• Title/Summary/Keyword: C Band

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Characteristics of Light Harvesting Chlorophyll-Protein Complex and Singlet Oxygen ($^1O_2$) Quenching in Leaf-burning Disease from Panax ginseng C. A. Meyer (인삼 Light Harvesting Chlorophyll Protein의 특성 및 엽소병에서 Singlet Oxygen($^1O_2$) Quenching)

  • 양덕조;이성택
    • Journal of Ginseng Research
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    • v.13 no.2
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    • pp.158-164
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    • 1989
  • In order to determine the relationships between the lea(-burning disease and the light harvesting chlorophyll-protein (LHCP) complex in Panax ginseng C. A. Meyer, we investigated the chlorophyll-protein (CP) complex of the thylakoid membrane and its characteristics. In P. ginseng four Cp-complex bands determined by non-denaturing SDS-PAGE were identified CP I'(containing reaction center of photosystem I and LHCP I antennae), CP I (reaction center of photosystem I) LHCP II** (oligoform of LHCP II), and LHCP II (photosystem II antennae, CP 26 and CP 29) by Bassis and Dunahay's procedures. Under our experimental condition, the CP I band was only observed in P. ginseng and the band intensity of LHCP II** in P ginseng was higher than in spinach and soybean. There were differences in the absorption and fluorescence spectra and chlorophyll a/b ratio of the CP-complex bands between P. ginseng and other Plants. The Polypeptidr content of P. ginseng thylakoid was lower than in spinach and soybean thylakoid, and the Polypeptide profiles of P. ginseng was low band intensity, especially about 29-35 kD, 55 kD, and 60 kD, compared to spinach and soybean. The inhibitory effects of 2,5-dimethylfuran, specific singlet oxygen ($^1O_2$) quencher, showed that singlet oxygen destroyed 60% of chl.a, 90% of chl.b and 70% of carotenoid in bleaching P. ginseng with leaf-burning disease.

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Design and Fabrication of C-Band GaN Based on Solid State High Power Amplifier Unit for a Radar System (레이다용 C-대역 GaN 기반 고출력전력증폭장치 설계 및 제작)

  • Jung, Hyoung Jin;Park, Ji Woong;Jin, Hyoung Seok;Lim, Jae Hwan;Park, Se Jun;Kang, Min Woo;Kang, Hyun Chul
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.28 no.9
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    • pp.685-697
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    • 2017
  • In this paper, it is presented the result of design and fabrication for C-band solid state high power amplifier unit and components using in search radar. The solid state power amplifier(SSPA) assembly was fabricated using GaN(Gallium Nitride), which is semiconductor device, and the transmit signal output power of the solid state high power amplifier unit is generated by combining the transmit signal power of the solid state power amplifier configured in parallel through a design and fabricated waveguide type transmit signal combine assembler. Designed solid state high power amplifier unit demonstrated C-band 500 MHz bandwidth, maximum 10.5% duty cycle, transmit pulse width from $0.0{\mu}s{\sim}000{\mu}s$, and transmit signal power is 44.98 kW(76.53 dBm).

Core Technology and Service Trends of Multimedia Service Using Satellite (위성을 이용한 멀티미디어 서비스의 요소 기술과 제공 현황)

  • 김정호
    • Journal of the Korean Professional Engineers Association
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    • v.34 no.4
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    • pp.36-40
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    • 2001
  • Multimedia service via satellite Is supported voice, data, Image and video signals. The representation case model of satellite multimedia are satellite TV. satellite Internet. In the early 1990s, satellite communication and broad casting services successfully expanded form C/Ku band to Ka band. The benefits of operation at Ka-band are greater bandwidth available to accommodate the increased demand for high-speed Information exchange. By the early years of the 21s1 century, millions of households worldwide with dual Ku / Ka-band dishes Satellite multimedia systems receive hundreds of TV channels, originating from around the world, and delivering entertainment, information and education. Many Ku-band satellites have been ordered, but few Ka-band systems are moving into production. So Ka-band systems are characterized that low-cost access to low and high peed, two-way voice, data, and video communications.

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A Dual-Mode Narrow-Band Channel Filter and Group-Delay Equalizer for a Ka-Band Satellite Transponder

  • Kahng, Sung-Tek;Uhm, Man-Seok;Lee, Seong-Pal
    • ETRI Journal
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    • v.25 no.5
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    • pp.379-386
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    • 2003
  • This paper presents the design of a narrow-band channel filter and its group-delay equalizer for a Ka-band satellite transponder. We used an 8th order channel filter for high selectivity with an elliptic-integral function response and an inline configuration. We designed a 2-pole, reflection-type, group-delay equalizer to compensate for the steep variation of the group-delay at the output of the channel filter, keeping the thermal stability at ${\pm}7$ ns of group-delay variation at the band edges over 15-55$^{\circ}C$. We devised a new tuning technique using short-ended dummy cavities and used it for tuning both the filter and equalizer; this removes the necessity of additional tuning after the cavities are assembled. Through measurement, we demonstrate that the group-delay-equalized filter meets the equipment requirements and is appropriate for satellite input multiplexers.

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Application of Taguchi Methodology for Optimization of Parameters of CVD Influencing Formation of a Desired Optical Band Gap of Carbon Film

  • Mishra, D.K.;Bejoy, N.;Sharon, Maheshwar.
    • Carbon letters
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    • v.6 no.2
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    • pp.96-100
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    • 2005
  • Taguchi methodology has been applied to get an idea about the parameters related to the chemical vapour deposition technique, which influences the formation of semiconducting carbon thin film of a desired band gap. L9 orthogonal array was used for this purpose. The analysis based on Taguchi methodology suggests that amongst the parameters selected, the temperature of pyrolysis significantly controls the magnitude of band gap (46%). Sintering time has a small influence (30%) on the band gap formation and other factors have almost no influence on the band gap formation. Moreover this analysis suggests that lower temperature of pyrolysis (${\leq}$ $750^{\circ}C$) and lower time of sintering (${\leq}$ 1 h) should be preferred to get carbon thin film with the desired band gap of 1.2eV.

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위성통신 주파수이용 현황과 전망

  • 서종수
    • Information and Communications Magazine
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    • v.12 no.6
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    • pp.65-73
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    • 1995
  • 위성통신용 궤도와 주파수 자원은 매우 한정적이며 최근에 정지궤도 위성과 저궤도 위성을 이용한 다양하나 형태의 서비스에 대한 수요가 급증하고 있으므로 한정된 주파수 자원에 대한 효율적인 활용기술과 새로운 주파수자원 및 서비스 개발이 필요하다. 북미, 유럽, 일본은 1970년도 중반기부터 C-band를 이용하는 위성통신의 연구를 시작으로, 최근에는 L-band, Ku-band, Ka-band를 이용하는 위성통신에서 효율적으로 전력 및 주파수를 활용하는 방안에 대한 연구를 활발하게 진행하고 있다. 국내는 1980년도 하반기부터 Ku-band를 이용하는 위성통신에 대한 연구가 시작되었으나 아직도 장기적이고 구체적인 연구개발 계획이 미비한 상황이며 Ka-band 정지궤도와 L-band 저궤도 위성통신 기술의 연구개발은 아직 초보적인 단계이다. 따라서 본 논문에서는 위성통신용 주파수의 국제적인 이용현황과 추세를 분석하여 향후 국내에서 정지궤도 및 저궤도 위성의 궤도와 주파수 확보 및 활용에 참고가 되도록 한다.

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추적레이다에 의한 인체에 대한 영향(HERP) 및 전자파 간섭(EMI) 분석

  • Kim, Dae-Oh;Sin, Han-Seop;Kim, Tae-Hyung;Lee, Hyo-Keun
    • Aerospace Engineering and Technology
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    • v.4 no.1
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    • pp.239-246
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    • 2005
  • This paper analyze the hazard of electromagnetic radiation to personnel (HERP) and electromagnetic interference (EMI) by C-band tracking radar. Especially, this analysis defines the safety distance for the controlled & uncontrolled personnel from high power radiation of electromagnetic wave within the main beam of 3 degrees by C-band tracking radar. In addition to HERP, the analysis of electromagnetic interference between tracking radar and weather radar was accomplished to decide the safety distance for EMI protection.

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A Compact C-Band 50 W AlGaN/GaN High-Power MMIC Amplifier for Radar Applications

  • Jeong, Jin-Cheol;Jang, Dong-Pil;Han, Byoung-Gon;Yom, In-Bok
    • ETRI Journal
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    • v.36 no.3
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    • pp.498-501
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    • 2014
  • A C-band 50 W high-power microwave monolithic integrated circuit amplifier for use in a phased-array radar system was designed and fabricated using commercial $0.25{\mu}m$ AlGaN/GaN technology. This two-stage amplifier can achieve a saturated output power of 50 W with higher than 35% power-added efficiency and 22 dB small-signal gain over a frequency range of 5.5 GHz to 6.2 GHz. With a compact $14.82mm^2$ chip area, an output power density of $3.2W/mm^2$ is demonstrated.

TRANSMISSION OF C-BAND VARIANTS IN JAPANESE QUAIL

  • Sohn, S.H.;Fechheimer, N.S.;Nestor, K.E.
    • Asian-Australasian Journal of Animal Sciences
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    • v.8 no.2
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    • pp.171-174
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    • 1995
  • Heteromorphisms of chromosome banding patterns can be useful markers for gene mapping and other kinds of genetic studies. In Japanese quail, the centromere region of chromosome No. 4 is the site of a heteromorphism. One form of the C-band at this region is relatively small ("a" form); an alternative form is much larger ("b" form). To identify the transmission patterns, all possible matings were made between birds with karyotype a/a, a/b, and b/b. The outcome from all crosses are entirely consistent with the expectation from simple Mendelian transmission. No evidence was found for segregation distortion or gametic selection. This dimorphism, therefore, is a reliable marker.

A Study on a Human Body Detection Sensor Using Microwave Radiometer Technologies (마이크로파 라디오미터 기술을 응용한 인체 감지 센서에 관한 연구)

  • Son, Hong-Min;Park, Hong-Kyun
    • The Journal of the Korea institute of electronic communication sciences
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    • v.10 no.3
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    • pp.333-340
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    • 2015
  • In this paper, we propose a passive microwave sensor for detecting human body using microwave radiometer technologies. The proposed sensor detects human body by measuring the change of the received radiation power from fixed background object due to human body. A C-band microwave radiometer is designed and implemented. The received radiation power changes due to human body is measured by the C-band microwave radiometer, and the effectiveness of the proposed sensor is evaluated by the measurement result analysis.