• Title/Summary/Keyword: exposure sources

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FABRY-PEROT SPECTROMETER IN ASTRONOMY (FABRY-PEROT 분광기의 특성과 천문학의 적용)

  • PAK SOOJONG
    • Publications of The Korean Astronomical Society
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    • v.15 no.spc1
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    • pp.127-132
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    • 2000
  • The purposes of spectroscopy in astronomy are to measure the radiation flux of the spectroscopic emission or absorption line and to measure the dynamical parameters of the line profile. In order to use an appropriate instrument for the scientific purpose, we need to understand the characteristics of various spectrometers, e.g., a prism spectrometer, a grating spectrometer, and a Fabry-Perot spectrometer (FPS), which are being used in ultra-violet, optical, and infrared bands. The Fabry­Perot spectrometer is not very popular compared to the grating spectrometer, because of its complex and tricky operations. The Fabry-Perot spectrometer, however, can get a two-dimensional image at one exposure, so we can study radiation mechanisms and dynamical properties of extended sources, e.g., clusters, nebula, and galaxies.

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Selection of Microorganisms for Probiotics and Their Characterization (생균제로서 가능성이 있는 미생물의 선별 및 특성)

  • 박홍석;이선희;엄태붕
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.3
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    • pp.433-440
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    • 1998
  • In order to select probiotics with a high survival rate in gut and the growth inhibition of virulent pathogens to human beings or animals, we have examined a variety of microorganisms to assess the acid, bile, and pancreatic tolerance and the growth inhibition of E. colt O8 and Salmonella choleraesuis ATCC 8391. Lactobacillus acidophilus KCTC 3155 was shown to inhibit the growth of E. coli and Salmonella dramatically within 24 h of incubation, although it was vulnerable to the exposure of bile acids. Bacillus polyfermenticus showed a good growth inhibition against E. coli, with a moderate acid and bile tolerance, while Clostridium butyricum KCTC 1786 inhibited the growth of E. coli and Salmonella slightly with a good bile tolerance. However, Saccharomyces cerevisiae KCTC 7928 and Aspergillus oryzae KCTC 6075 did not inhibit the growth of E. coli and Salmonella, suggesting that these microorganisms can be used as the sources of nutritional suppliment rather than as probiotics itself.

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Analysis of 3-Monochloro-1,2-Propanediol (3-MCPD) in Soy Sauce Products in Korea (국내 시판 간장에서의 3-Monochloro-1,2-propanediol(3-MCPD) 분석 평가)

  • 송현수;이병무
    • Toxicological Research
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    • v.18 no.2
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    • pp.191-194
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    • 2002
  • 3-Monochloro-1,2-propanediol(3-MCPD) was analyzed in soy sauce products commercially available in Korea. A total of 24 samples were collected and 3-MCPD was determined by GC/MS. Sources of 24 samples were classified by manufacturing methods as naturally brewed(NB), acid hydrolyzed (AH) and mixed (M = NB + AH) soy sauces. 3-MCPD was not detected in NB soy sauce products (< 0.01 ppm, mg/kg) whereas AH and M soy sauce products showed a wide range of 3-MCPD contamination (0.0l ∼ 2.038 ppm). The contaminated levels of 3-MCPD in soy sauce products were higher than the permissible or tentative permissible level of 3-MCPD in both European Community (0.02 ppm) and Korea (0.3 ppm). These data suggest that 3-MCPD levels contaminated in soy sauce products in Korea were shown to be too high and should be reduced to as low a level technologically feasible to protect Korean from the exposure to toxic chemical, 3-MCPD.

Seoul National University Camera II (SNUCAM-II) : The New SED Camera for Lee Sang Gak Telescope (LSGT)

  • Choi, Changsu;Im, Myungshin
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.1
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    • pp.35.1-35.1
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    • 2017
  • We present the characteristics and the performance of the new CCD camera system, SNUCAM-II (Seoul National University CAMera system II) that was installed on the Lee Sang Gak Telescope (LSGT) at the Siding Spring Observatory Australia in 2016. SNUCAM-II consists of a deep depletion chip covering a wide wavelength from $0.3{\mu}m$ to $1.1{\mu}m$ with high sensitivity (QE at 90%). It is equipped with SDSS ugriz filters and 13 medium band width (50nm) filters. On LSGT, SNUCAM-II covers $15.7{\times}15.7arcmin$ FOV at pixel scale of 0.92 arcsec and a limiting magnitude of g = 19.91 AB mag at $5{\sigma}$ with 180s exposure time. SNUCAM-II will enable us to study Spectral Energy Distributions (SEDs) of diverse objects from extragalactic sources to solar objects in the southern hemisphere for research and education activities.

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Comparison of Noise Abatement Policies in Advanced Countries and Korea (선진국과 한국의 소음저감정책 비교)

  • Kang, Dae-Joon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.10a
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    • pp.558-567
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    • 2011
  • One of the main objectives of noise control act is to define and ensure application and respect of noise exposure limits. Most advanced countries have prepared a legal framework for noise limits either by national laws, ordinances or municipal by-laws. A large number of advaced countries have adopted the $L_{eq}$ index for the main sources of noise (road, railway, industry). The exception is aircraft noise for which regulatory practice is highly disparate. These differences in the indices adopted, the periods and areas to which regulations apply, definitions of measurement conditions and ways in which noise levels are calculated make it difficult to compare the current advanced countries standards. This study presents the current noise abatement policy of the advanced countries and proposes the improvement of the current noise abatement policy of Korea to catch up with it of the advanced countries.

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Methodology of Human Cancer Risk Assessment for Chemical Carcinogens (화학 발암물질에 대한 인체 암 위해성 평가)

  • Lee, Byung-Mu
    • Toxicological Research
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    • v.8 no.2
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    • pp.317-329
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    • 1992
  • Fifty chemicals are currently classified as human carcinogens based on epidemiologic and animal data. Humans are daily exposed to them from various sources of exposure via inhalation, dermal contact and oral ingestion. To reduce cancer risk to man, these human carcinogens should be appropriately regulated and monitored environmentally or biologically for routine human cancer risk assessment. A number of mathematical risk assessment models have been introduced, but any realistic and relevant model system is not available for humans. A mechanistic process for human cancer risk assessment was comprehensively reviewed and problems were also discussed. Here, a new conceptual approach using epidemiology and biological human monitoring was suggested for the most relevant method to study human cancer risk assessment.

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Adsorption properties of non-cement boards using adsorbent (흡착재를 활용한 흡착형 무시멘트 보드의 흡착 특성)

  • Pyeon, Su-Jeong;Lim, Hyun-ung;Lee, Sang-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.05a
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    • pp.226-227
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    • 2018
  • Recently, as the interest of the government and the public on energy saving has increased, the airtightness of buildings has been improved to improve the insulation performance of buildings. However, indoor air pollution due to increase of pollution source in indoor space and lack of ventilation is increasing and interest in indoor air quality is increasing. In 2003, the Ministry of Environment enacted and promulgated the Act on Indoor Air Quality Control in Multi-use Facilities. Radon is a naturally occurring radioactive inert gas with colorless, tasteless and odorless nature. The concentration is high in a room where radon can not escape. Although lononggas is naturally occurring, it is not interested in living environment, but it is easily inhaled through human body through respiration and causes lung cancer in long-term exposure. Therefore, this study intends to carry out an experiment for the reduction of radon gas, which is the first carcinogen in indoor air pollution sources.

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The Clinical Application of Radioactive Iridium (Ir-192) Brachytherapy (방사선 이리디움(Ir-192) 근접치료의 임상적 응용)

  • Yoo, Seong-Yul
    • The Journal of Korean Society for Radiation Therapy
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    • v.3 no.1
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    • pp.11-18
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    • 1989
  • Brachytherapy is known to be a good modality to achieve local control as a boost treatment following limited external irradiation, which may reduce the external beam related complication particularly in head and neck cancer. The authors developed iridium-192 ribbons recently to replace the radium needles in the field of brachytherapy. Total of 48 cases of head and neck and pelvic-perineal cancer patients had been treated with Ir-192 ribbons during last two years from October 1986 to September 1988, and the results were analyzed to assess the applicability of the fabricated sources. The conclusion is as follows; 1. Iridium implant resulted excellent tumor control effect in clinical application. 2. Iridium is superior than radium and cecium in brachytherapy because of easier to use and lesser exposure to the personnel. 3. Afterloading technique is useful to modify dose distribution, to expand treatment site and method, and to develop interstitial hyperthermia.

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Multi-camera based Images through Feature Points Algorithm for HDR Panorama

  • Yeong, Jung-Ho
    • International journal of advanced smart convergence
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    • v.4 no.2
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    • pp.6-13
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    • 2015
  • With the spread of various kinds of cameras such as digital cameras and DSLR and a growing interest in high-definition and high-resolution images, a method that synthesizes multiple images is being studied among various methods. High Dynamic Range (HDR) images store light exposure with even wider range of number than normal digital images. Therefore, it can store the intensity of light inherent in specific scenes expressed by light sources in real life quite accurately. This study suggests feature points synthesis algorithm to improve the performance of HDR panorama recognition method (algorithm) at recognition and coordination level through classifying the feature points for image recognition using more than one multi frames.

Application of Naturally Antioxidant for Inhibition of Brightness Reversion of Paper Made from High Yield Bagasse Pulp

  • El-Sakhawy Mohamed;El-Ghorab Ahmed;El-Gendy Ahmed;El-Sabour Mona A.;El-Sayed Essam S. A.
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.37 no.5 s.113
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    • pp.15-24
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    • 2005
  • Different types of antioxidants compounds were prepared economically from natural sources. Application of these compounds towards photo stabilization of high yield bagasse pulp has been investigated. It was found that potato peel antioxidant followed by clove volatile oil provides lower brightness reversion and better photo stabilization effect for paper made from high yield bagasse pulp after exposure to UV lights in comparison with butyl hydroxy anisol or chamomile volatile oil.