• 제목/요약/키워드: EL Efficiency

검색결과 339건 처리시간 0.027초

고분자 유기 EL 제조를 위한 멀티헤드형 잉크젯 패터닝 시스템 (Multi-head Inkjet Patterning System for Manufacturing a Full Color Polymer Light Emitting Device (pLED))

  • 오제훈;김시경;윤희열;오세일;강유명;김광일
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.1219-1225
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    • 2003
  • According to the increase of lifetime and efficiency, the interest in the pLED has dramatically increased recently because pLED can be applied to large-size and flexible displays. The core process in the manufacture of pLED is the printing process of red, green and blue light emitting polymers (LEP), and inkjet printing method is one of the promising technology to print red, green and blue LEP on glass substrates. In this work, we developed a multi-head inkjet patterning system with 3 heads for each color. The developed inkjet patterning system is composed of the precise positioning system, head controller circuit, real-time ink drop evaluation system, maintenance system, and stable ink supply system. Finally, we investigated the stability and reliability of the system by printing red, green and blue LEP on the dummy substrate.

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Effective technique to analyze transmission line conductors under high intensity winds

  • Aboshosha, Haitham;El Damatty, Ashraf
    • Wind and Structures
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    • 제18권3호
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    • pp.235-252
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    • 2014
  • An effective numerical technique to calculate the reactions of a multi-spanned transmission line conductor system, under arbitrary loads varying along the spans, is developed. Such variable loads are generated by High Intensity Wind (HIW) events in the form of tornadoes and downburst. First, a semi-closed form solution is derived to obtain the displacements and the reactions at the ends of each conductor span. The solution accounts for the nonlinearity of the system and the flexibility of the insulators. Second, a numerical scheme to solve the derived closed-form solution is proposed. Two conductor systems are analyzed under loads resulting from HIW events for validation of the proposed technique. Non-linear Finite Element Analyses (FEA) are also conducted for the same two systems. The responses resulting from the technique are shown to be in a very good agreement with those resulting from the FEA, which confirms the technique accuracy. Meanwhile, the semi-closed form technique shows superior efficiency in terms of the required computational time. The saving in computational time has a great advantage in predicting the response of the conductors under HIW events, since this requires a large number of analyses to cover different potential locations and sizes of those localized events.

Efficient Blue Light Emitting Diode by Using Anthracene Derivative with 3,5-Diphenylphenyl Wings at 9- and 10-Position

  • Kim, Yun-Hi;Lee, Sung-Joong;Jung, Sang-Yun;Byeon, Ki-Nam;Kim, Jeong-Sik;Shin, Sung-Chul;Kwon, Soon-Ki
    • Bulletin of the Korean Chemical Society
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    • 제28권3호
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    • pp.443-446
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    • 2007
  • The novel blue light emitting material, 9,10-bis(3',5'-diphenylphenyl)anthracene (BDA) was synthesized by Suzuki coupling reaction and characterized by the measurements of 1H NMR, 13C NMR and FT-IR. The new anthracene derivative, which contains anthracene as a main core unit and 3',5'-diphenylphenyl group derivative as wings, has high fluorescence yield, good thermal stability, and high glass transition temperature at 188 oC. With the newly non-doped blue emitting material in the multilayer device structure, it was possible to achieve the current efficiency of 3.0 cd/A. The EL spectrum of the ITO/CuPc/α-NPD/BDA/Alq3/LiF/Al device showed a maximum wavelength (λmax) at 440 nm. The emitting color of device showed the blue emission (x,y) = (0.18,0.19) at 10 mA/cm2 in CIE (Commission Internationale de l'Eclairage) chromaticity coordinates.

THE USE OF SEAWEED MEAL IN FEEDING COMMON CARP (Cyprinus carpio L.)

  • Zaki, M.A.;Nour, A.M.;Omar, E.;Tag El-Din, A.E.
    • Asian-Australasian Journal of Animal Sciences
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    • 제7권2호
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    • pp.183-189
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    • 1994
  • Two experiments were made. In experiment 1, four diets containing 0, 5, 15 and 25% washed seaweed meal were prepared to study the effects of incorporating seaweed meal instead of equivalent amounts of berseem leaf meal in fish feeds on growth performance and feed utilization of common carp. The results showed that average daily gain (ADG), specific growth rate (SGR%), dry matter (DM) and ether extract (EE) of the carcasses were decreased (p<0.05) with the increasing level of seaweed meal in the feeds. Inclusion of 5% seaweed meal in the diet gave the best feed conversion ratio (FCR) among all diets, however, protein productive value (PPV) and energy utilization (EU) were decreased (p<0.05) with increasing level of seaweed meal in the diet. In experiment 2, washed seaweed meal was either steam cooked or sprayed with NaOH (0.5% or 1% NaOH) and incorporated in the diets at the level of 25% instead of equivalent amount of berseem leaf meal. The results showed that steam cooked seaweed gave the best (p<0.05) growth performance, FCR and protein efficiency ratios, PER and PPV, for other treatments in descending order were NaOH treated seaweed, washed seaweed and unwashed seaweed.

The Impact of Financial Technology on Facilitating E-Government Services in Egypt

  • GOHARY, Esam El
    • 유통과학연구
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    • 제17권5호
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    • pp.51-59
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    • 2019
  • Purpose - Nowadays financial technology is crucial for each organization to facilitate business transactions and make them easier. This paper was conducted with the purpose of determining the effect of fintech including services e-payment, bills e-payment, ways of payment and bank accounts with e-government on facilitating e-government services in terms of availability, accessibility, efficiency and responsiveness. Research design, data, and methodology - The problem of this paper is summarized in the lack of studies in this subject. So, a survey was applied on 400 respondents in Egypt to investigate the impact of fintech on facilitating e-government services, in order to determine which fintech item can affect any of facilitating services dimensions. Results - The results revealed that bank accounts with e-government doesn't affect any of facilitating services dimension, while each of the remain items has an effect on some dimensions and does not has effect on others. Conclusions - Data analysis revealed that the most obstacles that face respondents resulted in the weakness of internet networks, lack of efficient employees in e-government portal and lack of system effectiveness. In general, it clears that fintech implementation affect the dimensions of facilitating e-government services, however not all fintech implementation components have the same effect on the dimensions.

Eddy Loss Analysis and Parameter Optimization of the WPT System in Seawater

  • Zhang, Ke-Han;Zhu, Zheng-Biao;Du, Luo-Na;Song, Bao-Wei
    • Journal of Power Electronics
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    • 제18권3호
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    • pp.778-788
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    • 2018
  • Magnetic resonance wireless power transfer (WPT) in the marine environment can be utilized in many applications. However, energy loss in seawater through eddy loss (EL) is another consideration other than WPT in air. Therefore, the effect of system parameters on electric field intensity (EFI) needs to be measured and ELs calculated to optimize such a system. In this paper, the usually complicated analytical expression of EFI is simplified to the product of frequency, current, coil turns, and a coefficient to analyze the eddy current loss (ECL). Moreover, as the calculation of ECL through volume integral is time-consuming, the equivalent eddy loss impedance (EELI) is proposed to help designers determine the optimum parameters quickly. Then, a power distribution model in seawater is conceived based on the introduction of EELI. An optimization flow chart is also proposed according to this power distribution model, from which a prototype system is developed which can deliver 100 W at 90% efficiency with a gap of 30 mm and a frequency of 107.1 kHz.

금속-킬레이트계($Snq_2,Snq_4$) 발광층을 이용한 유기 전기 발광 소자의 제작과 전기.광학적 특성 (Fabrication of Organic Electroluminescent Device and electro-optical properties using metal-chelates($Snq_2,Snq_4$) for Emitting Material Layer)

  • 윤희찬;유정현;김병상;김정균;권영수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 C
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    • pp.1575-1577
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    • 2002
  • In this study, multi layer type OLED(Organic Light Emitting Diode) has been fabricated using $Snq_2$, $Snq_4$, and $Alq_3$ for development of high efficiency, electrical and optical properties of multi layer type OLED investigated. The HTL(Hole Transfer Layer) and EML(Emitting Material Layer) were fabricated by using vacuum evaporation on ITO electrode, and its thickness controlled using thickness monitor. Al was used as a cathode. The electrical and optical properties such as J-V, brightness-V and EL spectrum of OLED device was measured using I.V.L.T system. The result, brightness of $Alq_3$, $Snq_2$ and $Snq_4$ were $3900cd/m^2$, $63cd/m^2$ and $23cd/m^2$ respectively.

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도핑한 음극을 이용한 유기전기발광소자의 전자주입 특성에 관한 연구 (A STUDY ON ELECTRON INJECT10N CHARACTERISTICS WITH DOPED CATHODES OF ORGANIC LIGHT EMITTING DIODES)

  • 곽윤희;이용수;박재훈;이종혁;홍성진;강창헌;김연주;최종선
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 C
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    • pp.1609-1611
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    • 2002
  • Multi-layer organic electroluminescent(EL) devices with Al-CsF composite as a cathode were fabricated. This device privides low driving voltage and high quantum efficiency. CsF is evaporated onto and diffuse into electron transport layer. $Alq_3$. The Fermi level of $Alq_3$ moves towards the LUMO level.

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Characteristics of SiOx thin films deposited by atmospheric pressure chemical vapor deposition using a double discharge system

  • 박재범;길엘리;염근영
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.261-262
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    • 2011
  • 본 연구는 HMDS/$O_2$/He/Ar의 gas mixture를 이용하여 remote-type의 DBD source를 통한 APPECVD를 통한 SiOx 양질의 무기막 증착 공정을 개발하였다. 이때 기판에 바이어스를 인가 하거나 혹은 접지를 하여 대기압 플라즈마의 환경 내에서도 바이어스 효과를 확인할 수 있도록 double discharge system을 구축하였다. 그리고 이 double discharge system의 다양한 특성과 기존의 전형적인 DBD와 비교 하였을 때 어떠한 차이점을 가지는지에 대해서도 관찰하였다. 그리하여 전형적인 DBD system과 double discharge를 통해 증착된 SiOx 무기막의 특성을 역시 비교 관찰하였다. Gas mixture 중 HMDS의 유량이 증가함에 따라, 그리고 $O_2$ gas의 유량이 감소함에 따라 SiOx 무기막의 증착률은 감소하였다. 그러나, SiOx 무기막 내의 불순물들, 예를 들어, carbon 혹은 hydrogen 계열의 chemical bond에 대한 정성적인 양은 HMDS 의 유량이 증가하거나 혹은 $O_2$ gas의 양이 감소함에 따라 오히려 증가함을 관찰할 수 있었다. 그리고 기판에 바이어스를 인가하는 double discharge system을 사용하였을 경우, 같은 HMDS, $O_2$ gas 유량을 사용한 전형적인 DBD type의 증착 공정 보다 더 높은 공정 효율을 나타냄과 동시에 더 낮은 불순물 함량을 가짐을 알 수 있었다. 이러한 double discharge system을 통해 증착된 양질의 SiOx 무기막이 증착 되었음을 FT-IR을 통한 막질 분석을 통해 확인 할 수 있었다. 이러한 double discharge system의 증착 공정에 대한 긍정적인 효과들은 atmospheric discharge의 효율 향상에 따른 gas dissociation efficiency 증가와 이를 통한 HMDS 분해 및 산소와의 recombination 효율의 증가에 따른 결과로 사료된다.

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Minimizing Sensing Decision Error in Cognitive Radio Networks using Evolutionary Algorithms

  • Akbari, Mohsen;Hossain, Md. Kamal;Manesh, Mohsen Riahi;El-Saleh, Ayman A.;Kareem, Aymen M.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제6권9호
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    • pp.2037-2051
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    • 2012
  • Cognitive radio (CR) is envisioned as a promising paradigm of exploiting intelligence for enhancing efficiency of underutilized spectrum bands. In CR, the main concern is to reliably sense the presence of primary users (PUs) to attain protection against harmful interference caused by potential spectrum access of secondary users (SUs). In this paper, evolutionary algorithms, namely, particle swarm optimization (PSO) and genetic algorithm (GA) are proposed to minimize the total sensing decision error at the common soft data fusion (SDF) centre of a structurally-centralized cognitive radio network (CRN). Using these techniques, evolutionary operations are invoked to optimize the weighting coefficients applied on the sensing measurement components received from multiple cooperative SUs. The proposed methods are compared with each other as well as with other conventional deterministic algorithms such as maximal ratio combining (MRC) and equal gain combining (EGC). Computer simulations confirm the superiority of the PSO-based scheme over the GA-based and other conventional MRC and EGC schemes in terms of detection performance. In addition, the PSO-based scheme also shows promising convergence performance as compared to the GA-based scheme. This makes PSO an adequate solution to meet real-time requirements.