• Title, Summary, Keyword: 대기투과도

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Attenuation of the Atmospheric Aerosol Transmissivity due to Air Pollution (대기오염에 의한 대기투과도 감쇠에 대한 연구)

  • Kim, Yoo-Keun;Lee, Hwa-Woon;Lee, Yong-Seob
    • Journal of Korean Society for Atmospheric Environment
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    • v.11 no.E
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    • pp.23-29
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    • 1995
  • Relationship between atmospheric aerosol transmissivity and air pollution was analyzed using observed data in a large industrial city, Pusan, Korea. The atmospheric aerosol transmissivity predicted by method of present study in Pusan was assessed by the method of Yamamoto et al.(1968) in order to set up an empirical model to predict the transmissivity using the various meteorological parameters and air pollution. As a result, good correlation between these tow method re observed. Thus, it is possible to conclude that the parameterization of air pollution suggested by this study is another method to give reliable estimate of atmospheric aerosol transmissivity and direct solar irradiance in Pusan.

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Evaluation of Uncertainty in the Primary $O_3$-SRP by the Precise Determination of Light Path Length (광로 길이의 세부적인 결정에 의한 일차 오존 표준분광기 (O$_3$-SRP)의 측정 불확도 평가)

  • 우진춘;배현길;김용두;김영진;문광융;조성일
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • pp.243-244
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    • 2003
  • 오존은 매우 불안정한 물질로서, 기타의 환경 대기 가스 분석법에서와 같이 해당 성분의 측정기를 표준 가스로 교정한 후 분석할 수 없다. 이러한 이유로, 환경 대기 중의 오존을 분석하는 일반 분석기의 교정을 목적으로, 본 연구실에서는, 국가 일차 오존 표준분광기(O$_3$-SRP)를 제작하여 운영하고 있다. 운영되고 있는 $O_3$-SRP의 측정 원리는 자외선 흡광 광도법이며, 농도값의 결정은 순수하게 Beer-Lambert 법칙에 따른다. Beer-Lambert 법칙에 따라서 오존 농도를 절대적으로 측정하기 위해서는 몰 흡광계수, 광로의 길이, 투과도, 온도 및 압력을 정확히 측정하여야 한다. (중략)

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대기압 플라즈마를 이용한 보호 유리 표면 처리를 통한 태양광 발전 효율 향상

  • Han, Deok-Seon;Mun, Se-Yeon
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.175.2-175.2
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    • 2016
  • 외부에서 운용되는 태양광 시스템에 있어서 셀 보호를 위해 사용되는 보호용 유리는 다양한 기후 변화를 겪으며 직면 하게 되는 먼지, 비 그리고 바람으로 부터 그 시스템을 보호하는데 필수적이다. 그러나 유리 자체의 제한된 투과도는 태양으로 부터의 에너지 전달에 있어서 일부 손실을 야기 한다. 많은 연구자들은 유리의 투과도를 향상시킴으로써 주어진 태양광 발전 시스템의 효율을 높이고자 노력 하였다. 한 예로써 패터닝 및 화학 공정을 통해 특정 크기의 표면 구조를 형성 하게 되면 유리의 투과도가 향상됨으로써 태양광 효율을 높이는 방법이 제시 된 바 있다. 본 연구에서는 기존의 고비용 장시간을 요하는 공정 대신 1분 이내의 단 시간에 He/CH4/C4F8 대기압 플라즈마를 이용한 공정의 최적화를 통하여 유리 표면에 마이크로 나노 구조 형성 및 표면 장력 에너지를 낮추어 투과도 향상은 물론 자가 세정 기능을 더함으로써 태양광 시스템의 장기적인 외부 운용 효율을 약 0.3% 가량 높일 수 있었다. 또한 표면 처리에 사용한 대기압 플라즈마의 optical emission spectroscopy 를 통하여 공정의 최적화 과정에서의 반응 가스 온도, 전자 여기 온도 그리고 라디칼 등의 생성 반응 기작을 연구 하였다.

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A Comparative Study between Measurement and Prediction Results of a Naval Ship Infrared Signature in the Marine Environment (해상환경에서 함정 적외선 신호 측정 및 예측결과 비교 분석 연구)

  • Kim, Jung-Ho;Yoon, Yoon-Sik
    • Journal of the Society of Naval Architects of Korea
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    • v.48 no.4
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    • pp.336-341
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    • 2011
  • Ship infrared signature is the cause of detection and tracking by infrared sensor and anti-ship missile seeker. Recent warships have been applied the infrared stealth technology to reduce own ship infrared signature and tested to validate own ship infrared signature level. This study describes the two issues. Firstly, we describe the infrared measurement concept and infrared signature level establishment method that have been performed. Secondly, we compare and analyze the error components between the infrared measurement and simulation result.

Study on IR Signature Characteristics for different Transmittance over the Korean South Sea during Summer and Winter Seasons (거제도 해양의 여름 및 겨울철 환경에서 거리에 따른 대기투과도를 고려한 함정의 적외선 신호 특성 분석)

  • Choi, Jun-Hyuk;Kim, Jung-Ho;Jung, In-Hwa;Lee, Phil-Ho;Kim, Tae-Kuk
    • Journal of the Korea Institute of Military Science and Technology
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    • v.13 no.2
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    • pp.320-327
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    • 2010
  • The IR signature data of a ship is mainly affected by location, meteorological conditions(atmosphere temperature, wind direction and velocity, humidity etc.), atmospheric transmittance, solar position and ship surface temperature etc. The IR signatures received by a remote sensor at a given temperature and wavelength region is consisted of the self-emitted component directly from the object surface, the reflected component of the solar irradiation at the object surface, and the scattered component by the atmosphere without ever reaching the object surface. Computer simulations for prediction of the IR signatures of ships are very useful to examine the effects of various sensor positions. In this paper, we have acquired the IR signature for different sensor positions by using computer program for prediction of the IR signatures. The numerical results show that the IR signature contrast as compared to the background sea considering the meteorological conditions, solar and sky irradiations.

Effect of the East Asian Reference Atmosphere on a Synthetic Infrared Image (동아시아 표준 대기가 합성 적외선 영상에 미치는 효과)

  • Shin, Jong-Jin
    • Journal of the Korea Institute of Military Science and Technology
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    • v.9 no.4
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    • pp.97-103
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    • 2006
  • A synthetic infrared image can be effectively utilized in various fields such as the recognition and tracking of targets as long as its quality is good enough to reflect the real situations. One way to improve its quality is to use the reference atmosphere which best describes atmospheric properties of regional areas. The east asian reference atmosphere has been developed to represent atmospheric properties of the east asia including Korean peninsula. However, few research has been conducted to examine the effects of this east asian reference atmosphere on the modeling and simulation. In this regard, this paper analyzes the effects of the east asian reference atmosphere on a synthetic infrared image. The research compares the atmospheric transmittance, the surface temperature, and the radiance obtained by using the east asian reference atmosphere with those of the midlatitude reference atmosphere which has been widely applied in the east asia. The results show that the differences of the atmospheric transmittance, the surface temperature, and the radiance between the east asian reference atmosphere and the midlatitude reference atmosphere are significant especially during the daytime. Therefore, it is recommended to apply the east asian reference atmosphere for generating a synthetic infrared image with targets in the east asia.

Measurement of Radioactive Surface Contamination of the Restroom in the Hospital (병원 내 화장실의 방사성 표면오염도 측정)

  • Han, Sang-Hyun
    • Journal of the Korea Convergence Society
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    • v.11 no.8
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    • pp.71-76
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    • 2020
  • This study measured radioactive surface contamination in general public restrooms in hospitals and in dedicated toilets for nuclear medicine. The measurement method was measured using Berthold (LB 124, Germany) at the entrance to the restroom, inside the restroom, around the restroom, in the urinal, and around the urinal. As a result of the use of the restroom, there was no dedicated place waiting for patients who received radioisotopes in one of the three hospitals. As a result of measuring the restroom for exclusive use of radioisotopes, all measurement sites in the radioiodine therapy room were the highest, and the results of measuring the public restrooms showed background level contamination at all hospitals except hospital B. However, it was measured as 8.073 Bq/㎠ and 6.426 Bq/㎠ in the urinals in the public restroom on the first floor of the B hospital. Therefore, it is recommended to explain the dangers of radiation exposure to patients and provide a place for patients to wait. In addition, a plan should be sought to prevent patients from receiving radioisotopes from using unnecessary movements and general public restrooms.

ANALYSIS OF IRSIGNAL CHARACTERISTICS OF A SHIP FOR NON-UNIFORM ATMOSPHERIC CONDITIONS (비균일 대기상태를 고려한 함정의 적외선 신호 특성 분석)

  • Choi, J.H.;Kim, D.H.;Han, K.I.;Ha, N.K.;Jang, H.S.;Lee, S.H.;Kim, D.G.;Kim, T.K.
    • Journal of computational fluids engineering
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    • v.22 no.1
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    • pp.88-94
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    • 2017
  • The IR signal entering into a sensor is composed of the following components: the self-emitted component directly from the object surface, the reflected components of the solar and sky irradiance at the object surface, and the scattered component by the atmosphere without reference to any object surfaces. The self-emitted and reflected components from the object can be lowered by the atmospheric layer between the object and the IR sensor. The principle factors influencing the atmospheric transmittance are the air temperature, the relative humidity and the observation distance. Previous studies on IR signal transmission through the atmosphere are focused on uniform atmospheric conditions and the non-uniform nature of the atmosphere was not properly treated in modeling. In this study, we use the local atmospheric transmittance to simulate the non-uniform atmosphere in analyzing the IR signal from the object surface. The results show that the nonuniform analysis of the atmosphere becomes more important as the wavelength of IR signal increases.