• Title/Summary/Keyword: COB

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Design & Fabrication of an InGaP/GaAs HBT MMIC Power Amplifier for IMT-2000 Handsets (IMT-2000 단말기용 InGaP/GaAs HBT MMIC 전력증폭기 설계 및 제작)

  • 채규성;김성일;이경호;김창우
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.11A
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    • pp.902-911
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    • 2003
  • Using InGaP/GaAs HBT power cells with a 2.0${\times}$20$\mu\textrm{m}$$^2$ emitter area of a unit HBT, a two stage MMIC power amplifier has been developed for IMT-2000 handsets. An active-bias circuit has been used for temperature compensation and reduction in the idling current. Fitting on measured S-parameters of the HBT cells, circuit elements of HBT's nonlinear equivalent model have been extracted. The matching circuits have been designed basically with the extracted model. A two stage HBT MMIC power amplifier fabricated using ETRI's HBT process. The power amplifier produces an 1-㏈ compressed output power(P$\_$l-㏈/) of 28.4 ㏈m with 31% power added efficiency(PAE) and 23-㏈ power gain at 1.95 GHz in on-wafer measurement. Also, the power amplifier produces a 26 ㏈m output power, 28% PAE and a 22.3-㏈ power gain with a -40 ㏈c ACPR at a 3.84 ㎒ off-center frequency in COB measurement.quency in COB measurement.

Kinematical Analysis on the Head Hitting Motion Based on Weight Change of Bamboo Swords (죽도 무게변화에 따른 검도 머리치기 동작의 운동학적 분석)

  • Chung, Nam-Ju;Kim, Jae-Pil;Ku, Jong-Mo
    • Korean Journal of Applied Biomechanics
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    • v.20 no.1
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    • pp.25-32
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    • 2010
  • This study was performed to investigate the kinematic factors on the head hitting motion based on weight change of bamboo swords in kumdo. The kinematic factors, needed time per phase, COB displacement and velocity, angle(wrist, elbow, shoulder joint, hip joint, knee joint), were analyzed by the 3-D motion analysis method against 6 male middle school athletes. The results were as follows. 1. The needed time of head hitting motion based on weight change of bamboo swords was shorter when weight was heavier. 2. The COB displacement of left/right was bigger when weight was heavier. the displacement of right foot was higher at backswing phase and impact phase when weight was heavier and at impact time when weight was lighter. 3. The COB velocity was faster at impact time when weight was heavier, the velocity of sword tip was fastest for each event with bamboo sword weight of 440 g. 4. The angle of left elbow was smaller at top of backswing and impact when weight was heavier, the angle of left shoulder was bigger when weight was heavier, the right knee angle was biger at start when weight was heavier, at impact when weight was lighter.

Influence of Maize Cob Inclusion Level in Pig Diets on Growth Performance and Carcass Traits of Mukota × Large White F1 Crossbred Male Pigs

  • Chimonyo, M.;Kanengoni, A.T.;Dzama, K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.12
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    • pp.1724-1727
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    • 2001
  • A trial was conducted to evaluate the growth performance and carcass characteristics of LW ${\times}$ Mukota $F_1$ crosses when fed diets containing graded levels of maize cob meal. Sixteen LW ${\times}$ Mukota $F_1$ crossbred pigs of approximately 4.5 months of age, were randomly allocated to four diets that contained 0, 100, 200 and 300 g maize cobs/kg, which corresponded to 276.4, 360.3, 402.9 and 523.5 g NDF/kg, respectively. The pigs were fed ad libitum for 14 weeks. The diets were formulated to contain similar levels of energy (ca. 9MJ ME/kg) and protein (ca.160 g CP/kg). Average daily feed intake (ADFI), daily gain (ADG) and feed conversion ratio (FCR) were monitored for 14 weeks. At slaughter, the cold dressed weight (CDM) and backfat thickness (BFT) were determined. There was no significant linear relationship (p>0.05) between level of cob inclusion and ADFI. The ADG decreased as level of maize cobs increased (p<0.001). The pigs that were on 300 g cobs/kg had the highest FCR (p<0.05) as compared to pigs on the other three diets. No differences (p>0.05) were observed in the CDM between pigs that were fed diets that had 0 and 100 g maize cobs/kg. In addition, pigs on 100 and 200 g cobs/kg diets had the same CDM (p>0.05). The diet that contained 300 g cobs/kg gave the lowest (p< 0.001) CDM. Both BFT parameters showed a decrease (p<0.05) as level of maize cobs increased. An increase in CDM was associated with an increase in BFT (p<0.001), with the correlation coefficient between K7.5 and CDM being 0.84 (p<0.001). It can, therefore, be concluded that crossbred pigs perform well on diets containing up to 200 g/kg maize cobs.

Lipoxygenase and Off-flavor Development in Some Frozen Foods (일부냉동식품에서의 Lipoxygenase와 이취발생관계)

  • Lee, Young-Chun
    • Korean Journal of Food Science and Technology
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    • v.13 no.1
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    • pp.53-56
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    • 1981
  • Several tests were conducted to study lipoxygenase activity and off-flavor developement in frozen sweet corn. Fresh corn contained about 60% of total lipoxygenase activity in the germ section. When non-blanched frozen sweet corn was stored at $-10^{\circ}F$, it developed off-flavor and most significant changes in the flavor profile of off-flavored sweet corn was $4{\sim}5$ times higher hexanal peaks. The high hexanal peaks observed in the sterilized sweet corn with added lipoxygenase, alone and in combination with other enzymes, suggested the fact that high hexanal peaks in off-flavored sweet corn could be due to an oxidative reaction of lionleic acid (and other unsaturated fatty acids) catalyzed by lipoxygenase. Based on lipoxygenase activity and linoleic acid content in sweet corn, this reaction occur most heavily in the germ section of sweet corn. There was a significant relationship between flavor score of frozen stored corn-on-the-cob and hexanal peak in the germ section of corn-on-the-cob. This result indicated that hexanal peak could be used as an objective index of off-flavor development in frozen sweet corn.

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Effects of silica fillers on the reliability of COB flip chip package using NCP (NCP 적용 COB 플립칩 패키지의 신뢰성에 미치는 실리카 필러의 영향)

  • Lee, So-Jeong;Kim, Jun-Ki;Lee, Chang-Woo;Kim, Jeong-Han;Lee, Ji-Hwan
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.158-158
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    • 2008
  • 모바일 정보통신기기를 중심으로 실장모듈의 초소형화, 고집적화로 인해 접속단자의 피치가 점점 미세화 됨에 따라 플립칩 본딩용 접착제에 함유되는 무기충전제인 실리카 필러의 크기도 미세화되고 있다. 본 연구에서는 NCP (non-conductive paste)의 실리카 필러의 크기가 COB(chip-on-board) 플립칩 패키지의 신뢰성에 미치는 영향을 조사하였다. 실험에 사용된 실리카 필러는 Fused silica 3 종과 Fumed silica 3종이며 response surface 실험계획법에 따라 혼합하여 최적의 혼합비를 정하였다. 테스트베드로 사용된 실리콘 다이는 투께 $700{\mu}m$, 면적 5.2$\times$7.2mm로 $50\times50{\mu}m$ 크기의 Au 도금범프를 $100{\mu}m$ 피치, peripheral 방식으로 형성시켰으며, 기판은 패드를 Sn으로 finish 하였다. 기판을 플라즈마 전처리 후 Panasonic FCB-3 플립칩 본더를 이용하여 플립칩 본딩을 수행하였다. 패키지의 신뢰성 평가를 위해 $-40^{\circ}C{\sim}80^{\circ}C$의 열충격시험과 $85^{\circ}C$/85%R.H.의 고온고습시험을 수행하였으며 Die shear를 통한 접합 강도와 4-point probe를 통한 접속저항을 측정하였다.

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Cultivation of Oyster Mushroom Using Non Sterilized Media (무살균 배지를 이용한 느타리버섯 재배)

  • Jang, Hyun-Yu;Kim, Hyuk
    • Korean Journal of Plant Resources
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    • v.14 no.3
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    • pp.196-205
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    • 2001
  • The results of examining cultivation of tlyster mushroom using NSM(Non Sterilized Media) for determining the condition of artificially culturing oyster mushroom(Pleurotus ostreatus) are as follows. Mycelial growth an[1 density of oyster mushroom. were the highest in the medium of waste cotton(spinning) : corn cob(80 : 20, V/V) followed by the order of rice bran, beet pulp. Expecially, mycelial growth and density of oyster mushroom is the lowest at the mixture rate of 80% waste cotton(spinning) : 10% beet pulp. Mycelial growth and density of oyster mushroom. were the highest in the medium of cotton seed hull and beet pulp mixture followed by the order of rice bran, corn cob. Expecially, mycelial growth and density of oyster mushroom is the lowest at the mixture rate of 80% cotton seed hull : above 20% rice bran. Mycelial growth and density of oyster mushroom were the highest in the medium rate of 70% waste cotton(spinning), 10% corn cob and 10% beet pulp(V/V). Mycelial growth and density of oyster mushroom were the highest in the medium rate of 70% cotton seed hull , 10% corn cob and 10% beet pulp(V/V). Optimal concentration of NSM for the mycelial growth and density of oyster mushroom were shown to be 500 times concentration. Optimal water contents for the mycelial growth and density of NSM was 70%.

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이성화 효소의 생산에 관한 연구 (2) Streptomyces sp. K-14 균주에 의한 이선화 효소의 생산과 성질에 관하여

  • 정태화;한문희
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 1975.12a
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    • pp.180.4-181
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    • 1975
  • 토양에서 분리한 한주인 Streptomyces sp. No.14를 당질인 xylose 및 xylan과 천연배지로 wheat Bran 및 Corn Cob를 함유한 영양배지에 배양한 결과 균체로부터 강력한 glucose isomerase를 생산하였다. 따라서 이 균주의 배양 및 효소적 특성을 몇 가지 조사한 결과는 다음과 같다.(중략)

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포커스-e기업 - (주)모던하이테크, LED 조명 산업의 발전을 위한 글로벌 COB형 LED 조명 솔루션 기술교류회 현장

  • 한국광학기기협회
    • The Optical Journal
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    • s.141
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    • pp.24-25
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    • 2012
  • 한국산업기술대학교가 주최하고 (주)모던하이테크가 후원한 '글로벌 COB형 LED 조명 솔루션 기술교류회'가 지난 7월 6일 한국산업기술대학교 TIP 아트센터에서 개최됐다. 이에 (주)모던하이테크는 독일 옵시라(opsira) 제품을 전시하였으며, 강연자로 옵시라의 폴케르 슈마커(Volker Schumacher) 대표를 초청해 'Near-field 측정과 COB 광원 모델링'을 주제로 강의를 진행했다.

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Reliability Testing and Materials Evaluation of Si Sub-Mount based LED Package (실리콘 서브 마운틴 기반의 LED 패키지 재료평가 및 신뢰성 시험)

  • Kim, Young-Pil;Ko, Seok-Cheol
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.4
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    • pp.1-10
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    • 2015
  • The light emitting diodes(LED) package of new structure is proposed to promote the reliability and lifespan by maximize heat dissipation occurred on the chip. We designed and fabricated the LED packages mixing the advantages of chip on board(COB) based on conventional metal printed circuit board(PCB) and the merits of Si sub-mount using base as a substrate. The proposed LED package samples were selected for the superior efficiency of the material through the sealant properties, chip characteristics, and phosphor properties evaluations. Reliability test was conducted the thermal shock test and flux rate according to the usage time at room temperature, high-temperature operation, high-temperature operation, high-temperature storage, low-temperature storage, high-temperature and high-humidity storage. Reliability test result, the average flux rate was maintained at 97.04% for each items. Thus, the Si sub-mount based LED package is expected to be applicable to high power down-light type LED light sources.