method of designing multi-loop PID controllers is presented in this paper. By using the generalized IMC-PID method for multi-loop systems, the optimization problem involved in finding the PID parameters is efficiently simplified to find the optimum closed-loop time constant in a reduced search space. A weighted sum Mp criterion is proposed as a performance cost function to cope with both the performance and robustness of a multi-loop control system. Several illustrative examples are included to demonstrate the improved performance of the multi-loop PID controllers obtained by the proposed design method.

• Journal of Astronomy and Space Sciences
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• 제24권3호
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• pp.235-248
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• 2007

이 연구는 통신해양기상위성의 영상위치유지 (Image Navigation and Registration, INR) 시스템의 시뮬레이션을 위한 프로그램을 개발하고, 영상오차보상(Image Motion Compensation, IMC) 알고리즘의 성능을 비교분석 하였다. 통신해양기상위성 궤도와 자세 요소를 모델링 하고 궤도오차와 자세오차를 계산하여 이러한 궤도 및 자세오차가 영상왜곡에 미치는 영향을 분석하였다. 또한 영상오차보상을 하지 않았을 경우와 GOES 위성의 영상오차보상 알고리즘을 적용하였을 경우, 그리고 선행 연구를 통해 개발되었던 개량된 영상오차보상 알고리즘을 적용하였을 경우의 영상들을 비교하여 각 알고리즘의 성능을 확인하였다. 개량된 영상오차보상 알고리즘은 GOES위성의 알고리즘보다 효율적으로 영상왜곡을 보상하였다. 이러한 연구는 통신해양기상위성의 INR시스템을 효과적으로 운용하고 그 성능을 향상시킬 수 있는 기술적 토대를 마련하는데 기여할 것이다.

• 대한치과보철학회지
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• 제34권1호
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• pp.31-69
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• 1996

The purpose of this investigation was to analyze stress distribution in implant supporting tissue according to different types of attachments such as combination bar attachment, Hader bar attachment, O-Ring attachment and Dal-Ro attachment that are used in mandibular overdenture by using two osseointegrated implants, to study the influence that POM IMC used in bar type attachment has in implant supporting tissue and compare the preceding analyses to find out an effective stress distribution method. Three dimensional photoelastic method was used to obtain the following results. (A) Analysis of stress distribution according to attachment type 1. Under vertical load condition, compressive stress was seen at implant supporting area of working side on all the photoelastic models but in Hader bar attachment tensional stress was seen at distal upper area of implant supporting area. Relatively Hader bar and O-Ring attachment showed even stress distribution pattern. 2. Under vertical load condition, compressive stress at implant apex area and tensional stress at implant lateral supporting area were seen at nonworking side of all models. 3. Under $25^{\circ}$ lateral load condition, general compressive stress was seen at working side implant supporting area in most of the models, especially at distal upper supporting area higher compressive stress concentration was seen in combination bar attachment and tensional stress concentration, in Hader bar attachment. 4. Under $25^{\circ}$ lateral load condition, compressive stress at implant apex area and tensional stress at implant lateral supporting area were seen at nonworking side of all models, except O-Ring model which showed compressive stress only. (B) Influence of POM IMC to stress distribution in bar type attachment 5. Under vertical load condition, better stress distribution pattern was seen at working side of combination bar and Hader bar attachment model using POM IMC. 6. Under vertical load condition, stress value was increased at nonworking side of combination bar attachment model using POM IMC and tendency of increasing compression was seen at nonworking side of Hader bar attachment model using POM IMC. 7. Under $25^{\circ}$ lateral load condition, better stress distribution pattern was seen at working side of combination bar attachment model using POM IMC but tendency of increasing stress was seen on working side of Hader bar attachment model using POM IMC. 8. Under $25^{\circ}$ lateral load condition, stress reduction was seen at nonworking side of combination bar attachment model using POM IMC but tendency of increasing stress was seen at nonworking side of Hader bar attachment model using POM IMC.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.66-68
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• 2004

PID제어기를 플랜트 파라미터를 이용하여 구성하는 IMC-PID제어에 대해 연구한다. 특히 변하는 플랜트에 대해서는 자기동조(ST, Self-Tuning)를 사용하여 시스템을 식별하여 활용한다. 특히 실시간으로 개루프의 위상여유 및 이득여유를 모니터링하여 정해진 구역을 벗어나게 되면 식별된 시스템파라미터를 이용하여 IMC-PID제어기를 구성한다. 또 시간영역 지표로 과도한 오차가 발생하는 경우에도 제어기를 갱신함으로서 전체적으로 보면 견실 PID제어기 형태를 갖게 한다.

• 제어로봇시스템학회논문지
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• 제16권1호
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• pp.77-82
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• 2010

An analytical method for robust design of the multi-loop proportional-integral (PI) controller is proposed for various types of multi-delay processes. On the basis of the direct synthesis and generalized IMC-PID approach, the analytical tuning rules of the multi-loop PI controller are firstly derived for achieving the desired closed-loop response, and the structured singular value synthesis is then utilized for the tradeoffs between the robust stability and performance by adjusting only one design parameter (i.e., the closed-loop time constant). To verify the superiority of the proposed method, the simulation studies have been conducted on a wide variety of multivariable processes. The multi-loop PI controller designed by the proposed method shows a fast, well-balanced and robust response with the minimum integral absolute error (IAE) in compared with other renowned methods.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.40-46
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• 1993

In this paper, we design a multirate controller for a given multirate sampled-data system which has a periodic output measurement scheme. A sufficient condition for maintaining observability in multirate sampled-data systems is given first. The design strategy for disturbance rejection is proposed. The proposed controller has IMC structure, and can be deomposed into a disturbance estimator and the inverse of fast plants.

• Journal of Radiation Protection and Research
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• 제32권4호
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• pp.190-193
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• 2007

The objective of this study is to recommend the radiation protection design parameters from the shielding point of view for concrete wall between the decay tank room and the primary pump room in TRIGA Mark-II Research Reactor Facility. The shield design for this concrete wall has been performed with the help of Point-kernel Shielding Code Micro-Shield 5.05 and this design was also validated based on the measured dose rate values with Radiation Survey Meter (G-M Counter) considering the ICRP-60 (1990) recommendations for occupational dose rate limit ($10{\mu}Sv/hr$). The recommended shield design parameters are: (i) thickness of 114.3 cm Ilmenite-Magnetite Concrete (IMC) or 129.54 cm Ordinary Reinforced Concrete (ORC) for concrete wall A (ii) thickness of 66.04 cm Ilmenite-Magnetite Concrete (IMC) or 78.74 cm Ordinary Reinforced Concrete (ORC) for concrete wall B and (iii) door thickness of 3.175 cm Mild Steel (MS) on the entrance of decay tank room. In shielding efficiency analysis, the use of I-M concrete in the design of this concrete wall shows that it reduced the dose rate by a factor of at least 3.52 times approximately compared to ordinary reinforced concrete.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.50.5-50
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• 2001

Although many advanced control strategies and concepts have been proposed recently, the most popular controller in the process industries is the PID controller because of its simplicity, easy implementation, and robustness. A multiloop PID controller design method using the general IMC tuning rule is presented in this paper. The IMC-PID controller is formed by combining the integral term designed by considering interactions between the individual loops with the proportional and derivative terms designed in circumstance neglecting the interactions. The multiloop PID controller designed by the proposed method can approximate the ideal multiloop controller throughout overall frequency range, and ...

• 전자공학회논문지SC
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• 제46권3호
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• pp.8-14
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• 2009

본 논문은 성능 향상을 위하여 IMC 제어 구조를 갖는 PID 제어기 설계를 제안했다. 내부 모델은 최종값 정리와 유전자 알고리즘을 이용하여 2차의 지연시간을 갖는 모델로 동정 하였다. 그리고 제어기 파라미터 값은 성능지수 (IAE, ITAE)값이 최소가 되도록 내부 모델과 수치적 계산에 의해서 자동 동조된다. 시뮬레이션을 통하여 다양한 공정에 대하여 본 논문에서 새롭게 제안된 방법이 기존의 방법보다 우수함을 확인 할 수 있었다.