• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.4
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• pp.232-238
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• 2000

PZT thin films(3500 ) have been prepared onto $Pt/Ti/SiO_2/Si$ substrates with a RF magnetron sputtering system using PB1.05(Zr0.52,Ti0.48)O3 ceramic target. We used two-step annealing techniques. As the RTA times and temperatures were increased, crystallization of PZT thin films were enhanced. The ferroelectric characteristics of PZT capacitors fabricated at $700^{\circ}C$ for 60 seconds were like these remanent polarization were $12.1 \muC/cm^2$, coercive field were 110 kV/cm, leakage current density were $4.1\times10-7 A/cm^2,\; \varepsilonr=442,$ and remanent polarization were decreased by 22% after 1010 cycles, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04b
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• pp.26-30
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• 2000

In this paper, carbon and silver electrode properties of power electroluminescent device were investigated. Devices were manufactured by screen-printing and manufactured devices were measured following things with variable applied voltage; emission spectra, transferred charge density, brightness and current. A continuous test at $65 ^{\circ}C$ of temperature and 95% of humidity was operated. The brightness of devices which were made of silver and carbon electrode at 100V was $67.03cd/m^2$ and $60.02cd/m^2$ respectively. In case of device, which was made of silver electrode, a black spot was formed after 72 hours and degraded but carbon electrode was stable.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04b
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• pp.18-21
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• 2000

진공 분위기에서 소성하여 ZnS 형광체를 제작하였다. ZnS 형광체는 소성온도가 $950^{\circ}C$ 이하인 경우 sphalerite 구조로 성장되었고, $1050^{\circ}C$ 이상인 경우 sphalerite 구조와 wurtize 구조의 공존이 확인되었다. Sphalerite 구조일 때 나타나는 460 nm를 중심으로 하는 발광 peak과 wurtize 구조일 때 나타나는 440 nm를 중심으로 하는 발광 peak은 ZnS 형광체 내에 형성된 $V_{Zn}$에 기인한다. Sphalerite 구조로 성장되었을 때 발광 스펙트럼에서 관측되는 528 nm를 중심으로 하는 발광 peak과 sphalerite와 wurtize 구조가 공존할 때 발광 스펙트럼에서 관측되는 515 nm를 중심으로 하는 발광 peak은 ZnS 형광체 내에 형성된 S의 결핍($V_s$) 준위로부터 가전자 띠로 복사 전이에 기인하는 것으로 설명된다.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.506-508
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• 2008

In this work, we used impedance spectroscopy analysis to determine the effect of the $HfO_X$ treatment on the surface of ITO and to model the equivalent circuit for OLEDs. Devices with an ITO/Organic material/Al structure can be modeled as resistances and capacitances arranged in parallel or in series. The number of elements depends on the composition of the structure, essentially the number of layers, and the contacts.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.1
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• pp.91-99
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• 2006

Fatigue properties of INVAR/AW wires have been investigated under the heat exposure in order to ensure stable operation and to estimate life span of their power line. In the case of heat exposure for 10000 hr, fatigue life and limit increased. For further heat exposure, fatigue limit decreased due to the decrease in yield strength. The variation fatigue of strand wire was strongly dependent on its amplitude. Also, cracks in wires of 7 strands were caused by stress concentration at the outer surface and fretting between each wire during vibration.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.431-432
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• 2008

HIT Solar Cell은 단결정 실리콘 웨이퍼가 초박막 amorphos 실리콘 층으로 싸여있는 구조이다. HIT Solar Cell에서 amorphos 실리콘의 두께와 도핑 농도는 태양전지의 효율을 결정하는 매우 중요한 요인이다. 본 논문에서는 높은 효율을 갖는 태양전지 설계를 위해 AFORS HET 프로그램을 이용하여 TCO_a-Si:H(p)_a-Si:H(i)_c-Si(n)_Al 구조를 설계했다. 후에 a-Si:H(p)의 두께와 a-Si:H(i) 의 두께를 가변하며 효율을 측정하였고, p-i-n 구조에서 n+ 층을 추가함에 따라 변하는 효율을 측정하였다. 최적화 한 결과 $V_{oc}$ = 693mV, $J_{sc}$ = 3891mA/$cm^{-2}$, FF = 8363%, $E_{ff}$ = 22.55% 의 고효율을 얻었다.

• YAKHAK HOEJI
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• v.38 no.4
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• pp.451-454
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• 1994

In accordance with reported references, 8-methyl-8,14-cycloberbine was derived from berberinephenolbetaine. On acidic treatment the 8-methyl-8,14-cycloberbines were converted easily to the compounds $1{\sim}7$ in good yields. We developed a novel method for a synthesis of the C8-N bond adduct compounds 8 and 9 from 8-methyl-8,14-cycloberbine by treatment with oxalyl chloride, and 1,3-dichloroaceton.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.135-138
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• 2009

자동차 디젤 분사장치의 하우징인 튜브 인젝터는 부품의 특성상 내식성, 내산화성, 강도 등을 필요로 하는 STS소재를 주로 사용하는데, 기존의 제조방법은 절삭가공이 주류를 이루었다. 그러나 생산성증대 필요성과 소재 이용률향상 및 제품의 고급화를 위하여 정밀냉간단조를 이용한 소성가공 방법이 최근에 시도되고 있다. 본 논문은 최적 정밀냉간단조 성형을 위해 유한요소법을 이용함으로써 정밀냉간 단조 공정 및 금형설계의 기초자료를 제시하였다.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1730-1732
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• 2000

Powder Electroluminescent Device is the solid state device which has a low power consumption, large area emission with uniformity, easy manufacturing, simple structure, and flexible mechanically. In this paper, we made the information display with the powder electroluminescent device using back-light and designed the driving circuit.

• Journal of Korean Society for Quality Management
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• v.44 no.1
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• pp.43-60
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• 2016

Purpose: This paper reviews the papers on TQM issues which are published in the Journal of the Korean Society for Quality Management (KSQM) since 1965. The literature review is purposed to survey a variety of TQM issues for several categories. Methods: We divide all of TQM issues into 6 categories: ISO system, quality assurance, quality management theory, empirical study on quality management, quality awards, and quality management etc. Results: Dividing all of papers on TQM published in KSQM for 50 years into 6 categories, we provide a chronological roadmap for individual categories, and summarize the contents and contributions of surveyed papers. Conclusion: The review paper is expected to provide future direction to improve TQM theories and applications in manufacturing and service industries.