• Title/Summary/Keyword: NPD

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Luminance Properties of Organic Light Emitting Diodes Using Zn-Complexes (Zn-Complexes를 이용한 OLEDs의 발광 특성 연구)

  • Jang, Yoon-Ki;Kim, Doo-Seok;Kim, Byoung-Sang;Kwon, Oh-Kwan;Lee, Burm-Jong;Kwon, Young-Soo
    • Proceedings of the KIEE Conference
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    • 2005.07c
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    • pp.1890-1892
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    • 2005
  • Recently, high luminance and high efficiency were realized in OLEDs with multilayer structure including emitting materials such as metal-chelate complexes. New luminescent materials, [2- (2-hydroxyphenyl)-quinoline] (Zn(HPB)q), [(1,10-phenanthroline)- (8-hydroxyquinoline)] Zn(Phen)q was synthesized. Zn-Complexes have low molecular compound and thermal stability. The ionization potential(IP) and electron affinity(EA) of Zn-complexes were measured by cyclic-voltammetry(CV). The fundamental structure of the OLEDs was $ITO/{\alpha}$-NPD/Zn-Complex/Al and then we made device structure rightly in energy band gap. We using Zn(Phen)q as emitting layer and Zn(HPB)q as electron transport layer. We measured current density-voltage, luminance-voltage characteristics.

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발광층에 Dotted-Line Doping Structure(DLDS)를 적용한 Red-Oranic Light-Emitting Diodes(OLEDs)의 발광특성

  • Lee, Chang-Min;Han, Jeong-Hwan
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07a
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    • pp.177-180
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    • 2004
  • 발광층에 Alq3와 rubrene을 mixed host로 사용하고 DCJTB를 형광 dopant로 사용한 다층 박막 구조의 red OLEDs를 제작하였다. 소자의 구조는 $ITO:Anode(120nm)/{\alpha}-NPD:HTL(40nm)/Alq_3+Rubrene(mixed\;host\;1:1)+DCJTB(red\;dopant\;3%)+:EML(20nm)/Alq_3:ETL(40nm)/MgAg(Mg\;5%\;wt):Cathode(150nm)$ 로서 EML내부에 DCJTB를 Totally Doping Method와 Dotted-Line Doping Method의 두 가지 방법으로 도핑 하였다. Mixed host구조에 DCJTB를 6구간으로 나누어 Dotted Line Doping한 소자는 luminance yield가 $9.2cd/A@10mA/cm^2$ 이었다. 이 소자는 DCJTB만을 Totally Doping한 소자의 luminance yield $3.2cd/A@10mA/cm^2$에 비해 약 190%정도의 높은 효율 향상을 보였다. 또한 $10mA/cm^2$에 도달하는 전압은 5.5V Vs. 8.5V로서 mixed host를 사용한 소자에서 약 3V정도 구동전압이 낮아지는 효과가 있었다. 발광 스펙트럼의 Full Width Half Maximum(FWHM)은 각각 56.6nm와 61nm로서 rubrene을 mixed host로 사용한 소자에서 높은 색 순도를 얻을 수 있었다. 이러한 성능의 향상은 $Alq_3$와 혼합된 rubrene에 의한 낮은 전하주 입장벽, 높은 전류밀도에서 나타나는 발광감쇄현상의 감소, 그리고 발광층의 DLD구조에 의한 전하의 trap & confinement 에 따른 발광 exciton의 형성확률이 증가한데서 나타났다고 생각된다.

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A Study on the High-Efficiency Red OLEDs using Phosphorescent Materials (인광재료를 이용한 고효율 적색 유기발광 다이오드에 관한 연구)

  • Shim, Ju-Yong;Jeon, Hyeon-Seong;Cho, Jae-Young;Jung, Jin-Ha;Yoon, Seok-Beom;Kang, Myung-Goo;Oh, Hwan-Sool
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.428-429
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    • 2006
  • In this thesis, verifies electrical-optical characteristics of phosphorescent materials. basic structure of fabricating devices is glass/ITO/$\alpha$-NPD($300{\AA}$)/CBP:Guest($300{\AA}$)/BCP($80{\AA}$)/$Alq_3(100{\AA})$/Al($1000{\AA}$). In efficiency, fabrication of organic light emitting diodes using $Ir(btp)_2acac$ phosphorescent material is external quantum efficiency 0.268% as doping concentration 3%. At CIE coordinates, phosphorescent material $Ir(btp)_2acac$ following materials moves high purity red color(x=0.6686, y=0.3243). The brightness shows $285cd/cm^2$.

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A Study on the Analysis Method of Noise Standard Reflecting Aircraft Performance according to Flight Condition - Focusing on A330-300 at Gimpo International Airport - (비행조건에 따른 항공기 성능을 반영한 소음기준 분석방법 연구 - A330-300 항공기와 김포국제공항을 중심으로 -)

  • Myeongsik Lee;Sungwoo Jang;Jun ho Lee
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.31 no.1
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    • pp.37-42
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    • 2023
  • In an effort to reduce aircraft noise, noise abatement areas are designated and notified, and noise abatement procedures are implemented. However, residents in noise abatement areas are increasingly complaining about the increase in noise, and airlines are exceeding the criteria for noise. In this study, A330-300 airplane set flight conditions that are predicted to generate the most noise when taking off 32 runway at Gimpo International Airport, and predicted the noise as the NPD curve of the INM and AEDT programs. As a result of the analysis, it was considered that the noise at a specific point would generate higher noise than the noise criteria. Therefore, to avoid exceeding aircraft noise criteria at a particular point, supplementing the departure procedures by reflecting aircraft performance under flight conditions would reduce complaints from both airlines and local residents.

New Fashion Products Development through Consumer Co-Creation

  • Jaekyong Lee;Ho Jung Choo
    • Journal of the Korean Society of Clothing and Textiles
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    • v.47 no.3
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    • pp.475-491
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    • 2023
  • New product development (NPD) is crucial for fashion brands as they are required to constantly innovate in product design and technology to remain competitive in the global fashion market. In this study, we investigated the co-creative new fashion product development (NFPD) process to understand its structural characteristics and examined the components of this business model through case studies. Fashion companies frequently collaborate with consumers to create unique and innovative fashion items that both satisfy consumer demand and expand their economic potential. Base on case studied involving consumer participation in NFPD, our study analyzed the structural characteristics of the co-creative NFPD process. Consequently, our investigation identified five key factors of the co-creative NFPD business model: co-value, co-creator, co-activity, co-platform, and co-partner. The co-creation approach established in this study will help advance research on new fashion strategies and provide foundational information for Korean fashion companies that are facing an increasingly competitive global market, thus making a significant contribution to the literature.

Current Trends and Prospects of High Value-added Seafood Processing Technology Development (고부가가치 수산식품 가공기술 개발 트랜드 및 전망)

  • Young Chul Lee;Hyung Gyun Kim;Jae Cheon Jeong;Chang Soo Kang
    • Journal of Practical Agriculture & Fisheries Research
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    • v.25 no.4
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    • pp.148-157
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    • 2024
  • The market size of Korea's seafood industry is estimated to be about 62 trillion won ('19), of which the seafood processing industry is about 10 trillion won ('19), accounting for approximately 16% of the total market size. However, the current level of processing technology required for the development of seafood products is mainly simple primary processing, such as freezing and drying raw materials (in Jeollanam-do, which ranks first in the country in terms of seafood production, primary processors account for 86% of all seafood processors).In the future, trends in the development of processing technology for seafood will become more advanced in response to changes in domestic and international food consumption patterns. Blue food tech linked to ESG, convergence and digitalization linked to the 4th industry revolution will be further advanced in line with the national seafood industry policy direction. Through this, it is expected to establish itself as an axis of future technology management in the fisheries sector based on the large and small success stories of accumulated seafood R&D commercialization.

Distribution of Organophosphorus Pesticides in some Estuarine Environments in Korea

  • Yu Jun;Lee Dong Ho;Kim Kyung Tae;Yang Dong Beom;Yang Jae Sam
    • Fisheries and Aquatic Sciences
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    • v.4 no.4
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    • pp.201-207
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    • 2001
  • To study the distribution of organophosphorus pesticides which are extensively used for agriculture in Korea. Sea water samples were taken from 4 coastal areas during May and August of 1997 and sediment samples were collected from two coastal areas in August of 1997. These samples were analyzed using a Gas Chromatography/Nitrogen Phosphorus Detector (GC/NPD). In August the most commonly found organophosphorus pesticides in the surface waters of Kunsan area were IBP < S-Benzyl O,O-di-isopropyl phosphorothioate > $(m=432.5ng\;L^{-1})$ and EDDP < O-ethyl S,S-diphenyl phosphorodithioate > $(m=37.4ng\;L^{-1}) $ which are largely used between June and September to prevent rice blast disease. In Danghang Bay, dry fields located near the mouth of the estuary seemed to affect the concentrations of certain organophosphorus pesticides in the surface waters. Since organophosphorus pesticides applied in the watershed are rapidly decomposed while being transported along freshwater streams, watershed size is not proportional to the concentrations of these pesticides in the coastal waters. Pesticides concentrations measured in August were compared with those in May. IBP concentrations in coastal waters were about an order of magnitude higher in August than in May. Temporal and geographical distribution of individual organophosphorus pesticides is likely to be affected by types of agricultural practices in the watershed. Chloropyrifos was the most important of the organophosphorus pesticides in the sediments of the study area because of its persistent nature and high affinity to particulates.

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Highly Efficient Multi-Functional Material for Organic Light-Emitting Diodes; Hole Transporting Material, Blue and White Light Emitter

  • Kim, Myoung-Ki;Kwon, Jong-Chul;Hong, Jung-Pyo;Lee, Seong-Hoon;Hong, Jong-In
    • Bulletin of the Korean Chemical Society
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    • v.32 no.spc8
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    • pp.2899-2905
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    • 2011
  • We have demonstrated that TPyPA can be used as an efficient multi-functional material for OLEDs; hole transporting material (HTL), blue and white-light emitter. The device based on TPyPA as the HTL exhibited an external quantum efficiency of 1.7% and a luminance efficiency of 4.2 cd/A; these values are 40% higher than the external quantum efficiency and luminance efficiency of the NPD-based reference device. The device based on TPyPA as a blue-light emitter exhibited an external quantum efficiency of 4.2% and a luminance efficiency of 5.3 $cdA^{-1}$ with CIE coordinates at (0.16, 0.14), the device based on TPyPA as a white-light emitter exhibited an external quantum efficiency of 3.2% and a luminance efficiency of 7.7 $cdA^{-1}$ with CIE coordinates at (0.33, 0.39). Also, TPyPA-based organic solar cell (OSC) exhibited a maximum power conversion efficiency of 0.35%. TPyPA-based organic thin-film transistors (OTFTs) exhibited highly efficient field-effect mobility (${\mu}_{FET}$) of $1.7{\times}10^{-4}cm^2V^{-1}s^{-1}$, a threshold voltage ($V_{th}$) of -15.9 V, and an on/off current ratio of $8.6{\times}10^3$.

Simple Analytical Method for Acrylamide in the Workplace Air Adsorbed by Charcoal Tube (활성탄관을 사용하여 포집한 작업환경 공기중 아크릴아마이드의 분석법)

  • Yang, J.S.;Lee, M.Y.;Park, I.J.;Kang, S.K.
    • Analytical Science and Technology
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    • v.11 no.2
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    • pp.139-144
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    • 1998
  • For the ambient monitoring of acrylamide, the adequate condition of sampling and analysis was checked. The adequate adsorbents and desorption solvents were tested. The combination of charcoal tube as a adsorbent and acetone as a desorption solvent showed 87% desorption efficiency. Flame ionization detector was used to detect acrylamide. The detection limit was 0.814 mg acrylamide in 1 L acetone. It is the equivalent concentration of 0.0203 mg acrylamide in $1m^3$ air if the volume of air collected was 40L. The permissible exposure level (PEL) of acrylamide in the workplace air recommended by Occupational Safety and Health Administration (OSHA, USA) is 0.3 mg acrylamide in $1m^3$ air. So, it is very simple and economic analytical method for acrylamide to be set in the industrial hygiene laboratories.

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The Effectiveness of Virtual R&D Teams in SMEs: Experiences of Malaysian SMEs

  • Ale Ebrahim, Nader;Abdul Rashid, Salwa Hanim;Ahmed, Shamsuddin;Taha, Zahari
    • Industrial Engineering and Management Systems
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    • v.10 no.2
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    • pp.109-114
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    • 2011
  • The number of small and medium enterprises (SMEs), especially those involved with research and development (R&D) programs and employed virtual teams to create the greatest competitive advantage from limited labor are increasing. Global and localized virtual R&D teams are believed to have high potential for the growth of SMEs. Due to the fast-growing complexity of new products coupled with new emerging opportunities of virtual teams, a collaborative approach is believed to be the future trend. This research explores the effectiveness of virtuality in SMEs' virtual R&D teams. Online questionnaires were emailed to Malaysian manufacturing SMEs and 74 usable questionnaires were received, representing a 20.8 percent return rate. In order to avoid biases which may result from pre-suggested answers, a series of open-ended questions were retrieved from the experts. This study was focused on analyzing an open-ended question, whereby four main themes were extracted from the experts' recommendations regarding the effectiveness of virtual teams for the growth and performance of SMEs. The findings of this study would be useful to product design managers of SMEs in order to realize the key advantages and significance of virtual R&D teams during the new product development (NPD) process. This is turn, leads to increased effectiveness in new product development's procedure.