• 제목/요약/키워드: IR52

검색결과 168건 처리시간 0.03초

Calibrating the stellar velocity dispersion in near-IR

  • 강월랑;우종학
    • 천문학회보
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    • 제36권1호
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    • pp.52.2-52.2
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    • 2011
  • The correlation between black hole mass and galaxy stellar velocity dispersion gives an important clue on the black hole growth and galaxy evolution. In the case of AGN, however, it is extremely difficult to measure stellar velocity dispersions in the optical spectra since AGN continuum dilutes stellar absorption features. In contrast, stellar velocity dispersions of active galaxies can be measured in the near-IR, where AGN-to-star flux ratio is much smaller, particularly with the laser-guide-star adaptive optics. However, it is crucial to test whether the stellar velocity dispersion measured from the near-IR spectra is consistent with that measured from the optical spectra. Using the TripleSpec at the Palomar 5-m Telescope, we obtained high quality spectra ranging from 1 to 2.4 micron for a sample of 35 nearby galaxies, for which dynamical black hole masses and optical stellar velocity dispersion measurements are available, in order to calibrate the stellar velocity dispersion in the near-IR. In this poster, we present the initial results based on 10 galaxies, with the stellar velocity dispersion measured in the H-band.

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위치 기반 시스템을 위한 CMOS IR-UWB RFIC (A CMOS IR-UWB RFIC for Location Based Systems)

  • 이중무;박명철;어윤성
    • 전자공학회논문지
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    • 제52권12호
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    • pp.67-73
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    • 2015
  • 본 논문에서는 근거리 위치 기반 시스템을 위한 3 - 5 GHz IR-UWB(impulse radio-ultra wide band) RFIC를 제안한다. 수신기의 구조는 에너지 검출 방식으로 설계되었고, 고속 sampling을 하기 위해서 4 bit ADC 와 DLL(delay locked loop) 을 이용하여 equivalent-time sampling 기술을 사용하도록 설계되었다. 송신기는 저전력의 디지털 UWB impulse generator 를 설계하였다. 설계된 IR-UWB RFIC 는 CMOS $0.18{\mu}m$ 공정을 이용하여 제작되었다. 측정된 수신기의 감도는 -85.7 dBm 이며, 송신기와 수신기는 1.8 V 전원 전압에서 각각 32 mA 와 25.5 mA 의 전류를 소모한다.

Relationship between Peripheral Plasma Inhibin and Progesterone Concentrations in Sahiwal Cattle (Bos Indicus) and Murrah Buffaloes (Bubalus bubalis)

  • Mondal, S.;Prakash, B.S.;Palta, P.
    • Asian-Australasian Journal of Animal Sciences
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    • 제16권1호
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    • pp.6-10
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    • 2003
  • The present study investigated peripheral plasma immunoreactive inhibin (ir-inhibin) concentrations in relation to the stage of oestrous cycle and progesterone concentrations in cycling Sahiwal cattle (Bos indicus) and Murrah buffaloes (Bubalus bubalis). Blood samples were collected once daily for thirty-two consecutive days from cattle and buffaloes (5 each) during winter months of January and February. Mean (${\pm}$S.E.M.) plasma ir-inhibin concentrations ranged from $0.40{\pm}0.01$ to $0.59{\pm}0.03ng/ml$ in cattle and from $0.29{\pm}0.03$ to $0.52{\pm}0.05ng/ml$ in buffaloes. In cattle, ir-inhibin concentrations increased from $0.47{\pm}0.07ng/ml$ on day -4 (day 0=day of oestrus) to reach a maximum value of $0.59{\pm}0.03ng/ml$ on day -2. Thereafter, ir-inhibin concentrations showed a decline to reach a low of $0.40{\pm}0.01ng/ml$ on day 11 of the oestrous cycle. In buffaloes, ir-inhibin concentrations increased from $0.38{\pm}0.04 ng/ml$ on day -4 to reach a maximum concentration of $0.52{\pm}0.05ng/ml$ on day -2. Ir-inhibin concentrations then declined to reach a low of $0.29{\pm}0.03ng/ml on day 9 of the cycle. In both cattle and buffaloes, ir-inhibin concentrations which were lowest ($0.43{\pm}0.02$ and $0.34{\pm}0.02ng/ml$, respectively) during the mid-luteal phase of the oestrous cycle increased (p<0.05) to $0.52{\pm}0.03$ and $0.44{\pm}0.04ng/ml$, respectively, during the late luteal phase, and then further to the highest value of $0.53{\pm}0.02$ and $0.49{\pm}0.04ng/ml$, respectively, during the perioestrus phase, following which these declined to $0.50{\pm}0.02$ and $0.39{\pm}0.03ng/ml$, respectively, during the early luteal phase. The variations in peripheral plasma ir-inhibin profile in both the species appear to be related to the changes in characteristics of follicular populations during the oestrous cycle. Peripheral plasma ir-inhibin concentrations were negatively correlated with progesterone concentrations in cattle (r=-0.51, p<0.01) and buffaloes (r=-0.30, p<0.01) indicating that the corpus luteum is not a source of peripheral ir-inhibin in these species.

국내동정

  • 한국방사성동위원소협회
    • 동위원소뉴스
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    • 1호통권121호
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    • pp.9-10
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    • 2007
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Dust Radiative Transfer Model of Spectral Energy Distributions in Clumpy, Galactic Environments

  • 선광일
    • 천문학회보
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    • 제43권2호
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    • pp.52.2-52.2
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    • 2018
  • The shape of a galaxy's spectral energy distribution ranging from ultraviolet (UV) to infrared (IR) wavelengths provides crucial information about the underlying stellar populations, metal contents, and star-formation history. Therefore, analysis of the SED is the main means through which astronomers study distant galaxies. However, interstellar dust absorbs and scatters UV and optical light, re-emitting the absorbed energy in the mid-IR and Far-IR. I present the updated 3D Monte-Carlo radaitive transfer code MoCafe to compute the radiative transfer of stellar, dust emission through a dusty medium. The code calculates the emission expected from dust not only in pure thermal equilibrium state but also in non-thermal equilibrium state. The stochastic heating of very small dust grains and/or PAHs is calculated by solving the transition probability matrix equation between different vibrational, internal energy states. The calculation of stochastic heating is computationally expensive. A pilot study of radiative transfer models of SEDs in clumpy (turbulent), galactic environments, which has been successfully used to understand the Calzetti attenuation curves in Seon & Draine (2016), is also presented.

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수도 한발저항성 품종 선발에 관한 연구 (Studies on Screening Rice Cultivars for Drought Resistance I. Screening at Seedling Stage)

  • 서학수
    • 한국작물학회지
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    • 제24권3호
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    • pp.7-12
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    • 1979
  • 748개의 벼 품종을 파종하여 토양수분이 포화된 상태로 30일간 재배한 후 40일간 단수하여 한발을 조장한 다음 각 품종들의 한발에 대한 반응을 검정한 결과는 다음과 같다. 1. 한발처리기간 중 초장의 신장정도는 일본품종들이 가장 컸고 IRRI 도입품종, 한국재래품종 및 Indica / Japonica 품종 순이었다. 2. 한발처리후의 위조정도는 IRRI도입 품종들이 가장 경미하였고 일본도입품종, Indica / Japonica 품종 및 한국재래품종 순이었다. 3. 유묘기 내한성품종으로 원길조, 한양도, YR 52-$_{x}\textrm{BF}_7-67, Satominori, Mamoriaka, 적야난11004, 죽 홍난, IR 937-55-3, IR2735-F_3B-6-2, IR 2871-53-2, $_{x}\textrm{BFI76}^9/Dwan, Khoo Dook Mali-4-2-105, Os6, Palawan, IRAT10, TOS 2583 및 H-l05 등이 발달되었다. 4. 한발처리후의 조장, 조장신장량 및 초장신장율과 위조정도와는 높은 부의 상관이 인정되었다. 5. 한발처리후의 지상부 생체중, 건물중 및 수분함량과 위조정보와는 높은 부의 상관이 인정되었고 특히 수분함량과 위조정도와의 상관이 높았다.(r=0.860, n=21). 6. 한발처리후의 도열병발병과 위조정도와는 높은 정의 상관이 인정되었다. 7. 발아속도 및 처리전초장 (30일묘)과 내한성과는 상관이 없었다.

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