• 대한전자공학회논문지
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• 제24권6호
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• pp.930-935
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• 1987

This paper presents a decentralized model reference adaptive control scheme for an interconnected continuous linear system composed of a number of single input single output subsystems. The scheme can treat the unknown strengh of interconnections as well as the uncertainty of subsystems. The scheme automatically adjusts the local feedback gains so that the output of each subsystem exponetially tracks that of the reference model.

• 대한전자공학회논문지
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• 제20권1호
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• pp.37-44
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• 1983

본 논문에서는 MRAC 방식을 이용하여 이산 시간이고 잡음이 없는 단일한 입출력을 갖는 선형계에 직접제어 방식으로 적응 제어 알고리즘을 원용하였다. 직접 제어 방식에서 제어기는 매개변수형으로 구성되고 그리고 매개변수 조정을 위한 검증 알고리즘은 일련의 축차방정식으로 주어지는데 이는 가중 최소 자승법에 따라 유도되었다. 가중 최소 자승법으로 제어기 매개변수를 검증했을 때 출력 추적오차가 영에 수검하는 속도가 경도법 또는 최소 자승법을 사용했을 때보다 빠르다는 것이 컴퓨터 시뮬레이견으로 확인되었으며 또한 λ를 변화시키는 제안된 가중 최소 자승법은 규범형 모델 입력의 동파수 성분에 관계언이 사용될 수 있음을 보였다. 또한 이런 경우에 있어서 수험성과 안정도에 관해서도 고찰했다.

• 전자공학회논문지C
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• 제34C권2호
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• pp.71-79
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• 1997

In this paper, we propose a new nearest-neighbor classifier with reduced computational complexity in search process. In the proposed classifier, the classes are divided into two sets: reference and non-reference sets. It reduces computational requriement by approximating the distance between the input and a class iwth the information of distances among the calsses. It calculates only the distance between the input and the reference classes. We convert a given classifier into RCC (reduced computational complexity but smal lincrease in misclassification probability of its corresponding RCC classifier. We designed RCC classifiers for the recognition of digits from the NIST database. We obtained an RCC classifier with 60% reduction in the computational complexity with the cost of 0.5% increase in misclassification probability.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2001년도 춘계학술대회 학술발표 논문집
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• pp.144-147
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• 2001

This paper presents adaptive fuzzy controller which is uncertainty or unknown variation in different parameters with nonlinear system of helicopter. The proposed adaptive fuzzy controller applied TSK(Takagi-Sugeno-Kang) fuzzy system which is not only low number of fuzzy rule, and a linear input-output equation with a constant term, but also can represent a large class of nonlinear system with good accuracy. The adaptive law was designed by using Lyapunov stability theory. The adaptive fuzzy controller is a model reference adaptive controller which can adjust the parameter $\theta$ so that the plant output tracks the reference model output. First of all, system of helicopter was considered as stopping state, and design of controller was simulated from dynamics equation with stopping state. Results show that it is controlled more successfully with a model reference adaptive controller than with a non-adaptive fuzzy controller when there is a modelling error between system and model or a continuous added noise in such unstable system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.322-327
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• 2006

Banwol bridge with steel plate girder and Pyongtaek bridge with PSC bos girder have been operated maintenance measuring system by the Seoul-Chonan of Kyongbu express railway. By analyzing the theoretical and experimental values of design load for these two bridge, the establishment of reference maintenance for measuring items was deduced from research. Two materials, steel and concrete plates, were considered as the upper structure. Actual measurement data for the behavior under speed, structural analysis results, and the presented references were analyzed and used to set up the reference establishment. The measuring items are stress(strain), displacement, dynamic acceleration, expansion movement, and dynamic frequency. The maintenance reference was established by comparing analytical and measuring values of the five items with respect to structural state class.

• 한국CDE학회논문집
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• 제13권2호
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• pp.98-108
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• 2008

Plant, civil engineering and construction equipment data of overseas construction are obtained and then analyzed, classified and integrated by experts. With those refined data set, we built classification system and defined property information with reference to international standard (ISO 15926, IRDL). If class in ISO 15926 is predefined for equipment of interest, we used the class as is. If not, we created and defined new classes on the basis of ISO 15926 classes. If there is similar class for equipment of interest, extension or inheritance methods were used. As a result, classification system of five levels and 637 classes were built and construction equipment information were expressed in open structure of XML such as tree structure of classification system and detailed information with number equipments for each specific equipment. We also developed the electronic catalog system which is basically equipment information management system providing various product search functions.

• 대한치과교정학회지
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• 제28권2호
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• pp.219-229
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• 1998

심한 골격성 III급 부정교합을 가진 성인환자는 많은 경우 심미성증진과 기능증진을 위해 악교정수술과 교정치료를 병행하여 치료하게 된다. 이러한 경우 진단과 치료계획 수립시 중요한 의미를 가지는 경조직 및 연조직 측모윤곽선의 형태를 정상교합자와 비교 분석하고, 두개악안면구조의 특성을 파악하여 부조화의 소재를 규명하고자 이 연구가 시행되었다. 골격성 III급 부정교합으로 진단된 환자 중 ANB각의 차이가 -2이하인 18세 이상의 성인남녀 환자 112명의 측모두부 규격 엑스선 사진을 연구자료로 이용하였으며 평균연령은 23.1세였다. 대조군으로는 성인 정상교합자 50명의 측모 두부 규격 엑스선 사진을 대상으로 하였으며 남, 녀 각 25명씩이었다. 전후방기준으로는 Nasion perpendicular to FH line을 사용하였으며, 수평 기준선으로는 FH line을 사용하였다. 이 연구에서 정상교합자와 비교한 심한 III급 부정교합자 안면골격의 특징을 다음과 같다. 1. 나지온점에서 프랑크프르트 수평선에 내린 수선을 기준선으로 III급 부정교합자의 경조직 측모 윤곽을 평가하였을 때, III급 부정교합자의 전두부, 상악의 전방돌출도는 정상과 유사하였으나, 하악은 정상에 비하여 심하게 돌출되어 있었다. 2. III급 부정교합자의 연조직 측모윤곽은 오목하였다. III급 부정교합자의 연조직 두께는 전두부에서는 정상과 차이가 없었으나, 상순은 두껍고 비상순각은 작았으며, 하순과 하순구부위의 연조직은 얇고 하순의 외번도는 작았다. 3. III급 부정교합자의 두개저(전방두개저의 길이, 후방두개저의 길이 및 안상각)는 정상에 비하여 작았다. 4. III급 부정교합자에서 두개저에 대한 중안면부(안와하연점)의 전후관계는 정상과 유사하였으나,중안면부의 길이는 짧았다. 5. III급 부정교합자에서 두개저에 대한 상악의 전후방관계는 정상과 유사하였으나 상악골의 길이는 짧았다. 6. III급 부정교합자에서 두개저에 대한 하악의 전후관계는 전방돌출되어 있었으며, 하악지 및 하악체 길이는 크고, 하악각이 크며, 이부각(Chin angle)이 작았다. 7. III급 부정교합자의 상악 절치는 전방경사되어 있었으며, 하악 절치는 설측경사되어 있었다.

• 한국전기전자재료학회논문지
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• 제19권4호
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• pp.398-403
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• 2006

This paper describes the evaluation of the long duration current impulse withstand characteristics of ZnO blocks for high voltage surge arresters. Four ZnO varistors were manufactured with the general ceramic production method and the long duration current impulse withstand test, electrical uniformity evaluation test and microstructure observation were performed. All varistors exhibited high density, which was in the range of $5.42{\sim}5.46g/cm^3$. In the electrical properties, the reference voltage of samples was in the range of $5.11{\sim}5.25\;kV$ and the residual voltage was in the range of $8.314{\sim}8.523\;kV$. In the long duration current impulse withstand test, sample No.2 and No.3 failed at the 2nd and 4th shot of series impulse currents, respectively, but the rest survived 18 shots during the test. Before and after this test, the variation ratio of the residual voltage of samples survived was below 0.5 %, which was in the acceptance range of 5 %. According to the results of the test, it is thought that if the soldering method is improved, ZnO varistors would be possible to apply to the high voltage arresters like the station class and transmission line arresters in the near future.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.963-968
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• 1990

An iterative learning control scheme for tracking control of a class of uncertain nonlinear systems is presented. By introducing a model reference adaptive controller in the learning control structure, it is possible to achieve zero tracking of unknown system even when the upperbound of uncertainty in system dynamics is not known apriori. The adaptive controller pull the state of the system to the state of reference model via control gain adaptation at each iteration, while the learning controller attracts the model state to the desired one by synthesizing a suitable control input along with iteration numbers. In the controller role transition from the adaptive to the learning controller takes place in gradually as learning proceeds. Another feature of this control scheme is that robustness to bounded input disturbances is guaranteed by the linear controller in the feedback loop of the learning control scheme. In addition, since the proposed controller does not require any knowledge of the dynamic parameters of the system, it is flexible under uncertain environments. With these facts, computational easiness makes the learning scheme more feasible. Computer simulation results for the dynamic control of a two-axis robot manipulator shows a good performance of the scheme in relatively high speed operation of trajectory tracking.

• Nuclear Engineering and Technology
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• 제53권3호
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• pp.1004-1012
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• 2021

High density polyethylene (HDPE) pipe has many advantages over metallic pipe, and has been used in non-safety related application for years in some nuclear power plants (NPPs). Recently, HDPE pipe was introduced into safety related applications. The main difference between safety-related and non-safety-related pipes in NPPs is the design method of extra loadings such as gravity, temperature, and earthquake. In this paper, the mechanical behavior of HDPE pipe under various loads in pipe gallery was studied by finite element analysis (FEA). Stress concentrations were found at the fusion regions on inner surface of mitered elbows of HDPE pipe system. The effects of various factors were analyzed, and the influence of various loads on the damage of HDPE pipe system were evaluated. The results of this paper provide a reference for the design of nuclear safety-related Class 3 HDPE pipe. In addition, as the HDPE pipes analyzed in this paper were suspended in pipe gallery, it can also serve as a supplementary reference for current ASME standard on Class 3 HDPE pipe, which only covers the application for buried pipe application.