• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.598-602
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• 2002

This paper presents the 3-phase hybrid series active power filter with dynamic voltage restorer(DVR) which serve as an energy buffer and current harmonics blocking resistor connected to sensitive loads, such as, to compensate voltage dips and current harmonics in power distribution system. The DVR is to inject a dynamically controlled voltage generated by a forced commutated converter in series to the bus voltage by means of a booster transformer. The momentary amplitudes of the three injected phase voltages are controlled such as to eliminate any detrimental effects of a bus fault to the load voltage. The proposed system is able to simultaneously compensate current harmonics, voltage fluctuating and voltage unbalance in power distribution systems. The reference phase angle detected by synchronized with the positive sequence component of the unbalanced source by using symmetrical component transformation. The effectiveness of proposed system is verified by the computer simulation.

• International Journal of Reliability and Applications
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• 제2권4호
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• pp.253-262
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• 2001

A k-out-of-n standby system is considered where all of its components are s-independent and classified either working or cold standby connected with imperfect switches. The probability density function of the life length for this system is established in closed form, when the underlying components have constant failure rates. Also the reliability function of the system is derived. Finally, the reliability functions for one, two and three out of four systems are deduced for perfect or imperfect switches and identical or non-identical constant failure rates for working and standby components.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.65-67
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• 2017

다양한 연소불안정 모델링 기법이 로켓 및 가스터빈 등 연소시스템에 적용되어 개발, 검증되고 있다. 이 중 본 연구에서는 시스템의 각 요소를 음향 네트워크로 구성하여 질량, 운동량, 에너지 보존 방정식을 푼 다음, 각 요소들의 경계 조건을 대입하여 전체 시스템의 불안정 특성을 해석하는 1D 네트워크 모델의 기초 이론부터 최신 연구 동향을 소개하고자 한다. 특히 화염전달함수(flame transfer function)와 음향전달함수(acoustic transfer function)을 각각 정의하고, 서로의 상호 관계에 대하여 규명하였다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2018년도 추계학술발표대회
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• pp.333-334
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• 2018

This is a study on controlling a drone (DJI Mavic Air) with simple hand gesture using Leap Motion controller. Four component involve are MacBook, Leap Motion controller, Android device, and DJI Mavic Air. All of this component are connected through USB, Bluetooth, and Wi-Fi technology. The studies main purpose are to show that by controlling a drone through Leap Motion, drone amateur user can easily learn how to control a drone, and because of longer drone control range can be archived things such as search and rescue mission will be possible.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 추계학술대회
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• pp.74-75
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• 2010

As global warming due to burning fossil fuels and natural resource depletion issues have emerged, the development of renewable energy sources such as photovoltaics (PV) has been brought to recent interest. Amongst the vast efforts to harvest and convert solar energy into electricity, the module integrated converters (MIC) has become a worthy topic of research for grid-connected photovoltaic systems. Due to the required high-boosting qualities, only a restricted amount of DC/DC converter topologies can be applied to MICs. This paper investigates the possibility of a tapped-inductor boost converter as a candidate for PV MICs. A dual-inductor interleaving scheme operating slightly above the boundary of the two conduction modes (BCM) is suggested for reduction of input current ripple and minimization of component stress. A digital controller is used for implementation, assuring maximum power tracking and transfer while providing sufficient computational space for other grid connectivity applications, etc. For verification, a 200W converter is designed and simulated via computer software including component losses. High efficiency over a wide power range proves the feasibility of the proposed PV MIC system.

• 한국지진공학회논문집
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• 제25권6호
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• pp.267-274
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• 2021

Seismic fragility analysis of a structure is generally performed for the expected critical component of a structure. The seismic fragility analysis assumes that all the components behave independently in a structural system. A bridge system consists of many inter-connected components. Thus, for an accurate evaluation of the seismic fragility of a bridge, the seismic fragility analysis requires the composition of probabilities considering the correlation between structural components. This study presented a procedure to obtain the seismic fragility curve of a bridge system, considering the correlation between bridge components. Seismic fragility analysis was performed on a PSC bridge that is considered as the central infrastructure. The analysis results showed that the probability of the seismic fragility curve of the bridge system was higher than that of each bridge component.

• 디지털산업정보학회논문지
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• 제16권4호
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• pp.67-74
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• 2020

As the information age develops, Online education and Non-face-to-face work are becoming common. Telecommuting such as tele-education and video conferencing through the application of information technology is also becoming common due to the COVID-19. Unexpected information leakage can occur online when the company conducts work remotely or holds meetings. A system to authenticate users is needed to reduce information leakage. In this study, there are various ways to authenticate remote access users. By applying burn authentication using a biometric system, a method to identify users is proposed. The method used in the study was studied the main component analysis method, which recognizes several characteristics in facial recognition and processes interrelationships. It proposed a method that can be easily utilized without additional devices by utilizing a camera connected to a computer by authenticating the user using the shape and characteristics of the face by using the PCA method.

• 대한수학회보
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• 제59권6호
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• pp.1409-1422
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• 2022

A 3-fold quotient terminal singularity is of the type $\frac{1}{r}(b,1,-1)$ with gcd(r, b) = 1. In [6], it is proved that the economic resolution of a 3-fold terminal quotient singularity is isomorphic to a distinguished component of a moduli space 𝓜_𝜃 of 𝜃-stable G-constellations for a suitable 𝜃. This paper proves that each connected component of the moduli space 𝓜_𝜃 has a torus fixed point and classifies all torus fixed points on 𝓜_𝜃. By product, we show that for $\frac{1}{2k+1}(k+1,1,-1)$ case the moduli space 𝓜_𝜃 is irreducible.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 전력전자학술대회
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• pp.406-407
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• 2011

The dc link voltage in a single-phase PV system has necessarily twice component of fundamental wave. It makes high THD in the grid current, and according to the problem, power quality is lower. This paper proposes the new method for removing ripple voltage. The performance was verified through computer simulation using MATLAB.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2002년도 봄 학술발표논문집 Vol.29 No.1 (B)
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• pp.646-648
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• 2002

본 논문에서는 차량번호판의 용도구분 문자를 자소 단위로 분리하는 효율적인 방법을 제안하고, 신경망을 이용하여 자소를 인식하는 방법을 소개한다. 용도구분 문자(가, 거, 나, 너‥‥)는 실제 번호판의 훼손, 카메라의 성능, 기타 여러 가지 조건에 의해서 번호판 영상에 많은 잡영이 포함된다. 따라서 차량번호판 한글문자를 자소분리하는 것은 어려운 작업이다. 제안하는 이진 영상처리 기법(morphological operation, connected component labeling 등) 으로 분리된 자소가 인식시스템으로의 입력벡터로 입력되었을 때 높은 인식률을 보이는 것을 실험을 통하여 확인하였다