• 한국인쇄학회:학술대회논문집
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• 한국인쇄학회 2000년도 춘계 학술발표회 논문집
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• pp.45-55
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• 2000

Recently, as the prepress mainstream is changed to the digital wolkflow, various digital proofing systems such as high price dye sublimation printers and low price ink jet printers are widely used in printing industry. Generally, CRT monitors are also often used as a soft proofing device for hard-copy image output. However, displayed color image on CRT monitor does not match to the actual color printing sheets. Because, the color space of CRT monitor used RGB color space, and it is differ with printing device color space, CMY. Therefore, proper color compensations are needed to match the colors between hard-copy proofs on the printing device and soft copy proofs on the monitor. For the proper compensation, we used LUT and gamut mapping method for color space transformation between device dependent color space and device independent color space, vis a vis. This paper shows the application method and the usefulness of CRT monitor for the soft-copy proofing using the output characteristics of printing device.

• 한국방사선학회논문지
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• 제13권2호
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• pp.209-216
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• 2019

본 논문은 초음파 검사 및 판독에 사용되는 CRT, LCD 모니터에서 영상검사와 판독 시 적절한 시각화에 대한 최적의 주변 조도 수준을 제안하고자 하였다. 평가자들은 4그룹 20명(Ultra-sonographer 20명(4 groups; ultra-sonographer 1~5 years 5명, ultra-sonographer 6~10 years 5명, ultra-sonographer 11~15 years 5명, ultra-sonographer 16~20 years 5명)을 대상으로 하였으며, 문항수는 32문항이었다. 평가방법은 10, 25, 100 Lux 3가지 주변광 조도에서 초음파 soft copy 영상을 1문항 당 30초간 영상 평가하였으며, 평가 결과를 6점 척도로 1점=Normal (Definitely no lesion), 2점=possibly not a lesion, 3점=probably not a lesion, 4점=possibly a lesion, 5점=probably a lesion, 6점=Definitely a lesion으로 나타내었다. 본 연구에서 주변광에 따른 초음파 영상들에 대한 병변 감지에 사용되는 소프트 카피(soft copy) 영상 판독 ROC분석 결과는 10 Lux에서 높은 민감도, 특이도, 곡선하면적 결과를 나타내었다. 주변광 조도로 10 Lux를 이용한다면 초음파(ultrasound) 소프트 카피(soft copy) 영상의 병변 탐지에 있어 최적의 효과를 얻을 수 있음을 알 수 있었다. 추후 연구 자료를 기초로 하여 초음파 영상 검사실 및 판독실의 주변광 조명밝기를 설계하면서 기초자료로 제시될 것으로 생각한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.75-79
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• 2001

This paper presents a novel version of an active voltage clamped ZVS-PWM high frequency inverter using IGBTs for electromagnetic induction eddy current-based rolling drum heating in new generation copy and printing machines in consumer business use. The operating principle of this inverter circuit and unique features are described herein. Its constant frequency duty cycle (asymmetrical PWM) controlled voltage source quasi-resonant soft switching high frequency inverter employing IGBTs is proposed, which is capable of achieving stable and efficient zero voltage soft switching commutation over a widely specified power regulation range from full power to low power. The operating performances in a steady state of this inverter is discussed and evaluated on basis of simulation and experimental results as an induction heated roller in new generation copy machine.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.499-502
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• 2003

This paper presents the voltage source type half bridge lossless auxiliary inductor snubber assisted series capacitor compensated resonant high frequency inverter for induction heated fixing roller in copy machines. This high-frequency inverter treated here can completely achieve zero current soft switching (ZCS) commutation for wide power regulation range under its constant frequency pulse density modulation (PDM) scheme. Its transient and steady-state operating principle is originally presented fur a constant frequency PDM control strategy under a ZCS operation commutation, together with its output effective power regulation characteristics-based on the PDM strategy. The experimental operating performances of this ZCS-PDM high frequency inverter using IGBTs are illustrated as compared with computer simulation ones. Its power losses and actual efficiency are evaluated and discussed on the basis of simulation and experimental results.

• 한국인쇄학회지
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• 제18권2호
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• pp.69-82
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• 2000

Recently, as the prepress mainstream is changed to the digital workflow, various digital proofing systems such as high price dye sublimation printers and low price ink jet printers are widely used in printing industry. CRT monitors are also often used as a soft proofing device. However, it is very difficult to match the color image displayed on CRT monitors to the actual images printed on papers, because the color space of CRT monitors is RGB color system, and it is different with the CMY color system of the printing devices. Therefore, proper color compensations are needed to match the colors between hard-copy proofs on the printing device and soft copy proofs on CRT monitors. This paper shows the LUT and gamut mapping method considering the printing characteristics of output device is useful for the compensation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1066-1071
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• 2005

This paper presents the two lossless auxiliary inductors-assisted voltage source type half bridge (single ended push pull: SEPP) series resonant high frequency inverter for induction heated fixing roller in copy and printing machines. The simple high-frequency inverter treated here can completely achieve stable zero current soft switching (ZCS) commutation for wide its output power regulation ranges and load variations under its constant high frequency pulse density modulation (PDM) scheme. Its transient and steady state operating principle is originally described and discussed for a constant high-frequency PDM control strategy under a stable ZCS operation commutation, together with its output effective power regulation characteristics-based on the high frequency PDM strategy. The experimental operating performances of this voltage source SEPP ZCS-PDM series resonant high frequency inverter using IGBTs are illustrated as compared with computer simulation results and experimental ones. Its power losses analysis and actual efficiency are evaluated and discussed on the basis of simulation and experimental results. The feasible effectiveness of this high frequency inverter appliance implemented here is proved from the practical point of view.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.304-308
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• 2001

This paper presents a novel prototype of ZCS-PFM high frequency series resonant inverter using IGBT power module for electromagnetic induction eddy current-heated roller in copy and printing machines. The operating principle and unique features of this voltage source half bridge inverter with two additional soft commutation inductor snubber are presented including the transformer modeling of induction heated rolling drum. This soft switching inverter can achieve stable zero current soft commutation under a discontinuous and continuous resonant load current for a widely specified power regulation processing. The experimental results and computer-aided analysis of this inverter are discussed from a practical point of view.

• 조명전기설비학회논문지
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• 제22권7호
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• pp.28-36
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• 2008

This paper presents a novel prototype of zero current switching pulse frequency modulation (ZCS-PFM )high frequency series resonant inverter using IGBT power module for electromagnetic induction eddy current heated roller in copy and printing machines. The operating principle and unique features of this voltage-fed half bridge inverter with two additional soft commutation inductor snubber are presented including the transformer modeling of induction heated rolling drum. This soft switching inverter can achieve stable zero current soft commutation under a discontinuous and continuous resonant load current for a widely specified power regulation processing. The experimental results and computer-aided analysis of this inverter are discussed from a practical point of view.

• Journal of information and communication convergence engineering
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• 제6권3호
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• pp.301-304
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• 2008

This paper presents a lossless inductor snubber-assisted series resonant high frequency inverter using the trench gate IGBTs for the electromagnetic induction eddy current-heated fixing roller in copy and printing machines in a new generation. This soft switching high-frequency inverter can completely achieve zero current soft switching (ZCS) commutation mode transitions and wide power regulation under its constant frequency pulse density modulation (PDM) scheme. Its transient and steady state operating principle is originally presented for a constant frequency PDM strategy under a ZCS operation, together with its output power regulation characteristics-based on the pulse density modulation. The effectiveness of this soft switching high-frequency inverter is confirmed for the fixing equipment with the induction-heated fixing roller.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.419-422
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• 2008

This paper presents a novel prototype of ZCS-PFM high frequency series resonant Inverter using IGBT power module for electromagnetic induction eddy current-heated roller in copy and printing machines. The operating principle and unique features of this voltage source half bridge inverter with two additional soft commutation inductor snubber are presented Including the transformer modeling of induction heated rolling drum. This soft switching inverter can achieve stable zero current soft commutation under a discontinuous and continuous resonant load current for a widely specified power regulation processing. The experimental results and computer-aided analysis of this inverter are discussed from a practical point of view.