• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1998.05a
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• pp.321-326
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• 1998

본 논문에서는 정밀 제어와 온-라인 제어를 위하여 유전 알고리즘을 이용한 퍼지-신경망 제어기를 제안하였다. 제안된 제어기의 설계방법은 다음과 같은 3단계의 동조과정으로 구성한다. 1) 퍼지 제어기의 비퍼지화 연산을 신경망을 이용하여 함수근사화 시킨 후, 퍼지-신경망 제어기를 구성한다. 2) 플랜트에 적합한 퍼지 소속함수의 형태를 얻기 위해 유전 알고리즘을 이용하여 근사화된 퍼지 소속함수를 찾는다. 3) 근사화된 초기 퍼지 소속함수를 퍼지-신경망 제어기에 의해 적응학습으로 최적의 퍼지 소속함수를 얻고, 또한 플랜트의 파라미터 변동이나 외부환경의 변화에 대해 적응할 수 있도록 최적의 퍼지 소속함수를 추정한다. 제안된 제어기의 성능을 평가하기 위하여 DC 서보모터의 속도제어에 적용하였다.

• Journal of information and communication convergence engineering
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• v.9 no.4
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• pp.369-374
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• 2011

Generally the neural network and the Fuzzy compensative algorithms are applied to forecast the time series for power demand with the characteristics of a nonlinear dynamic system, but, relatively, they have a few prediction errors. They also make long term forecasts difficult because of sensitivity to the initial conditions. In this paper, we evaluate the chaotic characteristic of electrical power demand with qualitative and quantitative analysis methods and perform a forecast simulation of electrical power demand in regular sequence, attractor reconstruction and a time series forecast for multi dimension using Lyapunov Exponent (L.E.) quantitatively. We compare simulated results with previous methods and verify that the present method is more practical and effective than the previous methods. We also obtain the hourly predictability of time series for power demand using the L.E. and evaluate its accuracy.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06b
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• pp.460-463
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• 2007

기존 공간 분류 시스템은 애매모호한 데이터나 불완전한 데이터, 결손 데이터의 처리에는 취약하다는 단점을 가지고 있다. 수치 형태의 애매모호성을 효과적으로 처리하기 위해 신경망을 이용할 수 있다. 그러나, 신경망을 이용한 공간 데이터 분류 방법은 불완전한 데이터나 결손 데이터들을 무시하지 않고 처리 할 수 있으나, 다양한 수치형태를 가지는 공간 데이터들로 인해 네트워크 구조의 복잡도가 증가하고 학습성능이 저하된다는 문제점을 야기한다. 본 논문에서는 이러한 문제점을 해결하기 위해서 퍼지 신경망을 적용한 새로운 공간 분류시스템을 제안하고 구현하였다. 실험 결과 기존의 방법에 비해 좋은 성능을 보임을 확인하였다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1011-1012
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• 2007

The paper is proposed maximum torque control of SynRM drive using learning mechanism-fuzzy neural network(LM-FNN) controlle. The control method is applicable over the entire speed range and considered the limits of the inverter's current and voltage rated value. For each control mode, a condition that determines the optimal d-axis current ${^{i}}_d$ for maximum torque operation is derived. The proposed control algorithm is applied to SynRM drive system controlled LM-FNN controller, the operating characteristics controlled by maximum torque control are examined in detail. Also, this paper is proposed the analysis results to verify the effectiveness of the LM-FNN controller.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1724-1725
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• 2007

This paper presents a fault detection and isolation(FDI) scheme for a nonlinear systems with a actuator and sensor faults. A residual generator based on the observer model generate the information for a fault detection. The proposed fault estimators are activated for a fault isolation and applied to estimate the time-varying lumped faults(model uncertainty + fault). but a fault estimator error dose not converge to zero since the derivative of lumped fault is not zero. Then the fuzzy neural network(FNN) is used to estimate the fault estimator error. Simulation results are presented to illustrate the effectiveness and the applicability of the approaches proposed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.566-567
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• 2005

Until now variable pattern classification methods have been introduced. So, variable methods in PD source classification were applied. NN(neural network) the most used scheme as a PD(partial discharge) source classification. But in recent year another method were developed. These methods is present superior to NN in the field of image and signal process function of classification. In this paper, it is show classification result in PD source using three methods; that is, BP(back-propagation), ANFIS(adaptive neuro-fuzzy inference system), PCA-LDA(principle component analysis-linear discriminant analysis).

• Journal of Power System Engineering
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• v.15 no.5
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• pp.83-90
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• 2011

In general, 20-high Sendzimir mills(ZRM) use small diameter work rolls to provide massive rolling force. Because of small diameter of work rolls, steel strip has a complex shape mixed with quarter, edge and center waves. Especially when the shape of the strip is controlled automatically, the actuator saturation occurs. These problems affect the productivity and quality of products. In this paper, the problems in automatic shape control of ZRM were analyzed. In order to evaluate the problems for the automatic shape control in ZRM, recognition performance was analyzed by comparing the measured shape and the recognized shape. The actuator positions by the shape recognition and the manual operation were compared. From the analysis results, the necessity of the improvement of recognition performance in ZRM is suggested.

• Journal of Information Management
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• v.31 no.3
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• pp.21-34
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• 2000

In recent year, much progress has been made in understanding the application of the chaos in the engineering. In the electrical engineering, electronics, communication, mechanical, chemistry as well as mathematics, physics, there are extended to the application of chaos. In this review, I explained chaos engineering application and future application possibility.

• Computers and Concrete
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• v.24 no.3
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• pp.271-282
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• 2019

Concrete undergoes a series of thermo-based physio-chemical changes once exposed to elevated temperatures. Such changes adversely alter the composition of concrete and oftentimes lead to fire-induced explosive spalling. Spalling is a multidimensional, complex and most of all sophisticated phenomenon with the potential to cause significant damage to fire-exposed concrete structures. Despite past and recent research efforts, we continue to be short of a systematic methodology that is able of accurately assessing the tendency of concrete to spall under fire conditions. In order to bridge this knowledge gap, this study explores integrating novel artificial intelligence (AI) techniques; namely, artificial neural network (ANN), adaptive neuro-fuzzy inference system (ANFIS) and genetic algorithm (GA), together with traditional statistical analysis (multilinear regression (MLR)), to arrive at state-of-the-art procedures to predict occurrence of fire-induced spalling. Through a comprehensive datadriven examination of actual fire tests, this study demonstrates that AI techniques provide attractive tools capable of predicting fire-induced spalling phenomenon with high precision.

• Advances in nano research
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• v.15 no.2
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• pp.129-139
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• 2023

Emerge of nanotechnology has affected many aspects of our life and also triggers research studies in many fields. Nano-medicine are proven to be effective in encountering diseases. In the present study, aspects of the applications and effectiveness of nano-medicine in pediatrics patients are studied. In this regard, using experimental data of previous published researches, combination and dose of nano-medicines are optimized using response surface method and neural-fuzzy inference network. The input parameters of the selected multiple nano-medicines are dose and type and the output is the effectiveness of the combinations using IC50 parameter. A detailed parameter study is presented to observe effects of each inputs on the IC50. The results indicate that personalized scaling of nano-medicine is required in therapy of pediatric diseases such as cancers.