• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 추계학술대회 논문집
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• pp.109-114
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• 2001

Photovoltaic systems normally use a maximum power point tracking (MPPT) technique to continuously deliver the highest possible power to the load when variations in the insolation and temperature occur. A simple method of tracking the maximum power points (MPPs) and forcing the boost converter system to operate close to these points is presented through deriving small-signal model and transfer function of boost converter. This paper aims at modeling boost converter including equivalent series resistance of input reservoir capacitor by state-space-averaging method. In the future, properly designed controller for compensation will be constructed for maximum photovoltaic power tracking control.

• 한국컴퓨터정보학회논문지
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• 제19권3호
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• pp.37-43
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• 2014

본 논문에서는 색상 군집화를 이용한 입술탐지 알고리즘을 제안한다. RGB 색상 모델로 주어진 입력영상에서 AdaBoost 알고리즘을 이용하여 얼굴영역을 추출한 후, 얼굴영역을 Lab 컬러 모델로 변환한다. Lab 컬러 모델에서 a 성분은 입술과 유사한 색상을 잘 표현할 수 있는 반면 b 성분은 입술의 보색을 표현할 수 있기 때문에 Lab 컬러로 표현된 얼굴영역에서 a와 b 성분을 기준으로 최단 이웃(nearest neighbour) 군집화 알고리즘을 이용하여 피부 영역을 분리한 후, K-means 색상 군집화를 통해 입술 후보 영역을 추출하고, 마지막으로 기하학적 특징을 이용하여 최종적인 입술영역을 탐지하였다. 실험 결과는 제안된 방법이 강건하게 입술을 탐지함을 보인다.

• Journal of the Optical Society of Korea
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• 제13권1호
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• pp.116-122
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• 2009

In this paper, a robust method is developed to locate the irises of both eyes. The method doesn't put any restrictions on the background. The method is based on the AdaBoost algorithm for face and eye candidate points detection. Candidate points are tuned such that two candidate points are exactly in the centers of the irises. Mean crossing function and convolution template are proposed to filter out candidate points and select the iris pair. The advantage of using this kind of hybrid method is that AdaBoost is robust to different illumination conditions and backgrounds. The tuning step improves the precision of iris localization while the convolution filter and mean crossing function reliably filter out candidate points and select the iris pair. The proposed structure is evaluated on three public databases, Bern, Yale and BioID. Extensive experimental results verified the robustness and accuracy of the proposed method. Using the Bern database, the performance of the proposed algorithm is also compared with some of the existing methods.

• 한국인터넷방송통신학회논문지
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• 제9권4호
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• pp.53-57
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• 2009

본 논문에서는 환자관리의 전산화를 위한 안면 특징점 추출 알고리즘을 적용한 환자 인식 u-Healthcare 환경의 구현을 제안한다. 먼저 모바일 기기 등으로 환자의 사진용 촬영하고 이 사진 데이터를 AdaBoost 알고리즘의 입력데이터로 활용하여 특징점 패턴 추출한 후, 기존 데이터에이스에 저장된 환자의 샘플사진에서 추출한 특징점 패턴과 매칭 시킨다. 그 결과, 동일 환자라고 인식한 경우에는 환자정보 데이터베이스에서 질병, 담당의, 진료분야 등의 관련정보를 추출하여 기기 화면에 출력하는 환자인식 시스템의 구현 방법을 제시한다.

• Journal of Electrical Engineering and Technology
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• 제12권3호
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• pp.1146-1155
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• 2017

Normally, the artificial intelligence algorithms are widely applied to the optimal controller design. Then, it is expected that the best output performance is achieved. Unfortunately, when resulting controller parameters are implemented by using the practical devices, the output performance cannot be the best as expected. Therefore, the paper presents the optimal controller design using the combination between the state-space averaging model and the adaptive Tabu search algorithm with the new criteria as two penalty conditions to handle the mentioned problem. The buck-boost converter regulated by the cascade PI controllers is used as the example power system. The results show that the output performance is better than those from the conventional design method for both input and load variations. Moreover, it is confirmed that the reported controllers can be implemented using the realistic devices without the limitation and the stable operation is also guaranteed. The results are also validated by the simulation using the topology model of MATLAB and also experimentally verified by the testing rig.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 전력전자학술대회 논문집
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• pp.285-286
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• 2016

This paper proposes a method for designing the inductor to minimize power loss for boost converter. The proposed inductor design method uses genetic algorithm to find an optimal inductance and an optimal frequency which minimize the power loss at rated power. The validity of proposed inductor design method is verified by simulation and experiment.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.80-82
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• 2007

In this paper, we proposed new maximum electric power tracking algorithm by composing Buck-boost chopper circuit to charge electric power from wind energy generator which is under low and high wind velocity. The break function is also proposed with the existed buck-boost chopper switch. We made a proto-type as a lab level to verify appropriateness of using proposed circuit.

• 전력전자학회논문지
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• 제20권2호
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• pp.182-192
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• 2015

This study develops a digital control scheme with power factor correction for a front-end converter in an electric vehicle battery charger. The front-end converter acts as the boost-type switching-mode rectifier. The converter assumes the two roles of the battery charger, which include power factor control and robust charging performance. The proposed control scheme consists of a charging control algorithm and a grid current control algorithm. The scheme aims to obtain unity input power factor and robust performance. Based on the linear average model of the converter, a constant-current constant-voltage charging control algorithm that passes through only one proportional-integral controller and a current feed-forward path is proposed. In the current control algorithm, we utilized a second band pass filter, a single-phase phase-locked loop technique, and a duty-ratio feed-forward term to control the grid current to be in phase with the grid voltage and achieve pure sinusoidal waveform. Simulations and experiments were conducted to verify the effectiveness of the proposed control scheme, both simulations and experiments.

• 한국산학기술학회논문지
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• 제14권8호
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• pp.3971-3975
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• 2013

본 논문은 핸드 제스쳐에 의해 증강현실 내의 가상 객체 제어기술로, HOG기반의 핸드 제스쳐 인식을 제안하고 있다. 인식을 위한 특징점들은 HOG불럭들에 의하여 결정되며, 크기가 다른 여러 불럭들을 시험하여 가장 적절한 불럭구성을 결정하며, AdaBoostSVM기법을 사용하여 분류 목적에 가장 적절한 불럭들을 추출한다. 실험 결과 핸드 제스쳐 인식률은 94% 이었다.

• 한국컴퓨터정보학회논문지
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• 제15권2호
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• pp.47-53
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• 2010

본 논문은 동영상에서 실시간 얼굴검출을 위하여 Residual Image 검출과 색상정보를 이용한 얼굴검출 기법을 제안하였다. 제안된 기법은 동영상에서 빠른 처리 속도와 높은 얼굴 검출율을 나타냈으며 기울어진 얼굴영상에 대한 보정작업을 통하여 검출 에러율을 줄였다. 실시간으로 전송된 동영상에서 검출의 대상이 되는 정지영상을 추출한다. 추출된 영상은 기울어진 얼굴검출을 위한 window회전 알고리즘을 사용하고 이렇게 보정된 영상은 얼굴 검출에 필요한 특징을 추출하기 위해 AdaBoost알고리즘을 사용하여 실시간으로 얼굴이 검출된 영상을 획득하게 된다.