• 제목/요약/키워드: atmospheric condition

검색결과 846건 처리시간 0.027초

신비한 화성 (Mysterious Mars)

  • 김진원
    • 기술사
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    • 제37권3호
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    • pp.47-49
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    • 2004
  • Mysterious Mars - long distance from earth rovers(spirite, oppertunity) went to survey geological, biological, atmospheric condition sending photo that Is wonderful big development of science technology.

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서울 지역 $SO_2$ 농도 분포에 미치는 지형의 영향 (The Influence of Topography on $SO_2$ Concentration is Seoul Area)

  • 박일수;김정우
    • 한국대기환경학회지
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    • 제7권2호
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    • pp.105-113
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    • 1991
  • An investigation is carried out for the role of topography in governign the mesoscale distribution of $SO_2$ concentration in Seoul. The three dimensional wind fields computed for a given synoptic meteorological condition by an atmospheric mesoscale model in the terrain following coordinate have been employed to compute the three dimensional mesoscale distributions of $SO_2$ concentration by the diffusion model in Seoul area. Terrain may affect the mesoscale distributions of $SO_2$ concentration through its influence on the mesoscale wind fields. This study discusses only the terrain effect on the concentration through its modification of the wind. This effect is to produce higher concentration in lower area according to the structure of divergence fields derived from and atmospheric mesoscale model.

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최악의 대기 조건 하의 공기조력 비행선 운전 (Aeroassisted Orbital Maneuvering in a Worst-Case Atmosphere)

  • 이병수
    • 제어로봇시스템학회논문지
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    • 제6권10호
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    • pp.936-941
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    • 2000
  • Advanced space transportation systems, such as the National Aerospace Plane or an Orbital Transfer Vehicle, have atmospheric maneuvering capabilities. For such vehicles the use of aeroassisted orbital transfer from a high Earth orbit to a low Earth orbit, with unpowered flight in the atmosphere, has the potential for significant fuel savings compared to exoatmospheric Hohmann transfer. However, to exploit the fuel savings that can be achieved by using the Earths atmosphere to reduce the vehicles energy, a guidance law is required, and it must be able to handle large unpredictable fluctuations in atmospheric density, on the order of ${\pm}$50% relative to the 1962 US Standard Atmosphere. In this paper aeroassisted orbital transfer is considered as a differential game, with Nature controlling the atmosphere density to yield a worst case (min-max fuel required) atmosphere, from which the guaranteed playable set boundary are achieved. Inside the playable set, it is guaranteed that the vehicle achieves the optimal atmospheric exit condition for the minimum fuel consumption regardless of the atmospheric density variations.

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A Study on Enhancements of Aerosol, Ozone, and Its Precursors over Korea during Asian Dust Events Related to Regional Climate Condition

  • Moon, Yun-Seob;Shin, Hye-Jung;Kim, Yoo-Keun;Oh, Sung-Nam;Park, Byoung-Cheol;Chung, Hyo-Sang;Jeong, Ju-Hee;Kim, Seong-Kyoun;Kim, Jeong-Sik
    • 한국대기환경학회:학술대회논문집
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    • 한국대기환경학회 2002년도 추계학술대회 논문집
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    • pp.255-258
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    • 2002
  • The vertical exchange of trace gases and aerosols in upper regions of the atmosphere is primarily controlled by the atmospheric conditions. The study of the vertical and temporal variation of the upward transport of $H_2O$ and the downward transport of $O_3$, NO$_2$, CO and other long-lived trace species will enable a better understanding of these transport mechanisms. (omitted)

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Surface Cleaning of Polyethylene Terephthalate Film with Non-equilibrium Atmospheric Discharge Plasma

  • Sung, Youl-Moon
    • Transactions on Electrical and Electronic Materials
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    • 제9권2호
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    • pp.79-83
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    • 2008
  • The dampness by treating the surface with polyethylene terephthalate (PET) film was measured to grasp the plasma parameters and was observed the surface condition with an atomic force microscope (AFM) to find the causes of the dampness. Also, the vibrational and rotational temperatures in the plasma were calculated after identifying the radicals within the plasma by analyzing the emission spectral with an emission spectrum. The hydrophilic properties were enhanced, by treating the surface of the PET film with non-equilibrium atmospheric discharge plasma. When the rotational temperature was 0.22 to 0.31 eV within the plasma, surface modification control could be easily carried out to surface treatment of PET film on non-equilibrium atmospheric pressure plasma.

대기 굴절이 고해상도 영상에 미치는 영향 (Effects of Atmospheric Refraction on High Resolution Image Geometry)

  • 신동석
    • 대한원격탐사학회지
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    • 제12권1호
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    • pp.81-88
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    • 1996
  • 이 논문에서는 대기 굴절이 다목적 실용 위성 영상과 같은 고해상도 영상의 기하학적 성 질에 미치는 영향이 연구되었다. 대기 굴절 모델이 유도 되었고, 기준 대기 모델을 사용하여 영상 의 기하학적 오차를 시뮬레이션을 통하여 구하였다. 표준 대기 중에서 최대 약 7m (1 pixel의 크 기)의 오차가 대기 굴절에 의해 발생하며 이상 대기 상에서는 더 큰 오차를 일으킬 수도 있을 것 이다.

기상해일사례분석을 통한 기상해일발생 임계조건 도출 (A Study on the Meteorological Threshold of the Meteo-Tsunami Occurrence in the Yellow Sea, Korea)

  • 최요환;김현수;우승범;김명석;김유근
    • 한국환경과학회지
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    • 제27권1호
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    • pp.11-25
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    • 2018
  • Both the propagation velocity and the direction of atmospheric waves are important factors for analyzing and forecasting meteo-tsunami. In this study, a total of 14 events of meteo-tsunami over 11 years (2006-2016) are selected through analyzing sea-level data observed from tidal stations along the west coast of the Korean peninsula. The propagation velocity and direction are calculated by tracing the atmospheric disturbance of each meteo-tsunami event predicted by the WRF model. Then, the Froude number is calculated using the propagation velocity of atmospheric waves and oceanic long waves from bathymetry data. To derive the critical condition for the occurrence of meteo-tsunami, supervised learning using a logistic regression algorithm is conducted. It is concluded that the threshold distance of meteo-tsunami occurrence, from a propagation direction, can be calculated by the amplitude of air-pressure tendency and the resonance factor, which are found using the Froude number. According to the critical condition, the distance increases logarithmically with the ratio of the amplitude of air-pressure tendency and the square of the resonance factor, and meteo-tsunami do not occur when the ratio is less than 5.11 hPa/10 min.

Tropospheric Anomaly Detection in Multi-Reference Stations Environment during Localized Atmospheric Conditions-(2) : Analytic Results of Anomaly Detection Algorithm

  • Yoo, Yun-Ja
    • 한국항해항만학회지
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    • 제40권5호
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    • pp.271-278
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    • 2016
  • Localized atmospheric conditions between multi-reference stations can bring the tropospheric delay irregularity that becomes an error terms affecting positioning accuracy in network RTK environment. Imbalanced network error can affect the network solutions and it can corrupt the entire network solution and degrade the correction accuracy. If an anomaly could be detected before the correction message was generated, it is possible to eliminate the anomalous satellite that can cause degradation of the network solution during the tropospheric delay anomaly. An atmospheric grid that consists of four meteorological stations was used to detect an inhomogeneous weather conditions and tropospheric anomaly applied AWSs (automatic weather stations) meteorological data. The threshold of anomaly detection algorithm was determined based on the statistical weather data of AWSs for 5 years in an atmospheric grid. From the analytic results of anomaly detection algorithm it showed that the proposed algorithm can detect an anomalous satellite with an anomaly flag generation caused tropospheric delay anomaly during localized atmospheric conditions between stations. It was shown that the different precipitation condition between stations is the main factor affecting tropospheric anomalies.

부산지역에서의 대기확산모델의 적용 및 평가 -TCM2, CDM2.0, ISCLT2 모델을 중심으로 (The Application and Evaluation of Atmospheric Dispersion Models in Pusan Area - Based on TCM2, CDM2.0, ISCLT2 -)

  • 방종선;김유근
    • 한국환경과학회지
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    • 제5권6호
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    • pp.699-712
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    • 1996
  • For the efficient control of atmospheric quality, it is so important to predict the influence accurately of which the air pollutant emitted into the atmosphere. Atmospheric dispersion model enables to simulate and grasp the atmospheric condition occurred due to the emission of pollutants. The result of model is largely affected by the amount of emission, the characteristics of physical and chemical process, meteorological input data, and the receptor which the concentration is calculated. The aim of this research, therefore, is to suggest more suitable model in Pusan area than other areas by performing TCM2, CDM2.0 and ISCLT2 models. As the basic work for executing the model, we computed the amount of emission of air pollutants in Pusan at 1992 and analyzed the occurrence frequency of atmospheric stability for recent decade(1985~19941, CDM2.0 showed the similar result relatively with observed value in the case of full year(1992), fall and winter, and ISCLT2 brought more suitable result in spring for Pusan area. As the result of this research, in future, it is necessary for us to develop the numerical model considering the topographical characteristics, to select the proper observation site and to increase the observation site for Pusan.

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해수면온도와 식생효과를 고려한 연안도시지역의 대기환경예측 (Atmospheric Environment Prediction to Consider SST and Vegetation Effect in Coastal Urban Region)

  • 지효은;이화운;원경미
    • 한국환경과학회지
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    • 제18권4호
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    • pp.375-388
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    • 2009
  • Numerical simulation is essential to indicate the flow of the atmosphere in the region with a complicated topography which consists of many mountains in the inland while it is neighboring the seashore. Such complicated topography produces land and sea breeze as the mesoscale phenomenon of meteorology which results from the effect of the sea and inland. In the mesoscale simulation examines, the change of the temperature in relation to the one of the sea surface for the boundary condition and, in the inland, the interaction between the atmosphere and land surface reflecting the characteristic of the land surface. This research developed and simulated PNULSM to reflect both the SST and vegetation effect as a bottom boundary for detailed meteorological numerical simulation in coastal urban area. The result from four experiments performed according to this protocol revealed the change of temperature field and wind field depending on each effect. Therefore, the lower level of establishment of bottom boundary suitable for the characteristic of the region is necessary to figure out the atmospheric flow more precisely, and if the characteristic of the surface is improved to more realistic conditions, it will facilitate the simulation of regional environment.