• 제목/요약/키워드: photometric method

검색결과 149건 처리시간 0.026초

경관조명의 시점거리별 표면휘도 특성분식 (Analysis on the Surface Luminance of Outdoor Lighting by Viewing Distance)

  • 최윤석;정인영;안현태;김정태
    • 조명전기설비학회논문지
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    • 제20권6호
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    • pp.18-25
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    • 2006
  • 야간도시경관의 미적향상, 시각적 안전의 확보 및 빛 공해 방지 등을 고려한 기존의 경관조명 평가방법은 대부분 측정점을 한 지점으로 한정하여 조명물리량을 분석함으로써 거리에 따른 평가결과의 다양성이 소홀히 취급되었다. 본 연구는 측정거리의 변화에 따른 평가대상 구조물의 표면휘도를 고려한 경관조명 평가방법을 제시하는데 연구의 목적이 있다. 이를 위하여 경관조명이 설치된 한강의 교량을 대상으로 CS-100과 ProMetric 1400 등 디지털 측광기기와 경관조명 소프트웨어 Lightscape v3.2를 활용하였다. 즉 측정거리 100[m], 300[m], 500[m]로 구분하여 현장측정 및 컴퓨터 시뮬레이션을 실시한 결과 거리변화에 따른 휘도의 평가방법은 대상 구조물로부터 약 100[m] 이내에서 실시하는 것이 휘도측면에서 유리한 것으로 나타났다.

Spin and 3D shape model of Mars-crossing asteroid (2078) Nanking

  • Kim, Dong-Heun;Choi, Jung-Yong;Kim, Myung-Jin;Lee, Hee-Jae;Moon, Hong-Kyu;Choi, Yong-Jun;Kim, Yonggi
    • 천문학회보
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    • 제44권1호
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    • pp.80.1-80.1
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    • 2019
  • Photometric investigations of asteroids allow us to determine their rotation states and shape models (Apostolovska et al. 2014). Our main target, asteroid (2078) Nanking's perihelion distance (q) is 1.480 AU, which belongs to the Mars-crossing asteroid (1.3 < q < 1.66 AU). Mars-crossing asteroids are objects that cross the orbit of Mars and regarded as one of the primary sources of near-Earth asteroids due to the unstable nature of their orbits. We present the analysis of the spin parameters and 3D shape model of (2078) Nanking. We conducted Cousins_R-band time-series photometry of this asteroid from November 26, 2014 to January 17, 2015 at the Sobaeksan Optical Astronomy Observatory (SOAO) and for 25 nights from March to April 2016 using the Korea Microlensing Telescope Network (KMTNet) to reconstruct its physical model with our dense photometric datasets. Using the lightcurve inversion method (Kaasalainen & Torppa 2001; Kaasalainen et al. 2001), we determine the pole orientation and shape model of this object based on our lightcurves along with the archival data obtained from the literatures. We derived rotational period of 6.461 h, the preliminary ecliptic longitude (${\lambda}_p$) and latitude (${\beta}_p$) of its pole as ${\lambda}_p{\sim}8^{\circ}$ and ${\beta}_p{\sim}-52^{\circ}$ which indicates a retrograde rotation of the body. From the apparent W UMa-shaped lightcurve and its location in the rotation frequency-amplitude plot of Sheppard and Jewitt (2004), we suspect the contact binary nature of the body (Choi 2016).

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A Deep Optical Survey of Young Stars in the Carina Nebula. I. UBVRI Photometric Data and Fundamental Parameters

  • Hyeonoh Hur;Beomdu Lim;Moo-Young Chun
    • 천문학회지
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    • 제56권1호
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    • pp.97-115
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    • 2023
  • We present the deep homogeneous UBV RI photometric data of 135,071 stars down to V ~ 23 mag and I ~ 22 mag toward the Carina Nebula. These stars are cross-matched with those from the previous surveys in the X-ray, near-infrared, and mid-infrared wavelengths as well as the Gaia Early Data Release 3 (EDR3). This master catalog allows us to select reliable members and determine the fundamental parameters distance, size, stellar density of stellar clusters in this star-forming region. We revisit the reddening toward the nebula using the optical and the near-infrared colors of early-type stars. The foreground reddening [E(B-V)fg] is determined to be 0.35 ± 0.02, and it seems to follow the standard reddening law. On the other hand, the total-to-selective extinction ratio of the intracluster medium (RV,cl) decreases from the central region (Trumpler 14 and 16, RV,cl ~ 4.5) to the northern region (Trumpler 15, RV,cl ~ 3.4). It implies that the central region is more dusty than the northern region. We find that the distance modulus of the Carina Nebula to be 11.9 ± 0.3 mag (d = 2.4 ± 0.35 kpc) using a zero-age main-sequence fitting method, which is in good agreement with that derived from the Gaia EDR3 parallaxes. We also present the catalog of 3,331 pre-main-sequence (PMS) members and 14,974 PMS candidates down to V ~ 22 mag based on spectrophotometric properties of young stars at infrared, optical, and X-ray wavelengths. From the spatial distribution of PMS members and PMS candidates, we confirm that the member selection is very reliable down to faint stars. Our data will have a legacy value for follow-up studies with different scientific purposes.

환원황화합물의 분석과 검량기준의 선택에 따른 오차발생의 특성 (Selection of Calibration Approaches and Their Impact on the Quantification of Unknown Samples: Case Study on Reduced Sulfur Gases)

  • 조효재;홍원필;김기현
    • 한국대기환경학회지
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    • 제27권2호
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    • pp.133-141
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    • 2011
  • In this study, different calibration approaches for reduced sulfur compounds (RSCs) were investigated by using thermal desorption coupled with gas chromatography (GC) and pulsed flame photometric detection (PFPD). To evaluate the effects of calibration procedures, gaseous standards of 4 RSCs ($H_2S$, $CH_3SH$, DMS, and DMDS) prepared at 10 ppm level were analyzed at 7 loading injection volumes (40, 60, 80, 100, 160, 240, and 320 ${\mu}L$). The results were then compared with calibration curves made with the Z (zero offset) and N (non-zero offset) method. The concentrations of unknown samples were then quantified by using R (ratio) method in which the slope values are compared between standards and samples. Secondly, in A (average) method, results obtained from a multi-point analysis of unknown samples were also averaged to extract representative values for each sample. Results of both experiments showed that analytical error of low molecular weight components (such as $H_2S$ and $CH_3SH$) was greatly expanded with the Z method. In conclusion, the combined application of N-A method was the more realistic approach to reduce biases in the quantification of RSCs.

컬러 카메라를 이용한 측면유동 면역 어세이 정량분석 방법 (A Method for Quantitative Measurement of Lateral Flow Immunoassay Using Color Camera)

  • 박종원
    • 대한의용생체공학회:의공학회지
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    • 제35권1호
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    • pp.1-7
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    • 2014
  • Among semi-quantitative or fully quantitative lateral flow assay readers, an image sensor-based instrument has been widely used because of its simple setup, cheap sensor price, and compact equipment size. For all previous approaches, monochrome CCD or CMOS cameras were used for lateral flow assay imaging in which the overall intensities of all colors were taken into consideration to estimate the analyte content, although the analyte related color information is only limited to a narrow wavelength range. In the present work, we introduced a color CCD camera as a sensor and a color decomposition method to improve the sensitivity of the quantitative biosensor system which utilizes the lateral flow assay successfully. The proposed setup and image processing method were applied to achieve the quantification of imitatively dispensed particles on the surface of a porous membrane first, and the measurement result was then compared with that using a monochrome CCD. The compensation method was proposed in different illumination conditions. Eventually, the color decomposition method was introduced to the commercially available lateral flow immunochromatographic assay for the diagnosis of myocardial infarction. The measurement sensitivity utilizing the color image sensor is significantly improved since the slopes of the linear curve fit are enhanced from 0.0026 to 0.0040 and from 0.0802 to 0.1141 for myoglobin and creatine kinase (CK)-MB detection, respectively.

A Study on the Distribution Characteristics of Sulfur Compounds in Ambient air using Continuous Monitoring Method in Incheon Area

  • Seo, Seok-Jun;Lim, Yong-Jae;Hong, You-deok;Park, Geon-Young
    • 통합자연과학논문집
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    • 제8권2호
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    • pp.128-134
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    • 2015
  • This paper focuses on the applicability of a continuous monitoring method on trace sulfur compounds in the ambient air by TD and GC/PFPD. The target compounds for monitoring include H2S(hydrogen sulfide), Methyl mercaptan, Dimethyl Sulfide, and Dimethyl disulfide. The result of QA/QC on monitoring instruments satisfies all the standards of Odor Measurement and Analysis Method, showing that the reproductivity of the compounds by concentration is within 10%, linearity is above 0.98 of a correlation efficient, method detection limit is 0.16 ppb by MM standard, and recovery rate is over 70%. Monitoring was conducted for two years from March 2006 to February 2008. As a result of the monitoring, the average concentration of H2S was 0.08 ppb, with the maximum concentration at 16.15 ppb. The result indicates that it is reasonable to do continuous monitoring as there appears a spontaneous event of high concentration by the condition of the site during monitoring odor-causing substances. Therefore, it is suggested that the continuous monitoring method used in this paper is appropriate to identify the characteristics of sudden occurrence and concentration variations of sulfur compounds.

A SOURCE EXTRACTION METHOD FOR THE AKARI MID-IR FAINT SOURCE CATALOGUE

  • Nakamichi, Keichiro;Ishihara, Daisuke;Kaneda, Hidehiro;Oyabu, Shinki;Kondo, Toru;Amatsutsu, Tomoya;Sano, Hidetoshi;Onaka, Takashi
    • 천문학논총
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    • 제32권1호
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    • pp.29-31
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    • 2017
  • We plan to produce a faint source catalogue from the AKARI mid-infrared (IR) all-sky diffuse maps. In the publicly-available AKARI mid-IR point source catalogue (PSC), sources were extracted from single-scan images, and confirmed by using the other scan images. By stacking multiple scan images, we can detect fainter sources which are not listed in the PSC. We optimized the source extraction process using a $6^{\circ}{\times}6^{\circ}C$ area around the star-forming region, Cepheus B. Then, we divided the all-sky data into three seasonal images, and checked the positions and the fluxes of the detected sources on the images. As a result, our new source extraction method works well; 90% of the sources are also identified in the WISE catalogue. In this method, we obtain the detection limit twice deeper than that of the PSC. The number of sources increases by a factor of 2, as compared with the PSC.

리파제 활성측정을 위한 간편한 비색정량법 (A Simple and Modified Photometric Method for Measuring Lipase Activity)

  • 김철진;최홍식;변시명
    • 한국식품과학회지
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    • 제16권2호
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    • pp.251-253
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    • 1984
  • 리파제 활성을 측정하는 간편한 방법을 개발하였다. 본 방법에 의하면 효소작용에 의해 생성된 유리지방산과 측정하는 색도와 서로 직선관계를 보였으며. 측정 범위는 long chain지방산인 경우 올레인산으로 환산하여 $0.05-1.5\;{\mu}moles$이었으며 short chain지방산인 경우 카프로인산으로 환산하여 $0.2-2.0\;{\mu}moles$의 범위였다. 본 방법의 장점은 종래의 "Copper Soap" 추출방법에서 상부 용매층 제거에 많은 시간을 소비하는 과정을 클로로포름-핵산-에타놀 혼합용매와 NaCl로 포화시킨 copper reagent를 사용하므로서 손쉽게 해결하였다.

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Simultaneous Determination of Alkaline Earth Metal Ions by a Conventional High Performance Liquid Chromatographic System

  • Rho, Young-Soo;Choi, Seung-Gi
    • Archives of Pharmacal Research
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    • 제9권4호
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    • pp.211-214
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    • 1986
  • A simultaneous determination method of alkaline earth metals was attempted with the conventional high performance liquid chromatographic system. Four cations, namely, magnesium, calcium, strontium and barium ion, were injected directly as aqueous solution into an eluent containing copper chloride solution and and were successfully separated and determined on a separating column (Zipax SCX, 4.6 mm i.d. ${\times}25$ cm length, Du Pont, USA) by using a variable wavelength UV detector. The linear calibration curves were obtianed in the range from $1.0{\times}10^{-4}M$ to $5.0{\times}10^{-4}M$ and the correlation coefficient of the calibration curve for each metal of magnesium and calcium in tap water. Alkaline earth metals were determined with the conventional high performance liquid chromatographic system.

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접촉형 쌍성의 진화 검증을 위한 TY UMa의 CCD 측광관측 (CCD PHOTOMETRY OF W UMa TYPE BINARY TY UMa)

  • 강영운;황창덕;이희원;김천휘
    • Journal of Astronomy and Space Sciences
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    • 제18권1호
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    • pp.55-62
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    • 2001
  • W UMa 형 쌍성 TY UMa를 소백산천문대 61cm 반사망원경과 PM512 CCD 카메라를 이용하여 2001년 3월 19일부터 21일까지 3일간 측광관측하여 광도곡선을 완성하였다. 광도곡선의 형태는 제 2극심이 제 1극심보다 더 깊고, 식 바같부분의 max 1은 max II에 비하여 평균 $0.^m023$밝게 나타나는 비대칭이다. 비대칭 광도곡선을 분석하기 위하여 흑점 모델을 도입하고, Wilson & Devinney의 차등보정법을 이용하여 측광학적인 해를 구하였다.

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