• Title/Summary/Keyword: 대기모델

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Climate Change and Regional Land Use Planning : The Formulation of California Senate Bill No. 375 (기후변화와 광역토지사용계획: 캘리포니아의 Senate Bill No. 375의 사례)

  • Choi, Hyun-Sun;Choi, Simon
    • Journal of Environmental Policy
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    • v.9 no.1
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    • pp.3-29
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    • 2010
  • This paper explores how effectively the newly introduced planning process - California Senate Bill No. 375 will achieve the regional GHG emissions target under the California policy and planning framework and how well incentive based environmental policy might perform. The new legislation creates a future growth scenario to reduce greenhouse gas (GHG) emissions with incentives as means of implementation of AB 32 - the Global Warming Solution Act of 2006 and includes five important policy and planning aspects: 1) the role of sustainable communities strategies (SCS) as one of the key elements in their regional transportation plans; 2) planning for transportation and housing; 3) specified incentives for the implementation of SCS; 4) the regional planning approach toward reducing GHG emissions; and the role of the California Air Resources Board to establish the regional GHG emissions target. This has significant implications for regional and environmental planning with incentives - resources allocation and approval process.

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Applicability of Climate Change Impact Assessment Models to Korean Forest (산림에 대한 기후변화 영향평가 모형의 국내 적용성 분석)

  • Kim, Su-na;Lee, Woo-Kyun;Son, Yowhan;Cho, Yongsung;Lee, Mi-Sun
    • Journal of Korean Society of Forest Science
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    • v.98 no.1
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    • pp.33-48
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    • 2009
  • Forests store carbon dioxide ($CO_2$), one of the major factors of global warming, in vegetation and soils through photosynthesis process. In addition, woods deposit $CO_2$ for a long term until the harvested wood is decomposed or burned, and deforested areas could be expanded the carbon sinks through reforestation. Forests are a lso able to decrease temperature through transpiration and contribute to control the micro climate in global climate systems. Consequently, forests are considered as one of major sinks of greenhouse gases for mitigating global warming. It is very important to develop a Korea specific forest carbon flux model for preparing adaptation measures to climate change. In this study, we compared the climate change impact models in forests developed in foreign countries and analyzed the applicability of the models to Korean forest. Also we selected models applicable to Korean forest and suggested approaches for developing Korean specific model.

Study on the GIS Based Environmental Assesment Techniques for Environmental Friendly Road Route Plan (환경친화적인 도로노선 계획을 위한 GIS 기반 환경성 평가기법 연구 - 도로노선대 선정방법 개발 -)

  • Kang, Ho-Geun;Park, Tae-Kwen;Kim, Heung-Lae;Kim, Sang-Tae;Lee, Sang-Eun
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.3
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    • pp.223-231
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    • 2009
  • This study intends to develop a GIS-based environmental assesment technique for environmental friendly road route plan using a spatial analysis function. After embodying an impact range based on the analysis of factors which cause the environmental damage by the road construction, a literature survey on a diverse grading cases and legal regulations was conducted. As a quantitative model for the spatial analysis, AHP was selected. As the environmental assessment, 8 items such as topography & geology, animals & plants, soil ecology, water quality, air quality, noise, land use, and landscape were selected. and then finally classified into three-grades using a pairwise comparison of the alate collected by a questionnaire surveying, weighting values were applied to there 8 items. The highest weight value, the grade 1 among eight was 0.191 for animals & plants. As the result of verifying the above method for the case region, the most environment-friendly road route could be generated.

Vaporization of Hydrocarbon Fuel Droplet in Supercritical Environments (아임계 및 초임계 탄화수소 연료 액적의 기화 특성 연구)

  • Lee,Gyeong-Jae;Lee,Bong-Su;Kim,Jong-Hyeon;Gu,Ja-Ye
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.7
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    • pp.85-93
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    • 2003
  • Droplet vaporization at various ambient pressures is studied numerically by formulating one dimensional evaporation model in the mixture of hydrocarbon fuel and air. The ambient pressure ranged from atmospheric conditions to the supercritical conditions. The modified Soave-Redlich-Kwong state equation is used to account for the real gas effects in the high pressure condition. Non-ideal thermodynamic and transport properties at near critical and supercritical conditions are considered. Some computational results are compared with Sato's experimental data for the validation of calculations. The comparison between predictions and experiments showed quite a good agreement. The droplet lifetime increases with increasing pressure at temperature lower than the critical temperature, however, it decreases with increasing pressure at temperature higher than the critical temperature. The solubility of nitrogen can not be neglected in the high pressure and it becomes higher as the temperature and the pressure go up.

A Numerical Analysis on Transient Fuel Temperatures in a Military Aircraft with Additional Fuel Supplies and Return (추가연료 공급,회송량에 따른 항공기내 연료온도 변화에 대한 수치해석적 연구)

  • Kim,Yeong-Jun;Kim,Chang-Nyeong;Kim,Cheol-In
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.1
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    • pp.73-84
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    • 2003
  • A transient analysis on fuel temperatures in an aircraft was studied using the finite difference method. Numerical calculation was performed by an explicit method of modified Dufort-Frankel scheme. Among various missions, close air support mission was considered with 20% hot day ambient condition in subsonic region. The aircraft was assumed to be in turbulent flow. The fuel system model with additional fuel supplies and return concept was considered. As a result of this analysis, the fuel tank temperatures have increased with the increase of the additional fuel supplies. In contrast to tank temperatures, the fuel temperature at the engine inlet has decreased with the increase of additional fuel supplies except in some in-flight phases having high engine fuel flow. From this analysis, the fuel system with the additional fuel supplies and return concept has been shown to be an effective method to decrease the engine inlet fuel temperature. Also, it has been shown that fuel flow rate through fuel/oil heat exchanger is a key factor influencing fuel temperature.

Analysis of the Interaction Between Hypersonic Free Stream and Side Jet Flow Using a DSMC Method (직접모사법을 이용한 극음속 대기 유동과 측면 제트의 상호 작용 해석)

  • Kim, Min-Gyu;Kwon, Oh-Joon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.3
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    • pp.1-9
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    • 2005
  • The interaction between hypersonic free stream and side jet flow at high altitudes is investigated by using the direct simulation Monte Carlo (DSMC) method. In order to alleviate the difficulty associated with the large density difference between the free stream and the side jet flow and to simulate the two flows simultaneously, a weighting factor technique is applied. For validation, the corner flow over a pair of plates perpendicularly attached is calculated with and without a side jet, and the results are compared with experiment. For a more realistic configuration, the flow past a blunted cone cylinder shape is solved. The leeward or windward jet is injected into the free stream and the effect on the aerodynamic force and moment is observed at various flow angles. The lambda shock effect and the wake structure are studied in terms of the surface pressure differential. A higher interaction between the free stream and the side jet flow is observed when the side jet is injected in the windward direction.

Stability Analysis on Guided Munition at Slow Spin (유도포탄 저속 회전 시 안정성 분석)

  • Kim, Youngjoo;Bang, Hyochoong;Seo, Songwon;Pak, Chang-Ho;Kim, Jin-Won;Seo, Ilwon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.9
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    • pp.752-759
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    • 2018
  • This paper presents methods and results of nonlinear simulations for a guided munition for verifying stability at slow spin. The munition is launched by an artillery and it deploys the rear fins to reduce its spin. While the spin speed command is set to 1 rps and 3 rps, wind gusts of 3m/s, 7m/s, 10m/s, and 15m/s in amplitude, and 26 different directions were generated as disturbance for each simulation run. Whereas the munition with the spin speed of 3 rps didn't flip, that with 1-rps spin flipped under some gusts. However, the gusts which increase airspeed in the flight direction didn't introduce harmful effect. Most importantly, all the flips of the munition was observed near the end of the simulation where the munition is going down. No problem was observed near the summit of trajectory.

Time-dependent variations of accretion disk (Accretion disk의 시간에 따른 변화)

  • 나혜원;김경미;최규홍
    • Journal of Astronomy and Space Sciences
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    • v.4 no.1
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    • pp.11-23
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    • 1987
  • In dward nova we assume the primary star as a white dwarf and the secondary as the late type star which filled Roche lobe. Mass flow from the secondary star leads to the formation of thin accretion disk around the white dwarf. We use the $\alpha$ parameter as viscosity to maintain the disk form and propose that the outburst in dwarf nova cause the step increase of source term. With these assumptions we solve the basic equations of stellar structure using New-Raphson method. We show the physical parameters like temperature, density, pressure, opacity, surface density, height and flux to the radius of disk. Changing the value of $\alpha$, we compare several parameters when mass flow rate is constant with those of when luminosity of disk is brightest. At the same time, we obtain time-dependent variations of luminosity and mass of disk. We propose the suitable range of $\alpha$is 0.15-0.18 to the difference of luminosity. We compare several parameters of disk with those of the normal late type stars which have the same molecular weight of disk. These show the temperature and pressure of disk are similar to those of normal stars but the density of disk is lower. Maybe the outburst in dwarf nova is due to the variation of the $\alpha$ value instead of increment of mass flow from the secondary star.

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Anti-allergic Effects of Jagamcho-tang in Ovalbumin-induced Atopic Dermatitis Mouse Model (Ovalbumin으로 유발된 아토피피부염 마우스 모델에서 자감초탕(炙甘草湯)의 항알레르기 효과)

  • Noh, Hyeon-Min;Park, Sung-gu;Kim, Wonjeong;Jo, Eun-Hee;Ki, Hyeon-Hui;Kim, Dae-Ki;Park, Min-Cheol
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.31 no.5
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    • pp.277-283
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    • 2017
  • Activated T helper 2 (Th2) immune function is hallmark of various allergic diseases. We investigated the anti-allergic effect of Jagamcho-tang extract(JE) on ovalbumin(OVA)-induced atopic dermatitis mice model and OVA-stimulated splenocytes isolated from the mice. Mice were intraperitoneally injected OVA/alum solution 2 times at interval of 14 days, followed by oral administration of JE for 7 days. After administration, mice were subcutaneously injected with OVA in ear. JE treatment reduced ear swelling and infiltration of inflammatory cells in ear. Serum levels of interleukin(IL)-4 and immunoglobulins, such as total-IgE and OVA-specific IgE, were decreased in JE treated group. Furthermore, JE treatment decreased OVA-induced Th2-associated cytokines like IL-4, IL-5 and IL-13 mRNA levels in splenocytes. In conclusion, JE reduced allergic immune response via IgE production and Th2 response in OVA-sensitized mice, suggesting that JE could be useful prescription for allergic diseases including atopic dermatitis.

Analysis of Forest Cover Information Extracted by Spectral Mixture Analysis (분광혼합분석 기법에 의한 산림피복 정보의 특성 분석)

  • 이지민;이규성
    • Korean Journal of Remote Sensing
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    • v.19 no.6
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    • pp.411-419
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    • 2003
  • An area corresponding to the spatial resolution of optical remote sensor imagery often includes more than one pure surface material. In such case, a pixel value represents a mixture of spectral reflectance of several materials within it. This study attempts to apply the spectral mixture analysis on forest and to evaluate the information content of endmember fractions resulted from the spectral unmixing. Landsat-7 ETM+ image obtained over the study area in the Kwangneung Experimental Forest was initially geo-referenced and radiometrically corrected to reduce the atmospheric and topographic attenuations. Linear mixture model was applied to separate each pixel by the fraction of six endmember: deciduous, coniferous, soil, built-up, shadow, and rice/grass. The fractional values of six endmember could be used to separate forest cover in more detailed spatial scale. In addition, the soil fraction can be further used to extract the information related to the canopy closure. We also found that the shadow effect is more distinctive at coniferous stands.