• 제목/요약/키워드: Cole-Cole model

검색결과 26건 처리시간 0.031초

$ITO/Alq_3/Al$ 소자의 주파수 의존 응답을 이용한 유기 발광소자의 등가회 로 분석 (Equivalent-Circuit Analysis of Organic Light-Emitting Diodes using Frequency-dependent Response of $ITO/Alq_3/Al$ Device)

  • 안준호;정동회;허성우;이준웅;송민종;이원재;김태완
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 제6회 학술대회 논문집 일렉트렛트 및 응용기술연구회
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    • pp.5-8
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    • 2004
  • We have investigated equivalent-circuit analysis of organic light-emitting diodes using frequency-dependent response of $ITO/Alq_3(60nm)/Al$ device at two different bias voltages. Complex impedance Z of the device was measured in the frequency range of 40Hz~1MHz. A Cole-Cole plot shows that there are two dielectric relaxations at the bias below turn-on voltage, and one relaxation at the bias above turn-on voltage. We are able to interpret the frequency-dependent response in terms of equivalent-circuit model of contact resistance $R_s$ in series with parallel combination of resistance $R_p$ and capacitance $C_p$. We have obtained contact resistance $R_s$ around $90{\Omega}$, mainly from the ITO anode.

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미술가들의 음영 표현 특성과 CG 쉐이딩 알고리즘 간의 상관관계 분석 (Correlation Analysis between Artists' Shading and CG Shading)

  • 변혜원;박윤영
    • 한국멀티미디어학회논문지
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    • 제14권5호
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    • pp.691-702
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    • 2011
  • 최근 컴퓨터 그래픽스와 사용자의 인지를 결합한 다양한 연구들이 진행되고 있다. Cole 등은 미술가들의 라인 드로잉 데이터를 수집하여 기존의 CG(Computer-Generated) 라인 드로잉 알고리즘들이 미술가들의 드로잉 특성을 반영하고 있는지 비교하고, 사용자들이 어떤 라인 드로잉 알고리즘의 결과에서 형태를 효과적으로 인지하는지 평가하는 실험을 수행하였다. 그러나 라인 드로잉 알고리즘의 결과보다 BRDF 쉐이딩 모델이 적용된 결과에서 형태를 더욱 효과적으로 인지한다는 결과를 보였는데, 이는 음영이 형태 정보를 전단하기에 더욱 효과적인 요소임을 반증한다. 따라서 본 논문에서는 물체에서 인지한 음영과 미술가들의 음영 표현, 그리고 CG 쉐이딩 알고리즘 간의 상관관계에 대해서 연구한다. 특히, 미술가들의 음영 표현 특성과 CG 쉐이딩 알고리즘에서 나타나는 특성에 초점을 맞추고 이를 정량적으로 분석한다. 본 논문에서 수집한 실험 데이터 및 분석 결과는 효과적인 형태 전달을 목적으로 하는 새로운 CG 쉐이딩 알고리즘을 설계하는데 활용한 것으로 기대된다.

유전함수를 이용한 ZnO 바리스터의 입계 특성 분석 (Analysis of Grain Boundary Phenomena in ZnO Varistor Using Dielectric Functions)

  • 홍연우;신효순;여동훈;김종희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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    • pp.178-178
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    • 2008
  • ZnO 바리스터는 인가되는 전압에 따라 저항이 변하는 전압 의존형 저항체이며 각종 전기 전자 정보통신용 제품에 정전기(ESD) 대책용 소자로 폭 넓게 사용되는 전자 세라믹스 부품이다. 특별히 Bi-based ZnO 바리스터는 다양한 상(phase)으로 구성되어 있으며 그 입계의 전기적 특성은 소량 첨가되는 dopant의 종류에 따라 다양하게 변하는 것으로 알려져 있다. 본 연구에서는 Bi-based ZnO 바리스터 (ZnO-$Bi_2O_3$, ZnO-$Bi_2O_3-Mn_3O_4$)에서 각종 유전함수$(Z^*,M^*,\varepsilon^*,Y^*,tan{\delta})$를 이용하여 입계의 주파수-온도에 대한 특성을 살펴 보았다. 일반적인 ZnO 바리스터 제조법으로 시편을 제작하여 78K~800K 온도 범위에서 각종 유전함수를 이용하여 복소 평면도(complex plane plot)와 주파수 응답도(frequency explicit plot)의 방법으로 defect level과 입계 특성(활성화 에너지, 정전용량, 저항, 입계 안정성 등)에 대하여 고찰하였다. ZnO-$Bi_2O_3$(ZB)계와 ZnO-$Bi_2O_3-Mn_3O_4$(ZBM)계 모두 상온 이하의 온도에서 $Zn_i$$V_o$의 결함이 나타났으며, 이들의 결함 준위는 각 유전함수에 따라 다소 차이가 났다. 입계 특성으로 ZB계는 이상구간(560~660K)을 전후로 1.15 eV $\rightarrow$ 1.49 eV의 활성화 에너지의 변화가 나타났지만, ZBM계는 이러한 현상이 나타나지 않았다. 또한 입계 전위 장벽의 온도 안정성에 대해서는 Cole-Cole model을 적용하여 분포 파라미터 (distribution parameter; $\alpha$)를 구하여 고찰하였다. ZB계의 입계 안정성은 온도에 따라 불안정해 졌지만, ZBM계는 안정하였다.

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Legal Culture and Commercial Arbitration in the United States and Japan

  • Kim, Chin-Hyon;Chung, Yong-Kyun
    • 한국중재학회지:중재연구
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    • 제23권3호
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    • pp.185-212
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    • 2013
  • In this paper, a conceptual model of legal culture based on Ehrlich's "living law" theory and Cole's social-cultural explanation can explain the low utilization rates of arbitration of Japan and the high utilization rates of arbitration in the United States, simultaneously. This model highlights the clash between social norms and legal provisions in Japan. Japan has developed a two-tiered system of dispute resolution. At the official level, Japanese people accept the legal system imposed by the outside world. But, at a deeper level, they utilize diverse forms of informal dispute resolution mechanisms, such as reconcilement and conciliation, reflecting their own social norms. In contrast, there is no conflict between social norms and legal provisions in United States. This study may show that there are distinctions between American-style arbitration and Japanese-style arbitration, reflecting their own respective social norms. The question of reconciliation between the American style of arbitration and the Japanese style of arbitration can be resolved by an international arbitrator.

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PWR Hot Leg Natural Circulation Modeling with MELCOR Code

  • Park, Jae-Hong;Lee, Jong-In;Randall. K. Cole;Randall. O. Gauntt
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 1997년도 추계학술발표회논문집(1)
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    • pp.772-777
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    • 1997
  • Previous MELCOR and SCDAP/RELAP5 nodalizations for simulating the counter-current, natural circulation behavior of vapor flow within the RCS hot legs and SG U-tubes when core damage progress can not be applied to the steady state and water-filled conditions during the initial period of accident progression because of the artificially high loss coefficients in the hot legs and SG U-tubes which were chosen from results of COMMIX calculation and the Westinghouse natural circulation experiments in a 1/7-scale facility for simulating steam natural circulation behavior in the vessel and in the hot leg and SG during the TMLB' scenrio. The objective of this study is to develop a natural circulation modeling which can be used both for the liquid flow condition at steady state and for the vapor flow condition at the later period of in-vessel core damage. For this, the drag forces resulting from the momentum exchange effects between the two vapor streams in the hot leg was modeled as a pressure drop by pump model. This hot leg natural circulation modeling of MELCOR was able to reproduce similar mass flow rates with those predicted by previous models.

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농도의 기층 및 보조기층 공법연구 -노상 및 시멘트 안정 처리층의 Mr 특성을 중심으로- (Study on the Base and Subbase Method of Agricultural Road -On the Resilient Modulus Characteristics of the Subgrade and Cement Treated Base-)

  • 도덕현
    • 한국농공학회지
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    • 제31권2호
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    • pp.66-81
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    • 1989
  • The characteristics of resilient modulus(Mr) which dominates the life of pavement and the design of pavement were investigated on the test specimens which were cement treated and non-treated of the three different soil types. The results are summarized as follows : 1. The resilient modulus was decreased by increasing the cyclic deviator stress ($\sigma$d) , especially the resilient modulus was gradually decreased or sometimes increased when the value of ad was greater than 0.75- 1. 0kg/cm$^2$. 2. The resilient modulus was increased by increasing the homogeneous confined stress ($\sigma$do) and such phenomena were distinct on the coarse soils. 3. The resilient modulus was increased by increasing the ratio of confined stress(Kc), and this phenomena were eminent on the coarse soils too, and the higher permanent strain was showed by increasing the value of Kc. 4. In the drained cyclic triaxial compression test, the value of ad, Kc, and (Oho) was introduced by the following interrelated equations which were similar to the Mr model of Cole. Kcn/Mr=K1(J$_2$/ $\tau$oct)K2 ............. (coarse soli) Mcn/Mr=K3($\sigma$dp/ $\tau$f)k4 ...............(fine soils) 5. The stress path was not much affected by the value of Mr, however, moisture content, dry desity, and contant of fines affected the value of Mr. 6. In the soil-cement specimens, the resilient compression strain($\varepsilon$d) was decreased by the increment of the $\sigma$ho, and Mr was decreased by increasing the $\sigma$d 7. In the flexible pavement. the cement treated layer should be designed not to fail by the fatigue before the designed traffic load, and actually the pavement could cover the traffic load to a certain extent under the post-crack phase, therefore farther studies on this phenomena' are required in the design analysis. 8. The finite element computer program (ANALYS) was used for displacement analysis of pavement containing the cement-treated layer, The result showed that the program used for this analysis was proved to be usable.

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