• 산업기술연구
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• 제30권A호
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• pp.69-73
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• 2010

In this paper, we designed the RF-DC converter used in wireless power transmission system and studied how to design the RF-DC converter of high conversion efficiency. The RF-DC converter operate at 2.45GHz and the diode is connected with series. The RF-DC converter uses shorted stub for DC loop and matching. We can divide the RF-DC converter circuit into four blocks. The reflection coefficients between the blocks were optimized for the maximum conversion efficiency at 0 dBm input power and $1300{\Omega}$ load impedance. The final design of the RF-DC converter has a 52 percent conversion efficiency.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.757-760
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• 1999

Depending upon the existence of the battery, transponder is divided into active and passive transponder. The passive transponder operates without battery and so has no limitation in its operating range and life time. But it needs the RF-DC conversion circuit. In this paper, the analysis and design of the RF-DC conversion circuit in passive transponder operated in high frequency is presented and is confirmed by simulation and experiment.

• 한국의상디자인학회지
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• 제19권1호
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• pp.121-134
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• 2017

The purpose of this study is to investigate the effect of educational satisfaction on the school conversion intention according to the quality of university education service. To survey the perception of students majoring in Department of Beauty on both colleges and universities of beauty education, we distributed 600 questionnaires and utilized them as final analysis data except for 60 unreturned or defective papers. As a result of t-test and one-way ANOVA, there were differences among university education service quality, education satisfaction and school transfer intention. In addition, the effect of the quality of education service on the education service, the effect of the quality of education service on the school conversion intention, and the quality of the university education service influenced the school conversion intention. The results of this study suggest that, for the development of the beauty education, priority should be given to the facilities and equipments related to the beauty education as well as the importance of leadership and professional teachers and instructors.

• 패션비즈니스
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• 제16권4호
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• pp.75-87
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• 2012

This study was to investigate the conversion intent of fashion store among college undergraduates. The conversion intent in internet shopping mall and local store was associated with store attributes and relationship quality. A random sample of undergraduate students completed a questionnaire that contained measure of Store attributes, Relationship quality, Conversion intent of fashion store. The results revealed that store attributes of local store were store comport/salesman service, product diversity, store location, price and the store attributes of internet shopping mall were product diversity/easy of navigation, store reliability, screen configuration, sales promotion. Also, the result founded that the conversion intent of fashion store is related to store comport/salesman service in local store and is related to product diversity/easy of navigation, screen configuration, promotion in internet shopping mall. Relationship quality is highly effected of the conversion intent of local store and internet shopping mall. We expect that this research results can be used as a basic material for another study and setting up the marketing strategies in fashion store.

• 디자인학연구
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• 제15권1호
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• pp.309-318
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• 2002

시각디자인(visual communication design)에서 이미지의 표현은 전통적으로 여러 표현매체(Media)의 매커니컬한 부분과 깊은 관계가 있다. 특히 디지털방식을 이용한 이미지 표현에서는 회화적인 표한 도면작성, 광학적인 표현, 영상이미지 등 다양한 형식의 이미지들이 디지털데이터로 전환됨으로써 이미지의 변환이 쉬워졌다. 한편 디지털형식으로 각종 표현매체가 통합됨으로써 여러 형식의 시각이미지들간의 함성이 활성화됨으로써 이미지표현의 범위가 다양해지고 있으며, 나아가 기존의 평면적인 표현에서 3D, 4D 등 다양한 차원의(dimensional) 표현들이 디지털디자인의 이미지표현에서 종합되고 있는 경향을 보이고 있다. 또한 이렇게 여러 이미지형식들이 종합되는 과정에서 부분적이거나 전체적인 이미지의 변환이 자주 발생하고 있으며, 그 변환은 크게 조형적인 측면과 기술적인 측면의 두 가지 요인으로 요약된다. 본 논문에서는 조형적 측면으로 기존의 회화적 표현과 사진술로 대표되는 광학적 표한 그리고 컴퓨터그래픽에서의 이미지 변환 원리를 유형화하고 기술적인 측면으로 데이터형식에 따른 이미지의 변환과 디멘션에 따른 세부적인 내용을 기술하였다. 이 중 특히 기술적이고 정량적인 측정이 필요한 내용에 대해서는 컴퓨터를 이용한 간단한 시뮬레이션을 통해 객관적이고 실증적인 결과를 요약하였고, 연구내용의 세부적인 결과를 실제 시각디자인 작업에서 활용하는 방안을 사안별로 제시했다.

• 전기전자학회논문지
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• 제4권2호
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• pp.202-211
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• 2000

회로 시뮬레이터인 SPICE를 이용하여 1.9GHz 대역의 CMOS up-conversion 믹서를 설계하였고, 회로 설계를 위한 시뮬레이션 과정을 소자 모델링을 포함하여 상세히 설명하였다. $0.5{\mu}m$ 표준 CMOS 공정을 이용하여 칩을 제작한 결과, 제작된 칩의 특성과 초기 시뮬레이션에 의해 예상되는 특성 사이에 큰 차이점이 발견되어 이에 대한 원인 분석을 시도하였다. 발견된 문제점들을 고려한 경우의 시뮬레이션을 통해 시도한 시뮬레이션 방법의 타당성을 증명하였고, 이러한 문제점들을 보완할 경우 사용한 표준 CMOS 공정으로도 GaAs MESFET 공정을 사용한 유사 칩의 특성에 근접하는 칩 특성의 구현이 가능함을 보였다.

• Journal of Power Electronics
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• 제11권4호
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• pp.464-470
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• 2011

In this paper, the feasibility of applying a position sensorless control technique to hybrid electric vehicles (HEVs) is practically evaluated. The proposed position estimator has a straightforward structure with properties that combines the model and the saliency tracking-based rotor position estimation for interior permanent magnet synchronous motors (IPMSMs). The proposed method can be used in the event of sensor loss or sensor recovery to sustain continuity of operations. The developed system takes into account the estimated position transition between two distinct sensorless methods. The transition is enhanced by introducing a synchronized transition algorithm based on a single tracking observer. Extensive experimental results are presented to verify the principles and show a reliable estimation performance over the entire speed range including standstill under 150% load conditions.

• Journal of Electrical Engineering and Technology
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• 제13권1호
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• pp.326-332
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• 2018

In this paper, the design process and the control method of the power conversion system (PCS) that consists of a bidirectional DC-DC converter and a 3-level T-type inverter for an energy storage system is presented. Especially the design method of the output LCL filter for a 3-lvel T-type inverter without complex mathematical process are proposed. The validity of the control method and design process in this paper are verified through simulation and experimental analysis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1756-1758
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• 2005

This paper deals with the power conversion and design of permanent magnet generator for wind power applications. This paper derives analytical solutions for open-circuit field, armature reaction field, torque, back-emf, inductance and resistance of permanent magnet generators for wind power applications. And then, by presenting the variation of torque according to design parameters and by applying restrict conditions to it, we determine proper design parameter appropriate to rated power and speed. Finally, this paper also presents power conversion system resonable in wind power applications.

• Journal of Power Electronics
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• 제15권6호
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• pp.1446-1455
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• 2015

This paper illustrates resonant tank design considerations and the implementation of a LLC resonant converter with a wide battery voltage range based on the fundamental harmonic approximation (FHA) analysis. Unlike the conventional design at zero load, the parameter K (the ratio of the transformer magnetizing inductor L_m to the resonant inductor L_r) of the LLC converter in this paper is designed with two charging points, (V_{o_min}, I_{o_max1}) and (V_{o_max}, I_{o_max2}), according to the battery charging strategy. A 2.9kW prototype with an output voltage range of 36V to 72V dc is built to verify the design. It achieves a peak efficiency of 96%.