• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 하계종합학술대회 논문집(2)
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• pp.509-512
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• 2004

This paper proposed a new solid State Relay(SSR) structure that can replace the conventional SSR as a power IC. The photodiode arrays, the main part of this structure, were designed and integrated in the same power It chip with the output parts, LDMOSFET and BJT, on a SOI substrate. The fabrication of this input part shared the same output LDMOSFET fabrication processs, except the additional deposition of Silicon nitride($Si_3N_4$) for the photo-detection part. According to LED illumination intensites and photo detecting areas, we could obtain voltage of 0.49V ${\~}$0.52V and current of 5.5uA ${\~}$ 108uA respectively from the fabricated unit photodiode. The maximum value of the voltage and the current we could obtain from the photodiode array were 3.58V and 24.4uA respectively, and the voltage was enough to operate the output LDMOSFET

• 전자공학회논문지D
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• 제36D권9호
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• pp.64-70
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• 1999

$100{\mu}m$ 이하의 길이를 가지는 두 개의 영역으로 구성된 수직 방향성 결합기의 영역 1의 출력단과 영역 2의 출력단에서 각각 30 dB 이상의 소멸비를 가지는 cross state와 bar state를 얻을 수 있었다. 각 영역의 두 도파로가 가질수 있는 여러 굴걸율 값에 대하여 향상된 결합모드 이론과 beam propagation method를 사용한 계산 결과의 분석을 통해 영역 1의 출력단과 영역 2의 출력단에서 각각 30 dB 이상의 소멸비를 가지는 cross state와 bar state를 얻을 수 있는 수직 방향성 결합기의 설계 지침을 제시하였다.

• 전기학회논문지
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• 제66권10호
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• pp.1516-1522
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• 2017

We propose a novel monitoring system for diagnosing crack faults of the wind turbine using image information. The proposed method classifies a normal state and a abnormal state for the blade parts of the wind turbine. Specifically, the images are input to the proposed system in various states of wind turbine rotation. according to the blade condition. Then, the video of rotating blades on the wind turbine is divided into several image frames. Motion vectors are estimated using the previous and current images using the motion estimation, and the change of the motion vectors is analyzed according to the blade state. Finally, we determine the final blade state using the Support Vector Machine (SVM) classifier. In SVM, features are constructed using the area information of the blades and the motion vector values. The experimental results showed that the proposed method had high classification performance and its $F_1$ score was 0.9790.

• 한국CDE학회논문집
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• 제12권2호
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• pp.87-94
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• 2007

The functional behavior of a consumer electronic product is nearly all expressed with human-machine interaction (HMI) tasks. Although physical prototyping and computer aided design (CAD) software can show the appearance of the product, they cannot properly reflect its functional behavior. In this paper, we propose an approach to virtual prototyping (VP) that incorporates HMI functional simulation into virtual reality techniques in order to enables users to capture not only the realistic look of a consumer electronic product but also its functional behavior. We adopt state transition methodology to capture the HMI functional behavior of the product into a state transition chart, which is later used to construct a finite state machine (FSM) for the functional simulation of the product. The FSM plays an important role to control the transition between states of the product. We have developed a VP system based on the proposed approach. The system receives input events such as mouse clicks on buttons and switches of the virtual prototype model, and it reacts to the events based on the FSM by activating associated activities. The system provides the realistic visualization of the product and the vivid simulation of its functional behavior using head-mounted displays (HMD) and stereo speakers. It can easily allow users to perform functional evaluation and usability testing. A case study about the virtual prototyping of an MP3 player is given to show the usefulness of the proposed approach.

• 한국결정학회지
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• 제14권1호
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• pp.16-23
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• 2003

β-MnO₂ 전자상태와 화학결합을 하트리-폭-슬레이터 근사를 사용하는 제 1원리 분자 궤도법의 일종인 DV-X/sub α/ 법에 의해 이론적으로 조사하였다. 벌크상의 β-MnO₂에 대한 상태를 해석하기에 적합한 클러스터 모델을 결정하기 위하여, 여러 가지 다른 크기를 지닌 수종의 클러스터 모델들에 대한 계산을 행하였다. 실험적으로 측정된 XPS와 이론적으로 계산된 XPS를 비교함으로써, Mn/sub 15/O/sub 56/ 모델이 β-MnO₂의 전자 상태와 화학 결합을 계산하기에 가장 적합한 모델임을 결정하였다. 이 모델을 사용하여 에너지 준위, 상태 밀도, 유효 공유 결합 전하, 유효 전하, 전자 밀도 분포를 구하고, 이에 대한 고찰을 행하였다.

• Journal of Power Electronics
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• 제13권6호
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• pp.1058-1069
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• 2013

This paper proposes and designs a new output filter called an LCFL filter for application to three phase three wire shunt active power filters (SAPF). This LCFL filter is derived from a traditional LCL filter by replacing its capacitor with a C-type filter, and then constructing an L-C-type Filter-L (LCFL) topology. The LCFL filter can provide better switching ripple attenuation capability than traditional passive damped LCL filters. The LC branch series resonant frequency of the LCFL filter is set at the switching frequency, which can bypass most of the switching harmonic current generated by a SAPF converter. As a result, the power losses in the damping resistor of the LCFL filter can be reduced when compared to traditional passive damped LCL filters. The principle and parameter design of the LCFL filter are presented in this paper, as well as a comparison to traditional passive damped LCL filters. Simulation and experimental results are presented to validate the theoretical analyses and effectiveness of the LCFL filter.

• 한국전기전자재료학회논문지
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• 제35권3호
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• pp.275-280
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• 2022

An all-solid-state electrochromic film was fabricated by laminating tungsten oxide (WO₃) and nickel oxide (NiO) thin films deposited by a reactive DC magnetron sputtering on flexible ITO films. The influence of oxygen partial pressure on the crystal structure, microstructure, optical properties, and electrochromic properties of WO₃ and NiO thin films were investigated. WO₃ and NiO films showed the best electrochromic properties under the flow of Ar:O₂=80:20 and Ar:O₂=90:10, respectively. The EC film fabricated with an optimized WO₃ and NiO films showed a high coloration efficiency, a fast response time, and a stable optical modulation. It is expected that flexible EC window films will pave the way for the next-generation energy-saving windows.

• 한국음향학회지
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• 제34권2호
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• pp.171-176
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• 2015

본 논문에서는 Hidden Markov Model(HMM) - Universal Background Model(UBM)의 주 상태 정보 기반의 i-vector 추출 기술을 제안한다. Ergodic HMM이 UBM을 추정하는데 쓰였으며, 이를 통해 동일 화자 음성에도 다양하게 존재하는 특성을 HMM states로 분류할 수 있다. 제안한 방법을 이용하면 HMM의 state 개수에 따라 i-vector 들이 추출되는데, 주 상태 정보 방법을 통해 이들 중 하나를 선택한다. 제안한 방법을 검증하기 위해 National Institute of Standards and Technology(NIST) Speaker Recognition Evaluation(SRE) database를 이용하여 실험을 하였으며, Equal Error Rate(EER) 성능 수치에서 12 %의 성능 향상을 확인할 수 있었다.

• 한국전자통신학회논문지
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• 제17권5호
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• pp.859-866
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• 2022

능동 외란제거 제어기는 루엔버거 관측기를 이용하여 상태변수를 추정하여 제어기에서 외란을 제거하는 방식이다. 루엔버거 관측기는 정상상태에서 상수의 특징을 갖는 외란을 포함하는 비선형항을 상태변수로 정의하여 추정한다. 추정된 상태변수 값을 비례적분 제어기와 적분비례 제어기에 보상하여 개선된 속도 추종 성능을 보일 수 있다. 추정된 상태의 오차는 부하변동의 경우 1.9 [%] 이내임과 정상상태 상태 추종 오차가 영으로 수렴함을 보여 상태 추종 제어기의 외란 제거성능을 보임을 확인할 수 있다.

• ETRI Journal
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• 제28권2호
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• pp.250-252
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• 2006

In this letter, a discrete state, discrete time chaotic pseudo random number generator (CPRNG) is presented for stream ciphering of text, audio, or image data. The CPRNG is treated as a finite state machine, and its state is modulated according to the input bit sequence of the signal to be encrypted. The modulated state sequence obtained can be transmitted as a spread spectrum or encrypted data.