• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.277-280
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• 2007

Field emission-back light unit (FE-BLU) was fabricated using carbon nanotube (CNT) emitter. Local dimming and local brightening techniques were achieved, which results in very high contrast ratio. In addition, the motion blur phenomenon, one of the serious problems of liquid crystal display (LCD) with cold cathode fluorescent lamp (CCFL)-BLU, was removed from LCD-TV by using FE-BLU.

• Journal of Korean Association for Spatial Structures
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• v.23 no.3
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• pp.4-10
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• 2023

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.606-608
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• 1994

This paper presents a low speed (1m/sec) elevator controller with a IGBT inverter (9.5KW). The major engineering problems of this development are noise suppression, thermal-dissipation and reliability improvement. The characteristic marks of this elevator are a single board controller, 40% reduced component, 40% reduced cubic content, EMI filter, vector controlled IGBT inverter.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2013-2015
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• 1997

Elevator stops emergently when power failures happen during operation. In that case, the passenger should wait with frightened in the car untill they are rescued by repair man or power resumes. This paper describes an automatic landing device for power-failure(ALP) that consists of UPS and battery charge control system. The excellence of the ALP operation is verified by experiments in elevator test tower.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.47-50
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• 2008

We propose a new method evaluating the image quality of display devices using the CIECAM02 that is the recently developed CIE color appearance model and provides an extension of the previously recommended CIE color spaces. We develop the evaluation method that quantifies the color reproduction capability, emotional gray scale (gradation), and visual perception contrast (perceptual contrast range) based on the gamut in this model.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1398-1401
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• 1987

• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.709-711
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• 1999

In this paper, we propose the design methodologies for the range tracker which is designed for minimizing the range tracking error. The range discriminator has been implemented digitally. Finally, experimental results of the Digital Range Tracker are provided.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.129-131
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• 2021

Living Lab은 기존의 전문가 위주의 R&D 방법론을 탈피하여 각종 사용자가 연구 주체로 포함시키며 사회가 직면한 도면과제의 직접적 해결은 물론 R&D 성과물의 용이한 사업화가 가능하도록 한다. 본 연구에서는 이러한 Living Lab의 정의를 파악하고 각종 운영사례와 환경 분석을 통해 R&D에서의 Living Lab의 적용 방법과 보완점을 도출하여 Living Lab의 새로운 개념을 제시하고 이를 통해 향후 R&D 과제에서 어떻게 적용할 것인지에 대한 시사점을 제시하고자 한다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.4
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• pp.291-299
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• 2021

This paper presents the control logic for the momentum wheel and gimbals in the CMG system. First, the design of the control logic for the momentum wheel is described in consideration of the power consumption and stability. Second, the design of the control logic for the gimbals considering the resonance of the vibration absorber and stability is explained. Third, the measurement configuration for the force and torque generated by the CMG is described. Fourth, the results of the frequency and time response test of the momentum wheel and gimbals are shown. Last, the measurements of the force and the torque generated through the CMG are explained.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.6
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• pp.413-422
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• 2022

In this paper, the fault analysis of the momentum wheel, which is a high-speed rotary machinery of 'Control Moment Gyro' for medium and large satellite, was described. For fault diagnosis, envelope spectrum analysis was performed using Hilbert transformation method and signal demodulation method to find the impact signals periodically generated from amplitude modulated signals. Through this, the fault of the momentum wheel was diagnosed by analyzing whether there was a harmonic component of the rotational frequency and a bearing fault frequency in a specific frequency band with a high peak.