• Title/Summary/Keyword: COB

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Optimization of Thermal Performance in Nano-Pore Silicon-Based LED Module for High Power Applications

  • Chuluunbaatar, Zorigt;Kim, Nam-Young
    • International Journal of Internet, Broadcasting and Communication
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    • v.7 no.2
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    • pp.161-167
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    • 2015
  • The performance of high power LEDs highly depends on the junction temperature. Operating at high junction temperature causes elevation of the overall thermal resistance which causes degradation of light intensity and lifetime. Thus, appropriate thermal management is critical for LED packaging. The main goal of this research is to improve thermal resistance by optimizing and comparing nano-pore silicon-based thermal substrate to insulated metal substrate and direct bonded copper thermal substrate. The thermal resistance of the packages are evaluated using computation fluid dynamic approach for 1 W single chip LED module.

A Study on the LED Spotlight with a High Power using an Aspherical Optical System (비구면 광학계를 이용한 고출력 LED 스포트라이트에 관한 연구)

  • Moon, Jae-Il;Yoo, Kyung-Sun;Hyun, Dong-Hoon
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.3
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    • pp.487-492
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    • 2012
  • In this study we researched a spotlight in LED lighting. Ordinary LED spotlight was manufactured with characterized property of traveling straightness of LED light source, but multiple use of shell type LED, a yellow band has formed caused by light source interference between the LED. Also, there was a high miscellaneous light efficiency with losing light source homogeneity and efficiency due to light source control uneasiness. The study uses aspheric reflector and aspheric lens, so we can control the light source of LED spotlight with effectively and we reached surface light source by using COB/COM for LED module. Furthermore it can change its use by a reduced scale of light system. It has been designed to make its various application from low power consumption of bicycle lamp, up to high power consumption of automobile lamps and lighthouse.

Generation of Mini-compacted Thin Film Hybrid Package by Ceramic Ball Grid Array (CBGA를 통한 초소형/박형 박막하이브리드 패키지 구현)

  • 김상희
    • Journal of the Microelectronics and Packaging Society
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    • v.2 no.1
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    • pp.59-68
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    • 1995
  • 박막제조 기술 및 BGA패캐지를 이용하여 Wellcom 2000 system 소요 OCU Board 의 집적화를 구현하였다. 기존 PCB에 실장되는 소자 일부를 2 Channel BGA 패캐지로 모 듈화한 결과 약 1/6로 소형화시킬수 있었으며 8 Channel의 모율화는 현재 진행중인 다층 구조의 제조 기술 개발과 아울러 BGA 패캐지로 실현이 가능하며 1/10로집접화할수 있음을 알수 있었다. 또한 PCB위에 Bare Chip을 실장하여 Wire Bonding 한 COB를 구현하여 CBGGA의 PCB실장과 함께한 모듈을 형성해 보았다. CBGA패캐지에 Ball Shear Test, In Circuit Test 온도 환경주기시험(TCT) 진동시험을 통하여 신뢰성을 입증하였다. 이때 CBGA의 Coplanarity(3.2%) 증진을 위하여 Ceramic Pad에 선택적인 도금 방식을 개발적용 하였다.

Remote Phosphor with Array of Blue Light-emitting Diodes on Board Used in Liquid-crystal Backlight Module

  • Huang, Hsin-Tao;Tsai, Chuang-Chuang;Huang, Yi-Pai;Lin, Jeremy;Chang, Wen-Chi
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.79-82
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    • 2009
  • This work presents a novel lighting technology based on a YAG:$Ce^{3+}$ phosphor converter with micro line lenticular structure, to accompany an array of bare LED chips on a board. This technology is especially effective in TFT-LCD backlight applications as it offers the advantages of high light radiation efficiency, low color deviation, uniform luminance distribution and compact backlight thickness. Additionally, the proposed configuration is low-cost, can be manufactured quickly, and can be mass-produced economically.

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Water Quality Comparison in the Three Streams of Pusan Area (부산지역 3개 하천의 수질 특성 비교)

  • 황선출;이봉헌
    • Journal of Environmental Science International
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    • v.7 no.2
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    • pp.165-170
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    • 1998
  • The purpose of thins study was to investigate the pollutions of water Qualities in 30 water samples from Nakdong River Western Nakdong River, and Suyoung Stream. COB, BOD. T-N and negative ion(F, Cl+, NO3-, SO42-) of water samples were analysed and the correlationships between water qualities were examined. The mean concentrations of COD(20.26ppm), BOD(25.36ppm), and T-N(18.05ppm) were the highest in the water sample of Suyoung Stream among the three streams and those of F-(0.25ppm), Cl+(2770ppm), and SO42-(37.66ppm) In Western Nakdong River, that of NO3-(10.8 ppm) in Nakdong River. The water quality of Suyoung Stream was the worst among the three streams in hsn area. The correlationships between water qualities were as follows , BOD and COD showed very high correlationship(correlation cofficient, r=0.97),50,2- and NO3'did high one(0.75), and NOa'and COD, BOD did relatively high ones(0.56 and 0.48, respectively).

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Key Account Management: Towards a Multidimensional Definition

  • Ahmmed, Kawsar;Noor, Nor Azila Mohd.
    • Asian Journal of Business Environment
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    • v.2 no.1
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    • pp.5-13
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    • 2012
  • The aim of this paper is to propose an integrative definition of key account management (KAM) at the organizational level through a content analysis of the existing definitions of KAM available in the business literatures. A representative pool of definitions of key account management was generated through literature review from twenty three journals that covers the divergence of name variety like global account management, strategic account management, national account management, international key account management, key client management, major account management, key customers management and key account management. Relating to the definition of key account management various attributes are identified through content analysis and according to the relevance, profile for each attributes are developed. On the basis of these attributes a diagrammatic and textual definition is proposed that covers the different standpoints and aspects of key account management approach and captures its essence as well. Eventually, several strategic implications are derived that create the field for further empirical investigation.

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Inhibitory Effect of Purple Corn 'Seakso 1' Husk and Cob Extracts on Lipid Accumulation in Oleic Acid- Induced Non-Alcoholic Fatty Liver Disease HepG2 Model (올레산 유도 비알코올성 지방간세포에서 자색옥수수 색소 1호 포엽과 속대 추출물의 지질 축적 억제 효과)

  • Lee, Ki Yeon;Kim, Tae hee;Kim, Jai Eun;Bae, Son wha;Park, A-Reum;Lee, Hyo Young;Choi, Sun jin;Park, Jong yeol;Kwon, Soon bae;Kim, Hee Yeon
    • Journal of Food Hygiene and Safety
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    • v.35 no.1
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    • pp.93-101
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    • 2020
  • Seakso 1, a maize hybrid, was developed in 2008 by Gangwon Agricultural Research and Extension Services in Korea and registered in 2011. It is single-cross hybrid, semi-flint, deep-purple variety of corn, variety of are yellow, while the husks and cobs are purple. Due to the sensitivity of Seakso 1 to excess moisture after seeding, water supply should be carefully managed, and it should be harvested at a suitable time to obtain the highest anthocyanin content. This study investigated the hepatoprotective effect of Saekso 1 corn husk and cob extracts (EHCS) in oleic acid-induced non-alcoholic fatty liver disease (NAFLD) in HepG2 cells. EHCS showed a high level of lipid accumulation inhibiting effect. EHCS also suppressed triglyceride accumulation and inhibited expression of lipid marker genes, such as sterol regulatory element binding protein-1c (SREBP-1c) and sterol regulatory element binding protein-1a (SREBP-1a). Analysis by western blot of the expression of p-AMPK, p-SREBP1, PPARα, and FAS proteins showed that the incidence of SREBP1 protein, a major factor involved in lipid metabolism in the liver, has decreased significantly after treatment with the extracts. Moreover, the protein-induced expression of FAS, a major enzyme involved in the biosynthetic pathways of fatty acids, was decreased significantly in all concentrations. These results suggest that EHCS is a potent agent for the treatment of NAFLD.

Inhibition of Pancreatic Lipase Activity and Adipocyte Differentiation in 3T3-L1 Cells Treated with Purple Corn Husk and Cob Extracts (자색옥수수 포엽과 속대 추출물의 리파아제 저해활성 및 3T3-L1 지방전구세포에서의 지방분화 억제효과)

  • Lee, Ki Yeon;Hong, Soo Young;Kim, Tae Hee;Kim, Jai Eun;Park, A-Reum;Noh, Hee Sun;Kim, Si Chang;Park, Jong Yeol;Ahn, Mun Seob;Jeong, Won Jin;Kim, Hee Yeon
    • Journal of Food Hygiene and Safety
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    • v.33 no.2
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    • pp.131-139
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    • 2018
  • Our review begins with the maize hybrid for grain, called 'Seakso 1,' which was developed in 2008 by the Gangwon Agricultural Research and Extension Services in Korea, and subsequently registered in 2011. In this study, we aimed to investigate the lipid metabolic enzyme activity and inhibitory effect on the adipocyte differentiation, in 3T3-L1 cells of the identified Seakso 1 corn husk and cob extracts (EHCS). We investigated the pancreatic lipase inhibitory effect and anti-adipogenic effect of EHCS.The lipid accumulation and adipocyte differentiation were measured by the procedure of Oil Red O staining, Real-time PCR and the Western blot analysis. The pancreatic lipase inhibitory activity of EHCS was measured at higher levels than those of the positive control (orlistat) at 100, 500, and $1,000{\mu}g/mL$. In particular, EHCS was noted as being significantly inhibited and including a measured adipocyte differentiation and lipid accumulation, when treated during the adipocyte differentiation process in 3T3-L1 cells. Based on the Oil Red O staining, EHCS inhibited lipid accumulation at 19.19%, 33.30% at $1000{\mu}g/mL$, $2000{\mu}g/mL$, respectively. The real-time PCR and Western blot analysis showed that EHCS significantly decreased in the mRNA expression and protein level of obesity-related factors, such as peroxisome-proliferatorsactivated-receptor-${\gamma}$ ($PPAR{\gamma}$) and CCAAT enhancer-binding-proteins ${\alpha}$ ($C/EBP{\alpha}$). This study potentially suggests that the Saekso 1 corn husk and cob extracts may improve lipid metabolism and reduce lipid accumulation.

Effect of Dietary Fiber Sources on Chewing Activity in Sheep (섬유소 공급원이 면양의 저작행동에 미치는 영향)

  • Kim, M.H.;Lee, S.R.;Seo, I.J.;Maeng, W.J.
    • Journal of Animal Science and Technology
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    • v.49 no.5
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    • pp.639-646
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    • 2007
  • To evaluate the effect of fiber sources on chewing activity, five sheep were consecutively fed diets containing 45% of a fiber source selected from 7 tested fiber sources of alfalfa hay cube(AHC), corn cob (CC), corn silage(CS), cotton seed hull(CSH), peanut hull(PHL), rice straw(RS) and sugarcane bagasse (SCB). Number of chew showed significantly higher value in CC(p<0.001) then other sources. RS and CC had highest(p<0.01) rumination times of 352 and 367 min/d, respectively. CC also showed the highest number of chew per kg NDF intake(p<0.01), but rumination time per kg NDF intake showed no difference except CSH(p<0.001). These results suggest that chewing activities were greatly affected by the fiber sources, and therefore it should be accounted in the formulation for ruminant feed.