• 대한산업공학회지
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• 제20권4호
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• pp.113-134
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• 1994

A radial basis hybrid neural network (RHNN) is presented for an on-line detection of machine condition change. Two-phase modeling by RHNN is designed for describing a machine condition process and for predicting future signal. A moving block procedure is also designed for detecting a process change. A fast on-line learning algorithm, the recursive least square estimation, is introduced. Experimental results showed the RHNN could be utilized efficiently for on-line machine condition monitoring.

• International Journal of Contents
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• 제8권1호
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• pp.30-38
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• 2012

Text extraction and binarization are the important pre-processing steps for text recognition. The performance of text binarization strongly related to the accuracy of recognition stage. In our proposed method, the first stage based on line detection and shape feature analysis applied to locate the position of a business card and detect the shape from the complex environment. In the second stage, several local regions contained the possible text components are separated based on the projection histogram. In each local region, the pixels grouped into several connected components based on the connected component labeling and projection histogram. Then, classify each connect component into text region and reject the non-text region based on the feature information analysis such as size of connected component and stroke width estimation.

• 스마트미디어저널
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• 제1권4호
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• pp.27-34
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• 2012

In this paper, a novel text binarization is presented that can deal with some complex conditions, such as shadows, non-uniform illumination due to highlight or object projection, and messy backgrounds. To locate the target text region, a focus line is assumed to pass through a text region. Next, connected component analysis and stroke width estimation based on location information of the focus line is used to locate the bounding box of the text region, and each box of connected components. A series of classifications are applied to identify whether each CC(Connected component) is text or non-text. Also, a modified K-means clustering method based on an HCL color space is applied to reduce the color dimension. A text binarization procedure based on location of text component and seed color pixel is then used to generate the final result.

• Journal of Power Electronics
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• 제13권4호
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• pp.516-527
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• 2013

This paper presents a new overall system for state-of-available-power (SoAP) prediction for a lithium-ion battery pack. The essential part of this method is based on an adaptive network architecture which utilizes both fuzzy model (FIS) and artificial neural network (ANN) into the framework of adaptive neuro-fuzzy inference system (ANFIS). While battery aging proceeds, the system is capable of delivering accurate power prediction not only for room temperature, but also at lower temperatures at which power prediction is most challenging. Due to design property of ANN, the network parameters are adapted on-line to the current battery states (state-of-charge (SoC), state-of-health (SoH), temperature). SoC is required as an input parameter to SoAP module and high accuracy is crucial for a reliable on-line adaptation. Therefore, a reasonable way to determine the battery state variables is proposed applying a combination of several partly different algorithms. Among other SoC boundary estimation methods, robust extended Kalman filter (REKF) for recalibration of amp hour counters was implemented. ANFIS then achieves the SoAP estimation by means of time forward voltage prognosis (TFVP) before a power pulse occurs. The trade-off between computational cost of batch-learning and accuracy during on-line adaptation was optimized resulting in a real-time system with TFVP absolute error less than 1%. The verification was performed on a software-in-the-loop test bench setup using a 53 Ah lithium-ion cell.

• 전력전자학회논문지
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• 제3권4호
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• pp.346-352
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• 1998

본 논문에서는 새로운 신경 회로망 유도 전동기 속도 추정 방법을 제안하고, 추정된 속도를 이용하여 속도 센서리스 벡터 제어를 구현한다. 제안된 신경 회로망 속도 추정 방법은 정상 상태뿐 아니라 과도 상태에서도 정확한 속도를 추정한다. 또한 off-line에 의해 사전 학습을 필요로 하지 않고, 유도 전동기의 구동과 동시에 on-line 학습을 통하여 속도를 실시간으로 추정함으로써 구현이 용이하다. 디지털 시뮬레이션과 2.2kW 유도 전동기 시스템을 이용한 실험을 통하여 제안된 알고리즘의 효용성과 성능을 입증한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.403-403
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• 2000

Generally estimation of driving direction uses the way which uses lane detection and vanishing point in autonomous-driving system. Especially we use Sub-window for decreasing Process time when we detect lane, but fixed sub-window can not detect lane because of some factors in road image. So we suggest algorithm using one-dimension line scan method to detect an exact position of lane.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.522-524
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• 2003

This paper presents a stability estimation method for subspan oscillation on overhead transmission line. It has been used method by conductor's fatigue limit or subspan oscillation amplitude. But it is not proper to estimation of subspan oscillation. We suggest to instability index for estimation method of subspan oscillation. And we tried to 4 bundled conductor system. This result will use to establish of the subspan location rules.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.386-391
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• 1998

Parameter estimation method of induction motor for vector control is presented in this paper. It can be easily implemented and applied to inverters in the industrial field, because it needs no additional hardware such as voltage sensors and measuring equipment. The proposed algorithm in this paper is so straightforward and practical that it can be easily implemented on the built-in controllers with little overhead. The proposed estimation algorithm has good accuracy and repeatability for parameters due to the sensitivity of estimation errors. This enables its total consuming time to be made shorter. Experimental results and applications in the industrial fields verify the validity and usefulness of the proposed method.

• 전기학회논문지P
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• 제59권1호
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• pp.40-46
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• 2010

DC link electrolytic capacitors are widely used in various PWM power converter system, such as adjustable speed driver(ASD) or DC/DC converter. Electrolytic capacitors, which is the most of the time affected by aging effect, plays a very important role for the power electronics system quality and reliability. This objective of this paper is to propose a improvement method to detect the rise of equivalent series resistor(ESR) in order to realize the online failure prediction of electrolytic capacitor for DC link of PWM power converter. The ESR detection scheme is based on the determination of the electrolytic capacitor AC losses calculated from voltage/current measurement using AC coupling. Therefore, the preposed online failure prediction method has the merits of easy ESR computation and circuit simplicity compare with BPF method. Simulation results show the veridity of the proposed on-line ESR estimation method.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제3B권2호
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• pp.97-102
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• 2003

In this paper, a recurrent artificial neural network (RNN) based self-tuning speed controller is proposed for the high-performance drives of induction motors. The RNN provides a nonlinear modeling of a motor drive system and could provide the controller with information regarding the load variation system noise, and parameter variation of the induction motor through the on-line estimated weights of the corresponding RNN. Thus, the proposed self-tuning controller can change the gains of the controller according to system conditions. The gain is composed with the weights of the RNN. For the on-line estimation of the RNN weights, an extended Kalman filter (EKF) algorithm is used. A self-tuning controller is designed that is adequate for the speed control of the induction motor The availability of the proposed controller is verified through MATLAB simulations and is compared with the conventional PI controller.