Development of High Efficiency and High Power LED Package for Applying Silicone-Reflector Jeong, Hee-Suk ; Lee, Young-Sik ; Lee, Jung-Geun ; Kang, Han-Lim ; Hwang, Myung-Keun

Development of High Efficiency and High Power LED Package for Applying Silicone-Reflector Jeong, Hee-Suk ; Lee, Young-Sik ; Lee, Jung-Geun ; Kang, Han-Lim ; Hwang, Myung-Keun Journal of the Korean Institute of Illuminating and Electrical Installation Engineers, volume 27, issue 9, 2013, Pages 1-5 Abstract 
We developed high-efficient 6W-LED package with simple structure by applying Heat Slug and silicone-reflector. LED package was manufactured in sized multi-chip structure having thickness of achieved by bonding silicon-reflector with prepreg on top of the plate after implementing the reflector placed on copper substrate Half Etching by thickness of . The luminous flux, luminous efficacy, correlated color temperature, color rendering index and thermal resistance of developed LED was evaluated, and it verified the application of products by applying it to 120W-LED road luminaires through simulation. The luminous efficacy of LED package reached over 130lm/W, and it is possible to be manufactured into 120W-LED road luminaires using 18 packages. In addition, the simulation results showed average of horizontal illuminance and overall illuminance uniformity that is suitable for three-lane road.
LINK
http://ocean.kisti.re.kr/downfile/volume/kiiee/JMJGCE/2013/v27n9/JMJGCE_2013_v27n9_1.pdf

Quatro Medalhas Brasileiras Na Olimpíada Cone Sul

Hoje, 20 de agosto de 2014, foi divulgado o resultado da Olimpíada Matemática do Cone Sul. A Olimpíada Cone Sul é uma competição internacional da qual países são representados por equipes de 4 estudantes que não tenham feito 16 anos de idade em 31 de dezembro do ano imediatamente anterior à celebração da Olimpíada. A Olimpíada este ano aconteceu no Uruguai.
O resultado brasileiro foi:
Pedro Henrique Sacramento de Oliveira – Ouro
Gabriel Toneatti Vercelli – Ouro

João César Campos Vargas – Prata

Andrey Jhen Shan Chen – Bronze

Parabéns a toda a equipe brasileira!!

FONTE ORIGINAL
http://noic.com.br/2014/08/20/quatro-medalhas-brasileiras-na-olimpiada-cone-sul/ 

PERU PRIMEIRA POSIÇÃO XXV OLIMPIADA DE MATEMATICAS CONE SUL URUGUAY

PERU PRIMEIRA POSIÇÃO XXV OLIMPIADAS MATEMATICAS CONO SUL URUGUAY 

Resultados de la cono sur. Christian Altamirano Modesto (50 puntos) medalla de oro Anthony Huarcaya Palomino (49 puntos) medalla de plata Jemisson Coronel Baldeón (46 puntos) medalla de plata Henry Fabrizio Felen Chavez (40 puntos) medalla de plata Peru (185) quedo primero por paises nuevamente.

CORTESIA DO DISTIGUIDO PROF. MATEMATICAS PERUANO JOHN CUYA

EXPERIMENT AND ANALYSIS FOR GRID CONNECTED 5KW LEAD-ACID BATTERY CHARGER SYSTEM WUJONG LEE

LINK
https://www.mediafire.com/?cnna97o7k7mv159

Dynamic Paralleling Behaviors of High Power Trench and Fieldstop IGBTs Yu Wu, Yaojie Sun, and Yandan Lin

 

Dynamic Paralleling Behaviors of High Power Trench and Fieldstop IGBTs Yu Wu, Yaojie Sun, and Yandan Lin JPE, vol.14, no.4, pp.788-795 , 2014 Yu Wu*, Yaojie Sun†, and Yandan Lin* *†Department of Light Sources and Illuminating Engineering, Fudan University, Shanghai, China Abstract This paper demonstrates the dynamic behaviors of paralleled high power IGBTs using trench and fieldstop technologies. Four IGBTs are paralleled and standard deviation is adopted to represent the imbalance. Experiments are conducted under three different operation conditions and at different temperatures ranging from -25°C to 125°C. The experimental results show that operation at very low and very high temperatures usually aggravates the switching behaviors. There is a trade-off between the balance and the losses at low temperatures. These results can help in the design of heat sinks in paralleling applications confronting very low temperatures.
 LINK FULL PAPER
http://manuscript.jpe.or.kr/ltkPSWeb/pub/pubfpfile.aspx?ppseq=888